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| author | Kevin Wolf <kwolf@redhat.com> | 2013-12-13 13:04:35 +0100 |
|---|---|---|
| committer | Kevin Wolf <kwolf@redhat.com> | 2014-01-24 17:40:02 +0100 |
| commit | 6460440f34c709461b84375cfd8a86b27d433225 (patch) | |
| tree | a1bd62cb84945fbd5fb1719be49cd5558405e1fa /include/block | |
| parent | 7327145f63a224c9ba9c16d0c29781feffef8dc6 (diff) | |
| download | qemu-6460440f34c709461b84375cfd8a86b27d433225.zip qemu-6460440f34c709461b84375cfd8a86b27d433225.tar.gz qemu-6460440f34c709461b84375cfd8a86b27d433225.tar.bz2 | |
block: Allow wait_serialising_requests() at any point
We can only have a single wait_serialising_requests() call per request
because otherwise we can run into deadlocks where requests are waiting
for each other. The same is true when wait_serialising_requests() is not
at the very beginning of a request, so that other requests can be issued
between the start of the tracking and wait_serialising_requests().
Fix this by changing wait_serialising_requests() to ignore requests that
are already (directly or indirectly) waiting for the calling request.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Benoit Canet <benoit@irqsave.net>
Diffstat (limited to 'include/block')
| -rw-r--r-- | include/block/block_int.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/include/block/block_int.h b/include/block/block_int.h index 0ee955c..0bcf1c9 100644 --- a/include/block/block_int.h +++ b/include/block/block_int.h @@ -68,6 +68,8 @@ typedef struct BdrvTrackedRequest { QLIST_ENTRY(BdrvTrackedRequest) list; Coroutine *co; /* owner, used for deadlock detection */ CoQueue wait_queue; /* coroutines blocked on this request */ + + struct BdrvTrackedRequest *waiting_for; } BdrvTrackedRequest; struct BlockDriver { |