1// SPDX-License-Identifier: GPL-2.0
2/*
3 * symlink.c
4 *
5 * Copyright (c) 1999 Al Smith
6 *
7 * Portions derived from work (c) 1995,1996 Christian Vogelgsang.
8 */
9
10#include <linux/string.h>
11#include <linux/pagemap.h>
12#include <linux/buffer_head.h>
13#include "efs.h"
14
15static int efs_symlink_read_folio(struct file *file, struct folio *folio)
16{
17	struct page *page = &folio->page;
18	char *link = page_address(page);
19	struct buffer_head * bh;
20	struct inode * inode = page->mapping->host;
21	efs_block_t size = inode->i_size;
22	int err;
23
24	err = -ENAMETOOLONG;
25	if (size > 2 * EFS_BLOCKSIZE)
26		goto fail;
27
28	/* read first 512 bytes of link target */
29	err = -EIO;
30	bh = sb_bread(inode->i_sb, efs_bmap(inode, 0));
31	if (!bh)
32		goto fail;
33	memcpy(link, bh->b_data, (size > EFS_BLOCKSIZE) ? EFS_BLOCKSIZE : size);
34	brelse(bh);
35	if (size > EFS_BLOCKSIZE) {
36		bh = sb_bread(inode->i_sb, efs_bmap(inode, 1));
37		if (!bh)
38			goto fail;
39		memcpy(link + EFS_BLOCKSIZE, bh->b_data, size - EFS_BLOCKSIZE);
40		brelse(bh);
41	}
42	link[size] = '\0';
43	SetPageUptodate(page);
44	unlock_page(page);
45	return 0;
46fail:
47	SetPageError(page);
48	unlock_page(page);
49	return err;
50}
51
52const struct address_space_operations efs_symlink_aops = {
53	.read_folio	= efs_symlink_read_folio
54};
55