erofs: add erofs_inode_set_aops helper to set the aops

Add erofs_inode_set_aops helper to set the inode->i_mapping->a_ops
and use IS_ENABLED to make it cleaner.

Signed-off-by: Hongbo Li <lihongbo22@huawei.com>
Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>

Author: Hongbo Li

fs/erofs/inode.c

@@ -203,7 +203,6 @@ static int erofs_read_inode(struct inode *inode)
 
 static int erofs_fill_inode(struct inode *inode)
 {
-	struct erofs_inode *vi = EROFS_I(inode);
 	int err;
 
 	trace_erofs_fill_inode(inode);
@@ -235,28 +234,7 @@ static int erofs_fill_inode(struct inode *inode)
 	}
 
 	mapping_set_large_folios(inode->i_mapping);
-	if (erofs_inode_is_data_compressed(vi->datalayout)) {
-#ifdef CONFIG_EROFS_FS_ZIP
-		DO_ONCE_LITE_IF(inode->i_blkbits != PAGE_SHIFT,
-			  erofs_info, inode->i_sb,
-			  "EXPERIMENTAL EROFS subpage compressed block support in use. Use at your own risk!");
-		inode->i_mapping->a_ops = &z_erofs_aops;
-#else
-		err = -EOPNOTSUPP;
-#endif
-	} else {
-		inode->i_mapping->a_ops = &erofs_aops;
-#ifdef CONFIG_EROFS_FS_ONDEMAND
-		if (erofs_is_fscache_mode(inode->i_sb))
-			inode->i_mapping->a_ops = &erofs_fscache_access_aops;
-#endif
-#ifdef CONFIG_EROFS_FS_BACKED_BY_FILE
-		if (erofs_is_fileio_mode(EROFS_SB(inode->i_sb)))
-			inode->i_mapping->a_ops = &erofs_fileio_aops;
-#endif
-	}
-
-	return err;
+	return erofs_inode_set_aops(inode, inode, false);
 }
 
 /*

fs/erofs/internal.h

@@ -452,6 +452,28 @@ static inline void *erofs_vm_map_ram(struct page **pages, unsigned int count)
 	return NULL;
 }
 
+static inline int erofs_inode_set_aops(struct inode *inode,
+				       struct inode *realinode, bool no_fscache)
+{
+	if (erofs_inode_is_data_compressed(EROFS_I(realinode)->datalayout)) {
+		if (!IS_ENABLED(CONFIG_EROFS_FS_ZIP))
+			return -EOPNOTSUPP;
+		DO_ONCE_LITE_IF(realinode->i_blkbits != PAGE_SHIFT,
+			  erofs_info, realinode->i_sb,
+			  "EXPERIMENTAL EROFS subpage compressed block support in use. Use at your own risk!");
+		inode->i_mapping->a_ops = &z_erofs_aops;
+		return 0;
+	}
+	inode->i_mapping->a_ops = &erofs_aops;
+	if (IS_ENABLED(CONFIG_EROFS_FS_ONDEMAND) && !no_fscache &&
+	    erofs_is_fscache_mode(realinode->i_sb))
+		inode->i_mapping->a_ops = &erofs_fscache_access_aops;
+	if (IS_ENABLED(CONFIG_EROFS_FS_BACKED_BY_FILE) &&
+	    erofs_is_fileio_mode(EROFS_SB(realinode->i_sb)))
+		inode->i_mapping->a_ops = &erofs_fileio_aops;
+	return 0;
+}
+
 int erofs_register_sysfs(struct super_block *sb);
 void erofs_unregister_sysfs(struct super_block *sb);
 int __init erofs_init_sysfs(void);