Re: [f2fs-dev] [PATCH 1/2] ext4: only set project inherit bit for directory

[Eric Biggers <ebiggers@kernel.org>]

On Thu, Jun 06, 2019 at 01:32:24PM +0900, Wang Shilong wrote:
> From: Wang Shilong <wshilong@ddn.com>
> 
> It doesn't make any sense to have project inherit bits
> for regular files, even though this won't cause any
> problem, but it is better fix this.
> 
> Cc: Andreas Dilger <adilger@dilger.ca>
> Signed-off-by: Wang Shilong <wshilong@ddn.com>
> ---
>  fs/ext4/ext4.h | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
> index 1cb67859e051..ceb74093e138 100644
> --- a/fs/ext4/ext4.h
> +++ b/fs/ext4/ext4.h
> @@ -421,7 +421,8 @@ struct flex_groups {
>  			   EXT4_PROJINHERIT_FL | EXT4_CASEFOLD_FL)
>  
>  /* Flags that are appropriate for regular files (all but dir-specific ones). */
> -#define EXT4_REG_FLMASK (~(EXT4_DIRSYNC_FL | EXT4_TOPDIR_FL | EXT4_CASEFOLD_FL))
> +#define EXT4_REG_FLMASK (~(EXT4_DIRSYNC_FL | EXT4_TOPDIR_FL | EXT4_CASEFOLD_FL |\
> +			   EXT4_PROJINHERIT_FL))
>  
>  /* Flags that are appropriate for non-directories/regular files. */
>  #define EXT4_OTHER_FLMASK (EXT4_NODUMP_FL | EXT4_NOATIME_FL)
> -- 
> 2.21.0

Won't this break 'chattr' on files that already have this flag set?
FS_IOC_GETFLAGS will return this flag, so 'chattr' will pass it back to
FS_IOC_SETFLAGS which will return EOPNOTSUPP due to this:

	if (ext4_mask_flags(inode->i_mode, flags) != flags)
		return -EOPNOTSUPP;

- Eric