diff options
| author | Nilay Shroff <nilay@linux.ibm.com> | 2025-03-04 15:52:34 +0530 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2025-03-10 07:30:18 -0600 |
| commit | 3efe7571c3ae2b6481253a2616c2bb3fbadd503b (patch) | |
| tree | c3d4cfe406cc1a6b48f863e2086d468c294898eb /block | |
| parent | 1bf70d08cc3b55abd1763e6dff5855cb8dd8318b (diff) | |
block: protect nr_requests update using q->elevator_lock
The sysfs attribute nr_requests could be simultaneously updated from
elevator switch/update or nr_hw_queue update code path. The update to
nr_requests for each of those code paths runs holding q->elevator_lock.
So we should protect access to sysfs attribute nr_requests using q->
elevator_lock instead of q->sysfs_lock.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Nilay Shroff <nilay@linux.ibm.com>
Link: https://lore.kernel.org/r/20250304102551.2533767-6-nilay@linux.ibm.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block')
| -rw-r--r-- | block/blk-sysfs.c | 10 |
1 files changed, 5 insertions, 5 deletions
diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c index 1562e22877e1..f1fa57de29ed 100644 --- a/block/blk-sysfs.c +++ b/block/blk-sysfs.c @@ -55,9 +55,9 @@ static ssize_t queue_requests_show(struct gendisk *disk, char *page) { ssize_t ret; - mutex_lock(&disk->queue->sysfs_lock); + mutex_lock(&disk->queue->elevator_lock); ret = queue_var_show(disk->queue->nr_requests, page); - mutex_unlock(&disk->queue->sysfs_lock); + mutex_unlock(&disk->queue->elevator_lock); return ret; } @@ -76,16 +76,16 @@ queue_requests_store(struct gendisk *disk, const char *page, size_t count) if (ret < 0) return ret; - mutex_lock(&q->sysfs_lock); memflags = blk_mq_freeze_queue(q); + mutex_lock(&q->elevator_lock); if (nr < BLKDEV_MIN_RQ) nr = BLKDEV_MIN_RQ; err = blk_mq_update_nr_requests(disk->queue, nr); if (err) ret = err; + mutex_unlock(&q->elevator_lock); blk_mq_unfreeze_queue(q, memflags); - mutex_unlock(&q->sysfs_lock); return ret; } @@ -692,7 +692,6 @@ static struct attribute *blk_mq_queue_attrs[] = { /* * Attributes which are protected with q->sysfs_lock. */ - &queue_requests_entry.attr, #ifdef CONFIG_BLK_WBT &queue_wb_lat_entry.attr, #endif @@ -701,6 +700,7 @@ static struct attribute *blk_mq_queue_attrs[] = { * q->sysfs_lock. */ &elv_iosched_entry.attr, + &queue_requests_entry.attr, /* * Attributes which don't require locking. |