xref: /openbmc/u-boot/drivers/mtd/ubi/fastmap.c (revision d66ff4ba)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright (c) 2012 Linutronix GmbH
4  * Copyright (c) 2014 sigma star gmbh
5  * Author: Richard Weinberger <richard@nod.at>
6  *
7  */
8 
9 #ifndef __UBOOT__
10 #include <linux/crc32.h>
11 #else
12 #include <div64.h>
13 #include <malloc.h>
14 #include <ubi_uboot.h>
15 #endif
16 
17 #include <linux/compat.h>
18 #include <linux/math64.h>
19 #include "ubi.h"
20 
21 /**
22  * init_seen - allocate memory for used for debugging.
23  * @ubi: UBI device description object
24  */
25 static inline int *init_seen(struct ubi_device *ubi)
26 {
27 	int *ret;
28 
29 	if (!ubi_dbg_chk_fastmap(ubi))
30 		return NULL;
31 
32 	ret = kcalloc(ubi->peb_count, sizeof(int), GFP_KERNEL);
33 	if (!ret)
34 		return ERR_PTR(-ENOMEM);
35 
36 	return ret;
37 }
38 
39 /**
40  * free_seen - free the seen logic integer array.
41  * @seen: integer array of @ubi->peb_count size
42  */
43 static inline void free_seen(int *seen)
44 {
45 	kfree(seen);
46 }
47 
48 /**
49  * set_seen - mark a PEB as seen.
50  * @ubi: UBI device description object
51  * @pnum: The PEB to be makred as seen
52  * @seen: integer array of @ubi->peb_count size
53  */
54 static inline void set_seen(struct ubi_device *ubi, int pnum, int *seen)
55 {
56 	if (!ubi_dbg_chk_fastmap(ubi) || !seen)
57 		return;
58 
59 	seen[pnum] = 1;
60 }
61 
62 /**
63  * self_check_seen - check whether all PEB have been seen by fastmap.
64  * @ubi: UBI device description object
65  * @seen: integer array of @ubi->peb_count size
66  */
67 static int self_check_seen(struct ubi_device *ubi, int *seen)
68 {
69 	int pnum, ret = 0;
70 
71 	if (!ubi_dbg_chk_fastmap(ubi) || !seen)
72 		return 0;
73 
74 	for (pnum = 0; pnum < ubi->peb_count; pnum++) {
75 		if (!seen[pnum] && ubi->lookuptbl[pnum]) {
76 			ubi_err(ubi, "self-check failed for PEB %d, fastmap didn't see it", pnum);
77 			ret = -EINVAL;
78 		}
79 	}
80 
81 	return ret;
82 }
83 
84 /**
85  * ubi_calc_fm_size - calculates the fastmap size in bytes for an UBI device.
86  * @ubi: UBI device description object
87  */
88 size_t ubi_calc_fm_size(struct ubi_device *ubi)
89 {
90 	size_t size;
91 
92 	size = sizeof(struct ubi_fm_sb) +
93 		sizeof(struct ubi_fm_hdr) +
94 		sizeof(struct ubi_fm_scan_pool) +
95 		sizeof(struct ubi_fm_scan_pool) +
96 		(ubi->peb_count * sizeof(struct ubi_fm_ec)) +
97 		(sizeof(struct ubi_fm_eba) +
98 		(ubi->peb_count * sizeof(__be32))) +
99 		sizeof(struct ubi_fm_volhdr) * UBI_MAX_VOLUMES;
100 	return roundup(size, ubi->leb_size);
101 }
102 
103 
104 /**
105  * new_fm_vhdr - allocate a new volume header for fastmap usage.
106  * @ubi: UBI device description object
107  * @vol_id: the VID of the new header
108  *
109  * Returns a new struct ubi_vid_hdr on success.
110  * NULL indicates out of memory.
111  */
112 static struct ubi_vid_hdr *new_fm_vhdr(struct ubi_device *ubi, int vol_id)
113 {
114 	struct ubi_vid_hdr *new;
115 
116 	new = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
117 	if (!new)
118 		goto out;
119 
120 	new->vol_type = UBI_VID_DYNAMIC;
121 	new->vol_id = cpu_to_be32(vol_id);
122 
123 	/* UBI implementations without fastmap support have to delete the
124 	 * fastmap.
125 	 */
126 	new->compat = UBI_COMPAT_DELETE;
127 
128 out:
129 	return new;
130 }
131 
132 /**
133  * add_aeb - create and add a attach erase block to a given list.
134  * @ai: UBI attach info object
135  * @list: the target list
136  * @pnum: PEB number of the new attach erase block
137  * @ec: erease counter of the new LEB
138  * @scrub: scrub this PEB after attaching
139  *
140  * Returns 0 on success, < 0 indicates an internal error.
141  */
142 static int add_aeb(struct ubi_attach_info *ai, struct list_head *list,
143 		   int pnum, int ec, int scrub)
144 {
145 	struct ubi_ainf_peb *aeb;
146 
147 	aeb = kmem_cache_alloc(ai->aeb_slab_cache, GFP_KERNEL);
148 	if (!aeb)
149 		return -ENOMEM;
150 
151 	aeb->pnum = pnum;
152 	aeb->ec = ec;
153 	aeb->lnum = -1;
154 	aeb->scrub = scrub;
155 	aeb->copy_flag = aeb->sqnum = 0;
156 
157 	ai->ec_sum += aeb->ec;
158 	ai->ec_count++;
159 
160 	if (ai->max_ec < aeb->ec)
161 		ai->max_ec = aeb->ec;
162 
163 	if (ai->min_ec > aeb->ec)
164 		ai->min_ec = aeb->ec;
165 
166 	list_add_tail(&aeb->u.list, list);
167 
168 	return 0;
169 }
170 
171 /**
172  * add_vol - create and add a new volume to ubi_attach_info.
173  * @ai: ubi_attach_info object
174  * @vol_id: VID of the new volume
175  * @used_ebs: number of used EBS
176  * @data_pad: data padding value of the new volume
177  * @vol_type: volume type
178  * @last_eb_bytes: number of bytes in the last LEB
179  *
180  * Returns the new struct ubi_ainf_volume on success.
181  * NULL indicates an error.
182  */
183 static struct ubi_ainf_volume *add_vol(struct ubi_attach_info *ai, int vol_id,
184 				       int used_ebs, int data_pad, u8 vol_type,
185 				       int last_eb_bytes)
186 {
187 	struct ubi_ainf_volume *av;
188 	struct rb_node **p = &ai->volumes.rb_node, *parent = NULL;
189 
190 	while (*p) {
191 		parent = *p;
192 		av = rb_entry(parent, struct ubi_ainf_volume, rb);
193 
194 		if (vol_id > av->vol_id)
195 			p = &(*p)->rb_left;
196 		else if (vol_id < av->vol_id)
197 			p = &(*p)->rb_right;
198 		else
199 			return ERR_PTR(-EINVAL);
200 	}
201 
202 	av = kmalloc(sizeof(struct ubi_ainf_volume), GFP_KERNEL);
203 	if (!av)
204 		goto out;
205 
206 	av->highest_lnum = av->leb_count = av->used_ebs = 0;
207 	av->vol_id = vol_id;
208 	av->data_pad = data_pad;
209 	av->last_data_size = last_eb_bytes;
210 	av->compat = 0;
211 	av->vol_type = vol_type;
212 	av->root = RB_ROOT;
213 	if (av->vol_type == UBI_STATIC_VOLUME)
214 		av->used_ebs = used_ebs;
215 
216 	dbg_bld("found volume (ID %i)", vol_id);
217 
218 	rb_link_node(&av->rb, parent, p);
219 	rb_insert_color(&av->rb, &ai->volumes);
220 
221 out:
222 	return av;
223 }
224 
225 /**
226  * assign_aeb_to_av - assigns a SEB to a given ainf_volume and removes it
227  * from it's original list.
228  * @ai: ubi_attach_info object
229  * @aeb: the to be assigned SEB
230  * @av: target scan volume
231  */
232 static void assign_aeb_to_av(struct ubi_attach_info *ai,
233 			     struct ubi_ainf_peb *aeb,
234 			     struct ubi_ainf_volume *av)
235 {
236 	struct ubi_ainf_peb *tmp_aeb;
237 	struct rb_node **p = &ai->volumes.rb_node, *parent = NULL;
238 
239 	p = &av->root.rb_node;
240 	while (*p) {
241 		parent = *p;
242 
243 		tmp_aeb = rb_entry(parent, struct ubi_ainf_peb, u.rb);
244 		if (aeb->lnum != tmp_aeb->lnum) {
245 			if (aeb->lnum < tmp_aeb->lnum)
246 				p = &(*p)->rb_left;
247 			else
248 				p = &(*p)->rb_right;
249 
250 			continue;
251 		} else
252 			break;
253 	}
254 
255 	list_del(&aeb->u.list);
256 	av->leb_count++;
257 
258 	rb_link_node(&aeb->u.rb, parent, p);
259 	rb_insert_color(&aeb->u.rb, &av->root);
260 }
261 
262 /**
263  * update_vol - inserts or updates a LEB which was found a pool.
264  * @ubi: the UBI device object
265  * @ai: attach info object
266  * @av: the volume this LEB belongs to
267  * @new_vh: the volume header derived from new_aeb
268  * @new_aeb: the AEB to be examined
269  *
270  * Returns 0 on success, < 0 indicates an internal error.
271  */
272 static int update_vol(struct ubi_device *ubi, struct ubi_attach_info *ai,
273 		      struct ubi_ainf_volume *av, struct ubi_vid_hdr *new_vh,
274 		      struct ubi_ainf_peb *new_aeb)
275 {
276 	struct rb_node **p = &av->root.rb_node, *parent = NULL;
277 	struct ubi_ainf_peb *aeb, *victim;
278 	int cmp_res;
279 
280 	while (*p) {
281 		parent = *p;
282 		aeb = rb_entry(parent, struct ubi_ainf_peb, u.rb);
283 
284 		if (be32_to_cpu(new_vh->lnum) != aeb->lnum) {
285 			if (be32_to_cpu(new_vh->lnum) < aeb->lnum)
286 				p = &(*p)->rb_left;
287 			else
288 				p = &(*p)->rb_right;
289 
290 			continue;
291 		}
292 
293 		/* This case can happen if the fastmap gets written
294 		 * because of a volume change (creation, deletion, ..).
295 		 * Then a PEB can be within the persistent EBA and the pool.
296 		 */
297 		if (aeb->pnum == new_aeb->pnum) {
298 			ubi_assert(aeb->lnum == new_aeb->lnum);
299 			kmem_cache_free(ai->aeb_slab_cache, new_aeb);
300 
301 			return 0;
302 		}
303 
304 		cmp_res = ubi_compare_lebs(ubi, aeb, new_aeb->pnum, new_vh);
305 		if (cmp_res < 0)
306 			return cmp_res;
307 
308 		/* new_aeb is newer */
309 		if (cmp_res & 1) {
310 			victim = kmem_cache_alloc(ai->aeb_slab_cache,
311 				GFP_KERNEL);
312 			if (!victim)
313 				return -ENOMEM;
314 
315 			victim->ec = aeb->ec;
316 			victim->pnum = aeb->pnum;
317 			list_add_tail(&victim->u.list, &ai->erase);
318 
319 			if (av->highest_lnum == be32_to_cpu(new_vh->lnum))
320 				av->last_data_size =
321 					be32_to_cpu(new_vh->data_size);
322 
323 			dbg_bld("vol %i: AEB %i's PEB %i is the newer",
324 				av->vol_id, aeb->lnum, new_aeb->pnum);
325 
326 			aeb->ec = new_aeb->ec;
327 			aeb->pnum = new_aeb->pnum;
328 			aeb->copy_flag = new_vh->copy_flag;
329 			aeb->scrub = new_aeb->scrub;
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  */
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  */
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  */
453 #ifndef __UBOOT__
454 static int scan_pool(struct ubi_device *ubi, struct ubi_attach_info *ai,
455 		     __be32 *pebs, int pool_size, unsigned long long *max_sqnum,
456 		     struct list_head *free)
457 #else
458 static int scan_pool(struct ubi_device *ubi, struct ubi_attach_info *ai,
459 		     __be32 *pebs, int pool_size, unsigned long long *max_sqnum,
460 		     struct list_head *free)
461 #endif
462 {
463 	struct ubi_vid_hdr *vh;
464 	struct ubi_ec_hdr *ech;
465 	struct ubi_ainf_peb *new_aeb;
466 	int i, pnum, err, ret = 0;
467 
468 	ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
469 	if (!ech)
470 		return -ENOMEM;
471 
472 	vh = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
473 	if (!vh) {
474 		kfree(ech);
475 		return -ENOMEM;
476 	}
477 
478 	dbg_bld("scanning fastmap pool: size = %i", pool_size);
479 
480 	/*
481 	 * Now scan all PEBs in the pool to find changes which have been made
482 	 * after the creation of the fastmap
483 	 */
484 	for (i = 0; i < pool_size; i++) {
485 		int scrub = 0;
486 		int image_seq;
487 
488 		pnum = be32_to_cpu(pebs[i]);
489 
490 		if (ubi_io_is_bad(ubi, pnum)) {
491 			ubi_err(ubi, "bad PEB in fastmap pool!");
492 			ret = UBI_BAD_FASTMAP;
493 			goto out;
494 		}
495 
496 		err = ubi_io_read_ec_hdr(ubi, pnum, ech, 0);
497 		if (err && err != UBI_IO_BITFLIPS) {
498 			ubi_err(ubi, "unable to read EC header! PEB:%i err:%i",
499 				pnum, err);
500 			ret = err > 0 ? UBI_BAD_FASTMAP : err;
501 			goto out;
502 		} else if (err == UBI_IO_BITFLIPS)
503 			scrub = 1;
504 
505 		/*
506 		 * Older UBI implementations have image_seq set to zero, so
507 		 * we shouldn't fail if image_seq == 0.
508 		 */
509 		image_seq = be32_to_cpu(ech->image_seq);
510 
511 		if (image_seq && (image_seq != ubi->image_seq)) {
512 			ubi_err(ubi, "bad image seq: 0x%x, expected: 0x%x",
513 				be32_to_cpu(ech->image_seq), ubi->image_seq);
514 			ret = UBI_BAD_FASTMAP;
515 			goto out;
516 		}
517 
518 		err = ubi_io_read_vid_hdr(ubi, pnum, vh, 0);
519 		if (err == UBI_IO_FF || err == UBI_IO_FF_BITFLIPS) {
520 			unsigned long long ec = be64_to_cpu(ech->ec);
521 			unmap_peb(ai, pnum);
522 			dbg_bld("Adding PEB to free: %i", pnum);
523 			if (err == UBI_IO_FF_BITFLIPS)
524 				add_aeb(ai, free, pnum, ec, 1);
525 			else
526 				add_aeb(ai, free, pnum, ec, 0);
527 			continue;
528 		} else if (err == 0 || err == UBI_IO_BITFLIPS) {
529 			dbg_bld("Found non empty PEB:%i in pool", pnum);
530 
531 			if (err == UBI_IO_BITFLIPS)
532 				scrub = 1;
533 
534 			new_aeb = kmem_cache_alloc(ai->aeb_slab_cache,
535 						   GFP_KERNEL);
536 			if (!new_aeb) {
537 				ret = -ENOMEM;
538 				goto out;
539 			}
540 
541 			new_aeb->ec = be64_to_cpu(ech->ec);
542 			new_aeb->pnum = pnum;
543 			new_aeb->lnum = be32_to_cpu(vh->lnum);
544 			new_aeb->sqnum = be64_to_cpu(vh->sqnum);
545 			new_aeb->copy_flag = vh->copy_flag;
546 			new_aeb->scrub = scrub;
547 
548 			if (*max_sqnum < new_aeb->sqnum)
549 				*max_sqnum = new_aeb->sqnum;
550 
551 			err = process_pool_aeb(ubi, ai, vh, new_aeb);
552 			if (err) {
553 				ret = err > 0 ? UBI_BAD_FASTMAP : err;
554 				goto out;
555 			}
556 		} else {
557 			/* We are paranoid and fall back to scanning mode */
558 			ubi_err(ubi, "fastmap pool PEBs contains damaged PEBs!");
559 			ret = err > 0 ? UBI_BAD_FASTMAP : err;
560 			goto out;
561 		}
562 
563 	}
564 
565 out:
566 	ubi_free_vid_hdr(ubi, vh);
567 	kfree(ech);
568 	return ret;
569 }
570 
571 /**
572  * count_fastmap_pebs - Counts the PEBs found by fastmap.
573  * @ai: The UBI attach info object
574  */
575 static int count_fastmap_pebs(struct ubi_attach_info *ai)
576 {
577 	struct ubi_ainf_peb *aeb;
578 	struct ubi_ainf_volume *av;
579 	struct rb_node *rb1, *rb2;
580 	int n = 0;
581 
582 	list_for_each_entry(aeb, &ai->erase, u.list)
583 		n++;
584 
585 	list_for_each_entry(aeb, &ai->free, u.list)
586 		n++;
587 
588 	 ubi_rb_for_each_entry(rb1, av, &ai->volumes, rb)
589 		ubi_rb_for_each_entry(rb2, aeb, &av->root, u.rb)
590 			n++;
591 
592 	return n;
593 }
594 
595 /**
596  * ubi_attach_fastmap - creates ubi_attach_info from a fastmap.
597  * @ubi: UBI device object
598  * @ai: UBI attach info object
599  * @fm: the fastmap to be attached
600  *
601  * Returns 0 on success, UBI_BAD_FASTMAP if the found fastmap was unusable.
602  * < 0 indicates an internal error.
603  */
604 static int ubi_attach_fastmap(struct ubi_device *ubi,
605 			      struct ubi_attach_info *ai,
606 			      struct ubi_fastmap_layout *fm)
607 {
608 	struct list_head used, free;
609 	struct ubi_ainf_volume *av;
610 	struct ubi_ainf_peb *aeb, *tmp_aeb, *_tmp_aeb;
611 	struct ubi_fm_sb *fmsb;
612 	struct ubi_fm_hdr *fmhdr;
613 	struct ubi_fm_scan_pool *fmpl, *fmpl_wl;
614 	struct ubi_fm_ec *fmec;
615 	struct ubi_fm_volhdr *fmvhdr;
616 	struct ubi_fm_eba *fm_eba;
617 	int ret, i, j, pool_size, wl_pool_size;
618 	size_t fm_pos = 0, fm_size = ubi->fm_size;
619 	unsigned long long max_sqnum = 0;
620 	void *fm_raw = ubi->fm_buf;
621 
622 	INIT_LIST_HEAD(&used);
623 	INIT_LIST_HEAD(&free);
624 	ai->min_ec = UBI_MAX_ERASECOUNTER;
625 
626 	fmsb = (struct ubi_fm_sb *)(fm_raw);
627 	ai->max_sqnum = fmsb->sqnum;
628 	fm_pos += sizeof(struct ubi_fm_sb);
629 	if (fm_pos >= fm_size)
630 		goto fail_bad;
631 
632 	fmhdr = (struct ubi_fm_hdr *)(fm_raw + fm_pos);
633 	fm_pos += sizeof(*fmhdr);
634 	if (fm_pos >= fm_size)
635 		goto fail_bad;
636 
637 	if (be32_to_cpu(fmhdr->magic) != UBI_FM_HDR_MAGIC) {
638 		ubi_err(ubi, "bad fastmap header magic: 0x%x, expected: 0x%x",
639 			be32_to_cpu(fmhdr->magic), UBI_FM_HDR_MAGIC);
640 		goto fail_bad;
641 	}
642 
643 	fmpl = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
644 	fm_pos += sizeof(*fmpl);
645 	if (fm_pos >= fm_size)
646 		goto fail_bad;
647 	if (be32_to_cpu(fmpl->magic) != UBI_FM_POOL_MAGIC) {
648 		ubi_err(ubi, "bad fastmap pool magic: 0x%x, expected: 0x%x",
649 			be32_to_cpu(fmpl->magic), UBI_FM_POOL_MAGIC);
650 		goto fail_bad;
651 	}
652 
653 	fmpl_wl = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
654 	fm_pos += sizeof(*fmpl_wl);
655 	if (fm_pos >= fm_size)
656 		goto fail_bad;
657 	if (be32_to_cpu(fmpl_wl->magic) != UBI_FM_POOL_MAGIC) {
658 		ubi_err(ubi, "bad fastmap WL pool magic: 0x%x, expected: 0x%x",
659 			be32_to_cpu(fmpl_wl->magic), UBI_FM_POOL_MAGIC);
660 		goto fail_bad;
661 	}
662 
663 	pool_size = be16_to_cpu(fmpl->size);
664 	wl_pool_size = be16_to_cpu(fmpl_wl->size);
665 	fm->max_pool_size = be16_to_cpu(fmpl->max_size);
666 	fm->max_wl_pool_size = be16_to_cpu(fmpl_wl->max_size);
667 
668 	if (pool_size > UBI_FM_MAX_POOL_SIZE || pool_size < 0) {
669 		ubi_err(ubi, "bad pool size: %i", pool_size);
670 		goto fail_bad;
671 	}
672 
673 	if (wl_pool_size > UBI_FM_MAX_POOL_SIZE || wl_pool_size < 0) {
674 		ubi_err(ubi, "bad WL pool size: %i", wl_pool_size);
675 		goto fail_bad;
676 	}
677 
678 
679 	if (fm->max_pool_size > UBI_FM_MAX_POOL_SIZE ||
680 	    fm->max_pool_size < 0) {
681 		ubi_err(ubi, "bad maximal pool size: %i", fm->max_pool_size);
682 		goto fail_bad;
683 	}
684 
685 	if (fm->max_wl_pool_size > UBI_FM_MAX_POOL_SIZE ||
686 	    fm->max_wl_pool_size < 0) {
687 		ubi_err(ubi, "bad maximal WL pool size: %i",
688 			fm->max_wl_pool_size);
689 		goto fail_bad;
690 	}
691 
692 	/* read EC values from free list */
693 	for (i = 0; i < be32_to_cpu(fmhdr->free_peb_count); i++) {
694 		fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
695 		fm_pos += sizeof(*fmec);
696 		if (fm_pos >= fm_size)
697 			goto fail_bad;
698 
699 		add_aeb(ai, &ai->free, be32_to_cpu(fmec->pnum),
700 			be32_to_cpu(fmec->ec), 0);
701 	}
702 
703 	/* read EC values from used list */
704 	for (i = 0; i < be32_to_cpu(fmhdr->used_peb_count); i++) {
705 		fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
706 		fm_pos += sizeof(*fmec);
707 		if (fm_pos >= fm_size)
708 			goto fail_bad;
709 
710 		add_aeb(ai, &used, be32_to_cpu(fmec->pnum),
711 			be32_to_cpu(fmec->ec), 0);
712 	}
713 
714 	/* read EC values from scrub list */
715 	for (i = 0; i < be32_to_cpu(fmhdr->scrub_peb_count); i++) {
716 		fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
717 		fm_pos += sizeof(*fmec);
718 		if (fm_pos >= fm_size)
719 			goto fail_bad;
720 
721 		add_aeb(ai, &used, be32_to_cpu(fmec->pnum),
722 			be32_to_cpu(fmec->ec), 1);
723 	}
724 
725 	/* read EC values from erase list */
726 	for (i = 0; i < be32_to_cpu(fmhdr->erase_peb_count); i++) {
727 		fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
728 		fm_pos += sizeof(*fmec);
729 		if (fm_pos >= fm_size)
730 			goto fail_bad;
731 
732 		add_aeb(ai, &ai->erase, be32_to_cpu(fmec->pnum),
733 			be32_to_cpu(fmec->ec), 1);
734 	}
735 
736 	ai->mean_ec = div_u64(ai->ec_sum, ai->ec_count);
737 	ai->bad_peb_count = be32_to_cpu(fmhdr->bad_peb_count);
738 
739 	/* Iterate over all volumes and read their EBA table */
740 	for (i = 0; i < be32_to_cpu(fmhdr->vol_count); i++) {
741 		fmvhdr = (struct ubi_fm_volhdr *)(fm_raw + fm_pos);
742 		fm_pos += sizeof(*fmvhdr);
743 		if (fm_pos >= fm_size)
744 			goto fail_bad;
745 
746 		if (be32_to_cpu(fmvhdr->magic) != UBI_FM_VHDR_MAGIC) {
747 			ubi_err(ubi, "bad fastmap vol header magic: 0x%x, expected: 0x%x",
748 				be32_to_cpu(fmvhdr->magic), UBI_FM_VHDR_MAGIC);
749 			goto fail_bad;
750 		}
751 
752 		av = add_vol(ai, be32_to_cpu(fmvhdr->vol_id),
753 			     be32_to_cpu(fmvhdr->used_ebs),
754 			     be32_to_cpu(fmvhdr->data_pad),
755 			     fmvhdr->vol_type,
756 			     be32_to_cpu(fmvhdr->last_eb_bytes));
757 
758 		if (!av)
759 			goto fail_bad;
760 		if (PTR_ERR(av) == -EINVAL) {
761 			ubi_err(ubi, "volume (ID %i) already exists",
762 				fmvhdr->vol_id);
763 			goto fail_bad;
764 		}
765 
766 		ai->vols_found++;
767 		if (ai->highest_vol_id < be32_to_cpu(fmvhdr->vol_id))
768 			ai->highest_vol_id = be32_to_cpu(fmvhdr->vol_id);
769 
770 		fm_eba = (struct ubi_fm_eba *)(fm_raw + fm_pos);
771 		fm_pos += sizeof(*fm_eba);
772 		fm_pos += (sizeof(__be32) * be32_to_cpu(fm_eba->reserved_pebs));
773 		if (fm_pos >= fm_size)
774 			goto fail_bad;
775 
776 		if (be32_to_cpu(fm_eba->magic) != UBI_FM_EBA_MAGIC) {
777 			ubi_err(ubi, "bad fastmap EBA header magic: 0x%x, expected: 0x%x",
778 				be32_to_cpu(fm_eba->magic), UBI_FM_EBA_MAGIC);
779 			goto fail_bad;
780 		}
781 
782 		for (j = 0; j < be32_to_cpu(fm_eba->reserved_pebs); j++) {
783 			int pnum = be32_to_cpu(fm_eba->pnum[j]);
784 
785 			if ((int)be32_to_cpu(fm_eba->pnum[j]) < 0)
786 				continue;
787 
788 			aeb = NULL;
789 			list_for_each_entry(tmp_aeb, &used, u.list) {
790 				if (tmp_aeb->pnum == pnum) {
791 					aeb = tmp_aeb;
792 					break;
793 				}
794 			}
795 
796 			if (!aeb) {
797 				ubi_err(ubi, "PEB %i is in EBA but not in used list", pnum);
798 				goto fail_bad;
799 			}
800 
801 			aeb->lnum = j;
802 
803 			if (av->highest_lnum <= aeb->lnum)
804 				av->highest_lnum = aeb->lnum;
805 
806 			assign_aeb_to_av(ai, aeb, av);
807 
808 			dbg_bld("inserting PEB:%i (LEB %i) to vol %i",
809 				aeb->pnum, aeb->lnum, av->vol_id);
810 		}
811 	}
812 
813 	ret = scan_pool(ubi, ai, fmpl->pebs, pool_size, &max_sqnum, &free);
814 	if (ret)
815 		goto fail;
816 
817 	ret = scan_pool(ubi, ai, fmpl_wl->pebs, wl_pool_size, &max_sqnum, &free);
818 	if (ret)
819 		goto fail;
820 
821 	if (max_sqnum > ai->max_sqnum)
822 		ai->max_sqnum = max_sqnum;
823 
824 	list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &free, u.list)
825 		list_move_tail(&tmp_aeb->u.list, &ai->free);
826 
827 	list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &used, u.list)
828 		list_move_tail(&tmp_aeb->u.list, &ai->erase);
829 
830 	ubi_assert(list_empty(&free));
831 
832 	/*
833 	 * If fastmap is leaking PEBs (must not happen), raise a
834 	 * fat warning and fall back to scanning mode.
835 	 * We do this here because in ubi_wl_init() it's too late
836 	 * and we cannot fall back to scanning.
837 	 */
838 #ifndef __UBOOT__
839 	if (WARN_ON(count_fastmap_pebs(ai) != ubi->peb_count -
840 		    ai->bad_peb_count - fm->used_blocks))
841 		goto fail_bad;
842 #else
843 	if (count_fastmap_pebs(ai) != ubi->peb_count -
844 		    ai->bad_peb_count - fm->used_blocks) {
845 		WARN_ON(1);
846 		goto fail_bad;
847 	}
848 #endif
849 
850 	return 0;
851 
852 fail_bad:
853 	ret = UBI_BAD_FASTMAP;
854 fail:
855 	list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &used, u.list) {
856 		list_del(&tmp_aeb->u.list);
857 		kmem_cache_free(ai->aeb_slab_cache, tmp_aeb);
858 	}
859 	list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &free, u.list) {
860 		list_del(&tmp_aeb->u.list);
861 		kmem_cache_free(ai->aeb_slab_cache, tmp_aeb);
862 	}
863 
864 	return ret;
865 }
866 
867 /**
868  * ubi_scan_fastmap - scan the fastmap.
869  * @ubi: UBI device object
870  * @ai: UBI attach info to be filled
871  * @fm_anchor: The fastmap starts at this PEB
872  *
873  * Returns 0 on success, UBI_NO_FASTMAP if no fastmap was found,
874  * UBI_BAD_FASTMAP if one was found but is not usable.
875  * < 0 indicates an internal error.
876  */
877 int ubi_scan_fastmap(struct ubi_device *ubi, struct ubi_attach_info *ai,
878 		     int fm_anchor)
879 {
880 	struct ubi_fm_sb *fmsb, *fmsb2;
881 	struct ubi_vid_hdr *vh;
882 	struct ubi_ec_hdr *ech;
883 	struct ubi_fastmap_layout *fm;
884 	int i, used_blocks, pnum, ret = 0;
885 	size_t fm_size;
886 	__be32 crc, tmp_crc;
887 	unsigned long long sqnum = 0;
888 
889 	down_write(&ubi->fm_protect);
890 	memset(ubi->fm_buf, 0, ubi->fm_size);
891 
892 	fmsb = kmalloc(sizeof(*fmsb), GFP_KERNEL);
893 	if (!fmsb) {
894 		ret = -ENOMEM;
895 		goto out;
896 	}
897 
898 	fm = kzalloc(sizeof(*fm), GFP_KERNEL);
899 	if (!fm) {
900 		ret = -ENOMEM;
901 		kfree(fmsb);
902 		goto out;
903 	}
904 
905 	ret = ubi_io_read(ubi, fmsb, fm_anchor, ubi->leb_start, sizeof(*fmsb));
906 	if (ret && ret != UBI_IO_BITFLIPS)
907 		goto free_fm_sb;
908 	else if (ret == UBI_IO_BITFLIPS)
909 		fm->to_be_tortured[0] = 1;
910 
911 	if (be32_to_cpu(fmsb->magic) != UBI_FM_SB_MAGIC) {
912 		ubi_err(ubi, "bad super block magic: 0x%x, expected: 0x%x",
913 			be32_to_cpu(fmsb->magic), UBI_FM_SB_MAGIC);
914 		ret = UBI_BAD_FASTMAP;
915 		goto free_fm_sb;
916 	}
917 
918 	if (fmsb->version != UBI_FM_FMT_VERSION) {
919 		ubi_err(ubi, "bad fastmap version: %i, expected: %i",
920 			fmsb->version, UBI_FM_FMT_VERSION);
921 		ret = UBI_BAD_FASTMAP;
922 		goto free_fm_sb;
923 	}
924 
925 	used_blocks = be32_to_cpu(fmsb->used_blocks);
926 	if (used_blocks > UBI_FM_MAX_BLOCKS || used_blocks < 1) {
927 		ubi_err(ubi, "number of fastmap blocks is invalid: %i",
928 			used_blocks);
929 		ret = UBI_BAD_FASTMAP;
930 		goto free_fm_sb;
931 	}
932 
933 	fm_size = ubi->leb_size * used_blocks;
934 	if (fm_size != ubi->fm_size) {
935 		ubi_err(ubi, "bad fastmap size: %zi, expected: %zi",
936 			fm_size, ubi->fm_size);
937 		ret = UBI_BAD_FASTMAP;
938 		goto free_fm_sb;
939 	}
940 
941 	ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
942 	if (!ech) {
943 		ret = -ENOMEM;
944 		goto free_fm_sb;
945 	}
946 
947 	vh = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
948 	if (!vh) {
949 		ret = -ENOMEM;
950 		goto free_hdr;
951 	}
952 
953 	for (i = 0; i < used_blocks; i++) {
954 		int image_seq;
955 
956 		pnum = be32_to_cpu(fmsb->block_loc[i]);
957 
958 		if (ubi_io_is_bad(ubi, pnum)) {
959 			ret = UBI_BAD_FASTMAP;
960 			goto free_hdr;
961 		}
962 
963 		ret = ubi_io_read_ec_hdr(ubi, pnum, ech, 0);
964 		if (ret && ret != UBI_IO_BITFLIPS) {
965 			ubi_err(ubi, "unable to read fastmap block# %i EC (PEB: %i)",
966 				i, pnum);
967 			if (ret > 0)
968 				ret = UBI_BAD_FASTMAP;
969 			goto free_hdr;
970 		} else if (ret == UBI_IO_BITFLIPS)
971 			fm->to_be_tortured[i] = 1;
972 
973 		image_seq = be32_to_cpu(ech->image_seq);
974 		if (!ubi->image_seq)
975 			ubi->image_seq = image_seq;
976 
977 		/*
978 		 * Older UBI implementations have image_seq set to zero, so
979 		 * we shouldn't fail if image_seq == 0.
980 		 */
981 		if (image_seq && (image_seq != ubi->image_seq)) {
982 			ubi_err(ubi, "wrong image seq:%d instead of %d",
983 				be32_to_cpu(ech->image_seq), ubi->image_seq);
984 			ret = UBI_BAD_FASTMAP;
985 			goto free_hdr;
986 		}
987 
988 		ret = ubi_io_read_vid_hdr(ubi, pnum, vh, 0);
989 		if (ret && ret != UBI_IO_BITFLIPS) {
990 			ubi_err(ubi, "unable to read fastmap block# %i (PEB: %i)",
991 				i, pnum);
992 			goto free_hdr;
993 		}
994 
995 		if (i == 0) {
996 			if (be32_to_cpu(vh->vol_id) != UBI_FM_SB_VOLUME_ID) {
997 				ubi_err(ubi, "bad fastmap anchor vol_id: 0x%x, expected: 0x%x",
998 					be32_to_cpu(vh->vol_id),
999 					UBI_FM_SB_VOLUME_ID);
1000 				ret = UBI_BAD_FASTMAP;
1001 				goto free_hdr;
1002 			}
1003 		} else {
1004 			if (be32_to_cpu(vh->vol_id) != UBI_FM_DATA_VOLUME_ID) {
1005 				ubi_err(ubi, "bad fastmap data vol_id: 0x%x, 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(ubi, "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(ubi, "fastmap data CRC is invalid");
1034 		ubi_err(ubi, "CRC should be: 0x%x, calc: 0x%x",
1035 			tmp_crc, crc);
1036 		ret = UBI_BAD_FASTMAP;
1037 		goto free_hdr;
1038 	}
1039 
1040 	fmsb2->sqnum = sqnum;
1041 
1042 	fm->used_blocks = used_blocks;
1043 
1044 	ret = ubi_attach_fastmap(ubi, ai, fm);
1045 	if (ret) {
1046 		if (ret > 0)
1047 			ret = UBI_BAD_FASTMAP;
1048 		goto free_hdr;
1049 	}
1050 
1051 	for (i = 0; i < used_blocks; i++) {
1052 		struct ubi_wl_entry *e;
1053 
1054 		e = kmem_cache_alloc(ubi_wl_entry_slab, GFP_KERNEL);
1055 		if (!e) {
1056 			while (i--)
1057 				kfree(fm->e[i]);
1058 
1059 			ret = -ENOMEM;
1060 			goto free_hdr;
1061 		}
1062 
1063 		e->pnum = be32_to_cpu(fmsb2->block_loc[i]);
1064 		e->ec = be32_to_cpu(fmsb2->block_ec[i]);
1065 		fm->e[i] = e;
1066 	}
1067 
1068 	ubi->fm = fm;
1069 	ubi->fm_pool.max_size = ubi->fm->max_pool_size;
1070 	ubi->fm_wl_pool.max_size = ubi->fm->max_wl_pool_size;
1071 	ubi_msg(ubi, "attached by fastmap");
1072 	ubi_msg(ubi, "fastmap pool size: %d", ubi->fm_pool.max_size);
1073 	ubi_msg(ubi, "fastmap WL pool size: %d",
1074 		ubi->fm_wl_pool.max_size);
1075 	ubi->fm_disabled = 0;
1076 
1077 	ubi_free_vid_hdr(ubi, vh);
1078 	kfree(ech);
1079 out:
1080 	up_write(&ubi->fm_protect);
1081 	if (ret == UBI_BAD_FASTMAP)
1082 		ubi_err(ubi, "Attach by fastmap failed, doing a full scan!");
1083 	return ret;
1084 
1085 free_hdr:
1086 	ubi_free_vid_hdr(ubi, vh);
1087 	kfree(ech);
1088 free_fm_sb:
1089 	kfree(fmsb);
1090 	kfree(fm);
1091 	goto out;
1092 }
1093 
1094 /**
1095  * ubi_write_fastmap - writes a fastmap.
1096  * @ubi: UBI device object
1097  * @new_fm: the to be written fastmap
1098  *
1099  * Returns 0 on success, < 0 indicates an internal error.
1100  */
1101 static int ubi_write_fastmap(struct ubi_device *ubi,
1102 			     struct ubi_fastmap_layout *new_fm)
1103 {
1104 	size_t fm_pos = 0;
1105 	void *fm_raw;
1106 	struct ubi_fm_sb *fmsb;
1107 	struct ubi_fm_hdr *fmh;
1108 	struct ubi_fm_scan_pool *fmpl, *fmpl_wl;
1109 	struct ubi_fm_ec *fec;
1110 	struct ubi_fm_volhdr *fvh;
1111 	struct ubi_fm_eba *feba;
1112 	struct ubi_wl_entry *wl_e;
1113 	struct ubi_volume *vol;
1114 	struct ubi_vid_hdr *avhdr, *dvhdr;
1115 	struct ubi_work *ubi_wrk;
1116 	struct rb_node *tmp_rb;
1117 	int ret, i, j, free_peb_count, used_peb_count, vol_count;
1118 	int scrub_peb_count, erase_peb_count;
1119 	int *seen_pebs = NULL;
1120 
1121 	fm_raw = ubi->fm_buf;
1122 	memset(ubi->fm_buf, 0, ubi->fm_size);
1123 
1124 	avhdr = new_fm_vhdr(ubi, UBI_FM_SB_VOLUME_ID);
1125 	if (!avhdr) {
1126 		ret = -ENOMEM;
1127 		goto out;
1128 	}
1129 
1130 	dvhdr = new_fm_vhdr(ubi, UBI_FM_DATA_VOLUME_ID);
1131 	if (!dvhdr) {
1132 		ret = -ENOMEM;
1133 		goto out_kfree;
1134 	}
1135 
1136 	seen_pebs = init_seen(ubi);
1137 	if (IS_ERR(seen_pebs)) {
1138 		ret = PTR_ERR(seen_pebs);
1139 		goto out_kfree;
1140 	}
1141 
1142 	spin_lock(&ubi->volumes_lock);
1143 	spin_lock(&ubi->wl_lock);
1144 
1145 	fmsb = (struct ubi_fm_sb *)fm_raw;
1146 	fm_pos += sizeof(*fmsb);
1147 	ubi_assert(fm_pos <= ubi->fm_size);
1148 
1149 	fmh = (struct ubi_fm_hdr *)(fm_raw + fm_pos);
1150 	fm_pos += sizeof(*fmh);
1151 	ubi_assert(fm_pos <= ubi->fm_size);
1152 
1153 	fmsb->magic = cpu_to_be32(UBI_FM_SB_MAGIC);
1154 	fmsb->version = UBI_FM_FMT_VERSION;
1155 	fmsb->used_blocks = cpu_to_be32(new_fm->used_blocks);
1156 	/* the max sqnum will be filled in while *reading* the fastmap */
1157 	fmsb->sqnum = 0;
1158 
1159 	fmh->magic = cpu_to_be32(UBI_FM_HDR_MAGIC);
1160 	free_peb_count = 0;
1161 	used_peb_count = 0;
1162 	scrub_peb_count = 0;
1163 	erase_peb_count = 0;
1164 	vol_count = 0;
1165 
1166 	fmpl = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
1167 	fm_pos += sizeof(*fmpl);
1168 	fmpl->magic = cpu_to_be32(UBI_FM_POOL_MAGIC);
1169 	fmpl->size = cpu_to_be16(ubi->fm_pool.size);
1170 	fmpl->max_size = cpu_to_be16(ubi->fm_pool.max_size);
1171 
1172 	for (i = 0; i < ubi->fm_pool.size; i++) {
1173 		fmpl->pebs[i] = cpu_to_be32(ubi->fm_pool.pebs[i]);
1174 		set_seen(ubi, ubi->fm_pool.pebs[i], seen_pebs);
1175 	}
1176 
1177 	fmpl_wl = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
1178 	fm_pos += sizeof(*fmpl_wl);
1179 	fmpl_wl->magic = cpu_to_be32(UBI_FM_POOL_MAGIC);
1180 	fmpl_wl->size = cpu_to_be16(ubi->fm_wl_pool.size);
1181 	fmpl_wl->max_size = cpu_to_be16(ubi->fm_wl_pool.max_size);
1182 
1183 	for (i = 0; i < ubi->fm_wl_pool.size; i++) {
1184 		fmpl_wl->pebs[i] = cpu_to_be32(ubi->fm_wl_pool.pebs[i]);
1185 		set_seen(ubi, ubi->fm_wl_pool.pebs[i], seen_pebs);
1186 	}
1187 
1188 	ubi_for_each_free_peb(ubi, wl_e, tmp_rb) {
1189 		fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1190 
1191 		fec->pnum = cpu_to_be32(wl_e->pnum);
1192 		set_seen(ubi, wl_e->pnum, seen_pebs);
1193 		fec->ec = cpu_to_be32(wl_e->ec);
1194 
1195 		free_peb_count++;
1196 		fm_pos += sizeof(*fec);
1197 		ubi_assert(fm_pos <= ubi->fm_size);
1198 	}
1199 	fmh->free_peb_count = cpu_to_be32(free_peb_count);
1200 
1201 	ubi_for_each_used_peb(ubi, wl_e, tmp_rb) {
1202 		fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1203 
1204 		fec->pnum = cpu_to_be32(wl_e->pnum);
1205 		set_seen(ubi, wl_e->pnum, seen_pebs);
1206 		fec->ec = cpu_to_be32(wl_e->ec);
1207 
1208 		used_peb_count++;
1209 		fm_pos += sizeof(*fec);
1210 		ubi_assert(fm_pos <= ubi->fm_size);
1211 	}
1212 
1213 	ubi_for_each_protected_peb(ubi, i, wl_e) {
1214 		fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1215 
1216 		fec->pnum = cpu_to_be32(wl_e->pnum);
1217 		set_seen(ubi, wl_e->pnum, seen_pebs);
1218 		fec->ec = cpu_to_be32(wl_e->ec);
1219 
1220 		used_peb_count++;
1221 		fm_pos += sizeof(*fec);
1222 		ubi_assert(fm_pos <= ubi->fm_size);
1223 	}
1224 	fmh->used_peb_count = cpu_to_be32(used_peb_count);
1225 
1226 	ubi_for_each_scrub_peb(ubi, wl_e, tmp_rb) {
1227 		fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1228 
1229 		fec->pnum = cpu_to_be32(wl_e->pnum);
1230 		set_seen(ubi, wl_e->pnum, seen_pebs);
1231 		fec->ec = cpu_to_be32(wl_e->ec);
1232 
1233 		scrub_peb_count++;
1234 		fm_pos += sizeof(*fec);
1235 		ubi_assert(fm_pos <= ubi->fm_size);
1236 	}
1237 	fmh->scrub_peb_count = cpu_to_be32(scrub_peb_count);
1238 
1239 
1240 	list_for_each_entry(ubi_wrk, &ubi->works, list) {
1241 		if (ubi_is_erase_work(ubi_wrk)) {
1242 			wl_e = ubi_wrk->e;
1243 			ubi_assert(wl_e);
1244 
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 			erase_peb_count++;
1252 			fm_pos += sizeof(*fec);
1253 			ubi_assert(fm_pos <= ubi->fm_size);
1254 		}
1255 	}
1256 	fmh->erase_peb_count = cpu_to_be32(erase_peb_count);
1257 
1258 	for (i = 0; i < UBI_MAX_VOLUMES + UBI_INT_VOL_COUNT; i++) {
1259 		vol = ubi->volumes[i];
1260 
1261 		if (!vol)
1262 			continue;
1263 
1264 		vol_count++;
1265 
1266 		fvh = (struct ubi_fm_volhdr *)(fm_raw + fm_pos);
1267 		fm_pos += sizeof(*fvh);
1268 		ubi_assert(fm_pos <= ubi->fm_size);
1269 
1270 		fvh->magic = cpu_to_be32(UBI_FM_VHDR_MAGIC);
1271 		fvh->vol_id = cpu_to_be32(vol->vol_id);
1272 		fvh->vol_type = vol->vol_type;
1273 		fvh->used_ebs = cpu_to_be32(vol->used_ebs);
1274 		fvh->data_pad = cpu_to_be32(vol->data_pad);
1275 		fvh->last_eb_bytes = cpu_to_be32(vol->last_eb_bytes);
1276 
1277 		ubi_assert(vol->vol_type == UBI_DYNAMIC_VOLUME ||
1278 			vol->vol_type == UBI_STATIC_VOLUME);
1279 
1280 		feba = (struct ubi_fm_eba *)(fm_raw + fm_pos);
1281 		fm_pos += sizeof(*feba) + (sizeof(__be32) * vol->reserved_pebs);
1282 		ubi_assert(fm_pos <= ubi->fm_size);
1283 
1284 		for (j = 0; j < vol->reserved_pebs; j++)
1285 			feba->pnum[j] = cpu_to_be32(vol->eba_tbl[j]);
1286 
1287 		feba->reserved_pebs = cpu_to_be32(j);
1288 		feba->magic = cpu_to_be32(UBI_FM_EBA_MAGIC);
1289 	}
1290 	fmh->vol_count = cpu_to_be32(vol_count);
1291 	fmh->bad_peb_count = cpu_to_be32(ubi->bad_peb_count);
1292 
1293 	avhdr->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
1294 	avhdr->lnum = 0;
1295 
1296 	spin_unlock(&ubi->wl_lock);
1297 	spin_unlock(&ubi->volumes_lock);
1298 
1299 	dbg_bld("writing fastmap SB to PEB %i", new_fm->e[0]->pnum);
1300 	ret = ubi_io_write_vid_hdr(ubi, new_fm->e[0]->pnum, avhdr);
1301 	if (ret) {
1302 		ubi_err(ubi, "unable to write vid_hdr to fastmap SB!");
1303 		goto out_kfree;
1304 	}
1305 
1306 	for (i = 0; i < new_fm->used_blocks; i++) {
1307 		fmsb->block_loc[i] = cpu_to_be32(new_fm->e[i]->pnum);
1308 		set_seen(ubi, new_fm->e[i]->pnum, seen_pebs);
1309 		fmsb->block_ec[i] = cpu_to_be32(new_fm->e[i]->ec);
1310 	}
1311 
1312 	fmsb->data_crc = 0;
1313 	fmsb->data_crc = cpu_to_be32(crc32(UBI_CRC32_INIT, fm_raw,
1314 					   ubi->fm_size));
1315 
1316 	for (i = 1; i < new_fm->used_blocks; i++) {
1317 		dvhdr->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
1318 		dvhdr->lnum = cpu_to_be32(i);
1319 		dbg_bld("writing fastmap data to PEB %i sqnum %llu",
1320 			new_fm->e[i]->pnum, be64_to_cpu(dvhdr->sqnum));
1321 		ret = ubi_io_write_vid_hdr(ubi, new_fm->e[i]->pnum, dvhdr);
1322 		if (ret) {
1323 			ubi_err(ubi, "unable to write vid_hdr to PEB %i!",
1324 				new_fm->e[i]->pnum);
1325 			goto out_kfree;
1326 		}
1327 	}
1328 
1329 	for (i = 0; i < new_fm->used_blocks; i++) {
1330 		ret = ubi_io_write(ubi, fm_raw + (i * ubi->leb_size),
1331 			new_fm->e[i]->pnum, ubi->leb_start, ubi->leb_size);
1332 		if (ret) {
1333 			ubi_err(ubi, "unable to write fastmap to PEB %i!",
1334 				new_fm->e[i]->pnum);
1335 			goto out_kfree;
1336 		}
1337 	}
1338 
1339 	ubi_assert(new_fm);
1340 	ubi->fm = new_fm;
1341 
1342 	ret = self_check_seen(ubi, seen_pebs);
1343 	dbg_bld("fastmap written!");
1344 
1345 out_kfree:
1346 	ubi_free_vid_hdr(ubi, avhdr);
1347 	ubi_free_vid_hdr(ubi, dvhdr);
1348 	free_seen(seen_pebs);
1349 out:
1350 	return ret;
1351 }
1352 
1353 /**
1354  * erase_block - Manually erase a PEB.
1355  * @ubi: UBI device object
1356  * @pnum: PEB to be erased
1357  *
1358  * Returns the new EC value on success, < 0 indicates an internal error.
1359  */
1360 static int erase_block(struct ubi_device *ubi, int pnum)
1361 {
1362 	int ret;
1363 	struct ubi_ec_hdr *ec_hdr;
1364 	long long ec;
1365 
1366 	ec_hdr = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
1367 	if (!ec_hdr)
1368 		return -ENOMEM;
1369 
1370 	ret = ubi_io_read_ec_hdr(ubi, pnum, ec_hdr, 0);
1371 	if (ret < 0)
1372 		goto out;
1373 	else if (ret && ret != UBI_IO_BITFLIPS) {
1374 		ret = -EINVAL;
1375 		goto out;
1376 	}
1377 
1378 	ret = ubi_io_sync_erase(ubi, pnum, 0);
1379 	if (ret < 0)
1380 		goto out;
1381 
1382 	ec = be64_to_cpu(ec_hdr->ec);
1383 	ec += ret;
1384 	if (ec > UBI_MAX_ERASECOUNTER) {
1385 		ret = -EINVAL;
1386 		goto out;
1387 	}
1388 
1389 	ec_hdr->ec = cpu_to_be64(ec);
1390 	ret = ubi_io_write_ec_hdr(ubi, pnum, ec_hdr);
1391 	if (ret < 0)
1392 		goto out;
1393 
1394 	ret = ec;
1395 out:
1396 	kfree(ec_hdr);
1397 	return ret;
1398 }
1399 
1400 /**
1401  * invalidate_fastmap - destroys a fastmap.
1402  * @ubi: UBI device object
1403  *
1404  * This function ensures that upon next UBI attach a full scan
1405  * is issued. We need this if UBI is about to write a new fastmap
1406  * but is unable to do so. In this case we have two options:
1407  * a) Make sure that the current fastmap will not be usued upon
1408  * attach time and contine or b) fall back to RO mode to have the
1409  * current fastmap in a valid state.
1410  * Returns 0 on success, < 0 indicates an internal error.
1411  */
1412 static int invalidate_fastmap(struct ubi_device *ubi)
1413 {
1414 	int ret;
1415 	struct ubi_fastmap_layout *fm;
1416 	struct ubi_wl_entry *e;
1417 	struct ubi_vid_hdr *vh = NULL;
1418 
1419 	if (!ubi->fm)
1420 		return 0;
1421 
1422 	ubi->fm = NULL;
1423 
1424 	ret = -ENOMEM;
1425 	fm = kzalloc(sizeof(*fm), GFP_KERNEL);
1426 	if (!fm)
1427 		goto out;
1428 
1429 	vh = new_fm_vhdr(ubi, UBI_FM_SB_VOLUME_ID);
1430 	if (!vh)
1431 		goto out_free_fm;
1432 
1433 	ret = -ENOSPC;
1434 	e = ubi_wl_get_fm_peb(ubi, 1);
1435 	if (!e)
1436 		goto out_free_fm;
1437 
1438 	/*
1439 	 * Create fake fastmap such that UBI will fall back
1440 	 * to scanning mode.
1441 	 */
1442 	vh->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
1443 	ret = ubi_io_write_vid_hdr(ubi, e->pnum, vh);
1444 	if (ret < 0) {
1445 		ubi_wl_put_fm_peb(ubi, e, 0, 0);
1446 		goto out_free_fm;
1447 	}
1448 
1449 	fm->used_blocks = 1;
1450 	fm->e[0] = e;
1451 
1452 	ubi->fm = fm;
1453 
1454 out:
1455 	ubi_free_vid_hdr(ubi, vh);
1456 	return ret;
1457 
1458 out_free_fm:
1459 	kfree(fm);
1460 	goto out;
1461 }
1462 
1463 /**
1464  * return_fm_pebs - returns all PEBs used by a fastmap back to the
1465  * WL sub-system.
1466  * @ubi: UBI device object
1467  * @fm: fastmap layout object
1468  */
1469 static void return_fm_pebs(struct ubi_device *ubi,
1470 			   struct ubi_fastmap_layout *fm)
1471 {
1472 	int i;
1473 
1474 	if (!fm)
1475 		return;
1476 
1477 	for (i = 0; i < fm->used_blocks; i++) {
1478 		if (fm->e[i]) {
1479 			ubi_wl_put_fm_peb(ubi, fm->e[i], i,
1480 					  fm->to_be_tortured[i]);
1481 			fm->e[i] = NULL;
1482 		}
1483 	}
1484 }
1485 
1486 /**
1487  * ubi_update_fastmap - will be called by UBI if a volume changes or
1488  * a fastmap pool becomes full.
1489  * @ubi: UBI device object
1490  *
1491  * Returns 0 on success, < 0 indicates an internal error.
1492  */
1493 int ubi_update_fastmap(struct ubi_device *ubi)
1494 {
1495 	int ret, i, j;
1496 	struct ubi_fastmap_layout *new_fm, *old_fm;
1497 	struct ubi_wl_entry *tmp_e;
1498 
1499 	down_write(&ubi->fm_protect);
1500 
1501 	ubi_refill_pools(ubi);
1502 
1503 	if (ubi->ro_mode || ubi->fm_disabled) {
1504 		up_write(&ubi->fm_protect);
1505 		return 0;
1506 	}
1507 
1508 	ret = ubi_ensure_anchor_pebs(ubi);
1509 	if (ret) {
1510 		up_write(&ubi->fm_protect);
1511 		return ret;
1512 	}
1513 
1514 	new_fm = kzalloc(sizeof(*new_fm), GFP_KERNEL);
1515 	if (!new_fm) {
1516 		up_write(&ubi->fm_protect);
1517 		return -ENOMEM;
1518 	}
1519 
1520 	new_fm->used_blocks = ubi->fm_size / ubi->leb_size;
1521 	old_fm = ubi->fm;
1522 	ubi->fm = NULL;
1523 
1524 	if (new_fm->used_blocks > UBI_FM_MAX_BLOCKS) {
1525 		ubi_err(ubi, "fastmap too large");
1526 		ret = -ENOSPC;
1527 		goto err;
1528 	}
1529 
1530 	for (i = 1; i < new_fm->used_blocks; i++) {
1531 		spin_lock(&ubi->wl_lock);
1532 		tmp_e = ubi_wl_get_fm_peb(ubi, 0);
1533 		spin_unlock(&ubi->wl_lock);
1534 
1535 		if (!tmp_e) {
1536 			if (old_fm && old_fm->e[i]) {
1537 				ret = erase_block(ubi, old_fm->e[i]->pnum);
1538 				if (ret < 0) {
1539 					ubi_err(ubi, "could not erase old fastmap PEB");
1540 
1541 					for (j = 1; j < i; j++) {
1542 						ubi_wl_put_fm_peb(ubi, new_fm->e[j],
1543 								  j, 0);
1544 						new_fm->e[j] = NULL;
1545 					}
1546 					goto err;
1547 				}
1548 				new_fm->e[i] = old_fm->e[i];
1549 				old_fm->e[i] = NULL;
1550 			} else {
1551 				ubi_err(ubi, "could not get any free erase block");
1552 
1553 				for (j = 1; j < i; j++) {
1554 					ubi_wl_put_fm_peb(ubi, new_fm->e[j], j, 0);
1555 					new_fm->e[j] = NULL;
1556 				}
1557 
1558 				ret = -ENOSPC;
1559 				goto err;
1560 			}
1561 		} else {
1562 			new_fm->e[i] = tmp_e;
1563 
1564 			if (old_fm && old_fm->e[i]) {
1565 				ubi_wl_put_fm_peb(ubi, old_fm->e[i], i,
1566 						  old_fm->to_be_tortured[i]);
1567 				old_fm->e[i] = NULL;
1568 			}
1569 		}
1570 	}
1571 
1572 	/* Old fastmap is larger than the new one */
1573 	if (old_fm && new_fm->used_blocks < old_fm->used_blocks) {
1574 		for (i = new_fm->used_blocks; i < old_fm->used_blocks; i++) {
1575 			ubi_wl_put_fm_peb(ubi, old_fm->e[i], i,
1576 					  old_fm->to_be_tortured[i]);
1577 			old_fm->e[i] = NULL;
1578 		}
1579 	}
1580 
1581 	spin_lock(&ubi->wl_lock);
1582 	tmp_e = ubi_wl_get_fm_peb(ubi, 1);
1583 	spin_unlock(&ubi->wl_lock);
1584 
1585 	if (old_fm) {
1586 		/* no fresh anchor PEB was found, reuse the old one */
1587 		if (!tmp_e) {
1588 			ret = erase_block(ubi, old_fm->e[0]->pnum);
1589 			if (ret < 0) {
1590 				ubi_err(ubi, "could not erase old anchor PEB");
1591 
1592 				for (i = 1; i < new_fm->used_blocks; i++) {
1593 					ubi_wl_put_fm_peb(ubi, new_fm->e[i],
1594 							  i, 0);
1595 					new_fm->e[i] = NULL;
1596 				}
1597 				goto err;
1598 			}
1599 			new_fm->e[0] = old_fm->e[0];
1600 			new_fm->e[0]->ec = ret;
1601 			old_fm->e[0] = NULL;
1602 		} else {
1603 			/* we've got a new anchor PEB, return the old one */
1604 			ubi_wl_put_fm_peb(ubi, old_fm->e[0], 0,
1605 					  old_fm->to_be_tortured[0]);
1606 			new_fm->e[0] = tmp_e;
1607 			old_fm->e[0] = NULL;
1608 		}
1609 	} else {
1610 		if (!tmp_e) {
1611 			ubi_err(ubi, "could not find any anchor PEB");
1612 
1613 			for (i = 1; i < new_fm->used_blocks; i++) {
1614 				ubi_wl_put_fm_peb(ubi, new_fm->e[i], i, 0);
1615 				new_fm->e[i] = NULL;
1616 			}
1617 
1618 			ret = -ENOSPC;
1619 			goto err;
1620 		}
1621 		new_fm->e[0] = tmp_e;
1622 	}
1623 
1624 	down_write(&ubi->work_sem);
1625 	down_write(&ubi->fm_eba_sem);
1626 	ret = ubi_write_fastmap(ubi, new_fm);
1627 	up_write(&ubi->fm_eba_sem);
1628 	up_write(&ubi->work_sem);
1629 
1630 	if (ret)
1631 		goto err;
1632 
1633 out_unlock:
1634 	up_write(&ubi->fm_protect);
1635 	kfree(old_fm);
1636 	return ret;
1637 
1638 err:
1639 	ubi_warn(ubi, "Unable to write new fastmap, err=%i", ret);
1640 
1641 	ret = invalidate_fastmap(ubi);
1642 	if (ret < 0) {
1643 		ubi_err(ubi, "Unable to invalidiate current fastmap!");
1644 		ubi_ro_mode(ubi);
1645 	} else {
1646 		return_fm_pebs(ubi, old_fm);
1647 		return_fm_pebs(ubi, new_fm);
1648 		ret = 0;
1649 	}
1650 
1651 	kfree(new_fm);
1652 	goto out_unlock;
1653 }
1654