df6cb001995f0cdc1d7364c9d5b51221dd274008
[yaffs2.git] / yaffs_guts.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 "yportenv.h"
15 #include "yaffs_trace.h"
16
17 #include "yaffs_guts.h"
18 #include "yaffs_getblockinfo.h"
19 #include "yaffs_tagscompat.h"
20 #include "yaffs_nand.h"
21 #include "yaffs_yaffs1.h"
22 #include "yaffs_yaffs2.h"
23 #include "yaffs_bitmap.h"
24 #include "yaffs_verify.h"
25 #include "yaffs_nand.h"
26 #include "yaffs_packedtags2.h"
27 #include "yaffs_nameval.h"
28 #include "yaffs_allocator.h"
29 #include "yaffs_attribs.h"
30 #include "yaffs_summary.h"
31
32 /* Note YAFFS_GC_GOOD_ENOUGH must be <= YAFFS_GC_PASSIVE_THRESHOLD */
33 #define YAFFS_GC_GOOD_ENOUGH 2
34 #define YAFFS_GC_PASSIVE_THRESHOLD 4
35
36 #include "yaffs_ecc.h"
37
38 /* Forward declarations */
39
40 static int yaffs_wr_data_obj(struct yaffs_obj *in, int inode_chunk,
41                              const u8 *buffer, int n_bytes, int use_reserve);
42
43
44
45 /* Function to calculate chunk and offset */
46
47 void yaffs_addr_to_chunk(struct yaffs_dev *dev, loff_t addr,
48                                 int *chunk_out, u32 *offset_out)
49 {
50         int chunk;
51         u32 offset;
52
53         chunk = (u32) (addr >> dev->chunk_shift);
54
55         if (dev->chunk_div == 1) {
56                 /* easy power of 2 case */
57                 offset = (u32) (addr & dev->chunk_mask);
58         } else {
59                 /* Non power-of-2 case */
60
61                 loff_t chunk_base;
62
63                 chunk /= dev->chunk_div;
64
65                 chunk_base = ((loff_t) chunk) * dev->data_bytes_per_chunk;
66                 offset = (u32) (addr - chunk_base);
67         }
68
69         *chunk_out = chunk;
70         *offset_out = offset;
71 }
72
73 /* Function to return the number of shifts for a power of 2 greater than or
74  * equal to the given number
75  * Note we don't try to cater for all possible numbers and this does not have to
76  * be hellishly efficient.
77  */
78
79 static inline u32 calc_shifts_ceiling(u32 x)
80 {
81         int extra_bits;
82         int shifts;
83
84         shifts = extra_bits = 0;
85
86         while (x > 1) {
87                 if (x & 1)
88                         extra_bits++;
89                 x >>= 1;
90                 shifts++;
91         }
92
93         if (extra_bits)
94                 shifts++;
95
96         return shifts;
97 }
98
99 /* Function to return the number of shifts to get a 1 in bit 0
100  */
101
102 static inline u32 calc_shifts(u32 x)
103 {
104         u32 shifts;
105
106         shifts = 0;
107
108         if (!x)
109                 return 0;
110
111         while (!(x & 1)) {
112                 x >>= 1;
113                 shifts++;
114         }
115
116         return shifts;
117 }
118
119 /*
120  * Temporary buffer manipulations.
121  */
122
123 static int yaffs_init_tmp_buffers(struct yaffs_dev *dev)
124 {
125         int i;
126         u8 *buf = (u8 *) 1;
127
128         memset(dev->temp_buffer, 0, sizeof(dev->temp_buffer));
129
130         for (i = 0; buf && i < YAFFS_N_TEMP_BUFFERS; i++) {
131                 dev->temp_buffer[i].in_use = 0;
132                 buf = kmalloc(dev->param.total_bytes_per_chunk, GFP_NOFS);
133                 dev->temp_buffer[i].buffer = buf;
134         }
135
136         return buf ? YAFFS_OK : YAFFS_FAIL;
137 }
138
139 u8 *yaffs_get_temp_buffer(struct yaffs_dev * dev)
140 {
141         int i;
142
143         dev->temp_in_use++;
144         if (dev->temp_in_use > dev->max_temp)
145                 dev->max_temp = dev->temp_in_use;
146
147         for (i = 0; i < YAFFS_N_TEMP_BUFFERS; i++) {
148                 if (dev->temp_buffer[i].in_use == 0) {
149                         dev->temp_buffer[i].in_use = 1;
150                         return dev->temp_buffer[i].buffer;
151                 }
152         }
153
154         yaffs_trace(YAFFS_TRACE_BUFFERS, "Out of temp buffers");
155         /*
156          * If we got here then we have to allocate an unmanaged one
157          * This is not good.
158          */
159
160         dev->unmanaged_buffer_allocs++;
161         return kmalloc(dev->data_bytes_per_chunk, GFP_NOFS);
162
163 }
164
165 void yaffs_release_temp_buffer(struct yaffs_dev *dev, u8 *buffer)
166 {
167         int i;
168
169         dev->temp_in_use--;
170
171         for (i = 0; i < YAFFS_N_TEMP_BUFFERS; i++) {
172                 if (dev->temp_buffer[i].buffer == buffer) {
173                         dev->temp_buffer[i].in_use = 0;
174                         return;
175                 }
176         }
177
178         if (buffer) {
179                 /* assume it is an unmanaged one. */
180                 yaffs_trace(YAFFS_TRACE_BUFFERS,
181                         "Releasing unmanaged temp buffer");
182                 kfree(buffer);
183                 dev->unmanaged_buffer_deallocs++;
184         }
185
186 }
187
188 /*
189  * Determine if we have a managed buffer.
190  */
191 int yaffs_is_managed_tmp_buffer(struct yaffs_dev *dev, const u8 *buffer)
192 {
193         int i;
194
195         for (i = 0; i < YAFFS_N_TEMP_BUFFERS; i++) {
196                 if (dev->temp_buffer[i].buffer == buffer)
197                         return 1;
198         }
199
200         for (i = 0; i < dev->param.n_caches; i++) {
201                 if (dev->cache[i].data == buffer)
202                         return 1;
203         }
204
205         if (buffer == dev->checkpt_buffer)
206                 return 1;
207
208         yaffs_trace(YAFFS_TRACE_ALWAYS,
209           "yaffs: unmaged buffer detected.");
210         return 0;
211 }
212
213 /*
214  * Functions for robustisizing TODO
215  *
216  */
217
218 static void yaffs_handle_chunk_wr_ok(struct yaffs_dev *dev, int nand_chunk,
219                                      const u8 *data,
220                                      const struct yaffs_ext_tags *tags)
221 {
222         dev = dev;
223         nand_chunk = nand_chunk;
224         data = data;
225         tags = tags;
226 }
227
228 static void yaffs_handle_chunk_update(struct yaffs_dev *dev, int nand_chunk,
229                                       const struct yaffs_ext_tags *tags)
230 {
231         dev = dev;
232         nand_chunk = nand_chunk;
233         tags = tags;
234 }
235
236 void yaffs_handle_chunk_error(struct yaffs_dev *dev,
237                               struct yaffs_block_info *bi)
238 {
239         if (!bi->gc_prioritise) {
240                 bi->gc_prioritise = 1;
241                 dev->has_pending_prioritised_gc = 1;
242                 bi->chunk_error_strikes++;
243
244                 if (bi->chunk_error_strikes > 3) {
245                         bi->needs_retiring = 1; /* Too many stikes, so retire */
246                         yaffs_trace(YAFFS_TRACE_ALWAYS,
247                                 "yaffs: Block struck out");
248
249                 }
250         }
251 }
252
253 static void yaffs_handle_chunk_wr_error(struct yaffs_dev *dev, int nand_chunk,
254                                         int erased_ok)
255 {
256         int flash_block = nand_chunk / dev->param.chunks_per_block;
257         struct yaffs_block_info *bi = yaffs_get_block_info(dev, flash_block);
258
259         yaffs_handle_chunk_error(dev, bi);
260
261         if (erased_ok) {
262                 /* Was an actual write failure,
263                  * so mark the block for retirement.*/
264                 bi->needs_retiring = 1;
265                 yaffs_trace(YAFFS_TRACE_ERROR | YAFFS_TRACE_BAD_BLOCKS,
266                   "**>> Block %d needs retiring", flash_block);
267         }
268
269         /* Delete the chunk */
270         yaffs_chunk_del(dev, nand_chunk, 1, __LINE__);
271         yaffs_skip_rest_of_block(dev);
272 }
273
274 /*
275  * Verification code
276  */
277
278 /*
279  *  Simple hash function. Needs to have a reasonable spread
280  */
281
282 static inline int yaffs_hash_fn(int n)
283 {
284         if (n < 0)
285                 n = -n;
286         return n % YAFFS_NOBJECT_BUCKETS;
287 }
288
289 /*
290  * Access functions to useful fake objects.
291  * Note that root might have a presence in NAND if permissions are set.
292  */
293
294 struct yaffs_obj *yaffs_root(struct yaffs_dev *dev)
295 {
296         return dev->root_dir;
297 }
298
299 struct yaffs_obj *yaffs_lost_n_found(struct yaffs_dev *dev)
300 {
301         return dev->lost_n_found;
302 }
303
304 /*
305  *  Erased NAND checking functions
306  */
307
308 int yaffs_check_ff(u8 *buffer, int n_bytes)
309 {
310         /* Horrible, slow implementation */
311         while (n_bytes--) {
312                 if (*buffer != 0xff)
313                         return 0;
314                 buffer++;
315         }
316         return 1;
317 }
318
319 static int yaffs_check_chunk_erased(struct yaffs_dev *dev, int nand_chunk)
320 {
321         int retval = YAFFS_OK;
322         u8 *data = yaffs_get_temp_buffer(dev);
323         struct yaffs_ext_tags tags;
324         int result;
325
326         result = yaffs_rd_chunk_tags_nand(dev, nand_chunk, data, &tags);
327
328         if (tags.ecc_result > YAFFS_ECC_RESULT_NO_ERROR)
329                 retval = YAFFS_FAIL;
330
331         if (!yaffs_check_ff(data, dev->data_bytes_per_chunk) ||
332                 tags.chunk_used) {
333                 yaffs_trace(YAFFS_TRACE_NANDACCESS,
334                         "Chunk %d not erased", nand_chunk);
335                 retval = YAFFS_FAIL;
336         }
337
338         yaffs_release_temp_buffer(dev, data);
339
340         return retval;
341
342 }
343
344 static int yaffs_verify_chunk_written(struct yaffs_dev *dev,
345                                       int nand_chunk,
346                                       const u8 *data,
347                                       struct yaffs_ext_tags *tags)
348 {
349         int retval = YAFFS_OK;
350         struct yaffs_ext_tags temp_tags;
351         u8 *buffer = yaffs_get_temp_buffer(dev);
352         int result;
353
354         result = yaffs_rd_chunk_tags_nand(dev, nand_chunk, buffer, &temp_tags);
355         if (memcmp(buffer, data, dev->data_bytes_per_chunk) ||
356             temp_tags.obj_id != tags->obj_id ||
357             temp_tags.chunk_id != tags->chunk_id ||
358             temp_tags.n_bytes != tags->n_bytes)
359                 retval = YAFFS_FAIL;
360
361         yaffs_release_temp_buffer(dev, buffer);
362
363         return retval;
364 }
365
366
367 int yaffs_check_alloc_available(struct yaffs_dev *dev, int n_chunks)
368 {
369         int reserved_chunks;
370         int reserved_blocks = dev->param.n_reserved_blocks;
371         int checkpt_blocks;
372
373         checkpt_blocks = yaffs_calc_checkpt_blocks_required(dev);
374
375         reserved_chunks =
376             (reserved_blocks + checkpt_blocks) * dev->param.chunks_per_block;
377
378         return (dev->n_free_chunks > (reserved_chunks + n_chunks));
379 }
380
381 static int yaffs_find_alloc_block(struct yaffs_dev *dev)
382 {
383         int i;
384         struct yaffs_block_info *bi;
385
386         if (dev->n_erased_blocks < 1) {
387                 /* Hoosterman we've got a problem.
388                  * Can't get space to gc
389                  */
390                 yaffs_trace(YAFFS_TRACE_ERROR,
391                   "yaffs tragedy: no more erased blocks");
392
393                 return -1;
394         }
395
396         /* Find an empty block. */
397
398         for (i = dev->internal_start_block; i <= dev->internal_end_block; i++) {
399                 dev->alloc_block_finder++;
400                 if (dev->alloc_block_finder < dev->internal_start_block
401                     || dev->alloc_block_finder > dev->internal_end_block) {
402                         dev->alloc_block_finder = dev->internal_start_block;
403                 }
404
405                 bi = yaffs_get_block_info(dev, dev->alloc_block_finder);
406
407                 if (bi->block_state == YAFFS_BLOCK_STATE_EMPTY) {
408                         bi->block_state = YAFFS_BLOCK_STATE_ALLOCATING;
409                         dev->seq_number++;
410                         bi->seq_number = dev->seq_number;
411                         dev->n_erased_blocks--;
412                         yaffs_trace(YAFFS_TRACE_ALLOCATE,
413                           "Allocated block %d, seq  %d, %d left" ,
414                            dev->alloc_block_finder, dev->seq_number,
415                            dev->n_erased_blocks);
416                         return dev->alloc_block_finder;
417                 }
418         }
419
420         yaffs_trace(YAFFS_TRACE_ALWAYS,
421                 "yaffs tragedy: no more erased blocks, but there should have been %d",
422                 dev->n_erased_blocks);
423
424         return -1;
425 }
426
427 static int yaffs_alloc_chunk(struct yaffs_dev *dev, int use_reserver,
428                              struct yaffs_block_info **block_ptr)
429 {
430         int ret_val;
431         struct yaffs_block_info *bi;
432
433         if (dev->alloc_block < 0) {
434                 /* Get next block to allocate off */
435                 dev->alloc_block = yaffs_find_alloc_block(dev);
436                 dev->alloc_page = 0;
437         }
438
439         if (!use_reserver && !yaffs_check_alloc_available(dev, 1)) {
440                 /* No space unless we're allowed to use the reserve. */
441                 return -1;
442         }
443
444         if (dev->n_erased_blocks < dev->param.n_reserved_blocks
445             && dev->alloc_page == 0)
446                 yaffs_trace(YAFFS_TRACE_ALLOCATE, "Allocating reserve");
447
448         /* Next page please.... */
449         if (dev->alloc_block >= 0) {
450                 bi = yaffs_get_block_info(dev, dev->alloc_block);
451
452                 ret_val = (dev->alloc_block * dev->param.chunks_per_block) +
453                     dev->alloc_page;
454                 bi->pages_in_use++;
455                 yaffs_set_chunk_bit(dev, dev->alloc_block, dev->alloc_page);
456
457                 dev->alloc_page++;
458
459                 dev->n_free_chunks--;
460
461                 /* If the block is full set the state to full */
462                 if (dev->alloc_page >= dev->param.chunks_per_block) {
463                         bi->block_state = YAFFS_BLOCK_STATE_FULL;
464                         dev->alloc_block = -1;
465                 }
466
467                 if (block_ptr)
468                         *block_ptr = bi;
469
470                 return ret_val;
471         }
472
473         yaffs_trace(YAFFS_TRACE_ERROR,
474                 "!!!!!!!!! Allocator out !!!!!!!!!!!!!!!!!");
475
476         return -1;
477 }
478
479 static int yaffs_get_erased_chunks(struct yaffs_dev *dev)
480 {
481         int n;
482
483         n = dev->n_erased_blocks * dev->param.chunks_per_block;
484
485         if (dev->alloc_block > 0)
486                 n += (dev->param.chunks_per_block - dev->alloc_page);
487
488         return n;
489
490 }
491
492 /*
493  * yaffs_skip_rest_of_block() skips over the rest of the allocation block
494  * if we don't want to write to it.
495  */
496 void yaffs_skip_rest_of_block(struct yaffs_dev *dev)
497 {
498         struct yaffs_block_info *bi;
499
500         if (dev->alloc_block > 0) {
501                 bi = yaffs_get_block_info(dev, dev->alloc_block);
502                 if (bi->block_state == YAFFS_BLOCK_STATE_ALLOCATING) {
503                         bi->block_state = YAFFS_BLOCK_STATE_FULL;
504                         dev->alloc_block = -1;
505                 }
506         }
507 }
508
509 static int yaffs_write_new_chunk(struct yaffs_dev *dev,
510                                  const u8 *data,
511                                  struct yaffs_ext_tags *tags, int use_reserver)
512 {
513         int attempts = 0;
514         int write_ok = 0;
515         int chunk;
516
517         yaffs2_checkpt_invalidate(dev);
518
519         do {
520                 struct yaffs_block_info *bi = 0;
521                 int erased_ok = 0;
522
523                 chunk = yaffs_alloc_chunk(dev, use_reserver, &bi);
524                 if (chunk < 0) {
525                         /* no space */
526                         break;
527                 }
528
529                 /* First check this chunk is erased, if it needs
530                  * checking.  The checking policy (unless forced
531                  * always on) is as follows:
532                  *
533                  * Check the first page we try to write in a block.
534                  * If the check passes then we don't need to check any
535                  * more.        If the check fails, we check again...
536                  * If the block has been erased, we don't need to check.
537                  *
538                  * However, if the block has been prioritised for gc,
539                  * then we think there might be something odd about
540                  * this block and stop using it.
541                  *
542                  * Rationale: We should only ever see chunks that have
543                  * not been erased if there was a partially written
544                  * chunk due to power loss.  This checking policy should
545                  * catch that case with very few checks and thus save a
546                  * lot of checks that are most likely not needed.
547                  *
548                  * Mods to the above
549                  * If an erase check fails or the write fails we skip the
550                  * rest of the block.
551                  */
552
553                 /* let's give it a try */
554                 attempts++;
555
556                 if (dev->param.always_check_erased)
557                         bi->skip_erased_check = 0;
558
559                 if (!bi->skip_erased_check) {
560                         erased_ok = yaffs_check_chunk_erased(dev, chunk);
561                         if (erased_ok != YAFFS_OK) {
562                                 yaffs_trace(YAFFS_TRACE_ERROR,
563                                   "**>> yaffs chunk %d was not erased",
564                                   chunk);
565
566                                 /* If not erased, delete this one,
567                                  * skip rest of block and
568                                  * try another chunk */
569                                 yaffs_chunk_del(dev, chunk, 1, __LINE__);
570                                 yaffs_skip_rest_of_block(dev);
571                                 continue;
572                         }
573                 }
574
575                 write_ok = yaffs_wr_chunk_tags_nand(dev, chunk, data, tags);
576
577                 if (!bi->skip_erased_check)
578                         write_ok =
579                             yaffs_verify_chunk_written(dev, chunk, data, tags);
580
581                 if (write_ok != YAFFS_OK) {
582                         /* Clean up aborted write, skip to next block and
583                          * try another chunk */
584                         yaffs_handle_chunk_wr_error(dev, chunk, erased_ok);
585                         continue;
586                 }
587
588                 bi->skip_erased_check = 1;
589
590                 /* Copy the data into the robustification buffer */
591                 yaffs_handle_chunk_wr_ok(dev, chunk, data, tags);
592
593         } while (write_ok != YAFFS_OK &&
594                  (yaffs_wr_attempts <= 0 || attempts <= yaffs_wr_attempts));
595
596         if (!write_ok)
597                 chunk = -1;
598
599         if (attempts > 1) {
600                 yaffs_trace(YAFFS_TRACE_ERROR,
601                         "**>> yaffs write required %d attempts",
602                         attempts);
603                 dev->n_retried_writes += (attempts - 1);
604         }
605
606         return chunk;
607 }
608
609 /*
610  * Block retiring for handling a broken block.
611  */
612
613 static void yaffs_retire_block(struct yaffs_dev *dev, int flash_block)
614 {
615         struct yaffs_block_info *bi = yaffs_get_block_info(dev, flash_block);
616
617         yaffs2_checkpt_invalidate(dev);
618
619         yaffs2_clear_oldest_dirty_seq(dev, bi);
620
621         if (yaffs_mark_bad(dev, flash_block) != YAFFS_OK) {
622                 if (yaffs_erase_block(dev, flash_block) != YAFFS_OK) {
623                         yaffs_trace(YAFFS_TRACE_ALWAYS,
624                                 "yaffs: Failed to mark bad and erase block %d",
625                                 flash_block);
626                 } else {
627                         struct yaffs_ext_tags tags;
628                         int chunk_id =
629                             flash_block * dev->param.chunks_per_block;
630
631                         u8 *buffer = yaffs_get_temp_buffer(dev);
632
633                         memset(buffer, 0xff, dev->data_bytes_per_chunk);
634                         memset(&tags, 0, sizeof(tags));
635                         tags.seq_number = YAFFS_SEQUENCE_BAD_BLOCK;
636                         if (dev->param.write_chunk_tags_fn(dev, chunk_id -
637                                                            dev->chunk_offset,
638                                                            buffer,
639                                                            &tags) != YAFFS_OK)
640                                 yaffs_trace(YAFFS_TRACE_ALWAYS,
641                                         "yaffs: Failed to write bad block marker to block %d",
642                                         flash_block);
643
644                         yaffs_release_temp_buffer(dev, buffer);
645                 }
646         }
647
648         bi->block_state = YAFFS_BLOCK_STATE_DEAD;
649         bi->gc_prioritise = 0;
650         bi->needs_retiring = 0;
651
652         dev->n_retired_blocks++;
653 }
654
655 /*---------------- Name handling functions ------------*/
656
657 static u16 yaffs_calc_name_sum(const YCHAR *name)
658 {
659         u16 sum = 0;
660         u16 i = 1;
661
662         if (!name)
663                 return 0;
664
665         while ((*name) && i < (YAFFS_MAX_NAME_LENGTH / 2)) {
666
667                 /* 0x1f mask is case insensitive */
668                 sum += ((*name) & 0x1f) * i;
669                 i++;
670                 name++;
671         }
672         return sum;
673 }
674
675 void yaffs_set_obj_name(struct yaffs_obj *obj, const YCHAR * name)
676 {
677         memset(obj->short_name, 0, sizeof(obj->short_name));
678         if (name &&
679                 strnlen(name, YAFFS_SHORT_NAME_LENGTH + 1) <=
680                 YAFFS_SHORT_NAME_LENGTH)
681                 strcpy(obj->short_name, name);
682         else
683                 obj->short_name[0] = _Y('\0');
684         obj->sum = yaffs_calc_name_sum(name);
685 }
686
687 void yaffs_set_obj_name_from_oh(struct yaffs_obj *obj,
688                                 const struct yaffs_obj_hdr *oh)
689 {
690 #ifdef CONFIG_YAFFS_AUTO_UNICODE
691         YCHAR tmp_name[YAFFS_MAX_NAME_LENGTH + 1];
692         memset(tmp_name, 0, sizeof(tmp_name));
693         yaffs_load_name_from_oh(obj->my_dev, tmp_name, oh->name,
694                                 YAFFS_MAX_NAME_LENGTH + 1);
695         yaffs_set_obj_name(obj, tmp_name);
696 #else
697         yaffs_set_obj_name(obj, oh->name);
698 #endif
699 }
700
701 loff_t yaffs_max_file_size(struct yaffs_dev *dev)
702 {
703         return ((loff_t) YAFFS_MAX_CHUNK_ID) * dev->data_bytes_per_chunk;
704 }
705
706 /*-------------------- TNODES -------------------
707
708  * List of spare tnodes
709  * The list is hooked together using the first pointer
710  * in the tnode.
711  */
712
713 struct yaffs_tnode *yaffs_get_tnode(struct yaffs_dev *dev)
714 {
715         struct yaffs_tnode *tn = yaffs_alloc_raw_tnode(dev);
716
717         if (tn) {
718                 memset(tn, 0, dev->tnode_size);
719                 dev->n_tnodes++;
720         }
721
722         dev->checkpoint_blocks_required = 0;    /* force recalculation */
723
724         return tn;
725 }
726
727 /* FreeTnode frees up a tnode and puts it back on the free list */
728 static void yaffs_free_tnode(struct yaffs_dev *dev, struct yaffs_tnode *tn)
729 {
730         yaffs_free_raw_tnode(dev, tn);
731         dev->n_tnodes--;
732         dev->checkpoint_blocks_required = 0;    /* force recalculation */
733 }
734
735 static void yaffs_deinit_tnodes_and_objs(struct yaffs_dev *dev)
736 {
737         yaffs_deinit_raw_tnodes_and_objs(dev);
738         dev->n_obj = 0;
739         dev->n_tnodes = 0;
740 }
741
742 void yaffs_load_tnode_0(struct yaffs_dev *dev, struct yaffs_tnode *tn,
743                         unsigned pos, unsigned val)
744 {
745         u32 *map = (u32 *) tn;
746         u32 bit_in_map;
747         u32 bit_in_word;
748         u32 word_in_map;
749         u32 mask;
750
751         pos &= YAFFS_TNODES_LEVEL0_MASK;
752         val >>= dev->chunk_grp_bits;
753
754         bit_in_map = pos * dev->tnode_width;
755         word_in_map = bit_in_map / 32;
756         bit_in_word = bit_in_map & (32 - 1);
757
758         mask = dev->tnode_mask << bit_in_word;
759
760         map[word_in_map] &= ~mask;
761         map[word_in_map] |= (mask & (val << bit_in_word));
762
763         if (dev->tnode_width > (32 - bit_in_word)) {
764                 bit_in_word = (32 - bit_in_word);
765                 word_in_map++;
766                 mask =
767                     dev->tnode_mask >> bit_in_word;
768                 map[word_in_map] &= ~mask;
769                 map[word_in_map] |= (mask & (val >> bit_in_word));
770         }
771 }
772
773 u32 yaffs_get_group_base(struct yaffs_dev *dev, struct yaffs_tnode *tn,
774                          unsigned pos)
775 {
776         u32 *map = (u32 *) tn;
777         u32 bit_in_map;
778         u32 bit_in_word;
779         u32 word_in_map;
780         u32 val;
781
782         pos &= YAFFS_TNODES_LEVEL0_MASK;
783
784         bit_in_map = pos * dev->tnode_width;
785         word_in_map = bit_in_map / 32;
786         bit_in_word = bit_in_map & (32 - 1);
787
788         val = map[word_in_map] >> bit_in_word;
789
790         if (dev->tnode_width > (32 - bit_in_word)) {
791                 bit_in_word = (32 - bit_in_word);
792                 word_in_map++;
793                 val |= (map[word_in_map] << bit_in_word);
794         }
795
796         val &= dev->tnode_mask;
797         val <<= dev->chunk_grp_bits;
798
799         return val;
800 }
801
802 /* ------------------- End of individual tnode manipulation -----------------*/
803
804 /* ---------Functions to manipulate the look-up tree (made up of tnodes) ------
805  * The look up tree is represented by the top tnode and the number of top_level
806  * in the tree. 0 means only the level 0 tnode is in the tree.
807  */
808
809 /* FindLevel0Tnode finds the level 0 tnode, if one exists. */
810 struct yaffs_tnode *yaffs_find_tnode_0(struct yaffs_dev *dev,
811                                        struct yaffs_file_var *file_struct,
812                                        u32 chunk_id)
813 {
814         struct yaffs_tnode *tn = file_struct->top;
815         u32 i;
816         int required_depth;
817         int level = file_struct->top_level;
818
819         dev = dev;
820
821         /* Check sane level and chunk Id */
822         if (level < 0 || level > YAFFS_TNODES_MAX_LEVEL)
823                 return NULL;
824
825         if (chunk_id > YAFFS_MAX_CHUNK_ID)
826                 return NULL;
827
828         /* First check we're tall enough (ie enough top_level) */
829
830         i = chunk_id >> YAFFS_TNODES_LEVEL0_BITS;
831         required_depth = 0;
832         while (i) {
833                 i >>= YAFFS_TNODES_INTERNAL_BITS;
834                 required_depth++;
835         }
836
837         if (required_depth > file_struct->top_level)
838                 return NULL;    /* Not tall enough, so we can't find it */
839
840         /* Traverse down to level 0 */
841         while (level > 0 && tn) {
842                 tn = tn->internal[(chunk_id >>
843                                    (YAFFS_TNODES_LEVEL0_BITS +
844                                     (level - 1) *
845                                     YAFFS_TNODES_INTERNAL_BITS)) &
846                                   YAFFS_TNODES_INTERNAL_MASK];
847                 level--;
848         }
849
850         return tn;
851 }
852
853 /* add_find_tnode_0 finds the level 0 tnode if it exists,
854  * otherwise first expands the tree.
855  * This happens in two steps:
856  *  1. If the tree isn't tall enough, then make it taller.
857  *  2. Scan down the tree towards the level 0 tnode adding tnodes if required.
858  *
859  * Used when modifying the tree.
860  *
861  *  If the tn argument is NULL, then a fresh tnode will be added otherwise the
862  *  specified tn will be plugged into the ttree.
863  */
864
865 struct yaffs_tnode *yaffs_add_find_tnode_0(struct yaffs_dev *dev,
866                                            struct yaffs_file_var *file_struct,
867                                            u32 chunk_id,
868                                            struct yaffs_tnode *passed_tn)
869 {
870         int required_depth;
871         int i;
872         int l;
873         struct yaffs_tnode *tn;
874         u32 x;
875
876         /* Check sane level and page Id */
877         if (file_struct->top_level < 0 ||
878             file_struct->top_level > YAFFS_TNODES_MAX_LEVEL)
879                 return NULL;
880
881         if (chunk_id > YAFFS_MAX_CHUNK_ID)
882                 return NULL;
883
884         /* First check we're tall enough (ie enough top_level) */
885
886         x = chunk_id >> YAFFS_TNODES_LEVEL0_BITS;
887         required_depth = 0;
888         while (x) {
889                 x >>= YAFFS_TNODES_INTERNAL_BITS;
890                 required_depth++;
891         }
892
893         if (required_depth > file_struct->top_level) {
894                 /* Not tall enough, gotta make the tree taller */
895                 for (i = file_struct->top_level; i < required_depth; i++) {
896
897                         tn = yaffs_get_tnode(dev);
898
899                         if (tn) {
900                                 tn->internal[0] = file_struct->top;
901                                 file_struct->top = tn;
902                                 file_struct->top_level++;
903                         } else {
904                                 yaffs_trace(YAFFS_TRACE_ERROR,
905                                         "yaffs: no more tnodes");
906                                 return NULL;
907                         }
908                 }
909         }
910
911         /* Traverse down to level 0, adding anything we need */
912
913         l = file_struct->top_level;
914         tn = file_struct->top;
915
916         if (l > 0) {
917                 while (l > 0 && tn) {
918                         x = (chunk_id >>
919                              (YAFFS_TNODES_LEVEL0_BITS +
920                               (l - 1) * YAFFS_TNODES_INTERNAL_BITS)) &
921                             YAFFS_TNODES_INTERNAL_MASK;
922
923                         if ((l > 1) && !tn->internal[x]) {
924                                 /* Add missing non-level-zero tnode */
925                                 tn->internal[x] = yaffs_get_tnode(dev);
926                                 if (!tn->internal[x])
927                                         return NULL;
928                         } else if (l == 1) {
929                                 /* Looking from level 1 at level 0 */
930                                 if (passed_tn) {
931                                         /* If we already have one, release it */
932                                         if (tn->internal[x])
933                                                 yaffs_free_tnode(dev,
934                                                         tn->internal[x]);
935                                         tn->internal[x] = passed_tn;
936
937                                 } else if (!tn->internal[x]) {
938                                         /* Don't have one, none passed in */
939                                         tn->internal[x] = yaffs_get_tnode(dev);
940                                         if (!tn->internal[x])
941                                                 return NULL;
942                                 }
943                         }
944
945                         tn = tn->internal[x];
946                         l--;
947                 }
948         } else {
949                 /* top is level 0 */
950                 if (passed_tn) {
951                         memcpy(tn, passed_tn,
952                                (dev->tnode_width * YAFFS_NTNODES_LEVEL0) / 8);
953                         yaffs_free_tnode(dev, passed_tn);
954                 }
955         }
956
957         return tn;
958 }
959
960 static int yaffs_tags_match(const struct yaffs_ext_tags *tags, int obj_id,
961                             int chunk_obj)
962 {
963         return (tags->chunk_id == chunk_obj &&
964                 tags->obj_id == obj_id &&
965                 !tags->is_deleted) ? 1 : 0;
966
967 }
968
969 static int yaffs_find_chunk_in_group(struct yaffs_dev *dev, int the_chunk,
970                                         struct yaffs_ext_tags *tags, int obj_id,
971                                         int inode_chunk)
972 {
973         int j;
974
975         for (j = 0; the_chunk && j < dev->chunk_grp_size; j++) {
976                 if (yaffs_check_chunk_bit
977                     (dev, the_chunk / dev->param.chunks_per_block,
978                      the_chunk % dev->param.chunks_per_block)) {
979
980                         if (dev->chunk_grp_size == 1)
981                                 return the_chunk;
982                         else {
983                                 yaffs_rd_chunk_tags_nand(dev, the_chunk, NULL,
984                                                          tags);
985                                 if (yaffs_tags_match(tags,
986                                                         obj_id, inode_chunk)) {
987                                         /* found it; */
988                                         return the_chunk;
989                                 }
990                         }
991                 }
992                 the_chunk++;
993         }
994         return -1;
995 }
996
997 static int yaffs_find_chunk_in_file(struct yaffs_obj *in, int inode_chunk,
998                                     struct yaffs_ext_tags *tags)
999 {
1000         /*Get the Tnode, then get the level 0 offset chunk offset */
1001         struct yaffs_tnode *tn;
1002         int the_chunk = -1;
1003         struct yaffs_ext_tags local_tags;
1004         int ret_val = -1;
1005         struct yaffs_dev *dev = in->my_dev;
1006
1007         if (!tags) {
1008                 /* Passed a NULL, so use our own tags space */
1009                 tags = &local_tags;
1010         }
1011
1012         tn = yaffs_find_tnode_0(dev, &in->variant.file_variant, inode_chunk);
1013
1014         if (!tn)
1015                 return ret_val;
1016
1017         the_chunk = yaffs_get_group_base(dev, tn, inode_chunk);
1018
1019         ret_val = yaffs_find_chunk_in_group(dev, the_chunk, tags, in->obj_id,
1020                                               inode_chunk);
1021         return ret_val;
1022 }
1023
1024 static int yaffs_find_del_file_chunk(struct yaffs_obj *in, int inode_chunk,
1025                                      struct yaffs_ext_tags *tags)
1026 {
1027         /* Get the Tnode, then get the level 0 offset chunk offset */
1028         struct yaffs_tnode *tn;
1029         int the_chunk = -1;
1030         struct yaffs_ext_tags local_tags;
1031         struct yaffs_dev *dev = in->my_dev;
1032         int ret_val = -1;
1033
1034         if (!tags) {
1035                 /* Passed a NULL, so use our own tags space */
1036                 tags = &local_tags;
1037         }
1038
1039         tn = yaffs_find_tnode_0(dev, &in->variant.file_variant, inode_chunk);
1040
1041         if (!tn)
1042                 return ret_val;
1043
1044         the_chunk = yaffs_get_group_base(dev, tn, inode_chunk);
1045
1046         ret_val = yaffs_find_chunk_in_group(dev, the_chunk, tags, in->obj_id,
1047                                               inode_chunk);
1048
1049         /* Delete the entry in the filestructure (if found) */
1050         if (ret_val != -1)
1051                 yaffs_load_tnode_0(dev, tn, inode_chunk, 0);
1052
1053         return ret_val;
1054 }
1055
1056 int yaffs_put_chunk_in_file(struct yaffs_obj *in, int inode_chunk,
1057                             int nand_chunk, int in_scan)
1058 {
1059         /* NB in_scan is zero unless scanning.
1060          * For forward scanning, in_scan is > 0;
1061          * for backward scanning in_scan is < 0
1062          *
1063          * nand_chunk = 0 is a dummy insert to make sure the tnodes are there.
1064          */
1065
1066         struct yaffs_tnode *tn;
1067         struct yaffs_dev *dev = in->my_dev;
1068         int existing_cunk;
1069         struct yaffs_ext_tags existing_tags;
1070         struct yaffs_ext_tags new_tags;
1071         unsigned existing_serial, new_serial;
1072
1073         if (in->variant_type != YAFFS_OBJECT_TYPE_FILE) {
1074                 /* Just ignore an attempt at putting a chunk into a non-file
1075                  * during scanning.
1076                  * If it is not during Scanning then something went wrong!
1077                  */
1078                 if (!in_scan) {
1079                         yaffs_trace(YAFFS_TRACE_ERROR,
1080                                 "yaffs tragedy:attempt to put data chunk into a non-file"
1081                                 );
1082                         BUG();
1083                 }
1084
1085                 yaffs_chunk_del(dev, nand_chunk, 1, __LINE__);
1086                 return YAFFS_OK;
1087         }
1088
1089         tn = yaffs_add_find_tnode_0(dev,
1090                                     &in->variant.file_variant,
1091                                     inode_chunk, NULL);
1092         if (!tn)
1093                 return YAFFS_FAIL;
1094
1095         if (!nand_chunk)
1096                 /* Dummy insert, bail now */
1097                 return YAFFS_OK;
1098
1099         existing_cunk = yaffs_get_group_base(dev, tn, inode_chunk);
1100
1101         if (in_scan != 0) {
1102                 /* If we're scanning then we need to test for duplicates
1103                  * NB This does not need to be efficient since it should only
1104                  * happen when the power fails during a write, then only one
1105                  * chunk should ever be affected.
1106                  *
1107                  * Correction for YAFFS2: This could happen quite a lot and we
1108                  * need to think about efficiency! TODO
1109                  * Update: For backward scanning we don't need to re-read tags
1110                  * so this is quite cheap.
1111                  */
1112
1113                 if (existing_cunk > 0) {
1114                         /* NB Right now existing chunk will not be real
1115                          * chunk_id if the chunk group size > 1
1116                          * thus we have to do a FindChunkInFile to get the
1117                          * real chunk id.
1118                          *
1119                          * We have a duplicate now we need to decide which
1120                          * one to use:
1121                          *
1122                          * Backwards scanning YAFFS2: The old one is what
1123                          * we use, dump the new one.
1124                          * YAFFS1: Get both sets of tags and compare serial
1125                          * numbers.
1126                          */
1127
1128                         if (in_scan > 0) {
1129                                 /* Only do this for forward scanning */
1130                                 yaffs_rd_chunk_tags_nand(dev,
1131                                                          nand_chunk,
1132                                                          NULL, &new_tags);
1133
1134                                 /* Do a proper find */
1135                                 existing_cunk =
1136                                     yaffs_find_chunk_in_file(in, inode_chunk,
1137                                                              &existing_tags);
1138                         }
1139
1140                         if (existing_cunk <= 0) {
1141                                 /*Hoosterman - how did this happen? */
1142
1143                                 yaffs_trace(YAFFS_TRACE_ERROR,
1144                                         "yaffs tragedy: existing chunk < 0 in scan"
1145                                         );
1146
1147                         }
1148
1149                         /* NB The deleted flags should be false, otherwise
1150                          * the chunks will not be loaded during a scan
1151                          */
1152
1153                         if (in_scan > 0) {
1154                                 new_serial = new_tags.serial_number;
1155                                 existing_serial = existing_tags.serial_number;
1156                         }
1157
1158                         if ((in_scan > 0) &&
1159                             (existing_cunk <= 0 ||
1160                              ((existing_serial + 1) & 3) == new_serial)) {
1161                                 /* Forward scanning.
1162                                  * Use new
1163                                  * Delete the old one and drop through to
1164                                  * update the tnode
1165                                  */
1166                                 yaffs_chunk_del(dev, existing_cunk, 1,
1167                                                 __LINE__);
1168                         } else {
1169                                 /* Backward scanning or we want to use the
1170                                  * existing one
1171                                  * Delete the new one and return early so that
1172                                  * the tnode isn't changed
1173                                  */
1174                                 yaffs_chunk_del(dev, nand_chunk, 1, __LINE__);
1175                                 return YAFFS_OK;
1176                         }
1177                 }
1178
1179         }
1180
1181         if (existing_cunk == 0)
1182                 in->n_data_chunks++;
1183
1184         yaffs_load_tnode_0(dev, tn, inode_chunk, nand_chunk);
1185
1186         return YAFFS_OK;
1187 }
1188
1189 static void yaffs_soft_del_chunk(struct yaffs_dev *dev, int chunk)
1190 {
1191         struct yaffs_block_info *the_block;
1192         unsigned block_no;
1193
1194         yaffs_trace(YAFFS_TRACE_DELETION, "soft delete chunk %d", chunk);
1195
1196         block_no = chunk / dev->param.chunks_per_block;
1197         the_block = yaffs_get_block_info(dev, block_no);
1198         if (the_block) {
1199                 the_block->soft_del_pages++;
1200                 dev->n_free_chunks++;
1201                 yaffs2_update_oldest_dirty_seq(dev, block_no, the_block);
1202         }
1203 }
1204
1205 /* SoftDeleteWorker scans backwards through the tnode tree and soft deletes all
1206  * the chunks in the file.
1207  * All soft deleting does is increment the block's softdelete count and pulls
1208  * the chunk out of the tnode.
1209  * Thus, essentially this is the same as DeleteWorker except that the chunks
1210  * are soft deleted.
1211  */
1212
1213 static int yaffs_soft_del_worker(struct yaffs_obj *in, struct yaffs_tnode *tn,
1214                                  u32 level, int chunk_offset)
1215 {
1216         int i;
1217         int the_chunk;
1218         int all_done = 1;
1219         struct yaffs_dev *dev = in->my_dev;
1220
1221         if (!tn)
1222                 return 1;
1223
1224         if (level > 0) {
1225                 for (i = YAFFS_NTNODES_INTERNAL - 1;
1226                         all_done && i >= 0;
1227                         i--) {
1228                         if (tn->internal[i]) {
1229                                 all_done =
1230                                     yaffs_soft_del_worker(in,
1231                                         tn->internal[i],
1232                                         level - 1,
1233                                         (chunk_offset <<
1234                                         YAFFS_TNODES_INTERNAL_BITS)
1235                                         + i);
1236                                 if (all_done) {
1237                                         yaffs_free_tnode(dev,
1238                                                 tn->internal[i]);
1239                                         tn->internal[i] = NULL;
1240                                 } else {
1241                                         /* Can this happen? */
1242                                 }
1243                         }
1244                 }
1245                 return (all_done) ? 1 : 0;
1246         }
1247
1248         /* level 0 */
1249          for (i = YAFFS_NTNODES_LEVEL0 - 1; i >= 0; i--) {
1250                 the_chunk = yaffs_get_group_base(dev, tn, i);
1251                 if (the_chunk) {
1252                         yaffs_soft_del_chunk(dev, the_chunk);
1253                         yaffs_load_tnode_0(dev, tn, i, 0);
1254                 }
1255         }
1256         return 1;
1257 }
1258
1259 static void yaffs_remove_obj_from_dir(struct yaffs_obj *obj)
1260 {
1261         struct yaffs_dev *dev = obj->my_dev;
1262         struct yaffs_obj *parent;
1263
1264         yaffs_verify_obj_in_dir(obj);
1265         parent = obj->parent;
1266
1267         yaffs_verify_dir(parent);
1268
1269         if (dev && dev->param.remove_obj_fn)
1270                 dev->param.remove_obj_fn(obj);
1271
1272         list_del_init(&obj->siblings);
1273         obj->parent = NULL;
1274
1275         yaffs_verify_dir(parent);
1276 }
1277
1278 void yaffs_add_obj_to_dir(struct yaffs_obj *directory, struct yaffs_obj *obj)
1279 {
1280         if (!directory) {
1281                 yaffs_trace(YAFFS_TRACE_ALWAYS,
1282                         "tragedy: Trying to add an object to a null pointer directory"
1283                         );
1284                 BUG();
1285                 return;
1286         }
1287         if (directory->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY) {
1288                 yaffs_trace(YAFFS_TRACE_ALWAYS,
1289                         "tragedy: Trying to add an object to a non-directory"
1290                         );
1291                 BUG();
1292         }
1293
1294         if (obj->siblings.prev == NULL) {
1295                 /* Not initialised */
1296                 BUG();
1297         }
1298
1299         yaffs_verify_dir(directory);
1300
1301         yaffs_remove_obj_from_dir(obj);
1302
1303         /* Now add it */
1304         list_add(&obj->siblings, &directory->variant.dir_variant.children);
1305         obj->parent = directory;
1306
1307         if (directory == obj->my_dev->unlinked_dir
1308             || directory == obj->my_dev->del_dir) {
1309                 obj->unlinked = 1;
1310                 obj->my_dev->n_unlinked_files++;
1311                 obj->rename_allowed = 0;
1312         }
1313
1314         yaffs_verify_dir(directory);
1315         yaffs_verify_obj_in_dir(obj);
1316 }
1317
1318 static int yaffs_change_obj_name(struct yaffs_obj *obj,
1319                                  struct yaffs_obj *new_dir,
1320                                  const YCHAR *new_name, int force, int shadows)
1321 {
1322         int unlink_op;
1323         int del_op;
1324         struct yaffs_obj *existing_target;
1325
1326         if (new_dir == NULL)
1327                 new_dir = obj->parent;  /* use the old directory */
1328
1329         if (new_dir->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY) {
1330                 yaffs_trace(YAFFS_TRACE_ALWAYS,
1331                         "tragedy: yaffs_change_obj_name: new_dir is not a directory"
1332                         );
1333                 BUG();
1334         }
1335
1336         unlink_op = (new_dir == obj->my_dev->unlinked_dir);
1337         del_op = (new_dir == obj->my_dev->del_dir);
1338
1339         existing_target = yaffs_find_by_name(new_dir, new_name);
1340
1341         /* If the object is a file going into the unlinked directory,
1342          *   then it is OK to just stuff it in since duplicate names are OK.
1343          *   else only proceed if the new name does not exist and we're putting
1344          *   it into a directory.
1345          */
1346         if (!(unlink_op || del_op || force ||
1347               shadows > 0 || !existing_target) ||
1348               new_dir->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY)
1349                 return YAFFS_FAIL;
1350
1351         yaffs_set_obj_name(obj, new_name);
1352         obj->dirty = 1;
1353         yaffs_add_obj_to_dir(new_dir, obj);
1354
1355         if (unlink_op)
1356                 obj->unlinked = 1;
1357
1358         /* If it is a deletion then we mark it as a shrink for gc  */
1359         if (yaffs_update_oh(obj, new_name, 0, del_op, shadows, NULL) >= 0)
1360                 return YAFFS_OK;
1361
1362         return YAFFS_FAIL;
1363 }
1364
1365 /*------------------------ Short Operations Cache ------------------------------
1366  *   In many situations where there is no high level buffering  a lot of
1367  *   reads might be short sequential reads, and a lot of writes may be short
1368  *   sequential writes. eg. scanning/writing a jpeg file.
1369  *   In these cases, a short read/write cache can provide a huge perfomance
1370  *   benefit with dumb-as-a-rock code.
1371  *   In Linux, the page cache provides read buffering and the short op cache
1372  *   provides write buffering.
1373  *
1374  *   There are a small number (~10) of cache chunks per device so that we don't
1375  *   need a very intelligent search.
1376  */
1377
1378 static int yaffs_obj_cache_dirty(struct yaffs_obj *obj)
1379 {
1380         struct yaffs_dev *dev = obj->my_dev;
1381         int i;
1382         struct yaffs_cache *cache;
1383         int n_caches = obj->my_dev->param.n_caches;
1384
1385         for (i = 0; i < n_caches; i++) {
1386                 cache = &dev->cache[i];
1387                 if (cache->object == obj && cache->dirty)
1388                         return 1;
1389         }
1390
1391         return 0;
1392 }
1393
1394 static void yaffs_flush_file_cache(struct yaffs_obj *obj)
1395 {
1396         struct yaffs_dev *dev = obj->my_dev;
1397         int lowest = -99;       /* Stop compiler whining. */
1398         int i;
1399         struct yaffs_cache *cache;
1400         int chunk_written = 0;
1401         int n_caches = obj->my_dev->param.n_caches;
1402
1403         if (n_caches < 1)
1404                 return;
1405         do {
1406                 cache = NULL;
1407
1408                 /* Find the lowest dirty chunk for this object */
1409                 for (i = 0; i < n_caches; i++) {
1410                         if (dev->cache[i].object == obj &&
1411                             dev->cache[i].dirty) {
1412                                 if (!cache ||
1413                                     dev->cache[i].chunk_id < lowest) {
1414                                         cache = &dev->cache[i];
1415                                         lowest = cache->chunk_id;
1416                                 }
1417                         }
1418                 }
1419
1420                 if (cache && !cache->locked) {
1421                         /* Write it out and free it up */
1422                         chunk_written =
1423                             yaffs_wr_data_obj(cache->object,
1424                                               cache->chunk_id,
1425                                               cache->data,
1426                                               cache->n_bytes, 1);
1427                         cache->dirty = 0;
1428                         cache->object = NULL;
1429                 }
1430         } while (cache && chunk_written > 0);
1431
1432         if (cache)
1433                 /* Hoosterman, disk full while writing cache out. */
1434                 yaffs_trace(YAFFS_TRACE_ERROR,
1435                         "yaffs tragedy: no space during cache write");
1436 }
1437
1438 /*yaffs_flush_whole_cache(dev)
1439  *
1440  *
1441  */
1442
1443 void yaffs_flush_whole_cache(struct yaffs_dev *dev)
1444 {
1445         struct yaffs_obj *obj;
1446         int n_caches = dev->param.n_caches;
1447         int i;
1448
1449         /* Find a dirty object in the cache and flush it...
1450          * until there are no further dirty objects.
1451          */
1452         do {
1453                 obj = NULL;
1454                 for (i = 0; i < n_caches && !obj; i++) {
1455                         if (dev->cache[i].object && dev->cache[i].dirty)
1456                                 obj = dev->cache[i].object;
1457                 }
1458                 if (obj)
1459                         yaffs_flush_file_cache(obj);
1460         } while (obj);
1461
1462 }
1463
1464 /* Grab us a cache chunk for use.
1465  * First look for an empty one.
1466  * Then look for the least recently used non-dirty one.
1467  * Then look for the least recently used dirty one...., flush and look again.
1468  */
1469 static struct yaffs_cache *yaffs_grab_chunk_worker(struct yaffs_dev *dev)
1470 {
1471         int i;
1472
1473         if (dev->param.n_caches > 0) {
1474                 for (i = 0; i < dev->param.n_caches; i++) {
1475                         if (!dev->cache[i].object)
1476                                 return &dev->cache[i];
1477                 }
1478         }
1479         return NULL;
1480 }
1481
1482 static struct yaffs_cache *yaffs_grab_chunk_cache(struct yaffs_dev *dev)
1483 {
1484         struct yaffs_cache *cache;
1485         struct yaffs_obj *the_obj;
1486         int usage;
1487         int i;
1488         int pushout;
1489
1490         if (dev->param.n_caches < 1)
1491                 return NULL;
1492
1493         /* Try find a non-dirty one... */
1494
1495         cache = yaffs_grab_chunk_worker(dev);
1496
1497         if (!cache) {
1498                 /* They were all dirty, find the LRU object and flush
1499                  * its cache, then  find again.
1500                  * NB what's here is not very accurate,
1501                  * we actually flush the object with the LRU chunk.
1502                  */
1503
1504                 /* With locking we can't assume we can use entry zero,
1505                  * Set the_obj to a valid pointer for Coverity. */
1506                 the_obj = dev->cache[0].object;
1507                 usage = -1;
1508                 cache = NULL;
1509                 pushout = -1;
1510
1511                 for (i = 0; i < dev->param.n_caches; i++) {
1512                         if (dev->cache[i].object &&
1513                             !dev->cache[i].locked &&
1514                             (dev->cache[i].last_use < usage ||
1515                             !cache)) {
1516                                 usage = dev->cache[i].last_use;
1517                                 the_obj = dev->cache[i].object;
1518                                 cache = &dev->cache[i];
1519                                 pushout = i;
1520                         }
1521                 }
1522
1523                 if (!cache || cache->dirty) {
1524                         /* Flush and try again */
1525                         yaffs_flush_file_cache(the_obj);
1526                         cache = yaffs_grab_chunk_worker(dev);
1527                 }
1528         }
1529         return cache;
1530 }
1531
1532 /* Find a cached chunk */
1533 static struct yaffs_cache *yaffs_find_chunk_cache(const struct yaffs_obj *obj,
1534                                                   int chunk_id)
1535 {
1536         struct yaffs_dev *dev = obj->my_dev;
1537         int i;
1538
1539         if (dev->param.n_caches < 1)
1540                 return NULL;
1541
1542         for (i = 0; i < dev->param.n_caches; i++) {
1543                 if (dev->cache[i].object == obj &&
1544                     dev->cache[i].chunk_id == chunk_id) {
1545                         dev->cache_hits++;
1546
1547                         return &dev->cache[i];
1548                 }
1549         }
1550         return NULL;
1551 }
1552
1553 /* Mark the chunk for the least recently used algorithym */
1554 static void yaffs_use_cache(struct yaffs_dev *dev, struct yaffs_cache *cache,
1555                             int is_write)
1556 {
1557         int i;
1558
1559         if (dev->param.n_caches < 1)
1560                 return;
1561
1562         if (dev->cache_last_use < 0 ||
1563                 dev->cache_last_use > 100000000) {
1564                 /* Reset the cache usages */
1565                 for (i = 1; i < dev->param.n_caches; i++)
1566                         dev->cache[i].last_use = 0;
1567
1568                 dev->cache_last_use = 0;
1569         }
1570         dev->cache_last_use++;
1571         cache->last_use = dev->cache_last_use;
1572
1573         if (is_write)
1574                 cache->dirty = 1;
1575 }
1576
1577 /* Invalidate a single cache page.
1578  * Do this when a whole page gets written,
1579  * ie the short cache for this page is no longer valid.
1580  */
1581 static void yaffs_invalidate_chunk_cache(struct yaffs_obj *object, int chunk_id)
1582 {
1583         struct yaffs_cache *cache;
1584
1585         if (object->my_dev->param.n_caches > 0) {
1586                 cache = yaffs_find_chunk_cache(object, chunk_id);
1587
1588                 if (cache)
1589                         cache->object = NULL;
1590         }
1591 }
1592
1593 /* Invalidate all the cache pages associated with this object
1594  * Do this whenever ther file is deleted or resized.
1595  */
1596 static void yaffs_invalidate_whole_cache(struct yaffs_obj *in)
1597 {
1598         int i;
1599         struct yaffs_dev *dev = in->my_dev;
1600
1601         if (dev->param.n_caches > 0) {
1602                 /* Invalidate it. */
1603                 for (i = 0; i < dev->param.n_caches; i++) {
1604                         if (dev->cache[i].object == in)
1605                                 dev->cache[i].object = NULL;
1606                 }
1607         }
1608 }
1609
1610 static void yaffs_unhash_obj(struct yaffs_obj *obj)
1611 {
1612         int bucket;
1613         struct yaffs_dev *dev = obj->my_dev;
1614
1615         /* If it is still linked into the bucket list, free from the list */
1616         if (!list_empty(&obj->hash_link)) {
1617                 list_del_init(&obj->hash_link);
1618                 bucket = yaffs_hash_fn(obj->obj_id);
1619                 dev->obj_bucket[bucket].count--;
1620         }
1621 }
1622
1623 /*  FreeObject frees up a Object and puts it back on the free list */
1624 static void yaffs_free_obj(struct yaffs_obj *obj)
1625 {
1626         struct yaffs_dev *dev;
1627
1628         if (!obj) {
1629                 BUG();
1630                 return;
1631         }
1632         dev = obj->my_dev;
1633         yaffs_trace(YAFFS_TRACE_OS, "FreeObject %p inode %p",
1634                 obj, obj->my_inode);
1635         if (obj->parent)
1636                 BUG();
1637         if (!list_empty(&obj->siblings))
1638                 BUG();
1639
1640         if (obj->my_inode) {
1641                 /* We're still hooked up to a cached inode.
1642                  * Don't delete now, but mark for later deletion
1643                  */
1644                 obj->defered_free = 1;
1645                 return;
1646         }
1647
1648         yaffs_unhash_obj(obj);
1649
1650         yaffs_free_raw_obj(dev, obj);
1651         dev->n_obj--;
1652         dev->checkpoint_blocks_required = 0;    /* force recalculation */
1653 }
1654
1655 void yaffs_handle_defered_free(struct yaffs_obj *obj)
1656 {
1657         if (obj->defered_free)
1658                 yaffs_free_obj(obj);
1659 }
1660
1661 static int yaffs_generic_obj_del(struct yaffs_obj *in)
1662 {
1663         /* Iinvalidate the file's data in the cache, without flushing. */
1664         yaffs_invalidate_whole_cache(in);
1665
1666         if (in->my_dev->param.is_yaffs2 && in->parent != in->my_dev->del_dir) {
1667                 /* Move to unlinked directory so we have a deletion record */
1668                 yaffs_change_obj_name(in, in->my_dev->del_dir, _Y("deleted"), 0,
1669                                       0);
1670         }
1671
1672         yaffs_remove_obj_from_dir(in);
1673         yaffs_chunk_del(in->my_dev, in->hdr_chunk, 1, __LINE__);
1674         in->hdr_chunk = 0;
1675
1676         yaffs_free_obj(in);
1677         return YAFFS_OK;
1678
1679 }
1680
1681 static void yaffs_soft_del_file(struct yaffs_obj *obj)
1682 {
1683         if (!obj->deleted ||
1684             obj->variant_type != YAFFS_OBJECT_TYPE_FILE ||
1685             obj->soft_del)
1686                 return;
1687
1688         if (obj->n_data_chunks <= 0) {
1689                 /* Empty file with no duplicate object headers,
1690                  * just delete it immediately */
1691                 yaffs_free_tnode(obj->my_dev, obj->variant.file_variant.top);
1692                 obj->variant.file_variant.top = NULL;
1693                 yaffs_trace(YAFFS_TRACE_TRACING,
1694                         "yaffs: Deleting empty file %d",
1695                         obj->obj_id);
1696                 yaffs_generic_obj_del(obj);
1697         } else {
1698                 yaffs_soft_del_worker(obj,
1699                                       obj->variant.file_variant.top,
1700                                       obj->variant.
1701                                       file_variant.top_level, 0);
1702                 obj->soft_del = 1;
1703         }
1704 }
1705
1706 /* Pruning removes any part of the file structure tree that is beyond the
1707  * bounds of the file (ie that does not point to chunks).
1708  *
1709  * A file should only get pruned when its size is reduced.
1710  *
1711  * Before pruning, the chunks must be pulled from the tree and the
1712  * level 0 tnode entries must be zeroed out.
1713  * Could also use this for file deletion, but that's probably better handled
1714  * by a special case.
1715  *
1716  * This function is recursive. For levels > 0 the function is called again on
1717  * any sub-tree. For level == 0 we just check if the sub-tree has data.
1718  * If there is no data in a subtree then it is pruned.
1719  */
1720
1721 static struct yaffs_tnode *yaffs_prune_worker(struct yaffs_dev *dev,
1722                                               struct yaffs_tnode *tn, u32 level,
1723                                               int del0)
1724 {
1725         int i;
1726         int has_data;
1727
1728         if (!tn)
1729                 return tn;
1730
1731         has_data = 0;
1732
1733         if (level > 0) {
1734                 for (i = 0; i < YAFFS_NTNODES_INTERNAL; i++) {
1735                         if (tn->internal[i]) {
1736                                 tn->internal[i] =
1737                                     yaffs_prune_worker(dev,
1738                                                 tn->internal[i],
1739                                                 level - 1,
1740                                                 (i == 0) ? del0 : 1);
1741                         }
1742
1743                         if (tn->internal[i])
1744                                 has_data++;
1745                 }
1746         } else {
1747                 int tnode_size_u32 = dev->tnode_size / sizeof(u32);
1748                 u32 *map = (u32 *) tn;
1749
1750                 for (i = 0; !has_data && i < tnode_size_u32; i++) {
1751                         if (map[i])
1752                                 has_data++;
1753                 }
1754         }
1755
1756         if (has_data == 0 && del0) {
1757                 /* Free and return NULL */
1758                 yaffs_free_tnode(dev, tn);
1759                 tn = NULL;
1760         }
1761         return tn;
1762 }
1763
1764 static int yaffs_prune_tree(struct yaffs_dev *dev,
1765                             struct yaffs_file_var *file_struct)
1766 {
1767         int i;
1768         int has_data;
1769         int done = 0;
1770         struct yaffs_tnode *tn;
1771
1772         if (file_struct->top_level < 1)
1773                 return YAFFS_OK;
1774
1775         file_struct->top =
1776            yaffs_prune_worker(dev, file_struct->top, file_struct->top_level, 0);
1777
1778         /* Now we have a tree with all the non-zero branches NULL but
1779          * the height is the same as it was.
1780          * Let's see if we can trim internal tnodes to shorten the tree.
1781          * We can do this if only the 0th element in the tnode is in use
1782          * (ie all the non-zero are NULL)
1783          */
1784
1785         while (file_struct->top_level && !done) {
1786                 tn = file_struct->top;
1787
1788                 has_data = 0;
1789                 for (i = 1; i < YAFFS_NTNODES_INTERNAL; i++) {
1790                         if (tn->internal[i])
1791                                 has_data++;
1792                 }
1793
1794                 if (!has_data) {
1795                         file_struct->top = tn->internal[0];
1796                         file_struct->top_level--;
1797                         yaffs_free_tnode(dev, tn);
1798                 } else {
1799                         done = 1;
1800                 }
1801         }
1802
1803         return YAFFS_OK;
1804 }
1805
1806 /*-------------------- End of File Structure functions.-------------------*/
1807
1808 /* alloc_empty_obj gets us a clean Object.*/
1809 static struct yaffs_obj *yaffs_alloc_empty_obj(struct yaffs_dev *dev)
1810 {
1811         struct yaffs_obj *obj = yaffs_alloc_raw_obj(dev);
1812
1813         if (!obj)
1814                 return obj;
1815
1816         dev->n_obj++;
1817
1818         /* Now sweeten it up... */
1819
1820         memset(obj, 0, sizeof(struct yaffs_obj));
1821         obj->being_created = 1;
1822
1823         obj->my_dev = dev;
1824         obj->hdr_chunk = 0;
1825         obj->variant_type = YAFFS_OBJECT_TYPE_UNKNOWN;
1826         INIT_LIST_HEAD(&(obj->hard_links));
1827         INIT_LIST_HEAD(&(obj->hash_link));
1828         INIT_LIST_HEAD(&obj->siblings);
1829
1830         /* Now make the directory sane */
1831         if (dev->root_dir) {
1832                 obj->parent = dev->root_dir;
1833                 list_add(&(obj->siblings),
1834                          &dev->root_dir->variant.dir_variant.children);
1835         }
1836
1837         /* Add it to the lost and found directory.
1838          * NB Can't put root or lost-n-found in lost-n-found so
1839          * check if lost-n-found exists first
1840          */
1841         if (dev->lost_n_found)
1842                 yaffs_add_obj_to_dir(dev->lost_n_found, obj);
1843
1844         obj->being_created = 0;
1845
1846         dev->checkpoint_blocks_required = 0;    /* force recalculation */
1847
1848         return obj;
1849 }
1850
1851 static int yaffs_find_nice_bucket(struct yaffs_dev *dev)
1852 {
1853         int i;
1854         int l = 999;
1855         int lowest = 999999;
1856
1857         /* Search for the shortest list or one that
1858          * isn't too long.
1859          */
1860
1861         for (i = 0; i < 10 && lowest > 4; i++) {
1862                 dev->bucket_finder++;
1863                 dev->bucket_finder %= YAFFS_NOBJECT_BUCKETS;
1864                 if (dev->obj_bucket[dev->bucket_finder].count < lowest) {
1865                         lowest = dev->obj_bucket[dev->bucket_finder].count;
1866                         l = dev->bucket_finder;
1867                 }
1868         }
1869
1870         return l;
1871 }
1872
1873 static int yaffs_new_obj_id(struct yaffs_dev *dev)
1874 {
1875         int bucket = yaffs_find_nice_bucket(dev);
1876         int found = 0;
1877         struct list_head *i;
1878         u32 n = (u32) bucket;
1879
1880         /* Now find an object value that has not already been taken
1881          * by scanning the list.
1882          */
1883
1884         while (!found) {
1885                 found = 1;
1886                 n += YAFFS_NOBJECT_BUCKETS;
1887                 if (1 || dev->obj_bucket[bucket].count > 0) {
1888                         list_for_each(i, &dev->obj_bucket[bucket].list) {
1889                                 /* If there is already one in the list */
1890                                 if (i && list_entry(i, struct yaffs_obj,
1891                                                     hash_link)->obj_id == n) {
1892                                         found = 0;
1893                                 }
1894                         }
1895                 }
1896         }
1897         return n;
1898 }
1899
1900 static void yaffs_hash_obj(struct yaffs_obj *in)
1901 {
1902         int bucket = yaffs_hash_fn(in->obj_id);
1903         struct yaffs_dev *dev = in->my_dev;
1904
1905         list_add(&in->hash_link, &dev->obj_bucket[bucket].list);
1906         dev->obj_bucket[bucket].count++;
1907 }
1908
1909 struct yaffs_obj *yaffs_find_by_number(struct yaffs_dev *dev, u32 number)
1910 {
1911         int bucket = yaffs_hash_fn(number);
1912         struct list_head *i;
1913         struct yaffs_obj *in;
1914
1915         list_for_each(i, &dev->obj_bucket[bucket].list) {
1916                 /* Look if it is in the list */
1917                 in = list_entry(i, struct yaffs_obj, hash_link);
1918                 if (in->obj_id == number) {
1919                         /* Don't show if it is defered free */
1920                         if (in->defered_free)
1921                                 return NULL;
1922                         return in;
1923                 }
1924         }
1925
1926         return NULL;
1927 }
1928
1929 struct yaffs_obj *yaffs_new_obj(struct yaffs_dev *dev, int number,
1930                                 enum yaffs_obj_type type)
1931 {
1932         struct yaffs_obj *the_obj = NULL;
1933         struct yaffs_tnode *tn = NULL;
1934
1935         if (number < 0)
1936                 number = yaffs_new_obj_id(dev);
1937
1938         if (type == YAFFS_OBJECT_TYPE_FILE) {
1939                 tn = yaffs_get_tnode(dev);
1940                 if (!tn)
1941                         return NULL;
1942         }
1943
1944         the_obj = yaffs_alloc_empty_obj(dev);
1945         if (!the_obj) {
1946                 if (tn)
1947                         yaffs_free_tnode(dev, tn);
1948                 return NULL;
1949         }
1950
1951         the_obj->fake = 0;
1952         the_obj->rename_allowed = 1;
1953         the_obj->unlink_allowed = 1;
1954         the_obj->obj_id = number;
1955         yaffs_hash_obj(the_obj);
1956         the_obj->variant_type = type;
1957         yaffs_load_current_time(the_obj, 1, 1);
1958
1959         switch (type) {
1960         case YAFFS_OBJECT_TYPE_FILE:
1961                 the_obj->variant.file_variant.file_size = 0;
1962                 the_obj->variant.file_variant.scanned_size = 0;
1963                 the_obj->variant.file_variant.shrink_size =
1964                                                 yaffs_max_file_size(dev);
1965                 the_obj->variant.file_variant.top_level = 0;
1966                 the_obj->variant.file_variant.top = tn;
1967                 break;
1968         case YAFFS_OBJECT_TYPE_DIRECTORY:
1969                 INIT_LIST_HEAD(&the_obj->variant.dir_variant.children);
1970                 INIT_LIST_HEAD(&the_obj->variant.dir_variant.dirty);
1971                 break;
1972         case YAFFS_OBJECT_TYPE_SYMLINK:
1973         case YAFFS_OBJECT_TYPE_HARDLINK:
1974         case YAFFS_OBJECT_TYPE_SPECIAL:
1975                 /* No action required */
1976                 break;
1977         case YAFFS_OBJECT_TYPE_UNKNOWN:
1978                 /* todo this should not happen */
1979                 break;
1980         }
1981         return the_obj;
1982 }
1983
1984 static struct yaffs_obj *yaffs_create_fake_dir(struct yaffs_dev *dev,
1985                                                int number, u32 mode)
1986 {
1987
1988         struct yaffs_obj *obj =
1989             yaffs_new_obj(dev, number, YAFFS_OBJECT_TYPE_DIRECTORY);
1990
1991         if (!obj)
1992                 return NULL;
1993
1994         obj->fake = 1;  /* it is fake so it might not use NAND */
1995         obj->rename_allowed = 0;
1996         obj->unlink_allowed = 0;
1997         obj->deleted = 0;
1998         obj->unlinked = 0;
1999         obj->yst_mode = mode;
2000         obj->my_dev = dev;
2001         obj->hdr_chunk = 0;     /* Not a valid chunk. */
2002         return obj;
2003
2004 }
2005
2006
2007 static void yaffs_init_tnodes_and_objs(struct yaffs_dev *dev)
2008 {
2009         int i;
2010
2011         dev->n_obj = 0;
2012         dev->n_tnodes = 0;
2013         yaffs_init_raw_tnodes_and_objs(dev);
2014
2015         for (i = 0; i < YAFFS_NOBJECT_BUCKETS; i++) {
2016                 INIT_LIST_HEAD(&dev->obj_bucket[i].list);
2017                 dev->obj_bucket[i].count = 0;
2018         }
2019 }
2020
2021 struct yaffs_obj *yaffs_find_or_create_by_number(struct yaffs_dev *dev,
2022                                                  int number,
2023                                                  enum yaffs_obj_type type)
2024 {
2025         struct yaffs_obj *the_obj = NULL;
2026
2027         if (number > 0)
2028                 the_obj = yaffs_find_by_number(dev, number);
2029
2030         if (!the_obj)
2031                 the_obj = yaffs_new_obj(dev, number, type);
2032
2033         return the_obj;
2034
2035 }
2036
2037 YCHAR *yaffs_clone_str(const YCHAR *str)
2038 {
2039         YCHAR *new_str = NULL;
2040         int len;
2041
2042         if (!str)
2043                 str = _Y("");
2044
2045         len = strnlen(str, YAFFS_MAX_ALIAS_LENGTH);
2046         new_str = kmalloc((len + 1) * sizeof(YCHAR), GFP_NOFS);
2047         if (new_str) {
2048                 strncpy(new_str, str, len);
2049                 new_str[len] = 0;
2050         }
2051         return new_str;
2052
2053 }
2054 /*
2055  *yaffs_update_parent() handles fixing a directories mtime and ctime when a new
2056  * link (ie. name) is created or deleted in the directory.
2057  *
2058  * ie.
2059  *   create dir/a : update dir's mtime/ctime
2060  *   rm dir/a:   update dir's mtime/ctime
2061  *   modify dir/a: don't update dir's mtimme/ctime
2062  *
2063  * This can be handled immediately or defered. Defering helps reduce the number
2064  * of updates when many files in a directory are changed within a brief period.
2065  *
2066  * If the directory updating is defered then yaffs_update_dirty_dirs must be
2067  * called periodically.
2068  */
2069
2070 static void yaffs_update_parent(struct yaffs_obj *obj)
2071 {
2072         struct yaffs_dev *dev;
2073
2074         if (!obj)
2075                 return;
2076         dev = obj->my_dev;
2077         obj->dirty = 1;
2078         yaffs_load_current_time(obj, 0, 1);
2079         if (dev->param.defered_dir_update) {
2080                 struct list_head *link = &obj->variant.dir_variant.dirty;
2081
2082                 if (list_empty(link)) {
2083                         list_add(link, &dev->dirty_dirs);
2084                         yaffs_trace(YAFFS_TRACE_BACKGROUND,
2085                           "Added object %d to dirty directories",
2086                            obj->obj_id);
2087                 }
2088
2089         } else {
2090                 yaffs_update_oh(obj, NULL, 0, 0, 0, NULL);
2091         }
2092 }
2093
2094 void yaffs_update_dirty_dirs(struct yaffs_dev *dev)
2095 {
2096         struct list_head *link;
2097         struct yaffs_obj *obj;
2098         struct yaffs_dir_var *d_s;
2099         union yaffs_obj_var *o_v;
2100
2101         yaffs_trace(YAFFS_TRACE_BACKGROUND, "Update dirty directories");
2102
2103         while (!list_empty(&dev->dirty_dirs)) {
2104                 link = dev->dirty_dirs.next;
2105                 list_del_init(link);
2106
2107                 d_s = list_entry(link, struct yaffs_dir_var, dirty);
2108                 o_v = list_entry(d_s, union yaffs_obj_var, dir_variant);
2109                 obj = list_entry(o_v, struct yaffs_obj, variant);
2110
2111                 yaffs_trace(YAFFS_TRACE_BACKGROUND, "Update directory %d",
2112                         obj->obj_id);
2113
2114                 if (obj->dirty)
2115                         yaffs_update_oh(obj, NULL, 0, 0, 0, NULL);
2116         }
2117 }
2118
2119 /*
2120  * Mknod (create) a new object.
2121  * equiv_obj only has meaning for a hard link;
2122  * alias_str only has meaning for a symlink.
2123  * rdev only has meaning for devices (a subset of special objects)
2124  */
2125
2126 static struct yaffs_obj *yaffs_create_obj(enum yaffs_obj_type type,
2127                                           struct yaffs_obj *parent,
2128                                           const YCHAR *name,
2129                                           u32 mode,
2130                                           u32 uid,
2131                                           u32 gid,
2132                                           struct yaffs_obj *equiv_obj,
2133                                           const YCHAR *alias_str, u32 rdev)
2134 {
2135         struct yaffs_obj *in;
2136         YCHAR *str = NULL;
2137         struct yaffs_dev *dev = parent->my_dev;
2138
2139         /* Check if the entry exists.
2140          * If it does then fail the call since we don't want a dup. */
2141         if (yaffs_find_by_name(parent, name))
2142                 return NULL;
2143
2144         if (type == YAFFS_OBJECT_TYPE_SYMLINK) {
2145                 str = yaffs_clone_str(alias_str);
2146                 if (!str)
2147                         return NULL;
2148         }
2149
2150         in = yaffs_new_obj(dev, -1, type);
2151
2152         if (!in) {
2153                 kfree(str);
2154                 return NULL;
2155         }
2156
2157         in->hdr_chunk = 0;
2158         in->valid = 1;
2159         in->variant_type = type;
2160
2161         in->yst_mode = mode;
2162
2163         yaffs_attribs_init(in, gid, uid, rdev);
2164
2165         in->n_data_chunks = 0;
2166
2167         yaffs_set_obj_name(in, name);
2168         in->dirty = 1;
2169
2170         yaffs_add_obj_to_dir(parent, in);
2171
2172         in->my_dev = parent->my_dev;
2173
2174         switch (type) {
2175         case YAFFS_OBJECT_TYPE_SYMLINK:
2176                 in->variant.symlink_variant.alias = str;
2177                 break;
2178         case YAFFS_OBJECT_TYPE_HARDLINK:
2179                 in->variant.hardlink_variant.equiv_obj = equiv_obj;
2180                 in->variant.hardlink_variant.equiv_id = equiv_obj->obj_id;
2181                 list_add(&in->hard_links, &equiv_obj->hard_links);
2182                 break;
2183         case YAFFS_OBJECT_TYPE_FILE:
2184         case YAFFS_OBJECT_TYPE_DIRECTORY:
2185         case YAFFS_OBJECT_TYPE_SPECIAL:
2186         case YAFFS_OBJECT_TYPE_UNKNOWN:
2187                 /* do nothing */
2188                 break;
2189         }
2190
2191         if (yaffs_update_oh(in, name, 0, 0, 0, NULL) < 0) {
2192                 /* Could not create the object header, fail */
2193                 yaffs_del_obj(in);
2194                 in = NULL;
2195         }
2196
2197         if (in)
2198                 yaffs_update_parent(parent);
2199
2200         return in;
2201 }
2202
2203 struct yaffs_obj *yaffs_create_file(struct yaffs_obj *parent,
2204                                     const YCHAR *name, u32 mode, u32 uid,
2205                                     u32 gid)
2206 {
2207         return yaffs_create_obj(YAFFS_OBJECT_TYPE_FILE, parent, name, mode,
2208                                 uid, gid, NULL, NULL, 0);
2209 }
2210
2211 struct yaffs_obj *yaffs_create_dir(struct yaffs_obj *parent, const YCHAR *name,
2212                                    u32 mode, u32 uid, u32 gid)
2213 {
2214         return yaffs_create_obj(YAFFS_OBJECT_TYPE_DIRECTORY, parent, name,
2215                                 mode, uid, gid, NULL, NULL, 0);
2216 }
2217
2218 struct yaffs_obj *yaffs_create_special(struct yaffs_obj *parent,
2219                                        const YCHAR *name, u32 mode, u32 uid,
2220                                        u32 gid, u32 rdev)
2221 {
2222         return yaffs_create_obj(YAFFS_OBJECT_TYPE_SPECIAL, parent, name, mode,
2223                                 uid, gid, NULL, NULL, rdev);
2224 }
2225
2226 struct yaffs_obj *yaffs_create_symlink(struct yaffs_obj *parent,
2227                                        const YCHAR *name, u32 mode, u32 uid,
2228                                        u32 gid, const YCHAR *alias)
2229 {
2230         return yaffs_create_obj(YAFFS_OBJECT_TYPE_SYMLINK, parent, name, mode,
2231                                 uid, gid, NULL, alias, 0);
2232 }
2233
2234 /* yaffs_link_obj returns the object id of the equivalent object.*/
2235 struct yaffs_obj *yaffs_link_obj(struct yaffs_obj *parent, const YCHAR * name,
2236                                  struct yaffs_obj *equiv_obj)
2237 {
2238         /* Get the real object in case we were fed a hard link obj */
2239         equiv_obj = yaffs_get_equivalent_obj(equiv_obj);
2240
2241         if (yaffs_create_obj(YAFFS_OBJECT_TYPE_HARDLINK,
2242                         parent, name, 0, 0, 0,
2243                         equiv_obj, NULL, 0))
2244                 return equiv_obj;
2245
2246         return NULL;
2247
2248 }
2249
2250
2251
2252 /*---------------------- Block Management and Page Allocation -------------*/
2253
2254 static void yaffs_deinit_blocks(struct yaffs_dev *dev)
2255 {
2256         if (dev->block_info_alt && dev->block_info)
2257                 vfree(dev->block_info);
2258         else
2259                 kfree(dev->block_info);
2260
2261         dev->block_info_alt = 0;
2262
2263         dev->block_info = NULL;
2264
2265         if (dev->chunk_bits_alt && dev->chunk_bits)
2266                 vfree(dev->chunk_bits);
2267         else
2268                 kfree(dev->chunk_bits);
2269         dev->chunk_bits_alt = 0;
2270         dev->chunk_bits = NULL;
2271 }
2272
2273 static int yaffs_init_blocks(struct yaffs_dev *dev)
2274 {
2275         int n_blocks = dev->internal_end_block - dev->internal_start_block + 1;
2276
2277         dev->block_info = NULL;
2278         dev->chunk_bits = NULL;
2279         dev->alloc_block = -1;  /* force it to get a new one */
2280
2281         /* If the first allocation strategy fails, thry the alternate one */
2282         dev->block_info =
2283                 kmalloc(n_blocks * sizeof(struct yaffs_block_info), GFP_NOFS);
2284         if (!dev->block_info) {
2285                 dev->block_info =
2286                     vmalloc(n_blocks * sizeof(struct yaffs_block_info));
2287                 dev->block_info_alt = 1;
2288         } else {
2289                 dev->block_info_alt = 0;
2290         }
2291
2292         if (!dev->block_info)
2293                 goto alloc_error;
2294
2295         /* Set up dynamic blockinfo stuff. Round up bytes. */
2296         dev->chunk_bit_stride = (dev->param.chunks_per_block + 7) / 8;
2297         dev->chunk_bits =
2298                 kmalloc(dev->chunk_bit_stride * n_blocks, GFP_NOFS);
2299         if (!dev->chunk_bits) {
2300                 dev->chunk_bits =
2301                     vmalloc(dev->chunk_bit_stride * n_blocks);
2302                 dev->chunk_bits_alt = 1;
2303         } else {
2304                 dev->chunk_bits_alt = 0;
2305         }
2306         if (!dev->chunk_bits)
2307                 goto alloc_error;
2308
2309
2310         memset(dev->block_info, 0, n_blocks * sizeof(struct yaffs_block_info));
2311         memset(dev->chunk_bits, 0, dev->chunk_bit_stride * n_blocks);
2312         return YAFFS_OK;
2313
2314 alloc_error:
2315         yaffs_deinit_blocks(dev);
2316         return YAFFS_FAIL;
2317 }
2318
2319
2320 void yaffs_block_became_dirty(struct yaffs_dev *dev, int block_no)
2321 {
2322         struct yaffs_block_info *bi = yaffs_get_block_info(dev, block_no);
2323         int erased_ok = 0;
2324         int i;
2325
2326         /* If the block is still healthy erase it and mark as clean.
2327          * If the block has had a data failure, then retire it.
2328          */
2329
2330         yaffs_trace(YAFFS_TRACE_GC | YAFFS_TRACE_ERASE,
2331                 "yaffs_block_became_dirty block %d state %d %s",
2332                 block_no, bi->block_state,
2333                 (bi->needs_retiring) ? "needs retiring" : "");
2334
2335         yaffs2_clear_oldest_dirty_seq(dev, bi);
2336
2337         bi->block_state = YAFFS_BLOCK_STATE_DIRTY;
2338
2339         /* If this is the block being garbage collected then stop gc'ing */
2340         if (block_no == dev->gc_block)
2341                 dev->gc_block = 0;
2342
2343         /* If this block is currently the best candidate for gc
2344          * then drop as a candidate */
2345         if (block_no == dev->gc_dirtiest) {
2346                 dev->gc_dirtiest = 0;
2347                 dev->gc_pages_in_use = 0;
2348         }
2349
2350         if (!bi->needs_retiring) {
2351                 yaffs2_checkpt_invalidate(dev);
2352                 erased_ok = yaffs_erase_block(dev, block_no);
2353                 if (!erased_ok) {
2354                         dev->n_erase_failures++;
2355                         yaffs_trace(YAFFS_TRACE_ERROR | YAFFS_TRACE_BAD_BLOCKS,
2356                           "**>> Erasure failed %d", block_no);
2357                 }
2358         }
2359
2360         /* Verify erasure if needed */
2361         if (erased_ok &&
2362             ((yaffs_trace_mask & YAFFS_TRACE_ERASE) ||
2363              !yaffs_skip_verification(dev))) {
2364                 for (i = 0; i < dev->param.chunks_per_block; i++) {
2365                         if (!yaffs_check_chunk_erased(dev,
2366                                 block_no * dev->param.chunks_per_block + i)) {
2367                                 yaffs_trace(YAFFS_TRACE_ERROR,
2368                                         ">>Block %d erasure supposedly OK, but chunk %d not erased",
2369                                         block_no, i);
2370                         }
2371                 }
2372         }
2373
2374         if (!erased_ok) {
2375                 /* We lost a block of free space */
2376                 dev->n_free_chunks -= dev->param.chunks_per_block;
2377                 yaffs_retire_block(dev, block_no);
2378                 yaffs_trace(YAFFS_TRACE_ERROR | YAFFS_TRACE_BAD_BLOCKS,
2379                         "**>> Block %d retired", block_no);
2380                 return;
2381         }
2382
2383         /* Clean it up... */
2384         bi->block_state = YAFFS_BLOCK_STATE_EMPTY;
2385         bi->seq_number = 0;
2386         dev->n_erased_blocks++;
2387         bi->pages_in_use = 0;
2388         bi->soft_del_pages = 0;
2389         bi->has_shrink_hdr = 0;
2390         bi->skip_erased_check = 1;      /* Clean, so no need to check */
2391         bi->gc_prioritise = 0;
2392         bi->has_summary = 0;
2393
2394         yaffs_clear_chunk_bits(dev, block_no);
2395
2396         yaffs_trace(YAFFS_TRACE_ERASE, "Erased block %d", block_no);
2397 }
2398
2399 static inline int yaffs_gc_process_chunk(struct yaffs_dev *dev,
2400                                         struct yaffs_block_info *bi,
2401                                         int old_chunk, u8 *buffer)
2402 {
2403         int new_chunk;
2404         int mark_flash = 1;
2405         struct yaffs_ext_tags tags;
2406         struct yaffs_obj *object;
2407         int matching_chunk;
2408         int ret_val = YAFFS_OK;
2409
2410         memset(&tags, 0, sizeof(tags));
2411         yaffs_rd_chunk_tags_nand(dev, old_chunk,
2412                                  buffer, &tags);
2413         object = yaffs_find_by_number(dev, tags.obj_id);
2414
2415         yaffs_trace(YAFFS_TRACE_GC_DETAIL,
2416                 "Collecting chunk in block %d, %d %d %d ",
2417                 dev->gc_chunk, tags.obj_id,
2418                 tags.chunk_id, tags.n_bytes);
2419
2420         if (object && !yaffs_skip_verification(dev)) {
2421                 if (tags.chunk_id == 0)
2422                         matching_chunk =
2423                             object->hdr_chunk;
2424                 else if (object->soft_del)
2425                         /* Defeat the test */
2426                         matching_chunk = old_chunk;
2427                 else
2428                         matching_chunk =
2429                             yaffs_find_chunk_in_file
2430                             (object, tags.chunk_id,
2431                              NULL);
2432
2433                 if (old_chunk != matching_chunk)
2434                         yaffs_trace(YAFFS_TRACE_ERROR,
2435                                 "gc: page in gc mismatch: %d %d %d %d",
2436                                 old_chunk,
2437                                 matching_chunk,
2438                                 tags.obj_id,
2439                                 tags.chunk_id);
2440         }
2441
2442         if (!object) {
2443                 yaffs_trace(YAFFS_TRACE_ERROR,
2444                         "page %d in gc has no object: %d %d %d ",
2445                         old_chunk,
2446                         tags.obj_id, tags.chunk_id,
2447                         tags.n_bytes);
2448         }
2449
2450         if (object &&
2451             object->deleted &&
2452             object->soft_del && tags.chunk_id != 0) {
2453                 /* Data chunk in a soft deleted file,
2454                  * throw it away.
2455                  * It's a soft deleted data chunk,
2456                  * No need to copy this, just forget
2457                  * about it and fix up the object.
2458                  */
2459
2460                 /* Free chunks already includes
2461                  * softdeleted chunks, how ever this
2462                  * chunk is going to soon be really
2463                  * deleted which will increment free
2464                  * chunks. We have to decrement free
2465                  * chunks so this works out properly.
2466                  */
2467                 dev->n_free_chunks--;
2468                 bi->soft_del_pages--;
2469
2470                 object->n_data_chunks--;
2471                 if (object->n_data_chunks <= 0) {
2472                         /* remeber to clean up obj */
2473                         dev->gc_cleanup_list[dev->n_clean_ups] = tags.obj_id;
2474                         dev->n_clean_ups++;
2475                 }
2476                 mark_flash = 0;
2477         } else if (object) {
2478                 /* It's either a data chunk in a live
2479                  * file or an ObjectHeader, so we're
2480                  * interested in it.
2481                  * NB Need to keep the ObjectHeaders of
2482                  * deleted files until the whole file
2483                  * has been deleted off
2484                  */
2485                 tags.serial_number++;
2486                 dev->n_gc_copies++;
2487
2488                 if (tags.chunk_id == 0) {
2489                         /* It is an object Id,
2490                          * We need to nuke the
2491                          * shrinkheader flags since its
2492                          * work is done.
2493                          * Also need to clean up
2494                          * shadowing.
2495                          */
2496                         struct yaffs_obj_hdr *oh;
2497                         oh = (struct yaffs_obj_hdr *) buffer;
2498
2499                         oh->is_shrink = 0;
2500                         tags.extra_is_shrink = 0;
2501                         oh->shadows_obj = 0;
2502                         oh->inband_shadowed_obj_id = 0;
2503                         tags.extra_shadows = 0;
2504
2505                         /* Update file size */
2506                         if (object->variant_type == YAFFS_OBJECT_TYPE_FILE) {
2507                                 yaffs_oh_size_load(oh,
2508                                     object->variant.file_variant.file_size);
2509                                 tags.extra_file_size =
2510                                     object->variant.file_variant.file_size;
2511                         }
2512
2513                         yaffs_verify_oh(object, oh, &tags, 1);
2514                         new_chunk =
2515                             yaffs_write_new_chunk(dev, (u8 *) oh, &tags, 1);
2516                 } else {
2517                         new_chunk =
2518                             yaffs_write_new_chunk(dev, buffer, &tags, 1);
2519                 }
2520
2521                 if (new_chunk < 0) {
2522                         ret_val = YAFFS_FAIL;
2523                 } else {
2524
2525                         /* Now fix up the Tnodes etc. */
2526
2527                         if (tags.chunk_id == 0) {
2528                                 /* It's a header */
2529                                 object->hdr_chunk = new_chunk;
2530                                 object->serial = tags.serial_number;
2531                         } else {
2532                                 /* It's a data chunk */
2533                                 yaffs_put_chunk_in_file(object, tags.chunk_id,
2534                                                         new_chunk, 0);
2535                         }
2536                 }
2537         }
2538         if (ret_val == YAFFS_OK)
2539                 yaffs_chunk_del(dev, old_chunk, mark_flash, __LINE__);
2540         return ret_val;
2541 }
2542
2543 static int yaffs_gc_block(struct yaffs_dev *dev, int block, int whole_block)
2544 {
2545         int old_chunk;
2546         int ret_val = YAFFS_OK;
2547         int i;
2548         int is_checkpt_block;
2549         int max_copies;
2550         int chunks_before = yaffs_get_erased_chunks(dev);
2551         int chunks_after;
2552         struct yaffs_block_info *bi = yaffs_get_block_info(dev, block);
2553
2554         is_checkpt_block = (bi->block_state == YAFFS_BLOCK_STATE_CHECKPOINT);
2555
2556         yaffs_trace(YAFFS_TRACE_TRACING,
2557                 "Collecting block %d, in use %d, shrink %d, whole_block %d",
2558                 block, bi->pages_in_use, bi->has_shrink_hdr,
2559                 whole_block);
2560
2561         /*yaffs_verify_free_chunks(dev); */
2562
2563         if (bi->block_state == YAFFS_BLOCK_STATE_FULL)
2564                 bi->block_state = YAFFS_BLOCK_STATE_COLLECTING;
2565
2566         bi->has_shrink_hdr = 0; /* clear the flag so that the block can erase */
2567
2568         dev->gc_disable = 1;
2569
2570         yaffs_summary_gc(dev, block);
2571
2572         if (is_checkpt_block || !yaffs_still_some_chunks(dev, block)) {
2573                 yaffs_trace(YAFFS_TRACE_TRACING,
2574                         "Collecting block %d that has no chunks in use",
2575                         block);
2576                 yaffs_block_became_dirty(dev, block);
2577         } else {
2578
2579                 u8 *buffer = yaffs_get_temp_buffer(dev);
2580
2581                 yaffs_verify_blk(dev, bi, block);
2582
2583                 max_copies = (whole_block) ? dev->param.chunks_per_block : 5;
2584                 old_chunk = block * dev->param.chunks_per_block + dev->gc_chunk;
2585
2586                 for (/* init already done */ ;
2587                      ret_val == YAFFS_OK &&
2588                      dev->gc_chunk < dev->param.chunks_per_block &&
2589                      (bi->block_state == YAFFS_BLOCK_STATE_COLLECTING) &&
2590                      max_copies > 0;
2591                      dev->gc_chunk++, old_chunk++) {
2592                         if (yaffs_check_chunk_bit(dev, block, dev->gc_chunk)) {
2593                                 /* Page is in use and might need to be copied */
2594                                 max_copies--;
2595                                 ret_val = yaffs_gc_process_chunk(dev, bi,
2596                                                         old_chunk, buffer);
2597                         }
2598                 }
2599                 yaffs_release_temp_buffer(dev, buffer);
2600         }
2601
2602         yaffs_verify_collected_blk(dev, bi, block);
2603
2604         if (bi->block_state == YAFFS_BLOCK_STATE_COLLECTING) {
2605                 /*
2606                  * The gc did not complete. Set block state back to FULL
2607                  * because checkpointing does not restore gc.
2608                  */
2609                 bi->block_state = YAFFS_BLOCK_STATE_FULL;
2610         } else {
2611                 /* The gc completed. */
2612                 /* Do any required cleanups */
2613                 for (i = 0; i < dev->n_clean_ups; i++) {
2614                         /* Time to delete the file too */
2615                         struct yaffs_obj *object =
2616                             yaffs_find_by_number(dev, dev->gc_cleanup_list[i]);
2617                         if (object) {
2618                                 yaffs_free_tnode(dev,
2619                                           object->variant.file_variant.top);
2620                                 object->variant.file_variant.top = NULL;
2621                                 yaffs_trace(YAFFS_TRACE_GC,
2622                                         "yaffs: About to finally delete object %d",
2623                                         object->obj_id);
2624                                 yaffs_generic_obj_del(object);
2625                                 object->my_dev->n_deleted_files--;
2626                         }
2627
2628                 }
2629                 chunks_after = yaffs_get_erased_chunks(dev);
2630                 if (chunks_before >= chunks_after)
2631                         yaffs_trace(YAFFS_TRACE_GC,
2632                                 "gc did not increase free chunks before %d after %d",
2633                                 chunks_before, chunks_after);
2634                 dev->gc_block = 0;
2635                 dev->gc_chunk = 0;
2636                 dev->n_clean_ups = 0;
2637         }
2638
2639         dev->gc_disable = 0;
2640
2641         return ret_val;
2642 }
2643
2644 /*
2645  * find_gc_block() selects the dirtiest block (or close enough)
2646  * for garbage collection.
2647  */
2648
2649 static unsigned yaffs_find_gc_block(struct yaffs_dev *dev,
2650                                     int aggressive, int background)
2651 {
2652         int i;
2653         int iterations;
2654         unsigned selected = 0;
2655         int prioritised = 0;
2656         int prioritised_exist = 0;
2657         struct yaffs_block_info *bi;
2658         int threshold;
2659
2660         /* First let's see if we need to grab a prioritised block */
2661         if (dev->has_pending_prioritised_gc && !aggressive) {
2662                 dev->gc_dirtiest = 0;
2663                 bi = dev->block_info;
2664                 for (i = dev->internal_start_block;
2665                      i <= dev->internal_end_block && !selected; i++) {
2666
2667                         if (bi->gc_prioritise) {
2668                                 prioritised_exist = 1;
2669                                 if (bi->block_state == YAFFS_BLOCK_STATE_FULL &&
2670                                     yaffs_block_ok_for_gc(dev, bi)) {
2671                                         selected = i;
2672                                         prioritised = 1;
2673                                 }
2674                         }
2675                         bi++;
2676                 }
2677
2678                 /*
2679                  * If there is a prioritised block and none was selected then
2680                  * this happened because there is at least one old dirty block
2681                  * gumming up the works. Let's gc the oldest dirty block.
2682                  */
2683
2684                 if (prioritised_exist &&
2685                     !selected && dev->oldest_dirty_block > 0)
2686                         selected = dev->oldest_dirty_block;
2687
2688                 if (!prioritised_exist) /* None found, so we can clear this */
2689                         dev->has_pending_prioritised_gc = 0;
2690         }
2691
2692         /* If we're doing aggressive GC then we are happy to take a less-dirty
2693          * block, and search harder.
2694          * else (leasurely gc), then we only bother to do this if the
2695          * block has only a few pages in use.
2696          */
2697
2698         if (!selected) {
2699                 int pages_used;
2700                 int n_blocks =
2701                     dev->internal_end_block - dev->internal_start_block + 1;
2702                 if (aggressive) {
2703                         threshold = dev->param.chunks_per_block;
2704                         iterations = n_blocks;
2705                 } else {
2706                         int max_threshold;
2707
2708                         if (background)
2709                                 max_threshold = dev->param.chunks_per_block / 2;
2710                         else
2711                                 max_threshold = dev->param.chunks_per_block / 8;
2712
2713                         if (max_threshold < YAFFS_GC_PASSIVE_THRESHOLD)
2714                                 max_threshold = YAFFS_GC_PASSIVE_THRESHOLD;
2715
2716                         threshold = background ? (dev->gc_not_done + 2) * 2 : 0;
2717                         if (threshold < YAFFS_GC_PASSIVE_THRESHOLD)
2718                                 threshold = YAFFS_GC_PASSIVE_THRESHOLD;
2719                         if (threshold > max_threshold)
2720                                 threshold = max_threshold;
2721
2722                         iterations = n_blocks / 16 + 1;
2723                         if (iterations > 100)
2724                                 iterations = 100;
2725                 }
2726
2727                 for (i = 0;
2728                      i < iterations &&
2729                      (dev->gc_dirtiest < 1 ||
2730                       dev->gc_pages_in_use > YAFFS_GC_GOOD_ENOUGH);
2731                      i++) {
2732                         dev->gc_block_finder++;
2733                         if (dev->gc_block_finder < dev->internal_start_block ||
2734                             dev->gc_block_finder > dev->internal_end_block)
2735                                 dev->gc_block_finder =
2736                                     dev->internal_start_block;
2737
2738                         bi = yaffs_get_block_info(dev, dev->gc_block_finder);
2739
2740                         pages_used = bi->pages_in_use - bi->soft_del_pages;
2741
2742                         if (bi->block_state == YAFFS_BLOCK_STATE_FULL &&
2743                             pages_used < dev->param.chunks_per_block &&
2744                             (dev->gc_dirtiest < 1 ||
2745                              pages_used < dev->gc_pages_in_use) &&
2746                             yaffs_block_ok_for_gc(dev, bi)) {
2747                                 dev->gc_dirtiest = dev->gc_block_finder;
2748                                 dev->gc_pages_in_use = pages_used;
2749                         }
2750                 }
2751
2752                 if (dev->gc_dirtiest > 0 && dev->gc_pages_in_use <= threshold)
2753                         selected = dev->gc_dirtiest;
2754         }
2755
2756         /*
2757          * If nothing has been selected for a while, try the oldest dirty
2758          * because that's gumming up the works.
2759          */
2760
2761         if (!selected && dev->param.is_yaffs2 &&
2762             dev->gc_not_done >= (background ? 10 : 20)) {
2763                 yaffs2_find_oldest_dirty_seq(dev);
2764                 if (dev->oldest_dirty_block > 0) {
2765                         selected = dev->oldest_dirty_block;
2766                         dev->gc_dirtiest = selected;
2767                         dev->oldest_dirty_gc_count++;
2768                         bi = yaffs_get_block_info(dev, selected);
2769                         dev->gc_pages_in_use =
2770                             bi->pages_in_use - bi->soft_del_pages;
2771                 } else {
2772                         dev->gc_not_done = 0;
2773                 }
2774         }
2775
2776         if (selected) {
2777                 yaffs_trace(YAFFS_TRACE_GC,
2778                         "GC Selected block %d with %d free, prioritised:%d",
2779                         selected,
2780                         dev->param.chunks_per_block - dev->gc_pages_in_use,
2781                         prioritised);
2782
2783                 dev->n_gc_blocks++;
2784                 if (background)
2785                         dev->bg_gcs++;
2786
2787                 dev->gc_dirtiest = 0;
2788                 dev->gc_pages_in_use = 0;
2789                 dev->gc_not_done = 0;
2790                 if (dev->refresh_skip > 0)
2791                         dev->refresh_skip--;
2792         } else {
2793                 dev->gc_not_done++;
2794                 yaffs_trace(YAFFS_TRACE_GC,
2795                         "GC none: finder %d skip %d threshold %d dirtiest %d using %d oldest %d%s",
2796                         dev->gc_block_finder, dev->gc_not_done, threshold,
2797                         dev->gc_dirtiest, dev->gc_pages_in_use,
2798                         dev->oldest_dirty_block, background ? " bg" : "");
2799         }
2800
2801         return selected;
2802 }
2803
2804 /* New garbage collector
2805  * If we're very low on erased blocks then we do aggressive garbage collection
2806  * otherwise we do "leasurely" garbage collection.
2807  * Aggressive gc looks further (whole array) and will accept less dirty blocks.
2808  * Passive gc only inspects smaller areas and only accepts more dirty blocks.
2809  *
2810  * The idea is to help clear out space in a more spread-out manner.
2811  * Dunno if it really does anything useful.
2812  */
2813 static int yaffs_check_gc(struct yaffs_dev *dev, int background)
2814 {
2815         int aggressive = 0;
2816         int gc_ok = YAFFS_OK;
2817         int max_tries = 0;
2818         int min_erased;
2819         int erased_chunks;
2820         int checkpt_block_adjust;
2821
2822         if (dev->param.gc_control && (dev->param.gc_control(dev) & 1) == 0)
2823                 return YAFFS_OK;
2824
2825         if (dev->gc_disable)
2826                 /* Bail out so we don't get recursive gc */
2827                 return YAFFS_OK;
2828
2829         /* This loop should pass the first time.
2830          * Only loops here if the collection does not increase space.
2831          */
2832
2833         do {
2834                 max_tries++;
2835
2836                 checkpt_block_adjust = yaffs_calc_checkpt_blocks_required(dev);
2837
2838                 min_erased =
2839                     dev->param.n_reserved_blocks + checkpt_block_adjust + 1;
2840                 erased_chunks =
2841                     dev->n_erased_blocks * dev->param.chunks_per_block;
2842
2843                 /* If we need a block soon then do aggressive gc. */
2844                 if (dev->n_erased_blocks < min_erased)
2845                         aggressive = 1;
2846                 else {
2847                         if (!background
2848                             && erased_chunks > (dev->n_free_chunks / 4))
2849                                 break;
2850
2851                         if (dev->gc_skip > 20)
2852                                 dev->gc_skip = 20;
2853                         if (erased_chunks < dev->n_free_chunks / 2 ||
2854                             dev->gc_skip < 1 || background)
2855                                 aggressive = 0;
2856                         else {
2857                                 dev->gc_skip--;
2858                                 break;
2859                         }
2860                 }
2861
2862                 dev->gc_skip = 5;
2863
2864                 /* If we don't already have a block being gc'd then see if we
2865                  * should start another */
2866
2867                 if (dev->gc_block < 1 && !aggressive) {
2868                         dev->gc_block = yaffs2_find_refresh_block(dev);
2869                         dev->gc_chunk = 0;
2870                         dev->n_clean_ups = 0;
2871                 }
2872                 if (dev->gc_block < 1) {
2873                         dev->gc_block =
2874                             yaffs_find_gc_block(dev, aggressive, background);
2875                         dev->gc_chunk = 0;
2876                         dev->n_clean_ups = 0;
2877                 }
2878
2879                 if (dev->gc_block > 0) {
2880                         dev->all_gcs++;
2881                         if (!aggressive)
2882                                 dev->passive_gc_count++;
2883
2884                         yaffs_trace(YAFFS_TRACE_GC,
2885                                 "yaffs: GC n_erased_blocks %d aggressive %d",
2886                                 dev->n_erased_blocks, aggressive);
2887
2888                         gc_ok = yaffs_gc_block(dev, dev->gc_block, aggressive);
2889                 }
2890
2891                 if (dev->n_erased_blocks < (dev->param.n_reserved_blocks) &&
2892                     dev->gc_block > 0) {
2893                         yaffs_trace(YAFFS_TRACE_GC,
2894                                 "yaffs: GC !!!no reclaim!!! n_erased_blocks %d after try %d block %d",
2895                                 dev->n_erased_blocks, max_tries,
2896                                 dev->gc_block);
2897                 }
2898         } while ((dev->n_erased_blocks < dev->param.n_reserved_blocks) &&
2899                  (dev->gc_block > 0) && (max_tries < 2));
2900
2901         return aggressive ? gc_ok : YAFFS_OK;
2902 }
2903
2904 /*
2905  * yaffs_bg_gc()
2906  * Garbage collects. Intended to be called from a background thread.
2907  * Returns non-zero if at least half the free chunks are erased.
2908  */
2909 int yaffs_bg_gc(struct yaffs_dev *dev, unsigned urgency)
2910 {
2911         int erased_chunks = dev->n_erased_blocks * dev->param.chunks_per_block;
2912
2913         yaffs_trace(YAFFS_TRACE_BACKGROUND, "Background gc %u", urgency);
2914
2915         yaffs_check_gc(dev, 1);
2916         return erased_chunks > dev->n_free_chunks / 2;
2917 }
2918
2919 /*-------------------- Data file manipulation -----------------*/
2920
2921 static int yaffs_rd_data_obj(struct yaffs_obj *in, int inode_chunk, u8 * buffer)
2922 {
2923         int nand_chunk = yaffs_find_chunk_in_file(in, inode_chunk, NULL);
2924
2925         if (nand_chunk >= 0)
2926                 return yaffs_rd_chunk_tags_nand(in->my_dev, nand_chunk,
2927                                                 buffer, NULL);
2928         else {
2929                 yaffs_trace(YAFFS_TRACE_NANDACCESS,
2930                         "Chunk %d not found zero instead",
2931                         nand_chunk);
2932                 /* get sane (zero) data if you read a hole */
2933                 memset(buffer, 0, in->my_dev->data_bytes_per_chunk);
2934                 return 0;
2935         }
2936
2937 }
2938
2939 void yaffs_chunk_del(struct yaffs_dev *dev, int chunk_id, int mark_flash,
2940                      int lyn)
2941 {
2942         int block;
2943         int page;
2944         struct yaffs_ext_tags tags;
2945         struct yaffs_block_info *bi;
2946
2947         if (chunk_id <= 0)
2948                 return;
2949
2950         dev->n_deletions++;
2951         block = chunk_id / dev->param.chunks_per_block;
2952         page = chunk_id % dev->param.chunks_per_block;
2953
2954         if (!yaffs_check_chunk_bit(dev, block, page))
2955                 yaffs_trace(YAFFS_TRACE_VERIFY,
2956                         "Deleting invalid chunk %d", chunk_id);
2957
2958         bi = yaffs_get_block_info(dev, block);
2959
2960         yaffs2_update_oldest_dirty_seq(dev, block, bi);
2961
2962         yaffs_trace(YAFFS_TRACE_DELETION,
2963                 "line %d delete of chunk %d",
2964                 lyn, chunk_id);
2965
2966         if (!dev->param.is_yaffs2 && mark_flash &&
2967             bi->block_state != YAFFS_BLOCK_STATE_COLLECTING) {
2968
2969                 memset(&tags, 0, sizeof(tags));
2970                 tags.is_deleted = 1;
2971                 yaffs_wr_chunk_tags_nand(dev, chunk_id, NULL, &tags);
2972                 yaffs_handle_chunk_update(dev, chunk_id, &tags);
2973         } else {
2974                 dev->n_unmarked_deletions++;
2975         }
2976
2977         /* Pull out of the management area.
2978          * If the whole block became dirty, this will kick off an erasure.
2979          */
2980         if (bi->block_state == YAFFS_BLOCK_STATE_ALLOCATING ||
2981             bi->block_state == YAFFS_BLOCK_STATE_FULL ||
2982             bi->block_state == YAFFS_BLOCK_STATE_NEEDS_SCAN ||
2983             bi->block_state == YAFFS_BLOCK_STATE_COLLECTING) {
2984                 dev->n_free_chunks++;
2985                 yaffs_clear_chunk_bit(dev, block, page);
2986                 bi->pages_in_use--;
2987
2988                 if (bi->pages_in_use == 0 &&
2989                     !bi->has_shrink_hdr &&
2990                     bi->block_state != YAFFS_BLOCK_STATE_ALLOCATING &&
2991                     bi->block_state != YAFFS_BLOCK_STATE_NEEDS_SCAN) {
2992                         yaffs_block_became_dirty(dev, block);
2993                 }
2994         }
2995 }
2996
2997 static int yaffs_wr_data_obj(struct yaffs_obj *in, int inode_chunk,
2998                              const u8 *buffer, int n_bytes, int use_reserve)
2999 {
3000         /* Find old chunk Need to do this to get serial number
3001          * Write new one and patch into tree.
3002          * Invalidate old tags.
3003          */
3004
3005         int prev_chunk_id;
3006         struct yaffs_ext_tags prev_tags;
3007         int new_chunk_id;
3008         struct yaffs_ext_tags new_tags;
3009         struct yaffs_dev *dev = in->my_dev;
3010
3011         yaffs_check_gc(dev, 0);
3012
3013         /* Get the previous chunk at this location in the file if it exists.
3014          * If it does not exist then put a zero into the tree. This creates
3015          * the tnode now, rather than later when it is harder to clean up.
3016          */
3017         prev_chunk_id = yaffs_find_chunk_in_file(in, inode_chunk, &prev_tags);
3018         if (prev_chunk_id < 1 &&
3019             !yaffs_put_chunk_in_file(in, inode_chunk, 0, 0))
3020                 return 0;
3021
3022         /* Set up new tags */
3023         memset(&new_tags, 0, sizeof(new_tags));
3024
3025         new_tags.chunk_id = inode_chunk;
3026         new_tags.obj_id = in->obj_id;
3027         new_tags.serial_number =
3028             (prev_chunk_id > 0) ? prev_tags.serial_number + 1 : 1;
3029         new_tags.n_bytes = n_bytes;
3030
3031         if (n_bytes < 1 || n_bytes > dev->param.total_bytes_per_chunk) {
3032                 yaffs_trace(YAFFS_TRACE_ERROR,
3033                   "Writing %d bytes to chunk!!!!!!!!!",
3034                    n_bytes);
3035                 BUG();
3036         }
3037
3038         new_chunk_id =
3039             yaffs_write_new_chunk(dev, buffer, &new_tags, use_reserve);
3040
3041         if (new_chunk_id > 0) {
3042                 yaffs_put_chunk_in_file(in, inode_chunk, new_chunk_id, 0);
3043
3044                 if (prev_chunk_id > 0)
3045                         yaffs_chunk_del(dev, prev_chunk_id, 1, __LINE__);
3046
3047                 yaffs_verify_file_sane(in);
3048         }
3049         return new_chunk_id;
3050
3051 }
3052
3053
3054
3055 static int yaffs_do_xattrib_mod(struct yaffs_obj *obj, int set,
3056                                 const YCHAR *name, const void *value, int size,
3057                                 int flags)
3058 {
3059         struct yaffs_xattr_mod xmod;
3060         int result;
3061
3062         xmod.set = set;
3063         xmod.name = name;
3064         xmod.data = value;
3065         xmod.size = size;
3066         xmod.flags = flags;
3067         xmod.result = -ENOSPC;
3068
3069         result = yaffs_update_oh(obj, NULL, 0, 0, 0, &xmod);
3070
3071         if (result > 0)
3072                 return xmod.result;
3073         else
3074                 return -ENOSPC;
3075 }
3076
3077 static int yaffs_apply_xattrib_mod(struct yaffs_obj *obj, char *buffer,
3078                                    struct yaffs_xattr_mod *xmod)
3079 {
3080         int retval = 0;
3081         int x_offs = sizeof(struct yaffs_obj_hdr);
3082         struct yaffs_dev *dev = obj->my_dev;
3083         int x_size = dev->data_bytes_per_chunk - sizeof(struct yaffs_obj_hdr);
3084         char *x_buffer = buffer + x_offs;
3085
3086         if (xmod->set)
3087                 retval =
3088                     nval_set(x_buffer, x_size, xmod->name, xmod->data,
3089                              xmod->size, xmod->flags);
3090         else
3091                 retval = nval_del(x_buffer, x_size, xmod->name);
3092
3093         obj->has_xattr = nval_hasvalues(x_buffer, x_size);
3094         obj->xattr_known = 1;
3095         xmod->result = retval;
3096
3097         return retval;
3098 }
3099
3100 static int yaffs_do_xattrib_fetch(struct yaffs_obj *obj, const YCHAR *name,
3101                                   void *value, int size)
3102 {
3103         char *buffer = NULL;
3104         int result;
3105         struct yaffs_ext_tags tags;
3106         struct yaffs_dev *dev = obj->my_dev;
3107         int x_offs = sizeof(struct yaffs_obj_hdr);
3108         int x_size = dev->data_bytes_per_chunk - sizeof(struct yaffs_obj_hdr);
3109         char *x_buffer;
3110         int retval = 0;
3111
3112         if (obj->hdr_chunk < 1)
3113                 return -ENODATA;
3114
3115         /* If we know that the object has no xattribs then don't do all the
3116          * reading and parsing.
3117          */
3118         if (obj->xattr_known && !obj->has_xattr) {
3119                 if (name)
3120                         return -ENODATA;
3121                 else
3122                         return 0;
3123         }
3124
3125         buffer = (char *)yaffs_get_temp_buffer(dev);
3126         if (!buffer)
3127                 return -ENOMEM;
3128
3129         result =
3130             yaffs_rd_chunk_tags_nand(dev, obj->hdr_chunk, (u8 *) buffer, &tags);
3131
3132         if (result != YAFFS_OK)
3133                 retval = -ENOENT;
3134         else {
3135                 x_buffer = buffer + x_offs;
3136
3137                 if (!obj->xattr_known) {
3138                         obj->has_xattr = nval_hasvalues(x_buffer, x_size);
3139                         obj->xattr_known = 1;
3140                 }
3141
3142                 if (name)
3143                         retval = nval_get(x_buffer, x_size, name, value, size);
3144                 else
3145                         retval = nval_list(x_buffer, x_size, value, size);
3146         }
3147         yaffs_release_temp_buffer(dev, (u8 *) buffer);
3148         return retval;
3149 }
3150
3151 int yaffs_set_xattrib(struct yaffs_obj *obj, const YCHAR * name,
3152                       const void *value, int size, int flags)
3153 {
3154         return yaffs_do_xattrib_mod(obj, 1, name, value, size, flags);
3155 }
3156
3157 int yaffs_remove_xattrib(struct yaffs_obj *obj, const YCHAR * name)
3158 {
3159         return yaffs_do_xattrib_mod(obj, 0, name, NULL, 0, 0);
3160 }
3161
3162 int yaffs_get_xattrib(struct yaffs_obj *obj, const YCHAR * name, void *value,
3163                       int size)
3164 {
3165         return yaffs_do_xattrib_fetch(obj, name, value, size);
3166 }
3167
3168 int yaffs_list_xattrib(struct yaffs_obj *obj, char *buffer, int size)
3169 {
3170         return yaffs_do_xattrib_fetch(obj, NULL, buffer, size);
3171 }
3172
3173 static void yaffs_check_obj_details_loaded(struct yaffs_obj *in)
3174 {
3175         u8 *buf;
3176         struct yaffs_obj_hdr *oh;
3177         struct yaffs_dev *dev;
3178         struct yaffs_ext_tags tags;
3179         int result;
3180         int alloc_failed = 0;
3181
3182         if (!in || !in->lazy_loaded || in->hdr_chunk < 1)
3183                 return;
3184
3185         dev = in->my_dev;
3186         in->lazy_loaded = 0;
3187         buf = yaffs_get_temp_buffer(dev);
3188
3189         result = yaffs_rd_chunk_tags_nand(dev, in->hdr_chunk, buf, &tags);
3190         oh = (struct yaffs_obj_hdr *)buf;
3191
3192         in->yst_mode = oh->yst_mode;
3193         yaffs_load_attribs(in, oh);
3194         yaffs_set_obj_name_from_oh(in, oh);
3195
3196         if (in->variant_type == YAFFS_OBJECT_TYPE_SYMLINK) {
3197                 in->variant.symlink_variant.alias =
3198                     yaffs_clone_str(oh->alias);
3199                 if (!in->variant.symlink_variant.alias)
3200                         alloc_failed = 1;       /* Not returned */
3201         }
3202         yaffs_release_temp_buffer(dev, buf);
3203 }
3204
3205 static void yaffs_load_name_from_oh(struct yaffs_dev *dev, YCHAR *name,
3206                                     const YCHAR *oh_name, int buff_size)
3207 {
3208 #ifdef CONFIG_YAFFS_AUTO_UNICODE
3209         if (dev->param.auto_unicode) {
3210                 if (*oh_name) {
3211                         /* It is an ASCII name, do an ASCII to
3212                          * unicode conversion */
3213                         const char *ascii_oh_name = (const char *)oh_name;
3214                         int n = buff_size - 1;
3215                         while (n > 0 && *ascii_oh_name) {
3216                                 *name = *ascii_oh_name;
3217                                 name++;
3218                                 ascii_oh_name++;
3219                                 n--;
3220                         }
3221                 } else {
3222                         strncpy(name, oh_name + 1, buff_size - 1);
3223                 }
3224         } else {
3225 #else
3226         dev = dev;
3227         {
3228 #endif
3229                 strncpy(name, oh_name, buff_size - 1);
3230         }
3231 }
3232
3233 static void yaffs_load_oh_from_name(struct yaffs_dev *dev, YCHAR *oh_name,
3234                                     const YCHAR *name)
3235 {
3236 #ifdef CONFIG_YAFFS_AUTO_UNICODE
3237
3238         int is_ascii;
3239         YCHAR *w;
3240
3241         if (dev->param.auto_unicode) {
3242
3243                 is_ascii = 1;
3244                 w = name;
3245
3246                 /* Figure out if the name will fit in ascii character set */
3247                 while (is_ascii && *w) {
3248                         if ((*w) & 0xff00)
3249                                 is_ascii = 0;
3250                         w++;
3251                 }
3252
3253                 if (is_ascii) {
3254                         /* It is an ASCII name, so convert unicode to ascii */
3255                         char *ascii_oh_name = (char *)oh_name;
3256                         int n = YAFFS_MAX_NAME_LENGTH - 1;
3257                         while (n > 0 && *name) {
3258                                 *ascii_oh_name = *name;
3259                                 name++;
3260                                 ascii_oh_name++;
3261                                 n--;
3262                         }
3263                 } else {
3264                         /* Unicode name, so save starting at the second YCHAR */
3265                         *oh_name = 0;
3266                         strncpy(oh_name + 1, name, YAFFS_MAX_NAME_LENGTH - 2);
3267                 }
3268         } else {
3269 #else
3270         dev = dev;
3271         {
3272 #endif
3273                 strncpy(oh_name, name, YAFFS_MAX_NAME_LENGTH - 1);
3274         }
3275 }
3276
3277 /* UpdateObjectHeader updates the header on NAND for an object.
3278  * If name is not NULL, then that new name is used.
3279  */
3280 int yaffs_update_oh(struct yaffs_obj *in, const YCHAR *name, int force,
3281                     int is_shrink, int shadows, struct yaffs_xattr_mod *xmod)
3282 {
3283
3284         struct yaffs_block_info *bi;
3285         struct yaffs_dev *dev = in->my_dev;
3286         int prev_chunk_id;
3287         int ret_val = 0;
3288         int result = 0;
3289         int new_chunk_id;
3290         struct yaffs_ext_tags new_tags;
3291         struct yaffs_ext_tags old_tags;
3292         const YCHAR *alias = NULL;
3293         u8 *buffer = NULL;
3294         YCHAR old_name[YAFFS_MAX_NAME_LENGTH + 1];
3295         struct yaffs_obj_hdr *oh = NULL;
3296         loff_t file_size = 0;
3297
3298         strcpy(old_name, _Y("silly old name"));
3299
3300         if (in->fake && in != dev->root_dir && !force && !xmod)
3301                 return ret_val;
3302
3303         yaffs_check_gc(dev, 0);
3304         yaffs_check_obj_details_loaded(in);
3305
3306         buffer = yaffs_get_temp_buffer(in->my_dev);
3307         oh = (struct yaffs_obj_hdr *)buffer;
3308
3309         prev_chunk_id = in->hdr_chunk;
3310
3311         if (prev_chunk_id > 0) {
3312                 result = yaffs_rd_chunk_tags_nand(dev, prev_chunk_id,
3313                                                   buffer, &old_tags);
3314
3315                 yaffs_verify_oh(in, oh, &old_tags, 0);
3316                 memcpy(old_name, oh->name, sizeof(oh->name));
3317                 memset(buffer, 0xff, sizeof(struct yaffs_obj_hdr));
3318         } else {
3319                 memset(buffer, 0xff, dev->data_bytes_per_chunk);
3320         }
3321
3322         oh->type = in->variant_type;
3323         oh->yst_mode = in->yst_mode;
3324         oh->shadows_obj = oh->inband_shadowed_obj_id = shadows;
3325
3326         yaffs_load_attribs_oh(oh, in);
3327
3328         if (in->parent)
3329                 oh->parent_obj_id = in->parent->obj_id;
3330         else
3331                 oh->parent_obj_id = 0;
3332
3333         if (name && *name) {
3334                 memset(oh->name, 0, sizeof(oh->name));
3335                 yaffs_load_oh_from_name(dev, oh->name, name);
3336         } else if (prev_chunk_id > 0) {
3337                 memcpy(oh->name, old_name, sizeof(oh->name));
3338         } else {
3339                 memset(oh->name, 0, sizeof(oh->name));
3340         }
3341
3342         oh->is_shrink = is_shrink;
3343
3344         switch (in->variant_type) {
3345         case YAFFS_OBJECT_TYPE_UNKNOWN:
3346                 /* Should not happen */
3347                 break;
3348         case YAFFS_OBJECT_TYPE_FILE:
3349                 if (oh->parent_obj_id != YAFFS_OBJECTID_DELETED &&
3350                     oh->parent_obj_id != YAFFS_OBJECTID_UNLINKED)
3351                         file_size = in->variant.file_variant.file_size;
3352                 yaffs_oh_size_load(oh, file_size);
3353                 break;
3354         case YAFFS_OBJECT_TYPE_HARDLINK:
3355                 oh->equiv_id = in->variant.hardlink_variant.equiv_id;
3356                 break;
3357         case YAFFS_OBJECT_TYPE_SPECIAL:
3358                 /* Do nothing */
3359                 break;
3360         case YAFFS_OBJECT_TYPE_DIRECTORY:
3361                 /* Do nothing */
3362                 break;
3363         case YAFFS_OBJECT_TYPE_SYMLINK:
3364                 alias = in->variant.symlink_variant.alias;
3365                 if (!alias)
3366                         alias = _Y("no alias");
3367                 strncpy(oh->alias, alias, YAFFS_MAX_ALIAS_LENGTH);
3368                 oh->alias[YAFFS_MAX_ALIAS_LENGTH] = 0;
3369                 break;
3370         }
3371
3372         /* process any xattrib modifications */
3373         if (xmod)
3374                 yaffs_apply_xattrib_mod(in, (char *)buffer, xmod);
3375
3376         /* Tags */
3377         memset(&new_tags, 0, sizeof(new_tags));
3378         in->serial++;
3379         new_tags.chunk_id = 0;
3380         new_tags.obj_id = in->obj_id;
3381         new_tags.serial_number = in->serial;
3382
3383         /* Add extra info for file header */
3384         new_tags.extra_available = 1;
3385         new_tags.extra_parent_id = oh->parent_obj_id;
3386         new_tags.extra_file_size = file_size;
3387         new_tags.extra_is_shrink = oh->is_shrink;
3388         new_tags.extra_equiv_id = oh->equiv_id;
3389         new_tags.extra_shadows = (oh->shadows_obj > 0) ? 1 : 0;
3390         new_tags.extra_obj_type = in->variant_type;
3391         yaffs_verify_oh(in, oh, &new_tags, 1);
3392
3393         /* Create new chunk in NAND */
3394         new_chunk_id =
3395             yaffs_write_new_chunk(dev, buffer, &new_tags,
3396                                   (prev_chunk_id > 0) ? 1 : 0);
3397
3398         if (buffer)
3399                 yaffs_release_temp_buffer(dev, buffer);
3400
3401         if (new_chunk_id < 0)
3402                 return new_chunk_id;
3403
3404         in->hdr_chunk = new_chunk_id;
3405
3406         if (prev_chunk_id > 0)
3407                 yaffs_chunk_del(dev, prev_chunk_id, 1, __LINE__);
3408
3409         if (!yaffs_obj_cache_dirty(in))
3410                 in->dirty = 0;
3411
3412         /* If this was a shrink, then mark the block
3413          * that the chunk lives on */
3414         if (is_shrink) {
3415                 bi = yaffs_get_block_info(in->my_dev,
3416                                           new_chunk_id /
3417                                           in->my_dev->param.chunks_per_block);
3418                 bi->has_shrink_hdr = 1;
3419         }
3420
3421
3422         return new_chunk_id;
3423 }
3424
3