Commit f27a2742 authored by Max Reitz's avatar Max Reitz Committed by Kevin Wolf
Browse files

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: default avatarMax Reitz <mreitz@redhat.com>
Reviewed-by: default avatarFam Zheng <famz@redhat.com>
Signed-off-by: default avatarKevin Wolf <kwolf@redhat.com>
parent 9c83625b

block/mirror.c

+5 −0
Original line number Diff line number Diff line
@@ -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++;

    }