block: async_bio_lock does not need to be bh-safe

async_bio_lock is only taken from bio submission and workqueue context,
both are never in bottom halves.

Reviewed-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 9f5f326..c524eca 100644 (file)
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -198,10 +198,10 @@ static void blkg_async_bio_workfn(struct work_struct *work)
        bool need_plug = false;
 
        /* as long as there are pending bios, @blkg can't go away */
-       spin_lock_bh(&blkg->async_bio_lock);
+       spin_lock(&blkg->async_bio_lock);
        bio_list_merge(&bios, &blkg->async_bios);
        bio_list_init(&blkg->async_bios);
-       spin_unlock_bh(&blkg->async_bio_lock);
+       spin_unlock(&blkg->async_bio_lock);
 
        /* start plug only when bio_list contains at least 2 bios */
        if (bios.head && bios.head->bi_next) {
@@ -1699,9 +1699,9 @@ void blkcg_punt_bio_submit(struct bio *bio)
        struct blkcg_gq *blkg = bio->bi_blkg;
 
        if (blkg->parent) {
-               spin_lock_bh(&blkg->async_bio_lock);
+               spin_lock(&blkg->async_bio_lock);
                bio_list_add(&blkg->async_bios, bio);
-               spin_unlock_bh(&blkg->async_bio_lock);
+               spin_unlock(&blkg->async_bio_lock);
                queue_work(blkcg_punt_bio_wq, &blkg->async_bio_work);
        } else {
                /* never bounce for the root cgroup */