On Fri 23-02-18 16:43:11, Dan Williams wrote:
> Gerd reports that ->i_mode may contain other bits besides S_IFCHR. Use
> S_ISCHR() instead. Otherwise, get_user_pages_longterm() may fail on
> device-dax instances when those are meant to be explicitly allowed.
>
> Fixes: 2bb6d2837083 ("mm: introduce get_user_pages_longterm")
> Cc: <stable@xxxxxxxxxxxxxxx>
> Reported-by: Gerd Rausch <gerd.rausch@xxxxxxxxxx>
> Acked-by: Jane Chu <jane.chu@xxxxxxxxxx>
> Reported-by: Haozhong Zhang <haozhong.zhang@xxxxxxxxx>
> Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
I wonder how I didn't notice this when reading the original patch. Anyway
the fix looks good. You can add:
Reviewed-by: Jan Kara <jack@xxxxxxx>
Honza
> ---
> include/linux/fs.h | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/include/linux/fs.h b/include/linux/fs.h
> index 2a815560fda0..79c413985305 100644
> --- a/include/linux/fs.h
> +++ b/include/linux/fs.h
> @@ -3198,7 +3198,7 @@ static inline bool vma_is_fsdax(struct vm_area_struct *vma)
> if (!vma_is_dax(vma))
> return false;
> inode = file_inode(vma->vm_file);
> - if (inode->i_mode == S_IFCHR)
> + if (S_ISCHR(inode->i_mode))
> return false; /* device-dax */
> return true;
> }
>
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR