isofs: Convert symlinks and zisofs to read_folio

This is a "weak" conversion which converts straight back to using pages.
A full conversion should be performed at some point, hopefully by
someone familiar with the filesystem.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>

fs/isofs/compress.c

@@ -296,8 +296,9 @@ static int zisofs_fill_pages(struct inode *inode, int full_page, int pcount,
  * per reference.  We inject the additional pages into the page
  * cache as a form of readahead.
  */
-static int zisofs_readpage(struct file *file, struct page *page)
+static int zisofs_read_folio(struct file *file, struct folio *folio)
 {
+	struct page *page = &folio->page;
 	struct inode *inode = file_inode(file);
 	struct address_space *mapping = inode->i_mapping;
 	int err;
@@ -369,7 +370,7 @@ static int zisofs_readpage(struct file *file, struct page *page)
 }
 
 const struct address_space_operations zisofs_aops = {
-	.readpage = zisofs_readpage,
+	.read_folio = zisofs_read_folio,
 	/* No bmap operation supported */
 };
 

fs/isofs/rock.c

@@ -687,11 +687,12 @@ int parse_rock_ridge_inode(struct iso_directory_record *de, struct inode *inode,
 }
 
 /*
- * readpage() for symlinks: reads symlink contents into the page and either
+ * read_folio() for symlinks: reads symlink contents into the folio and either
  * makes it uptodate and returns 0 or returns error (-EIO)
  */
-static int rock_ridge_symlink_readpage(struct file *file, struct page *page)
+static int rock_ridge_symlink_read_folio(struct file *file, struct folio *folio)
 {
+	struct page *page = &folio->page;
 	struct inode *inode = page->mapping->host;
 	struct iso_inode_info *ei = ISOFS_I(inode);
 	struct isofs_sb_info *sbi = ISOFS_SB(inode->i_sb);
@@ -804,5 +805,5 @@ static int rock_ridge_symlink_readpage(struct file *file, struct page *page)
 }
 
 const struct address_space_operations isofs_symlink_aops = {
-	.readpage = rock_ridge_symlink_readpage
+	.read_folio = rock_ridge_symlink_read_folio
 };