mm/frame_vector.c: release a semaphore in 'get_vaddr_frames()'

[ Upstream commit 1f704fd0d14043e76e80f6b8b2251b9b2cedcca6 ]

A semaphore is acquired before this check, so we must release it before
leaving.

Link: http://lkml.kernel.org/r/20171211211009.4971-1-christophe.jaillet@wanadoo.fr
Fixes: b7f0554a56f2 ("mm: fail get_vaddr_frames() for filesystem-dax mappings")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: David Sterba <dsterba@suse.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/mm/frame_vector.c b/mm/frame_vector.c
index 375a103..d73eed0 100644 (file)
--- a/mm/frame_vector.c
+++ b/mm/frame_vector.c
@@ -61,8 +61,10 @@ 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;