Messages in this thread Patch in this message | | | From | Satyam Sharma <> | Date | Wed, 04 Jul 2007 16:37:16 +0530 | Subject | [PATCH -mm 3/3] configfs+dlm: Rename config_group_find_obj and state semantics clearly |
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From: Satyam Sharma <ssatyam@cse.iitk.ac.in>
[3/3] configfs+dlm: Rename config_group_find_obj and state semantics clearly
[ Ok, this might sound like a gratuitous patch, but I believe there are good reasons for it. ]
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. ]
Signed-off-by: Satyam Sharma <ssatyam@cse.iitk.ac.in> Cc: Joel Becker <joel.becker@oracle.com> Cc: David Teigland <teigland@redhat.com>
---
fs/configfs/item.c | 18 ++++++++---------- fs/dlm/config.c | 2 +- include/linux/configfs.h | 8 ++------ 3 files changed, 11 insertions(+), 17 deletions(-)
---
diff -ruNp a/fs/configfs/item.c b/fs/configfs/item.c --- a/fs/configfs/item.c 2007-06-28 17:32:57.000000000 +0530 +++ b/fs/configfs/item.c 2007-07-03 19:42:00.000000000 +0530 @@ -183,27 +183,25 @@ void config_group_init(struct config_gro 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); diff -ruNp a/fs/dlm/config.c b/fs/dlm/config.c --- a/fs/dlm/config.c 2007-07-03 18:52:25.000000000 +0530 +++ b/fs/dlm/config.c 2007-07-03 19:43:57.000000000 +0530 @@ -752,7 +752,7 @@ static struct space *get_space(char *nam return NULL; mutex_lock(&space_list->cg_subsys->su_mtx); - i = config_group_find_obj(space_list, name); + i = config_group_find_item(space_list, name); mutex_unlock(&space_list->cg_subsys->su_mtx); return to_space(i); diff -ruNp a/include/linux/configfs.h b/include/linux/configfs.h --- a/include/linux/configfs.h 2007-07-03 18:52:25.000000000 +0530 +++ b/include/linux/configfs.h 2007-07-03 19:46:56.000000000 +0530 @@ -85,12 +85,10 @@ 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; @@ -98,13 +96,11 @@ 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; @@ -120,8 +116,8 @@ static inline void config_group_put(stru 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 { const char *ca_name; - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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