mm: use mm_populate() for blocking remap_file_pages()

Signed-off-by: Michel Lespinasse <walken@google.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Tested-by: Andy Lutomirski <luto@amacapital.net>
Cc: Greg Ungerer <gregungerer@westnet.com.au>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/fremap.c b/mm/fremap.c
index 2db886e310445f25b8b4abee9217a88e44bffde9..b42e3217153032984bd32356447cd9d80c1874c0 100644 (file)
--- a/mm/fremap.c
+++ b/mm/fremap.c
@@ -129,6 +129,7 @@ SYSCALL_DEFINE5(remap_file_pages, unsigned long, start, unsigned long, size,
        struct vm_area_struct *vma;
        int err = -EINVAL;
        int has_write_lock = 0;
+       vm_flags_t vm_flags;
 
        if (prot)
                return err;
@@ -228,30 +229,16 @@ get_write_lock:
                /*
                 * drop PG_Mlocked flag for over-mapped range
                 */
-               vm_flags_t saved_flags = vma->vm_flags;
                if (!has_write_lock)
                        goto get_write_lock;
+               vm_flags = vma->vm_flags;
                munlock_vma_pages_range(vma, start, start + size);
-               vma->vm_flags = saved_flags;
+               vma->vm_flags = vm_flags;
        }
 
        mmu_notifier_invalidate_range_start(mm, start, start + size);
        err = vma->vm_ops->remap_pages(vma, start, size, pgoff);
        mmu_notifier_invalidate_range_end(mm, start, start + size);
-       if (!err) {
-               if (vma->vm_flags & VM_LOCKED) {
-                       /*
-                        * might be mapping previously unmapped range of file
-                        */
-                       mlock_vma_pages_range(vma, start, start + size);
-               } else if (!(flags & MAP_NONBLOCK)) {
-                       if (unlikely(has_write_lock)) {
-                               downgrade_write(&mm->mmap_sem);
-                               has_write_lock = 0;
-                       }
-                       make_pages_present(start, start+size);
-               }
-       }
 
        /*
         * We can't clear VM_NONLINEAR because we'd have to do
@@ -260,10 +247,13 @@ get_write_lock:
         */
 
 out:
+       vm_flags = vma->vm_flags;
        if (likely(!has_write_lock))
                up_read(&mm->mmap_sem);
        else
                up_write(&mm->mmap_sem);
+       if (!err && ((vm_flags & VM_LOCKED) || !(flags & MAP_NONBLOCK)))
+               mm_populate(start, size);
 
        return err;
 }