[PATCH] dm mirror log: sync_count fix
When a mirror is reduced in size, clear the part of the bitmap that is no
longer used.
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/drivers/md/dm-log.c b/drivers/md/dm-log.c
index 33d8072..ba98bf5 100644
--- a/drivers/md/dm-log.c
+++ b/drivers/md/dm-log.c
@@ -447,7 +447,7 @@
if (r)
return r;
- /* set or clear any new bits */
+ /* set or clear any new bits -- device has grown */
if (lc->sync == NOSYNC)
for (i = lc->header.nr_regions; i < lc->region_count; i++)
/* FIXME: amazingly inefficient */
@@ -457,6 +457,10 @@
/* FIXME: amazingly inefficient */
log_clear_bit(lc, lc->clean_bits, i);
+ /* clear any old bits -- device has shrunk */
+ for (i = lc->region_count; i % (sizeof(*lc->clean_bits) << BYTE_SHIFT); i++)
+ log_clear_bit(lc, lc->clean_bits, i);
+
/* copy clean across to sync */
memcpy(lc->sync_bits, lc->clean_bits, size);
lc->sync_count = count_bits32(lc->clean_bits, lc->bitset_uint32_count);
