Commit 1663e93c authored by Anand Jain's avatar Anand Jain Committed by Yifan Qiao
Browse files

btrfs: update latest_dev when we create a sprout device 

mainline inclusion
from mainline-v5.16-rc1
commit b7cb29e6
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/IA77UW
CVE: CVE-2021-47599

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=b7cb29e666fe79dda5dbe5f57fb7c92413bf161c



--------------------------------

When we add a device to the seed filesystem (sprouting) it is a new
filesystem (and fsid) on the device added. Update the latest_dev so
that /proc/self/mounts shows the correct device.

Example:

  $ btrfstune -S1 /dev/vg/seed
  $ mount /dev/vg/seed /btrfs
  mount: /btrfs: WARNING: device write-protected, mounted read-only.

  $ cat /proc/self/mounts | grep btrfs
  /dev/mapper/vg-seed /btrfs btrfs ro,relatime,space_cache,subvolid=5,subvol=/ 0 0

  $ btrfs dev add -f /dev/vg/new /btrfs

Before:

  $ cat /proc/self/mounts | grep btrfs
  /dev/mapper/vg-seed /btrfs btrfs ro,relatime,space_cache,subvolid=5,subvol=/ 0 0

After:

  $ cat /proc/self/mounts | grep btrfs
  /dev/mapper/vg-new /btrfs btrfs ro,relatime,space_cache,subvolid=5,subvol=/ 0 0

Tested-by: default avatarSu Yue <l@damenly.su>
Signed-off-by: default avatarAnand Jain <anand.jain@oracle.com>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarYifan Qiao <qiaoyifan4@huawei.com>
parent f8c4d100

fs/btrfs/volumes.c

+2 −0
Original line number Diff line number Diff line
@@ -2629,6 +2629,8 @@ int btrfs_init_new_device(struct btrfs_fs_info *fs_info, const char *device_path 
			btrfs_abort_transaction(trans, ret);

			goto error_trans;

		}

		btrfs_assign_next_active_device(fs_info->fs_devices->latest_dev,

						device);

	}



	device->fs_devices = fs_devices;