erofs: get rid of z_erofs_fill_inode()

Prior to big pclusters, non-compact compression indexes could have
empty headers.

Let's just avoid the legacy path since it can be handled properly
as a specific compression header with z_erofs_fill_inode_lazy() too.

Tested with erofs-utils exist versions.

Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Reviewed-by: Yue Hu <huyue2@coolpad.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Link: https://lore.kernel.org/r/20230413092241.73829-1-hsiangkao@linux.alibaba.com

fs/erofs/inode.c

@@ -291,11 +291,15 @@ static int erofs_fill_inode(struct inode *inode)
 	}
 
 	if (erofs_inode_is_data_compressed(vi->datalayout)) {
+#ifdef CONFIG_EROFS_FS_ZIP
 		if (!erofs_is_fscache_mode(inode->i_sb) &&
-		    inode->i_sb->s_blocksize_bits == PAGE_SHIFT)
-			err = z_erofs_fill_inode(inode);
-		else
-			err = -EOPNOTSUPP;
+		    inode->i_sb->s_blocksize_bits == PAGE_SHIFT) {
+			inode->i_mapping->a_ops = &z_erofs_aops;
+			err = 0;
+			goto out_unlock;
+		}
+#endif
+		err = -EOPNOTSUPP;
 		goto out_unlock;
 	}
 	inode->i_mapping->a_ops = &erofs_raw_access_aops;

fs/erofs/internal.h

@@ -522,7 +522,6 @@ int erofs_try_to_free_cached_page(struct page *page);
 int z_erofs_load_lz4_config(struct super_block *sb,
 			    struct erofs_super_block *dsb,
 			    struct z_erofs_lz4_cfgs *lz4, int len);
-int z_erofs_fill_inode(struct inode *inode);
 int z_erofs_map_blocks_iter(struct inode *inode, struct erofs_map_blocks *map,
 			    int flags);
 #else
@@ -542,7 +541,6 @@ static inline int z_erofs_load_lz4_config(struct super_block *sb,
 	}
 	return 0;
 }
-static inline int z_erofs_fill_inode(struct inode *inode) { return -EOPNOTSUPP; }
 #endif	/* !CONFIG_EROFS_FS_ZIP */
 
 #ifdef CONFIG_EROFS_FS_ZIP_LZMA

fs/erofs/zmap.c

@@ -7,24 +7,6 @@
 #include <asm/unaligned.h>
 #include <trace/events/erofs.h>
 
-int z_erofs_fill_inode(struct inode *inode)
-{
-	struct erofs_inode *const vi = EROFS_I(inode);
-	struct erofs_sb_info *sbi = EROFS_SB(inode->i_sb);
-
-	if (!erofs_sb_has_big_pcluster(sbi) &&
-	    !erofs_sb_has_ztailpacking(sbi) && !erofs_sb_has_fragments(sbi) &&
-	    vi->datalayout == EROFS_INODE_COMPRESSED_FULL) {
-		vi->z_advise = 0;
-		vi->z_algorithmtype[0] = 0;
-		vi->z_algorithmtype[1] = 0;
-		vi->z_logical_clusterbits = inode->i_sb->s_blocksize_bits;
-		set_bit(EROFS_I_Z_INITED_BIT, &vi->flags);
-	}
-	inode->i_mapping->a_ops = &z_erofs_aops;
-	return 0;
-}
-
 struct z_erofs_maprecorder {
 	struct inode *inode;
 	struct erofs_map_blocks *map;