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authorBart Van Assche <bart.vanassche@wdc.com>2018-08-09 07:53:37 -0700
committerJens Axboe <axboe@kernel.dk>2018-08-09 09:12:59 -0600
commit4cf6324b17e96b7b7ab4021c6929500934d46750 (patch)
tree90cb9d674a125eaea0aff01df982da74dd933e1b /block
parent6bad9b210a228d2fe0e0efe26d9b115348529cee (diff)
block: Introduce blk_exit_queue()
This patch does not change any functionality. Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Cc: Christoph Hellwig <hch@lst.de> Cc: Ming Lei <ming.lei@redhat.com> Cc: Omar Sandoval <osandov@fb.com> Cc: Alexandru Moise <00moses.alexander00@gmail.com> Cc: Joseph Qi <joseph.qi@linux.alibaba.com> Cc: <stable@vger.kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block')
-rw-r--r--block/blk-core.c54
-rw-r--r--block/blk.h1
2 files changed, 31 insertions, 24 deletions
diff --git a/block/blk-core.c b/block/blk-core.c
index f9ad73d8573c..49af34bf2119 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -715,6 +715,35 @@ void blk_set_queue_dying(struct request_queue *q)
}
EXPORT_SYMBOL_GPL(blk_set_queue_dying);
+/* Unconfigure the I/O scheduler and dissociate from the cgroup controller. */
+void blk_exit_queue(struct request_queue *q)
+{
+ /*
+ * Since the I/O scheduler exit code may access cgroup information,
+ * perform I/O scheduler exit before disassociating from the block
+ * cgroup controller.
+ */
+ if (q->elevator) {
+ ioc_clear_queue(q);
+ elevator_exit(q, q->elevator);
+ q->elevator = NULL;
+ }
+
+ /*
+ * Remove all references to @q from the block cgroup controller before
+ * restoring @q->queue_lock to avoid that restoring this pointer causes
+ * e.g. blkcg_print_blkgs() to crash.
+ */
+ blkcg_exit_queue(q);
+
+ /*
+ * Since the cgroup code may dereference the @q->backing_dev_info
+ * pointer, only decrease its reference count after having removed the
+ * association with the block cgroup controller.
+ */
+ bdi_put(q->backing_dev_info);
+}
+
/**
* blk_cleanup_queue - shutdown a request queue
* @q: request queue to shutdown
@@ -784,30 +813,7 @@ void blk_cleanup_queue(struct request_queue *q)
*/
WARN_ON_ONCE(q->kobj.state_in_sysfs);
- /*
- * Since the I/O scheduler exit code may access cgroup information,
- * perform I/O scheduler exit before disassociating from the block
- * cgroup controller.
- */
- if (q->elevator) {
- ioc_clear_queue(q);
- elevator_exit(q, q->elevator);
- q->elevator = NULL;
- }
-
- /*
- * Remove all references to @q from the block cgroup controller before
- * restoring @q->queue_lock to avoid that restoring this pointer causes
- * e.g. blkcg_print_blkgs() to crash.
- */
- blkcg_exit_queue(q);
-
- /*
- * Since the cgroup code may dereference the @q->backing_dev_info
- * pointer, only decrease its reference count after having removed the
- * association with the block cgroup controller.
- */
- bdi_put(q->backing_dev_info);
+ blk_exit_queue(q);
if (q->mq_ops)
blk_mq_free_queue(q);
diff --git a/block/blk.h b/block/blk.h
index 69b14cd2bb22..d4d67e948920 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -130,6 +130,7 @@ void blk_free_flush_queue(struct blk_flush_queue *q);
int blk_init_rl(struct request_list *rl, struct request_queue *q,
gfp_t gfp_mask);
void blk_exit_rl(struct request_queue *q, struct request_list *rl);
+void blk_exit_queue(struct request_queue *q);
void blk_rq_bio_prep(struct request_queue *q, struct request *rq,
struct bio *bio);
void blk_queue_bypass_start(struct request_queue *q);