[PATCH 4.14 021/237] btrfs: log message when rw remount is attempted with unclean tree-log

Greg Kroah-Hartman
2020-02-27T14:40:36Z

From: David Sterba <dsterba@suse.com>

commit 10a3a3edc5b89a8cd095bc63495fb1e0f42047d9 upstream.

A remount to a read-write filesystem is not safe when there's tree-log
to be replayed. Files that could be opened until now might be affected
by the changes in the tree-log.

A regular mount is needed to replay the log so the filesystem presents
the consistent view with the pending changes included.

CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
fs/btrfs/super.c | 2 ++
1 file changed, 2 insertions(+)

--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -1801,6 +1801,8 @@ static int btrfs_remount(struct super_bl
}

if (btrfs_super_log_root(fs_info->super_copy) != 0) {
+ btrfs_warn(fs_info,
+ "mount required to replay tree-log, cannot remount read-write");
ret = -EINVAL;
goto restore;
}