diff options
| author | Nilay Shroff <nilay@linux.ibm.com> | 2025-01-28 20:04:14 +0530 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2025-01-29 07:16:47 -0700 |
| commit | 14ef49657ff3b7156952b2eadcf2e5bafd735795 (patch) | |
| tree | aa1ede3f316d5037e030900684af1372c398310a /block | |
| parent | fe6628608627424fb4a6d4c8d2235822457c5d9c (diff) | |
block: fix nr_hw_queue update racing with disk addition/removal
The nr_hw_queue update could potentially race with disk addtion/removal
while registering/unregistering hctx sysfs files. The __blk_mq_update_
nr_hw_queues() runs with q->tag_list_lock held and so to avoid it racing
with disk addition/removal we should acquire q->tag_list_lock while
registering/unregistering hctx sysfs files.
With this patch, blk_mq_sysfs_register() (called during disk addition)
and blk_mq_sysfs_unregister() (called during disk removal) now runs
with q->tag_list_lock held so that it avoids racing with __blk_mq_update
_nr_hw_queues().
Signed-off-by: Nilay Shroff <nilay@linux.ibm.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Link: https://lore.kernel.org/r/20250128143436.874357-3-nilay@linux.ibm.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block')
| -rw-r--r-- | block/blk-mq-sysfs.c | 17 |
1 files changed, 9 insertions, 8 deletions
diff --git a/block/blk-mq-sysfs.c b/block/blk-mq-sysfs.c index 6113328abd70..3feeeccf8a99 100644 --- a/block/blk-mq-sysfs.c +++ b/block/blk-mq-sysfs.c @@ -225,25 +225,25 @@ int blk_mq_sysfs_register(struct gendisk *disk) ret = kobject_add(q->mq_kobj, &disk_to_dev(disk)->kobj, "mq"); if (ret < 0) - goto out; + return ret; kobject_uevent(q->mq_kobj, KOBJ_ADD); + mutex_lock(&q->tag_set->tag_list_lock); queue_for_each_hw_ctx(q, hctx, i) { ret = blk_mq_register_hctx(hctx); if (ret) - goto unreg; + goto out_unreg; } + mutex_unlock(&q->tag_set->tag_list_lock); + return 0; - -out: - return ret; - -unreg: +out_unreg: queue_for_each_hw_ctx(q, hctx, j) { if (j < i) blk_mq_unregister_hctx(hctx); } + mutex_unlock(&q->tag_set->tag_list_lock); kobject_uevent(q->mq_kobj, KOBJ_REMOVE); kobject_del(q->mq_kobj); @@ -256,9 +256,10 @@ void blk_mq_sysfs_unregister(struct gendisk *disk) struct blk_mq_hw_ctx *hctx; unsigned long i; - + mutex_lock(&q->tag_set->tag_list_lock); queue_for_each_hw_ctx(q, hctx, i) blk_mq_unregister_hctx(hctx); + mutex_unlock(&q->tag_set->tag_list_lock); kobject_uevent(q->mq_kobj, KOBJ_REMOVE); kobject_del(q->mq_kobj); |