From: Goldwyn Rodrigues <[email protected]> Bail and status to EAGAIN if raid10 is going to wait for: + barriers + reshape operation + Too many queued requests
Signed-off-by: Goldwyn Rodrigues <[email protected]> --- drivers/md/raid10.c | 67 ++++++++++++++++++++++++++++++++++++++++------------- 1 file changed, 51 insertions(+), 16 deletions(-) diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c index 374df5796649..b0701f5751fe 100644 --- a/drivers/md/raid10.c +++ b/drivers/md/raid10.c @@ -969,8 +969,9 @@ static void lower_barrier(struct r10conf *conf) wake_up(&conf->wait_barrier); } -static void wait_barrier(struct r10conf *conf) +static bool wait_barrier(struct r10conf *conf, bool nowait) { + bool ret = true; spin_lock_irq(&conf->resync_lock); if (conf->barrier) { conf->nr_waiting++; @@ -984,19 +985,25 @@ static void wait_barrier(struct r10conf *conf) * count down. */ raid10_log(conf->mddev, "wait barrier"); - wait_event_lock_irq(conf->wait_barrier, - !conf->barrier || - (atomic_read(&conf->nr_pending) && - current->bio_list && - (!bio_list_empty(¤t->bio_list[0]) || - !bio_list_empty(¤t->bio_list[1]))), - conf->resync_lock); + if (!nowait) + wait_event_lock_irq(conf->wait_barrier, + !conf->barrier || + (atomic_read(&conf->nr_pending) && + current->bio_list && + (!bio_list_empty(¤t->bio_list[0]) || + !bio_list_empty(¤t->bio_list[1]))), + conf->resync_lock); + else + ret = false; conf->nr_waiting--; if (!conf->nr_waiting) wake_up(&conf->wait_barrier); } - atomic_inc(&conf->nr_pending); + /* Do not increment nr_pending if we din't wait */ + if (ret) + atomic_inc(&conf->nr_pending); spin_unlock_irq(&conf->resync_lock); + return ret; } static void allow_barrier(struct r10conf *conf) @@ -1148,7 +1155,10 @@ static void raid10_read_request(struct mddev *mddev, struct bio *bio, * thread has put up a bar for new requests. * Continue immediately if no resync is active currently. */ - wait_barrier(conf); + if (!wait_barrier(conf, bio->bi_opf & REQ_NOWAIT)) { + bio_wouldblock_error(bio); + return; + } sectors = r10_bio->sectors; while (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) && @@ -1159,12 +1169,16 @@ static void raid10_read_request(struct mddev *mddev, struct bio *bio, * pass */ raid10_log(conf->mddev, "wait reshape"); + if (bio->bi_opf & REQ_NOWAIT) { + bio_wouldblock_error(bio); + return; + } allow_barrier(conf); wait_event(conf->wait_barrier, conf->reshape_progress <= bio->bi_iter.bi_sector || conf->reshape_progress >= bio->bi_iter.bi_sector + sectors); - wait_barrier(conf); + wait_barrier(conf, false); } rdev = read_balance(conf, r10_bio, &max_sectors); @@ -1298,12 +1312,19 @@ static void raid10_write_request(struct mddev *mddev, struct bio *bio, * thread has put up a bar for new requests. * Continue immediately if no resync is active currently. */ - wait_barrier(conf); + if (!wait_barrier(conf, bio->bi_opf & REQ_NOWAIT)) { + bio_wouldblock_error(bio); + return; + } sectors = r10_bio->sectors; while (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) && bio->bi_iter.bi_sector < conf->reshape_progress && bio->bi_iter.bi_sector + sectors > conf->reshape_progress) { + if (bio->bi_opf & REQ_NOWAIT) { + bio_wouldblock_error(bio); + return; + } /* * IO spans the reshape position. Need to wait for reshape to * pass @@ -1314,7 +1335,7 @@ static void raid10_write_request(struct mddev *mddev, struct bio *bio, conf->reshape_progress <= bio->bi_iter.bi_sector || conf->reshape_progress >= bio->bi_iter.bi_sector + sectors); - wait_barrier(conf); + wait_barrier(conf, false); } if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) && @@ -1328,6 +1349,10 @@ static void raid10_write_request(struct mddev *mddev, struct bio *bio, set_mask_bits(&mddev->sb_flags, 0, BIT(MD_SB_CHANGE_DEVS) | BIT(MD_SB_CHANGE_PENDING)); md_wakeup_thread(mddev->thread); + if (bio->bi_opf & REQ_NOWAIT) { + bio_wouldblock_error(bio); + return; + } raid10_log(conf->mddev, "wait reshape metadata"); wait_event(mddev->sb_wait, !test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags)); @@ -1337,6 +1362,10 @@ static void raid10_write_request(struct mddev *mddev, struct bio *bio, if (conf->pending_count >= max_queued_requests) { md_wakeup_thread(mddev->thread); + if (bio->bi_opf & REQ_NOWAIT) { + bio_wouldblock_error(bio); + return; + } raid10_log(mddev, "wait queued"); wait_event(conf->wait_barrier, conf->pending_count < max_queued_requests); @@ -1462,9 +1491,15 @@ static void raid10_write_request(struct mddev *mddev, struct bio *bio, } } allow_barrier(conf); + + /* Don't wait for REQ_NOWAIT */ + if (bio->bi_opf & REQ_NOWAIT) { + bio_wouldblock_error(bio); + return; + } raid10_log(conf->mddev, "wait rdev %d blocked", blocked_rdev->raid_disk); md_wait_for_blocked_rdev(blocked_rdev, mddev); - wait_barrier(conf); + wait_barrier(conf, false); goto retry_write; } @@ -1693,7 +1728,7 @@ static void print_conf(struct r10conf *conf) static void close_sync(struct r10conf *conf) { - wait_barrier(conf); + wait_barrier(conf, false); allow_barrier(conf); mempool_destroy(conf->r10buf_pool); @@ -4365,7 +4400,7 @@ static sector_t reshape_request(struct mddev *mddev, sector_t sector_nr, if (need_flush || time_after(jiffies, conf->reshape_checkpoint + 10*HZ)) { /* Need to update reshape_position in metadata */ - wait_barrier(conf); + wait_barrier(conf, false); mddev->reshape_position = conf->reshape_progress; if (mddev->reshape_backwards) mddev->curr_resync_completed = raid10_size(mddev, 0, 0) -- 2.14.2
