From: NeilBrown Date: Mon, 5 May 2014 03:34:37 +0000 (+1000) Subject: md/raid10: call wait_barrier() for each request submitted. X-Git-Tag: v3.14.6~179 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=8c7311a1c4a8d804bde91b00a2f2c1a22a954c30;p=platform%2Fkernel%2Flinux-stable.git md/raid10: call wait_barrier() for each request submitted. commit cc13b1d1500656a20e41960668f3392dda9fa6e2 upstream. wait_barrier() includes a counter, so we must call it precisely once (unless balanced by allow_barrier()) for each request submitted. Since commit 20d0189b1012a37d2533a87fb451f7852f2418d1 block: Introduce new bio_split() in 3.14-rc1, we don't call it for the extra requests generated when we need to split a bio. When this happens the counter goes negative, any resync/recovery will never start, and "mdadm --stop" will hang. Reported-by: Chris Murphy Fixes: 20d0189b1012a37d2533a87fb451f7852f2418d1 Cc: Kent Overstreet Signed-off-by: NeilBrown Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c index 33fc408..cb882aa 100644 --- a/drivers/md/raid10.c +++ b/drivers/md/raid10.c @@ -1172,6 +1172,13 @@ static void __make_request(struct mddev *mddev, struct bio *bio) int max_sectors; int sectors; + /* + * Register the new request and wait if the reconstruction + * thread has put up a bar for new requests. + * Continue immediately if no resync is active currently. + */ + wait_barrier(conf); + sectors = bio_sectors(bio); while (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) && bio->bi_iter.bi_sector < conf->reshape_progress && @@ -1552,12 +1559,6 @@ static void make_request(struct mddev *mddev, struct bio *bio) md_write_start(mddev, bio); - /* - * Register the new request and wait if the reconstruction - * thread has put up a bar for new requests. - * Continue immediately if no resync is active currently. - */ - wait_barrier(conf); do {