configfs: Convert subsystem semaphore to mutex
Convert the su_sem member of struct configfs_subsystem to a struct
mutex, as that's what it is. Also convert all the users and update
Documentation/configfs.txt and Documentation/configfs_example.c
accordingly.
[ Conflict in fs/dlm/config.c with commit
3168b0780d06ace875696f8a648d04d6089654e5 manually resolved. --Mark ]
Inspired-by: Satyam Sharma <ssatyam@cse.iitk.ac.in>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
diff --git a/fs/configfs/dir.c b/fs/configfs/dir.c
index 5e6e37e..d3b1dbb 100644
--- a/fs/configfs/dir.c
+++ b/fs/configfs/dir.c
@@ -562,7 +562,7 @@
/*
* All of link_obj/unlink_obj/link_group/unlink_group require that
- * subsys->su_sem is held.
+ * subsys->su_mutex is held.
*/
static void unlink_obj(struct config_item *item)
@@ -783,7 +783,7 @@
snprintf(name, dentry->d_name.len + 1, "%s", dentry->d_name.name);
- down(&subsys->su_sem);
+ mutex_lock(&subsys->su_mutex);
group = NULL;
item = NULL;
if (type->ct_group_ops->make_group) {
@@ -797,7 +797,7 @@
if (item)
link_obj(parent_item, item);
}
- up(&subsys->su_sem);
+ mutex_unlock(&subsys->su_mutex);
kfree(name);
if (!item) {
@@ -841,13 +841,13 @@
out_unlink:
if (ret) {
/* Tear down everything we built up */
- down(&subsys->su_sem);
+ mutex_lock(&subsys->su_mutex);
if (group)
unlink_group(group);
else
unlink_obj(item);
client_drop_item(parent_item, item);
- up(&subsys->su_sem);
+ mutex_unlock(&subsys->su_mutex);
if (module_got)
module_put(owner);
@@ -910,17 +910,17 @@
if (sd->s_type & CONFIGFS_USET_DIR) {
configfs_detach_group(item);
- down(&subsys->su_sem);
+ mutex_lock(&subsys->su_mutex);
unlink_group(to_config_group(item));
} else {
configfs_detach_item(item);
- down(&subsys->su_sem);
+ mutex_lock(&subsys->su_mutex);
unlink_obj(item);
}
client_drop_item(parent_item, item);
- up(&subsys->su_sem);
+ mutex_unlock(&subsys->su_mutex);
/* Drop our reference from above */
config_item_put(item);
