Re: [PATCH v2] erofs: relax sanity check for tail pclusters due to ztailpacking

Tested-by: Yifan Zhao <[email protected]>

On 2026/7/8 11:18, Gao Xiang wrote:
> If the tail data can be inlined into the inode meta block, it should
> be converted into a regular tail pcluster.
>
> In principle, it should be converted into an uncompressed pcluster if
> there is not enough gain to use compression (map->m_llen < map->m_plen);
> but since there are various shipped images, relax the condition for
> ztailpacking tail pcluster fallback instead of reporting corruption
> incorrectly.
>
> Reported-by: Yifan Zhao <[email protected]>
> Reported-by: Alberto Salvia Novella <[email protected]>
> Closes: https://github.com/erofs/erofs-utils/issues/51
> Fixes: a5242d37c83a ("erofs: error out obviously illegal extents in advance")
> Signed-off-by: Gao Xiang <[email protected]>
> ---
> v2:
>   - Drop ztailpacking sb feature check since it might not be set for
>     single-file ztailpacking fallback images.
>
>   fs/erofs/zmap.c | 3 ++-
>   1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/fs/erofs/zmap.c b/fs/erofs/zmap.c
> index bab521613552..5811556a7b71 100644
> --- a/fs/erofs/zmap.c
> +++ b/fs/erofs/zmap.c
> @@ -732,7 +732,8 @@ static int z_erofs_map_sanity_check(struct inode *inode,
>   				  map->m_algorithmformat, EROFS_I(inode)->nid);
>   			return -EFSCORRUPTED;
>   		}
> -		if (EROFS_MAP_FULL(map->m_flags) && map->m_llen < map->m_plen) {
> +		if (EROFS_MAP_FULL(map->m_flags) && map->m_llen < map->m_plen &&
> +		    map->m_la + map->m_llen < inode->i_size) {
>   			erofs_err(inode->i_sb, "too much compressed data @ la %llu of nid %llu",
>   				  map->m_la, EROFS_I(inode)->nid);
>   			return -EFSCORRUPTED;