1 files changed, 15 insertions, 5 deletions

diff --git a/include/linux/fs.h b/include/linux/fs.h
index 48c1f5fc7411..23467d768cab 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -768,7 +768,17 @@ struct inode {
 
         /* Stat data, not accessed from path walking */
         unsigned long           i_ino;
-        unsigned int            i_nlink;
+        /*
+         * Filesystems may only read i_nlink directly.  They shall use the
+         * following functions for modification:
+         *
+         *    (set|clear|inc|drop)_nlink
+         *    inode_(inc|dec)_link_count
+         */
+        union {
+                const unsigned int i_nlink;
+                unsigned int __i_nlink;
+        };
         dev_t                   i_rdev;
         loff_t                  i_size;
         struct timespec         i_atime;
@@ -1764,7 +1774,7 @@ static inline void mark_inode_dirty_sync(struct inode *inode)
  */
 static inline void set_nlink(struct inode *inode, unsigned int nlink)
 {
-        inode->i_nlink = nlink;
+        inode->__i_nlink = nlink;
 }
 
 /**
@@ -1777,7 +1787,7 @@ static inline void set_nlink(struct inode *inode, unsigned int nlink)
  */
 static inline void inc_nlink(struct inode *inode)
 {
-        inode->i_nlink++;
+        inode->__i_nlink++;
 }
 
 static inline void inode_inc_link_count(struct inode *inode)
@@ -1799,7 +1809,7 @@ static inline void inode_inc_link_count(struct inode *inode)
  */
 static inline void drop_nlink(struct inode *inode)
 {
-        inode->i_nlink--;
+        inode->__i_nlink--;
 }
 
 /**
@@ -1812,7 +1822,7 @@ static inline void drop_nlink(struct inode *inode)
  */
 static inline void clear_nlink(struct inode *inode)
 {
-        inode->i_nlink = 0;
+        inode->__i_nlink = 0;
 }
 
 static inline void inode_dec_link_count(struct inode *inode)