btrfs: remove stale comment about the btrfs_show_devname

There were few lockdep warnings because btrfs_show_devname() was using
device_list_mutex as recorded in the commits:

  0ccd05285e ("btrfs: fix a possible umount deadlock")
  779bf3fefa ("btrfs: fix lock dep warning, move scratch dev out of device_list_mutex and uuid_mutex")

And finally, commit 88c14590cd ("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 removes a stale comment about the function
btrfs_show_devname and device_list_mutex.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
Anand Jain 2021-08-24 13:05:22 +08:00 committed by David Sterba
parent b7cb29e666
commit cdccc03a8a

View File

@ -2305,13 +2305,6 @@ void btrfs_destroy_dev_replace_tgtdev(struct btrfs_device *tgtdev)
mutex_unlock(&fs_devices->device_list_mutex);
/*
* 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.
*/
btrfs_scratch_superblocks(tgtdev->fs_info, tgtdev->bdev,
tgtdev->name->str);