mm: move VM_LOCKED check to __mlock_vma_pages_range()

Use a single code path for faulting in pages during mlock.

The reason to have it in this patch series is that I did not want to
update both code paths in a later change that releases mmap_sem when
blocking on disk.

Signed-off-by: Michel Lespinasse <walken@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 13 insertions, 13 deletions

diff --git a/mm/mlock.c b/mm/mlock.c
index 25cc9e88c540..84da66b7bbf0 100644
--- a/mm/mlock.c
+++ b/mm/mlock.c
@@ -169,7 +169,7 @@ static long __mlock_vma_pages_range(struct vm_area_struct *vma,
         VM_BUG_ON(end   > vma->vm_end);
         VM_BUG_ON(!rwsem_is_locked(&mm->mmap_sem));
 
-        gup_flags = FOLL_TOUCH | FOLL_MLOCK;
+        gup_flags = FOLL_TOUCH;
         /*
          * We want to touch writable mappings with a write fault in order
          * to break COW, except for shared mappings because these don't COW
@@ -178,6 +178,9 @@ static long __mlock_vma_pages_range(struct vm_area_struct *vma,
         if ((vma->vm_flags & (VM_WRITE | VM_SHARED)) == VM_WRITE)
                 gup_flags |= FOLL_WRITE;
 
+        if (vma->vm_flags & VM_LOCKED)
+                gup_flags |= FOLL_MLOCK;
+
         /* We don't try to access the guard page of a stack vma */
         if (stack_guard_page(vma, start)) {
                 addr += PAGE_SIZE;
@@ -456,18 +459,15 @@ static int do_mlock_pages(unsigned long start, size_t len, int ignore_errors)
                 /*
                  * Now fault in a range of pages within the first VMA.
                  */
-                if (vma->vm_flags & VM_LOCKED) {
-                        ret = __mlock_vma_pages_range(vma, nstart, nend);
-                        if (ret < 0 && ignore_errors) {
-                                ret = 0;
-                                continue;       /* continue at next VMA */
-                        }
-                        if (ret) {
-                                ret = __mlock_posix_error_return(ret);
-                                break;
-                        }
-                } else
-                        make_pages_present(nstart, nend);
+                ret = __mlock_vma_pages_range(vma, nstart, nend);
+                if (ret < 0 && ignore_errors) {
+                        ret = 0;
+                        continue;       /* continue at next VMA */
+                }
+                if (ret) {
+                        ret = __mlock_posix_error_return(ret);
+                        break;
+                }
         }
         up_read(&mm->mmap_sem);
         return ret;     /* 0 or negative error code */