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/buffer_head.h>
11#include "adfs.h"
12#include "dir_fplus.h"
13
14static int
15adfs_fplus_read(struct super_block *sb, unsigned int id, unsigned int sz, struct adfs_dir *dir)
16{
17	struct adfs_bigdirheader *h;
18	struct adfs_bigdirtail *t;
19	unsigned long block;
20	unsigned int blk, size;
21	int i, ret = -EIO;
22
23	dir->nr_buffers = 0;
24
25	block = __adfs_block_map(sb, id, 0);
26	if (!block) {
27		adfs_error(sb, "dir object %X has a hole at offset 0", id);
28		goto out;
29	}
30
31	dir->bh[0] = sb_bread(sb, block);
32	if (!dir->bh[0])
33		goto out;
34	dir->nr_buffers += 1;
35
36	h = (struct adfs_bigdirheader *)dir->bh[0]->b_data;
37	size = le32_to_cpu(h->bigdirsize);
38	if (size != sz) {
39		printk(KERN_WARNING "adfs: adfs_fplus_read: directory header size\n"
40				" does not match directory size\n");
41	}
42
43	if (h->bigdirversion[0] != 0 || h->bigdirversion[1] != 0 ||
44	    h->bigdirversion[2] != 0 || size & 2047 ||
45	    h->bigdirstartname != cpu_to_le32(BIGDIRSTARTNAME))
46		goto out;
47
48	size >>= sb->s_blocksize_bits;
49	for (blk = 1; blk < size; blk++) {
50		block = __adfs_block_map(sb, id, blk);
51		if (!block) {
52			adfs_error(sb, "dir object %X has a hole at offset %d", id, blk);
53			goto out;
54		}
55
56		dir->bh[blk] = sb_bread(sb, block);
57		if (!dir->bh[blk])
58			goto out;
59		dir->nr_buffers = blk;
60	}
61
62	t = (struct adfs_bigdirtail *)(dir->bh[size - 1]->b_data + (sb->s_blocksize - 8));
63
64	if (t->bigdirendname != cpu_to_le32(BIGDIRENDNAME) ||
65	    t->bigdirendmasseq != h->startmasseq ||
66	    t->reserved[0] != 0 || t->reserved[1] != 0)
67		goto out;
68
69	dir->parent_id = le32_to_cpu(h->bigdirparent);
70	dir->sb = sb;
71	return 0;
72out:
73	for (i = 0; i < dir->nr_buffers; i++)
74		brelse(dir->bh[i]);
75	dir->sb = NULL;
76	return ret;
77}
78
79static int
80adfs_fplus_setpos(struct adfs_dir *dir, unsigned int fpos)
81{
82	struct adfs_bigdirheader *h = (struct adfs_bigdirheader *)dir->bh[0]->b_data;
83	int ret = -ENOENT;
84
85	if (fpos <= le32_to_cpu(h->bigdirentries)) {
86		dir->pos = fpos;
87		ret = 0;
88	}
89
90	return ret;
91}
92
93static void
94dir_memcpy(struct adfs_dir *dir, unsigned int offset, void *to, int len)
95{
96	struct super_block *sb = dir->sb;
97	unsigned int buffer, partial, remainder;
98
99	buffer = offset >> sb->s_blocksize_bits;
100	offset &= sb->s_blocksize - 1;
101
102	partial = sb->s_blocksize - offset;
103
104	if (partial >= len)
105		memcpy(to, dir->bh[buffer]->b_data + offset, len);
106	else {
107		char *c = (char *)to;
108
109		remainder = len - partial;
110
111		memcpy(c, dir->bh[buffer]->b_data + offset, partial);
112		memcpy(c + partial, dir->bh[buffer + 1]->b_data, remainder);
113	}
114}
115
116static int
117adfs_fplus_getnext(struct adfs_dir *dir, struct object_info *obj)
118{
119	struct adfs_bigdirheader *h = (struct adfs_bigdirheader *)dir->bh[0]->b_data;
120	struct adfs_bigdirentry bde;
121	unsigned int offset;
122	int i, ret = -ENOENT;
123
124	if (dir->pos >= le32_to_cpu(h->bigdirentries))
125		goto out;
126
127	offset = offsetof(struct adfs_bigdirheader, bigdirname);
128	offset += ((le32_to_cpu(h->bigdirnamelen) + 4) & ~3);
129	offset += dir->pos * sizeof(struct adfs_bigdirentry);
130
131	dir_memcpy(dir, offset, &bde, sizeof(struct adfs_bigdirentry));
132
133	obj->loadaddr = le32_to_cpu(bde.bigdirload);
134	obj->execaddr = le32_to_cpu(bde.bigdirexec);
135	obj->size     = le32_to_cpu(bde.bigdirlen);
136	obj->file_id  = le32_to_cpu(bde.bigdirindaddr);
137	obj->attr     = le32_to_cpu(bde.bigdirattr);
138	obj->name_len = le32_to_cpu(bde.bigdirobnamelen);
139
140	offset = offsetof(struct adfs_bigdirheader, bigdirname);
141	offset += ((le32_to_cpu(h->bigdirnamelen) + 4) & ~3);
142	offset += le32_to_cpu(h->bigdirentries) * sizeof(struct adfs_bigdirentry);
143	offset += le32_to_cpu(bde.bigdirobnameptr);
144
145	dir_memcpy(dir, offset, obj->name, obj->name_len);
146	for (i = 0; i < obj->name_len; i++)
147		if (obj->name[i] == '/')
148			obj->name[i] = '.';
149
150	dir->pos += 1;
151	ret = 0;
152out:
153	return ret;
154}
155
156static int
157adfs_fplus_sync(struct adfs_dir *dir)
158{
159	int err = 0;
160	int i;
161
162	for (i = dir->nr_buffers - 1; i >= 0; i--) {
163		struct buffer_head *bh = dir->bh[i];
164		sync_dirty_buffer(bh);
165		if (buffer_req(bh) && !buffer_uptodate(bh))
166			err = -EIO;
167	}
168
169	return err;
170}
171
172static void
173adfs_fplus_free(struct adfs_dir *dir)
174{
175	int i;
176
177	for (i = 0; i < dir->nr_buffers; i++)
178		brelse(dir->bh[i]);
179	dir->sb = NULL;
180}
181
182struct adfs_dir_ops adfs_fplus_dir_ops = {
183	.read		= adfs_fplus_read,
184	.setpos		= adfs_fplus_setpos,
185	.getnext	= adfs_fplus_getnext,
186	.sync		= adfs_fplus_sync,
187	.free		= adfs_fplus_free
188};
189