add defrag ioctl

btrfsctl.c

@@ -77,6 +77,12 @@ int main(int ac, char **av)
 				exit(1);
 			}
 			command = BTRFS_IOC_SNAP_CREATE;
+		} else if (strcmp(av[i], "-d") == 0) {
+			if (i >= ac - 1) {
+				fprintf(stderr, "-d requires an arg");
+				print_usage();
+			}
+			command = BTRFS_IOC_DEFRAG;
 		}
 	}
 	if (command == 0) {
@@ -102,7 +108,10 @@ int main(int ac, char **av)
 		perror("open");
 		exit(1);
 	}
-	strcpy(args.name, name);
+	if (name)
+		strcpy(args.name, name);
+	else
+		args.name[0] = '\0';
 	ret = ioctl(fd, command, &args);
 	printf("ioctl returns %d\n", ret);
 	return 0;

ioctl.h

@@ -28,6 +28,6 @@ struct btrfs_ioctl_vol_args {
 
 #define BTRFS_IOC_SNAP_CREATE _IOW(BTRFS_IOCTL_MAGIC, 1, \
 				   struct btrfs_ioctl_vol_args)
-#define BTRFS_IOC_ADD_DISK _IOW(BTRFS_IOCTL_MAGIC, 2, \
+#define BTRFS_IOC_DEFRAG _IOW(BTRFS_IOCTL_MAGIC, 2, \
 				   struct btrfs_ioctl_vol_args)
 #endif

mkfs.c

@@ -225,6 +225,7 @@ int mkfs(int fd, char *pathname, u64 num_blocks, u32 blocksize)
 	btrfs_set_inode_nblocks(inode_item, 1);
 	btrfs_set_inode_mode(inode_item, S_IFDIR | 0755);
 
+	// memset(&root_item, 0, sizeof(root_item));
 	btrfs_set_root_dirid(&root_item, 0);
 	btrfs_set_root_refs(&root_item, 1);
 	btrfs_set_disk_key_offset(&item.key, 0);

print-tree.c

@@ -96,6 +96,16 @@ void btrfs_print_leaf(struct btrfs_root *root, struct btrfs_leaf *l)
 				(unsigned long long)btrfs_root_blocknr(ri),
 				(unsigned long long)btrfs_root_dirid(ri),
 				btrfs_root_refs(ri));
+			if (1 || btrfs_root_refs(ri) == 0) {
+				struct btrfs_key drop_key;
+				btrfs_disk_key_to_cpu(&drop_key,
+						      &ri->drop_progress);
+				printf("\t\tdrop key %Lu %x %Lu level %d\n",
+				       (unsigned long long)drop_key.objectid,
+				       drop_key.flags,
+				       (unsigned long long)drop_key.offset,
+				       ri->drop_level);
+			}
 			break;
 		case BTRFS_EXTENT_ITEM_KEY:
 			ei = btrfs_item_ptr(l, i, struct btrfs_extent_item);