Re: [PATCH 10/16] blk-cgroup: move locking into blkg_destroy_all

[Hannes Reinecke]

On 11/14/18 5:02 PM, Christoph Hellwig wrote:

Signed-off-by: Christoph Hellwig 
---
  block/blk-cgroup.c | 9 ++---
  1 file changed, 2 insertions(+), 7 deletions(-)


Reviewed-by: Hannes Reinecke 

Cheers,

Hannes
--
Dr. Hannes ReineckeTeamlead Storage & Networking
h...@suse.de   +49 911 74053 688
SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg
GF: F. Imendörffer, J. Smithard, J. Guild, D. Upmanyu, G. Norton
HRB 21284 (AG Nürnberg)

[PATCH 10/16] blk-cgroup: move locking into blkg_destroy_all

[Christoph Hellwig]

Signed-off-by: Christoph Hellwig 
---
 block/blk-cgroup.c | 9 ++---
 1 file changed, 2 insertions(+), 7 deletions(-)

diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 717ab38a6c67..3ba23b9bfeb9 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -349,8 +349,7 @@ static void blkg_destroy_all(struct request_queue *q)
 {
struct blkcg_gq *blkg, *n;
 
-   lockdep_assert_held(q->queue_lock);
-
+   spin_lock_irq(q->queue_lock);
list_for_each_entry_safe(blkg, n, >blkg_list, q_node) {
struct blkcg *blkcg = blkg->blkcg;
 
@@ -360,6 +359,7 @@ static void blkg_destroy_all(struct request_queue *q)
}
 
q->root_blkg = NULL;
+   spin_unlock_irq(q->queue_lock);
 }
 
 /*
@@ -1182,9 +1182,7 @@ int blkcg_init_queue(struct request_queue *q)
return 0;
 
 err_destroy_all:
-   spin_lock_irq(q->queue_lock);
blkg_destroy_all(q);
-   spin_unlock_irq(q->queue_lock);
return ret;
 err_unlock:
spin_unlock_irq(q->queue_lock);
@@ -1222,10 +1220,7 @@ void blkcg_drain_queue(struct request_queue *q)
  */
 void blkcg_exit_queue(struct request_queue *q)
 {
-   spin_lock_irq(q->queue_lock);
blkg_destroy_all(q);
-   spin_unlock_irq(q->queue_lock);
-
blk_throtl_exit(q);
 }
 
-- 
2.19.1