Re: [PATCH v2] ext4: Disallow modifying DAX inode flag if inline_data has been set

[Ira Weiny <ira.weiny@intel.com>]

On Fri, Aug 28, 2020 at 04:43:30PM +0800, Xiao Yang wrote:
> inline_data is mutually exclusive to DAX so enabling both of them triggers
> the following issue:
> ------------------------------------------
> # mkfs.ext4 -F -O inline_data /dev/pmem1
> ...
> # mount /dev/pmem1 /mnt
> # echo 'test' >/mnt/file
> # lsattr -l /mnt/file
> /mnt/file                    Inline_Data
> # xfs_io -c "chattr +x" /mnt/file
> # xfs_io -c "lsattr -v" /mnt/file
> [dax] /mnt/file
> # umount /mnt
> # mount /dev/pmem1 /mnt
> # cat /mnt/file
> cat: /mnt/file: Numerical result out of range
> ------------------------------------------
> 
> Fixes: b383a73f2b83 ("fs/ext4: Introduce DAX inode flag")
> Signed-off-by: Xiao Yang <yangx.jy@cn.fujitsu.com>
> Reviewed-by: Jan Kara <jack@suse.cz>

Reviewed-by: Ira Weiny <ira.weiny@intel.com>

> ---
>  fs/ext4/ext4.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
> index 523e00d7b392..69187b6205b2 100644
> --- a/fs/ext4/ext4.h
> +++ b/fs/ext4/ext4.h
> @@ -492,7 +492,7 @@ struct flex_groups {
>  
>  /* Flags which are mutually exclusive to DAX */
>  #define EXT4_DAX_MUT_EXCL (EXT4_VERITY_FL | EXT4_ENCRYPT_FL |\
> -			   EXT4_JOURNAL_DATA_FL)
> +			   EXT4_JOURNAL_DATA_FL | EXT4_INLINE_DATA_FL)
>  
>  /* Mask out flags that are inappropriate for the given type of inode. */
>  static inline __u32 ext4_mask_flags(umode_t mode, __u32 flags)
> -- 
> 2.25.1
> 
> 
>