fs/yaffs2/yaffs_checkptrw.c

25 static int apply_chunk_offset(struct yaffs_dev *dev, int chunk)
27 	return chunk - dev->chunk_offset;
30 static int apply_block_offset(struct yaffs_dev *dev, int block)
32 	return block - dev->block_offset;
35 static void yaffs2_checkpt_init_chunk_hdr(struct yaffs_dev *dev)
40 	hdr.seq = dev->checkpt_page_seq;
41 	hdr.sum = dev->checkpt_sum;
42 	hdr.xor = dev->checkpt_xor;
44 	dev->checkpt_byte_offs = sizeof(hdr);
46 	memcpy(dev->checkpt_buffer, &hdr, sizeof(hdr));
49 static int yaffs2_checkpt_check_chunk_hdr(struct yaffs_dev *dev)
53 	memcpy(&hdr, dev->checkpt_buffer, sizeof(hdr));
55 	dev->checkpt_byte_offs = sizeof(hdr);
58 		hdr.seq == dev->checkpt_page_seq &&
59 		hdr.sum == dev->checkpt_sum &&
60 		hdr.xor == dev->checkpt_xor;
63 static int yaffs2_checkpt_space_ok(struct yaffs_dev *dev)
65 	int blocks_avail = dev->n_erased_blocks - dev->param.n_reserved_blocks;
73 static int yaffs_checkpt_erase(struct yaffs_dev *dev)
77 	if (!dev->drv.drv_erase_fn)
81 		dev->internal_start_block, dev->internal_end_block);
83 	for (i = dev->internal_start_block; i <= dev->internal_end_block; i++) {
84 		struct yaffs_block_info *bi = yaffs_get_block_info(dev, i);
85 		int offset_i = apply_block_offset(dev, i);
92 			dev->n_erasures++;
94 			result = dev->drv.drv_erase_fn(dev, offset_i);
97 				dev->n_erased_blocks++;
98 				dev->n_free_chunks +=
99 				    dev->param.chunks_per_block;
101 				dev->drv.drv_mark_bad_fn(dev, offset_i);
107 	dev->blocks_in_checkpt = 0;
112 static void yaffs2_checkpt_find_erased_block(struct yaffs_dev *dev)
115 	int blocks_avail = dev->n_erased_blocks - dev->param.n_reserved_blocks;
119 		dev->n_erased_blocks, dev->param.n_reserved_blocks,
120 		blocks_avail, dev->checkpt_next_block);
122 	if (dev->checkpt_next_block >= 0 &&
123 	    dev->checkpt_next_block <= dev->internal_end_block &&
126 		for (i = dev->checkpt_next_block; i <= dev->internal_end_block;
130 			bi = yaffs_get_block_info(dev, i);
132 				dev->checkpt_next_block = i + 1;
133 				dev->checkpt_cur_block = i;
142 	dev->checkpt_next_block = -1;
143 	dev->checkpt_cur_block = -1;
146 static void yaffs2_checkpt_find_block(struct yaffs_dev *dev)
153 		dev->blocks_in_checkpt, dev->checkpt_next_block);
155 	if (dev->blocks_in_checkpt < dev->checkpt_max_blocks)
156 		for (i = dev->checkpt_next_block; i <= dev->internal_end_block;
158 			int chunk = i * dev->param.chunks_per_block;
162 			dev->tagger.read_chunk_tags_fn(dev,
163 					apply_chunk_offset(dev, chunk),
174 			dev->tagger.query_block_fn(dev,
175 						apply_block_offset(dev, i),
181 			dev->checkpt_next_block = tags.obj_id;
182 			dev->checkpt_cur_block = i;
183 			dev->checkpt_block_list[dev->blocks_in_checkpt] = i;
184 			dev->blocks_in_checkpt++;
192 	dev->checkpt_next_block = -1;
193 	dev->checkpt_cur_block = -1;
196 int yaffs2_checkpt_open(struct yaffs_dev *dev, int writing)
200 	dev->checkpt_open_write = writing;
203 	if (!dev->tagger.write_chunk_tags_fn ||
204 	    !dev->tagger.read_chunk_tags_fn ||
205 	    !dev->drv.drv_erase_fn ||
206 	    !dev->drv.drv_mark_bad_fn)
209 	if (writing && !yaffs2_checkpt_space_ok(dev))
212 	if (!dev->checkpt_buffer)
213 		dev->checkpt_buffer =
214 		    kmalloc(dev->param.total_bytes_per_chunk, GFP_NOFS);
215 	if (!dev->checkpt_buffer)
218 	dev->checkpt_page_seq = 0;
219 	dev->checkpt_byte_count = 0;
220 	dev->checkpt_sum = 0;
221 	dev->checkpt_xor = 0;
222 	dev->checkpt_cur_block = -1;
223 	dev->checkpt_cur_chunk = -1;
224 	dev->checkpt_next_block = dev->internal_start_block;
227 		memset(dev->checkpt_buffer, 0, dev->data_bytes_per_chunk);
228 		yaffs2_checkpt_init_chunk_hdr(dev);
229 		return yaffs_checkpt_erase(dev);
234 	dev->checkpt_byte_offs = dev->data_bytes_per_chunk;
237 	dev->blocks_in_checkpt = 0;
238 	dev->checkpt_max_blocks =
239 	    (dev->internal_end_block - dev->internal_start_block) / 16 + 2;
240 	if (!dev->checkpt_block_list)
241 		dev->checkpt_block_list =
242 		      kmalloc(sizeof(int) * dev->checkpt_max_blocks, GFP_NOFS);
244 	if (!dev->checkpt_block_list)
247 	for (i = 0; i < dev->checkpt_max_blocks; i++)
248 		dev->checkpt_block_list[i] = -1;
253 int yaffs2_get_checkpt_sum(struct yaffs_dev *dev, u32 * sum)
257 	composite_sum = (dev->checkpt_sum << 8) | (dev->checkpt_xor & 0xff);
262 static int yaffs2_checkpt_flush_buffer(struct yaffs_dev *dev)
268 	if (dev->checkpt_cur_block < 0) {
269 		yaffs2_checkpt_find_erased_block(dev);
270 		dev->checkpt_cur_chunk = 0;
273 	if (dev->checkpt_cur_block < 0)
277 	tags.obj_id = dev->checkpt_next_block;	/* Hint to next place to look */
278 	tags.chunk_id = dev->checkpt_page_seq + 1;
280 	tags.n_bytes = dev->data_bytes_per_chunk;
281 	if (dev->checkpt_cur_chunk == 0) {
285 		    yaffs_get_block_info(dev, dev->checkpt_cur_block);
287 		dev->blocks_in_checkpt++;
291 	    dev->checkpt_cur_block * dev->param.chunks_per_block +
292 	    dev->checkpt_cur_chunk;
296 		chunk, dev->checkpt_cur_block, dev->checkpt_cur_chunk,
299 	offset_chunk = apply_chunk_offset(dev, chunk);
301 	dev->n_page_writes++;
303 	dev->tagger.write_chunk_tags_fn(dev, offset_chunk,
304 				       dev->checkpt_buffer, &tags);
305 	dev->checkpt_page_seq++;
306 	dev->checkpt_cur_chunk++;
307 	if (dev->checkpt_cur_chunk >= dev->param.chunks_per_block) {
308 		dev->checkpt_cur_chunk = 0;
309 		dev->checkpt_cur_block = -1;
311 	memset(dev->checkpt_buffer, 0, dev->data_bytes_per_chunk);
313 	yaffs2_checkpt_init_chunk_hdr(dev);
319 int yaffs2_checkpt_wr(struct yaffs_dev *dev, const void *data, int n_bytes)
325 	if (!dev->checkpt_buffer)
328 	if (!dev->checkpt_open_write)
332 		dev->checkpt_buffer[dev->checkpt_byte_offs] = *data_bytes;
333 		dev->checkpt_sum += *data_bytes;
334 		dev->checkpt_xor ^= *data_bytes;
336 		dev->checkpt_byte_offs++;
339 		dev->checkpt_byte_count++;
341 		if (dev->checkpt_byte_offs < 0 ||
342 		    dev->checkpt_byte_offs >= dev->data_bytes_per_chunk)
343 			ok = yaffs2_checkpt_flush_buffer(dev);
349 int yaffs2_checkpt_rd(struct yaffs_dev *dev, void *data, int n_bytes)
357 	if (!dev->checkpt_buffer)
360 	if (dev->checkpt_open_write)
365 		if (dev->checkpt_byte_offs < 0 ||
366 		    dev->checkpt_byte_offs >= dev->data_bytes_per_chunk) {
368 			if (dev->checkpt_cur_block < 0) {
369 				yaffs2_checkpt_find_block(dev);
370 				dev->checkpt_cur_chunk = 0;
374 			if (dev->checkpt_cur_block < 0)
377 			chunk = dev->checkpt_cur_block *
378 			    dev->param.chunks_per_block +
379 			    dev->checkpt_cur_chunk;
381 			offset_chunk = apply_chunk_offset(dev, chunk);
382 			dev->n_page_reads++;
385 			dev->tagger.read_chunk_tags_fn(dev,
387 						dev->checkpt_buffer,
391 			if (tags.chunk_id != (dev->checkpt_page_seq + 1) ||
397 			if(!yaffs2_checkpt_check_chunk_hdr(dev))
400 			dev->checkpt_page_seq++;
401 			dev->checkpt_cur_chunk++;
403 			if (dev->checkpt_cur_chunk >=
404 					dev->param.chunks_per_block)
405 				dev->checkpt_cur_block = -1;
409 		*data_bytes = dev->checkpt_buffer[dev->checkpt_byte_offs];
410 		dev->checkpt_sum += *data_bytes;
411 		dev->checkpt_xor ^= *data_bytes;
412 		dev->checkpt_byte_offs++;
415 		dev->checkpt_byte_count++;
421 int yaffs_checkpt_close(struct yaffs_dev *dev)
425 	if (dev->checkpt_open_write) {
426 		if (dev->checkpt_byte_offs !=
428 			yaffs2_checkpt_flush_buffer(dev);
429 	} else if (dev->checkpt_block_list) {
431 		     i < dev->blocks_in_checkpt &&
432 		     dev->checkpt_block_list[i] >= 0; i++) {
433 			int blk = dev->checkpt_block_list[i];
436 			if (dev->internal_start_block <= blk &&
437 			    blk <= dev->internal_end_block)
438 				bi = yaffs_get_block_info(dev, blk);
444 	dev->n_free_chunks -=
445 		dev->blocks_in_checkpt * dev->param.chunks_per_block;
446 	dev->n_erased_blocks -= dev->blocks_in_checkpt;
449 		dev->checkpt_byte_count);
451 	if (dev->checkpt_buffer)
457 int yaffs2_checkpt_invalidate_stream(struct yaffs_dev *dev)
463 		dev->blocks_in_checkpt);
465 	return yaffs_checkpt_erase(dev);