From: Anand Jain <anand.jain@oracle.com> mainline inclusion from mainline-v5.16-rc1 commit b7cb29e666fe79dda5dbe5f57fb7c92413bf161c 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/?i... -------------------------------- 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: Su Yue <l@damenly.su> Signed-off-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Yifan Qiao <qiaoyifan4@huawei.com> --- fs/btrfs/volumes.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index 5088fd10a434..c6a845950451 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -2664,6 +2664,8 @@ 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; -- 2.39.2