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authorNeilBrown <neilb@suse.de>2014-09-09 13:49:46 +1000
committerNeilBrown <neilb@suse.de>2014-09-22 10:26:41 +1000
commitc6d119cf1b5a778e9ed60a006e2a434fcc4471a2 (patch)
tree78b0d77bf219226141bffe4be2a868aec0bbf6e3 /drivers/md/raid1.c
parentf0cc9a057151892b885be21a1d19b0185568281d (diff)
md/raid1: be more cautious where we read-balance during resync.
commit 79ef3a8aa1cb1523cc231c9a90a278333c21f761 made it possible for reads to happen concurrently with resync. This means that we need to be more careful where read_balancing is allowed during resync - we can no longer be sure that any resync that has already started will definitely finish. So keep read_balancing to before recovery_cp, which is conservative but safe. This bug makes it possible to read from a device that doesn't have up-to-date data, so it can cause data corruption. So it is suitable for any kernel since 3.11. Fixes: 79ef3a8aa1cb1523cc231c9a90a278333c21f761 cc: stable@vger.kernel.org (v3.13+) Signed-off-by: NeilBrown <neilb@suse.de>
Diffstat (limited to 'drivers/md/raid1.c')
-rw-r--r--drivers/md/raid1.c6
1 files changed, 1 insertions, 5 deletions
diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index 9ebccf624571..ad0468c42d23 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -540,11 +540,7 @@ static int read_balance(struct r1conf *conf, struct r1bio *r1_bio, int *max_sect
has_nonrot_disk = 0;
choose_next_idle = 0;
- if (conf->mddev->recovery_cp < MaxSector &&
- (this_sector + sectors >= conf->next_resync))
- choose_first = 1;
- else
- choose_first = 0;
+ choose_first = (conf->mddev->recovery_cp < this_sector + sectors);
for (disk = 0 ; disk < conf->raid_disks * 2 ; disk++) {
sector_t dist;