[dm-devel] [PATCH 2/2] dm log: remove struct dm_dirty_log_internal
Jonathan Brassow
jbrassow at redhat.com
Mon Mar 30 14:14:52 UTC 2009
Code looks good. I haven't tested.
brassow
On Mar 26, 2009, at 12:33 PM, Mike Snitzer wrote:
> 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 at redhat.com>
> ---
> drivers/md/dm-log.c | 60 +++++++++
> +-------------------------------
> include/linux/dm-dirty-log.h | 3 ++
> 2 files changed, 18 insertions(+), 45 deletions(-)
>
> diff --git a/drivers/md/dm-log.c b/drivers/md/dm-log.c
> index 094c8f0..f5e5e11 100644
> --- a/drivers/md/dm-log.c
> +++ b/drivers/md/dm-log.c
> @@ -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)
> + spin_lock(&_lock);
> + 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;
> }
> diff --git a/include/linux/dm-dirty-log.h b/include/linux/dm-dirty-
> log.h
> index a6600a5..5e8b11d 100644
> --- a/include/linux/dm-dirty-log.h
> +++ b/include/linux/dm-dirty-log.h
> @@ -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);
> --
> 1.6.0.6
>
> --
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> dm-devel at redhat.com
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