Re: [PATCH 5/5] vfs: only allow FSSETXATTR to set DAX flag on files and dirs

From: Jan Kara
Date: Sat Jun 29 2019 - 16:09:15 EST


On Fri 28-06-19 11:34:31, Darrick J. Wong wrote:
> From: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
>
> The DAX flag only applies to files and directories, so don't let it get
> set for other types of files.
>
> Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>

Looks good to me. You can add:

Reviewed-by: Jan Kara <jack@xxxxxxx>

Honza

> ---
> fs/inode.c | 8 ++++++++
> 1 file changed, 8 insertions(+)
>
>
> diff --git a/fs/inode.c b/fs/inode.c
> index 670d5408d022..f08711b34341 100644
> --- a/fs/inode.c
> +++ b/fs/inode.c
> @@ -2259,6 +2259,14 @@ int vfs_ioc_fssetxattr_check(struct inode *inode, const struct fsxattr *old_fa,
> !S_ISREG(inode->i_mode) && !S_ISDIR(inode->i_mode))
> return -EINVAL;
>
> + /*
> + * It is only valid to set the DAX flag on regular files and
> + * directories on filesystems.
> + */
> + if ((fa->fsx_xflags & FS_XFLAG_DAX) &&
> + !(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode)))
> + return -EINVAL;
> +
> /* Extent size hints of zero turn off the flags. */
> if (fa->fsx_extsize == 0)
> fa->fsx_xflags &= ~(FS_XFLAG_EXTSIZE | FS_XFLAG_EXTSZINHERIT);
>
>
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR