diff mbox series

[09/14] block: move blkcg initialization/destroy into disk allocation/release handler

Message ID 20220304160331.399757-10-hch@lst.de
State Superseded
Headers show
Series [01/14] blk-mq: do not include passthrough requests in I/O accounting | expand

Commit Message

Christoph Hellwig March 4, 2022, 4:03 p.m. UTC 
From: Ming Lei <ming.lei@redhat.com>

blkcg works on FS bio level, so it is reasonable to make both blkcg and
gendisk sharing same lifetime. Meantime there won't be any FS IO when
releasing disk, so safe to move blkcg initialization/destroy into disk
allocation/release handler

Long term, we can move blkcg into gendisk completely.

Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 block/blk-core.c  | 5 -----
 block/blk-sysfs.c | 7 -------
 block/genhd.c     | 8 ++++++++
 3 files changed, 8 insertions(+), 12 deletions(-)

Comments

Chaitanya Kulkarni March 7, 2022, 3:18 a.m. UTC | #1 
On 3/4/22 08:03, Christoph Hellwig wrote:
> From: Ming Lei <ming.lei@redhat.com>
> 
> blkcg works on FS bio level, so it is reasonable to make both blkcg and
> gendisk sharing same lifetime. Meantime there won't be any FS IO when
> releasing disk, so safe to move blkcg initialization/destroy into disk
> allocation/release handler
> 
> Long term, we can move blkcg into gendisk completely.
> 
> Signed-off-by: Ming Lei <ming.lei@redhat.com>
> Reviewed-by: Bart Van Assche <bvanassche@acm.org>
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---


Looks good.

Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
diff mbox series

Patch

diff --git a/block/blk-core.c b/block/blk-core.c
index 94bf37f8e61d2..b2f2c65774812 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -496,17 +496,12 @@  struct request_queue *blk_alloc_queue(int node_id, bool alloc_srcu)
 				PERCPU_REF_INIT_ATOMIC, GFP_KERNEL))
 		goto fail_stats;
 
-	if (blkcg_init_queue(q))
-		goto fail_ref;
-
 	blk_queue_dma_alignment(q, 511);
 	blk_set_default_limits(&q->limits);
 	q->nr_requests = BLKDEV_DEFAULT_RQ;
 
 	return q;
 
-fail_ref:
-	percpu_ref_exit(&q->q_usage_counter);
 fail_stats:
 	blk_free_queue_stats(q->stats);
 fail_split:
diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
index 241ded62f458f..220085109d7f0 100644
--- a/block/blk-sysfs.c
+++ b/block/blk-sysfs.c
@@ -751,13 +751,6 @@  static void blk_exit_queue(struct request_queue *q)
 		ioc_clear_queue(q);
 		elevator_exit(q);
 	}
-
-	/*
-	 * 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);
 }
 
 /**
diff --git a/block/genhd.c b/block/genhd.c
index 54f60ded2ee6f..073e93f2fc40b 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -1120,9 +1120,12 @@  static void disk_release(struct device *dev)
 
 	blk_mq_cancel_work_sync(disk->queue);
 
+	blkcg_exit_queue(disk->queue);
+
 	disk_release_events(disk);
 	kfree(disk->random);
 	xa_destroy(&disk->part_tbl);
+
 	disk->queue->disk = NULL;
 	blk_put_queue(disk->queue);
 
@@ -1328,6 +1331,9 @@  struct gendisk *__alloc_disk_node(struct request_queue *q, int node_id,
 	if (xa_insert(&disk->part_tbl, 0, disk->part0, GFP_KERNEL))
 		goto out_destroy_part_tbl;
 
+	if (blkcg_init_queue(q))
+		goto out_erase_part0;
+
 	rand_initialize_disk(disk);
 	disk_to_dev(disk)->class = &block_class;
 	disk_to_dev(disk)->type = &disk_type;
@@ -1340,6 +1346,8 @@  struct gendisk *__alloc_disk_node(struct request_queue *q, int node_id,
 #endif
 	return disk;
 
+out_erase_part0:
+	xa_erase(&disk->part_tbl, 0);
 out_destroy_part_tbl:
 	xa_destroy(&disk->part_tbl);
 	disk->part0->bd_disk = NULL;