[sheepdog] [PATCH] sheep: don't clean stale dir if there are no enough nodes

[Hitoshi Mitake]

At Thu,  4 Dec 2014 16:05:39 +0900,
Hitoshi Mitake wrote:
> 
> Current recovery process has a bug of data wipe. After an epoch which
> consists only gateway nodes, objects stored in dying nodes will be
> wiped when the nodes join to the cluster. This patch solves the
> problem with removing invalid call of sd_store->cleanup() during
> recovery completion.
> 
> Related issue:
> https://bugs.launchpad.net/sheepdog-project/+bug/1327037
> 
> Cc: duron800 at qq.com
> Cc: 张扬 <3100100878 at zju.edu.cn>
> Cc: 徐小龙 <nxtxiaolong at gmail.com>
> Signed-off-by: Hitoshi Mitake <mitake.hitoshi at lab.ntt.co.jp>
> ---
>  sheep/ops.c        |  5 +++--
>  sheep/sheep_priv.h |  1 +
>  sheep/vdi.c        | 12 ++++++++++++
>  3 files changed, 16 insertions(+), 2 deletions(-)

张扬, 徐小龙, could you test this patch if you have time? It would be
the simplest solution for the problem.

Thanks,
Hitoshi

> 
> diff --git a/sheep/ops.c b/sheep/ops.c
> index a617a83..b418bda 100644
> --- a/sheep/ops.c
> +++ b/sheep/ops.c
> @@ -726,8 +726,9 @@ static int cluster_recovery_completion(const struct sd_req *req,
>  			sd_notice("all nodes are recovered, epoch %d", epoch);
>  			last_gathered_epoch = epoch;
>  			/* sd_store can be NULL if this node is a gateway */
> -			if (vnode_info->nr_zones >= ec_max_data_strip &&
> -			    sd_store && sd_store->cleanup)
> +			if (vnode_info->nr_zones >=
> +			    max(ec_max_data_strip, max_nr_copies)
> +			    && sd_store && sd_store->cleanup)
>  				sd_store->cleanup();
>  		}
>  	}
> diff --git a/sheep/sheep_priv.h b/sheep/sheep_priv.h
> index 5fc6b90..699f352 100644
> --- a/sheep/sheep_priv.h
> +++ b/sheep/sheep_priv.h
> @@ -357,6 +357,7 @@ int inode_coherence_update(uint32_t vid, bool validate,
>  void remove_node_from_participants(const struct node_id *left);
>  
>  extern int ec_max_data_strip;
> +extern int max_nr_copies;
>  
>  int read_vdis(char *data, int len, unsigned int *rsp_len);
>  int read_del_vdis(char *data, int len, unsigned int *rsp_len);
> diff --git a/sheep/vdi.c b/sheep/vdi.c
> index 1c8fb36..d815196 100644
> --- a/sheep/vdi.c
> +++ b/sheep/vdi.c
> @@ -40,6 +40,12 @@ static struct sd_rw_lock vdi_state_lock = SD_RW_LOCK_INITIALIZER;
>   */
>  int ec_max_data_strip;
>  
> +/*
> + * max_nr_copies represent max number of copies of replicated VDIs. It is used
> + * for the same purpose of ec_max_data_strip.
> + */
> +int max_nr_copies;
> +
>  int sheep_bnode_writer(uint64_t oid, void *mem, unsigned int len,
>  		       uint64_t offset, uint32_t flags, int copies,
>  		       int copy_policy, bool create, bool direct)
> @@ -171,6 +177,12 @@ int add_vdi_state(uint32_t vid, int nr_copies, bool snapshot, uint8_t cp)
>  		sd_mutex_lock(&m);
>  		ec_max_data_strip = max(d, ec_max_data_strip);
>  		sd_mutex_unlock(&m);
> +	} else {
> +		static struct sd_mutex m = SD_MUTEX_INITIALIZER;
> +
> +		sd_mutex_lock(&m);
> +		max_nr_copies = max(nr_copies, max_nr_copies);
> +		sd_mutex_unlock(&m);
>  	}
>  
>  	sd_debug("%" PRIx32 ", %d, %d", vid, nr_copies, cp);
> -- 
> 1.8.3.2
>