diff options
| author | Li Lingfeng <lilingfeng3@huawei.com> | 2023-08-10 11:51:11 +0800 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2023-08-10 07:20:31 -0600 |
| commit | 4eb44d10766ac0fae5973998fd2a0103df1d3fe1 (patch) | |
| tree | 2580c861923412ef148897924352d347cdec321a /block/blk-iolatency.c | |
| parent | c8659bbb15cd42577a9b16a23b527436b028c8b2 (diff) | |
block: remove init_mutex and open-code blk_iolatency_try_init
Commit a13696b83da4 ("blk-iolatency: Make initialization lazy") adds
a mutex named "init_mutex" in blk_iolatency_try_init for the race
condition of initializing RQ_QOS_LATENCY.
Now a new lock has been add to struct request_queue by commit a13bd91be223
("block/rq_qos: protect rq_qos apis with a new lock"). And it has been
held in blkg_conf_open_bdev before calling blk_iolatency_init.
So it's not necessary to keep init_mutex in blk_iolatency_try_init, just
remove it.
Since init_mutex has been removed, blk_iolatency_try_init can be
open-coded back to iolatency_set_limit() like ioc_qos_write().
Signed-off-by: Li Lingfeng <lilingfeng3@huawei.com>
Reviewed-by: Michal Koutný <mkoutny@suse.com>
Link: https://lore.kernel.org/r/20230810035111.2236335-1-lilingfeng@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block/blk-iolatency.c')
| -rw-r--r-- | block/blk-iolatency.c | 35 |
1 files changed, 11 insertions, 24 deletions
diff --git a/block/blk-iolatency.c b/block/blk-iolatency.c index fd5fec989e39..c16aef4be036 100644 --- a/block/blk-iolatency.c +++ b/block/blk-iolatency.c @@ -824,29 +824,6 @@ static void iolatency_clear_scaling(struct blkcg_gq *blkg) } } -static int blk_iolatency_try_init(struct blkg_conf_ctx *ctx) -{ - static DEFINE_MUTEX(init_mutex); - int ret; - - ret = blkg_conf_open_bdev(ctx); - if (ret) - return ret; - - /* - * blk_iolatency_init() may fail after rq_qos_add() succeeds which can - * confuse iolat_rq_qos() test. Make the test and init atomic. - */ - mutex_lock(&init_mutex); - - if (!iolat_rq_qos(ctx->bdev->bd_queue)) - ret = blk_iolatency_init(ctx->bdev->bd_disk); - - mutex_unlock(&init_mutex); - - return ret; -} - static ssize_t iolatency_set_limit(struct kernfs_open_file *of, char *buf, size_t nbytes, loff_t off) { @@ -861,7 +838,17 @@ static ssize_t iolatency_set_limit(struct kernfs_open_file *of, char *buf, blkg_conf_init(&ctx, buf); - ret = blk_iolatency_try_init(&ctx); + ret = blkg_conf_open_bdev(&ctx); + if (ret) + goto out; + + /* + * blk_iolatency_init() may fail after rq_qos_add() succeeds which can + * confuse iolat_rq_qos() test. Make the test and init atomic. + */ + lockdep_assert_held(ctx.bdev->bd_queue->rq_qos_mutex); + if (!iolat_rq_qos(ctx.bdev->bd_queue)) + ret = blk_iolatency_init(ctx.bdev->bd_disk); if (ret) goto out; |