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/fuse/dir.c b/fs/fuse/dir.c
index 712601f..4b855b6 100644
--- a/fs/fuse/dir.c
+++ b/fs/fuse/dir.c
@@ -944,7 +944,7 @@
 	if (!parent)
 		return -ENOENT;
 
-	mutex_lock(&parent->i_mutex);
+	inode_lock(parent);
 	if (!S_ISDIR(parent->i_mode))
 		goto unlock;
 
@@ -962,7 +962,7 @@
 	fuse_invalidate_entry(entry);
 
 	if (child_nodeid != 0 && d_really_is_positive(entry)) {
-		mutex_lock(&d_inode(entry)->i_mutex);
+		inode_lock(d_inode(entry));
 		if (get_node_id(d_inode(entry)) != child_nodeid) {
 			err = -ENOENT;
 			goto badentry;
@@ -983,7 +983,7 @@
 		clear_nlink(d_inode(entry));
 		err = 0;
  badentry:
-		mutex_unlock(&d_inode(entry)->i_mutex);
+		inode_unlock(d_inode(entry));
 		if (!err)
 			d_delete(entry);
 	} else {
@@ -992,7 +992,7 @@
 	dput(entry);
 
  unlock:
-	mutex_unlock(&parent->i_mutex);
+	inode_unlock(parent);
 	iput(parent);
 	return err;
 }
@@ -1504,7 +1504,7 @@
 	struct fuse_conn *fc = get_fuse_conn(inode);
 	struct fuse_inode *fi = get_fuse_inode(inode);
 
-	BUG_ON(!mutex_is_locked(&inode->i_mutex));
+	BUG_ON(!inode_is_locked(inode));
 
 	spin_lock(&fc->lock);
 	BUG_ON(fi->writectr < 0);