From: Wei Fang <fangwei1@xxxxxxxxxx> This patch has been added to the 3.12 stable tree. If you have any objections, please let us know. =============== commit 816b0acf3deb6d6be5d0519b286fdd4bafade905 upstream. If first_bad == this_sector when we get the WriteMostly disk in read_balance(), valid disk will be returned with zero max_sectors. It'll lead to a dead loop in make_request(), and OOM will happen because of endless allocation of struct bio. Since we can't get data from this disk in this case, so continue for another disk. Signed-off-by: Wei Fang <fangwei1@xxxxxxxxxx> Signed-off-by: Shaohua Li <shli@xxxxxx> Cc: Julia Lawall <julia.lawall@xxxxxxx> Signed-off-by: Jiri Slaby <jslaby@xxxxxxx> --- drivers/md/raid1.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c index 479828ad2021..e5f8fd19e47d 100644 --- a/drivers/md/raid1.c +++ b/drivers/md/raid1.c @@ -560,7 +560,7 @@ static int read_balance(struct r1conf *conf, struct r1bio *r1_bio, int *max_sect if (best_dist_disk < 0) { if (is_badblock(rdev, this_sector, sectors, &first_bad, &bad_sectors)) { - if (first_bad < this_sector) + if (first_bad <= this_sector) /* Cannot use this */ continue; best_good_sectors = first_bad - this_sector; -- 2.12.2