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/ecryptfs/inode.c b/fs/ecryptfs/inode.c
index 040aa87..4e685ac 100644
--- a/fs/ecryptfs/inode.c
+++ b/fs/ecryptfs/inode.c
@@ -41,13 +41,13 @@
 	struct dentry *dir;
 
 	dir = dget_parent(dentry);
-	mutex_lock_nested(&(d_inode(dir)->i_mutex), I_MUTEX_PARENT);
+	inode_lock_nested(d_inode(dir), I_MUTEX_PARENT);
 	return dir;
 }
 
 static void unlock_dir(struct dentry *dir)
 {
-	mutex_unlock(&d_inode(dir)->i_mutex);
+	inode_unlock(d_inode(dir));
 	dput(dir);
 }
 
@@ -397,11 +397,11 @@
 	int rc = 0;
 
 	lower_dir_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry->d_parent);
-	mutex_lock(&d_inode(lower_dir_dentry)->i_mutex);
+	inode_lock(d_inode(lower_dir_dentry));
 	lower_dentry = lookup_one_len(ecryptfs_dentry->d_name.name,
 				      lower_dir_dentry,
 				      ecryptfs_dentry->d_name.len);
-	mutex_unlock(&d_inode(lower_dir_dentry)->i_mutex);
+	inode_unlock(d_inode(lower_dir_dentry));
 	if (IS_ERR(lower_dentry)) {
 		rc = PTR_ERR(lower_dentry);
 		ecryptfs_printk(KERN_DEBUG, "%s: lookup_one_len() returned "
@@ -426,11 +426,11 @@
 		       "filename; rc = [%d]\n", __func__, rc);
 		goto out;
 	}
-	mutex_lock(&d_inode(lower_dir_dentry)->i_mutex);
+	inode_lock(d_inode(lower_dir_dentry));
 	lower_dentry = lookup_one_len(encrypted_and_encoded_name,
 				      lower_dir_dentry,
 				      encrypted_and_encoded_name_size);
-	mutex_unlock(&d_inode(lower_dir_dentry)->i_mutex);
+	inode_unlock(d_inode(lower_dir_dentry));
 	if (IS_ERR(lower_dentry)) {
 		rc = PTR_ERR(lower_dentry);
 		ecryptfs_printk(KERN_DEBUG, "%s: lookup_one_len() returned "
@@ -869,9 +869,9 @@
 	if (!rc && lower_ia.ia_valid & ATTR_SIZE) {
 		struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
 
-		mutex_lock(&d_inode(lower_dentry)->i_mutex);
+		inode_lock(d_inode(lower_dentry));
 		rc = notify_change(lower_dentry, &lower_ia, NULL);
-		mutex_unlock(&d_inode(lower_dentry)->i_mutex);
+		inode_unlock(d_inode(lower_dentry));
 	}
 	return rc;
 }
@@ -970,9 +970,9 @@
 	if (lower_ia.ia_valid & (ATTR_KILL_SUID | ATTR_KILL_SGID))
 		lower_ia.ia_valid &= ~ATTR_MODE;
 
-	mutex_lock(&d_inode(lower_dentry)->i_mutex);
+	inode_lock(d_inode(lower_dentry));
 	rc = notify_change(lower_dentry, &lower_ia, NULL);
-	mutex_unlock(&d_inode(lower_dentry)->i_mutex);
+	inode_unlock(d_inode(lower_dentry));
 out:
 	fsstack_copy_attr_all(inode, lower_inode);
 	return rc;
@@ -1048,10 +1048,10 @@
 		rc = -EOPNOTSUPP;
 		goto out;
 	}
-	mutex_lock(&d_inode(lower_dentry)->i_mutex);
+	inode_lock(d_inode(lower_dentry));
 	rc = d_inode(lower_dentry)->i_op->getxattr(lower_dentry, name, value,
 						   size);
-	mutex_unlock(&d_inode(lower_dentry)->i_mutex);
+	inode_unlock(d_inode(lower_dentry));
 out:
 	return rc;
 }
@@ -1075,9 +1075,9 @@
 		rc = -EOPNOTSUPP;
 		goto out;
 	}
-	mutex_lock(&d_inode(lower_dentry)->i_mutex);
+	inode_lock(d_inode(lower_dentry));
 	rc = d_inode(lower_dentry)->i_op->listxattr(lower_dentry, list, size);
-	mutex_unlock(&d_inode(lower_dentry)->i_mutex);
+	inode_unlock(d_inode(lower_dentry));
 out:
 	return rc;
 }
@@ -1092,9 +1092,9 @@
 		rc = -EOPNOTSUPP;
 		goto out;
 	}
-	mutex_lock(&d_inode(lower_dentry)->i_mutex);
+	inode_lock(d_inode(lower_dentry));
 	rc = d_inode(lower_dentry)->i_op->removexattr(lower_dentry, name);
-	mutex_unlock(&d_inode(lower_dentry)->i_mutex);
+	inode_unlock(d_inode(lower_dentry));
 out:
 	return rc;
 }