diff mbox series

[09/44] dm: remove the block_device reference in struct mapped_device

Message ID 20201126130422.92945-10-hch@lst.de (mailing list archive)
State New, archived
Headers show
Series [01/44] blk-cgroup: fix a hd_struct leak in blkcg_fill_root_iostats | expand

Commit Message

Christoph Hellwig Nov. 26, 2020, 1:03 p.m. UTC 
Get rid of the long-lasting struct block_device reference in
struct mapped_device.  The only remaining user is the freeze code,
where we can trivially look up the block device at freeze time
and release the reference at thaw time.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Mike Snitzer <snitzer@redhat.com>
---
 drivers/md/dm-core.h |  2 --
 drivers/md/dm.c      | 25 ++++++++++++++-----------
 2 files changed, 14 insertions(+), 13 deletions(-)

Comments

Hannes Reinecke Nov. 27, 2020, 10:36 a.m. UTC | #1 
On 11/26/20 2:03 PM, Christoph Hellwig wrote:
> Get rid of the long-lasting struct block_device reference in
> struct mapped_device.  The only remaining user is the freeze code,
> where we can trivially look up the block device at freeze time
> and release the reference at thaw time.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> Acked-by: Mike Snitzer <snitzer@redhat.com>
> ---
>   drivers/md/dm-core.h |  2 --
>   drivers/md/dm.c      | 25 ++++++++++++++-----------
>   2 files changed, 14 insertions(+), 13 deletions(-)
> 
Reviewed-by: Hannes Reinecke <hare@suse.de>

Cheers,

Hannes
diff mbox series

Patch

diff --git a/drivers/md/dm-core.h b/drivers/md/dm-core.h
index aace147effcacb..086d293c2b036c 100644
--- a/drivers/md/dm-core.h
+++ b/drivers/md/dm-core.h
@@ -102,8 +102,6 @@  struct mapped_device {
 	/* kobject and completion */
 	struct dm_kobject_holder kobj_holder;
 
-	struct block_device *bdev;
-
 	struct dm_stats stats;
 
 	/* for blk-mq request-based DM support */
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index ab0a8335f098d9..48051db006f30c 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -1744,11 +1744,6 @@  static void cleanup_mapped_device(struct mapped_device *md)
 
 	cleanup_srcu_struct(&md->io_barrier);
 
-	if (md->bdev) {
-		bdput(md->bdev);
-		md->bdev = NULL;
-	}
-
 	mutex_destroy(&md->suspend_lock);
 	mutex_destroy(&md->type_lock);
 	mutex_destroy(&md->table_devices_lock);
@@ -1840,10 +1835,6 @@  static struct mapped_device *alloc_dev(int minor)
 	if (!md->wq)
 		goto bad;
 
-	md->bdev = bdget_disk(md->disk, 0);
-	if (!md->bdev)
-		goto bad;
-
 	dm_stats_init(&md->stats);
 
 	/* Populate the mapping, nobody knows we exist yet */
@@ -2384,11 +2375,16 @@  struct dm_table *dm_swap_table(struct mapped_device *md, struct dm_table *table)
  */
 static int lock_fs(struct mapped_device *md)
 {
+	struct block_device *bdev;
 	int r;
 
 	WARN_ON(test_bit(DMF_FROZEN, &md->flags));
 
-	r = freeze_bdev(md->bdev);
+	bdev = bdget_disk(md->disk, 0);
+	if (!bdev)
+		return -ENOMEM;
+	r = freeze_bdev(bdev);
+	bdput(bdev);
 	if (!r)
 		set_bit(DMF_FROZEN, &md->flags);
 	return r;
@@ -2396,9 +2392,16 @@  static int lock_fs(struct mapped_device *md)
 
 static void unlock_fs(struct mapped_device *md)
 {
+	struct block_device *bdev;
+
 	if (!test_bit(DMF_FROZEN, &md->flags))
 		return;
-	thaw_bdev(md->bdev);
+
+	bdev = bdget_disk(md->disk, 0);
+	if (!bdev)
+		return;
+	thaw_bdev(bdev);
+	bdput(bdev);
 	clear_bit(DMF_FROZEN, &md->flags);
 }