| From af3a2cd6b8a479345786e7fe5e199ad2f6240e56 Mon Sep 17 00:00:00 2001 |
| From: NeilBrown <neilb@suse.de> |
| Date: Sat, 8 May 2010 08:20:17 +1000 |
| Subject: md: Fix read balancing in RAID1 and RAID10 on drives > 2TB |
| |
| From: NeilBrown <neilb@suse.de> |
| |
| commit af3a2cd6b8a479345786e7fe5e199ad2f6240e56 upstream. |
| |
| read_balance uses a "unsigned long" for a sector number which |
| will get truncated beyond 2TB. |
| This will cause read-balancing to be non-optimal, and can cause |
| data to be read from the 'wrong' branch during a resync. This has a |
| very small chance of returning wrong data. |
| |
| Reported-by: Jordan Russell <jr-list-2010@quo.to> |
| Signed-off-by: NeilBrown <neilb@suse.de> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> |
| |
| --- |
| drivers/md/raid1.c | 4 ++-- |
| drivers/md/raid10.c | 2 +- |
| 2 files changed, 3 insertions(+), 3 deletions(-) |
| |
| --- a/drivers/md/raid1.c |
| +++ b/drivers/md/raid1.c |
| @@ -413,7 +413,7 @@ static void raid1_end_write_request(stru |
| */ |
| static int read_balance(conf_t *conf, r1bio_t *r1_bio) |
| { |
| - const unsigned long this_sector = r1_bio->sector; |
| + const sector_t this_sector = r1_bio->sector; |
| int new_disk = conf->last_used, disk = new_disk; |
| int wonly_disk = -1; |
| const int sectors = r1_bio->sectors; |
| @@ -429,7 +429,7 @@ static int read_balance(conf_t *conf, r1 |
| retry: |
| if (conf->mddev->recovery_cp < MaxSector && |
| (this_sector + sectors >= conf->next_resync)) { |
| - /* Choose the first operation device, for consistancy */ |
| + /* Choose the first operational device, for consistancy */ |
| new_disk = 0; |
| |
| for (rdev = rcu_dereference(conf->mirrors[new_disk].rdev); |
| --- a/drivers/md/raid10.c |
| +++ b/drivers/md/raid10.c |
| @@ -490,7 +490,7 @@ static int raid10_mergeable_bvec(struct |
| */ |
| static int read_balance(conf_t *conf, r10bio_t *r10_bio) |
| { |
| - const unsigned long this_sector = r10_bio->sector; |
| + const sector_t this_sector = r10_bio->sector; |
| int disk, slot, nslot; |
| const int sectors = r10_bio->sectors; |
| sector_t new_distance, current_distance; |
