erofs: fix ztailpacking for subpage compressed blocks

hsiangkao · hsiangkao · commit e5aba911dee5 · 2023-12-18T15:49:07.000+08:00
`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
diff --git a/fs/erofs/zdata.c b/fs/erofs/zdata.c
@@ -810,7 +810,6 @@ 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);
 	} else {
 		pcl->obj.index = erofs_blknr(sb, map->m_pa);
 
@@ -887,6 +886,7 @@ 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 */

Original file line number	Diff line number	Diff line change
`@@ -810,7 +810,6 @@ static int z_erofs_register_pcluster(struct z_erofs_decompress_frontend *fe)`
`810`	`810`
`811`	`811`	`if (ztailpacking) {`
`812`	`812`	`pcl->obj.index = 0; /* which indicates ztailpacking */`
`813`		`- pcl->pageofs_in = erofs_blkoff(fe->inode->i_sb, map->m_pa);`
`814`	`813`	`} else {`
`815`	`814`	`pcl->obj.index = erofs_blknr(sb, map->m_pa);`
`816`	`815`
`@@ -887,6 +886,7 @@ static int z_erofs_pcluster_begin(struct z_erofs_decompress_frontend *fe)`
`887`	`886`	`}`
`888`	`887`	`get_page(map->buf.page);`
`889`	`888`	`WRITE_ONCE(fe->pcl->compressed_bvecs[0].page, map->buf.page);`
	`889`	`+ fe->pcl->pageofs_in = map->m_pa & ~PAGE_MASK;`
`890`	`890`	`fe->mode = Z_EROFS_PCLUSTER_FOLLOWED_NOINPLACE;`
`891`	`891`	`}`
`892`	`892`	`/* file-backed inplace I/O pages are traversed in reverse order */`