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authorNeilBrown <neilb@suse.de>2011-12-23 09:57:48 +1100
committerNeilBrown <neilb@suse.de>2011-12-23 09:57:48 +1100
commit961902c0f8240175729274cd14198872f42072b7 (patch)
tree808b47d32174e970465dc00cea9150ff978bfc95
parent60fc13702a1b35118c1548e9c257fa038cecb658 (diff)
downloadlinux-961902c0f8240175729274cd14198872f42072b7.tar.bz2
md/bitmap: It is OK to clear bits during recovery.
commit d0a4bb492772ce5c4bdfba3744a99ed6f6fb238f introduced a regression which is annoying but fairly harmless. When writing to an array that is undergoing recovery (a spare in being integrated into the array), writing to the array will set bits in the bitmap, but they will not be cleared when the write completes. For bits covering areas that have not been recovered yet this is not a problem as the recovery will clear the bits. However bits set in already-recovered region will stay set and never be cleared. This doesn't risk data integrity. The only negatives are: - next time there is a crash, more resyncing than necessary will be done. - the bitmap doesn't look clean, which is confusing. While an array is recovering we don't want to update the 'events_cleared' setting in the bitmap but we do still want to clear bits that have very recently been set - providing they were written to the recovering device. So split those two needs - which previously both depended on 'success' and always clear the bit of the write went to all devices. Signed-off-by: NeilBrown <neilb@suse.de>
-rw-r--r--drivers/md/bitmap.c5
1 files changed, 1 insertions, 4 deletions
diff --git a/drivers/md/bitmap.c b/drivers/md/bitmap.c
index b6907118283a..6d03774b176e 100644
--- a/drivers/md/bitmap.c
+++ b/drivers/md/bitmap.c
@@ -1393,9 +1393,6 @@ void bitmap_endwrite(struct bitmap *bitmap, sector_t offset, unsigned long secto
atomic_read(&bitmap->behind_writes),
bitmap->mddev->bitmap_info.max_write_behind);
}
- if (bitmap->mddev->degraded)
- /* Never clear bits or update events_cleared when degraded */
- success = 0;
while (sectors) {
sector_t blocks;
@@ -1409,7 +1406,7 @@ void bitmap_endwrite(struct bitmap *bitmap, sector_t offset, unsigned long secto
return;
}
- if (success &&
+ if (success && !bitmap->mddev->degraded &&
bitmap->events_cleared < bitmap->mddev->events) {
bitmap->events_cleared = bitmap->mddev->events;
bitmap->need_sync = 1;