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| author | Ming Lei <ming.lei@redhat.com> | 2019-08-27 19:01:46 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-02-13 13:51:15 +0100 |
| commit | 6ff18507a7c165b90f1fe51822c65d10265f5714 (patch) | |
| tree | 18c1141c2cf0be9cf085b01c90a60b52ff821300 /block | |
| parent | 44b07600cec4df051b7ecbd6831febdeca252e54 (diff) | |
| download | linux-stable-6ff18507a7c165b90f1fe51822c65d10265f5714.tar.gz linux-stable-6ff18507a7c165b90f1fe51822c65d10265f5714.tar.bz2 linux-stable-6ff18507a7c165b90f1fe51822c65d10265f5714.zip | |
blk-mq: don't hold q->sysfs_lock in blk_mq_map_swqueue
commit c6ba933358f0d7a6a042b894dba20cc70396a6d3 upstream.
blk_mq_map_swqueue() is called from blk_mq_init_allocated_queue()
and blk_mq_update_nr_hw_queues(). For the former caller, the kobject
isn't exposed to userspace yet. For the latter caller, hctx sysfs entries
and debugfs are un-registered before updating nr_hw_queues.
On the other hand, commit 2f8f1336a48b ("blk-mq: always free hctx after
request queue is freed") moves freeing hctx into queue's release
handler, so there won't be race with queue release path too.
So don't hold q->sysfs_lock in blk_mq_map_swqueue().
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Jack Wang <jinpu.wang@cloud.ionos.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'block')
| -rw-r--r-- | block/blk-mq.c | 7 |
1 files changed, 0 insertions, 7 deletions
diff --git a/block/blk-mq.c b/block/blk-mq.c index 0df43515ff94..195526b93895 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -2324,11 +2324,6 @@ static void blk_mq_map_swqueue(struct request_queue *q) struct blk_mq_ctx *ctx; struct blk_mq_tag_set *set = q->tag_set; - /* - * Avoid others reading imcomplete hctx->cpumask through sysfs - */ - mutex_lock(&q->sysfs_lock); - queue_for_each_hw_ctx(q, hctx, i) { cpumask_clear(hctx->cpumask); hctx->nr_ctx = 0; @@ -2362,8 +2357,6 @@ static void blk_mq_map_swqueue(struct request_queue *q) hctx->ctxs[hctx->nr_ctx++] = ctx; } - mutex_unlock(&q->sysfs_lock); - queue_for_each_hw_ctx(q, hctx, i) { /* * If no software queues are mapped to this hardware queue, |