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