diff mbox series

[V2,03/13] block: move blkcg initialization/destroy into disk allocation/release handler

Message ID 20220122111054.1126146-4-ming.lei@redhat.com (mailing list archive)
State New, archived
Headers show
Series block: don't drain file system I/O on del_gendisk | expand

Commit Message

Ming Lei Jan. 22, 2022, 11:10 a.m. UTC 
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>
---
 block/blk-core.c  |  5 -----
 block/blk-sysfs.c |  7 -------
 block/genhd.c     | 14 ++++++++++++++
 3 files changed, 14 insertions(+), 12 deletions(-)

Comments

Christoph Hellwig Jan. 24, 2022, 1:02 p.m. UTC | #1 
> @@ -1308,6 +1316,10 @@ 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;
>  
> +	/* todo: move blkcg into gendisk */
> +	if (blkcg_init_queue(q))
> +		goto out_erase_part0;
> +

I don't think having this todo comment here is helpful (even if I agree
with the move and actually half old preliminary patches for that).

With this comment dropped:

Reviewed-by: Christoph Hellwig <hch@lst.de>
diff mbox series

Patch

diff --git a/block/blk-core.c b/block/blk-core.c
index 2a400fa8cabd..d9477191b303 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -495,17 +495,12 @@  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 e20eadfcf5c8..6f326b44fb00 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 626c8406f21a..b9b0db168ce1 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -1112,6 +1112,14 @@  static void disk_release(struct device *dev)
 	disk_release_events(disk);
 	kfree(disk->random);
 	xa_destroy(&disk->part_tbl);
+
+	/*
+	 * 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(disk->queue);
+
 	disk->queue->disk = NULL;
 	blk_put_queue(disk->queue);
 	iput(disk->part0->bd_inode);	/* frees the disk */
@@ -1308,6 +1316,10 @@  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;
 
+	/* todo: move blkcg into gendisk */
+	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;
@@ -1320,6 +1332,8 @@  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;