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authorMax Reitz <mreitz@redhat.com>2016-04-20 00:59:48 +0200
committerKevin Wolf <kwolf@redhat.com>2016-04-20 16:52:55 +0200
commitf27a27425901bacc69fb579e1dd8a5878eadd6e9 (patch)
tree34dc0ecd7df4645017ff6b9048738fede4eaf084
parent9c83625bdd3c1900d304058ece152040ef5d1ead (diff)
downloadqemu-f27a27425901bacc69fb579e1dd8a5878eadd6e9.tar.gz
block/mirror: Refresh stale bitmap iterator cache
If the drive's dirty bitmap is dirtied while the mirror operation is running, the cache of the iterator used by the mirror code may become stale and not contain all dirty bits. This only becomes an issue if we are looking for contiguously dirty chunks on the drive. In that case, we can easily detect the discrepancy and just refresh the iterator if one occurs. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
-rw-r--r--block/mirror.c5
1 files changed, 5 insertions, 0 deletions
diff --git a/block/mirror.c b/block/mirror.c
index 2714a77d69..9df1fae5ea 100644
--- a/block/mirror.c
+++ b/block/mirror.c
@@ -334,6 +334,11 @@ static uint64_t coroutine_fn mirror_iteration(MirrorBlockJob *s)
}
hbitmap_next = hbitmap_iter_next(&s->hbi);
+ if (hbitmap_next > next_sector || hbitmap_next < 0) {
+ /* The bitmap iterator's cache is stale, refresh it */
+ bdrv_set_dirty_iter(&s->hbi, next_sector);
+ hbitmap_next = hbitmap_iter_next(&s->hbi);
+ }
assert(hbitmap_next == next_sector);
nb_chunks++;
}