change system file

hc

2024-10-09 244b2c5ca8b14627e4a17755e5922221e121c771

 kernel/fs/adfs/dir_fplus.c
..
..
@@ -1,132 +1,166 @@
1
+// SPDX-License-Identifier: GPL-2.0-only
1
2
 /*
2
3
  *  linux/fs/adfs/dir_fplus.c
3
4
  *
4
5
  *  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
6
  */
10
-#include <linux/buffer_head.h>
11
-#include <linux/slab.h>
12
7
 #include "adfs.h"
13
8
 #include "dir_fplus.h"
14
9
 
15
-static int
16
-adfs_fplus_read(struct super_block *sb, unsigned int id, unsigned int sz, struct adfs_dir *dir)
10
+/* Return the byte offset to directory entry pos */
11
+static 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
+
19
+static 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
+
59
+static 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
+
70
+static 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
+
103
+static int adfs_fplus_read(struct super_block *sb, u32 indaddr,
104
+			   unsigned int size, struct adfs_dir *dir)
17
105
 {
18
106
 	struct adfs_bigdirheader *h;
19
107
 	struct adfs_bigdirtail *t;
20
-	unsigned long block;
21
-	unsigned int blk, size;
22
-	int i, ret = -EIO;
108
+	unsigned int dirsize;
109
+	int ret;
23
110
 
24
-	dir->nr_buffers = 0;
111
+	/* Read first buffer */
112
+	ret = adfs_dir_read_buffers(sb, indaddr, sb->s_blocksize, dir);
113
+	if (ret)
114
+		return ret;
25
115
 
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);
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);
32
120
 		goto out;
33
121
 	}
34
122
 
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);
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);
47
128
 	}
48
129
 
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);
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);
54
141
 		goto out;
55
142
 	}
56
143
 
57
-	size >>= sb->s_blocksize_bits;
58
-	if (size > ARRAY_SIZE(dir->bh)) {
59
-		/* this directory is too big for fixed bh set, must allocate */
60
-		struct buffer_head **bh_fplus =
61
-			kcalloc(size, sizeof(struct buffer_head *),
62
-				GFP_KERNEL);
63
-		if (!bh_fplus) {
64
-			ret = -ENOMEM;
65
-			adfs_error(sb, "not enough memory for"
66
-					" dir object %X (%d blocks)", id, size);
67
-			goto out;
68
-		}
69
-		dir->bh_fplus = bh_fplus;
70
-		/* copy over the pointer to the block that we've already read */
71
-		dir->bh_fplus[0] = dir->bh[0];
72
-	}
73
-
74
-	for (blk = 1; blk < size; blk++) {
75
-		block = __adfs_block_map(sb, id, blk);
76
-		if (!block) {
77
-			adfs_error(sb, "dir object %X has a hole at offset %d", id, blk);
78
-			goto out;
79
-		}
80
-
81
-		dir->bh_fplus[blk] = sb_bread(sb, block);
82
-		if (!dir->bh_fplus[blk]) {
83
-			adfs_error(sb,	"dir object %x failed read for offset %d, mapped block %lX",
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);
144
+	if (adfs_fplus_checkbyte(dir) != t->bigdircheckbyte) {
145
+		adfs_error(sb, "dir %06x checkbyte mismatch\n", indaddr);
99
146
 		goto out;
100
147
 	}
101
148
 
102
149
 	dir->parent_id = le32_to_cpu(h->bigdirparent);
103
-	dir->sb = sb;
104
150
 	return 0;
105
151
 
106
152
 out:
107
-	if (dir->bh_fplus) {
108
-		for (i = 0; i < dir->nr_buffers; i++)
109
-			brelse(dir->bh_fplus[i]);
153
+	adfs_dir_relse(dir);
110
154
 
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
155
 	return ret;
120
156
 }
121
157
 
122
158
 static int
123
159
 adfs_fplus_setpos(struct adfs_dir *dir, unsigned int fpos)
124
160
 {
125
-	struct adfs_bigdirheader *h =
126
-		(struct adfs_bigdirheader *) dir->bh_fplus[0]->b_data;
127
161
 	int ret = -ENOENT;
128
162
 
129
-	if (fpos <= le32_to_cpu(h->bigdirentries)) {
163
+	if (fpos <= le32_to_cpu(dir->bighead->bigdirentries)) {
130
164
 		dir->pos = fpos;
131
165
 		ret = 0;
132
166
 	}
..
..
@@ -134,132 +168,120 @@
134
168
 	return ret;
135
169
 }
136
170
 
137
-static void
138
-dir_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
-
165
171
 static int
166
172
 adfs_fplus_getnext(struct adfs_dir *dir, struct object_info *obj)
167
173
 {
168
-	struct adfs_bigdirheader *h =
169
-		(struct adfs_bigdirheader *) dir->bh_fplus[0]->b_data;
174
+	struct adfs_bigdirheader *h = dir->bighead;
170
175
 	struct adfs_bigdirentry bde;
171
176
 	unsigned int offset;
172
-	int i, ret = -ENOENT;
177
+	int ret;
173
178
 
174
179
 	if (dir->pos >= le32_to_cpu(h->bigdirentries))
175
-		goto out;
180
+		return -ENOENT;
176
181
 
177
-	offset = offsetof(struct adfs_bigdirheader, bigdirname);
178
-	offset += ((le32_to_cpu(h->bigdirnamelen) + 4) & ~3);
179
-	offset += dir->pos * sizeof(struct adfs_bigdirentry);
182
+	offset = adfs_fplus_offset(h, dir->pos);
180
183
 
181
-	dir_memcpy(dir, offset, &bde, sizeof(struct adfs_bigdirentry));
184
+	ret = adfs_dir_copyfrom(&bde, dir, offset,
185
+				sizeof(struct adfs_bigdirentry));
186
+	if (ret)
187
+		return ret;
182
188
 
183
189
 	obj->loadaddr = le32_to_cpu(bde.bigdirload);
184
190
 	obj->execaddr = le32_to_cpu(bde.bigdirexec);
185
191
 	obj->size     = le32_to_cpu(bde.bigdirlen);
186
-	obj->file_id  = le32_to_cpu(bde.bigdirindaddr);
192
+	obj->indaddr  = le32_to_cpu(bde.bigdirindaddr);
187
193
 	obj->attr     = le32_to_cpu(bde.bigdirattr);
188
194
 	obj->name_len = le32_to_cpu(bde.bigdirobnamelen);
189
195
 
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);
196
+	offset = adfs_fplus_offset(h, le32_to_cpu(h->bigdirentries));
193
197
 	offset += le32_to_cpu(bde.bigdirobnameptr);
194
198
 
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
+	ret = adfs_dir_copyfrom(obj->name, dir, offset, obj->name_len);
200
+	if (ret)
201
+		return ret;
199
202
 
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
-	}
203
+	adfs_object_fixup(dir, obj);
217
204
 
218
205
 	dir->pos += 1;
219
-	ret = 0;
220
-out:
206
+
207
+	return 0;
208
+}
209
+
210
+static 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
+
230
+static 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
+
261
+static 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
+
221
277
 	return ret;
222
-}
223
-
224
-static int
225
-adfs_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
-
240
-static void
241
-adfs_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
278
 }
258
279
 
259
280
 const struct adfs_dir_ops adfs_fplus_dir_ops = {
260
281
 	.read		= adfs_fplus_read,
282
+	.iterate	= adfs_fplus_iterate,
261
283
 	.setpos		= adfs_fplus_setpos,
262
284
 	.getnext	= adfs_fplus_getnext,
263
-	.sync		= adfs_fplus_sync,
264
-	.free		= adfs_fplus_free
285
+	.update		= adfs_fplus_update,
286
+	.commit		= adfs_fplus_commit,
265
287
 };