configfs: switch ->default groups to a linked list
Replace the current NULL-terminated array of default groups with a linked
list. This gets rid of lots of nasty code to size and/or dynamically
allocate the array.
While we're at it also provide a conveniant helper to remove the default
groups.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Felipe Balbi <balbi@kernel.org> [drivers/usb/gadget]
Acked-by: Joel Becker <jlbec@evilplan.org>
Acked-by: Nicholas Bellinger <nab@linux-iscsi.org>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
diff --git a/Documentation/filesystems/configfs/configfs.txt b/Documentation/filesystems/configfs/configfs.txt
index e5fe521..8ec9136 100644
--- a/Documentation/filesystems/configfs/configfs.txt
+++ b/Documentation/filesystems/configfs/configfs.txt
@@ -250,7 +250,8 @@
struct config_item cg_item;
struct list_head cg_children;
struct configfs_subsystem *cg_subsys;
- struct config_group **default_groups;
+ struct list_head default_groups;
+ struct list_head group_entry;
};
void config_group_init(struct config_group *group);
@@ -420,15 +421,15 @@
children of the parent group. If ct_group_ops->make_group() exists,
other child groups can be created on the parent group directly.
-A configfs subsystem specifies default groups by filling in the
-NULL-terminated array default_groups on the config_group structure.
-Each group in that array is populated in the configfs tree at the same
+A configfs subsystem specifies default groups by adding them using the
+configfs_add_default_group() function to the parent config_group
+structure. Each added group is populated in the configfs tree at the same
time as the parent group. Similarly, they are removed at the same time
as the parent. No extra notification is provided. When a ->drop_item()
method call notifies the subsystem the parent group is going away, it
also means every default group child associated with that parent group.
-As a consequence of this, default_groups cannot be removed directly via
+As a consequence of this, default groups cannot be removed directly via
rmdir(2). They also are not considered when rmdir(2) on the parent
group is checking for children.