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

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

On Fri, Aug 28, 2020 at 10:49:21AM +0200, Jan Kara wrote:
> On Fri 28-08-20 15:15:01, 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
> > ------------------------------------------
> > 
> > Signed-off-by: Xiao Yang <yangx.jy@cn.fujitsu.com>
> 
> Thanks. The patch looks good to me. You can add:
> 
> Reviewed-by: Jan Kara <jack@suse.cz>
> 
> Please also add the following tag to the changelog:
> 
> Fixes: b383a73f2b83 ("fs/ext4: Introduce DAX inode flag")
> 
> so that the patch gets properly picked up to stable trees etc. Thanks!

And +1 on getting this to stable.

Thanks!
Ira

> 
> 								Honza
> 
> > ---
> >  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
> > 
> > 
> > 
> -- 
> Jan Kara <jack@suse.com>
> SUSE Labs, CR