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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 <linux/slab.h>
12#include "adfs.h"
13#include "dir_fplus.h"
14
15static int
16adfs_fplus_read(struct super_block *sb, unsigned int id, unsigned int sz, struct adfs_dir *dir)
17{
18 struct adfs_bigdirheader *h;
19 struct adfs_bigdirtail *t;
20 unsigned long block;
21 unsigned int blk, size;
22 int i, ret = -EIO;
23
24 dir->nr_buffers = 0;
25
26 /* start off using fixed bh set - only alloc for big dirs */
27 dir->bh_fplus = &dir->bh[0];
28
29 block = __adfs_block_map(sb, id, 0);
30 if (!block) {
31 adfs_error(sb, "dir object %X has a hole at offset 0", id);
32 goto out;
33 }
34
35 dir->bh_fplus[0] = sb_bread(sb, block);
36 if (!dir->bh_fplus[0])
37 goto out;
38 dir->nr_buffers += 1;
39
40 h = (struct adfs_bigdirheader *)dir->bh_fplus[0]->b_data;
41 size = le32_to_cpu(h->bigdirsize);
42 if (size != sz) {
43 printk(KERN_WARNING "adfs: adfs_fplus_read:"
44 " directory header size %X\n"
45 " does not match directory size %X\n",
46 size, sz);
47 }
48
49 if (h->bigdirversion[0] != 0 || h->bigdirversion[1] != 0 ||
50 h->bigdirversion[2] != 0 || size & 2047 ||
51 h->bigdirstartname != cpu_to_le32(BIGDIRSTARTNAME)) {
52 printk(KERN_WARNING "adfs: dir object %X has"
53 " malformed dir header\n", id);
54 goto out;
55 }
56
57 size >>= sb->s_blocksize_bits;
58 if (size > sizeof(dir->bh)/sizeof(dir->bh[0])) {
59 /* this directory is too big for fixed bh set, must allocate */
60 struct buffer_head **bh_fplus =
61 kzalloc(size * sizeof(struct buffer_head *),
62 GFP_KERNEL);
63 if (!bh_fplus) {
64 adfs_error(sb, "not enough memory for"
65 " dir object %X (%d blocks)", id, size);
66 goto out;
67 }
68 dir->bh_fplus = bh_fplus;
69 /* copy over the pointer to the block that we've already read */
70 dir->bh_fplus[0] = dir->bh[0];
71 }
72
73 for (blk = 1; blk < size; blk++) {
74 block = __adfs_block_map(sb, id, blk);
75 if (!block) {
76 adfs_error(sb, "dir object %X has a hole at offset %d", id, blk);
77 goto out;
78 }
79
80 dir->bh_fplus[blk] = sb_bread(sb, block);
81 if (!dir->bh_fplus[blk]) {
82 adfs_error(sb, "dir object %X failed read for"
83 " offset %d, mapped block %X",
84 id, blk, block);
85 goto out;
86 }
87
88 dir->nr_buffers += 1;
89 }
90
91 t = (struct adfs_bigdirtail *)
92 (dir->bh_fplus[size - 1]->b_data + (sb->s_blocksize - 8));
93
94 if (t->bigdirendname != cpu_to_le32(BIGDIRENDNAME) ||
95 t->bigdirendmasseq != h->startmasseq ||
96 t->reserved[0] != 0 || t->reserved[1] != 0) {
97 printk(KERN_WARNING "adfs: dir object %X has "
98 "malformed dir end\n", id);
99 goto out;
100 }
101
102 dir->parent_id = le32_to_cpu(h->bigdirparent);
103 dir->sb = sb;
104 return 0;
105
106out:
107 if (dir->bh_fplus) {
108 for (i = 0; i < dir->nr_buffers; i++)
109 brelse(dir->bh_fplus[i]);
110
111 if (&dir->bh[0] != dir->bh_fplus)
112 kfree(dir->bh_fplus);
113
114 dir->bh_fplus = NULL;
115 }
116
117 dir->nr_buffers = 0;
118 dir->sb = NULL;
119 return ret;
120}
121
122static int
123adfs_fplus_setpos(struct adfs_dir *dir, unsigned int fpos)
124{
125 struct adfs_bigdirheader *h =
126 (struct adfs_bigdirheader *) dir->bh_fplus[0]->b_data;
127 int ret = -ENOENT;
128
129 if (fpos <= le32_to_cpu(h->bigdirentries)) {
130 dir->pos = fpos;
131 ret = 0;
132 }
133
134 return ret;
135}
136
137static void
138dir_memcpy(struct adfs_dir *dir, unsigned int offset, void *to, int len)
139{
140 struct super_block *sb = dir->sb;
141 unsigned int buffer, partial, remainder;
142
143 buffer = offset >> sb->s_blocksize_bits;
144 offset &= sb->s_blocksize - 1;
145
146 partial = sb->s_blocksize - offset;
147
148 if (partial >= len)
149 memcpy(to, dir->bh_fplus[buffer]->b_data + offset, len);
150 else {
151 char *c = (char *)to;
152
153 remainder = len - partial;
154
155 memcpy(c,
156 dir->bh_fplus[buffer]->b_data + offset,
157 partial);
158
159 memcpy(c + partial,
160 dir->bh_fplus[buffer + 1]->b_data,
161 remainder);
162 }
163}
164
165static int
166adfs_fplus_getnext(struct adfs_dir *dir, struct object_info *obj)
167{
168 struct adfs_bigdirheader *h =
169 (struct adfs_bigdirheader *) dir->bh_fplus[0]->b_data;
170 struct adfs_bigdirentry bde;
171 unsigned int offset;
172 int i, ret = -ENOENT;
173
174 if (dir->pos >= le32_to_cpu(h->bigdirentries))
175 goto out;
176
177 offset = offsetof(struct adfs_bigdirheader, bigdirname);
178 offset += ((le32_to_cpu(h->bigdirnamelen) + 4) & ~3);
179 offset += dir->pos * sizeof(struct adfs_bigdirentry);
180
181 dir_memcpy(dir, offset, &bde, sizeof(struct adfs_bigdirentry));
182
183 obj->loadaddr = le32_to_cpu(bde.bigdirload);
184 obj->execaddr = le32_to_cpu(bde.bigdirexec);
185 obj->size = le32_to_cpu(bde.bigdirlen);
186 obj->file_id = le32_to_cpu(bde.bigdirindaddr);
187 obj->attr = le32_to_cpu(bde.bigdirattr);
188 obj->name_len = le32_to_cpu(bde.bigdirobnamelen);
189
190 offset = offsetof(struct adfs_bigdirheader, bigdirname);
191 offset += ((le32_to_cpu(h->bigdirnamelen) + 4) & ~3);
192 offset += le32_to_cpu(h->bigdirentries) * sizeof(struct adfs_bigdirentry);
193 offset += le32_to_cpu(bde.bigdirobnameptr);
194
195 dir_memcpy(dir, offset, obj->name, obj->name_len);
196 for (i = 0; i < obj->name_len; i++)
197 if (obj->name[i] == '/')
198 obj->name[i] = '.';
199
200 obj->filetype = -1;
201
202 /*
203 * object is a file and is filetyped and timestamped?
204 * RISC OS 12-bit filetype is stored in load_address[19:8]
205 */
206 if ((0 == (obj->attr & ADFS_NDA_DIRECTORY)) &&
207 (0xfff00000 == (0xfff00000 & obj->loadaddr))) {
208 obj->filetype = (__u16) ((0x000fff00 & obj->loadaddr) >> 8);
209
210 /* optionally append the ,xyz hex filetype suffix */
211 if (ADFS_SB(dir->sb)->s_ftsuffix)
212 obj->name_len +=
213 append_filetype_suffix(
214 &obj->name[obj->name_len],
215 obj->filetype);
216 }
217
218 dir->pos += 1;
219 ret = 0;
220out:
221 return ret;
222}
223
224static int
225adfs_fplus_sync(struct adfs_dir *dir)
226{
227 int err = 0;
228 int i;
229
230 for (i = dir->nr_buffers - 1; i >= 0; i--) {
231 struct buffer_head *bh = dir->bh_fplus[i];
232 sync_dirty_buffer(bh);
233 if (buffer_req(bh) && !buffer_uptodate(bh))
234 err = -EIO;
235 }
236
237 return err;
238}
239
240static void
241adfs_fplus_free(struct adfs_dir *dir)
242{
243 int i;
244
245 if (dir->bh_fplus) {
246 for (i = 0; i < dir->nr_buffers; i++)
247 brelse(dir->bh_fplus[i]);
248
249 if (&dir->bh[0] != dir->bh_fplus)
250 kfree(dir->bh_fplus);
251
252 dir->bh_fplus = NULL;
253 }
254
255 dir->nr_buffers = 0;
256 dir->sb = NULL;
257}
258
259struct adfs_dir_ops adfs_fplus_dir_ops = {
260 .read = adfs_fplus_read,
261 .setpos = adfs_fplus_setpos,
262 .getnext = adfs_fplus_getnext,
263 .sync = adfs_fplus_sync,
264 .free = adfs_fplus_free
265};
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * linux/fs/adfs/dir_fplus.c
4 *
5 * Copyright (C) 1997-1999 Russell King
6 */
7#include "adfs.h"
8#include "dir_fplus.h"
9
10/* Return the byte offset to directory entry pos */
11static unsigned int adfs_fplus_offset(const struct adfs_bigdirheader *h,
12 unsigned int pos)
13{
14 return offsetof(struct adfs_bigdirheader, bigdirname) +
15 ALIGN(le32_to_cpu(h->bigdirnamelen), 4) +
16 pos * sizeof(struct adfs_bigdirentry);
17}
18
19static int adfs_fplus_validate_header(const struct adfs_bigdirheader *h)
20{
21 unsigned int size = le32_to_cpu(h->bigdirsize);
22 unsigned int len;
23
24 if (h->bigdirversion[0] != 0 || h->bigdirversion[1] != 0 ||
25 h->bigdirversion[2] != 0 ||
26 h->bigdirstartname != cpu_to_le32(BIGDIRSTARTNAME) ||
27 !size || size & 2047 || size > SZ_4M)
28 return -EIO;
29
30 size -= sizeof(struct adfs_bigdirtail) +
31 offsetof(struct adfs_bigdirheader, bigdirname);
32
33 /* Check that bigdirnamelen fits within the directory */
34 len = ALIGN(le32_to_cpu(h->bigdirnamelen), 4);
35 if (len > size)
36 return -EIO;
37
38 size -= len;
39
40 /* Check that bigdirnamesize fits within the directory */
41 len = le32_to_cpu(h->bigdirnamesize);
42 if (len > size)
43 return -EIO;
44
45 size -= len;
46
47 /*
48 * Avoid division, we know that absolute maximum number of entries
49 * can not be so large to cause overflow of the multiplication below.
50 */
51 len = le32_to_cpu(h->bigdirentries);
52 if (len > SZ_4M / sizeof(struct adfs_bigdirentry) ||
53 len * sizeof(struct adfs_bigdirentry) > size)
54 return -EIO;
55
56 return 0;
57}
58
59static int adfs_fplus_validate_tail(const struct adfs_bigdirheader *h,
60 const struct adfs_bigdirtail *t)
61{
62 if (t->bigdirendname != cpu_to_le32(BIGDIRENDNAME) ||
63 t->bigdirendmasseq != h->startmasseq ||
64 t->reserved[0] != 0 || t->reserved[1] != 0)
65 return -EIO;
66
67 return 0;
68}
69
70static u8 adfs_fplus_checkbyte(struct adfs_dir *dir)
71{
72 struct adfs_bigdirheader *h = dir->bighead;
73 struct adfs_bigdirtail *t = dir->bigtail;
74 unsigned int end, bs, bi, i;
75 __le32 *bp;
76 u32 dircheck;
77
78 end = adfs_fplus_offset(h, le32_to_cpu(h->bigdirentries)) +
79 le32_to_cpu(h->bigdirnamesize);
80
81 /* Accumulate the contents of the header, entries and names */
82 for (dircheck = 0, bi = 0; end; bi++) {
83 bp = (void *)dir->bhs[bi]->b_data;
84 bs = dir->bhs[bi]->b_size;
85 if (bs > end)
86 bs = end;
87
88 for (i = 0; i < bs; i += sizeof(u32))
89 dircheck = ror32(dircheck, 13) ^ le32_to_cpup(bp++);
90
91 end -= bs;
92 }
93
94 /* Accumulate the contents of the tail except for the check byte */
95 dircheck = ror32(dircheck, 13) ^ le32_to_cpu(t->bigdirendname);
96 dircheck = ror32(dircheck, 13) ^ t->bigdirendmasseq;
97 dircheck = ror32(dircheck, 13) ^ t->reserved[0];
98 dircheck = ror32(dircheck, 13) ^ t->reserved[1];
99
100 return dircheck ^ dircheck >> 8 ^ dircheck >> 16 ^ dircheck >> 24;
101}
102
103static int adfs_fplus_read(struct super_block *sb, u32 indaddr,
104 unsigned int size, struct adfs_dir *dir)
105{
106 struct adfs_bigdirheader *h;
107 struct adfs_bigdirtail *t;
108 unsigned int dirsize;
109 int ret;
110
111 /* Read first buffer */
112 ret = adfs_dir_read_buffers(sb, indaddr, sb->s_blocksize, dir);
113 if (ret)
114 return ret;
115
116 dir->bighead = h = (void *)dir->bhs[0]->b_data;
117 ret = adfs_fplus_validate_header(h);
118 if (ret) {
119 adfs_error(sb, "dir %06x has malformed header", indaddr);
120 goto out;
121 }
122
123 dirsize = le32_to_cpu(h->bigdirsize);
124 if (size && dirsize != size) {
125 adfs_msg(sb, KERN_WARNING,
126 "dir %06x header size %X does not match directory size %X",
127 indaddr, dirsize, size);
128 }
129
130 /* Read remaining buffers */
131 ret = adfs_dir_read_buffers(sb, indaddr, dirsize, dir);
132 if (ret)
133 return ret;
134
135 dir->bigtail = t = (struct adfs_bigdirtail *)
136 (dir->bhs[dir->nr_buffers - 1]->b_data + (sb->s_blocksize - 8));
137
138 ret = adfs_fplus_validate_tail(h, t);
139 if (ret) {
140 adfs_error(sb, "dir %06x has malformed tail", indaddr);
141 goto out;
142 }
143
144 if (adfs_fplus_checkbyte(dir) != t->bigdircheckbyte) {
145 adfs_error(sb, "dir %06x checkbyte mismatch\n", indaddr);
146 goto out;
147 }
148
149 dir->parent_id = le32_to_cpu(h->bigdirparent);
150 return 0;
151
152out:
153 adfs_dir_relse(dir);
154
155 return ret;
156}
157
158static int
159adfs_fplus_setpos(struct adfs_dir *dir, unsigned int fpos)
160{
161 int ret = -ENOENT;
162
163 if (fpos <= le32_to_cpu(dir->bighead->bigdirentries)) {
164 dir->pos = fpos;
165 ret = 0;
166 }
167
168 return ret;
169}
170
171static int
172adfs_fplus_getnext(struct adfs_dir *dir, struct object_info *obj)
173{
174 struct adfs_bigdirheader *h = dir->bighead;
175 struct adfs_bigdirentry bde;
176 unsigned int offset;
177 int ret;
178
179 if (dir->pos >= le32_to_cpu(h->bigdirentries))
180 return -ENOENT;
181
182 offset = adfs_fplus_offset(h, dir->pos);
183
184 ret = adfs_dir_copyfrom(&bde, dir, offset,
185 sizeof(struct adfs_bigdirentry));
186 if (ret)
187 return ret;
188
189 obj->loadaddr = le32_to_cpu(bde.bigdirload);
190 obj->execaddr = le32_to_cpu(bde.bigdirexec);
191 obj->size = le32_to_cpu(bde.bigdirlen);
192 obj->indaddr = le32_to_cpu(bde.bigdirindaddr);
193 obj->attr = le32_to_cpu(bde.bigdirattr);
194 obj->name_len = le32_to_cpu(bde.bigdirobnamelen);
195
196 offset = adfs_fplus_offset(h, le32_to_cpu(h->bigdirentries));
197 offset += le32_to_cpu(bde.bigdirobnameptr);
198
199 ret = adfs_dir_copyfrom(obj->name, dir, offset, obj->name_len);
200 if (ret)
201 return ret;
202
203 adfs_object_fixup(dir, obj);
204
205 dir->pos += 1;
206
207 return 0;
208}
209
210static int adfs_fplus_iterate(struct adfs_dir *dir, struct dir_context *ctx)
211{
212 struct object_info obj;
213
214 if ((ctx->pos - 2) >> 32)
215 return 0;
216
217 if (adfs_fplus_setpos(dir, ctx->pos - 2))
218 return 0;
219
220 while (!adfs_fplus_getnext(dir, &obj)) {
221 if (!dir_emit(ctx, obj.name, obj.name_len,
222 obj.indaddr, DT_UNKNOWN))
223 break;
224 ctx->pos++;
225 }
226
227 return 0;
228}
229
230static int adfs_fplus_update(struct adfs_dir *dir, struct object_info *obj)
231{
232 struct adfs_bigdirheader *h = dir->bighead;
233 struct adfs_bigdirentry bde;
234 int offset, end, ret;
235
236 offset = adfs_fplus_offset(h, 0) - sizeof(bde);
237 end = adfs_fplus_offset(h, le32_to_cpu(h->bigdirentries));
238
239 do {
240 offset += sizeof(bde);
241 if (offset >= end) {
242 adfs_error(dir->sb, "unable to locate entry to update");
243 return -ENOENT;
244 }
245 ret = adfs_dir_copyfrom(&bde, dir, offset, sizeof(bde));
246 if (ret) {
247 adfs_error(dir->sb, "error reading directory entry");
248 return -ENOENT;
249 }
250 } while (le32_to_cpu(bde.bigdirindaddr) != obj->indaddr);
251
252 bde.bigdirload = cpu_to_le32(obj->loadaddr);
253 bde.bigdirexec = cpu_to_le32(obj->execaddr);
254 bde.bigdirlen = cpu_to_le32(obj->size);
255 bde.bigdirindaddr = cpu_to_le32(obj->indaddr);
256 bde.bigdirattr = cpu_to_le32(obj->attr);
257
258 return adfs_dir_copyto(dir, offset, &bde, sizeof(bde));
259}
260
261static int adfs_fplus_commit(struct adfs_dir *dir)
262{
263 int ret;
264
265 /* Increment directory sequence number */
266 dir->bighead->startmasseq += 1;
267 dir->bigtail->bigdirendmasseq += 1;
268
269 /* Update directory check byte */
270 dir->bigtail->bigdircheckbyte = adfs_fplus_checkbyte(dir);
271
272 /* Make sure the directory still validates correctly */
273 ret = adfs_fplus_validate_header(dir->bighead);
274 if (ret == 0)
275 ret = adfs_fplus_validate_tail(dir->bighead, dir->bigtail);
276
277 return ret;
278}
279
280const struct adfs_dir_ops adfs_fplus_dir_ops = {
281 .read = adfs_fplus_read,
282 .iterate = adfs_fplus_iterate,
283 .setpos = adfs_fplus_setpos,
284 .getnext = adfs_fplus_getnext,
285 .update = adfs_fplus_update,
286 .commit = adfs_fplus_commit,
287};