Btrfs: Add root tree pointer transaction ids
This patch adds transaction IDs to root tree pointers.
Transaction IDs in tree pointers are compared with the
generation numbers in block headers when reading root
blocks of trees. This can detect some types of IO errors.
Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 48b455f..924af6f 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -439,6 +439,7 @@
root->node->start);
btrfs_set_root_level(&root->root_item,
btrfs_header_level(root->node));
+ btrfs_set_root_generation(&root->root_item, trans->transid);
ret = btrfs_update_root(trans, tree_root,
&root->root_key,
&root->root_item);
@@ -456,6 +457,12 @@
{
struct btrfs_fs_info *fs_info = root->fs_info;
struct list_head *next;
+ struct extent_buffer *eb;
+
+ eb = btrfs_lock_root_node(fs_info->tree_root);
+ btrfs_cow_block(trans, fs_info->tree_root, eb, NULL, 0, &eb, 0);
+ btrfs_tree_unlock(eb);
+ free_extent_buffer(eb);
while(!list_empty(&fs_info->dirty_cowonly_roots)) {
next = fs_info->dirty_cowonly_roots.next;
@@ -559,6 +566,9 @@
root->node->start);
btrfs_set_root_level(&root->root_item,
btrfs_header_level(root->node));
+ btrfs_set_root_generation(&root->root_item,
+ root->root_key.offset);
+
err = btrfs_insert_root(trans, root->fs_info->tree_root,
&root->root_key,
&root->root_item);
@@ -756,6 +766,7 @@
btrfs_set_root_bytenr(new_root_item, tmp->start);
btrfs_set_root_level(new_root_item, btrfs_header_level(tmp));
+ btrfs_set_root_generation(new_root_item, trans->transid);
ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key,
new_root_item);
btrfs_tree_unlock(tmp);
@@ -946,6 +957,8 @@
chunk_root->node->start);
btrfs_set_super_chunk_root_level(&root->fs_info->super_copy,
btrfs_header_level(chunk_root->node));
+ btrfs_set_super_chunk_root_generation(&root->fs_info->super_copy,
+ btrfs_header_generation(chunk_root->node));
if (!root->fs_info->log_root_recovering) {
btrfs_set_super_log_root(&root->fs_info->super_copy, 0);
