From 0a6dbcc507586e43a2d8795de6f9ee9a4943206a Mon Sep 17 00:00:00 2001
From: Linus Torvalds <torvalds@linux-foundation.org>
Date: Fri, 30 Jan 2009 11:37:22 -0800
Subject: [PATCH] --- yaml --- r: 130531 b: refs/heads/master c:
 33bfad54b58cf05cfe6678c3ec9235d4bc8db4c2 h: refs/heads/master i:   130529:
 dab2817709b5b6ca7f2ab2d95a68d9114e923abf   130527:
 675d6ec908eec3a62201fce378741d2067dc4a6d v: v3

---
 [refs]          | 2 +-
 trunk/mm/mmap.c | 5 ++++-
 2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/[refs] b/[refs]
index 2c5c1a753dd0..e22330d27b5f 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: c01a25e7cf6dcb0fa69c155706d5dd1e76e53796
+refs/heads/master: 33bfad54b58cf05cfe6678c3ec9235d4bc8db4c2
diff --git a/trunk/mm/mmap.c b/trunk/mm/mmap.c
index d3fa10a726cf..c581df14d0de 100644
--- a/trunk/mm/mmap.c
+++ b/trunk/mm/mmap.c
@@ -658,6 +658,9 @@ again:			remove_next = 1 + (end > next->vm_end);
 	validate_mm(mm);
 }
 
+/* Flags that can be inherited from an existing mapping when merging */
+#define VM_MERGEABLE_FLAGS (VM_CAN_NONLINEAR)
+
 /*
  * If the vma has a ->close operation then the driver probably needs to release
  * per-vma resources, so we don't attempt to merge those.
@@ -665,7 +668,7 @@ again:			remove_next = 1 + (end > next->vm_end);
 static inline int is_mergeable_vma(struct vm_area_struct *vma,
 			struct file *file, unsigned long vm_flags)
 {
-	if (vma->vm_flags != vm_flags)
+	if ((vma->vm_flags ^ vm_flags) & ~VM_MERGEABLE_FLAGS)
 		return 0;
 	if (vma->vm_file != file)
 		return 0;