Re: [PATCH] btrfs: log message when rw remount is attempted with unclean tree-log

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

On 2/6/20 12:12 AM, David Sterba wrote:
> 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+
> Signed-off-by: David Sterba <dsterba@suse.com>
> ---
>   fs/btrfs/super.c | 2 ++
>   1 file changed, 2 insertions(+)
> 
> diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
> index 580ba7db67e5..a2554c651548 100644
> --- a/fs/btrfs/super.c
> +++ b/fs/btrfs/super.c
> @@ -1834,6 +1834,8 @@ static int btrfs_remount(struct super_block *sb, int *flags, char *data)
>   		}
>   
>   		if (btrfs_super_log_root(fs_info->super_copy) != 0) {



> +			btrfs_warn(f_info,

                                  ^^^^
                               fs_info,

Thanks, Anand

> +		"mount required to replay tree-log, cannot remount read-write");
>   			ret = -EINVAL;
>   			goto restore;
>   		}
>