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| author | Ming Lei <ming.lei@redhat.com> | 2025-05-05 22:17:47 +0800 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2025-05-06 07:43:42 -0600 |
| commit | b126d9d7475e3a35155f31418e54d9221b971ca1 (patch) | |
| tree | 4cbf109753f7b040777858efdf1418969ddf7aa0 /block | |
| parent | block: prevent adding/deleting disk during updating nr_hw_queues (diff) | |
| download | linux-b126d9d7475e3a35155f31418e54d9221b971ca1.tar.gz linux-b126d9d7475e3a35155f31418e54d9221b971ca1.zip | |
block: don't allow to switch elevator if updating nr_hw_queues is in-progress
Elevator switch code is another `nr_hw_queue` reader in non-fast-IO code
path, so it can't be done if updating `nr_hw_queues` is in-progress.
Take same approach with not allowing add/del disk when updating
nr_hw_queues is in-progress, by grabbing read lock of
set->update_nr_hwq_sema.
Reviewed-by: Hannes Reinecke <hare@suse.de>
Link: https://lore.kernel.org/linux-block/aAWv3NPtNIKKvJZc@fedora/ [1]
Reported-by: Shinichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Closes: https://lore.kernel.org/linux-block/mz4t4tlwiqjijw3zvqnjb7ovvvaegkqganegmmlc567tt5xj67@xal5ro544cnc/
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Nilay Shroff <nilay@linux.ibm.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20250505141805.2751237-10-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block')
| -rw-r--r-- | block/elevator.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/block/elevator.c b/block/elevator.c index 4400eb8fe54f..2e18513dcd73 100644 --- a/block/elevator.c +++ b/block/elevator.c @@ -723,6 +723,7 @@ ssize_t elv_iosched_store(struct gendisk *disk, const char *buf, int ret; unsigned int memflags; struct request_queue *q = disk->queue; + struct blk_mq_tag_set *set = q->tag_set; /* * If the attribute needs to load a module, do it before freezing the @@ -734,6 +735,7 @@ ssize_t elv_iosched_store(struct gendisk *disk, const char *buf, elv_iosched_load_module(name); + down_read(&set->update_nr_hwq_lock); memflags = blk_mq_freeze_queue(q); mutex_lock(&q->elevator_lock); ret = elevator_change(q, name); @@ -741,6 +743,7 @@ ssize_t elv_iosched_store(struct gendisk *disk, const char *buf, ret = count; mutex_unlock(&q->elevator_lock); blk_mq_unfreeze_queue(q, memflags); + up_read(&set->update_nr_hwq_lock); return ret; } |