Series comparison

The following changes since commit c4e0780ed1ffd056f205348d387a61b4136a45df:

Merge remote-tracking branch 'remotes/vivier2/tags/linux-user-for-4.0-pull-request' into staging (2019-03-07 18:40:43 +0000)

are available in the Git repository at:

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

for you to fetch changes up to e88153ea9a40009a8ae7648282c0eac1b7f5494f:

qcow2 spec: Describe string header extensions (2019-03-08 12:26:46 +0100)

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

- qcow2: Support for external data files
- qcow2: Default to 4KB for the qcow2 cache entry size
- Apply block driver whitelist for -drive format=help
- Several qemu-iotests improvements

----------------------------------------------------------------
Alberto Garcia (1):
      qcow2: Default to 4KB for the qcow2 cache entry size

Andrey Shinkevich (4):
      iotests: open notrun files in text mode
      block: iterate_format with account of whitelisting
      iotests: ask QEMU for supported formats
      iotests: check whitelisted formats

Kevin Wolf (21):
      qemu-iotests: Test qcow2 preallocation modes
      qcow2: Simplify preallocation code
      qcow2: Extend spec for external data files
      qcow2: Basic definitions for external data files
      qcow2: Pass bs to qcow2_get_cluster_type()
      qcow2: Prepare qcow2_get_cluster_type() for external data file
      qcow2: Prepare count_contiguous_clusters() for external data file
      qcow2: Don't assume 0 is an invalid cluster offset
      qcow2: Return 0/-errno in qcow2_alloc_compressed_cluster_offset()
      qcow2: Prepare qcow2_co_block_status() for data file
      qcow2: External file I/O
      qcow2: Return error for snapshot operation with data file
      qcow2: Support external data file in qemu-img check
      qcow2: Add basic data-file infrastructure
      qcow2: Creating images with external data file
      qcow2: Store data file name in the image
      qcow2: Implement data-file-raw create option
      qemu-iotests: Preallocation with external data file
      qemu-iotests: General tests for qcow2 with external data file
      qemu-iotests: amend with external data file
      qcow2 spec: Describe string header extensions

Philippe Mathieu-Daudé (6):
      tests/multiboot: Improve portability by searching bash in the $PATH
      tests/bios-tables: Improve portability by searching bash in the $PATH
      qemu-iotests: Improve portability by searching bash in the $PATH
      qemu-iotests: Ensure GNU sed is used
      ahci-test: Add dependency to qemu-img tool
      qemu-iotests: Add dependency to qemu-nbd tool

Stefan Hajnoczi (1):
      iotests: use iotests.VM in 238

From: Stefan Hajnoczi <stefanha@redhat.com>

Test 238 does not require the kvm accelerator.  Using the qtest
accelerator allows the test to run in both non-kvm and non-tcg
environments.

iotests.VM implicitly uses the qtest accelerator and is really the class
that this test should be using.  Switch to that instead of
qemu.QEMUMachine.

Suggested-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 tests/qemu-iotests/238 | 7 +------
 1 file changed, 1 insertion(+), 6 deletions(-)

diff --git a/tests/qemu-iotests/238 b/tests/qemu-iotests/238
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/238
+++ b/tests/qemu-iotests/238
@@ -XXX,XX +XXX,XX @@ import os
 import iotests
 from iotests import log
 
-sys.path.append(os.path.join(os.path.dirname(__file__), '..', '..', 'python'))
-
-from qemu import QEMUMachine
-
 if iotests.qemu_default_machine == 's390-ccw-virtio':
     virtio_scsi_device = 'virtio-scsi-ccw'
 else:
     virtio_scsi_device = 'virtio-scsi-pci'
 
-vm = QEMUMachine(iotests.qemu_prog)
-vm.add_args('-machine', 'accel=kvm')
+vm = iotests.VM()
 vm.launch()
 
 log(vm.qmp('blockdev-add', node_name='hd0', driver='null-co'))
-- 
2.20.1

From: Alberto Garcia <berto@igalia.com>

QEMU 2.12 (commit 1221fe6f636754ab5f2c1c87caa77633e9123622) introduced
a new setting called l2-cache-entry-size that allows making entries on
the qcow2 L2 cache smaller than the cluster size.

I have been performing several tests with different cluster and entry
sizes and all of them show that reducing the entry size (aka L2 slice)
consistently improves I/O performance, notably during random I/O (all
tests done with sequential I/O show similar results). This is to be
expected because loading and evicting an L2 slice is more expensive
the larger the slice is.

Here are some numbers on fully populated 40GB qcow2 images. The
rightmost column represents the maximum L2 cache size in both cases.

Cluster size = 64 KB
   |-------------+--------------+--------------+--------------|
   |             | 1MB L2 cache | 3MB L2 cache | 5MB L2 cache |
   |-------------+--------------+--------------+--------------|
   |  4KB slices |    6545 IOPS |   12045 IOPS |   55680 IOPS |
   | 16KB slices |    5177 IOPS |    9798 IOPS |   56278 IOPS |
   | 64KB slices |    2718 IOPS |    5326 IOPS |   57355 IOPS |
   |-------------+--------------+--------------+--------------|

Cluster size = 256 KB
   |--------------+----------------+--------------+-----------------|
   |              | 512KB L2 cache | 1MB L2 cache | 1280KB L2 cache |
   |--------------+----------------+--------------+-----------------|
   |   4KB slices |      8539 IOPS |   21071 IOPS |      55417 IOPS |
   |  64KB slices |      3598 IOPS |    9772 IOPS |      57687 IOPS |
   | 256KB slices |      1415 IOPS |    4120 IOPS |      58001 IOPS |
   |--------------+----------------+--------------+-----------------|

As can be seen in the numbers, the only exception to the rule is when
the cache is large enough to hold all L2 tables. This is also to be
expected because in this case no cache entry is ever evicted so
reducing its size doesn't bring any benefit.

This patch sets the default L2 cache entry size to 4KB except when the
cache is large enough for the whole disk.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 docs/qcow2-cache.txt | 17 +++++++++++------
 block/qcow2.c        | 12 ++++++++++++
 2 files changed, 23 insertions(+), 6 deletions(-)

diff --git a/docs/qcow2-cache.txt b/docs/qcow2-cache.txt
index XXXXXXX..XXXXXXX 100644
--- a/docs/qcow2-cache.txt
+++ b/docs/qcow2-cache.txt
@@ -XXX,XX +XXX,XX @@ refcount cache is as small as possible unless overridden by the user.
 
 Using smaller cache entries
 ---------------------------
-The qcow2 L2 cache stores complete tables by default. This means that
-if QEMU needs an entry from an L2 table then the whole table is read
-from disk and is kept in the cache. If the cache is full then a
-complete table needs to be evicted first.
+The qcow2 L2 cache can store complete tables. This means that if QEMU
+needs an entry from an L2 table then the whole table is read from disk
+and is kept in the cache. If the cache is full then a complete table
+needs to be evicted first.
 
 This can be inefficient with large cluster sizes since it results in
 more disk I/O and wastes more cache memory.
@@ -XXX,XX +XXX,XX @@ it smaller than the cluster size. This can be configured using the
 
    -drive file=hd.qcow2,l2-cache-size=2097152,l2-cache-entry-size=4096
 
+Since QEMU 4.0 the value of l2-cache-entry-size defaults to 4KB (or
+the cluster size if it's smaller).
+
 Some things to take into account:
 
  - The L2 cache entry size has the same restrictions as the cluster
@@ -XXX,XX +XXX,XX @@ Some things to take into account:
 
  - Try different entry sizes to see which one gives faster performance
    in your case. The block size of the host filesystem is generally a
-   good default (usually 4096 bytes in the case of ext4).
+   good default (usually 4096 bytes in the case of ext4, hence the
+   default).
 
  - Only the L2 cache can be configured this way. The refcount cache
    always uses the cluster size as the entry size.
@@ -XXX,XX +XXX,XX @@ Some things to take into account:
    (as explained in the "Choosing the right cache sizes" and "How to
    configure the cache sizes" sections in this document) then none of
    this is necessary and you can omit the "l2-cache-entry-size"
-   parameter altogether.
+   parameter altogether. In this case QEMU makes the entry size
+   equal to the cluster size by default.
 
 
 Reducing the memory usage
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 void read_cache_sizes(BlockDriverState *bs, QemuOpts *opts,
     BDRVQcow2State *s = bs->opaque;
     uint64_t combined_cache_size, l2_cache_max_setting;
     bool l2_cache_size_set, refcount_cache_size_set, combined_cache_size_set;
+    bool l2_cache_entry_size_set;
     int min_refcount_cache = MIN_REFCOUNT_CACHE_SIZE * s->cluster_size;
     uint64_t virtual_disk_size = bs->total_sectors * BDRV_SECTOR_SIZE;
     uint64_t max_l2_cache = virtual_disk_size / (s->cluster_size / 8);
@@ -XXX,XX +XXX,XX @@ static void read_cache_sizes(BlockDriverState *bs, QemuOpts *opts,
     combined_cache_size_set = qemu_opt_get(opts, QCOW2_OPT_CACHE_SIZE);
     l2_cache_size_set = qemu_opt_get(opts, QCOW2_OPT_L2_CACHE_SIZE);
     refcount_cache_size_set = qemu_opt_get(opts, QCOW2_OPT_REFCOUNT_CACHE_SIZE);
+    l2_cache_entry_size_set = qemu_opt_get(opts, QCOW2_OPT_L2_CACHE_ENTRY_SIZE);
 
     combined_cache_size = qemu_opt_get_size(opts, QCOW2_OPT_CACHE_SIZE, 0);
     l2_cache_max_setting = qemu_opt_get_size(opts, QCOW2_OPT_L2_CACHE_SIZE,
@@ -XXX,XX +XXX,XX @@ static void read_cache_sizes(BlockDriverState *bs, QemuOpts *opts,
             }
         }
     }
+
+    /*
+     * If the L2 cache is not enough to cover the whole disk then
+     * default to 4KB entries. Smaller entries reduce the cost of
+     * loads and evictions and increase I/O performance.
+     */
+    if (*l2_cache_size < max_l2_cache && !l2_cache_entry_size_set) {
+        *l2_cache_entry_size = MIN(s->cluster_size, 4096);
+    }
+
     /* l2_cache_size and refcount_cache_size are ensured to have at least
      * their minimum values in qcow2_update_options_prepare() */
 
-- 
2.20.1

From: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>

Replace the binary mode with the default text one when *.notrun
files are opened for skipped tests. That change is made for the
compatibility with Python 3 which returns error otherwise.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 tests/qemu-iotests/iotests.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tests/qemu-iotests/iotests.py b/tests/qemu-iotests/iotests.py
index XXXXXXX..XXXXXXX 100644
--- a/tests/qemu-iotests/iotests.py
+++ b/tests/qemu-iotests/iotests.py
@@ -XXX,XX +XXX,XX @@ def notrun(reason):
     # Each test in qemu-iotests has a number ("seq")
     seq = os.path.basename(sys.argv[0])
 
-    open('%s/%s.notrun' % (output_dir, seq), 'wb').write(reason + '\n')
+    open('%s/%s.notrun' % (output_dir, seq), 'w').write(reason + '\n')
     print('%s not run: %s' % (seq, reason))
     sys.exit(0)
 
-- 
2.20.1

From: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>

bdrv_iterate_format (which is currently only used for printing out the
formats supported by the block layer) doesn't take format whitelisting
into account.

This creates a problem for tests: they enumerate supported formats to
decide which tests to enable, but then discover that QEMU doesn't let
them actually use some of those formats.

To avoid that, exclude formats that are not whitelisted from
enumeration, if whitelisting is in use.  Since we have separate
whitelists for r/w and r/o, take this a parameter to
bdrv_iterate_format, and print two lists of supported formats (r/w and
r/o) in main qemu.

Signed-off-by: Roman Kagan <rkagan@virtuozzo.com>
Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 include/block/block.h |  2 +-
 block.c               | 23 +++++++++++++++++++----
 blockdev.c            |  4 +++-
 qemu-img.c            |  2 +-
 4 files changed, 24 insertions(+), 7 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 @@ void bdrv_next_cleanup(BdrvNextIterator *it);
 BlockDriverState *bdrv_next_monitor_owned(BlockDriverState *bs);
 bool bdrv_is_encrypted(BlockDriverState *bs);
 void bdrv_iterate_format(void (*it)(void *opaque, const char *name),
-                         void *opaque);
+                         void *opaque, bool read_only);
 const char *bdrv_get_node_name(const BlockDriverState *bs);
 const char *bdrv_get_device_name(const BlockDriverState *bs);
 const char *bdrv_get_device_or_node_name(const BlockDriverState *bs);
diff --git a/block.c b/block.c
index XXXXXXX..XXXXXXX 100644
--- a/block.c
+++ b/block.c
@@ -XXX,XX +XXX,XX @@ BlockDriver *bdrv_find_format(const char *format_name)
     return bdrv_do_find_format(format_name);
 }
 
-int bdrv_is_whitelisted(BlockDriver *drv, bool read_only)
+static int bdrv_format_is_whitelisted(const char *format_name, bool read_only)
 {
     static const char *whitelist_rw[] = {
         CONFIG_BDRV_RW_WHITELIST
@@ -XXX,XX +XXX,XX @@ int bdrv_is_whitelisted(BlockDriver *drv, bool read_only)
     }
 
     for (p = whitelist_rw; *p; p++) {
-        if (!strcmp(drv->format_name, *p)) {
+        if (!strcmp(format_name, *p)) {
             return 1;
         }
     }
     if (read_only) {
         for (p = whitelist_ro; *p; p++) {
-            if (!strcmp(drv->format_name, *p)) {
+            if (!strcmp(format_name, *p)) {
                 return 1;
             }
         }
@@ -XXX,XX +XXX,XX @@ int bdrv_is_whitelisted(BlockDriver *drv, bool read_only)
     return 0;
 }
 
+int bdrv_is_whitelisted(BlockDriver *drv, bool read_only)
+{
+    return bdrv_format_is_whitelisted(drv->format_name, read_only);
+}
+
 bool bdrv_uses_whitelist(void)
 {
     return use_bdrv_whitelist;
@@ -XXX,XX +XXX,XX @@ static int qsort_strcmp(const void *a, const void *b)
 }
 
 void bdrv_iterate_format(void (*it)(void *opaque, const char *name),
-                         void *opaque)
+                         void *opaque, bool read_only)
 {
     BlockDriver *drv;
     int count = 0;
@@ -XXX,XX +XXX,XX @@ void bdrv_iterate_format(void (*it)(void *opaque, const char *name),
         if (drv->format_name) {
             bool found = false;
             int i = count;
+
+            if (use_bdrv_whitelist && !bdrv_is_whitelisted(drv, read_only)) {
+                continue;
+            }
+
             while (formats && i && !found) {
                 found = !strcmp(formats[--i], drv->format_name);
             }
@@ -XXX,XX +XXX,XX @@ void bdrv_iterate_format(void (*it)(void *opaque, const char *name),
             bool found = false;
             int j = count;
 
+            if (use_bdrv_whitelist &&
+                !bdrv_format_is_whitelisted(format_name, read_only)) {
+                continue;
+            }
+
             while (formats && j && !found) {
                 found = !strcmp(formats[--j], format_name);
             }
diff --git a/blockdev.c b/blockdev.c
index XXXXXXX..XXXXXXX 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -XXX,XX +XXX,XX @@ static BlockBackend *blockdev_init(const char *file, QDict *bs_opts,
     if ((buf = qemu_opt_get(opts, "format")) != NULL) {
         if (is_help_option(buf)) {
             error_printf("Supported formats:");
-            bdrv_iterate_format(bdrv_format_print, NULL);
+            bdrv_iterate_format(bdrv_format_print, NULL, false);
+            error_printf("\nSupported formats (read-only):");
+            bdrv_iterate_format(bdrv_format_print, NULL, true);
             error_printf("\n");
             goto early_err;
         }
diff --git a/qemu-img.c b/qemu-img.c
index XXXXXXX..XXXXXXX 100644
--- a/qemu-img.c
+++ b/qemu-img.c
@@ -XXX,XX +XXX,XX @@ static void QEMU_NORETURN help(void)
            "  'skip=N' skip N bs-sized blocks at the start of input\n";
 
     printf("%s\nSupported formats:", help_msg);
-    bdrv_iterate_format(format_print, NULL);
+    bdrv_iterate_format(format_print, NULL, false);
     printf("\n\n" QEMU_HELP_BOTTOM "\n");
     exit(EXIT_SUCCESS);
 }
-- 
2.20.1

From: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>

Supported formats listed by 'qemu' may differ from those listed by
'qemu-img' due to whitelists. Some test cases require specific formats
that may be used with qemu. They can be inquired directly by running
'qemu -drive format=help'. The response takes whitelists into account.
The method supported_formats() serves for that. The method decorator
skip_if_unsupported() checks if all requested formats are whitelisted.
If not, the test case will be skipped. That has been implemented in
the 'check' file in the way similar to the 'test notrun' mechanism.

Suggested-by: Roman Kagan <rkagan@virtuozzo.com>
Suggested-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Suggested-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 tests/qemu-iotests/check      | 13 ++++++++++-
 tests/qemu-iotests/iotests.py | 43 +++++++++++++++++++++++++++++++++++
 2 files changed, 55 insertions(+), 1 deletion(-)

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 @@ try=0
 n_bad=0
 bad=""
 notrun=""
+casenotrun=""
 interrupt=true
 
 # by default don't output timestamps
@@ -XXX,XX +XXX,XX @@ END        { if (NR > 0) {
             echo "Not run:$notrun"
             echo "Not run:$notrun" >>check.log
         fi
+        if [ ! -z "$casenotrun" ]
+        then
+            echo "Some cases not run in:$casenotrun"
+            echo "Some cases not run in:$casenotrun" >>check.log
+        fi
         if [ ! -z "$n_bad" -a $n_bad != 0 ]
         then
             echo "Failures:$bad"
@@ -XXX,XX +XXX,XX @@ do
                 printf "        "        # prettier output with timestamps.
         fi
         rm -f core $seq.notrun
+        rm -f $seq.casenotrun
 
         start=$(_wallclock)
         $timestamp && printf %s "        [$(date "+%T")]"
@@ -XXX,XX +XXX,XX @@ do
                 fi
             fi
         fi
-
+        if [ -f $seq.casenotrun ]
+        then
+            cat $seq.casenotrun
+            casenotrun="$casenotrun $seq"
+        fi
     fi
 
     # come here for each test, except when $showme is true
diff --git a/tests/qemu-iotests/iotests.py b/tests/qemu-iotests/iotests.py
index XXXXXXX..XXXXXXX 100644
--- a/tests/qemu-iotests/iotests.py
+++ b/tests/qemu-iotests/iotests.py
@@ -XXX,XX +XXX,XX @@ def notrun(reason):
     print('%s not run: %s' % (seq, reason))
     sys.exit(0)
 
+def case_notrun(reason):
+    '''Skip this test case'''
+    # Each test in qemu-iotests has a number ("seq")
+    seq = os.path.basename(sys.argv[0])
+
+    open('%s/%s.casenotrun' % (output_dir, seq), 'a').write(
+        '    [case not run] ' + reason + '\n')
+
 def verify_image_format(supported_fmts=[], unsupported_fmts=[]):
     assert not (supported_fmts and unsupported_fmts)
 
@@ -XXX,XX +XXX,XX @@ def verify_quorum():
     if not supports_quorum():
         notrun('quorum support missing')
 
+def qemu_pipe(*args):
+    '''Run qemu with an option to print something and exit (e.g. a help option),
+    and return its output'''
+    args = [qemu_prog] + qemu_opts + list(args)
+    subp = subprocess.Popen(args, stdout=subprocess.PIPE,
+                            stderr=subprocess.STDOUT,
+                            universal_newlines=True)
+    exitcode = subp.wait()
+    if exitcode < 0:
+        sys.stderr.write('qemu received signal %i: %s\n' % (-exitcode,
+                         ' '.join(args)))
+    return subp.communicate()[0]
+
+def supported_formats(read_only=False):
+    '''Set 'read_only' to True to check ro-whitelist
+       Otherwise, rw-whitelist is checked'''
+    format_message = qemu_pipe("-drive", "format=help")
+    line = 1 if read_only else 0
+    return format_message.splitlines()[line].split(":")[1].split()
+
+def skip_if_unsupported(required_formats=[], read_only=False):
+    '''Skip Test Decorator
+       Runs the test if all the required formats are whitelisted'''
+    def skip_test_decorator(func):
+        def func_wrapper(*args, **kwargs):
+            usf_list = list(set(required_formats) -
+                            set(supported_formats(read_only)))
+            if usf_list:
+                case_notrun('{}: formats {} are not whitelisted'.format(
+                    args[0], usf_list))
+            else:
+                return func(*args, **kwargs)
+        return func_wrapper
+    return skip_test_decorator
+
 def main(supported_fmts=[], supported_oses=['linux'], supported_cache_modes=[],
          unsupported_fmts=[]):
     '''Run tests'''
-- 
2.20.1

From: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>

Some test cases require specific formats. The method decorator
skip_if_unsupported() checks if requested formats are whitelisted.
The test #139 was selected for a sample output, after running
$ ./check -qcow2 131-140

137 3s ...
138 0s ...
139 2s ...
    [case not run] testBlkDebug (__main__.TestBlockdevDel): formats ['blkdebug'] are not whitelisted
    [case not run] testBlkVerify (__main__.TestBlockdevDel): formats ['blkverify'] are not whitelisted
    [case not run] testQuorum (__main__.TestBlockdevDel): formats ['quorum'] are not whitelisted
140 0s ...
Not run: 131 135 136
Some cases not run in: 139
Passed all 7 tests

Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 tests/qemu-iotests/139 | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/tests/qemu-iotests/139 b/tests/qemu-iotests/139
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/139
+++ b/tests/qemu-iotests/139
@@ -XXX,XX +XXX,XX @@ class TestBlockdevDel(iotests.QMPTestCase):
         # FIXME mirror0 disappears, drive-mirror doesn't take a reference
         #self.delBlockDriverState('mirror0')
 
+    @iotests.skip_if_unsupported(['blkdebug'])
     def testBlkDebug(self):
         self.addBlkDebug('debug0', 'node0')
         # 'node0' is used by the blkdebug node
@@ -XXX,XX +XXX,XX @@ class TestBlockdevDel(iotests.QMPTestCase):
         self.delBlockDriverState('debug0')
         self.checkBlockDriverState('node0', False)
 
+    @iotests.skip_if_unsupported(['blkverify'])
     def testBlkVerify(self):
         self.addBlkVerify('verify0', 'node0', 'node1')
         # We cannot remove the children of a blkverify device
@@ -XXX,XX +XXX,XX @@ class TestBlockdevDel(iotests.QMPTestCase):
         self.checkBlockDriverState('node0', False)
         self.checkBlockDriverState('node1', False)
 
+    @iotests.skip_if_unsupported(['quorum'])
     def testQuorum(self):
         if not iotests.supports_quorum():
             return
-- 
2.20.1

From: Philippe Mathieu-Daudé <philmd@redhat.com>

Bash is not always installed as /bin/bash. In particular on OpenBSD,
the package installs it in /usr/local/bin.
Use the 'env' shebang to search bash in the $PATH.

Patch created mechanically by running:

$ git grep -lE '#! ?/bin/bash' -- tests/qemu-iotests \
    | while read f; do \
      sed -i 's|^#!.\?/bin/bash$|#!/usr/bin/env bash|' $f; \
    done

diff --git a/tests/qemu-iotests/001 b/tests/qemu-iotests/001
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/001
+++ b/tests/qemu-iotests/001
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test simple read/write using plain bdrv_read/bdrv_write
 #
diff --git a/tests/qemu-iotests/002 b/tests/qemu-iotests/002
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/002
+++ b/tests/qemu-iotests/002
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test simple read/write using plain bdrv_pread/bdrv_pwrite
 #
diff --git a/tests/qemu-iotests/003 b/tests/qemu-iotests/003
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/003
+++ b/tests/qemu-iotests/003
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test simple read/write using bdrv_aio_readv/bdrv_aio_writev
 #
diff --git a/tests/qemu-iotests/004 b/tests/qemu-iotests/004
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/004
+++ b/tests/qemu-iotests/004
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Make sure we can't read and write outside of the image size.
 #
diff --git a/tests/qemu-iotests/005 b/tests/qemu-iotests/005
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/005
+++ b/tests/qemu-iotests/005
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Make sure qemu-img can create 5TB images
 #
diff --git a/tests/qemu-iotests/007 b/tests/qemu-iotests/007
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/007
+++ b/tests/qemu-iotests/007
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Check for one possible case of qcow2 refcount corruption.
 #
diff --git a/tests/qemu-iotests/008 b/tests/qemu-iotests/008
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/008
+++ b/tests/qemu-iotests/008
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test simple asynchronous read/write operations.
 #
diff --git a/tests/qemu-iotests/009 b/tests/qemu-iotests/009
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/009
+++ b/tests/qemu-iotests/009
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Nolan I qcow2 corruption - incorrectly reports free clusters
 #
diff --git a/tests/qemu-iotests/010 b/tests/qemu-iotests/010
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/010
+++ b/tests/qemu-iotests/010
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Nolan II qcow2 corruption - wrong used cluster
 #
diff --git a/tests/qemu-iotests/011 b/tests/qemu-iotests/011
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/011
+++ b/tests/qemu-iotests/011
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test for AIO allocation on the same cluster
 #
diff --git a/tests/qemu-iotests/012 b/tests/qemu-iotests/012
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/012
+++ b/tests/qemu-iotests/012
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Make sure we can open read-only images
 #
diff --git a/tests/qemu-iotests/013 b/tests/qemu-iotests/013
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/013
+++ b/tests/qemu-iotests/013
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # qcow2 pattern test, empty and compressed image - 4k cluster patterns
 #
diff --git a/tests/qemu-iotests/014 b/tests/qemu-iotests/014
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/014
+++ b/tests/qemu-iotests/014
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # qcow2 pattern test, complex patterns including compression and snapshots
 # Using patterns for 4k cluster size.
diff --git a/tests/qemu-iotests/015 b/tests/qemu-iotests/015
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/015
+++ b/tests/qemu-iotests/015
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Combined test to grow the refcount table and test snapshots.
 #
diff --git a/tests/qemu-iotests/017 b/tests/qemu-iotests/017
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/017
+++ b/tests/qemu-iotests/017
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Simple backing file reads
 #
diff --git a/tests/qemu-iotests/018 b/tests/qemu-iotests/018
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/018
+++ b/tests/qemu-iotests/018
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Merge backing file into test image when converting the image
 #
diff --git a/tests/qemu-iotests/019 b/tests/qemu-iotests/019
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/019
+++ b/tests/qemu-iotests/019
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # When using a backing file for the output image in qemu-img convert,
 # the backing file clusters must not copied. The data must still be
diff --git a/tests/qemu-iotests/020 b/tests/qemu-iotests/020
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/020
+++ b/tests/qemu-iotests/020
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Commit changes to backing file
 #
diff --git a/tests/qemu-iotests/021 b/tests/qemu-iotests/021
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/021
+++ b/tests/qemu-iotests/021
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test handling of invalid patterns arguments to qemu-io
 #
diff --git a/tests/qemu-iotests/022 b/tests/qemu-iotests/022
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/022
+++ b/tests/qemu-iotests/022
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test bdrv_load/save_vmstate using the usual patterns
 #
diff --git a/tests/qemu-iotests/023 b/tests/qemu-iotests/023
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/023
+++ b/tests/qemu-iotests/023
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # qcow2 pattern test with various cluster sizes
 #
diff --git a/tests/qemu-iotests/024 b/tests/qemu-iotests/024
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/024
+++ b/tests/qemu-iotests/024
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Rebasing COW images
 #
diff --git a/tests/qemu-iotests/025 b/tests/qemu-iotests/025
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/025
+++ b/tests/qemu-iotests/025
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Resizing images
 #
diff --git a/tests/qemu-iotests/026 b/tests/qemu-iotests/026
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/026
+++ b/tests/qemu-iotests/026
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # qcow2 error path testing
 #
diff --git a/tests/qemu-iotests/027 b/tests/qemu-iotests/027
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/027
+++ b/tests/qemu-iotests/027
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test that sub-cluster allocating writes zero the rest of the cluster
 #
diff --git a/tests/qemu-iotests/028 b/tests/qemu-iotests/028
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/028
+++ b/tests/qemu-iotests/028
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test that backing files can be smaller than the image
 #
diff --git a/tests/qemu-iotests/029 b/tests/qemu-iotests/029
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/029
+++ b/tests/qemu-iotests/029
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # qcow2 internal snapshots/VM state tests
 #
diff --git a/tests/qemu-iotests/031 b/tests/qemu-iotests/031
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/031
+++ b/tests/qemu-iotests/031
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test that all qcow2 header extensions survive a header rewrite
 #
diff --git a/tests/qemu-iotests/032 b/tests/qemu-iotests/032
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/032
+++ b/tests/qemu-iotests/032
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test that AIO requests are drained before an image is closed. This used
 # to segfault because the request coroutine kept running even after the
diff --git a/tests/qemu-iotests/033 b/tests/qemu-iotests/033
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/033
+++ b/tests/qemu-iotests/033
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test aligned and misaligned write zeroes operations.
 #
diff --git a/tests/qemu-iotests/034 b/tests/qemu-iotests/034
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/034
+++ b/tests/qemu-iotests/034
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test bdrv_pwrite_zeroes with backing files (see also 154)
 #
diff --git a/tests/qemu-iotests/035 b/tests/qemu-iotests/035
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/035
+++ b/tests/qemu-iotests/035
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Let a few AIO requests run in parallel and have them access different L2
 # tables so that the cache has a chance to get used up.
diff --git a/tests/qemu-iotests/036 b/tests/qemu-iotests/036
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/036
+++ b/tests/qemu-iotests/036
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test qcow2 feature bits
 #
diff --git a/tests/qemu-iotests/037 b/tests/qemu-iotests/037
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/037
+++ b/tests/qemu-iotests/037
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test COW from backing files
 #
diff --git a/tests/qemu-iotests/038 b/tests/qemu-iotests/038
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/038
+++ b/tests/qemu-iotests/038
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test COW from backing files with AIO
 #
diff --git a/tests/qemu-iotests/039 b/tests/qemu-iotests/039
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/039
+++ b/tests/qemu-iotests/039
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test qcow2 lazy refcounts
 #
diff --git a/tests/qemu-iotests/042 b/tests/qemu-iotests/042
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/042
+++ b/tests/qemu-iotests/042
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test qemu-img operation on zero size images
 #
diff --git a/tests/qemu-iotests/043 b/tests/qemu-iotests/043
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/043
+++ b/tests/qemu-iotests/043
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test that qemu-img info --backing-chain detects infinite loops
 #
diff --git a/tests/qemu-iotests/046 b/tests/qemu-iotests/046
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/046
+++ b/tests/qemu-iotests/046
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test concurrent cluster allocations
 #
diff --git a/tests/qemu-iotests/047 b/tests/qemu-iotests/047
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/047
+++ b/tests/qemu-iotests/047
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Regression test for commit b7ab0fea (which was a corruption fix,
 # despite the commit message claiming otherwise)
diff --git a/tests/qemu-iotests/048 b/tests/qemu-iotests/048
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/048
+++ b/tests/qemu-iotests/048
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 ##
 ## qemu-img compare test
 ##
diff --git a/tests/qemu-iotests/049 b/tests/qemu-iotests/049
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/049
+++ b/tests/qemu-iotests/049
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Check qemu-img option parsing
 #
diff --git a/tests/qemu-iotests/050 b/tests/qemu-iotests/050
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/050
+++ b/tests/qemu-iotests/050
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test qemu-img rebase with zero clusters
 #
diff --git a/tests/qemu-iotests/051 b/tests/qemu-iotests/051
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/051
+++ b/tests/qemu-iotests/051
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test command line configuration of block devices and driver-specific options
 #
diff --git a/tests/qemu-iotests/052 b/tests/qemu-iotests/052
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/052
+++ b/tests/qemu-iotests/052
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test bdrv_read/bdrv_write using BDRV_O_SNAPSHOT
 #
diff --git a/tests/qemu-iotests/053 b/tests/qemu-iotests/053
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/053
+++ b/tests/qemu-iotests/053
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test qemu-img convert when image length is not a multiple of cluster size
 #
diff --git a/tests/qemu-iotests/054 b/tests/qemu-iotests/054
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/054
+++ b/tests/qemu-iotests/054
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test huge qcow2 images
 #
diff --git a/tests/qemu-iotests/058 b/tests/qemu-iotests/058
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/058
+++ b/tests/qemu-iotests/058
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test export internal snapshot by qemu-nbd, convert it by qemu-img.
 #
diff --git a/tests/qemu-iotests/059 b/tests/qemu-iotests/059
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/059
+++ b/tests/qemu-iotests/059
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test case for vmdk
 #
diff --git a/tests/qemu-iotests/060 b/tests/qemu-iotests/060
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/060
+++ b/tests/qemu-iotests/060
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test case for image corruption (overlapping data structures) in qcow2
 #
diff --git a/tests/qemu-iotests/061 b/tests/qemu-iotests/061
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/061
+++ b/tests/qemu-iotests/061
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test case for image option amendment in qcow2.
 #
diff --git a/tests/qemu-iotests/062 b/tests/qemu-iotests/062
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/062
+++ b/tests/qemu-iotests/062
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test case for snapshotting images with unallocated zero clusters in
 # qcow2
diff --git a/tests/qemu-iotests/063 b/tests/qemu-iotests/063
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/063
+++ b/tests/qemu-iotests/063
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # test of qemu-img convert -n - convert without creation
 #
diff --git a/tests/qemu-iotests/064 b/tests/qemu-iotests/064
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/064
+++ b/tests/qemu-iotests/064
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test VHDX read/write from a sample image created with Hyper-V
 #
diff --git a/tests/qemu-iotests/066 b/tests/qemu-iotests/066
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/066
+++ b/tests/qemu-iotests/066
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test case for preallocated zero clusters in qcow2
 #
diff --git a/tests/qemu-iotests/067 b/tests/qemu-iotests/067
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/067
+++ b/tests/qemu-iotests/067
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test automatic deletion of BDSes created by -drive/drive_add
 #
diff --git a/tests/qemu-iotests/068 b/tests/qemu-iotests/068
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/068
+++ b/tests/qemu-iotests/068
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test case for loading a saved VM state from a qcow2 image
 #
diff --git a/tests/qemu-iotests/069 b/tests/qemu-iotests/069
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/069
+++ b/tests/qemu-iotests/069
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test case for deleting a backing file
 #
diff --git a/tests/qemu-iotests/070 b/tests/qemu-iotests/070
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/070
+++ b/tests/qemu-iotests/070
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test VHDX log replay from an image with a journal that needs to be
 # replayed
diff --git a/tests/qemu-iotests/071 b/tests/qemu-iotests/071
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/071
+++ b/tests/qemu-iotests/071
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test case for the QMP blkdebug and blkverify interfaces
 #
diff --git a/tests/qemu-iotests/072 b/tests/qemu-iotests/072
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/072
+++ b/tests/qemu-iotests/072
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test case for nested image formats
 #
diff --git a/tests/qemu-iotests/073 b/tests/qemu-iotests/073
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/073
+++ b/tests/qemu-iotests/073
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test count_contiguous_clusters in qcow2
 #
diff --git a/tests/qemu-iotests/074 b/tests/qemu-iotests/074
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/074
+++ b/tests/qemu-iotests/074
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 ##
 ## qemu-img compare test (qcow2 only ones)
 ##
diff --git a/tests/qemu-iotests/075 b/tests/qemu-iotests/075
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/075
+++ b/tests/qemu-iotests/075
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # cloop format input validation tests
 #
diff --git a/tests/qemu-iotests/076 b/tests/qemu-iotests/076
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/076
+++ b/tests/qemu-iotests/076
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # parallels format input validation tests
 #
diff --git a/tests/qemu-iotests/077 b/tests/qemu-iotests/077
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/077
+++ b/tests/qemu-iotests/077
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test concurrent pread/pwrite
 #
diff --git a/tests/qemu-iotests/078 b/tests/qemu-iotests/078
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/078
+++ b/tests/qemu-iotests/078
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # bochs format input validation tests
 #
diff --git a/tests/qemu-iotests/079 b/tests/qemu-iotests/079
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/079
+++ b/tests/qemu-iotests/079
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test qcow2 preallocation with different cluster_sizes
 #
diff --git a/tests/qemu-iotests/080 b/tests/qemu-iotests/080
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/080
+++ b/tests/qemu-iotests/080
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # qcow2 format input validation tests
 #
diff --git a/tests/qemu-iotests/081 b/tests/qemu-iotests/081
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/081
+++ b/tests/qemu-iotests/081
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test Quorum block driver
 #
diff --git a/tests/qemu-iotests/082 b/tests/qemu-iotests/082
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/082
+++ b/tests/qemu-iotests/082
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test qemu-img command line parsing
 #
diff --git a/tests/qemu-iotests/083 b/tests/qemu-iotests/083
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/083
+++ b/tests/qemu-iotests/083
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test NBD client unexpected disconnect
 #
diff --git a/tests/qemu-iotests/084 b/tests/qemu-iotests/084
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/084
+++ b/tests/qemu-iotests/084
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test case for VDI header corruption; image too large, and too many blocks.
 # Also simple test for creating dynamic and static VDI images.
diff --git a/tests/qemu-iotests/085 b/tests/qemu-iotests/085
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/085
+++ b/tests/qemu-iotests/085
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Live snapshot tests
 #
diff --git a/tests/qemu-iotests/086 b/tests/qemu-iotests/086
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/086
+++ b/tests/qemu-iotests/086
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test qemu-img progress output
 #
diff --git a/tests/qemu-iotests/087 b/tests/qemu-iotests/087
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/087
+++ b/tests/qemu-iotests/087
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test unsupported blockdev-add cases
 #
diff --git a/tests/qemu-iotests/088 b/tests/qemu-iotests/088
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/088
+++ b/tests/qemu-iotests/088
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # vpc (VHD) format input validation tests
 #
diff --git a/tests/qemu-iotests/089 b/tests/qemu-iotests/089
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/089
+++ b/tests/qemu-iotests/089
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test case for support of JSON filenames
 #
diff --git a/tests/qemu-iotests/090 b/tests/qemu-iotests/090
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/090
+++ b/tests/qemu-iotests/090
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test for discarding compressed clusters on qcow2 images
 #
diff --git a/tests/qemu-iotests/091 b/tests/qemu-iotests/091
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/091
+++ b/tests/qemu-iotests/091
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Live migration test
 #
diff --git a/tests/qemu-iotests/092 b/tests/qemu-iotests/092
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/092
+++ b/tests/qemu-iotests/092
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # qcow1 format input validation tests
 #
diff --git a/tests/qemu-iotests/094 b/tests/qemu-iotests/094
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/094
+++ b/tests/qemu-iotests/094
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test case for drive-mirror to NBD
 #
diff --git a/tests/qemu-iotests/095 b/tests/qemu-iotests/095
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/095
+++ b/tests/qemu-iotests/095
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test for commit of larger active layer
 #
diff --git a/tests/qemu-iotests/097 b/tests/qemu-iotests/097
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/097
+++ b/tests/qemu-iotests/097
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Commit changes into backing chains and empty the top image if the
 # backing image is not explicitly specified
diff --git a/tests/qemu-iotests/098 b/tests/qemu-iotests/098
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/098
+++ b/tests/qemu-iotests/098
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test qcow2's bdrv_make_empty for images without internal snapshots
 #
diff --git a/tests/qemu-iotests/099 b/tests/qemu-iotests/099
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/099
+++ b/tests/qemu-iotests/099
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test valid filenames for blkdebug and blkverify representatively for
 # other protocols (such as NBD) when queried
diff --git a/tests/qemu-iotests/101 b/tests/qemu-iotests/101
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/101
+++ b/tests/qemu-iotests/101
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test short file I/O
 #
diff --git a/tests/qemu-iotests/102 b/tests/qemu-iotests/102
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/102
+++ b/tests/qemu-iotests/102
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test case for qemu-io -c map and qemu-img map
 #
diff --git a/tests/qemu-iotests/103 b/tests/qemu-iotests/103
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/103
+++ b/tests/qemu-iotests/103
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test case for qcow2 metadata cache size specification
 #
diff --git a/tests/qemu-iotests/104 b/tests/qemu-iotests/104
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/104
+++ b/tests/qemu-iotests/104
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test image creation with aligned and unaligned sizes
 #
diff --git a/tests/qemu-iotests/105 b/tests/qemu-iotests/105
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/105
+++ b/tests/qemu-iotests/105
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Create, read, write big image
 #
diff --git a/tests/qemu-iotests/106 b/tests/qemu-iotests/106
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/106
+++ b/tests/qemu-iotests/106
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test preallocated resize of raw images
 #
diff --git a/tests/qemu-iotests/107 b/tests/qemu-iotests/107
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/107
+++ b/tests/qemu-iotests/107
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Tests updates of the qcow2 L1 table
 #
diff --git a/tests/qemu-iotests/108 b/tests/qemu-iotests/108
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/108
+++ b/tests/qemu-iotests/108
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test case for repairing qcow2 images which cannot be repaired using
 # the on-disk refcount structures
diff --git a/tests/qemu-iotests/109 b/tests/qemu-iotests/109
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/109
+++ b/tests/qemu-iotests/109
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test writing image headers of other formats into raw images
 #
diff --git a/tests/qemu-iotests/110 b/tests/qemu-iotests/110
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/110
+++ b/tests/qemu-iotests/110
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test case for relative backing file names in complex BDS trees
 #
diff --git a/tests/qemu-iotests/111 b/tests/qemu-iotests/111
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/111
+++ b/tests/qemu-iotests/111
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test case for non-existing backing file when creating a qcow2 image
 # and not specifying the size
diff --git a/tests/qemu-iotests/112 b/tests/qemu-iotests/112
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/112
+++ b/tests/qemu-iotests/112
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test cases for different refcount_bits values
 #
diff --git a/tests/qemu-iotests/113 b/tests/qemu-iotests/113
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/113
+++ b/tests/qemu-iotests/113
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test case for accessing creation options on image formats and
 # protocols not supporting image creation
diff --git a/tests/qemu-iotests/114 b/tests/qemu-iotests/114
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/114
+++ b/tests/qemu-iotests/114
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test invalid backing file format in qcow2 images
 #
diff --git a/tests/qemu-iotests/115 b/tests/qemu-iotests/115
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/115
+++ b/tests/qemu-iotests/115
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test case for non-self-referential qcow2 refcount blocks
 #
diff --git a/tests/qemu-iotests/116 b/tests/qemu-iotests/116
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/116
+++ b/tests/qemu-iotests/116
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test error code paths for invalid QED images
 #
diff --git a/tests/qemu-iotests/117 b/tests/qemu-iotests/117
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/117
+++ b/tests/qemu-iotests/117
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test case for shared BDS between backend trees
 #
diff --git a/tests/qemu-iotests/119 b/tests/qemu-iotests/119
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/119
+++ b/tests/qemu-iotests/119
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # NBD test case for overriding BDRV_O_PROTOCOL by explicitly specifying
 # a driver
diff --git a/tests/qemu-iotests/120 b/tests/qemu-iotests/120
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/120
+++ b/tests/qemu-iotests/120
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Non-NBD test cases for overriding BDRV_O_PROTOCOL by explicitly
 # specifying a driver
diff --git a/tests/qemu-iotests/121 b/tests/qemu-iotests/121
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/121
+++ b/tests/qemu-iotests/121
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test cases for qcow2 refcount table growth
 #
diff --git a/tests/qemu-iotests/122 b/tests/qemu-iotests/122
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/122
+++ b/tests/qemu-iotests/122
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test some qemu-img convert cases
 #
diff --git a/tests/qemu-iotests/123 b/tests/qemu-iotests/123
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/123
+++ b/tests/qemu-iotests/123
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test case for qemu-img convert to NBD
 #
diff --git a/tests/qemu-iotests/125 b/tests/qemu-iotests/125
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/125
+++ b/tests/qemu-iotests/125
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test preallocated growth of qcow2 images
 #
diff --git a/tests/qemu-iotests/126 b/tests/qemu-iotests/126
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/126
+++ b/tests/qemu-iotests/126
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Tests handling of colons in filenames (which may be confused with protocol
 # prefixes)
diff --git a/tests/qemu-iotests/127 b/tests/qemu-iotests/127
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/127
+++ b/tests/qemu-iotests/127
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test case for mirroring with dataplane
 #
diff --git a/tests/qemu-iotests/128 b/tests/qemu-iotests/128
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/128
+++ b/tests/qemu-iotests/128
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test that opening O_DIRECT succeeds when image file I/O produces EIO
 #
diff --git a/tests/qemu-iotests/130 b/tests/qemu-iotests/130
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/130
+++ b/tests/qemu-iotests/130
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test that temporary backing file overrides (on the command line or in
 # blockdev-add) don't replace the original path stored in the image during
diff --git a/tests/qemu-iotests/131 b/tests/qemu-iotests/131
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/131
+++ b/tests/qemu-iotests/131
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # parallels format validation tests (created by QEMU)
 #
diff --git a/tests/qemu-iotests/133 b/tests/qemu-iotests/133
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/133
+++ b/tests/qemu-iotests/133
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test for reopen
 #
diff --git a/tests/qemu-iotests/134 b/tests/qemu-iotests/134
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/134
+++ b/tests/qemu-iotests/134
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test encrypted read/write using plain bdrv_read/bdrv_write
 #
diff --git a/tests/qemu-iotests/135 b/tests/qemu-iotests/135
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/135
+++ b/tests/qemu-iotests/135
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test VPC open of image with large Max Table Entries value.
 #
diff --git a/tests/qemu-iotests/137 b/tests/qemu-iotests/137
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/137
+++ b/tests/qemu-iotests/137
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test qcow2 reopen
 #
diff --git a/tests/qemu-iotests/138 b/tests/qemu-iotests/138
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/138
+++ b/tests/qemu-iotests/138
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # General test case for qcow2's image check
 #
diff --git a/tests/qemu-iotests/140 b/tests/qemu-iotests/140
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/140
+++ b/tests/qemu-iotests/140
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test case for ejecting a BlockBackend with an NBD server attached to it
 #
diff --git a/tests/qemu-iotests/141 b/tests/qemu-iotests/141
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/141
+++ b/tests/qemu-iotests/141
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test case for ejecting BDSs with block jobs still running on them
 #
diff --git a/tests/qemu-iotests/142 b/tests/qemu-iotests/142
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/142
+++ b/tests/qemu-iotests/142
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test for configuring cache modes of arbitrary nodes (requires O_DIRECT)
 #
diff --git a/tests/qemu-iotests/143 b/tests/qemu-iotests/143
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/143
+++ b/tests/qemu-iotests/143
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test case for connecting to a non-existing NBD export name
 #
diff --git a/tests/qemu-iotests/144 b/tests/qemu-iotests/144
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/144
+++ b/tests/qemu-iotests/144
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 # Check live snapshot, followed by active commit, and another snapshot.
 #
 # This test is to catch the error case of BZ #1300209:
diff --git a/tests/qemu-iotests/145 b/tests/qemu-iotests/145
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/145
+++ b/tests/qemu-iotests/145
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test the combination of -incoming and snapshot=on
 #
diff --git a/tests/qemu-iotests/146 b/tests/qemu-iotests/146
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/146
+++ b/tests/qemu-iotests/146
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test VHD image format creator detection and override
 #
diff --git a/tests/qemu-iotests/150 b/tests/qemu-iotests/150
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/150
+++ b/tests/qemu-iotests/150
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test that qemu-img convert -S 0 fully allocates the target image
 #
diff --git a/tests/qemu-iotests/153 b/tests/qemu-iotests/153
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/153
+++ b/tests/qemu-iotests/153
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test image locking
 #
diff --git a/tests/qemu-iotests/154 b/tests/qemu-iotests/154
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/154
+++ b/tests/qemu-iotests/154
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # qcow2 specific bdrv_pwrite_zeroes tests with backing files (complements 034)
 #
diff --git a/tests/qemu-iotests/156 b/tests/qemu-iotests/156
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/156
+++ b/tests/qemu-iotests/156
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Tests oVirt-like storage migration:
 #  - Create snapshot
diff --git a/tests/qemu-iotests/157 b/tests/qemu-iotests/157
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/157
+++ b/tests/qemu-iotests/157
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test command line configuration of block devices with qdev
 #
diff --git a/tests/qemu-iotests/158 b/tests/qemu-iotests/158
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/158
+++ b/tests/qemu-iotests/158
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test encrypted read/write using backing files
 #
diff --git a/tests/qemu-iotests/159 b/tests/qemu-iotests/159
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/159
+++ b/tests/qemu-iotests/159
@@ -XXX,XX +XXX,XX @@
-#! /bin/bash
+#!/usr/bin/env bash
 #
 # qemu-img dd test with different block sizes
 #
diff --git a/tests/qemu-iotests/160 b/tests/qemu-iotests/160
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/160
+++ b/tests/qemu-iotests/160
@@ -XXX,XX +XXX,XX @@
-#! /bin/bash
+#!/usr/bin/env bash
 #
 # qemu-img dd test for the skip option
 #
diff --git a/tests/qemu-iotests/161 b/tests/qemu-iotests/161
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/161
+++ b/tests/qemu-iotests/161
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test reopening a backing image after block-stream and block-commit
 #
diff --git a/tests/qemu-iotests/162 b/tests/qemu-iotests/162
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/162
+++ b/tests/qemu-iotests/162
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test case for specifying runtime options of the wrong type to some
 # block drivers
diff --git a/tests/qemu-iotests/170 b/tests/qemu-iotests/170
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/170
+++ b/tests/qemu-iotests/170
@@ -XXX,XX +XXX,XX @@
-#! /bin/bash
+#!/usr/bin/env bash
 #
 # qemu-img dd test
 #
diff --git a/tests/qemu-iotests/171 b/tests/qemu-iotests/171
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/171
+++ b/tests/qemu-iotests/171
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test 'offset' and 'size' options of the raw driver. Make sure we can't
 # (or can) read and write outside of the image size.
diff --git a/tests/qemu-iotests/172 b/tests/qemu-iotests/172
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/172
+++ b/tests/qemu-iotests/172
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test floppy configuration
 #
diff --git a/tests/qemu-iotests/173 b/tests/qemu-iotests/173
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/173
+++ b/tests/qemu-iotests/173
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test QAPI commands looking up protocol based images with relative
 # filename backing strings
diff --git a/tests/qemu-iotests/174 b/tests/qemu-iotests/174
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/174
+++ b/tests/qemu-iotests/174
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test that qemu-io fail with non-zero exit code
 #
diff --git a/tests/qemu-iotests/175 b/tests/qemu-iotests/175
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/175
+++ b/tests/qemu-iotests/175
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test creating raw image preallocation mode
 #
diff --git a/tests/qemu-iotests/176 b/tests/qemu-iotests/176
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/176
+++ b/tests/qemu-iotests/176
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Commit changes into backing chains and empty the top image if the
 # backing image is not explicitly specified.
diff --git a/tests/qemu-iotests/177 b/tests/qemu-iotests/177
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/177
+++ b/tests/qemu-iotests/177
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test corner cases with unusual block geometries
 #
diff --git a/tests/qemu-iotests/178 b/tests/qemu-iotests/178
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/178
+++ b/tests/qemu-iotests/178
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # qemu-img measure sub-command tests
 #
diff --git a/tests/qemu-iotests/179 b/tests/qemu-iotests/179
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/179
+++ b/tests/qemu-iotests/179
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test case for write zeroes with unmap
 #
diff --git a/tests/qemu-iotests/181 b/tests/qemu-iotests/181
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/181
+++ b/tests/qemu-iotests/181
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test postcopy live migration with shared storage
 #
diff --git a/tests/qemu-iotests/182 b/tests/qemu-iotests/182
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/182
+++ b/tests/qemu-iotests/182
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test image locking for POSIX locks
 #
diff --git a/tests/qemu-iotests/183 b/tests/qemu-iotests/183
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/183
+++ b/tests/qemu-iotests/183
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test old-style block migration (migrate -b)
 #
diff --git a/tests/qemu-iotests/184 b/tests/qemu-iotests/184
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/184
+++ b/tests/qemu-iotests/184
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test I/O throttle block filter driver interface
 #
diff --git a/tests/qemu-iotests/185 b/tests/qemu-iotests/185
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/185
+++ b/tests/qemu-iotests/185
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test exiting qemu while jobs are still running
 #
diff --git a/tests/qemu-iotests/186 b/tests/qemu-iotests/186
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/186
+++ b/tests/qemu-iotests/186
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test 'info block' with all kinds of configurations
 #
diff --git a/tests/qemu-iotests/187 b/tests/qemu-iotests/187
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/187
+++ b/tests/qemu-iotests/187
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test switching between read-only and read-write
 #
diff --git a/tests/qemu-iotests/188 b/tests/qemu-iotests/188
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/188
+++ b/tests/qemu-iotests/188
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test encrypted read/write using plain bdrv_read/bdrv_write
 #
diff --git a/tests/qemu-iotests/189 b/tests/qemu-iotests/189
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/189
+++ b/tests/qemu-iotests/189
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test encrypted read/write using backing files
 #
diff --git a/tests/qemu-iotests/190 b/tests/qemu-iotests/190
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/190
+++ b/tests/qemu-iotests/190
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # qemu-img measure sub-command tests on huge qcow2 files
 #
diff --git a/tests/qemu-iotests/191 b/tests/qemu-iotests/191
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/191
+++ b/tests/qemu-iotests/191
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test commit block job where top has two parents
 #
diff --git a/tests/qemu-iotests/192 b/tests/qemu-iotests/192
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/192
+++ b/tests/qemu-iotests/192
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test NBD export with -incoming (non-shared storage migration use case from
 # libvirt)
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 @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test change-backing-file command
 #
diff --git a/tests/qemu-iotests/197 b/tests/qemu-iotests/197
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/197
+++ b/tests/qemu-iotests/197
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test case for copy-on-read into qcow2
 #
diff --git a/tests/qemu-iotests/198 b/tests/qemu-iotests/198
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/198
+++ b/tests/qemu-iotests/198
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test commit of encrypted qcow2 files
 #
diff --git a/tests/qemu-iotests/200 b/tests/qemu-iotests/200
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/200
+++ b/tests/qemu-iotests/200
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Block job co-routine race condition test.
 #
diff --git a/tests/qemu-iotests/201 b/tests/qemu-iotests/201
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/201
+++ b/tests/qemu-iotests/201
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test savevm and loadvm after live migration with postcopy flag
 #
diff --git a/tests/qemu-iotests/204 b/tests/qemu-iotests/204
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/204
+++ b/tests/qemu-iotests/204
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test corner cases with unusual block geometries
 #
diff --git a/tests/qemu-iotests/214 b/tests/qemu-iotests/214
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/214
+++ b/tests/qemu-iotests/214
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test qcow2 image compression
 #
diff --git a/tests/qemu-iotests/215 b/tests/qemu-iotests/215
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/215
+++ b/tests/qemu-iotests/215
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test case for copy-on-read into qcow2, using the COR filter driver
 #
diff --git a/tests/qemu-iotests/217 b/tests/qemu-iotests/217
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/217
+++ b/tests/qemu-iotests/217
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # I/O errors when working with internal qcow2 snapshots, and repairing
 # the result
diff --git a/tests/qemu-iotests/220 b/tests/qemu-iotests/220
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/220
+++ b/tests/qemu-iotests/220
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # max limits on compression in huge qcow2 files
 #
diff --git a/tests/qemu-iotests/221 b/tests/qemu-iotests/221
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/221
+++ b/tests/qemu-iotests/221
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test qemu-img vs. unaligned images
 #
diff --git a/tests/qemu-iotests/223 b/tests/qemu-iotests/223
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/223
+++ b/tests/qemu-iotests/223
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test reading dirty bitmap over NBD
 #
diff --git a/tests/qemu-iotests/225 b/tests/qemu-iotests/225
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/225
+++ b/tests/qemu-iotests/225
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test vmdk backing file correlation
 #
diff --git a/tests/qemu-iotests/226 b/tests/qemu-iotests/226
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/226
+++ b/tests/qemu-iotests/226
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # This test covers expected filetypes for the file, host_cdrom and
 # host_device drivers.
diff --git a/tests/qemu-iotests/227 b/tests/qemu-iotests/227
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/227
+++ b/tests/qemu-iotests/227
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test query-blockstats with different ways to create a BB
 #
diff --git a/tests/qemu-iotests/229 b/tests/qemu-iotests/229
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/229
+++ b/tests/qemu-iotests/229
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test for force canceling a running blockjob that is paused in
 # an error state.
diff --git a/tests/qemu-iotests/231 b/tests/qemu-iotests/231
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/231
+++ b/tests/qemu-iotests/231
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test legacy and modern option parsing for rbd/ceph.  This will not
 # actually connect to a ceph server, but rather looks for the appropriate
diff --git a/tests/qemu-iotests/232 b/tests/qemu-iotests/232
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/232
+++ b/tests/qemu-iotests/232
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test for auto-read-only
 #
diff --git a/tests/qemu-iotests/233 b/tests/qemu-iotests/233
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/233
+++ b/tests/qemu-iotests/233
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Test NBD TLS certificate / authorization integration
 #
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 @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Copyright (C) 2009 Red Hat, Inc.
 # Copyright (c) 2000-2002,2006 Silicon Graphics, Inc.  All Rights Reserved.
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 @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Copyright (C) 2009 Red Hat, Inc.
 # Copyright (c) 2000-2003,2006 Silicon Graphics, Inc.  All Rights Reserved.
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 @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Copyright (C) 2009 Red Hat, Inc.
 # Copyright (c) 2000-2001 Silicon Graphics, Inc.  All Rights Reserved.
diff --git a/tests/qemu-iotests/common.nbd b/tests/qemu-iotests/common.nbd
index XXXXXXX..XXXXXXX 100644
--- a/tests/qemu-iotests/common.nbd
+++ b/tests/qemu-iotests/common.nbd
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 # -*- shell-script-mode -*-
 #
 # Helpers for NBD server related config
diff --git a/tests/qemu-iotests/common.pattern b/tests/qemu-iotests/common.pattern
index XXXXXXX..XXXXXXX 100644
--- a/tests/qemu-iotests/common.pattern
+++ b/tests/qemu-iotests/common.pattern
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Copyright (C) 2009 Red Hat, Inc.
 #
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 @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # This allows for launching of multiple QEMU instances, with independent
 # communication possible to each instance.
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 @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Copyright (C) 2009 Red Hat, Inc.
 # Copyright (c) 2000-2006 Silicon Graphics, Inc.  All Rights Reserved.
diff --git a/tests/qemu-iotests/common.tls b/tests/qemu-iotests/common.tls
index XXXXXXX..XXXXXXX 100644
--- a/tests/qemu-iotests/common.tls
+++ b/tests/qemu-iotests/common.tls
@@ -XXX,XX +XXX,XX @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Helpers for TLS related config
 #
-- 
2.20.1

From: Philippe Mathieu-Daudé <philmd@redhat.com>

Various sed regexp from common.filter use sed GNU extensions.
Instead of spending time to write these regex to be POSIX compliant,
verify the GNU sed is available and use it.

Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 tests/qemu-iotests/common.filter | 36 ++++++++++++++++----------------
 tests/qemu-iotests/common.rc     | 13 ++++++++++++
 2 files changed, 31 insertions(+), 18 deletions(-)

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_date()
 {
-    sed \
+    $SED \
         -e 's/[A-Z][a-z][a-z] [A-z][a-z][a-z]  *[0-9][0-9]* [0-9][0-9]:[0-9][0-9]:[0-9][0-9] [0-9][0-9][0-9][0-9]$/DATE/'
 }
 
 _filter_generated_node_ids()
 {
-     sed -re 's/\#block[0-9]{3,}/NODE_NAME/'
+    $SED -re 's/\#block[0-9]{3,}/NODE_NAME/'
 }
 
 _filter_qom_path()
 {
-    sed -e 's#$Attached to: *$ /.*#\1 PATH#'
+    $SED -e 's#$Attached to: *$ /.*#\1 PATH#'
 }
 
 # replace occurrences of the actual TEST_DIR value with TEST_DIR
 _filter_testdir()
 {
-    sed -e "s#$TEST_DIR/#TEST_DIR/#g"
+    $SED -e "s#$TEST_DIR/#TEST_DIR/#g"
 }
 
 # replace occurrences of the actual IMGFMT value with IMGFMT
 _filter_imgfmt()
 {
-    sed -e "s#$IMGFMT#IMGFMT#g"
+    $SED -e "s#$IMGFMT#IMGFMT#g"
 }
 
 # Replace error message when the format is not supported and delete
 # the output lines after the first one
 _filter_qemu_img_check()
 {
-    sed -e '/allocated.*fragmented.*compressed clusters/d' \
+    $SED -e '/allocated.*fragmented.*compressed clusters/d' \
         -e 's/qemu-img: This image format does not support checks/No errors were found on the image./' \
         -e '/Image end offset: [0-9]\+/d'
 }
@@ -XXX,XX +XXX,XX @@ _filter_qemu_img_check()
 # Removes \r from messages
 _filter_win32()
 {
-    sed -e 's/\r//g'
+    $SED -e 's/\r//g'
 }
 
 # sanitize qemu-io output
 _filter_qemu_io()
 {
-    _filter_win32 | sed -e "s/[0-9]* ops\; [0-9/:. sec]* ([0-9/.inf]* [EPTGMKiBbytes]*\/sec and [0-9/.inf]* ops\/sec)/X ops\; XX:XX:XX.X (XXX YYY\/sec and XXX ops\/sec)/" \
+    _filter_win32 | $SED -e "s/[0-9]* ops\; [0-9/:. sec]* ([0-9/.inf]* [EPTGMKiBbytes]*\/sec and [0-9/.inf]* ops\/sec)/X ops\; XX:XX:XX.X (XXX YYY\/sec and XXX ops\/sec)/" \
         -e "s/: line [0-9][0-9]*:  *[0-9][0-9]*$ Aborted\| Killed$/:\1/" \
         -e "s/qemu-io> //g"
 }
@@ -XXX,XX +XXX,XX @@ _filter_qemu_io()
 # replace occurrences of QEMU_PROG with "qemu"
 _filter_qemu()
 {
-    sed -e "s#\$^\\|(qemu) \$$(basename $QEMU_PROG):#\1QEMU_PROG:#" \
+    $SED -e "s#\$^\\|(qemu) \$$(basename $QEMU_PROG):#\1QEMU_PROG:#" \
         -e 's#^QEMU [0-9]\+\.[0-9]\+\.[0-9]\+ monitor#QEMU X.Y.Z monitor#' \
         -e $'s#\r##' # QEMU monitor uses \r\n line endings
 }
@@ -XXX,XX +XXX,XX @@ _filter_qemu()
 _filter_qmp()
 {
     _filter_win32 | \
-    sed -e 's#$"\(micro$\?seconds": \)[0-9]\+#\1 TIMESTAMP#g' \
+    $SED -e 's#$"\(micro$\?seconds": \)[0-9]\+#\1 TIMESTAMP#g' \
         -e 's#^{"QMP":.*}$#QMP_VERSION#' \
         -e '/^    "QMP": {\s*$/, /^    }\s*$/ c\' \
         -e '    QMP_VERSION'
@@ -XXX,XX +XXX,XX @@ _filter_qmp()
 # readline makes HMP command strings so long that git complains
 _filter_hmp()
 {
-    sed -e $'s/^\$(qemu) \$\\?.*\e\\[D/\\1/g' \
+    $SED -e $'s/^\$(qemu) \$\\?.*\e\\[D/\\1/g' \
         -e $'s/\e\\[K//g'
 }
 
 # replace block job offset
 _filter_block_job_offset()
 {
-    sed -e 's/, "offset": [0-9]\+,/, "offset": OFFSET,/'
+    $SED -e 's/, "offset": [0-9]\+,/, "offset": OFFSET,/'
 }
 
 # replace block job len
 _filter_block_job_len()
 {
-    sed -e 's/, "len": [0-9]\+,/, "len": LEN,/g'
+    $SED -e 's/, "len": [0-9]\+,/, "len": LEN,/g'
 }
 
 # replace actual image size (depends on the host filesystem)
 _filter_actual_image_size()
 {
-    sed -s 's/$"actual-size":\s*$[0-9]\+/\1SIZE/g'
+    $SED -s 's/$"actual-size":\s*$[0-9]\+/\1SIZE/g'
 }
 
 # replace driver-specific options in the "Formatting..." line
 _filter_img_create()
 {
-    sed -e "s#$REMOTE_TEST_DIR#TEST_DIR#g" \
+    $SED -e "s#$REMOTE_TEST_DIR#TEST_DIR#g" \
         -e "s#$IMGPROTO:$TEST_DIR#TEST_DIR#g" \
         -e "s#$TEST_DIR#TEST_DIR#g" \
         -e "s#$IMGFMT#IMGFMT#g" \
@@ -XXX,XX +XXX,XX @@ _filter_img_info()
 
     discard=0
     regex_json_spec_start='^ *"format-specific": \{'
-    sed -e "s#$REMOTE_TEST_DIR#TEST_DIR#g" \
+    $SED -e "s#$REMOTE_TEST_DIR#TEST_DIR#g" \
         -e "s#$IMGPROTO:$TEST_DIR#TEST_DIR#g" \
         -e "s#$TEST_DIR#TEST_DIR#g" \
         -e "s#$IMGFMT#IMGFMT#g" \
@@ -XXX,XX +XXX,XX @@ _filter_img_info()
 # human and json output
 _filter_qemu_img_map()
 {
-    sed -e 's/$[0-9a-fx]* *[0-9a-fx]* *$[0-9a-fx]* */\1/g' \
+    $SED -e 's/$[0-9a-fx]* *[0-9a-fx]* *$[0-9a-fx]* */\1/g' \
         -e 's/"offset": [0-9]\+/"offset": OFFSET/g' \
         -e 's/Mapped to *//' | _filter_testdir | _filter_imgfmt
 }
@@ -XXX,XX +XXX,XX @@ _filter_nbd()
     # receive callbacks sometimes, making them unreliable.
     #
     # Filter out the TCP port number since this changes between runs.
-    sed -e '/nbd\/.*\.c:/d' \
+    $SED -e '/nbd\/.*\.c:/d' \
         -e 's#127\.0\.0\.1:[0-9]*#127.0.0.1:PORT#g' \
         -e "s#?socket=$TEST_DIR#?socket=TEST_DIR#g" \
         -e 's#$foo\|PORT/\?\|.sock$: Failed to .*$#\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 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #
 
+SED=
+for sed in sed gsed; do
+    ($sed --version | grep 'GNU sed') > /dev/null 2>&1
+    if [ "$?" -eq 0 ]; then
+        SED=$sed
+        break
+    fi
+done
+if [ -z "$SED" ]; then
+    echo "$0: GNU sed not found"
+    exit 1
+fi
+
 dd()
 {
    if [ "$HOSTOS" == "Linux" ]
-- 
2.20.1

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
---
 tests/qemu-iotests/243     | 63 ++++++++++++++++++++++++++++++++++++++
 tests/qemu-iotests/243.out | 26 ++++++++++++++++
 tests/qemu-iotests/group   |  1 +
 3 files changed, 90 insertions(+)
 create mode 100755 tests/qemu-iotests/243
 create mode 100644 tests/qemu-iotests/243.out

diff --git a/tests/qemu-iotests/243 b/tests/qemu-iotests/243
new file mode 100755
index XXXXXXX..XXXXXXX
--- /dev/null
+++ b/tests/qemu-iotests/243
@@ -XXX,XX +XXX,XX @@
+#!/bin/bash
+#
+# Test qcow2 preallocation
+#
+# Copyright (C) 2019 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 $seq"
+
+status=1	# failure is the default!
+
+_cleanup()
+{
+    _cleanup_test_img
+}
+trap "_cleanup; exit \$status" 0 1 2 3 15
+
+# get standard environment, filters and checks
+. ./common.rc
+. ./common.filter
+
+_supported_fmt qcow2
+_supported_proto file
+_supported_os Linux
+
+for mode in off metadata falloc full; do
+
+    echo
+    echo "=== preallocation=$mode ==="
+    echo
+
+    IMGOPTS="preallocation=$mode" _make_test_img 64M
+
+    printf "File size: "
+    du -b $TEST_IMG | cut -f1
+
+    # Can't use precise numbers here because they differ between filesystems
+    printf "Disk usage: "
+    [ $(du -B1 $TEST_IMG | cut -f1) -lt 1048576 ] && echo "low" || echo "high"
+
+done
+
+# success, all done
+echo "*** done"
+rm -f $seq.full
+status=0
diff --git a/tests/qemu-iotests/243.out b/tests/qemu-iotests/243.out
new file mode 100644
index XXXXXXX..XXXXXXX
--- /dev/null
+++ b/tests/qemu-iotests/243.out
@@ -XXX,XX +XXX,XX @@
+QA output created by 243
+
+=== preallocation=off ===
+
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864 preallocation=off
+File size: 196616
+Disk usage: low
+
+=== preallocation=metadata ===
+
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864 preallocation=metadata
+File size: 67436544
+Disk usage: low
+
+=== preallocation=falloc ===
+
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864 preallocation=falloc
+File size: 67436544
+Disk usage: high
+
+=== preallocation=full ===
+
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864 preallocation=full
+File size: 67436544
+Disk usage: high
+*** 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 @@
 239 rw auto quick
 240 auto quick
 242 rw auto quick
+243 rw auto quick
-- 
2.20.1

Image creation already involves a bdrv_co_truncate() call, which allows
to specify a preallocation mode. Just pass the right mode there and
remove the code that is made redundant by this.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block/qcow2.c | 28 +---------------------------
 1 file changed, 1 insertion(+), 27 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 @@ qcow2_co_create(BlockdevCreateOptions *create_options, Error **errp)
         goto out;
     }
 
-    if (qcow2_opts->preallocation == PREALLOC_MODE_FULL ||
-        qcow2_opts->preallocation == PREALLOC_MODE_FALLOC)
-    {
-        int64_t prealloc_size =
-            qcow2_calc_prealloc_size(qcow2_opts->size, cluster_size,
-                                     refcount_order);
-
-        ret = blk_truncate(blk, prealloc_size, qcow2_opts->preallocation, errp);
-        if (ret < 0) {
-            goto out;
-        }
-    }
-
     /* Write the header */
     QEMU_BUILD_BUG_ON((1 << MIN_CLUSTER_BITS) < sizeof(*header));
     header = g_malloc0(cluster_size);
@@ -XXX,XX +XXX,XX @@ qcow2_co_create(BlockdevCreateOptions *create_options, Error **errp)
     }
 
     /* Okay, now that we have a valid image, let's give it the right size */
-    ret = blk_truncate(blk, qcow2_opts->size, PREALLOC_MODE_OFF, errp);
+    ret = blk_truncate(blk, qcow2_opts->size, qcow2_opts->preallocation, errp);
     if (ret < 0) {
         error_prepend(errp, "Could not resize image: ");
         goto out;
@@ -XXX,XX +XXX,XX @@ qcow2_co_create(BlockdevCreateOptions *create_options, Error **errp)
         }
     }
 
-    /* And if we're supposed to preallocate metadata, do that now */
-    if (qcow2_opts->preallocation != PREALLOC_MODE_OFF) {
-        BDRVQcow2State *s = blk_bs(blk)->opaque;
-        qemu_co_mutex_lock(&s->lock);
-        ret = preallocate_co(blk_bs(blk), 0, qcow2_opts->size);
-        qemu_co_mutex_unlock(&s->lock);
-
-        if (ret < 0) {
-            error_setg_errno(errp, -ret, "Could not preallocate metadata");
-            goto out;
-        }
-    }
-
     blk_unref(blk);
     blk = NULL;
 
-- 
2.20.1

This adds external data file to the qcow2 spec as a new incompatible
feature.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 docs/interop/qcow2.txt | 42 ++++++++++++++++++++++++++++++++++++++----
 1 file changed, 38 insertions(+), 4 deletions(-)

diff --git a/docs/interop/qcow2.txt b/docs/interop/qcow2.txt
index XXXXXXX..XXXXXXX 100644
--- a/docs/interop/qcow2.txt
+++ b/docs/interop/qcow2.txt
@@ -XXX,XX +XXX,XX @@ in the description of a field.
                                 be written to (unless for regaining
                                 consistency).
 
-                    Bits 2-63:  Reserved (set to 0)
+                    Bit 2:      External data file bit.  If this bit is set, an
+                                external data file is used. Guest clusters are
+                                then stored in the external data file. For such
+                                images, clusters in the external data file are
+                                not refcounted. The offset field in the
+                                Standard Cluster Descriptor must match the
+                                guest offset and neither compressed clusters
+                                nor internal snapshots are supported.
+
+                                An External Data File Name header extension may
+                                be present if this bit is set.
+
+                    Bits 3-63:  Reserved (set to 0)
 
          80 -  87:  compatible_features
                     Bitmask of compatible features. An implementation can
@@ -XXX,XX +XXX,XX @@ in the description of a field.
                                 bit is unset, the bitmaps extension data must be
                                 considered inconsistent.
 
-                    Bits 1-63:  Reserved (set to 0)
+                    Bit 1:      If this bit is set, the external data file can
+                                be read as a consistent standalone raw image
+                                without looking at the qcow2 metadata.
+
+                                Setting this bit has a performance impact for
+                                some operations on the image (e.g. writing
+                                zeros requires writing to the data file instead
+                                of only setting the zero flag in the L2 table
+                                entry) and conflicts with backing files.
+
+                                This bit may only be set if the External Data
+                                File bit (incompatible feature bit 1) is also
+                                set.
+
+                    Bits 2-63:  Reserved (set to 0)
 
          96 -  99:  refcount_order
                     Describes the width of a reference count block entry (width
@@ -XXX,XX +XXX,XX @@ be stored. Each extension has a structure like the following:
                         0x6803f857 - Feature name table
                         0x23852875 - Bitmaps extension
                         0x0537be77 - Full disk encryption header pointer
+                        0x44415441 - External data file name
                         other      - Unknown header extension, can be safely
                                      ignored
 
@@ -XXX,XX +XXX,XX @@ L2 table entry:
                     This information is only accurate in L2 tables
                     that are reachable from the active L1 table.
 
+                    With external data files, all guest clusters have an
+                    implicit refcount of 1 (because of the fixed host = guest
+                    mapping for guest cluster offsets), so this bit should be 1
+                    for all allocated clusters.
+
 Standard Cluster Descriptor:
 
     Bit       0:    If set to 1, the cluster reads as all zeros. The host
@@ -XXX,XX +XXX,XX @@ Standard Cluster Descriptor:
          1 -  8:    Reserved (set to 0)
 
          9 - 55:    Bits 9-55 of host cluster offset. Must be aligned to a
-                    cluster boundary. If the offset is 0, the cluster is
-                    unallocated.
+                    cluster boundary. If the offset is 0 and bit 63 is clear,
+                    the cluster is unallocated. The offset may only be 0 with
+                    bit 63 set (indicating a host cluster offset of 0) when an
+                    external data file is used.
 
         56 - 61:    Reserved (set to 0)
 
-- 
2.20.1

This adds basic constants, struct fields and helper function for
external data file support to the implementation.

QCOW2_INCOMPAT_MASK and QCOW2_AUTOCLEAR_MASK are not updated yet so that
opening images with an external data file still fails (we don't handle
them correctly yet).

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block/qcow2.h              | 32 ++++++++++++++++++++++----------
 block/qcow2.c              |  9 +++++++++
 tests/qemu-iotests/031.out |  8 ++++----
 tests/qemu-iotests/036.out |  4 ++--
 tests/qemu-iotests/061.out | 14 +++++++-------
 5 files changed, 44 insertions(+), 23 deletions(-)

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 @@ enum {
 
 /* Incompatible feature bits */
 enum {
-    QCOW2_INCOMPAT_DIRTY_BITNR   = 0,
-    QCOW2_INCOMPAT_CORRUPT_BITNR = 1,
-    QCOW2_INCOMPAT_DIRTY         = 1 << QCOW2_INCOMPAT_DIRTY_BITNR,
-    QCOW2_INCOMPAT_CORRUPT       = 1 << QCOW2_INCOMPAT_CORRUPT_BITNR,
-
-    QCOW2_INCOMPAT_MASK          = QCOW2_INCOMPAT_DIRTY
-                                 | QCOW2_INCOMPAT_CORRUPT,
+    QCOW2_INCOMPAT_DIRTY_BITNR      = 0,
+    QCOW2_INCOMPAT_CORRUPT_BITNR    = 1,
+    QCOW2_INCOMPAT_DATA_FILE_BITNR  = 2,
+    QCOW2_INCOMPAT_DIRTY            = 1 << QCOW2_INCOMPAT_DIRTY_BITNR,
+    QCOW2_INCOMPAT_CORRUPT          = 1 << QCOW2_INCOMPAT_CORRUPT_BITNR,
+    QCOW2_INCOMPAT_DATA_FILE        = 1 << QCOW2_INCOMPAT_DATA_FILE_BITNR,
+
+    QCOW2_INCOMPAT_MASK             = QCOW2_INCOMPAT_DIRTY
+                                    | QCOW2_INCOMPAT_CORRUPT,
 };
 
 /* Compatible feature bits */
@@ -XXX,XX +XXX,XX @@ enum {
 
 /* Autoclear feature bits */
 enum {
-    QCOW2_AUTOCLEAR_BITMAPS_BITNR = 0,
-    QCOW2_AUTOCLEAR_BITMAPS       = 1 << QCOW2_AUTOCLEAR_BITMAPS_BITNR,
+    QCOW2_AUTOCLEAR_BITMAPS_BITNR       = 0,
+    QCOW2_AUTOCLEAR_DATA_FILE_RAW_BITNR = 1,
+    QCOW2_AUTOCLEAR_BITMAPS             = 1 << QCOW2_AUTOCLEAR_BITMAPS_BITNR,
+    QCOW2_AUTOCLEAR_DATA_FILE_RAW       = 1 << QCOW2_AUTOCLEAR_DATA_FILE_RAW_BITNR,
 
-    QCOW2_AUTOCLEAR_MASK          = QCOW2_AUTOCLEAR_BITMAPS,
+    QCOW2_AUTOCLEAR_MASK                = QCOW2_AUTOCLEAR_BITMAPS,
 };
 
 enum qcow2_discard_type {
@@ -XXX,XX +XXX,XX @@ typedef struct BDRVQcow2State {
 
     CoQueue compress_wait_queue;
     int nb_compress_threads;
+
+    BdrvChild *data_file;
 } BDRVQcow2State;
 
 typedef struct Qcow2COWRegion {
@@ -XXX,XX +XXX,XX @@ typedef enum QCow2MetadataOverlap {
 
 #define REFT_OFFSET_MASK 0xfffffffffffffe00ULL
 
+static inline bool has_data_file(BlockDriverState *bs)
+{
+    BDRVQcow2State *s = bs->opaque;
+    return (s->data_file != bs->file);
+}
+
 static inline int64_t start_of_cluster(BDRVQcow2State *s, int64_t offset)
 {
     return offset & ~(s->cluster_size - 1);
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 @@ typedef struct {
 #define  QCOW2_EXT_MAGIC_FEATURE_TABLE 0x6803f857
 #define  QCOW2_EXT_MAGIC_CRYPTO_HEADER 0x0537be77
 #define  QCOW2_EXT_MAGIC_BITMAPS 0x23852875
+#define  QCOW2_EXT_MAGIC_DATA_FILE 0x44415441
 
 static int coroutine_fn
 qcow2_co_preadv_compressed(BlockDriverState *bs,
@@ -XXX,XX +XXX,XX @@ static int coroutine_fn qcow2_do_open(BlockDriverState *bs, QDict *options,
         goto fail;
     }
 
+    /* TODO Open external data file */
+    s->data_file = bs->file;
+
     /* qcow2_read_extension may have set up the crypto context
      * if the crypt method needs a header region, some methods
      * don't need header extensions, so must check here
@@ -XXX,XX +XXX,XX @@ int qcow2_update_header(BlockDriverState *bs)
                 .bit  = QCOW2_INCOMPAT_CORRUPT_BITNR,
                 .name = "corrupt bit",
             },
+            {
+                .type = QCOW2_FEAT_TYPE_INCOMPATIBLE,
+                .bit  = QCOW2_INCOMPAT_DATA_FILE_BITNR,
+                .name = "external data file",
+            },
             {
                 .type = QCOW2_FEAT_TYPE_COMPATIBLE,
                 .bit  = QCOW2_COMPAT_LAZY_REFCOUNTS_BITNR,
diff --git a/tests/qemu-iotests/031.out b/tests/qemu-iotests/031.out
index XXXXXXX..XXXXXXX 100644
--- a/tests/qemu-iotests/031.out
+++ b/tests/qemu-iotests/031.out
@@ -XXX,XX +XXX,XX @@ header_length             104
 
 Header extension:
 magic                     0x6803f857
-length                    144
+length                    192
 data                      <binary>
 
 Header extension:
@@ -XXX,XX +XXX,XX @@ header_length             104
 
 Header extension:
 magic                     0x6803f857
-length                    144
+length                    192
 data                      <binary>
 
 Header extension:
@@ -XXX,XX +XXX,XX @@ No errors were found on the image.
 
 magic                     0x514649fb
 version                   3
-backing_file_offset       0x148
+backing_file_offset       0x178
 backing_file_size         0x17
 cluster_bits              16
 size                      67108864
@@ -XXX,XX +XXX,XX @@ data                      'host_device'
 
 Header extension:
 magic                     0x6803f857
-length                    144
+length                    192
 data                      <binary>
 
 Header extension:
diff --git a/tests/qemu-iotests/036.out b/tests/qemu-iotests/036.out
index XXXXXXX..XXXXXXX 100644
--- a/tests/qemu-iotests/036.out
+++ b/tests/qemu-iotests/036.out
@@ -XXX,XX +XXX,XX @@ header_length             104
 
 Header extension:
 magic                     0x6803f857
-length                    144
+length                    192
 data                      <binary>
 
 
@@ -XXX,XX +XXX,XX @@ header_length             104
 
 Header extension:
 magic                     0x6803f857
-length                    144
+length                    192
 data                      <binary>
 
 *** done
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 @@ header_length             104
 
 Header extension:
 magic                     0x6803f857
-length                    144
+length                    192
 data                      <binary>
 
 magic                     0x514649fb
@@ -XXX,XX +XXX,XX @@ header_length             104
 
 Header extension:
 magic                     0x6803f857
-length                    144
+length                    192
 data                      <binary>
 
 magic                     0x514649fb
@@ -XXX,XX +XXX,XX @@ header_length             104
 
 Header extension:
 magic                     0x6803f857
-length                    144
+length                    192
 data                      <binary>
 
 ERROR cluster 5 refcount=0 reference=1
@@ -XXX,XX +XXX,XX @@ header_length             104
 
 Header extension:
 magic                     0x6803f857
-length                    144
+length                    192
 data                      <binary>
 
 magic                     0x514649fb
@@ -XXX,XX +XXX,XX @@ header_length             104
 
 Header extension:
 magic                     0x6803f857
-length                    144
+length                    192
 data                      <binary>
 
 read 65536/65536 bytes at offset 44040192
@@ -XXX,XX +XXX,XX @@ header_length             104
 
 Header extension:
 magic                     0x6803f857
-length                    144
+length                    192
 data                      <binary>
 
 ERROR cluster 5 refcount=0 reference=1
@@ -XXX,XX +XXX,XX @@ header_length             104
 
 Header extension:
 magic                     0x6803f857
-length                    144
+length                    192
 data                      <binary>
 
 read 131072/131072 bytes at offset 0
-- 
2.20.1

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block/qcow2.h          |  3 ++-
 block/qcow2-cluster.c  | 37 +++++++++++++++++++------------------
 block/qcow2-refcount.c | 10 +++++-----
 3 files changed, 26 insertions(+), 24 deletions(-)

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 @@ static inline int64_t qcow2_vm_state_offset(BDRVQcow2State *s)
     return (int64_t)s->l1_vm_state_index << (s->cluster_bits + s->l2_bits);
 }
 
-static inline QCow2ClusterType qcow2_get_cluster_type(uint64_t l2_entry)
+static inline QCow2ClusterType qcow2_get_cluster_type(BlockDriverState *bs,
+                                                      uint64_t l2_entry)
 {
     if (l2_entry & QCOW_OFLAG_COMPRESSED) {
         return QCOW2_CLUSTER_COMPRESSED;
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 @@ fail:
  * as contiguous. (This allows it, for example, to stop at the first compressed
  * cluster which may require a different handling)
  */
-static int count_contiguous_clusters(int nb_clusters, int cluster_size,
-        uint64_t *l2_slice, uint64_t stop_flags)
+static int count_contiguous_clusters(BlockDriverState *bs, int nb_clusters,
+        int cluster_size, uint64_t *l2_slice, uint64_t stop_flags)
 {
     int i;
     QCow2ClusterType first_cluster_type;
@@ -XXX,XX +XXX,XX @@ static int count_contiguous_clusters(int nb_clusters, int cluster_size,
     }
 
     /* must be allocated */
-    first_cluster_type = qcow2_get_cluster_type(first_entry);
+    first_cluster_type = qcow2_get_cluster_type(bs, first_entry);
     assert(first_cluster_type == QCOW2_CLUSTER_NORMAL ||
            first_cluster_type == QCOW2_CLUSTER_ZERO_ALLOC);
 
@@ -XXX,XX +XXX,XX @@ static int count_contiguous_clusters(int nb_clusters, int cluster_size,
  * Checks how many consecutive unallocated clusters in a given L2
  * slice have the same cluster type.
  */
-static int count_contiguous_clusters_unallocated(int nb_clusters,
+static int count_contiguous_clusters_unallocated(BlockDriverState *bs,
+                                                 int nb_clusters,
                                                  uint64_t *l2_slice,
                                                  QCow2ClusterType wanted_type)
 {
@@ -XXX,XX +XXX,XX @@ static int count_contiguous_clusters_unallocated(int nb_clusters,
            wanted_type == QCOW2_CLUSTER_UNALLOCATED);
     for (i = 0; i < nb_clusters; i++) {
         uint64_t entry = be64_to_cpu(l2_slice[i]);
-        QCow2ClusterType type = qcow2_get_cluster_type(entry);
+        QCow2ClusterType type = qcow2_get_cluster_type(bs, entry);
 
         if (type != wanted_type) {
             break;
@@ -XXX,XX +XXX,XX @@ int qcow2_get_cluster_offset(BlockDriverState *bs, uint64_t offset,
      * true */
     assert(nb_clusters <= INT_MAX);
 
-    type = qcow2_get_cluster_type(*cluster_offset);
+    type = qcow2_get_cluster_type(bs, *cluster_offset);
     if (s->qcow_version < 3 && (type == QCOW2_CLUSTER_ZERO_PLAIN ||
                                 type == QCOW2_CLUSTER_ZERO_ALLOC)) {
         qcow2_signal_corruption(bs, true, -1, -1, "Zero cluster entry found"
@@ -XXX,XX +XXX,XX @@ int qcow2_get_cluster_offset(BlockDriverState *bs, uint64_t offset,
     case QCOW2_CLUSTER_ZERO_PLAIN:
     case QCOW2_CLUSTER_UNALLOCATED:
         /* how many empty clusters ? */
-        c = count_contiguous_clusters_unallocated(nb_clusters,
+        c = count_contiguous_clusters_unallocated(bs, nb_clusters,
                                                   &l2_slice[l2_index], type);
         *cluster_offset = 0;
         break;
     case QCOW2_CLUSTER_ZERO_ALLOC:
     case QCOW2_CLUSTER_NORMAL:
         /* how many allocated clusters ? */
-        c = count_contiguous_clusters(nb_clusters, s->cluster_size,
+        c = count_contiguous_clusters(bs, nb_clusters, s->cluster_size,
                                       &l2_slice[l2_index], QCOW_OFLAG_ZERO);
         *cluster_offset &= L2E_OFFSET_MASK;
         if (offset_into_cluster(s, *cluster_offset)) {
@@ -XXX,XX +XXX,XX @@ void qcow2_alloc_cluster_abort(BlockDriverState *bs, QCowL2Meta *m)
  * write, but require COW to be performed (this includes yet unallocated space,
  * which must copy from the backing file)
  */
-static int count_cow_clusters(BDRVQcow2State *s, int nb_clusters,
+static int count_cow_clusters(BlockDriverState *bs, int nb_clusters,
     uint64_t *l2_slice, int l2_index)
 {
     int i;
 
     for (i = 0; i < nb_clusters; i++) {
         uint64_t l2_entry = be64_to_cpu(l2_slice[l2_index + i]);
-        QCow2ClusterType cluster_type = qcow2_get_cluster_type(l2_entry);
+        QCow2ClusterType cluster_type = qcow2_get_cluster_type(bs, l2_entry);
 
         switch(cluster_type) {
         case QCOW2_CLUSTER_NORMAL:
@@ -XXX,XX +XXX,XX @@ static int handle_copied(BlockDriverState *bs, uint64_t guest_offset,
     cluster_offset = be64_to_cpu(l2_slice[l2_index]);
 
     /* Check how many clusters are already allocated and don't need COW */
-    if (qcow2_get_cluster_type(cluster_offset) == QCOW2_CLUSTER_NORMAL
+    if (qcow2_get_cluster_type(bs, cluster_offset) == QCOW2_CLUSTER_NORMAL
         && (cluster_offset & QCOW_OFLAG_COPIED))
     {
         /* If a specific host_offset is required, check it */
@@ -XXX,XX +XXX,XX @@ static int handle_copied(BlockDriverState *bs, uint64_t guest_offset,
 
         /* We keep all QCOW_OFLAG_COPIED clusters */
         keep_clusters =
-            count_contiguous_clusters(nb_clusters, s->cluster_size,
+            count_contiguous_clusters(bs, nb_clusters, s->cluster_size,
                                       &l2_slice[l2_index],
                                       QCOW_OFLAG_COPIED | QCOW_OFLAG_ZERO);
         assert(keep_clusters <= nb_clusters);
@@ -XXX,XX +XXX,XX @@ static int handle_alloc(BlockDriverState *bs, uint64_t guest_offset,
     if (entry & QCOW_OFLAG_COMPRESSED) {
         nb_clusters = 1;
     } else {
-        nb_clusters = count_cow_clusters(s, nb_clusters, l2_slice, l2_index);
+        nb_clusters = count_cow_clusters(bs, nb_clusters, l2_slice, l2_index);
     }
 
     /* This function is only called when there were no non-COW clusters, so if
@@ -XXX,XX +XXX,XX @@ static int handle_alloc(BlockDriverState *bs, uint64_t guest_offset,
      * wrong with our code. */
     assert(nb_clusters > 0);
 
-    if (qcow2_get_cluster_type(entry) == QCOW2_CLUSTER_ZERO_ALLOC &&
+    if (qcow2_get_cluster_type(bs, entry) == QCOW2_CLUSTER_ZERO_ALLOC &&
         (entry & QCOW_OFLAG_COPIED) &&
         (!*host_offset ||
          start_of_cluster(s, *host_offset) == (entry & L2E_OFFSET_MASK)))
@@ -XXX,XX +XXX,XX @@ static int handle_alloc(BlockDriverState *bs, uint64_t guest_offset,
          * would be fine, too, but count_cow_clusters() above has limited
          * nb_clusters already to a range of COW clusters */
         preallocated_nb_clusters =
-            count_contiguous_clusters(nb_clusters, s->cluster_size,
+            count_contiguous_clusters(bs, nb_clusters, s->cluster_size,
                                       &l2_slice[l2_index], QCOW_OFLAG_COPIED);
         assert(preallocated_nb_clusters > 0);
 
@@ -XXX,XX +XXX,XX @@ static int discard_in_l2_slice(BlockDriverState *bs, uint64_t offset,
          * If full_discard is true, the sector should not read back as zeroes,
          * but rather fall through to the backing file.
          */
-        switch (qcow2_get_cluster_type(old_l2_entry)) {
+        switch (qcow2_get_cluster_type(bs, old_l2_entry)) {
         case QCOW2_CLUSTER_UNALLOCATED:
             if (full_discard || !bs->backing) {
                 continue;
@@ -XXX,XX +XXX,XX @@ static int zero_in_l2_slice(BlockDriverState *bs, uint64_t offset,
          * Minimize L2 changes if the cluster already reads back as
          * zeroes with correct allocation.
          */
-        cluster_type = qcow2_get_cluster_type(old_offset);
+        cluster_type = qcow2_get_cluster_type(bs, old_offset);
         if (cluster_type == QCOW2_CLUSTER_ZERO_PLAIN ||
             (cluster_type == QCOW2_CLUSTER_ZERO_ALLOC && !unmap)) {
             continue;
@@ -XXX,XX +XXX,XX @@ static int expand_zero_clusters_in_l1(BlockDriverState *bs, uint64_t *l1_table,
                 uint64_t l2_entry = be64_to_cpu(l2_slice[j]);
                 int64_t offset = l2_entry & L2E_OFFSET_MASK;
                 QCow2ClusterType cluster_type =
-                    qcow2_get_cluster_type(l2_entry);
+                    qcow2_get_cluster_type(bs, l2_entry);
 
                 if (cluster_type != QCOW2_CLUSTER_ZERO_PLAIN &&
                     cluster_type != QCOW2_CLUSTER_ZERO_ALLOC) {
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 @@ void qcow2_free_any_clusters(BlockDriverState *bs, uint64_t l2_entry,
 {
     BDRVQcow2State *s = bs->opaque;
 
-    switch (qcow2_get_cluster_type(l2_entry)) {
+    switch (qcow2_get_cluster_type(bs, l2_entry)) {
     case QCOW2_CLUSTER_COMPRESSED:
         {
             int nb_csectors;
@@ -XXX,XX +XXX,XX @@ int qcow2_update_snapshot_refcount(BlockDriverState *bs,
                     entry &= ~QCOW_OFLAG_COPIED;
                     offset = entry & L2E_OFFSET_MASK;
 
-                    switch (qcow2_get_cluster_type(entry)) {
+                    switch (qcow2_get_cluster_type(bs, entry)) {
                     case QCOW2_CLUSTER_COMPRESSED:
                         nb_csectors = ((entry >> s->csize_shift) &
                                        s->csize_mask) + 1;
@@ -XXX,XX +XXX,XX @@ static int check_refcounts_l2(BlockDriverState *bs, BdrvCheckResult *res,
     for(i = 0; i < s->l2_size; i++) {
         l2_entry = be64_to_cpu(l2_table[i]);
 
-        switch (qcow2_get_cluster_type(l2_entry)) {
+        switch (qcow2_get_cluster_type(bs, l2_entry)) {
         case QCOW2_CLUSTER_COMPRESSED:
             /* Compressed clusters don't have QCOW_OFLAG_COPIED */
             if (l2_entry & QCOW_OFLAG_COPIED) {
@@ -XXX,XX +XXX,XX @@ static int check_refcounts_l2(BlockDriverState *bs, BdrvCheckResult *res,
 
             /* Correct offsets are cluster aligned */
             if (offset_into_cluster(s, offset)) {
-                if (qcow2_get_cluster_type(l2_entry) ==
+                if (qcow2_get_cluster_type(bs, l2_entry) ==
                     QCOW2_CLUSTER_ZERO_ALLOC)
                 {
                     fprintf(stderr, "%s offset=%" PRIx64 ": Preallocated zero "
@@ -XXX,XX +XXX,XX @@ static int check_oflag_copied(BlockDriverState *bs, BdrvCheckResult *res,
         for (j = 0; j < s->l2_size; j++) {
             uint64_t l2_entry = be64_to_cpu(l2_table[j]);
             uint64_t data_offset = l2_entry & L2E_OFFSET_MASK;
-            QCow2ClusterType cluster_type = qcow2_get_cluster_type(l2_entry);
+            QCow2ClusterType cluster_type = qcow2_get_cluster_type(bs, l2_entry);
 
             if (cluster_type == QCOW2_CLUSTER_NORMAL ||
                 cluster_type == QCOW2_CLUSTER_ZERO_ALLOC) {
-- 
2.20.1

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block/qcow2.h | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

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 @@ static inline QCow2ClusterType qcow2_get_cluster_type(BlockDriverState *bs,
         }
         return QCOW2_CLUSTER_ZERO_PLAIN;
     } else if (!(l2_entry & L2E_OFFSET_MASK)) {
-        return QCOW2_CLUSTER_UNALLOCATED;
+        /* Offset 0 generally means unallocated, but it is ambiguous with
+         * external data files because 0 is a valid offset there. However, all
+         * clusters in external data files always have refcount 1, so we can
+         * rely on QCOW_OFLAG_COPIED to disambiguate. */
+        if (has_data_file(bs) && (l2_entry & QCOW_OFLAG_COPIED)) {
+            return QCOW2_CLUSTER_NORMAL;
+        } else {
+            return QCOW2_CLUSTER_UNALLOCATED;
+        }
     } else {
         return QCOW2_CLUSTER_NORMAL;
     }
-- 
2.20.1

The cluster allocation code uses 0 as an invalid offset that is used in
case of errors or as "offset not yet determined". With external data
files, a host cluster offset of 0 becomes valid, though.

Define a constant INV_OFFSET (which is not cluster aligned and will
therefore never be a valid offset) that can be used for such purposes.

This removes the additional host_offset == 0 check that commit
ff52aab2df5 introduced; the confusion between an invalid offset and
(erroneous) allocation at offset 0 is removed with this change.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block/qcow2.h         |  2 ++
 block/qcow2-cluster.c | 59 ++++++++++++++++++++-----------------------
 2 files changed, 29 insertions(+), 32 deletions(-)

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 @@ typedef enum QCow2MetadataOverlap {
 
 #define REFT_OFFSET_MASK 0xfffffffffffffe00ULL
 
+#define INV_OFFSET (-1ULL)
+
 static inline bool has_data_file(BlockDriverState *bs)
 {
     BDRVQcow2State *s = bs->opaque;
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 int handle_dependencies(BlockDriverState *bs, uint64_t guest_offset,
 
 /*
  * Checks how many already allocated clusters that don't require a copy on
- * write there are at the given guest_offset (up to *bytes). If
- * *host_offset is not zero, only physically contiguous clusters beginning at
- * this host offset are counted.
+ * write there are at the given guest_offset (up to *bytes). If *host_offset is
+ * not INV_OFFSET, only physically contiguous clusters beginning at this host
+ * offset are counted.
  *
  * Note that guest_offset may not be cluster aligned. In this case, the
  * returned *host_offset points to exact byte referenced by guest_offset and
@@ -XXX,XX +XXX,XX @@ static int handle_copied(BlockDriverState *bs, uint64_t guest_offset,
     trace_qcow2_handle_copied(qemu_coroutine_self(), guest_offset, *host_offset,
                               *bytes);
 
-    assert(*host_offset == 0 ||    offset_into_cluster(s, guest_offset)
-                                == offset_into_cluster(s, *host_offset));
+    assert(*host_offset == INV_OFFSET || offset_into_cluster(s, guest_offset)
+                                      == offset_into_cluster(s, *host_offset));
 
     /*
      * Calculate the number of clusters to look for. We stop at L2 slice
@@ -XXX,XX +XXX,XX @@ static int handle_copied(BlockDriverState *bs, uint64_t guest_offset,
             goto out;
         }
 
-        if (*host_offset != 0 && !offset_matches) {
+        if (*host_offset != INV_OFFSET && !offset_matches) {
             *bytes = 0;
             ret = 0;
             goto out;
@@ -XXX,XX +XXX,XX @@ out:
  * contain the number of clusters that have been allocated and are contiguous
  * in the image file.
  *
- * If *host_offset is non-zero, it specifies the offset in the image file at
- * which the new clusters must start. *nb_clusters can be 0 on return in this
- * case if the cluster at host_offset is already in use. If *host_offset is
- * zero, the clusters can be allocated anywhere in the image file.
+ * If *host_offset is not INV_OFFSET, it specifies the offset in the image file
+ * at which the new clusters must start. *nb_clusters can be 0 on return in
+ * this case if the cluster at host_offset is already in use. If *host_offset
+ * is INV_OFFSET, the clusters can be allocated anywhere in the image file.
  *
  * *host_offset is updated to contain the offset into the image file at which
  * the first allocated cluster starts.
@@ -XXX,XX +XXX,XX @@ static int do_alloc_cluster_offset(BlockDriverState *bs, uint64_t guest_offset,
 
     /* Allocate new clusters */
     trace_qcow2_cluster_alloc_phys(qemu_coroutine_self());
-    if (*host_offset == 0) {
+    if (*host_offset == INV_OFFSET) {
         int64_t cluster_offset =
             qcow2_alloc_clusters(bs, *nb_clusters * s->cluster_size);
         if (cluster_offset < 0) {
@@ -XXX,XX +XXX,XX @@ static int do_alloc_cluster_offset(BlockDriverState *bs, uint64_t guest_offset,
 
 /*
  * Allocates new clusters for an area that either is yet unallocated or needs a
- * copy on write. If *host_offset is non-zero, clusters are only allocated if
- * the new allocation can match the specified host offset.
+ * copy on write. If *host_offset is not INV_OFFSET, clusters are only
+ * allocated if the new allocation can match the specified host offset.
  *
  * Note that guest_offset may not be cluster aligned. In this case, the
  * returned *host_offset points to exact byte referenced by guest_offset and
@@ -XXX,XX +XXX,XX @@ static int handle_alloc(BlockDriverState *bs, uint64_t guest_offset,
     int ret;
     bool keep_old_clusters = false;
 
-    uint64_t alloc_cluster_offset = 0;
+    uint64_t alloc_cluster_offset = INV_OFFSET;
 
     trace_qcow2_handle_alloc(qemu_coroutine_self(), guest_offset, *host_offset,
                              *bytes);
@@ -XXX,XX +XXX,XX @@ static int handle_alloc(BlockDriverState *bs, uint64_t guest_offset,
 
     if (qcow2_get_cluster_type(bs, entry) == QCOW2_CLUSTER_ZERO_ALLOC &&
         (entry & QCOW_OFLAG_COPIED) &&
-        (!*host_offset ||
+        (*host_offset == INV_OFFSET ||
          start_of_cluster(s, *host_offset) == (entry & L2E_OFFSET_MASK)))
     {
         int preallocated_nb_clusters;
@@ -XXX,XX +XXX,XX @@ static int handle_alloc(BlockDriverState *bs, uint64_t guest_offset,
 
     qcow2_cache_put(s->l2_table_cache, (void **) &l2_slice);
 
-    if (!alloc_cluster_offset) {
+    if (alloc_cluster_offset == INV_OFFSET) {
         /* Allocate, if necessary at a given offset in the image file */
-        alloc_cluster_offset = start_of_cluster(s, *host_offset);
+        alloc_cluster_offset = *host_offset == INV_OFFSET ? INV_OFFSET :
+                               start_of_cluster(s, *host_offset);
         ret = do_alloc_cluster_offset(bs, guest_offset, &alloc_cluster_offset,
                                       &nb_clusters);
         if (ret < 0) {
@@ -XXX,XX +XXX,XX @@ static int handle_alloc(BlockDriverState *bs, uint64_t guest_offset,
             return 0;
         }
 
-        /* !*host_offset would overwrite the image header and is reserved for
-         * "no host offset preferred". If 0 was a valid host offset, it'd
-         * trigger the following overlap check; do that now to avoid having an
-         * invalid value in *host_offset. */
-        if (!alloc_cluster_offset) {
-            ret = qcow2_pre_write_overlap_check(bs, 0, alloc_cluster_offset,
-                                                nb_clusters * s->cluster_size);
-            assert(ret < 0);
-            goto fail;
-        }
+        assert(alloc_cluster_offset != INV_OFFSET);
     }
 
     /*
@@ -XXX,XX +XXX,XX @@ int qcow2_alloc_cluster_offset(BlockDriverState *bs, uint64_t offset,
 again:
     start = offset;
     remaining = *bytes;
-    cluster_offset = 0;
-    *host_offset = 0;
+    cluster_offset = INV_OFFSET;
+    *host_offset = INV_OFFSET;
     cur_bytes = 0;
     *m = NULL;
 
     while (true) {
 
-        if (!*host_offset) {
+        if (*host_offset == INV_OFFSET && cluster_offset != INV_OFFSET) {
             *host_offset = start_of_cluster(s, cluster_offset);
         }
 
@@ -XXX,XX +XXX,XX @@ again:
 
         start           += cur_bytes;
         remaining       -= cur_bytes;
-        cluster_offset  += cur_bytes;
+
+        if (cluster_offset != INV_OFFSET) {
+            cluster_offset += cur_bytes;
+        }
 
         if (remaining == 0) {
             break;
@@ -XXX,XX +XXX,XX @@ again:
 
     *bytes -= remaining;
     assert(*bytes > 0);
-    assert(*host_offset != 0);
+    assert(*host_offset != INV_OFFSET);
 
     return 0;
 }
-- 
2.20.1

qcow2_alloc_compressed_cluster_offset() used to return the cluster
offset for success and 0 for error. This doesn't only conflict with 0 as
a valid host offset, but also loses the error code.

Similar to the change made to qcow2_alloc_cluster_offset() for
uncompressed clusters in commit 148da7ea9d6, make the function return
0/-errno and return the allocated cluster offset in a by-reference
parameter.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block/qcow2.h              |  7 ++++---
 block/qcow2-cluster.c      | 28 +++++++++++++---------------
 block/qcow2.c              | 19 ++++++++-----------
 tests/qemu-iotests/220.out |  2 +-
 4 files changed, 26 insertions(+), 30 deletions(-)

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_get_cluster_offset(BlockDriverState *bs, uint64_t offset,
 int qcow2_alloc_cluster_offset(BlockDriverState *bs, uint64_t offset,
                                unsigned int *bytes, uint64_t *host_offset,
                                QCowL2Meta **m);
-uint64_t qcow2_alloc_compressed_cluster_offset(BlockDriverState *bs,
-                                         uint64_t offset,
-                                         int compressed_size);
+int qcow2_alloc_compressed_cluster_offset(BlockDriverState *bs,
+                                          uint64_t offset,
+                                          int compressed_size,
+                                          uint64_t *host_offset);
 
 int qcow2_alloc_cluster_link_l2(BlockDriverState *bs, QCowL2Meta *m);
 void qcow2_alloc_cluster_abort(BlockDriverState *bs, QCowL2Meta *m);
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 int get_cluster_table(BlockDriverState *bs, uint64_t offset,
 /*
  * alloc_compressed_cluster_offset
  *
- * For a given offset of the disk image, return cluster offset in
- * qcow2 file.
- *
- * If the offset is not found, allocate a new compressed cluster.
- *
- * Return the cluster offset if successful,
- * Return 0, otherwise.
+ * For a given offset on the virtual disk, allocate a new compressed cluster
+ * and put the host offset of the cluster into *host_offset. If a cluster is
+ * already allocated at the offset, return an error.
  *
+ * Return 0 on success and -errno in error cases
  */
-
-uint64_t qcow2_alloc_compressed_cluster_offset(BlockDriverState *bs,
-                                               uint64_t offset,
-                                               int compressed_size)
+int qcow2_alloc_compressed_cluster_offset(BlockDriverState *bs,
+                                          uint64_t offset,
+                                          int compressed_size,
+                                          uint64_t *host_offset)
 {
     BDRVQcow2State *s = bs->opaque;
     int l2_index, ret;
@@ -XXX,XX +XXX,XX @@ uint64_t qcow2_alloc_compressed_cluster_offset(BlockDriverState *bs,
 
     ret = get_cluster_table(bs, offset, &l2_slice, &l2_index);
     if (ret < 0) {
-        return 0;
+        return ret;
     }
 
     /* Compression can't overwrite anything. Fail if the cluster was already
@@ -XXX,XX +XXX,XX @@ uint64_t qcow2_alloc_compressed_cluster_offset(BlockDriverState *bs,
     cluster_offset = be64_to_cpu(l2_slice[l2_index]);
     if (cluster_offset & L2E_OFFSET_MASK) {
         qcow2_cache_put(s->l2_table_cache, (void **) &l2_slice);
-        return 0;
+        return -EIO;
     }
 
     cluster_offset = qcow2_alloc_bytes(bs, compressed_size);
     if (cluster_offset < 0) {
         qcow2_cache_put(s->l2_table_cache, (void **) &l2_slice);
-        return 0;
+        return cluster_offset;
     }
 
     nb_csectors = ((cluster_offset + compressed_size - 1) >> 9) -
@@ -XXX,XX +XXX,XX @@ uint64_t qcow2_alloc_compressed_cluster_offset(BlockDriverState *bs,
     l2_slice[l2_index] = cpu_to_be64(cluster_offset);
     qcow2_cache_put(s->l2_table_cache, (void **) &l2_slice);
 
-    return cluster_offset;
+    *host_offset = cluster_offset & s->cluster_offset_mask;
+    return 0;
 }
 
 static int perform_cow(BlockDriverState *bs, QCowL2Meta *m)
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 @@ qcow2_co_pwritev_compressed(BlockDriverState *bs, uint64_t offset,
     int ret;
     size_t out_len;
     uint8_t *buf, *out_buf;
-    int64_t cluster_offset;
+    uint64_t cluster_offset;
 
     if (bytes == 0) {
         /* align end of file to a sector boundary to ease reading with
            sector based I/Os */
-        cluster_offset = bdrv_getlength(bs->file->bs);
-        if (cluster_offset < 0) {
-            return cluster_offset;
+        int64_t len = bdrv_getlength(bs->file->bs);
+        if (len < 0) {
+            return len;
         }
-        return bdrv_co_truncate(bs->file, cluster_offset, PREALLOC_MODE_OFF,
-                                NULL);
+        return bdrv_co_truncate(bs->file, len, PREALLOC_MODE_OFF, NULL);
     }
 
     if (offset_into_cluster(s, offset)) {
@@ -XXX,XX +XXX,XX @@ qcow2_co_pwritev_compressed(BlockDriverState *bs, uint64_t offset,
     }
 
     qemu_co_mutex_lock(&s->lock);
-    cluster_offset =
-        qcow2_alloc_compressed_cluster_offset(bs, offset, out_len);
-    if (!cluster_offset) {
+    ret = qcow2_alloc_compressed_cluster_offset(bs, offset, out_len,
+                                                &cluster_offset);
+    if (ret < 0) {
         qemu_co_mutex_unlock(&s->lock);
-        ret = -EIO;
         goto fail;
     }
-    cluster_offset &= s->cluster_offset_mask;
 
     ret = qcow2_pre_write_overlap_check(bs, 0, cluster_offset, out_len);
     qemu_co_mutex_unlock(&s->lock);
diff --git a/tests/qemu-iotests/220.out b/tests/qemu-iotests/220.out
index XXXXXXX..XXXXXXX 100644
--- a/tests/qemu-iotests/220.out
+++ b/tests/qemu-iotests/220.out
@@ -XXX,XX +XXX,XX @@ wrote 2097152/2097152 bytes at offset 37748736
 No errors were found on the image.
 image size 39845888
 == Trying to write compressed cluster ==
-write failed: Input/output error
+write failed: File too large
 image size 562949957615616
 == Writing normal cluster ==
 wrote 2097152/2097152 bytes at offset 0
-- 
2.20.1

Offset 0 cannot be assumed to mean an unallocated cluster any more.
Instead, the cluster type needs to be checked.

*file must refer to the data file instead of the image file if a valid
offset is returned from qcow2_co_block_status().

Signed-off-by: Kevin Wolf <kwolf@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 coroutine_fn qcow2_co_block_status(BlockDriverState *bs,
 
     *pnum = bytes;
 
-    if (cluster_offset != 0 && ret != QCOW2_CLUSTER_COMPRESSED &&
+    if ((ret == QCOW2_CLUSTER_NORMAL || ret == QCOW2_CLUSTER_ZERO_ALLOC) &&
         !s->crypto) {
         index_in_cluster = offset & (s->cluster_size - 1);
         *map = cluster_offset | index_in_cluster;
-        *file = bs->file->bs;
+        *file = s->data_file->bs;
         status |= BDRV_BLOCK_OFFSET_VALID;
     }
     if (ret == QCOW2_CLUSTER_ZERO_PLAIN || ret == QCOW2_CLUSTER_ZERO_ALLOC) {
-- 
2.20.1

This changes the qcow2 implementation to direct all guest data I/O to
s->data_file rather than bs->file, while metadata I/O still uses
bs->file. At the moment, this is still always the same, but soon we'll
add options to set s->data_file to an external data file.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block/qcow2.h          |  2 +-
 block/qcow2-bitmap.c   |  7 +++---
 block/qcow2-cache.c    |  6 ++---
 block/qcow2-cluster.c  | 46 +++++++++++++++++++++++++++++++------
 block/qcow2-refcount.c | 39 +++++++++++++++++++++++--------
 block/qcow2-snapshot.c |  7 +++---
 block/qcow2.c          | 52 +++++++++++++++++++++++++++++++++---------
 7 files changed, 122 insertions(+), 37 deletions(-)

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 @@ void qcow2_process_discards(BlockDriverState *bs, int ret);
 int qcow2_check_metadata_overlap(BlockDriverState *bs, int ign, int64_t offset,
                                  int64_t size);
 int qcow2_pre_write_overlap_check(BlockDriverState *bs, int ign, int64_t offset,
-                                  int64_t size);
+                                  int64_t size, bool data_file);
 int qcow2_inc_refcounts_imrt(BlockDriverState *bs, BdrvCheckResult *res,
                              void **refcount_table,
                              int64_t *refcount_table_size,
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 bitmap_list_store(BlockDriverState *bs, Qcow2BitmapList *bm_list,
      * directory in-place (actually, turn-off the extension), which is checked
      * in qcow2_check_metadata_overlap() */
     ret = qcow2_pre_write_overlap_check(
-            bs, in_place ? QCOW2_OL_BITMAP_DIRECTORY : 0, dir_offset, dir_size);
+            bs, in_place ? QCOW2_OL_BITMAP_DIRECTORY : 0, dir_offset, dir_size,
+            false);
     if (ret < 0) {
         goto fail;
     }
@@ -XXX,XX +XXX,XX @@ static uint64_t *store_bitmap_data(BlockDriverState *bs,
             memset(buf + write_size, 0, s->cluster_size - write_size);
         }
 
-        ret = qcow2_pre_write_overlap_check(bs, 0, off, s->cluster_size);
+        ret = qcow2_pre_write_overlap_check(bs, 0, off, s->cluster_size, false);
         if (ret < 0) {
             error_setg_errno(errp, -ret, "Qcow2 overlap check failed");
             goto fail;
@@ -XXX,XX +XXX,XX @@ static int store_bitmap(BlockDriverState *bs, Qcow2Bitmap *bm, Error **errp)
     }
 
     ret = qcow2_pre_write_overlap_check(bs, 0, tb_offset,
-                                        tb_size * sizeof(tb[0]));
+                                        tb_size * sizeof(tb[0]), false);
     if (ret < 0) {
         error_setg_errno(errp, -ret, "Qcow2 overlap check failed");
         goto fail;
diff --git a/block/qcow2-cache.c b/block/qcow2-cache.c
index XXXXXXX..XXXXXXX 100644
--- a/block/qcow2-cache.c
+++ b/block/qcow2-cache.c
@@ -XXX,XX +XXX,XX @@ static int qcow2_cache_entry_flush(BlockDriverState *bs, Qcow2Cache *c, int i)
 
     if (c == s->refcount_block_cache) {
         ret = qcow2_pre_write_overlap_check(bs, QCOW2_OL_REFCOUNT_BLOCK,
-                c->entries[i].offset, c->table_size);
+                c->entries[i].offset, c->table_size, false);
     } else if (c == s->l2_table_cache) {
         ret = qcow2_pre_write_overlap_check(bs, QCOW2_OL_ACTIVE_L2,
-                c->entries[i].offset, c->table_size);
+                c->entries[i].offset, c->table_size, false);
     } else {
         ret = qcow2_pre_write_overlap_check(bs, 0,
-                c->entries[i].offset, c->table_size);
+                c->entries[i].offset, c->table_size, false);
     }
 
     if (ret < 0) {
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 @@ int qcow2_grow_l1_table(BlockDriverState *bs, uint64_t min_size,
     /* the L1 position has not yet been updated, so these clusters must
      * indeed be completely free */
     ret = qcow2_pre_write_overlap_check(bs, 0, new_l1_table_offset,
-                                        new_l1_size2);
+                                        new_l1_size2, false);
     if (ret < 0) {
         goto fail;
     }
@@ -XXX,XX +XXX,XX @@ int qcow2_write_l1_entry(BlockDriverState *bs, int l1_index)
     }
 
     ret = qcow2_pre_write_overlap_check(bs, QCOW2_OL_ACTIVE_L1,
-            s->l1_table_offset + 8 * l1_start_index, sizeof(buf));
+            s->l1_table_offset + 8 * l1_start_index, sizeof(buf), false);
     if (ret < 0) {
         return ret;
     }
@@ -XXX,XX +XXX,XX @@ static int coroutine_fn do_perform_cow_write(BlockDriverState *bs,
                                              unsigned offset_in_cluster,
                                              QEMUIOVector *qiov)
 {
+    BDRVQcow2State *s = bs->opaque;
     int ret;
 
     if (qiov->size == 0) {
@@ -XXX,XX +XXX,XX @@ static int coroutine_fn do_perform_cow_write(BlockDriverState *bs,
     }
 
     ret = qcow2_pre_write_overlap_check(bs, 0,
-            cluster_offset + offset_in_cluster, qiov->size);
+            cluster_offset + offset_in_cluster, qiov->size, true);
     if (ret < 0) {
         return ret;
     }
 
     BLKDBG_EVENT(bs->file, BLKDBG_COW_WRITE);
-    ret = bdrv_co_pwritev(bs->file, cluster_offset + offset_in_cluster,
+    ret = bdrv_co_pwritev(s->data_file, cluster_offset + offset_in_cluster,
                           qiov->size, qiov, 0);
     if (ret < 0) {
         return ret;
@@ -XXX,XX +XXX,XX @@ int qcow2_get_cluster_offset(BlockDriverState *bs, uint64_t offset,
     }
     switch (type) {
     case QCOW2_CLUSTER_COMPRESSED:
+        if (has_data_file(bs)) {
+            qcow2_signal_corruption(bs, true, -1, -1, "Compressed cluster "
+                                    "entry found in image with external data "
+                                    "file (L2 offset: %#" PRIx64 ", L2 index: "
+                                    "%#x)", l2_offset, l2_index);
+            ret = -EIO;
+            goto fail;
+        }
         /* Compressed clusters can only be processed one by one */
         c = 1;
         *cluster_offset &= L2E_COMPRESSED_OFFSET_SIZE_MASK;
@@ -XXX,XX +XXX,XX @@ int qcow2_get_cluster_offset(BlockDriverState *bs, uint64_t offset,
             ret = -EIO;
             goto fail;
         }
+        if (has_data_file(bs) && *cluster_offset != offset - offset_in_cluster)
+        {
+            qcow2_signal_corruption(bs, true, -1, -1,
+                                    "External data file host cluster offset %#"
+                                    PRIx64 " does not match guest cluster "
+                                    "offset: %#" PRIx64
+                                    ", L2 index: %#x)", *cluster_offset,
+                                    offset - offset_in_cluster, l2_index);
+            ret = -EIO;
+            goto fail;
+        }
         break;
     default:
         abort();
@@ -XXX,XX +XXX,XX @@ int qcow2_alloc_compressed_cluster_offset(BlockDriverState *bs,
     int64_t cluster_offset;
     int nb_csectors;
 
+    if (has_data_file(bs)) {
+        return 0;
+    }
+
     ret = get_cluster_table(bs, offset, &l2_slice, &l2_index);
     if (ret < 0) {
         return ret;
@@ -XXX,XX +XXX,XX @@ static int do_alloc_cluster_offset(BlockDriverState *bs, uint64_t guest_offset,
     trace_qcow2_do_alloc_clusters_offset(qemu_coroutine_self(), guest_offset,
                                          *host_offset, *nb_clusters);
 
+    if (has_data_file(bs)) {
+        assert(*host_offset == INV_OFFSET ||
+               *host_offset == start_of_cluster(s, guest_offset));
+        *host_offset = start_of_cluster(s, guest_offset);
+        return 0;
+    }
+
     /* Allocate new clusters */
     trace_qcow2_cluster_alloc_phys(qemu_coroutine_self());
     if (*host_offset == INV_OFFSET) {
@@ -XXX,XX +XXX,XX @@ static int expand_zero_clusters_in_l1(BlockDriverState *bs, uint64_t *l1_table,
                 }
 
                 ret = qcow2_pre_write_overlap_check(bs, 0, offset,
-                                                    s->cluster_size);
+                                                    s->cluster_size, true);
                 if (ret < 0) {
                     if (cluster_type == QCOW2_CLUSTER_ZERO_PLAIN) {
                         qcow2_free_clusters(bs, offset, s->cluster_size,
@@ -XXX,XX +XXX,XX @@ static int expand_zero_clusters_in_l1(BlockDriverState *bs, uint64_t *l1_table,
                     goto fail;
                 }
 
-                ret = bdrv_pwrite_zeroes(bs->file, offset, s->cluster_size, 0);
+                ret = bdrv_pwrite_zeroes(s->data_file, offset,
+                                         s->cluster_size, 0);
                 if (ret < 0) {
                     if (cluster_type == QCOW2_CLUSTER_ZERO_PLAIN) {
                         qcow2_free_clusters(bs, offset, s->cluster_size,
@@ -XXX,XX +XXX,XX @@ static int expand_zero_clusters_in_l1(BlockDriverState *bs, uint64_t *l1_table,
                 if (l2_dirty) {
                     ret = qcow2_pre_write_overlap_check(
                         bs, QCOW2_OL_INACTIVE_L2 | QCOW2_OL_ACTIVE_L2,
-                        slice_offset, slice_size2);
+                        slice_offset, slice_size2, false);
                     if (ret < 0) {
                         goto fail;
                     }
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 @@ void qcow2_free_any_clusters(BlockDriverState *bs, uint64_t l2_entry,
                              int nb_clusters, enum qcow2_discard_type type)
 {
     BDRVQcow2State *s = bs->opaque;
+    QCow2ClusterType ctype = qcow2_get_cluster_type(bs, l2_entry);
 
-    switch (qcow2_get_cluster_type(bs, l2_entry)) {
+    if (has_data_file(bs)) {
+        if (s->discard_passthrough[type] &&
+            (ctype == QCOW2_CLUSTER_NORMAL ||
+             ctype == QCOW2_CLUSTER_ZERO_ALLOC))
+        {
+            bdrv_pdiscard(s->data_file, l2_entry & L2E_OFFSET_MASK,
+                          nb_clusters << s->cluster_bits);
+        }
+        return;
+    }
+
+    switch (ctype) {
     case QCOW2_CLUSTER_COMPRESSED:
         {
             int nb_csectors;
@@ -XXX,XX +XXX,XX @@ static int check_refcounts_l2(BlockDriverState *bs, BdrvCheckResult *res,
                         l2_table[i] = cpu_to_be64(l2_entry);
                         ret = qcow2_pre_write_overlap_check(bs,
                                 QCOW2_OL_ACTIVE_L2 | QCOW2_OL_INACTIVE_L2,
-                                l2e_offset, sizeof(uint64_t));
+                                l2e_offset, sizeof(uint64_t), false);
                         if (ret < 0) {
                             fprintf(stderr, "ERROR: Overlap check failed\n");
                             res->check_errors++;
@@ -XXX,XX +XXX,XX @@ static int check_oflag_copied(BlockDriverState *bs, BdrvCheckResult *res,
 
         if (l2_dirty) {
             ret = qcow2_pre_write_overlap_check(bs, QCOW2_OL_ACTIVE_L2,
-                                                l2_offset, s->cluster_size);
+                                                l2_offset, s->cluster_size,
+                                                false);
             if (ret < 0) {
                 fprintf(stderr, "ERROR: Could not write L2 table; metadata "
                         "overlap check failed: %s\n", strerror(-ret));
@@ -XXX,XX +XXX,XX @@ write_refblocks:
         }
 
         ret = qcow2_pre_write_overlap_check(bs, 0, refblock_offset,
-                                            s->cluster_size);
+                                            s->cluster_size, false);
         if (ret < 0) {
             fprintf(stderr, "ERROR writing refblock: %s\n", strerror(-ret));
             goto fail;
@@ -XXX,XX +XXX,XX @@ write_refblocks:
     }
 
     ret = qcow2_pre_write_overlap_check(bs, 0, reftable_offset,
-                                        reftable_size * sizeof(uint64_t));
+                                        reftable_size * sizeof(uint64_t),
+                                        false);
     if (ret < 0) {
         fprintf(stderr, "ERROR writing reftable: %s\n", strerror(-ret));
         goto fail;
@@ -XXX,XX +XXX,XX @@ QEMU_BUILD_BUG_ON(QCOW2_OL_MAX_BITNR != ARRAY_SIZE(metadata_ol_names));
  * overlaps; or a negative value (-errno) on error.
  */
 int qcow2_pre_write_overlap_check(BlockDriverState *bs, int ign, int64_t offset,
-                                  int64_t size)
+                                  int64_t size, bool data_file)
 {
-    int ret = qcow2_check_metadata_overlap(bs, ign, offset, size);
+    int ret;
+
+    if (data_file && has_data_file(bs)) {
+        return 0;
+    }
 
+    ret = qcow2_check_metadata_overlap(bs, ign, offset, size);
     if (ret < 0) {
         return ret;
     } else if (ret > 0) {
@@ -XXX,XX +XXX,XX @@ static int flush_refblock(BlockDriverState *bs, uint64_t **reftable,
     if (reftable_index < *reftable_size && (*reftable)[reftable_index]) {
         offset = (*reftable)[reftable_index];
 
-        ret = qcow2_pre_write_overlap_check(bs, 0, offset, s->cluster_size);
+        ret = qcow2_pre_write_overlap_check(bs, 0, offset, s->cluster_size,
+                                            false);
         if (ret < 0) {
             error_setg_errno(errp, -ret, "Overlap check failed");
             return ret;
@@ -XXX,XX +XXX,XX @@ int qcow2_change_refcount_order(BlockDriverState *bs, int refcount_order,
 
     /* Write the new reftable */
     ret = qcow2_pre_write_overlap_check(bs, 0, new_reftable_offset,
-                                        new_reftable_size * sizeof(uint64_t));
+                                        new_reftable_size * sizeof(uint64_t),
+                                        false);
     if (ret < 0) {
         error_setg_errno(errp, -ret, "Overlap check failed");
         goto done;
diff --git a/block/qcow2-snapshot.c b/block/qcow2-snapshot.c
index XXXXXXX..XXXXXXX 100644
--- a/block/qcow2-snapshot.c
+++ b/block/qcow2-snapshot.c
@@ -XXX,XX +XXX,XX @@ static int qcow2_write_snapshots(BlockDriverState *bs)
 
     /* The snapshot list position has not yet been updated, so these clusters
      * must indeed be completely free */
-    ret = qcow2_pre_write_overlap_check(bs, 0, offset, snapshots_size);
+    ret = qcow2_pre_write_overlap_check(bs, 0, offset, snapshots_size, false);
     if (ret < 0) {
         goto fail;
     }
@@ -XXX,XX +XXX,XX @@ int qcow2_snapshot_create(BlockDriverState *bs, QEMUSnapshotInfo *sn_info)
     }
 
     ret = qcow2_pre_write_overlap_check(bs, 0, sn->l1_table_offset,
-                                        s->l1_size * sizeof(uint64_t));
+                                        s->l1_size * sizeof(uint64_t), false);
     if (ret < 0) {
         goto fail;
     }
@@ -XXX,XX +XXX,XX @@ int qcow2_snapshot_goto(BlockDriverState *bs, const char *snapshot_id)
     }
 
     ret = qcow2_pre_write_overlap_check(bs, QCOW2_OL_ACTIVE_L1,
-                                        s->l1_table_offset, cur_l1_bytes);
+                                        s->l1_table_offset, cur_l1_bytes,
+                                        false);
     if (ret < 0) {
         goto fail;
     }
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 ssize_t qcow2_crypto_hdr_init_func(QCryptoBlock *block, size_t headerlen,
     /* Zero fill remaining space in cluster so it has predictable
      * content in case of future spec changes */
     clusterlen = size_to_clusters(s, headerlen) * s->cluster_size;
-    assert(qcow2_pre_write_overlap_check(bs, 0, ret, clusterlen) == 0);
+    assert(qcow2_pre_write_overlap_check(bs, 0, ret, clusterlen, false) == 0);
     ret = bdrv_pwrite_zeroes(bs->file,
                              ret + headerlen,
                              clusterlen - headerlen, 0);
@@ -XXX,XX +XXX,XX @@ static coroutine_fn int qcow2_co_preadv(BlockDriverState *bs, uint64_t offset,
                  */
                 if (!cluster_data) {
                     cluster_data =
-                        qemu_try_blockalign(bs->file->bs,
+                        qemu_try_blockalign(s->data_file->bs,
                                             QCOW_MAX_CRYPT_CLUSTERS
                                             * s->cluster_size);
                     if (cluster_data == NULL) {
@@ -XXX,XX +XXX,XX @@ static coroutine_fn int qcow2_co_preadv(BlockDriverState *bs, uint64_t offset,
 
             BLKDBG_EVENT(bs->file, BLKDBG_READ_AIO);
             qemu_co_mutex_unlock(&s->lock);
-            ret = bdrv_co_preadv(bs->file,
+            ret = bdrv_co_preadv(s->data_file,
                                  cluster_offset + offset_in_cluster,
                                  cur_bytes, &hd_qiov, 0);
             qemu_co_mutex_lock(&s->lock);
@@ -XXX,XX +XXX,XX @@ static coroutine_fn int qcow2_co_pwritev(BlockDriverState *bs, uint64_t offset,
         }
 
         ret = qcow2_pre_write_overlap_check(bs, 0,
-                cluster_offset + offset_in_cluster, cur_bytes);
+                cluster_offset + offset_in_cluster, cur_bytes, true);
         if (ret < 0) {
             goto fail;
         }
@@ -XXX,XX +XXX,XX @@ static coroutine_fn int qcow2_co_pwritev(BlockDriverState *bs, uint64_t offset,
             BLKDBG_EVENT(bs->file, BLKDBG_WRITE_AIO);
             trace_qcow2_writev_data(qemu_coroutine_self(),
                                     cluster_offset + offset_in_cluster);
-            ret = bdrv_co_pwritev(bs->file,
+            ret = bdrv_co_pwritev(s->data_file,
                                   cluster_offset + offset_in_cluster,
                                   cur_bytes, &hd_qiov, 0);
             qemu_co_mutex_lock(&s->lock);
@@ -XXX,XX +XXX,XX @@ qcow2_co_copy_range_from(BlockDriverState *bs,
             goto out;
 
         case QCOW2_CLUSTER_NORMAL:
-            child = bs->file;
+            child = s->data_file;
             copy_offset += offset_into_cluster(s, src_offset);
             if ((copy_offset & 511) != 0) {
                 ret = -EIO;
@@ -XXX,XX +XXX,XX @@ qcow2_co_copy_range_to(BlockDriverState *bs,
         assert((cluster_offset & 511) == 0);
 
         ret = qcow2_pre_write_overlap_check(bs, 0,
-                cluster_offset + offset_in_cluster, cur_bytes);
+                cluster_offset + offset_in_cluster, cur_bytes, true);
         if (ret < 0) {
             goto fail;
         }
 
         qemu_co_mutex_unlock(&s->lock);
         ret = bdrv_co_copy_range_to(src, src_offset,
-                                    bs->file,
+                                    s->data_file,
                                     cluster_offset + offset_in_cluster,
                                     cur_bytes, read_flags, write_flags);
         qemu_co_mutex_lock(&s->lock);
@@ -XXX,XX +XXX,XX @@ static int coroutine_fn qcow2_co_truncate(BlockDriverState *bs, int64_t offset,
         int64_t old_file_size, new_file_size;
         uint64_t nb_new_data_clusters, nb_new_l2_tables;
 
+        /* With a data file, preallocation means just allocating the metadata
+         * and forwarding the truncate request to the data file */
+        if (has_data_file(bs)) {
+            ret = preallocate_co(bs, old_length, offset);
+            if (ret < 0) {
+                error_setg_errno(errp, -ret, "Preallocation failed");
+                goto fail;
+            }
+            break;
+        }
+
         old_file_size = bdrv_getlength(bs->file->bs);
         if (old_file_size < 0) {
             error_setg_errno(errp, -old_file_size,
@@ -XXX,XX +XXX,XX @@ static int coroutine_fn qcow2_co_truncate(BlockDriverState *bs, int64_t offset,
 
     bs->total_sectors = offset / BDRV_SECTOR_SIZE;
 
+    if (has_data_file(bs)) {
+        if (prealloc == PREALLOC_MODE_METADATA) {
+            prealloc = PREALLOC_MODE_OFF;
+        }
+        ret = bdrv_co_truncate(s->data_file, offset, prealloc, errp);
+        if (ret < 0) {
+            goto fail;
+        }
+    }
+
     /* write updated header.size */
     offset = cpu_to_be64(offset);
     ret = bdrv_pwrite_sync(bs->file, offsetof(QCowHeader, size),
@@ -XXX,XX +XXX,XX @@ qcow2_co_pwritev_compressed(BlockDriverState *bs, uint64_t offset,
     uint8_t *buf, *out_buf;
     uint64_t cluster_offset;
 
+    if (has_data_file(bs)) {
+        return -ENOTSUP;
+    }
+
     if (bytes == 0) {
         /* align end of file to a sector boundary to ease reading with
            sector based I/Os */
@@ -XXX,XX +XXX,XX @@ qcow2_co_pwritev_compressed(BlockDriverState *bs, uint64_t offset,
         goto fail;
     }
 
-    ret = qcow2_pre_write_overlap_check(bs, 0, cluster_offset, out_len);
+    ret = qcow2_pre_write_overlap_check(bs, 0, cluster_offset, out_len, true);
     qemu_co_mutex_unlock(&s->lock);
     if (ret < 0) {
         goto fail;
@@ -XXX,XX +XXX,XX @@ qcow2_co_pwritev_compressed(BlockDriverState *bs, uint64_t offset,
 
     qemu_iovec_init_buf(&hd_qiov, out_buf, out_len);
 
-    BLKDBG_EVENT(bs->file, BLKDBG_WRITE_COMPRESSED);
-    ret = bdrv_co_pwritev(bs->file, cluster_offset, out_len, &hd_qiov, 0);
+    BLKDBG_EVENT(s->data_file, BLKDBG_WRITE_COMPRESSED);
+    ret = bdrv_co_pwritev(s->data_file, cluster_offset, out_len, &hd_qiov, 0);
     if (ret < 0) {
         goto fail;
     }
@@ -XXX,XX +XXX,XX @@ static int qcow2_downgrade(BlockDriverState *bs, int target_version,
         return -ENOTSUP;
     }
 
+    if (has_data_file(bs)) {
+        error_setg(errp, "Cannot downgrade an image with a data file");
+        return -ENOTSUP;
+    }
+
     /* clear incompatible features */
     if (s->incompatible_features & QCOW2_INCOMPAT_DIRTY) {
         ret = qcow2_mark_clean(bs);
-- 
2.20.1

Internal snapshots and an external data file are incompatible because
snapshots require refcounting and non-linear mapping. Return an error
for all of the snapshot operations if an external data file is in use.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block/qcow2-snapshot.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/block/qcow2-snapshot.c b/block/qcow2-snapshot.c
index XXXXXXX..XXXXXXX 100644
--- a/block/qcow2-snapshot.c
+++ b/block/qcow2-snapshot.c
@@ -XXX,XX +XXX,XX @@ int qcow2_snapshot_create(BlockDriverState *bs, QEMUSnapshotInfo *sn_info)
         return -EFBIG;
     }
 
+    if (has_data_file(bs)) {
+        return -ENOTSUP;
+    }
+
     memset(sn, 0, sizeof(*sn));
 
     /* Generate an ID */
@@ -XXX,XX +XXX,XX @@ int qcow2_snapshot_goto(BlockDriverState *bs, const char *snapshot_id)
     int ret;
     uint64_t *sn_l1_table = NULL;
 
+    if (has_data_file(bs)) {
+        return -ENOTSUP;
+    }
+
     /* Search the snapshot */
     snapshot_index = find_snapshot_by_id_or_name(bs, snapshot_id);
     if (snapshot_index < 0) {
@@ -XXX,XX +XXX,XX @@ int qcow2_snapshot_delete(BlockDriverState *bs,
     QCowSnapshot sn;
     int snapshot_index, ret;
 
+    if (has_data_file(bs)) {
+        return -ENOTSUP;
+    }
+
     /* Search the snapshot */
     snapshot_index = find_snapshot_by_id_and_name(bs, snapshot_id, name);
     if (snapshot_index < 0) {
@@ -XXX,XX +XXX,XX @@ int qcow2_snapshot_list(BlockDriverState *bs, QEMUSnapshotInfo **psn_tab)
     QCowSnapshot *sn;
     int i;
 
+    if (has_data_file(bs)) {
+        return -ENOTSUP;
+    }
     if (!s->nb_snapshots) {
         *psn_tab = NULL;
         return s->nb_snapshots;
-- 
2.20.1

For external data files, data clusters must be excluded from the
refcount calculations. Instead, an implicit refcount of 1 is assumed for
the COPIED flag.

Compressed clusters and internal snapshots are incompatible with
external data files, so print an error if they are in use for images
with an external data file.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block/qcow2-refcount.c | 41 ++++++++++++++++++++++++++++++-----------
 1 file changed, 30 insertions(+), 11 deletions(-)

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 @@ static int check_refcounts_l2(BlockDriverState *bs, BdrvCheckResult *res,
                 res->corruptions++;
             }
 
+            if (has_data_file(bs)) {
+                fprintf(stderr, "ERROR compressed cluster %d with data file, "
+                        "entry=0x%" PRIx64 "\n", i, l2_entry);
+                res->corruptions++;
+                break;
+            }
+
             /* Mark cluster as used */
             nb_csectors = ((l2_entry >> s->csize_shift) &
                            s->csize_mask) + 1;
@@ -XXX,XX +XXX,XX @@ static int check_refcounts_l2(BlockDriverState *bs, BdrvCheckResult *res,
             }
 
             /* Mark cluster as used */
-            ret = qcow2_inc_refcounts_imrt(bs, res,
-                                           refcount_table, refcount_table_size,
-                                           offset, s->cluster_size);
-            if (ret < 0) {
-                goto fail;
+            if (!has_data_file(bs)) {
+                ret = qcow2_inc_refcounts_imrt(bs, res, refcount_table,
+                                               refcount_table_size,
+                                               offset, s->cluster_size);
+                if (ret < 0) {
+                    goto fail;
+                }
             }
             break;
         }
@@ -XXX,XX +XXX,XX @@ static int check_oflag_copied(BlockDriverState *bs, BdrvCheckResult *res,
 
             if (cluster_type == QCOW2_CLUSTER_NORMAL ||
                 cluster_type == QCOW2_CLUSTER_ZERO_ALLOC) {
-                ret = qcow2_get_refcount(bs,
-                                         data_offset >> s->cluster_bits,
-                                         &refcount);
-                if (ret < 0) {
-                    /* don't print message nor increment check_errors */
-                    continue;
+                if (has_data_file(bs)) {
+                    refcount = 1;
+                } else {
+                    ret = qcow2_get_refcount(bs,
+                                             data_offset >> s->cluster_bits,
+                                             &refcount);
+                    if (ret < 0) {
+                        /* don't print message nor increment check_errors */
+                        continue;
+                    }
                 }
                 if ((refcount == 1) != ((l2_entry & QCOW_OFLAG_COPIED) != 0)) {
                     fprintf(stderr, "%s OFLAG_COPIED data cluster: "
@@ -XXX,XX +XXX,XX @@ static int calculate_refcounts(BlockDriverState *bs, BdrvCheckResult *res,
     }
 
     /* snapshots */
+    if (has_data_file(bs) && s->nb_snapshots) {
+        fprintf(stderr, "ERROR %d snapshots in image with data file\n",
+                s->nb_snapshots);
+        res->corruptions++;
+    }
+
     for (i = 0; i < s->nb_snapshots; i++) {
         sn = s->snapshots + i;
         if (offset_into_cluster(s, sn->l1_table_offset)) {
-- 
2.20.1

This adds a .bdrv_open option to specify the external data file node.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 qapi/block-core.json |  7 ++++++-
 block/qcow2.h        |  4 +++-
 block/qcow2.c        | 34 ++++++++++++++++++++++++++++++++--
 3 files changed, 41 insertions(+), 4 deletions(-)

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 @@
 #                         encrypted images, except when doing a metadata-only
 #                         probe of the image. (since 2.10)
 #
+# @data-file:             reference to or definition of the external data file.
+#                         This may only be specified for images that require an
+#                         external data file. (since 4.0)
+#
 # Since: 2.9
 ##
 { 'struct': 'BlockdevOptionsQcow2',
@@ -XXX,XX +XXX,XX @@
             '*l2-cache-entry-size': 'int',
             '*refcount-cache-size': 'int',
             '*cache-clean-interval': 'int',
-            '*encrypt': 'BlockdevQcow2Encryption' } }
+            '*encrypt': 'BlockdevQcow2Encryption',
+            '*data-file': 'BlockdevRef' } }
 
 ##
 # @SshHostKeyCheckMode:
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 @@
 
 #define DEFAULT_CLUSTER_SIZE 65536
 
+#define QCOW2_OPT_DATA_FILE "data-file"
 #define QCOW2_OPT_LAZY_REFCOUNTS "lazy-refcounts"
 #define QCOW2_OPT_DISCARD_REQUEST "pass-discard-request"
 #define QCOW2_OPT_DISCARD_SNAPSHOT "pass-discard-snapshot"
@@ -XXX,XX +XXX,XX @@ enum {
     QCOW2_INCOMPAT_DATA_FILE        = 1 << QCOW2_INCOMPAT_DATA_FILE_BITNR,
 
     QCOW2_INCOMPAT_MASK             = QCOW2_INCOMPAT_DIRTY
-                                    | QCOW2_INCOMPAT_CORRUPT,
+                                    | QCOW2_INCOMPAT_CORRUPT
+                                    | QCOW2_INCOMPAT_DATA_FILE,
 };
 
 /* Compatible feature bits */
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 coroutine_fn qcow2_do_open(BlockDriverState *bs, QDict *options,
         goto fail;
     }
 
-    /* TODO Open external data file */
-    s->data_file = bs->file;
+    /* Open external data file */
+    s->data_file = bdrv_open_child(NULL, options, "data-file", bs, &child_file,
+                                   true, &local_err);
+    if (local_err) {
+        error_propagate(errp, local_err);
+        ret = -EINVAL;
+        goto fail;
+    }
+
+    if (s->incompatible_features & QCOW2_INCOMPAT_DATA_FILE) {
+        if (!s->data_file) {
+            error_setg(errp, "'data-file' is required for this image");
+            ret = -EINVAL;
+            goto fail;
+        }
+    } else {
+        if (s->data_file) {
+            error_setg(errp, "'data-file' can only be set for images with an "
+                             "external data file");
+            ret = -EINVAL;
+            goto fail;
+        } else {
+            s->data_file = bs->file;
+        }
+    }
 
     /* qcow2_read_extension may have set up the crypto context
      * if the crypt method needs a header region, some methods
@@ -XXX,XX +XXX,XX @@ static int coroutine_fn qcow2_do_open(BlockDriverState *bs, QDict *options,
     return ret;
 
  fail:
+    if (has_data_file(bs)) {
+        bdrv_unref_child(bs, s->data_file);
+    }
     g_free(s->unknown_header_fields);
     cleanup_unknown_header_ext(bs);
     qcow2_free_snapshots(bs);
@@ -XXX,XX +XXX,XX @@ static void qcow2_close(BlockDriverState *bs)
     g_free(s->image_backing_file);
     g_free(s->image_backing_format);
 
+    if (has_data_file(bs)) {
+        bdrv_unref_child(bs, s->data_file);
+    }
+
     qcow2_refcount_close(bs);
     qcow2_free_snapshots(bs);
 }
-- 
2.20.1

This adds a .bdrv_create option to use an external data file.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 qapi/block-core.json      |  4 ++++
 include/block/block_int.h |  1 +
 block/qcow2.c             | 26 ++++++++++++++++++++++++++
 3 files changed, 31 insertions(+)

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 @@
 # Driver specific image creation options for qcow2.
 #
 # @file             Node to create the image format on
+# @data-file        Node to use as an external data file in which all guest
+#                   data is stored so that only metadata remains in the qcow2
+#                   file (since: 4.0)
 # @size             Size of the virtual disk in bytes
 # @version          Compatibility level (default: v3)
 # @backing-file     File name of the backing file if a backing file
@@ -XXX,XX +XXX,XX @@
 ##
 { 'struct': 'BlockdevCreateOptionsQcow2',
   'data': { 'file':             'BlockdevRef',
+            '*data-file':       'BlockdevRef',
             'size':             'size',
             '*version':         'BlockdevQcow2Version',
             '*backing-file':    'str',
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 @@
 #define BLOCK_OPT_NOCOW             "nocow"
 #define BLOCK_OPT_OBJECT_SIZE       "object_size"
 #define BLOCK_OPT_REFCOUNT_BITS     "refcount_bits"
+#define BLOCK_OPT_DATA_FILE         "data_file"
 
 #define BLOCK_PROBE_BUF_SIZE        512
 
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 @@ qcow2_co_create(BlockdevCreateOptions *create_options, Error **errp)
      */
     BlockBackend *blk = NULL;
     BlockDriverState *bs = NULL;
+    BlockDriverState *data_bs = NULL;
     QCowHeader *header;
     size_t cluster_size;
     int version;
@@ -XXX,XX +XXX,XX @@ qcow2_co_create(BlockdevCreateOptions *create_options, Error **errp)
     }
     refcount_order = ctz32(qcow2_opts->refcount_bits);
 
+    if (qcow2_opts->data_file) {
+        if (version < 3) {
+            error_setg(errp, "External data files are only supported with "
+                       "compatibility level 1.1 and above (use version=v3 or "
+                       "greater)");
+            ret = -EINVAL;
+            goto out;
+        }
+        data_bs = bdrv_open_blockdev_ref(qcow2_opts->data_file, errp);
+        if (bs == NULL) {
+            ret = -EIO;
+            goto out;
+        }
+    }
 
     /* Create BlockBackend to write to the image */
     blk = blk_new(BLK_PERM_WRITE | BLK_PERM_RESIZE, BLK_PERM_ALL);
@@ -XXX,XX +XXX,XX @@ qcow2_co_create(BlockdevCreateOptions *create_options, Error **errp)
         header->compatible_features |=
             cpu_to_be64(QCOW2_COMPAT_LAZY_REFCOUNTS);
     }
+    if (data_bs) {
+        header->incompatible_features |=
+            cpu_to_be64(QCOW2_INCOMPAT_DATA_FILE);
+    }
 
     ret = blk_pwrite(blk, 0, header, cluster_size, 0);
     g_free(header);
@@ -XXX,XX +XXX,XX @@ qcow2_co_create(BlockdevCreateOptions *create_options, Error **errp)
     options = qdict_new();
     qdict_put_str(options, "driver", "qcow2");
     qdict_put_str(options, "file", bs->node_name);
+    if (data_bs) {
+        qdict_put_str(options, "data-file", data_bs->node_name);
+    }
     blk = blk_new_open(NULL, NULL, options,
                        BDRV_O_RDWR | BDRV_O_RESIZE | BDRV_O_NO_FLUSH,
                        &local_err);
@@ -XXX,XX +XXX,XX @@ qcow2_co_create(BlockdevCreateOptions *create_options, Error **errp)
     options = qdict_new();
     qdict_put_str(options, "driver", "qcow2");
     qdict_put_str(options, "file", bs->node_name);
+    if (data_bs) {
+        qdict_put_str(options, "data-file", data_bs->node_name);
+    }
     blk = blk_new_open(NULL, NULL, options,
                        BDRV_O_RDWR | BDRV_O_NO_BACKING | BDRV_O_NO_IO,
                        &local_err);
@@ -XXX,XX +XXX,XX @@ qcow2_co_create(BlockdevCreateOptions *create_options, Error **errp)
 out:
     blk_unref(blk);
     bdrv_unref(bs);
+    bdrv_unref(data_bs);
     return ret;
 }
 
-- 
2.20.1

Rather than requiring that the external data file node is passed
explicitly when creating the qcow2 node, store the filename in the
designated header extension during .bdrv_create and read it from there
as a default during .bdrv_open.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 qapi/block-core.json       |  8 +++-
 block/qcow2.h              |  1 +
 block/qcow2.c              | 94 +++++++++++++++++++++++++++++++++++++-
 tests/qemu-iotests/082.out | 27 +++++++++++
 4 files changed, 128 insertions(+), 2 deletions(-)

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 @@
 #
 # @compat: compatibility level
 #
+# @data-file: the filename of the external data file that is stored in the
+#             image and used as a default for opening the image (since: 4.0)
+#
 # @lazy-refcounts: on or off; only valid for compat >= 1.1
 #
 # @corrupt: true if the image has been marked corrupt; only valid for
@@ -XXX,XX +XXX,XX @@
 { 'struct': 'ImageInfoSpecificQCow2',
   'data': {
       'compat': 'str',
+      '*data-file': 'str',
       '*lazy-refcounts': 'bool',
       '*corrupt': 'bool',
       'refcount-bits': 'int',
@@ -XXX,XX +XXX,XX @@
 #
 # @data-file:             reference to or definition of the external data file.
 #                         This may only be specified for images that require an
-#                         external data file. (since 4.0)
+#                         external data file. If it is not specified for such
+#                         an image, the data file name is loaded from the image
+#                         file. (since 4.0)
 #
 # Since: 2.9
 ##
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 @@ typedef struct BDRVQcow2State {
      * override) */
     char *image_backing_file;
     char *image_backing_format;
+    char *image_data_file;
 
     CoQueue compress_wait_queue;
     int nb_compress_threads;
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_read_extensions(BlockDriverState *bs, uint64_t start_offset,
 #endif
             break;
 
+        case QCOW2_EXT_MAGIC_DATA_FILE:
+        {
+            s->image_data_file = g_malloc0(ext.len + 1);
+            ret = bdrv_pread(bs->file, offset, s->image_data_file, ext.len);
+            if (ret < 0) {
+                error_setg_errno(errp, -ret,
+                                 "ERROR: Could not read data file name");
+                return ret;
+            }
+#ifdef DEBUG_EXT
+            printf("Qcow2: Got external data file %s\n", s->image_data_file);
+#endif
+            break;
+        }
+
         default:
             /* unknown magic - save it in case we need to rewrite the header */
             /* If you add a new feature, make sure to also update the fast
@@ -XXX,XX +XXX,XX @@ static int coroutine_fn qcow2_do_open(BlockDriverState *bs, QDict *options,
     }
 
     if (s->incompatible_features & QCOW2_INCOMPAT_DATA_FILE) {
+        if (!s->data_file && s->image_data_file) {
+            s->data_file = bdrv_open_child(s->image_data_file, options,
+                                           "data-file", bs, &child_file,
+                                           false, errp);
+            if (!s->data_file) {
+                ret = -EINVAL;
+                goto fail;
+            }
+        }
         if (!s->data_file) {
             error_setg(errp, "'data-file' is required for this image");
             ret = -EINVAL;
@@ -XXX,XX +XXX,XX @@ static int coroutine_fn qcow2_do_open(BlockDriverState *bs, QDict *options,
     return ret;
 
  fail:
+    g_free(s->image_data_file);
     if (has_data_file(bs)) {
         bdrv_unref_child(bs, s->data_file);
     }
@@ -XXX,XX +XXX,XX @@ static void qcow2_close(BlockDriverState *bs)
     g_free(s->unknown_header_fields);
     cleanup_unknown_header_ext(bs);
 
+    g_free(s->image_data_file);
     g_free(s->image_backing_file);
     g_free(s->image_backing_format);
 
@@ -XXX,XX +XXX,XX @@ int qcow2_update_header(BlockDriverState *bs)
         buflen -= ret;
     }
 
+    /* External data file header extension */
+    if (has_data_file(bs) && s->image_data_file) {
+        ret = header_ext_add(buf, QCOW2_EXT_MAGIC_DATA_FILE,
+                             s->image_data_file, strlen(s->image_data_file),
+                             buflen);
+        if (ret < 0) {
+            goto fail;
+        }
+
+        buf += ret;
+        buflen -= ret;
+    }
+
     /* Full disk encryption header pointer extension */
     if (s->crypto_header.offset != 0) {
         s->crypto_header.offset = cpu_to_be64(s->crypto_header.offset);
@@ -XXX,XX +XXX,XX @@ qcow2_co_create(BlockdevCreateOptions *create_options, Error **errp)
         abort();
     }
 
+    /* Set the external data file if necessary */
+    if (data_bs) {
+        BDRVQcow2State *s = blk_bs(blk)->opaque;
+        s->image_data_file = g_strdup(data_bs->filename);
+    }
+
     /* Create a full header (including things like feature table) */
     ret = qcow2_update_header(blk_bs(blk));
     if (ret < 0) {
@@ -XXX,XX +XXX,XX @@ static int coroutine_fn qcow2_co_create_opts(const char *filename, QemuOpts *opt
     QDict *qdict;
     Visitor *v;
     BlockDriverState *bs = NULL;
+    BlockDriverState *data_bs = NULL;
     Error *local_err = NULL;
     const char *val;
     int ret;
@@ -XXX,XX +XXX,XX @@ static int coroutine_fn qcow2_co_create_opts(const char *filename, QemuOpts *opt
         goto finish;
     }
 
+    /* Create and open an external data file (protocol layer) */
+    val = qdict_get_try_str(qdict, BLOCK_OPT_DATA_FILE);
+    if (val) {
+        ret = bdrv_create_file(val, opts, errp);
+        if (ret < 0) {
+            goto finish;
+        }
+
+        data_bs = bdrv_open(val, NULL, NULL,
+                            BDRV_O_RDWR | BDRV_O_RESIZE | BDRV_O_PROTOCOL,
+                            errp);
+        if (data_bs == NULL) {
+            ret = -EIO;
+            goto finish;
+        }
+
+        qdict_del(qdict, BLOCK_OPT_DATA_FILE);
+        qdict_put_str(qdict, "data-file", data_bs->node_name);
+    }
+
     /* Set 'driver' and 'node' options */
     qdict_put_str(qdict, "driver", "qcow2");
     qdict_put_str(qdict, "file", bs->node_name);
@@ -XXX,XX +XXX,XX @@ static int coroutine_fn qcow2_co_create_opts(const char *filename, QemuOpts *opt
 finish:
     qobject_unref(qdict);
     bdrv_unref(bs);
+    bdrv_unref(data_bs);
     qapi_free_BlockdevCreateOptions(create_options);
     return ret;
 }
@@ -XXX,XX +XXX,XX @@ static ImageInfoSpecific *qcow2_get_specific_info(BlockDriverState *bs,
             .refcount_bits      = s->refcount_bits,
             .has_bitmaps        = !!bitmaps,
             .bitmaps            = bitmaps,
+            .has_data_file      = !!s->image_data_file,
+            .data_file          = g_strdup(s->image_data_file),
         };
     } else {
         /* if this assertion fails, this probably means a new version was
@@ -XXX,XX +XXX,XX @@ static int qcow2_amend_options(BlockDriverState *bs, QemuOpts *opts,
     BDRVQcow2State *s = bs->opaque;
     int old_version = s->qcow_version, new_version = old_version;
     uint64_t new_size = 0;
-    const char *backing_file = NULL, *backing_format = NULL;
+    const char *backing_file = NULL, *backing_format = NULL, *data_file = NULL;
     bool lazy_refcounts = s->use_lazy_refcounts;
     const char *compat = NULL;
     uint64_t cluster_size = s->cluster_size;
@@ -XXX,XX +XXX,XX @@ static int qcow2_amend_options(BlockDriverState *bs, QemuOpts *opts,
                            "may not exceed 64 bits");
                 return -EINVAL;
             }
+        } else if (!strcmp(desc->name, BLOCK_OPT_DATA_FILE)) {
+            data_file = qemu_opt_get(opts, BLOCK_OPT_DATA_FILE);
+            if (data_file && !has_data_file(bs)) {
+                error_setg(errp, "data-file can only be set for images that "
+                                 "use an external data file");
+                return -EINVAL;
+            }
         } else {
             /* if this point is reached, this probably means a new option was
              * added without having it covered here */
@@ -XXX,XX +XXX,XX @@ static int qcow2_amend_options(BlockDriverState *bs, QemuOpts *opts,
         }
     }
 
+    if (data_file) {
+        g_free(s->image_data_file);
+        s->image_data_file = *data_file ? g_strdup(data_file) : NULL;
+    }
+
+    ret = qcow2_update_header(bs);
+    if (ret < 0) {
+        error_setg_errno(errp, -ret, "Failed to update the image header");
+        return ret;
+    }
+
     if (backing_file || backing_format) {
         ret = qcow2_change_backing_file(bs,
                     backing_file ?: s->image_backing_file,
@@ -XXX,XX +XXX,XX @@ static QemuOptsList qcow2_create_opts = {
             .type = QEMU_OPT_STRING,
             .help = "Image format of the base image"
         },
+        {
+            .name = BLOCK_OPT_DATA_FILE,
+            .type = QEMU_OPT_STRING,
+            .help = "File name of an external data file"
+        },
         {
             .name = BLOCK_OPT_ENCRYPT,
             .type = QEMU_OPT_BOOL,
diff --git a/tests/qemu-iotests/082.out b/tests/qemu-iotests/082.out
index XXXXXXX..XXXXXXX 100644
--- a/tests/qemu-iotests/082.out
+++ b/tests/qemu-iotests/082.out
@@ -XXX,XX +XXX,XX @@ Supported options:
   backing_fmt=<str>      - Image format of the base image
   cluster_size=<size>    - qcow2 cluster size
   compat=<str>           - Compatibility level (0.10 or 1.1)
+  data_file=<str>        - File name of an external data file
   encrypt.cipher-alg=<str> - Name of encryption cipher algorithm
   encrypt.cipher-mode=<str> - Name of encryption cipher mode
   encrypt.format=<str>   - Encrypt the image, format choices: 'aes', 'luks'
@@ -XXX,XX +XXX,XX @@ Supported options:
   backing_fmt=<str>      - Image format of the base image
   cluster_size=<size>    - qcow2 cluster size
   compat=<str>           - Compatibility level (0.10 or 1.1)
+  data_file=<str>        - File name of an external data file
   encrypt.cipher-alg=<str> - Name of encryption cipher algorithm
   encrypt.cipher-mode=<str> - Name of encryption cipher mode
   encrypt.format=<str>   - Encrypt the image, format choices: 'aes', 'luks'
@@ -XXX,XX +XXX,XX @@ Supported options:
   backing_fmt=<str>      - Image format of the base image
   cluster_size=<size>    - qcow2 cluster size
   compat=<str>           - Compatibility level (0.10 or 1.1)
+  data_file=<str>        - File name of an external data file
   encrypt.cipher-alg=<str> - Name of encryption cipher algorithm
   encrypt.cipher-mode=<str> - Name of encryption cipher mode
   encrypt.format=<str>   - Encrypt the image, format choices: 'aes', 'luks'
@@ -XXX,XX +XXX,XX @@ Supported options:
   backing_fmt=<str>      - Image format of the base image
   cluster_size=<size>    - qcow2 cluster size
   compat=<str>           - Compatibility level (0.10 or 1.1)
+  data_file=<str>        - File name of an external data file
   encrypt.cipher-alg=<str> - Name of encryption cipher algorithm
   encrypt.cipher-mode=<str> - Name of encryption cipher mode
   encrypt.format=<str>   - Encrypt the image, format choices: 'aes', 'luks'
@@ -XXX,XX +XXX,XX @@ Supported options:
   backing_fmt=<str>      - Image format of the base image
   cluster_size=<size>    - qcow2 cluster size
   compat=<str>           - Compatibility level (0.10 or 1.1)
+  data_file=<str>        - File name of an external data file
   encrypt.cipher-alg=<str> - Name of encryption cipher algorithm
   encrypt.cipher-mode=<str> - Name of encryption cipher mode
   encrypt.format=<str>   - Encrypt the image, format choices: 'aes', 'luks'
@@ -XXX,XX +XXX,XX @@ Supported options:
   backing_fmt=<str>      - Image format of the base image
   cluster_size=<size>    - qcow2 cluster size
   compat=<str>           - Compatibility level (0.10 or 1.1)
+  data_file=<str>        - File name of an external data file
   encrypt.cipher-alg=<str> - Name of encryption cipher algorithm
   encrypt.cipher-mode=<str> - Name of encryption cipher mode
   encrypt.format=<str>   - Encrypt the image, format choices: 'aes', 'luks'
@@ -XXX,XX +XXX,XX @@ Supported options:
   backing_fmt=<str>      - Image format of the base image
   cluster_size=<size>    - qcow2 cluster size
   compat=<str>           - Compatibility level (0.10 or 1.1)
+  data_file=<str>        - File name of an external data file
   encrypt.cipher-alg=<str> - Name of encryption cipher algorithm
   encrypt.cipher-mode=<str> - Name of encryption cipher mode
   encrypt.format=<str>   - Encrypt the image, format choices: 'aes', 'luks'
@@ -XXX,XX +XXX,XX @@ Supported options:
   backing_fmt=<str>      - Image format of the base image
   cluster_size=<size>    - qcow2 cluster size
   compat=<str>           - Compatibility level (0.10 or 1.1)
+  data_file=<str>        - File name of an external data file
   encrypt.cipher-alg=<str> - Name of encryption cipher algorithm
   encrypt.cipher-mode=<str> - Name of encryption cipher mode
   encrypt.format=<str>   - Encrypt the image, format choices: 'aes', 'luks'
@@ -XXX,XX +XXX,XX @@ Supported options:
   backing_fmt=<str>      - Image format of the base image
   cluster_size=<size>    - qcow2 cluster size
   compat=<str>           - Compatibility level (0.10 or 1.1)
+  data_file=<str>        - File name of an external data file
   encrypt.cipher-alg=<str> - Name of encryption cipher algorithm
   encrypt.cipher-mode=<str> - Name of encryption cipher mode
   encrypt.format=<str>   - Encrypt the image, format choices: 'aes', 'luks'
@@ -XXX,XX +XXX,XX @@ Supported options:
   backing_fmt=<str>      - Image format of the base image
   cluster_size=<size>    - qcow2 cluster size
   compat=<str>           - Compatibility level (0.10 or 1.1)
+  data_file=<str>        - File name of an external data file
   encrypt.cipher-alg=<str> - Name of encryption cipher algorithm
   encrypt.cipher-mode=<str> - Name of encryption cipher mode
   encrypt.format=<str>   - Encrypt the image, format choices: 'aes', 'luks'
@@ -XXX,XX +XXX,XX @@ Supported options:
   backing_fmt=<str>      - Image format of the base image
   cluster_size=<size>    - qcow2 cluster size
   compat=<str>           - Compatibility level (0.10 or 1.1)
+  data_file=<str>        - File name of an external data file
   encrypt.cipher-alg=<str> - Name of encryption cipher algorithm
   encrypt.cipher-mode=<str> - Name of encryption cipher mode
   encrypt.format=<str>   - Encrypt the image, format choices: 'aes', 'luks'
@@ -XXX,XX +XXX,XX @@ Supported options:
   backing_fmt=<str>      - Image format of the base image
   cluster_size=<size>    - qcow2 cluster size
   compat=<str>           - Compatibility level (0.10 or 1.1)
+  data_file=<str>        - File name of an external data file
   encrypt.cipher-alg=<str> - Name of encryption cipher algorithm
   encrypt.cipher-mode=<str> - Name of encryption cipher mode
   encrypt.format=<str>   - Encrypt the image, format choices: 'aes', 'luks'
@@ -XXX,XX +XXX,XX @@ Supported options:
   backing_fmt=<str>      - Image format of the base image
   cluster_size=<size>    - qcow2 cluster size
   compat=<str>           - Compatibility level (0.10 or 1.1)
+  data_file=<str>        - File name of an external data file
   encrypt.cipher-alg=<str> - Name of encryption cipher algorithm
   encrypt.cipher-mode=<str> - Name of encryption cipher mode
   encrypt.format=<str>   - Encrypt the image, format choices: 'aes', 'luks'
@@ -XXX,XX +XXX,XX @@ Supported options:
   backing_fmt=<str>      - Image format of the base image
   cluster_size=<size>    - qcow2 cluster size
   compat=<str>           - Compatibility level (0.10 or 1.1)
+  data_file=<str>        - File name of an external data file
   encrypt.cipher-alg=<str> - Name of encryption cipher algorithm
   encrypt.cipher-mode=<str> - Name of encryption cipher mode
   encrypt.format=<str>   - Encrypt the image, format choices: 'aes', 'luks'
@@ -XXX,XX +XXX,XX @@ Supported options:
   backing_fmt=<str>      - Image format of the base image
   cluster_size=<size>    - qcow2 cluster size
   compat=<str>           - Compatibility level (0.10 or 1.1)
+  data_file=<str>        - File name of an external data file
   encrypt.cipher-alg=<str> - Name of encryption cipher algorithm
   encrypt.cipher-mode=<str> - Name of encryption cipher mode
   encrypt.format=<str>   - Encrypt the image, format choices: 'aes', 'luks'
@@ -XXX,XX +XXX,XX @@ Supported options:
   backing_fmt=<str>      - Image format of the base image
   cluster_size=<size>    - qcow2 cluster size
   compat=<str>           - Compatibility level (0.10 or 1.1)
+  data_file=<str>        - File name of an external data file
   encrypt.cipher-alg=<str> - Name of encryption cipher algorithm
   encrypt.cipher-mode=<str> - Name of encryption cipher mode
   encrypt.format=<str>   - Encrypt the image, format choices: 'aes', 'luks'
@@ -XXX,XX +XXX,XX @@ Supported options:
   backing_fmt=<str>      - Image format of the base image
   cluster_size=<size>    - qcow2 cluster size
   compat=<str>           - Compatibility level (0.10 or 1.1)
+  data_file=<str>        - File name of an external data file
   encrypt.cipher-alg=<str> - Name of encryption cipher algorithm
   encrypt.cipher-mode=<str> - Name of encryption cipher mode
   encrypt.format=<str>   - Encrypt the image, format choices: 'aes', 'luks'
@@ -XXX,XX +XXX,XX @@ Supported options:
   backing_fmt=<str>      - Image format of the base image
   cluster_size=<size>    - qcow2 cluster size
   compat=<str>           - Compatibility level (0.10 or 1.1)
+  data_file=<str>        - File name of an external data file
   encrypt.cipher-alg=<str> - Name of encryption cipher algorithm
   encrypt.cipher-mode=<str> - Name of encryption cipher mode
   encrypt.format=<str>   - Encrypt the image, format choices: 'aes', 'luks'
@@ -XXX,XX +XXX,XX @@ Creation options for 'qcow2':
   backing_fmt=<str>      - Image format of the base image
   cluster_size=<size>    - qcow2 cluster size
   compat=<str>           - Compatibility level (0.10 or 1.1)
+  data_file=<str>        - File name of an external data file
   encrypt.cipher-alg=<str> - Name of encryption cipher algorithm
   encrypt.cipher-mode=<str> - Name of encryption cipher mode
   encrypt.format=<str>   - Encrypt the image, format choices: 'aes', 'luks'
@@ -XXX,XX +XXX,XX @@ Creation options for 'qcow2':
   backing_fmt=<str>      - Image format of the base image
   cluster_size=<size>    - qcow2 cluster size
   compat=<str>           - Compatibility level (0.10 or 1.1)
+  data_file=<str>        - File name of an external data file
   encrypt.cipher-alg=<str> - Name of encryption cipher algorithm
   encrypt.cipher-mode=<str> - Name of encryption cipher mode
   encrypt.format=<str>   - Encrypt the image, format choices: 'aes', 'luks'
@@ -XXX,XX +XXX,XX @@ Creation options for 'qcow2':
   backing_fmt=<str>      - Image format of the base image
   cluster_size=<size>    - qcow2 cluster size
   compat=<str>           - Compatibility level (0.10 or 1.1)
+  data_file=<str>        - File name of an external data file
   encrypt.cipher-alg=<str> - Name of encryption cipher algorithm
   encrypt.cipher-mode=<str> - Name of encryption cipher mode
   encrypt.format=<str>   - Encrypt the image, format choices: 'aes', 'luks'
@@ -XXX,XX +XXX,XX @@ Creation options for 'qcow2':
   backing_fmt=<str>      - Image format of the base image
   cluster_size=<size>    - qcow2 cluster size
   compat=<str>           - Compatibility level (0.10 or 1.1)
+  data_file=<str>        - File name of an external data file
   encrypt.cipher-alg=<str> - Name of encryption cipher algorithm
   encrypt.cipher-mode=<str> - Name of encryption cipher mode
   encrypt.format=<str>   - Encrypt the image, format choices: 'aes', 'luks'
@@ -XXX,XX +XXX,XX @@ Creation options for 'qcow2':
   backing_fmt=<str>      - Image format of the base image
   cluster_size=<size>    - qcow2 cluster size
   compat=<str>           - Compatibility level (0.10 or 1.1)
+  data_file=<str>        - File name of an external data file
   encrypt.cipher-alg=<str> - Name of encryption cipher algorithm
   encrypt.cipher-mode=<str> - Name of encryption cipher mode
   encrypt.format=<str>   - Encrypt the image, format choices: 'aes', 'luks'
@@ -XXX,XX +XXX,XX @@ Creation options for 'qcow2':
   backing_fmt=<str>      - Image format of the base image
   cluster_size=<size>    - qcow2 cluster size
   compat=<str>           - Compatibility level (0.10 or 1.1)
+  data_file=<str>        - File name of an external data file
   encrypt.cipher-alg=<str> - Name of encryption cipher algorithm
   encrypt.cipher-mode=<str> - Name of encryption cipher mode
   encrypt.format=<str>   - Encrypt the image, format choices: 'aes', 'luks'
@@ -XXX,XX +XXX,XX @@ Creation options for 'qcow2':
   backing_fmt=<str>      - Image format of the base image
   cluster_size=<size>    - qcow2 cluster size
   compat=<str>           - Compatibility level (0.10 or 1.1)
+  data_file=<str>        - File name of an external data file
   encrypt.cipher-alg=<str> - Name of encryption cipher algorithm
   encrypt.cipher-mode=<str> - Name of encryption cipher mode
   encrypt.format=<str>   - Encrypt the image, format choices: 'aes', 'luks'
@@ -XXX,XX +XXX,XX @@ Creation options for 'qcow2':
   backing_fmt=<str>      - Image format of the base image
   cluster_size=<size>    - qcow2 cluster size
   compat=<str>           - Compatibility level (0.10 or 1.1)
+  data_file=<str>        - File name of an external data file
   encrypt.cipher-alg=<str> - Name of encryption cipher algorithm
   encrypt.cipher-mode=<str> - Name of encryption cipher mode
   encrypt.format=<str>   - Encrypt the image, format choices: 'aes', 'luks'
@@ -XXX,XX +XXX,XX @@ Creation options for 'qcow2':
   backing_fmt=<str>      - Image format of the base image
   cluster_size=<size>    - qcow2 cluster size
   compat=<str>           - Compatibility level (0.10 or 1.1)
+  data_file=<str>        - File name of an external data file
   encrypt.cipher-alg=<str> - Name of encryption cipher algorithm
   encrypt.cipher-mode=<str> - Name of encryption cipher mode
   encrypt.format=<str>   - Encrypt the image, format choices: 'aes', 'luks'
-- 
2.20.1

Provide an option to force QEMU to always keep the external data file
consistent as a standalone read-only raw image.

At the moment, this means making sure that write_zeroes requests are
forwarded to the data file instead of just updating the metadata, and
checking that no backing file is used.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 qapi/block-core.json       |  9 ++++++
 block/qcow2.h              |  9 +++++-
 include/block/block_int.h  |  1 +
 block/qcow2-cluster.c      | 10 +++++++
 block/qcow2.c              | 56 ++++++++++++++++++++++++++++++++++++--
 tests/qemu-iotests/082.out | 27 ++++++++++++++++++
 6 files changed, 109 insertions(+), 3 deletions(-)

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 @@
 # @data-file: the filename of the external data file that is stored in the
 #             image and used as a default for opening the image (since: 4.0)
 #
+# @data-file-raw: True if the external data file must stay valid as a
+#                 standalone (read-only) raw image without looking at qcow2
+#                 metadata (since: 4.0)
+#
 # @lazy-refcounts: on or off; only valid for compat >= 1.1
 #
 # @corrupt: true if the image has been marked corrupt; only valid for
@@ -XXX,XX +XXX,XX @@
   'data': {
       'compat': 'str',
       '*data-file': 'str',
+      '*data-file-raw': 'bool',
       '*lazy-refcounts': 'bool',
       '*corrupt': 'bool',
       'refcount-bits': 'int',
@@ -XXX,XX +XXX,XX @@
 # @data-file        Node to use as an external data file in which all guest
 #                   data is stored so that only metadata remains in the qcow2
 #                   file (since: 4.0)
+# @data-file-raw    True if the external data file must stay valid as a
+#                   standalone (read-only) raw image without looking at qcow2
+#                   metadata (default: false; since: 4.0)
 # @size             Size of the virtual disk in bytes
 # @version          Compatibility level (default: v3)
 # @backing-file     File name of the backing file if a backing file
@@ -XXX,XX +XXX,XX @@
 { 'struct': 'BlockdevCreateOptionsQcow2',
   'data': { 'file':             'BlockdevRef',
             '*data-file':       'BlockdevRef',
+            '*data-file-raw':   'bool',
             'size':             'size',
             '*version':         'BlockdevQcow2Version',
             '*backing-file':    'str',
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 @@ enum {
     QCOW2_AUTOCLEAR_BITMAPS             = 1 << QCOW2_AUTOCLEAR_BITMAPS_BITNR,
     QCOW2_AUTOCLEAR_DATA_FILE_RAW       = 1 << QCOW2_AUTOCLEAR_DATA_FILE_RAW_BITNR,
 
-    QCOW2_AUTOCLEAR_MASK                = QCOW2_AUTOCLEAR_BITMAPS,
+    QCOW2_AUTOCLEAR_MASK                = QCOW2_AUTOCLEAR_BITMAPS
+                                        | QCOW2_AUTOCLEAR_DATA_FILE_RAW,
 };
 
 enum qcow2_discard_type {
@@ -XXX,XX +XXX,XX @@ static inline bool has_data_file(BlockDriverState *bs)
     return (s->data_file != bs->file);
 }
 
+static inline bool data_file_is_raw(BlockDriverState *bs)
+{
+    BDRVQcow2State *s = bs->opaque;
+    return !!(s->autoclear_features & QCOW2_AUTOCLEAR_DATA_FILE_RAW);
+}
+
 static inline int64_t start_of_cluster(BDRVQcow2State *s, int64_t offset)
 {
     return offset & ~(s->cluster_size - 1);
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 @@
 #define BLOCK_OPT_OBJECT_SIZE       "object_size"
 #define BLOCK_OPT_REFCOUNT_BITS     "refcount_bits"
 #define BLOCK_OPT_DATA_FILE         "data_file"
+#define BLOCK_OPT_DATA_FILE_RAW     "data_file_raw"
 
 #define BLOCK_PROBE_BUF_SIZE        512
 
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 @@ int qcow2_cluster_zeroize(BlockDriverState *bs, uint64_t offset,
     int64_t cleared;
     int ret;
 
+    /* If we have to stay in sync with an external data file, zero out
+     * s->data_file first. */
+    if (data_file_is_raw(bs)) {
+        assert(has_data_file(bs));
+        ret = bdrv_co_pwrite_zeroes(s->data_file, offset, bytes, flags);
+        if (ret < 0) {
+            return ret;
+        }
+    }
+
     /* Caller must pass aligned values, except at image end */
     assert(QEMU_IS_ALIGNED(offset, s->cluster_size));
     assert(QEMU_IS_ALIGNED(end_offset, s->cluster_size) ||
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 coroutine_fn qcow2_do_open(BlockDriverState *bs, QDict *options,
                              "external data file");
             ret = -EINVAL;
             goto fail;
-        } else {
-            s->data_file = bs->file;
+        }
+
+        s->data_file = bs->file;
+
+        if (data_file_is_raw(bs)) {
+            error_setg(errp, "data-file-raw requires a data file");
+            ret = -EINVAL;
+            goto fail;
         }
     }
 
@@ -XXX,XX +XXX,XX @@ static int qcow2_change_backing_file(BlockDriverState *bs,
 {
     BDRVQcow2State *s = bs->opaque;
 
+    /* Adding a backing file means that the external data file alone won't be
+     * enough to make sense of the content */
+    if (backing_file && data_file_is_raw(bs)) {
+        return -EINVAL;
+    }
+
     if (backing_file && strlen(backing_file) > 1023) {
         return -EINVAL;
     }
@@ -XXX,XX +XXX,XX @@ qcow2_co_create(BlockdevCreateOptions *create_options, Error **errp)
     }
     refcount_order = ctz32(qcow2_opts->refcount_bits);
 
+    if (qcow2_opts->data_file_raw && !qcow2_opts->data_file) {
+        error_setg(errp, "data-file-raw requires data-file");
+        ret = -EINVAL;
+        goto out;
+    }
+    if (qcow2_opts->data_file_raw && qcow2_opts->has_backing_file) {
+        error_setg(errp, "Backing file and data-file-raw cannot be used at "
+                   "the same time");
+        ret = -EINVAL;
+        goto out;
+    }
+
     if (qcow2_opts->data_file) {
         if (version < 3) {
             error_setg(errp, "External data files are only supported with "
@@ -XXX,XX +XXX,XX @@ qcow2_co_create(BlockdevCreateOptions *create_options, Error **errp)
         header->incompatible_features |=
             cpu_to_be64(QCOW2_INCOMPAT_DATA_FILE);
     }
+    if (qcow2_opts->data_file_raw) {
+        header->autoclear_features |=
+            cpu_to_be64(QCOW2_AUTOCLEAR_DATA_FILE_RAW);
+    }
 
     ret = blk_pwrite(blk, 0, header, cluster_size, 0);
     g_free(header);
@@ -XXX,XX +XXX,XX @@ static int coroutine_fn qcow2_co_create_opts(const char *filename, QemuOpts *opt
         { BLOCK_OPT_REFCOUNT_BITS,      "refcount-bits" },
         { BLOCK_OPT_ENCRYPT,            BLOCK_OPT_ENCRYPT_FORMAT },
         { BLOCK_OPT_COMPAT_LEVEL,       "version" },
+        { BLOCK_OPT_DATA_FILE_RAW,      "data-file-raw" },
         { NULL, NULL },
     };
 
@@ -XXX,XX +XXX,XX @@ static ImageInfoSpecific *qcow2_get_specific_info(BlockDriverState *bs,
             .bitmaps            = bitmaps,
             .has_data_file      = !!s->image_data_file,
             .data_file          = g_strdup(s->image_data_file),
+            .has_data_file_raw  = has_data_file(bs),
+            .data_file_raw      = data_file_is_raw(bs),
         };
     } else {
         /* if this assertion fails, this probably means a new version was
@@ -XXX,XX +XXX,XX @@ static int qcow2_amend_options(BlockDriverState *bs, QemuOpts *opts,
     uint64_t new_size = 0;
     const char *backing_file = NULL, *backing_format = NULL, *data_file = NULL;
     bool lazy_refcounts = s->use_lazy_refcounts;
+    bool data_file_raw = data_file_is_raw(bs);
     const char *compat = NULL;
     uint64_t cluster_size = s->cluster_size;
     bool encrypt;
@@ -XXX,XX +XXX,XX @@ static int qcow2_amend_options(BlockDriverState *bs, QemuOpts *opts,
                                  "use an external data file");
                 return -EINVAL;
             }
+        } else if (!strcmp(desc->name, BLOCK_OPT_DATA_FILE_RAW)) {
+            data_file_raw = qemu_opt_get_bool(opts, BLOCK_OPT_DATA_FILE_RAW,
+                                              data_file_raw);
+            if (data_file_raw && !data_file_is_raw(bs)) {
+                error_setg(errp, "data-file-raw cannot be set on existing "
+                                 "images");
+                return -EINVAL;
+            }
         } else {
             /* if this point is reached, this probably means a new option was
              * added without having it covered here */
@@ -XXX,XX +XXX,XX @@ static int qcow2_amend_options(BlockDriverState *bs, QemuOpts *opts,
         }
     }
 
+    /* data-file-raw blocks backing files, so clear it first if requested */
+    if (data_file_raw) {
+        s->autoclear_features |= QCOW2_AUTOCLEAR_DATA_FILE_RAW;
+    } else {
+        s->autoclear_features &= ~QCOW2_AUTOCLEAR_DATA_FILE_RAW;
+    }
+
     if (data_file) {
         g_free(s->image_data_file);
         s->image_data_file = *data_file ? g_strdup(data_file) : NULL;
@@ -XXX,XX +XXX,XX @@ static QemuOptsList qcow2_create_opts = {
             .type = QEMU_OPT_STRING,
             .help = "File name of an external data file"
         },
+        {
+            .name = BLOCK_OPT_DATA_FILE_RAW,
+            .type = QEMU_OPT_BOOL,
+            .help = "The external data file must stay valid as a raw image"
+        },
         {
             .name = BLOCK_OPT_ENCRYPT,
             .type = QEMU_OPT_BOOL,
diff --git a/tests/qemu-iotests/082.out b/tests/qemu-iotests/082.out
index XXXXXXX..XXXXXXX 100644
--- a/tests/qemu-iotests/082.out
+++ b/tests/qemu-iotests/082.out
@@ -XXX,XX +XXX,XX @@ Supported options:
   cluster_size=<size>    - qcow2 cluster size
   compat=<str>           - Compatibility level (0.10 or 1.1)
   data_file=<str>        - File name of an external data file
+  data_file_raw=<bool (on/off)> - The external data file must stay valid as a raw image
   encrypt.cipher-alg=<str> - Name of encryption cipher algorithm
   encrypt.cipher-mode=<str> - Name of encryption cipher mode
   encrypt.format=<str>   - Encrypt the image, format choices: 'aes', 'luks'
@@ -XXX,XX +XXX,XX @@ Supported options:
   cluster_size=<size>    - qcow2 cluster size
   compat=<str>           - Compatibility level (0.10 or 1.1)
   data_file=<str>        - File name of an external data file
+  data_file_raw=<bool (on/off)> - The external data file must stay valid as a raw image
   encrypt.cipher-alg=<str> - Name of encryption cipher algorithm
   encrypt.cipher-mode=<str> - Name of encryption cipher mode
   encrypt.format=<str>   - Encrypt the image, format choices: 'aes', 'luks'
@@ -XXX,XX +XXX,XX @@ Supported options:
   cluster_size=<size>    - qcow2 cluster size
   compat=<str>           - Compatibility level (0.10 or 1.1)
   data_file=<str>        - File name of an external data file
+  data_file_raw=<bool (on/off)> - The external data file must stay valid as a raw image
   encrypt.cipher-alg=<str> - Name of encryption cipher algorithm
   encrypt.cipher-mode=<str> - Name of encryption cipher mode
   encrypt.format=<str>   - Encrypt the image, format choices: 'aes', 'luks'
@@ -XXX,XX +XXX,XX @@ Supported options:
   cluster_size=<size>    - qcow2 cluster size
   compat=<str>           - Compatibility level (0.10 or 1.1)
   data_file=<str>        - File name of an external data file
+  data_file_raw=<bool (on/off)> - The external data file must stay valid as a raw image
   encrypt.cipher-alg=<str> - Name of encryption cipher algorithm
   encrypt.cipher-mode=<str> - Name of encryption cipher mode
   encrypt.format=<str>   - Encrypt the image, format choices: 'aes', 'luks'
@@ -XXX,XX +XXX,XX @@ Supported options:
   cluster_size=<size>    - qcow2 cluster size
   compat=<str>           - Compatibility level (0.10 or 1.1)
   data_file=<str>        - File name of an external data file
+  data_file_raw=<bool (on/off)> - The external data file must stay valid as a raw image
   encrypt.cipher-alg=<str> - Name of encryption cipher algorithm
   encrypt.cipher-mode=<str> - Name of encryption cipher mode
   encrypt.format=<str>   - Encrypt the image, format choices: 'aes', 'luks'
@@ -XXX,XX +XXX,XX @@ Supported options:
   cluster_size=<size>    - qcow2 cluster size
   compat=<str>           - Compatibility level (0.10 or 1.1)
   data_file=<str>        - File name of an external data file
+  data_file_raw=<bool (on/off)> - The external data file must stay valid as a raw image
   encrypt.cipher-alg=<str> - Name of encryption cipher algorithm
   encrypt.cipher-mode=<str> - Name of encryption cipher mode
   encrypt.format=<str>   - Encrypt the image, format choices: 'aes', 'luks'
@@ -XXX,XX +XXX,XX @@ Supported options:
   cluster_size=<size>    - qcow2 cluster size
   compat=<str>           - Compatibility level (0.10 or 1.1)
   data_file=<str>        - File name of an external data file
+  data_file_raw=<bool (on/off)> - The external data file must stay valid as a raw image
   encrypt.cipher-alg=<str> - Name of encryption cipher algorithm
   encrypt.cipher-mode=<str> - Name of encryption cipher mode
   encrypt.format=<str>   - Encrypt the image, format choices: 'aes', 'luks'
@@ -XXX,XX +XXX,XX @@ Supported options:
   cluster_size=<size>    - qcow2 cluster size
   compat=<str>           - Compatibility level (0.10 or 1.1)
   data_file=<str>        - File name of an external data file
+  data_file_raw=<bool (on/off)> - The external data file must stay valid as a raw image
   encrypt.cipher-alg=<str> - Name of encryption cipher algorithm
   encrypt.cipher-mode=<str> - Name of encryption cipher mode
   encrypt.format=<str>   - Encrypt the image, format choices: 'aes', 'luks'
@@ -XXX,XX +XXX,XX @@ Supported options:
   cluster_size=<size>    - qcow2 cluster size
   compat=<str>           - Compatibility level (0.10 or 1.1)
   data_file=<str>        - File name of an external data file
+  data_file_raw=<bool (on/off)> - The external data file must stay valid as a raw image
   encrypt.cipher-alg=<str> - Name of encryption cipher algorithm
   encrypt.cipher-mode=<str> - Name of encryption cipher mode
   encrypt.format=<str>   - Encrypt the image, format choices: 'aes', 'luks'
@@ -XXX,XX +XXX,XX @@ Supported options:
   cluster_size=<size>    - qcow2 cluster size
   compat=<str>           - Compatibility level (0.10 or 1.1)
   data_file=<str>        - File name of an external data file
+  data_file_raw=<bool (on/off)> - The external data file must stay valid as a raw image
   encrypt.cipher-alg=<str> - Name of encryption cipher algorithm
   encrypt.cipher-mode=<str> - Name of encryption cipher mode
   encrypt.format=<str>   - Encrypt the image, format choices: 'aes', 'luks'
@@ -XXX,XX +XXX,XX @@ Supported options:
   cluster_size=<size>    - qcow2 cluster size
   compat=<str>           - Compatibility level (0.10 or 1.1)
   data_file=<str>        - File name of an external data file
+  data_file_raw=<bool (on/off)> - The external data file must stay valid as a raw image
   encrypt.cipher-alg=<str> - Name of encryption cipher algorithm
   encrypt.cipher-mode=<str> - Name of encryption cipher mode
   encrypt.format=<str>   - Encrypt the image, format choices: 'aes', 'luks'
@@ -XXX,XX +XXX,XX @@ Supported options:
   cluster_size=<size>    - qcow2 cluster size
   compat=<str>           - Compatibility level (0.10 or 1.1)
   data_file=<str>        - File name of an external data file
+  data_file_raw=<bool (on/off)> - The external data file must stay valid as a raw image
   encrypt.cipher-alg=<str> - Name of encryption cipher algorithm
   encrypt.cipher-mode=<str> - Name of encryption cipher mode
   encrypt.format=<str>   - Encrypt the image, format choices: 'aes', 'luks'
@@ -XXX,XX +XXX,XX @@ Supported options:
   cluster_size=<size>    - qcow2 cluster size
   compat=<str>           - Compatibility level (0.10 or 1.1)
   data_file=<str>        - File name of an external data file
+  data_file_raw=<bool (on/off)> - The external data file must stay valid as a raw image
   encrypt.cipher-alg=<str> - Name of encryption cipher algorithm
   encrypt.cipher-mode=<str> - Name of encryption cipher mode
   encrypt.format=<str>   - Encrypt the image, format choices: 'aes', 'luks'
@@ -XXX,XX +XXX,XX @@ Supported options:
   cluster_size=<size>    - qcow2 cluster size
   compat=<str>           - Compatibility level (0.10 or 1.1)
   data_file=<str>        - File name of an external data file
+  data_file_raw=<bool (on/off)> - The external data file must stay valid as a raw image
   encrypt.cipher-alg=<str> - Name of encryption cipher algorithm
   encrypt.cipher-mode=<str> - Name of encryption cipher mode
   encrypt.format=<str>   - Encrypt the image, format choices: 'aes', 'luks'
@@ -XXX,XX +XXX,XX @@ Supported options:
   cluster_size=<size>    - qcow2 cluster size
   compat=<str>           - Compatibility level (0.10 or 1.1)
   data_file=<str>        - File name of an external data file
+  data_file_raw=<bool (on/off)> - The external data file must stay valid as a raw image
   encrypt.cipher-alg=<str> - Name of encryption cipher algorithm
   encrypt.cipher-mode=<str> - Name of encryption cipher mode
   encrypt.format=<str>   - Encrypt the image, format choices: 'aes', 'luks'
@@ -XXX,XX +XXX,XX @@ Supported options:
   cluster_size=<size>    - qcow2 cluster size
   compat=<str>           - Compatibility level (0.10 or 1.1)
   data_file=<str>        - File name of an external data file
+  data_file_raw=<bool (on/off)> - The external data file must stay valid as a raw image
   encrypt.cipher-alg=<str> - Name of encryption cipher algorithm
   encrypt.cipher-mode=<str> - Name of encryption cipher mode
   encrypt.format=<str>   - Encrypt the image, format choices: 'aes', 'luks'
@@ -XXX,XX +XXX,XX @@ Supported options:
   cluster_size=<size>    - qcow2 cluster size
   compat=<str>           - Compatibility level (0.10 or 1.1)
   data_file=<str>        - File name of an external data file
+  data_file_raw=<bool (on/off)> - The external data file must stay valid as a raw image
   encrypt.cipher-alg=<str> - Name of encryption cipher algorithm
   encrypt.cipher-mode=<str> - Name of encryption cipher mode
   encrypt.format=<str>   - Encrypt the image, format choices: 'aes', 'luks'
@@ -XXX,XX +XXX,XX @@ Supported options:
   cluster_size=<size>    - qcow2 cluster size
   compat=<str>           - Compatibility level (0.10 or 1.1)
   data_file=<str>        - File name of an external data file
+  data_file_raw=<bool (on/off)> - The external data file must stay valid as a raw image
   encrypt.cipher-alg=<str> - Name of encryption cipher algorithm
   encrypt.cipher-mode=<str> - Name of encryption cipher mode
   encrypt.format=<str>   - Encrypt the image, format choices: 'aes', 'luks'
@@ -XXX,XX +XXX,XX @@ Creation options for 'qcow2':
   cluster_size=<size>    - qcow2 cluster size
   compat=<str>           - Compatibility level (0.10 or 1.1)
   data_file=<str>        - File name of an external data file
+  data_file_raw=<bool (on/off)> - The external data file must stay valid as a raw image
   encrypt.cipher-alg=<str> - Name of encryption cipher algorithm
   encrypt.cipher-mode=<str> - Name of encryption cipher mode
   encrypt.format=<str>   - Encrypt the image, format choices: 'aes', 'luks'
@@ -XXX,XX +XXX,XX @@ Creation options for 'qcow2':
   cluster_size=<size>    - qcow2 cluster size
   compat=<str>           - Compatibility level (0.10 or 1.1)
   data_file=<str>        - File name of an external data file
+  data_file_raw=<bool (on/off)> - The external data file must stay valid as a raw image
   encrypt.cipher-alg=<str> - Name of encryption cipher algorithm
   encrypt.cipher-mode=<str> - Name of encryption cipher mode
   encrypt.format=<str>   - Encrypt the image, format choices: 'aes', 'luks'
@@ -XXX,XX +XXX,XX @@ Creation options for 'qcow2':
   cluster_size=<size>    - qcow2 cluster size
   compat=<str>           - Compatibility level (0.10 or 1.1)
   data_file=<str>        - File name of an external data file
+  data_file_raw=<bool (on/off)> - The external data file must stay valid as a raw image
   encrypt.cipher-alg=<str> - Name of encryption cipher algorithm
   encrypt.cipher-mode=<str> - Name of encryption cipher mode
   encrypt.format=<str>   - Encrypt the image, format choices: 'aes', 'luks'
@@ -XXX,XX +XXX,XX @@ Creation options for 'qcow2':
   cluster_size=<size>    - qcow2 cluster size
   compat=<str>           - Compatibility level (0.10 or 1.1)
   data_file=<str>        - File name of an external data file
+  data_file_raw=<bool (on/off)> - The external data file must stay valid as a raw image
   encrypt.cipher-alg=<str> - Name of encryption cipher algorithm
   encrypt.cipher-mode=<str> - Name of encryption cipher mode
   encrypt.format=<str>   - Encrypt the image, format choices: 'aes', 'luks'
@@ -XXX,XX +XXX,XX @@ Creation options for 'qcow2':
   cluster_size=<size>    - qcow2 cluster size
   compat=<str>           - Compatibility level (0.10 or 1.1)
   data_file=<str>        - File name of an external data file
+  data_file_raw=<bool (on/off)> - The external data file must stay valid as a raw image
   encrypt.cipher-alg=<str> - Name of encryption cipher algorithm
   encrypt.cipher-mode=<str> - Name of encryption cipher mode
   encrypt.format=<str>   - Encrypt the image, format choices: 'aes', 'luks'
@@ -XXX,XX +XXX,XX @@ Creation options for 'qcow2':
   cluster_size=<size>    - qcow2 cluster size
   compat=<str>           - Compatibility level (0.10 or 1.1)
   data_file=<str>        - File name of an external data file
+  data_file_raw=<bool (on/off)> - The external data file must stay valid as a raw image
   encrypt.cipher-alg=<str> - Name of encryption cipher algorithm
   encrypt.cipher-mode=<str> - Name of encryption cipher mode
   encrypt.format=<str>   - Encrypt the image, format choices: 'aes', 'luks'
@@ -XXX,XX +XXX,XX @@ Creation options for 'qcow2':
   cluster_size=<size>    - qcow2 cluster size
   compat=<str>           - Compatibility level (0.10 or 1.1)
   data_file=<str>        - File name of an external data file
+  data_file_raw=<bool (on/off)> - The external data file must stay valid as a raw image
   encrypt.cipher-alg=<str> - Name of encryption cipher algorithm
   encrypt.cipher-mode=<str> - Name of encryption cipher mode
   encrypt.format=<str>   - Encrypt the image, format choices: 'aes', 'luks'
@@ -XXX,XX +XXX,XX @@ Creation options for 'qcow2':
   cluster_size=<size>    - qcow2 cluster size
   compat=<str>           - Compatibility level (0.10 or 1.1)
   data_file=<str>        - File name of an external data file
+  data_file_raw=<bool (on/off)> - The external data file must stay valid as a raw image
   encrypt.cipher-alg=<str> - Name of encryption cipher algorithm
   encrypt.cipher-mode=<str> - Name of encryption cipher mode
   encrypt.format=<str>   - Encrypt the image, format choices: 'aes', 'luks'
@@ -XXX,XX +XXX,XX @@ Creation options for 'qcow2':
   cluster_size=<size>    - qcow2 cluster size
   compat=<str>           - Compatibility level (0.10 or 1.1)
   data_file=<str>        - File name of an external data file
+  data_file_raw=<bool (on/off)> - The external data file must stay valid as a raw image
   encrypt.cipher-alg=<str> - Name of encryption cipher algorithm
   encrypt.cipher-mode=<str> - Name of encryption cipher mode
   encrypt.format=<str>   - Encrypt the image, format choices: 'aes', 'luks'
-- 
2.20.1

Test that preallocating metadata results in a somewhat larger qcow2
file, but preallocating data only affects the disk usage of the data
file and the qcow2 file stays small.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 tests/qemu-iotests/243     | 22 ++++++++++++++++++++++
 tests/qemu-iotests/243.out | 32 ++++++++++++++++++++++++++++++++
 2 files changed, 54 insertions(+)

diff --git a/tests/qemu-iotests/243 b/tests/qemu-iotests/243
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/243
+++ b/tests/qemu-iotests/243
@@ -XXX,XX +XXX,XX @@ status=1	# failure is the default!
 _cleanup()
 {
     _cleanup_test_img
+    rm -f $TEST_IMG.data
 }
 trap "_cleanup; exit \$status" 0 1 2 3 15
 
@@ -XXX,XX +XXX,XX @@ for mode in off metadata falloc full; do
 
 done
 
+for mode in off metadata falloc full; do
+
+    echo
+    echo "=== External data file: preallocation=$mode ==="
+    echo
+
+    IMGOPTS="data_file=$TEST_IMG.data,preallocation=$mode" _make_test_img 64M
+
+    echo -n "qcow2 file size: "
+    du -b $TEST_IMG | cut -f1
+    echo -n "data file size:  "
+    du -b $TEST_IMG.data | cut -f1
+
+    # Can't use precise numbers here because they differ between filesystems
+    echo -n "qcow2 disk usage: "
+    [ $(du -B1 $TEST_IMG | cut -f1) -lt 1048576 ] && echo "low" || echo "high"
+    echo -n "data disk usage:  "
+    [ $(du -B1 $TEST_IMG.data | cut -f1) -lt 1048576 ] && echo "low" || echo "high"
+
+done
+
 # success, all done
 echo "*** done"
 rm -f $seq.full
diff --git a/tests/qemu-iotests/243.out b/tests/qemu-iotests/243.out
index XXXXXXX..XXXXXXX 100644
--- a/tests/qemu-iotests/243.out
+++ b/tests/qemu-iotests/243.out
@@ -XXX,XX +XXX,XX @@ Disk usage: high
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864 preallocation=full
 File size: 67436544
 Disk usage: high
+
+=== External data file: preallocation=off ===
+
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864 data_file=TEST_DIR/t.IMGFMT.data preallocation=off
+qcow2 file size: 196616
+data file size:  67108864
+qcow2 disk usage: low
+data disk usage:  low
+
+=== External data file: preallocation=metadata ===
+
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864 data_file=TEST_DIR/t.IMGFMT.data preallocation=metadata
+qcow2 file size: 327680
+data file size:  67108864
+qcow2 disk usage: low
+data disk usage:  low
+
+=== External data file: preallocation=falloc ===
+
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864 data_file=TEST_DIR/t.IMGFMT.data preallocation=falloc
+qcow2 file size: 327680
+data file size:  67108864
+qcow2 disk usage: low
+data disk usage:  high
+
+=== External data file: preallocation=full ===
+
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864 data_file=TEST_DIR/t.IMGFMT.data preallocation=full
+qcow2 file size: 327680
+data file size:  67108864
+qcow2 disk usage: low
+data disk usage:  high
 *** done
-- 
2.20.1

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 tests/qemu-iotests/244     | 200 +++++++++++++++++++++++++++++++++++++
 tests/qemu-iotests/244.out | 125 +++++++++++++++++++++++
 tests/qemu-iotests/group   |   1 +
 3 files changed, 326 insertions(+)
 create mode 100755 tests/qemu-iotests/244
 create mode 100644 tests/qemu-iotests/244.out

diff --git a/tests/qemu-iotests/244 b/tests/qemu-iotests/244
new file mode 100755
index XXXXXXX..XXXXXXX
--- /dev/null
+++ b/tests/qemu-iotests/244
@@ -XXX,XX +XXX,XX @@
+#!/bin/bash
+#
+# Test qcow2 with external data files
+#
+# Copyright (C) 2019 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"
+
+status=1	# failure is the default!
+
+_cleanup()
+{
+    _cleanup_test_img
+    rm -f $TEST_IMG.data
+    rm -f $TEST_IMG.src
+}
+trap "_cleanup; exit \$status" 0 1 2 3 15
+
+# get standard environment, filters and checks
+. ./common.rc
+. ./common.filter
+
+_supported_fmt qcow2
+_supported_proto file
+_supported_os Linux
+
+echo
+echo "=== Create and open image with external data file ==="
+echo
+
+echo "With data file name in the image:"
+IMGOPTS="data_file=$TEST_IMG.data" _make_test_img 64M
+_check_test_img
+
+$QEMU_IO -c "open $TEST_IMG" -c "read -P 0 0 64k" 2>&1 | _filter_qemu_io | _filter_testdir
+$QEMU_IO -c "open -odata-file.filename=$TEST_IMG.data $TEST_IMG" -c "read -P 0 0 64k" 2>&1 | _filter_qemu_io | _filter_testdir
+$QEMU_IO -c "open -odata-file.filename=inexistent $TEST_IMG" -c "read -P 0 0 64k" 2>&1 | _filter_qemu_io | _filter_testdir
+
+echo
+echo "Data file required, but without data file name in the image:"
+$QEMU_IMG amend -odata_file= $TEST_IMG
+
+$QEMU_IO -c "open $TEST_IMG" -c "read -P 0 0 64k" 2>&1 | _filter_qemu_io | _filter_testdir
+$QEMU_IO -c "open -odata-file.filename=$TEST_IMG.data $TEST_IMG" -c "read -P 0 0 64k" 2>&1 | _filter_qemu_io | _filter_testdir
+$QEMU_IO -c "open -odata-file.filename=inexistent $TEST_IMG" -c "read -P 0 0 64k" 2>&1 | _filter_qemu_io | _filter_testdir
+
+echo
+echo "Setting data-file for an image with internal data:"
+_make_test_img 64M
+
+$QEMU_IO -c "open -odata-file.filename=$TEST_IMG.data $TEST_IMG" -c "read -P 0 0 64k" 2>&1 | _filter_qemu_io | _filter_testdir
+$QEMU_IO -c "open -odata-file.filename=inexistent $TEST_IMG" -c "read -P 0 0 64k" 2>&1 | _filter_qemu_io | _filter_testdir
+
+echo
+echo "=== Conflicting features ==="
+echo
+
+echo "Convert to compressed target with data file:"
+TEST_IMG="$TEST_IMG.src" _make_test_img 64M
+
+$QEMU_IO -c 'write -P 0x11 0 1M' \
+         -f $IMGFMT "$TEST_IMG.src" |
+         _filter_qemu_io
+
+$QEMU_IMG convert -f $IMGFMT -O $IMGFMT -c -odata_file="$TEST_IMG.data" \
+    "$TEST_IMG.src" "$TEST_IMG"
+
+echo
+echo "Convert uncompressed, then write compressed data manually:"
+$QEMU_IMG convert -f $IMGFMT -O $IMGFMT -odata_file="$TEST_IMG.data" \
+    "$TEST_IMG.src" "$TEST_IMG"
+$QEMU_IMG compare "$TEST_IMG.src" "$TEST_IMG"
+
+$QEMU_IO -c 'write -c -P 0x22 0 1M' \
+         -f $IMGFMT "$TEST_IMG" |
+         _filter_qemu_io
+_check_test_img
+
+echo
+echo "Take an internal snapshot:"
+
+$QEMU_IMG snapshot -c test "$TEST_IMG"
+_check_test_img
+
+echo
+echo "=== Standalone image with external data file (efficient) ==="
+echo
+
+IMGOPTS="data_file=$TEST_IMG.data" _make_test_img 64M
+
+echo -n "qcow2 file size before I/O: "
+du -b $TEST_IMG | cut -f1
+
+# Create image with the following layout
+# 0-1 MB: Unallocated
+# 1-2 MB: Written (pattern 0x11)
+# 2-3 MB: Discarded
+# 3-4 MB: Zero write over discarded space
+# 4-5 MB: Zero write over written space
+# 5-6 MB: Zero write over unallocated space
+
+echo
+$QEMU_IO -c 'write -P 0x11 1M 4M' \
+         -c 'discard 2M 2M' \
+         -c 'write -z 3M 3M' \
+         -f $IMGFMT "$TEST_IMG" |
+         _filter_qemu_io
+_check_test_img
+
+echo
+$QEMU_IMG map --output=json "$TEST_IMG"
+
+echo
+$QEMU_IO -c 'read -P 0 0 1M' \
+         -c 'read -P 0x11 1M 1M' \
+         -c 'read -P 0 2M 4M' \
+         -f $IMGFMT "$TEST_IMG" |
+         _filter_qemu_io
+
+# Zero clusters are only marked as such in the qcow2 metadata, but contain
+# stale data in the external data file
+echo
+$QEMU_IO -c 'read -P 0 0 1M' \
+         -c 'read -P 0x11 1M 1M' \
+         -c 'read -P 0 2M 2M' \
+         -c 'read -P 0x11 4M 1M' \
+         -c 'read -P 0 5M 1M' \
+         -f raw "$TEST_IMG.data" |
+         _filter_qemu_io
+
+
+echo -n "qcow2 file size after I/O: "
+du -b $TEST_IMG | cut -f1
+
+echo
+echo "=== Standalone image with external data file (valid raw) ==="
+echo
+
+IMGOPTS="data_file=$TEST_IMG.data,data_file_raw=on" _make_test_img 64M
+
+echo -n "qcow2 file size before I/O: "
+du -b $TEST_IMG | cut -f1
+
+echo
+$QEMU_IO -c 'write -P 0x11 1M 4M' \
+         -c 'discard 2M 2M' \
+         -c 'write -z 3M 3M' \
+         -f $IMGFMT "$TEST_IMG" |
+         _filter_qemu_io
+_check_test_img
+
+echo
+$QEMU_IMG map --output=json "$TEST_IMG"
+
+echo
+$QEMU_IO -c 'read -P 0 0 1M' \
+         -c 'read -P 0x11 1M 1M' \
+         -c 'read -P 0 2M 4M' \
+         -f $IMGFMT "$TEST_IMG" |
+         _filter_qemu_io
+
+echo
+$QEMU_IMG compare "$TEST_IMG" "$TEST_IMG.data"
+
+echo -n "qcow2 file size after I/O: "
+du -b $TEST_IMG | cut -f1
+
+echo
+echo "=== bdrv_co_block_status test for file and offset=0 ==="
+echo
+
+IMGOPTS="data_file=$TEST_IMG.data" _make_test_img 64M
+
+$QEMU_IO -c 'write -P 0x11 0 1M' -f $IMGFMT "$TEST_IMG" | _filter_qemu_io
+$QEMU_IO -c 'read -P 0x11 0 1M' -f $IMGFMT "$TEST_IMG" | _filter_qemu_io
+$QEMU_IMG map --output=human "$TEST_IMG" | _filter_testdir
+$QEMU_IMG map --output=json "$TEST_IMG"
+
+# success, all done
+echo "*** done"
+rm -f $seq.full
+status=0
diff --git a/tests/qemu-iotests/244.out b/tests/qemu-iotests/244.out
new file mode 100644
index XXXXXXX..XXXXXXX
--- /dev/null
+++ b/tests/qemu-iotests/244.out
@@ -XXX,XX +XXX,XX @@
+QA output created by 244
+
+=== Create and open image with external data file ===
+
+With data file name in the image:
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864 data_file=TEST_DIR/t.IMGFMT.data
+No errors were found on the image.
+read 65536/65536 bytes at offset 0
+64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+read 65536/65536 bytes at offset 0
+64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+can't open device TEST_DIR/t.qcow2: Could not open 'inexistent': No such file or directory
+no file open, try 'help open'
+
+Data file required, but without data file name in the image:
+can't open device TEST_DIR/t.qcow2: 'data-file' is required for this image
+no file open, try 'help open'
+read 65536/65536 bytes at offset 0
+64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+can't open device TEST_DIR/t.qcow2: Could not open 'inexistent': No such file or directory
+no file open, try 'help open'
+
+Setting data-file for an image with internal data:
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
+can't open device TEST_DIR/t.qcow2: 'data-file' can only be set for images with an external data file
+no file open, try 'help open'
+can't open device TEST_DIR/t.qcow2: Could not open 'inexistent': No such file or directory
+no file open, try 'help open'
+
+=== Conflicting features ===
+
+Convert to compressed target with data file:
+Formatting 'TEST_DIR/t.IMGFMT.src', fmt=IMGFMT size=67108864
+wrote 1048576/1048576 bytes at offset 0
+1 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+qemu-img: error while writing sector 0: Operation not supported
+
+Convert uncompressed, then write compressed data manually:
+Images are identical.
+write failed: Operation not supported
+No errors were found on the image.
+
+Take an internal snapshot:
+qemu-img: Could not create snapshot 'test': -95 (Operation not supported)
+No errors were found on the image.
+
+=== Standalone image with external data file (efficient) ===
+
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864 data_file=TEST_DIR/t.IMGFMT.data
+qcow2 file size before I/O: 196616
+
+wrote 4194304/4194304 bytes at offset 1048576
+4 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+discard 2097152/2097152 bytes at offset 2097152
+2 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+wrote 3145728/3145728 bytes at offset 3145728
+3 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+No errors were found on the image.
+
+[{ "start": 0, "length": 1048576, "depth": 0, "zero": true, "data": false},
+{ "start": 1048576, "length": 1048576, "depth": 0, "zero": false, "data": true, "offset": 1048576},
+{ "start": 2097152, "length": 2097152, "depth": 0, "zero": true, "data": false},
+{ "start": 4194304, "length": 1048576, "depth": 0, "zero": true, "data": false, "offset": 4194304},
+{ "start": 5242880, "length": 61865984, "depth": 0, "zero": true, "data": false}]
+
+read 1048576/1048576 bytes at offset 0
+1 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+read 1048576/1048576 bytes at offset 1048576
+1 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+read 4194304/4194304 bytes at offset 2097152
+4 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+
+read 1048576/1048576 bytes at offset 0
+1 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+read 1048576/1048576 bytes at offset 1048576
+1 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+read 2097152/2097152 bytes at offset 2097152
+2 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+read 1048576/1048576 bytes at offset 4194304
+1 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+read 1048576/1048576 bytes at offset 5242880
+1 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+qcow2 file size after I/O: 327680
+
+=== Standalone image with external data file (valid raw) ===
+
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864 data_file=TEST_DIR/t.IMGFMT.data data_file_raw=on
+qcow2 file size before I/O: 196616
+
+wrote 4194304/4194304 bytes at offset 1048576
+4 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+discard 2097152/2097152 bytes at offset 2097152
+2 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+wrote 3145728/3145728 bytes at offset 3145728
+3 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+No errors were found on the image.
+
+[{ "start": 0, "length": 1048576, "depth": 0, "zero": true, "data": false},
+{ "start": 1048576, "length": 1048576, "depth": 0, "zero": false, "data": true, "offset": 1048576},
+{ "start": 2097152, "length": 2097152, "depth": 0, "zero": true, "data": false},
+{ "start": 4194304, "length": 1048576, "depth": 0, "zero": true, "data": false, "offset": 4194304},
+{ "start": 5242880, "length": 61865984, "depth": 0, "zero": true, "data": false}]
+
+read 1048576/1048576 bytes at offset 0
+1 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+read 1048576/1048576 bytes at offset 1048576
+1 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+read 4194304/4194304 bytes at offset 2097152
+4 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+
+Images are identical.
+qcow2 file size after I/O: 327680
+
+=== bdrv_co_block_status test for file and offset=0 ===
+
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864 data_file=TEST_DIR/t.IMGFMT.data
+wrote 1048576/1048576 bytes at offset 0
+1 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+read 1048576/1048576 bytes at offset 0
+1 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+Offset          Length          Mapped to       File
+0               0x100000        0               TEST_DIR/t.qcow2.data
+[{ "start": 0, "length": 1048576, "depth": 0, "zero": false, "data": true, "offset": 0},
+{ "start": 1048576, "length": 66060288, "depth": 0, "zero": true, "data": false}]
+*** 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 @@
 240 auto quick
 242 rw auto quick
 243 rw auto quick
+244 rw auto quick
-- 
2.20.1

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 tests/qemu-iotests/061     | 45 ++++++++++++++++++-
 tests/qemu-iotests/061.out | 89 ++++++++++++++++++++++++++++++++++++++
 2 files changed, 133 insertions(+), 1 deletion(-)

diff --git a/tests/qemu-iotests/061 b/tests/qemu-iotests/061
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/061
+++ b/tests/qemu-iotests/061
@@ -XXX,XX +XXX,XX @@ status=1	# failure is the default!
 
 _cleanup()
 {
-	_cleanup_test_img
+    _cleanup_test_img
+    rm -f $TEST_IMG.data
 }
 trap "_cleanup; exit \$status" 0 1 2 3 15
 
@@ -XXX,XX +XXX,XX @@ $QEMU_IMG snapshot -c foo "$TEST_IMG"
 $QEMU_IMG amend -p -o "compat=0.10" "$TEST_IMG"
 _check_test_img
 
+echo
+echo "=== Testing version downgrade with external data file ==="
+echo
+IMGOPTS="compat=1.1,data_file=$TEST_IMG.data" _make_test_img 64M
+$QEMU_IMG amend -o "compat=0.10" "$TEST_IMG"
+_img_info --format-specific
+_check_test_img
+
+echo
+echo "=== Try changing the external data file ==="
+echo
+IMGOPTS="compat=1.1" _make_test_img 64M
+$QEMU_IMG amend -o "data_file=foo" "$TEST_IMG"
+
+echo
+IMGOPTS="compat=1.1,data_file=$TEST_IMG.data" _make_test_img 64M
+$QEMU_IMG amend -o "data_file=foo" "$TEST_IMG"
+_img_info --format-specific
+TEST_IMG="data-file.filename=$TEST_IMG.data,file.filename=$TEST_IMG" _img_info --format-specific --image-opts
+
+echo
+$QEMU_IMG amend -o "data_file=" --image-opts "data-file.filename=$TEST_IMG.data,file.filename=$TEST_IMG"
+_img_info --format-specific
+TEST_IMG="data-file.filename=$TEST_IMG.data,file.filename=$TEST_IMG" _img_info --format-specific --image-opts
+
+echo
+echo "=== Clearing and setting data-file-raw ==="
+echo
+IMGOPTS="compat=1.1,data_file=$TEST_IMG.data,data_file_raw=on" _make_test_img 64M
+$QEMU_IMG amend -o "data_file_raw=on" "$TEST_IMG"
+_img_info --format-specific
+_check_test_img
+
+$QEMU_IMG amend -o "data_file_raw=off" "$TEST_IMG"
+_img_info --format-specific
+_check_test_img
+
+$QEMU_IMG amend -o "data_file_raw=on" "$TEST_IMG"
+_img_info --format-specific
+_check_test_img
+
+
 # success, all done
 echo "*** done"
 rm -f $seq.full
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 @@ wrote 65536/65536 bytes at offset 3221225472
 64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
     (0.00/100%)
    (6.25/100%)
    (12.50/100%)
    (18.75/100%)
    (25.00/100%)
    (31.25/100%)
    (37.50/100%)
    (43.75/100%)
    (50.00/100%)
    (56.25/100%)
    (62.50/100%)
    (68.75/100%)
    (75.00/100%)
    (81.25/100%)
    (87.50/100%)
    (93.75/100%)
    (100.00/100%)
    (100.00/100%)
 No errors were found on the image.
+
+=== Testing version downgrade with external data file ===
+
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864 data_file=TEST_DIR/t.IMGFMT.data
+qemu-img: Cannot downgrade an image with a data file
+image: TEST_DIR/t.IMGFMT
+file format: IMGFMT
+virtual size: 64M (67108864 bytes)
+cluster_size: 65536
+Format specific information:
+    compat: 1.1
+    lazy refcounts: false
+    refcount bits: 16
+    data file: TEST_DIR/t.IMGFMT.data
+    data file raw: false
+    corrupt: false
+No errors were found on the image.
+
+=== Try changing the external data file ===
+
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
+qemu-img: data-file can only be set for images that use an external data file
+
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864 data_file=TEST_DIR/t.IMGFMT.data
+qemu-img: Could not open 'TEST_DIR/t.IMGFMT': Could not open 'foo': No such file or directory
+image: TEST_DIR/t.IMGFMT
+file format: IMGFMT
+virtual size: 64M (67108864 bytes)
+cluster_size: 65536
+Format specific information:
+    compat: 1.1
+    lazy refcounts: false
+    refcount bits: 16
+    data file: foo
+    data file raw: false
+    corrupt: false
+
+qemu-img: Could not open 'TEST_DIR/t.IMGFMT': 'data-file' is required for this image
+image: TEST_DIR/t.IMGFMT
+file format: IMGFMT
+virtual size: 64M (67108864 bytes)
+cluster_size: 65536
+Format specific information:
+    compat: 1.1
+    lazy refcounts: false
+    refcount bits: 16
+    data file raw: false
+    corrupt: false
+
+=== Clearing and setting data-file-raw ===
+
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864 data_file=TEST_DIR/t.IMGFMT.data data_file_raw=on
+image: TEST_DIR/t.IMGFMT
+file format: IMGFMT
+virtual size: 64M (67108864 bytes)
+cluster_size: 65536
+Format specific information:
+    compat: 1.1
+    lazy refcounts: false
+    refcount bits: 16
+    data file: TEST_DIR/t.IMGFMT.data
+    data file raw: true
+    corrupt: false
+No errors were found on the image.
+image: TEST_DIR/t.IMGFMT
+file format: IMGFMT
+virtual size: 64M (67108864 bytes)
+cluster_size: 65536
+Format specific information:
+    compat: 1.1
+    lazy refcounts: false
+    refcount bits: 16
+    data file: TEST_DIR/t.IMGFMT.data
+    data file raw: false
+    corrupt: false
+No errors were found on the image.
+qemu-img: data-file-raw cannot be set on existing images
+image: TEST_DIR/t.IMGFMT
+file format: IMGFMT
+virtual size: 64M (67108864 bytes)
+cluster_size: 65536
+Format specific information:
+    compat: 1.1
+    lazy refcounts: false
+    refcount bits: 16
+    data file: TEST_DIR/t.IMGFMT.data
+    data file raw: false
+    corrupt: false
+No errors were found on the image.
 *** done
-- 
2.20.1

From: Philippe Mathieu-Daudé <philmd@redhat.com>

Since the ahci-test uses qemu-img, add a dependency to build it
before using it.
This fixes:

$ gmake check-qtest V=1
  QTEST_QEMU_BINARY=x86_64-softmmu/qemu-system-x86_64 QTEST_QEMU_IMG=qemu-img tests/ahci-test
  Failed to execute child process "/tmp/qemu-test.19tMRF/qemu-img" (No such file or directory)
  ERROR:tests/libqos/libqos.c:192:mkimg: assertion failed: (ret && !err)

Reviewed-by: John Snow <jsnow@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 tests/Makefile.include | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tests/Makefile.include b/tests/Makefile.include
index XXXXXXX..XXXXXXX 100644
--- a/tests/Makefile.include
+++ b/tests/Makefile.include
@@ -XXX,XX +XXX,XX @@ tests/prom-env-test$(EXESUF): tests/prom-env-test.o $(libqos-obj-y)
 tests/rtas-test$(EXESUF): tests/rtas-test.o $(libqos-spapr-obj-y)
 tests/fdc-test$(EXESUF): tests/fdc-test.o
 tests/ide-test$(EXESUF): tests/ide-test.o $(libqos-pc-obj-y)
-tests/ahci-test$(EXESUF): tests/ahci-test.o $(libqos-pc-obj-y)
+tests/ahci-test$(EXESUF): tests/ahci-test.o $(libqos-pc-obj-y) qemu-img$(EXESUF)
 tests/ipmi-kcs-test$(EXESUF): tests/ipmi-kcs-test.o
 tests/ipmi-bt-test$(EXESUF): tests/ipmi-bt-test.o
 tests/hd-geo-test$(EXESUF): tests/hd-geo-test.o
-- 
2.20.1

From: Philippe Mathieu-Daudé <philmd@redhat.com>

Since a9660664fde, some iotests use qemu-nbd.
Add a dependency to build it before using it.
This fixes:

$ make check-block
    GEN     qemu-img-cmds.h
    CC      qemu-img.o
    LINK    qemu-img
    CC      qemu-io.o
    LINK    qemu-io
    CC      tests/qemu-iotests/socket_scm_helper.o
    LINK    tests/qemu-iotests/socket_scm_helper
  tests/qemu-iotests-quick.sh
  check: qemu-nbd not found
  make: *** [tests/Makefile.include:1059: check-tests/qemu-iotests-quick.sh] Error 1

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 tests/Makefile.include | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tests/Makefile.include b/tests/Makefile.include
index XXXXXXX..XXXXXXX 100644
--- a/tests/Makefile.include
+++ b/tests/Makefile.include
@@ -XXX,XX +XXX,XX @@ clean-tcg: $(CLEAN_TCG_TARGET_RULES)
 QEMU_IOTESTS_HELPERS-$(call land,$(CONFIG_SOFTMMU),$(CONFIG_LINUX)) = tests/qemu-iotests/socket_scm_helper$(EXESUF)
 
 .PHONY: check-tests/qemu-iotests-quick.sh
-check-tests/qemu-iotests-quick.sh: tests/qemu-iotests-quick.sh qemu-img$(EXESUF) qemu-io$(EXESUF) $(QEMU_IOTESTS_HELPERS-y)
+check-tests/qemu-iotests-quick.sh: tests/qemu-iotests-quick.sh qemu-img$(EXESUF) qemu-io$(EXESUF) qemu-nbd$(EXESUF) $(QEMU_IOTESTS_HELPERS-y)
 	$<
 
 .PHONY: $(patsubst %, check-%, $(check-qapi-schema-y))
-- 
2.20.1

Be more specific about the string representation in header extensions.

Suggested-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 docs/interop/qcow2.txt | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/docs/interop/qcow2.txt b/docs/interop/qcow2.txt
index XXXXXXX..XXXXXXX 100644
--- a/docs/interop/qcow2.txt
+++ b/docs/interop/qcow2.txt
@@ -XXX,XX +XXX,XX @@ be stored. Each extension has a structure like the following:
 
     Byte  0 -  3:   Header extension type:
                         0x00000000 - End of the header extension area
-                        0xE2792ACA - Backing file format name
+                        0xE2792ACA - Backing file format name string
                         0x6803f857 - Feature name table
                         0x23852875 - Bitmaps extension
                         0x0537be77 - Full disk encryption header pointer
-                        0x44415441 - External data file name
+                        0x44415441 - External data file name string
                         other      - Unknown header extension, can be safely
                                      ignored
 
@@ -XXX,XX +XXX,XX @@ data of compatible features that it doesn't support. Compatible features that
 need space for additional data can use a header extension.
 
 
+== String header extensions ==
+
+Some header extensions (such as the backing file format name and the external
+data file name) are just a single string. In this case, the header extension
+length is the string length and the string is not '\0' terminated. (The header
+extension padding can make it look like a string is '\0' terminated, but
+neither is padding always necessary nor is there a guarantee that zero bytes
+are used for padding.)
+
+
 == Feature name table ==
 
 The feature name table is an optional header extension that contains the name
-- 
2.20.1

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