Re: [PATCH] erofs-utils: mkfs: also handle last compacted 2B pack in z_erofs_drop_inline_pcluster

Hi Zhiguo,

On 2026/4/29 15:59, Zhiguo Niu wrote:
> With ztailpacking enabled, the current process assumes that a compacted_4b_end
> always exists in the compacted pack. However, in some specific files, the
> compacted pack may not have a compacted_4b_end. This leads to an incorrect
> modification of the last compacted_2B entry, resulting in incorrect modification
> of its clusterofs. In subsequent fsck operations, incorrect parameters will
> affect the decompression of the penultimate pcluster.
> 
> This patch determines whether the last entry of the current compacted pack
> belongs to compacted 2B or 4B and then updates the correct bits accordingly.
> 
> Fixes: a7c1f0575ef8 ("erofs-utils: lib: refine tailpcluster compression approach")
> Signed-off-by: Zhiguo Niu <[email protected]>

Sorry for late response.

I do think the issue is valid, but either the previous
solution or the proposed one is ugly.

I wonder if there exists a better way to fixup the last lcluster
type into plain instead: I've thought about for a while but without
any valid suggestion.

Thanks,
Gao Xiang