The code is mostly ported from kernel with minimal change.
Since btrfs-progs doesn't support replaying log, there is some code
unnecessary for btrfs-progs, but to keep the code the same, that
unnecessary code is kept as it.
Now "btrfs check --repair" will update backup roots correctly.
Signed-off-by: Qu Wenruo <w...@suse.com>
---
disk-io.c | 78 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 78 insertions(+)
diff --git a/disk-io.c b/disk-io.c
index 133835a4d063..f28a6b526391 100644
--- a/disk-io.c
+++ b/disk-io.c
@@ -1621,6 +1621,83 @@ write_err:
return ret;
}
+/*
+ * copy all the root pointers into the super backup array.
+ * this will bump the backup pointer by one when it is
+ * done
+ */
+static void backup_super_roots(struct btrfs_fs_info *info)
+{
+ struct btrfs_root_backup *root_backup;
+ int next_backup;
+ int last_backup;
+
+ last_backup = find_best_backup_root(info->super_copy);
+ next_backup = (last_backup + 1) % BTRFS_NUM_BACKUP_ROOTS;
+
+ /* just overwrite the last backup if we're at the same generation */
+ root_backup = info->super_copy->super_roots + last_backup;
+ if (btrfs_backup_tree_root_gen(root_backup) ==
+ btrfs_header_generation(info->tree_root->node))
+ next_backup = last_backup;
+
+ root_backup = info->super_copy->super_roots + next_backup;
+
+ /*
+ * make sure all of our padding and empty slots get zero filled
+ * regardless of which ones we use today
+ */
+ memset(root_backup, 0, sizeof(*root_backup));
+ btrfs_set_backup_tree_root(root_backup, info->tree_root->node->start);
+ btrfs_set_backup_tree_root_gen(root_backup,
+ btrfs_header_generation(info->tree_root->node));
+ btrfs_set_backup_tree_root_level(root_backup,
+ btrfs_header_level(info->tree_root->node));
+
+ btrfs_set_backup_chunk_root(root_backup, info->chunk_root->node->start);
+ btrfs_set_backup_chunk_root_gen(root_backup,
+ btrfs_header_generation(info->chunk_root->node));
+ btrfs_set_backup_chunk_root_level(root_backup,
+ btrfs_header_level(info->chunk_root->node));
+
+ btrfs_set_backup_extent_root(root_backup,
info->extent_root->node->start);
+ btrfs_set_backup_extent_root_gen(root_backup,
+
btrfs_header_generation(info->extent_root->node));
+ btrfs_set_backup_extent_root_level(root_backup,
+ btrfs_header_level(info->extent_root->node));
+ /*
+ * we might commit during log recovery, which happens before we set
+ * the fs_root. Make sure it is valid before we fill it in.
+ */
+ if (info->fs_root && info->fs_root->node) {
+ btrfs_set_backup_fs_root(root_backup,
+ info->fs_root->node->start);
+ btrfs_set_backup_fs_root_gen(root_backup,
+ btrfs_header_generation(info->fs_root->node));
+ btrfs_set_backup_fs_root_level(root_backup,
+ btrfs_header_level(info->fs_root->node));
+ }
+
+ btrfs_set_backup_dev_root(root_backup, info->dev_root->node->start);
+ btrfs_set_backup_dev_root_gen(root_backup,
+ btrfs_header_generation(info->dev_root->node));
+ btrfs_set_backup_dev_root_level(root_backup,
+
btrfs_header_level(info->dev_root->node));
+
+ btrfs_set_backup_csum_root(root_backup, info->csum_root->node->start);
+ btrfs_set_backup_csum_root_gen(root_backup,
+ btrfs_header_generation(info->csum_root->node));
+ btrfs_set_backup_csum_root_level(root_backup,
+ btrfs_header_level(info->csum_root->node));
+
+ btrfs_set_backup_total_bytes(root_backup,
+ btrfs_super_total_bytes(info->super_copy));
+ btrfs_set_backup_bytes_used(root_backup,
+ btrfs_super_bytes_used(info->super_copy));
+ btrfs_set_backup_num_devices(root_backup,
+ btrfs_super_num_devices(info->super_copy));
+};
+
int write_all_supers(struct btrfs_fs_info *fs_info)
{
struct list_head *head = &fs_info->fs_devices->devices;
@@ -1630,6 +1707,7 @@ int write_all_supers(struct btrfs_fs_info *fs_info)
int ret;
u64 flags;
+ backup_super_roots(fs_info);
sb = fs_info->super_copy;
dev_item = &sb->dev_item;
list_for_each_entry(dev, head, dev_list) {
--
2.20.1
