1/*
2 *  linux/fs/adfs/dir_fplus.c
3 *
4 *  Copyright (C) 1997-1999 Russell King
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 */
10#include <linux/errno.h>
11#include <linux/fs.h>
12#include <linux/adfs_fs.h>
13#include <linux/time.h>
14#include <linux/stat.h>
15#include <linux/spinlock.h>
16#include <linux/buffer_head.h>
17#include <linux/string.h>
18
19#include "adfs.h"
20#include "dir_fplus.h"
21
22static int
23adfs_fplus_read(struct super_block *sb, unsigned int id, unsigned int sz, struct adfs_dir *dir)
24{
25	struct adfs_bigdirheader *h;
26	struct adfs_bigdirtail *t;
27	unsigned long block;
28	unsigned int blk, size;
29	int i, ret = -EIO;
30
31	dir->nr_buffers = 0;
32
33	block = __adfs_block_map(sb, id, 0);
34	if (!block) {
35		adfs_error(sb, "dir object %X has a hole at offset 0", id);
36		goto out;
37	}
38
39	dir->bh[0] = sb_bread(sb, block);
40	if (!dir->bh[0])
41		goto out;
42	dir->nr_buffers += 1;
43
44	h = (struct adfs_bigdirheader *)dir->bh[0]->b_data;
45	size = le32_to_cpu(h->bigdirsize);
46	if (size != sz) {
47		printk(KERN_WARNING "adfs: adfs_fplus_read: directory header size\n"
48				" does not match directory size\n");
49	}
50
51	if (h->bigdirversion[0] != 0 || h->bigdirversion[1] != 0 ||
52	    h->bigdirversion[2] != 0 || size & 2047 ||
53	    h->bigdirstartname != cpu_to_le32(BIGDIRSTARTNAME))
54		goto out;
55
56	size >>= sb->s_blocksize_bits;
57	for (blk = 1; blk < size; blk++) {
58		block = __adfs_block_map(sb, id, blk);
59		if (!block) {
60			adfs_error(sb, "dir object %X has a hole at offset %d", id, blk);
61			goto out;
62		}
63
64		dir->bh[blk] = sb_bread(sb, block);
65		if (!dir->bh[blk])
66			goto out;
67		dir->nr_buffers = blk;
68	}
69
70	t = (struct adfs_bigdirtail *)(dir->bh[size - 1]->b_data + (sb->s_blocksize - 8));
71
72	if (t->bigdirendname != cpu_to_le32(BIGDIRENDNAME) ||
73	    t->bigdirendmasseq != h->startmasseq ||
74	    t->reserved[0] != 0 || t->reserved[1] != 0)
75		goto out;
76
77	dir->parent_id = le32_to_cpu(h->bigdirparent);
78	dir->sb = sb;
79	return 0;
80out:
81	for (i = 0; i < dir->nr_buffers; i++)
82		brelse(dir->bh[i]);
83	dir->sb = NULL;
84	return ret;
85}
86
87static int
88adfs_fplus_setpos(struct adfs_dir *dir, unsigned int fpos)
89{
90	struct adfs_bigdirheader *h = (struct adfs_bigdirheader *)dir->bh[0]->b_data;
91	int ret = -ENOENT;
92
93	if (fpos <= le32_to_cpu(h->bigdirentries)) {
94		dir->pos = fpos;
95		ret = 0;
96	}
97
98	return ret;
99}
100
101static void
102dir_memcpy(struct adfs_dir *dir, unsigned int offset, void *to, int len)
103{
104	struct super_block *sb = dir->sb;
105	unsigned int buffer, partial, remainder;
106
107	buffer = offset >> sb->s_blocksize_bits;
108	offset &= sb->s_blocksize - 1;
109
110	partial = sb->s_blocksize - offset;
111
112	if (partial >= len)
113		memcpy(to, dir->bh[buffer]->b_data + offset, len);
114	else {
115		char *c = (char *)to;
116
117		remainder = len - partial;
118
119		memcpy(c, dir->bh[buffer]->b_data + offset, partial);
120		memcpy(c + partial, dir->bh[buffer + 1]->b_data, remainder);
121	}
122}
123
124static int
125adfs_fplus_getnext(struct adfs_dir *dir, struct object_info *obj)
126{
127	struct adfs_bigdirheader *h = (struct adfs_bigdirheader *)dir->bh[0]->b_data;
128	struct adfs_bigdirentry bde;
129	unsigned int offset;
130	int i, ret = -ENOENT;
131
132	if (dir->pos >= le32_to_cpu(h->bigdirentries))
133		goto out;
134
135	offset = offsetof(struct adfs_bigdirheader, bigdirname);
136	offset += ((le32_to_cpu(h->bigdirnamelen) + 4) & ~3);
137	offset += dir->pos * sizeof(struct adfs_bigdirentry);
138
139	dir_memcpy(dir, offset, &bde, sizeof(struct adfs_bigdirentry));
140
141	obj->loadaddr = le32_to_cpu(bde.bigdirload);
142	obj->execaddr = le32_to_cpu(bde.bigdirexec);
143	obj->size     = le32_to_cpu(bde.bigdirlen);
144	obj->file_id  = le32_to_cpu(bde.bigdirindaddr);
145	obj->attr     = le32_to_cpu(bde.bigdirattr);
146	obj->name_len = le32_to_cpu(bde.bigdirobnamelen);
147
148	offset = offsetof(struct adfs_bigdirheader, bigdirname);
149	offset += ((le32_to_cpu(h->bigdirnamelen) + 4) & ~3);
150	offset += le32_to_cpu(h->bigdirentries) * sizeof(struct adfs_bigdirentry);
151	offset += le32_to_cpu(bde.bigdirobnameptr);
152
153	dir_memcpy(dir, offset, obj->name, obj->name_len);
154	for (i = 0; i < obj->name_len; i++)
155		if (obj->name[i] == '/')
156			obj->name[i] = '.';
157
158	dir->pos += 1;
159	ret = 0;
160out:
161	return ret;
162}
163
164static void
165adfs_fplus_free(struct adfs_dir *dir)
166{
167	int i;
168
169	for (i = 0; i < dir->nr_buffers; i++)
170		brelse(dir->bh[i]);
171	dir->sb = NULL;
172}
173
174struct adfs_dir_ops adfs_fplus_dir_ops = {
175	.read		= adfs_fplus_read,
176	.setpos		= adfs_fplus_setpos,
177	.getnext	= adfs_fplus_getnext,
178	.free		= adfs_fplus_free
179};
180