From 26a9750aa875126e4b7fc5ee6de652a529c5b7ee Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Wed, 2 Jun 2021 09:53:17 +0300 Subject: blk-mq: improve the blk_mq_init_allocated_queue interface Don't return the passed in request_queue but a normal error code, and drop the elevator_init argument in favor of just calling elevator_init_mq directly from dm-rq. Signed-off-by: Christoph Hellwig Reviewed-by: Chaitanya Kulkarni Link: https://lore.kernel.org/r/20210602065345.355274-3-hch@lst.de Signed-off-by: Jens Axboe --- include/linux/elevator.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux/elevator.h') diff --git a/include/linux/elevator.h b/include/linux/elevator.h index dcb2f9022c1d..783ecb3cb77a 100644 --- a/include/linux/elevator.h +++ b/include/linux/elevator.h @@ -120,6 +120,7 @@ extern void elv_merged_request(struct request_queue *, struct request *, extern bool elv_attempt_insert_merge(struct request_queue *, struct request *); extern struct request *elv_former_request(struct request_queue *, struct request *); extern struct request *elv_latter_request(struct request_queue *, struct request *); +void elevator_init_mq(struct request_queue *q); /* * io scheduler registration -- cgit v1.2.3 From fd2ef39cc9a6b9c4c41864ac506906c52f94b06a Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Wed, 23 Jun 2021 11:36:34 +0200 Subject: blk: Fix lock inversion between ioc lock and bfqd lock Lockdep complains about lock inversion between ioc->lock and bfqd->lock: bfqd -> ioc: put_io_context+0x33/0x90 -> ioc->lock grabbed blk_mq_free_request+0x51/0x140 blk_put_request+0xe/0x10 blk_attempt_req_merge+0x1d/0x30 elv_attempt_insert_merge+0x56/0xa0 blk_mq_sched_try_insert_merge+0x4b/0x60 bfq_insert_requests+0x9e/0x18c0 -> bfqd->lock grabbed blk_mq_sched_insert_requests+0xd6/0x2b0 blk_mq_flush_plug_list+0x154/0x280 blk_finish_plug+0x40/0x60 ext4_writepages+0x696/0x1320 do_writepages+0x1c/0x80 __filemap_fdatawrite_range+0xd7/0x120 sync_file_range+0xac/0xf0 ioc->bfqd: bfq_exit_icq+0xa3/0xe0 -> bfqd->lock grabbed put_io_context_active+0x78/0xb0 -> ioc->lock grabbed exit_io_context+0x48/0x50 do_exit+0x7e9/0xdd0 do_group_exit+0x54/0xc0 To avoid this inversion we change blk_mq_sched_try_insert_merge() to not free the merged request but rather leave that upto the caller similarly to blk_mq_sched_try_merge(). And in bfq_insert_requests() we make sure to free all the merged requests after dropping bfqd->lock. Fixes: aee69d78dec0 ("block, bfq: introduce the BFQ-v0 I/O scheduler as an extra scheduler") Reviewed-by: Ming Lei Acked-by: Paolo Valente Signed-off-by: Jan Kara Link: https://lore.kernel.org/r/20210623093634.27879-3-jack@suse.cz Signed-off-by: Jens Axboe --- include/linux/elevator.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'include/linux/elevator.h') diff --git a/include/linux/elevator.h b/include/linux/elevator.h index 783ecb3cb77a..ef9ceead3db1 100644 --- a/include/linux/elevator.h +++ b/include/linux/elevator.h @@ -117,7 +117,8 @@ extern void elv_merge_requests(struct request_queue *, struct request *, struct request *); extern void elv_merged_request(struct request_queue *, struct request *, enum elv_merge); -extern bool elv_attempt_insert_merge(struct request_queue *, struct request *); +extern bool elv_attempt_insert_merge(struct request_queue *, struct request *, + struct list_head *); extern struct request *elv_former_request(struct request_queue *, struct request *); extern struct request *elv_latter_request(struct request_queue *, struct request *); void elevator_init_mq(struct request_queue *q); -- cgit v1.2.3