From: NeilBrown Date: Fri, 7 May 2010 22:20:17 +0000 (+1000) Subject: md: Fix read balancing in RAID1 and RAID10 on drives > 2TB X-Git-Tag: v2.6.33.6~101 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=fcab0185eddfe15e4bd7f484db0d4441186a7b01;p=thirdparty%2Fkernel%2Fstable.git md: Fix read balancing in RAID1 and RAID10 on drives > 2TB 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 Signed-off-by: NeilBrown Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c index 81f3317bb3992..db2de5ada3b78 100644 --- a/drivers/md/raid1.c +++ b/drivers/md/raid1.c @@ -417,7 +417,7 @@ static void raid1_end_write_request(struct bio *bio, int error) */ 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; @@ -433,7 +433,7 @@ static int read_balance(conf_t *conf, r1bio_t *r1_bio) 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); diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c index 047c468e3d28b..5fb1ad68b7e91 100644 --- a/drivers/md/raid10.c +++ b/drivers/md/raid10.c @@ -493,7 +493,7 @@ static int raid10_mergeable_bvec(struct request_queue *q, */ 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;