dm log: auto load modules

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

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
This commit is contained in:
Jonathan Brassow 2008-02-08 02:11:19 +00:00 committed by Alasdair G Kergon
parent 304f3f6a58
commit fb8b284806

View File

@ -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);