On 2018年03月27日 15:06, Lu Fengqi wrote: > The function will create lost+found directory, link the deleted > subvolume specified by the subvol_id to the directory, update the > information of root_item and cleanup the associated orphan item. > > Signed-off-by: Lu Fengqi <lufq.f...@cn.fujitsu.com> > --- > undelete-subvol.c | 76 > +++++++++++++++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 76 insertions(+) > > diff --git a/undelete-subvol.c b/undelete-subvol.c > index 781057df2b84..9243e35545c5 100644 > --- a/undelete-subvol.c > +++ b/undelete-subvol.c > @@ -106,3 +106,79 @@ out: > btrfs_release_path(&path); > return ret; > } > + > +/* > + * Recover a subvolume specified by subvol_id, and link it to the lost+found > + * directory. > + * > + * @root: the root of the root tree.
In that case, @fs_info would case less confusion.
Otherwise looks good.
Reviewed-by: Qu Wenruo <w...@suse.com>
Thanks,
Qu
> + * @subvol_id: specify the subvolume which will be linked, and also be the
> part
> + * of the subvolume name.
> + *
> + * Return 0 if no error occurred.
> + */
> +static int link_subvol_to_lostfound(struct btrfs_root *root, u64 subvol_id)
> +{
> + struct btrfs_trans_handle *trans;
> + struct btrfs_fs_info *fs_info = root->fs_info;
> + struct btrfs_root *fs_root = fs_info->fs_root;
> + char buf[BTRFS_NAME_LEN + 1] = {0}; /* 1 for snprintf null */
> + char *dir_name = "lost+found";
> + u64 lost_found_ino = 0;
> + u32 mode = 0700;
> + int ret;
> +
> + /*
> + * For link subvolume to lost+found,
> + * 2 for parent(256)'s dir_index and dir_item
> + * 2 for lost+found dir's inode_item and inode_ref
> + * 2 for lost+found dir's dir_index and dir_item for the subvolume
> + * 2 for the subvolume's root_ref and root_backref
> + */
> + trans = btrfs_start_transaction(fs_root, 8);
> + if (IS_ERR(trans)) {
> + error("unable to start transaction");
> + ret = PTR_ERR(trans);
> + goto out;
> + }
> +
> + /* Create lost+found directory */
> + ret = btrfs_mkdir(trans, fs_root, dir_name, strlen(dir_name),
> + BTRFS_FIRST_FREE_OBJECTID, &lost_found_ino,
> + mode);
> + if (ret < 0) {
> + error("failed to create '%s' dir: %d", dir_name, ret);
> + goto out;
> + }
> +
> + /* Link the subvolume to lost+found directory */
> + snprintf(buf, BTRFS_NAME_LEN + 1, "sub%llu", subvol_id);
> + ret = btrfs_link_subvol(trans, fs_root, buf, subvol_id, lost_found_ino,
> + false);
> + if (ret) {
> + error("failed to link the subvol %llu: %d", subvol_id, ret);
> + goto out;
> + }
> +
> + /* Clear root flags BTRFS_ROOT_SUBVOL_DEAD and increase root refs */
> + ret = recover_dead_root(trans, root, subvol_id);
> + if (ret)
> + goto out;
> +
> + /* Delete the orphan item after undeletion is completed. */
> + ret = btrfs_del_orphan_item(trans, root, subvol_id);
> + if (ret) {
> + error("failed to delete the orphan_item for %llu: %d",
> + subvol_id, ret);
> + goto out;
> + }
> +
> + ret = btrfs_commit_transaction(trans, fs_root);
> + if (ret) {
> + error("transaction commit failed: %d", ret);
> + goto out;
> + }
> +
> +out:
> + return ret;
> +}
>
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