diff options
author | Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> | 2020-01-21 17:28:01 +0300 |
---|---|---|
committer | Max Reitz <mreitz@redhat.com> | 2020-02-06 13:47:45 +0100 |
commit | 0df62f45c1de6c020f1e6fba4eeafd248209b003 (patch) | |
tree | 4013a0cb0ed58a50709235cfce09d68a88b042df | |
parent | 3afea40243d7ccba7b569daa4dc7b174e594f792 (diff) |
block/backup-top: fix failure path
We can't access top after call bdrv_backup_top_drop, as it is already
freed at this time.
Also, no needs to unref target child by hand, it will be unrefed on
bdrv_close() automatically.
So, just do bdrv_backup_top_drop if append succeed and one bdrv_unref
otherwise.
Note, that in !appended case bdrv_unref(top) moved into drained section
on source. It doesn't really matter, but just for code simplicity.
Fixes: 7df7868b96404
Cc: qemu-stable@nongnu.org # v4.2.0
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 20200121142802.21467-2-vsementsov@virtuozzo.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
-rw-r--r-- | block/backup-top.c | 21 |
1 files changed, 12 insertions, 9 deletions
diff --git a/block/backup-top.c b/block/backup-top.c index 9aed2eb4c0..fa78f3256d 100644 --- a/block/backup-top.c +++ b/block/backup-top.c @@ -190,6 +190,7 @@ BlockDriverState *bdrv_backup_top_append(BlockDriverState *source, BlockDriverState *top = bdrv_new_open_driver(&bdrv_backup_top_filter, filter_node_name, BDRV_O_RDWR, errp); + bool appended = false; if (!top) { return NULL; @@ -212,8 +213,9 @@ BlockDriverState *bdrv_backup_top_append(BlockDriverState *source, bdrv_append(top, source, &local_err); if (local_err) { error_prepend(&local_err, "Cannot append backup-top filter: "); - goto append_failed; + goto fail; } + appended = true; /* * bdrv_append() finished successfully, now we can require permissions @@ -224,14 +226,14 @@ BlockDriverState *bdrv_backup_top_append(BlockDriverState *source, if (local_err) { error_prepend(&local_err, "Cannot set permissions for backup-top filter: "); - goto failed_after_append; + goto fail; } state->bcs = block_copy_state_new(top->backing, state->target, cluster_size, write_flags, &local_err); if (local_err) { error_prepend(&local_err, "Cannot create block-copy-state: "); - goto failed_after_append; + goto fail; } *bcs = state->bcs; @@ -239,14 +241,15 @@ BlockDriverState *bdrv_backup_top_append(BlockDriverState *source, return top; -failed_after_append: - state->active = false; - bdrv_backup_top_drop(top); +fail: + if (appended) { + state->active = false; + bdrv_backup_top_drop(top); + } else { + bdrv_unref(top); + } -append_failed: bdrv_drained_end(source); - bdrv_unref_child(top, state->target); - bdrv_unref(top); error_propagate(errp, local_err); return NULL; |