Re: [PATCH v3 1/6] dax: fix vma_is_fsdax() helper

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(a)vger.kernel.org&gt; Reported-by: Gerd Rausch <gerd.rausch(a)oracle.com&gt; Acked-by: Jane Chu <jane.chu(a)oracle.com&gt; Reported-by: Haozhong Zhang <haozhong.zhang(a)intel.com&gt; Signed-off-by: Dan Williams <dan.j.williams(a)intel.com&gt;

--- 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; }