[sheepdog] [PATCH 1/2] sheep, dog: make recycling VID selectable

[Hitoshi Mitake]

This patch adds a new option -R to "dog cluster format". If user
specifies the option during cluster format, the cluster will enable
recycling VID (disabled in default).

Signed-off-by: Hitoshi Mitake <mitake.hitoshi at lab.ntt.co.jp>
---
 dog/cluster.c            | 9 ++++++++-
 include/internal_proto.h | 1 +
 sheep/ops.c              | 4 +++-
 sheep/vdi.c              | 2 +-
 4 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/dog/cluster.c b/dog/cluster.c
index e252316..bb61fcc 100644
--- a/dog/cluster.c
+++ b/dog/cluster.c
@@ -25,6 +25,7 @@ static struct sd_option cluster_options[] = {
 	{'l', "lock", false, "Lock vdi to exclude multiple users"},
 	{'m', "multithread", false,
 	 "use multi-thread for 'cluster snapshot save'"},
+	{'R', "recyclevid", false, "enable recycling of VID"},
 	{'t', "strict", false,
 	 "do not serve write request if number of nodes is not sufficient"},
 	{'z', "block_size_shift", true, "specify the shift num of default"
@@ -43,6 +44,7 @@ static struct cluster_cmd_data {
 	char name[STORE_LEN];
 	bool fixed_vnodes;
 	bool use_lock;
+	bool recycle_vid;
 } cluster_cmd_data;
 
 #define DEFAULT_STORE	"plain"
@@ -169,6 +171,8 @@ static int cluster_format(int argc, char **argv)
 		hdr.cluster.flags |= SD_CLUSTER_FLAG_STRICT;
 	if (cluster_cmd_data.use_lock)
 		hdr.cluster.flags |= SD_CLUSTER_FLAG_USE_LOCK;
+	if (cluster_cmd_data.recycle_vid)
+		hdr.cluster.flags |= SD_CLUSTER_FLAG_RECYCLE_VID;
 
 #ifdef HAVE_DISKVNODES
 	hdr.cluster.flags |= SD_CLUSTER_FLAG_DISKMODE;
@@ -820,7 +824,7 @@ failure:
 static struct subcommand cluster_cmd[] = {
 	{"info", NULL, "aprhvT", "show cluster information",
 	 NULL, CMD_NEED_NODELIST, cluster_info, cluster_options},
-	{"format", NULL, "bcltaphzTV", "create a Sheepdog store",
+	{"format", NULL, "bcltaphzTVR", "create a Sheepdog store",
 	 NULL, CMD_NEED_NODELIST, cluster_format, cluster_options},
 	{"shutdown", NULL, "aphT", "stop Sheepdog",
 	 NULL, 0, cluster_shutdown, cluster_options},
@@ -890,6 +894,9 @@ static int cluster_parser(int ch, const char *opt)
 	case 'V':
 		cluster_cmd_data.fixed_vnodes = true;
 		break;
+	case 'R':
+		cluster_cmd_data.recycle_vid = true;
+		break;
 	}
 
 	return 0;
diff --git a/include/internal_proto.h b/include/internal_proto.h
index defbe6d..3a370b6 100644
--- a/include/internal_proto.h
+++ b/include/internal_proto.h
@@ -157,6 +157,7 @@
 #define SD_CLUSTER_FLAG_DISKMODE	0x0002 /* Disk mode for cluster */
 #define SD_CLUSTER_FLAG_AUTO_VNODES	0x0004 /* Cluster vnodes strategy */
 #define SD_CLUSTER_FLAG_USE_LOCK	0x0008 /* Lock/Unlock vdi */
+#define SD_CLUSTER_FLAG_RECYCLE_VID	0x0010 /* Enable recycling of VID */
 
 
 enum sd_status {
diff --git a/sheep/ops.c b/sheep/ops.c
index 0e5ac64..8c79a84 100644
--- a/sheep/ops.c
+++ b/sheep/ops.c
@@ -198,7 +198,9 @@ static int post_cluster_del_vdi(const struct sd_req *req, struct sd_rsp *rsp,
 	if (ret == SD_RES_SUCCESS) {
 		atomic_set_bit(vid, sys->vdi_deleted);
 		vdi_mark_deleted(vid);
-		run_vid_gc(vid);
+
+		if (sys->cinfo.flags & SD_CLUSTER_FLAG_RECYCLE_VID)
+			run_vid_gc(vid);
 	}
 
 	if (!sys->enable_object_cache)
diff --git a/sheep/vdi.c b/sheep/vdi.c
index 8114fb5..c2b9fdc 100644
--- a/sheep/vdi.c
+++ b/sheep/vdi.c
@@ -384,7 +384,7 @@ static int do_add_vdi_state(uint32_t vid, int nr_copies, bool snapshot,
 		already_exists = true;
 	}
 
-	if (!already_exists)
+	if (!already_exists && sys->cinfo.flags & SD_CLUSTER_FLAG_RECYCLE_VID)
 		update_vdi_family(parent_vid, entry, unordered);
 
 	sd_rw_unlock(&vdi_state_lock);
-- 
1.9.1