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* [Qemu-devel] [PATCH] block: fix aio_flush segfaults for read-only protocols (e.g. curl)
@ 2010-05-16 11:59 Avi Kivity
  2010-05-16 13:21 ` Christoph Hellwig
  2010-05-17  9:10 ` [Qemu-devel] " Kevin Wolf
  0 siblings, 2 replies; 3+ messages in thread
From: Avi Kivity @ 2010-05-16 11:59 UTC (permalink / raw)
  To: Kevin Wolf; +Cc: qemu-devel

Not all block format drivers expose an io_flush method (reasonable for
read-only protocols), so calling io_flush there will immediately segfault.

Fix by checking for the method's existence before calling it.

Signed-off-by: Avi Kivity <avi@redhat.com>
---
 aio.c |    4 +++-
 1 files changed, 3 insertions(+), 1 deletions(-)

diff --git a/aio.c b/aio.c
index f164a47..2f08655 100644
--- a/aio.c
+++ b/aio.c
@@ -113,7 +113,9 @@ void qemu_aio_flush(void)
         qemu_aio_wait();
 
         QLIST_FOREACH(node, &aio_handlers, node) {
-            ret |= node->io_flush(node->opaque);
+            if (node->io_flush) {
+                ret |= node->io_flush(node->opaque);
+            }
         }
     } while (qemu_bh_poll() || ret > 0);
 }
-- 
1.7.0.4

^ permalink raw reply related	[flat|nested] 3+ messages in thread

* Re: [Qemu-devel] [PATCH] block: fix aio_flush segfaults for read-only protocols (e.g. curl)
  2010-05-16 11:59 [Qemu-devel] [PATCH] block: fix aio_flush segfaults for read-only protocols (e.g. curl) Avi Kivity
@ 2010-05-16 13:21 ` Christoph Hellwig
  2010-05-17  9:10 ` [Qemu-devel] " Kevin Wolf
  1 sibling, 0 replies; 3+ messages in thread
From: Christoph Hellwig @ 2010-05-16 13:21 UTC (permalink / raw)
  To: Avi Kivity; +Cc: Kevin Wolf, qemu-devel

On Sun, May 16, 2010 at 02:59:57PM +0300, Avi Kivity wrote:
> Not all block format drivers expose an io_flush method (reasonable for
> read-only protocols), so calling io_flush there will immediately segfault.
> 
> Fix by checking for the method's existence before calling it.

Looks good,


Reviewed-by: Christoph Hellwig <hch@lst.de>

^ permalink raw reply	[flat|nested] 3+ messages in thread

* [Qemu-devel] Re: [PATCH] block: fix aio_flush segfaults for read-only protocols (e.g. curl)
  2010-05-16 11:59 [Qemu-devel] [PATCH] block: fix aio_flush segfaults for read-only protocols (e.g. curl) Avi Kivity
  2010-05-16 13:21 ` Christoph Hellwig
@ 2010-05-17  9:10 ` Kevin Wolf
  1 sibling, 0 replies; 3+ messages in thread
From: Kevin Wolf @ 2010-05-17  9:10 UTC (permalink / raw)
  To: Avi Kivity; +Cc: qemu-devel

Am 16.05.2010 13:59, schrieb Avi Kivity:
> Not all block format drivers expose an io_flush method (reasonable for
> read-only protocols), so calling io_flush there will immediately segfault.
> 
> Fix by checking for the method's existence before calling it.
> 
> Signed-off-by: Avi Kivity <avi@redhat.com>

Thanks, applied to the block branch.

Kevin

^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2010-05-17  9:10 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
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2010-05-16 11:59 [Qemu-devel] [PATCH] block: fix aio_flush segfaults for read-only protocols (e.g. curl) Avi Kivity
2010-05-16 13:21 ` Christoph Hellwig
2010-05-17  9:10 ` [Qemu-devel] " Kevin Wolf

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