diff options
| author | Kevin Wolf <kwolf@redhat.com> | 2013-01-16 19:25:51 +0100 |
|---|---|---|
| committer | Michael Roth <mdroth@linux.vnet.ibm.com> | 2013-01-21 13:23:52 -0600 |
| commit | 9d173df5538a73cb8be53684ab19ea201c783663 (patch) | |
| tree | 217e70c1c4efbae80bd39a3ea29d1561123a73cf | |
| parent | 204dd38c2da72687848d1a6fd2a81a8eaac6bf78 (diff) | |
| download | qemu-9d173df5538a73cb8be53684ab19ea201c783663.tar.gz | |
aio: Fix return value of aio_poll()
aio_poll() must return true if any work is still pending, even if it
didn't make progress, so that bdrv_drain_all() doesn't stop waiting too
early. The possibility of stopping early occasionally lead to a failed
assertion in bdrv_drain_all(), when some in-flight request was missed
and the function didn't really drain all requests.
In order to make that change, the return value as specified in the
function comment must change for blocking = false; fortunately, the
return value of blocking = false callers is only used in test cases, so
this change shouldn't cause any trouble.
Cc: qemu-stable@nongnu.org
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
(cherry picked from commit 2ea9b58f0bc62445b7ace2381b4c4db7d5597e19)
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
| -rw-r--r-- | aio-posix.c | 3 | ||||
| -rw-r--r-- | aio-win32.c | 3 | ||||
| -rw-r--r-- | qemu-aio.h | 6 | ||||
| -rw-r--r-- | tests/test-aio.c | 4 |
4 files changed, 8 insertions, 8 deletions
diff --git a/aio-posix.c b/aio-posix.c index 05cc84e121..13d4572f33 100644 --- a/aio-posix.c +++ b/aio-posix.c @@ -264,5 +264,6 @@ bool aio_poll(AioContext *ctx, bool blocking) } } - return progress; + assert(progress || busy); + return true; } diff --git a/aio-win32.c b/aio-win32.c index cec4646635..7886e9829f 100644 --- a/aio-win32.c +++ b/aio-win32.c @@ -214,5 +214,6 @@ bool aio_poll(AioContext *ctx, bool blocking) events[ret - WAIT_OBJECT_0] = events[--count]; } - return progress; + assert(progress || busy); + return true; } diff --git a/qemu-aio.h b/qemu-aio.h index 3889fe97a4..2b6bdbc701 100644 --- a/qemu-aio.h +++ b/qemu-aio.h @@ -177,16 +177,14 @@ bool aio_pending(AioContext *ctx); * aio as a result of executing I/O completion or bh callbacks. * * If there is no pending AIO operation or completion (bottom half), - * return false. If there are pending bottom halves, return true. + * return false. If there are pending AIO operations of bottom halves, + * return true. * * If there are no pending bottom halves, but there are pending AIO * operations, it may not be possible to make any progress without * blocking. If @blocking is true, this function will wait until one * or more AIO events have completed, to ensure something has moved * before returning. - * - * If @blocking is false, this function will also return false if the - * function cannot make any progress without blocking. */ bool aio_poll(AioContext *ctx, bool blocking); diff --git a/tests/test-aio.c b/tests/test-aio.c index f53c908707..096a6e8e69 100644 --- a/tests/test-aio.c +++ b/tests/test-aio.c @@ -315,13 +315,13 @@ static void test_wait_event_notifier_noflush(void) event_notifier_set(&data.e); g_assert(aio_poll(ctx, false)); g_assert_cmpint(data.n, ==, 1); - g_assert(!aio_poll(ctx, false)); + g_assert(aio_poll(ctx, false)); g_assert_cmpint(data.n, ==, 1); event_notifier_set(&data.e); g_assert(aio_poll(ctx, false)); g_assert_cmpint(data.n, ==, 2); - g_assert(!aio_poll(ctx, false)); + g_assert(aio_poll(ctx, false)); g_assert_cmpint(data.n, ==, 2); event_notifier_set(&dummy.e); |