erofs: fix ztailpacking for subpage compressed blocks

[ Upstream commit e5aba911dee5e20fa82efbe13e0af8f38ea459e7 ]

`pageofs_in` should be the compressed data offset of the page rather
than of the block.

Acked-by: Chao Yu <chao@kernel.org>
Reviewed-by: Yue Hu <huyue2@coolpad.com>
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Link: https://lore.kernel.org/r/20231214161337.753049-1-hsiangkao@linux.alibaba.com
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/fs/erofs/zdata.c b/fs/erofs/zdata.c
index a33cd67..1c0e616 100644 (file)
--- a/fs/erofs/zdata.c
+++ b/fs/erofs/zdata.c
@@ -815,7 +815,6 @@ static int z_erofs_register_pcluster(struct z_erofs_decompress_frontend *fe)
 
        if (ztailpacking) {
                pcl->obj.index = 0;     /* which indicates ztailpacking */
-               pcl->pageofs_in = erofs_blkoff(fe->inode->i_sb, map->m_pa);
                pcl->tailpacking_size = map->m_plen;
        } else {
                pcl->obj.index = map->m_pa >> PAGE_SHIFT;
@@ -893,6 +892,7 @@ static int z_erofs_pcluster_begin(struct z_erofs_decompress_frontend *fe)
                }
                get_page(map->buf.page);
                WRITE_ONCE(fe->pcl->compressed_bvecs[0].page, map->buf.page);
+               fe->pcl->pageofs_in = map->m_pa & ~PAGE_MASK;
                fe->mode = Z_EROFS_PCLUSTER_FOLLOWED_NOINPLACE;
        }
        /* file-backed inplace I/O pages are traversed in reverse order */