lkml.org 
[lkml]   [2018]   [Apr]   [6]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[PATCH] blk-cgroup: remove entries in blkg_tree before queue release
The q->id is used as an index within the blkg_tree radix tree.

If the entry is not released before reclaiming the blk_queue_ida's id
blkcg_init_queue() within a different driver from which this id
was originally for can fail due to the entry at that index within
the radix tree already existing.

Signed-off-by: Alexandru Moise <00moses.alexander00@gmail.com>
---
block/blk-cgroup.c | 2 +-
block/blk-sysfs.c | 4 ++++
include/linux/blk-cgroup.h | 2 ++
3 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 1c16694ae145..224e937dbb59 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -369,7 +369,7 @@ static void blkg_destroy(struct blkcg_gq *blkg)
*
* Destroy all blkgs associated with @q.
*/
-static void blkg_destroy_all(struct request_queue *q)
+void blkg_destroy_all(struct request_queue *q)
{
struct blkcg_gq *blkg, *n;

diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
index d00d1b0ec109..a72866458f22 100644
--- a/block/blk-sysfs.c
+++ b/block/blk-sysfs.c
@@ -816,6 +816,10 @@ static void __blk_release_queue(struct work_struct *work)
if (q->bio_split)
bioset_free(q->bio_split);

+ spin_lock_irq(q->queue_lock);
+ blkg_destroy_all(q);
+ spin_unlock_irq(q->queue_lock);
+
ida_simple_remove(&blk_queue_ida, q->id);
call_rcu(&q->rcu_head, blk_free_queue_rcu);
}
diff --git a/include/linux/blk-cgroup.h b/include/linux/blk-cgroup.h
index 6c666fd7de3c..4470fdb6ea8f 100644
--- a/include/linux/blk-cgroup.h
+++ b/include/linux/blk-cgroup.h
@@ -179,6 +179,8 @@ struct blkcg_gq *blkg_lookup_create(struct blkcg *blkcg,
int blkcg_init_queue(struct request_queue *q);
void blkcg_drain_queue(struct request_queue *q);
void blkcg_exit_queue(struct request_queue *q);
+void blkg_destroy_all(struct request_queue *q);
+

/* Blkio controller policy registration */
int blkcg_policy_register(struct blkcg_policy *pol);
--
2.16.3
\
 
 \ /
  Last update: 2018-04-06 17:07    [W:1.673 / U:0.080 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site