vfs: rename I_MUTEX_QUOTA now that it's not used for quotas

I_MUTEX_QUOTA is now just being used whenever we want to lock two
non-directories.  So the name isn't right.  I_MUTEX_NONDIR2 isn't
especially elegant but it's the best I could think of.

Also fix some outdated documentation.

Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

2 files changed, 8 insertions, 5 deletions

diff --git a/fs/inode.c b/fs/inode.c
index 51f329b98aa4..ce48c359ce9e 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -957,10 +957,10 @@ void lock_two_nondirectories(struct inode *inode1, struct inode *inode2)
         WARN_ON_ONCE(S_ISDIR(inode2->i_mode));
         if (inode1 < inode2) {
                 mutex_lock(&inode1->i_mutex);
-                mutex_lock_nested(&inode2->i_mutex, I_MUTEX_QUOTA);
+                mutex_lock_nested(&inode2->i_mutex, I_MUTEX_NONDIR2);
         } else {
                 mutex_lock(&inode2->i_mutex);
-                mutex_lock_nested(&inode1->i_mutex, I_MUTEX_QUOTA);
+                mutex_lock_nested(&inode1->i_mutex, I_MUTEX_NONDIR2);
         }
 }
 EXPORT_SYMBOL(lock_two_nondirectories);
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 4e1a0b41f966..ed7f94af1ab2 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -623,10 +623,13 @@ static inline int inode_unhashed(struct inode *inode)
  * 0: the object of the current VFS operation
  * 1: parent
  * 2: child/target
- * 3: quota file
+ * 3: xattr
+ * 4: second non-directory
+ * The last is for certain operations (such as rename) which lock two
+ * non-directories at once.
  *
  * The locking order between these classes is
- * parent -> child -> normal -> xattr -> quota
+ * parent -> child -> normal -> xattr -> second non-directory
  */
 enum inode_i_mutex_lock_class
 {
@@ -634,7 +637,7 @@ enum inode_i_mutex_lock_class
         I_MUTEX_PARENT,
         I_MUTEX_CHILD,
         I_MUTEX_XATTR,
-        I_MUTEX_QUOTA
+        I_MUTEX_NONDIR2
 };
 
 void lock_two_nondirectories(struct inode *, struct inode*);