block/gluster.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
On 64-bit platforms, assigning SIZE_MAX to the int64_t max_pdiscard
results in a negative value, and the following assertion would trigger
down the line (it's not the same max_pdiscard, but computed from the
other one):
qemu-system-x86_64: ../block/io.c:3166: bdrv_co_pdiscard: Assertion
`max_pdiscard >= bs->bl.request_alignment' failed.
On 32-bit platforms, it's fine to keep using SIZE_MAX.
The assertion in qemu_gluster_co_pdiscard() is checking that the value
of 'bytes' can safely be passed to glfs_discard_async(), which takes a
size_t for the argument in question, so it is kept as is. And since
max_pdiscard is still <= SIZE_MAX, relying on max_pdiscard is still
fine.
Fixes: 0c8022876f ("block: use int64_t instead of int in driver discard handlers")
Cc: qemu-stable@nongnu.org
Signed-off-by: Fabian Ebner <f.ebner@proxmox.com>
---
v2 -> v3:
* Keep assertion in qemu_gluster_co_pdiscard() as is.
* Improve commit message.
v1 -> v2:
* Use an expression that works for both 64-bit and 32-bit platforms.
block/gluster.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/block/gluster.c b/block/gluster.c
index 398976bc66..b60213ab80 100644
--- a/block/gluster.c
+++ b/block/gluster.c
@@ -891,7 +891,7 @@ out:
static void qemu_gluster_refresh_limits(BlockDriverState *bs, Error **errp)
{
bs->bl.max_transfer = GLUSTER_MAX_TRANSFER;
- bs->bl.max_pdiscard = SIZE_MAX;
+ bs->bl.max_pdiscard = MIN(SIZE_MAX, INT64_MAX);
}
static int qemu_gluster_reopen_prepare(BDRVReopenState *state,
--
2.30.2
Am 20.05.2022 um 09:59 hat Fabian Ebner geschrieben: > On 64-bit platforms, assigning SIZE_MAX to the int64_t max_pdiscard > results in a negative value, and the following assertion would trigger > down the line (it's not the same max_pdiscard, but computed from the > other one): > qemu-system-x86_64: ../block/io.c:3166: bdrv_co_pdiscard: Assertion > `max_pdiscard >= bs->bl.request_alignment' failed. > > On 32-bit platforms, it's fine to keep using SIZE_MAX. > > The assertion in qemu_gluster_co_pdiscard() is checking that the value > of 'bytes' can safely be passed to glfs_discard_async(), which takes a > size_t for the argument in question, so it is kept as is. And since > max_pdiscard is still <= SIZE_MAX, relying on max_pdiscard is still > fine. > > Fixes: 0c8022876f ("block: use int64_t instead of int in driver discard handlers") > Cc: qemu-stable@nongnu.org > Signed-off-by: Fabian Ebner <f.ebner@proxmox.com> Thanks, applied to the block branch. Kevin
On 5/20/22 10:59, Fabian Ebner wrote: > On 64-bit platforms, assigning SIZE_MAX to the int64_t max_pdiscard > results in a negative value, and the following assertion would trigger Oops. Good catch! > down the line (it's not the same max_pdiscard, but computed from the > other one): > qemu-system-x86_64: ../block/io.c:3166: bdrv_co_pdiscard: Assertion > `max_pdiscard >= bs->bl.request_alignment' failed. > > On 32-bit platforms, it's fine to keep using SIZE_MAX. > > The assertion in qemu_gluster_co_pdiscard() is checking that the value > of 'bytes' can safely be passed to glfs_discard_async(), which takes a > size_t for the argument in question, so it is kept as is. And since > max_pdiscard is still <= SIZE_MAX, relying on max_pdiscard is still > fine. > > Fixes: 0c8022876f ("block: use int64_t instead of int in driver discard handlers") > Cc: qemu-stable@nongnu.org > Signed-off-by: Fabian Ebner <f.ebner@proxmox.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru> -- Best regards, Vladimir
On Fri, May 20, 2022 at 09:59:22AM +0200, Fabian Ebner wrote: >On 64-bit platforms, assigning SIZE_MAX to the int64_t max_pdiscard >results in a negative value, and the following assertion would trigger >down the line (it's not the same max_pdiscard, but computed from the >other one): >qemu-system-x86_64: ../block/io.c:3166: bdrv_co_pdiscard: Assertion >`max_pdiscard >= bs->bl.request_alignment' failed. > >On 32-bit platforms, it's fine to keep using SIZE_MAX. > >The assertion in qemu_gluster_co_pdiscard() is checking that the value >of 'bytes' can safely be passed to glfs_discard_async(), which takes a >size_t for the argument in question, so it is kept as is. And since >max_pdiscard is still <= SIZE_MAX, relying on max_pdiscard is still >fine. > >Fixes: 0c8022876f ("block: use int64_t instead of int in driver discard handlers") >Cc: qemu-stable@nongnu.org >Signed-off-by: Fabian Ebner <f.ebner@proxmox.com> >--- > >v2 -> v3: > * Keep assertion in qemu_gluster_co_pdiscard() as is. > * Improve commit message. > >v1 -> v2: > * Use an expression that works for both 64-bit and 32-bit platforms. > > block/gluster.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) Reviewed-by: Stefano Garzarella <sgarzare@redhat.com> > >diff --git a/block/gluster.c b/block/gluster.c >index 398976bc66..b60213ab80 100644 >--- a/block/gluster.c >+++ b/block/gluster.c >@@ -891,7 +891,7 @@ out: > static void qemu_gluster_refresh_limits(BlockDriverState *bs, Error **errp) > { > bs->bl.max_transfer = GLUSTER_MAX_TRANSFER; >- bs->bl.max_pdiscard = SIZE_MAX; >+ bs->bl.max_pdiscard = MIN(SIZE_MAX, INT64_MAX); > } > > static int qemu_gluster_reopen_prepare(BDRVReopenState *state, >-- >2.30.2 > >
On Fri, May 20, 2022 at 09:59:22AM +0200, Fabian Ebner wrote: > On 64-bit platforms, assigning SIZE_MAX to the int64_t max_pdiscard > results in a negative value, and the following assertion would trigger > down the line (it's not the same max_pdiscard, but computed from the > other one): > qemu-system-x86_64: ../block/io.c:3166: bdrv_co_pdiscard: Assertion > `max_pdiscard >= bs->bl.request_alignment' failed. > > On 32-bit platforms, it's fine to keep using SIZE_MAX. > > The assertion in qemu_gluster_co_pdiscard() is checking that the value > of 'bytes' can safely be passed to glfs_discard_async(), which takes a > size_t for the argument in question, so it is kept as is. And since > max_pdiscard is still <= SIZE_MAX, relying on max_pdiscard is still > fine. > > Fixes: 0c8022876f ("block: use int64_t instead of int in driver discard handlers") > Cc: qemu-stable@nongnu.org > Signed-off-by: Fabian Ebner <f.ebner@proxmox.com> > --- Reviewed-by: Eric Blake <eblake@redhat.com> -- Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3266 Virtualization: qemu.org | libvirt.org
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