btrfs-progs: fsck: clear out log tree in repair mode

Repair mode will commit transaction which will make us
fail to load log tree anymore.

Give a warning to common users, if they really want to
coninue, we will clear out log tree.

Signed-off-by: Wang Shilong <wangsl.fnst@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.cz>

diff --git a/cmds-check.c b/cmds-check.c
index afdd044..59ef607 100644 (file)
--- a/cmds-check.c
+++ b/cmds-check.c
@@ -6551,6 +6551,22 @@ out:
        return ret;
 }
 
+static int zero_log_tree(struct btrfs_root *root)
+{
+       struct btrfs_trans_handle *trans;
+       int ret;
+
+       trans = btrfs_start_transaction(root, 1);
+       if (IS_ERR(trans)) {
+               ret = PTR_ERR(trans);
+               return ret;
+       }
+       btrfs_set_super_log_root(root->fs_info->super_copy, 0);
+       btrfs_set_super_log_root_level(root->fs_info->super_copy, 0);
+       ret = btrfs_commit_transaction(trans, root);
+       return ret;
+}
+
 static struct option long_options[] = {
        { "super", 1, NULL, 's' },
        { "repair", 0, NULL, 0 },
@@ -6670,6 +6686,23 @@ int cmd_check(int argc, char **argv)
        }
 
        root = info->fs_root;
+       /*
+        * repair mode will force us to commit transaction which
+        * will make us fail to load log tree when mounting.
+        */
+       if (repair && btrfs_super_log_root(info->super_copy)) {
+               ret = ask_user("repair mode will force to clear out log tree, Are you sure?");
+               if (!ret) {
+                       ret = 1;
+                       goto close_out;
+               }
+               ret = zero_log_tree(root);
+               if (ret) {
+                       fprintf(stderr, "fail to zero log tree\n");
+                       goto close_out;
+               }
+       }
+
        uuid_unparse(info->super_copy->fsid, uuidbuf);
        if (qgroup_report) {
                printf("Print quota groups for %s\nUUID: %s\n", argv[optind],