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
22 static int
adfs_fplus_read(struct super_block * sb,unsigned int id,unsigned int sz,struct adfs_dir * dir)23 adfs_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;
80 out:
81 for (i = 0; i < dir->nr_buffers; i++)
82 brelse(dir->bh[i]);
83 dir->sb = NULL;
84 return ret;
85 }
86
87 static int
adfs_fplus_setpos(struct adfs_dir * dir,unsigned int fpos)88 adfs_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
101 static void
dir_memcpy(struct adfs_dir * dir,unsigned int offset,void * to,int len)102 dir_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
124 static int
adfs_fplus_getnext(struct adfs_dir * dir,struct object_info * obj)125 adfs_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;
160 out:
161 return ret;
162 }
163
164 static void
adfs_fplus_free(struct adfs_dir * dir)165 adfs_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
174 struct 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