[sheepdog] [PATCH 1/2] sheep: change terminology for vdi state synchronization during node joining

Hitoshi Mitake mitake.hitoshi at gmail.com
Tue Jun 9 16:46:06 CEST 2015


At Mon,  8 Jun 2015 22:34:44 +0900,
Hitoshi Mitake wrote:
> 
> Currently, sheepdog is using a word "snapshot" as a terminology for
> vdi state synchronization during node joining
> (e.g. SD_OP_VDI_STATE_SNAPSHOT_CTL). It is confusing because the word
> snapshot resembles snapshot of VDIs.
> 
> This patch changes the terminology to checkpoint based on the famous
> textbook:
> http://www.cs.cornell.edu/projects/quicksilver/public_pdfs/History.pdf
> 
> Signed-off-by: Hitoshi Mitake <mitake.hitoshi at lab.ntt.co.jp>
> ---
>  include/internal_proto.h |  2 +-
>  include/sheepdog_proto.h |  2 +-
>  sheep/group.c            | 24 +++++++++---------
>  sheep/ops.c              | 22 ++++++++---------
>  sheep/sheep_priv.h       |  8 +++---
>  sheep/vdi.c              | 63 ++++++++++++++++++++++++------------------------
>  6 files changed, 61 insertions(+), 60 deletions(-)

Applied this series with trivial style fix.

Thanks,
Hitoshi

> 
> diff --git a/include/internal_proto.h b/include/internal_proto.h
> index a1a073d..b3cbbc5 100644
> --- a/include/internal_proto.h
> +++ b/include/internal_proto.h
> @@ -108,7 +108,7 @@
>  #define SD_OP_ALLOW_INODE_UPDATE      0xC4
>  #define SD_OP_REPAIR_REPLICA	0xC5
>  #define SD_OP_OIDS_EXIST	0xC6
> -#define SD_OP_VDI_STATE_SNAPSHOT_CTL  0xC7
> +#define SD_OP_VDI_STATE_CHECKPOINT_CTL  0xC7
>  #define SD_OP_INODE_COHERENCE 0xC8
>  #define SD_OP_READ_DEL_VDIS  0xC9
>  #define SD_OP_GET_RECOVERY      0xCA
> diff --git a/include/sheepdog_proto.h b/include/sheepdog_proto.h
> index 4a6edbe..4b9dacc 100644
> --- a/include/sheepdog_proto.h
> +++ b/include/sheepdog_proto.h
> @@ -198,7 +198,7 @@ struct sd_req {
>  		struct {
>  			uint32_t        get; /* 0 means free, 1 means get */
>  			uint32_t        tgt_epoch;
> -		} vdi_state_snapshot;
> +		} vdi_state_checkpoint;
>  		struct {
>  			/* 1 means validate, 0 means invalidate */
>  			uint32_t        vid;
> diff --git a/sheep/group.c b/sheep/group.c
> index 7c7cb6d..e342453 100644
> --- a/sheep/group.c
> +++ b/sheep/group.c
> @@ -710,18 +710,18 @@ static struct vdi_state *do_cinfo_collection_work(uint32_t epoch,
>  	vs = xcalloc(rlen, sizeof(*vs));
>  
>  retry:
> -	sd_init_req(&hdr, SD_OP_VDI_STATE_SNAPSHOT_CTL);
> -	hdr.vdi_state_snapshot.get = 1;
> -	hdr.vdi_state_snapshot.tgt_epoch = epoch;
> +	sd_init_req(&hdr, SD_OP_VDI_STATE_CHECKPOINT_CTL);
> +	hdr.vdi_state_checkpoint.get = 1;
> +	hdr.vdi_state_checkpoint.tgt_epoch = epoch;
>  	hdr.data_length = rlen;
>  
>  	ret = sheep_exec_req(&n->nid, &hdr, (char *)vs);
>  	if (ret == SD_RES_SUCCESS) {
> -		sd_debug("succeed to obtain snapshot of vdi states");
> +		sd_debug("succeed to obtain checkpoint of vdi states");
>  		*nr_vdi_states = rsp->data_length / sizeof(*vs);
>  		return vs;
>  	} else if (ret == SD_RES_BUFFER_SMALL) {
> -		sd_debug("buffer is small for obtaining snapshot of vdi states,"
> +		sd_debug("buffer is small for obtaining checkpoint of vdi states,"
>  			 " doubling it (%lu -> %lu)", rlen * sizeof(*vs),
>  			 rlen * 2 * sizeof(*vs));
>  		rlen *= 2;
> @@ -729,7 +729,7 @@ retry:
>  		goto retry;
>  	}
>  
> -	sd_err("failed to obtain snapshot of vdi states from node %s",
> +	sd_err("failed to obtain checkpoint of vdi states from node %s",
>  	       node_to_str(n));
>  	return NULL;
>  }
> @@ -756,7 +756,7 @@ static void cinfo_collection_work(struct work *work)
>  			goto get_succeed;
>  	}
>  
> -	panic("getting a snapshot of vdi state at epoch %d failed", w->epoch);
> +	panic("getting a checkpoint of vdi state at epoch %d failed", w->epoch);
>  
>  get_succeed:
>  	w->nr_vdi_states = nr_vdi_states;
> @@ -768,13 +768,13 @@ get_succeed:
>  		if (node_is_local(n))
>  			continue;
>  
> -		sd_init_req(&hdr, SD_OP_VDI_STATE_SNAPSHOT_CTL);
> -		hdr.vdi_state_snapshot.get = 0;
> -		hdr.vdi_state_snapshot.tgt_epoch = w->epoch;
> +		sd_init_req(&hdr, SD_OP_VDI_STATE_CHECKPOINT_CTL);
> +		hdr.vdi_state_checkpoint.get = 0;
> +		hdr.vdi_state_checkpoint.tgt_epoch = w->epoch;
>  
>  		ret = sheep_exec_req(&n->nid, &hdr, (char *)vs);
>  		if (ret != SD_RES_SUCCESS)
> -			sd_err("error at freeing a snapshot of vdi state"
> +			sd_err("error at freeing a checkpoint of vdi state"
>  			       " at epoch %d", w->epoch);
>  	}
>  
> @@ -906,7 +906,7 @@ static void update_cluster_info(const struct cluster_info *cinfo,
>  		}
>  	} else {
>  		if (0 < cinfo->epoch && cinfo->status == SD_STATUS_OK)
> -			take_vdi_state_snapshot(cinfo->epoch - 1);
> +			create_vdi_state_checkpoint(cinfo->epoch - 1);
>  	}
>  
>  	sockfd_cache_add(&joined->nid);
> diff --git a/sheep/ops.c b/sheep/ops.c
> index 7b92f8c..223994c 100644
> --- a/sheep/ops.c
> +++ b/sheep/ops.c
> @@ -1454,30 +1454,30 @@ static int cluster_release_vdi_main(const struct sd_req *req,
>  	return SD_RES_SUCCESS;
>  }
>  
> -static int local_vdi_state_snapshot_ctl(const struct sd_req *req,
> +static int local_vdi_state_checkpoint_ctl(const struct sd_req *req,
>  					struct sd_rsp *rsp, void *data,
>  					const struct sd_node *sender)
>  {
> -	bool get = !!req->vdi_state_snapshot.get;
> -	int epoch = req->vdi_state_snapshot.tgt_epoch;
> +	bool get = !!req->vdi_state_checkpoint.get;
> +	int epoch = req->vdi_state_checkpoint.tgt_epoch;
>  	int ret, length = 0;
>  
> -	sd_info("%s vdi state snapshot at epoch %d",
> +	sd_info("%s vdi state checkpoint at epoch %d",
>  		get ? "getting" : "freeing", epoch);
>  
>  	if (get) {
> -		ret = get_vdi_state_snapshot(epoch, data, req->data_length,
> -					     &length);
> +		ret = get_vdi_state_checkpoint(epoch, data, req->data_length,
> +					       &length);
>  		if (ret == SD_RES_SUCCESS)
>  			rsp->data_length = length;
>  		else {
> -			sd_info("failed to get vdi state snapshot: %s",
> +			sd_info("failed to get vdi state checkpoint: %s",
>  			       sd_strerror(ret));
>  
>  			return ret;
>  		}
>  	} else
> -		free_vdi_state_snapshot(epoch);
> +		free_vdi_state_checkpoint(epoch);
>  
>  	return SD_RES_SUCCESS;
>  }
> @@ -1948,10 +1948,10 @@ static struct sd_op_template sd_ops[] = {
>  		.process_work = local_repair_replica,
>  	},
>  
> -	[SD_OP_VDI_STATE_SNAPSHOT_CTL] = {
> -		.name = "VDI_STATE_SNAPSHOT_CTL",
> +	[SD_OP_VDI_STATE_CHECKPOINT_CTL] = {
> +		.name = "VDI_STATE_CHECKPOINT_CTL",
>  		.type = SD_OP_TYPE_LOCAL,
> -		.process_main = local_vdi_state_snapshot_ctl,
> +		.process_main = local_vdi_state_checkpoint_ctl,
>  	},
>  
>  	[SD_OP_GET_CLUSTER_DEFAULT] = {
> diff --git a/sheep/sheep_priv.h b/sheep/sheep_priv.h
> index 7becf6e..8c173a9 100644
> --- a/sheep/sheep_priv.h
> +++ b/sheep/sheep_priv.h
> @@ -371,10 +371,10 @@ int sd_create_hyper_volume(const char *name, uint32_t *vdi_id);
>  bool vdi_lock(uint32_t vid, const struct node_id *owner, int type);
>  bool vdi_unlock(uint32_t vid, const struct node_id *owner, int type);
>  void apply_vdi_lock_state(struct vdi_state *vs);
> -void take_vdi_state_snapshot(int epoch);
> -int get_vdi_state_snapshot(int epoch, void *data, int data_len_max,
> -			   int *data_len_result);
> -void free_vdi_state_snapshot(int epoch);
> +void create_vdi_state_checkpoint(int epoch);
> +int get_vdi_state_checkpoint(int epoch, void *data, int data_len_max,
> +			     int *data_len_result);
> +void free_vdi_state_checkpoint(int epoch);
>  void log_vdi_op_lock(uint32_t vid, const struct node_id *owner, int type);
>  void log_vdi_op_unlock(uint32_t vid, const struct node_id *owner, int type);
>  void play_logged_vdi_ops(void);
> diff --git a/sheep/vdi.c b/sheep/vdi.c
> index 7f6cf67..aeb6e68 100644
> --- a/sheep/vdi.c
> +++ b/sheep/vdi.c
> @@ -2118,83 +2118,84 @@ out:
>  	return ret;
>  }
>  
> -struct vdi_state_snapshot {
> +struct vdi_state_checkpoint {
>  	int epoch, nr_vs;
>  	struct vdi_state *vs;
>  
>  	struct list_node list;
>  };
>  
> -static LIST_HEAD(vdi_state_snapshot_list);
> +static LIST_HEAD(vdi_state_checkpoint_list);
>  
> -main_fn void take_vdi_state_snapshot(int epoch)
> +main_fn void create_vdi_state_checkpoint(int epoch)
>  {
>  	/*
> -	 * take a snapshot of current vdi state and associate it with
> +	 * take a checkpoint of current vdi state and associate it with
>  	 * the given epoch
>  	 */
> -	struct vdi_state_snapshot *snapshot;
> +	struct vdi_state_checkpoint *checkpoint;
>  
> -	list_for_each_entry(snapshot, &vdi_state_snapshot_list, list) {
> -		if (snapshot->epoch == epoch) {
> -			sd_debug("duplicate snapshot of epoch %d", epoch);
> +	list_for_each_entry(checkpoint, &vdi_state_checkpoint_list, list) {
> +		if (checkpoint->epoch == epoch) {
> +			sd_debug("duplicate checkpoint of epoch %d", epoch);
>  			return;
>  		}
>  
>  	}
>  
> -	snapshot = xzalloc(sizeof(*snapshot));
> -	snapshot->epoch = epoch;
> -	snapshot->vs = fill_vdi_state_list_with_alloc(&snapshot->nr_vs);
> -	INIT_LIST_NODE(&snapshot->list);
> -	list_add_tail(&snapshot->list, &vdi_state_snapshot_list);
> +	checkpoint = xzalloc(sizeof(*checkpoint));
> +	checkpoint->epoch = epoch;
> +	checkpoint->vs = fill_vdi_state_list_with_alloc(&checkpoint->nr_vs);
> +	INIT_LIST_NODE(&checkpoint->list);
> +	list_add_tail(&checkpoint->list, &vdi_state_checkpoint_list);
>  
> -	sd_debug("taking a snapshot of vdi state at epoch %d succeed", epoch);
> -	sd_debug("a number of vdi state: %d", snapshot->nr_vs);
> +	sd_debug("creating a checkpoint of vdi state at epoch %d succeed",
> +		 epoch);
> +	sd_debug("a number of vdi state: %d", checkpoint->nr_vs);
>  }
>  
> -main_fn int get_vdi_state_snapshot(int epoch, void *data, int data_len_max,
> -				   int *data_len_result)
> +main_fn int get_vdi_state_checkpoint(int epoch, void *data, int data_len_max,
> +				     int *data_len_result)
>  {
> -	struct vdi_state_snapshot *snapshot;
> +	struct vdi_state_checkpoint *checkpoint;
>  	int len;
>  
> -	list_for_each_entry(snapshot, &vdi_state_snapshot_list, list) {
> -		if (snapshot->epoch == epoch)
> +	list_for_each_entry(checkpoint, &vdi_state_checkpoint_list, list) {
> +		if (checkpoint->epoch == epoch)
>  			goto found;
>  	}
>  
> -	sd_info("get request for not prepared vdi state snapshot, epoch: %d",
> +	sd_info("get request for not prepared vdi state checkpoint, epoch: %d",
>  		epoch);
>  	return SD_RES_AGAIN;
>  
>  found:
> -	len = sizeof(*snapshot->vs) * snapshot->nr_vs;
> +	len = sizeof(*checkpoint->vs) * checkpoint->nr_vs;
>  	if (data_len_max < len) {
>  		sd_info("maximum allowed length: %d, required length: %d",
>  			data_len_max, len);
>  		return SD_RES_BUFFER_SMALL;
>  	}
>  
> -	memcpy(data, snapshot->vs, len);
> +	memcpy(data, checkpoint->vs, len);
>  	return SD_RES_SUCCESS;
>  }
>  
> -main_fn void free_vdi_state_snapshot(int epoch)
> +main_fn void free_vdi_state_checkpoint(int epoch)
>  {
> -	struct vdi_state_snapshot *snapshot;
> +	struct vdi_state_checkpoint *checkpoint;
>  
> -	list_for_each_entry(snapshot, &vdi_state_snapshot_list, list) {
> -		if (snapshot->epoch == epoch) {
> -			list_del(&snapshot->list);
> -			free(snapshot->vs);
> -			free(snapshot);
> +	list_for_each_entry(checkpoint, &vdi_state_checkpoint_list, list) {
> +		if (checkpoint->epoch == epoch) {
> +			list_del(&checkpoint->list);
> +			free(checkpoint->vs);
> +			free(checkpoint);
>  
>  			return;
>  		}
>  	}
>  
> -	panic("invalid free request for vdi state snapshot, epoch: %d", epoch);
> +	panic("invalid free request for vdi state checkpoint, epoch: %d", epoch);
>  }
>  
>  static int clean_matched_obj(uint64_t oid, const char *path,
> -- 
> 1.9.1
> 


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