1 files changed, 23 insertions, 1 deletions

diff --git a/include/linux/fs.h b/include/linux/fs.h
index bb29b02d9bb6..4193a0bd99b0 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -18,6 +18,7 @@
 #include <linux/pid.h>
 #include <linux/bug.h>
 #include <linux/mutex.h>
+#include <linux/rwsem.h>
 #include <linux/capability.h>
 #include <linux/semaphore.h>
 #include <linux/fiemap.h>
@@ -401,7 +402,7 @@ struct address_space {
         atomic_t                i_mmap_writable;/* count VM_SHARED mappings */
         struct rb_root          i_mmap;         /* tree of private and shared mappings */
         struct list_head        i_mmap_nonlinear;/*list VM_NONLINEAR mappings */
-        struct mutex            i_mmap_mutex;   /* protect tree, count, list */
+        struct rw_semaphore     i_mmap_rwsem;   /* protect tree, count, list */
         /* Protected by tree_lock together with the radix tree */
         unsigned long           nrpages;        /* number of total pages */
         unsigned long           nrshadows;      /* number of shadow entries */
@@ -467,6 +468,26 @@ struct block_device {
 
 int mapping_tagged(struct address_space *mapping, int tag);
 
+static inline void i_mmap_lock_write(struct address_space *mapping)
+{
+        down_write(&mapping->i_mmap_rwsem);
+}
+
+static inline void i_mmap_unlock_write(struct address_space *mapping)
+{
+        up_write(&mapping->i_mmap_rwsem);
+}
+
+static inline void i_mmap_lock_read(struct address_space *mapping)
+{
+        down_read(&mapping->i_mmap_rwsem);
+}
+
+static inline void i_mmap_unlock_read(struct address_space *mapping)
+{
+        up_read(&mapping->i_mmap_rwsem);
+}
+
 /*
  * Might pages of this file be mapped into userspace?
  */
@@ -2075,6 +2096,7 @@ extern int vfs_open(const struct path *, struct file *, const struct cred *);
 extern struct file * dentry_open(const struct path *, int, const struct cred *);
 extern int filp_close(struct file *, fl_owner_t id);
 
+extern struct filename *getname_flags(const char __user *, int, int *);
 extern struct filename *getname(const char __user *);
 extern struct filename *getname_kernel(const char *);