From af3a2cd6b8a479345786e7fe5e199ad2f6240e56 Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Sat, 8 May 2010 08:20:17 +1000 Subject: [PATCH] md: Fix read balancing in RAID1 and RAID10 on drives > 2TB 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 Cc: stable@kernel.org Signed-off-by: NeilBrown --- drivers/md/raid1.c | 4 ++-- drivers/md/raid10.c | 2 +- 2 files changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c index 1db02c4955a9..a9b9972ff703 100644 --- a/drivers/md/raid1.c +++ b/drivers/md/raid1.c @@ -418,7 +418,7 @@ 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; @@ -434,7 +434,7 @@ 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 e0742c439484..a1f5fd2d69ce 100644 --- a/drivers/md/raid10.c +++ b/drivers/md/raid10.c @@ -495,7 +495,7 @@ 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;