xref: /openbmc/linux/fs/affs/symlink.c (revision 0545810f)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *  linux/fs/affs/symlink.c
4  *
5  *  1995  Hans-Joachim Widmaier - Modified for affs.
6  *
7  *  Copyright (C) 1991, 1992  Linus Torvalds
8  *
9  *  affs symlink handling code
10  */
11 
12 #include "affs.h"
13 
14 static int affs_symlink_read_folio(struct file *file, struct folio *folio)
15 {
16 	struct page *page = &folio->page;
17 	struct buffer_head *bh;
18 	struct inode *inode = page->mapping->host;
19 	char *link = page_address(page);
20 	struct slink_front *lf;
21 	int			 i, j;
22 	char			 c;
23 	char			 lc;
24 
25 	pr_debug("get_link(ino=%lu)\n", inode->i_ino);
26 
27 	bh = affs_bread(inode->i_sb, inode->i_ino);
28 	if (!bh)
29 		goto fail;
30 	i  = 0;
31 	j  = 0;
32 	lf = (struct slink_front *)bh->b_data;
33 	lc = 0;
34 
35 	if (strchr(lf->symname,':')) {	/* Handle assign or volume name */
36 		struct affs_sb_info *sbi = AFFS_SB(inode->i_sb);
37 		char *pf;
38 		spin_lock(&sbi->symlink_lock);
39 		pf = sbi->s_prefix ? sbi->s_prefix : "/";
40 		while (i < 1023 && (c = pf[i]))
41 			link[i++] = c;
42 		spin_unlock(&sbi->symlink_lock);
43 		while (i < 1023 && lf->symname[j] != ':')
44 			link[i++] = lf->symname[j++];
45 		if (i < 1023)
46 			link[i++] = '/';
47 		j++;
48 		lc = '/';
49 	}
50 	while (i < 1023 && (c = lf->symname[j])) {
51 		if (c == '/' && lc == '/' && i < 1020) {	/* parent dir */
52 			link[i++] = '.';
53 			link[i++] = '.';
54 		}
55 		link[i++] = c;
56 		lc = c;
57 		j++;
58 	}
59 	link[i] = '\0';
60 	affs_brelse(bh);
61 	SetPageUptodate(page);
62 	unlock_page(page);
63 	return 0;
64 fail:
65 	SetPageError(page);
66 	unlock_page(page);
67 	return -EIO;
68 }
69 
70 const struct address_space_operations affs_symlink_aops = {
71 	.read_folio	= affs_symlink_read_folio,
72 };
73 
74 const struct inode_operations affs_symlink_inode_operations = {
75 	.get_link	= page_get_link,
76 	.setattr	= affs_notify_change,
77 };
78