[PATCH] erofs: shouldn't churn the mapping page for duplicated copies

[Chao Yu]

On 2022/10/12 12:50, Gao Xiang wrote:
> If other duplicated copies exist in one decompression shot, should
> leave the old page as is rather than replace it with the new duplicated
> one.  Otherwise, the following cold path to deal with duplicated copies
> will use the invalid bvec.  It impacts compressed data deduplication.
> 
> Also, shift the onlinepage EIO bit to avoid touching the signed bit.
> 
> Fixes: 267f2492c8f7 ("erofs: introduce multi-reference pclusters (fully-referenced)")
> Signed-off-by: Gao Xiang <hsiangkao at linux.alibaba.com>

Reviewed-by: Chao Yu <chao at kernel.org>

Thanks,