diff options
| author | Tejun Heo <tj@kernel.org> | 2023-04-13 02:06:46 +0200 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2023-04-13 14:46:48 +0200 |
| commit | 83462a6c971cdc550475b672cf29bd3b53bedf84 (patch) | |
| tree | 4233724720c205a3798d7642ae8d22d12900bc8a /block | |
| parent | s390/dasd: fix hanging blockdevice after request requeue (diff) | |
| download | linux-83462a6c971cdc550475b672cf29bd3b53bedf84.tar.xz linux-83462a6c971cdc550475b672cf29bd3b53bedf84.zip | |
blkcg: Drop unnecessary RCU read [un]locks from blkg_conf_prep/finish()
Now that all RCU flavors have been combined either holding a spin lock,
disabling irq or disabling preemption implies RCU read lock, so there's no
need to use rcu_read_[un]lock() explicitly while holding queue_lock. This
shouldn't cause any behavior changes.
v2: Description updated. Leave __acquires/release on queue_lock alone.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20230413000649.115785-2-tj@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block')
| -rw-r--r-- | block/blk-cgroup.c | 13 |
1 files changed, 4 insertions, 9 deletions
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c index 18331cb92914..0a2c19d74d95 100644 --- a/block/blk-cgroup.c +++ b/block/blk-cgroup.c @@ -699,12 +699,12 @@ struct block_device *blkcg_conf_open_bdev(char **inputp) * * Parse per-blkg config update from @input and initialize @ctx with the * result. @ctx->blkg points to the blkg to be updated and @ctx->body the - * part of @input following MAJ:MIN. This function returns with RCU read - * lock and queue lock held and must be paired with blkg_conf_finish(). + * part of @input following MAJ:MIN. This function returns with queue lock + * held and must be paired with blkg_conf_finish(). */ int blkg_conf_prep(struct blkcg *blkcg, const struct blkcg_policy *pol, char *input, struct blkg_conf_ctx *ctx) - __acquires(rcu) __acquires(&bdev->bd_queue->queue_lock) + __acquires(&bdev->bd_queue->queue_lock) { struct block_device *bdev; struct gendisk *disk; @@ -726,7 +726,6 @@ int blkg_conf_prep(struct blkcg *blkcg, const struct blkcg_policy *pol, if (ret) goto fail; - rcu_read_lock(); spin_lock_irq(&q->queue_lock); if (!blkcg_policy_enabled(q, pol)) { @@ -755,7 +754,6 @@ int blkg_conf_prep(struct blkcg *blkcg, const struct blkcg_policy *pol, /* Drop locks to do new blkg allocation with GFP_KERNEL. */ spin_unlock_irq(&q->queue_lock); - rcu_read_unlock(); new_blkg = blkg_alloc(pos, disk, GFP_KERNEL); if (unlikely(!new_blkg)) { @@ -769,7 +767,6 @@ int blkg_conf_prep(struct blkcg *blkcg, const struct blkcg_policy *pol, goto fail_exit_queue; } - rcu_read_lock(); spin_lock_irq(&q->queue_lock); if (!blkcg_policy_enabled(q, pol)) { @@ -805,7 +802,6 @@ fail_preloaded: radix_tree_preload_end(); fail_unlock: spin_unlock_irq(&q->queue_lock); - rcu_read_unlock(); fail_exit_queue: blk_queue_exit(q); fail: @@ -832,10 +828,9 @@ EXPORT_SYMBOL_GPL(blkg_conf_prep); * with blkg_conf_prep(). */ void blkg_conf_finish(struct blkg_conf_ctx *ctx) - __releases(&ctx->bdev->bd_queue->queue_lock) __releases(rcu) + __releases(&ctx->bdev->bd_queue->queue_lock) { spin_unlock_irq(&bdev_get_queue(ctx->bdev)->queue_lock); - rcu_read_unlock(); blkdev_put_no_open(ctx->bdev); } EXPORT_SYMBOL_GPL(blkg_conf_finish); |