1 /*
2 * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
3 *
4 * Copyright (C) 2002-2011 Aleph One Ltd.
5 * for Toby Churchill Ltd and Brightstar Engineering
6 *
7 * Created by Charles Manning <charles@aleph1.co.uk>
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2 as
11 * published by the Free Software Foundation.
12 */
13
14 #include "yaffs_yaffs1.h"
15 #include "yportenv.h"
16 #include "yaffs_trace.h"
17 #include "yaffs_bitmap.h"
18 #include "yaffs_getblockinfo.h"
19 #include "yaffs_nand.h"
20 #include "yaffs_attribs.h"
21 #include <dm/devres.h>
22
yaffs1_scan(struct yaffs_dev * dev)23 int yaffs1_scan(struct yaffs_dev *dev)
24 {
25 struct yaffs_ext_tags tags;
26 int blk;
27 int chunk;
28 int c;
29 int deleted;
30 enum yaffs_block_state state;
31 LIST_HEAD(hard_list);
32 struct yaffs_block_info *bi;
33 u32 seq_number;
34 struct yaffs_obj_hdr *oh;
35 struct yaffs_obj *in;
36 struct yaffs_obj *parent;
37 int alloc_failed = 0;
38 struct yaffs_shadow_fixer *shadow_fixers = NULL;
39 u8 *chunk_data;
40
41 yaffs_trace(YAFFS_TRACE_SCAN,
42 "yaffs1_scan starts intstartblk %d intendblk %d...",
43 dev->internal_start_block, dev->internal_end_block);
44
45 chunk_data = yaffs_get_temp_buffer(dev);
46
47 dev->seq_number = YAFFS_LOWEST_SEQUENCE_NUMBER;
48
49 /* Scan all the blocks to determine their state */
50 bi = dev->block_info;
51 for (blk = dev->internal_start_block; blk <= dev->internal_end_block;
52 blk++) {
53 yaffs_clear_chunk_bits(dev, blk);
54 bi->pages_in_use = 0;
55 bi->soft_del_pages = 0;
56
57 yaffs_query_init_block_state(dev, blk, &state, &seq_number);
58
59 bi->block_state = state;
60 bi->seq_number = seq_number;
61
62 if (bi->seq_number == YAFFS_SEQUENCE_BAD_BLOCK)
63 bi->block_state = state = YAFFS_BLOCK_STATE_DEAD;
64
65 yaffs_trace(YAFFS_TRACE_SCAN_DEBUG,
66 "Block scanning block %d state %d seq %d",
67 blk, state, seq_number);
68
69 if (state == YAFFS_BLOCK_STATE_DEAD) {
70 yaffs_trace(YAFFS_TRACE_BAD_BLOCKS,
71 "block %d is bad", blk);
72 } else if (state == YAFFS_BLOCK_STATE_EMPTY) {
73 yaffs_trace(YAFFS_TRACE_SCAN_DEBUG, "Block empty ");
74 dev->n_erased_blocks++;
75 dev->n_free_chunks += dev->param.chunks_per_block;
76 }
77 bi++;
78 }
79
80 /* For each block.... */
81 for (blk = dev->internal_start_block;
82 !alloc_failed && blk <= dev->internal_end_block; blk++) {
83
84 cond_resched();
85
86 bi = yaffs_get_block_info(dev, blk);
87 state = bi->block_state;
88
89 deleted = 0;
90
91 /* For each chunk in each block that needs scanning.... */
92 for (c = 0;
93 !alloc_failed && c < dev->param.chunks_per_block &&
94 state == YAFFS_BLOCK_STATE_NEEDS_SCAN; c++) {
95 /* Read the tags and decide what to do */
96 chunk = blk * dev->param.chunks_per_block + c;
97
98 yaffs_rd_chunk_tags_nand(dev, chunk, NULL, &tags);
99
100 /* Let's have a good look at this chunk... */
101
102 if (tags.ecc_result == YAFFS_ECC_RESULT_UNFIXED ||
103 tags.is_deleted) {
104 /* YAFFS1 only...
105 * A deleted chunk
106 */
107 deleted++;
108 dev->n_free_chunks++;
109 } else if (!tags.chunk_used) {
110 /* An unassigned chunk in the block
111 * This means that either the block is empty or
112 * this is the one being allocated from
113 */
114
115 if (c == 0) {
116 /* We're looking at the first chunk in
117 *the block so the block is unused */
118 state = YAFFS_BLOCK_STATE_EMPTY;
119 dev->n_erased_blocks++;
120 } else {
121 /* this is the block being allocated */
122 yaffs_trace(YAFFS_TRACE_SCAN,
123 " Allocating from %d %d",
124 blk, c);
125 state = YAFFS_BLOCK_STATE_ALLOCATING;
126 dev->alloc_block = blk;
127 dev->alloc_page = c;
128 dev->alloc_block_finder = blk;
129
130 }
131
132 dev->n_free_chunks +=
133 (dev->param.chunks_per_block - c);
134 } else if (tags.chunk_id > 0) {
135 /* chunk_id > 0 so it is a data chunk... */
136 unsigned int endpos;
137
138 yaffs_set_chunk_bit(dev, blk, c);
139 bi->pages_in_use++;
140
141 in = yaffs_find_or_create_by_number(dev,
142 tags.obj_id,
143 YAFFS_OBJECT_TYPE_FILE);
144 /* PutChunkIntoFile checks for a clash
145 * (two data chunks with the same chunk_id).
146 */
147
148 if (!in)
149 alloc_failed = 1;
150
151 if (in) {
152 if (!yaffs_put_chunk_in_file
153 (in, tags.chunk_id, chunk, 1))
154 alloc_failed = 1;
155 }
156
157 endpos =
158 (tags.chunk_id - 1) *
159 dev->data_bytes_per_chunk +
160 tags.n_bytes;
161 if (in &&
162 in->variant_type ==
163 YAFFS_OBJECT_TYPE_FILE &&
164 in->variant.file_variant.scanned_size <
165 endpos) {
166 in->variant.file_variant.scanned_size =
167 endpos;
168 if (!dev->param.use_header_file_size) {
169 in->variant.
170 file_variant.file_size =
171 in->variant.
172 file_variant.scanned_size;
173 }
174
175 }
176 } else {
177 /* chunk_id == 0, so it is an ObjectHeader.
178 * Make the object
179 */
180 yaffs_set_chunk_bit(dev, blk, c);
181 bi->pages_in_use++;
182
183 yaffs_rd_chunk_tags_nand(dev, chunk,
184 chunk_data, NULL);
185
186 oh = (struct yaffs_obj_hdr *)chunk_data;
187
188 in = yaffs_find_by_number(dev, tags.obj_id);
189 if (in && in->variant_type != oh->type) {
190 /* This should not happen, but somehow
191 * Wev'e ended up with an obj_id that
192 * has been reused but not yet deleted,
193 * and worse still it has changed type.
194 * Delete the old object.
195 */
196
197 yaffs_del_obj(in);
198 in = NULL;
199 }
200
201 in = yaffs_find_or_create_by_number(dev,
202 tags.obj_id,
203 oh->type);
204
205 if (!in)
206 alloc_failed = 1;
207
208 if (in && oh->shadows_obj > 0) {
209
210 struct yaffs_shadow_fixer *fixer;
211 fixer =
212 kmalloc(sizeof
213 (struct yaffs_shadow_fixer),
214 GFP_NOFS);
215 if (fixer) {
216 fixer->next = shadow_fixers;
217 shadow_fixers = fixer;
218 fixer->obj_id = tags.obj_id;
219 fixer->shadowed_id =
220 oh->shadows_obj;
221 yaffs_trace(YAFFS_TRACE_SCAN,
222 " Shadow fixer: %d shadows %d",
223 fixer->obj_id,
224 fixer->shadowed_id);
225
226 }
227
228 }
229
230 if (in && in->valid) {
231 /* We have already filled this one.
232 * We have a duplicate and need to
233 * resolve it. */
234
235 unsigned existing_serial = in->serial;
236 unsigned new_serial =
237 tags.serial_number;
238
239 if (((existing_serial + 1) & 3) ==
240 new_serial) {
241 /* Use new one - destroy the
242 * exisiting one */
243 yaffs_chunk_del(dev,
244 in->hdr_chunk,
245 1, __LINE__);
246 in->valid = 0;
247 } else {
248 /* Use existing - destroy
249 * this one. */
250 yaffs_chunk_del(dev, chunk, 1,
251 __LINE__);
252 }
253 }
254
255 if (in && !in->valid &&
256 (tags.obj_id == YAFFS_OBJECTID_ROOT ||
257 tags.obj_id ==
258 YAFFS_OBJECTID_LOSTNFOUND)) {
259 /* We only load some info, don't fiddle
260 * with directory structure */
261 in->valid = 1;
262 in->variant_type = oh->type;
263
264 in->yst_mode = oh->yst_mode;
265 yaffs_load_attribs(in, oh);
266 in->hdr_chunk = chunk;
267 in->serial = tags.serial_number;
268
269 } else if (in && !in->valid) {
270 /* we need to load this info */
271
272 in->valid = 1;
273 in->variant_type = oh->type;
274
275 in->yst_mode = oh->yst_mode;
276 yaffs_load_attribs(in, oh);
277 in->hdr_chunk = chunk;
278 in->serial = tags.serial_number;
279
280 yaffs_set_obj_name_from_oh(in, oh);
281 in->dirty = 0;
282
283 /* directory stuff...
284 * hook up to parent
285 */
286
287 parent =
288 yaffs_find_or_create_by_number
289 (dev, oh->parent_obj_id,
290 YAFFS_OBJECT_TYPE_DIRECTORY);
291 if (!parent)
292 alloc_failed = 1;
293 if (parent && parent->variant_type ==
294 YAFFS_OBJECT_TYPE_UNKNOWN) {
295 /* Set up as a directory */
296 parent->variant_type =
297 YAFFS_OBJECT_TYPE_DIRECTORY;
298 INIT_LIST_HEAD(&parent->
299 variant.dir_variant.
300 children);
301 } else if (!parent ||
302 parent->variant_type !=
303 YAFFS_OBJECT_TYPE_DIRECTORY) {
304 /* Hoosterman, a problem....
305 * We're trying to use a
306 * non-directory as a directory
307 */
308
309 yaffs_trace(YAFFS_TRACE_ERROR,
310 "yaffs tragedy: attempting to use non-directory as a directory in scan. Put in lost+found."
311 );
312 parent = dev->lost_n_found;
313 }
314
315 yaffs_add_obj_to_dir(parent, in);
316
317 switch (in->variant_type) {
318 case YAFFS_OBJECT_TYPE_UNKNOWN:
319 /* Todo got a problem */
320 break;
321 case YAFFS_OBJECT_TYPE_FILE:
322 if (dev->param.
323 use_header_file_size)
324 in->variant.
325 file_variant.file_size
326 = yaffs_oh_to_size(oh);
327 break;
328 case YAFFS_OBJECT_TYPE_HARDLINK:
329 in->variant.
330 hardlink_variant.equiv_id =
331 oh->equiv_id;
332 list_add(&in->hard_links,
333 &hard_list);
334 break;
335 case YAFFS_OBJECT_TYPE_DIRECTORY:
336 /* Do nothing */
337 break;
338 case YAFFS_OBJECT_TYPE_SPECIAL:
339 /* Do nothing */
340 break;
341 case YAFFS_OBJECT_TYPE_SYMLINK:
342 in->variant.symlink_variant.
343 alias =
344 yaffs_clone_str(oh->alias);
345 if (!in->variant.
346 symlink_variant.alias)
347 alloc_failed = 1;
348 break;
349 }
350 }
351 }
352 }
353
354 if (state == YAFFS_BLOCK_STATE_NEEDS_SCAN) {
355 /* If we got this far while scanning,
356 * then the block is fully allocated. */
357 state = YAFFS_BLOCK_STATE_FULL;
358 }
359
360 if (state == YAFFS_BLOCK_STATE_ALLOCATING) {
361 /* If the block was partially allocated then
362 * treat it as fully allocated. */
363 state = YAFFS_BLOCK_STATE_FULL;
364 dev->alloc_block = -1;
365 }
366
367 bi->block_state = state;
368
369 /* Now let's see if it was dirty */
370 if (bi->pages_in_use == 0 &&
371 !bi->has_shrink_hdr &&
372 bi->block_state == YAFFS_BLOCK_STATE_FULL)
373 yaffs_block_became_dirty(dev, blk);
374 }
375
376 /* Ok, we've done all the scanning.
377 * Fix up the hard link chains.
378 * We should now have scanned all the objects, now it's time to add
379 * these hardlinks.
380 */
381
382 yaffs_link_fixup(dev, &hard_list);
383
384 /*
385 * Fix up any shadowed objects.
386 * There should not be more than one of these.
387 */
388 {
389 struct yaffs_shadow_fixer *fixer;
390 struct yaffs_obj *obj;
391
392 while (shadow_fixers) {
393 fixer = shadow_fixers;
394 shadow_fixers = fixer->next;
395 /* Complete the rename transaction by deleting the
396 * shadowed object then setting the object header
397 to unshadowed.
398 */
399 obj = yaffs_find_by_number(dev, fixer->shadowed_id);
400 if (obj)
401 yaffs_del_obj(obj);
402
403 obj = yaffs_find_by_number(dev, fixer->obj_id);
404
405 if (obj)
406 yaffs_update_oh(obj, NULL, 1, 0, 0, NULL);
407
408 kfree(fixer);
409 }
410 }
411
412 yaffs_release_temp_buffer(dev, chunk_data);
413
414 if (alloc_failed)
415 return YAFFS_FAIL;
416
417 yaffs_trace(YAFFS_TRACE_SCAN, "yaffs1_scan ends");
418
419 return YAFFS_OK;
420 }
421