From a7b780750e1a1c7833812681e1f8fa30bbb06802 Mon Sep 17 00:00:00 2001
From: Andrea Arcangeli <aarcange@redhat.com>
Date: Wed, 11 Feb 2015 15:27:23 -0800
Subject: mm: gup: use get_user_pages_unlocked within get_user_pages_fast

This allows the get_user_pages_fast slow path to release the mmap_sem
before blocking.

Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Andres Lagar-Cavilla <andreslc@google.com>
Cc: Peter Feiner <pfeiner@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
 mm/gup.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

(limited to 'mm/gup.c')

diff --git a/mm/gup.c b/mm/gup.c
index dad5875fb766..c2da1163986a 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -1243,10 +1243,8 @@ int get_user_pages_fast(unsigned long start, int nr_pages, int write,
 		start += nr << PAGE_SHIFT;
 		pages += nr;
 
-		down_read(&mm->mmap_sem);
-		ret = get_user_pages(current, mm, start,
-				     nr_pages - nr, write, 0, pages, NULL);
-		up_read(&mm->mmap_sem);
+		ret = get_user_pages_unlocked(current, mm, start,
+					      nr_pages - nr, write, 0, pages);
 
 		/* Have to be a bit careful with return values */
 		if (nr > 0) {
-- 
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