| Message ID | 20220520075922.43972-1-f.ebner@proxmox.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v3] block/gluster: correctly set max_pdiscard | expand |
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>
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 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>
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
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,
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(-)