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authorYu Kuai <yukuai3@huawei.com>2023-05-27 04:06:43 +0300
committerJens Axboe <axboe@kernel.dk>2023-06-26 18:53:36 +0300
commiteebc21d12f56c1e09a163abf91e351fa2a55a938 (patch)
tree31b8644fe6536bd0d886911844505c91abf68bb4 /block
parent06257fda83ebfd1c33fb992e41dba7be4e1184d4 (diff)
downloadlinux-eebc21d12f56c1e09a163abf91e351fa2a55a938.tar.xz
blk-iocost: move wbt_enable/disable_default() out of spinlock
There are following smatch warning: block/blk-wbt.c:843 wbt_init() warn: sleeping in atomic context ioc_qos_write() <- disables preempt -> wbt_enable_default() -> wbt_init() wbt_init() will be called from wbt_enable_default() if wbt is not initialized, currently this is only possible in blk_register_queue(), hence wbt_init() will never be called from iocost and this warning is false positive. However, we might support rq_qos destruction dynamically in the future, and it's better to prevent that, hence move wbt_enable_default() outside 'ioc->lock'. This is safe because queue is still freezed. Reported-by: Dan Carpenter <error27@gmail.com> Link: https://lore.kernel.org/lkml/Y+Ja5SRs886CEz7a@kadam/ Signed-off-by: Yu Kuai <yukuai3@huawei.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20230527010644.647900-5-yukuai1@huaweicloud.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block')
-rw-r--r--block/blk-iocost.c7
1 files changed, 5 insertions, 2 deletions
diff --git a/block/blk-iocost.c b/block/blk-iocost.c
index 6084a9519883..9dfcf540f400 100644
--- a/block/blk-iocost.c
+++ b/block/blk-iocost.c
@@ -3301,11 +3301,9 @@ static ssize_t ioc_qos_write(struct kernfs_open_file *of, char *input,
blk_stat_enable_accounting(disk->queue);
blk_queue_flag_set(QUEUE_FLAG_RQ_ALLOC_TIME, disk->queue);
ioc->enabled = true;
- wbt_disable_default(disk);
} else {
blk_queue_flag_clear(QUEUE_FLAG_RQ_ALLOC_TIME, disk->queue);
ioc->enabled = false;
- wbt_enable_default(disk);
}
if (user) {
@@ -3318,6 +3316,11 @@ static ssize_t ioc_qos_write(struct kernfs_open_file *of, char *input,
ioc_refresh_params(ioc, true);
spin_unlock_irq(&ioc->lock);
+ if (enable)
+ wbt_disable_default(disk);
+ else
+ wbt_enable_default(disk);
+
blk_mq_unquiesce_queue(disk->queue);
blk_mq_unfreeze_queue(disk->queue);