The function will find the root_item specified by the subvol_id,
clear the BTRFS_ROOT_SUBVOL_DEAD flag and set root_refs to one.
Signed-off-by: Lu Fengqi <lufq.f...@cn.fujitsu.com>
---
ctree.h | 1 +
undelete-subvol.c | 55 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 56 insertions(+)
diff --git a/ctree.h b/ctree.h
index 18f7c79ddeec..3df062cc7c25 100644
--- a/ctree.h
+++ b/ctree.h
@@ -185,6 +185,7 @@ static int btrfs_csum_sizes[] = { 4 };
#define BTRFS_FT_MAX 9
#define BTRFS_ROOT_SUBVOL_RDONLY (1ULL << 0)
+#define BTRFS_ROOT_SUBVOL_DEAD (1ULL << 48)
/*
* the key defines the order in the tree, and so it also defines (optimal)
diff --git a/undelete-subvol.c b/undelete-subvol.c
index 00fcc4895778..781057df2b84 100644
--- a/undelete-subvol.c
+++ b/undelete-subvol.c
@@ -12,6 +12,9 @@
*/
#include "ctree.h"
+#include "transaction.h"
+#include "disk-io.h"
+#include "messages.h"
/*
* Determines whether the subvolume is intact, according to the drop_progress
@@ -51,3 +54,55 @@ out:
btrfs_release_path(&path);
return ret;
}
+
+/*
+ * Clear BTRFS_ROOT_SUBVOL_DEAD flag and set the root_refs to one.
+ *
+ * @root the root of root tree.
+ * @subvol_id specify the root_item which will be modified.
+ *
+ * Return 0 if no error occurred.
+ */
+static int recover_dead_root(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, u64 subvol_id)
+{
+ struct btrfs_key key;
+ struct btrfs_path path;
+ struct extent_buffer *leaf;
+ struct btrfs_root_item root_item;
+ u64 root_flags;
+ 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(trans, root, &key, &path, 0, 0);
+ if (ret) {
+ error("couldn't find ROOT_ITEM for %llu failed: %d",
+ subvol_id, ret);
+ 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));
+
+ /* Clear BTRFS_ROOT_SUBVOL_DEAD */
+ root_flags = btrfs_root_flags(&root_item);
+ btrfs_set_root_flags(&root_item,
+ root_flags & ~BTRFS_ROOT_SUBVOL_DEAD);
+
+ /* Increase the refs */
+ btrfs_set_root_refs(&root_item, 1);
+
+ write_extent_buffer(leaf, &root_item, offset, sizeof(root_item));
+ btrfs_mark_buffer_dirty(leaf);
+
+out:
+ btrfs_release_path(&path);
+ return ret;
+}
--
2.16.1
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