xref: /openbmc/linux/fs/affs/symlink.c (revision 9470114d)
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 buffer_head *bh;
17 	struct inode *inode = folio->mapping->host;
18 	char *link = folio_address(folio);
19 	struct slink_front *lf;
20 	int			 i, j;
21 	char			 c;
22 	char			 lc;
23 
24 	pr_debug("get_link(ino=%lu)\n", inode->i_ino);
25 
26 	bh = affs_bread(inode->i_sb, inode->i_ino);
27 	if (!bh)
28 		goto fail;
29 	i  = 0;
30 	j  = 0;
31 	lf = (struct slink_front *)bh->b_data;
32 	lc = 0;
33 
34 	if (strchr(lf->symname,':')) {	/* Handle assign or volume name */
35 		struct affs_sb_info *sbi = AFFS_SB(inode->i_sb);
36 		char *pf;
37 		spin_lock(&sbi->symlink_lock);
38 		pf = sbi->s_prefix ? sbi->s_prefix : "/";
39 		while (i < 1023 && (c = pf[i]))
40 			link[i++] = c;
41 		spin_unlock(&sbi->symlink_lock);
42 		while (i < 1023 && lf->symname[j] != ':')
43 			link[i++] = lf->symname[j++];
44 		if (i < 1023)
45 			link[i++] = '/';
46 		j++;
47 		lc = '/';
48 	}
49 	while (i < 1023 && (c = lf->symname[j])) {
50 		if (c == '/' && lc == '/' && i < 1020) {	/* parent dir */
51 			link[i++] = '.';
52 			link[i++] = '.';
53 		}
54 		link[i++] = c;
55 		lc = c;
56 		j++;
57 	}
58 	link[i] = '\0';
59 	affs_brelse(bh);
60 	folio_mark_uptodate(folio);
61 	folio_unlock(folio);
62 	return 0;
63 fail:
64 	folio_unlock(folio);
65 	return -EIO;
66 }
67 
68 const struct address_space_operations affs_symlink_aops = {
69 	.read_folio	= affs_symlink_read_folio,
70 };
71 
72 const struct inode_operations affs_symlink_inode_operations = {
73 	.get_link	= page_get_link,
74 	.setattr	= affs_notify_change,
75 };
76