[sheepdog] [PATCH 3/4 v3] sheep : add new strage type "tree"

[Saeki Masaki]

On 2015/03/21 21:02, Liu Yuan wrote:
> On Fri, Mar 20, 2015 at 06:39:08PM +0900, Saeki Masaki wrote:
>> Current sheepdog stores whole objects in single directory like "/var/lib/sheepdog/obj"
>> This mechanism is difficult to handle massive files when increasing cluster volume.
>>
>> In particular, inode object having special informations about VDI,
>> so it is preferable to divide.
>>
>> new storage type named "tree"
>> It separates the inode object and data object.
>>
>> How to use ,
>> specify the --store option at the time format
>> dog cluster format --store tree
>>
>> v2: refactor using common functions for store driver
>>      use check_store_type to identify tree store_driver
>>
>> v3: rename and little modify function
>>
>> Signed-off-by: Masaki Saeki <saeki.masaki at po.ntts.co.jp>
>> ---
>>   sheep/Makefile.am         |    2 +-
>>   sheep/sheep_priv.h        |   21 ++
>>   sheep/store/common.c      |    5 +
>>   sheep/store/md.c          |   14 +
>>   sheep/store/plain_store.c |    1 +
>>   sheep/store/tree_store.c  |  758 +++++++++++++++++++++++++++++++++++++++++++++
>>   6 files changed, 800 insertions(+), 1 deletions(-)
>>   create mode 100644 sheep/store/tree_store.c
>>
>> diff --git a/sheep/Makefile.am b/sheep/Makefile.am
>> index 3ddd761..9dedb03 100644
>> --- a/sheep/Makefile.am
>> +++ b/sheep/Makefile.am
>> @@ -28,7 +28,7 @@ sheep_SOURCES		= sheep.c group.c request.c gateway.c vdi.c \
>>   			  journal.c ops.c recovery.c cluster/local.c \
>>   			  object_cache.c object_list_cache.c \
>>   			  store/common.c store/md.c \
>> -			  store/plain_store.c \
>> +			  store/plain_store.c store/tree_store.c \
>>   			  config.c migrate.c
>>   if BUILD_HTTP
>> diff --git a/sheep/sheep_priv.h b/sheep/sheep_priv.h
>> index e58901f..3f1bf6e 100644
>> --- a/sheep/sheep_priv.h
>> +++ b/sheep/sheep_priv.h
>> @@ -84,6 +84,11 @@ enum REQUST_STATUS {
>>   	REQUEST_DROPPED
>>   };
>> +enum store_id {
>> +	PLAIN_STORE,
>> +	TREE_STORE
>> +};
>> +
>>   struct request_iocb {
>>   	uint32_t count;
>>   	int efd;
>> @@ -235,6 +240,7 @@ struct vdi_info {
>>   struct store_driver {
>>   	struct list_node list;
>> +	enum store_id id;
>>   	const char *name;
>>   	int (*init)(void);
>>   	bool (*exist)(uint64_t oid, uint8_t ec_index);
>> @@ -269,6 +275,20 @@ int default_format(void);
>>   int default_remove_object(uint64_t oid, uint8_t ec_index);
>>   int default_get_hash(uint64_t oid, uint32_t epoch, uint8_t *sha1);
>>   int default_purge_obj(void);
>> +
>> +int tree_init(void);
>> +bool tree_exist(uint64_t oid, uint8_t ec_index);
>> +int tree_create_and_write(uint64_t oid, const struct siocb *iocb);
>> +int tree_write(uint64_t oid, const struct siocb *iocb);
>> +int tree_read(uint64_t oid, const struct siocb *iocb);
>> +int tree_link(uint64_t oid, uint32_t tgt_epoch);
>> +int tree_update_epoch(uint32_t epoch);
>> +int tree_cleanup(void);
>> +int tree_format(void);
>> +int tree_remove_object(uint64_t oid, uint8_t ec_index);
>> +int tree_get_hash(uint64_t oid, uint32_t epoch, uint8_t *sha1);
>> +int tree_purge_obj(void);
>> +
>>   int for_each_object_in_wd(int (*func)(uint64_t, const char *, uint32_t,
>>   				      uint8_t, struct vnode_info *, void *),
>>   			  bool, void *);
>> @@ -404,6 +424,7 @@ void queue_cluster_request(struct request *req);
>>   int prepare_iocb(uint64_t oid, const struct siocb *iocb, bool create);
>>   int err_to_sderr(const char *path, uint64_t oid, int err);
>>   int discard(int fd, uint64_t start, uint32_t end);
>> +bool store_id_match(enum store_id id);
>>   int update_epoch_log(uint32_t epoch, struct sd_node *nodes, size_t nr_nodes);
>>   int inc_and_log_epoch(void);
>> diff --git a/sheep/store/common.c b/sheep/store/common.c
>> index 8959392..22a915f 100644
>> --- a/sheep/store/common.c
>> +++ b/sheep/store/common.c
>> @@ -102,6 +102,11 @@ int discard(int fd, uint64_t start, uint32_t end)
>>   	return ret;
>>   }
>> +bool store_id_match(enum store_id id)
>> +{
>> +	return (sd_store->id == id);
>> +}
>> +
>>   int update_epoch_log(uint32_t epoch, struct sd_node *nodes, size_t nr_nodes)
>>   {
>>   	int ret, len, nodes_len;
>> diff --git a/sheep/store/md.c b/sheep/store/md.c
>> index 87ab759..09438d8 100644
>> --- a/sheep/store/md.c
>> +++ b/sheep/store/md.c
>> @@ -212,6 +212,20 @@ static int for_each_object_in_path(const char *path,
>>   		if (unlikely(!strncmp(d->d_name, ".", 1)))
>>   			continue;
>> +		/* recursive call for tree store driver sub directories*/
>> +		if (store_id_match(TREE_STORE)) {
>
> I just wonder, if store_id_match is necessary since we can check the store
> driver by strcmp(name) as your first version. So what is motivation behind
> to use store_id_match()?

In the future, I'm hoping that that store driver will increase.
At that time, it is considered to be desirable keep abstracts

Thanks, Saeki.

>
> Thanks,
> Yuan
>