Merge branch 'for-4.17' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq

Pull workqueue updates from Tejun Heo:
 "rcu_work addition and a couple trivial changes"

* 'for-4.17' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
  workqueue: remove the comment about the old manager_arb mutex
  workqueue: fix the comments of nr_idle
  fs/aio: Use rcu_work instead of explicit rcu and work item
  cgroup: Use rcu_work instead of explicit rcu and work item
  RCU, workqueue: Implement rcu_work

1 files changed, 6 insertions, 15 deletions

diff --git a/fs/aio.c b/fs/aio.c
index 6bcd3fb5265a..88d7927ffbc6 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -115,8 +115,7 @@ struct kioctx {
 	struct page		**ring_pages;
 	long			nr_pages;
 
-	struct rcu_head		free_rcu;
-	struct work_struct	free_work;	/* see free_ioctx() */
+	struct rcu_work		free_rwork;	/* see free_ioctx() */
 
 	/*
 	 * signals when all in-flight requests are done
@@ -592,13 +591,12 @@ static int kiocb_cancel(struct aio_kiocb *kiocb)
 /*
  * free_ioctx() should be RCU delayed to synchronize against the RCU
  * protected lookup_ioctx() and also needs process context to call
- * aio_free_ring(), so the double bouncing through kioctx->free_rcu and
- * ->free_work.
+ * aio_free_ring().  Use rcu_work.
  */
 static void free_ioctx(struct work_struct *work)
 {
-	struct kioctx *ctx = container_of(work, struct kioctx, free_work);
-
+	struct kioctx *ctx = container_of(to_rcu_work(work), struct kioctx,
+					  free_rwork);
 	pr_debug("freeing %p\n", ctx);
 
 	aio_free_ring(ctx);
@@ -608,14 +606,6 @@ static void free_ioctx(struct work_struct *work)
 	kmem_cache_free(kioctx_cachep, ctx);
 }
 
-static void free_ioctx_rcufn(struct rcu_head *head)
-{
-	struct kioctx *ctx = container_of(head, struct kioctx, free_rcu);
-
-	INIT_WORK(&ctx->free_work, free_ioctx);
-	schedule_work(&ctx->free_work);
-}
-
 static void free_ioctx_reqs(struct percpu_ref *ref)
 {
 	struct kioctx *ctx = container_of(ref, struct kioctx, reqs);
@@ -625,7 +615,8 @@ static void free_ioctx_reqs(struct percpu_ref *ref)
 		complete(&ctx->rq_wait->comp);
 
 	/* Synchronize against RCU protected table->table[] dereferences */
-	call_rcu(&ctx->free_rcu, free_ioctx_rcufn);
+	INIT_RCU_WORK(&ctx->free_rwork, free_ioctx);
+	queue_rcu_work(system_wq, &ctx->free_rwork);
 }
 
 /*