fs: Convert netfs_readpage to netfs_read_folio

This is straightforward because netfs already worked in terms of folios.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>

fs/9p/vfs_addr.c

@@ -336,7 +336,7 @@ static bool v9fs_dirty_folio(struct address_space *mapping, struct folio *folio)
 #endif
 
 const struct address_space_operations v9fs_addr_operations = {
-	.readpage = netfs_readpage,
+	.read_folio = netfs_read_folio,
 	.readahead = netfs_readahead,
 	.dirty_folio = v9fs_dirty_folio,
 	.writepage = v9fs_vfs_writepage,

fs/afs/file.c

@@ -50,7 +50,7 @@ const struct inode_operations afs_file_inode_operations = {
 };
 
 const struct address_space_operations afs_file_aops = {
-	.readpage	= netfs_readpage,
+	.read_folio	= netfs_read_folio,
 	.readahead	= netfs_readahead,
 	.dirty_folio	= afs_dirty_folio,
 	.launder_folio	= afs_launder_folio,

fs/ceph/addr.c

@@ -1372,7 +1372,7 @@ static int ceph_write_end(struct file *file, struct address_space *mapping,
 }
 
 const struct address_space_operations ceph_aops = {
-	.readpage = netfs_readpage,
+	.read_folio = netfs_read_folio,
 	.readahead = netfs_readahead,
 	.writepage = ceph_writepage,
 	.writepages = ceph_writepages_start,

fs/netfs/buffered_read.c

@@ -198,22 +198,21 @@ void netfs_readahead(struct readahead_control *ractl)
 EXPORT_SYMBOL(netfs_readahead);
 
 /**
- * netfs_readpage - Helper to manage a readpage request
+ * netfs_read_folio - Helper to manage a read_folio request
  * @file: The file to read from
- * @subpage: A subpage of the folio to read
+ * @folio: The folio to read
  *
- * Fulfil a readpage request by drawing data from the cache if possible, or the
- * netfs if not.  Space beyond the EOF is zero-filled.  Multiple I/O requests
- * from different sources will get munged together.
+ * Fulfil a read_folio request by drawing data from the cache if
+ * possible, or the netfs if not.  Space beyond the EOF is zero-filled.
+ * Multiple I/O requests from different sources will get munged together.
  *
  * The calling netfs must initialise a netfs context contiguous to the vfs
  * inode before calling this.
  *
  * This is usable whether or not caching is enabled.
  */
-int netfs_readpage(struct file *file, struct page *subpage)
+int netfs_read_folio(struct file *file, struct folio *folio)
 {
-	struct folio *folio = page_folio(subpage);
 	struct address_space *mapping = folio_file_mapping(folio);
 	struct netfs_io_request *rreq;
 	struct netfs_i_context *ctx = netfs_i_context(mapping->host);
@@ -245,7 +244,7 @@ int netfs_readpage(struct file *file, struct page *subpage)
 	folio_unlock(folio);
 	return ret;
 }
-EXPORT_SYMBOL(netfs_readpage);
+EXPORT_SYMBOL(netfs_read_folio);
 
 /*
  * Prepare a folio for writing without reading first

include/linux/netfs.h

@@ -274,7 +274,7 @@ struct netfs_cache_ops {
 
 struct readahead_control;
 extern void netfs_readahead(struct readahead_control *);
-extern int netfs_readpage(struct file *, struct page *);
+int netfs_read_folio(struct file *, struct folio *);
 extern int netfs_write_begin(struct file *, struct address_space *,
 			     loff_t, unsigned int, struct folio **,
 			     void **);