The function is used to determine whether the subvolume is intact.
Signed-off-by: Lu Fengqi <lufq.f...@cn.fujitsu.com>
---
Makefile | 3 ++-
undelete-subvol.c | 53 +++++++++++++++++++++++++++++++++++++++++++++++++++++
undelete-subvol.h | 17 +++++++++++++++++
3 files changed, 72 insertions(+), 1 deletion(-)
create mode 100644 undelete-subvol.c
create mode 100644 undelete-subvol.h
diff --git a/Makefile b/Makefile
index 327cdfa08eba..accbd4069ad9 100644
--- a/Makefile
+++ b/Makefile
@@ -106,7 +106,8 @@ objects = ctree.o disk-io.o kernel-lib/radix-tree.o
extent-tree.o print-tree.o \
qgroup.o free-space-cache.o kernel-lib/list_sort.o props.o \
kernel-shared/ulist.o qgroup-verify.o backref.o string-table.o
task-utils.o \
inode.o file.o find-root.o free-space-tree.o help.o send-dump.o \
- fsfeatures.o kernel-lib/tables.o kernel-lib/raid56.o transaction.o
+ fsfeatures.o kernel-lib/tables.o kernel-lib/raid56.o transaction.o \
+ undelete-subvol.o
cmds_objects = cmds-subvolume.o cmds-filesystem.o cmds-device.o cmds-scrub.o \
cmds-inspect.o cmds-balance.o cmds-send.o cmds-receive.o \
cmds-quota.o cmds-qgroup.o cmds-replace.o check/main.o \
diff --git a/undelete-subvol.c b/undelete-subvol.c
new file mode 100644
index 000000000000..00fcc4895778
--- /dev/null
+++ b/undelete-subvol.c
@@ -0,0 +1,53 @@
+/*
+ * Copyright (C) 2018 Fujitsu. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ */
+
+#include "ctree.h"
+
+/*
+ * Determines whether the subvolume is intact, according to the drop_progress
+ * of the root item specified by subvol_id.
+ *
+ * Return true if the subvolume is intact, otherwise return false.
+ */
+static bool is_subvol_intact(struct btrfs_root *root, u64 subvol_id)
+{
+ struct btrfs_path path;
+ struct btrfs_key key;
+ struct extent_buffer *leaf;
+ struct btrfs_root_item root_item;
+ u64 offset;
+ int ret;
+
+ key.objectid = subvol_id;
+ key.type = BTRFS_ROOT_ITEM_KEY;
+ key.offset = 0;
+
+ btrfs_init_path(&path);
+ ret = btrfs_search_slot(NULL, root, &key, &path, 0, 0);
+ if (ret) {
+ ret = false;
+ goto out;
+ }
+
+ leaf = path.nodes[0];
+ offset = btrfs_item_ptr_offset(leaf, path.slots[0]);
+
+ read_extent_buffer(leaf, &root_item, offset, sizeof(root_item));
+
+ /* the subvolume is intact if the objectid of drop_progress == 0 */
+ ret = btrfs_disk_key_objectid(&root_item.drop_progress) ? false : true;
+
+out:
+ btrfs_release_path(&path);
+ return ret;
+}
diff --git a/undelete-subvol.h b/undelete-subvol.h
new file mode 100644
index 000000000000..7cfd100cce37
--- /dev/null
+++ b/undelete-subvol.h
@@ -0,0 +1,17 @@
+/*
+ * Copyright (C) 2018 Fujitsu. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ */
+
+#ifndef __BTRFS_UNDELETE_SUBVOLUME_H__
+#define __BTRFS_UNDELETE_SUBVOLUME_H__
+
+#endif
--
2.16.1
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