UBI: Fastmap: Calc fastmap size correctly
[sfrench/cifs-2.6.git] / drivers / mtd / ubi / fastmap.c
1 /*
2  * Copyright (c) 2012 Linutronix GmbH
3  * Author: Richard Weinberger <richard@nod.at>
4  *
5  * This program is free software; you can redistribute it and/or modify
6  * it under the terms of the GNU General Public License as published by
7  * the Free Software Foundation; version 2.
8  *
9  * This program is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
12  * the GNU General Public License for more details.
13  *
14  */
15
16 #include <linux/crc32.h>
17 #include "ubi.h"
18
19 /**
20  * ubi_calc_fm_size - calculates the fastmap size in bytes for an UBI device.
21  * @ubi: UBI device description object
22  */
23 size_t ubi_calc_fm_size(struct ubi_device *ubi)
24 {
25         size_t size;
26
27         size = sizeof(struct ubi_fm_sb) + \
28                 sizeof(struct ubi_fm_hdr) + \
29                 sizeof(struct ubi_fm_scan_pool) + \
30                 sizeof(struct ubi_fm_scan_pool) + \
31                 (ubi->peb_count * sizeof(struct ubi_fm_ec)) + \
32                 (sizeof(struct ubi_fm_eba) + \
33                 (ubi->peb_count * sizeof(__be32))) + \
34                 sizeof(struct ubi_fm_volhdr) * UBI_MAX_VOLUMES;
35         return roundup(size, ubi->leb_size);
36 }
37
38
39 /**
40  * new_fm_vhdr - allocate a new volume header for fastmap usage.
41  * @ubi: UBI device description object
42  * @vol_id: the VID of the new header
43  *
44  * Returns a new struct ubi_vid_hdr on success.
45  * NULL indicates out of memory.
46  */
47 static struct ubi_vid_hdr *new_fm_vhdr(struct ubi_device *ubi, int vol_id)
48 {
49         struct ubi_vid_hdr *new;
50
51         new = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
52         if (!new)
53                 goto out;
54
55         new->vol_type = UBI_VID_DYNAMIC;
56         new->vol_id = cpu_to_be32(vol_id);
57
58         /* UBI implementations without fastmap support have to delete the
59          * fastmap.
60          */
61         new->compat = UBI_COMPAT_DELETE;
62
63 out:
64         return new;
65 }
66
67 /**
68  * add_aeb - create and add a attach erase block to a given list.
69  * @ai: UBI attach info object
70  * @list: the target list
71  * @pnum: PEB number of the new attach erase block
72  * @ec: erease counter of the new LEB
73  * @scrub: scrub this PEB after attaching
74  *
75  * Returns 0 on success, < 0 indicates an internal error.
76  */
77 static int add_aeb(struct ubi_attach_info *ai, struct list_head *list,
78                    int pnum, int ec, int scrub)
79 {
80         struct ubi_ainf_peb *aeb;
81
82         aeb = kmem_cache_alloc(ai->aeb_slab_cache, GFP_KERNEL);
83         if (!aeb)
84                 return -ENOMEM;
85
86         aeb->pnum = pnum;
87         aeb->ec = ec;
88         aeb->lnum = -1;
89         aeb->scrub = scrub;
90         aeb->copy_flag = aeb->sqnum = 0;
91
92         ai->ec_sum += aeb->ec;
93         ai->ec_count++;
94
95         if (ai->max_ec < aeb->ec)
96                 ai->max_ec = aeb->ec;
97
98         if (ai->min_ec > aeb->ec)
99                 ai->min_ec = aeb->ec;
100
101         list_add_tail(&aeb->u.list, list);
102
103         return 0;
104 }
105
106 /**
107  * add_vol - create and add a new volume to ubi_attach_info.
108  * @ai: ubi_attach_info object
109  * @vol_id: VID of the new volume
110  * @used_ebs: number of used EBS
111  * @data_pad: data padding value of the new volume
112  * @vol_type: volume type
113  * @last_eb_bytes: number of bytes in the last LEB
114  *
115  * Returns the new struct ubi_ainf_volume on success.
116  * NULL indicates an error.
117  */
118 static struct ubi_ainf_volume *add_vol(struct ubi_attach_info *ai, int vol_id,
119                                        int used_ebs, int data_pad, u8 vol_type,
120                                        int last_eb_bytes)
121 {
122         struct ubi_ainf_volume *av;
123         struct rb_node **p = &ai->volumes.rb_node, *parent = NULL;
124
125         while (*p) {
126                 parent = *p;
127                 av = rb_entry(parent, struct ubi_ainf_volume, rb);
128
129                 if (vol_id > av->vol_id)
130                         p = &(*p)->rb_left;
131                 else
132                         p = &(*p)->rb_right;
133         }
134
135         av = kmalloc(sizeof(struct ubi_ainf_volume), GFP_KERNEL);
136         if (!av)
137                 goto out;
138
139         av->highest_lnum = av->leb_count = 0;
140         av->vol_id = vol_id;
141         av->used_ebs = used_ebs;
142         av->data_pad = data_pad;
143         av->last_data_size = last_eb_bytes;
144         av->compat = 0;
145         av->vol_type = vol_type;
146         av->root = RB_ROOT;
147
148         dbg_bld("found volume (ID %i)", vol_id);
149
150         rb_link_node(&av->rb, parent, p);
151         rb_insert_color(&av->rb, &ai->volumes);
152
153 out:
154         return av;
155 }
156
157 /**
158  * assign_aeb_to_av - assigns a SEB to a given ainf_volume and removes it
159  * from it's original list.
160  * @ai: ubi_attach_info object
161  * @aeb: the to be assigned SEB
162  * @av: target scan volume
163  */
164 static void assign_aeb_to_av(struct ubi_attach_info *ai,
165                              struct ubi_ainf_peb *aeb,
166                              struct ubi_ainf_volume *av)
167 {
168         struct ubi_ainf_peb *tmp_aeb;
169         struct rb_node **p = &ai->volumes.rb_node, *parent = NULL;
170
171         p = &av->root.rb_node;
172         while (*p) {
173                 parent = *p;
174
175                 tmp_aeb = rb_entry(parent, struct ubi_ainf_peb, u.rb);
176                 if (aeb->lnum != tmp_aeb->lnum) {
177                         if (aeb->lnum < tmp_aeb->lnum)
178                                 p = &(*p)->rb_left;
179                         else
180                                 p = &(*p)->rb_right;
181
182                         continue;
183                 } else
184                         break;
185         }
186
187         list_del(&aeb->u.list);
188         av->leb_count++;
189
190         rb_link_node(&aeb->u.rb, parent, p);
191         rb_insert_color(&aeb->u.rb, &av->root);
192 }
193
194 /**
195  * update_vol - inserts or updates a LEB which was found a pool.
196  * @ubi: the UBI device object
197  * @ai: attach info object
198  * @av: the volume this LEB belongs to
199  * @new_vh: the volume header derived from new_aeb
200  * @new_aeb: the AEB to be examined
201  *
202  * Returns 0 on success, < 0 indicates an internal error.
203  */
204 static int update_vol(struct ubi_device *ubi, struct ubi_attach_info *ai,
205                       struct ubi_ainf_volume *av, struct ubi_vid_hdr *new_vh,
206                       struct ubi_ainf_peb *new_aeb)
207 {
208         struct rb_node **p = &av->root.rb_node, *parent = NULL;
209         struct ubi_ainf_peb *aeb, *victim;
210         int cmp_res;
211
212         while (*p) {
213                 parent = *p;
214                 aeb = rb_entry(parent, struct ubi_ainf_peb, u.rb);
215
216                 if (be32_to_cpu(new_vh->lnum) != aeb->lnum) {
217                         if (be32_to_cpu(new_vh->lnum) < aeb->lnum)
218                                 p = &(*p)->rb_left;
219                         else
220                                 p = &(*p)->rb_right;
221
222                         continue;
223                 }
224
225                 /* This case can happen if the fastmap gets written
226                  * because of a volume change (creation, deletion, ..).
227                  * Then a PEB can be within the persistent EBA and the pool.
228                  */
229                 if (aeb->pnum == new_aeb->pnum) {
230                         ubi_assert(aeb->lnum == new_aeb->lnum);
231                         kmem_cache_free(ai->aeb_slab_cache, new_aeb);
232
233                         return 0;
234                 }
235
236                 cmp_res = ubi_compare_lebs(ubi, aeb, new_aeb->pnum, new_vh);
237                 if (cmp_res < 0)
238                         return cmp_res;
239
240                 /* new_aeb is newer */
241                 if (cmp_res & 1) {
242                         victim = kmem_cache_alloc(ai->aeb_slab_cache,
243                                 GFP_KERNEL);
244                         if (!victim)
245                                 return -ENOMEM;
246
247                         victim->ec = aeb->ec;
248                         victim->pnum = aeb->pnum;
249                         list_add_tail(&victim->u.list, &ai->erase);
250
251                         if (av->highest_lnum == be32_to_cpu(new_vh->lnum))
252                                 av->last_data_size = \
253                                         be32_to_cpu(new_vh->data_size);
254
255                         dbg_bld("vol %i: AEB %i's PEB %i is the newer",
256                                 av->vol_id, aeb->lnum, new_aeb->pnum);
257
258                         aeb->ec = new_aeb->ec;
259                         aeb->pnum = new_aeb->pnum;
260                         aeb->copy_flag = new_vh->copy_flag;
261                         aeb->scrub = new_aeb->scrub;
262                         kmem_cache_free(ai->aeb_slab_cache, new_aeb);
263
264                 /* new_aeb is older */
265                 } else {
266                         dbg_bld("vol %i: AEB %i's PEB %i is old, dropping it",
267                                 av->vol_id, aeb->lnum, new_aeb->pnum);
268                         list_add_tail(&new_aeb->u.list, &ai->erase);
269                 }
270
271                 return 0;
272         }
273         /* This LEB is new, let's add it to the volume */
274
275         if (av->highest_lnum <= be32_to_cpu(new_vh->lnum)) {
276                 av->highest_lnum = be32_to_cpu(new_vh->lnum);
277                 av->last_data_size = be32_to_cpu(new_vh->data_size);
278         }
279
280         if (av->vol_type == UBI_STATIC_VOLUME)
281                 av->used_ebs = be32_to_cpu(new_vh->used_ebs);
282
283         av->leb_count++;
284
285         rb_link_node(&new_aeb->u.rb, parent, p);
286         rb_insert_color(&new_aeb->u.rb, &av->root);
287
288         return 0;
289 }
290
291 /**
292  * process_pool_aeb - we found a non-empty PEB in a pool.
293  * @ubi: UBI device object
294  * @ai: attach info object
295  * @new_vh: the volume header derived from new_aeb
296  * @new_aeb: the AEB to be examined
297  *
298  * Returns 0 on success, < 0 indicates an internal error.
299  */
300 static int process_pool_aeb(struct ubi_device *ubi, struct ubi_attach_info *ai,
301                             struct ubi_vid_hdr *new_vh,
302                             struct ubi_ainf_peb *new_aeb)
303 {
304         struct ubi_ainf_volume *av, *tmp_av = NULL;
305         struct rb_node **p = &ai->volumes.rb_node, *parent = NULL;
306         int found = 0;
307
308         if (be32_to_cpu(new_vh->vol_id) == UBI_FM_SB_VOLUME_ID ||
309                 be32_to_cpu(new_vh->vol_id) == UBI_FM_DATA_VOLUME_ID) {
310                 kmem_cache_free(ai->aeb_slab_cache, new_aeb);
311
312                 return 0;
313         }
314
315         /* Find the volume this SEB belongs to */
316         while (*p) {
317                 parent = *p;
318                 tmp_av = rb_entry(parent, struct ubi_ainf_volume, rb);
319
320                 if (be32_to_cpu(new_vh->vol_id) > tmp_av->vol_id)
321                         p = &(*p)->rb_left;
322                 else if (be32_to_cpu(new_vh->vol_id) < tmp_av->vol_id)
323                         p = &(*p)->rb_right;
324                 else {
325                         found = 1;
326                         break;
327                 }
328         }
329
330         if (found)
331                 av = tmp_av;
332         else {
333                 ubi_err("orphaned volume in fastmap pool!");
334                 kmem_cache_free(ai->aeb_slab_cache, new_aeb);
335                 return UBI_BAD_FASTMAP;
336         }
337
338         ubi_assert(be32_to_cpu(new_vh->vol_id) == av->vol_id);
339
340         return update_vol(ubi, ai, av, new_vh, new_aeb);
341 }
342
343 /**
344  * unmap_peb - unmap a PEB.
345  * If fastmap detects a free PEB in the pool it has to check whether
346  * this PEB has been unmapped after writing the fastmap.
347  *
348  * @ai: UBI attach info object
349  * @pnum: The PEB to be unmapped
350  */
351 static void unmap_peb(struct ubi_attach_info *ai, int pnum)
352 {
353         struct ubi_ainf_volume *av;
354         struct rb_node *node, *node2;
355         struct ubi_ainf_peb *aeb;
356
357         for (node = rb_first(&ai->volumes); node; node = rb_next(node)) {
358                 av = rb_entry(node, struct ubi_ainf_volume, rb);
359
360                 for (node2 = rb_first(&av->root); node2;
361                      node2 = rb_next(node2)) {
362                         aeb = rb_entry(node2, struct ubi_ainf_peb, u.rb);
363                         if (aeb->pnum == pnum) {
364                                 rb_erase(&aeb->u.rb, &av->root);
365                                 kmem_cache_free(ai->aeb_slab_cache, aeb);
366                                 return;
367                         }
368                 }
369         }
370 }
371
372 /**
373  * scan_pool - scans a pool for changed (no longer empty PEBs).
374  * @ubi: UBI device object
375  * @ai: attach info object
376  * @pebs: an array of all PEB numbers in the to be scanned pool
377  * @pool_size: size of the pool (number of entries in @pebs)
378  * @max_sqnum: pointer to the maximal sequence number
379  * @eba_orphans: list of PEBs which need to be scanned
380  * @free: list of PEBs which are most likely free (and go into @ai->free)
381  *
382  * Returns 0 on success, if the pool is unusable UBI_BAD_FASTMAP is returned.
383  * < 0 indicates an internal error.
384  */
385 static int scan_pool(struct ubi_device *ubi, struct ubi_attach_info *ai,
386                      int *pebs, int pool_size, unsigned long long *max_sqnum,
387                      struct list_head *eba_orphans, struct list_head *free)
388 {
389         struct ubi_vid_hdr *vh;
390         struct ubi_ec_hdr *ech;
391         struct ubi_ainf_peb *new_aeb, *tmp_aeb;
392         int i, pnum, err, found_orphan, ret = 0;
393
394         ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
395         if (!ech)
396                 return -ENOMEM;
397
398         vh = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
399         if (!vh) {
400                 kfree(ech);
401                 return -ENOMEM;
402         }
403
404         dbg_bld("scanning fastmap pool: size = %i", pool_size);
405
406         /*
407          * Now scan all PEBs in the pool to find changes which have been made
408          * after the creation of the fastmap
409          */
410         for (i = 0; i < pool_size; i++) {
411                 int scrub = 0;
412                 int image_seq;
413
414                 pnum = be32_to_cpu(pebs[i]);
415
416                 if (ubi_io_is_bad(ubi, pnum)) {
417                         ubi_err("bad PEB in fastmap pool!");
418                         ret = UBI_BAD_FASTMAP;
419                         goto out;
420                 }
421
422                 err = ubi_io_read_ec_hdr(ubi, pnum, ech, 0);
423                 if (err && err != UBI_IO_BITFLIPS) {
424                         ubi_err("unable to read EC header! PEB:%i err:%i",
425                                 pnum, err);
426                         ret = err > 0 ? UBI_BAD_FASTMAP : err;
427                         goto out;
428                 } else if (err == UBI_IO_BITFLIPS)
429                         scrub = 1;
430
431                 /*
432                  * Older UBI implementations have image_seq set to zero, so
433                  * we shouldn't fail if image_seq == 0.
434                  */
435                 image_seq = be32_to_cpu(ech->image_seq);
436
437                 if (image_seq && (image_seq != ubi->image_seq)) {
438                         ubi_err("bad image seq: 0x%x, expected: 0x%x",
439                                 be32_to_cpu(ech->image_seq), ubi->image_seq);
440                         ret = UBI_BAD_FASTMAP;
441                         goto out;
442                 }
443
444                 err = ubi_io_read_vid_hdr(ubi, pnum, vh, 0);
445                 if (err == UBI_IO_FF || err == UBI_IO_FF_BITFLIPS) {
446                         unsigned long long ec = be64_to_cpu(ech->ec);
447                         unmap_peb(ai, pnum);
448                         dbg_bld("Adding PEB to free: %i", pnum);
449                         if (err == UBI_IO_FF_BITFLIPS)
450                                 add_aeb(ai, free, pnum, ec, 1);
451                         else
452                                 add_aeb(ai, free, pnum, ec, 0);
453                         continue;
454                 } else if (err == 0 || err == UBI_IO_BITFLIPS) {
455                         dbg_bld("Found non empty PEB:%i in pool", pnum);
456
457                         if (err == UBI_IO_BITFLIPS)
458                                 scrub = 1;
459
460                         found_orphan = 0;
461                         list_for_each_entry(tmp_aeb, eba_orphans, u.list) {
462                                 if (tmp_aeb->pnum == pnum) {
463                                         found_orphan = 1;
464                                         break;
465                                 }
466                         }
467                         if (found_orphan) {
468                                 list_del(&tmp_aeb->u.list);
469                                 kmem_cache_free(ai->aeb_slab_cache, tmp_aeb);
470                         }
471
472                         new_aeb = kmem_cache_alloc(ai->aeb_slab_cache,
473                                                    GFP_KERNEL);
474                         if (!new_aeb) {
475                                 ret = -ENOMEM;
476                                 goto out;
477                         }
478
479                         new_aeb->ec = be64_to_cpu(ech->ec);
480                         new_aeb->pnum = pnum;
481                         new_aeb->lnum = be32_to_cpu(vh->lnum);
482                         new_aeb->sqnum = be64_to_cpu(vh->sqnum);
483                         new_aeb->copy_flag = vh->copy_flag;
484                         new_aeb->scrub = scrub;
485
486                         if (*max_sqnum < new_aeb->sqnum)
487                                 *max_sqnum = new_aeb->sqnum;
488
489                         err = process_pool_aeb(ubi, ai, vh, new_aeb);
490                         if (err) {
491                                 ret = err > 0 ? UBI_BAD_FASTMAP : err;
492                                 goto out;
493                         }
494                 } else {
495                         /* We are paranoid and fall back to scanning mode */
496                         ubi_err("fastmap pool PEBs contains damaged PEBs!");
497                         ret = err > 0 ? UBI_BAD_FASTMAP : err;
498                         goto out;
499                 }
500
501         }
502
503 out:
504         ubi_free_vid_hdr(ubi, vh);
505         kfree(ech);
506         return ret;
507 }
508
509 /**
510  * count_fastmap_pebs - Counts the PEBs found by fastmap.
511  * @ai: The UBI attach info object
512  */
513 static int count_fastmap_pebs(struct ubi_attach_info *ai)
514 {
515         struct ubi_ainf_peb *aeb;
516         struct ubi_ainf_volume *av;
517         struct rb_node *rb1, *rb2;
518         int n = 0;
519
520         list_for_each_entry(aeb, &ai->erase, u.list)
521                 n++;
522
523         list_for_each_entry(aeb, &ai->free, u.list)
524                 n++;
525
526          ubi_rb_for_each_entry(rb1, av, &ai->volumes, rb)
527                 ubi_rb_for_each_entry(rb2, aeb, &av->root, u.rb)
528                         n++;
529
530         return n;
531 }
532
533 /**
534  * ubi_attach_fastmap - creates ubi_attach_info from a fastmap.
535  * @ubi: UBI device object
536  * @ai: UBI attach info object
537  * @fm: the fastmap to be attached
538  *
539  * Returns 0 on success, UBI_BAD_FASTMAP if the found fastmap was unusable.
540  * < 0 indicates an internal error.
541  */
542 static int ubi_attach_fastmap(struct ubi_device *ubi,
543                               struct ubi_attach_info *ai,
544                               struct ubi_fastmap_layout *fm)
545 {
546         struct list_head used, eba_orphans, free;
547         struct ubi_ainf_volume *av;
548         struct ubi_ainf_peb *aeb, *tmp_aeb, *_tmp_aeb;
549         struct ubi_ec_hdr *ech;
550         struct ubi_fm_sb *fmsb;
551         struct ubi_fm_hdr *fmhdr;
552         struct ubi_fm_scan_pool *fmpl1, *fmpl2;
553         struct ubi_fm_ec *fmec;
554         struct ubi_fm_volhdr *fmvhdr;
555         struct ubi_fm_eba *fm_eba;
556         int ret, i, j, pool_size, wl_pool_size;
557         size_t fm_pos = 0, fm_size = ubi->fm_size;
558         unsigned long long max_sqnum = 0;
559         void *fm_raw = ubi->fm_buf;
560
561         INIT_LIST_HEAD(&used);
562         INIT_LIST_HEAD(&free);
563         INIT_LIST_HEAD(&eba_orphans);
564         INIT_LIST_HEAD(&ai->corr);
565         INIT_LIST_HEAD(&ai->free);
566         INIT_LIST_HEAD(&ai->erase);
567         INIT_LIST_HEAD(&ai->alien);
568         ai->volumes = RB_ROOT;
569         ai->min_ec = UBI_MAX_ERASECOUNTER;
570
571         ai->aeb_slab_cache = kmem_cache_create("ubi_ainf_peb_slab",
572                                                sizeof(struct ubi_ainf_peb),
573                                                0, 0, NULL);
574         if (!ai->aeb_slab_cache) {
575                 ret = -ENOMEM;
576                 goto fail;
577         }
578
579         fmsb = (struct ubi_fm_sb *)(fm_raw);
580         ai->max_sqnum = fmsb->sqnum;
581         fm_pos += sizeof(struct ubi_fm_sb);
582         if (fm_pos >= fm_size)
583                 goto fail_bad;
584
585         fmhdr = (struct ubi_fm_hdr *)(fm_raw + fm_pos);
586         fm_pos += sizeof(*fmhdr);
587         if (fm_pos >= fm_size)
588                 goto fail_bad;
589
590         if (be32_to_cpu(fmhdr->magic) != UBI_FM_HDR_MAGIC) {
591                 ubi_err("bad fastmap header magic: 0x%x, expected: 0x%x",
592                         be32_to_cpu(fmhdr->magic), UBI_FM_HDR_MAGIC);
593                 goto fail_bad;
594         }
595
596         fmpl1 = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
597         fm_pos += sizeof(*fmpl1);
598         if (fm_pos >= fm_size)
599                 goto fail_bad;
600         if (be32_to_cpu(fmpl1->magic) != UBI_FM_POOL_MAGIC) {
601                 ubi_err("bad fastmap pool magic: 0x%x, expected: 0x%x",
602                         be32_to_cpu(fmpl1->magic), UBI_FM_POOL_MAGIC);
603                 goto fail_bad;
604         }
605
606         fmpl2 = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
607         fm_pos += sizeof(*fmpl2);
608         if (fm_pos >= fm_size)
609                 goto fail_bad;
610         if (be32_to_cpu(fmpl2->magic) != UBI_FM_POOL_MAGIC) {
611                 ubi_err("bad fastmap pool magic: 0x%x, expected: 0x%x",
612                         be32_to_cpu(fmpl2->magic), UBI_FM_POOL_MAGIC);
613                 goto fail_bad;
614         }
615
616         pool_size = be16_to_cpu(fmpl1->size);
617         wl_pool_size = be16_to_cpu(fmpl2->size);
618         fm->max_pool_size = be16_to_cpu(fmpl1->max_size);
619         fm->max_wl_pool_size = be16_to_cpu(fmpl2->max_size);
620
621         if (pool_size > UBI_FM_MAX_POOL_SIZE || pool_size < 0) {
622                 ubi_err("bad pool size: %i", pool_size);
623                 goto fail_bad;
624         }
625
626         if (wl_pool_size > UBI_FM_MAX_POOL_SIZE || wl_pool_size < 0) {
627                 ubi_err("bad WL pool size: %i", wl_pool_size);
628                 goto fail_bad;
629         }
630
631
632         if (fm->max_pool_size > UBI_FM_MAX_POOL_SIZE ||
633             fm->max_pool_size < 0) {
634                 ubi_err("bad maximal pool size: %i", fm->max_pool_size);
635                 goto fail_bad;
636         }
637
638         if (fm->max_wl_pool_size > UBI_FM_MAX_POOL_SIZE ||
639             fm->max_wl_pool_size < 0) {
640                 ubi_err("bad maximal WL pool size: %i", fm->max_wl_pool_size);
641                 goto fail_bad;
642         }
643
644         /* read EC values from free list */
645         for (i = 0; i < be32_to_cpu(fmhdr->free_peb_count); i++) {
646                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
647                 fm_pos += sizeof(*fmec);
648                 if (fm_pos >= fm_size)
649                         goto fail_bad;
650
651                 add_aeb(ai, &ai->free, be32_to_cpu(fmec->pnum),
652                         be32_to_cpu(fmec->ec), 0);
653         }
654
655         /* read EC values from used list */
656         for (i = 0; i < be32_to_cpu(fmhdr->used_peb_count); i++) {
657                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
658                 fm_pos += sizeof(*fmec);
659                 if (fm_pos >= fm_size)
660                         goto fail_bad;
661
662                 add_aeb(ai, &used, be32_to_cpu(fmec->pnum),
663                         be32_to_cpu(fmec->ec), 0);
664         }
665
666         /* read EC values from scrub list */
667         for (i = 0; i < be32_to_cpu(fmhdr->scrub_peb_count); i++) {
668                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
669                 fm_pos += sizeof(*fmec);
670                 if (fm_pos >= fm_size)
671                         goto fail_bad;
672
673                 add_aeb(ai, &used, be32_to_cpu(fmec->pnum),
674                         be32_to_cpu(fmec->ec), 1);
675         }
676
677         /* read EC values from erase list */
678         for (i = 0; i < be32_to_cpu(fmhdr->erase_peb_count); i++) {
679                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
680                 fm_pos += sizeof(*fmec);
681                 if (fm_pos >= fm_size)
682                         goto fail_bad;
683
684                 add_aeb(ai, &ai->erase, be32_to_cpu(fmec->pnum),
685                         be32_to_cpu(fmec->ec), 1);
686         }
687
688         ai->mean_ec = div_u64(ai->ec_sum, ai->ec_count);
689         ai->bad_peb_count = be32_to_cpu(fmhdr->bad_peb_count);
690
691         /* Iterate over all volumes and read their EBA table */
692         for (i = 0; i < be32_to_cpu(fmhdr->vol_count); i++) {
693                 fmvhdr = (struct ubi_fm_volhdr *)(fm_raw + fm_pos);
694                 fm_pos += sizeof(*fmvhdr);
695                 if (fm_pos >= fm_size)
696                         goto fail_bad;
697
698                 if (be32_to_cpu(fmvhdr->magic) != UBI_FM_VHDR_MAGIC) {
699                         ubi_err("bad fastmap vol header magic: 0x%x, " \
700                                 "expected: 0x%x",
701                                 be32_to_cpu(fmvhdr->magic), UBI_FM_VHDR_MAGIC);
702                         goto fail_bad;
703                 }
704
705                 av = add_vol(ai, be32_to_cpu(fmvhdr->vol_id),
706                              be32_to_cpu(fmvhdr->used_ebs),
707                              be32_to_cpu(fmvhdr->data_pad),
708                              fmvhdr->vol_type,
709                              be32_to_cpu(fmvhdr->last_eb_bytes));
710
711                 if (!av)
712                         goto fail_bad;
713
714                 ai->vols_found++;
715                 if (ai->highest_vol_id < be32_to_cpu(fmvhdr->vol_id))
716                         ai->highest_vol_id = be32_to_cpu(fmvhdr->vol_id);
717
718                 fm_eba = (struct ubi_fm_eba *)(fm_raw + fm_pos);
719                 fm_pos += sizeof(*fm_eba);
720                 fm_pos += (sizeof(__be32) * be32_to_cpu(fm_eba->reserved_pebs));
721                 if (fm_pos >= fm_size)
722                         goto fail_bad;
723
724                 if (be32_to_cpu(fm_eba->magic) != UBI_FM_EBA_MAGIC) {
725                         ubi_err("bad fastmap EBA header magic: 0x%x, " \
726                                 "expected: 0x%x",
727                                 be32_to_cpu(fm_eba->magic), UBI_FM_EBA_MAGIC);
728                         goto fail_bad;
729                 }
730
731                 for (j = 0; j < be32_to_cpu(fm_eba->reserved_pebs); j++) {
732                         int pnum = be32_to_cpu(fm_eba->pnum[j]);
733
734                         if ((int)be32_to_cpu(fm_eba->pnum[j]) < 0)
735                                 continue;
736
737                         aeb = NULL;
738                         list_for_each_entry(tmp_aeb, &used, u.list) {
739                                 if (tmp_aeb->pnum == pnum) {
740                                         aeb = tmp_aeb;
741                                         break;
742                                 }
743                         }
744
745                         /* This can happen if a PEB is already in an EBA known
746                          * by this fastmap but the PEB itself is not in the used
747                          * list.
748                          * In this case the PEB can be within the fastmap pool
749                          * or while writing the fastmap it was in the protection
750                          * queue.
751                          */
752                         if (!aeb) {
753                                 aeb = kmem_cache_alloc(ai->aeb_slab_cache,
754                                                        GFP_KERNEL);
755                                 if (!aeb) {
756                                         ret = -ENOMEM;
757
758                                         goto fail;
759                                 }
760
761                                 aeb->lnum = j;
762                                 aeb->pnum = be32_to_cpu(fm_eba->pnum[j]);
763                                 aeb->ec = -1;
764                                 aeb->scrub = aeb->copy_flag = aeb->sqnum = 0;
765                                 list_add_tail(&aeb->u.list, &eba_orphans);
766                                 continue;
767                         }
768
769                         aeb->lnum = j;
770
771                         if (av->highest_lnum <= aeb->lnum)
772                                 av->highest_lnum = aeb->lnum;
773
774                         assign_aeb_to_av(ai, aeb, av);
775
776                         dbg_bld("inserting PEB:%i (LEB %i) to vol %i",
777                                 aeb->pnum, aeb->lnum, av->vol_id);
778                 }
779
780                 ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
781                 if (!ech) {
782                         ret = -ENOMEM;
783                         goto fail;
784                 }
785
786                 list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &eba_orphans,
787                                          u.list) {
788                         int err;
789
790                         if (ubi_io_is_bad(ubi, tmp_aeb->pnum)) {
791                                 ubi_err("bad PEB in fastmap EBA orphan list");
792                                 ret = UBI_BAD_FASTMAP;
793                                 kfree(ech);
794                                 goto fail;
795                         }
796
797                         err = ubi_io_read_ec_hdr(ubi, tmp_aeb->pnum, ech, 0);
798                         if (err && err != UBI_IO_BITFLIPS) {
799                                 ubi_err("unable to read EC header! PEB:%i " \
800                                         "err:%i", tmp_aeb->pnum, err);
801                                 ret = err > 0 ? UBI_BAD_FASTMAP : err;
802                                 kfree(ech);
803
804                                 goto fail;
805                         } else if (err == UBI_IO_BITFLIPS)
806                                 tmp_aeb->scrub = 1;
807
808                         tmp_aeb->ec = be64_to_cpu(ech->ec);
809                         assign_aeb_to_av(ai, tmp_aeb, av);
810                 }
811
812                 kfree(ech);
813         }
814
815         ret = scan_pool(ubi, ai, fmpl1->pebs, pool_size, &max_sqnum,
816                         &eba_orphans, &free);
817         if (ret)
818                 goto fail;
819
820         ret = scan_pool(ubi, ai, fmpl2->pebs, wl_pool_size, &max_sqnum,
821                         &eba_orphans, &free);
822         if (ret)
823                 goto fail;
824
825         if (max_sqnum > ai->max_sqnum)
826                 ai->max_sqnum = max_sqnum;
827
828         list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &free, u.list)
829                 list_move_tail(&tmp_aeb->u.list, &ai->free);
830
831         ubi_assert(list_empty(&used));
832         ubi_assert(list_empty(&eba_orphans));
833         ubi_assert(list_empty(&free));
834
835         /*
836          * If fastmap is leaking PEBs (must not happen), raise a
837          * fat warning and fall back to scanning mode.
838          * We do this here because in ubi_wl_init() it's too late
839          * and we cannot fall back to scanning.
840          */
841         if (WARN_ON(count_fastmap_pebs(ai) != ubi->peb_count -
842                     ai->bad_peb_count - fm->used_blocks))
843                 goto fail_bad;
844
845         return 0;
846
847 fail_bad:
848         ret = UBI_BAD_FASTMAP;
849 fail:
850         list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &used, u.list) {
851                 list_del(&tmp_aeb->u.list);
852                 kmem_cache_free(ai->aeb_slab_cache, tmp_aeb);
853         }
854         list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &eba_orphans, u.list) {
855                 list_del(&tmp_aeb->u.list);
856                 kmem_cache_free(ai->aeb_slab_cache, tmp_aeb);
857         }
858         list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &free, u.list) {
859                 list_del(&tmp_aeb->u.list);
860                 kmem_cache_free(ai->aeb_slab_cache, tmp_aeb);
861         }
862
863         return ret;
864 }
865
866 /**
867  * ubi_scan_fastmap - scan the fastmap.
868  * @ubi: UBI device object
869  * @ai: UBI attach info to be filled
870  * @fm_anchor: The fastmap starts at this PEB
871  *
872  * Returns 0 on success, UBI_NO_FASTMAP if no fastmap was found,
873  * UBI_BAD_FASTMAP if one was found but is not usable.
874  * < 0 indicates an internal error.
875  */
876 int ubi_scan_fastmap(struct ubi_device *ubi, struct ubi_attach_info *ai,
877                      int fm_anchor)
878 {
879         struct ubi_fm_sb *fmsb, *fmsb2;
880         struct ubi_vid_hdr *vh;
881         struct ubi_ec_hdr *ech;
882         struct ubi_fastmap_layout *fm;
883         int i, used_blocks, pnum, ret = 0;
884         size_t fm_size;
885         __be32 crc, tmp_crc;
886         unsigned long long sqnum = 0;
887
888         mutex_lock(&ubi->fm_mutex);
889         memset(ubi->fm_buf, 0, ubi->fm_size);
890
891         fmsb = kmalloc(sizeof(*fmsb), GFP_KERNEL);
892         if (!fmsb) {
893                 ret = -ENOMEM;
894                 goto out;
895         }
896
897         fm = kzalloc(sizeof(*fm), GFP_KERNEL);
898         if (!fm) {
899                 ret = -ENOMEM;
900                 kfree(fmsb);
901                 goto out;
902         }
903
904         ret = ubi_io_read(ubi, fmsb, fm_anchor, ubi->leb_start, sizeof(*fmsb));
905         if (ret && ret != UBI_IO_BITFLIPS)
906                 goto free_fm_sb;
907         else if (ret == UBI_IO_BITFLIPS)
908                 fm->to_be_tortured[0] = 1;
909
910         if (be32_to_cpu(fmsb->magic) != UBI_FM_SB_MAGIC) {
911                 ubi_err("bad super block magic: 0x%x, expected: 0x%x",
912                         be32_to_cpu(fmsb->magic), UBI_FM_SB_MAGIC);
913                 ret = UBI_BAD_FASTMAP;
914                 goto free_fm_sb;
915         }
916
917         if (fmsb->version != UBI_FM_FMT_VERSION) {
918                 ubi_err("bad fastmap version: %i, expected: %i",
919                         fmsb->version, UBI_FM_FMT_VERSION);
920                 ret = UBI_BAD_FASTMAP;
921                 goto free_fm_sb;
922         }
923
924         used_blocks = be32_to_cpu(fmsb->used_blocks);
925         if (used_blocks > UBI_FM_MAX_BLOCKS || used_blocks < 1) {
926                 ubi_err("number of fastmap blocks is invalid: %i", used_blocks);
927                 ret = UBI_BAD_FASTMAP;
928                 goto free_fm_sb;
929         }
930
931         fm_size = ubi->leb_size * used_blocks;
932         if (fm_size != ubi->fm_size) {
933                 ubi_err("bad fastmap size: %zi, expected: %zi", fm_size,
934                         ubi->fm_size);
935                 ret = UBI_BAD_FASTMAP;
936                 goto free_fm_sb;
937         }
938
939         ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
940         if (!ech) {
941                 ret = -ENOMEM;
942                 goto free_fm_sb;
943         }
944
945         vh = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
946         if (!vh) {
947                 ret = -ENOMEM;
948                 goto free_hdr;
949         }
950
951         for (i = 0; i < used_blocks; i++) {
952                 int image_seq;
953
954                 pnum = be32_to_cpu(fmsb->block_loc[i]);
955
956                 if (ubi_io_is_bad(ubi, pnum)) {
957                         ret = UBI_BAD_FASTMAP;
958                         goto free_hdr;
959                 }
960
961                 ret = ubi_io_read_ec_hdr(ubi, pnum, ech, 0);
962                 if (ret && ret != UBI_IO_BITFLIPS) {
963                         ubi_err("unable to read fastmap block# %i EC (PEB: %i)",
964                                 i, pnum);
965                         if (ret > 0)
966                                 ret = UBI_BAD_FASTMAP;
967                         goto free_hdr;
968                 } else if (ret == UBI_IO_BITFLIPS)
969                         fm->to_be_tortured[i] = 1;
970
971                 image_seq = be32_to_cpu(ech->image_seq);
972                 if (!ubi->image_seq)
973                         ubi->image_seq = image_seq;
974
975                 /*
976                  * Older UBI implementations have image_seq set to zero, so
977                  * we shouldn't fail if image_seq == 0.
978                  */
979                 if (image_seq && (image_seq != ubi->image_seq)) {
980                         ubi_err("wrong image seq:%d instead of %d",
981                                 be32_to_cpu(ech->image_seq), ubi->image_seq);
982                         ret = UBI_BAD_FASTMAP;
983                         goto free_hdr;
984                 }
985
986                 ret = ubi_io_read_vid_hdr(ubi, pnum, vh, 0);
987                 if (ret && ret != UBI_IO_BITFLIPS) {
988                         ubi_err("unable to read fastmap block# %i (PEB: %i)",
989                                 i, pnum);
990                         goto free_hdr;
991                 }
992
993                 if (i == 0) {
994                         if (be32_to_cpu(vh->vol_id) != UBI_FM_SB_VOLUME_ID) {
995                                 ubi_err("bad fastmap anchor vol_id: 0x%x," \
996                                         " expected: 0x%x",
997                                         be32_to_cpu(vh->vol_id),
998                                         UBI_FM_SB_VOLUME_ID);
999                                 ret = UBI_BAD_FASTMAP;
1000                                 goto free_hdr;
1001                         }
1002                 } else {
1003                         if (be32_to_cpu(vh->vol_id) != UBI_FM_DATA_VOLUME_ID) {
1004                                 ubi_err("bad fastmap data vol_id: 0x%x," \
1005                                         " expected: 0x%x",
1006                                         be32_to_cpu(vh->vol_id),
1007                                         UBI_FM_DATA_VOLUME_ID);
1008                                 ret = UBI_BAD_FASTMAP;
1009                                 goto free_hdr;
1010                         }
1011                 }
1012
1013                 if (sqnum < be64_to_cpu(vh->sqnum))
1014                         sqnum = be64_to_cpu(vh->sqnum);
1015
1016                 ret = ubi_io_read(ubi, ubi->fm_buf + (ubi->leb_size * i), pnum,
1017                                   ubi->leb_start, ubi->leb_size);
1018                 if (ret && ret != UBI_IO_BITFLIPS) {
1019                         ubi_err("unable to read fastmap block# %i (PEB: %i, " \
1020                                 "err: %i)", i, pnum, ret);
1021                         goto free_hdr;
1022                 }
1023         }
1024
1025         kfree(fmsb);
1026         fmsb = NULL;
1027
1028         fmsb2 = (struct ubi_fm_sb *)(ubi->fm_buf);
1029         tmp_crc = be32_to_cpu(fmsb2->data_crc);
1030         fmsb2->data_crc = 0;
1031         crc = crc32(UBI_CRC32_INIT, ubi->fm_buf, fm_size);
1032         if (crc != tmp_crc) {
1033                 ubi_err("fastmap data CRC is invalid");
1034                 ubi_err("CRC should be: 0x%x, calc: 0x%x", tmp_crc, crc);
1035                 ret = UBI_BAD_FASTMAP;
1036                 goto free_hdr;
1037         }
1038
1039         fmsb2->sqnum = sqnum;
1040
1041         fm->used_blocks = used_blocks;
1042
1043         ret = ubi_attach_fastmap(ubi, ai, fm);
1044         if (ret) {
1045                 if (ret > 0)
1046                         ret = UBI_BAD_FASTMAP;
1047                 goto free_hdr;
1048         }
1049
1050         for (i = 0; i < used_blocks; i++) {
1051                 struct ubi_wl_entry *e;
1052
1053                 e = kmem_cache_alloc(ubi_wl_entry_slab, GFP_KERNEL);
1054                 if (!e) {
1055                         while (i--)
1056                                 kfree(fm->e[i]);
1057
1058                         ret = -ENOMEM;
1059                         goto free_hdr;
1060                 }
1061
1062                 e->pnum = be32_to_cpu(fmsb2->block_loc[i]);
1063                 e->ec = be32_to_cpu(fmsb2->block_ec[i]);
1064                 fm->e[i] = e;
1065         }
1066
1067         ubi->fm = fm;
1068         ubi->fm_pool.max_size = ubi->fm->max_pool_size;
1069         ubi->fm_wl_pool.max_size = ubi->fm->max_wl_pool_size;
1070         ubi_msg("attached by fastmap");
1071         ubi_msg("fastmap pool size: %d", ubi->fm_pool.max_size);
1072         ubi_msg("fastmap WL pool size: %d", ubi->fm_wl_pool.max_size);
1073         ubi->fm_disabled = 0;
1074
1075         ubi_free_vid_hdr(ubi, vh);
1076         kfree(ech);
1077 out:
1078         mutex_unlock(&ubi->fm_mutex);
1079         if (ret == UBI_BAD_FASTMAP)
1080                 ubi_err("Attach by fastmap failed, doing a full scan!");
1081         return ret;
1082
1083 free_hdr:
1084         ubi_free_vid_hdr(ubi, vh);
1085         kfree(ech);
1086 free_fm_sb:
1087         kfree(fmsb);
1088         kfree(fm);
1089         goto out;
1090 }
1091
1092 /**
1093  * ubi_write_fastmap - writes a fastmap.
1094  * @ubi: UBI device object
1095  * @new_fm: the to be written fastmap
1096  *
1097  * Returns 0 on success, < 0 indicates an internal error.
1098  */
1099 static int ubi_write_fastmap(struct ubi_device *ubi,
1100                              struct ubi_fastmap_layout *new_fm)
1101 {
1102         size_t fm_pos = 0;
1103         void *fm_raw;
1104         struct ubi_fm_sb *fmsb;
1105         struct ubi_fm_hdr *fmh;
1106         struct ubi_fm_scan_pool *fmpl1, *fmpl2;
1107         struct ubi_fm_ec *fec;
1108         struct ubi_fm_volhdr *fvh;
1109         struct ubi_fm_eba *feba;
1110         struct rb_node *node;
1111         struct ubi_wl_entry *wl_e;
1112         struct ubi_volume *vol;
1113         struct ubi_vid_hdr *avhdr, *dvhdr;
1114         struct ubi_work *ubi_wrk;
1115         int ret, i, j, free_peb_count, used_peb_count, vol_count;
1116         int scrub_peb_count, erase_peb_count;
1117
1118         fm_raw = ubi->fm_buf;
1119         memset(ubi->fm_buf, 0, ubi->fm_size);
1120
1121         avhdr = new_fm_vhdr(ubi, UBI_FM_SB_VOLUME_ID);
1122         if (!avhdr) {
1123                 ret = -ENOMEM;
1124                 goto out;
1125         }
1126
1127         dvhdr = new_fm_vhdr(ubi, UBI_FM_DATA_VOLUME_ID);
1128         if (!dvhdr) {
1129                 ret = -ENOMEM;
1130                 goto out_kfree;
1131         }
1132
1133         spin_lock(&ubi->volumes_lock);
1134         spin_lock(&ubi->wl_lock);
1135
1136         fmsb = (struct ubi_fm_sb *)fm_raw;
1137         fm_pos += sizeof(*fmsb);
1138         ubi_assert(fm_pos <= ubi->fm_size);
1139
1140         fmh = (struct ubi_fm_hdr *)(fm_raw + fm_pos);
1141         fm_pos += sizeof(*fmh);
1142         ubi_assert(fm_pos <= ubi->fm_size);
1143
1144         fmsb->magic = cpu_to_be32(UBI_FM_SB_MAGIC);
1145         fmsb->version = UBI_FM_FMT_VERSION;
1146         fmsb->used_blocks = cpu_to_be32(new_fm->used_blocks);
1147         /* the max sqnum will be filled in while *reading* the fastmap */
1148         fmsb->sqnum = 0;
1149
1150         fmh->magic = cpu_to_be32(UBI_FM_HDR_MAGIC);
1151         free_peb_count = 0;
1152         used_peb_count = 0;
1153         scrub_peb_count = 0;
1154         erase_peb_count = 0;
1155         vol_count = 0;
1156
1157         fmpl1 = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
1158         fm_pos += sizeof(*fmpl1);
1159         fmpl1->magic = cpu_to_be32(UBI_FM_POOL_MAGIC);
1160         fmpl1->size = cpu_to_be16(ubi->fm_pool.size);
1161         fmpl1->max_size = cpu_to_be16(ubi->fm_pool.max_size);
1162
1163         for (i = 0; i < ubi->fm_pool.size; i++)
1164                 fmpl1->pebs[i] = cpu_to_be32(ubi->fm_pool.pebs[i]);
1165
1166         fmpl2 = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
1167         fm_pos += sizeof(*fmpl2);
1168         fmpl2->magic = cpu_to_be32(UBI_FM_POOL_MAGIC);
1169         fmpl2->size = cpu_to_be16(ubi->fm_wl_pool.size);
1170         fmpl2->max_size = cpu_to_be16(ubi->fm_wl_pool.max_size);
1171
1172         for (i = 0; i < ubi->fm_wl_pool.size; i++)
1173                 fmpl2->pebs[i] = cpu_to_be32(ubi->fm_wl_pool.pebs[i]);
1174
1175         for (node = rb_first(&ubi->free); node; node = rb_next(node)) {
1176                 wl_e = rb_entry(node, struct ubi_wl_entry, u.rb);
1177                 fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1178
1179                 fec->pnum = cpu_to_be32(wl_e->pnum);
1180                 fec->ec = cpu_to_be32(wl_e->ec);
1181
1182                 free_peb_count++;
1183                 fm_pos += sizeof(*fec);
1184                 ubi_assert(fm_pos <= ubi->fm_size);
1185         }
1186         fmh->free_peb_count = cpu_to_be32(free_peb_count);
1187
1188         for (node = rb_first(&ubi->used); node; node = rb_next(node)) {
1189                 wl_e = rb_entry(node, struct ubi_wl_entry, u.rb);
1190                 fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1191
1192                 fec->pnum = cpu_to_be32(wl_e->pnum);
1193                 fec->ec = cpu_to_be32(wl_e->ec);
1194
1195                 used_peb_count++;
1196                 fm_pos += sizeof(*fec);
1197                 ubi_assert(fm_pos <= ubi->fm_size);
1198         }
1199         fmh->used_peb_count = cpu_to_be32(used_peb_count);
1200
1201         for (node = rb_first(&ubi->scrub); node; node = rb_next(node)) {
1202                 wl_e = rb_entry(node, struct ubi_wl_entry, u.rb);
1203                 fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1204
1205                 fec->pnum = cpu_to_be32(wl_e->pnum);
1206                 fec->ec = cpu_to_be32(wl_e->ec);
1207
1208                 scrub_peb_count++;
1209                 fm_pos += sizeof(*fec);
1210                 ubi_assert(fm_pos <= ubi->fm_size);
1211         }
1212         fmh->scrub_peb_count = cpu_to_be32(scrub_peb_count);
1213
1214
1215         list_for_each_entry(ubi_wrk, &ubi->works, list) {
1216                 if (ubi_is_erase_work(ubi_wrk)) {
1217                         wl_e = ubi_wrk->e;
1218                         ubi_assert(wl_e);
1219
1220                         fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1221
1222                         fec->pnum = cpu_to_be32(wl_e->pnum);
1223                         fec->ec = cpu_to_be32(wl_e->ec);
1224
1225                         erase_peb_count++;
1226                         fm_pos += sizeof(*fec);
1227                         ubi_assert(fm_pos <= ubi->fm_size);
1228                 }
1229         }
1230         fmh->erase_peb_count = cpu_to_be32(erase_peb_count);
1231
1232         for (i = 0; i < UBI_MAX_VOLUMES + UBI_INT_VOL_COUNT; i++) {
1233                 vol = ubi->volumes[i];
1234
1235                 if (!vol)
1236                         continue;
1237
1238                 vol_count++;
1239
1240                 fvh = (struct ubi_fm_volhdr *)(fm_raw + fm_pos);
1241                 fm_pos += sizeof(*fvh);
1242                 ubi_assert(fm_pos <= ubi->fm_size);
1243
1244                 fvh->magic = cpu_to_be32(UBI_FM_VHDR_MAGIC);
1245                 fvh->vol_id = cpu_to_be32(vol->vol_id);
1246                 fvh->vol_type = vol->vol_type;
1247                 fvh->used_ebs = cpu_to_be32(vol->used_ebs);
1248                 fvh->data_pad = cpu_to_be32(vol->data_pad);
1249                 fvh->last_eb_bytes = cpu_to_be32(vol->last_eb_bytes);
1250
1251                 ubi_assert(vol->vol_type == UBI_DYNAMIC_VOLUME ||
1252                         vol->vol_type == UBI_STATIC_VOLUME);
1253
1254                 feba = (struct ubi_fm_eba *)(fm_raw + fm_pos);
1255                 fm_pos += sizeof(*feba) + (sizeof(__be32) * vol->reserved_pebs);
1256                 ubi_assert(fm_pos <= ubi->fm_size);
1257
1258                 for (j = 0; j < vol->reserved_pebs; j++)
1259                         feba->pnum[j] = cpu_to_be32(vol->eba_tbl[j]);
1260
1261                 feba->reserved_pebs = cpu_to_be32(j);
1262                 feba->magic = cpu_to_be32(UBI_FM_EBA_MAGIC);
1263         }
1264         fmh->vol_count = cpu_to_be32(vol_count);
1265         fmh->bad_peb_count = cpu_to_be32(ubi->bad_peb_count);
1266
1267         avhdr->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
1268         avhdr->lnum = 0;
1269
1270         spin_unlock(&ubi->wl_lock);
1271         spin_unlock(&ubi->volumes_lock);
1272
1273         dbg_bld("writing fastmap SB to PEB %i", new_fm->e[0]->pnum);
1274         ret = ubi_io_write_vid_hdr(ubi, new_fm->e[0]->pnum, avhdr);
1275         if (ret) {
1276                 ubi_err("unable to write vid_hdr to fastmap SB!");
1277                 goto out_kfree;
1278         }
1279
1280         for (i = 0; i < new_fm->used_blocks; i++) {
1281                 fmsb->block_loc[i] = cpu_to_be32(new_fm->e[i]->pnum);
1282                 fmsb->block_ec[i] = cpu_to_be32(new_fm->e[i]->ec);
1283         }
1284
1285         fmsb->data_crc = 0;
1286         fmsb->data_crc = cpu_to_be32(crc32(UBI_CRC32_INIT, fm_raw,
1287                                            ubi->fm_size));
1288
1289         for (i = 1; i < new_fm->used_blocks; i++) {
1290                 dvhdr->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
1291                 dvhdr->lnum = cpu_to_be32(i);
1292                 dbg_bld("writing fastmap data to PEB %i sqnum %llu",
1293                         new_fm->e[i]->pnum, be64_to_cpu(dvhdr->sqnum));
1294                 ret = ubi_io_write_vid_hdr(ubi, new_fm->e[i]->pnum, dvhdr);
1295                 if (ret) {
1296                         ubi_err("unable to write vid_hdr to PEB %i!",
1297                                 new_fm->e[i]->pnum);
1298                         goto out_kfree;
1299                 }
1300         }
1301
1302         for (i = 0; i < new_fm->used_blocks; i++) {
1303                 ret = ubi_io_write(ubi, fm_raw + (i * ubi->leb_size),
1304                         new_fm->e[i]->pnum, ubi->leb_start, ubi->leb_size);
1305                 if (ret) {
1306                         ubi_err("unable to write fastmap to PEB %i!",
1307                                 new_fm->e[i]->pnum);
1308                         goto out_kfree;
1309                 }
1310         }
1311
1312         ubi_assert(new_fm);
1313         ubi->fm = new_fm;
1314
1315         dbg_bld("fastmap written!");
1316
1317 out_kfree:
1318         ubi_free_vid_hdr(ubi, avhdr);
1319         ubi_free_vid_hdr(ubi, dvhdr);
1320 out:
1321         return ret;
1322 }
1323
1324 /**
1325  * erase_block - Manually erase a PEB.
1326  * @ubi: UBI device object
1327  * @pnum: PEB to be erased
1328  *
1329  * Returns the new EC value on success, < 0 indicates an internal error.
1330  */
1331 static int erase_block(struct ubi_device *ubi, int pnum)
1332 {
1333         int ret;
1334         struct ubi_ec_hdr *ec_hdr;
1335         long long ec;
1336
1337         ec_hdr = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
1338         if (!ec_hdr)
1339                 return -ENOMEM;
1340
1341         ret = ubi_io_read_ec_hdr(ubi, pnum, ec_hdr, 0);
1342         if (ret < 0)
1343                 goto out;
1344         else if (ret && ret != UBI_IO_BITFLIPS) {
1345                 ret = -EINVAL;
1346                 goto out;
1347         }
1348
1349         ret = ubi_io_sync_erase(ubi, pnum, 0);
1350         if (ret < 0)
1351                 goto out;
1352
1353         ec = be64_to_cpu(ec_hdr->ec);
1354         ec += ret;
1355         if (ec > UBI_MAX_ERASECOUNTER) {
1356                 ret = -EINVAL;
1357                 goto out;
1358         }
1359
1360         ec_hdr->ec = cpu_to_be64(ec);
1361         ret = ubi_io_write_ec_hdr(ubi, pnum, ec_hdr);
1362         if (ret < 0)
1363                 goto out;
1364
1365         ret = ec;
1366 out:
1367         kfree(ec_hdr);
1368         return ret;
1369 }
1370
1371 /**
1372  * invalidate_fastmap - destroys a fastmap.
1373  * @ubi: UBI device object
1374  * @fm: the fastmap to be destroyed
1375  *
1376  * Returns 0 on success, < 0 indicates an internal error.
1377  */
1378 static int invalidate_fastmap(struct ubi_device *ubi,
1379                               struct ubi_fastmap_layout *fm)
1380 {
1381         int ret;
1382         struct ubi_vid_hdr *vh;
1383
1384         ret = erase_block(ubi, fm->e[0]->pnum);
1385         if (ret < 0)
1386                 return ret;
1387
1388         vh = new_fm_vhdr(ubi, UBI_FM_SB_VOLUME_ID);
1389         if (!vh)
1390                 return -ENOMEM;
1391
1392         /* deleting the current fastmap SB is not enough, an old SB may exist,
1393          * so create a (corrupted) SB such that fastmap will find it and fall
1394          * back to scanning mode in any case */
1395         vh->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
1396         ret = ubi_io_write_vid_hdr(ubi, fm->e[0]->pnum, vh);
1397
1398         return ret;
1399 }
1400
1401 /**
1402  * ubi_update_fastmap - will be called by UBI if a volume changes or
1403  * a fastmap pool becomes full.
1404  * @ubi: UBI device object
1405  *
1406  * Returns 0 on success, < 0 indicates an internal error.
1407  */
1408 int ubi_update_fastmap(struct ubi_device *ubi)
1409 {
1410         int ret, i;
1411         struct ubi_fastmap_layout *new_fm, *old_fm;
1412         struct ubi_wl_entry *tmp_e;
1413
1414         mutex_lock(&ubi->fm_mutex);
1415
1416         ubi_refill_pools(ubi);
1417
1418         if (ubi->ro_mode || ubi->fm_disabled) {
1419                 mutex_unlock(&ubi->fm_mutex);
1420                 return 0;
1421         }
1422
1423         ret = ubi_ensure_anchor_pebs(ubi);
1424         if (ret) {
1425                 mutex_unlock(&ubi->fm_mutex);
1426                 return ret;
1427         }
1428
1429         new_fm = kzalloc(sizeof(*new_fm), GFP_KERNEL);
1430         if (!new_fm) {
1431                 mutex_unlock(&ubi->fm_mutex);
1432                 return -ENOMEM;
1433         }
1434
1435         new_fm->used_blocks = ubi->fm_size / ubi->leb_size;
1436
1437         for (i = 0; i < new_fm->used_blocks; i++) {
1438                 new_fm->e[i] = kmem_cache_alloc(ubi_wl_entry_slab, GFP_KERNEL);
1439                 if (!new_fm->e[i]) {
1440                         while (i--)
1441                                 kfree(new_fm->e[i]);
1442
1443                         kfree(new_fm);
1444                         mutex_unlock(&ubi->fm_mutex);
1445                         return -ENOMEM;
1446                 }
1447         }
1448
1449         old_fm = ubi->fm;
1450         ubi->fm = NULL;
1451
1452         if (new_fm->used_blocks > UBI_FM_MAX_BLOCKS) {
1453                 ubi_err("fastmap too large");
1454                 ret = -ENOSPC;
1455                 goto err;
1456         }
1457
1458         for (i = 1; i < new_fm->used_blocks; i++) {
1459                 spin_lock(&ubi->wl_lock);
1460                 tmp_e = ubi_wl_get_fm_peb(ubi, 0);
1461                 spin_unlock(&ubi->wl_lock);
1462
1463                 if (!tmp_e && !old_fm) {
1464                         int j;
1465                         ubi_err("could not get any free erase block");
1466
1467                         for (j = 1; j < i; j++)
1468                                 ubi_wl_put_fm_peb(ubi, new_fm->e[j], j, 0);
1469
1470                         ret = -ENOSPC;
1471                         goto err;
1472                 } else if (!tmp_e && old_fm) {
1473                         ret = erase_block(ubi, old_fm->e[i]->pnum);
1474                         if (ret < 0) {
1475                                 int j;
1476
1477                                 for (j = 1; j < i; j++)
1478                                         ubi_wl_put_fm_peb(ubi, new_fm->e[j],
1479                                                           j, 0);
1480
1481                                 ubi_err("could not erase old fastmap PEB");
1482                                 goto err;
1483                         }
1484
1485                         new_fm->e[i]->pnum = old_fm->e[i]->pnum;
1486                         new_fm->e[i]->ec = old_fm->e[i]->ec;
1487                 } else {
1488                         new_fm->e[i]->pnum = tmp_e->pnum;
1489                         new_fm->e[i]->ec = tmp_e->ec;
1490
1491                         if (old_fm)
1492                                 ubi_wl_put_fm_peb(ubi, old_fm->e[i], i,
1493                                                   old_fm->to_be_tortured[i]);
1494                 }
1495         }
1496
1497         spin_lock(&ubi->wl_lock);
1498         tmp_e = ubi_wl_get_fm_peb(ubi, 1);
1499         spin_unlock(&ubi->wl_lock);
1500
1501         if (old_fm) {
1502                 /* no fresh anchor PEB was found, reuse the old one */
1503                 if (!tmp_e) {
1504                         ret = erase_block(ubi, old_fm->e[0]->pnum);
1505                         if (ret < 0) {
1506                                 int i;
1507                                 ubi_err("could not erase old anchor PEB");
1508
1509                                 for (i = 1; i < new_fm->used_blocks; i++)
1510                                         ubi_wl_put_fm_peb(ubi, new_fm->e[i],
1511                                                           i, 0);
1512                                 goto err;
1513                         }
1514
1515                         new_fm->e[0]->pnum = old_fm->e[0]->pnum;
1516                         new_fm->e[0]->ec = ret;
1517                 } else {
1518                         /* we've got a new anchor PEB, return the old one */
1519                         ubi_wl_put_fm_peb(ubi, old_fm->e[0], 0,
1520                                           old_fm->to_be_tortured[0]);
1521
1522                         new_fm->e[0]->pnum = tmp_e->pnum;
1523                         new_fm->e[0]->ec = tmp_e->ec;
1524                 }
1525         } else {
1526                 if (!tmp_e) {
1527                         int i;
1528                         ubi_err("could not find any anchor PEB");
1529
1530                         for (i = 1; i < new_fm->used_blocks; i++)
1531                                 ubi_wl_put_fm_peb(ubi, new_fm->e[i], i, 0);
1532
1533                         ret = -ENOSPC;
1534                         goto err;
1535                 }
1536
1537                 new_fm->e[0]->pnum = tmp_e->pnum;
1538                 new_fm->e[0]->ec = tmp_e->ec;
1539         }
1540
1541         down_write(&ubi->work_sem);
1542         down_write(&ubi->fm_sem);
1543         ret = ubi_write_fastmap(ubi, new_fm);
1544         up_write(&ubi->fm_sem);
1545         up_write(&ubi->work_sem);
1546
1547         if (ret)
1548                 goto err;
1549
1550 out_unlock:
1551         mutex_unlock(&ubi->fm_mutex);
1552         kfree(old_fm);
1553         return ret;
1554
1555 err:
1556         kfree(new_fm);
1557
1558         ubi_warn("Unable to write new fastmap, err=%i", ret);
1559
1560         ret = 0;
1561         if (old_fm) {
1562                 ret = invalidate_fastmap(ubi, old_fm);
1563                 if (ret < 0)
1564                         ubi_err("Unable to invalidiate current fastmap!");
1565                 else if (ret)
1566                         ret = 0;
1567         }
1568         goto out_unlock;
1569 }