---

yaml
---
r: 61531
b: refs/heads/master
c: ed2f2f9
h: refs/heads/master
i:
  61529: 918482b
  61527: 9754efa
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 6967614761fd305b3414d9485d89dc2e0a407410
+refs/heads/master: ed2f2f9b3ff8debdf512f7687b232c3c1d7d60d7

trunk/Documentation/filesystems/Locking

@@ -512,13 +512,22 @@ prototypes:
 	void (*close)(struct vm_area_struct*);
 	struct page *(*fault)(struct vm_area_struct*, struct fault_data *);
 	struct page *(*nopage)(struct vm_area_struct*, unsigned long, int *);
+	int (*page_mkwrite)(struct vm_area_struct *, struct page *);
 
 locking rules:
-		BKL	mmap_sem
+		BKL	mmap_sem	PageLocked(page)
 open:		no	yes
 close:		no	yes
 fault:		no	yes
 nopage:		no	yes
+page_mkwrite:	no	yes		no
+
+	->page_mkwrite() is called when a previously read-only page is
+about to become writeable. The file system is responsible for
+protecting against truncate races. Once appropriate action has been
+taking to lock out truncate, the page range should be verified to be
+within i_size. The page mapping should also be checked that it is not
+NULL.
 
 ================================================================================
 			Dubious stuff