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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: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
This commit is contained in:
Mike Snitzer 2009-04-02 19:55:30 +01:00 committed by Alasdair G Kergon
parent 84e67c9319
commit ec44ab9d66
2 changed files with 17 additions and 44 deletions
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58
drivers/md/dm-log.c
View File

@ -16,34 +16,28 @@
#define DM_MSG_PREFIX "dirty region log" #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 LIST_HEAD(_log_types);
static DEFINE_SPINLOCK(_lock); 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) 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 log_type;
return NULL; 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); spin_lock(&_lock);
log_type = __find_dirty_log_type(name); 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; log_type = NULL;
spin_unlock(&_lock); 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) static struct dm_dirty_log_type *get_type(const char *type_name)
{ {
char *p, *type_name_dup; char *p, *type_name_dup;
struct dm_dirty_log_internal *log_type; struct dm_dirty_log_type *log_type;
if (!type_name) if (!type_name)
return NULL; return NULL;
log_type = _get_dirty_log_type(type_name); log_type = _get_dirty_log_type(type_name);
if (log_type) if (log_type)
return log_type->type; return log_type;
type_name_dup = kstrdup(type_name, GFP_KERNEL); type_name_dup = kstrdup(type_name, GFP_KERNEL);
if (!type_name_dup) { if (!type_name_dup) {
@ -100,19 +94,16 @@ static struct dm_dirty_log_type *get_type(const char *type_name)
kfree(type_name_dup); kfree(type_name_dup);
return log_type ? log_type->type : NULL; return log_type;
} }
static void put_type(struct dm_dirty_log_type *type) static void put_type(struct dm_dirty_log_type *type)
{ {
struct dm_dirty_log_internal *log_type;
if (!type) if (!type)
return; return;
spin_lock(&_lock); spin_lock(&_lock);
log_type = __find_dirty_log_type(type->name); if (!__find_dirty_log_type(type->name))
if (!log_type)
goto out; goto out;
module_put(type->module); module_put(type->module);
@ -121,32 +112,15 @@ out:
spin_unlock(&_lock); 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) 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; int r = 0;
if (!log_type)
return -ENOMEM;
spin_lock(&_lock); spin_lock(&_lock);
if (!__find_dirty_log_type(type->name)) if (!__find_dirty_log_type(type->name))
list_add(&log_type->list, &_log_types); list_add(&type->list, &_log_types);
else { else
kfree(log_type);
r = -EEXIST; r = -EEXIST;
}
spin_unlock(&_lock); spin_unlock(&_lock);
return r; 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) int dm_dirty_log_type_unregister(struct dm_dirty_log_type *type)
{ {
struct dm_dirty_log_internal *log_type;
spin_lock(&_lock); spin_lock(&_lock);
log_type = __find_dirty_log_type(type->name); if (!__find_dirty_log_type(type->name)) {
if (!log_type) {
spin_unlock(&_lock); spin_unlock(&_lock);
return -EINVAL; return -EINVAL;
} }
list_del(&log_type->list); list_del(&type->list);
spin_unlock(&_lock); spin_unlock(&_lock);
kfree(log_type);
return 0; return 0;
} }

3
include/linux/dm-dirty-log.h
View File

@ -28,6 +28,9 @@ struct dm_dirty_log_type {
const char *name; const char *name;
struct module *module; struct module *module;
/* For internal device-mapper use */
struct list_head list;
int (*ctr)(struct dm_dirty_log *log, struct dm_target *ti, int (*ctr)(struct dm_dirty_log *log, struct dm_target *ti,
unsigned argc, char **argv); unsigned argc, char **argv);
void (*dtr)(struct dm_dirty_log *log); void (*dtr)(struct dm_dirty_log *log);