summaryrefslogtreecommitdiff
path: root/fs/yaffs2/yaffs_checkptrw.c
blob: 997a618aee86c80435e722a22e87a58f7bc9b620 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
/*
 * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
 *
 * Copyright (C) 2002-2011 Aleph One Ltd.
 *   for Toby Churchill Ltd and Brightstar Engineering
 *
 * Created by Charles Manning <charles@aleph1.co.uk>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include "yaffs_checkptrw.h"
#include "yaffs_getblockinfo.h"

static int yaffs2_checkpt_space_ok(struct yaffs_dev *dev)
{
	int blocks_avail = dev->n_erased_blocks - dev->param.n_reserved_blocks;

	yaffs_trace(YAFFS_TRACE_CHECKPOINT,
		"checkpt blocks_avail = %d", blocks_avail);

	return (blocks_avail <= 0) ? 0 : 1;
}

static int yaffs_checkpt_erase(struct yaffs_dev *dev)
{
	int i;

	if (!dev->param.erase_fn)
		return 0;
	yaffs_trace(YAFFS_TRACE_CHECKPOINT,
		"checking blocks %d to %d",
		dev->internal_start_block, dev->internal_end_block);

	for (i = dev->internal_start_block; i <= dev->internal_end_block; i++) {
		struct yaffs_block_info *bi = yaffs_get_block_info(dev, i);
		if (bi->block_state == YAFFS_BLOCK_STATE_CHECKPOINT) {
			yaffs_trace(YAFFS_TRACE_CHECKPOINT,
			"erasing checkpt block %d", i);

			dev->n_erasures++;

			if (dev->param.
			    erase_fn(dev,
				     i - dev->block_offset /* realign */)) {
				bi->block_state = YAFFS_BLOCK_STATE_EMPTY;
				dev->n_erased_blocks++;
				dev->n_free_chunks +=
				    dev->param.chunks_per_block;
			} else {
				dev->param.bad_block_fn(dev, i);
				bi->block_state = YAFFS_BLOCK_STATE_DEAD;
			}
		}
	}

	dev->blocks_in_checkpt = 0;

	return 1;
}

static void yaffs2_checkpt_find_erased_block(struct yaffs_dev *dev)
{
	int i;
	int blocks_avail = dev->n_erased_blocks - dev->param.n_reserved_blocks;

	yaffs_trace(YAFFS_TRACE_CHECKPOINT,
		"allocating checkpt block: erased %d reserved %d avail %d next %d ",
		dev->n_erased_blocks, dev->param.n_reserved_blocks,
		blocks_avail, dev->checkpt_next_block);

	if (dev->checkpt_next_block >= 0 &&
	    dev->checkpt_next_block <= dev->internal_end_block &&
	    blocks_avail > 0) {

		for (i = dev->checkpt_next_block; i <= dev->internal_end_block;
		     i++) {
			struct yaffs_block_info *bi =
			    yaffs_get_block_info(dev, i);
			if (bi->block_state == YAFFS_BLOCK_STATE_EMPTY) {
				dev->checkpt_next_block = i + 1;
				dev->checkpt_cur_block = i;
				yaffs_trace(YAFFS_TRACE_CHECKPOINT,
					"allocating checkpt block %d", i);
				return;
			}
		}
	}
	yaffs_trace(YAFFS_TRACE_CHECKPOINT, "out of checkpt blocks");

	dev->checkpt_next_block = -1;
	dev->checkpt_cur_block = -1;
}

static void yaffs2_checkpt_find_block(struct yaffs_dev *dev)
{
	int i;
	struct yaffs_ext_tags tags;

	yaffs_trace(YAFFS_TRACE_CHECKPOINT,
		"find next checkpt block: start:  blocks %d next %d",
		dev->blocks_in_checkpt, dev->checkpt_next_block);

	if (dev->blocks_in_checkpt < dev->checkpt_max_blocks)
		for (i = dev->checkpt_next_block; i <= dev->internal_end_block;
		     i++) {
			int chunk = i * dev->param.chunks_per_block;
			int realigned_chunk = chunk - dev->chunk_offset;

			dev->param.read_chunk_tags_fn(dev, realigned_chunk,
						      NULL, &tags);
			yaffs_trace(YAFFS_TRACE_CHECKPOINT,
				"find next checkpt block: search: block %d oid %d seq %d eccr %d",
				i, tags.obj_id, tags.seq_number,
				tags.ecc_result);

			if (tags.seq_number == YAFFS_SEQUENCE_CHECKPOINT_DATA) {
				/* Right kind of block */
				dev->checkpt_next_block = tags.obj_id;
				dev->checkpt_cur_block = i;
				dev->checkpt_block_list[dev->
							blocks_in_checkpt] = i;
				dev->blocks_in_checkpt++;
				yaffs_trace(YAFFS_TRACE_CHECKPOINT,
					"found checkpt block %d", i);
				return;
			}
		}

	yaffs_trace(YAFFS_TRACE_CHECKPOINT, "found no more checkpt blocks");

	dev->checkpt_next_block = -1;
	dev->checkpt_cur_block = -1;
}

int yaffs2_checkpt_open(struct yaffs_dev *dev, int writing)
{
	int i;

	dev->checkpt_open_write = writing;

	/* Got the functions we need? */
	if (!dev->param.write_chunk_tags_fn ||
	    !dev->param.read_chunk_tags_fn ||
	    !dev->param.erase_fn || !dev->param.bad_block_fn)
		return 0;

	if (writing && !yaffs2_checkpt_space_ok(dev))
		return 0;

	if (!dev->checkpt_buffer)
		dev->checkpt_buffer =
		    kmalloc(dev->param.total_bytes_per_chunk, GFP_NOFS);
	if (!dev->checkpt_buffer)
		return 0;

	dev->checkpt_page_seq = 0;
	dev->checkpt_byte_count = 0;
	dev->checkpt_sum = 0;
	dev->checkpt_xor = 0;
	dev->checkpt_cur_block = -1;
	dev->checkpt_cur_chunk = -1;
	dev->checkpt_next_block = dev->internal_start_block;

	/* Erase all the blocks in the checkpoint area */
	if (writing) {
		memset(dev->checkpt_buffer, 0, dev->data_bytes_per_chunk);
		dev->checkpt_byte_offs = 0;
		return yaffs_checkpt_erase(dev);
	}

	/* Set to a value that will kick off a read */
	dev->checkpt_byte_offs = dev->data_bytes_per_chunk;
	/* A checkpoint block list of 1 checkpoint block per 16 block is
	 * (hopefully) going to be way more than we need */
	dev->blocks_in_checkpt = 0;
	dev->checkpt_max_blocks =
	    (dev->internal_end_block - dev->internal_start_block) / 16 + 2;
	dev->checkpt_block_list =
	    kmalloc(sizeof(int) * dev->checkpt_max_blocks, GFP_NOFS);

	if (!dev->checkpt_block_list)
		return 0;

	for (i = 0; i < dev->checkpt_max_blocks; i++)
		dev->checkpt_block_list[i] = -1;

	return 1;
}

int yaffs2_get_checkpt_sum(struct yaffs_dev *dev, u32 * sum)
{
	u32 composite_sum;

	composite_sum = (dev->checkpt_sum << 8) | (dev->checkpt_xor & 0xff);
	*sum = composite_sum;
	return 1;
}

static int yaffs2_checkpt_flush_buffer(struct yaffs_dev *dev)
{
	int chunk;
	int realigned_chunk;
	struct yaffs_ext_tags tags;

	if (dev->checkpt_cur_block < 0) {
		yaffs2_checkpt_find_erased_block(dev);
		dev->checkpt_cur_chunk = 0;
	}

	if (dev->checkpt_cur_block < 0)
		return 0;

	tags.is_deleted = 0;
	tags.obj_id = dev->checkpt_next_block;	/* Hint to next place to look */
	tags.chunk_id = dev->checkpt_page_seq + 1;
	tags.seq_number = YAFFS_SEQUENCE_CHECKPOINT_DATA;
	tags.n_bytes = dev->data_bytes_per_chunk;
	if (dev->checkpt_cur_chunk == 0) {
		/* First chunk we write for the block? Set block state to
		   checkpoint */
		struct yaffs_block_info *bi =
		    yaffs_get_block_info(dev, dev->checkpt_cur_block);
		bi->block_state = YAFFS_BLOCK_STATE_CHECKPOINT;
		dev->blocks_in_checkpt++;
	}

	chunk =
	    dev->checkpt_cur_block * dev->param.chunks_per_block +
	    dev->checkpt_cur_chunk;

	yaffs_trace(YAFFS_TRACE_CHECKPOINT,
		"checkpoint wite buffer nand %d(%d:%d) objid %d chId %d",
		chunk, dev->checkpt_cur_block, dev->checkpt_cur_chunk,
		tags.obj_id, tags.chunk_id);

	realigned_chunk = chunk - dev->chunk_offset;

	dev->n_page_writes++;

	dev->param.write_chunk_tags_fn(dev, realigned_chunk,
				       dev->checkpt_buffer, &tags);
	dev->checkpt_byte_offs = 0;
	dev->checkpt_page_seq++;
	dev->checkpt_cur_chunk++;
	if (dev->checkpt_cur_chunk >= dev->param.chunks_per_block) {
		dev->checkpt_cur_chunk = 0;
		dev->checkpt_cur_block = -1;
	}
	memset(dev->checkpt_buffer, 0, dev->data_bytes_per_chunk);

	return 1;
}

int yaffs2_checkpt_wr(struct yaffs_dev *dev, const void *data, int n_bytes)
{
	int i = 0;
	int ok = 1;
	u8 *data_bytes = (u8 *) data;

	if (!dev->checkpt_buffer)
		return 0;

	if (!dev->checkpt_open_write)
		return -1;

	while (i < n_bytes && ok) {
		dev->checkpt_buffer[dev->checkpt_byte_offs] = *data_bytes;
		dev->checkpt_sum += *data_bytes;
		dev->checkpt_xor ^= *data_bytes;

		dev->checkpt_byte_offs++;
		i++;
		data_bytes++;
		dev->checkpt_byte_count++;

		if (dev->checkpt_byte_offs < 0 ||
		    dev->checkpt_byte_offs >= dev->data_bytes_per_chunk)
			ok = yaffs2_checkpt_flush_buffer(dev);
	}

	return i;
}

int yaffs2_checkpt_rd(struct yaffs_dev *dev, void *data, int n_bytes)
{
	int i = 0;
	int ok = 1;
	struct yaffs_ext_tags tags;
	int chunk;
	int realigned_chunk;
	u8 *data_bytes = (u8 *) data;

	if (!dev->checkpt_buffer)
		return 0;

	if (dev->checkpt_open_write)
		return -1;

	while (i < n_bytes && ok) {

		if (dev->checkpt_byte_offs < 0 ||
		    dev->checkpt_byte_offs >= dev->data_bytes_per_chunk) {

			if (dev->checkpt_cur_block < 0) {
				yaffs2_checkpt_find_block(dev);
				dev->checkpt_cur_chunk = 0;
			}

			if (dev->checkpt_cur_block < 0) {
				ok = 0;
				break;
			}

			chunk = dev->checkpt_cur_block *
			    dev->param.chunks_per_block +
			    dev->checkpt_cur_chunk;

			realigned_chunk = chunk - dev->chunk_offset;
			dev->n_page_reads++;

			/* read in the next chunk */
			dev->param.read_chunk_tags_fn(dev,
						realigned_chunk,
						dev->checkpt_buffer,
						&tags);

			if (tags.chunk_id != (dev->checkpt_page_seq + 1) ||
			    tags.ecc_result > YAFFS_ECC_RESULT_FIXED ||
			    tags.seq_number != YAFFS_SEQUENCE_CHECKPOINT_DATA) {
				ok = 0;
				break;
			}

			dev->checkpt_byte_offs = 0;
			dev->checkpt_page_seq++;
			dev->checkpt_cur_chunk++;

			if (dev->checkpt_cur_chunk >=
					dev->param.chunks_per_block)
				dev->checkpt_cur_block = -1;
		}

		*data_bytes = dev->checkpt_buffer[dev->checkpt_byte_offs];
		dev->checkpt_sum += *data_bytes;
		dev->checkpt_xor ^= *data_bytes;
		dev->checkpt_byte_offs++;
		i++;
		data_bytes++;
		dev->checkpt_byte_count++;
	}

	return i;
}

int yaffs_checkpt_close(struct yaffs_dev *dev)
{
	int i;

	if (dev->checkpt_open_write) {
		if (dev->checkpt_byte_offs != 0)
			yaffs2_checkpt_flush_buffer(dev);
	} else if (dev->checkpt_block_list) {
		for (i = 0;
		     i < dev->blocks_in_checkpt &&
		     dev->checkpt_block_list[i] >= 0; i++) {
			int blk = dev->checkpt_block_list[i];
			struct yaffs_block_info *bi = NULL;

			if (dev->internal_start_block <= blk &&
			    blk <= dev->internal_end_block)
				bi = yaffs_get_block_info(dev, blk);
			if (bi && bi->block_state == YAFFS_BLOCK_STATE_EMPTY)
				bi->block_state = YAFFS_BLOCK_STATE_CHECKPOINT;
		}
		kfree(dev->checkpt_block_list);
		dev->checkpt_block_list = NULL;
	}

	dev->n_free_chunks -=
		dev->blocks_in_checkpt * dev->param.chunks_per_block;
	dev->n_erased_blocks -= dev->blocks_in_checkpt;

	yaffs_trace(YAFFS_TRACE_CHECKPOINT, "checkpoint byte count %d",
		dev->checkpt_byte_count);

	if (dev->checkpt_buffer) {
		/* free the buffer */
		kfree(dev->checkpt_buffer);
		dev->checkpt_buffer = NULL;
		return 1;
	} else {
		return 0;
	}
}

int yaffs2_checkpt_invalidate_stream(struct yaffs_dev *dev)
{
	/* Erase the checkpoint data */

	yaffs_trace(YAFFS_TRACE_CHECKPOINT,
		"checkpoint invalidate of %d blocks",
		dev->blocks_in_checkpt);

	return yaffs_checkpt_erase(dev);
}