wrappers for ->i_mutex access

parallel to mutex_{lock,unlock,trylock,is_locked,lock_nested},
inode_foo(inode) being mutex_foo(&inode->i_mutex).

Please, use those for access to ->i_mutex; over the coming cycle
->i_mutex will become rwsem, with ->lookup() done with it held
only shared.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/ext2/ioctl.c b/fs/ext2/ioctl.c
index 5d46c09..b386af2 100644
--- a/fs/ext2/ioctl.c
+++ b/fs/ext2/ioctl.c
@@ -51,10 +51,10 @@
 
 		flags = ext2_mask_flags(inode->i_mode, flags);
 
-		mutex_lock(&inode->i_mutex);
+		inode_lock(inode);
 		/* Is it quota file? Do not allow user to mess with it */
 		if (IS_NOQUOTA(inode)) {
-			mutex_unlock(&inode->i_mutex);
+			inode_unlock(inode);
 			ret = -EPERM;
 			goto setflags_out;
 		}
@@ -68,7 +68,7 @@
 		 */
 		if ((flags ^ oldflags) & (EXT2_APPEND_FL | EXT2_IMMUTABLE_FL)) {
 			if (!capable(CAP_LINUX_IMMUTABLE)) {
-				mutex_unlock(&inode->i_mutex);
+				inode_unlock(inode);
 				ret = -EPERM;
 				goto setflags_out;
 			}
@@ -80,7 +80,7 @@
 
 		ext2_set_inode_flags(inode);
 		inode->i_ctime = CURRENT_TIME_SEC;
-		mutex_unlock(&inode->i_mutex);
+		inode_unlock(inode);
 
 		mark_inode_dirty(inode);
 setflags_out:
@@ -102,10 +102,10 @@
 			goto setversion_out;
 		}
 
-		mutex_lock(&inode->i_mutex);
+		inode_lock(inode);
 		inode->i_ctime = CURRENT_TIME_SEC;
 		inode->i_generation = generation;
-		mutex_unlock(&inode->i_mutex);
+		inode_unlock(inode);
 
 		mark_inode_dirty(inode);
 setversion_out: