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| author | Kevin Wolf | 2015-05-06 13:21:51 +0200 |
|---|---|---|
| committer | Kevin Wolf | 2015-05-22 17:08:00 +0200 |
| commit | ecbda7a22576591a84f44de1be0150faf6001f1c (patch) | |
| tree | d01afef7f41119ede1366f027b0023c9a709d240 /block | |
| parent | Merge remote-tracking branch 'remotes/stefanha/tags/block-pull-request' into ... (diff) | |
| download | qemu-ecbda7a22576591a84f44de1be0150faf6001f1c.tar.gz qemu-ecbda7a22576591a84f44de1be0150faf6001f1c.tar.xz qemu-ecbda7a22576591a84f44de1be0150faf6001f1c.zip | |
qcow2: Flush pending discards before allocating cluster
Before a freed cluster can be reused, pending discards for this cluster
must be processed.
The original assumption was that this was not a problem because discards
are only cached during discard/write zeroes operations, which are
synchronous so that no concurrent write requests can cause cluster
allocations.
However, the discard/write zeroes operation itself can allocate a new L2
table (and it has to in order to put zero flags there), so make sure we
can cope with the situation.
This fixes https://bugs.launchpad.net/bugs/1349972.
Cc: qemu-stable@nongnu.org
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Diffstat (limited to 'block')
| -rw-r--r-- | block/qcow2-refcount.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/block/qcow2-refcount.c b/block/qcow2-refcount.c index f47260b808..83467c31c3 100644 --- a/block/qcow2-refcount.c +++ b/block/qcow2-refcount.c @@ -833,6 +833,11 @@ static int64_t alloc_clusters_noref(BlockDriverState *bs, uint64_t size) uint64_t i, nb_clusters, refcount; int ret; + /* We can't allocate clusters if they may still be queued for discard. */ + if (s->cache_discards) { + qcow2_process_discards(bs, 0); + } + nb_clusters = size_to_clusters(s, size); retry: for(i = 0; i < nb_clusters; i++) { |