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[v2,15/20] rbd: Handle failure for potentially large allocations

Message ID 1401287873-25805-16-git-send-email-kwolf@redhat.com
State New
Headers show

Commit Message

Kevin Wolf May 28, 2014, 2:37 p.m. UTC 
Some code in the block layer makes potentially huge allocations. Failure
is not completely unexpected there, so avoid aborting qemu and handle
out-of-memory situations gracefully.

This patch addresses the allocations in the rbd block driver.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 block/rbd.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

Comments

Markus Armbruster May 30, 2014, 9:33 a.m. UTC | #1 
Kevin Wolf <kwolf@redhat.com> writes:

> Some code in the block layer makes potentially huge allocations. Failure
> is not completely unexpected there, so avoid aborting qemu and handle
> out-of-memory situations gracefully.
>
> This patch addresses the allocations in the rbd block driver.
>
> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
> ---
>  block/rbd.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/block/rbd.c b/block/rbd.c
> index dbc79f4..2ac65a8 100644
> --- a/block/rbd.c
> +++ b/block/rbd.c
> @@ -630,7 +630,10 @@ static BlockDriverAIOCB *rbd_start_aio(BlockDriverState *bs,
>      if (cmd == RBD_AIO_DISCARD || cmd == RBD_AIO_FLUSH) {
>          acb->bounce = NULL;
>      } else {
> -        acb->bounce = qemu_blockalign(bs, qiov->size);
> +        acb->bounce = qemu_try_blockalign(bs, qiov->size);
> +        if (acb->bounce == NULL) {
> +            goto failed;
> +        }
>      }
>      acb->ret = 0;
>      acb->error = 0;

/work/armbru/qemu/block/rbd.c: In function ‘rbd_start_aio’:
/work/armbru/qemu/block/rbd.c:696:11: warning: ‘rcb’ may be used uninitialized in this function [-Wmaybe-uninitialized]
     g_free(rcb);
           ^

Fix is obvious: initialize it to null.
diff mbox

Patch

diff --git a/block/rbd.c b/block/rbd.c
index dbc79f4..2ac65a8 100644
--- a/block/rbd.c
+++ b/block/rbd.c
@@ -630,7 +630,10 @@  static BlockDriverAIOCB *rbd_start_aio(BlockDriverState *bs,
     if (cmd == RBD_AIO_DISCARD || cmd == RBD_AIO_FLUSH) {
         acb->bounce = NULL;
     } else {
-        acb->bounce = qemu_blockalign(bs, qiov->size);
+        acb->bounce = qemu_try_blockalign(bs, qiov->size);
+        if (acb->bounce == NULL) {
+            goto failed;
+        }
     }
     acb->ret = 0;
     acb->error = 0;