xref: /openbmc/linux/fs/affs/symlink.c (revision 609e478b)
1 /*
2  *  linux/fs/affs/symlink.c
3  *
4  *  1995  Hans-Joachim Widmaier - Modified for affs.
5  *
6  *  Copyright (C) 1991, 1992  Linus Torvalds
7  *
8  *  affs symlink handling code
9  */
10 
11 #include "affs.h"
12 
13 static int affs_symlink_readpage(struct file *file, struct page *page)
14 {
15 	struct buffer_head *bh;
16 	struct inode *inode = page->mapping->host;
17 	char *link = kmap(page);
18 	struct slink_front *lf;
19 	int err;
20 	int			 i, j;
21 	char			 c;
22 	char			 lc;
23 
24 	pr_debug("follow_link(ino=%lu)\n", inode->i_ino);
25 
26 	err = -EIO;
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 	kunmap(page);
63 	unlock_page(page);
64 	return 0;
65 fail:
66 	SetPageError(page);
67 	kunmap(page);
68 	unlock_page(page);
69 	return err;
70 }
71 
72 const struct address_space_operations affs_symlink_aops = {
73 	.readpage	= affs_symlink_readpage,
74 };
75 
76 const struct inode_operations affs_symlink_inode_operations = {
77 	.readlink	= generic_readlink,
78 	.follow_link	= page_follow_link_light,
79 	.put_link	= page_put_link,
80 	.setattr	= affs_notify_change,
81 };
82