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authorKevin Wolf <kwolf@redhat.com>2013-06-19 13:44:19 +0200
committerStefan Hajnoczi <stefanha@redhat.com>2013-06-24 10:25:17 +0200
commit67af674e478054086f972811dd0a11289afa39a9 (patch)
tree9d1fbd115bc79b44f4ae73345158d623976e06ee /block/qcow2-refcount.c
parent6cfcb9b8b91d303ab51b78623f2299b5288d2d51 (diff)
qcow2: Options to enable discard for freed clusters
Deleted snapshots are discarded in the image file by default, discard requests take their default from the -drive discard=... option and other places that free clusters must always be enabled explicitly. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Diffstat (limited to 'block/qcow2-refcount.c')
-rw-r--r--block/qcow2-refcount.c5
1 files changed, 5 insertions, 0 deletions
diff --git a/block/qcow2-refcount.c b/block/qcow2-refcount.c
index 6d35e49d32..7488988a9a 100644
--- a/block/qcow2-refcount.c
+++ b/block/qcow2-refcount.c
@@ -488,6 +488,11 @@ static int QEMU_WARN_UNUSED_RESULT update_refcount(BlockDriverState *bs,
s->free_cluster_index = cluster_index;
}
refcount_block[block_index] = cpu_to_be16(refcount);
+ if (refcount == 0 && s->discard_passthrough[type]) {
+ /* Try discarding, ignore errors */
+ /* FIXME Doing this cluster by cluster will be painfully slow */
+ bdrv_discard(bs->file, cluster_offset, 1);
+ }
}
ret = 0;