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| author |   Kevin Wolf <kwolf@redhat.com> | 2010-05-28 12:21:27 +0200 |
|---|---|---|
| committer |   Doug Goldstein <cardoe@gentoo.org> | 2010-07-20 17:36:00 -0500 |
| commit | fdbec203bb2483e4533e62ef5c2dd0cc66f09234 (patch) | |
| tree | eaaa975cd489627f70e94ecee469b077eec65686 /block/qcow2-refcount.c | |
| parent | qcow2: Fix corruption after refblock allocation (diff) | |
| download | qemu-kvm-fdbec203bb2483e4533e62ef5c2dd0cc66f09234.tar.gz qemu-kvm-fdbec203bb2483e4533e62ef5c2dd0cc66f09234.tar.bz2 qemu-kvm-fdbec203bb2483e4533e62ef5c2dd0cc66f09234.zip | |
qcow2: Fix corruption after error in update_refcount
After it is done with updating refcounts in the cache, update_refcount writes
all changed entries to disk. If a refcount block allocation fails, however,
there was no change yet and therefore first_index = last_index = -1. Don't
treat -1 as a normal sector index (resulting in a 512 byte write!) but return
without updating anything in this case.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
(cherry picked from commit 86fa8da83771238de55dc44819a1a27bafef5353)
Diffstat (limited to 'block/qcow2-refcount.c')
| -rw-r--r-- | block/qcow2-refcount.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/block/qcow2-refcount.c b/block/qcow2-refcount.c index fa78e46ee..465d5d36e 100644 --- a/block/qcow2-refcount.c +++ b/block/qcow2-refcount.c @@ -402,6 +402,10 @@ static int write_refcount_block_entries(BDRVQcowState *s, return 0; } + if (first_index < 0) { + return 0; + } + first_index &= ~(REFCOUNTS_PER_SECTOR - 1); last_index = (last_index + REFCOUNTS_PER_SECTOR) & ~(REFCOUNTS_PER_SECTOR - 1); |