6.17-stable review patch. If anyone has any objections, please let me know.
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From: Yu Kuai yukuai3@huawei.com
[ Upstream commit b46d4c447db76e36906ed59ebb9b3ef8f3383322 ]
queue_requests_store() is the only caller of blk_mq_update_nr_requests(), and blk_mq_update_nr_requests() is the only caller of blk_mq_tag_update_depth(), however, they all have checkings for nr_requests input by user.
Make code cleaner by moving all the checkings to the top function:
1) nr_requests > reserved tags; 2) if there is elevator, 4 <= nr_requests <= 2048; 3) if elevator is none, 4 <= nr_requests <= tag_set->queue_depth;
Meanwhile, case 2 is the only case tags can grow and -ENOMEM might be returned.
Signed-off-by: Yu Kuai yukuai3@huawei.com Reviewed-by: Nilay Shroff nilay@linux.ibm.com Signed-off-by: Jens Axboe axboe@kernel.dk Stable-dep-of: b86433721f46 ("blk-mq: fix potential deadlock while nr_requests grown") Signed-off-by: Sasha Levin sashal@kernel.org --- block/blk-mq-tag.c | 16 +--------------- block/blk-mq.c | 8 ++------ block/blk-mq.h | 2 +- block/blk-sysfs.c | 13 +++++++++++++ 4 files changed, 17 insertions(+), 22 deletions(-)
diff --git a/block/blk-mq-tag.c b/block/blk-mq-tag.c index 5cffa5668d0c3..725210f27471c 100644 --- a/block/blk-mq-tag.c +++ b/block/blk-mq-tag.c @@ -584,14 +584,10 @@ void blk_mq_free_tags(struct blk_mq_tags *tags) }
int blk_mq_tag_update_depth(struct blk_mq_hw_ctx *hctx, - struct blk_mq_tags **tagsptr, unsigned int tdepth, - bool can_grow) + struct blk_mq_tags **tagsptr, unsigned int tdepth) { struct blk_mq_tags *tags = *tagsptr;
- if (tdepth <= tags->nr_reserved_tags) - return -EINVAL; - /* * If we are allowed to grow beyond the original size, allocate * a new set of tags before freeing the old one. @@ -600,16 +596,6 @@ int blk_mq_tag_update_depth(struct blk_mq_hw_ctx *hctx, struct blk_mq_tag_set *set = hctx->queue->tag_set; struct blk_mq_tags *new;
- if (!can_grow) - return -EINVAL; - - /* - * We need some sort of upper limit, set it high enough that - * no valid use cases should require more. - */ - if (tdepth > MAX_SCHED_RQ) - return -EINVAL; - /* * Only the sbitmap needs resizing since we allocated the max * initially. diff --git a/block/blk-mq.c b/block/blk-mq.c index f5e713224d819..a81ef562014d6 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -4932,9 +4932,6 @@ int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr) int ret = 0; unsigned long i;
- if (q->nr_requests == nr) - return 0; - blk_mq_quiesce_queue(q);
queue_for_each_hw_ctx(q, hctx, i) { @@ -4946,10 +4943,9 @@ int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr) */ if (hctx->sched_tags) { ret = blk_mq_tag_update_depth(hctx, &hctx->sched_tags, - nr, true); + nr); } else { - ret = blk_mq_tag_update_depth(hctx, &hctx->tags, nr, - false); + ret = blk_mq_tag_update_depth(hctx, &hctx->tags, nr); } if (ret) goto out; diff --git a/block/blk-mq.h b/block/blk-mq.h index affb2e14b56e3..2b3ade60c90b2 100644 --- a/block/blk-mq.h +++ b/block/blk-mq.h @@ -171,7 +171,7 @@ void blk_mq_put_tag(struct blk_mq_tags *tags, struct blk_mq_ctx *ctx, unsigned int tag); void blk_mq_put_tags(struct blk_mq_tags *tags, int *tag_array, int nr_tags); int blk_mq_tag_update_depth(struct blk_mq_hw_ctx *hctx, - struct blk_mq_tags **tags, unsigned int depth, bool can_grow); + struct blk_mq_tags **tags, unsigned int depth); void blk_mq_tag_resize_shared_tags(struct blk_mq_tag_set *set, unsigned int size); void blk_mq_tag_update_sched_shared_tags(struct request_queue *q); diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c index 4a7f1a349998b..b61e956a868e7 100644 --- a/block/blk-sysfs.c +++ b/block/blk-sysfs.c @@ -78,12 +78,25 @@ queue_requests_store(struct gendisk *disk, const char *page, size_t count)
memflags = blk_mq_freeze_queue(q); mutex_lock(&q->elevator_lock); + + if (nr == q->nr_requests) + goto unlock; + if (nr < BLKDEV_MIN_RQ) nr = BLKDEV_MIN_RQ;
+ if (nr <= q->tag_set->reserved_tags || + (q->elevator && nr > MAX_SCHED_RQ) || + (!q->elevator && nr > q->tag_set->queue_depth)) { + ret = -EINVAL; + goto unlock; + } + err = blk_mq_update_nr_requests(disk->queue, nr); if (err) ret = err; + +unlock: mutex_unlock(&q->elevator_lock); blk_mq_unfreeze_queue(q, memflags); return ret;