[PATCH 01/15] blk-cgroup: don't defer blkg_free to a workqueue

[Christoph Hellwig <hch@lst.de>]

Now that blk_put_queue can be called from process context, ther is no
need for the asynchronous execution.

This effectively reverts commit d578c770c85233af592e54537f93f3831bde7e9a.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 block/blk-cgroup.c | 32 ++++++++++----------------------
 block/blk-cgroup.h |  5 +----
 2 files changed, 11 insertions(+), 26 deletions(-)

diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index ce6a2b7d3dfb2b..30d493b43f9272 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -114,12 +114,19 @@ static bool blkcg_policy_enabled(struct request_queue *q,
 	return pol && test_bit(pol->plid, q->blkcg_pols);
 }
 
-static void blkg_free_workfn(struct work_struct *work)
+/**
+ * blkg_free - free a blkg
+ * @blkg: blkg to free
+ *
+ * Free @blkg which may be partially allocated.
+ */
+static void blkg_free(struct blkcg_gq *blkg)
 {
-	struct blkcg_gq *blkg = container_of(work, struct blkcg_gq,
-					     free_work);
 	int i;
 
+	if (!blkg)
+		return;
+
 	for (i = 0; i < BLKCG_MAX_POLS; i++)
 		if (blkg->pd[i])
 			blkcg_policy[i]->pd_free_fn(blkg->pd[i]);
@@ -131,25 +138,6 @@ static void blkg_free_workfn(struct work_struct *work)
 	kfree(blkg);
 }
 
-/**
- * blkg_free - free a blkg
- * @blkg: blkg to free
- *
- * Free @blkg which may be partially allocated.
- */
-static void blkg_free(struct blkcg_gq *blkg)
-{
-	if (!blkg)
-		return;
-
-	/*
-	 * Both ->pd_free_fn() and request queue's release handler may
-	 * sleep, so free us by scheduling one work func
-	 */
-	INIT_WORK(&blkg->free_work, blkg_free_workfn);
-	schedule_work(&blkg->free_work);
-}
-
 static void __blkg_release(struct rcu_head *rcu)
 {
 	struct blkcg_gq *blkg = container_of(rcu, struct blkcg_gq, rcu_head);
diff --git a/block/blk-cgroup.h b/block/blk-cgroup.h
index 1e94e404eaa80a..f126fe36001eb3 100644
--- a/block/blk-cgroup.h
+++ b/block/blk-cgroup.h
@@ -75,10 +75,7 @@ struct blkcg_gq {
 
 	spinlock_t			async_bio_lock;
 	struct bio_list			async_bios;
-	union {
-		struct work_struct	async_bio_work;
-		struct work_struct	free_work;
-	};
+	struct work_struct		async_bio_work;
 
 	atomic_t			use_delay;
 	atomic64_t			delay_nsec;
-- 
2.39.0