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

[Christophe JAILLET]

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.jail...@wanadoo.fr>
---
-- 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