[sheepdog] [PATCH v2] dog/vdi: stop preallocation for no share option in vdi cloning

[Ruoyu]

Previous patch add a -n (--no-share) option in dog vdi clone.
Preallocation is also enabled by this option. However, it is
unnecessary to preallocate data object. In fact, we only need to
copy parent's data objects into its own.

This patch fix this problem to carry out thin-provision.

Signed-off-by: Ruoyu <liangry at ucweb.com>
---
 dog/vdi.c | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/dog/vdi.c b/dog/vdi.c
index a8491c3..866cb36 100644
--- a/dog/vdi.c
+++ b/dog/vdi.c
@@ -23,8 +23,7 @@
 
 static struct sd_option vdi_options[] = {
 	{'P', "prealloc", false, "preallocate all the data objects"},
-	{'n', "no-share", false, "share nothing with its parent, "
-				"prealloc also enabled"},
+	{'n', "no-share", false, "share nothing with its parent"},
 	{'i', "index", true, "specify the index of data objects"},
 	{'s', "snapshot", true, "specify a snapshot id or tag name"},
 	{'x', "exclusive", false, "write in an exclusive mode"},
@@ -575,7 +574,8 @@ static int vdi_clone(int argc, char **argv)
 	ret = do_vdi_create(dst_vdi, inode->vdi_size, base_vid, &new_vid, false,
 			    inode->nr_copies, inode->copy_policy,
 			    inode->store_policy);
-	if (ret != EXIT_SUCCESS || !vdi_cmd_data.prealloc)
+	if (ret != EXIT_SUCCESS ||
+			(!vdi_cmd_data.prealloc && !vdi_cmd_data.no_share))
 		goto out;
 
 	new_inode = xmalloc(sizeof(*inode));
@@ -601,8 +601,11 @@ static int vdi_clone(int argc, char **argv)
 				goto out;
 			}
 			size = SD_DATA_OBJ_SIZE;
-		} else
+		} else {
+			if (vdi_cmd_data.no_share && !vdi_cmd_data.prealloc)
+				continue;
 			size = 0;
+		}
 
 		oid = vid_to_data_oid(new_vid, idx);
 		ret = dog_write_object(oid, 0, buf, size, 0, 0,
@@ -2424,7 +2427,6 @@ static int vdi_parser(int ch, const char *opt)
 		break;
 	case 'n':
 		vdi_cmd_data.no_share = true;
-		vdi_cmd_data.prealloc = true;
 		break;
 	case 'i':
 		vdi_cmd_data.index = strtol(opt, &p, 10);
-- 
1.8.3.2