diff options
| author | Nilay Shroff <nilay@linux.ibm.com> | 2025-03-04 13:22:34 +0300 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2025-03-10 16:30:18 +0300 |
| commit | 3efe7571c3ae2b6481253a2616c2bb3fbadd503b (patch) | |
| tree | c3d4cfe406cc1a6b48f863e2086d468c294898eb /include | |
| parent | 1bf70d08cc3b55abd1763e6dff5855cb8dd8318b (diff) | |
| download | linux-3efe7571c3ae2b6481253a2616c2bb3fbadd503b.tar.xz | |
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 'include')
| -rw-r--r-- | include/linux/blkdev.h | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 31b1b635c710..3e66ad016a23 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -561,10 +561,12 @@ struct request_queue { struct list_head flush_list; /* - * Protects against I/O scheduler switching, specifically when - * updating q->elevator. To ensure proper locking order during - * an elevator update, first freeze the queue, then acquire - * ->elevator_lock. + * Protects against I/O scheduler switching, particularly when + * updating q->elevator. Since the elevator update code path may + * also modify q->nr_requests, this lock also protects the sysfs + * attribute nr_requests. + * To ensure proper locking order during an elevator update, first + * freeze the queue, then acquire ->elevator_lock. */ struct mutex elevator_lock; |