diff options
| -rw-r--r-- | drivers/md/raid10.c | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c index dbf51e9f0dc..6fcedbe31fe 100644 --- a/drivers/md/raid10.c +++ b/drivers/md/raid10.c @@ -818,11 +818,29 @@ static int make_request(struct request_queue *q, struct bio * bio) */ bp = bio_split(bio, bio_split_pool, chunk_sects - (bio->bi_sector & (chunk_sects - 1)) ); + + /* Each of these 'make_request' calls will call 'wait_barrier'. + * If the first succeeds but the second blocks due to the resync + * thread raising the barrier, we will deadlock because the + * IO to the underlying device will be queued in generic_make_request + * and will never complete, so will never reduce nr_pending. + * So increment nr_waiting here so no new raise_barriers will + * succeed, and so the second wait_barrier cannot block. + */ + spin_lock_irq(&conf->resync_lock); + conf->nr_waiting++; + spin_unlock_irq(&conf->resync_lock); + if (make_request(q, &bp->bio1)) generic_make_request(&bp->bio1); if (make_request(q, &bp->bio2)) generic_make_request(&bp->bio2); + spin_lock_irq(&conf->resync_lock); + conf->nr_waiting--; + wake_up(&conf->wait_barrier); + spin_unlock_irq(&conf->resync_lock); + bio_pair_release(bp); return 0; bad_map: |