Commit fb8b2848 authored by Jonathan Brassow's avatar Jonathan Brassow Committed by Alasdair G Kergon
Browse files

dm log: auto load modules 



If the log type is not recognised, attempt to load the module
'dm-log-<type>.ko'.

Signed-off-by: default avatarJonathan Brassow <jbrassow@redhat.com>
Signed-off-by: default avatarAlasdair G Kergon <agk@redhat.com>
parent 304f3f6a

drivers/md/dm-log.c

+50 −1
Original line number Diff line number Diff line
@@ -41,7 +41,7 @@ int dm_unregister_dirty_log_type(struct dirty_log_type *type) 
	return 0;

}



static struct dirty_log_type *get_type(const char *type_name)

static struct dirty_log_type *_get_type(const char *type_name)

{

	struct dirty_log_type *type;
@@ -61,6 +61,55 @@ static struct dirty_log_type *get_type(const char *type_name) 
	return NULL;

}



/*

 * get_type

 * @type_name

 *

 * Attempt to retrieve the 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'.

 * Modules may contain multiple types.

 * This function will first try the module "dm-log-<type_name>",

 * then truncate 'type_name' on the last '-' and try again.

 *

 * For example, if type_name was "clustered-disk", it would search

 * 'dm-log-clustered-disk' then 'dm-log-clustered'.

 *

 * Returns: dirty_log_type* on success, NULL on failure

 */

static struct dirty_log_type *get_type(const char *type_name)

{

	char *p, *type_name_dup;

	struct dirty_log_type *type;



	type = _get_type(type_name);

	if (type)

		return type;



	type_name_dup = kstrdup(type_name, GFP_KERNEL);

	if (!type_name_dup) {

		DMWARN("No memory left to attempt log module load for \"%s\"",

		       type_name);

		return NULL;

	}



	while (request_module("dm-log-%s", type_name_dup) ||

	       !(type = _get_type(type_name))) {

		p = strrchr(type_name_dup, '-');

		if (!p)

			break;

		p[0] = '\0';

	}



	if (!type)

		DMWARN("Module for logging type \"%s\" not found.", type_name);



	kfree(type_name_dup);



	return type;

}



static void put_type(struct dirty_log_type *type)

{

	spin_lock(&_lock);