diff mbox series

[03/14] blk-cgroup: Reduce scope of blkg_array lock

Message ID 20190318194821.3470-4-willy@infradead.org (mailing list archive)
State New, archived
Headers show
Series Convert block layer & drivers to XArray | expand

Commit Message

Matthew Wilcox (Oracle) March 18, 2019, 7:48 p.m. UTC 
We can now take and release the blkg_array lock within blkg_destroy()
instead of forcing the caller to hold it across the call.

Signed-off-by: Matthew Wilcox <willy@infradead.org>
---
 block/blk-cgroup.c | 9 +--------
 1 file changed, 1 insertion(+), 8 deletions(-)
diff mbox series

Patch

diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index bd6eea0587fb..6962e2fc612d 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -367,7 +367,6 @@  static void blkg_destroy(struct blkcg_gq *blkg)
 	int i;
 
 	lockdep_assert_held(&blkg->q->queue_lock);
-	lockdep_assert_held(&blkcg->blkg_array.xa_lock);
 
 	/* Something wrong if we are trying to remove same group twice */
 	WARN_ON_ONCE(list_empty(&blkg->q_node));
@@ -386,7 +385,7 @@  static void blkg_destroy(struct blkcg_gq *blkg)
 
 	blkg->online = false;
 
-	__xa_erase(&blkcg->blkg_array, blkg->q->id);
+	xa_erase(&blkcg->blkg_array, blkg->q->id);
 	list_del_init(&blkg->q_node);
 
 	/*
@@ -416,11 +415,7 @@  static void blkg_destroy_all(struct request_queue *q)
 
 	spin_lock_irq(&q->queue_lock);
 	list_for_each_entry_safe(blkg, n, &q->blkg_list, q_node) {
-		struct blkcg *blkcg = blkg->blkcg;
-
-		xa_lock(&blkcg->blkg_array);
 		blkg_destroy(blkg);
-		xa_unlock(&blkcg->blkg_array);
 	}
 
 	q->root_blkg = NULL;
@@ -1080,9 +1075,7 @@  void blkcg_destroy_blkgs(struct blkcg *blkcg)
 		struct request_queue *q = blkg->q;
 
 		spin_lock_irq(&q->queue_lock);
-		xa_lock(&blkcg->blkg_array);
 		blkg_destroy(blkg);
-		xa_unlock(&blkcg->blkg_array);
 		spin_unlock_irq(&q->queue_lock);
 	}
 }