Re: [PATCH v2] mm: Release a semaphore in 'get_vaddr_frames()'

From: Michal Hocko
Date: Tue Dec 12 2017 - 02:50:23 EST


On Mon 11-12-17 22:10:09, Christophe JAILLET wrote:
> A semaphore is acquired before this check, so we must release it before
> leaving.
>
> Fixes: b7f0554a56f2 ("mm: fail get_vaddr_frames() for filesystem-dax mappings")
> Signed-off-by: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>

Looks good to me now.
Acked-by: Michal Hocko <mhocko@xxxxxxxx>

Thanks

> ---
> -- Untested --
>
> v1 -> v2: 'goto out' instead of duplicating code
> ---
> mm/frame_vector.c | 6 ++++--
> 1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/mm/frame_vector.c b/mm/frame_vector.c
> index 297c7238f7d4..c64dca6e27c2 100644
> --- a/mm/frame_vector.c
> +++ b/mm/frame_vector.c
> @@ -62,8 +62,10 @@ int get_vaddr_frames(unsigned long start, unsigned int nr_frames,
> * get_user_pages_longterm() and disallow it for filesystem-dax
> * mappings.
> */
> - if (vma_is_fsdax(vma))
> - return -EOPNOTSUPP;
> + if (vma_is_fsdax(vma)) {
> + ret = -EOPNOTSUPP;
> + goto out;
> + }
>
> if (!(vma->vm_flags & (VM_IO | VM_PFNMAP))) {
> vec->got_ref = true;
> --
> 2.14.1
>

--
Michal Hocko
SUSE Labs