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[PATCH] configfs+dlm: Rename config_group_find_obj and state semantics clearly

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Configfs being based upon sysfs code, config_group_find_obj() is probably
so named because of the similar kset_find_obj() in sysfs. However,
"kobject"s in sysfs become "config_item"s in configfs, so let's call it
config_group_find_item() instead, for sake of uniformity, and make
corresponding change in the users of this function.

BTW a crucial difference between kset_find_obj and config_group_find_item
is in locking expectations. kset_find_obj does its locking by itself, but
config_group_find_item expects the *caller* to do the locking. The reason
for this: kset's have their own locks, config_group's don't but instead
rely on the subsystem mutex. And, subsystem needn't necessarily be around
when config_group_find_item() is called.

So let's state these locking semantics explicitly, and rectify the comment,
otherwise bugs could continue to occur in future, as they did in the past
(refer commit d82b8191e238 in gfs2-2.6-fixes.git).

[ I also took the opportunity to fix some bad whitespace and
double-empty lines. --Joel ]

[ Conflict in fs/dlm/config.c with commit
  3168b0780d manually resolved. --Mark ]

Signed-off-by: Satyam Sharma <ssatyam@cse.iitk.ac.in>
Cc: David Teigland <teigland@redhat.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
This commit is contained in:
Satyam Sharma 2007-07-04 16:37:16 +05:30 committed by Mark Fasheh
parent 9b1d9aa4e9
commit 3fe6c5ce11
3 changed files with 11 additions and 16 deletions
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18
fs/configfs/item.c
View file

@ -183,27 +183,25 @@ void config_group_init(struct config_group *group)
INIT_LIST_HEAD(&group->cg_children);
}
/**
* config_group_find_obj - search for item in group.
* config_group_find_item - search for item in group.
* @group: group we're looking in.
* @name: item's name.
*
* Lock group via @group->cg_subsys, and iterate over @group->cg_list,
* looking for a matching config_item. If matching item is found
* take a reference and return the item.
* Iterate over @group->cg_list, looking for a matching config_item.
* If matching item is found take a reference and return the item.
* Caller must have locked group via @group->cg_subsys->su_mtx.
*/
struct config_item *config_group_find_obj(struct config_group *group,
const char * name)
struct config_item *config_group_find_item(struct config_group *group,
const char *name)
{
struct list_head * entry;
struct config_item * ret = NULL;
/* XXX LOCKING! */
list_for_each(entry,&group->cg_children) {
struct config_item * item = to_item(entry);
if (config_item_name(item) &&
!strcmp(config_item_name(item), name)) {
!strcmp(config_item_name(item), name)) {
ret = config_item_get(item);
break;
}
@ -215,4 +213,4 @@ EXPORT_SYMBOL(config_item_init);
EXPORT_SYMBOL(config_group_init);
EXPORT_SYMBOL(config_item_get);
EXPORT_SYMBOL(config_item_put);
EXPORT_SYMBOL(config_group_find_obj);
EXPORT_SYMBOL(config_group_find_item);

2
fs/dlm/config.c
View file

@ -752,7 +752,7 @@ static struct space *get_space(char *name)
return NULL;
down(&space_list->cg_subsys->su_sem);
i = config_group_find_obj(space_list, name);
i = config_group_find_item(space_list, name);
up(&space_list->cg_subsys->su_sem);
return to_space(i);

7
include/linux/configfs.h
View file

@ -86,12 +86,10 @@ struct config_item_type {
struct configfs_attribute **ct_attrs;
};
/**
* group - a group of config_items of a specific type, belonging
* to a specific subsystem.
*/
struct config_group {
struct config_item cg_item;
struct list_head cg_children;
@ -99,13 +97,11 @@ struct config_group {
struct config_group **default_groups;
};
extern void config_group_init(struct config_group *group);
extern void config_group_init_type_name(struct config_group *group,
const char *name,
struct config_item_type *type);
static inline struct config_group *to_config_group(struct config_item *item)
{
return item ? container_of(item,struct config_group,cg_item) : NULL;
@ -121,7 +117,8 @@ static inline void config_group_put(struct config_group *group)
config_item_put(&group->cg_item);
}
extern struct config_item *config_group_find_obj(struct config_group *, const char *);
extern struct config_item *config_group_find_item(struct config_group *,
const char *);
struct configfs_attribute {