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authorMing Lei <ming.lei@redhat.com>2022-07-14 18:32:01 +0800
committerJens Axboe <axboe@kernel.dk>2022-07-14 07:16:04 -0600
commitcebbe577cb17ed9b04b50d9e6802a8bacffbadca (patch)
tree7ce64abd80d8b9f19a9ea8ef0d6af7955ddcf7c2
parent0edb3696c1713c42f52acbd8355b545e58f782b1 (diff)
downloadlinux-cebbe577cb17ed9b04b50d9e6802a8bacffbadca.tar.gz
ublk_drv: fix request queue leak
Call blk_cleanup_queue() in release code path for fixing request
queue leak.

Also for-5.20/block has cleaned up blk_cleanup_queue(), which is
basically merged to del_gendisk() if blk_mq_alloc_disk() is used
for allocating disk and queue.

However, ublk may not add disk in case of starting device failure, then
del_gendisk() won't be called when removing ublk device, so blk_mq_exit_queue
will not be callsed, and it can be bit hard to deal with this kind of
merge conflict.

Turns out ublk's queue/disk use model is very similar with scsi, so switch
to scsi's model by allocating disk and queue independently, then it can be
quite easy to handle v5.20 merge conflict by replacing blk_cleanup_queue
with blk_mq_destroy_queue.

Reported-by: Jens Axboe <axboe@kernel.dk>
Fixes: 71f28f3136af ("ublk_drv: add io_uring based userspace block driver")
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20220714103201.131648-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
-rw-r--r--drivers/block/ublk_drv.c21
1 files changed, 15 insertions, 6 deletions
diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c
index 35fa06ee70ff..f10c4319dc1f 100644
--- a/drivers/block/ublk_drv.c
+++ b/drivers/block/ublk_drv.c
@@ -155,6 +155,8 @@ static DEFINE_MUTEX(ublk_ctl_mutex);
 
 static struct miscdevice ublk_misc;
 
+static struct lock_class_key ublk_bio_compl_lkclass;
+
 static inline bool ublk_can_use_task_work(const struct ublk_queue *ubq)
 {
 	if (IS_BUILTIN(CONFIG_BLK_DEV_UBLK) &&
@@ -634,7 +636,7 @@ static void ublk_commit_rqs(struct blk_mq_hw_ctx *hctx)
 static int ublk_init_hctx(struct blk_mq_hw_ctx *hctx, void *driver_data,
 		unsigned int hctx_idx)
 {
-	struct ublk_device *ub = hctx->queue->queuedata;
+	struct ublk_device *ub = driver_data;
 	struct ublk_queue *ubq = ublk_get_queue(ub, hctx->queue_num);
 
 	hctx->driver_data = ubq;
@@ -1076,6 +1078,8 @@ static void ublk_cdev_rel(struct device *dev)
 {
 	struct ublk_device *ub = container_of(dev, struct ublk_device, cdev_dev);
 
+	blk_mq_destroy_queue(ub->ub_queue);
+
 	put_disk(ub->ub_disk);
 
 	blk_mq_free_tag_set(&ub->tag_set);
@@ -1165,14 +1169,17 @@ static int ublk_add_dev(struct ublk_device *ub)
 	if (err)
 		goto out_deinit_queues;
 
-	disk = ub->ub_disk = blk_mq_alloc_disk(&ub->tag_set, ub);
+	ub->ub_queue = blk_mq_init_queue(&ub->tag_set);
+	if (IS_ERR(ub->ub_queue))
+		goto out_cleanup_tags;
+	ub->ub_queue->queuedata = ub;
+
+	disk = ub->ub_disk = blk_mq_alloc_disk_for_queue(ub->ub_queue,
+						 &ublk_bio_compl_lkclass);
 	if (IS_ERR(disk)) {
 		err = PTR_ERR(disk);
-		goto out_cleanup_tags;
+		goto out_free_request_queue;
 	}
-	ub->ub_queue = ub->ub_disk->queue;
-
-	ub->ub_queue->queuedata = ub;
 
 	blk_queue_logical_block_size(ub->ub_queue, bsize);
 	blk_queue_physical_block_size(ub->ub_queue, bsize);
@@ -1204,6 +1211,8 @@ static int ublk_add_dev(struct ublk_device *ub)
 
 	return 0;
 
+out_free_request_queue:
+	blk_mq_destroy_queue(ub->ub_queue);
 out_cleanup_tags:
 	blk_mq_free_tag_set(&ub->tag_set);
 out_deinit_queues: