Commit ec44ab9d authored by Mike Snitzer's avatar Mike Snitzer Committed by Alasdair G Kergon
Browse files

dm log: remove struct dm_dirty_log_internal 



Remove the 'dm_dirty_log_internal' structure.  The resulting cleanup
eliminates extra memory allocations.  Therefore exposing the internal
list_head to the external 'dm_dirty_log_type' structure is a worthwhile
compromise.

Signed-off-by: default avatarMike Snitzer <snitzer@redhat.com>
Signed-off-by: default avatarAlasdair G Kergon <agk@redhat.com>
parent 84e67c93

drivers/md/dm-log.c

+14 −44
Original line number Diff line number Diff line
@@ -16,34 +16,28 @@ 


#define DM_MSG_PREFIX "dirty region log"



struct dm_dirty_log_internal {

	struct dm_dirty_log_type *type;



	struct list_head list;

};



static LIST_HEAD(_log_types);

static DEFINE_SPINLOCK(_lock);



static struct dm_dirty_log_internal *__find_dirty_log_type(const char *name)

static struct dm_dirty_log_type *__find_dirty_log_type(const char *name)

{

	struct dm_dirty_log_internal *log_type;

	struct dm_dirty_log_type *log_type;



	list_for_each_entry(log_type, &_log_types, list)

		if (!strcmp(name, log_type->type->name))

		if (!strcmp(name, log_type->name))

			return log_type;



	return NULL;

}



static struct dm_dirty_log_internal *_get_dirty_log_type(const char *name)

static struct dm_dirty_log_type *_get_dirty_log_type(const char *name)

{

	struct dm_dirty_log_internal *log_type;

	struct dm_dirty_log_type *log_type;



	spin_lock(&_lock);



	log_type = __find_dirty_log_type(name);

	if (log_type && !try_module_get(log_type->type->module))

	if (log_type && !try_module_get(log_type->module))

		log_type = NULL;



	spin_unlock(&_lock);
@@ -71,14 +65,14 @@ static struct dm_dirty_log_internal *_get_dirty_log_type(const char *name) 
static struct dm_dirty_log_type *get_type(const char *type_name)

{

	char *p, *type_name_dup;

	struct dm_dirty_log_internal *log_type;

	struct dm_dirty_log_type *log_type;



	if (!type_name)

		return NULL;



	log_type = _get_dirty_log_type(type_name);

	if (log_type)

		return log_type->type;

		return log_type;



	type_name_dup = kstrdup(type_name, GFP_KERNEL);

	if (!type_name_dup) {
@@ -100,19 +94,16 @@ static struct dm_dirty_log_type *get_type(const char *type_name) 


	kfree(type_name_dup);



	return log_type ? log_type->type : NULL;

	return log_type;

}



static void put_type(struct dm_dirty_log_type *type)

{

	struct dm_dirty_log_internal *log_type;



	if (!type)

		return;



	spin_lock(&_lock);

	log_type = __find_dirty_log_type(type->name);

	if (!log_type)

	if (!__find_dirty_log_type(type->name))

		goto out;



	module_put(type->module);
@@ -121,32 +112,15 @@ 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);

	if (!__find_dirty_log_type(type->name))

		list_add(&log_type->list, &_log_types);

	else {

		kfree(log_type);

		list_add(&type->list, &_log_types);

	else

		r = -EEXIST;

	}

	spin_unlock(&_lock);



	return r;
@@ -155,20 +129,16 @@ 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);



	log_type = __find_dirty_log_type(type->name);

	if (!log_type) {

	if (!__find_dirty_log_type(type->name)) {

		spin_unlock(&_lock);

		return -EINVAL;

	}



	list_del(&log_type->list);

	list_del(&type->list);



	spin_unlock(&_lock);

	kfree(log_type);



	return 0;

}

include/linux/dm-dirty-log.h

+3 −0
Original line number Diff line number Diff line
@@ -28,6 +28,9 @@ struct dm_dirty_log_type { 
	const char *name;

	struct module *module;



	/* For internal device-mapper use */

	struct list_head list;



	int (*ctr)(struct dm_dirty_log *log, struct dm_target *ti,

		   unsigned argc, char **argv);

	void (*dtr)(struct dm_dirty_log *log);

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