fat: Remove FAT Directory Bread message
[linux-2.6.git] / fs / yaffs2 / yaffs_yaffs1.c
1 /*
2  * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
3  *
4  * Copyright (C) 2002-2010 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
28         int chunk;
29         int c;
30         int deleted;
31         enum yaffs_block_state state;
32         struct yaffs_obj *hard_list = NULL;
33         struct yaffs_block_info *bi;
34         u32 seq_number;
35         struct yaffs_obj_hdr *oh;
36         struct yaffs_obj *in;
37         struct yaffs_obj *parent;
38
39         int alloc_failed = 0;
40
41         struct yaffs_shadow_fixer *shadow_fixers = NULL;
42
43         u8 *chunk_data;
44
45         yaffs_trace(YAFFS_TRACE_SCAN,
46                 "yaffs1_scan starts  intstartblk %d intendblk %d...",
47                 dev->internal_start_block, dev->internal_end_block);
48
49         chunk_data = yaffs_get_temp_buffer(dev, __LINE__);
50
51         dev->seq_number = YAFFS_LOWEST_SEQUENCE_NUMBER;
52
53         /* Scan all the blocks to determine their state */
54         bi = dev->block_info;
55         for (blk = dev->internal_start_block; blk <= dev->internal_end_block;
56              blk++) {
57                 yaffs_clear_chunk_bits(dev, blk);
58                 bi->pages_in_use = 0;
59                 bi->soft_del_pages = 0;
60
61                 yaffs_query_init_block_state(dev, blk, &state, &seq_number);
62
63                 bi->block_state = state;
64                 bi->seq_number = seq_number;
65
66                 if (bi->seq_number == YAFFS_SEQUENCE_BAD_BLOCK)
67                         bi->block_state = state = YAFFS_BLOCK_STATE_DEAD;
68
69                 yaffs_trace(YAFFS_TRACE_SCAN_DEBUG,
70                         "Block scanning block %d state %d seq %d",
71                         blk, state, seq_number);
72
73                 if (state == YAFFS_BLOCK_STATE_DEAD) {
74                         yaffs_trace(YAFFS_TRACE_BAD_BLOCKS,
75                                 "block %d is bad", blk);
76                 } else if (state == YAFFS_BLOCK_STATE_EMPTY) {
77                         yaffs_trace(YAFFS_TRACE_SCAN_DEBUG, "Block empty ");
78                         dev->n_erased_blocks++;
79                         dev->n_free_chunks += dev->param.chunks_per_block;
80                 }
81                 bi++;
82         }
83
84         /* For each block.... */
85         for (blk = dev->internal_start_block;
86              !alloc_failed && blk <= dev->internal_end_block; blk++) {
87
88                 cond_resched();
89
90                 bi = yaffs_get_block_info(dev, blk);
91                 state = bi->block_state;
92
93                 deleted = 0;
94
95                 /* For each chunk in each block that needs scanning.... */
96                 for (c = 0; !alloc_failed && c < dev->param.chunks_per_block &&
97                      state == YAFFS_BLOCK_STATE_NEEDS_SCANNING; c++) {
98                         /* Read the tags and decide what to do */
99                         chunk = blk * dev->param.chunks_per_block + c;
100
101                         result = yaffs_rd_chunk_tags_nand(dev, chunk, NULL,
102                                                           &tags);
103
104                         /* Let's have a good look at this chunk... */
105
106                         if (tags.ecc_result == YAFFS_ECC_RESULT_UNFIXED
107                             || tags.is_deleted) {
108                                 /* YAFFS1 only...
109                                  * A deleted chunk
110                                  */
111                                 deleted++;
112                                 dev->n_free_chunks++;
113                                 /*T((" %d %d deleted\n",blk,c)); */
114                         } else if (!tags.chunk_used) {
115                                 /* An unassigned chunk in the block
116                                  * This means that either the block is empty or
117                                  * this is the one being allocated from
118                                  */
119
120                                 if (c == 0) {
121                                         /* We're looking at the first chunk in the block so the block is unused */
122                                         state = YAFFS_BLOCK_STATE_EMPTY;
123                                         dev->n_erased_blocks++;
124                                 } else {
125                                         /* this is the block being allocated from */
126                                         yaffs_trace(YAFFS_TRACE_SCAN,
127                                                 " Allocating from %d %d",
128                                                 blk, c);
129                                         state = YAFFS_BLOCK_STATE_ALLOCATING;
130                                         dev->alloc_block = blk;
131                                         dev->alloc_page = c;
132                                         dev->alloc_block_finder = blk;
133                                         /* Set block finder here to encourage the allocator to go forth from here. */
134
135                                 }
136
137                                 dev->n_free_chunks +=
138                                     (dev->param.chunks_per_block - c);
139                         } else if (tags.chunk_id > 0) {
140                                 /* chunk_id > 0 so it is a data chunk... */
141                                 unsigned int endpos;
142
143                                 yaffs_set_chunk_bit(dev, blk, c);
144                                 bi->pages_in_use++;
145
146                                 in = yaffs_find_or_create_by_number(dev,
147                                                                     tags.obj_id,
148                                                                     YAFFS_OBJECT_TYPE_FILE);
149                                 /* PutChunkIntoFile checks for a clash (two data chunks with
150                                  * the same chunk_id).
151                                  */
152
153                                 if (!in)
154                                         alloc_failed = 1;
155
156                                 if (in) {
157                                         if (!yaffs_put_chunk_in_file
158                                             (in, tags.chunk_id, chunk, 1))
159                                                 alloc_failed = 1;
160                                 }
161
162                                 endpos =
163                                     (tags.chunk_id -
164                                      1) * dev->data_bytes_per_chunk +
165                                     tags.n_bytes;
166                                 if (in
167                                     && in->variant_type ==
168                                     YAFFS_OBJECT_TYPE_FILE
169                                     && in->variant.file_variant.scanned_size <
170                                     endpos) {
171                                         in->variant.file_variant.scanned_size =
172                                             endpos;
173                                         if (!dev->param.use_header_file_size) {
174                                                 in->variant.
175                                                     file_variant.file_size =
176                                                     in->variant.
177                                                     file_variant.scanned_size;
178                                         }
179
180                                 }
181                                 /* T((" %d %d data %d %d\n",blk,c,tags.obj_id,tags.chunk_id));   */
182                         } else {
183                                 /* chunk_id == 0, so it is an ObjectHeader.
184                                  * Thus, we read in the object header and make the object
185                                  */
186                                 yaffs_set_chunk_bit(dev, blk, c);
187                                 bi->pages_in_use++;
188
189                                 result = yaffs_rd_chunk_tags_nand(dev, chunk,
190                                                                   chunk_data,
191                                                                   NULL);
192
193                                 oh = (struct yaffs_obj_hdr *)chunk_data;
194
195                                 in = yaffs_find_by_number(dev, tags.obj_id);
196                                 if (in && in->variant_type != oh->type) {
197                                         /* This should not happen, but somehow
198                                          * Wev'e ended up with an obj_id that has been reused but not yet
199                                          * deleted, and worse still it has changed type. Delete the old object.
200                                          */
201
202                                         yaffs_del_obj(in);
203
204                                         in = 0;
205                                 }
206
207                                 in = yaffs_find_or_create_by_number(dev,
208                                                                     tags.obj_id,
209                                                                     oh->type);
210
211                                 if (!in)
212                                         alloc_failed = 1;
213
214                                 if (in && oh->shadows_obj > 0) {
215
216                                         struct yaffs_shadow_fixer *fixer;
217                                         fixer =
218                                                 kmalloc(sizeof
219                                                 (struct yaffs_shadow_fixer),
220                                                 GFP_NOFS);
221                                         if (fixer) {
222                                                 fixer->next = shadow_fixers;
223                                                 shadow_fixers = fixer;
224                                                 fixer->obj_id = tags.obj_id;
225                                                 fixer->shadowed_id =
226                                                     oh->shadows_obj;
227                                                 yaffs_trace(YAFFS_TRACE_SCAN,
228                                                         " Shadow fixer: %d shadows %d",
229                                                         fixer->obj_id,
230                                                         fixer->shadowed_id);
231
232                                         }
233
234                                 }
235
236                                 if (in && in->valid) {
237                                         /* We have already filled this one. We have a duplicate and need to resolve it. */
238
239                                         unsigned existing_serial = in->serial;
240                                         unsigned new_serial =
241                                             tags.serial_number;
242
243                                         if (((existing_serial + 1) & 3) ==
244                                             new_serial) {
245                                                 /* Use new one - destroy the exisiting one */
246                                                 yaffs_chunk_del(dev,
247                                                                 in->hdr_chunk,
248                                                                 1, __LINE__);
249                                                 in->valid = 0;
250                                         } else {
251                                                 /* Use existing - destroy 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 with directory structure */
262                                         in->valid = 1;
263                                         in->variant_type = oh->type;
264
265                                         in->yst_mode = oh->yst_mode;
266                                         yaffs_load_attribs(in, oh);
267                                         in->hdr_chunk = chunk;
268                                         in->serial = tags.serial_number;
269
270                                 } else if (in && !in->valid) {
271                                         /* we need to load this info */
272
273                                         in->valid = 1;
274                                         in->variant_type = oh->type;
275
276                                         in->yst_mode = oh->yst_mode;
277                                         yaffs_load_attribs(in, oh);
278                                         in->hdr_chunk = chunk;
279                                         in->serial = tags.serial_number;
280
281                                         yaffs_set_obj_name_from_oh(in, oh);
282                                         in->dirty = 0;
283
284                                         /* directory stuff...
285                                          * hook up to parent
286                                          */
287
288                                         parent =
289                                             yaffs_find_or_create_by_number
290                                             (dev, oh->parent_obj_id,
291                                              YAFFS_OBJECT_TYPE_DIRECTORY);
292                                         if (!parent)
293                                                 alloc_failed = 1;
294                                         if (parent && parent->variant_type ==
295                                             YAFFS_OBJECT_TYPE_UNKNOWN) {
296                                                 /* Set up as a directory */
297                                                 parent->variant_type =
298                                                     YAFFS_OBJECT_TYPE_DIRECTORY;
299                                                 INIT_LIST_HEAD(&parent->
300                                                                variant.dir_variant.children);
301                                         } else if (!parent
302                                                    || parent->variant_type !=
303                                                    YAFFS_OBJECT_TYPE_DIRECTORY) {
304                                                 /* Hoosterman, another problem....
305                                                  * We're trying to use a 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                                         if (0 && (parent == dev->del_dir ||
317                                                   parent ==
318                                                   dev->unlinked_dir)) {
319                                                 in->deleted = 1;        /* If it is unlinked at start up then it wants deleting */
320                                                 dev->n_deleted_files++;
321                                         }
322                                         /* Note re hardlinks.
323                                          * Since we might scan a hardlink before its equivalent object is scanned
324                                          * we put them all in a list.
325                                          * After scanning is complete, we should have all the objects, so we run through this
326                                          * list and fix up all the chains.
327                                          */
328
329                                         switch (in->variant_type) {
330                                         case YAFFS_OBJECT_TYPE_UNKNOWN:
331                                                 /* Todo got a problem */
332                                                 break;
333                                         case YAFFS_OBJECT_TYPE_FILE:
334                                                 if (dev->param.
335                                                     use_header_file_size)
336
337                                                         in->variant.
338                                                             file_variant.file_size
339                                                             = oh->file_size;
340
341                                                 break;
342                                         case YAFFS_OBJECT_TYPE_HARDLINK:
343                                                 in->variant.
344                                                     hardlink_variant.equiv_id =
345                                                     oh->equiv_id;
346                                                 in->hard_links.next =
347                                                     (struct list_head *)
348                                                     hard_list;
349                                                 hard_list = in;
350                                                 break;
351                                         case YAFFS_OBJECT_TYPE_DIRECTORY:
352                                                 /* Do nothing */
353                                                 break;
354                                         case YAFFS_OBJECT_TYPE_SPECIAL:
355                                                 /* Do nothing */
356                                                 break;
357                                         case YAFFS_OBJECT_TYPE_SYMLINK:
358                                                 in->variant.symlink_variant.
359                                                     alias =
360                                                     yaffs_clone_str(oh->alias);
361                                                 if (!in->variant.
362                                                     symlink_variant.alias)
363                                                         alloc_failed = 1;
364                                                 break;
365                                         }
366
367                                 }
368                         }
369                 }
370
371                 if (state == YAFFS_BLOCK_STATE_NEEDS_SCANNING) {
372                         /* If we got this far while scanning, then the block is fully allocated. */
373                         state = YAFFS_BLOCK_STATE_FULL;
374                 }
375
376                 if (state == YAFFS_BLOCK_STATE_ALLOCATING) {
377                         /* If the block was partially allocated then treat it as fully allocated. */
378                         state = YAFFS_BLOCK_STATE_FULL;
379                         dev->alloc_block = -1;
380                 }
381
382                 bi->block_state = state;
383
384                 /* Now let's see if it was dirty */
385                 if (bi->pages_in_use == 0 &&
386                     !bi->has_shrink_hdr &&
387                     bi->block_state == YAFFS_BLOCK_STATE_FULL) {
388                         yaffs_block_became_dirty(dev, blk);
389                 }
390
391         }
392
393         /* Ok, we've done all the scanning.
394          * Fix up the hard link chains.
395          * We should now have scanned all the objects, now it's time to add these
396          * hardlinks.
397          */
398
399         yaffs_link_fixup(dev, hard_list);
400
401         /* Fix up any shadowed objects */
402         {
403                 struct yaffs_shadow_fixer *fixer;
404                 struct yaffs_obj *obj;
405
406                 while (shadow_fixers) {
407                         fixer = shadow_fixers;
408                         shadow_fixers = fixer->next;
409                         /* Complete the rename transaction by deleting the shadowed object
410                          * then setting the object header to unshadowed.
411                          */
412                         obj = yaffs_find_by_number(dev, fixer->shadowed_id);
413                         if (obj)
414                                 yaffs_del_obj(obj);
415
416                         obj = yaffs_find_by_number(dev, fixer->obj_id);
417
418                         if (obj)
419                                 yaffs_update_oh(obj, NULL, 1, 0, 0, NULL);
420
421                         kfree(fixer);
422                 }
423         }
424
425         yaffs_release_temp_buffer(dev, chunk_data, __LINE__);
426
427         if (alloc_failed)
428                 return YAFFS_FAIL;
429
430         yaffs_trace(YAFFS_TRACE_SCAN, "yaffs1_scan ends");
431
432         return YAFFS_OK;
433 }