From ac514ffc968bf14649dd0e048447dc966ee49555 Mon Sep 17 00:00:00 2001 From: Mike Snitzer Date: Fri, 12 Jan 2018 19:53:40 -0500 Subject: dm mpath: delay the retry of a request if the target responded as busy Add DM_ENDIO_DELAY_REQUEUE to allow request-based multipath's multipath_end_io() to instruct dm-rq.c:dm_done() to delay a requeue. This is beneficial to do if BLK_STS_RESOURCE is returned from the target (because target is busy). Relative to blk-mq: kick the hw queues via blk_mq_requeue_work(), indirectly from dm-rq.c:__dm_mq_kick_requeue_list(), after a delay. For old .request_fn: use blk_delay_queue(). bio-based multipath doesn't have feature parity with request-based for retryable error requeues; that is something that'll need fixing in the future. Suggested-by: Bart Van Assche Signed-off-by: Mike Snitzer Acked-by: Bart Van Assche [as interpreted from Bart's "... patch looks fine to me."] --- drivers/md/dm-rq.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'drivers/md/dm-rq.c') diff --git a/drivers/md/dm-rq.c b/drivers/md/dm-rq.c index 9d32f25489c2..b78ff6921cfb 100644 --- a/drivers/md/dm-rq.c +++ b/drivers/md/dm-rq.c @@ -315,6 +315,10 @@ static void dm_done(struct request *clone, blk_status_t error, bool mapped) /* The target wants to requeue the I/O */ dm_requeue_original_request(tio, false); break; + case DM_ENDIO_DELAY_REQUEUE: + /* The target wants to requeue the I/O after a delay */ + dm_requeue_original_request(tio, true); + break; default: DMWARN("unimplemented target endio return value: %d", r); BUG(); -- cgit v1.2.3 From c12c9a3c3860c76ba273798c0c34c6f1294cc759 Mon Sep 17 00:00:00 2001 From: Mike Snitzer Date: Fri, 12 Jan 2018 09:32:21 -0500 Subject: dm: various cleanups to md->queue initialization code Also, add dm_sysfs_init() error handling to dm_create(). Signed-off-by: Mike Snitzer --- drivers/md/dm-rq.c | 2 -- 1 file changed, 2 deletions(-) (limited to 'drivers/md/dm-rq.c') diff --git a/drivers/md/dm-rq.c b/drivers/md/dm-rq.c index b78ff6921cfb..c59c59cfd2a5 100644 --- a/drivers/md/dm-rq.c +++ b/drivers/md/dm-rq.c @@ -704,7 +704,6 @@ int dm_old_init_request_queue(struct mapped_device *md, struct dm_table *t) /* disable dm_old_request_fn's merge heuristic by default */ md->seq_rq_merge_deadline_usecs = 0; - dm_init_normal_md_queue(md); blk_queue_softirq_done(md->queue, dm_softirq_done); /* Initialize the request-based DM worker thread */ @@ -814,7 +813,6 @@ int dm_mq_init_request_queue(struct mapped_device *md, struct dm_table *t) err = PTR_ERR(q); goto out_tag_set; } - dm_init_md_queue(md); /* backfill 'mq' sysfs registration normally done in blk_register_queue */ err = blk_mq_register_dev(disk_to_dev(md->disk), q); -- cgit v1.2.3