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1 /*
2  * Copyright (c) 2012 Linutronix GmbH
3  * Copyright (c) 2014 sigma star gmbh
4  * Author: Richard Weinberger <richard@nod.at>
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; version 2.
9  *
10  * This program is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
13  * the GNU General Public License for more details.
14  *
15  */
16 
17 #include <linux/crc32.h>
18 #include "ubi.h"
19 
20 /**
21  * init_seen - allocate memory for used for debugging.
22  * @ubi: UBI device description object
23  */
init_seen(struct ubi_device * ubi)24 static inline int *init_seen(struct ubi_device *ubi)
25 {
26 	int *ret;
27 
28 	if (!ubi_dbg_chk_fastmap(ubi))
29 		return NULL;
30 
31 	ret = kcalloc(ubi->peb_count, sizeof(int), GFP_KERNEL);
32 	if (!ret)
33 		return ERR_PTR(-ENOMEM);
34 
35 	return ret;
36 }
37 
38 /**
39  * free_seen - free the seen logic integer array.
40  * @seen: integer array of @ubi->peb_count size
41  */
free_seen(int * seen)42 static inline void free_seen(int *seen)
43 {
44 	kfree(seen);
45 }
46 
47 /**
48  * set_seen - mark a PEB as seen.
49  * @ubi: UBI device description object
50  * @pnum: The PEB to be makred as seen
51  * @seen: integer array of @ubi->peb_count size
52  */
set_seen(struct ubi_device * ubi,int pnum,int * seen)53 static inline void set_seen(struct ubi_device *ubi, int pnum, int *seen)
54 {
55 	if (!ubi_dbg_chk_fastmap(ubi) || !seen)
56 		return;
57 
58 	seen[pnum] = 1;
59 }
60 
61 /**
62  * self_check_seen - check whether all PEB have been seen by fastmap.
63  * @ubi: UBI device description object
64  * @seen: integer array of @ubi->peb_count size
65  */
self_check_seen(struct ubi_device * ubi,int * seen)66 static int self_check_seen(struct ubi_device *ubi, int *seen)
67 {
68 	int pnum, ret = 0;
69 
70 	if (!ubi_dbg_chk_fastmap(ubi) || !seen)
71 		return 0;
72 
73 	for (pnum = 0; pnum < ubi->peb_count; pnum++) {
74 		if (!seen[pnum] && ubi->lookuptbl[pnum]) {
75 			ubi_err(ubi, "self-check failed for PEB %d, fastmap didn't see it", pnum);
76 			ret = -EINVAL;
77 		}
78 	}
79 
80 	return ret;
81 }
82 
83 /**
84  * ubi_calc_fm_size - calculates the fastmap size in bytes for an UBI device.
85  * @ubi: UBI device description object
86  */
ubi_calc_fm_size(struct ubi_device * ubi)87 size_t ubi_calc_fm_size(struct ubi_device *ubi)
88 {
89 	size_t size;
90 
91 	size = sizeof(struct ubi_fm_sb) +
92 		sizeof(struct ubi_fm_hdr) +
93 		sizeof(struct ubi_fm_scan_pool) +
94 		sizeof(struct ubi_fm_scan_pool) +
95 		(ubi->peb_count * sizeof(struct ubi_fm_ec)) +
96 		(sizeof(struct ubi_fm_eba) +
97 		(ubi->peb_count * sizeof(__be32))) +
98 		sizeof(struct ubi_fm_volhdr) * UBI_MAX_VOLUMES;
99 	return roundup(size, ubi->leb_size);
100 }
101 
102 
103 /**
104  * new_fm_vhdr - allocate a new volume header for fastmap usage.
105  * @ubi: UBI device description object
106  * @vol_id: the VID of the new header
107  *
108  * Returns a new struct ubi_vid_hdr on success.
109  * NULL indicates out of memory.
110  */
new_fm_vhdr(struct ubi_device * ubi,int vol_id)111 static struct ubi_vid_hdr *new_fm_vhdr(struct ubi_device *ubi, int vol_id)
112 {
113 	struct ubi_vid_hdr *new;
114 
115 	new = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
116 	if (!new)
117 		goto out;
118 
119 	new->vol_type = UBI_VID_DYNAMIC;
120 	new->vol_id = cpu_to_be32(vol_id);
121 
122 	/* UBI implementations without fastmap support have to delete the
123 	 * fastmap.
124 	 */
125 	new->compat = UBI_COMPAT_DELETE;
126 
127 out:
128 	return new;
129 }
130 
131 /**
132  * add_aeb - create and add a attach erase block to a given list.
133  * @ai: UBI attach info object
134  * @list: the target list
135  * @pnum: PEB number of the new attach erase block
136  * @ec: erease counter of the new LEB
137  * @scrub: scrub this PEB after attaching
138  *
139  * Returns 0 on success, < 0 indicates an internal error.
140  */
add_aeb(struct ubi_attach_info * ai,struct list_head * list,int pnum,int ec,int scrub)141 static int add_aeb(struct ubi_attach_info *ai, struct list_head *list,
142 		   int pnum, int ec, int scrub)
143 {
144 	struct ubi_ainf_peb *aeb;
145 
146 	aeb = kmem_cache_alloc(ai->aeb_slab_cache, GFP_KERNEL);
147 	if (!aeb)
148 		return -ENOMEM;
149 
150 	aeb->pnum = pnum;
151 	aeb->ec = ec;
152 	aeb->lnum = -1;
153 	aeb->scrub = scrub;
154 	aeb->copy_flag = aeb->sqnum = 0;
155 
156 	ai->ec_sum += aeb->ec;
157 	ai->ec_count++;
158 
159 	if (ai->max_ec < aeb->ec)
160 		ai->max_ec = aeb->ec;
161 
162 	if (ai->min_ec > aeb->ec)
163 		ai->min_ec = aeb->ec;
164 
165 	list_add_tail(&aeb->u.list, list);
166 
167 	return 0;
168 }
169 
170 /**
171  * add_vol - create and add a new volume to ubi_attach_info.
172  * @ai: ubi_attach_info object
173  * @vol_id: VID of the new volume
174  * @used_ebs: number of used EBS
175  * @data_pad: data padding value of the new volume
176  * @vol_type: volume type
177  * @last_eb_bytes: number of bytes in the last LEB
178  *
179  * Returns the new struct ubi_ainf_volume on success.
180  * NULL indicates an error.
181  */
add_vol(struct ubi_attach_info * ai,int vol_id,int used_ebs,int data_pad,u8 vol_type,int last_eb_bytes)182 static struct ubi_ainf_volume *add_vol(struct ubi_attach_info *ai, int vol_id,
183 				       int used_ebs, int data_pad, u8 vol_type,
184 				       int last_eb_bytes)
185 {
186 	struct ubi_ainf_volume *av;
187 	struct rb_node **p = &ai->volumes.rb_node, *parent = NULL;
188 
189 	while (*p) {
190 		parent = *p;
191 		av = rb_entry(parent, struct ubi_ainf_volume, rb);
192 
193 		if (vol_id > av->vol_id)
194 			p = &(*p)->rb_left;
195 		else if (vol_id < av->vol_id)
196 			p = &(*p)->rb_right;
197 		else
198 			return ERR_PTR(-EINVAL);
199 	}
200 
201 	av = kmalloc(sizeof(struct ubi_ainf_volume), GFP_KERNEL);
202 	if (!av)
203 		goto out;
204 
205 	av->highest_lnum = av->leb_count = av->used_ebs = 0;
206 	av->vol_id = vol_id;
207 	av->data_pad = data_pad;
208 	av->last_data_size = last_eb_bytes;
209 	av->compat = 0;
210 	av->vol_type = vol_type;
211 	av->root = RB_ROOT;
212 	if (av->vol_type == UBI_STATIC_VOLUME)
213 		av->used_ebs = used_ebs;
214 
215 	dbg_bld("found volume (ID %i)", vol_id);
216 
217 	rb_link_node(&av->rb, parent, p);
218 	rb_insert_color(&av->rb, &ai->volumes);
219 
220 out:
221 	return av;
222 }
223 
224 /**
225  * assign_aeb_to_av - assigns a SEB to a given ainf_volume and removes it
226  * from it's original list.
227  * @ai: ubi_attach_info object
228  * @aeb: the to be assigned SEB
229  * @av: target scan volume
230  */
assign_aeb_to_av(struct ubi_attach_info * ai,struct ubi_ainf_peb * aeb,struct ubi_ainf_volume * av)231 static void assign_aeb_to_av(struct ubi_attach_info *ai,
232 			     struct ubi_ainf_peb *aeb,
233 			     struct ubi_ainf_volume *av)
234 {
235 	struct ubi_ainf_peb *tmp_aeb;
236 	struct rb_node **p = &ai->volumes.rb_node, *parent = NULL;
237 
238 	p = &av->root.rb_node;
239 	while (*p) {
240 		parent = *p;
241 
242 		tmp_aeb = rb_entry(parent, struct ubi_ainf_peb, u.rb);
243 		if (aeb->lnum != tmp_aeb->lnum) {
244 			if (aeb->lnum < tmp_aeb->lnum)
245 				p = &(*p)->rb_left;
246 			else
247 				p = &(*p)->rb_right;
248 
249 			continue;
250 		} else
251 			break;
252 	}
253 
254 	list_del(&aeb->u.list);
255 	av->leb_count++;
256 
257 	rb_link_node(&aeb->u.rb, parent, p);
258 	rb_insert_color(&aeb->u.rb, &av->root);
259 }
260 
261 /**
262  * update_vol - inserts or updates a LEB which was found a pool.
263  * @ubi: the UBI device object
264  * @ai: attach info object
265  * @av: the volume this LEB belongs to
266  * @new_vh: the volume header derived from new_aeb
267  * @new_aeb: the AEB to be examined
268  *
269  * Returns 0 on success, < 0 indicates an internal error.
270  */
update_vol(struct ubi_device * ubi,struct ubi_attach_info * ai,struct ubi_ainf_volume * av,struct ubi_vid_hdr * new_vh,struct ubi_ainf_peb * new_aeb)271 static int update_vol(struct ubi_device *ubi, struct ubi_attach_info *ai,
272 		      struct ubi_ainf_volume *av, struct ubi_vid_hdr *new_vh,
273 		      struct ubi_ainf_peb *new_aeb)
274 {
275 	struct rb_node **p = &av->root.rb_node, *parent = NULL;
276 	struct ubi_ainf_peb *aeb, *victim;
277 	int cmp_res;
278 
279 	while (*p) {
280 		parent = *p;
281 		aeb = rb_entry(parent, struct ubi_ainf_peb, u.rb);
282 
283 		if (be32_to_cpu(new_vh->lnum) != aeb->lnum) {
284 			if (be32_to_cpu(new_vh->lnum) < aeb->lnum)
285 				p = &(*p)->rb_left;
286 			else
287 				p = &(*p)->rb_right;
288 
289 			continue;
290 		}
291 
292 		/* This case can happen if the fastmap gets written
293 		 * because of a volume change (creation, deletion, ..).
294 		 * Then a PEB can be within the persistent EBA and the pool.
295 		 */
296 		if (aeb->pnum == new_aeb->pnum) {
297 			ubi_assert(aeb->lnum == new_aeb->lnum);
298 			kmem_cache_free(ai->aeb_slab_cache, new_aeb);
299 
300 			return 0;
301 		}
302 
303 		cmp_res = ubi_compare_lebs(ubi, aeb, new_aeb->pnum, new_vh);
304 		if (cmp_res < 0)
305 			return cmp_res;
306 
307 		/* new_aeb is newer */
308 		if (cmp_res & 1) {
309 			victim = kmem_cache_alloc(ai->aeb_slab_cache,
310 				GFP_KERNEL);
311 			if (!victim)
312 				return -ENOMEM;
313 
314 			victim->ec = aeb->ec;
315 			victim->pnum = aeb->pnum;
316 			list_add_tail(&victim->u.list, &ai->erase);
317 
318 			if (av->highest_lnum == be32_to_cpu(new_vh->lnum))
319 				av->last_data_size =
320 					be32_to_cpu(new_vh->data_size);
321 
322 			dbg_bld("vol %i: AEB %i's PEB %i is the newer",
323 				av->vol_id, aeb->lnum, new_aeb->pnum);
324 
325 			aeb->ec = new_aeb->ec;
326 			aeb->pnum = new_aeb->pnum;
327 			aeb->copy_flag = new_vh->copy_flag;
328 			aeb->scrub = new_aeb->scrub;
329 			aeb->sqnum = new_aeb->sqnum;
330 			kmem_cache_free(ai->aeb_slab_cache, new_aeb);
331 
332 		/* new_aeb is older */
333 		} else {
334 			dbg_bld("vol %i: AEB %i's PEB %i is old, dropping it",
335 				av->vol_id, aeb->lnum, new_aeb->pnum);
336 			list_add_tail(&new_aeb->u.list, &ai->erase);
337 		}
338 
339 		return 0;
340 	}
341 	/* This LEB is new, let's add it to the volume */
342 
343 	if (av->highest_lnum <= be32_to_cpu(new_vh->lnum)) {
344 		av->highest_lnum = be32_to_cpu(new_vh->lnum);
345 		av->last_data_size = be32_to_cpu(new_vh->data_size);
346 	}
347 
348 	if (av->vol_type == UBI_STATIC_VOLUME)
349 		av->used_ebs = be32_to_cpu(new_vh->used_ebs);
350 
351 	av->leb_count++;
352 
353 	rb_link_node(&new_aeb->u.rb, parent, p);
354 	rb_insert_color(&new_aeb->u.rb, &av->root);
355 
356 	return 0;
357 }
358 
359 /**
360  * process_pool_aeb - we found a non-empty PEB in a pool.
361  * @ubi: UBI device object
362  * @ai: attach info object
363  * @new_vh: the volume header derived from new_aeb
364  * @new_aeb: the AEB to be examined
365  *
366  * Returns 0 on success, < 0 indicates an internal error.
367  */
process_pool_aeb(struct ubi_device * ubi,struct ubi_attach_info * ai,struct ubi_vid_hdr * new_vh,struct ubi_ainf_peb * new_aeb)368 static int process_pool_aeb(struct ubi_device *ubi, struct ubi_attach_info *ai,
369 			    struct ubi_vid_hdr *new_vh,
370 			    struct ubi_ainf_peb *new_aeb)
371 {
372 	struct ubi_ainf_volume *av, *tmp_av = NULL;
373 	struct rb_node **p = &ai->volumes.rb_node, *parent = NULL;
374 	int found = 0;
375 
376 	if (be32_to_cpu(new_vh->vol_id) == UBI_FM_SB_VOLUME_ID ||
377 		be32_to_cpu(new_vh->vol_id) == UBI_FM_DATA_VOLUME_ID) {
378 		kmem_cache_free(ai->aeb_slab_cache, new_aeb);
379 
380 		return 0;
381 	}
382 
383 	/* Find the volume this SEB belongs to */
384 	while (*p) {
385 		parent = *p;
386 		tmp_av = rb_entry(parent, struct ubi_ainf_volume, rb);
387 
388 		if (be32_to_cpu(new_vh->vol_id) > tmp_av->vol_id)
389 			p = &(*p)->rb_left;
390 		else if (be32_to_cpu(new_vh->vol_id) < tmp_av->vol_id)
391 			p = &(*p)->rb_right;
392 		else {
393 			found = 1;
394 			break;
395 		}
396 	}
397 
398 	if (found)
399 		av = tmp_av;
400 	else {
401 		ubi_err(ubi, "orphaned volume in fastmap pool!");
402 		kmem_cache_free(ai->aeb_slab_cache, new_aeb);
403 		return UBI_BAD_FASTMAP;
404 	}
405 
406 	ubi_assert(be32_to_cpu(new_vh->vol_id) == av->vol_id);
407 
408 	return update_vol(ubi, ai, av, new_vh, new_aeb);
409 }
410 
411 /**
412  * unmap_peb - unmap a PEB.
413  * If fastmap detects a free PEB in the pool it has to check whether
414  * this PEB has been unmapped after writing the fastmap.
415  *
416  * @ai: UBI attach info object
417  * @pnum: The PEB to be unmapped
418  */
unmap_peb(struct ubi_attach_info * ai,int pnum)419 static void unmap_peb(struct ubi_attach_info *ai, int pnum)
420 {
421 	struct ubi_ainf_volume *av;
422 	struct rb_node *node, *node2;
423 	struct ubi_ainf_peb *aeb;
424 
425 	for (node = rb_first(&ai->volumes); node; node = rb_next(node)) {
426 		av = rb_entry(node, struct ubi_ainf_volume, rb);
427 
428 		for (node2 = rb_first(&av->root); node2;
429 		     node2 = rb_next(node2)) {
430 			aeb = rb_entry(node2, struct ubi_ainf_peb, u.rb);
431 			if (aeb->pnum == pnum) {
432 				rb_erase(&aeb->u.rb, &av->root);
433 				av->leb_count--;
434 				kmem_cache_free(ai->aeb_slab_cache, aeb);
435 				return;
436 			}
437 		}
438 	}
439 }
440 
441 /**
442  * scan_pool - scans a pool for changed (no longer empty PEBs).
443  * @ubi: UBI device object
444  * @ai: attach info object
445  * @pebs: an array of all PEB numbers in the to be scanned pool
446  * @pool_size: size of the pool (number of entries in @pebs)
447  * @max_sqnum: pointer to the maximal sequence number
448  * @free: list of PEBs which are most likely free (and go into @ai->free)
449  *
450  * Returns 0 on success, if the pool is unusable UBI_BAD_FASTMAP is returned.
451  * < 0 indicates an internal error.
452  */
scan_pool(struct ubi_device * ubi,struct ubi_attach_info * ai,__be32 * pebs,int pool_size,unsigned long long * max_sqnum,struct list_head * free)453 static int scan_pool(struct ubi_device *ubi, struct ubi_attach_info *ai,
454 		     __be32 *pebs, int pool_size, unsigned long long *max_sqnum,
455 		     struct list_head *free)
456 {
457 	struct ubi_vid_hdr *vh;
458 	struct ubi_ec_hdr *ech;
459 	struct ubi_ainf_peb *new_aeb;
460 	int i, pnum, err, ret = 0;
461 
462 	ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
463 	if (!ech)
464 		return -ENOMEM;
465 
466 	vh = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
467 	if (!vh) {
468 		kfree(ech);
469 		return -ENOMEM;
470 	}
471 
472 	dbg_bld("scanning fastmap pool: size = %i", pool_size);
473 
474 	/*
475 	 * Now scan all PEBs in the pool to find changes which have been made
476 	 * after the creation of the fastmap
477 	 */
478 	for (i = 0; i < pool_size; i++) {
479 		int scrub = 0;
480 		int image_seq;
481 
482 		pnum = be32_to_cpu(pebs[i]);
483 
484 		if (ubi_io_is_bad(ubi, pnum)) {
485 			ubi_err(ubi, "bad PEB in fastmap pool!");
486 			ret = UBI_BAD_FASTMAP;
487 			goto out;
488 		}
489 
490 		err = ubi_io_read_ec_hdr(ubi, pnum, ech, 0);
491 		if (err && err != UBI_IO_BITFLIPS) {
492 			ubi_err(ubi, "unable to read EC header! PEB:%i err:%i",
493 				pnum, err);
494 			ret = err > 0 ? UBI_BAD_FASTMAP : err;
495 			goto out;
496 		} else if (err == UBI_IO_BITFLIPS)
497 			scrub = 1;
498 
499 		/*
500 		 * Older UBI implementations have image_seq set to zero, so
501 		 * we shouldn't fail if image_seq == 0.
502 		 */
503 		image_seq = be32_to_cpu(ech->image_seq);
504 
505 		if (image_seq && (image_seq != ubi->image_seq)) {
506 			ubi_err(ubi, "bad image seq: 0x%x, expected: 0x%x",
507 				be32_to_cpu(ech->image_seq), ubi->image_seq);
508 			ret = UBI_BAD_FASTMAP;
509 			goto out;
510 		}
511 
512 		err = ubi_io_read_vid_hdr(ubi, pnum, vh, 0);
513 		if (err == UBI_IO_FF || err == UBI_IO_FF_BITFLIPS) {
514 			unsigned long long ec = be64_to_cpu(ech->ec);
515 			unmap_peb(ai, pnum);
516 			dbg_bld("Adding PEB to free: %i", pnum);
517 
518 			if (err == UBI_IO_FF_BITFLIPS)
519 				scrub = 1;
520 
521 			add_aeb(ai, free, pnum, ec, scrub);
522 			continue;
523 		} else if (err == 0 || err == UBI_IO_BITFLIPS) {
524 			dbg_bld("Found non empty PEB:%i in pool", pnum);
525 
526 			if (err == UBI_IO_BITFLIPS)
527 				scrub = 1;
528 
529 			new_aeb = kmem_cache_alloc(ai->aeb_slab_cache,
530 						   GFP_KERNEL);
531 			if (!new_aeb) {
532 				ret = -ENOMEM;
533 				goto out;
534 			}
535 
536 			new_aeb->ec = be64_to_cpu(ech->ec);
537 			new_aeb->pnum = pnum;
538 			new_aeb->lnum = be32_to_cpu(vh->lnum);
539 			new_aeb->sqnum = be64_to_cpu(vh->sqnum);
540 			new_aeb->copy_flag = vh->copy_flag;
541 			new_aeb->scrub = scrub;
542 
543 			if (*max_sqnum < new_aeb->sqnum)
544 				*max_sqnum = new_aeb->sqnum;
545 
546 			err = process_pool_aeb(ubi, ai, vh, new_aeb);
547 			if (err) {
548 				ret = err > 0 ? UBI_BAD_FASTMAP : err;
549 				goto out;
550 			}
551 		} else {
552 			/* We are paranoid and fall back to scanning mode */
553 			ubi_err(ubi, "fastmap pool PEBs contains damaged PEBs!");
554 			ret = err > 0 ? UBI_BAD_FASTMAP : err;
555 			goto out;
556 		}
557 
558 	}
559 
560 out:
561 	ubi_free_vid_hdr(ubi, vh);
562 	kfree(ech);
563 	return ret;
564 }
565 
566 /**
567  * count_fastmap_pebs - Counts the PEBs found by fastmap.
568  * @ai: The UBI attach info object
569  */
count_fastmap_pebs(struct ubi_attach_info * ai)570 static int count_fastmap_pebs(struct ubi_attach_info *ai)
571 {
572 	struct ubi_ainf_peb *aeb;
573 	struct ubi_ainf_volume *av;
574 	struct rb_node *rb1, *rb2;
575 	int n = 0;
576 
577 	list_for_each_entry(aeb, &ai->erase, u.list)
578 		n++;
579 
580 	list_for_each_entry(aeb, &ai->free, u.list)
581 		n++;
582 
583 	 ubi_rb_for_each_entry(rb1, av, &ai->volumes, rb)
584 		ubi_rb_for_each_entry(rb2, aeb, &av->root, u.rb)
585 			n++;
586 
587 	return n;
588 }
589 
590 /**
591  * ubi_attach_fastmap - creates ubi_attach_info from a fastmap.
592  * @ubi: UBI device object
593  * @ai: UBI attach info object
594  * @fm: the fastmap to be attached
595  *
596  * Returns 0 on success, UBI_BAD_FASTMAP if the found fastmap was unusable.
597  * < 0 indicates an internal error.
598  */
ubi_attach_fastmap(struct ubi_device * ubi,struct ubi_attach_info * ai,struct ubi_fastmap_layout * fm)599 static int ubi_attach_fastmap(struct ubi_device *ubi,
600 			      struct ubi_attach_info *ai,
601 			      struct ubi_fastmap_layout *fm)
602 {
603 	struct list_head used, free;
604 	struct ubi_ainf_volume *av;
605 	struct ubi_ainf_peb *aeb, *tmp_aeb, *_tmp_aeb;
606 	struct ubi_fm_sb *fmsb;
607 	struct ubi_fm_hdr *fmhdr;
608 	struct ubi_fm_scan_pool *fmpl, *fmpl_wl;
609 	struct ubi_fm_ec *fmec;
610 	struct ubi_fm_volhdr *fmvhdr;
611 	struct ubi_fm_eba *fm_eba;
612 	int ret, i, j, pool_size, wl_pool_size;
613 	size_t fm_pos = 0, fm_size = ubi->fm_size;
614 	unsigned long long max_sqnum = 0;
615 	void *fm_raw = ubi->fm_buf;
616 
617 	INIT_LIST_HEAD(&used);
618 	INIT_LIST_HEAD(&free);
619 	ai->min_ec = UBI_MAX_ERASECOUNTER;
620 
621 	fmsb = (struct ubi_fm_sb *)(fm_raw);
622 	ai->max_sqnum = fmsb->sqnum;
623 	fm_pos += sizeof(struct ubi_fm_sb);
624 	if (fm_pos >= fm_size)
625 		goto fail_bad;
626 
627 	fmhdr = (struct ubi_fm_hdr *)(fm_raw + fm_pos);
628 	fm_pos += sizeof(*fmhdr);
629 	if (fm_pos >= fm_size)
630 		goto fail_bad;
631 
632 	if (be32_to_cpu(fmhdr->magic) != UBI_FM_HDR_MAGIC) {
633 		ubi_err(ubi, "bad fastmap header magic: 0x%x, expected: 0x%x",
634 			be32_to_cpu(fmhdr->magic), UBI_FM_HDR_MAGIC);
635 		goto fail_bad;
636 	}
637 
638 	fmpl = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
639 	fm_pos += sizeof(*fmpl);
640 	if (fm_pos >= fm_size)
641 		goto fail_bad;
642 	if (be32_to_cpu(fmpl->magic) != UBI_FM_POOL_MAGIC) {
643 		ubi_err(ubi, "bad fastmap pool magic: 0x%x, expected: 0x%x",
644 			be32_to_cpu(fmpl->magic), UBI_FM_POOL_MAGIC);
645 		goto fail_bad;
646 	}
647 
648 	fmpl_wl = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
649 	fm_pos += sizeof(*fmpl_wl);
650 	if (fm_pos >= fm_size)
651 		goto fail_bad;
652 	if (be32_to_cpu(fmpl_wl->magic) != UBI_FM_POOL_MAGIC) {
653 		ubi_err(ubi, "bad fastmap WL pool magic: 0x%x, expected: 0x%x",
654 			be32_to_cpu(fmpl_wl->magic), UBI_FM_POOL_MAGIC);
655 		goto fail_bad;
656 	}
657 
658 	pool_size = be16_to_cpu(fmpl->size);
659 	wl_pool_size = be16_to_cpu(fmpl_wl->size);
660 	fm->max_pool_size = be16_to_cpu(fmpl->max_size);
661 	fm->max_wl_pool_size = be16_to_cpu(fmpl_wl->max_size);
662 
663 	if (pool_size > UBI_FM_MAX_POOL_SIZE || pool_size < 0) {
664 		ubi_err(ubi, "bad pool size: %i", pool_size);
665 		goto fail_bad;
666 	}
667 
668 	if (wl_pool_size > UBI_FM_MAX_POOL_SIZE || wl_pool_size < 0) {
669 		ubi_err(ubi, "bad WL pool size: %i", wl_pool_size);
670 		goto fail_bad;
671 	}
672 
673 
674 	if (fm->max_pool_size > UBI_FM_MAX_POOL_SIZE ||
675 	    fm->max_pool_size < 0) {
676 		ubi_err(ubi, "bad maximal pool size: %i", fm->max_pool_size);
677 		goto fail_bad;
678 	}
679 
680 	if (fm->max_wl_pool_size > UBI_FM_MAX_POOL_SIZE ||
681 	    fm->max_wl_pool_size < 0) {
682 		ubi_err(ubi, "bad maximal WL pool size: %i",
683 			fm->max_wl_pool_size);
684 		goto fail_bad;
685 	}
686 
687 	/* read EC values from free list */
688 	for (i = 0; i < be32_to_cpu(fmhdr->free_peb_count); i++) {
689 		fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
690 		fm_pos += sizeof(*fmec);
691 		if (fm_pos >= fm_size)
692 			goto fail_bad;
693 
694 		add_aeb(ai, &ai->free, be32_to_cpu(fmec->pnum),
695 			be32_to_cpu(fmec->ec), 0);
696 	}
697 
698 	/* read EC values from used list */
699 	for (i = 0; i < be32_to_cpu(fmhdr->used_peb_count); i++) {
700 		fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
701 		fm_pos += sizeof(*fmec);
702 		if (fm_pos >= fm_size)
703 			goto fail_bad;
704 
705 		add_aeb(ai, &used, be32_to_cpu(fmec->pnum),
706 			be32_to_cpu(fmec->ec), 0);
707 	}
708 
709 	/* read EC values from scrub list */
710 	for (i = 0; i < be32_to_cpu(fmhdr->scrub_peb_count); i++) {
711 		fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
712 		fm_pos += sizeof(*fmec);
713 		if (fm_pos >= fm_size)
714 			goto fail_bad;
715 
716 		add_aeb(ai, &used, be32_to_cpu(fmec->pnum),
717 			be32_to_cpu(fmec->ec), 1);
718 	}
719 
720 	/* read EC values from erase list */
721 	for (i = 0; i < be32_to_cpu(fmhdr->erase_peb_count); i++) {
722 		fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
723 		fm_pos += sizeof(*fmec);
724 		if (fm_pos >= fm_size)
725 			goto fail_bad;
726 
727 		add_aeb(ai, &ai->erase, be32_to_cpu(fmec->pnum),
728 			be32_to_cpu(fmec->ec), 1);
729 	}
730 
731 	ai->mean_ec = div_u64(ai->ec_sum, ai->ec_count);
732 	ai->bad_peb_count = be32_to_cpu(fmhdr->bad_peb_count);
733 
734 	/* Iterate over all volumes and read their EBA table */
735 	for (i = 0; i < be32_to_cpu(fmhdr->vol_count); i++) {
736 		fmvhdr = (struct ubi_fm_volhdr *)(fm_raw + fm_pos);
737 		fm_pos += sizeof(*fmvhdr);
738 		if (fm_pos >= fm_size)
739 			goto fail_bad;
740 
741 		if (be32_to_cpu(fmvhdr->magic) != UBI_FM_VHDR_MAGIC) {
742 			ubi_err(ubi, "bad fastmap vol header magic: 0x%x, expected: 0x%x",
743 				be32_to_cpu(fmvhdr->magic), UBI_FM_VHDR_MAGIC);
744 			goto fail_bad;
745 		}
746 
747 		av = add_vol(ai, be32_to_cpu(fmvhdr->vol_id),
748 			     be32_to_cpu(fmvhdr->used_ebs),
749 			     be32_to_cpu(fmvhdr->data_pad),
750 			     fmvhdr->vol_type,
751 			     be32_to_cpu(fmvhdr->last_eb_bytes));
752 
753 		if (IS_ERR(av)) {
754 			if (PTR_ERR(av) == -EEXIST)
755 				ubi_err(ubi, "volume (ID %i) already exists",
756 					fmvhdr->vol_id);
757 
758 			goto fail_bad;
759 		}
760 
761 		ai->vols_found++;
762 		if (ai->highest_vol_id < be32_to_cpu(fmvhdr->vol_id))
763 			ai->highest_vol_id = be32_to_cpu(fmvhdr->vol_id);
764 
765 		fm_eba = (struct ubi_fm_eba *)(fm_raw + fm_pos);
766 		fm_pos += sizeof(*fm_eba);
767 		fm_pos += (sizeof(__be32) * be32_to_cpu(fm_eba->reserved_pebs));
768 		if (fm_pos >= fm_size)
769 			goto fail_bad;
770 
771 		if (be32_to_cpu(fm_eba->magic) != UBI_FM_EBA_MAGIC) {
772 			ubi_err(ubi, "bad fastmap EBA header magic: 0x%x, expected: 0x%x",
773 				be32_to_cpu(fm_eba->magic), UBI_FM_EBA_MAGIC);
774 			goto fail_bad;
775 		}
776 
777 		for (j = 0; j < be32_to_cpu(fm_eba->reserved_pebs); j++) {
778 			int pnum = be32_to_cpu(fm_eba->pnum[j]);
779 
780 			if (pnum < 0)
781 				continue;
782 
783 			aeb = NULL;
784 			list_for_each_entry(tmp_aeb, &used, u.list) {
785 				if (tmp_aeb->pnum == pnum) {
786 					aeb = tmp_aeb;
787 					break;
788 				}
789 			}
790 
791 			if (!aeb) {
792 				ubi_err(ubi, "PEB %i is in EBA but not in used list", pnum);
793 				goto fail_bad;
794 			}
795 
796 			aeb->lnum = j;
797 
798 			if (av->highest_lnum <= aeb->lnum)
799 				av->highest_lnum = aeb->lnum;
800 
801 			assign_aeb_to_av(ai, aeb, av);
802 
803 			dbg_bld("inserting PEB:%i (LEB %i) to vol %i",
804 				aeb->pnum, aeb->lnum, av->vol_id);
805 		}
806 	}
807 
808 	ret = scan_pool(ubi, ai, fmpl->pebs, pool_size, &max_sqnum, &free);
809 	if (ret)
810 		goto fail;
811 
812 	ret = scan_pool(ubi, ai, fmpl_wl->pebs, wl_pool_size, &max_sqnum, &free);
813 	if (ret)
814 		goto fail;
815 
816 	if (max_sqnum > ai->max_sqnum)
817 		ai->max_sqnum = max_sqnum;
818 
819 	list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &free, u.list)
820 		list_move_tail(&tmp_aeb->u.list, &ai->free);
821 
822 	list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &used, u.list)
823 		list_move_tail(&tmp_aeb->u.list, &ai->erase);
824 
825 	ubi_assert(list_empty(&free));
826 
827 	/*
828 	 * If fastmap is leaking PEBs (must not happen), raise a
829 	 * fat warning and fall back to scanning mode.
830 	 * We do this here because in ubi_wl_init() it's too late
831 	 * and we cannot fall back to scanning.
832 	 */
833 	if (WARN_ON(count_fastmap_pebs(ai) != ubi->peb_count -
834 		    ai->bad_peb_count - fm->used_blocks))
835 		goto fail_bad;
836 
837 	return 0;
838 
839 fail_bad:
840 	ret = UBI_BAD_FASTMAP;
841 fail:
842 	list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &used, u.list) {
843 		list_del(&tmp_aeb->u.list);
844 		kmem_cache_free(ai->aeb_slab_cache, tmp_aeb);
845 	}
846 	list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &free, u.list) {
847 		list_del(&tmp_aeb->u.list);
848 		kmem_cache_free(ai->aeb_slab_cache, tmp_aeb);
849 	}
850 
851 	return ret;
852 }
853 
854 /**
855  * find_fm_anchor - find the most recent Fastmap superblock (anchor)
856  * @ai: UBI attach info to be filled
857  */
find_fm_anchor(struct ubi_attach_info * ai)858 static int find_fm_anchor(struct ubi_attach_info *ai)
859 {
860 	int ret = -1;
861 	struct ubi_ainf_peb *aeb;
862 	unsigned long long max_sqnum = 0;
863 
864 	list_for_each_entry(aeb, &ai->fastmap, u.list) {
865 		if (aeb->vol_id == UBI_FM_SB_VOLUME_ID && aeb->sqnum > max_sqnum) {
866 			max_sqnum = aeb->sqnum;
867 			ret = aeb->pnum;
868 		}
869 	}
870 
871 	return ret;
872 }
873 
874 /**
875  * ubi_scan_fastmap - scan the fastmap.
876  * @ubi: UBI device object
877  * @ai: UBI attach info to be filled
878  * @scan_ai: UBI attach info from the first 64 PEBs,
879  *           used to find the most recent Fastmap data structure
880  *
881  * Returns 0 on success, UBI_NO_FASTMAP if no fastmap was found,
882  * UBI_BAD_FASTMAP if one was found but is not usable.
883  * < 0 indicates an internal error.
884  */
ubi_scan_fastmap(struct ubi_device * ubi,struct ubi_attach_info * ai,struct ubi_attach_info * scan_ai)885 int ubi_scan_fastmap(struct ubi_device *ubi, struct ubi_attach_info *ai,
886 		     struct ubi_attach_info *scan_ai)
887 {
888 	struct ubi_fm_sb *fmsb, *fmsb2;
889 	struct ubi_vid_hdr *vh;
890 	struct ubi_ec_hdr *ech;
891 	struct ubi_fastmap_layout *fm;
892 	struct ubi_ainf_peb *tmp_aeb, *aeb;
893 	int i, used_blocks, pnum, fm_anchor, ret = 0;
894 	size_t fm_size;
895 	__be32 crc, tmp_crc;
896 	unsigned long long sqnum = 0;
897 
898 	fm_anchor = find_fm_anchor(scan_ai);
899 	if (fm_anchor < 0)
900 		return UBI_NO_FASTMAP;
901 
902 	/* Move all (possible) fastmap blocks into our new attach structure. */
903 	list_for_each_entry_safe(aeb, tmp_aeb, &scan_ai->fastmap, u.list)
904 		list_move_tail(&aeb->u.list, &ai->fastmap);
905 
906 	down_write(&ubi->fm_protect);
907 	memset(ubi->fm_buf, 0, ubi->fm_size);
908 
909 	fmsb = kmalloc(sizeof(*fmsb), GFP_KERNEL);
910 	if (!fmsb) {
911 		ret = -ENOMEM;
912 		goto out;
913 	}
914 
915 	fm = kzalloc(sizeof(*fm), GFP_KERNEL);
916 	if (!fm) {
917 		ret = -ENOMEM;
918 		kfree(fmsb);
919 		goto out;
920 	}
921 
922 	ret = ubi_io_read(ubi, fmsb, fm_anchor, ubi->leb_start, sizeof(*fmsb));
923 	if (ret && ret != UBI_IO_BITFLIPS)
924 		goto free_fm_sb;
925 	else if (ret == UBI_IO_BITFLIPS)
926 		fm->to_be_tortured[0] = 1;
927 
928 	if (be32_to_cpu(fmsb->magic) != UBI_FM_SB_MAGIC) {
929 		ubi_err(ubi, "bad super block magic: 0x%x, expected: 0x%x",
930 			be32_to_cpu(fmsb->magic), UBI_FM_SB_MAGIC);
931 		ret = UBI_BAD_FASTMAP;
932 		goto free_fm_sb;
933 	}
934 
935 	if (fmsb->version != UBI_FM_FMT_VERSION) {
936 		ubi_err(ubi, "bad fastmap version: %i, expected: %i",
937 			fmsb->version, UBI_FM_FMT_VERSION);
938 		ret = UBI_BAD_FASTMAP;
939 		goto free_fm_sb;
940 	}
941 
942 	used_blocks = be32_to_cpu(fmsb->used_blocks);
943 	if (used_blocks > UBI_FM_MAX_BLOCKS || used_blocks < 1) {
944 		ubi_err(ubi, "number of fastmap blocks is invalid: %i",
945 			used_blocks);
946 		ret = UBI_BAD_FASTMAP;
947 		goto free_fm_sb;
948 	}
949 
950 	fm_size = ubi->leb_size * used_blocks;
951 	if (fm_size != ubi->fm_size) {
952 		ubi_err(ubi, "bad fastmap size: %zi, expected: %zi",
953 			fm_size, ubi->fm_size);
954 		ret = UBI_BAD_FASTMAP;
955 		goto free_fm_sb;
956 	}
957 
958 	ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
959 	if (!ech) {
960 		ret = -ENOMEM;
961 		goto free_fm_sb;
962 	}
963 
964 	vh = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
965 	if (!vh) {
966 		ret = -ENOMEM;
967 		goto free_hdr;
968 	}
969 
970 	for (i = 0; i < used_blocks; i++) {
971 		int image_seq;
972 
973 		pnum = be32_to_cpu(fmsb->block_loc[i]);
974 
975 		if (ubi_io_is_bad(ubi, pnum)) {
976 			ret = UBI_BAD_FASTMAP;
977 			goto free_hdr;
978 		}
979 
980 		ret = ubi_io_read_ec_hdr(ubi, pnum, ech, 0);
981 		if (ret && ret != UBI_IO_BITFLIPS) {
982 			ubi_err(ubi, "unable to read fastmap block# %i EC (PEB: %i)",
983 				i, pnum);
984 			if (ret > 0)
985 				ret = UBI_BAD_FASTMAP;
986 			goto free_hdr;
987 		} else if (ret == UBI_IO_BITFLIPS)
988 			fm->to_be_tortured[i] = 1;
989 
990 		image_seq = be32_to_cpu(ech->image_seq);
991 		if (!ubi->image_seq)
992 			ubi->image_seq = image_seq;
993 
994 		/*
995 		 * Older UBI implementations have image_seq set to zero, so
996 		 * we shouldn't fail if image_seq == 0.
997 		 */
998 		if (image_seq && (image_seq != ubi->image_seq)) {
999 			ubi_err(ubi, "wrong image seq:%d instead of %d",
1000 				be32_to_cpu(ech->image_seq), ubi->image_seq);
1001 			ret = UBI_BAD_FASTMAP;
1002 			goto free_hdr;
1003 		}
1004 
1005 		ret = ubi_io_read_vid_hdr(ubi, pnum, vh, 0);
1006 		if (ret && ret != UBI_IO_BITFLIPS) {
1007 			ubi_err(ubi, "unable to read fastmap block# %i (PEB: %i)",
1008 				i, pnum);
1009 			goto free_hdr;
1010 		}
1011 
1012 		if (i == 0) {
1013 			if (be32_to_cpu(vh->vol_id) != UBI_FM_SB_VOLUME_ID) {
1014 				ubi_err(ubi, "bad fastmap anchor vol_id: 0x%x, expected: 0x%x",
1015 					be32_to_cpu(vh->vol_id),
1016 					UBI_FM_SB_VOLUME_ID);
1017 				ret = UBI_BAD_FASTMAP;
1018 				goto free_hdr;
1019 			}
1020 		} else {
1021 			if (be32_to_cpu(vh->vol_id) != UBI_FM_DATA_VOLUME_ID) {
1022 				ubi_err(ubi, "bad fastmap data vol_id: 0x%x, expected: 0x%x",
1023 					be32_to_cpu(vh->vol_id),
1024 					UBI_FM_DATA_VOLUME_ID);
1025 				ret = UBI_BAD_FASTMAP;
1026 				goto free_hdr;
1027 			}
1028 		}
1029 
1030 		if (sqnum < be64_to_cpu(vh->sqnum))
1031 			sqnum = be64_to_cpu(vh->sqnum);
1032 
1033 		ret = ubi_io_read(ubi, ubi->fm_buf + (ubi->leb_size * i), pnum,
1034 				  ubi->leb_start, ubi->leb_size);
1035 		if (ret && ret != UBI_IO_BITFLIPS) {
1036 			ubi_err(ubi, "unable to read fastmap block# %i (PEB: %i, "
1037 				"err: %i)", i, pnum, ret);
1038 			goto free_hdr;
1039 		}
1040 	}
1041 
1042 	kfree(fmsb);
1043 	fmsb = NULL;
1044 
1045 	fmsb2 = (struct ubi_fm_sb *)(ubi->fm_buf);
1046 	tmp_crc = be32_to_cpu(fmsb2->data_crc);
1047 	fmsb2->data_crc = 0;
1048 	crc = crc32(UBI_CRC32_INIT, ubi->fm_buf, fm_size);
1049 	if (crc != tmp_crc) {
1050 		ubi_err(ubi, "fastmap data CRC is invalid");
1051 		ubi_err(ubi, "CRC should be: 0x%x, calc: 0x%x",
1052 			tmp_crc, crc);
1053 		ret = UBI_BAD_FASTMAP;
1054 		goto free_hdr;
1055 	}
1056 
1057 	fmsb2->sqnum = sqnum;
1058 
1059 	fm->used_blocks = used_blocks;
1060 
1061 	ret = ubi_attach_fastmap(ubi, ai, fm);
1062 	if (ret) {
1063 		if (ret > 0)
1064 			ret = UBI_BAD_FASTMAP;
1065 		goto free_hdr;
1066 	}
1067 
1068 	for (i = 0; i < used_blocks; i++) {
1069 		struct ubi_wl_entry *e;
1070 
1071 		e = kmem_cache_alloc(ubi_wl_entry_slab, GFP_KERNEL);
1072 		if (!e) {
1073 			while (i--)
1074 				kfree(fm->e[i]);
1075 
1076 			ret = -ENOMEM;
1077 			goto free_hdr;
1078 		}
1079 
1080 		e->pnum = be32_to_cpu(fmsb2->block_loc[i]);
1081 		e->ec = be32_to_cpu(fmsb2->block_ec[i]);
1082 		fm->e[i] = e;
1083 	}
1084 
1085 	ubi->fm = fm;
1086 	ubi->fm_pool.max_size = ubi->fm->max_pool_size;
1087 	ubi->fm_wl_pool.max_size = ubi->fm->max_wl_pool_size;
1088 	ubi_msg(ubi, "attached by fastmap");
1089 	ubi_msg(ubi, "fastmap pool size: %d", ubi->fm_pool.max_size);
1090 	ubi_msg(ubi, "fastmap WL pool size: %d",
1091 		ubi->fm_wl_pool.max_size);
1092 	ubi->fm_disabled = 0;
1093 	ubi->fast_attach = 1;
1094 
1095 	ubi_free_vid_hdr(ubi, vh);
1096 	kfree(ech);
1097 out:
1098 	up_write(&ubi->fm_protect);
1099 	if (ret == UBI_BAD_FASTMAP)
1100 		ubi_err(ubi, "Attach by fastmap failed, doing a full scan!");
1101 	return ret;
1102 
1103 free_hdr:
1104 	ubi_free_vid_hdr(ubi, vh);
1105 	kfree(ech);
1106 free_fm_sb:
1107 	kfree(fmsb);
1108 	kfree(fm);
1109 	goto out;
1110 }
1111 
1112 /**
1113  * ubi_write_fastmap - writes a fastmap.
1114  * @ubi: UBI device object
1115  * @new_fm: the to be written fastmap
1116  *
1117  * Returns 0 on success, < 0 indicates an internal error.
1118  */
ubi_write_fastmap(struct ubi_device * ubi,struct ubi_fastmap_layout * new_fm)1119 static int ubi_write_fastmap(struct ubi_device *ubi,
1120 			     struct ubi_fastmap_layout *new_fm)
1121 {
1122 	size_t fm_pos = 0;
1123 	void *fm_raw;
1124 	struct ubi_fm_sb *fmsb;
1125 	struct ubi_fm_hdr *fmh;
1126 	struct ubi_fm_scan_pool *fmpl, *fmpl_wl;
1127 	struct ubi_fm_ec *fec;
1128 	struct ubi_fm_volhdr *fvh;
1129 	struct ubi_fm_eba *feba;
1130 	struct ubi_wl_entry *wl_e;
1131 	struct ubi_volume *vol;
1132 	struct ubi_vid_hdr *avhdr, *dvhdr;
1133 	struct ubi_work *ubi_wrk;
1134 	struct rb_node *tmp_rb;
1135 	int ret, i, j, free_peb_count, used_peb_count, vol_count;
1136 	int scrub_peb_count, erase_peb_count;
1137 	int *seen_pebs = NULL;
1138 
1139 	fm_raw = ubi->fm_buf;
1140 	memset(ubi->fm_buf, 0, ubi->fm_size);
1141 
1142 	avhdr = new_fm_vhdr(ubi, UBI_FM_SB_VOLUME_ID);
1143 	if (!avhdr) {
1144 		ret = -ENOMEM;
1145 		goto out;
1146 	}
1147 
1148 	dvhdr = new_fm_vhdr(ubi, UBI_FM_DATA_VOLUME_ID);
1149 	if (!dvhdr) {
1150 		ret = -ENOMEM;
1151 		goto out_kfree;
1152 	}
1153 
1154 	seen_pebs = init_seen(ubi);
1155 	if (IS_ERR(seen_pebs)) {
1156 		ret = PTR_ERR(seen_pebs);
1157 		goto out_kfree;
1158 	}
1159 
1160 	spin_lock(&ubi->volumes_lock);
1161 	spin_lock(&ubi->wl_lock);
1162 
1163 	fmsb = (struct ubi_fm_sb *)fm_raw;
1164 	fm_pos += sizeof(*fmsb);
1165 	ubi_assert(fm_pos <= ubi->fm_size);
1166 
1167 	fmh = (struct ubi_fm_hdr *)(fm_raw + fm_pos);
1168 	fm_pos += sizeof(*fmh);
1169 	ubi_assert(fm_pos <= ubi->fm_size);
1170 
1171 	fmsb->magic = cpu_to_be32(UBI_FM_SB_MAGIC);
1172 	fmsb->version = UBI_FM_FMT_VERSION;
1173 	fmsb->used_blocks = cpu_to_be32(new_fm->used_blocks);
1174 	/* the max sqnum will be filled in while *reading* the fastmap */
1175 	fmsb->sqnum = 0;
1176 
1177 	fmh->magic = cpu_to_be32(UBI_FM_HDR_MAGIC);
1178 	free_peb_count = 0;
1179 	used_peb_count = 0;
1180 	scrub_peb_count = 0;
1181 	erase_peb_count = 0;
1182 	vol_count = 0;
1183 
1184 	fmpl = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
1185 	fm_pos += sizeof(*fmpl);
1186 	fmpl->magic = cpu_to_be32(UBI_FM_POOL_MAGIC);
1187 	fmpl->size = cpu_to_be16(ubi->fm_pool.size);
1188 	fmpl->max_size = cpu_to_be16(ubi->fm_pool.max_size);
1189 
1190 	for (i = 0; i < ubi->fm_pool.size; i++) {
1191 		fmpl->pebs[i] = cpu_to_be32(ubi->fm_pool.pebs[i]);
1192 		set_seen(ubi, ubi->fm_pool.pebs[i], seen_pebs);
1193 	}
1194 
1195 	fmpl_wl = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
1196 	fm_pos += sizeof(*fmpl_wl);
1197 	fmpl_wl->magic = cpu_to_be32(UBI_FM_POOL_MAGIC);
1198 	fmpl_wl->size = cpu_to_be16(ubi->fm_wl_pool.size);
1199 	fmpl_wl->max_size = cpu_to_be16(ubi->fm_wl_pool.max_size);
1200 
1201 	for (i = 0; i < ubi->fm_wl_pool.size; i++) {
1202 		fmpl_wl->pebs[i] = cpu_to_be32(ubi->fm_wl_pool.pebs[i]);
1203 		set_seen(ubi, ubi->fm_wl_pool.pebs[i], seen_pebs);
1204 	}
1205 
1206 	ubi_for_each_free_peb(ubi, wl_e, tmp_rb) {
1207 		fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1208 
1209 		fec->pnum = cpu_to_be32(wl_e->pnum);
1210 		set_seen(ubi, wl_e->pnum, seen_pebs);
1211 		fec->ec = cpu_to_be32(wl_e->ec);
1212 
1213 		free_peb_count++;
1214 		fm_pos += sizeof(*fec);
1215 		ubi_assert(fm_pos <= ubi->fm_size);
1216 	}
1217 	fmh->free_peb_count = cpu_to_be32(free_peb_count);
1218 
1219 	ubi_for_each_used_peb(ubi, wl_e, tmp_rb) {
1220 		fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1221 
1222 		fec->pnum = cpu_to_be32(wl_e->pnum);
1223 		set_seen(ubi, wl_e->pnum, seen_pebs);
1224 		fec->ec = cpu_to_be32(wl_e->ec);
1225 
1226 		used_peb_count++;
1227 		fm_pos += sizeof(*fec);
1228 		ubi_assert(fm_pos <= ubi->fm_size);
1229 	}
1230 
1231 	ubi_for_each_protected_peb(ubi, i, wl_e) {
1232 		fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1233 
1234 		fec->pnum = cpu_to_be32(wl_e->pnum);
1235 		set_seen(ubi, wl_e->pnum, seen_pebs);
1236 		fec->ec = cpu_to_be32(wl_e->ec);
1237 
1238 		used_peb_count++;
1239 		fm_pos += sizeof(*fec);
1240 		ubi_assert(fm_pos <= ubi->fm_size);
1241 	}
1242 	fmh->used_peb_count = cpu_to_be32(used_peb_count);
1243 
1244 	ubi_for_each_scrub_peb(ubi, wl_e, tmp_rb) {
1245 		fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1246 
1247 		fec->pnum = cpu_to_be32(wl_e->pnum);
1248 		set_seen(ubi, wl_e->pnum, seen_pebs);
1249 		fec->ec = cpu_to_be32(wl_e->ec);
1250 
1251 		scrub_peb_count++;
1252 		fm_pos += sizeof(*fec);
1253 		ubi_assert(fm_pos <= ubi->fm_size);
1254 	}
1255 	fmh->scrub_peb_count = cpu_to_be32(scrub_peb_count);
1256 
1257 
1258 	list_for_each_entry(ubi_wrk, &ubi->works, list) {
1259 		if (ubi_is_erase_work(ubi_wrk)) {
1260 			wl_e = ubi_wrk->e;
1261 			ubi_assert(wl_e);
1262 
1263 			fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1264 
1265 			fec->pnum = cpu_to_be32(wl_e->pnum);
1266 			set_seen(ubi, wl_e->pnum, seen_pebs);
1267 			fec->ec = cpu_to_be32(wl_e->ec);
1268 
1269 			erase_peb_count++;
1270 			fm_pos += sizeof(*fec);
1271 			ubi_assert(fm_pos <= ubi->fm_size);
1272 		}
1273 	}
1274 	fmh->erase_peb_count = cpu_to_be32(erase_peb_count);
1275 
1276 	for (i = 0; i < UBI_MAX_VOLUMES + UBI_INT_VOL_COUNT; i++) {
1277 		vol = ubi->volumes[i];
1278 
1279 		if (!vol)
1280 			continue;
1281 
1282 		vol_count++;
1283 
1284 		fvh = (struct ubi_fm_volhdr *)(fm_raw + fm_pos);
1285 		fm_pos += sizeof(*fvh);
1286 		ubi_assert(fm_pos <= ubi->fm_size);
1287 
1288 		fvh->magic = cpu_to_be32(UBI_FM_VHDR_MAGIC);
1289 		fvh->vol_id = cpu_to_be32(vol->vol_id);
1290 		fvh->vol_type = vol->vol_type;
1291 		fvh->used_ebs = cpu_to_be32(vol->used_ebs);
1292 		fvh->data_pad = cpu_to_be32(vol->data_pad);
1293 		fvh->last_eb_bytes = cpu_to_be32(vol->last_eb_bytes);
1294 
1295 		ubi_assert(vol->vol_type == UBI_DYNAMIC_VOLUME ||
1296 			vol->vol_type == UBI_STATIC_VOLUME);
1297 
1298 		feba = (struct ubi_fm_eba *)(fm_raw + fm_pos);
1299 		fm_pos += sizeof(*feba) + (sizeof(__be32) * vol->reserved_pebs);
1300 		ubi_assert(fm_pos <= ubi->fm_size);
1301 
1302 		for (j = 0; j < vol->reserved_pebs; j++)
1303 			feba->pnum[j] = cpu_to_be32(vol->eba_tbl[j]);
1304 
1305 		feba->reserved_pebs = cpu_to_be32(j);
1306 		feba->magic = cpu_to_be32(UBI_FM_EBA_MAGIC);
1307 	}
1308 	fmh->vol_count = cpu_to_be32(vol_count);
1309 	fmh->bad_peb_count = cpu_to_be32(ubi->bad_peb_count);
1310 
1311 	avhdr->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
1312 	avhdr->lnum = 0;
1313 
1314 	spin_unlock(&ubi->wl_lock);
1315 	spin_unlock(&ubi->volumes_lock);
1316 
1317 	dbg_bld("writing fastmap SB to PEB %i", new_fm->e[0]->pnum);
1318 	ret = ubi_io_write_vid_hdr(ubi, new_fm->e[0]->pnum, avhdr);
1319 	if (ret) {
1320 		ubi_err(ubi, "unable to write vid_hdr to fastmap SB!");
1321 		goto out_kfree;
1322 	}
1323 
1324 	for (i = 0; i < new_fm->used_blocks; i++) {
1325 		fmsb->block_loc[i] = cpu_to_be32(new_fm->e[i]->pnum);
1326 		set_seen(ubi, new_fm->e[i]->pnum, seen_pebs);
1327 		fmsb->block_ec[i] = cpu_to_be32(new_fm->e[i]->ec);
1328 	}
1329 
1330 	fmsb->data_crc = 0;
1331 	fmsb->data_crc = cpu_to_be32(crc32(UBI_CRC32_INIT, fm_raw,
1332 					   ubi->fm_size));
1333 
1334 	for (i = 1; i < new_fm->used_blocks; i++) {
1335 		dvhdr->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
1336 		dvhdr->lnum = cpu_to_be32(i);
1337 		dbg_bld("writing fastmap data to PEB %i sqnum %llu",
1338 			new_fm->e[i]->pnum, be64_to_cpu(dvhdr->sqnum));
1339 		ret = ubi_io_write_vid_hdr(ubi, new_fm->e[i]->pnum, dvhdr);
1340 		if (ret) {
1341 			ubi_err(ubi, "unable to write vid_hdr to PEB %i!",
1342 				new_fm->e[i]->pnum);
1343 			goto out_kfree;
1344 		}
1345 	}
1346 
1347 	for (i = 0; i < new_fm->used_blocks; i++) {
1348 		ret = ubi_io_write(ubi, fm_raw + (i * ubi->leb_size),
1349 			new_fm->e[i]->pnum, ubi->leb_start, ubi->leb_size);
1350 		if (ret) {
1351 			ubi_err(ubi, "unable to write fastmap to PEB %i!",
1352 				new_fm->e[i]->pnum);
1353 			goto out_kfree;
1354 		}
1355 	}
1356 
1357 	ubi_assert(new_fm);
1358 	ubi->fm = new_fm;
1359 
1360 	ret = self_check_seen(ubi, seen_pebs);
1361 	dbg_bld("fastmap written!");
1362 
1363 out_kfree:
1364 	ubi_free_vid_hdr(ubi, avhdr);
1365 	ubi_free_vid_hdr(ubi, dvhdr);
1366 	free_seen(seen_pebs);
1367 out:
1368 	return ret;
1369 }
1370 
1371 /**
1372  * erase_block - Manually erase a PEB.
1373  * @ubi: UBI device object
1374  * @pnum: PEB to be erased
1375  *
1376  * Returns the new EC value on success, < 0 indicates an internal error.
1377  */
erase_block(struct ubi_device * ubi,int pnum)1378 static int erase_block(struct ubi_device *ubi, int pnum)
1379 {
1380 	int ret;
1381 	struct ubi_ec_hdr *ec_hdr;
1382 	long long ec;
1383 
1384 	ec_hdr = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
1385 	if (!ec_hdr)
1386 		return -ENOMEM;
1387 
1388 	ret = ubi_io_read_ec_hdr(ubi, pnum, ec_hdr, 0);
1389 	if (ret < 0)
1390 		goto out;
1391 	else if (ret && ret != UBI_IO_BITFLIPS) {
1392 		ret = -EINVAL;
1393 		goto out;
1394 	}
1395 
1396 	ret = ubi_io_sync_erase(ubi, pnum, 0);
1397 	if (ret < 0)
1398 		goto out;
1399 
1400 	ec = be64_to_cpu(ec_hdr->ec);
1401 	ec += ret;
1402 	if (ec > UBI_MAX_ERASECOUNTER) {
1403 		ret = -EINVAL;
1404 		goto out;
1405 	}
1406 
1407 	ec_hdr->ec = cpu_to_be64(ec);
1408 	ret = ubi_io_write_ec_hdr(ubi, pnum, ec_hdr);
1409 	if (ret < 0)
1410 		goto out;
1411 
1412 	ret = ec;
1413 out:
1414 	kfree(ec_hdr);
1415 	return ret;
1416 }
1417 
1418 /**
1419  * invalidate_fastmap - destroys a fastmap.
1420  * @ubi: UBI device object
1421  *
1422  * This function ensures that upon next UBI attach a full scan
1423  * is issued. We need this if UBI is about to write a new fastmap
1424  * but is unable to do so. In this case we have two options:
1425  * a) Make sure that the current fastmap will not be usued upon
1426  * attach time and contine or b) fall back to RO mode to have the
1427  * current fastmap in a valid state.
1428  * Returns 0 on success, < 0 indicates an internal error.
1429  */
invalidate_fastmap(struct ubi_device * ubi)1430 static int invalidate_fastmap(struct ubi_device *ubi)
1431 {
1432 	int ret;
1433 	struct ubi_fastmap_layout *fm;
1434 	struct ubi_wl_entry *e;
1435 	struct ubi_vid_hdr *vh = NULL;
1436 
1437 	if (!ubi->fm)
1438 		return 0;
1439 
1440 	ubi->fm = NULL;
1441 
1442 	ret = -ENOMEM;
1443 	fm = kzalloc(sizeof(*fm), GFP_KERNEL);
1444 	if (!fm)
1445 		goto out;
1446 
1447 	vh = new_fm_vhdr(ubi, UBI_FM_SB_VOLUME_ID);
1448 	if (!vh)
1449 		goto out_free_fm;
1450 
1451 	ret = -ENOSPC;
1452 	e = ubi_wl_get_fm_peb(ubi, 1);
1453 	if (!e)
1454 		goto out_free_fm;
1455 
1456 	/*
1457 	 * Create fake fastmap such that UBI will fall back
1458 	 * to scanning mode.
1459 	 */
1460 	vh->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
1461 	ret = ubi_io_write_vid_hdr(ubi, e->pnum, vh);
1462 	if (ret < 0) {
1463 		ubi_wl_put_fm_peb(ubi, e, 0, 0);
1464 		goto out_free_fm;
1465 	}
1466 
1467 	fm->used_blocks = 1;
1468 	fm->e[0] = e;
1469 
1470 	ubi->fm = fm;
1471 
1472 out:
1473 	ubi_free_vid_hdr(ubi, vh);
1474 	return ret;
1475 
1476 out_free_fm:
1477 	kfree(fm);
1478 	goto out;
1479 }
1480 
1481 /**
1482  * return_fm_pebs - returns all PEBs used by a fastmap back to the
1483  * WL sub-system.
1484  * @ubi: UBI device object
1485  * @fm: fastmap layout object
1486  */
return_fm_pebs(struct ubi_device * ubi,struct ubi_fastmap_layout * fm)1487 static void return_fm_pebs(struct ubi_device *ubi,
1488 			   struct ubi_fastmap_layout *fm)
1489 {
1490 	int i;
1491 
1492 	if (!fm)
1493 		return;
1494 
1495 	for (i = 0; i < fm->used_blocks; i++) {
1496 		if (fm->e[i]) {
1497 			ubi_wl_put_fm_peb(ubi, fm->e[i], i,
1498 					  fm->to_be_tortured[i]);
1499 			fm->e[i] = NULL;
1500 		}
1501 	}
1502 }
1503 
1504 /**
1505  * ubi_update_fastmap - will be called by UBI if a volume changes or
1506  * a fastmap pool becomes full.
1507  * @ubi: UBI device object
1508  *
1509  * Returns 0 on success, < 0 indicates an internal error.
1510  */
ubi_update_fastmap(struct ubi_device * ubi)1511 int ubi_update_fastmap(struct ubi_device *ubi)
1512 {
1513 	int ret, i, j;
1514 	struct ubi_fastmap_layout *new_fm, *old_fm;
1515 	struct ubi_wl_entry *tmp_e;
1516 
1517 	down_write(&ubi->fm_protect);
1518 	down_write(&ubi->work_sem);
1519 	down_write(&ubi->fm_eba_sem);
1520 
1521 	ubi_refill_pools(ubi);
1522 
1523 	if (ubi->ro_mode || ubi->fm_disabled) {
1524 		up_write(&ubi->fm_eba_sem);
1525 		up_write(&ubi->work_sem);
1526 		up_write(&ubi->fm_protect);
1527 		return 0;
1528 	}
1529 
1530 	ret = ubi_ensure_anchor_pebs(ubi);
1531 	if (ret) {
1532 		up_write(&ubi->fm_eba_sem);
1533 		up_write(&ubi->work_sem);
1534 		up_write(&ubi->fm_protect);
1535 		return ret;
1536 	}
1537 
1538 	new_fm = kzalloc(sizeof(*new_fm), GFP_KERNEL);
1539 	if (!new_fm) {
1540 		up_write(&ubi->fm_eba_sem);
1541 		up_write(&ubi->work_sem);
1542 		up_write(&ubi->fm_protect);
1543 		return -ENOMEM;
1544 	}
1545 
1546 	new_fm->used_blocks = ubi->fm_size / ubi->leb_size;
1547 	old_fm = ubi->fm;
1548 	ubi->fm = NULL;
1549 
1550 	if (new_fm->used_blocks > UBI_FM_MAX_BLOCKS) {
1551 		ubi_err(ubi, "fastmap too large");
1552 		ret = -ENOSPC;
1553 		goto err;
1554 	}
1555 
1556 	for (i = 1; i < new_fm->used_blocks; i++) {
1557 		spin_lock(&ubi->wl_lock);
1558 		tmp_e = ubi_wl_get_fm_peb(ubi, 0);
1559 		spin_unlock(&ubi->wl_lock);
1560 
1561 		if (!tmp_e) {
1562 			if (old_fm && old_fm->e[i]) {
1563 				ret = erase_block(ubi, old_fm->e[i]->pnum);
1564 				if (ret < 0) {
1565 					ubi_err(ubi, "could not erase old fastmap PEB");
1566 
1567 					for (j = 1; j < i; j++) {
1568 						ubi_wl_put_fm_peb(ubi, new_fm->e[j],
1569 								  j, 0);
1570 						new_fm->e[j] = NULL;
1571 					}
1572 					goto err;
1573 				}
1574 				new_fm->e[i] = old_fm->e[i];
1575 				old_fm->e[i] = NULL;
1576 			} else {
1577 				ubi_err(ubi, "could not get any free erase block");
1578 
1579 				for (j = 1; j < i; j++) {
1580 					ubi_wl_put_fm_peb(ubi, new_fm->e[j], j, 0);
1581 					new_fm->e[j] = NULL;
1582 				}
1583 
1584 				ret = -ENOSPC;
1585 				goto err;
1586 			}
1587 		} else {
1588 			new_fm->e[i] = tmp_e;
1589 
1590 			if (old_fm && old_fm->e[i]) {
1591 				ubi_wl_put_fm_peb(ubi, old_fm->e[i], i,
1592 						  old_fm->to_be_tortured[i]);
1593 				old_fm->e[i] = NULL;
1594 			}
1595 		}
1596 	}
1597 
1598 	/* Old fastmap is larger than the new one */
1599 	if (old_fm && new_fm->used_blocks < old_fm->used_blocks) {
1600 		for (i = new_fm->used_blocks; i < old_fm->used_blocks; i++) {
1601 			ubi_wl_put_fm_peb(ubi, old_fm->e[i], i,
1602 					  old_fm->to_be_tortured[i]);
1603 			old_fm->e[i] = NULL;
1604 		}
1605 	}
1606 
1607 	spin_lock(&ubi->wl_lock);
1608 	tmp_e = ubi_wl_get_fm_peb(ubi, 1);
1609 	spin_unlock(&ubi->wl_lock);
1610 
1611 	if (old_fm) {
1612 		/* no fresh anchor PEB was found, reuse the old one */
1613 		if (!tmp_e) {
1614 			ret = erase_block(ubi, old_fm->e[0]->pnum);
1615 			if (ret < 0) {
1616 				ubi_err(ubi, "could not erase old anchor PEB");
1617 
1618 				for (i = 1; i < new_fm->used_blocks; i++) {
1619 					ubi_wl_put_fm_peb(ubi, new_fm->e[i],
1620 							  i, 0);
1621 					new_fm->e[i] = NULL;
1622 				}
1623 				goto err;
1624 			}
1625 			new_fm->e[0] = old_fm->e[0];
1626 			new_fm->e[0]->ec = ret;
1627 			old_fm->e[0] = NULL;
1628 		} else {
1629 			/* we've got a new anchor PEB, return the old one */
1630 			ubi_wl_put_fm_peb(ubi, old_fm->e[0], 0,
1631 					  old_fm->to_be_tortured[0]);
1632 			new_fm->e[0] = tmp_e;
1633 			old_fm->e[0] = NULL;
1634 		}
1635 	} else {
1636 		if (!tmp_e) {
1637 			ubi_err(ubi, "could not find any anchor PEB");
1638 
1639 			for (i = 1; i < new_fm->used_blocks; i++) {
1640 				ubi_wl_put_fm_peb(ubi, new_fm->e[i], i, 0);
1641 				new_fm->e[i] = NULL;
1642 			}
1643 
1644 			ret = -ENOSPC;
1645 			goto err;
1646 		}
1647 		new_fm->e[0] = tmp_e;
1648 	}
1649 
1650 	ret = ubi_write_fastmap(ubi, new_fm);
1651 
1652 	if (ret)
1653 		goto err;
1654 
1655 out_unlock:
1656 	up_write(&ubi->fm_eba_sem);
1657 	up_write(&ubi->work_sem);
1658 	up_write(&ubi->fm_protect);
1659 	kfree(old_fm);
1660 	return ret;
1661 
1662 err:
1663 	ubi_warn(ubi, "Unable to write new fastmap, err=%i", ret);
1664 
1665 	ret = invalidate_fastmap(ubi);
1666 	if (ret < 0) {
1667 		ubi_err(ubi, "Unable to invalidiate current fastmap!");
1668 		ubi_ro_mode(ubi);
1669 	} else {
1670 		return_fm_pebs(ubi, old_fm);
1671 		return_fm_pebs(ubi, new_fm);
1672 		ret = 0;
1673 	}
1674 
1675 	kfree(new_fm);
1676 	goto out_unlock;
1677 }
1678