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[openwrt/staging/mkresin.git] / target / linux / generic / files / fs / yaffs2 / yaffs_yaffs1.c
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
22 int yaffs1_scan(struct yaffs_dev *dev)
23 {
24 struct yaffs_ext_tags tags;
25 int blk;
26 int result;
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 result = yaffs_rd_chunk_tags_nand(dev, chunk, NULL,
99 &tags);
100
101 /* Let's have a good look at this chunk... */
102
103 if (tags.ecc_result == YAFFS_ECC_RESULT_UNFIXED ||
104 tags.is_deleted) {
105 /* YAFFS1 only...
106 * A deleted chunk
107 */
108 deleted++;
109 dev->n_free_chunks++;
110 } else if (!tags.chunk_used) {
111 /* An unassigned chunk in the block
112 * This means that either the block is empty or
113 * this is the one being allocated from
114 */
115
116 if (c == 0) {
117 /* We're looking at the first chunk in
118 *the block so the block is unused */
119 state = YAFFS_BLOCK_STATE_EMPTY;
120 dev->n_erased_blocks++;
121 } else {
122 /* this is the block being allocated */
123 yaffs_trace(YAFFS_TRACE_SCAN,
124 " Allocating from %d %d",
125 blk, c);
126 state = YAFFS_BLOCK_STATE_ALLOCATING;
127 dev->alloc_block = blk;
128 dev->alloc_page = c;
129 dev->alloc_block_finder = blk;
130
131 }
132
133 dev->n_free_chunks +=
134 (dev->param.chunks_per_block - c);
135 } else if (tags.chunk_id > 0) {
136 /* chunk_id > 0 so it is a data chunk... */
137 unsigned int endpos;
138
139 yaffs_set_chunk_bit(dev, blk, c);
140 bi->pages_in_use++;
141
142 in = yaffs_find_or_create_by_number(dev,
143 tags.obj_id,
144 YAFFS_OBJECT_TYPE_FILE);
145 /* PutChunkIntoFile checks for a clash
146 * (two data chunks with the same chunk_id).
147 */
148
149 if (!in)
150 alloc_failed = 1;
151
152 if (in) {
153 if (!yaffs_put_chunk_in_file
154 (in, tags.chunk_id, chunk, 1))
155 alloc_failed = 1;
156 }
157
158 endpos =
159 (tags.chunk_id - 1) *
160 dev->data_bytes_per_chunk +
161 tags.n_bytes;
162 if (in &&
163 in->variant_type ==
164 YAFFS_OBJECT_TYPE_FILE &&
165 in->variant.file_variant.scanned_size <
166 endpos) {
167 in->variant.file_variant.scanned_size =
168 endpos;
169 if (!dev->param.use_header_file_size) {
170 in->variant.
171 file_variant.file_size =
172 in->variant.
173 file_variant.scanned_size;
174 }
175
176 }
177 } else {
178 /* chunk_id == 0, so it is an ObjectHeader.
179 * Make the object
180 */
181 yaffs_set_chunk_bit(dev, blk, c);
182 bi->pages_in_use++;
183
184 result = yaffs_rd_chunk_tags_nand(dev, chunk,
185 chunk_data,
186 NULL);
187
188 oh = (struct yaffs_obj_hdr *)chunk_data;
189
190 in = yaffs_find_by_number(dev, tags.obj_id);
191 if (in && in->variant_type != oh->type) {
192 /* This should not happen, but somehow
193 * Wev'e ended up with an obj_id that
194 * has been reused but not yet deleted,
195 * and worse still it has changed type.
196 * Delete the old object.
197 */
198
199 yaffs_del_obj(in);
200 in = NULL;
201 }
202
203 in = yaffs_find_or_create_by_number(dev,
204 tags.obj_id,
205 oh->type);
206
207 if (!in)
208 alloc_failed = 1;
209
210 if (in && oh->shadows_obj > 0) {
211
212 struct yaffs_shadow_fixer *fixer;
213 fixer =
214 kmalloc(sizeof
215 (struct yaffs_shadow_fixer),
216 GFP_NOFS);
217 if (fixer) {
218 fixer->next = shadow_fixers;
219 shadow_fixers = fixer;
220 fixer->obj_id = tags.obj_id;
221 fixer->shadowed_id =
222 oh->shadows_obj;
223 yaffs_trace(YAFFS_TRACE_SCAN,
224 " Shadow fixer: %d shadows %d",
225 fixer->obj_id,
226 fixer->shadowed_id);
227
228 }
229
230 }
231
232 if (in && in->valid) {
233 /* We have already filled this one.
234 * We have a duplicate and need to
235 * resolve it. */
236
237 unsigned existing_serial = in->serial;
238 unsigned new_serial =
239 tags.serial_number;
240
241 if (((existing_serial + 1) & 3) ==
242 new_serial) {
243 /* Use new one - destroy the
244 * exisiting one */
245 yaffs_chunk_del(dev,
246 in->hdr_chunk,
247 1, __LINE__);
248 in->valid = 0;
249 } else {
250 /* Use existing - destroy
251 * this one. */
252 yaffs_chunk_del(dev, chunk, 1,
253 __LINE__);
254 }
255 }
256
257 if (in && !in->valid &&
258 (tags.obj_id == YAFFS_OBJECTID_ROOT ||
259 tags.obj_id ==
260 YAFFS_OBJECTID_LOSTNFOUND)) {
261 /* We only load some info, don't fiddle
262 * with directory structure */
263 in->valid = 1;
264 in->variant_type = oh->type;
265
266 in->yst_mode = oh->yst_mode;
267 yaffs_load_attribs(in, oh);
268 in->hdr_chunk = chunk;
269 in->serial = tags.serial_number;
270
271 } else if (in && !in->valid) {
272 /* we need to load this info */
273
274 in->valid = 1;
275 in->variant_type = oh->type;
276
277 in->yst_mode = oh->yst_mode;
278 yaffs_load_attribs(in, oh);
279 in->hdr_chunk = chunk;
280 in->serial = tags.serial_number;
281
282 yaffs_set_obj_name_from_oh(in, oh);
283 in->dirty = 0;
284
285 /* directory stuff...
286 * hook up to parent
287 */
288
289 parent =
290 yaffs_find_or_create_by_number
291 (dev, oh->parent_obj_id,
292 YAFFS_OBJECT_TYPE_DIRECTORY);
293 if (!parent)
294 alloc_failed = 1;
295 if (parent && parent->variant_type ==
296 YAFFS_OBJECT_TYPE_UNKNOWN) {
297 /* Set up as a directory */
298 parent->variant_type =
299 YAFFS_OBJECT_TYPE_DIRECTORY;
300 INIT_LIST_HEAD(&parent->
301 variant.dir_variant.
302 children);
303 } else if (!parent ||
304 parent->variant_type !=
305 YAFFS_OBJECT_TYPE_DIRECTORY) {
306 /* Hoosterman, a problem....
307 * We're trying to use a
308 * non-directory as a directory
309 */
310
311 yaffs_trace(YAFFS_TRACE_ERROR,
312 "yaffs tragedy: attempting to use non-directory as a directory in scan. Put in lost+found."
313 );
314 parent = dev->lost_n_found;
315 }
316
317 yaffs_add_obj_to_dir(parent, in);
318
319 switch (in->variant_type) {
320 case YAFFS_OBJECT_TYPE_UNKNOWN:
321 /* Todo got a problem */
322 break;
323 case YAFFS_OBJECT_TYPE_FILE:
324 if (dev->param.
325 use_header_file_size)
326 in->variant.
327 file_variant.file_size
328 = yaffs_oh_to_size(oh);
329 break;
330 case YAFFS_OBJECT_TYPE_HARDLINK:
331 in->variant.
332 hardlink_variant.equiv_id =
333 oh->equiv_id;
334 list_add(&in->hard_links,
335 &hard_list);
336 break;
337 case YAFFS_OBJECT_TYPE_DIRECTORY:
338 /* Do nothing */
339 break;
340 case YAFFS_OBJECT_TYPE_SPECIAL:
341 /* Do nothing */
342 break;
343 case YAFFS_OBJECT_TYPE_SYMLINK:
344 in->variant.symlink_variant.
345 alias =
346 yaffs_clone_str(oh->alias);
347 if (!in->variant.
348 symlink_variant.alias)
349 alloc_failed = 1;
350 break;
351 }
352 }
353 }
354 }
355
356 if (state == YAFFS_BLOCK_STATE_NEEDS_SCAN) {
357 /* If we got this far while scanning,
358 * then the block is fully allocated. */
359 state = YAFFS_BLOCK_STATE_FULL;
360 }
361
362 if (state == YAFFS_BLOCK_STATE_ALLOCATING) {
363 /* If the block was partially allocated then
364 * treat it as fully allocated. */
365 state = YAFFS_BLOCK_STATE_FULL;
366 dev->alloc_block = -1;
367 }
368
369 bi->block_state = state;
370
371 /* Now let's see if it was dirty */
372 if (bi->pages_in_use == 0 &&
373 !bi->has_shrink_hdr &&
374 bi->block_state == YAFFS_BLOCK_STATE_FULL)
375 yaffs_block_became_dirty(dev, blk);
376 }
377
378 /* Ok, we've done all the scanning.
379 * Fix up the hard link chains.
380 * We should now have scanned all the objects, now it's time to add
381 * these hardlinks.
382 */
383
384 yaffs_link_fixup(dev, &hard_list);
385
386 /*
387 * Fix up any shadowed objects.
388 * There should not be more than one of these.
389 */
390 {
391 struct yaffs_shadow_fixer *fixer;
392 struct yaffs_obj *obj;
393
394 while (shadow_fixers) {
395 fixer = shadow_fixers;
396 shadow_fixers = fixer->next;
397 /* Complete the rename transaction by deleting the
398 * shadowed object then setting the object header
399 to unshadowed.
400 */
401 obj = yaffs_find_by_number(dev, fixer->shadowed_id);
402 if (obj)
403 yaffs_del_obj(obj);
404
405 obj = yaffs_find_by_number(dev, fixer->obj_id);
406
407 if (obj)
408 yaffs_update_oh(obj, NULL, 1, 0, 0, NULL);
409
410 kfree(fixer);
411 }
412 }
413
414 yaffs_release_temp_buffer(dev, chunk_data);
415
416 if (alloc_failed)
417 return YAFFS_FAIL;
418
419 yaffs_trace(YAFFS_TRACE_SCAN, "yaffs1_scan ends");
420
421 return YAFFS_OK;
422 }
Staging tree of Mathias Kresin