From: Jonathan Brassow <jbrassow@redhat.com>
Remove internal module reference fields from the interface.
Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
---
drivers/md/dm-log.c | 123 +++++++++++++++++++++++++++++++++++++++-------------
drivers/md/dm-log.h | 2
2 files changed, 94 insertions(+), 31 deletions(-)
Index: linux-2.6.25/drivers/md/dm-log.c
===================================================================
--- linux-2.6.25.orig/drivers/md/dm-log.c 2008-04-24 18:00:30.000000000 +0100
+++ linux-2.6.25/drivers/md/dm-log.c 2008-04-24 18:00:31.000000000 +0100
@@ -16,34 +16,51 @@
#define DM_MSG_PREFIX "dirty region log"
+struct dm_dirty_log_internal {
+ struct dm_dirty_log_type *type;
+
+ struct list_head list;
+ long use;
+};
+
static LIST_HEAD(_log_types);
static DEFINE_SPINLOCK(_lock);
-static struct dm_dirty_log_type *_get_type(const char *type_name)
+static struct dm_dirty_log_internal *__find_dirty_log_type(const char *name)
{
- struct dm_dirty_log_type *type;
+ struct dm_dirty_log_internal *log_type;
+
+ list_for_each_entry(log_type, &_log_types, list)
+ if (!strcmp(name, log_type->type->name))
+ return log_type;
+
+ return NULL;
+}
+
+static struct dm_dirty_log_internal *_get_dirty_log_type(const char *name)
+{
+ struct dm_dirty_log_internal *log_type;
spin_lock(&_lock);
- list_for_each_entry (type, &_log_types, list)
- if (!strcmp(type_name, type->name)) {
- if (!type->use_count && !try_module_get(type->module)){
- spin_unlock(&_lock);
- return NULL;
- }
- type->use_count++;
- spin_unlock(&_lock);
- return type;
- }
+
+ log_type = __find_dirty_log_type(name);
+ if (log_type) {
+ if (!log_type->use && !try_module_get(log_type->type->module))
+ log_type = NULL;
+ else
+ log_type->use++;
+ }
spin_unlock(&_lock);
- return NULL;
+
+ return log_type;
}
/*
* get_type
* @type_name
*
- * Attempt to retrieve the dirty_log_type by name. If not already
+ * Attempt to retrieve the dm_dirty_log_type by name. If not already
* available, attempt to load the appropriate module.
*
* Log modules are named "dm-log-" followed by the 'type_name'.
@@ -59,11 +76,14 @@ static struct dm_dirty_log_type *_get_ty
static struct dm_dirty_log_type *get_type(const char *type_name)
{
char *p, *type_name_dup;
- struct dm_dirty_log_type *type;
+ struct dm_dirty_log_internal *log_type;
- type = _get_type(type_name);
- if (type)
- return type;
+ if (!type_name)
+ return NULL;
+
+ log_type = _get_dirty_log_type(type_name);
+ if (log_type)
+ return log_type->type;
type_name_dup = kstrdup(type_name, GFP_KERNEL);
if (!type_name_dup) {
@@ -73,50 +93,95 @@ static struct dm_dirty_log_type *get_typ
}
while (request_module("dm-log-%s", type_name_dup) ||
- !(type = _get_type(type_name))) {
+ !(log_type = _get_dirty_log_type(type_name))) {
p = strrchr(type_name_dup, '-');
if (!p)
break;
p[0] = '\0';
}
- if (!type)
+ if (!log_type)
DMWARN("Module for logging type \"%s\" not found.", type_name);
kfree(type_name_dup);
- return type;
+ return log_type ? log_type->type : NULL;
}
static void put_type(struct dm_dirty_log_type *type)
{
+ struct dm_dirty_log_internal *log_type;
+
+ if (!type)
+ return;
+
spin_lock(&_lock);
- if (!--type->use_count)
+ log_type = __find_dirty_log_type(type->name);
+ if (!log_type)
+ goto out;
+
+ if (!--log_type->use)
module_put(type->module);
+
+ BUG_ON(log_type->use < 0);
+
+out:
spin_unlock(&_lock);
}
+static struct dm_dirty_log_internal *_alloc_dirty_log_type(struct dm_dirty_log_type *type)
+{
+ struct dm_dirty_log_internal *log_type = kzalloc(sizeof(*log_type),
+ GFP_KERNEL);
+
+ if (log_type)
+ log_type->type = type;
+
+ return log_type;
+}
+
int dm_dirty_log_type_register(struct dm_dirty_log_type *type)
{
+ struct dm_dirty_log_internal *log_type = _alloc_dirty_log_type(type);
+ int r = 0;
+
+ if (!log_type)
+ return -ENOMEM;
+
spin_lock(&_lock);
- type->use_count = 0;
- list_add(&type->list, &_log_types);
+ if (!__find_dirty_log_type(type->name))
+ list_add(&log_type->list, &_log_types);
+ else {
+ kfree(log_type);
+ r = -EEXIST;
+ }
spin_unlock(&_lock);
- return 0;
+ return r;
}
EXPORT_SYMBOL(dm_dirty_log_type_register);
int dm_dirty_log_type_unregister(struct dm_dirty_log_type *type)
{
+ struct dm_dirty_log_internal *log_type;
+
spin_lock(&_lock);
- if (type->use_count)
- DMWARN("Attempt to unregister a log type that is still in use");
- else
- list_del(&type->list);
+ log_type = __find_dirty_log_type(type->name);
+ if (!log_type) {
+ spin_unlock(&_lock);
+ return -EINVAL;
+ }
+
+ if (log_type->use) {
+ spin_unlock(&_lock);
+ return -ETXTBSY;
+ }
+
+ list_del(&log_type->list);
spin_unlock(&_lock);
+ kfree(log_type);
return 0;
}
Index: linux-2.6.25/drivers/md/dm-log.h
===================================================================
--- linux-2.6.25.orig/drivers/md/dm-log.h 2008-04-24 18:00:29.000000000 +0100
+++ linux-2.6.25/drivers/md/dm-log.h 2008-04-24 18:00:31.000000000 +0100
@@ -25,10 +25,8 @@ struct dm_dirty_log {
};
struct dm_dirty_log_type {
- struct list_head list;
const char *name;
struct module *module;
- unsigned use_count;
int (*ctr)(struct dm_dirty_log *log, struct dm_target *ti,
unsigned argc, char **argv);