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>

1 files changed, 7 insertions, 31 deletions

diff --git a/fs/dlm/config.c b/fs/dlm/config.c
index 8e294fbbac39..519112168a9e 100644
--- a/fs/dlm/config.c
+++ b/fs/dlm/config.c
@@ -346,7 +346,6 @@ static struct config_group *make_cluster(struct config_group *g,
         void *gps = NULL;
 
         cl = kzalloc(sizeof(struct dlm_cluster), GFP_NOFS);
-        gps = kcalloc(3, sizeof(struct config_group *), GFP_NOFS);
         sps = kzalloc(sizeof(struct dlm_spaces), GFP_NOFS);
         cms = kzalloc(sizeof(struct dlm_comms), GFP_NOFS);
 
@@ -357,10 +356,8 @@ static struct config_group *make_cluster(struct config_group *g,
         config_group_init_type_name(&sps->ss_group, "spaces", &spaces_type);
         config_group_init_type_name(&cms->cs_group, "comms", &comms_type);
 
-        cl->group.default_groups = gps;
-        cl->group.default_groups[0] = &sps->ss_group;
-        cl->group.default_groups[1] = &cms->cs_group;
-        cl->group.default_groups[2] = NULL;
+        configfs_add_default_group(&sps->ss_group, &cl->group);
+        configfs_add_default_group(&cms->cs_group, &cl->group);
 
         cl->cl_tcp_port = dlm_config.ci_tcp_port;
         cl->cl_buffer_size = dlm_config.ci_buffer_size;
@@ -383,7 +380,6 @@ static struct config_group *make_cluster(struct config_group *g,
 
  fail:
         kfree(cl);
-        kfree(gps);
         kfree(sps);
         kfree(cms);
         return ERR_PTR(-ENOMEM);
@@ -392,14 +388,8 @@ static struct config_group *make_cluster(struct config_group *g,
 static void drop_cluster(struct config_group *g, struct config_item *i)
 {
         struct dlm_cluster *cl = config_item_to_cluster(i);
-        struct config_item *tmp;
-        int j;
 
-        for (j = 0; cl->group.default_groups[j]; j++) {
-                tmp = &cl->group.default_groups[j]->cg_item;
-                cl->group.default_groups[j] = NULL;
-                config_item_put(tmp);
-        }
+        configfs_remove_default_groups(&cl->group);
 
         space_list = NULL;
         comm_list = NULL;
@@ -410,7 +400,6 @@ static void drop_cluster(struct config_group *g, struct config_item *i)
 static void release_cluster(struct config_item *i)
 {
         struct dlm_cluster *cl = config_item_to_cluster(i);
-        kfree(cl->group.default_groups);
         kfree(cl);
 }
 
@@ -418,21 +407,17 @@ static struct config_group *make_space(struct config_group *g, const char *name)
 {
         struct dlm_space *sp = NULL;
         struct dlm_nodes *nds = NULL;
-        void *gps = NULL;
 
         sp = kzalloc(sizeof(struct dlm_space), GFP_NOFS);
-        gps = kcalloc(2, sizeof(struct config_group *), GFP_NOFS);
         nds = kzalloc(sizeof(struct dlm_nodes), GFP_NOFS);
 
-        if (!sp || !gps || !nds)
+        if (!sp || !nds)
                 goto fail;
 
         config_group_init_type_name(&sp->group, name, &space_type);
-        config_group_init_type_name(&nds->ns_group, "nodes", &nodes_type);
 
-        sp->group.default_groups = gps;
-        sp->group.default_groups[0] = &nds->ns_group;
-        sp->group.default_groups[1] = NULL;
+        config_group_init_type_name(&nds->ns_group, "nodes", &nodes_type);
+        configfs_add_default_group(&nds->ns_group, &sp->group);
 
         INIT_LIST_HEAD(&sp->members);
         mutex_init(&sp->members_lock);
@@ -441,7 +426,6 @@ static struct config_group *make_space(struct config_group *g, const char *name)
 
  fail:
         kfree(sp);
-        kfree(gps);
         kfree(nds);
         return ERR_PTR(-ENOMEM);
 }
@@ -449,24 +433,16 @@ static struct config_group *make_space(struct config_group *g, const char *name)
 static void drop_space(struct config_group *g, struct config_item *i)
 {
         struct dlm_space *sp = config_item_to_space(i);
-        struct config_item *tmp;
-        int j;
 
         /* assert list_empty(&sp->members) */
 
-        for (j = 0; sp->group.default_groups[j]; j++) {
-                tmp = &sp->group.default_groups[j]->cg_item;
-                sp->group.default_groups[j] = NULL;
-                config_item_put(tmp);
-        }
-
+        configfs_remove_default_groups(&sp->group);
         config_item_put(i);
 }
 
 static void release_space(struct config_item *i)
 {
         struct dlm_space *sp = config_item_to_space(i);
-        kfree(sp->group.default_groups);
         kfree(sp);
 }