[PATCH 1/3] btrfs: fix comment about the btrfs_show_devname

[Anand Jain <anand.jain@oracle.com>]

There were few lock dep warnings because btrfs_show_devname() was using
device_list_mutex as recorded in the commits
  ccd05285e7f (btrfs: fix a possible umount deadlock)
  779bf3fefa8 (btrfs: fix lock dep warning, move scratch dev out of
  device_list_mutex and uuid_mutex)

And finally, commit 88c14590cdd6 (btrfs: use RCU in btrfs_show_devname
for device list traversal) removed the device_list_mutex from
btrfs_show_devname for performance reasons.

This patch fixes a stale comment about the function btrfs_show_devname.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
---
 fs/btrfs/volumes.c | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 9cb4ed90888d..91b8422b3f67 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -2278,10 +2278,7 @@ void btrfs_destroy_dev_replace_tgtdev(struct btrfs_device *tgtdev)
 
 	/*
 	 * The update_dev_time() with in btrfs_scratch_superblocks()
-	 * may lead to a call to btrfs_show_devname() which will try
-	 * to hold device_list_mutex. And here this device
-	 * is already out of device list, so we don't have to hold
-	 * the device_list_mutex lock.
+	 * may lead to a call to btrfs_show_devname().
 	 */
 	btrfs_scratch_superblocks(tgtdev->fs_info, tgtdev->bdev,
 				  tgtdev->name->str);
-- 
2.31.1