configfs: Allow ->make_item() and ->make_group() to return detailed errors.

The configfs operations ->make_item() and ->make_group() currently
return a new item/group.  A return of NULL signifies an error.  Because
of this, -ENOMEM is the only return code bubbled up the stack.

Multiple folks have requested the ability to return specific error codes
when these operations fail.  This patch adds that ability by changing the
->make_item/group() ops to return an int.

Also updated are the in-kernel users of configfs.

Signed-off-by: Joel Becker <joel.becker@oracle.com>

1 files changed, 6 insertions, 4 deletions

diff --git a/Documentation/filesystems/configfs/configfs.txt b/Documentation/filesystems/configfs/configfs.txt
index 44c97e6accb2..15838d706ea2 100644
--- a/Documentation/filesystems/configfs/configfs.txt
+++ b/Documentation/filesystems/configfs/configfs.txt
@@ -233,10 +233,12 @@ accomplished via the group operations specified on the group's
 config_item_type.
 
         struct configfs_group_operations {
-                struct config_item *(*make_item)(struct config_group *group,
-                                                 const char *name);
-                struct config_group *(*make_group)(struct config_group *group,
-                                                   const char *name);
+                int (*make_item)(struct config_group *group,
+                                 const char *name,
+                                 struct config_item **new_item);
+                int (*make_group)(struct config_group *group,
+                                  const char *name,
+                                  struct config_group **new_group);
                 int (*commit_item)(struct config_item *item);
                 void (*disconnect_notify)(struct config_group *group,
                                           struct config_item *item);