Series comparison

The following changes since commit a26a98dfb9d448d7234d931ae3720feddf6f0651:

Merge remote-tracking branch 'remotes/cohuck/tags/s390x-20171006' into staging (2017-10-06 13:19:03 +0100)

are available in the git repository at:

git://repo.or.cz/qemu/kevin.git tags/for-upstream

for you to fetch changes up to fc3fd63fc0573ffd2ee569591a2e7f6c7310fd18:

Merge remote-tracking branch 'mreitz/tags/pull-block-2017-10-06' into queue-block (2017-10-06 16:32:08 +0200)

----------------------------------------------------------------
Block layer patches

----------------------------------------------------------------
Daniel P. Berrange (6):
      block: use 1 MB bounce buffers for crypto instead of 16KB
      crypto: expose encryption sector size in APIs
      block: fix data type casting for crypto payload offset
      block: convert crypto driver to bdrv_co_preadv|pwritev
      block: convert qcrypto_block_encrypt|decrypt to take bytes offset
      block: support passthrough of BDRV_REQ_FUA in crypto driver

Eric Blake (27):
      block: Typo fix in copy_on_readv()
      block: Make bdrv_img_create() size selection easier to read
      hbitmap: Rename serialization_granularity to serialization_align
      qcow2: Ensure bitmap serialization is aligned
      dirty-bitmap: Drop unused functions
      dirty-bitmap: Avoid size query failure during truncate
      dirty-bitmap: Change bdrv_dirty_bitmap_size() to report bytes
      dirty-bitmap: Track bitmap size by bytes
      dirty-bitmap: Change bdrv_dirty_bitmap_*serialize*() to take bytes
      qcow2: Switch sectors_covered_by_bitmap_cluster() to byte-based
      dirty-bitmap: Set iterator start by offset, not sector
      dirty-bitmap: Change bdrv_dirty_iter_next() to report byte offset
      dirty-bitmap: Change bdrv_get_dirty_count() to report bytes
      dirty-bitmap: Change bdrv_get_dirty_locked() to take bytes
      dirty-bitmap: Change bdrv_[re]set_dirty_bitmap() to use bytes
      mirror: Switch mirror_dirty_init() to byte-based iteration
      qcow2: Switch qcow2_measure() to byte-based iteration
      qcow2: Switch load_bitmap_data() to byte-based iteration
      qcow2: Switch store_bitmap_data() to byte-based iteration
      dirty-bitmap: Switch bdrv_set_dirty() to bytes
      dirty-bitmap: Convert internal hbitmap size/granularity
      qemu-io: Add -C for opening with copy-on-read
      block: Uniform handling of 0-length bdrv_get_block_status()
      iotests: Restore stty settings on completion
      block: Add blkdebug hook for copy-on-read
      block: Perform copy-on-read in loop
      iotests: Add test 197 for covering copy-on-read

Kevin Wolf (6):
      block: Introduce BdrvChildRole.update_filename
      commit: Support multiple roots above top node
      qemu-iotests: Allow QMP pretty printing in common.qemu
      qemu-iotests: Test commit block job where top has two parents
      commit: Remove overlay_bs
      Merge remote-tracking branch 'mreitz/tags/pull-block-2017-10-06' into queue-block

Max Reitz (1):
      iotests: Fix 195 if IMGFMT is part of TEST_DIR

Paolo Bonzini (10):
      qemu-iotests: remove dead code
      qemu-iotests: get rid of AWK_PROG
      qemu-iotests: move "check" code out of common.rc
      qemu-iotests: cleanup and fix search for programs
      qemu-iotests: limit non-_PROG-suffixed variables to common.rc
      qemu-iotests: do not include common.rc in "check"
      qemu-iotests: disintegrate more parts of common.config
      qemu-iotests: fix uninitialized variable
      qemu-iotests: get rid of $iam
      qemu-iotests: merge "check" and "common"

Pavel Butsykin (2):
      qcow2: fix return error code in qcow2_truncate()
      qcow2: truncate the tail of the image file after shrinking the image

Thomas Huth (1):
      hw/block/onenand: Remove dead code block

Vladimir Sementsov-Ogievskiy (2):
      block/mirror: check backing in bdrv_mirror_top_refresh_filename
      block/mirror: check backing in bdrv_mirror_top_flush

From: Eric Blake <eblake@redhat.com>

All callers of bdrv_img_create() pass in a size, or -1 to read the
size from the backing file.  We then set that size as the QemuOpt
default, which means we will reuse that default rather than the
final parameter to qemu_opt_get_size() several lines later.  But
it is rather confusing to read subsequent checks of 'size == -1'
when it looks (without seeing the full context) like size defaults
to 0; it also doesn't help that a size of 0 is valid (for some
formats).

Rework the logic to make things more legible.

diff --git a/block.c b/block.c
index XXXXXXX..XXXXXXX 100644
--- a/block.c
+++ b/block.c
@@ -XXX,XX +XXX,XX @@ void bdrv_img_create(const char *filename, const char *fmt,
 
     /* The size for the image must always be specified, unless we have a backing
      * file and we have not been forbidden from opening it. */
-    size = qemu_opt_get_size(opts, BLOCK_OPT_SIZE, 0);
+    size = qemu_opt_get_size(opts, BLOCK_OPT_SIZE, img_size);
     if (backing_file && !(flags & BDRV_O_NO_BACKING)) {
         BlockDriverState *bs;
         char *full_backing = g_new0(char, PATH_MAX);
-- 
2.13.6

From: Eric Blake <eblake@redhat.com>

The only client of hbitmap_serialization_granularity() is dirty-bitmap's
bdrv_dirty_bitmap_serialization_align().  Keeping the two names consistent
is worthwhile, and the shorter name is more representative of what the
function returns (the required alignment to be used for start/count of
other serialization functions, where violating the alignment causes
assertion failures).

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 include/qemu/hbitmap.h |  8 ++++----
 block/dirty-bitmap.c   |  2 +-
 tests/test-hbitmap.c   | 10 +++++-----
 util/hbitmap.c         |  8 ++++----
 4 files changed, 14 insertions(+), 14 deletions(-)

diff --git a/include/qemu/hbitmap.h b/include/qemu/hbitmap.h
index XXXXXXX..XXXXXXX 100644
--- a/include/qemu/hbitmap.h
+++ b/include/qemu/hbitmap.h
@@ -XXX,XX +XXX,XX @@ bool hbitmap_get(const HBitmap *hb, uint64_t item);
 bool hbitmap_is_serializable(const HBitmap *hb);
 
 /**
- * hbitmap_serialization_granularity:
+ * hbitmap_serialization_align:
  * @hb: HBitmap to operate on.
  *
- * Granularity of serialization chunks, used by other serialization functions.
- * For every chunk:
+ * Required alignment of serialization chunks, used by other serialization
+ * functions. For every chunk:
  * 1. Chunk start should be aligned to this granularity.
  * 2. Chunk size should be aligned too, except for last chunk (for which
  *      start + count == hb->size)
  */
-uint64_t hbitmap_serialization_granularity(const HBitmap *hb);
+uint64_t hbitmap_serialization_align(const HBitmap *hb);
 
 /**
  * hbitmap_serialization_size:
diff --git a/block/dirty-bitmap.c b/block/dirty-bitmap.c
index XXXXXXX..XXXXXXX 100644
--- a/block/dirty-bitmap.c
+++ b/block/dirty-bitmap.c
@@ -XXX,XX +XXX,XX @@ uint64_t bdrv_dirty_bitmap_serialization_size(const BdrvDirtyBitmap *bitmap,
 
 uint64_t bdrv_dirty_bitmap_serialization_align(const BdrvDirtyBitmap *bitmap)
 {
-    return hbitmap_serialization_granularity(bitmap->bitmap);
+    return hbitmap_serialization_align(bitmap->bitmap);
 }
 
 void bdrv_dirty_bitmap_serialize_part(const BdrvDirtyBitmap *bitmap,
diff --git a/tests/test-hbitmap.c b/tests/test-hbitmap.c
index XXXXXXX..XXXXXXX 100644
--- a/tests/test-hbitmap.c
+++ b/tests/test-hbitmap.c
@@ -XXX,XX +XXX,XX @@ static void test_hbitmap_meta_one(TestHBitmapData *data, const void *unused)
     }
 }
 
-static void test_hbitmap_serialize_granularity(TestHBitmapData *data,
-                                               const void *unused)
+static void test_hbitmap_serialize_align(TestHBitmapData *data,
+                                         const void *unused)
 {
     int r;
 
     hbitmap_test_init(data, L3 * 2, 3);
     g_assert(hbitmap_is_serializable(data->hb));
 
-    r = hbitmap_serialization_granularity(data->hb);
+    r = hbitmap_serialization_align(data->hb);
     g_assert_cmpint(r, ==, 64 << 3);
 }
 
@@ -XXX,XX +XXX,XX @@ int main(int argc, char **argv)
     hbitmap_test_add("/hbitmap/meta/word", test_hbitmap_meta_word);
     hbitmap_test_add("/hbitmap/meta/sector", test_hbitmap_meta_sector);
 
-    hbitmap_test_add("/hbitmap/serialize/granularity",
-                     test_hbitmap_serialize_granularity);
+    hbitmap_test_add("/hbitmap/serialize/align",
+                     test_hbitmap_serialize_align);
     hbitmap_test_add("/hbitmap/serialize/basic",
                      test_hbitmap_serialize_basic);
     hbitmap_test_add("/hbitmap/serialize/part",
diff --git a/util/hbitmap.c b/util/hbitmap.c
index XXXXXXX..XXXXXXX 100644
--- a/util/hbitmap.c
+++ b/util/hbitmap.c
@@ -XXX,XX +XXX,XX @@ bool hbitmap_is_serializable(const HBitmap *hb)
 {
     /* Every serialized chunk must be aligned to 64 bits so that endianness
      * requirements can be fulfilled on both 64 bit and 32 bit hosts.
-     * We have hbitmap_serialization_granularity() which converts this
+     * We have hbitmap_serialization_align() which converts this
      * alignment requirement from bitmap bits to items covered (e.g. sectors).
      * That value is:
      *    64 << hb->granularity
      * Since this value must not exceed UINT64_MAX, hb->granularity must be
      * less than 58 (== 64 - 6, where 6 is ld(64), i.e. 1 << 6 == 64).
      *
-     * In order for hbitmap_serialization_granularity() to always return a
+     * In order for hbitmap_serialization_align() to always return a
      * meaningful value, bitmaps that are to be serialized must have a
      * granularity of less than 58. */
 
@@ -XXX,XX +XXX,XX @@ bool hbitmap_get(const HBitmap *hb, uint64_t item)
     return (hb->levels[HBITMAP_LEVELS - 1][pos >> BITS_PER_LEVEL] & bit) != 0;
 }
 
-uint64_t hbitmap_serialization_granularity(const HBitmap *hb)
+uint64_t hbitmap_serialization_align(const HBitmap *hb)
 {
     assert(hbitmap_is_serializable(hb));
 
@@ -XXX,XX +XXX,XX @@ static void serialization_chunk(const HBitmap *hb,
                                 unsigned long **first_el, uint64_t *el_count)
 {
     uint64_t last = start + count - 1;
-    uint64_t gran = hbitmap_serialization_granularity(hb);
+    uint64_t gran = hbitmap_serialization_align(hb);
 
     assert((start & (gran - 1)) == 0);
     assert((last >> hb->granularity) < hb->size);
-- 
2.13.6

From: Eric Blake <eblake@redhat.com>

When subdividing a bitmap serialization, the code in hbitmap.c
enforces that start/count parameters are aligned (except that
count can end early at end-of-bitmap).  We exposed this required
alignment through bdrv_dirty_bitmap_serialization_align(), but
forgot to actually check that we comply with it.

Fortunately, qcow2 is never dividing bitmap serialization smaller
than one cluster (which is a minimum of 512 bytes); so we are
always compliant with the serialization alignment (which insists
that we partition at least 64 bits per chunk) because we are doing
at least 4k bits per chunk.

Still, it's safer to add an assertion (for the unlikely case that
we'd ever support a cluster smaller than 512 bytes, or if the
hbitmap implementation changes what it considers to be aligned),
rather than leaving bdrv_dirty_bitmap_serialization_align()
without a caller.

diff --git a/block/qcow2-bitmap.c b/block/qcow2-bitmap.c
index XXXXXXX..XXXXXXX 100644
--- a/block/qcow2-bitmap.c
+++ b/block/qcow2-bitmap.c
@@ -XXX,XX +XXX,XX @@ static int free_bitmap_clusters(BlockDriverState *bs, Qcow2BitmapTable *tb)
 static uint64_t sectors_covered_by_bitmap_cluster(const BDRVQcow2State *s,
                                                   const BdrvDirtyBitmap *bitmap)
 {
-    uint32_t sector_granularity =
+    uint64_t sector_granularity =
             bdrv_dirty_bitmap_granularity(bitmap) >> BDRV_SECTOR_BITS;
+    uint64_t sbc = sector_granularity * (s->cluster_size << 3);
 
-    return (uint64_t)sector_granularity * (s->cluster_size << 3);
+    assert(QEMU_IS_ALIGNED(sbc,
+                           bdrv_dirty_bitmap_serialization_align(bitmap)));
+    return sbc;
 }
 
 /* load_bitmap_data
-- 
2.13.6

From: Eric Blake <eblake@redhat.com>

We had several functions that no one is currently using, and which
use sector-based interfaces.  I'm trying to convert towards byte-based
interfaces, so it's easier to just drop the unused functions:

bdrv_dirty_bitmap_get_meta
bdrv_dirty_bitmap_get_meta_locked
bdrv_dirty_bitmap_reset_meta
bdrv_dirty_bitmap_meta_granularity

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 include/block/dirty-bitmap.h | 10 ----------
 block/dirty-bitmap.c         | 44 --------------------------------------------
 2 files changed, 54 deletions(-)

diff --git a/include/block/dirty-bitmap.h b/include/block/dirty-bitmap.h
index XXXXXXX..XXXXXXX 100644
--- a/include/block/dirty-bitmap.h
+++ b/include/block/dirty-bitmap.h
@@ -XXX,XX +XXX,XX @@ void bdrv_enable_dirty_bitmap(BdrvDirtyBitmap *bitmap);
 BlockDirtyInfoList *bdrv_query_dirty_bitmaps(BlockDriverState *bs);
 uint32_t bdrv_get_default_bitmap_granularity(BlockDriverState *bs);
 uint32_t bdrv_dirty_bitmap_granularity(const BdrvDirtyBitmap *bitmap);
-uint32_t bdrv_dirty_bitmap_meta_granularity(BdrvDirtyBitmap *bitmap);
 bool bdrv_dirty_bitmap_enabled(BdrvDirtyBitmap *bitmap);
 bool bdrv_dirty_bitmap_frozen(BdrvDirtyBitmap *bitmap);
 const char *bdrv_dirty_bitmap_name(const BdrvDirtyBitmap *bitmap);
@@ -XXX,XX +XXX,XX @@ void bdrv_set_dirty_bitmap(BdrvDirtyBitmap *bitmap,
                            int64_t cur_sector, int64_t nr_sectors);
 void bdrv_reset_dirty_bitmap(BdrvDirtyBitmap *bitmap,
                              int64_t cur_sector, int64_t nr_sectors);
-int bdrv_dirty_bitmap_get_meta(BlockDriverState *bs,
-                               BdrvDirtyBitmap *bitmap, int64_t sector,
-                               int nb_sectors);
-int bdrv_dirty_bitmap_get_meta_locked(BlockDriverState *bs,
-                                      BdrvDirtyBitmap *bitmap, int64_t sector,
-                                      int nb_sectors);
-void bdrv_dirty_bitmap_reset_meta(BlockDriverState *bs,
-                                  BdrvDirtyBitmap *bitmap, int64_t sector,
-                                  int nb_sectors);
 BdrvDirtyBitmapIter *bdrv_dirty_meta_iter_new(BdrvDirtyBitmap *bitmap);
 BdrvDirtyBitmapIter *bdrv_dirty_iter_new(BdrvDirtyBitmap *bitmap,
                                          uint64_t first_sector);
diff --git a/block/dirty-bitmap.c b/block/dirty-bitmap.c
index XXXXXXX..XXXXXXX 100644
--- a/block/dirty-bitmap.c
+++ b/block/dirty-bitmap.c
@@ -XXX,XX +XXX,XX @@ void bdrv_release_meta_dirty_bitmap(BdrvDirtyBitmap *bitmap)
     qemu_mutex_unlock(bitmap->mutex);
 }
 
-int bdrv_dirty_bitmap_get_meta_locked(BlockDriverState *bs,
-                                      BdrvDirtyBitmap *bitmap, int64_t sector,
-                                      int nb_sectors)
-{
-    uint64_t i;
-    int sectors_per_bit = 1 << hbitmap_granularity(bitmap->meta);
-
-    /* To optimize: we can make hbitmap to internally check the range in a
-     * coarse level, or at least do it word by word. */
-    for (i = sector; i < sector + nb_sectors; i += sectors_per_bit) {
-        if (hbitmap_get(bitmap->meta, i)) {
-            return true;
-        }
-    }
-    return false;
-}
-
-int bdrv_dirty_bitmap_get_meta(BlockDriverState *bs,
-                               BdrvDirtyBitmap *bitmap, int64_t sector,
-                               int nb_sectors)
-{
-    bool dirty;
-
-    qemu_mutex_lock(bitmap->mutex);
-    dirty = bdrv_dirty_bitmap_get_meta_locked(bs, bitmap, sector, nb_sectors);
-    qemu_mutex_unlock(bitmap->mutex);
-
-    return dirty;
-}
-
-void bdrv_dirty_bitmap_reset_meta(BlockDriverState *bs,
-                                  BdrvDirtyBitmap *bitmap, int64_t sector,
-                                  int nb_sectors)
-{
-    qemu_mutex_lock(bitmap->mutex);
-    hbitmap_reset(bitmap->meta, sector, nb_sectors);
-    qemu_mutex_unlock(bitmap->mutex);
-}
-
 int64_t bdrv_dirty_bitmap_size(const BdrvDirtyBitmap *bitmap)
 {
     return bitmap->size;
@@ -XXX,XX +XXX,XX @@ uint32_t bdrv_dirty_bitmap_granularity(const BdrvDirtyBitmap *bitmap)
     return BDRV_SECTOR_SIZE << hbitmap_granularity(bitmap->bitmap);
 }
 
-uint32_t bdrv_dirty_bitmap_meta_granularity(BdrvDirtyBitmap *bitmap)
-{
-    return BDRV_SECTOR_SIZE << hbitmap_granularity(bitmap->meta);
-}
-
 BdrvDirtyBitmapIter *bdrv_dirty_iter_new(BdrvDirtyBitmap *bitmap,
                                          uint64_t first_sector)
 {
-- 
2.13.6

From: Eric Blake <eblake@redhat.com>

We've previously fixed several places where we failed to account
for possible errors from bdrv_nb_sectors().  Fix another one by
making bdrv_dirty_bitmap_truncate() take the new size from the
caller instead of querying itself; then adjust the sole caller
bdrv_truncate() to pass the size just determined by a successful
resize, or to reuse the size given to the original truncate
operation when refresh_total_sectors() was not able to confirm the
actual size (the two sizes can potentially differ according to
rounding constraints), thus avoiding sizing the bitmaps to -1.
This also fixes a bug where not all failure paths in
bdrv_truncate() would set errp.

Note that bdrv_truncate() is still a bit awkward.  We may want
to revisit it later and clean up things to better guarantee that
a resize attempt either fails cleanly up front, or cannot fail
after guest-visible changes have been made (if temporary changes
are made, then they need to be cleanly rolled back).  But that
is a task for another day; for now, the goal is the bare minimum
fix to ensure that just bdrv_dirty_bitmap_truncate() cannot fail.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 include/block/dirty-bitmap.h |  2 +-
 block.c                      | 16 +++++++++++-----
 block/dirty-bitmap.c         |  6 +++---
 3 files changed, 15 insertions(+), 9 deletions(-)

From: Eric Blake <eblake@redhat.com>

We're already reporting bytes for bdrv_dirty_bitmap_granularity();
mixing bytes and sectors in our return values is a recipe for
confusion.  A later cleanup will convert dirty bitmap internals
to be entirely byte-based, but in the meantime, we should report
the bitmap size in bytes.

The only external caller in qcow2-bitmap.c is temporarily more verbose
(because it is still using sector-based math), but will later be
switched to track progress by bytes instead of sectors.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block/dirty-bitmap.c |  2 +-
 block/qcow2-bitmap.c | 14 ++++++++------
 2 files changed, 9 insertions(+), 7 deletions(-)

diff --git a/block/dirty-bitmap.c b/block/dirty-bitmap.c
index XXXXXXX..XXXXXXX 100644
--- a/block/dirty-bitmap.c
+++ b/block/dirty-bitmap.c
@@ -XXX,XX +XXX,XX @@ void bdrv_release_meta_dirty_bitmap(BdrvDirtyBitmap *bitmap)
 
 int64_t bdrv_dirty_bitmap_size(const BdrvDirtyBitmap *bitmap)
 {
-    return bitmap->size;
+    return bitmap->size * BDRV_SECTOR_SIZE;
 }
 
 const char *bdrv_dirty_bitmap_name(const BdrvDirtyBitmap *bitmap)
diff --git a/block/qcow2-bitmap.c b/block/qcow2-bitmap.c
index XXXXXXX..XXXXXXX 100644
--- a/block/qcow2-bitmap.c
+++ b/block/qcow2-bitmap.c
@@ -XXX,XX +XXX,XX @@ static int load_bitmap_data(BlockDriverState *bs,
     BDRVQcow2State *s = bs->opaque;
     uint64_t sector, sbc;
     uint64_t bm_size = bdrv_dirty_bitmap_size(bitmap);
+    uint64_t bm_sectors = DIV_ROUND_UP(bm_size, BDRV_SECTOR_SIZE);
     uint8_t *buf = NULL;
     uint64_t i, tab_size =
             size_to_clusters(s,
-                bdrv_dirty_bitmap_serialization_size(bitmap, 0, bm_size));
+                bdrv_dirty_bitmap_serialization_size(bitmap, 0, bm_sectors));
 
     if (tab_size != bitmap_table_size || tab_size > BME_MAX_TABLE_SIZE) {
         return -EINVAL;
@@ -XXX,XX +XXX,XX @@ static int load_bitmap_data(BlockDriverState *bs,
     buf = g_malloc(s->cluster_size);
     sbc = sectors_covered_by_bitmap_cluster(s, bitmap);
     for (i = 0, sector = 0; i < tab_size; ++i, sector += sbc) {
-        uint64_t count = MIN(bm_size - sector, sbc);
+        uint64_t count = MIN(bm_sectors - sector, sbc);
         uint64_t entry = bitmap_table[i];
         uint64_t offset = entry & BME_TABLE_ENTRY_OFFSET_MASK;
 
@@ -XXX,XX +XXX,XX @@ static uint64_t *store_bitmap_data(BlockDriverState *bs,
     int64_t sector;
     uint64_t sbc;
     uint64_t bm_size = bdrv_dirty_bitmap_size(bitmap);
+    uint64_t bm_sectors = DIV_ROUND_UP(bm_size, BDRV_SECTOR_SIZE);
     const char *bm_name = bdrv_dirty_bitmap_name(bitmap);
     uint8_t *buf = NULL;
     BdrvDirtyBitmapIter *dbi;
     uint64_t *tb;
     uint64_t tb_size =
             size_to_clusters(s,
-                bdrv_dirty_bitmap_serialization_size(bitmap, 0, bm_size));
+                bdrv_dirty_bitmap_serialization_size(bitmap, 0, bm_sectors));
 
     if (tb_size > BME_MAX_TABLE_SIZE ||
         tb_size * s->cluster_size > BME_MAX_PHYS_SIZE)
@@ -XXX,XX +XXX,XX @@ static uint64_t *store_bitmap_data(BlockDriverState *bs,
     dbi = bdrv_dirty_iter_new(bitmap, 0);
     buf = g_malloc(s->cluster_size);
     sbc = sectors_covered_by_bitmap_cluster(s, bitmap);
-    assert(DIV_ROUND_UP(bm_size, sbc) == tb_size);
+    assert(DIV_ROUND_UP(bm_sectors, sbc) == tb_size);
 
     while ((sector = bdrv_dirty_iter_next(dbi)) != -1) {
         uint64_t cluster = sector / sbc;
@@ -XXX,XX +XXX,XX @@ static uint64_t *store_bitmap_data(BlockDriverState *bs,
         int64_t off;
 
         sector = cluster * sbc;
-        end = MIN(bm_size, sector + sbc);
+        end = MIN(bm_sectors, sector + sbc);
         write_size =
             bdrv_dirty_bitmap_serialization_size(bitmap, sector, end - sector);
         assert(write_size <= s->cluster_size);
@@ -XXX,XX +XXX,XX @@ static uint64_t *store_bitmap_data(BlockDriverState *bs,
             goto fail;
         }
 
-        if (end >= bm_size) {
+        if (end >= bm_sectors) {
             break;
         }
 
-- 
2.13.6

From: Eric Blake <eblake@redhat.com>

We are still using an internal hbitmap that tracks a size in sectors,
with the granularity scaled down accordingly, because it lets us
use a shortcut for our iterators which are currently sector-based.
But there's no reason we can't track the dirty bitmap size in bytes,
since it is (mostly) an internal-only variable (remember, the size
is how many bytes are covered by the bitmap, not how many bytes the
bitmap occupies).  A later cleanup will convert dirty bitmap
internals to be entirely byte-based, eliminating the intermediate
sector rounding added here; and technically, since bdrv_getlength()
already rounds up to sectors, our use of DIV_ROUND_UP is more for
theoretical completeness than for any actual rounding.

Use is_power_of_2() while at it, instead of open-coding that.

diff --git a/block/dirty-bitmap.c b/block/dirty-bitmap.c
index XXXXXXX..XXXXXXX 100644
--- a/block/dirty-bitmap.c
+++ b/block/dirty-bitmap.c
@@ -XXX,XX +XXX,XX @@ struct BdrvDirtyBitmap {
     HBitmap *meta;              /* Meta dirty bitmap */
     BdrvDirtyBitmap *successor; /* Anonymous child; implies frozen status */
     char *name;                 /* Optional non-empty unique ID */
-    int64_t size;               /* Size of the bitmap (Number of sectors) */
+    int64_t size;               /* Size of the bitmap, in bytes */
     bool disabled;              /* Bitmap is disabled. It ignores all writes to
                                    the device */
     int active_iterators;       /* How many iterators are active */
@@ -XXX,XX +XXX,XX @@ BdrvDirtyBitmap *bdrv_create_dirty_bitmap(BlockDriverState *bs,
 {
     int64_t bitmap_size;
     BdrvDirtyBitmap *bitmap;
-    uint32_t sector_granularity;
 
-    assert((granularity & (granularity - 1)) == 0);
+    assert(is_power_of_2(granularity) && granularity >= BDRV_SECTOR_SIZE);
 
     if (name && bdrv_find_dirty_bitmap(bs, name)) {
         error_setg(errp, "Bitmap already exists: %s", name);
         return NULL;
     }
-    sector_granularity = granularity >> BDRV_SECTOR_BITS;
-    assert(sector_granularity);
-    bitmap_size = bdrv_nb_sectors(bs);
+    bitmap_size = bdrv_getlength(bs);
     if (bitmap_size < 0) {
         error_setg_errno(errp, -bitmap_size, "could not get length of device");
         errno = -bitmap_size;
@@ -XXX,XX +XXX,XX @@ BdrvDirtyBitmap *bdrv_create_dirty_bitmap(BlockDriverState *bs,
     }
     bitmap = g_new0(BdrvDirtyBitmap, 1);
     bitmap->mutex = &bs->dirty_bitmap_mutex;
-    bitmap->bitmap = hbitmap_alloc(bitmap_size, ctz32(sector_granularity));
+    /*
+     * TODO - let hbitmap track full granularity. For now, it is tracking
+     * only sector granularity, as a shortcut for our iterators.
+     */
+    bitmap->bitmap = hbitmap_alloc(DIV_ROUND_UP(bitmap_size, BDRV_SECTOR_SIZE),
+                                   ctz32(granularity) - BDRV_SECTOR_BITS);
     bitmap->size = bitmap_size;
     bitmap->name = g_strdup(name);
     bitmap->disabled = false;
@@ -XXX,XX +XXX,XX @@ void bdrv_release_meta_dirty_bitmap(BdrvDirtyBitmap *bitmap)
 
 int64_t bdrv_dirty_bitmap_size(const BdrvDirtyBitmap *bitmap)
 {
-    return bitmap->size * BDRV_SECTOR_SIZE;
+    return bitmap->size;
 }
 
 const char *bdrv_dirty_bitmap_name(const BdrvDirtyBitmap *bitmap)
@@ -XXX,XX +XXX,XX @@ BdrvDirtyBitmap *bdrv_reclaim_dirty_bitmap(BlockDriverState *bs,
 void bdrv_dirty_bitmap_truncate(BlockDriverState *bs, int64_t bytes)
 {
     BdrvDirtyBitmap *bitmap;
-    int64_t size = DIV_ROUND_UP(bytes, BDRV_SECTOR_SIZE);
 
     bdrv_dirty_bitmaps_lock(bs);
     QLIST_FOREACH(bitmap, &bs->dirty_bitmaps, list) {
         assert(!bdrv_dirty_bitmap_frozen(bitmap));
         assert(!bitmap->active_iterators);
-        hbitmap_truncate(bitmap->bitmap, size);
-        bitmap->size = size;
+        hbitmap_truncate(bitmap->bitmap, DIV_ROUND_UP(bytes, BDRV_SECTOR_SIZE));
+        bitmap->size = bytes;
     }
     bdrv_dirty_bitmaps_unlock(bs);
 }
@@ -XXX,XX +XXX,XX @@ void bdrv_clear_dirty_bitmap(BdrvDirtyBitmap *bitmap, HBitmap **out)
         hbitmap_reset_all(bitmap->bitmap);
     } else {
         HBitmap *backup = bitmap->bitmap;
-        bitmap->bitmap = hbitmap_alloc(bitmap->size,
+        bitmap->bitmap = hbitmap_alloc(DIV_ROUND_UP(bitmap->size,
+                                                    BDRV_SECTOR_SIZE),
                                        hbitmap_granularity(backup));
         *out = backup;
     }
-- 
2.13.6

From: Eric Blake <eblake@redhat.com>

Right now, the dirty-bitmap code exposes the fact that we use
a scale of sector granularity in the underlying hbitmap to anything
that wants to serialize a dirty bitmap.  It's nicer to uniformly
expose bytes as our dirty-bitmap interface, matching the previous
change to bitmap size.  The only caller to serialization is currently
qcow2-cluster.c, which becomes a bit more verbose because it is still
tracking sectors for other reasons, but a later patch will fix that
to more uniformly use byte offsets everywhere.  Likewise, within
dirty-bitmap, we have to add more assertions that we are not
truncating incorrectly, which can go away once the internal hbitmap
is byte-based rather than sector-based.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 include/block/dirty-bitmap.h | 14 +++++++-------
 block/dirty-bitmap.c         | 37 ++++++++++++++++++++++++-------------
 block/qcow2-bitmap.c         | 22 ++++++++++++++--------
 3 files changed, 45 insertions(+), 28 deletions(-)

diff --git a/include/block/dirty-bitmap.h b/include/block/dirty-bitmap.h
index XXXXXXX..XXXXXXX 100644
--- a/include/block/dirty-bitmap.h
+++ b/include/block/dirty-bitmap.h
@@ -XXX,XX +XXX,XX @@ BdrvDirtyBitmapIter *bdrv_dirty_iter_new(BdrvDirtyBitmap *bitmap,
 void bdrv_dirty_iter_free(BdrvDirtyBitmapIter *iter);
 
 uint64_t bdrv_dirty_bitmap_serialization_size(const BdrvDirtyBitmap *bitmap,
-                                              uint64_t start, uint64_t count);
+                                              uint64_t offset, uint64_t bytes);
 uint64_t bdrv_dirty_bitmap_serialization_align(const BdrvDirtyBitmap *bitmap);
 void bdrv_dirty_bitmap_serialize_part(const BdrvDirtyBitmap *bitmap,
-                                      uint8_t *buf, uint64_t start,
-                                      uint64_t count);
+                                      uint8_t *buf, uint64_t offset,
+                                      uint64_t bytes);
 void bdrv_dirty_bitmap_deserialize_part(BdrvDirtyBitmap *bitmap,
-                                        uint8_t *buf, uint64_t start,
-                                        uint64_t count, bool finish);
+                                        uint8_t *buf, uint64_t offset,
+                                        uint64_t bytes, bool finish);
 void bdrv_dirty_bitmap_deserialize_zeroes(BdrvDirtyBitmap *bitmap,
-                                          uint64_t start, uint64_t count,
+                                          uint64_t offset, uint64_t bytes,
                                           bool finish);
 void bdrv_dirty_bitmap_deserialize_ones(BdrvDirtyBitmap *bitmap,
-                                        uint64_t start, uint64_t count,
+                                        uint64_t offset, uint64_t bytes,
                                         bool finish);
 void bdrv_dirty_bitmap_deserialize_finish(BdrvDirtyBitmap *bitmap);
 
diff --git a/block/dirty-bitmap.c b/block/dirty-bitmap.c
index XXXXXXX..XXXXXXX 100644
--- a/block/dirty-bitmap.c
+++ b/block/dirty-bitmap.c
@@ -XXX,XX +XXX,XX @@ void bdrv_undo_clear_dirty_bitmap(BdrvDirtyBitmap *bitmap, HBitmap *in)
 }
 
 uint64_t bdrv_dirty_bitmap_serialization_size(const BdrvDirtyBitmap *bitmap,
-                                              uint64_t start, uint64_t count)
+                                              uint64_t offset, uint64_t bytes)
 {
-    return hbitmap_serialization_size(bitmap->bitmap, start, count);
+    assert(QEMU_IS_ALIGNED(offset | bytes, BDRV_SECTOR_SIZE));
+    return hbitmap_serialization_size(bitmap->bitmap,
+                                      offset >> BDRV_SECTOR_BITS,
+                                      bytes >> BDRV_SECTOR_BITS);
 }
 
 uint64_t bdrv_dirty_bitmap_serialization_align(const BdrvDirtyBitmap *bitmap)
 {
-    return hbitmap_serialization_align(bitmap->bitmap);
+    return hbitmap_serialization_align(bitmap->bitmap) * BDRV_SECTOR_SIZE;
 }
 
 void bdrv_dirty_bitmap_serialize_part(const BdrvDirtyBitmap *bitmap,
-                                      uint8_t *buf, uint64_t start,
-                                      uint64_t count)
+                                      uint8_t *buf, uint64_t offset,
+                                      uint64_t bytes)
 {
-    hbitmap_serialize_part(bitmap->bitmap, buf, start, count);
+    assert(QEMU_IS_ALIGNED(offset | bytes, BDRV_SECTOR_SIZE));
+    hbitmap_serialize_part(bitmap->bitmap, buf, offset >> BDRV_SECTOR_BITS,
+                           bytes >> BDRV_SECTOR_BITS);
 }
 
 void bdrv_dirty_bitmap_deserialize_part(BdrvDirtyBitmap *bitmap,
-                                        uint8_t *buf, uint64_t start,
-                                        uint64_t count, bool finish)
+                                        uint8_t *buf, uint64_t offset,
+                                        uint64_t bytes, bool finish)
 {
-    hbitmap_deserialize_part(bitmap->bitmap, buf, start, count, finish);
+    assert(QEMU_IS_ALIGNED(offset | bytes, BDRV_SECTOR_SIZE));
+    hbitmap_deserialize_part(bitmap->bitmap, buf, offset >> BDRV_SECTOR_BITS,
+                             bytes >> BDRV_SECTOR_BITS, finish);
 }
 
 void bdrv_dirty_bitmap_deserialize_zeroes(BdrvDirtyBitmap *bitmap,
-                                          uint64_t start, uint64_t count,
+                                          uint64_t offset, uint64_t bytes,
                                           bool finish)
 {
-    hbitmap_deserialize_zeroes(bitmap->bitmap, start, count, finish);
+    assert(QEMU_IS_ALIGNED(offset | bytes, BDRV_SECTOR_SIZE));
+    hbitmap_deserialize_zeroes(bitmap->bitmap, offset >> BDRV_SECTOR_BITS,
+                               bytes >> BDRV_SECTOR_BITS, finish);
 }
 
 void bdrv_dirty_bitmap_deserialize_ones(BdrvDirtyBitmap *bitmap,
-                                        uint64_t start, uint64_t count,
+                                        uint64_t offset, uint64_t bytes,
                                         bool finish)
 {
-    hbitmap_deserialize_ones(bitmap->bitmap, start, count, finish);
+    assert(QEMU_IS_ALIGNED(offset | bytes, BDRV_SECTOR_SIZE));
+    hbitmap_deserialize_ones(bitmap->bitmap, offset >> BDRV_SECTOR_BITS,
+                             bytes >> BDRV_SECTOR_BITS, finish);
 }
 
 void bdrv_dirty_bitmap_deserialize_finish(BdrvDirtyBitmap *bitmap)
diff --git a/block/qcow2-bitmap.c b/block/qcow2-bitmap.c
index XXXXXXX..XXXXXXX 100644
--- a/block/qcow2-bitmap.c
+++ b/block/qcow2-bitmap.c
@@ -XXX,XX +XXX,XX @@ static uint64_t sectors_covered_by_bitmap_cluster(const BDRVQcow2State *s,
             bdrv_dirty_bitmap_granularity(bitmap) >> BDRV_SECTOR_BITS;
     uint64_t sbc = sector_granularity * (s->cluster_size << 3);
 
-    assert(QEMU_IS_ALIGNED(sbc,
+    assert(QEMU_IS_ALIGNED(sbc << BDRV_SECTOR_BITS,
                            bdrv_dirty_bitmap_serialization_align(bitmap)));
     return sbc;
 }
@@ -XXX,XX +XXX,XX @@ static int load_bitmap_data(BlockDriverState *bs,
     uint8_t *buf = NULL;
     uint64_t i, tab_size =
             size_to_clusters(s,
-                bdrv_dirty_bitmap_serialization_size(bitmap, 0, bm_sectors));
+                bdrv_dirty_bitmap_serialization_size(bitmap, 0, bm_size));
 
     if (tab_size != bitmap_table_size || tab_size > BME_MAX_TABLE_SIZE) {
         return -EINVAL;
@@ -XXX,XX +XXX,XX @@ static int load_bitmap_data(BlockDriverState *bs,
 
         if (offset == 0) {
             if (entry & BME_TABLE_ENTRY_FLAG_ALL_ONES) {
-                bdrv_dirty_bitmap_deserialize_ones(bitmap, sector, count,
+                bdrv_dirty_bitmap_deserialize_ones(bitmap,
+                                                   sector * BDRV_SECTOR_SIZE,
+                                                   count * BDRV_SECTOR_SIZE,
                                                    false);
             } else {
                 /* No need to deserialize zeros because the dirty bitmap is
@@ -XXX,XX +XXX,XX @@ static int load_bitmap_data(BlockDriverState *bs,
             if (ret < 0) {
                 goto finish;
             }
-            bdrv_dirty_bitmap_deserialize_part(bitmap, buf, sector, count,
+            bdrv_dirty_bitmap_deserialize_part(bitmap, buf,
+                                               sector * BDRV_SECTOR_SIZE,
+                                               count * BDRV_SECTOR_SIZE,
                                                false);
         }
     }
@@ -XXX,XX +XXX,XX @@ static uint64_t *store_bitmap_data(BlockDriverState *bs,
     uint64_t *tb;
     uint64_t tb_size =
             size_to_clusters(s,
-                bdrv_dirty_bitmap_serialization_size(bitmap, 0, bm_sectors));
+                bdrv_dirty_bitmap_serialization_size(bitmap, 0, bm_size));
 
     if (tb_size > BME_MAX_TABLE_SIZE ||
         tb_size * s->cluster_size > BME_MAX_PHYS_SIZE)
@@ -XXX,XX +XXX,XX @@ static uint64_t *store_bitmap_data(BlockDriverState *bs,
 
         sector = cluster * sbc;
         end = MIN(bm_sectors, sector + sbc);
-        write_size =
-            bdrv_dirty_bitmap_serialization_size(bitmap, sector, end - sector);
+        write_size = bdrv_dirty_bitmap_serialization_size(bitmap,
+            sector * BDRV_SECTOR_SIZE, (end - sector) * BDRV_SECTOR_SIZE);
         assert(write_size <= s->cluster_size);
 
         off = qcow2_alloc_clusters(bs, s->cluster_size);
@@ -XXX,XX +XXX,XX @@ static uint64_t *store_bitmap_data(BlockDriverState *bs,
         }
         tb[cluster] = off;
 
-        bdrv_dirty_bitmap_serialize_part(bitmap, buf, sector, end - sector);
+        bdrv_dirty_bitmap_serialize_part(bitmap, buf,
+                                         sector * BDRV_SECTOR_SIZE,
+                                         (end - sector) * BDRV_SECTOR_SIZE);
         if (write_size < s->cluster_size) {
             memset(buf + write_size, 0, s->cluster_size - write_size);
         }
-- 
2.13.6

From: Eric Blake <eblake@redhat.com>

We are gradually converting to byte-based interfaces, as they are
easier to reason about than sector-based.  Change the qcow2 bitmap
helper function sectors_covered_by_bitmap_cluster(), renaming it
to bytes_covered_by_bitmap_cluster() in the process.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block/qcow2-bitmap.c | 28 ++++++++++++++--------------
 1 file changed, 14 insertions(+), 14 deletions(-)

diff --git a/block/qcow2-bitmap.c b/block/qcow2-bitmap.c
index XXXXXXX..XXXXXXX 100644
--- a/block/qcow2-bitmap.c
+++ b/block/qcow2-bitmap.c
@@ -XXX,XX +XXX,XX @@ static int free_bitmap_clusters(BlockDriverState *bs, Qcow2BitmapTable *tb)
     return 0;
 }
 
-/* This function returns the number of disk sectors covered by a single qcow2
- * cluster of bitmap data. */
-static uint64_t sectors_covered_by_bitmap_cluster(const BDRVQcow2State *s,
-                                                  const BdrvDirtyBitmap *bitmap)
+/* Return the disk size covered by a single qcow2 cluster of bitmap data. */
+static uint64_t bytes_covered_by_bitmap_cluster(const BDRVQcow2State *s,
+                                                const BdrvDirtyBitmap *bitmap)
 {
-    uint64_t sector_granularity =
-            bdrv_dirty_bitmap_granularity(bitmap) >> BDRV_SECTOR_BITS;
-    uint64_t sbc = sector_granularity * (s->cluster_size << 3);
+    uint64_t granularity = bdrv_dirty_bitmap_granularity(bitmap);
+    uint64_t limit = granularity * (s->cluster_size << 3);
 
-    assert(QEMU_IS_ALIGNED(sbc << BDRV_SECTOR_BITS,
+    assert(QEMU_IS_ALIGNED(limit,
                            bdrv_dirty_bitmap_serialization_align(bitmap)));
-    return sbc;
+    return limit;
 }
 
 /* load_bitmap_data
@@ -XXX,XX +XXX,XX @@ static int load_bitmap_data(BlockDriverState *bs,
 {
     int ret = 0;
     BDRVQcow2State *s = bs->opaque;
-    uint64_t sector, sbc;
+    uint64_t sector, limit, sbc;
     uint64_t bm_size = bdrv_dirty_bitmap_size(bitmap);
     uint64_t bm_sectors = DIV_ROUND_UP(bm_size, BDRV_SECTOR_SIZE);
     uint8_t *buf = NULL;
@@ -XXX,XX +XXX,XX @@ static int load_bitmap_data(BlockDriverState *bs,
     }
 
     buf = g_malloc(s->cluster_size);
-    sbc = sectors_covered_by_bitmap_cluster(s, bitmap);
+    limit = bytes_covered_by_bitmap_cluster(s, bitmap);
+    sbc = limit >> BDRV_SECTOR_BITS;
     for (i = 0, sector = 0; i < tab_size; ++i, sector += sbc) {
         uint64_t count = MIN(bm_sectors - sector, sbc);
         uint64_t entry = bitmap_table[i];
@@ -XXX,XX +XXX,XX @@ static uint64_t *store_bitmap_data(BlockDriverState *bs,
     int ret;
     BDRVQcow2State *s = bs->opaque;
     int64_t sector;
-    uint64_t sbc;
+    uint64_t limit, sbc;
     uint64_t bm_size = bdrv_dirty_bitmap_size(bitmap);
     uint64_t bm_sectors = DIV_ROUND_UP(bm_size, BDRV_SECTOR_SIZE);
     const char *bm_name = bdrv_dirty_bitmap_name(bitmap);
@@ -XXX,XX +XXX,XX @@ static uint64_t *store_bitmap_data(BlockDriverState *bs,
 
     dbi = bdrv_dirty_iter_new(bitmap, 0);
     buf = g_malloc(s->cluster_size);
-    sbc = sectors_covered_by_bitmap_cluster(s, bitmap);
-    assert(DIV_ROUND_UP(bm_sectors, sbc) == tb_size);
+    limit = bytes_covered_by_bitmap_cluster(s, bitmap);
+    sbc = limit >> BDRV_SECTOR_BITS;
+    assert(DIV_ROUND_UP(bm_size, limit) == tb_size);
 
     while ((sector = bdrv_dirty_iter_next(dbi)) != -1) {
         uint64_t cluster = sector / sbc;
-- 
2.13.6

From: Eric Blake <eblake@redhat.com>

All callers to bdrv_dirty_iter_new() passed 0 for their initial
starting point, drop that parameter.

Most callers to bdrv_set_dirty_iter() were scaling a byte offset to
a sector number; the exception qcow2-bitmap will be converted later
to use byte rather than sector iteration.  Move the scaling to occur
internally to dirty bitmap code instead, so that callers now pass
in bytes.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 include/block/dirty-bitmap.h | 5 ++---
 block/backup.c               | 5 ++---
 block/dirty-bitmap.c         | 9 ++++-----
 block/mirror.c               | 4 ++--
 block/qcow2-bitmap.c         | 4 ++--
 5 files changed, 12 insertions(+), 15 deletions(-)

From: Eric Blake <eblake@redhat.com>

Thanks to recent cleanups, most callers were scaling a return value
of sectors into bytes (the exception, in qcow2-bitmap, will be
converted to byte-based iteration later).  Update the interface to
do the scaling internally instead.

In qcow2-bitmap, the code was specifically checking for an error
return of -1.  To avoid a regression, we either have to make sure
we continue to return -1 (rather than a scaled -512) on error, or
we have to fix the caller to treat all negative values as error
rather than just one magic value.  It's easy enough to make both
changes at the same time, even though either one in isolation
would work.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block/backup.c       | 2 +-
 block/dirty-bitmap.c | 3 ++-
 block/mirror.c       | 8 ++++----
 block/qcow2-bitmap.c | 2 +-
 4 files changed, 8 insertions(+), 7 deletions(-)

diff --git a/block/backup.c b/block/backup.c
index XXXXXXX..XXXXXXX 100644
--- a/block/backup.c
+++ b/block/backup.c
@@ -XXX,XX +XXX,XX @@ static int coroutine_fn backup_run_incremental(BackupBlockJob *job)
     dbi = bdrv_dirty_iter_new(job->sync_bitmap);
 
     /* Find the next dirty sector(s) */
-    while ((offset = bdrv_dirty_iter_next(dbi) * BDRV_SECTOR_SIZE) >= 0) {
+    while ((offset = bdrv_dirty_iter_next(dbi)) >= 0) {
         cluster = offset / job->cluster_size;
 
         /* Fake progress updates for any clusters we skipped */
diff --git a/block/dirty-bitmap.c b/block/dirty-bitmap.c
index XXXXXXX..XXXXXXX 100644
--- a/block/dirty-bitmap.c
+++ b/block/dirty-bitmap.c
@@ -XXX,XX +XXX,XX @@ void bdrv_dirty_iter_free(BdrvDirtyBitmapIter *iter)
 
 int64_t bdrv_dirty_iter_next(BdrvDirtyBitmapIter *iter)
 {
-    return hbitmap_iter_next(&iter->hbi);
+    int64_t ret = hbitmap_iter_next(&iter->hbi);
+    return ret < 0 ? -1 : ret * BDRV_SECTOR_SIZE;
 }
 
 /* Called within bdrv_dirty_bitmap_lock..unlock */
diff --git a/block/mirror.c b/block/mirror.c
index XXXXXXX..XXXXXXX 100644
--- a/block/mirror.c
+++ b/block/mirror.c
@@ -XXX,XX +XXX,XX @@ static uint64_t coroutine_fn mirror_iteration(MirrorBlockJob *s)
     int max_io_bytes = MAX(s->buf_size / MAX_IN_FLIGHT, MAX_IO_BYTES);
 
     bdrv_dirty_bitmap_lock(s->dirty_bitmap);
-    offset = bdrv_dirty_iter_next(s->dbi) * BDRV_SECTOR_SIZE;
+    offset = bdrv_dirty_iter_next(s->dbi);
     if (offset < 0) {
         bdrv_set_dirty_iter(s->dbi, 0);
-        offset = bdrv_dirty_iter_next(s->dbi) * BDRV_SECTOR_SIZE;
+        offset = bdrv_dirty_iter_next(s->dbi);
         trace_mirror_restart_iter(s, bdrv_get_dirty_count(s->dirty_bitmap) *
                                   BDRV_SECTOR_SIZE);
         assert(offset >= 0);
@@ -XXX,XX +XXX,XX @@ static uint64_t coroutine_fn mirror_iteration(MirrorBlockJob *s)
             break;
         }
 
-        next_dirty = bdrv_dirty_iter_next(s->dbi) * BDRV_SECTOR_SIZE;
+        next_dirty = bdrv_dirty_iter_next(s->dbi);
         if (next_dirty > next_offset || next_dirty < 0) {
             /* The bitmap iterator's cache is stale, refresh it */
             bdrv_set_dirty_iter(s->dbi, next_offset);
-            next_dirty = bdrv_dirty_iter_next(s->dbi) * BDRV_SECTOR_SIZE;
+            next_dirty = bdrv_dirty_iter_next(s->dbi);
         }
         assert(next_dirty == next_offset);
         nb_chunks++;
diff --git a/block/qcow2-bitmap.c b/block/qcow2-bitmap.c
index XXXXXXX..XXXXXXX 100644
--- a/block/qcow2-bitmap.c
+++ b/block/qcow2-bitmap.c
@@ -XXX,XX +XXX,XX @@ static uint64_t *store_bitmap_data(BlockDriverState *bs,
     sbc = limit >> BDRV_SECTOR_BITS;
     assert(DIV_ROUND_UP(bm_size, limit) == tb_size);
 
-    while ((sector = bdrv_dirty_iter_next(dbi)) != -1) {
+    while ((sector = bdrv_dirty_iter_next(dbi) >> BDRV_SECTOR_BITS) >= 0) {
         uint64_t cluster = sector / sbc;
         uint64_t end, write_size;
         int64_t off;
-- 
2.13.6

From: Eric Blake <eblake@redhat.com>

Thanks to recent cleanups, all callers were scaling a return value
of sectors into bytes; do the scaling internally instead.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block/dirty-bitmap.c |  4 ++--
 block/mirror.c       | 16 ++++++----------
 migration/block.c    |  2 +-
 3 files changed, 9 insertions(+), 13 deletions(-)

diff --git a/block/dirty-bitmap.c b/block/dirty-bitmap.c
index XXXXXXX..XXXXXXX 100644
--- a/block/dirty-bitmap.c
+++ b/block/dirty-bitmap.c
@@ -XXX,XX +XXX,XX @@ BlockDirtyInfoList *bdrv_query_dirty_bitmaps(BlockDriverState *bs)
     QLIST_FOREACH(bm, &bs->dirty_bitmaps, list) {
         BlockDirtyInfo *info = g_new0(BlockDirtyInfo, 1);
         BlockDirtyInfoList *entry = g_new0(BlockDirtyInfoList, 1);
-        info->count = bdrv_get_dirty_count(bm) << BDRV_SECTOR_BITS;
+        info->count = bdrv_get_dirty_count(bm);
         info->granularity = bdrv_dirty_bitmap_granularity(bm);
         info->has_name = !!bm->name;
         info->name = g_strdup(bm->name);
@@ -XXX,XX +XXX,XX @@ void bdrv_set_dirty_iter(BdrvDirtyBitmapIter *iter, int64_t offset)
 
 int64_t bdrv_get_dirty_count(BdrvDirtyBitmap *bitmap)
 {
-    return hbitmap_count(bitmap->bitmap);
+    return hbitmap_count(bitmap->bitmap) << BDRV_SECTOR_BITS;
 }
 
 int64_t bdrv_get_meta_dirty_count(BdrvDirtyBitmap *bitmap)
diff --git a/block/mirror.c b/block/mirror.c
index XXXXXXX..XXXXXXX 100644
--- a/block/mirror.c
+++ b/block/mirror.c
@@ -XXX,XX +XXX,XX @@ static uint64_t coroutine_fn mirror_iteration(MirrorBlockJob *s)
     if (offset < 0) {
         bdrv_set_dirty_iter(s->dbi, 0);
         offset = bdrv_dirty_iter_next(s->dbi);
-        trace_mirror_restart_iter(s, bdrv_get_dirty_count(s->dirty_bitmap) *
-                                  BDRV_SECTOR_SIZE);
+        trace_mirror_restart_iter(s, bdrv_get_dirty_count(s->dirty_bitmap));
         assert(offset >= 0);
     }
     bdrv_dirty_bitmap_unlock(s->dirty_bitmap);
@@ -XXX,XX +XXX,XX @@ static void coroutine_fn mirror_run(void *opaque)
 
         cnt = bdrv_get_dirty_count(s->dirty_bitmap);
         /* s->common.offset contains the number of bytes already processed so
-         * far, cnt is the number of dirty sectors remaining and
+         * far, cnt is the number of dirty bytes remaining and
          * s->bytes_in_flight is the number of bytes currently being
          * processed; together those are the current total operation length */
-        s->common.len = s->common.offset + s->bytes_in_flight +
-            cnt * BDRV_SECTOR_SIZE;
+        s->common.len = s->common.offset + s->bytes_in_flight + cnt;
 
         /* Note that even when no rate limit is applied we need to yield
          * periodically with no pending I/O so that bdrv_drain_all() returns.
@@ -XXX,XX +XXX,XX @@ static void coroutine_fn mirror_run(void *opaque)
             s->common.iostatus == BLOCK_DEVICE_IO_STATUS_OK) {
             if (s->in_flight >= MAX_IN_FLIGHT || s->buf_free_count == 0 ||
                 (cnt == 0 && s->in_flight > 0)) {
-                trace_mirror_yield(s, cnt * BDRV_SECTOR_SIZE,
-                                   s->buf_free_count, s->in_flight);
+                trace_mirror_yield(s, cnt, s->buf_free_count, s->in_flight);
                 mirror_wait_for_io(s);
                 continue;
             } else if (cnt != 0) {
@@ -XXX,XX +XXX,XX @@ static void coroutine_fn mirror_run(void *opaque)
              * whether to switch to target check one last time if I/O has
              * come in the meanwhile, and if not flush the data to disk.
              */
-            trace_mirror_before_drain(s, cnt * BDRV_SECTOR_SIZE);
+            trace_mirror_before_drain(s, cnt);
 
             bdrv_drained_begin(bs);
             cnt = bdrv_get_dirty_count(s->dirty_bitmap);
@@ -XXX,XX +XXX,XX @@ static void coroutine_fn mirror_run(void *opaque)
         }
 
         ret = 0;
-        trace_mirror_before_sleep(s, cnt * BDRV_SECTOR_SIZE,
-                                  s->synced, delay_ns);
+        trace_mirror_before_sleep(s, cnt, s->synced, delay_ns);
         if (!s->synced) {
             block_job_sleep_ns(&s->common, QEMU_CLOCK_REALTIME, delay_ns);
             if (block_job_is_cancelled(&s->common)) {
diff --git a/migration/block.c b/migration/block.c
index XXXXXXX..XXXXXXX 100644
--- a/migration/block.c
+++ b/migration/block.c
@@ -XXX,XX +XXX,XX @@ static int64_t get_remaining_dirty(void)
         aio_context_release(blk_get_aio_context(bmds->blk));
     }
 
-    return dirty << BDRV_SECTOR_BITS;
+    return dirty;
 }
 
 
-- 
2.13.6

From: Eric Blake <eblake@redhat.com>

Half the callers were already scaling bytes to sectors; the other
half can eventually be simplified to use byte iteration.  Both
callers were already using the result as a bool, so make that
explicit.  Making the change also makes it easier for a future
dirty-bitmap patch to offload scaling over to the internal hbitmap.

Remember, asking whether a byte is dirty is effectively asking
whether the entire granularity containing the byte is dirty, since
we only track dirtiness by granularity.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 include/block/dirty-bitmap.h | 4 ++--
 block/dirty-bitmap.c         | 8 ++++----
 block/mirror.c               | 3 +--
 migration/block.c            | 3 ++-
 4 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/include/block/dirty-bitmap.h b/include/block/dirty-bitmap.h
index XXXXXXX..XXXXXXX 100644
--- a/include/block/dirty-bitmap.h
+++ b/include/block/dirty-bitmap.h
@@ -XXX,XX +XXX,XX @@ void bdrv_dirty_bitmap_set_persistance(BdrvDirtyBitmap *bitmap,
 /* Functions that require manual locking.  */
 void bdrv_dirty_bitmap_lock(BdrvDirtyBitmap *bitmap);
 void bdrv_dirty_bitmap_unlock(BdrvDirtyBitmap *bitmap);
-int bdrv_get_dirty_locked(BlockDriverState *bs, BdrvDirtyBitmap *bitmap,
-                          int64_t sector);
+bool bdrv_get_dirty_locked(BlockDriverState *bs, BdrvDirtyBitmap *bitmap,
+                           int64_t offset);
 void bdrv_set_dirty_bitmap_locked(BdrvDirtyBitmap *bitmap,
                                   int64_t cur_sector, int64_t nr_sectors);
 void bdrv_reset_dirty_bitmap_locked(BdrvDirtyBitmap *bitmap,
diff --git a/block/dirty-bitmap.c b/block/dirty-bitmap.c
index XXXXXXX..XXXXXXX 100644
--- a/block/dirty-bitmap.c
+++ b/block/dirty-bitmap.c
@@ -XXX,XX +XXX,XX @@ BlockDirtyInfoList *bdrv_query_dirty_bitmaps(BlockDriverState *bs)
 }
 
 /* Called within bdrv_dirty_bitmap_lock..unlock */
-int bdrv_get_dirty_locked(BlockDriverState *bs, BdrvDirtyBitmap *bitmap,
-                          int64_t sector)
+bool bdrv_get_dirty_locked(BlockDriverState *bs, BdrvDirtyBitmap *bitmap,
+                           int64_t offset)
 {
     if (bitmap) {
-        return hbitmap_get(bitmap->bitmap, sector);
+        return hbitmap_get(bitmap->bitmap, offset >> BDRV_SECTOR_BITS);
     } else {
-        return 0;
+        return false;
     }
 }
 
diff --git a/block/mirror.c b/block/mirror.c
index XXXXXXX..XXXXXXX 100644
--- a/block/mirror.c
+++ b/block/mirror.c
@@ -XXX,XX +XXX,XX @@ static uint64_t coroutine_fn mirror_iteration(MirrorBlockJob *s)
         int64_t next_offset = offset + nb_chunks * s->granularity;
         int64_t next_chunk = next_offset / s->granularity;
         if (next_offset >= s->bdev_length ||
-            !bdrv_get_dirty_locked(source, s->dirty_bitmap,
-                                   next_offset >> BDRV_SECTOR_BITS)) {
+            !bdrv_get_dirty_locked(source, s->dirty_bitmap, next_offset)) {
             break;
         }
         if (test_bit(next_chunk, s->in_flight_bitmap)) {
diff --git a/migration/block.c b/migration/block.c
index XXXXXXX..XXXXXXX 100644
--- a/migration/block.c
+++ b/migration/block.c
@@ -XXX,XX +XXX,XX @@ static int mig_save_device_dirty(QEMUFile *f, BlkMigDevState *bmds,
             blk_mig_unlock();
         }
         bdrv_dirty_bitmap_lock(bmds->dirty_bitmap);
-        if (bdrv_get_dirty_locked(bs, bmds->dirty_bitmap, sector)) {
+        if (bdrv_get_dirty_locked(bs, bmds->dirty_bitmap,
+                                  sector * BDRV_SECTOR_SIZE)) {
             if (total_sectors - sector < BDRV_SECTORS_PER_DIRTY_CHUNK) {
                 nr_sectors = total_sectors - sector;
             } else {
-- 
2.13.6

From: Eric Blake <eblake@redhat.com>

Some of the callers were already scaling bytes to sectors; others
can be easily converted to pass byte offsets, all in our shift
towards a consistent byte interface everywhere.  Making the change
will also make it easier to write the hold-out callers to use byte
rather than sectors for their iterations; it also makes it easier
for a future dirty-bitmap patch to offload scaling over to the
internal hbitmap.  Although all callers happen to pass
sector-aligned values, make the internal scaling robust to any
sub-sector requests.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 include/block/dirty-bitmap.h |  8 ++++----
 block/dirty-bitmap.c         | 22 ++++++++++++++--------
 block/mirror.c               | 16 ++++++++--------
 migration/block.c            |  7 +++++--
 4 files changed, 31 insertions(+), 22 deletions(-)

diff --git a/include/block/dirty-bitmap.h b/include/block/dirty-bitmap.h
index XXXXXXX..XXXXXXX 100644
--- a/include/block/dirty-bitmap.h
+++ b/include/block/dirty-bitmap.h
@@ -XXX,XX +XXX,XX @@ const char *bdrv_dirty_bitmap_name(const BdrvDirtyBitmap *bitmap);
 int64_t bdrv_dirty_bitmap_size(const BdrvDirtyBitmap *bitmap);
 DirtyBitmapStatus bdrv_dirty_bitmap_status(BdrvDirtyBitmap *bitmap);
 void bdrv_set_dirty_bitmap(BdrvDirtyBitmap *bitmap,
-                           int64_t cur_sector, int64_t nr_sectors);
+                           int64_t offset, int64_t bytes);
 void bdrv_reset_dirty_bitmap(BdrvDirtyBitmap *bitmap,
-                             int64_t cur_sector, int64_t nr_sectors);
+                             int64_t offset, int64_t bytes);
 BdrvDirtyBitmapIter *bdrv_dirty_meta_iter_new(BdrvDirtyBitmap *bitmap);
 BdrvDirtyBitmapIter *bdrv_dirty_iter_new(BdrvDirtyBitmap *bitmap);
 void bdrv_dirty_iter_free(BdrvDirtyBitmapIter *iter);
@@ -XXX,XX +XXX,XX @@ void bdrv_dirty_bitmap_unlock(BdrvDirtyBitmap *bitmap);
 bool bdrv_get_dirty_locked(BlockDriverState *bs, BdrvDirtyBitmap *bitmap,
                            int64_t offset);
 void bdrv_set_dirty_bitmap_locked(BdrvDirtyBitmap *bitmap,
-                                  int64_t cur_sector, int64_t nr_sectors);
+                                  int64_t offset, int64_t bytes);
 void bdrv_reset_dirty_bitmap_locked(BdrvDirtyBitmap *bitmap,
-                                    int64_t cur_sector, int64_t nr_sectors);
+                                    int64_t offset, int64_t bytes);
 int64_t bdrv_dirty_iter_next(BdrvDirtyBitmapIter *iter);
 void bdrv_set_dirty_iter(BdrvDirtyBitmapIter *hbi, int64_t offset);
 int64_t bdrv_get_dirty_count(BdrvDirtyBitmap *bitmap);
diff --git a/block/dirty-bitmap.c b/block/dirty-bitmap.c
index XXXXXXX..XXXXXXX 100644
--- a/block/dirty-bitmap.c
+++ b/block/dirty-bitmap.c
@@ -XXX,XX +XXX,XX @@ int64_t bdrv_dirty_iter_next(BdrvDirtyBitmapIter *iter)
 
 /* Called within bdrv_dirty_bitmap_lock..unlock */
 void bdrv_set_dirty_bitmap_locked(BdrvDirtyBitmap *bitmap,
-                                  int64_t cur_sector, int64_t nr_sectors)
+                                  int64_t offset, int64_t bytes)
 {
+    int64_t end_sector = DIV_ROUND_UP(offset + bytes, BDRV_SECTOR_SIZE);
+
     assert(bdrv_dirty_bitmap_enabled(bitmap));
     assert(!bdrv_dirty_bitmap_readonly(bitmap));
-    hbitmap_set(bitmap->bitmap, cur_sector, nr_sectors);
+    hbitmap_set(bitmap->bitmap, offset >> BDRV_SECTOR_BITS,
+                end_sector - (offset >> BDRV_SECTOR_BITS));
 }
 
 void bdrv_set_dirty_bitmap(BdrvDirtyBitmap *bitmap,
-                           int64_t cur_sector, int64_t nr_sectors)
+                           int64_t offset, int64_t bytes)
 {
     bdrv_dirty_bitmap_lock(bitmap);
-    bdrv_set_dirty_bitmap_locked(bitmap, cur_sector, nr_sectors);
+    bdrv_set_dirty_bitmap_locked(bitmap, offset, bytes);
     bdrv_dirty_bitmap_unlock(bitmap);
 }
 
 /* Called within bdrv_dirty_bitmap_lock..unlock */
 void bdrv_reset_dirty_bitmap_locked(BdrvDirtyBitmap *bitmap,
-                                    int64_t cur_sector, int64_t nr_sectors)
+                                    int64_t offset, int64_t bytes)
 {
+    int64_t end_sector = DIV_ROUND_UP(offset + bytes, BDRV_SECTOR_SIZE);
+
     assert(bdrv_dirty_bitmap_enabled(bitmap));
     assert(!bdrv_dirty_bitmap_readonly(bitmap));
-    hbitmap_reset(bitmap->bitmap, cur_sector, nr_sectors);
+    hbitmap_reset(bitmap->bitmap, offset >> BDRV_SECTOR_BITS,
+                  end_sector - (offset >> BDRV_SECTOR_BITS));
 }
 
 void bdrv_reset_dirty_bitmap(BdrvDirtyBitmap *bitmap,
-                             int64_t cur_sector, int64_t nr_sectors)
+                             int64_t offset, int64_t bytes)
 {
     bdrv_dirty_bitmap_lock(bitmap);
-    bdrv_reset_dirty_bitmap_locked(bitmap, cur_sector, nr_sectors);
+    bdrv_reset_dirty_bitmap_locked(bitmap, offset, bytes);
     bdrv_dirty_bitmap_unlock(bitmap);
 }
 
diff --git a/block/mirror.c b/block/mirror.c
index XXXXXXX..XXXXXXX 100644
--- a/block/mirror.c
+++ b/block/mirror.c
@@ -XXX,XX +XXX,XX @@ static void mirror_write_complete(void *opaque, int ret)
     if (ret < 0) {
         BlockErrorAction action;
 
-        bdrv_set_dirty_bitmap(s->dirty_bitmap, op->offset >> BDRV_SECTOR_BITS,
-                              op->bytes >> BDRV_SECTOR_BITS);
+        bdrv_set_dirty_bitmap(s->dirty_bitmap, op->offset, op->bytes);
         action = mirror_error_action(s, false, -ret);
         if (action == BLOCK_ERROR_ACTION_REPORT && s->ret >= 0) {
             s->ret = ret;
@@ -XXX,XX +XXX,XX @@ static void mirror_read_complete(void *opaque, int ret)
     if (ret < 0) {
         BlockErrorAction action;
 
-        bdrv_set_dirty_bitmap(s->dirty_bitmap, op->offset >> BDRV_SECTOR_BITS,
-                              op->bytes >> BDRV_SECTOR_BITS);
+        bdrv_set_dirty_bitmap(s->dirty_bitmap, op->offset, op->bytes);
         action = mirror_error_action(s, true, -ret);
         if (action == BLOCK_ERROR_ACTION_REPORT && s->ret >= 0) {
             s->ret = ret;
@@ -XXX,XX +XXX,XX @@ static uint64_t coroutine_fn mirror_iteration(MirrorBlockJob *s)
      * calling bdrv_get_block_status_above could yield - if some blocks are
      * marked dirty in this window, we need to know.
      */
-    bdrv_reset_dirty_bitmap_locked(s->dirty_bitmap, offset >> BDRV_SECTOR_BITS,
-                                   nb_chunks * sectors_per_chunk);
+    bdrv_reset_dirty_bitmap_locked(s->dirty_bitmap, offset,
+                                   nb_chunks * s->granularity);
     bdrv_dirty_bitmap_unlock(s->dirty_bitmap);
 
     bitmap_set(s->in_flight_bitmap, offset / s->granularity, nb_chunks);
@@ -XXX,XX +XXX,XX @@ static int coroutine_fn mirror_dirty_init(MirrorBlockJob *s)
 
     if (base == NULL && !bdrv_has_zero_init(target_bs)) {
         if (!bdrv_can_write_zeroes_with_unmap(target_bs)) {
-            bdrv_set_dirty_bitmap(s->dirty_bitmap, 0, end);
+            bdrv_set_dirty_bitmap(s->dirty_bitmap, 0, s->bdev_length);
             return 0;
         }
 
@@ -XXX,XX +XXX,XX @@ static int coroutine_fn mirror_dirty_init(MirrorBlockJob *s)
         n = count >> BDRV_SECTOR_BITS;
         assert(n > 0);
         if (ret == 1) {
-            bdrv_set_dirty_bitmap(s->dirty_bitmap, sector_num, n);
+            bdrv_set_dirty_bitmap(s->dirty_bitmap,
+                                  sector_num * BDRV_SECTOR_SIZE,
+                                  n * BDRV_SECTOR_SIZE);
         }
         sector_num += n;
     }
diff --git a/migration/block.c b/migration/block.c
index XXXXXXX..XXXXXXX 100644
--- a/migration/block.c
+++ b/migration/block.c
@@ -XXX,XX +XXX,XX @@ static int mig_save_device_bulk(QEMUFile *f, BlkMigDevState *bmds)
     blk->aiocb = blk_aio_preadv(bb, cur_sector * BDRV_SECTOR_SIZE, &blk->qiov,
                                 0, blk_mig_read_cb, blk);
 
-    bdrv_reset_dirty_bitmap(bmds->dirty_bitmap, cur_sector, nr_sectors);
+    bdrv_reset_dirty_bitmap(bmds->dirty_bitmap, cur_sector * BDRV_SECTOR_SIZE,
+                            nr_sectors * BDRV_SECTOR_SIZE);
     aio_context_release(blk_get_aio_context(bmds->blk));
     qemu_mutex_unlock_iothread();
 
@@ -XXX,XX +XXX,XX @@ static int mig_save_device_dirty(QEMUFile *f, BlkMigDevState *bmds,
             } else {
                 nr_sectors = BDRV_SECTORS_PER_DIRTY_CHUNK;
             }
-            bdrv_reset_dirty_bitmap_locked(bmds->dirty_bitmap, sector, nr_sectors);
+            bdrv_reset_dirty_bitmap_locked(bmds->dirty_bitmap,
+                                           sector * BDRV_SECTOR_SIZE,
+                                           nr_sectors * BDRV_SECTOR_SIZE);
             bdrv_dirty_bitmap_unlock(bmds->dirty_bitmap);
 
             blk = g_new(BlkMigBlock, 1);
-- 
2.13.6

From: Eric Blake <eblake@redhat.com>

Now that we have adjusted the majority of the calls this function
makes to be byte-based, it is easier to read the code if it makes
passes over the image using bytes rather than sectors.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block/mirror.c | 38 ++++++++++++++------------------------
 1 file changed, 14 insertions(+), 24 deletions(-)

diff --git a/block/mirror.c b/block/mirror.c
index XXXXXXX..XXXXXXX 100644
--- a/block/mirror.c
+++ b/block/mirror.c
@@ -XXX,XX +XXX,XX @@ static void mirror_throttle(MirrorBlockJob *s)
 
 static int coroutine_fn mirror_dirty_init(MirrorBlockJob *s)
 {
-    int64_t sector_num, end;
+    int64_t offset;
     BlockDriverState *base = s->base;
     BlockDriverState *bs = s->source;
     BlockDriverState *target_bs = blk_bs(s->target);
-    int ret, n;
+    int ret;
     int64_t count;
 
-    end = s->bdev_length / BDRV_SECTOR_SIZE;
-
     if (base == NULL && !bdrv_has_zero_init(target_bs)) {
         if (!bdrv_can_write_zeroes_with_unmap(target_bs)) {
             bdrv_set_dirty_bitmap(s->dirty_bitmap, 0, s->bdev_length);
@@ -XXX,XX +XXX,XX @@ static int coroutine_fn mirror_dirty_init(MirrorBlockJob *s)
         }
 
         s->initial_zeroing_ongoing = true;
-        for (sector_num = 0; sector_num < end; ) {
-            int nb_sectors = MIN(end - sector_num,
-                QEMU_ALIGN_DOWN(INT_MAX, s->granularity) >> BDRV_SECTOR_BITS);
+        for (offset = 0; offset < s->bdev_length; ) {
+            int bytes = MIN(s->bdev_length - offset,
+                            QEMU_ALIGN_DOWN(INT_MAX, s->granularity));
 
             mirror_throttle(s);
 
@@ -XXX,XX +XXX,XX @@ static int coroutine_fn mirror_dirty_init(MirrorBlockJob *s)
                 continue;
             }
 
-            mirror_do_zero_or_discard(s, sector_num * BDRV_SECTOR_SIZE,
-                                      nb_sectors * BDRV_SECTOR_SIZE, false);
-            sector_num += nb_sectors;
+            mirror_do_zero_or_discard(s, offset, bytes, false);
+            offset += bytes;
         }
 
         mirror_wait_for_all_io(s);
@@ -XXX,XX +XXX,XX @@ static int coroutine_fn mirror_dirty_init(MirrorBlockJob *s)
     }
 
     /* First part, loop on the sectors and initialize the dirty bitmap.  */
-    for (sector_num = 0; sector_num < end; ) {
+    for (offset = 0; offset < s->bdev_length; ) {
         /* Just to make sure we are not exceeding int limit. */
-        int nb_sectors = MIN(INT_MAX >> BDRV_SECTOR_BITS,
-                             end - sector_num);
+        int bytes = MIN(s->bdev_length - offset,
+                        QEMU_ALIGN_DOWN(INT_MAX, s->granularity));
 
         mirror_throttle(s);
 
@@ -XXX,XX +XXX,XX @@ static int coroutine_fn mirror_dirty_init(MirrorBlockJob *s)
             return 0;
         }
 
-        ret = bdrv_is_allocated_above(bs, base, sector_num * BDRV_SECTOR_SIZE,
-                                      nb_sectors * BDRV_SECTOR_SIZE, &count);
+        ret = bdrv_is_allocated_above(bs, base, offset, bytes, &count);
         if (ret < 0) {
             return ret;
         }
 
-        /* TODO: Relax this once bdrv_is_allocated_above and dirty
-         * bitmaps no longer require sector alignment. */
-        assert(QEMU_IS_ALIGNED(count, BDRV_SECTOR_SIZE));
-        n = count >> BDRV_SECTOR_BITS;
-        assert(n > 0);
+        assert(count);
         if (ret == 1) {
-            bdrv_set_dirty_bitmap(s->dirty_bitmap,
-                                  sector_num * BDRV_SECTOR_SIZE,
-                                  n * BDRV_SECTOR_SIZE);
+            bdrv_set_dirty_bitmap(s->dirty_bitmap, offset, count);
         }
-        sector_num += n;
+        offset += count;
     }
     return 0;
 }
-- 
2.13.6

From: Eric Blake <eblake@redhat.com>

This is new code, but it is easier to read if it makes passes over
the image using bytes rather than sectors (and will get easier in
the future when bdrv_get_block_status is converted to byte-based).

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block/qcow2.c | 22 ++++++++++------------
 1 file changed, 10 insertions(+), 12 deletions(-)

diff --git a/block/qcow2.c b/block/qcow2.c
index XXXXXXX..XXXXXXX 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -XXX,XX +XXX,XX @@ static BlockMeasureInfo *qcow2_measure(QemuOpts *opts, BlockDriverState *in_bs,
              */
             required = virtual_size;
         } else {
-            int cluster_sectors = cluster_size / BDRV_SECTOR_SIZE;
-            int64_t sector_num;
+            int64_t offset;
             int pnum = 0;
 
-            for (sector_num = 0;
-                 sector_num < ssize / BDRV_SECTOR_SIZE;
-                 sector_num += pnum) {
-                int nb_sectors = MIN(ssize / BDRV_SECTOR_SIZE - sector_num,
-                                     BDRV_REQUEST_MAX_SECTORS);
+            for (offset = 0; offset < ssize;
+                 offset += pnum * BDRV_SECTOR_SIZE) {
+                int nb_sectors = MIN(ssize - offset,
+                                     BDRV_REQUEST_MAX_BYTES) / BDRV_SECTOR_SIZE;
                 BlockDriverState *file;
                 int64_t ret;
 
                 ret = bdrv_get_block_status_above(in_bs, NULL,
-                                                  sector_num, nb_sectors,
+                                                  offset >> BDRV_SECTOR_BITS,
+                                                  nb_sectors,
                                                   &pnum, &file);
                 if (ret < 0) {
                     error_setg_errno(&local_err, -ret,
@@ -XXX,XX +XXX,XX @@ static BlockMeasureInfo *qcow2_measure(QemuOpts *opts, BlockDriverState *in_bs,
                 } else if ((ret & (BDRV_BLOCK_DATA | BDRV_BLOCK_ALLOCATED)) ==
                            (BDRV_BLOCK_DATA | BDRV_BLOCK_ALLOCATED)) {
                     /* Extend pnum to end of cluster for next iteration */
-                    pnum = ROUND_UP(sector_num + pnum, cluster_sectors) -
-                           sector_num;
+                    pnum = (ROUND_UP(offset + pnum * BDRV_SECTOR_SIZE,
+                                 cluster_size) - offset) >> BDRV_SECTOR_BITS;
 
                     /* Count clusters we've seen */
-                    required += (sector_num % cluster_sectors + pnum) *
-                                BDRV_SECTOR_SIZE;
+                    required += offset % cluster_size + pnum * BDRV_SECTOR_SIZE;
                 }
             }
         }
-- 
2.13.6

From: Eric Blake <eblake@redhat.com>

Now that we have adjusted the majority of the calls this function
makes to be byte-based, it is easier to read the code if it makes
passes over the image using bytes rather than sectors.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block/qcow2-bitmap.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/block/qcow2-bitmap.c b/block/qcow2-bitmap.c
index XXXXXXX..XXXXXXX 100644
--- a/block/qcow2-bitmap.c
+++ b/block/qcow2-bitmap.c
@@ -XXX,XX +XXX,XX @@ static int load_bitmap_data(BlockDriverState *bs,
 {
     int ret = 0;
     BDRVQcow2State *s = bs->opaque;
-    uint64_t sector, limit, sbc;
+    uint64_t offset, limit;
     uint64_t bm_size = bdrv_dirty_bitmap_size(bitmap);
-    uint64_t bm_sectors = DIV_ROUND_UP(bm_size, BDRV_SECTOR_SIZE);
     uint8_t *buf = NULL;
     uint64_t i, tab_size =
             size_to_clusters(s,
@@ -XXX,XX +XXX,XX @@ static int load_bitmap_data(BlockDriverState *bs,
 
     buf = g_malloc(s->cluster_size);
     limit = bytes_covered_by_bitmap_cluster(s, bitmap);
-    sbc = limit >> BDRV_SECTOR_BITS;
-    for (i = 0, sector = 0; i < tab_size; ++i, sector += sbc) {
-        uint64_t count = MIN(bm_sectors - sector, sbc);
+    for (i = 0, offset = 0; i < tab_size; ++i, offset += limit) {
+        uint64_t count = MIN(bm_size - offset, limit);
         uint64_t entry = bitmap_table[i];
-        uint64_t offset = entry & BME_TABLE_ENTRY_OFFSET_MASK;
+        uint64_t data_offset = entry & BME_TABLE_ENTRY_OFFSET_MASK;
 
         assert(check_table_entry(entry, s->cluster_size) == 0);
 
-        if (offset == 0) {
+        if (data_offset == 0) {
             if (entry & BME_TABLE_ENTRY_FLAG_ALL_ONES) {
-                bdrv_dirty_bitmap_deserialize_ones(bitmap,
-                                                   sector * BDRV_SECTOR_SIZE,
-                                                   count * BDRV_SECTOR_SIZE,
+                bdrv_dirty_bitmap_deserialize_ones(bitmap, offset, count,
                                                    false);
             } else {
                 /* No need to deserialize zeros because the dirty bitmap is
                  * already cleared */
             }
         } else {
-            ret = bdrv_pread(bs->file, offset, buf, s->cluster_size);
+            ret = bdrv_pread(bs->file, data_offset, buf, s->cluster_size);
             if (ret < 0) {
                 goto finish;
             }
-            bdrv_dirty_bitmap_deserialize_part(bitmap, buf,
-                                               sector * BDRV_SECTOR_SIZE,
-                                               count * BDRV_SECTOR_SIZE,
+            bdrv_dirty_bitmap_deserialize_part(bitmap, buf, offset, count,
                                                false);
         }
     }
-- 
2.13.6

From: Eric Blake <eblake@redhat.com>

Now that we have adjusted the majority of the calls this function
makes to be byte-based, it is easier to read the code if it makes
passes over the image using bytes rather than sectors.

iotests 165 was rather weak - on a default 64k-cluster image, where
bitmap granularity also defaults to 64k bytes, a single cluster of
the bitmap table thus covers (64*1024*8) bits which each cover 64k
bytes, or 32G of image space.  But the test only uses a 1G image,
so it cannot trigger any more than one loop of the code in
store_bitmap_data(); and it was writing to the first cluster.  In
order to test that we are properly aligning which portions of the
bitmap are being written to the file, we really want to test a case
where the first dirty bit returned by bdrv_dirty_iter_next() is not
aligned to the start of a cluster, which we can do by modifying the
test to write data that doesn't happen to fall in the first cluster
of the image.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block/qcow2-bitmap.c   | 31 ++++++++++++++++---------------
 tests/qemu-iotests/165 |  2 +-
 2 files changed, 17 insertions(+), 16 deletions(-)

diff --git a/block/qcow2-bitmap.c b/block/qcow2-bitmap.c
index XXXXXXX..XXXXXXX 100644
--- a/block/qcow2-bitmap.c
+++ b/block/qcow2-bitmap.c
@@ -XXX,XX +XXX,XX @@ static uint64_t *store_bitmap_data(BlockDriverState *bs,
 {
     int ret;
     BDRVQcow2State *s = bs->opaque;
-    int64_t sector;
-    uint64_t limit, sbc;
+    int64_t offset;
+    uint64_t limit;
     uint64_t bm_size = bdrv_dirty_bitmap_size(bitmap);
-    uint64_t bm_sectors = DIV_ROUND_UP(bm_size, BDRV_SECTOR_SIZE);
     const char *bm_name = bdrv_dirty_bitmap_name(bitmap);
     uint8_t *buf = NULL;
     BdrvDirtyBitmapIter *dbi;
@@ -XXX,XX +XXX,XX @@ static uint64_t *store_bitmap_data(BlockDriverState *bs,
     dbi = bdrv_dirty_iter_new(bitmap);
     buf = g_malloc(s->cluster_size);
     limit = bytes_covered_by_bitmap_cluster(s, bitmap);
-    sbc = limit >> BDRV_SECTOR_BITS;
     assert(DIV_ROUND_UP(bm_size, limit) == tb_size);
 
-    while ((sector = bdrv_dirty_iter_next(dbi) >> BDRV_SECTOR_BITS) >= 0) {
-        uint64_t cluster = sector / sbc;
+    while ((offset = bdrv_dirty_iter_next(dbi)) >= 0) {
+        uint64_t cluster = offset / limit;
         uint64_t end, write_size;
         int64_t off;
 
-        sector = cluster * sbc;
-        end = MIN(bm_sectors, sector + sbc);
-        write_size = bdrv_dirty_bitmap_serialization_size(bitmap,
-            sector * BDRV_SECTOR_SIZE, (end - sector) * BDRV_SECTOR_SIZE);
+        /*
+         * We found the first dirty offset, but want to write out the
+         * entire cluster of the bitmap that includes that offset,
+         * including any leading zero bits.
+         */
+        offset = QEMU_ALIGN_DOWN(offset, limit);
+        end = MIN(bm_size, offset + limit);
+        write_size = bdrv_dirty_bitmap_serialization_size(bitmap, offset,
+                                                          end - offset);
         assert(write_size <= s->cluster_size);
 
         off = qcow2_alloc_clusters(bs, s->cluster_size);
@@ -XXX,XX +XXX,XX @@ static uint64_t *store_bitmap_data(BlockDriverState *bs,
         }
         tb[cluster] = off;
 
-        bdrv_dirty_bitmap_serialize_part(bitmap, buf,
-                                         sector * BDRV_SECTOR_SIZE,
-                                         (end - sector) * BDRV_SECTOR_SIZE);
+        bdrv_dirty_bitmap_serialize_part(bitmap, buf, offset, end - offset);
         if (write_size < s->cluster_size) {
             memset(buf + write_size, 0, s->cluster_size - write_size);
         }
@@ -XXX,XX +XXX,XX @@ static uint64_t *store_bitmap_data(BlockDriverState *bs,
             goto fail;
         }
 
-        if (end >= bm_sectors) {
+        if (end >= bm_size) {
             break;
         }
 
-        bdrv_set_dirty_iter(dbi, end * BDRV_SECTOR_SIZE);
+        bdrv_set_dirty_iter(dbi, end);
     }
 
     *bitmap_table_size = tb_size;
diff --git a/tests/qemu-iotests/165 b/tests/qemu-iotests/165
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/165
+++ b/tests/qemu-iotests/165
@@ -XXX,XX +XXX,XX @@ disk = os.path.join(iotests.test_dir, 'disk')
 disk_size = 0x40000000 # 1G
 
 # regions for qemu_io: (start, count) in bytes
-regions1 = ((0,        0x100000),
+regions1 = ((0x0fff00, 0x10000),
             (0x200000, 0x100000))
 
 regions2 = ((0x10000000, 0x20000),
-- 
2.13.6

From: Eric Blake <eblake@redhat.com>

Both callers already had bytes available, but were scaling to
sectors.  Move the scaling to internal code.  In the case of
bdrv_aligned_pwritev(), we are now passing the exact offset
rather than a rounded sector-aligned value, but that's okay
as long as dirty bitmap widens start/bytes to granularity
boundaries.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 include/block/block_int.h | 2 +-
 block/dirty-bitmap.c      | 7 ++++---
 block/io.c                | 6 ++----
 3 files changed, 7 insertions(+), 8 deletions(-)

diff --git a/include/block/block_int.h b/include/block/block_int.h
index XXXXXXX..XXXXXXX 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -XXX,XX +XXX,XX @@ void blk_dev_eject_request(BlockBackend *blk, bool force);
 bool blk_dev_is_tray_open(BlockBackend *blk);
 bool blk_dev_is_medium_locked(BlockBackend *blk);
 
-void bdrv_set_dirty(BlockDriverState *bs, int64_t cur_sector, int64_t nr_sect);
+void bdrv_set_dirty(BlockDriverState *bs, int64_t offset, int64_t bytes);
 bool bdrv_requests_pending(BlockDriverState *bs);
 
 void bdrv_clear_dirty_bitmap(BdrvDirtyBitmap *bitmap, HBitmap **out);
diff --git a/block/dirty-bitmap.c b/block/dirty-bitmap.c
index XXXXXXX..XXXXXXX 100644
--- a/block/dirty-bitmap.c
+++ b/block/dirty-bitmap.c
@@ -XXX,XX +XXX,XX @@ void bdrv_dirty_bitmap_deserialize_finish(BdrvDirtyBitmap *bitmap)
     hbitmap_deserialize_finish(bitmap->bitmap);
 }
 
-void bdrv_set_dirty(BlockDriverState *bs, int64_t cur_sector,
-                    int64_t nr_sectors)
+void bdrv_set_dirty(BlockDriverState *bs, int64_t offset, int64_t bytes)
 {
     BdrvDirtyBitmap *bitmap;
+    int64_t end_sector = DIV_ROUND_UP(offset + bytes, BDRV_SECTOR_SIZE);
 
     if (QLIST_EMPTY(&bs->dirty_bitmaps)) {
         return;
@@ -XXX,XX +XXX,XX @@ void bdrv_set_dirty(BlockDriverState *bs, int64_t cur_sector,
             continue;
         }
         assert(!bdrv_dirty_bitmap_readonly(bitmap));
-        hbitmap_set(bitmap->bitmap, cur_sector, nr_sectors);
+        hbitmap_set(bitmap->bitmap, offset >> BDRV_SECTOR_BITS,
+                    end_sector - (offset >> BDRV_SECTOR_BITS));
     }
     bdrv_dirty_bitmaps_unlock(bs);
 }
diff --git a/block/io.c b/block/io.c
index XXXXXXX..XXXXXXX 100644
--- a/block/io.c
+++ b/block/io.c
@@ -XXX,XX +XXX,XX @@ static int coroutine_fn bdrv_aligned_pwritev(BdrvChild *child,
     bool waited;
     int ret;
 
-    int64_t start_sector = offset >> BDRV_SECTOR_BITS;
     int64_t end_sector = DIV_ROUND_UP(offset + bytes, BDRV_SECTOR_SIZE);
     uint64_t bytes_remaining = bytes;
     int max_transfer;
@@ -XXX,XX +XXX,XX @@ static int coroutine_fn bdrv_aligned_pwritev(BdrvChild *child,
     bdrv_debug_event(bs, BLKDBG_PWRITEV_DONE);
 
     atomic_inc(&bs->write_gen);
-    bdrv_set_dirty(bs, start_sector, end_sector - start_sector);
+    bdrv_set_dirty(bs, offset, bytes);
 
     stat64_max(&bs->wr_highest_offset, offset + bytes);
 
@@ -XXX,XX +XXX,XX @@ int coroutine_fn bdrv_co_pdiscard(BlockDriverState *bs, int64_t offset,
     ret = 0;
 out:
     atomic_inc(&bs->write_gen);
-    bdrv_set_dirty(bs, req.offset >> BDRV_SECTOR_BITS,
-                   req.bytes >> BDRV_SECTOR_BITS);
+    bdrv_set_dirty(bs, req.offset, req.bytes);
     tracked_request_end(&req);
     bdrv_dec_in_flight(bs);
     return ret;
-- 
2.13.6

From: Eric Blake <eblake@redhat.com>

Now that all callers are using byte-based interfaces, there's no
reason for our internal hbitmap to remain with sector-based
granularity.  It also simplifies our internal scaling, since we
already know that hbitmap widens requests out to granularity
boundaries.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block/dirty-bitmap.c | 62 +++++++++++++++-------------------------------------
 1 file changed, 18 insertions(+), 44 deletions(-)

diff --git a/block/dirty-bitmap.c b/block/dirty-bitmap.c
index XXXXXXX..XXXXXXX 100644
--- a/block/dirty-bitmap.c
+++ b/block/dirty-bitmap.c
@@ -XXX,XX +XXX,XX @@
  */
 struct BdrvDirtyBitmap {
     QemuMutex *mutex;
-    HBitmap *bitmap;            /* Dirty sector bitmap implementation */
+    HBitmap *bitmap;            /* Dirty bitmap implementation */
     HBitmap *meta;              /* Meta dirty bitmap */
     BdrvDirtyBitmap *successor; /* Anonymous child; implies frozen status */
     char *name;                 /* Optional non-empty unique ID */
@@ -XXX,XX +XXX,XX @@ BdrvDirtyBitmap *bdrv_create_dirty_bitmap(BlockDriverState *bs,
     }
     bitmap = g_new0(BdrvDirtyBitmap, 1);
     bitmap->mutex = &bs->dirty_bitmap_mutex;
-    /*
-     * TODO - let hbitmap track full granularity. For now, it is tracking
-     * only sector granularity, as a shortcut for our iterators.
-     */
-    bitmap->bitmap = hbitmap_alloc(DIV_ROUND_UP(bitmap_size, BDRV_SECTOR_SIZE),
-                                   ctz32(granularity) - BDRV_SECTOR_BITS);
+    bitmap->bitmap = hbitmap_alloc(bitmap_size, ctz32(granularity));
     bitmap->size = bitmap_size;
     bitmap->name = g_strdup(name);
     bitmap->disabled = false;
@@ -XXX,XX +XXX,XX @@ void bdrv_dirty_bitmap_truncate(BlockDriverState *bs, int64_t bytes)
     QLIST_FOREACH(bitmap, &bs->dirty_bitmaps, list) {
         assert(!bdrv_dirty_bitmap_frozen(bitmap));
         assert(!bitmap->active_iterators);
-        hbitmap_truncate(bitmap->bitmap, DIV_ROUND_UP(bytes, BDRV_SECTOR_SIZE));
+        hbitmap_truncate(bitmap->bitmap, bytes);
         bitmap->size = bytes;
     }
     bdrv_dirty_bitmaps_unlock(bs);
@@ -XXX,XX +XXX,XX @@ bool bdrv_get_dirty_locked(BlockDriverState *bs, BdrvDirtyBitmap *bitmap,
                            int64_t offset)
 {
     if (bitmap) {
-        return hbitmap_get(bitmap->bitmap, offset >> BDRV_SECTOR_BITS);
+        return hbitmap_get(bitmap->bitmap, offset);
     } else {
         return false;
     }
@@ -XXX,XX +XXX,XX @@ uint32_t bdrv_get_default_bitmap_granularity(BlockDriverState *bs)
 
 uint32_t bdrv_dirty_bitmap_granularity(const BdrvDirtyBitmap *bitmap)
 {
-    return BDRV_SECTOR_SIZE << hbitmap_granularity(bitmap->bitmap);
+    return 1U << hbitmap_granularity(bitmap->bitmap);
 }
 
 BdrvDirtyBitmapIter *bdrv_dirty_iter_new(BdrvDirtyBitmap *bitmap)
@@ -XXX,XX +XXX,XX @@ void bdrv_dirty_iter_free(BdrvDirtyBitmapIter *iter)
 
 int64_t bdrv_dirty_iter_next(BdrvDirtyBitmapIter *iter)
 {
-    int64_t ret = hbitmap_iter_next(&iter->hbi);
-    return ret < 0 ? -1 : ret * BDRV_SECTOR_SIZE;
+    return hbitmap_iter_next(&iter->hbi);
 }
 
 /* Called within bdrv_dirty_bitmap_lock..unlock */
 void bdrv_set_dirty_bitmap_locked(BdrvDirtyBitmap *bitmap,
                                   int64_t offset, int64_t bytes)
 {
-    int64_t end_sector = DIV_ROUND_UP(offset + bytes, BDRV_SECTOR_SIZE);
-
     assert(bdrv_dirty_bitmap_enabled(bitmap));
     assert(!bdrv_dirty_bitmap_readonly(bitmap));
-    hbitmap_set(bitmap->bitmap, offset >> BDRV_SECTOR_BITS,
-                end_sector - (offset >> BDRV_SECTOR_BITS));
+    hbitmap_set(bitmap->bitmap, offset, bytes);
 }
 
 void bdrv_set_dirty_bitmap(BdrvDirtyBitmap *bitmap,
@@ -XXX,XX +XXX,XX @@ void bdrv_set_dirty_bitmap(BdrvDirtyBitmap *bitmap,
 void bdrv_reset_dirty_bitmap_locked(BdrvDirtyBitmap *bitmap,
                                     int64_t offset, int64_t bytes)
 {
-    int64_t end_sector = DIV_ROUND_UP(offset + bytes, BDRV_SECTOR_SIZE);
-
     assert(bdrv_dirty_bitmap_enabled(bitmap));
     assert(!bdrv_dirty_bitmap_readonly(bitmap));
-    hbitmap_reset(bitmap->bitmap, offset >> BDRV_SECTOR_BITS,
-                  end_sector - (offset >> BDRV_SECTOR_BITS));
+    hbitmap_reset(bitmap->bitmap, offset, bytes);
 }
 
 void bdrv_reset_dirty_bitmap(BdrvDirtyBitmap *bitmap,
@@ -XXX,XX +XXX,XX @@ void bdrv_clear_dirty_bitmap(BdrvDirtyBitmap *bitmap, HBitmap **out)
         hbitmap_reset_all(bitmap->bitmap);
     } else {
         HBitmap *backup = bitmap->bitmap;
-        bitmap->bitmap = hbitmap_alloc(DIV_ROUND_UP(bitmap->size,
-                                                    BDRV_SECTOR_SIZE),
+        bitmap->bitmap = hbitmap_alloc(bitmap->size,
                                        hbitmap_granularity(backup));
         *out = backup;
     }
@@ -XXX,XX +XXX,XX @@ void bdrv_undo_clear_dirty_bitmap(BdrvDirtyBitmap *bitmap, HBitmap *in)
 uint64_t bdrv_dirty_bitmap_serialization_size(const BdrvDirtyBitmap *bitmap,
                                               uint64_t offset, uint64_t bytes)
 {
-    assert(QEMU_IS_ALIGNED(offset | bytes, BDRV_SECTOR_SIZE));
-    return hbitmap_serialization_size(bitmap->bitmap,
-                                      offset >> BDRV_SECTOR_BITS,
-                                      bytes >> BDRV_SECTOR_BITS);
+    return hbitmap_serialization_size(bitmap->bitmap, offset, bytes);
 }
 
 uint64_t bdrv_dirty_bitmap_serialization_align(const BdrvDirtyBitmap *bitmap)
 {
-    return hbitmap_serialization_align(bitmap->bitmap) * BDRV_SECTOR_SIZE;
+    return hbitmap_serialization_align(bitmap->bitmap);
 }
 
 void bdrv_dirty_bitmap_serialize_part(const BdrvDirtyBitmap *bitmap,
                                       uint8_t *buf, uint64_t offset,
                                       uint64_t bytes)
 {
-    assert(QEMU_IS_ALIGNED(offset | bytes, BDRV_SECTOR_SIZE));
-    hbitmap_serialize_part(bitmap->bitmap, buf, offset >> BDRV_SECTOR_BITS,
-                           bytes >> BDRV_SECTOR_BITS);
+    hbitmap_serialize_part(bitmap->bitmap, buf, offset, bytes);
 }
 
 void bdrv_dirty_bitmap_deserialize_part(BdrvDirtyBitmap *bitmap,
                                         uint8_t *buf, uint64_t offset,
                                         uint64_t bytes, bool finish)
 {
-    assert(QEMU_IS_ALIGNED(offset | bytes, BDRV_SECTOR_SIZE));
-    hbitmap_deserialize_part(bitmap->bitmap, buf, offset >> BDRV_SECTOR_BITS,
-                             bytes >> BDRV_SECTOR_BITS, finish);
+    hbitmap_deserialize_part(bitmap->bitmap, buf, offset, bytes, finish);
 }
 
 void bdrv_dirty_bitmap_deserialize_zeroes(BdrvDirtyBitmap *bitmap,
                                           uint64_t offset, uint64_t bytes,
                                           bool finish)
 {
-    assert(QEMU_IS_ALIGNED(offset | bytes, BDRV_SECTOR_SIZE));
-    hbitmap_deserialize_zeroes(bitmap->bitmap, offset >> BDRV_SECTOR_BITS,
-                               bytes >> BDRV_SECTOR_BITS, finish);
+    hbitmap_deserialize_zeroes(bitmap->bitmap, offset, bytes, finish);
 }
 
 void bdrv_dirty_bitmap_deserialize_ones(BdrvDirtyBitmap *bitmap,
                                         uint64_t offset, uint64_t bytes,
                                         bool finish)
 {
-    assert(QEMU_IS_ALIGNED(offset | bytes, BDRV_SECTOR_SIZE));
-    hbitmap_deserialize_ones(bitmap->bitmap, offset >> BDRV_SECTOR_BITS,
-                             bytes >> BDRV_SECTOR_BITS, finish);
+    hbitmap_deserialize_ones(bitmap->bitmap, offset, bytes, finish);
 }
 
 void bdrv_dirty_bitmap_deserialize_finish(BdrvDirtyBitmap *bitmap)
@@ -XXX,XX +XXX,XX @@ void bdrv_dirty_bitmap_deserialize_finish(BdrvDirtyBitmap *bitmap)
 void bdrv_set_dirty(BlockDriverState *bs, int64_t offset, int64_t bytes)
 {
     BdrvDirtyBitmap *bitmap;
-    int64_t end_sector = DIV_ROUND_UP(offset + bytes, BDRV_SECTOR_SIZE);
 
     if (QLIST_EMPTY(&bs->dirty_bitmaps)) {
         return;
@@ -XXX,XX +XXX,XX @@ void bdrv_set_dirty(BlockDriverState *bs, int64_t offset, int64_t bytes)
             continue;
         }
         assert(!bdrv_dirty_bitmap_readonly(bitmap));
-        hbitmap_set(bitmap->bitmap, offset >> BDRV_SECTOR_BITS,
-                    end_sector - (offset >> BDRV_SECTOR_BITS));
+        hbitmap_set(bitmap->bitmap, offset, bytes);
     }
     bdrv_dirty_bitmaps_unlock(bs);
 }
@@ -XXX,XX +XXX,XX @@ void bdrv_set_dirty(BlockDriverState *bs, int64_t offset, int64_t bytes)
  */
 void bdrv_set_dirty_iter(BdrvDirtyBitmapIter *iter, int64_t offset)
 {
-    hbitmap_iter_init(&iter->hbi, iter->hbi.hb, offset >> BDRV_SECTOR_BITS);
+    hbitmap_iter_init(&iter->hbi, iter->hbi.hb, offset);
 }
 
 int64_t bdrv_get_dirty_count(BdrvDirtyBitmap *bitmap)
 {
-    return hbitmap_count(bitmap->bitmap) << BDRV_SECTOR_BITS;
+    return hbitmap_count(bitmap->bitmap);
 }
 
 int64_t bdrv_get_meta_dirty_count(BdrvDirtyBitmap *bitmap)
-- 
2.13.6

From: Paolo Bonzini <pbonzini@redhat.com>

This includes shell function, shell variables and command line options
(randomize.awk does not exist).

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 tests/qemu-iotests/check         | 28 -----------------
 tests/qemu-iotests/common        | 23 --------------
 tests/qemu-iotests/common.config | 26 ---------------
 tests/qemu-iotests/common.rc     | 68 ----------------------------------------
 4 files changed, 145 deletions(-)

diff --git a/tests/qemu-iotests/check b/tests/qemu-iotests/check
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/check
+++ b/tests/qemu-iotests/check
@@ -XXX,XX +XXX,XX @@ then
     export SOCKET_SCM_HELPER="$build_iotests/socket_scm_helper"
 fi
 
-# if ./qemu exists, it should be prioritized and will be chosen by common.config
 if [[ -z "$QEMU_PROG" && ! -x './qemu' ]]
 then
     arch=$(uname -m 2> /dev/null)
@@ -XXX,XX +XXX,XX @@ _timestamp()
 
 _wrapup()
 {
-    # for hangcheck ...
-    # remove files that were used by hangcheck
-    #
-    [ -f "${TEST_DIR}"/check.pid ] && rm -rf "${TEST_DIR}"/check.pid
-    [ -f "${TEST_DIR}"/check.sts ] && rm -rf "${TEST_DIR}"/check.sts
-
     if $showme
     then
         :
@@ -XXX,XX +XXX,XX @@ END        { if (NR > 0) {
 
 trap "_wrapup; exit \$status" 0 1 2 3 15
 
-# for hangcheck ...
-# Save pid of check in a well known place, so that hangcheck can be sure it
-# has the right pid (getting the pid from ps output is not reliable enough).
-#
-rm -rf "${TEST_DIR}"/check.pid
-echo $$ > "${TEST_DIR}"/check.pid
-
-# for hangcheck ...
-# Save the status of check in a well known place, so that hangcheck can be
-# sure to know where check is up to (getting test number from ps output is
-# not reliable enough since the trace stuff has been introduced).
-#
-rm -rf "${TEST_DIR}"/check.sts
-echo "preamble" > "${TEST_DIR}"/check.sts
-
-# don't leave old full output behind on a clean run
-rm -f check.full
-
 [ -f $TIMESTAMP_FILE ] || touch $TIMESTAMP_FILE
 
 FULL_IMGFMT_DETAILS=`_full_imgfmt_details`
@@ -XXX,XX +XXX,XX @@ do
         fi
         rm -f core $seq.notrun
 
-        # for hangcheck ...
-        echo "$seq" > "${TEST_DIR}"/check.sts
-
         start=`_wallclock`
         $timestamp && printf %s "        [$(date "+%T")]"
 
diff --git a/tests/qemu-iotests/common b/tests/qemu-iotests/common
index XXXXXXX..XXXXXXX 100644
--- a/tests/qemu-iotests/common
+++ b/tests/qemu-iotests/common
@@ -XXX,XX +XXX,XX @@
 # common procedures for QA scripts
 #
 
-_setenvironment()
-{
-    MSGVERB="text:action"
-    export MSGVERB
-}
-
-rm -f "$OUTPUT_DIR/$iam.out"
-_setenvironment
-
-check=${check-true}
-
 diff="diff -u"
 verbose=false
 debug=false
@@ -XXX,XX +XXX,XX @@ showme=false
 sortme=false
 expunge=true
 have_test_arg=false
-randomize=false
 cachemode=false
 rm -f $tmp.list $tmp.tmp $tmp.sed
 
@@ -XXX,XX +XXX,XX @@ other options
     -n                  show me, do not run tests
     -o options          -o options to pass to qemu-img create/convert
     -T                  output timestamps
-    -r                  randomize test order
     -c mode             cache mode
 
 testlist options
@@ -XXX,XX +XXX,XX @@ testlist options
             cachemode=true
             xpand=false
             ;;
-        -r)        # randomize test order
-            randomize=true
-            xpand=false
-            ;;
-
         -T)        # turn on timestamp output
             timestamp=true
             xpand=false
@@ -XXX,XX +XXX,XX @@ fi
 list=`sort $tmp.list`
 rm -f $tmp.list $tmp.tmp $tmp.sed
 
-if $randomize
-then
-    list=`echo $list | awk -f randomize.awk`
-fi
-
 [ "$QEMU" = "" ] && _fatal "qemu not found"
 [ "$QEMU_IMG" = "" ] && _fatal "qemu-img not found"
 [ "$QEMU_IO" = "" ] && _fatal "qemu-io not found"
diff --git a/tests/qemu-iotests/common.config b/tests/qemu-iotests/common.config
index XXXXXXX..XXXXXXX 100644
--- a/tests/qemu-iotests/common.config
+++ b/tests/qemu-iotests/common.config
@@ -XXX,XX +XXX,XX @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #
-#
-# setup and check for config parameters, and in particular
-#
-# EMAIL -           email of the script runner.
-# TEST_DIR -        scratch test directory
-#
-# - These can be added to $HOST_CONFIG_DIR (witch default to ./config)
-#   below or a separate local configuration file can be used (using
-#   the HOST_OPTIONS variable).
-# - This script is shared by the stress test system and the auto-qa
-#   system (includes both regression test and benchmark components).
-# - this script shouldn't make any assertions about filesystem
-#   validity or mountedness.
-#
-
 # all tests should use a common language setting to prevent golden
 # output mismatches.
 export LANG=C
 
 PATH=".:$PATH"
 
-HOST=`hostname -s 2> /dev/null`
 HOSTOS=`uname -s`
 
-EMAIL=root@localhost    # where auto-qa will send its status messages
-export HOST_OPTIONS=${HOST_OPTIONS:=local.config}
-export CHECK_OPTIONS=${CHECK_OPTIONS:="-g auto"}
 export PWD=`pwd`
 
 export _QEMU_HANDLE=0
@@ -XXX,XX +XXX,XX @@ _fatal()
 export AWK_PROG="`set_prog_path awk`"
 [ "$AWK_PROG" = "" ] && _fatal "awk not found"
 
-export SED_PROG="`set_prog_path sed`"
-[ "$SED_PROG" = "" ] && _fatal "sed not found"
-
-export PS_ALL_FLAGS="-ef"
-
 if [ -z "$QEMU_PROG" ]; then
     export QEMU_PROG="`set_prog_path qemu`"
 fi
@@ -XXX,XX +XXX,XX @@ fi
 
 export QEMU_DEFAULT_MACHINE="$default_machine"
 
-[ -f /etc/qemu-iotest.config ]       && . /etc/qemu-iotest.config
-
 if [ -z "$TEST_DIR" ]; then
         TEST_DIR=`pwd`/scratch
 fi
diff --git a/tests/qemu-iotests/common.rc b/tests/qemu-iotests/common.rc
index XXXXXXX..XXXXXXX 100644
--- a/tests/qemu-iotests/common.rc
+++ b/tests/qemu-iotests/common.rc
@@ -XXX,XX +XXX,XX @@ _img_info()
         done
 }
 
-_get_pids_by_name()
-{
-    if [ $# -ne 1 ]
-    then
-        echo "Usage: _get_pids_by_name process-name" 1>&2
-        exit 1
-    fi
-
-    # Algorithm ... all ps(1) variants have a time of the form MM:SS or
-    # HH:MM:SS before the psargs field, use this as the search anchor.
-    #
-    # Matches with $1 (process-name) occur if the first psarg is $1
-    # or ends in /$1 ... the matching uses sed's regular expressions,
-    # so passing a regex into $1 will work.
-
-    ps $PS_ALL_FLAGS \
-    | sed -n \
-        -e 's/$/ /' \
-        -e 's/[         ][         ]*/ /g' \
-        -e 's/^ //' \
-        -e 's/^[^ ]* //' \
-        -e "/[0-9]:[0-9][0-9]  *[^ ]*\/$1 /s/ .*//p" \
-        -e "/[0-9]:[0-9][0-9]  *$1 /s/ .*//p"
-}
-
-# fqdn for localhost
-#
-_get_fqdn()
-{
-    host=`hostname`
-    $NSLOOKUP_PROG $host | $AWK_PROG '{ if ($1 == "Name:") print $2 }'
-}
-
-# check if run as root
-#
-_need_to_be_root()
-{
-    id=`id | $SED_PROG -e 's/(.*//' -e 's/.*=//'`
-    if [ "$id" -ne 0 ]
-    then
-        echo "Arrgh ... you need to be root (not uid=$id) to run this test"
-        exit 1
-    fi
-}
-
 # bail out, setting up .notrun file
 #
 _notrun()
@@ -XXX,XX +XXX,XX @@ _full_platform_details()
     echo "$os/$platform $host $kernel"
 }
 
-_link_out_file()
-{
-   if [ -z "$1" ]; then
-      echo Error must pass \$seq.
-      exit
-   fi
-   rm -f $1
-   if [ "`uname`" == "IRIX64" ] || [ "`uname`" == "IRIX" ]; then
-      ln -s $1.irix $1
-   elif [ "`uname`" == "Linux" ]; then
-      ln -s $1.linux $1
-   else
-      echo Error test $seq does not run on the operating system: `uname`
-      exit
-   fi
-}
-
-_die()
-{
-        echo $@
-        exit 1
-}
-
 # make sure this script returns success
 true
-- 
2.13.6

From: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/tests/qemu-iotests/check b/tests/qemu-iotests/check
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/check
+++ b/tests/qemu-iotests/check
@@ -XXX,XX +XXX,XX @@ tmp="${TEST_DIR}"/$$
 
 _wallclock()
 {
-    date "+%H %M %S" | $AWK_PROG '{ print $1*3600 + $2*60 + $3 }'
+    date "+%H %M %S" | awk '{ print $1*3600 + $2*60 + $3 }'
 }
 
 _timestamp()
@@ -XXX,XX +XXX,XX @@ _wrapup()
         if [ -f $TIMESTAMP_FILE -a -f $tmp.time ]
         then
             cat $TIMESTAMP_FILE $tmp.time \
-            | $AWK_PROG '
+            | awk '
         { t[$1] = $2 }
 END        { if (NR > 0) {
             for (i in t) print i " " t[i]
diff --git a/tests/qemu-iotests/common b/tests/qemu-iotests/common
index XXXXXXX..XXXXXXX 100644
--- a/tests/qemu-iotests/common
+++ b/tests/qemu-iotests/common
@@ -XXX,XX +XXX,XX @@ testlist options
     if $xpand
     then
         have_test_arg=true
-        $AWK_PROG </dev/null '
+        awk </dev/null '
 BEGIN        { for (t='$start'; t<='$end'; t++) printf "%03d\n",t }' \
         | while read id
         do
diff --git a/tests/qemu-iotests/common.config b/tests/qemu-iotests/common.config
index XXXXXXX..XXXXXXX 100644
--- a/tests/qemu-iotests/common.config
+++ b/tests/qemu-iotests/common.config
@@ -XXX,XX +XXX,XX @@ _fatal()
     exit 1
 }
 
-export AWK_PROG="`set_prog_path awk`"
-[ "$AWK_PROG" = "" ] && _fatal "awk not found"
-
 if [ -z "$QEMU_PROG" ]; then
     export QEMU_PROG="`set_prog_path qemu`"
 fi
-- 
2.13.6

From: Paolo Bonzini <pbonzini@redhat.com>

Some functions in common.rc are never used by the tests.  Move
them out of that file and into common, which is already included
only by "check".

Code that actually *is* common to "check" and tests can be placed in
common.config.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 tests/qemu-iotests/common        | 25 ++++++++++++++++++++++++-
 tests/qemu-iotests/common.config | 12 ++++++++++++
 tests/qemu-iotests/common.rc     | 40 ----------------------------------------
 3 files changed, 36 insertions(+), 41 deletions(-)

diff --git a/tests/qemu-iotests/common b/tests/qemu-iotests/common
index XXXXXXX..XXXXXXX 100644
--- a/tests/qemu-iotests/common
+++ b/tests/qemu-iotests/common
@@ -XXX,XX +XXX,XX @@
 # common procedures for QA scripts
 #
 
+_full_imgfmt_details()
+{
+    if [ -n "$IMGOPTS" ]; then
+        echo "$IMGFMT ($IMGOPTS)"
+    else
+        echo "$IMGFMT"
+    fi
+}
+
+_full_platform_details()
+{
+    os=`uname -s`
+    host=`hostname -s`
+    kernel=`uname -r`
+    platform=`uname -m`
+    echo "$os/$platform $host $kernel"
+}
+
 diff="diff -u"
 verbose=false
 debug=false
@@ -XXX,XX +XXX,XX @@ if [ "$IMGOPTSSYNTAX" != "true" ]; then
 fi
 
 # Set default options for qemu-img create -o if they were not specified
-_set_default_imgopts
+if [ "$IMGFMT" == "qcow2" ] && ! (echo "$IMGOPTS" | grep "compat=" > /dev/null); then
+    IMGOPTS=$(_optstr_add "$IMGOPTS" "compat=1.1")
+fi
+if [ "$IMGFMT" == "luks" ] && ! (echo "$IMGOPTS" | grep "iter-time=" > /dev/null); then
+    IMGOPTS=$(_optstr_add "$IMGOPTS" "iter-time=10")
+fi
 
 if [ -s $tmp.list ]
 then
diff --git a/tests/qemu-iotests/common.config b/tests/qemu-iotests/common.config
index XXXXXXX..XXXXXXX 100644
--- a/tests/qemu-iotests/common.config
+++ b/tests/qemu-iotests/common.config
@@ -XXX,XX +XXX,XX @@ export PWD=`pwd`
 
 export _QEMU_HANDLE=0
 
+# make sure we have a standard umask
+umask 022
+
 # $1 = prog to look for, $2* = default pathnames if not found in $PATH
 set_prog_path()
 {
@@ -XXX,XX +XXX,XX @@ set_prog_path()
     return 1
 }
 
+_optstr_add()
+{
+    if [ -n "$1" ]; then
+        echo "$1,$2"
+    else
+        echo "$2"
+    fi
+}
+
 _fatal()
 {
     echo "$*"
diff --git a/tests/qemu-iotests/common.rc b/tests/qemu-iotests/common.rc
index XXXXXXX..XXXXXXX 100644
--- a/tests/qemu-iotests/common.rc
+++ b/tests/qemu-iotests/common.rc
@@ -XXX,XX +XXX,XX @@ then
     fi
 fi
 
-# make sure we have a standard umask
-umask 022
-
 if [ "$IMGOPTSSYNTAX" = "true" ]; then
     DRIVER="driver=$IMGFMT"
     if [ "$IMGFMT" = "luks" ]; then
@@ -XXX,XX +XXX,XX @@ else
 fi
 ORIG_TEST_IMG="$TEST_IMG"
 
-_optstr_add()
-{
-    if [ -n "$1" ]; then
-        echo "$1,$2"
-    else
-        echo "$2"
-    fi
-}
-
-_set_default_imgopts()
-{
-    if [ "$IMGFMT" == "qcow2" ] && ! (echo "$IMGOPTS" | grep "compat=" > /dev/null); then
-        IMGOPTS=$(_optstr_add "$IMGOPTS" "compat=1.1")
-    fi
-    if [ "$IMGFMT" == "luks" ] && ! (echo "$IMGOPTS" | grep "iter-time=" > /dev/null); then
-        IMGOPTS=$(_optstr_add "$IMGOPTS" "iter-time=10")
-    fi
-}
-
 _use_sample_img()
 {
     SAMPLE_IMG_FILE="${1%\.bz2}"
@@ -XXX,XX +XXX,XX @@ _require_command()
     [ -x "$c" ] || _notrun "$1 utility required, skipped this test"
 }
 
-_full_imgfmt_details()
-{
-    if [ -n "$IMGOPTS" ]; then
-        echo "$IMGFMT ($IMGOPTS)"
-    else
-        echo "$IMGFMT"
-    fi
-}
-
-_full_platform_details()
-{
-    os=`uname -s`
-    host=`hostname -s`
-    kernel=`uname -r`
-    platform=`uname -m`
-    echo "$os/$platform $host $kernel"
-}
-
 # make sure this script returns success
 true
-- 
2.13.6

From: Paolo Bonzini <pbonzini@redhat.com>

Instead of ./check failing when a binary is missing, we try each test
case now and each one fails with tons of test case diffs.  Also, all the
variables were initialized by "check" prior to "common" being sourced,
and then (uselessly) checked for emptiness again in "check".

Centralize the search for programs in "common" (which will soon be
one with "check"), including the "realpath" invocation which can be done
just once in "check" rather than in the tests.

For qnio_server, move the detection to "common", simplifying
set_prog_path to stop handling the unused second argument, and
embedding the "realpath" pass.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 tests/qemu-iotests/check         | 41 ---------------------
 tests/qemu-iotests/common        | 77 +++++++++++++++++++++++++++++++++++++---
 tests/qemu-iotests/common.config | 61 +------------------------------
 3 files changed, 73 insertions(+), 106 deletions(-)

diff --git a/tests/qemu-iotests/check b/tests/qemu-iotests/check
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/check
+++ b/tests/qemu-iotests/check
@@ -XXX,XX +XXX,XX @@ fi
 
 build_root="$build_iotests/../.."
 
-if [ -x "$build_iotests/socket_scm_helper" ]
-then
-    export SOCKET_SCM_HELPER="$build_iotests/socket_scm_helper"
-fi
-
-if [[ -z "$QEMU_PROG" && ! -x './qemu' ]]
-then
-    arch=$(uname -m 2> /dev/null)
-
-    if [[ -n $arch && -x "$build_root/$arch-softmmu/qemu-system-$arch" ]]
-    then
-        export QEMU_PROG="$build_root/$arch-softmmu/qemu-system-$arch"
-    else
-        pushd "$build_root" > /dev/null
-        for binary in *-softmmu/qemu-system-*
-        do
-            if [ -x "$binary" ]
-            then
-                export QEMU_PROG="$build_root/$binary"
-                break
-            fi
-        done
-        popd > /dev/null
-    fi
-fi
-
-if [[ -z $QEMU_IMG_PROG && -x "$build_root/qemu-img" && ! -x './qemu-img' ]]
-then
-    export QEMU_IMG_PROG="$build_root/qemu-img"
-fi
-
-if [[ -z $QEMU_IO_PROG && -x "$build_root/qemu-io" && ! -x './qemu-io' ]]
-then
-    export QEMU_IO_PROG="$build_root/qemu-io"
-fi
-
-if [[ -z $QEMU_NBD_PROG && -x "$build_root/qemu-nbd" && ! -x './qemu-nbd' ]]
-then
-    export QEMU_NBD_PROG="$build_root/qemu-nbd"
-fi
-
 # we need common.env
 if ! . "$build_iotests/common.env"
 then
diff --git a/tests/qemu-iotests/common b/tests/qemu-iotests/common
index XXXXXXX..XXXXXXX 100644
--- a/tests/qemu-iotests/common
+++ b/tests/qemu-iotests/common
@@ -XXX,XX +XXX,XX @@ _full_platform_details()
     echo "$os/$platform $host $kernel"
 }
 
+# $1 = prog to look for
+set_prog_path()
+{
+    p=`command -v $1 2> /dev/null`
+    if [ -n "$p" -a -x "$p" ]; then
+        realpath -- "$(type -p "$p")"
+    else
+        return 1
+    fi
+}
+
 diff="diff -u"
 verbose=false
 debug=false
@@ -XXX,XX +XXX,XX @@ fi
 list=`sort $tmp.list`
 rm -f $tmp.list $tmp.tmp $tmp.sed
 
-[ "$QEMU" = "" ] && _fatal "qemu not found"
-[ "$QEMU_IMG" = "" ] && _fatal "qemu-img not found"
-[ "$QEMU_IO" = "" ] && _fatal "qemu-io not found"
+if [ -z "$QEMU_PROG" ]
+then
+    if [ -x "$build_iotests/qemu" ]; then
+        export QEMU_PROG="$build_iotests/qemu"
+    elif [ -x "$build_root/$arch-softmmu/qemu-system-$arch" ]; then
+        export QEMU_PROG="$build_root/$arch-softmmu/qemu-system-$arch"
+    else
+        pushd "$build_root" > /dev/null
+        for binary in *-softmmu/qemu-system-*
+        do
+            if [ -x "$binary" ]
+            then
+                export QEMU_PROG="$build_root/$binary"
+                break
+            fi
+        done
+        popd > /dev/null
+        [ "$QEMU_PROG" = "" ] && _init_error "qemu not found"
+    fi
+fi
+export QEMU_PROG=$(realpath -- "$(type -p "$QEMU_PROG")")
+
+if [ -z "$QEMU_IMG_PROG" ]; then
+    if [ -x "$build_iotests/qemu-img" ]; then
+        export QEMU_IMG_PROG="$build_iotests/qemu-img"
+    elif [ -x "$build_root/qemu-img" ]; then
+        export QEMU_IMG_PROG="$build_root/qemu-img"
+    else
+        _init_error "qemu-img not found"
+    fi
+fi
+export QEMU_IMG_PROG=$(realpath -- "$(type -p "$QEMU_IMG_PROG")")
+
+if [ -z "$QEMU_IO_PROG" ]; then
+    if [ -x "$build_iotests/qemu-io" ]; then
+        export QEMU_IO_PROG="$build_iotests/qemu-io"
+    elif [ -x "$build_root/qemu-io" ]; then
+        export QEMU_IO_PROG="$build_root/qemu-io"
+    else
+        _init_error "qemu-io not found"
+    fi
+fi
+export QEMU_IO_PROG=$(realpath -- "$(type -p "$QEMU_IO_PROG")")
 
-if [ "$IMGPROTO" = "nbd" ] ; then
-    [ "$QEMU_NBD" = "" ] && _fatal "qemu-nbd not found"
+if [ -z $QEMU_NBD_PROG ]; then
+    if [ -x "$build_iotests/qemu-nbd" ]; then
+        export QEMU_NBD_PROG="$build_iotests/qemu-nbd"
+    elif [ -x "$build_root/qemu-nbd" ]; then
+        export QEMU_NBD_PROG="$build_root/qemu-nbd"
+    else
+        _init_error "qemu-nbd not found"
+    fi
+fi
+export QEMU_NBD_PROG=$(realpath -- "$(type -p "$QEMU_NBD_PROG")")
+
+if [ -z "$QEMU_VXHS_PROG" ]; then
+  export QEMU_VXHS_PROG="`set_prog_path qnio_server`"
+fi
+
+if [ -x "$build_iotests/socket_scm_helper" ]
+then
+    export SOCKET_SCM_HELPER="$build_iotests/socket_scm_helper"
 fi
diff --git a/tests/qemu-iotests/common.config b/tests/qemu-iotests/common.config
index XXXXXXX..XXXXXXX 100644
--- a/tests/qemu-iotests/common.config
+++ b/tests/qemu-iotests/common.config
@@ -XXX,XX +XXX,XX @@ export LANG=C
 PATH=".:$PATH"
 
 HOSTOS=`uname -s`
+arch=`uname -m`
 
 export PWD=`pwd`
 
@@ -XXX,XX +XXX,XX @@ export _QEMU_HANDLE=0
 # make sure we have a standard umask
 umask 022
 
-# $1 = prog to look for, $2* = default pathnames if not found in $PATH
-set_prog_path()
-{
-    p=`command -v $1 2> /dev/null`
-    if [ -n "$p" -a -x "$p" ]; then
-        echo $p
-        return 0
-    fi
-    p=$1
-
-    shift
-    for f; do
-        if [ -x $f ]; then
-            echo $f
-            return 0
-        fi
-    done
-
-    echo ""
-    return 1
-}
-
 _optstr_add()
 {
     if [ -n "$1" ]; then
@@ -XXX,XX +XXX,XX @@ _optstr_add()
     fi
 }
 
-_fatal()
-{
-    echo "$*"
-    status=1
-    exit 1
-}
-
-if [ -z "$QEMU_PROG" ]; then
-    export QEMU_PROG="`set_prog_path qemu`"
-fi
-
-if [ -z "$QEMU_IMG_PROG" ]; then
-    export QEMU_IMG_PROG="`set_prog_path qemu-img`"
-fi
-
-if [ -z "$QEMU_IO_PROG" ]; then
-    export QEMU_IO_PROG="`set_prog_path qemu-io`"
-fi
-
-if [ -z "$QEMU_NBD_PROG" ]; then
-    export QEMU_NBD_PROG="`set_prog_path qemu-nbd`"
-fi
-
-if [ -z "$QEMU_VXHS_PROG" ]; then
-    export QEMU_VXHS_PROG="`set_prog_path qnio_server`"
-fi
-
-export QEMU_PROG=$(realpath -- "$(type -p "$QEMU_PROG")")
-export QEMU_IMG_PROG=$(realpath -- "$(type -p "$QEMU_IMG_PROG")")
-export QEMU_IO_PROG=$(realpath -- "$(type -p "$QEMU_IO_PROG")")
-export QEMU_NBD_PROG=$(realpath -- "$(type -p "$QEMU_NBD_PROG")")
-
-# This program is not built as part of qemu but (possibly) provided by the
-# system, so it may not be present at all
-if [ -n "$QEMU_VXHS_PROG" ]; then
-    export QEMU_VXHS_PROG=$(realpath -- "$(type -p "$QEMU_VXHS_PROG")")
-fi
-
 _qemu_wrapper()
 {
     (
-- 
2.13.6

From: Paolo Bonzini <pbonzini@redhat.com>

These are never used by "check", with one exception that does not need
$QEMU_OPTIONS.  Keep them in common.rc, which will be soon included only
by the tests.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 tests/qemu-iotests/039.out       | 10 +++---
 tests/qemu-iotests/061.out       |  4 +--
 tests/qemu-iotests/137.out       |  2 +-
 tests/qemu-iotests/common.config | 69 ++--------------------------------------
 tests/qemu-iotests/common.rc     | 65 +++++++++++++++++++++++++++++++++++++
 5 files changed, 75 insertions(+), 75 deletions(-)

diff --git a/tests/qemu-iotests/039.out b/tests/qemu-iotests/039.out
index XXXXXXX..XXXXXXX 100644
--- a/tests/qemu-iotests/039.out
+++ b/tests/qemu-iotests/039.out
@@ -XXX,XX +XXX,XX @@ No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=134217728
 wrote 512/512 bytes at offset 0
 512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
-./common.config: Killed                  ( if [ "${VALGRIND_QEMU}" == "y" ]; then
+./common.rc: Killed                  ( if [ "${VALGRIND_QEMU}" == "y" ]; then
     exec valgrind --log-file="${VALGRIND_LOGFILE}" --error-exitcode=99 "$QEMU_IO_PROG" $QEMU_IO_ARGS "$@";
 else
     exec "$QEMU_IO_PROG" $QEMU_IO_ARGS "$@";
@@ -XXX,XX +XXX,XX @@ read 512/512 bytes at offset 0
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=134217728
 wrote 512/512 bytes at offset 0
 512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
-./common.config: Killed                  ( if [ "${VALGRIND_QEMU}" == "y" ]; then
+./common.rc: Killed                  ( if [ "${VALGRIND_QEMU}" == "y" ]; then
     exec valgrind --log-file="${VALGRIND_LOGFILE}" --error-exitcode=99 "$QEMU_IO_PROG" $QEMU_IO_ARGS "$@";
 else
     exec "$QEMU_IO_PROG" $QEMU_IO_ARGS "$@";
@@ -XXX,XX +XXX,XX @@ incompatible_features     0x0
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=134217728
 wrote 512/512 bytes at offset 0
 512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
-./common.config: Killed                  ( if [ "${VALGRIND_QEMU}" == "y" ]; then
+./common.rc: Killed                  ( if [ "${VALGRIND_QEMU}" == "y" ]; then
     exec valgrind --log-file="${VALGRIND_LOGFILE}" --error-exitcode=99 "$QEMU_IO_PROG" $QEMU_IO_ARGS "$@";
 else
     exec "$QEMU_IO_PROG" $QEMU_IO_ARGS "$@";
@@ -XXX,XX +XXX,XX @@ No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=134217728
 wrote 512/512 bytes at offset 0
 512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
-./common.config: Killed                  ( if [ "${VALGRIND_QEMU}" == "y" ]; then
+./common.rc: Killed                  ( if [ "${VALGRIND_QEMU}" == "y" ]; then
     exec valgrind --log-file="${VALGRIND_LOGFILE}" --error-exitcode=99 "$QEMU_IO_PROG" $QEMU_IO_ARGS "$@";
 else
     exec "$QEMU_IO_PROG" $QEMU_IO_ARGS "$@";
@@ -XXX,XX +XXX,XX @@ Data may be corrupted, or further writes to the image may corrupt it.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=134217728
 wrote 512/512 bytes at offset 0
 512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
-./common.config: Killed                  ( if [ "${VALGRIND_QEMU}" == "y" ]; then
+./common.rc: Killed                  ( if [ "${VALGRIND_QEMU}" == "y" ]; then
     exec valgrind --log-file="${VALGRIND_LOGFILE}" --error-exitcode=99 "$QEMU_IO_PROG" $QEMU_IO_ARGS "$@";
 else
     exec "$QEMU_IO_PROG" $QEMU_IO_ARGS "$@";
diff --git a/tests/qemu-iotests/061.out b/tests/qemu-iotests/061.out
index XXXXXXX..XXXXXXX 100644
--- a/tests/qemu-iotests/061.out
+++ b/tests/qemu-iotests/061.out
@@ -XXX,XX +XXX,XX @@ No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
 wrote 131072/131072 bytes at offset 0
 128 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
-./common.config: Killed                  ( if [ "${VALGRIND_QEMU}" == "y" ]; then
+./common.rc: Killed                  ( if [ "${VALGRIND_QEMU}" == "y" ]; then
     exec valgrind --log-file="${VALGRIND_LOGFILE}" --error-exitcode=99 "$QEMU_IO_PROG" $QEMU_IO_ARGS "$@";
 else
     exec "$QEMU_IO_PROG" $QEMU_IO_ARGS "$@";
@@ -XXX,XX +XXX,XX @@ No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
 wrote 131072/131072 bytes at offset 0
 128 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
-./common.config: Killed                  ( if [ "${VALGRIND_QEMU}" == "y" ]; then
+./common.rc: Killed                  ( if [ "${VALGRIND_QEMU}" == "y" ]; then
     exec valgrind --log-file="${VALGRIND_LOGFILE}" --error-exitcode=99 "$QEMU_IO_PROG" $QEMU_IO_ARGS "$@";
 else
     exec "$QEMU_IO_PROG" $QEMU_IO_ARGS "$@";
diff --git a/tests/qemu-iotests/137.out b/tests/qemu-iotests/137.out
index XXXXXXX..XXXXXXX 100644
--- a/tests/qemu-iotests/137.out
+++ b/tests/qemu-iotests/137.out
@@ -XXX,XX +XXX,XX @@ Cache clean interval too big
 Unsupported value 'blubb' for qcow2 option 'overlap-check'. Allowed are any of the following: none, constant, cached, all
 wrote 512/512 bytes at offset 0
 512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
-./common.config: Killed                  ( if [ "${VALGRIND_QEMU}" == "y" ]; then
+./common.rc: Killed                  ( if [ "${VALGRIND_QEMU}" == "y" ]; then
     exec valgrind --log-file="${VALGRIND_LOGFILE}" --error-exitcode=99 "$QEMU_IO_PROG" $QEMU_IO_ARGS "$@";
 else
     exec "$QEMU_IO_PROG" $QEMU_IO_ARGS "$@";
diff --git a/tests/qemu-iotests/common.config b/tests/qemu-iotests/common.config
index XXXXXXX..XXXXXXX 100644
--- a/tests/qemu-iotests/common.config
+++ b/tests/qemu-iotests/common.config
@@ -XXX,XX +XXX,XX @@ _optstr_add()
     fi
 }
 
-_qemu_wrapper()
-{
-    (
-        if [ -n "${QEMU_NEED_PID}" ]; then
-            echo $BASHPID > "${QEMU_TEST_DIR}/qemu-${_QEMU_HANDLE}.pid"
-        fi
-        exec "$QEMU_PROG" $QEMU_OPTIONS "$@"
-    )
-}
-
-_qemu_img_wrapper()
-{
-    (exec "$QEMU_IMG_PROG" $QEMU_IMG_OPTIONS "$@")
-}
-
-_qemu_io_wrapper()
-{
-    local VALGRIND_LOGFILE="${TEST_DIR}"/$$.valgrind
-    local QEMU_IO_ARGS="$QEMU_IO_OPTIONS"
-    if [ "$IMGOPTSSYNTAX" = "true" ]; then
-        QEMU_IO_ARGS="--image-opts $QEMU_IO_ARGS"
-        if [ -n "$IMGKEYSECRET" ]; then
-            QEMU_IO_ARGS="--object secret,id=keysec0,data=$IMGKEYSECRET $QEMU_IO_ARGS"
-        fi
-    fi
-    local RETVAL
-    (
-        if [ "${VALGRIND_QEMU}" == "y" ]; then
-            exec valgrind --log-file="${VALGRIND_LOGFILE}" --error-exitcode=99 "$QEMU_IO_PROG" $QEMU_IO_ARGS "$@"
-        else
-            exec "$QEMU_IO_PROG" $QEMU_IO_ARGS "$@"
-        fi
-    )
-    RETVAL=$?
-    if [ "${VALGRIND_QEMU}" == "y" ]; then
-        if [ $RETVAL == 99 ]; then
-            cat "${VALGRIND_LOGFILE}"
-        fi
-        rm -f "${VALGRIND_LOGFILE}"
-    fi
-    (exit $RETVAL)
-}
-
-_qemu_nbd_wrapper()
-{
-    (
-        echo $BASHPID > "${QEMU_TEST_DIR}/qemu-nbd.pid"
-        exec "$QEMU_NBD_PROG" $QEMU_NBD_OPTIONS "$@"
-    )
-}
-
-_qemu_vxhs_wrapper()
-{
-    (
-        echo $BASHPID > "${TEST_DIR}/qemu-vxhs.pid"
-        exec "$QEMU_VXHS_PROG" $QEMU_VXHS_OPTIONS "$@"
-    )
-}
-
-export QEMU=_qemu_wrapper
-export QEMU_IMG=_qemu_img_wrapper
-export QEMU_IO=_qemu_io_wrapper
-export QEMU_NBD=_qemu_nbd_wrapper
-export QEMU_VXHS=_qemu_vxhs_wrapper
-
 QEMU_IMG_EXTRA_ARGS=
 if [ "$IMGOPTSSYNTAX" = "true" ]; then
     QEMU_IMG_EXTRA_ARGS="--image-opts $QEMU_IMG_EXTRA_ARGS"
@@ -XXX,XX +XXX,XX @@ fi
 export QEMU_IMG_EXTRA_ARGS
 
 
-default_machine=$($QEMU -machine help | sed -n '/(default)/ s/ .*//p')
-default_alias_machine=$($QEMU -machine help | \
+default_machine=$($QEMU_PROG -machine help | sed -n '/(default)/ s/ .*//p')
+default_alias_machine=$($QEMU_PROG -machine help | \
    sed -n "/(alias of $default_machine)/ { s/ .*//p; q; }")
 if [[ "$default_alias_machine" ]]; then
     default_machine="$default_alias_machine"
diff --git a/tests/qemu-iotests/common.rc b/tests/qemu-iotests/common.rc
index XXXXXXX..XXXXXXX 100644
--- a/tests/qemu-iotests/common.rc
+++ b/tests/qemu-iotests/common.rc
@@ -XXX,XX +XXX,XX @@ then
     fi
 fi
 
+_qemu_wrapper()
+{
+    (
+        if [ -n "${QEMU_NEED_PID}" ]; then
+            echo $BASHPID > "${QEMU_TEST_DIR}/qemu-${_QEMU_HANDLE}.pid"
+        fi
+        exec "$QEMU_PROG" $QEMU_OPTIONS "$@"
+    )
+}
+
+_qemu_img_wrapper()
+{
+    (exec "$QEMU_IMG_PROG" $QEMU_IMG_OPTIONS "$@")
+}
+
+_qemu_io_wrapper()
+{
+    local VALGRIND_LOGFILE="${TEST_DIR}"/$$.valgrind
+    local QEMU_IO_ARGS="$QEMU_IO_OPTIONS"
+    if [ "$IMGOPTSSYNTAX" = "true" ]; then
+        QEMU_IO_ARGS="--image-opts $QEMU_IO_ARGS"
+        if [ -n "$IMGKEYSECRET" ]; then
+            QEMU_IO_ARGS="--object secret,id=keysec0,data=$IMGKEYSECRET $QEMU_IO_ARGS"
+        fi
+    fi
+    local RETVAL
+    (
+        if [ "${VALGRIND_QEMU}" == "y" ]; then
+            exec valgrind --log-file="${VALGRIND_LOGFILE}" --error-exitcode=99 "$QEMU_IO_PROG" $QEMU_IO_ARGS "$@"
+        else
+            exec "$QEMU_IO_PROG" $QEMU_IO_ARGS "$@"
+        fi
+    )
+    RETVAL=$?
+    if [ "${VALGRIND_QEMU}" == "y" ]; then
+        if [ $RETVAL == 99 ]; then
+            cat "${VALGRIND_LOGFILE}"
+        fi
+        rm -f "${VALGRIND_LOGFILE}"
+    fi
+    (exit $RETVAL)
+}
+
+_qemu_nbd_wrapper()
+{
+    (
+        echo $BASHPID > "${QEMU_TEST_DIR}/qemu-nbd.pid"
+        exec "$QEMU_NBD_PROG" $QEMU_NBD_OPTIONS "$@"
+    )
+}
+
+_qemu_vxhs_wrapper()
+{
+    (
+        echo $BASHPID > "${TEST_DIR}/qemu-vxhs.pid"
+        exec "$QEMU_VXHS_PROG" $QEMU_VXHS_OPTIONS "$@"
+    )
+}
+
+export QEMU=_qemu_wrapper
+export QEMU_IMG=_qemu_img_wrapper
+export QEMU_IO=_qemu_io_wrapper
+export QEMU_NBD=_qemu_nbd_wrapper
+export QEMU_VXHS=_qemu_vxhs_wrapper
+
 if [ "$IMGOPTSSYNTAX" = "true" ]; then
     DRIVER="driver=$IMGFMT"
     if [ "$IMGFMT" = "luks" ]; then
-- 
2.13.6

From: Paolo Bonzini <pbonzini@redhat.com>

It only provides functions used by the test programs.

From: Paolo Bonzini <pbonzini@redhat.com>

Split "check" parts from tests part.

For the directory setup, the actual computation of directories goes
in "check", while the sanity checks go in the tests.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 tests/qemu-iotests/common        | 24 ++++++++++++++++++++
 tests/qemu-iotests/common.config | 49 ----------------------------------------
 tests/qemu-iotests/common.qemu   |  1 +
 tests/qemu-iotests/common.rc     | 25 ++++++++++++++++++++
 4 files changed, 50 insertions(+), 49 deletions(-)

diff --git a/tests/qemu-iotests/common b/tests/qemu-iotests/common
index XXXXXXX..XXXXXXX 100644
--- a/tests/qemu-iotests/common
+++ b/tests/qemu-iotests/common
@@ -XXX,XX +XXX,XX @@ set_prog_path()
     fi
 }
 
+if [ -z "$TEST_DIR" ]; then
+        TEST_DIR=`pwd`/scratch
+fi
+
+if [ ! -e "$TEST_DIR" ]; then
+        mkdir "$TEST_DIR"
+fi
+
 diff="diff -u"
 verbose=false
 debug=false
@@ -XXX,XX +XXX,XX @@ if [ "$IMGFMT" == "luks" ] && ! (echo "$IMGOPTS" | grep "iter-time=" > /dev/null
     IMGOPTS=$(_optstr_add "$IMGOPTS" "iter-time=10")
 fi
 
+if [ -z "$SAMPLE_IMG_DIR" ]; then
+        SAMPLE_IMG_DIR="$source_iotests/sample_images"
+fi
+
+export TEST_DIR
+export SAMPLE_IMG_DIR
+
 if [ -s $tmp.list ]
 then
     # found some valid test numbers ... this is good
@@ -XXX,XX +XXX,XX @@ if [ -x "$build_iotests/socket_scm_helper" ]
 then
     export SOCKET_SCM_HELPER="$build_iotests/socket_scm_helper"
 fi
+
+default_machine=$($QEMU_PROG -machine help | sed -n '/(default)/ s/ .*//p')
+default_alias_machine=$($QEMU_PROG -machine help | \
+   sed -n "/(alias of $default_machine)/ { s/ .*//p; q; }")
+if [[ "$default_alias_machine" ]]; then
+    default_machine="$default_alias_machine"
+fi
+
+export QEMU_DEFAULT_MACHINE="$default_machine"
diff --git a/tests/qemu-iotests/common.config b/tests/qemu-iotests/common.config
index XXXXXXX..XXXXXXX 100644
--- a/tests/qemu-iotests/common.config
+++ b/tests/qemu-iotests/common.config
@@ -XXX,XX +XXX,XX @@ arch=`uname -m`
 
 export PWD=`pwd`
 
-export _QEMU_HANDLE=0
-
 # make sure we have a standard umask
 umask 022
 
@@ -XXX,XX +XXX,XX @@ _optstr_add()
     fi
 }
 
-QEMU_IMG_EXTRA_ARGS=
-if [ "$IMGOPTSSYNTAX" = "true" ]; then
-    QEMU_IMG_EXTRA_ARGS="--image-opts $QEMU_IMG_EXTRA_ARGS"
-    if [ -n "$IMGKEYSECRET" ]; then
-        QEMU_IMG_EXTRA_ARGS="--object secret,id=keysec0,data=$IMGKEYSECRET $QEMU_IMG_EXTRA_ARGS"
-    fi
-fi
-export QEMU_IMG_EXTRA_ARGS
-
-
-default_machine=$($QEMU_PROG -machine help | sed -n '/(default)/ s/ .*//p')
-default_alias_machine=$($QEMU_PROG -machine help | \
-   sed -n "/(alias of $default_machine)/ { s/ .*//p; q; }")
-if [[ "$default_alias_machine" ]]; then
-    default_machine="$default_alias_machine"
-fi
-
-export QEMU_DEFAULT_MACHINE="$default_machine"
-
-if [ -z "$TEST_DIR" ]; then
-        TEST_DIR=`pwd`/scratch
-fi
-
-QEMU_TEST_DIR="${TEST_DIR}"
-
-if [ ! -e "$TEST_DIR" ]; then
-        mkdir "$TEST_DIR"
-fi
-
-if [ ! -d "$TEST_DIR" ]; then
-    echo "common.config: Error: \$TEST_DIR ($TEST_DIR) is not a directory"
-    exit 1
-fi
-
-export TEST_DIR
-
-if [ -z "$SAMPLE_IMG_DIR" ]; then
-        SAMPLE_IMG_DIR="$source_iotests/sample_images"
-fi
-
-if [ ! -d "$SAMPLE_IMG_DIR" ]; then
-    echo "common.config: Error: \$SAMPLE_IMG_DIR ($SAMPLE_IMG_DIR) is not a directory"
-    exit 1
-fi
-
-export SAMPLE_IMG_DIR
-
 # make sure this script returns success
 true
diff --git a/tests/qemu-iotests/common.qemu b/tests/qemu-iotests/common.qemu
index XXXXXXX..XXXXXXX 100644
--- a/tests/qemu-iotests/common.qemu
+++ b/tests/qemu-iotests/common.qemu
@@ -XXX,XX +XXX,XX @@ QEMU_FIFO_IN="${QEMU_TEST_DIR}/qmp-in-$$"
 QEMU_FIFO_OUT="${QEMU_TEST_DIR}/qmp-out-$$"
 
 QEMU_HANDLE=0
+export _QEMU_HANDLE=0
 
 # If bash version is >= 4.1, these will be overwritten and dynamic
 # file descriptor values assigned.
diff --git a/tests/qemu-iotests/common.rc b/tests/qemu-iotests/common.rc
index XXXXXXX..XXXXXXX 100644
--- a/tests/qemu-iotests/common.rc
+++ b/tests/qemu-iotests/common.rc
@@ -XXX,XX +XXX,XX @@ export QEMU_VXHS=_qemu_vxhs_wrapper
 
 if [ "$IMGOPTSSYNTAX" = "true" ]; then
     DRIVER="driver=$IMGFMT"
+    QEMU_IMG_EXTRA_ARGS="--image-opts $QEMU_IMG_EXTRA_ARGS"
+    if [ -n "$IMGKEYSECRET" ]; then
+        QEMU_IMG_EXTRA_ARGS="--object secret,id=keysec0,data=$IMGKEYSECRET $QEMU_IMG_EXTRA_ARGS"
+    fi
     if [ "$IMGFMT" = "luks" ]; then
         DRIVER="$DRIVER,key-secret=keysec0"
     fi
@@ -XXX,XX +XXX,XX @@ if [ "$IMGOPTSSYNTAX" = "true" ]; then
         TEST_IMG="$DRIVER,file.driver=$IMGPROTO,file.filename=$TEST_DIR/t.$IMGFMT"
     fi
 else
+    QEMU_IMG_EXTRA_ARGS=
     if [ "$IMGPROTO" = "file" ]; then
         TEST_IMG=$TEST_DIR/t.$IMGFMT
     elif [ "$IMGPROTO" = "nbd" ]; then
@@ -XXX,XX +XXX,XX @@ else
 fi
 ORIG_TEST_IMG="$TEST_IMG"
 
+if [ -z "$TEST_DIR" ]; then
+        TEST_DIR=`pwd`/scratch
+fi
+
+QEMU_TEST_DIR="${TEST_DIR}"
+
+if [ ! -e "$TEST_DIR" ]; then
+        mkdir "$TEST_DIR"
+fi
+
+if [ ! -d "$TEST_DIR" ]; then
+    echo "common.config: Error: \$TEST_DIR ($TEST_DIR) is not a directory"
+    exit 1
+fi
+
+if [ ! -d "$SAMPLE_IMG_DIR" ]; then
+    echo "common.config: Error: \$SAMPLE_IMG_DIR ($SAMPLE_IMG_DIR) is not a directory"
+    exit 1
+fi
+
 _use_sample_img()
 {
     SAMPLE_IMG_FILE="${1%\.bz2}"
-- 
2.13.6

From: Paolo Bonzini <pbonzini@redhat.com>

The variable is used in "common" but defined only after the file
is sourced.

diff --git a/tests/qemu-iotests/check b/tests/qemu-iotests/check
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/check
+++ b/tests/qemu-iotests/check
@@ -XXX,XX +XXX,XX @@ fi
 
 TIMESTAMP_FILE=check.time-$IMGPROTO-$IMGFMT
 
-tmp="${TEST_DIR}"/$$
-
 _wallclock()
 {
     date "+%H %M %S" | awk '{ print $1*3600 + $2*60 + $3 }'
diff --git a/tests/qemu-iotests/common b/tests/qemu-iotests/common
index XXXXXXX..XXXXXXX 100644
--- a/tests/qemu-iotests/common
+++ b/tests/qemu-iotests/common
@@ -XXX,XX +XXX,XX @@ sortme=false
 expunge=true
 have_test_arg=false
 cachemode=false
+
+tmp="${TEST_DIR}"/$$
 rm -f $tmp.list $tmp.tmp $tmp.sed
 
 export IMGFMT=raw
-- 
2.13.6

From: Paolo Bonzini <pbonzini@redhat.com>

The variable is almost unused, and one of the two uses is actually
uninitialized.

diff --git a/tests/qemu-iotests/check b/tests/qemu-iotests/check
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/check
+++ b/tests/qemu-iotests/check
@@ -XXX,XX +XXX,XX @@ interrupt=true
 # by default don't output timestamps
 timestamp=${TIMESTAMP:=false}
 
-# generic initialization
-iam=check
-
 _init_error()
 {
-    echo "$iam: $1" >&2
+    echo "check: $1" >&2
     exit 1
 }
 
diff --git a/tests/qemu-iotests/common.rc b/tests/qemu-iotests/common.rc
index XXXXXXX..XXXXXXX 100644
--- a/tests/qemu-iotests/common.rc
+++ b/tests/qemu-iotests/common.rc
@@ -XXX,XX +XXX,XX @@ poke_file()
 
 if ! . ./common.config
     then
-    echo "$iam: failed to source common.config"
+    echo "$0: failed to source common.config"
     exit 1
 fi
 
-- 
2.13.6

From: Paolo Bonzini <pbonzini@redhat.com>

"check" is full of qemu-iotests--specific details.  Separating it
from "common" does not make much sense anymore.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 tests/qemu-iotests/check  | 533 +++++++++++++++++++++++++++++++++++++++++++-
 tests/qemu-iotests/common | 552 ----------------------------------------------
 2 files changed, 531 insertions(+), 554 deletions(-)
 delete mode 100644 tests/qemu-iotests/common

diff --git a/tests/qemu-iotests/check b/tests/qemu-iotests/check
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/check
+++ b/tests/qemu-iotests/check
@@ -XXX,XX +XXX,XX @@ then
     _init_error "failed to source common.config"
 fi
 
-# we need common
-. "$source_iotests/common"
+_full_imgfmt_details()
+{
+    if [ -n "$IMGOPTS" ]; then
+        echo "$IMGFMT ($IMGOPTS)"
+    else
+        echo "$IMGFMT"
+    fi
+}
+
+_full_platform_details()
+{
+    os=`uname -s`
+    host=`hostname -s`
+    kernel=`uname -r`
+    platform=`uname -m`
+    echo "$os/$platform $host $kernel"
+}
+
+# $1 = prog to look for
+set_prog_path()
+{
+    p=`command -v $1 2> /dev/null`
+    if [ -n "$p" -a -x "$p" ]; then
+        realpath -- "$(type -p "$p")"
+    else
+        return 1
+    fi
+}
+
+if [ -z "$TEST_DIR" ]; then
+        TEST_DIR=`pwd`/scratch
+fi
+
+if [ ! -e "$TEST_DIR" ]; then
+        mkdir "$TEST_DIR"
+fi
+
+diff="diff -u"
+verbose=false
+debug=false
+group=false
+xgroup=false
+imgopts=false
+showme=false
+sortme=false
+expunge=true
+have_test_arg=false
+cachemode=false
+
+tmp="${TEST_DIR}"/$$
+rm -f $tmp.list $tmp.tmp $tmp.sed
+
+export IMGFMT=raw
+export IMGFMT_GENERIC=true
+export IMGPROTO=file
+export IMGOPTS=""
+export CACHEMODE="writeback"
+export QEMU_IO_OPTIONS=""
+export QEMU_IO_OPTIONS_NO_FMT=""
+export CACHEMODE_IS_DEFAULT=true
+export QEMU_OPTIONS="-nodefaults -machine accel=qtest"
+export VALGRIND_QEMU=
+export IMGKEYSECRET=
+export IMGOPTSSYNTAX=false
+
+for r
+do
+
+    if $group
+    then
+        # arg after -g
+        group_list=`sed -n <"$source_iotests/group" -e 's/$/ /' -e "/^[0-9][0-9][0-9].* $r /"'{
+s/ .*//p
+}'`
+        if [ -z "$group_list" ]
+        then
+            echo "Group \"$r\" is empty or not defined?"
+            exit 1
+        fi
+        [ ! -s $tmp.list ] && touch $tmp.list
+        for t in $group_list
+        do
+            if grep -s "^$t\$" $tmp.list >/dev/null
+            then
+                :
+            else
+                echo "$t" >>$tmp.list
+            fi
+        done
+        group=false
+        continue
+
+    elif $xgroup
+    then
+        # arg after -x
+        # Populate $tmp.list with all tests
+        awk '/^[0-9]{3,}/ {print $1}' "${source_iotests}/group" > $tmp.list 2>/dev/null
+        group_list=`sed -n <"$source_iotests/group" -e 's/$/ /' -e "/^[0-9][0-9][0-9].* $r /"'{
+s/ .*//p
+}'`
+        if [ -z "$group_list" ]
+        then
+            echo "Group \"$r\" is empty or not defined?"
+            exit 1
+        fi
+        numsed=0
+        rm -f $tmp.sed
+        for t in $group_list
+        do
+            if [ $numsed -gt 100 ]
+            then
+                sed -f $tmp.sed <$tmp.list >$tmp.tmp
+                mv $tmp.tmp $tmp.list
+                numsed=0
+                rm -f $tmp.sed
+            fi
+            echo "/^$t\$/d" >>$tmp.sed
+            numsed=`expr $numsed + 1`
+        done
+        sed -f $tmp.sed <$tmp.list >$tmp.tmp
+        mv $tmp.tmp $tmp.list
+        xgroup=false
+        continue
+
+    elif $imgopts
+    then
+        IMGOPTS="$r"
+        imgopts=false
+        continue
+    elif $cachemode
+    then
+        CACHEMODE="$r"
+        CACHEMODE_IS_DEFAULT=false
+        cachemode=false
+        continue
+    fi
+
+    xpand=true
+    case "$r"
+    in
+
+        -\? | -h | --help)        # usage
+            echo "Usage: $0 [options] [testlist]"'
+
+common options
+    -v                  verbose
+    -d                  debug
+
+image format options
+    -raw                test raw (default)
+    -bochs              test bochs
+    -cloop              test cloop
+    -parallels          test parallels
+    -qcow               test qcow
+    -qcow2              test qcow2
+    -qed                test qed
+    -vdi                test vdi
+    -vpc                test vpc
+    -vhdx               test vhdx
+    -vmdk               test vmdk
+    -luks               test luks
+
+image protocol options
+    -file               test file (default)
+    -rbd                test rbd
+    -sheepdog           test sheepdog
+    -nbd                test nbd
+    -ssh                test ssh
+    -nfs                test nfs
+    -vxhs               test vxhs
+
+other options
+    -xdiff              graphical mode diff
+    -nocache            use O_DIRECT on backing file
+    -misalign           misalign memory allocations
+    -n                  show me, do not run tests
+    -o options          -o options to pass to qemu-img create/convert
+    -T                  output timestamps
+    -c mode             cache mode
+
+testlist options
+    -g group[,group...]        include tests from these groups
+    -x group[,group...]        exclude tests from these groups
+    NNN                        include test NNN
+    NNN-NNN                    include test range (eg. 012-021)
+'
+            exit 0
+            ;;
+
+        -raw)
+            IMGFMT=raw
+            xpand=false
+            ;;
+
+        -bochs)
+            IMGFMT=bochs
+            IMGFMT_GENERIC=false
+            xpand=false
+            ;;
+
+        -cloop)
+            IMGFMT=cloop
+            IMGFMT_GENERIC=false
+            xpand=false
+            ;;
+
+        -parallels)
+            IMGFMT=parallels
+            IMGFMT_GENERIC=false
+            xpand=false
+            ;;
+
+        -qcow)
+            IMGFMT=qcow
+            xpand=false
+            ;;
+
+        -qcow2)
+            IMGFMT=qcow2
+            xpand=false
+            ;;
+
+        -luks)
+            IMGOPTSSYNTAX=true
+            IMGFMT=luks
+            IMGKEYSECRET=123456
+            xpand=false
+            ;;
+
+        -qed)
+            IMGFMT=qed
+            xpand=false
+            ;;
+
+        -vdi)
+            IMGFMT=vdi
+            xpand=false
+            ;;
+
+        -vmdk)
+            IMGFMT=vmdk
+            xpand=false
+            ;;
+
+        -vpc)
+            IMGFMT=vpc
+            xpand=false
+            ;;
+
+        -vhdx)
+            IMGFMT=vhdx
+            xpand=false
+            ;;
+
+        -file)
+            IMGPROTO=file
+            xpand=false
+            ;;
+
+        -rbd)
+            IMGPROTO=rbd
+            xpand=false
+            ;;
+
+        -sheepdog)
+            IMGPROTO=sheepdog
+            xpand=false
+            ;;
+
+        -nbd)
+            IMGPROTO=nbd
+            xpand=false
+            ;;
+
+        -vxhs)
+            IMGPROTO=vxhs
+            xpand=false
+            ;;
+
+        -ssh)
+            IMGPROTO=ssh
+            xpand=false
+            ;;
+
+        -nfs)
+            IMGPROTO=nfs
+            xpand=false
+            ;;
+
+        -nocache)
+            CACHEMODE="none"
+            CACHEMODE_IS_DEFAULT=false
+            xpand=false
+            ;;
+
+        -misalign)
+            QEMU_IO_OPTIONS="$QEMU_IO_OPTIONS --misalign"
+            xpand=false
+            ;;
+
+        -valgrind)
+            VALGRIND_QEMU='y'
+            xpand=false
+            ;;
+
+        -g)        # -g group ... pick from group file
+            group=true
+            xpand=false
+            ;;
+
+        -xdiff)        # graphical diff mode
+            xpand=false
+
+            if [ ! -z "$DISPLAY" ]
+            then
+                command -v xdiff >/dev/null 2>&1 && diff=xdiff
+                command -v gdiff >/dev/null 2>&1 && diff=gdiff
+                command -v tkdiff >/dev/null 2>&1 && diff=tkdiff
+                command -v xxdiff >/dev/null 2>&1 && diff=xxdiff
+            fi
+            ;;
+
+        -n)        # show me, don't do it
+            showme=true
+            xpand=false
+            ;;
+        -o)
+            imgopts=true
+            xpand=false
+            ;;
+        -c)
+            cachemode=true
+            xpand=false
+            ;;
+        -T)        # turn on timestamp output
+            timestamp=true
+            xpand=false
+            ;;
+
+        -v)
+            verbose=true
+            xpand=false
+            ;;
+        -d)
+            debug=true
+            xpand=false
+            ;;
+        -x)        # -x group ... exclude from group file
+            xgroup=true
+            xpand=false
+            ;;
+        '[0-9][0-9][0-9] [0-9][0-9][0-9][0-9]')
+            echo "No tests?"
+            status=1
+            exit $status
+            ;;
+
+        [0-9]*-[0-9]*)
+            eval `echo $r | sed -e 's/^/start=/' -e 's/-/ end=/'`
+            ;;
+
+        [0-9]*-)
+            eval `echo $r | sed -e 's/^/start=/' -e 's/-//'`
+            end=`echo [0-9][0-9][0-9] [0-9][0-9][0-9][0-9] | sed -e 's/\[0-9]//g' -e 's/  *$//' -e 's/.* //'`
+            if [ -z "$end" ]
+            then
+                echo "No tests in range \"$r\"?"
+                status=1
+                exit $status
+            fi
+            ;;
+
+        *)
+            start=$r
+            end=$r
+            ;;
+
+    esac
+
+    # get rid of leading 0s as can be interpreted as octal
+    start=`echo $start | sed 's/^0*//'`
+    end=`echo $end | sed 's/^0*//'`
+
+    if $xpand
+    then
+        have_test_arg=true
+        awk </dev/null '
+BEGIN        { for (t='$start'; t<='$end'; t++) printf "%03d\n",t }' \
+        | while read id
+        do
+            if grep -s "^$id " "$source_iotests/group" >/dev/null
+            then
+                # in group file ... OK
+                echo $id >>$tmp.list
+            else
+                if [ -f expunged ] && $expunge && egrep "^$id([         ]|\$)" expunged >/dev/null
+                then
+                    # expunged ... will be reported, but not run, later
+                    echo $id >>$tmp.list
+                else
+                    # oops
+                    if [ "$start" == "$end" -a "$id" == "$end" ]
+                    then
+                        echo "$id - unknown test"
+                        exit 1
+                    else
+                        echo "$id - unknown test, ignored"
+                    fi
+                fi
+            fi
+        done || exit 1
+    fi
+
+done
+
+# Set qemu-io cache mode with $CACHEMODE we have
+QEMU_IO_OPTIONS="$QEMU_IO_OPTIONS --cache $CACHEMODE"
+
+QEMU_IO_OPTIONS_NO_FMT="$QEMU_IO_OPTIONS"
+if [ "$IMGOPTSSYNTAX" != "true" ]; then
+    QEMU_IO_OPTIONS="$QEMU_IO_OPTIONS -f $IMGFMT"
+fi
+
+# Set default options for qemu-img create -o if they were not specified
+if [ "$IMGFMT" == "qcow2" ] && ! (echo "$IMGOPTS" | grep "compat=" > /dev/null); then
+    IMGOPTS=$(_optstr_add "$IMGOPTS" "compat=1.1")
+fi
+if [ "$IMGFMT" == "luks" ] && ! (echo "$IMGOPTS" | grep "iter-time=" > /dev/null); then
+    IMGOPTS=$(_optstr_add "$IMGOPTS" "iter-time=10")
+fi
+
+if [ -z "$SAMPLE_IMG_DIR" ]; then
+        SAMPLE_IMG_DIR="$source_iotests/sample_images"
+fi
+
+export TEST_DIR
+export SAMPLE_IMG_DIR
+
+if [ -s $tmp.list ]
+then
+    # found some valid test numbers ... this is good
+    :
+else
+    if $have_test_arg
+    then
+        # had test numbers, but none in group file ... do nothing
+        touch $tmp.list
+    else
+        # no test numbers, do everything from group file
+        sed -n -e '/^[0-9][0-9][0-9]*/s/[         ].*//p' <"$source_iotests/group" >$tmp.list
+    fi
+fi
+
+# should be sort -n, but this did not work for Linux when this
+# was ported from IRIX
+#
+list=`sort $tmp.list`
+rm -f $tmp.list $tmp.tmp $tmp.sed
+
+if [ -z "$QEMU_PROG" ]
+then
+    if [ -x "$build_iotests/qemu" ]; then
+        export QEMU_PROG="$build_iotests/qemu"
+    elif [ -x "$build_root/$arch-softmmu/qemu-system-$arch" ]; then
+        export QEMU_PROG="$build_root/$arch-softmmu/qemu-system-$arch"
+    else
+        pushd "$build_root" > /dev/null
+        for binary in *-softmmu/qemu-system-*
+        do
+            if [ -x "$binary" ]
+            then
+                export QEMU_PROG="$build_root/$binary"
+                break
+            fi
+        done
+        popd > /dev/null
+        [ "$QEMU_PROG" = "" ] && _init_error "qemu not found"
+    fi
+fi
+export QEMU_PROG=$(realpath -- "$(type -p "$QEMU_PROG")")
+
+if [ -z "$QEMU_IMG_PROG" ]; then
+    if [ -x "$build_iotests/qemu-img" ]; then
+        export QEMU_IMG_PROG="$build_iotests/qemu-img"
+    elif [ -x "$build_root/qemu-img" ]; then
+        export QEMU_IMG_PROG="$build_root/qemu-img"
+    else
+        _init_error "qemu-img not found"
+    fi
+fi
+export QEMU_IMG_PROG=$(realpath -- "$(type -p "$QEMU_IMG_PROG")")
+
+if [ -z "$QEMU_IO_PROG" ]; then
+    if [ -x "$build_iotests/qemu-io" ]; then
+        export QEMU_IO_PROG="$build_iotests/qemu-io"
+    elif [ -x "$build_root/qemu-io" ]; then
+        export QEMU_IO_PROG="$build_root/qemu-io"
+    else
+        _init_error "qemu-io not found"
+    fi
+fi
+export QEMU_IO_PROG=$(realpath -- "$(type -p "$QEMU_IO_PROG")")
+
+if [ -z $QEMU_NBD_PROG ]; then
+    if [ -x "$build_iotests/qemu-nbd" ]; then
+        export QEMU_NBD_PROG="$build_iotests/qemu-nbd"
+    elif [ -x "$build_root/qemu-nbd" ]; then
+        export QEMU_NBD_PROG="$build_root/qemu-nbd"
+    else
+        _init_error "qemu-nbd not found"
+    fi
+fi
+export QEMU_NBD_PROG=$(realpath -- "$(type -p "$QEMU_NBD_PROG")")
+
+if [ -z "$QEMU_VXHS_PROG" ]; then
+  export QEMU_VXHS_PROG="`set_prog_path qnio_server`"
+fi
+
+if [ -x "$build_iotests/socket_scm_helper" ]
+then
+    export SOCKET_SCM_HELPER="$build_iotests/socket_scm_helper"
+fi
+
+default_machine=$($QEMU_PROG -machine help | sed -n '/(default)/ s/ .*//p')
+default_alias_machine=$($QEMU_PROG -machine help | \
+   sed -n "/(alias of $default_machine)/ { s/ .*//p; q; }")
+if [[ "$default_alias_machine" ]]; then
+    default_machine="$default_alias_machine"
+fi
+
+export QEMU_DEFAULT_MACHINE="$default_machine"
 
 TIMESTAMP_FILE=check.time-$IMGPROTO-$IMGFMT
 
diff --git a/tests/qemu-iotests/common b/tests/qemu-iotests/common
deleted file mode 100644
index XXXXXXX..XXXXXXX
--- a/tests/qemu-iotests/common
+++ /dev/null
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
-#
-# Copyright (C) 2009 Red Hat, Inc.
-# Copyright (c) 2000-2005 Silicon Graphics, Inc.  All Rights Reserved.
-#
-# This program is free software; you can redistribute it and/or
-# modify it under the terms of the GNU General Public License as
-# published by the Free Software Foundation.
-#
-# This program is distributed in the hope that it would be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License
-# along with this program.  If not, see <http://www.gnu.org/licenses/>.
-#
-#
-# common procedures for QA scripts
-#
-
-_full_imgfmt_details()
-{
-    if [ -n "$IMGOPTS" ]; then
-        echo "$IMGFMT ($IMGOPTS)"
-    else
-        echo "$IMGFMT"
-    fi
-}
-
-_full_platform_details()
-{
-    os=`uname -s`
-    host=`hostname -s`
-    kernel=`uname -r`
-    platform=`uname -m`
-    echo "$os/$platform $host $kernel"
-}
-
-# $1 = prog to look for
-set_prog_path()
-{
-    p=`command -v $1 2> /dev/null`
-    if [ -n "$p" -a -x "$p" ]; then
-        realpath -- "$(type -p "$p")"
-    else
-        return 1
-    fi
-}
-
-if [ -z "$TEST_DIR" ]; then
-        TEST_DIR=`pwd`/scratch
-fi
-
-if [ ! -e "$TEST_DIR" ]; then
-        mkdir "$TEST_DIR"
-fi
-
-diff="diff -u"
-verbose=false
-debug=false
-group=false
-xgroup=false
-imgopts=false
-showme=false
-sortme=false
-expunge=true
-have_test_arg=false
-cachemode=false
-
-tmp="${TEST_DIR}"/$$
-rm -f $tmp.list $tmp.tmp $tmp.sed
-
-export IMGFMT=raw
-export IMGFMT_GENERIC=true
-export IMGPROTO=file
-export IMGOPTS=""
-export CACHEMODE="writeback"
-export QEMU_IO_OPTIONS=""
-export QEMU_IO_OPTIONS_NO_FMT=""
-export CACHEMODE_IS_DEFAULT=true
-export QEMU_OPTIONS="-nodefaults -machine accel=qtest"
-export VALGRIND_QEMU=
-export IMGKEYSECRET=
-export IMGOPTSSYNTAX=false
-
-for r
-do
-
-    if $group
-    then
-        # arg after -g
-        group_list=`sed -n <"$source_iotests/group" -e 's/$/ /' -e "/^[0-9][0-9][0-9].* $r /"'{
-s/ .*//p
-}'`
-        if [ -z "$group_list" ]
-        then
-            echo "Group \"$r\" is empty or not defined?"
-            exit 1
-        fi
-        [ ! -s $tmp.list ] && touch $tmp.list
-        for t in $group_list
-        do
-            if grep -s "^$t\$" $tmp.list >/dev/null
-            then
-                :
-            else
-                echo "$t" >>$tmp.list
-            fi
-        done
-        group=false
-        continue
-
-    elif $xgroup
-    then
-        # arg after -x
-        # Populate $tmp.list with all tests
-        awk '/^[0-9]{3,}/ {print $1}' "${source_iotests}/group" > $tmp.list 2>/dev/null
-        group_list=`sed -n <"$source_iotests/group" -e 's/$/ /' -e "/^[0-9][0-9][0-9].* $r /"'{
-s/ .*//p
-}'`
-        if [ -z "$group_list" ]
-        then
-            echo "Group \"$r\" is empty or not defined?"
-            exit 1
-        fi
-        numsed=0
-        rm -f $tmp.sed
-        for t in $group_list
-        do
-            if [ $numsed -gt 100 ]
-            then
-                sed -f $tmp.sed <$tmp.list >$tmp.tmp
-                mv $tmp.tmp $tmp.list
-                numsed=0
-                rm -f $tmp.sed
-            fi
-            echo "/^$t\$/d" >>$tmp.sed
-            numsed=`expr $numsed + 1`
-        done
-        sed -f $tmp.sed <$tmp.list >$tmp.tmp
-        mv $tmp.tmp $tmp.list
-        xgroup=false
-        continue
-
-    elif $imgopts
-    then
-        IMGOPTS="$r"
-        imgopts=false
-        continue
-    elif $cachemode
-    then
-        CACHEMODE="$r"
-        CACHEMODE_IS_DEFAULT=false
-        cachemode=false
-        continue
-    fi
-
-    xpand=true
-    case "$r"
-    in
-
-        -\? | -h | --help)        # usage
-            echo "Usage: $0 [options] [testlist]"'
-
-common options
-    -v                  verbose
-    -d                  debug
-
-image format options
-    -raw                test raw (default)
-    -bochs              test bochs
-    -cloop              test cloop
-    -parallels          test parallels
-    -qcow               test qcow
-    -qcow2              test qcow2
-    -qed                test qed
-    -vdi                test vdi
-    -vpc                test vpc
-    -vhdx               test vhdx
-    -vmdk               test vmdk
-    -luks               test luks
-
-image protocol options
-    -file               test file (default)
-    -rbd                test rbd
-    -sheepdog           test sheepdog
-    -nbd                test nbd
-    -ssh                test ssh
-    -nfs                test nfs
-    -vxhs               test vxhs
-
-other options
-    -xdiff              graphical mode diff
-    -nocache            use O_DIRECT on backing file
-    -misalign           misalign memory allocations
-    -n                  show me, do not run tests
-    -o options          -o options to pass to qemu-img create/convert
-    -T                  output timestamps
-    -c mode             cache mode
-
-testlist options
-    -g group[,group...]        include tests from these groups
-    -x group[,group...]        exclude tests from these groups
-    NNN                        include test NNN
-    NNN-NNN                    include test range (eg. 012-021)
-'
-            exit 0
-            ;;
-
-        -raw)
-            IMGFMT=raw
-            xpand=false
-            ;;
-
-        -bochs)
-            IMGFMT=bochs
-            IMGFMT_GENERIC=false
-            xpand=false
-            ;;
-
-        -cloop)
-            IMGFMT=cloop
-            IMGFMT_GENERIC=false
-            xpand=false
-            ;;
-
-        -parallels)
-            IMGFMT=parallels
-            IMGFMT_GENERIC=false
-            xpand=false
-            ;;
-
-        -qcow)
-            IMGFMT=qcow
-            xpand=false
-            ;;
-
-        -qcow2)
-            IMGFMT=qcow2
-            xpand=false
-            ;;
-
-        -luks)
-            IMGOPTSSYNTAX=true
-            IMGFMT=luks
-            IMGKEYSECRET=123456
-            xpand=false
-            ;;
-
-        -qed)
-            IMGFMT=qed
-            xpand=false
-            ;;
-
-        -vdi)
-            IMGFMT=vdi
-            xpand=false
-            ;;
-
-        -vmdk)
-            IMGFMT=vmdk
-            xpand=false
-            ;;
-
-        -vpc)
-            IMGFMT=vpc
-            xpand=false
-            ;;
-
-        -vhdx)
-            IMGFMT=vhdx
-            xpand=false
-            ;;
-
-        -file)
-            IMGPROTO=file
-            xpand=false
-            ;;
-
-        -rbd)
-            IMGPROTO=rbd
-            xpand=false
-            ;;
-
-        -sheepdog)
-            IMGPROTO=sheepdog
-            xpand=false
-            ;;
-
-        -nbd)
-            IMGPROTO=nbd
-            xpand=false
-            ;;
-
-        -vxhs)
-            IMGPROTO=vxhs
-            xpand=false
-            ;;
-
-        -ssh)
-            IMGPROTO=ssh
-            xpand=false
-            ;;
-
-        -nfs)
-            IMGPROTO=nfs
-            xpand=false
-            ;;
-
-        -nocache)
-            CACHEMODE="none"
-            CACHEMODE_IS_DEFAULT=false
-            xpand=false
-            ;;
-
-        -misalign)
-            QEMU_IO_OPTIONS="$QEMU_IO_OPTIONS --misalign"
-            xpand=false
-            ;;
-
-        -valgrind)
-            VALGRIND_QEMU='y'
-            xpand=false
-            ;;
-
-        -g)        # -g group ... pick from group file
-            group=true
-            xpand=false
-            ;;
-
-        -xdiff)        # graphical diff mode
-            xpand=false
-
-            if [ ! -z "$DISPLAY" ]
-            then
-                command -v xdiff >/dev/null 2>&1 && diff=xdiff
-                command -v gdiff >/dev/null 2>&1 && diff=gdiff
-                command -v tkdiff >/dev/null 2>&1 && diff=tkdiff
-                command -v xxdiff >/dev/null 2>&1 && diff=xxdiff
-            fi
-            ;;
-
-        -n)        # show me, don't do it
-            showme=true
-            xpand=false
-            ;;
-        -o)
-            imgopts=true
-            xpand=false
-            ;;
-        -c)
-            cachemode=true
-            xpand=false
-            ;;
-        -T)        # turn on timestamp output
-            timestamp=true
-            xpand=false
-            ;;
-
-        -v)
-            verbose=true
-            xpand=false
-            ;;
-        -d)
-            debug=true
-            xpand=false
-            ;;
-        -x)        # -x group ... exclude from group file
-            xgroup=true
-            xpand=false
-            ;;
-        '[0-9][0-9][0-9] [0-9][0-9][0-9][0-9]')
-            echo "No tests?"
-            status=1
-            exit $status
-            ;;
-
-        [0-9]*-[0-9]*)
-            eval `echo $r | sed -e 's/^/start=/' -e 's/-/ end=/'`
-            ;;
-
-        [0-9]*-)
-            eval `echo $r | sed -e 's/^/start=/' -e 's/-//'`
-            end=`echo [0-9][0-9][0-9] [0-9][0-9][0-9][0-9] | sed -e 's/\[0-9]//g' -e 's/  *$//' -e 's/.* //'`
-            if [ -z "$end" ]
-            then
-                echo "No tests in range \"$r\"?"
-                status=1
-                exit $status
-            fi
-            ;;
-
-        *)
-            start=$r
-            end=$r
-            ;;
-
-    esac
-
-    # get rid of leading 0s as can be interpreted as octal
-    start=`echo $start | sed 's/^0*//'`
-    end=`echo $end | sed 's/^0*//'`
-
-    if $xpand
-    then
-        have_test_arg=true
-        awk </dev/null '
-BEGIN        { for (t='$start'; t<='$end'; t++) printf "%03d\n",t }' \
-        | while read id
-        do
-            if grep -s "^$id " "$source_iotests/group" >/dev/null
-            then
-                # in group file ... OK
-                echo $id >>$tmp.list
-            else
-                if [ -f expunged ] && $expunge && egrep "^$id([         ]|\$)" expunged >/dev/null
-                then
-                    # expunged ... will be reported, but not run, later
-                    echo $id >>$tmp.list
-                else
-                    # oops
-                    if [ "$start" == "$end" -a "$id" == "$end" ]
-                    then
-                        echo "$id - unknown test"
-                        exit 1
-                    else
-                        echo "$id - unknown test, ignored"
-                    fi
-                fi
-            fi
-        done || exit 1
-    fi
-
-done
-
-# Set qemu-io cache mode with $CACHEMODE we have
-QEMU_IO_OPTIONS="$QEMU_IO_OPTIONS --cache $CACHEMODE"
-
-QEMU_IO_OPTIONS_NO_FMT="$QEMU_IO_OPTIONS"
-if [ "$IMGOPTSSYNTAX" != "true" ]; then
-    QEMU_IO_OPTIONS="$QEMU_IO_OPTIONS -f $IMGFMT"
-fi
-
-# Set default options for qemu-img create -o if they were not specified
-if [ "$IMGFMT" == "qcow2" ] && ! (echo "$IMGOPTS" | grep "compat=" > /dev/null); then
-    IMGOPTS=$(_optstr_add "$IMGOPTS" "compat=1.1")
-fi
-if [ "$IMGFMT" == "luks" ] && ! (echo "$IMGOPTS" | grep "iter-time=" > /dev/null); then
-    IMGOPTS=$(_optstr_add "$IMGOPTS" "iter-time=10")
-fi
-
-if [ -z "$SAMPLE_IMG_DIR" ]; then
-        SAMPLE_IMG_DIR="$source_iotests/sample_images"
-fi
-
-export TEST_DIR
-export SAMPLE_IMG_DIR
-
-if [ -s $tmp.list ]
-then
-    # found some valid test numbers ... this is good
-    :
-else
-    if $have_test_arg
-    then
-        # had test numbers, but none in group file ... do nothing
-        touch $tmp.list
-    else
-        # no test numbers, do everything from group file
-        sed -n -e '/^[0-9][0-9][0-9]*/s/[         ].*//p' <"$source_iotests/group" >$tmp.list
-    fi
-fi
-
-# should be sort -n, but this did not work for Linux when this
-# was ported from IRIX
-#
-list=`sort $tmp.list`
-rm -f $tmp.list $tmp.tmp $tmp.sed
-
-if [ -z "$QEMU_PROG" ]
-then
-    if [ -x "$build_iotests/qemu" ]; then
-        export QEMU_PROG="$build_iotests/qemu"
-    elif [ -x "$build_root/$arch-softmmu/qemu-system-$arch" ]; then
-        export QEMU_PROG="$build_root/$arch-softmmu/qemu-system-$arch"
-    else
-        pushd "$build_root" > /dev/null
-        for binary in *-softmmu/qemu-system-*
-        do
-            if [ -x "$binary" ]
-            then
-                export QEMU_PROG="$build_root/$binary"
-                break
-            fi
-        done
-        popd > /dev/null
-        [ "$QEMU_PROG" = "" ] && _init_error "qemu not found"
-    fi
-fi
-export QEMU_PROG=$(realpath -- "$(type -p "$QEMU_PROG")")
-
-if [ -z "$QEMU_IMG_PROG" ]; then
-    if [ -x "$build_iotests/qemu-img" ]; then
-        export QEMU_IMG_PROG="$build_iotests/qemu-img"
-    elif [ -x "$build_root/qemu-img" ]; then
-        export QEMU_IMG_PROG="$build_root/qemu-img"
-    else
-        _init_error "qemu-img not found"
-    fi
-fi
-export QEMU_IMG_PROG=$(realpath -- "$(type -p "$QEMU_IMG_PROG")")
-
-if [ -z "$QEMU_IO_PROG" ]; then
-    if [ -x "$build_iotests/qemu-io" ]; then
-        export QEMU_IO_PROG="$build_iotests/qemu-io"
-    elif [ -x "$build_root/qemu-io" ]; then
-        export QEMU_IO_PROG="$build_root/qemu-io"
-    else
-        _init_error "qemu-io not found"
-    fi
-fi
-export QEMU_IO_PROG=$(realpath -- "$(type -p "$QEMU_IO_PROG")")
-
-if [ -z $QEMU_NBD_PROG ]; then
-    if [ -x "$build_iotests/qemu-nbd" ]; then
-        export QEMU_NBD_PROG="$build_iotests/qemu-nbd"
-    elif [ -x "$build_root/qemu-nbd" ]; then
-        export QEMU_NBD_PROG="$build_root/qemu-nbd"
-    else
-        _init_error "qemu-nbd not found"
-    fi
-fi
-export QEMU_NBD_PROG=$(realpath -- "$(type -p "$QEMU_NBD_PROG")")
-
-if [ -z "$QEMU_VXHS_PROG" ]; then
-  export QEMU_VXHS_PROG="`set_prog_path qnio_server`"
-fi
-
-if [ -x "$build_iotests/socket_scm_helper" ]
-then
-    export SOCKET_SCM_HELPER="$build_iotests/socket_scm_helper"
-fi
-
-default_machine=$($QEMU_PROG -machine help | sed -n '/(default)/ s/ .*//p')
-default_alias_machine=$($QEMU_PROG -machine help | \
-   sed -n "/(alias of $default_machine)/ { s/ .*//p; q; }")
-if [[ "$default_alias_machine" ]]; then
-    default_machine="$default_alias_machine"
-fi
-
-export QEMU_DEFAULT_MACHINE="$default_machine"
-- 
2.13.6

There is no good reason for bdrv_drop_intermediate() to know the active
layer above the subchain it is operating on - even more so, because
the assumption that there is a single active layer above it is not
generally true.

In order to prepare removal of the active parameter, use a BdrvChildRole
callback to update the backing file string in the overlay image instead
of directly calling bdrv_change_backing_file().

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
---
 include/block/block_int.h |  6 ++++++
 block.c                   | 33 ++++++++++++++++++++++++++++-----
 2 files changed, 34 insertions(+), 5 deletions(-)

diff --git a/include/block/block_int.h b/include/block/block_int.h
index XXXXXXX..XXXXXXX 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -XXX,XX +XXX,XX @@ struct BdrvChildRole {
 
     void (*attach)(BdrvChild *child);
     void (*detach)(BdrvChild *child);
+
+    /* Notifies the parent that the filename of its child has changed (e.g.
+     * because the direct child was removed from the backing chain), so that it
+     * can update its reference. */
+    int (*update_filename)(BdrvChild *child, BlockDriverState *new_base,
+                           const char *filename, Error **errp);
 };
 
 extern const BdrvChildRole child_file;
diff --git a/block.c b/block.c
index XXXXXXX..XXXXXXX 100644
--- a/block.c
+++ b/block.c
@@ -XXX,XX +XXX,XX @@ static void bdrv_backing_options(int *child_flags, QDict *child_options,
     *child_flags = flags;
 }
 
+static int bdrv_backing_update_filename(BdrvChild *c, BlockDriverState *base,
+                                        const char *filename, Error **errp)
+{
+    BlockDriverState *parent = c->opaque;
+    int ret;
+
+    ret = bdrv_change_backing_file(parent, filename,
+                                   base->drv ? base->drv->format_name : "");
+    if (ret < 0) {
+        error_setg_errno(errp, ret, "Could not update backing file link");
+    }
+
+    return ret;
+}
+
 const BdrvChildRole child_backing = {
     .get_parent_desc = bdrv_child_get_parent_desc,
     .attach          = bdrv_backing_attach,
@@ -XXX,XX +XXX,XX @@ const BdrvChildRole child_backing = {
     .drained_begin   = bdrv_child_cb_drained_begin,
     .drained_end     = bdrv_child_cb_drained_end,
     .inactivate      = bdrv_child_cb_inactivate,
+    .update_filename = bdrv_backing_update_filename,
 };
 
 static int bdrv_open_flags(BlockDriverState *bs, int flags)
@@ -XXX,XX +XXX,XX @@ int bdrv_drop_intermediate(BlockDriverState *active, BlockDriverState *top,
     Error *local_err = NULL;
     int ret = -EIO;
 
+    bdrv_ref(top);
+
     if (!top->drv || !base->drv) {
         goto exit;
     }
@@ -XXX,XX +XXX,XX @@ int bdrv_drop_intermediate(BlockDriverState *active, BlockDriverState *top,
     }
 
     /* success - we can delete the intermediate states, and link top->base */
-    backing_file_str = backing_file_str ? backing_file_str : base->filename;
-    ret = bdrv_change_backing_file(new_top_bs, backing_file_str,
-                                   base->drv ? base->drv->format_name : "");
-    if (ret) {
-        goto exit;
+    if (new_top_bs->backing->role->update_filename) {
+        backing_file_str = backing_file_str ? backing_file_str : base->filename;
+        ret = new_top_bs->backing->role->update_filename(new_top_bs->backing,
+                                                         base, backing_file_str,
+                                                         &local_err);
+        if (ret < 0) {
+            bdrv_set_backing_hd(new_top_bs, top, &error_abort);
+            goto exit;
+        }
     }
 
     bdrv_set_backing_hd(new_top_bs, base, &local_err);
@@ -XXX,XX +XXX,XX @@ int bdrv_drop_intermediate(BlockDriverState *active, BlockDriverState *top,
 
     ret = 0;
 exit:
+    bdrv_unref(top);
     return ret;
 }
 
-- 
2.13.6

This changes the commit block job to support operation in a graph where
there is more than a single active layer that references the top node.

This involves inserting the commit filter node not only on the path
between the given active node and the top node, but between the top node
and all of its parents.

On completion, bdrv_drop_intermediate() must consider all parents for
updating the backing file link. These parents may be backing files
themselves and as such read-only; reopen them temporarily if necessary.
Previously this was achieved by the bdrv_reopen() calls in the commit
block job that made overlay_bs read-write for the whole duration of the
block job, even though write access is only needed on completion.

Now that we consider all parents, overlay_bs is meaningless. It is left
in place in this commit, but we'll remove it soon.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block.c        | 68 ++++++++++++++++++++++++++++++++++------------------------
 block/commit.c |  2 +-
 2 files changed, 41 insertions(+), 29 deletions(-)

diff --git a/block.c b/block.c
index XXXXXXX..XXXXXXX 100644
--- a/block.c
+++ b/block.c
@@ -XXX,XX +XXX,XX @@ static int bdrv_backing_update_filename(BdrvChild *c, BlockDriverState *base,
                                         const char *filename, Error **errp)
 {
     BlockDriverState *parent = c->opaque;
+    int orig_flags = bdrv_get_flags(parent);
     int ret;
 
+    if (!(orig_flags & BDRV_O_RDWR)) {
+        ret = bdrv_reopen(parent, orig_flags | BDRV_O_RDWR, errp);
+        if (ret < 0) {
+            return ret;
+        }
+    }
+
     ret = bdrv_change_backing_file(parent, filename,
                                    base->drv ? base->drv->format_name : "");
     if (ret < 0) {
         error_setg_errno(errp, ret, "Could not update backing file link");
     }
 
+    if (!(orig_flags & BDRV_O_RDWR)) {
+        bdrv_reopen(parent, orig_flags, NULL);
+    }
+
     return ret;
 }
 
@@ -XXX,XX +XXX,XX @@ BlockDriverState *bdrv_find_base(BlockDriverState *bs)
 int bdrv_drop_intermediate(BlockDriverState *active, BlockDriverState *top,
                            BlockDriverState *base, const char *backing_file_str)
 {
-    BlockDriverState *new_top_bs = NULL;
+    BdrvChild *c, *next;
     Error *local_err = NULL;
     int ret = -EIO;
 
@@ -XXX,XX +XXX,XX @@ int bdrv_drop_intermediate(BlockDriverState *active, BlockDriverState *top,
         goto exit;
     }
 
-    new_top_bs = bdrv_find_overlay(active, top);
-
-    if (new_top_bs == NULL) {
-        /* we could not find the image above 'top', this is an error */
-        goto exit;
-    }
-
-    /* special case of new_top_bs->backing->bs already pointing to base - nothing
-     * to do, no intermediate images */
-    if (backing_bs(new_top_bs) == base) {
-        ret = 0;
-        goto exit;
-    }
-
     /* Make sure that base is in the backing chain of top */
     if (!bdrv_chain_contains(top, base)) {
         goto exit;
     }
 
     /* success - we can delete the intermediate states, and link top->base */
-    if (new_top_bs->backing->role->update_filename) {
-        backing_file_str = backing_file_str ? backing_file_str : base->filename;
-        ret = new_top_bs->backing->role->update_filename(new_top_bs->backing,
-                                                         base, backing_file_str,
-                                                         &local_err);
-        if (ret < 0) {
-            bdrv_set_backing_hd(new_top_bs, top, &error_abort);
+    backing_file_str = backing_file_str ? backing_file_str : base->filename;
+
+    QLIST_FOREACH_SAFE(c, &top->parents, next_parent, next) {
+        /* Check whether we are allowed to switch c from top to base */
+        GSList *ignore_children = g_slist_prepend(NULL, c);
+        bdrv_check_update_perm(base, NULL, c->perm, c->shared_perm,
+                               ignore_children, &local_err);
+        if (local_err) {
+            ret = -EPERM;
+            error_report_err(local_err);
             goto exit;
         }
-    }
+        g_slist_free(ignore_children);
 
-    bdrv_set_backing_hd(new_top_bs, base, &local_err);
-    if (local_err) {
-        ret = -EPERM;
-        error_report_err(local_err);
-        goto exit;
+        /* If so, update the backing file path in the image file */
+        if (c->role->update_filename) {
+            ret = c->role->update_filename(c, base, backing_file_str,
+                                           &local_err);
+            if (ret < 0) {
+                bdrv_abort_perm_update(base);
+                error_report_err(local_err);
+                goto exit;
+            }
+        }
+
+        /* Do the actual switch in the in-memory graph.
+         * Completes bdrv_check_update_perm() transaction internally. */
+        bdrv_ref(base);
+        bdrv_replace_child(c, base);
+        bdrv_unref(top);
     }
 
     ret = 0;
diff --git a/block/commit.c b/block/commit.c
index XXXXXXX..XXXXXXX 100644
--- a/block/commit.c
+++ b/block/commit.c
@@ -XXX,XX +XXX,XX @@ void commit_start(const char *job_id, BlockDriverState *bs,
         error_propagate(errp, local_err);
         goto fail;
     }
-    bdrv_set_backing_hd(overlay_bs, commit_top_bs, &local_err);
+    bdrv_replace_node(top, commit_top_bs, &local_err);
     if (local_err) {
         bdrv_unref(commit_top_bs);
         commit_top_bs = NULL;
-- 
2.13.6

QMP responses to certain commands can become quite long, which doesn't
only make reading them hard, but also means that the maximum line length
in patch emails can be exceeded. Allow tests to switch to QMP pretty
printing, which results in more, but shorter lines.

We also need to make sure to keep indentation in the response for this
to work as expected.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
---
 tests/qemu-iotests/common.qemu | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/tests/qemu-iotests/common.qemu b/tests/qemu-iotests/common.qemu
index XXXXXXX..XXXXXXX 100644
--- a/tests/qemu-iotests/common.qemu
+++ b/tests/qemu-iotests/common.qemu
@@ -XXX,XX +XXX,XX @@ function _timed_wait_for()
     shift
 
     QEMU_STATUS[$h]=0
-    while read -t ${QEMU_COMM_TIMEOUT} resp <&${QEMU_OUT[$h]}
+    while IFS= read -t ${QEMU_COMM_TIMEOUT} resp <&${QEMU_OUT[$h]}
     do
         if [ -z "${silent}" ]; then
             echo "${resp}" | _filter_testdir | _filter_qemu \
                            | _filter_qemu_io | _filter_qmp | _filter_hmp
         fi
-        grep -q "${*}" < <(echo ${resp})
+        grep -q "${*}" < <(echo "${resp}")
         if [ $? -eq 0 ]; then
             return
         fi
@@ -XXX,XX +XXX,XX @@ function _send_qemu_cmd()
 # $qemu_comm_method: set this variable to 'monitor' (case insensitive)
 #                    to use the QEMU HMP monitor for communication.
 #                    Otherwise, the default of QMP is used.
+# $qmp_pretty: Set this variable to 'y' to enable QMP pretty printing.
 # $keep_stderr: Set this variable to 'y' to keep QEMU's stderr output on stderr.
 #               If this variable is empty, stderr will be redirected to stdout.
 # Returns:
@@ -XXX,XX +XXX,XX @@ function _launch_qemu()
         comm="-monitor stdio"
     else
         local qemu_comm_method="qmp"
-        comm="-monitor none -qmp stdio"
+        if [ "$qmp_pretty" = "y" ]; then
+            comm="-monitor none -qmp-pretty stdio"
+        else
+            comm="-monitor none -qmp stdio"
+        fi
     fi
 
     fifo_out=${QEMU_FIFO_OUT}_${_QEMU_HANDLE}
@@ -XXX,XX +XXX,XX @@ function _launch_qemu()
     then
         # Don't print response, since it has version information in it
         silent=yes _timed_wait_for ${_QEMU_HANDLE} "capabilities"
+        if [ "$qmp_pretty" = "y" ]; then
+            silent=yes _timed_wait_for ${_QEMU_HANDLE} "^}"
+        fi
     fi
     QEMU_HANDLE=${_QEMU_HANDLE}
     let _QEMU_HANDLE++
-- 
2.13.6

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 tests/qemu-iotests/191     | 153 +++++++++
 tests/qemu-iotests/191.out | 827 +++++++++++++++++++++++++++++++++++++++++++++
 tests/qemu-iotests/group   |   1 +
 3 files changed, 981 insertions(+)
 create mode 100755 tests/qemu-iotests/191
 create mode 100644 tests/qemu-iotests/191.out

diff --git a/tests/qemu-iotests/191 b/tests/qemu-iotests/191
new file mode 100755
index XXXXXXX..XXXXXXX
--- /dev/null
+++ b/tests/qemu-iotests/191
@@ -XXX,XX +XXX,XX @@
+#!/bin/bash
+#
+# Test commit block job where top has two parents
+#
+# Copyright (C) 2017 Red Hat, Inc.
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+
+# creator
+owner=kwolf@redhat.com
+
+seq=`basename $0`
+echo "QA output created by $seq"
+
+here=`pwd`
+status=1 # failure is the default!
+
+MIG_SOCKET="${TEST_DIR}/migrate"
+
+_cleanup()
+{
+    rm -f "${TEST_IMG}.mid"
+    rm -f "${TEST_IMG}.ovl2"
+    rm -f "${TEST_IMG}.ovl3"
+    _cleanup_test_img
+    _cleanup_qemu
+}
+trap "_cleanup; exit \$status" 0 1 2 3 15
+
+# get standard environment, filters and checks
+. ./common.rc
+. ./common.filter
+. ./common.qemu
+
+_supported_fmt qcow2
+_unsupported_imgopts compat=0.10
+_supported_proto file
+_supported_os Linux
+
+size=64M
+
+echo
+echo === Preparing and starting VM ===
+echo
+
+TEST_IMG="${TEST_IMG}.base" _make_test_img $size
+TEST_IMG="${TEST_IMG}.mid" _make_test_img -b "${TEST_IMG}.base"
+_make_test_img -b "${TEST_IMG}.mid"
+TEST_IMG="${TEST_IMG}.ovl2" _make_test_img -b "${TEST_IMG}.mid"
+
+$QEMU_IO -c 'write -P 0x55 1M 64k' "${TEST_IMG}.mid" | _filter_qemu_io
+
+qemu_comm_method="qmp"
+qmp_pretty="y"
+
+_launch_qemu \
+    -blockdev "driver=${IMGFMT},file.driver=file,file.filename=${TEST_IMG}.base,node-name=base" \
+    -blockdev "driver=${IMGFMT},file.driver=file,file.filename=${TEST_IMG}.mid,node-name=mid,backing=base" \
+    -blockdev "driver=${IMGFMT},file.driver=file,file.filename=${TEST_IMG},node-name=top,backing=mid" \
+    -blockdev "driver=${IMGFMT},file.driver=file,file.filename=${TEST_IMG}.ovl2,node-name=top2,backing=mid"
+h=$QEMU_HANDLE
+_send_qemu_cmd $h "{ 'execute': 'qmp_capabilities' }" '^}'
+
+echo
+echo === Perform commit job ===
+echo
+
+_send_qemu_cmd $h \
+    "{ 'execute': 'block-commit',
+       'arguments': { 'job-id': 'commit0',
+                      'device': 'top',
+                      'base':'$TEST_IMG.base',
+                      'top': '$TEST_IMG.mid' } }" \
+    "BLOCK_JOB_COMPLETED"
+_send_qemu_cmd $h "" "^}"
+
+echo
+echo === Check that both top and top2 point to base now ===
+echo
+
+_send_qemu_cmd $h "{ 'execute': 'query-named-block-nodes' }" "^}" |
+    _filter_generated_node_ids
+
+_send_qemu_cmd $h "{ 'execute': 'quit' }" "^}"
+wait=1 _cleanup_qemu
+
+_img_info
+TEST_IMG="$TEST_IMG.ovl2" _img_info
+
+
+echo
+echo === Preparing and starting VM with -drive ===
+echo
+
+TEST_IMG="${TEST_IMG}.base" _make_test_img $size
+TEST_IMG="${TEST_IMG}.mid" _make_test_img -b "${TEST_IMG}.base"
+_make_test_img -b "${TEST_IMG}.mid"
+TEST_IMG="${TEST_IMG}.ovl2" _make_test_img -b "${TEST_IMG}.mid"
+TEST_IMG="${TEST_IMG}.ovl3" _make_test_img -b "${TEST_IMG}.ovl2"
+
+$QEMU_IO -c 'write -P 0x55 1M 64k' "${TEST_IMG}.mid" | _filter_qemu_io
+
+qemu_comm_method="qmp"
+qmp_pretty="y"
+
+_launch_qemu \
+    -drive "driver=${IMGFMT},file=${TEST_IMG},node-name=top,backing.node-name=mid" \
+    -drive "driver=${IMGFMT},file=${TEST_IMG}.ovl3,node-name=top2,backing.backing=mid"
+h=$QEMU_HANDLE
+_send_qemu_cmd $h "{ 'execute': 'qmp_capabilities' }" '^}'
+
+echo
+echo === Perform commit job ===
+echo
+
+_send_qemu_cmd $h \
+    "{ 'execute': 'block-commit',
+       'arguments': { 'job-id': 'commit0',
+                      'device': 'top',
+                      'base':'$TEST_IMG.base',
+                      'top': '$TEST_IMG.mid' } }" \
+    "BLOCK_JOB_COMPLETED"
+_send_qemu_cmd $h "" "^}"
+
+echo
+echo === Check that both top and top2 point to base now ===
+echo
+
+_send_qemu_cmd $h "{ 'execute': 'query-named-block-nodes' }" "^}" |
+    _filter_generated_node_ids
+
+_send_qemu_cmd $h "{ 'execute': 'quit' }" "^}"
+wait=1 _cleanup_qemu
+
+_img_info
+TEST_IMG="$TEST_IMG.ovl2" _img_info
+
+# success, all done
+echo "*** done"
+rm -f $seq.full
+status=0
diff --git a/tests/qemu-iotests/191.out b/tests/qemu-iotests/191.out
new file mode 100644
index XXXXXXX..XXXXXXX
--- /dev/null
+++ b/tests/qemu-iotests/191.out
@@ -XXX,XX +XXX,XX @@
+QA output created by 191
+
+=== Preparing and starting VM ===
+
+Formatting 'TEST_DIR/t.IMGFMT.base', fmt=IMGFMT size=67108864
+Formatting 'TEST_DIR/t.IMGFMT.mid', fmt=IMGFMT size=67108864 backing_file=TEST_DIR/t.IMGFMT.base
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864 backing_file=TEST_DIR/t.IMGFMT.mid
+Formatting 'TEST_DIR/t.IMGFMT.ovl2', fmt=IMGFMT size=67108864 backing_file=TEST_DIR/t.IMGFMT.mid
+wrote 65536/65536 bytes at offset 1048576
+64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+{
+    "return": {
+    }
+}
+
+=== Perform commit job ===
+
+{
+    "return": {
+    }
+}
+{
+    "timestamp": {
+        "seconds":  TIMESTAMP,
+        "microseconds":  TIMESTAMP
+    },
+    "event": "BLOCK_JOB_COMPLETED",
+    "data": {
+        "device": "commit0",
+        "len": 67108864,
+        "offset": 67108864,
+        "speed": 0,
+        "type": "commit"
+    }
+}
+
+=== Check that both top and top2 point to base now ===
+
+{
+    "return": [
+        {
+            "iops_rd": 0,
+            "detect_zeroes": "off",
+            "image": {
+                "backing-image": {
+                    "virtual-size": 67108864,
+                    "filename": "TEST_DIR/t.qcow2.base",
+                    "cluster-size": 65536,
+                    "format": "qcow2",
+                    "actual-size": 397312,
+                    "format-specific": {
+                        "type": "qcow2",
+                        "data": {
+                            "compat": "1.1",
+                            "lazy-refcounts": false,
+                            "refcount-bits": 16,
+                            "corrupt": false
+                        }
+                    },
+                    "dirty-flag": false
+                },
+                "backing-filename-format": "qcow2",
+                "virtual-size": 67108864,
+                "filename": "TEST_DIR/t.qcow2.ovl2",
+                "cluster-size": 65536,
+                "format": "qcow2",
+                "actual-size": 200704,
+                "format-specific": {
+                    "type": "qcow2",
+                    "data": {
+                        "compat": "1.1",
+                        "lazy-refcounts": false,
+                        "refcount-bits": 16,
+                        "corrupt": false
+                    }
+                },
+                "full-backing-filename": "TEST_DIR/t.qcow2.base",
+                "backing-filename": "TEST_DIR/t.qcow2.base",
+                "dirty-flag": false
+            },
+            "iops_wr": 0,
+            "ro": false,
+            "node-name": "top2",
+            "backing_file_depth": 1,
+            "drv": "qcow2",
+            "iops": 0,
+            "bps_wr": 0,
+            "write_threshold": 0,
+            "backing_file": "TEST_DIR/t.qcow2.base",
+            "encrypted": false,
+            "bps": 0,
+            "bps_rd": 0,
+            "cache": {
+                "no-flush": false,
+                "direct": false,
+                "writeback": true
+            },
+            "file": "TEST_DIR/t.qcow2.ovl2",
+            "encryption_key_missing": false
+        },
+        {
+            "iops_rd": 0,
+            "detect_zeroes": "off",
+            "image": {
+                "virtual-size": 197120,
+                "filename": "TEST_DIR/t.qcow2.ovl2",
+                "format": "file",
+                "actual-size": 200704,
+                "dirty-flag": false
+            },
+            "iops_wr": 0,
+            "ro": false,
+            "node-name": "NODE_NAME",
+            "backing_file_depth": 0,
+            "drv": "file",
+            "iops": 0,
+            "bps_wr": 0,
+            "write_threshold": 0,
+            "encrypted": false,
+            "bps": 0,
+            "bps_rd": 0,
+            "cache": {
+                "no-flush": false,
+                "direct": false,
+                "writeback": true
+            },
+            "file": "TEST_DIR/t.qcow2.ovl2",
+            "encryption_key_missing": false
+        },
+        {
+            "iops_rd": 0,
+            "detect_zeroes": "off",
+            "image": {
+                "backing-image": {
+                    "virtual-size": 67108864,
+                    "filename": "TEST_DIR/t.qcow2.base",
+                    "cluster-size": 65536,
+                    "format": "qcow2",
+                    "actual-size": 397312,
+                    "format-specific": {
+                        "type": "qcow2",
+                        "data": {
+                            "compat": "1.1",
+                            "lazy-refcounts": false,
+                            "refcount-bits": 16,
+                            "corrupt": false
+                        }
+                    },
+                    "dirty-flag": false
+                },
+                "backing-filename-format": "qcow2",
+                "virtual-size": 67108864,
+                "filename": "TEST_DIR/t.qcow2",
+                "cluster-size": 65536,
+                "format": "qcow2",
+                "actual-size": 200704,
+                "format-specific": {
+                    "type": "qcow2",
+                    "data": {
+                        "compat": "1.1",
+                        "lazy-refcounts": false,
+                        "refcount-bits": 16,
+                        "corrupt": false
+                    }
+                },
+                "full-backing-filename": "TEST_DIR/t.qcow2.base",
+                "backing-filename": "TEST_DIR/t.qcow2.base",
+                "dirty-flag": false
+            },
+            "iops_wr": 0,
+            "ro": false,
+            "node-name": "top",
+            "backing_file_depth": 1,
+            "drv": "qcow2",
+            "iops": 0,
+            "bps_wr": 0,
+            "write_threshold": 0,
+            "backing_file": "TEST_DIR/t.qcow2.base",
+            "encrypted": false,
+            "bps": 0,
+            "bps_rd": 0,
+            "cache": {
+                "no-flush": false,
+                "direct": false,
+                "writeback": true
+            },
+            "file": "TEST_DIR/t.qcow2",
+            "encryption_key_missing": false
+        },
+        {
+            "iops_rd": 0,
+            "detect_zeroes": "off",
+            "image": {
+                "virtual-size": 197120,
+                "filename": "TEST_DIR/t.qcow2",
+                "format": "file",
+                "actual-size": 200704,
+                "dirty-flag": false
+            },
+            "iops_wr": 0,
+            "ro": false,
+            "node-name": "NODE_NAME",
+            "backing_file_depth": 0,
+            "drv": "file",
+            "iops": 0,
+            "bps_wr": 0,
+            "write_threshold": 0,
+            "encrypted": false,
+            "bps": 0,
+            "bps_rd": 0,
+            "cache": {
+                "no-flush": false,
+                "direct": false,
+                "writeback": true
+            },
+            "file": "TEST_DIR/t.qcow2",
+            "encryption_key_missing": false
+        },
+        {
+            "iops_rd": 0,
+            "detect_zeroes": "off",
+            "image": {
+                "backing-image": {
+                    "virtual-size": 67108864,
+                    "filename": "TEST_DIR/t.qcow2.base",
+                    "cluster-size": 65536,
+                    "format": "qcow2",
+                    "actual-size": 397312,
+                    "format-specific": {
+                        "type": "qcow2",
+                        "data": {
+                            "compat": "1.1",
+                            "lazy-refcounts": false,
+                            "refcount-bits": 16,
+                            "corrupt": false
+                        }
+                    },
+                    "dirty-flag": false
+                },
+                "backing-filename-format": "qcow2",
+                "virtual-size": 67108864,
+                "filename": "TEST_DIR/t.qcow2.mid",
+                "cluster-size": 65536,
+                "format": "qcow2",
+                "actual-size": 397312,
+                "format-specific": {
+                    "type": "qcow2",
+                    "data": {
+                        "compat": "1.1",
+                        "lazy-refcounts": false,
+                        "refcount-bits": 16,
+                        "corrupt": false
+                    }
+                },
+                "full-backing-filename": "TEST_DIR/t.qcow2.base",
+                "backing-filename": "TEST_DIR/t.qcow2.base",
+                "dirty-flag": false
+            },
+            "iops_wr": 0,
+            "ro": false,
+            "node-name": "mid",
+            "backing_file_depth": 1,
+            "drv": "qcow2",
+            "iops": 0,
+            "bps_wr": 0,
+            "write_threshold": 0,
+            "backing_file": "TEST_DIR/t.qcow2.base",
+            "encrypted": false,
+            "bps": 0,
+            "bps_rd": 0,
+            "cache": {
+                "no-flush": false,
+                "direct": false,
+                "writeback": true
+            },
+            "file": "TEST_DIR/t.qcow2.mid",
+            "encryption_key_missing": false
+        },
+        {
+            "iops_rd": 0,
+            "detect_zeroes": "off",
+            "image": {
+                "virtual-size": 393216,
+                "filename": "TEST_DIR/t.qcow2.mid",
+                "format": "file",
+                "actual-size": 397312,
+                "dirty-flag": false
+            },
+            "iops_wr": 0,
+            "ro": false,
+            "node-name": "NODE_NAME",
+            "backing_file_depth": 0,
+            "drv": "file",
+            "iops": 0,
+            "bps_wr": 0,
+            "write_threshold": 0,
+            "encrypted": false,
+            "bps": 0,
+            "bps_rd": 0,
+            "cache": {
+                "no-flush": false,
+                "direct": false,
+                "writeback": true
+            },
+            "file": "TEST_DIR/t.qcow2.mid",
+            "encryption_key_missing": false
+        },
+        {
+            "iops_rd": 0,
+            "detect_zeroes": "off",
+            "image": {
+                "virtual-size": 67108864,
+                "filename": "TEST_DIR/t.qcow2.base",
+                "cluster-size": 65536,
+                "format": "qcow2",
+                "actual-size": 397312,
+                "format-specific": {
+                    "type": "qcow2",
+                    "data": {
+                        "compat": "1.1",
+                        "lazy-refcounts": false,
+                        "refcount-bits": 16,
+                        "corrupt": false
+                    }
+                },
+                "dirty-flag": false
+            },
+            "iops_wr": 0,
+            "ro": false,
+            "node-name": "base",
+            "backing_file_depth": 0,
+            "drv": "qcow2",
+            "iops": 0,
+            "bps_wr": 0,
+            "write_threshold": 0,
+            "encrypted": false,
+            "bps": 0,
+            "bps_rd": 0,
+            "cache": {
+                "no-flush": false,
+                "direct": false,
+                "writeback": true
+            },
+            "file": "TEST_DIR/t.qcow2.base",
+            "encryption_key_missing": false
+        },
+        {
+            "iops_rd": 0,
+            "detect_zeroes": "off",
+            "image": {
+                "virtual-size": 393216,
+                "filename": "TEST_DIR/t.qcow2.base",
+                "format": "file",
+                "actual-size": 397312,
+                "dirty-flag": false
+            },
+            "iops_wr": 0,
+            "ro": false,
+            "node-name": "NODE_NAME",
+            "backing_file_depth": 0,
+            "drv": "file",
+            "iops": 0,
+            "bps_wr": 0,
+            "write_threshold": 0,
+            "encrypted": false,
+            "bps": 0,
+            "bps_rd": 0,
+            "cache": {
+                "no-flush": false,
+                "direct": false,
+                "writeback": true
+            },
+            "file": "TEST_DIR/t.qcow2.base",
+            "encryption_key_missing": false
+        }
+    ]
+}
+{
+    "return": {
+    }
+}
+{
+    "timestamp": {
+        "seconds":  TIMESTAMP,
+        "microseconds":  TIMESTAMP
+    },
+    "event": "SHUTDOWN",
+    "data": {
+        "guest": false
+    }
+}
+image: TEST_DIR/t.IMGFMT
+file format: IMGFMT
+virtual size: 64M (67108864 bytes)
+cluster_size: 65536
+backing file: TEST_DIR/t.IMGFMT.base
+backing file format: IMGFMT
+image: TEST_DIR/t.IMGFMT.ovl2
+file format: IMGFMT
+virtual size: 64M (67108864 bytes)
+cluster_size: 65536
+backing file: TEST_DIR/t.IMGFMT.base
+backing file format: IMGFMT
+
+=== Preparing and starting VM with -drive ===
+
+Formatting 'TEST_DIR/t.IMGFMT.base', fmt=IMGFMT size=67108864
+Formatting 'TEST_DIR/t.IMGFMT.mid', fmt=IMGFMT size=67108864 backing_file=TEST_DIR/t.IMGFMT.base
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864 backing_file=TEST_DIR/t.IMGFMT.mid
+Formatting 'TEST_DIR/t.IMGFMT.ovl2', fmt=IMGFMT size=67108864 backing_file=TEST_DIR/t.IMGFMT.mid
+Formatting 'TEST_DIR/t.IMGFMT.ovl3', fmt=IMGFMT size=67108864 backing_file=TEST_DIR/t.IMGFMT.ovl2
+wrote 65536/65536 bytes at offset 1048576
+64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+{
+    "return": {
+    }
+}
+
+=== Perform commit job ===
+
+{
+    "return": {
+    }
+}
+{
+    "timestamp": {
+        "seconds":  TIMESTAMP,
+        "microseconds":  TIMESTAMP
+    },
+    "event": "BLOCK_JOB_COMPLETED",
+    "data": {
+        "device": "commit0",
+        "len": 67108864,
+        "offset": 67108864,
+        "speed": 0,
+        "type": "commit"
+    }
+}
+
+=== Check that both top and top2 point to base now ===
+
+{
+    "return": [
+        {
+            "iops_rd": 0,
+            "detect_zeroes": "off",
+            "image": {
+                "backing-image": {
+                    "virtual-size": 67108864,
+                    "filename": "TEST_DIR/t.qcow2.base",
+                    "cluster-size": 65536,
+                    "format": "qcow2",
+                    "actual-size": 397312,
+                    "format-specific": {
+                        "type": "qcow2",
+                        "data": {
+                            "compat": "1.1",
+                            "lazy-refcounts": false,
+                            "refcount-bits": 16,
+                            "corrupt": false
+                        }
+                    },
+                    "dirty-flag": false
+                },
+                "backing-filename-format": "qcow2",
+                "virtual-size": 67108864,
+                "filename": "TEST_DIR/t.qcow2.ovl2",
+                "cluster-size": 65536,
+                "format": "qcow2",
+                "actual-size": 200704,
+                "format-specific": {
+                    "type": "qcow2",
+                    "data": {
+                        "compat": "1.1",
+                        "lazy-refcounts": false,
+                        "refcount-bits": 16,
+                        "corrupt": false
+                    }
+                },
+                "full-backing-filename": "TEST_DIR/t.qcow2.base",
+                "backing-filename": "TEST_DIR/t.qcow2.base",
+                "dirty-flag": false
+            },
+            "iops_wr": 0,
+            "ro": true,
+            "node-name": "NODE_NAME",
+            "backing_file_depth": 1,
+            "drv": "qcow2",
+            "iops": 0,
+            "bps_wr": 0,
+            "write_threshold": 0,
+            "backing_file": "TEST_DIR/t.qcow2.base",
+            "encrypted": false,
+            "bps": 0,
+            "bps_rd": 0,
+            "cache": {
+                "no-flush": false,
+                "direct": false,
+                "writeback": true
+            },
+            "file": "TEST_DIR/t.qcow2.ovl2",
+            "encryption_key_missing": false
+        },
+        {
+            "iops_rd": 0,
+            "detect_zeroes": "off",
+            "image": {
+                "virtual-size": 197120,
+                "filename": "TEST_DIR/t.qcow2.ovl2",
+                "format": "file",
+                "actual-size": 200704,
+                "dirty-flag": false
+            },
+            "iops_wr": 0,
+            "ro": true,
+            "node-name": "NODE_NAME",
+            "backing_file_depth": 0,
+            "drv": "file",
+            "iops": 0,
+            "bps_wr": 0,
+            "write_threshold": 0,
+            "encrypted": false,
+            "bps": 0,
+            "bps_rd": 0,
+            "cache": {
+                "no-flush": false,
+                "direct": false,
+                "writeback": true
+            },
+            "file": "TEST_DIR/t.qcow2.ovl2",
+            "encryption_key_missing": false
+        },
+        {
+            "iops_rd": 0,
+            "detect_zeroes": "off",
+            "image": {
+                "backing-image": {
+                    "backing-image": {
+                        "virtual-size": 67108864,
+                        "filename": "TEST_DIR/t.qcow2.base",
+                        "cluster-size": 65536,
+                        "format": "qcow2",
+                        "actual-size": 397312,
+                        "format-specific": {
+                            "type": "qcow2",
+                            "data": {
+                                "compat": "1.1",
+                                "lazy-refcounts": false,
+                                "refcount-bits": 16,
+                                "corrupt": false
+                            }
+                        },
+                        "dirty-flag": false
+                    },
+                    "backing-filename-format": "qcow2",
+                    "virtual-size": 67108864,
+                    "filename": "TEST_DIR/t.qcow2.ovl2",
+                    "cluster-size": 65536,
+                    "format": "qcow2",
+                    "actual-size": 200704,
+                    "format-specific": {
+                        "type": "qcow2",
+                        "data": {
+                            "compat": "1.1",
+                            "lazy-refcounts": false,
+                            "refcount-bits": 16,
+                            "corrupt": false
+                        }
+                    },
+                    "full-backing-filename": "TEST_DIR/t.qcow2.base",
+                    "backing-filename": "TEST_DIR/t.qcow2.base",
+                    "dirty-flag": false
+                },
+                "backing-filename-format": "qcow2",
+                "virtual-size": 67108864,
+                "filename": "TEST_DIR/t.qcow2.ovl3",
+                "cluster-size": 65536,
+                "format": "qcow2",
+                "actual-size": 200704,
+                "format-specific": {
+                    "type": "qcow2",
+                    "data": {
+                        "compat": "1.1",
+                        "lazy-refcounts": false,
+                        "refcount-bits": 16,
+                        "corrupt": false
+                    }
+                },
+                "full-backing-filename": "TEST_DIR/t.qcow2.ovl2",
+                "backing-filename": "TEST_DIR/t.qcow2.ovl2",
+                "dirty-flag": false
+            },
+            "iops_wr": 0,
+            "ro": false,
+            "node-name": "top2",
+            "backing_file_depth": 2,
+            "drv": "qcow2",
+            "iops": 0,
+            "bps_wr": 0,
+            "write_threshold": 0,
+            "backing_file": "TEST_DIR/t.qcow2.ovl2",
+            "encrypted": false,
+            "bps": 0,
+            "bps_rd": 0,
+            "cache": {
+                "no-flush": false,
+                "direct": false,
+                "writeback": true
+            },
+            "file": "TEST_DIR/t.qcow2.ovl3",
+            "encryption_key_missing": false
+        },
+        {
+            "iops_rd": 0,
+            "detect_zeroes": "off",
+            "image": {
+                "virtual-size": 197120,
+                "filename": "TEST_DIR/t.qcow2.ovl3",
+                "format": "file",
+                "actual-size": 200704,
+                "dirty-flag": false
+            },
+            "iops_wr": 0,
+            "ro": false,
+            "node-name": "NODE_NAME",
+            "backing_file_depth": 0,
+            "drv": "file",
+            "iops": 0,
+            "bps_wr": 0,
+            "write_threshold": 0,
+            "encrypted": false,
+            "bps": 0,
+            "bps_rd": 0,
+            "cache": {
+                "no-flush": false,
+                "direct": false,
+                "writeback": true
+            },
+            "file": "TEST_DIR/t.qcow2.ovl3",
+            "encryption_key_missing": false
+        },
+        {
+            "iops_rd": 0,
+            "detect_zeroes": "off",
+            "image": {
+                "virtual-size": 67108864,
+                "filename": "TEST_DIR/t.qcow2.base",
+                "cluster-size": 65536,
+                "format": "qcow2",
+                "actual-size": 397312,
+                "format-specific": {
+                    "type": "qcow2",
+                    "data": {
+                        "compat": "1.1",
+                        "lazy-refcounts": false,
+                        "refcount-bits": 16,
+                        "corrupt": false
+                    }
+                },
+                "dirty-flag": false
+            },
+            "iops_wr": 0,
+            "ro": true,
+            "node-name": "NODE_NAME",
+            "backing_file_depth": 0,
+            "drv": "qcow2",
+            "iops": 0,
+            "bps_wr": 0,
+            "write_threshold": 0,
+            "encrypted": false,
+            "bps": 0,
+            "bps_rd": 0,
+            "cache": {
+                "no-flush": false,
+                "direct": false,
+                "writeback": true
+            },
+            "file": "TEST_DIR/t.qcow2.base",
+            "encryption_key_missing": false
+        },
+        {
+            "iops_rd": 0,
+            "detect_zeroes": "off",
+            "image": {
+                "virtual-size": 393216,
+                "filename": "TEST_DIR/t.qcow2.base",
+                "format": "file",
+                "actual-size": 397312,
+                "dirty-flag": false
+            },
+            "iops_wr": 0,
+            "ro": true,
+            "node-name": "NODE_NAME",
+            "backing_file_depth": 0,
+            "drv": "file",
+            "iops": 0,
+            "bps_wr": 0,
+            "write_threshold": 0,
+            "encrypted": false,
+            "bps": 0,
+            "bps_rd": 0,
+            "cache": {
+                "no-flush": false,
+                "direct": false,
+                "writeback": true
+            },
+            "file": "TEST_DIR/t.qcow2.base",
+            "encryption_key_missing": false
+        },
+        {
+            "iops_rd": 0,
+            "detect_zeroes": "off",
+            "image": {
+                "backing-image": {
+                    "virtual-size": 67108864,
+                    "filename": "TEST_DIR/t.qcow2.base",
+                    "cluster-size": 65536,
+                    "format": "qcow2",
+                    "actual-size": 397312,
+                    "format-specific": {
+                        "type": "qcow2",
+                        "data": {
+                            "compat": "1.1",
+                            "lazy-refcounts": false,
+                            "refcount-bits": 16,
+                            "corrupt": false
+                        }
+                    },
+                    "dirty-flag": false
+                },
+                "backing-filename-format": "qcow2",
+                "virtual-size": 67108864,
+                "filename": "TEST_DIR/t.qcow2",
+                "cluster-size": 65536,
+                "format": "qcow2",
+                "actual-size": 200704,
+                "format-specific": {
+                    "type": "qcow2",
+                    "data": {
+                        "compat": "1.1",
+                        "lazy-refcounts": false,
+                        "refcount-bits": 16,
+                        "corrupt": false
+                    }
+                },
+                "full-backing-filename": "TEST_DIR/t.qcow2.base",
+                "backing-filename": "TEST_DIR/t.qcow2.base",
+                "dirty-flag": false
+            },
+            "iops_wr": 0,
+            "ro": false,
+            "node-name": "top",
+            "backing_file_depth": 1,
+            "drv": "qcow2",
+            "iops": 0,
+            "bps_wr": 0,
+            "write_threshold": 0,
+            "backing_file": "TEST_DIR/t.qcow2.base",
+            "encrypted": false,
+            "bps": 0,
+            "bps_rd": 0,
+            "cache": {
+                "no-flush": false,
+                "direct": false,
+                "writeback": true
+            },
+            "file": "TEST_DIR/t.qcow2",
+            "encryption_key_missing": false
+        },
+        {
+            "iops_rd": 0,
+            "detect_zeroes": "off",
+            "image": {
+                "virtual-size": 197120,
+                "filename": "TEST_DIR/t.qcow2",
+                "format": "file",
+                "actual-size": 200704,
+                "dirty-flag": false
+            },
+            "iops_wr": 0,
+            "ro": false,
+            "node-name": "NODE_NAME",
+            "backing_file_depth": 0,
+            "drv": "file",
+            "iops": 0,
+            "bps_wr": 0,
+            "write_threshold": 0,
+            "encrypted": false,
+            "bps": 0,
+            "bps_rd": 0,
+            "cache": {
+                "no-flush": false,
+                "direct": false,
+                "writeback": true
+            },
+            "file": "TEST_DIR/t.qcow2",
+            "encryption_key_missing": false
+        }
+    ]
+}
+{
+    "return": {
+    }
+}
+{
+    "timestamp": {
+        "seconds":  TIMESTAMP,
+        "microseconds":  TIMESTAMP
+    },
+    "event": "SHUTDOWN",
+    "data": {
+        "guest": false
+    }
+}
+image: TEST_DIR/t.IMGFMT
+file format: IMGFMT
+virtual size: 64M (67108864 bytes)
+cluster_size: 65536
+backing file: TEST_DIR/t.IMGFMT.base
+backing file format: IMGFMT
+image: TEST_DIR/t.IMGFMT.ovl2
+file format: IMGFMT
+virtual size: 64M (67108864 bytes)
+cluster_size: 65536
+backing file: TEST_DIR/t.IMGFMT.base
+backing file format: IMGFMT
+*** done
diff --git a/tests/qemu-iotests/group b/tests/qemu-iotests/group
index XXXXXXX..XXXXXXX 100644
--- a/tests/qemu-iotests/group
+++ b/tests/qemu-iotests/group
@@ -XXX,XX +XXX,XX @@
 188 rw auto quick
 189 rw auto
 190 rw auto quick
+191 rw auto
 192 rw auto quick
 194 rw auto migration quick
 195 rw auto quick
-- 
2.13.6

We don't need to make any assumptions about the graph layout above the
top node of the commit operation any more. Remove the use of
bdrv_find_overlay() and related variables from the commit job code.

bdrv_drop_intermediate() doesn't use the 'active' parameter any more, so
we can just drop it.

The overlay node was previously added to the block job to get a
BLK_PERM_GRAPH_MOD. We really need to respect those permissions in
bdrv_drop_intermediate() now, but as long as we haven't figured out yet
how BLK_PERM_GRAPH_MOD is actually supposed to work, just leave a TODO
comment there.

With this change, it is now possible to perform another block job on an
overlay node without conflicts. qemu-iotests 030 is changed accordingly.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
---
 include/block/block.h  |  3 +--
 block.c                |  6 +++--
 block/commit.c         | 62 ++++++++++++--------------------------------------
 tests/qemu-iotests/030 |  4 ----
 4 files changed, 20 insertions(+), 55 deletions(-)

diff --git a/include/block/block.h b/include/block/block.h
index XXXXXXX..XXXXXXX 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -XXX,XX +XXX,XX @@ int bdrv_commit(BlockDriverState *bs);
 int bdrv_change_backing_file(BlockDriverState *bs,
     const char *backing_file, const char *backing_fmt);
 void bdrv_register(BlockDriver *bdrv);
-int bdrv_drop_intermediate(BlockDriverState *active, BlockDriverState *top,
-                           BlockDriverState *base,
+int bdrv_drop_intermediate(BlockDriverState *top, BlockDriverState *base,
                            const char *backing_file_str);
 BlockDriverState *bdrv_find_overlay(BlockDriverState *active,
                                     BlockDriverState *bs);
diff --git a/block.c b/block.c
index XXXXXXX..XXXXXXX 100644
--- a/block.c
+++ b/block.c
@@ -XXX,XX +XXX,XX @@ BlockDriverState *bdrv_find_base(BlockDriverState *bs)
  *  if active == top, that is considered an error
  *
  */
-int bdrv_drop_intermediate(BlockDriverState *active, BlockDriverState *top,
-                           BlockDriverState *base, const char *backing_file_str)
+int bdrv_drop_intermediate(BlockDriverState *top, BlockDriverState *base,
+                           const char *backing_file_str)
 {
     BdrvChild *c, *next;
     Error *local_err = NULL;
@@ -XXX,XX +XXX,XX @@ int bdrv_drop_intermediate(BlockDriverState *active, BlockDriverState *top,
     }
 
     /* success - we can delete the intermediate states, and link top->base */
+    /* TODO Check graph modification op blockers (BLK_PERM_GRAPH_MOD) once
+     * we've figured out how they should work. */
     backing_file_str = backing_file_str ? backing_file_str : base->filename;
 
     QLIST_FOREACH_SAFE(c, &top->parents, next_parent, next) {
diff --git a/block/commit.c b/block/commit.c
index XXXXXXX..XXXXXXX 100644
--- a/block/commit.c
+++ b/block/commit.c
@@ -XXX,XX +XXX,XX @@ enum {
 typedef struct CommitBlockJob {
     BlockJob common;
     RateLimit limit;
-    BlockDriverState *active;
     BlockDriverState *commit_top_bs;
     BlockBackend *top;
     BlockBackend *base;
     BlockdevOnError on_error;
     int base_flags;
-    int orig_overlay_flags;
     char *backing_file_str;
 } CommitBlockJob;
 
@@ -XXX,XX +XXX,XX @@ static void commit_complete(BlockJob *job, void *opaque)
 {
     CommitBlockJob *s = container_of(job, CommitBlockJob, common);
     CommitCompleteData *data = opaque;
-    BlockDriverState *active = s->active;
     BlockDriverState *top = blk_bs(s->top);
     BlockDriverState *base = blk_bs(s->base);
-    BlockDriverState *overlay_bs = bdrv_find_overlay(active, s->commit_top_bs);
+    BlockDriverState *commit_top_bs = s->commit_top_bs;
     int ret = data->ret;
     bool remove_commit_top_bs = false;
 
-    /* Make sure overlay_bs and top stay around until bdrv_set_backing_hd() */
+    /* Make sure commit_top_bs and top stay around until bdrv_replace_node() */
     bdrv_ref(top);
-    if (overlay_bs) {
-        bdrv_ref(overlay_bs);
-    }
+    bdrv_ref(commit_top_bs);
 
     /* Remove base node parent that still uses BLK_PERM_WRITE/RESIZE before
      * the normal backing chain can be restored. */
@@ -XXX,XX +XXX,XX @@ static void commit_complete(BlockJob *job, void *opaque)
 
     if (!block_job_is_cancelled(&s->common) && ret == 0) {
         /* success */
-        ret = bdrv_drop_intermediate(active, s->commit_top_bs, base,
+        ret = bdrv_drop_intermediate(s->commit_top_bs, base,
                                      s->backing_file_str);
-    } else if (overlay_bs) {
+    } else {
         /* XXX Can (or should) we somehow keep 'consistent read' blocked even
          * after the failed/cancelled commit job is gone? If we already wrote
          * something to base, the intermediate images aren't valid any more. */
@@ -XXX,XX +XXX,XX @@ static void commit_complete(BlockJob *job, void *opaque)
     if (s->base_flags != bdrv_get_flags(base)) {
         bdrv_reopen(base, s->base_flags, NULL);
     }
-    if (overlay_bs && s->orig_overlay_flags != bdrv_get_flags(overlay_bs)) {
-        bdrv_reopen(overlay_bs, s->orig_overlay_flags, NULL);
-    }
     g_free(s->backing_file_str);
     blk_unref(s->top);
 
@@ -XXX,XX +XXX,XX @@ static void commit_complete(BlockJob *job, void *opaque)
      * filter driver from the backing chain. Do this as the final step so that
      * the 'consistent read' permission can be granted.  */
     if (remove_commit_top_bs) {
-        bdrv_set_backing_hd(overlay_bs, top, &error_abort);
+        bdrv_child_try_set_perm(commit_top_bs->backing, 0, BLK_PERM_ALL,
+                                &error_abort);
+        bdrv_replace_node(commit_top_bs, backing_bs(commit_top_bs),
+                          &error_abort);
     }
 
-    bdrv_unref(overlay_bs);
+    bdrv_unref(commit_top_bs);
     bdrv_unref(top);
 }
 
@@ -XXX,XX +XXX,XX @@ void commit_start(const char *job_id, BlockDriverState *bs,
 {
     CommitBlockJob *s;
     BlockReopenQueue *reopen_queue = NULL;
-    int orig_overlay_flags;
     int orig_base_flags;
     BlockDriverState *iter;
-    BlockDriverState *overlay_bs;
     BlockDriverState *commit_top_bs = NULL;
     Error *local_err = NULL;
     int ret;
@@ -XXX,XX +XXX,XX @@ void commit_start(const char *job_id, BlockDriverState *bs,
         return;
     }
 
-    overlay_bs = bdrv_find_overlay(bs, top);
-
-    if (overlay_bs == NULL) {
-        error_setg(errp, "Could not find overlay image for %s:", top->filename);
-        return;
-    }
-
     s = block_job_create(job_id, &commit_job_driver, bs, 0, BLK_PERM_ALL,
                          speed, BLOCK_JOB_DEFAULT, NULL, NULL, errp);
     if (!s) {
         return;
     }
 
-    orig_base_flags    = bdrv_get_flags(base);
-    orig_overlay_flags = bdrv_get_flags(overlay_bs);
-
-    /* convert base & overlay_bs to r/w, if necessary */
+    /* convert base to r/w, if necessary */
+    orig_base_flags = bdrv_get_flags(base);
     if (!(orig_base_flags & BDRV_O_RDWR)) {
         reopen_queue = bdrv_reopen_queue(reopen_queue, base, NULL,
                                          orig_base_flags | BDRV_O_RDWR);
     }
-    if (!(orig_overlay_flags & BDRV_O_RDWR)) {
-        reopen_queue = bdrv_reopen_queue(reopen_queue, overlay_bs, NULL,
-                                         orig_overlay_flags | BDRV_O_RDWR);
-    }
+
     if (reopen_queue) {
         bdrv_reopen_multiple(bdrv_get_aio_context(bs), reopen_queue, &local_err);
         if (local_err != NULL) {
@@ -XXX,XX +XXX,XX @@ void commit_start(const char *job_id, BlockDriverState *bs,
         goto fail;
     }
 
-    /* overlay_bs must be blocked because it needs to be modified to
-     * update the backing image string. */
-    ret = block_job_add_bdrv(&s->common, "overlay of top", overlay_bs,
-                             BLK_PERM_GRAPH_MOD, BLK_PERM_ALL, errp);
-    if (ret < 0) {
-        goto fail;
-    }
-
     s->base = blk_new(BLK_PERM_CONSISTENT_READ
                       | BLK_PERM_WRITE
                       | BLK_PERM_RESIZE,
@@ -XXX,XX +XXX,XX @@ void commit_start(const char *job_id, BlockDriverState *bs,
         goto fail;
     }
 
-    s->active = bs;
-
-    s->base_flags          = orig_base_flags;
-    s->orig_overlay_flags  = orig_overlay_flags;
-
+    s->base_flags = orig_base_flags;
     s->backing_file_str = g_strdup(backing_file_str);
-
     s->on_error = on_error;
 
     trace_commit_start(bs, base, top, s);
@@ -XXX,XX +XXX,XX @@ fail:
         blk_unref(s->top);
     }
     if (commit_top_bs) {
-        bdrv_set_backing_hd(overlay_bs, top, &error_abort);
+        bdrv_replace_node(commit_top_bs, top, &error_abort);
     }
     block_job_early_fail(&s->common);
 }
diff --git a/tests/qemu-iotests/030 b/tests/qemu-iotests/030
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/030
+++ b/tests/qemu-iotests/030
@@ -XXX,XX +XXX,XX @@ class TestParallelOps(iotests.QMPTestCase):
         result = self.vm.qmp('block-stream', device='node6', base=self.imgs[4], job_id='stream-node6-v2')
         self.assert_qmp(result, 'error/class', 'GenericError')
 
-        # This fails because block-commit needs to block node6, the overlay of the 'top' image
-        result = self.vm.qmp('block-stream', device='node7', base=self.imgs[5], job_id='stream-node6-v3')
-        self.assert_qmp(result, 'error/class', 'GenericError')
-
         # This fails because block-commit currently blocks the active layer even if it's not used
         result = self.vm.qmp('block-stream', device='drive0', base=self.imgs[5], job_id='stream-drive0')
         self.assert_qmp(result, 'error/class', 'GenericError')
-- 
2.13.6

From: Eric Blake <eblake@redhat.com>

Make it easier to enable copy-on-read during iotests, by
exposing a new bool option to main and open.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 qemu-io.c | 15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/qemu-io.c b/qemu-io.c
index XXXXXXX..XXXXXXX 100644
--- a/qemu-io.c
+++ b/qemu-io.c
@@ -XXX,XX +XXX,XX @@ static void open_help(void)
 " Opens a file for subsequent use by all of the other qemu-io commands.\n"
 " -r, -- open file read-only\n"
 " -s, -- use snapshot file\n"
+" -C, -- use copy-on-read\n"
 " -n, -- disable host cache, short for -t none\n"
 " -U, -- force shared permissions\n"
 " -k, -- use kernel AIO implementation (on Linux only)\n"
@@ -XXX,XX +XXX,XX @@ static const cmdinfo_t open_cmd = {
     .argmin     = 1,
     .argmax     = -1,
     .flags      = CMD_NOFILE_OK,
-    .args       = "[-rsnkU] [-t cache] [-d discard] [-o options] [path]",
+    .args       = "[-rsCnkU] [-t cache] [-d discard] [-o options] [path]",
     .oneline    = "open the file specified by path",
     .help       = open_help,
 };
@@ -XXX,XX +XXX,XX @@ static int open_f(BlockBackend *blk, int argc, char **argv)
     QDict *opts;
     bool force_share = false;
 
-    while ((c = getopt(argc, argv, "snro:kt:d:U")) != -1) {
+    while ((c = getopt(argc, argv, "snCro:kt:d:U")) != -1) {
         switch (c) {
         case 's':
             flags |= BDRV_O_SNAPSHOT;
@@ -XXX,XX +XXX,XX @@ static int open_f(BlockBackend *blk, int argc, char **argv)
             flags |= BDRV_O_NOCACHE;
             writethrough = false;
             break;
+        case 'C':
+            flags |= BDRV_O_COPY_ON_READ;
+            break;
         case 'r':
             readonly = 1;
             break;
@@ -XXX,XX +XXX,XX @@ static void usage(const char *name)
 "  -r, --read-only      export read-only\n"
 "  -s, --snapshot       use snapshot file\n"
 "  -n, --nocache        disable host cache, short for -t none\n"
+"  -C, --copy-on-read   enable copy-on-read\n"
 "  -m, --misalign       misalign allocations for O_DIRECT\n"
 "  -k, --native-aio     use kernel AIO implementation (on Linux only)\n"
 "  -t, --cache=MODE     use the given cache mode for the image\n"
@@ -XXX,XX +XXX,XX @@ static QemuOptsList file_opts = {
 int main(int argc, char **argv)
 {
     int readonly = 0;
-    const char *sopt = "hVc:d:f:rsnmkt:T:U";
+    const char *sopt = "hVc:d:f:rsnCmkt:T:U";
     const struct option lopt[] = {
         { "help", no_argument, NULL, 'h' },
         { "version", no_argument, NULL, 'V' },
@@ -XXX,XX +XXX,XX @@ int main(int argc, char **argv)
         { "read-only", no_argument, NULL, 'r' },
         { "snapshot", no_argument, NULL, 's' },
         { "nocache", no_argument, NULL, 'n' },
+        { "copy-on-read", no_argument, NULL, 'C' },
         { "misalign", no_argument, NULL, 'm' },
         { "native-aio", no_argument, NULL, 'k' },
         { "discard", required_argument, NULL, 'd' },
@@ -XXX,XX +XXX,XX @@ int main(int argc, char **argv)
             flags |= BDRV_O_NOCACHE;
             writethrough = false;
             break;
+        case 'C':
+            flags |= BDRV_O_COPY_ON_READ;
+            break;
         case 'd':
             if (bdrv_parse_discard_flags(optarg, &flags) < 0) {
                 error_report("Invalid discard option: %s", optarg);
-- 
2.13.6

From: Eric Blake <eblake@redhat.com>

Handle a 0-length block status request up front, with a uniform
return value claiming the area is not allocated.

Most callers don't pass a length of 0 to bdrv_get_block_status()
and friends; but it definitely happens with a 0-length read when
copy-on-read is enabled.  While we could audit all callers to
ensure that they never make a 0-length request, and then assert
that fact, it was just as easy to fix things to always report
success (as long as the callers are careful to not go into an
infinite loop).  However, we had inconsistent behavior on whether
the status is reported as allocated or defers to the backing
layer, depending on what callbacks the driver implements, and
possibly wasting quite a few CPU cycles to get to that answer.
Consistently reporting unallocated up front doesn't really hurt
anything, and makes it easier both for callers (0-length requests
now have well-defined behavior) and for drivers (drivers don't
have to deal with 0-length requests).

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block/io.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/block/io.c b/block/io.c
index XXXXXXX..XXXXXXX 100644
--- a/block/io.c
+++ b/block/io.c
@@ -XXX,XX +XXX,XX @@ static int64_t coroutine_fn bdrv_co_get_block_status(BlockDriverState *bs,
         *pnum = 0;
         return BDRV_BLOCK_EOF;
     }
+    if (!nb_sectors) {
+        *pnum = 0;
+        return 0;
+    }
 
     n = total_sectors - sector_num;
     if (n < nb_sectors) {
-- 
2.13.6

From: Eric Blake <eblake@redhat.com>

Executing qemu with a terminal as stdin will temporarily alter stty
settings on that terminal (for example, disabling echo), because of
how we run both the monitor and any multiplexing with guest input.
Normally, qemu restores the original settings on exit; but if an
iotest triggers qemu to abort in the middle, we can be left with
the altered terminal setup.  This can make life very annoying when
debugging an iotest failure (not everyone remembers the trick of
blind-typing 'stty sane' without echo, and some people prefer
terminal settings that are slightly different than the defaults
picked by 'stty sane').

It is possible to avoid qemu corrupting the terminal by not passing
a terminal to qemu's stdin in the first place (as in, use
'./check ... </dev/null'), but that's extra typing to have to
remember.  But running 'exec </dev/null' in the harness seems like
it might be too heavy of a hammer.  So I instead went the the
solution of saving and restoring the stty settings, only when the
harness detects that it is run interactively.

I tested this patch by forcing an allocation failure (I can't
guarantee that this particular limit will work on all setups, but
it shows the idea):
 $ (ulimit -S -v 500000; ./check -qcow2 1)

Signed-off-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 tests/qemu-iotests/check | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/tests/qemu-iotests/check b/tests/qemu-iotests/check
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/check
+++ b/tests/qemu-iotests/check
@@ -XXX,XX +XXX,XX @@ export VALGRIND_QEMU=
 export IMGKEYSECRET=
 export IMGOPTSSYNTAX=false
 
+# Save current tty settings, since an aborting qemu call may leave things
+# screwed up
+STTY_RESTORE=
+if test -t 0; then
+    STTY_RESTORE=$(stty -g)
+fi
+
 for r
 do
 
@@ -XXX,XX +XXX,XX @@ END        { if (NR > 0) {
         needwrap=false
     fi
 
+    if test -n "$STTY_RESTORE"; then
+        stty $STTY_RESTORE
+    fi
     rm -f "${TEST_DIR}"/*.out "${TEST_DIR}"/*.err "${TEST_DIR}"/*.time
     rm -f "${TEST_DIR}"/check.pid "${TEST_DIR}"/check.sts
     rm -f $tmp.*
-- 
2.13.6

From: Eric Blake <eblake@redhat.com>

Make it possible to inject errors on writes performed during a
read operation due to copy-on-read semantics.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 qapi/block-core.json | 5 ++++-
 block/io.c           | 1 +
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/qapi/block-core.json b/qapi/block-core.json
index XXXXXXX..XXXXXXX 100644
--- a/qapi/block-core.json
+++ b/qapi/block-core.json
@@ -XXX,XX +XXX,XX @@
 #
 # @l1_shrink_free_l2_clusters: discard the l2 tables. (since 2.11)
 #
+# @cor_write: a write due to copy-on-read (since 2.11)
+#
 # Since: 2.9
 ##
 { 'enum': 'BlkdebugEvent', 'prefix': 'BLKDBG',
@@ -XXX,XX +XXX,XX @@
             'flush_to_disk', 'pwritev_rmw_head', 'pwritev_rmw_after_head',
             'pwritev_rmw_tail', 'pwritev_rmw_after_tail', 'pwritev',
             'pwritev_zero', 'pwritev_done', 'empty_image_prepare',
-            'l1_shrink_write_table', 'l1_shrink_free_l2_clusters' ] }
+            'l1_shrink_write_table', 'l1_shrink_free_l2_clusters',
+            'cor_write'] }
 
 ##
 # @BlkdebugInjectErrorOptions:
diff --git a/block/io.c b/block/io.c
index XXXXXXX..XXXXXXX 100644
--- a/block/io.c
+++ b/block/io.c
@@ -XXX,XX +XXX,XX @@ static int coroutine_fn bdrv_co_do_copy_on_readv(BdrvChild *child,
         goto err;
     }
 
+    bdrv_debug_event(bs, BLKDBG_COR_WRITE);
     if (drv->bdrv_co_pwrite_zeroes &&
         buffer_is_zero(bounce_buffer, iov.iov_len)) {
         /* FIXME: Should we (perhaps conditionally) be setting
-- 
2.13.6

From: Eric Blake <eblake@redhat.com>

Improve our braindead copy-on-read implementation.  Pre-patch,
we have multiple issues:
- we create a bounce buffer and perform a write for the entire
request, even if the active image already has 99% of the
clusters occupied, and really only needs to copy-on-read the
remaining 1% of the clusters
- our bounce buffer was as large as the read request, and can
needlessly exhaust our memory by using double the memory of
the request size (the original request plus our bounce buffer),
rather than a capped maximum overhead beyond the original
- if a driver has a max_transfer limit, we are bypassing the
normal code in bdrv_aligned_preadv() that fragments to that
limit, and instead attempt to read the entire buffer from the
driver in one go, which some drivers may assert on
- a client can request a large request of nearly 2G such that
rounding the request out to cluster boundaries results in a
byte count larger than 2G.  While this cannot exceed 32 bits,
it DOES have some follow-on problems:
-- the call to bdrv_driver_pread() can assert for exceeding
BDRV_REQUEST_MAX_BYTES, if the driver is old and lacks
.bdrv_co_preadv
-- if the buffer is all zeroes, the subsequent call to
bdrv_co_do_pwrite_zeroes is a no-op due to a negative size,
which means we did not actually copy on read

Fix all of these issues by breaking up the action into a loop,
where each iteration is capped to sane limits.  Also, querying
the allocation status allows us to optimize: when data is
already present in the active layer, we don't need to bounce.

Note that the code has a telling comment that copy-on-read
should probably be a filter driver rather than a bolt-on hack
in io.c; but that remains a task for another day.

CC: qemu-stable@nongnu.org
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block/io.c | 120 +++++++++++++++++++++++++++++++++++++++++--------------------
 1 file changed, 82 insertions(+), 38 deletions(-)

diff --git a/block/io.c b/block/io.c
index XXXXXXX..XXXXXXX 100644
--- a/block/io.c
+++ b/block/io.c
@@ -XXX,XX +XXX,XX @@
 
 #define NOT_DONE 0x7fffffff /* used while emulated sync operation in progress */
 
+/* Maximum bounce buffer for copy-on-read and write zeroes, in bytes */
+#define MAX_BOUNCE_BUFFER (32768 << BDRV_SECTOR_BITS)
+
 static int coroutine_fn bdrv_co_do_pwrite_zeroes(BlockDriverState *bs,
     int64_t offset, int bytes, BdrvRequestFlags flags);
 
@@ -XXX,XX +XXX,XX @@ static int coroutine_fn bdrv_co_do_copy_on_readv(BdrvChild *child,
 
     BlockDriver *drv = bs->drv;
     struct iovec iov;
-    QEMUIOVector bounce_qiov;
+    QEMUIOVector local_qiov;
     int64_t cluster_offset;
     unsigned int cluster_bytes;
     size_t skip_bytes;
     int ret;
+    int max_transfer = MIN_NON_ZERO(bs->bl.max_transfer,
+                                    BDRV_REQUEST_MAX_BYTES);
+    unsigned int progress = 0;
 
     /* FIXME We cannot require callers to have write permissions when all they
      * are doing is a read request. If we did things right, write permissions
@@ -XXX,XX +XXX,XX @@ static int coroutine_fn bdrv_co_do_copy_on_readv(BdrvChild *child,
     // assert(child->perm & (BLK_PERM_WRITE_UNCHANGED | BLK_PERM_WRITE));
 
     /* Cover entire cluster so no additional backing file I/O is required when
-     * allocating cluster in the image file.
+     * allocating cluster in the image file.  Note that this value may exceed
+     * BDRV_REQUEST_MAX_BYTES (even when the original read did not), which
+     * is one reason we loop rather than doing it all at once.
      */
     bdrv_round_to_clusters(bs, offset, bytes, &cluster_offset, &cluster_bytes);
+    skip_bytes = offset - cluster_offset;
 
     trace_bdrv_co_do_copy_on_readv(bs, offset, bytes,
                                    cluster_offset, cluster_bytes);
 
-    iov.iov_len = cluster_bytes;
-    iov.iov_base = bounce_buffer = qemu_try_blockalign(bs, iov.iov_len);
+    bounce_buffer = qemu_try_blockalign(bs,
+                                        MIN(MIN(max_transfer, cluster_bytes),
+                                            MAX_BOUNCE_BUFFER));
     if (bounce_buffer == NULL) {
         ret = -ENOMEM;
         goto err;
     }
 
-    qemu_iovec_init_external(&bounce_qiov, &iov, 1);
+    while (cluster_bytes) {
+        int64_t pnum;
 
-    ret = bdrv_driver_preadv(bs, cluster_offset, cluster_bytes,
-                             &bounce_qiov, 0);
-    if (ret < 0) {
-        goto err;
-    }
+        ret = bdrv_is_allocated(bs, cluster_offset,
+                                MIN(cluster_bytes, max_transfer), &pnum);
+        if (ret < 0) {
+            /* Safe to treat errors in querying allocation as if
+             * unallocated; we'll probably fail again soon on the
+             * read, but at least that will set a decent errno.
+             */
+            pnum = MIN(cluster_bytes, max_transfer);
+        }
 
-    bdrv_debug_event(bs, BLKDBG_COR_WRITE);
-    if (drv->bdrv_co_pwrite_zeroes &&
-        buffer_is_zero(bounce_buffer, iov.iov_len)) {
-        /* FIXME: Should we (perhaps conditionally) be setting
-         * BDRV_REQ_MAY_UNMAP, if it will allow for a sparser copy
-         * that still correctly reads as zero? */
-        ret = bdrv_co_do_pwrite_zeroes(bs, cluster_offset, cluster_bytes, 0);
-    } else {
-        /* This does not change the data on the disk, it is not necessary
-         * to flush even in cache=writethrough mode.
-         */
-        ret = bdrv_driver_pwritev(bs, cluster_offset, cluster_bytes,
-                                  &bounce_qiov, 0);
-    }
+        assert(skip_bytes < pnum);
 
-    if (ret < 0) {
-        /* It might be okay to ignore write errors for guest requests.  If this
-         * is a deliberate copy-on-read then we don't want to ignore the error.
-         * Simply report it in all cases.
-         */
-        goto err;
-    }
+        if (ret <= 0) {
+            /* Must copy-on-read; use the bounce buffer */
+            iov.iov_base = bounce_buffer;
+            iov.iov_len = pnum = MIN(pnum, MAX_BOUNCE_BUFFER);
+            qemu_iovec_init_external(&local_qiov, &iov, 1);
 
-    skip_bytes = offset - cluster_offset;
-    qemu_iovec_from_buf(qiov, 0, bounce_buffer + skip_bytes, bytes);
+            ret = bdrv_driver_preadv(bs, cluster_offset, pnum,
+                                     &local_qiov, 0);
+            if (ret < 0) {
+                goto err;
+            }
+
+            bdrv_debug_event(bs, BLKDBG_COR_WRITE);
+            if (drv->bdrv_co_pwrite_zeroes &&
+                buffer_is_zero(bounce_buffer, pnum)) {
+                /* FIXME: Should we (perhaps conditionally) be setting
+                 * BDRV_REQ_MAY_UNMAP, if it will allow for a sparser copy
+                 * that still correctly reads as zero? */
+                ret = bdrv_co_do_pwrite_zeroes(bs, cluster_offset, pnum, 0);
+            } else {
+                /* This does not change the data on the disk, it is not
+                 * necessary to flush even in cache=writethrough mode.
+                 */
+                ret = bdrv_driver_pwritev(bs, cluster_offset, pnum,
+                                          &local_qiov, 0);
+            }
+
+            if (ret < 0) {
+                /* It might be okay to ignore write errors for guest
+                 * requests.  If this is a deliberate copy-on-read
+                 * then we don't want to ignore the error.  Simply
+                 * report it in all cases.
+                 */
+                goto err;
+            }
+
+            qemu_iovec_from_buf(qiov, progress, bounce_buffer + skip_bytes,
+                                pnum - skip_bytes);
+        } else {
+            /* Read directly into the destination */
+            qemu_iovec_init(&local_qiov, qiov->niov);
+            qemu_iovec_concat(&local_qiov, qiov, progress, pnum - skip_bytes);
+            ret = bdrv_driver_preadv(bs, offset + progress, local_qiov.size,
+                                     &local_qiov, 0);
+            qemu_iovec_destroy(&local_qiov);
+            if (ret < 0) {
+                goto err;
+            }
+        }
+
+        cluster_offset += pnum;
+        cluster_bytes -= pnum;
+        progress += pnum - skip_bytes;
+        skip_bytes = 0;
+    }
+    ret = 0;
 
 err:
     qemu_vfree(bounce_buffer);
@@ -XXX,XX +XXX,XX @@ int coroutine_fn bdrv_co_readv(BdrvChild *child, int64_t sector_num,
     return bdrv_co_do_readv(child, sector_num, nb_sectors, qiov, 0);
 }
 
-/* Maximum buffer for write zeroes fallback, in bytes */
-#define MAX_WRITE_ZEROES_BOUNCE_BUFFER (32768 << BDRV_SECTOR_BITS)
-
 static int coroutine_fn bdrv_co_do_pwrite_zeroes(BlockDriverState *bs,
     int64_t offset, int bytes, BdrvRequestFlags flags)
 {
@@ -XXX,XX +XXX,XX @@ static int coroutine_fn bdrv_co_do_pwrite_zeroes(BlockDriverState *bs,
     int max_write_zeroes = MIN_NON_ZERO(bs->bl.max_pwrite_zeroes, INT_MAX);
     int alignment = MAX(bs->bl.pwrite_zeroes_alignment,
                         bs->bl.request_alignment);
-    int max_transfer = MIN_NON_ZERO(bs->bl.max_transfer,
-                                    MAX_WRITE_ZEROES_BOUNCE_BUFFER);
+    int max_transfer = MIN_NON_ZERO(bs->bl.max_transfer, MAX_BOUNCE_BUFFER);
 
     assert(alignment % bs->bl.request_alignment == 0);
     head = offset % alignment;
-- 
2.13.6

From: Eric Blake <eblake@redhat.com>

Add a test for qcow2 copy-on-read behavior, including exposure
for the just-fixed bugs.

The copy-on-read behavior is always to a qcow2 image, but the
test is careful to allow running with most image protocol/format
combos as the backing file being copied from (luks being the
exception, as it is harder to pass the right secret to all the
right places).  In fact, for './check nbd', this appears to be
the first time we've had a qcow2 image wrapping NBD, requiring
an additional line in _filter_img_create to match the similar
line in _filter_img_info.

Invoking blkdebug to prove we don't write too much took some
effort to get working; and it requires that $TEST_WRAP (based
on $TEST_DIR) not be subject to word splitting.  We may decide
later to have the entire iotests suite use relative rather than
absolute names, to avoid problems inherited by the absolute
name of $PWD or $TEST_DIR, at which point the sanity check in
this commit could be simplified.

This test requires at least 2G of consecutive memory to succeed;
as such, it is prone to spurious failures, particularly on
32-bit machines under load.  This situation is detected and
triggers an early exit to skip the test, rather than a failure.
To manually provoke this setup on a beefier machine, I used:
  $ (ulimit -S -v 1000000; ./check -qcow2 197)

Signed-off-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 tests/qemu-iotests/197           | 109 +++++++++++++++++++++++++++++++++++++++
 tests/qemu-iotests/197.out       |  26 ++++++++++
 tests/qemu-iotests/common.filter |   1 +
 tests/qemu-iotests/group         |   1 +
 4 files changed, 137 insertions(+)
 create mode 100755 tests/qemu-iotests/197
 create mode 100644 tests/qemu-iotests/197.out

diff --git a/tests/qemu-iotests/197 b/tests/qemu-iotests/197
new file mode 100755
index XXXXXXX..XXXXXXX
--- /dev/null
+++ b/tests/qemu-iotests/197
@@ -XXX,XX +XXX,XX @@
+#!/bin/bash
+#
+# Test case for copy-on-read into qcow2
+#
+# Copyright (C) 2017 Red Hat, Inc.
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+
+# creator
+owner=eblake@redhat.com
+
+seq="$(basename $0)"
+echo "QA output created by $seq"
+
+here="$PWD"
+status=1 # failure is the default!
+
+# get standard environment, filters and checks
+. ./common.rc
+. ./common.filter
+
+TEST_WRAP="$TEST_DIR/t.wrap.qcow2"
+BLKDBG_CONF="$TEST_DIR/blkdebug.conf"
+
+# Sanity check: our use of blkdebug fails if $TEST_DIR contains spaces
+# or other problems
+case "$TEST_DIR" in
+    *[^-_a-zA-Z0-9/]*)
+        _notrun "Suspicious TEST_DIR='$TEST_DIR', cowardly refusing to run" ;;
+esac
+
+_cleanup()
+{
+    _cleanup_test_img
+    rm -f "$BLKDBG_CONF"
+}
+trap "_cleanup; exit \$status" 0 1 2 3 15
+
+# Test is supported for any backing file; but we force qcow2 for our wrapper.
+_supported_fmt generic
+_supported_proto generic
+_supported_os Linux
+# LUKS support may be possible, but it complicates things.
+_unsupported_fmt luks
+
+echo
+echo '=== Copy-on-read ==='
+echo
+
+# Prep the images
+_make_test_img 4G
+$QEMU_IO -c "write -P 55 3G 1k" "$TEST_IMG" | _filter_qemu_io
+IMGPROTO=file IMGFMT=qcow2 IMGOPTS= TEST_IMG_FILE="$TEST_WRAP" \
+    _make_test_img -F "$IMGFMT" -b "$TEST_IMG" | _filter_img_create
+$QEMU_IO -f qcow2 -c "write -z -u 1M 64k" "$TEST_WRAP" | _filter_qemu_io
+
+# Ensure that a read of two clusters, but where one is already allocated,
+# does not re-write the allocated cluster
+cat > "$BLKDBG_CONF" <<EOF
+[inject-error]
+event = "cor_write"
+sector = "2048"
+EOF
+$QEMU_IO -c "open -C \
+ -o driver=blkdebug,config=$BLKDBG_CONF,image.driver=qcow2 $TEST_WRAP" \
+ -c "read -P 0 1M 128k" | _filter_qemu_io
+
+# Read the areas we want copied. A zero-length read should still be a
+# no-op.  The next read is under 2G, but aligned so that rounding to
+# clusters copies more than 2G of zeroes. The final read will pick up
+# the non-zero data in the same cluster.  Since a 2G read may exhaust
+# memory on some machines (particularly 32-bit), we skip the test if
+# that fails due to memory pressure.
+$QEMU_IO -f qcow2 -C -c "read 0 0" "$TEST_WRAP" | _filter_qemu_io
+output=$($QEMU_IO -f qcow2 -C -c "read -P 0 1k $((2*1024*1024*1024 - 512))" \
+        "$TEST_WRAP" 2>&1 | _filter_qemu_io)
+case $output in
+    *allocate*)
+        _notrun "Insufficent memory to run test" ;;
+    *) printf '%s\n' "$output" ;;
+esac
+$QEMU_IO -f qcow2 -C -c "read -P 0 $((3*1024*1024*1024 + 1024)) 1k" \
+    "$TEST_WRAP" | _filter_qemu_io
+
+# Copy-on-read is incompatible with read-only
+$QEMU_IO -f qcow2 -C -r "$TEST_WRAP" 2>&1 | _filter_testdir
+
+# Break the backing chain, and show that images are identical, and that
+# we properly copied over explicit zeros.
+$QEMU_IMG rebase -u -b "" -f qcow2 "$TEST_WRAP"
+$QEMU_IO -f qcow2 -c map "$TEST_WRAP"
+_check_test_img
+$QEMU_IMG compare -f $IMGFMT -F qcow2 "$TEST_IMG" "$TEST_WRAP"
+
+# success, all done
+echo '*** done'
+status=0
diff --git a/tests/qemu-iotests/197.out b/tests/qemu-iotests/197.out
new file mode 100644
index XXXXXXX..XXXXXXX
--- /dev/null
+++ b/tests/qemu-iotests/197.out
@@ -XXX,XX +XXX,XX @@
+QA output created by 197
+
+=== Copy-on-read ===
+
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=4294967296
+wrote 1024/1024 bytes at offset 3221225472
+1 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+Formatting 'TEST_DIR/t.wrap.IMGFMT', fmt=IMGFMT size=4294967296 backing_file=TEST_DIR/t.IMGFMT backing_fmt=IMGFMT
+wrote 65536/65536 bytes at offset 1048576
+64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+read 131072/131072 bytes at offset 1048576
+128 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+read 0/0 bytes at offset 0
+0 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+read 2147483136/2147483136 bytes at offset 1024
+2 GiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+read 1024/1024 bytes at offset 3221226496
+1 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+can't open device TEST_DIR/t.wrap.qcow2: Can't use copy-on-read on read-only device
+2 GiB (0x80010000) bytes     allocated at offset 0 bytes (0x0)
+1023.938 MiB (0x3fff0000) bytes not allocated at offset 2 GiB (0x80010000)
+64 KiB (0x10000) bytes     allocated at offset 3 GiB (0xc0000000)
+1023.938 MiB (0x3fff0000) bytes not allocated at offset 3 GiB (0xc0010000)
+No errors were found on the image.
+Images are identical.
+*** done
diff --git a/tests/qemu-iotests/common.filter b/tests/qemu-iotests/common.filter
index XXXXXXX..XXXXXXX 100644
--- a/tests/qemu-iotests/common.filter
+++ b/tests/qemu-iotests/common.filter
@@ -XXX,XX +XXX,XX @@ _filter_img_create()
     sed -e "s#$IMGPROTO:$TEST_DIR#TEST_DIR#g" \
         -e "s#$TEST_DIR#TEST_DIR#g" \
         -e "s#$IMGFMT#IMGFMT#g" \
+        -e 's#nbd:127.0.0.1:10810#TEST_DIR/t.IMGFMT#g' \
         -e "s# encryption=off##g" \
         -e "s# cluster_size=[0-9]\\+##g" \
         -e "s# table_size=[0-9]\\+##g" \
diff --git a/tests/qemu-iotests/group b/tests/qemu-iotests/group
index XXXXXXX..XXXXXXX 100644
--- a/tests/qemu-iotests/group
+++ b/tests/qemu-iotests/group
@@ -XXX,XX +XXX,XX @@
 192 rw auto quick
 194 rw auto migration quick
 195 rw auto quick
+197 rw auto quick
-- 
2.13.6

From: "Daniel P. Berrange" <berrange@redhat.com>

Using 16KB bounce buffers creates a significant performance
penalty for I/O to encrypted volumes on storage which high
I/O latency (rotating rust & network drives), because it
triggers lots of fairly small I/O operations.

On tests with rotating rust, and cache=none|directsync,
write speed increased from 2MiB/s to 32MiB/s, on a par
with that achieved by the in-kernel luks driver. With
other cache modes the in-kernel driver is still notably
faster because it is able to report completion of the
I/O request before any encryption is done, while the
in-QEMU driver must encrypt the data before completion.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 20170927125340.12360-2-berrange@redhat.com
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
---
 block/crypto.c | 28 +++++++++++++++-------------
 1 file changed, 15 insertions(+), 13 deletions(-)

diff --git a/block/crypto.c b/block/crypto.c
index XXXXXXX..XXXXXXX 100644
--- a/block/crypto.c
+++ b/block/crypto.c
@@ -XXX,XX +XXX,XX @@ static void block_crypto_close(BlockDriverState *bs)
 }
 
 
-#define BLOCK_CRYPTO_MAX_SECTORS 32
+/*
+ * 1 MB bounce buffer gives good performance / memory tradeoff
+ * when using cache=none|directsync.
+ */
+#define BLOCK_CRYPTO_MAX_IO_SIZE (1024 * 1024)
 
 static coroutine_fn int
 block_crypto_co_readv(BlockDriverState *bs, int64_t sector_num,
@@ -XXX,XX +XXX,XX @@ block_crypto_co_readv(BlockDriverState *bs, int64_t sector_num,
 
     qemu_iovec_init(&hd_qiov, qiov->niov);
 
-    /* Bounce buffer so we have a linear mem region for
-     * entire sector. XXX optimize so we avoid bounce
-     * buffer in case that qiov->niov == 1
+    /* Bounce buffer because we don't wish to expose cipher text
+     * in qiov which points to guest memory.
      */
     cipher_data =
-        qemu_try_blockalign(bs->file->bs, MIN(BLOCK_CRYPTO_MAX_SECTORS * 512,
+        qemu_try_blockalign(bs->file->bs, MIN(BLOCK_CRYPTO_MAX_IO_SIZE,
                                               qiov->size));
     if (cipher_data == NULL) {
         ret = -ENOMEM;
@@ -XXX,XX +XXX,XX @@ block_crypto_co_readv(BlockDriverState *bs, int64_t sector_num,
     while (remaining_sectors) {
         cur_nr_sectors = remaining_sectors;
 
-        if (cur_nr_sectors > BLOCK_CRYPTO_MAX_SECTORS) {
-            cur_nr_sectors = BLOCK_CRYPTO_MAX_SECTORS;
+        if (cur_nr_sectors > (BLOCK_CRYPTO_MAX_IO_SIZE / 512)) {
+            cur_nr_sectors = (BLOCK_CRYPTO_MAX_IO_SIZE / 512);
         }
 
         qemu_iovec_reset(&hd_qiov);
@@ -XXX,XX +XXX,XX @@ block_crypto_co_writev(BlockDriverState *bs, int64_t sector_num,
 
     qemu_iovec_init(&hd_qiov, qiov->niov);
 
-    /* Bounce buffer so we have a linear mem region for
-     * entire sector. XXX optimize so we avoid bounce
-     * buffer in case that qiov->niov == 1
+    /* Bounce buffer because we're not permitted to touch
+     * contents of qiov - it points to guest memory.
      */
     cipher_data =
-        qemu_try_blockalign(bs->file->bs, MIN(BLOCK_CRYPTO_MAX_SECTORS * 512,
+        qemu_try_blockalign(bs->file->bs, MIN(BLOCK_CRYPTO_MAX_IO_SIZE,
                                               qiov->size));
     if (cipher_data == NULL) {
         ret = -ENOMEM;
@@ -XXX,XX +XXX,XX @@ block_crypto_co_writev(BlockDriverState *bs, int64_t sector_num,
     while (remaining_sectors) {
         cur_nr_sectors = remaining_sectors;
 
-        if (cur_nr_sectors > BLOCK_CRYPTO_MAX_SECTORS) {
-            cur_nr_sectors = BLOCK_CRYPTO_MAX_SECTORS;
+        if (cur_nr_sectors > (BLOCK_CRYPTO_MAX_IO_SIZE / 512)) {
+            cur_nr_sectors = (BLOCK_CRYPTO_MAX_IO_SIZE / 512);
         }
 
         qemu_iovec_to_buf(qiov, bytes_done,
-- 
2.13.6

From: "Daniel P. Berrange" <berrange@redhat.com>

While current encryption schemes all have a fixed sector size of
512 bytes, this is not guaranteed to be the case in future. Expose
the sector size in the APIs so the block layer can remove assumptions
about fixed 512 byte sectors.

Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 20170927125340.12360-3-berrange@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
---
 crypto/blockpriv.h     |  1 +
 include/crypto/block.h | 15 +++++++++++++++
 crypto/block-luks.c    |  6 ++++--
 crypto/block-qcow.c    |  1 +
 crypto/block.c         |  6 ++++++
 5 files changed, 27 insertions(+), 2 deletions(-)

diff --git a/crypto/blockpriv.h b/crypto/blockpriv.h
index XXXXXXX..XXXXXXX 100644
--- a/crypto/blockpriv.h
+++ b/crypto/blockpriv.h
@@ -XXX,XX +XXX,XX @@ struct QCryptoBlock {
     QCryptoHashAlgorithm kdfhash;
     size_t niv;
     uint64_t payload_offset; /* In bytes */
+    uint64_t sector_size; /* In bytes */
 };
 
 struct QCryptoBlockDriver {
diff --git a/include/crypto/block.h b/include/crypto/block.h
index XXXXXXX..XXXXXXX 100644
--- a/include/crypto/block.h
+++ b/include/crypto/block.h
@@ -XXX,XX +XXX,XX @@ QCryptoHashAlgorithm qcrypto_block_get_kdf_hash(QCryptoBlock *block);
 uint64_t qcrypto_block_get_payload_offset(QCryptoBlock *block);
 
 /**
+ * qcrypto_block_get_sector_size:
+ * @block: the block encryption object
+ *
+ * Get the size of sectors used for payload encryption. A new
+ * IV is used at the start of each sector. The encryption
+ * sector size is not required to match the sector size of the
+ * underlying storage. For example LUKS will always use a 512
+ * byte sector size, even if the volume is on a disk with 4k
+ * sectors.
+ *
+ * Returns: the sector in bytes
+ */
+uint64_t qcrypto_block_get_sector_size(QCryptoBlock *block);
+
+/**
  * qcrypto_block_free:
  * @block: the block encryption object
  *
diff --git a/crypto/block-luks.c b/crypto/block-luks.c
index XXXXXXX..XXXXXXX 100644
--- a/crypto/block-luks.c
+++ b/crypto/block-luks.c
@@ -XXX,XX +XXX,XX @@ qcrypto_block_luks_open(QCryptoBlock *block,
         }
     }
 
+    block->sector_size = QCRYPTO_BLOCK_LUKS_SECTOR_SIZE;
     block->payload_offset = luks->header.payload_offset *
-        QCRYPTO_BLOCK_LUKS_SECTOR_SIZE;
+        block->sector_size;
 
     luks->cipher_alg = cipheralg;
     luks->cipher_mode = ciphermode;
@@ -XXX,XX +XXX,XX @@ qcrypto_block_luks_create(QCryptoBlock *block,
                    QCRYPTO_BLOCK_LUKS_SECTOR_SIZE)) *
          QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS);
 
+    block->sector_size = QCRYPTO_BLOCK_LUKS_SECTOR_SIZE;
     block->payload_offset = luks->header.payload_offset *
-        QCRYPTO_BLOCK_LUKS_SECTOR_SIZE;
+        block->sector_size;
 
     /* Reserve header space to match payload offset */
     initfunc(block, block->payload_offset, opaque, &local_err);
diff --git a/crypto/block-qcow.c b/crypto/block-qcow.c
index XXXXXXX..XXXXXXX 100644
--- a/crypto/block-qcow.c
+++ b/crypto/block-qcow.c
@@ -XXX,XX +XXX,XX @@ qcrypto_block_qcow_init(QCryptoBlock *block,
         goto fail;
     }
 
+    block->sector_size = QCRYPTO_BLOCK_QCOW_SECTOR_SIZE;
     block->payload_offset = 0;
 
     return 0;
diff --git a/crypto/block.c b/crypto/block.c
index XXXXXXX..XXXXXXX 100644
--- a/crypto/block.c
+++ b/crypto/block.c
@@ -XXX,XX +XXX,XX @@ uint64_t qcrypto_block_get_payload_offset(QCryptoBlock *block)
 }
 
 
+uint64_t qcrypto_block_get_sector_size(QCryptoBlock *block)
+{
+    return block->sector_size;
+}
+
+
 void qcrypto_block_free(QCryptoBlock *block)
 {
     if (!block) {
-- 
2.13.6

From: "Daniel P. Berrange" <berrange@redhat.com>

The crypto APIs report the offset of the data payload as an uint64_t
type, but the block driver is casting to size_t or ssize_t which will
potentially truncate.

Most of the block APIs use int64_t for offsets meanwhile, so even if
using uint64_t in the crypto block driver we are still at risk of
truncation.

Change the block crypto driver to use uint64_t, but add asserts that
the value is less than INT64_MAX.

diff --git a/block/crypto.c b/block/crypto.c
index XXXXXXX..XXXXXXX 100644
--- a/block/crypto.c
+++ b/block/crypto.c
@@ -XXX,XX +XXX,XX @@ static int block_crypto_truncate(BlockDriverState *bs, int64_t offset,
                                  PreallocMode prealloc, Error **errp)
 {
     BlockCrypto *crypto = bs->opaque;
-    size_t payload_offset =
+    uint64_t payload_offset =
         qcrypto_block_get_payload_offset(crypto->block);
+    assert(payload_offset < (INT64_MAX - offset));
 
     offset += payload_offset;
 
@@ -XXX,XX +XXX,XX @@ block_crypto_co_readv(BlockDriverState *bs, int64_t sector_num,
     uint8_t *cipher_data = NULL;
     QEMUIOVector hd_qiov;
     int ret = 0;
-    size_t payload_offset =
+    uint64_t payload_offset =
         qcrypto_block_get_payload_offset(crypto->block) / 512;
+    assert(payload_offset < (INT64_MAX / 512));
 
     qemu_iovec_init(&hd_qiov, qiov->niov);
 
@@ -XXX,XX +XXX,XX @@ block_crypto_co_writev(BlockDriverState *bs, int64_t sector_num,
     uint8_t *cipher_data = NULL;
     QEMUIOVector hd_qiov;
     int ret = 0;
-    size_t payload_offset =
+    uint64_t payload_offset =
         qcrypto_block_get_payload_offset(crypto->block) / 512;
+    assert(payload_offset < (INT64_MAX / 512));
 
     qemu_iovec_init(&hd_qiov, qiov->niov);
 
@@ -XXX,XX +XXX,XX @@ static int64_t block_crypto_getlength(BlockDriverState *bs)
     BlockCrypto *crypto = bs->opaque;
     int64_t len = bdrv_getlength(bs->file->bs);
 
-    ssize_t offset = qcrypto_block_get_payload_offset(crypto->block);
+    uint64_t offset = qcrypto_block_get_payload_offset(crypto->block);
+    assert(offset < INT64_MAX);
+    assert(offset < len);
 
     len -= offset;
 
-- 
2.13.6

From: "Daniel P. Berrange" <berrange@redhat.com>

Make the crypto driver implement the bdrv_co_preadv|pwritev
callbacks, and also use bdrv_co_preadv|pwritev for I/O
with the protocol driver beneath. This replaces sector based
I/O with byte based I/O, and allows us to stop assuming the
physical sector size matches the encryption sector size.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 20170927125340.12360-5-berrange@redhat.com
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
---
 block/crypto.c | 106 +++++++++++++++++++++++++++++----------------------------
 1 file changed, 54 insertions(+), 52 deletions(-)

diff --git a/block/crypto.c b/block/crypto.c
index XXXXXXX..XXXXXXX 100644
--- a/block/crypto.c
+++ b/block/crypto.c
@@ -XXX,XX +XXX,XX @@ static void block_crypto_close(BlockDriverState *bs)
 #define BLOCK_CRYPTO_MAX_IO_SIZE (1024 * 1024)
 
 static coroutine_fn int
-block_crypto_co_readv(BlockDriverState *bs, int64_t sector_num,
-                      int remaining_sectors, QEMUIOVector *qiov)
+block_crypto_co_preadv(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
+                       QEMUIOVector *qiov, int flags)
 {
     BlockCrypto *crypto = bs->opaque;
-    int cur_nr_sectors; /* number of sectors in current iteration */
+    uint64_t cur_bytes; /* number of bytes in current iteration */
     uint64_t bytes_done = 0;
     uint8_t *cipher_data = NULL;
     QEMUIOVector hd_qiov;
     int ret = 0;
-    uint64_t payload_offset =
-        qcrypto_block_get_payload_offset(crypto->block) / 512;
-    assert(payload_offset < (INT64_MAX / 512));
+    uint64_t sector_size = qcrypto_block_get_sector_size(crypto->block);
+    uint64_t payload_offset = qcrypto_block_get_payload_offset(crypto->block);
+    uint64_t sector_num = offset / sector_size;
+
+    assert(!flags);
+    assert(payload_offset < INT64_MAX);
+    assert(QEMU_IS_ALIGNED(offset, sector_size));
+    assert(QEMU_IS_ALIGNED(bytes, sector_size));
 
     qemu_iovec_init(&hd_qiov, qiov->niov);
 
@@ -XXX,XX +XXX,XX @@ block_crypto_co_readv(BlockDriverState *bs, int64_t sector_num,
         goto cleanup;
     }
 
-    while (remaining_sectors) {
-        cur_nr_sectors = remaining_sectors;
-
-        if (cur_nr_sectors > (BLOCK_CRYPTO_MAX_IO_SIZE / 512)) {
-            cur_nr_sectors = (BLOCK_CRYPTO_MAX_IO_SIZE / 512);
-        }
+    while (bytes) {
+        cur_bytes = MIN(bytes, BLOCK_CRYPTO_MAX_IO_SIZE);
 
         qemu_iovec_reset(&hd_qiov);
-        qemu_iovec_add(&hd_qiov, cipher_data, cur_nr_sectors * 512);
+        qemu_iovec_add(&hd_qiov, cipher_data, cur_bytes);
 
-        ret = bdrv_co_readv(bs->file,
-                            payload_offset + sector_num,
-                            cur_nr_sectors, &hd_qiov);
+        ret = bdrv_co_preadv(bs->file, payload_offset + offset + bytes_done,
+                             cur_bytes, &hd_qiov, 0);
         if (ret < 0) {
             goto cleanup;
         }
 
-        if (qcrypto_block_decrypt(crypto->block,
-                                  sector_num,
-                                  cipher_data, cur_nr_sectors * 512,
-                                  NULL) < 0) {
+        if (qcrypto_block_decrypt(crypto->block, sector_num, cipher_data,
+                                  cur_bytes, NULL) < 0) {
             ret = -EIO;
             goto cleanup;
         }
 
-        qemu_iovec_from_buf(qiov, bytes_done,
-                            cipher_data, cur_nr_sectors * 512);
+        qemu_iovec_from_buf(qiov, bytes_done, cipher_data, cur_bytes);
 
-        remaining_sectors -= cur_nr_sectors;
-        sector_num += cur_nr_sectors;
-        bytes_done += cur_nr_sectors * 512;
+        sector_num += cur_bytes / sector_size;
+        bytes -= cur_bytes;
+        bytes_done += cur_bytes;
     }
 
  cleanup:
@@ -XXX,XX +XXX,XX @@ block_crypto_co_readv(BlockDriverState *bs, int64_t sector_num,
 
 
 static coroutine_fn int
-block_crypto_co_writev(BlockDriverState *bs, int64_t sector_num,
-                       int remaining_sectors, QEMUIOVector *qiov)
+block_crypto_co_pwritev(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
+                        QEMUIOVector *qiov, int flags)
 {
     BlockCrypto *crypto = bs->opaque;
-    int cur_nr_sectors; /* number of sectors in current iteration */
+    uint64_t cur_bytes; /* number of bytes in current iteration */
     uint64_t bytes_done = 0;
     uint8_t *cipher_data = NULL;
     QEMUIOVector hd_qiov;
     int ret = 0;
-    uint64_t payload_offset =
-        qcrypto_block_get_payload_offset(crypto->block) / 512;
-    assert(payload_offset < (INT64_MAX / 512));
+    uint64_t sector_size = qcrypto_block_get_sector_size(crypto->block);
+    uint64_t payload_offset = qcrypto_block_get_payload_offset(crypto->block);
+    uint64_t sector_num = offset / sector_size;
+
+    assert(!flags);
+    assert(payload_offset < INT64_MAX);
+    assert(QEMU_IS_ALIGNED(offset, sector_size));
+    assert(QEMU_IS_ALIGNED(bytes, sector_size));
 
     qemu_iovec_init(&hd_qiov, qiov->niov);
 
@@ -XXX,XX +XXX,XX @@ block_crypto_co_writev(BlockDriverState *bs, int64_t sector_num,
         goto cleanup;
     }
 
-    while (remaining_sectors) {
-        cur_nr_sectors = remaining_sectors;
+    while (bytes) {
+        cur_bytes = MIN(bytes, BLOCK_CRYPTO_MAX_IO_SIZE);
 
-        if (cur_nr_sectors > (BLOCK_CRYPTO_MAX_IO_SIZE / 512)) {
-            cur_nr_sectors = (BLOCK_CRYPTO_MAX_IO_SIZE / 512);
-        }
-
-        qemu_iovec_to_buf(qiov, bytes_done,
-                          cipher_data, cur_nr_sectors * 512);
+        qemu_iovec_to_buf(qiov, bytes_done, cipher_data, cur_bytes);
 
-        if (qcrypto_block_encrypt(crypto->block,
-                                  sector_num,
-                                  cipher_data, cur_nr_sectors * 512,
-                                  NULL) < 0) {
+        if (qcrypto_block_encrypt(crypto->block, sector_num, cipher_data,
+                                  cur_bytes, NULL) < 0) {
             ret = -EIO;
             goto cleanup;
         }
 
         qemu_iovec_reset(&hd_qiov);
-        qemu_iovec_add(&hd_qiov, cipher_data, cur_nr_sectors * 512);
+        qemu_iovec_add(&hd_qiov, cipher_data, cur_bytes);
 
-        ret = bdrv_co_writev(bs->file,
-                             payload_offset + sector_num,
-                             cur_nr_sectors, &hd_qiov);
+        ret = bdrv_co_pwritev(bs->file, payload_offset + offset + bytes_done,
+                              cur_bytes, &hd_qiov, 0);
         if (ret < 0) {
             goto cleanup;
         }
 
-        remaining_sectors -= cur_nr_sectors;
-        sector_num += cur_nr_sectors;
-        bytes_done += cur_nr_sectors * 512;
+        sector_num += cur_bytes / sector_size;
+        bytes -= cur_bytes;
+        bytes_done += cur_bytes;
     }
 
  cleanup:
@@ -XXX,XX +XXX,XX @@ block_crypto_co_writev(BlockDriverState *bs, int64_t sector_num,
     return ret;
 }
 
+static void block_crypto_refresh_limits(BlockDriverState *bs, Error **errp)
+{
+    BlockCrypto *crypto = bs->opaque;
+    uint64_t sector_size = qcrypto_block_get_sector_size(crypto->block);
+    bs->bl.request_alignment = sector_size; /* No sub-sector I/O */
+}
+
 
 static int64_t block_crypto_getlength(BlockDriverState *bs)
 {
@@ -XXX,XX +XXX,XX @@ BlockDriver bdrv_crypto_luks = {
     .bdrv_truncate      = block_crypto_truncate,
     .create_opts        = &block_crypto_create_opts_luks,
 
-    .bdrv_co_readv      = block_crypto_co_readv,
-    .bdrv_co_writev     = block_crypto_co_writev,
+    .bdrv_refresh_limits = block_crypto_refresh_limits,
+    .bdrv_co_preadv     = block_crypto_co_preadv,
+    .bdrv_co_pwritev    = block_crypto_co_pwritev,
     .bdrv_getlength     = block_crypto_getlength,
     .bdrv_get_info      = block_crypto_get_info_luks,
     .bdrv_get_specific_info = block_crypto_get_specific_info_luks,
-- 
2.13.6

From: "Daniel P. Berrange" <berrange@redhat.com>

Instead of sector offset, take the bytes offset when encrypting
or decrypting data.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 20170927125340.12360-6-berrange@redhat.com
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
---
 crypto/blockpriv.h     |  4 ++--
 include/crypto/block.h | 14 ++++++++------
 block/crypto.c         | 12 ++++--------
 block/qcow.c           | 11 +++++++----
 block/qcow2-cluster.c  |  8 +++-----
 block/qcow2.c          |  4 ++--
 crypto/block-luks.c    | 12 ++++++++----
 crypto/block-qcow.c    | 12 ++++++++----
 crypto/block.c         | 20 ++++++++++++++------
 9 files changed, 56 insertions(+), 41 deletions(-)

diff --git a/crypto/blockpriv.h b/crypto/blockpriv.h
index XXXXXXX..XXXXXXX 100644
--- a/crypto/blockpriv.h
+++ b/crypto/blockpriv.h
@@ -XXX,XX +XXX,XX @@ int qcrypto_block_decrypt_helper(QCryptoCipher *cipher,
                                  size_t niv,
                                  QCryptoIVGen *ivgen,
                                  int sectorsize,
-                                 uint64_t startsector,
+                                 uint64_t offset,
                                  uint8_t *buf,
                                  size_t len,
                                  Error **errp);
@@ -XXX,XX +XXX,XX @@ int qcrypto_block_encrypt_helper(QCryptoCipher *cipher,
                                  size_t niv,
                                  QCryptoIVGen *ivgen,
                                  int sectorsize,
-                                 uint64_t startsector,
+                                 uint64_t offset,
                                  uint8_t *buf,
                                  size_t len,
                                  Error **errp);
diff --git a/include/crypto/block.h b/include/crypto/block.h
index XXXXXXX..XXXXXXX 100644
--- a/include/crypto/block.h
+++ b/include/crypto/block.h
@@ -XXX,XX +XXX,XX @@ QCryptoBlockInfo *qcrypto_block_get_info(QCryptoBlock *block,
 /**
  * @qcrypto_block_decrypt:
  * @block: the block encryption object
- * @startsector: the sector from which @buf was read
+ * @offset: the position at which @iov was read
  * @buf: the buffer to decrypt
  * @len: the length of @buf in bytes
  * @errp: pointer to a NULL-initialized error object
  *
  * Decrypt @len bytes of cipher text in @buf, writing
- * plain text back into @buf
+ * plain text back into @buf. @len and @offset must be
+ * a multiple of the encryption format sector size.
  *
  * Returns 0 on success, -1 on failure
  */
 int qcrypto_block_decrypt(QCryptoBlock *block,
-                          uint64_t startsector,
+                          uint64_t offset,
                           uint8_t *buf,
                           size_t len,
                           Error **errp);
@@ -XXX,XX +XXX,XX @@ int qcrypto_block_decrypt(QCryptoBlock *block,
 /**
  * @qcrypto_block_encrypt:
  * @block: the block encryption object
- * @startsector: the sector to which @buf will be written
+ * @offset: the position at which @iov will be written
  * @buf: the buffer to decrypt
  * @len: the length of @buf in bytes
  * @errp: pointer to a NULL-initialized error object
  *
  * Encrypt @len bytes of plain text in @buf, writing
- * cipher text back into @buf
+ * cipher text back into @buf. @len and @offset must be
+ * a multiple of the encryption format sector size.
  *
  * Returns 0 on success, -1 on failure
  */
 int qcrypto_block_encrypt(QCryptoBlock *block,
-                          uint64_t startsector,
+                          uint64_t offset,
                           uint8_t *buf,
                           size_t len,
                           Error **errp);
diff --git a/block/crypto.c b/block/crypto.c
index XXXXXXX..XXXXXXX 100644
--- a/block/crypto.c
+++ b/block/crypto.c
@@ -XXX,XX +XXX,XX @@ block_crypto_co_preadv(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
     int ret = 0;
     uint64_t sector_size = qcrypto_block_get_sector_size(crypto->block);
     uint64_t payload_offset = qcrypto_block_get_payload_offset(crypto->block);
-    uint64_t sector_num = offset / sector_size;
 
     assert(!flags);
     assert(payload_offset < INT64_MAX);
@@ -XXX,XX +XXX,XX @@ block_crypto_co_preadv(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
             goto cleanup;
         }
 
-        if (qcrypto_block_decrypt(crypto->block, sector_num, cipher_data,
-                                  cur_bytes, NULL) < 0) {
+        if (qcrypto_block_decrypt(crypto->block, offset + bytes_done,
+                                  cipher_data, cur_bytes, NULL) < 0) {
             ret = -EIO;
             goto cleanup;
         }
 
         qemu_iovec_from_buf(qiov, bytes_done, cipher_data, cur_bytes);
 
-        sector_num += cur_bytes / sector_size;
         bytes -= cur_bytes;
         bytes_done += cur_bytes;
     }
@@ -XXX,XX +XXX,XX @@ block_crypto_co_pwritev(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
     int ret = 0;
     uint64_t sector_size = qcrypto_block_get_sector_size(crypto->block);
     uint64_t payload_offset = qcrypto_block_get_payload_offset(crypto->block);
-    uint64_t sector_num = offset / sector_size;
 
     assert(!flags);
     assert(payload_offset < INT64_MAX);
@@ -XXX,XX +XXX,XX @@ block_crypto_co_pwritev(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
 
         qemu_iovec_to_buf(qiov, bytes_done, cipher_data, cur_bytes);
 
-        if (qcrypto_block_encrypt(crypto->block, sector_num, cipher_data,
-                                  cur_bytes, NULL) < 0) {
+        if (qcrypto_block_encrypt(crypto->block, offset + bytes_done,
+                                  cipher_data, cur_bytes, NULL) < 0) {
             ret = -EIO;
             goto cleanup;
         }
@@ -XXX,XX +XXX,XX @@ block_crypto_co_pwritev(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
             goto cleanup;
         }
 
-        sector_num += cur_bytes / sector_size;
         bytes -= cur_bytes;
         bytes_done += cur_bytes;
     }
diff --git a/block/qcow.c b/block/qcow.c
index XXXXXXX..XXXXXXX 100644
--- a/block/qcow.c
+++ b/block/qcow.c
@@ -XXX,XX +XXX,XX @@ static int get_cluster_offset(BlockDriverState *bs,
                     for(i = 0; i < s->cluster_sectors; i++) {
                         if (i < n_start || i >= n_end) {
                             memset(s->cluster_data, 0x00, 512);
-                            if (qcrypto_block_encrypt(s->crypto, start_sect + i,
+                            if (qcrypto_block_encrypt(s->crypto,
+                                                      (start_sect + i) *
+                                                      BDRV_SECTOR_SIZE,
                                                       s->cluster_data,
                                                       BDRV_SECTOR_SIZE,
                                                       NULL) < 0) {
@@ -XXX,XX +XXX,XX @@ static coroutine_fn int qcow_co_readv(BlockDriverState *bs, int64_t sector_num,
             }
             if (bs->encrypted) {
                 assert(s->crypto);
-                if (qcrypto_block_decrypt(s->crypto, sector_num, buf,
+                if (qcrypto_block_decrypt(s->crypto,
+                                          sector_num * BDRV_SECTOR_SIZE, buf,
                                           n * BDRV_SECTOR_SIZE, NULL) < 0) {
                     ret = -EIO;
                     break;
@@ -XXX,XX +XXX,XX @@ static coroutine_fn int qcow_co_writev(BlockDriverState *bs, int64_t sector_num,
         }
         if (bs->encrypted) {
             assert(s->crypto);
-            if (qcrypto_block_encrypt(s->crypto, sector_num, buf,
-                                      n * BDRV_SECTOR_SIZE, NULL) < 0) {
+            if (qcrypto_block_encrypt(s->crypto, sector_num * BDRV_SECTOR_SIZE,
+                                      buf, n * BDRV_SECTOR_SIZE, NULL) < 0) {
                 ret = -EIO;
                 break;
             }
diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c
index XXXXXXX..XXXXXXX 100644
--- a/block/qcow2-cluster.c
+++ b/block/qcow2-cluster.c
@@ -XXX,XX +XXX,XX @@ static bool coroutine_fn do_perform_cow_encrypt(BlockDriverState *bs,
 {
     if (bytes && bs->encrypted) {
         BDRVQcow2State *s = bs->opaque;
-        int64_t sector = (s->crypt_physical_offset ?
+        int64_t offset = (s->crypt_physical_offset ?
                           (cluster_offset + offset_in_cluster) :
-                          (src_cluster_offset + offset_in_cluster))
-                         >> BDRV_SECTOR_BITS;
+                          (src_cluster_offset + offset_in_cluster));
         assert((offset_in_cluster & ~BDRV_SECTOR_MASK) == 0);
         assert((bytes & ~BDRV_SECTOR_MASK) == 0);
         assert(s->crypto);
-        if (qcrypto_block_encrypt(s->crypto, sector, buffer,
-                                  bytes, NULL) < 0) {
+        if (qcrypto_block_encrypt(s->crypto, offset, buffer, bytes, NULL) < 0) {
             return false;
         }
     }
diff --git a/block/qcow2.c b/block/qcow2.c
index XXXXXXX..XXXXXXX 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -XXX,XX +XXX,XX @@ static coroutine_fn int qcow2_co_preadv(BlockDriverState *bs, uint64_t offset,
                 if (qcrypto_block_decrypt(s->crypto,
                                           (s->crypt_physical_offset ?
                                            cluster_offset + offset_in_cluster :
-                                           offset) >> BDRV_SECTOR_BITS,
+                                           offset),
                                           cluster_data,
                                           cur_bytes,
                                           NULL) < 0) {
@@ -XXX,XX +XXX,XX @@ static coroutine_fn int qcow2_co_pwritev(BlockDriverState *bs, uint64_t offset,
             if (qcrypto_block_encrypt(s->crypto,
                                       (s->crypt_physical_offset ?
                                        cluster_offset + offset_in_cluster :
-                                       offset) >> BDRV_SECTOR_BITS,
+                                       offset),
                                       cluster_data,
                                       cur_bytes, NULL) < 0) {
                 ret = -EIO;
diff --git a/crypto/block-luks.c b/crypto/block-luks.c
index XXXXXXX..XXXXXXX 100644
--- a/crypto/block-luks.c
+++ b/crypto/block-luks.c
@@ -XXX,XX +XXX,XX @@ static void qcrypto_block_luks_cleanup(QCryptoBlock *block)
 
 static int
 qcrypto_block_luks_decrypt(QCryptoBlock *block,
-                           uint64_t startsector,
+                           uint64_t offset,
                            uint8_t *buf,
                            size_t len,
                            Error **errp)
 {
+    assert(QEMU_IS_ALIGNED(offset, QCRYPTO_BLOCK_LUKS_SECTOR_SIZE));
+    assert(QEMU_IS_ALIGNED(len, QCRYPTO_BLOCK_LUKS_SECTOR_SIZE));
     return qcrypto_block_decrypt_helper(block->cipher,
                                         block->niv, block->ivgen,
                                         QCRYPTO_BLOCK_LUKS_SECTOR_SIZE,
-                                        startsector, buf, len, errp);
+                                        offset, buf, len, errp);
 }
 
 
 static int
 qcrypto_block_luks_encrypt(QCryptoBlock *block,
-                           uint64_t startsector,
+                           uint64_t offset,
                            uint8_t *buf,
                            size_t len,
                            Error **errp)
 {
+    assert(QEMU_IS_ALIGNED(offset, QCRYPTO_BLOCK_LUKS_SECTOR_SIZE));
+    assert(QEMU_IS_ALIGNED(len, QCRYPTO_BLOCK_LUKS_SECTOR_SIZE));
     return qcrypto_block_encrypt_helper(block->cipher,
                                         block->niv, block->ivgen,
                                         QCRYPTO_BLOCK_LUKS_SECTOR_SIZE,
-                                        startsector, buf, len, errp);
+                                        offset, buf, len, errp);
 }
 
 
diff --git a/crypto/block-qcow.c b/crypto/block-qcow.c
index XXXXXXX..XXXXXXX 100644
--- a/crypto/block-qcow.c
+++ b/crypto/block-qcow.c
@@ -XXX,XX +XXX,XX @@ qcrypto_block_qcow_cleanup(QCryptoBlock *block)
 
 static int
 qcrypto_block_qcow_decrypt(QCryptoBlock *block,
-                           uint64_t startsector,
+                           uint64_t offset,
                            uint8_t *buf,
                            size_t len,
                            Error **errp)
 {
+    assert(QEMU_IS_ALIGNED(offset, QCRYPTO_BLOCK_QCOW_SECTOR_SIZE));
+    assert(QEMU_IS_ALIGNED(len, QCRYPTO_BLOCK_QCOW_SECTOR_SIZE));
     return qcrypto_block_decrypt_helper(block->cipher,
                                         block->niv, block->ivgen,
                                         QCRYPTO_BLOCK_QCOW_SECTOR_SIZE,
-                                        startsector, buf, len, errp);
+                                        offset, buf, len, errp);
 }
 
 
 static int
 qcrypto_block_qcow_encrypt(QCryptoBlock *block,
-                           uint64_t startsector,
+                           uint64_t offset,
                            uint8_t *buf,
                            size_t len,
                            Error **errp)
 {
+    assert(QEMU_IS_ALIGNED(offset, QCRYPTO_BLOCK_QCOW_SECTOR_SIZE));
+    assert(QEMU_IS_ALIGNED(len, QCRYPTO_BLOCK_QCOW_SECTOR_SIZE));
     return qcrypto_block_encrypt_helper(block->cipher,
                                         block->niv, block->ivgen,
                                         QCRYPTO_BLOCK_QCOW_SECTOR_SIZE,
-                                        startsector, buf, len, errp);
+                                        offset, buf, len, errp);
 }
 
 
diff --git a/crypto/block.c b/crypto/block.c
index XXXXXXX..XXXXXXX 100644
--- a/crypto/block.c
+++ b/crypto/block.c
@@ -XXX,XX +XXX,XX @@ QCryptoBlockInfo *qcrypto_block_get_info(QCryptoBlock *block,
 
 
 int qcrypto_block_decrypt(QCryptoBlock *block,
-                          uint64_t startsector,
+                          uint64_t offset,
                           uint8_t *buf,
                           size_t len,
                           Error **errp)
 {
-    return block->driver->decrypt(block, startsector, buf, len, errp);
+    return block->driver->decrypt(block, offset, buf, len, errp);
 }
 
 
 int qcrypto_block_encrypt(QCryptoBlock *block,
-                          uint64_t startsector,
+                          uint64_t offset,
                           uint8_t *buf,
                           size_t len,
                           Error **errp)
 {
-    return block->driver->encrypt(block, startsector, buf, len, errp);
+    return block->driver->encrypt(block, offset, buf, len, errp);
 }
 
 
@@ -XXX,XX +XXX,XX @@ int qcrypto_block_decrypt_helper(QCryptoCipher *cipher,
                                  size_t niv,
                                  QCryptoIVGen *ivgen,
                                  int sectorsize,
-                                 uint64_t startsector,
+                                 uint64_t offset,
                                  uint8_t *buf,
                                  size_t len,
                                  Error **errp)
 {
     uint8_t *iv;
     int ret = -1;
+    uint64_t startsector = offset / sectorsize;
+
+    assert(QEMU_IS_ALIGNED(offset, sectorsize));
+    assert(QEMU_IS_ALIGNED(len, sectorsize));
 
     iv = niv ? g_new0(uint8_t, niv) : NULL;
 
@@ -XXX,XX +XXX,XX @@ int qcrypto_block_encrypt_helper(QCryptoCipher *cipher,
                                  size_t niv,
                                  QCryptoIVGen *ivgen,
                                  int sectorsize,
-                                 uint64_t startsector,
+                                 uint64_t offset,
                                  uint8_t *buf,
                                  size_t len,
                                  Error **errp)
 {
     uint8_t *iv;
     int ret = -1;
+    uint64_t startsector = offset / sectorsize;
+
+    assert(QEMU_IS_ALIGNED(offset, sectorsize));
+    assert(QEMU_IS_ALIGNED(len, sectorsize));
 
     iv = niv ? g_new0(uint8_t, niv) : NULL;
 
-- 
2.13.6

From: "Daniel P. Berrange" <berrange@redhat.com>

The BDRV_REQ_FUA flag can trivially be allowed in the crypt driver
as a passthrough to the underlying block driver.

diff --git a/block/crypto.c b/block/crypto.c
index XXXXXXX..XXXXXXX 100644
--- a/block/crypto.c
+++ b/block/crypto.c
@@ -XXX,XX +XXX,XX @@ static int block_crypto_open_generic(QCryptoBlockFormat format,
         return -EINVAL;
     }
 
+    bs->supported_write_flags = BDRV_REQ_FUA &
+        bs->file->bs->supported_write_flags;
+
     opts = qemu_opts_create(opts_spec, NULL, 0, &error_abort);
     qemu_opts_absorb_qdict(opts, options, &local_err);
     if (local_err) {
@@ -XXX,XX +XXX,XX @@ block_crypto_co_pwritev(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
     uint64_t sector_size = qcrypto_block_get_sector_size(crypto->block);
     uint64_t payload_offset = qcrypto_block_get_payload_offset(crypto->block);
 
-    assert(!flags);
+    assert(!(flags & ~BDRV_REQ_FUA));
     assert(payload_offset < INT64_MAX);
     assert(QEMU_IS_ALIGNED(offset, sector_size));
     assert(QEMU_IS_ALIGNED(bytes, sector_size));
@@ -XXX,XX +XXX,XX @@ block_crypto_co_pwritev(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
         qemu_iovec_add(&hd_qiov, cipher_data, cur_bytes);
 
         ret = bdrv_co_pwritev(bs->file, payload_offset + offset + bytes_done,
-                              cur_bytes, &hd_qiov, 0);
+                              cur_bytes, &hd_qiov, flags);
         if (ret < 0) {
             goto cleanup;
         }
-- 
2.13.6

From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>

Backing may be zero after failed bdrv_attach_child in
bdrv_set_backing_hd, which leads to SIGSEGV.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-id: 20170928120300.58164-1-vsementsov@virtuozzo.com
Reviewed-by: John Snow <jsnow@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
---
 block/mirror.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/block/mirror.c b/block/mirror.c
index XXXXXXX..XXXXXXX 100644
--- a/block/mirror.c
+++ b/block/mirror.c
@@ -XXX,XX +XXX,XX @@ static int coroutine_fn bdrv_mirror_top_pdiscard(BlockDriverState *bs,
 
 static void bdrv_mirror_top_refresh_filename(BlockDriverState *bs, QDict *opts)
 {
+    if (bs->backing == NULL) {
+        /* we can be here after failed bdrv_attach_child in
+         * bdrv_set_backing_hd */
+        return;
+    }
     bdrv_refresh_filename(bs->backing->bs);
     pstrcpy(bs->exact_filename, sizeof(bs->exact_filename),
             bs->backing->bs->filename);
-- 
2.13.6

From: Max Reitz <mreitz@redhat.com>

do_run_qemu() in iotest 195 first applies _filter_imgfmt when printing
qemu's command line and _filter_testdir only afterwards.  Therefore, if
the image format is part of the test directory path, _filter_testdir
will no longer apply and the actual output will differ from the
reference output even in case of success.

For example, TEST_DIR might be "/tmp/test-qcow2", in which case
_filter_imgfmt first transforms this to "/tmp/test-IMGFMT" which is no
longer recognized as the TEST_DIR by _filter_testdir.

Fix this by not applying _filter_imgfmt in do_run_qemu() but in
run_qemu() instead, and only after _filter_testdir.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20170927211334.3988-1-mreitz@redhat.com
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
---
 tests/qemu-iotests/195 | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/tests/qemu-iotests/195 b/tests/qemu-iotests/195
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/195
+++ b/tests/qemu-iotests/195
@@ -XXX,XX +XXX,XX @@ _supported_os Linux
 
 function do_run_qemu()
 {
-    echo Testing: "$@" | _filter_imgfmt
+    echo Testing: "$@"
     $QEMU -nographic -qmp-pretty stdio -serial none "$@"
     echo
 }
 
 function run_qemu()
 {
-    do_run_qemu "$@" 2>&1 | _filter_testdir | _filter_qemu | _filter_qmp \
-                          | _filter_qemu_io | _filter_generated_node_ids
+    do_run_qemu "$@" 2>&1 | _filter_testdir | _filter_imgfmt | _filter_qemu \
+                          | _filter_qmp | _filter_qemu_io \
+                          | _filter_generated_node_ids
 }
 
 size=64M
-- 
2.13.6

From: Pavel Butsykin <pbutsykin@virtuozzo.com>

Signed-off-by: Pavel Butsykin <pbutsykin@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 20170929121613.25997-2-pbutsykin@virtuozzo.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
---
 block/qcow2.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/block/qcow2.c b/block/qcow2.c
index XXXXXXX..XXXXXXX 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -XXX,XX +XXX,XX @@ static int qcow2_truncate(BlockDriverState *bs, int64_t offset,
         if (old_file_size < 0) {
             error_setg_errno(errp, -old_file_size,
                              "Failed to inquire current file length");
-            return ret;
+            return old_file_size;
         }
 
         nb_new_data_clusters = DIV_ROUND_UP(offset - old_length,
@@ -XXX,XX +XXX,XX @@ static int qcow2_truncate(BlockDriverState *bs, int64_t offset,
         if (allocation_start < 0) {
             error_setg_errno(errp, -allocation_start,
                              "Failed to resize refcount structures");
-            return -allocation_start;
+            return allocation_start;
         }
 
         clusters_allocated = qcow2_alloc_clusters_at(bs, allocation_start,
-- 
2.13.6

From: Pavel Butsykin <pbutsykin@virtuozzo.com>

Now after shrinking the image, at the end of the image file, there might be a
tail that probably will never be used. So we can find the last used cluster and
cut the tail.

Signed-off-by: Pavel Butsykin <pbutsykin@virtuozzo.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Message-id: 20170929121613.25997-3-pbutsykin@virtuozzo.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
---
 block/qcow2.h          |  1 +
 block/qcow2-refcount.c | 22 ++++++++++++++++++++++
 block/qcow2.c          | 23 +++++++++++++++++++++++
 3 files changed, 46 insertions(+)

diff --git a/block/qcow2.h b/block/qcow2.h
index XXXXXXX..XXXXXXX 100644
--- a/block/qcow2.h
+++ b/block/qcow2.h
@@ -XXX,XX +XXX,XX @@ int qcow2_change_refcount_order(BlockDriverState *bs, int refcount_order,
                                 BlockDriverAmendStatusCB *status_cb,
                                 void *cb_opaque, Error **errp);
 int qcow2_shrink_reftable(BlockDriverState *bs);
+int64_t qcow2_get_last_cluster(BlockDriverState *bs, int64_t size);
 
 /* qcow2-cluster.c functions */
 int qcow2_grow_l1_table(BlockDriverState *bs, uint64_t min_size,
diff --git a/block/qcow2-refcount.c b/block/qcow2-refcount.c
index XXXXXXX..XXXXXXX 100644
--- a/block/qcow2-refcount.c
+++ b/block/qcow2-refcount.c
@@ -XXX,XX +XXX,XX @@ out:
     g_free(reftable_tmp);
     return ret;
 }
+
+int64_t qcow2_get_last_cluster(BlockDriverState *bs, int64_t size)
+{
+    BDRVQcow2State *s = bs->opaque;
+    int64_t i;
+
+    for (i = size_to_clusters(s, size) - 1; i >= 0; i--) {
+        uint64_t refcount;
+        int ret = qcow2_get_refcount(bs, i, &refcount);
+        if (ret < 0) {
+            fprintf(stderr, "Can't get refcount for cluster %" PRId64 ": %s\n",
+                    i, strerror(-ret));
+            return ret;
+        }
+        if (refcount > 0) {
+            return i;
+        }
+    }
+    qcow2_signal_corruption(bs, true, -1, -1,
+                            "There are no references in the refcount table.");
+    return -EIO;
+}
diff --git a/block/qcow2.c b/block/qcow2.c
index XXXXXXX..XXXXXXX 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -XXX,XX +XXX,XX @@ static int qcow2_truncate(BlockDriverState *bs, int64_t offset,
     new_l1_size = size_to_l1(s, offset);
 
     if (offset < old_length) {
+        int64_t last_cluster, old_file_size;
         if (prealloc != PREALLOC_MODE_OFF) {
             error_setg(errp,
                        "Preallocation can't be used for shrinking an image");
@@ -XXX,XX +XXX,XX @@ static int qcow2_truncate(BlockDriverState *bs, int64_t offset,
                              "Failed to discard unused refblocks");
             return ret;
         }
+
+        old_file_size = bdrv_getlength(bs->file->bs);
+        if (old_file_size < 0) {
+            error_setg_errno(errp, -old_file_size,
+                             "Failed to inquire current file length");
+            return old_file_size;
+        }
+        last_cluster = qcow2_get_last_cluster(bs, old_file_size);
+        if (last_cluster < 0) {
+            error_setg_errno(errp, -last_cluster,
+                             "Failed to find the last cluster");
+            return last_cluster;
+        }
+        if ((last_cluster + 1) * s->cluster_size < old_file_size) {
+            ret = bdrv_truncate(bs->file, (last_cluster + 1) * s->cluster_size,
+                                PREALLOC_MODE_OFF, NULL);
+            if (ret < 0) {
+                warn_report("Failed to truncate the tail of the image: %s",
+                            strerror(-ret));
+                ret = 0;
+            }
+        }
     } else {
         ret = qcow2_grow_l1_table(bs, new_l1_size, true);
         if (ret < 0) {
-- 
2.13.6

The following changes since commit 13356edb87506c148b163b8c7eb0695647d00c2a:

Merge tag 'block-pull-request' of https://gitlab.com/stefanha/qemu into staging (2023-01-24 09:45:33 +0000)

are available in the Git repository at:

https://repo.or.cz/qemu/kevin.git tags/for-upstream

for you to fetch changes up to d570177b50c389f379f93183155a27d44856ab46:

qemu-img: Change info key names for protocol nodes (2023-02-01 16:52:33 +0100)

v4:
- Fixed the 'qemu-img-close-errors' test case to run only on Linux and
  only with the file protocol, use qemu-io instead of truncate

v3:
- Make the compiler happier on BSD and CentOS Stream 8

v2:
- Rebased to resolve merge conflicts in coroutine.h

----------------------------------------------------------------
Block layer patches

- qemu-img info: Show protocol-level information
- Move more functions to coroutines
- Make coroutine annotations ready for static analysis
- qemu-img: Fix exit code for errors closing the image
- qcow2 bitmaps: Fix theoretical corruption in error path
- pflash: Only load non-zero parts of backend image to save memory
- Code cleanup and test case improvements

----------------------------------------------------------------
Alberto Faria (2):
      coroutine: annotate coroutine_fn for libclang
      block: Add no_coroutine_fn and coroutine_mixed_fn marker

Emanuele Giuseppe Esposito (14):
      block-coroutine-wrapper: support void functions
      block: Convert bdrv_io_plug() to co_wrapper
      block: Convert bdrv_io_unplug() to co_wrapper
      block: Convert bdrv_is_inserted() to co_wrapper
      block: Rename refresh_total_sectors to bdrv_refresh_total_sectors
      block: Convert bdrv_refresh_total_sectors() to co_wrapper_mixed
      block-backend: use bdrv_getlength instead of blk_getlength
      block: use bdrv_co_refresh_total_sectors when possible
      block: Convert bdrv_get_allocated_file_size() to co_wrapper
      block: Convert bdrv_get_info() to co_wrapper_mixed
      block: Convert bdrv_eject() to co_wrapper
      block: Convert bdrv_lock_medium() to co_wrapper
      block: Convert bdrv_debug_event() to co_wrapper_mixed
      block: Rename bdrv_load/save_vmstate() to bdrv_co_load/save_vmstate()

Hanna Reitz (12):
      block: Improve empty format-specific info dump
      block/file: Add file-specific image info
      block/vmdk: Change extent info type
      block: Split BlockNodeInfo off of ImageInfo
      qemu-img: Use BlockNodeInfo
      block/qapi: Let bdrv_query_image_info() recurse
      block/qapi: Introduce BlockGraphInfo
      block/qapi: Add indentation to bdrv_node_info_dump()
      iotests: Filter child node information
      iotests/106, 214, 308: Read only one size line
      qemu-img: Let info print block graph
      qemu-img: Change info key names for protocol nodes

Kevin Wolf (4):
      qcow2: Fix theoretical corruption in store_bitmap() error path
      qemu-img commit: Report errors while closing the image
      qemu-img bitmap: Report errors while closing the image
      qemu-iotests: Test qemu-img bitmap/commit exit code on error

Paolo Bonzini (2):
      qemu-io: do not reinvent the blk_pwrite_zeroes wheel
      block: remove bdrv_coroutine_enter

Philippe Mathieu-Daudé (1):
      block/nbd: Add missing <qemu/bswap.h> include

Thomas Huth (2):
      tests/qemu-iotests/312: Mark "quorum" as required driver
      tests/qemu-iotests/262: Check for availability of "blkverify" first

Xiang Zheng (1):
      pflash: Only read non-zero parts of backend image