afs: Sort out symlink reading

afs_readpage() doesn't get a file pointer when called for a symlink, so
separate it from regular file pointer handling.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Link: https://lore.kernel.org/r/162687508008.276387.6418924257569297305.stgit@warthog.procyon.org.uk/ # rfc
Link: https://lore.kernel.org/r/162981152280.1901565.2264055504466731917.stgit@warthog.procyon.org.uk/
Link: https://lore.kernel.org/r/163005742570.2472992.7800423440314043178.stgit@warthog.procyon.org.uk/ # v2

fs/afs/file.c

@@ -19,6 +19,7 @@
 
 static int afs_file_mmap(struct file *file, struct vm_area_struct *vma);
 static int afs_readpage(struct file *file, struct page *page);
+static int afs_symlink_readpage(struct file *file, struct page *page);
 static void afs_invalidatepage(struct page *page, unsigned int offset,
 			       unsigned int length);
 static int afs_releasepage(struct page *page, gfp_t gfp_flags);
@@ -49,7 +50,7 @@ const struct inode_operations afs_file_inode_operations = {
 	.permission	= afs_permission,
 };
 
-const struct address_space_operations afs_fs_aops = {
+const struct address_space_operations afs_file_aops = {
 	.readpage	= afs_readpage,
 	.readahead	= afs_readahead,
 	.set_page_dirty	= afs_set_page_dirty,
@@ -62,6 +63,12 @@ const struct address_space_operations afs_fs_aops = {
 	.writepages	= afs_writepages,
 };
 
+const struct address_space_operations afs_symlink_aops = {
+	.readpage	= afs_symlink_readpage,
+	.releasepage	= afs_releasepage,
+	.invalidatepage	= afs_invalidatepage,
+};
+
 static const struct vm_operations_struct afs_vm_ops = {
 	.open		= afs_vm_open,
 	.close		= afs_vm_close,
@@ -313,7 +320,7 @@ static void afs_req_issue_op(struct netfs_read_subrequest *subreq)
 	afs_put_read(fsreq);
 }
 
-static int afs_symlink_readpage(struct page *page)
+static int afs_symlink_readpage(struct file *file, struct page *page)
 {
 	struct afs_vnode *vnode = AFS_FS_I(page->mapping->host);
 	struct afs_read *fsreq;
@@ -378,9 +385,6 @@ const struct netfs_read_request_ops afs_req_ops = {
 
 static int afs_readpage(struct file *file, struct page *page)
 {
-	if (!file)
-		return afs_symlink_readpage(page);
-
 	return netfs_readpage(file, page, &afs_req_ops, NULL);
 }
 

fs/afs/inode.c

@@ -95,7 +95,7 @@ static int afs_inode_init_from_status(struct afs_operation *op,
 		inode->i_mode	= S_IFREG | (status->mode & S_IALLUGO);
 		inode->i_op	= &afs_file_inode_operations;
 		inode->i_fop	= &afs_file_operations;
-		inode->i_mapping->a_ops	= &afs_fs_aops;
+		inode->i_mapping->a_ops	= &afs_file_aops;
 		break;
 	case AFS_FTYPE_DIR:
 		inode->i_mode	= S_IFDIR |  (status->mode & S_IALLUGO);
@@ -113,11 +113,11 @@ static int afs_inode_init_from_status(struct afs_operation *op,
 			inode->i_mode	= S_IFDIR | 0555;
 			inode->i_op	= &afs_mntpt_inode_operations;
 			inode->i_fop	= &afs_mntpt_file_operations;
-			inode->i_mapping->a_ops	= &afs_fs_aops;
+			inode->i_mapping->a_ops	= &afs_symlink_aops;
 		} else {
 			inode->i_mode	= S_IFLNK | status->mode;
 			inode->i_op	= &afs_symlink_inode_operations;
-			inode->i_mapping->a_ops	= &afs_fs_aops;
+			inode->i_mapping->a_ops	= &afs_symlink_aops;
 		}
 		inode_nohighmem(inode);
 		break;

fs/afs/internal.h

@@ -1055,7 +1055,8 @@ extern void afs_dynroot_depopulate(struct super_block *);
 /*
  * file.c
  */
-extern const struct address_space_operations afs_fs_aops;
+extern const struct address_space_operations afs_file_aops;
+extern const struct address_space_operations afs_symlink_aops;
 extern const struct inode_operations afs_file_inode_operations;
 extern const struct file_operations afs_file_operations;
 extern const struct netfs_read_request_ops afs_req_ops;