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
efs_symlink_read_folio(struct file * file,struct folio * folio)15 static 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;
46 fail:
47 SetPageError(page);
48 unlock_page(page);
49 return err;
50 }
51
52 const struct address_space_operations efs_symlink_aops = {
53 .read_folio = efs_symlink_read_folio
54 };
55