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