Re: [PATCH v2 1/3] btrfs-progs: lowmem fsck: Remove corupted link before re-add correct link

[Su Yue <suy.fnst@cn.fujitsu.com>]

On 01/19/2018 03:25 PM, Qu Wenruo wrote:
> For repair_ternary_lowmem() used in lowmem mode, if it found 1 of
> DIR_INDEX/DIR_ITEM/INODE_REF missing, it will try to insert correct
> link.
> 
> However for case like invalid type in DIR_INDEX, we should delete the
> corrupted DIR_INDEX first before inserting the correct link.
> 
> This patch will remove the corrupted link before re-insert.
> This should solve the duplicated DIR_INDEX problem in old lowmem mode
> repair.
> 
> Cc: Sebastian Andrzej Siewior <sebastian@breakpoint.cc>

Reviewed-by: Su Yue <suy.fnst@cn.fujitsu.com>
> Signed-off-by: Qu Wenruo <wqu@suse.com>
> ---
>   cmds-check.c | 4 ++++
>   1 file changed, 4 insertions(+)
> 
> diff --git a/cmds-check.c b/cmds-check.c
> index 7fc30da83ea1..f302724dd840 100644
> --- a/cmds-check.c
> +++ b/cmds-check.c
> @@ -4997,6 +4997,10 @@ int repair_ternary_lowmem(struct btrfs_root *root, u64 dir_ino, u64 ino,
>   		goto out;
>   	}
>   	if (stage == 1) {
> +		ret = btrfs_unlink(trans, root, ino, dir_ino, index, name,
> +				   name_len, 0);
> +		if (ret)
> +			goto out;
>   		ret = btrfs_add_link(trans, root, ino, dir_ino, name, name_len,
>   			       filetype, &index, 1, 1);
>   		goto out;
>