[sheepdog] [PATCH] collie: add vdi rollback support

[MORITA Kazutaka]

This adds a new command 'vdi rollback':

Usage: collie vdi rollback [-s snapshot] [-a address] [-p port] [-h] <vdiname>
Options:
  -s, --snapshot          specify a snapshot id or tag name
  -a, --address           specify the daemon address (default: localhost)
  -p, --port              specify the daemon port
  -h, --help              display this help and exit

This makes the current vdi a new snapshot, rollbacks to the requested
snapshot, and branches a new vdi as a new current one.  Removing the
previous current vdi is a future work.

Signed-off-by: MORITA Kazutaka <morita.kazutaka at lab.ntt.co.jp>
---
 collie/vdi.c |   34 ++++++++++++++++++++++++++++++++++
 1 files changed, 34 insertions(+), 0 deletions(-)

diff --git a/collie/vdi.c b/collie/vdi.c
index 966fb9f..39e04a7 100644
--- a/collie/vdi.c
+++ b/collie/vdi.c
@@ -752,6 +752,37 @@ static int vdi_delete(int argc, char **argv)
 	return EXIT_SUCCESS;
 }
 
+static int vdi_rollback(int argc, char **argv)
+{
+	char *vdiname = argv[optind++];
+	uint32_t base_vid;
+	int ret;
+	char buf[SD_INODE_HEADER_SIZE];
+	struct sheepdog_inode *inode = (struct sheepdog_inode *)buf;
+
+	if (!vdi_cmd_data.snapshot_id && !vdi_cmd_data.snapshot_tag[0]) {
+		fprintf(stderr, "Please specify the '-s' option\n");
+		return EXIT_USAGE;
+	}
+
+	ret = find_vdi_name(vdiname, vdi_cmd_data.snapshot_id,
+			    vdi_cmd_data.snapshot_tag, &base_vid, 0);
+	if (ret < 0) {
+		fprintf(stderr, "Failed to open VDI %s\n", vdiname);
+		return EXIT_FAILURE;
+	}
+
+	inode = xmalloc(sizeof(*inode));
+	ret = sd_read_object(vid_to_vdi_oid(base_vid), inode, SD_INODE_SIZE, 0);
+	if (ret != SD_RES_SUCCESS) {
+		fprintf(stderr, "Failed to read an inode\n");
+		return EXIT_FAILURE;
+	}
+
+	return do_vdi_create(vdiname, inode->vdi_size, base_vid, NULL,
+			     inode->snap_id, vdi_cmd_data.nr_copies);
+}
+
 static int vdi_object(int argc, char **argv)
 {
 	char *vdiname = argv[optind];
@@ -1537,6 +1568,9 @@ static struct subcommand vdi_cmd[] = {
 	{"delete", "<vdiname>", "saph", "delete an image",
 	 NULL, SUBCMD_FLAG_NEED_THIRD_ARG,
 	 vdi_delete, vdi_options},
+	{"rollback", "<vdiname>", "saph", "rollback to a snapshot",
+	 NULL, SUBCMD_FLAG_NEED_THIRD_ARG,
+	 vdi_rollback, vdi_options},
 	{"list", "[vdiname]", "aprh", "list images",
 	 NULL, 0, vdi_list, vdi_options},
 	{"tree", NULL, "aph", "show images in tree view format",
-- 
1.7.2.5