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   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * Copyright (c) 2012 Linutronix GmbH
   4 * Copyright (c) 2014 sigma star gmbh
   5 * Author: Richard Weinberger <richard@nod.at>
   6 */
   7
   8#include <linux/crc32.h>
   9#include <linux/bitmap.h>
  10#include "ubi.h"
  11
  12/**
  13 * init_seen - allocate memory for used for debugging.
  14 * @ubi: UBI device description object
  15 */
  16static inline unsigned long *init_seen(struct ubi_device *ubi)
  17{
  18	unsigned long *ret;
  19
  20	if (!ubi_dbg_chk_fastmap(ubi))
  21		return NULL;
  22
  23	ret = bitmap_zalloc(ubi->peb_count, GFP_NOFS);
  24	if (!ret)
  25		return ERR_PTR(-ENOMEM);
  26
  27	return ret;
  28}
  29
  30/**
  31 * free_seen - free the seen logic integer array.
  32 * @seen: integer array of @ubi->peb_count size
  33 */
  34static inline void free_seen(unsigned long *seen)
  35{
  36	bitmap_free(seen);
  37}
  38
  39/**
  40 * set_seen - mark a PEB as seen.
  41 * @ubi: UBI device description object
  42 * @pnum: The PEB to be makred as seen
  43 * @seen: integer array of @ubi->peb_count size
  44 */
  45static inline void set_seen(struct ubi_device *ubi, int pnum, unsigned long *seen)
  46{
  47	if (!ubi_dbg_chk_fastmap(ubi) || !seen)
  48		return;
  49
  50	set_bit(pnum, seen);
  51}
  52
  53/**
  54 * self_check_seen - check whether all PEB have been seen by fastmap.
  55 * @ubi: UBI device description object
  56 * @seen: integer array of @ubi->peb_count size
  57 */
  58static int self_check_seen(struct ubi_device *ubi, unsigned long *seen)
  59{
  60	int pnum, ret = 0;
  61
  62	if (!ubi_dbg_chk_fastmap(ubi) || !seen)
  63		return 0;
  64
  65	for (pnum = 0; pnum < ubi->peb_count; pnum++) {
  66		if (!test_bit(pnum, seen) && ubi->lookuptbl[pnum]) {
  67			ubi_err(ubi, "self-check failed for PEB %d, fastmap didn't see it", pnum);
  68			ret = -EINVAL;
  69		}
  70	}
  71
  72	return ret;
  73}
  74
  75/**
  76 * ubi_calc_fm_size - calculates the fastmap size in bytes for an UBI device.
  77 * @ubi: UBI device description object
  78 */
  79size_t ubi_calc_fm_size(struct ubi_device *ubi)
  80{
  81	size_t size;
  82
  83	size = sizeof(struct ubi_fm_sb) +
  84		sizeof(struct ubi_fm_hdr) +
  85		sizeof(struct ubi_fm_scan_pool) +
  86		sizeof(struct ubi_fm_scan_pool) +
  87		(ubi->peb_count * sizeof(struct ubi_fm_ec)) +
  88		(sizeof(struct ubi_fm_eba) +
  89		(ubi->peb_count * sizeof(__be32))) +
  90		sizeof(struct ubi_fm_volhdr) * UBI_MAX_VOLUMES;
  91	return roundup(size, ubi->leb_size);
  92}
  93
  94
  95/**
  96 * new_fm_vbuf() - allocate a new volume header for fastmap usage.
  97 * @ubi: UBI device description object
  98 * @vol_id: the VID of the new header
  99 *
 100 * Returns a new struct ubi_vid_hdr on success.
 101 * NULL indicates out of memory.
 102 */
 103static struct ubi_vid_io_buf *new_fm_vbuf(struct ubi_device *ubi, int vol_id)
 104{
 105	struct ubi_vid_io_buf *new;
 106	struct ubi_vid_hdr *vh;
 107
 108	new = ubi_alloc_vid_buf(ubi, GFP_NOFS);
 109	if (!new)
 110		goto out;
 111
 112	vh = ubi_get_vid_hdr(new);
 113	vh->vol_type = UBI_VID_DYNAMIC;
 114	vh->vol_id = cpu_to_be32(vol_id);
 115
 116	/* UBI implementations without fastmap support have to delete the
 117	 * fastmap.
 118	 */
 119	vh->compat = UBI_COMPAT_DELETE;
 120
 121out:
 122	return new;
 123}
 124
 125/**
 126 * add_aeb - create and add a attach erase block to a given list.
 127 * @ai: UBI attach info object
 128 * @list: the target list
 129 * @pnum: PEB number of the new attach erase block
 130 * @ec: erease counter of the new LEB
 131 * @scrub: scrub this PEB after attaching
 132 *
 133 * Returns 0 on success, < 0 indicates an internal error.
 134 */
 135static int add_aeb(struct ubi_attach_info *ai, struct list_head *list,
 136		   int pnum, int ec, int scrub)
 137{
 138	struct ubi_ainf_peb *aeb;
 139
 140	aeb = ubi_alloc_aeb(ai, pnum, ec);
 141	if (!aeb)
 142		return -ENOMEM;
 143
 144	aeb->lnum = -1;
 145	aeb->scrub = scrub;
 146	aeb->copy_flag = aeb->sqnum = 0;
 147
 148	ai->ec_sum += aeb->ec;
 149	ai->ec_count++;
 150
 151	if (ai->max_ec < aeb->ec)
 152		ai->max_ec = aeb->ec;
 153
 154	if (ai->min_ec > aeb->ec)
 155		ai->min_ec = aeb->ec;
 156
 157	list_add_tail(&aeb->u.list, list);
 158
 159	return 0;
 160}
 161
 162/**
 163 * add_vol - create and add a new volume to ubi_attach_info.
 164 * @ai: ubi_attach_info object
 165 * @vol_id: VID of the new volume
 166 * @used_ebs: number of used EBS
 167 * @data_pad: data padding value of the new volume
 168 * @vol_type: volume type
 169 * @last_eb_bytes: number of bytes in the last LEB
 170 *
 171 * Returns the new struct ubi_ainf_volume on success.
 172 * NULL indicates an error.
 173 */
 174static struct ubi_ainf_volume *add_vol(struct ubi_attach_info *ai, int vol_id,
 175				       int used_ebs, int data_pad, u8 vol_type,
 176				       int last_eb_bytes)
 177{
 178	struct ubi_ainf_volume *av;
 179
 180	av = ubi_add_av(ai, vol_id);
 181	if (IS_ERR(av))
 182		return av;
 183
 184	av->data_pad = data_pad;
 185	av->last_data_size = last_eb_bytes;
 186	av->compat = 0;
 187	av->vol_type = vol_type;
 188	if (av->vol_type == UBI_STATIC_VOLUME)
 189		av->used_ebs = used_ebs;
 190
 191	dbg_bld("found volume (ID %i)", vol_id);
 192	return av;
 193}
 194
 195/**
 196 * assign_aeb_to_av - assigns a SEB to a given ainf_volume and removes it
 197 * from it's original list.
 198 * @ai: ubi_attach_info object
 199 * @aeb: the to be assigned SEB
 200 * @av: target scan volume
 201 */
 202static void assign_aeb_to_av(struct ubi_attach_info *ai,
 203			     struct ubi_ainf_peb *aeb,
 204			     struct ubi_ainf_volume *av)
 205{
 206	struct ubi_ainf_peb *tmp_aeb;
 207	struct rb_node **p = &av->root.rb_node, *parent = NULL;
 208
 209	while (*p) {
 210		parent = *p;
 211
 212		tmp_aeb = rb_entry(parent, struct ubi_ainf_peb, u.rb);
 213		if (aeb->lnum != tmp_aeb->lnum) {
 214			if (aeb->lnum < tmp_aeb->lnum)
 215				p = &(*p)->rb_left;
 216			else
 217				p = &(*p)->rb_right;
 218
 219			continue;
 220		} else
 221			break;
 222	}
 223
 224	list_del(&aeb->u.list);
 225	av->leb_count++;
 226
 227	rb_link_node(&aeb->u.rb, parent, p);
 228	rb_insert_color(&aeb->u.rb, &av->root);
 229}
 230
 231/**
 232 * update_vol - inserts or updates a LEB which was found a pool.
 233 * @ubi: the UBI device object
 234 * @ai: attach info object
 235 * @av: the volume this LEB belongs to
 236 * @new_vh: the volume header derived from new_aeb
 237 * @new_aeb: the AEB to be examined
 238 *
 239 * Returns 0 on success, < 0 indicates an internal error.
 240 */
 241static int update_vol(struct ubi_device *ubi, struct ubi_attach_info *ai,
 242		      struct ubi_ainf_volume *av, struct ubi_vid_hdr *new_vh,
 243		      struct ubi_ainf_peb *new_aeb)
 244{
 245	struct rb_node **p = &av->root.rb_node, *parent = NULL;
 246	struct ubi_ainf_peb *aeb, *victim;
 247	int cmp_res;
 248
 249	while (*p) {
 250		parent = *p;
 251		aeb = rb_entry(parent, struct ubi_ainf_peb, u.rb);
 252
 253		if (be32_to_cpu(new_vh->lnum) != aeb->lnum) {
 254			if (be32_to_cpu(new_vh->lnum) < aeb->lnum)
 255				p = &(*p)->rb_left;
 256			else
 257				p = &(*p)->rb_right;
 258
 259			continue;
 260		}
 261
 262		/* This case can happen if the fastmap gets written
 263		 * because of a volume change (creation, deletion, ..).
 264		 * Then a PEB can be within the persistent EBA and the pool.
 265		 */
 266		if (aeb->pnum == new_aeb->pnum) {
 267			ubi_assert(aeb->lnum == new_aeb->lnum);
 268			ubi_free_aeb(ai, new_aeb);
 269
 270			return 0;
 271		}
 272
 273		cmp_res = ubi_compare_lebs(ubi, aeb, new_aeb->pnum, new_vh);
 274		if (cmp_res < 0)
 275			return cmp_res;
 276
 277		/* new_aeb is newer */
 278		if (cmp_res & 1) {
 279			victim = ubi_alloc_aeb(ai, aeb->pnum, aeb->ec);
 280			if (!victim)
 281				return -ENOMEM;
 282
 283			list_add_tail(&victim->u.list, &ai->erase);
 284
 285			if (av->highest_lnum == be32_to_cpu(new_vh->lnum))
 286				av->last_data_size =
 287					be32_to_cpu(new_vh->data_size);
 288
 289			dbg_bld("vol %i: AEB %i's PEB %i is the newer",
 290				av->vol_id, aeb->lnum, new_aeb->pnum);
 291
 292			aeb->ec = new_aeb->ec;
 293			aeb->pnum = new_aeb->pnum;
 294			aeb->copy_flag = new_vh->copy_flag;
 295			aeb->scrub = new_aeb->scrub;
 296			aeb->sqnum = new_aeb->sqnum;
 297			ubi_free_aeb(ai, new_aeb);
 298
 299		/* new_aeb is older */
 300		} else {
 301			dbg_bld("vol %i: AEB %i's PEB %i is old, dropping it",
 302				av->vol_id, aeb->lnum, new_aeb->pnum);
 303			list_add_tail(&new_aeb->u.list, &ai->erase);
 304		}
 305
 306		return 0;
 307	}
 308	/* This LEB is new, let's add it to the volume */
 309
 310	if (av->highest_lnum <= be32_to_cpu(new_vh->lnum)) {
 311		av->highest_lnum = be32_to_cpu(new_vh->lnum);
 312		av->last_data_size = be32_to_cpu(new_vh->data_size);
 313	}
 314
 315	if (av->vol_type == UBI_STATIC_VOLUME)
 316		av->used_ebs = be32_to_cpu(new_vh->used_ebs);
 317
 318	av->leb_count++;
 319
 320	rb_link_node(&new_aeb->u.rb, parent, p);
 321	rb_insert_color(&new_aeb->u.rb, &av->root);
 322
 323	return 0;
 324}
 325
 326/**
 327 * process_pool_aeb - we found a non-empty PEB in a pool.
 328 * @ubi: UBI device object
 329 * @ai: attach info object
 330 * @new_vh: the volume header derived from new_aeb
 331 * @new_aeb: the AEB to be examined
 332 *
 333 * Returns 0 on success, < 0 indicates an internal error.
 334 */
 335static int process_pool_aeb(struct ubi_device *ubi, struct ubi_attach_info *ai,
 336			    struct ubi_vid_hdr *new_vh,
 337			    struct ubi_ainf_peb *new_aeb)
 338{
 339	int vol_id = be32_to_cpu(new_vh->vol_id);
 340	struct ubi_ainf_volume *av;
 341
 342	if (vol_id == UBI_FM_SB_VOLUME_ID || vol_id == UBI_FM_DATA_VOLUME_ID) {
 343		ubi_free_aeb(ai, new_aeb);
 344
 345		return 0;
 346	}
 347
 348	/* Find the volume this SEB belongs to */
 349	av = ubi_find_av(ai, vol_id);
 350	if (!av) {
 351		ubi_err(ubi, "orphaned volume in fastmap pool!");
 352		ubi_free_aeb(ai, new_aeb);
 353		return UBI_BAD_FASTMAP;
 354	}
 355
 356	ubi_assert(vol_id == av->vol_id);
 357
 358	return update_vol(ubi, ai, av, new_vh, new_aeb);
 359}
 360
 361/**
 362 * unmap_peb - unmap a PEB.
 363 * If fastmap detects a free PEB in the pool it has to check whether
 364 * this PEB has been unmapped after writing the fastmap.
 365 *
 366 * @ai: UBI attach info object
 367 * @pnum: The PEB to be unmapped
 368 */
 369static void unmap_peb(struct ubi_attach_info *ai, int pnum)
 370{
 371	struct ubi_ainf_volume *av;
 372	struct rb_node *node, *node2;
 373	struct ubi_ainf_peb *aeb;
 374
 375	ubi_rb_for_each_entry(node, av, &ai->volumes, rb) {
 376		ubi_rb_for_each_entry(node2, aeb, &av->root, u.rb) {
 377			if (aeb->pnum == pnum) {
 378				rb_erase(&aeb->u.rb, &av->root);
 379				av->leb_count--;
 380				ubi_free_aeb(ai, aeb);
 381				return;
 382			}
 383		}
 384	}
 385}
 386
 387/**
 388 * scan_pool - scans a pool for changed (no longer empty PEBs).
 389 * @ubi: UBI device object
 390 * @ai: attach info object
 391 * @pebs: an array of all PEB numbers in the to be scanned pool
 392 * @pool_size: size of the pool (number of entries in @pebs)
 393 * @max_sqnum: pointer to the maximal sequence number
 394 * @free: list of PEBs which are most likely free (and go into @ai->free)
 395 *
 396 * Returns 0 on success, if the pool is unusable UBI_BAD_FASTMAP is returned.
 397 * < 0 indicates an internal error.
 398 */
 399static int scan_pool(struct ubi_device *ubi, struct ubi_attach_info *ai,
 400		     __be32 *pebs, int pool_size, unsigned long long *max_sqnum,
 401		     struct list_head *free)
 402{
 403	struct ubi_vid_io_buf *vb;
 404	struct ubi_vid_hdr *vh;
 405	struct ubi_ec_hdr *ech;
 406	struct ubi_ainf_peb *new_aeb;
 407	int i, pnum, err, ret = 0;
 408
 409	ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
 410	if (!ech)
 411		return -ENOMEM;
 412
 413	vb = ubi_alloc_vid_buf(ubi, GFP_KERNEL);
 414	if (!vb) {
 415		kfree(ech);
 416		return -ENOMEM;
 417	}
 418
 419	vh = ubi_get_vid_hdr(vb);
 420
 421	dbg_bld("scanning fastmap pool: size = %i", pool_size);
 422
 423	/*
 424	 * Now scan all PEBs in the pool to find changes which have been made
 425	 * after the creation of the fastmap
 426	 */
 427	for (i = 0; i < pool_size; i++) {
 428		int scrub = 0;
 429		int image_seq;
 430
 431		pnum = be32_to_cpu(pebs[i]);
 432
 433		if (ubi_io_is_bad(ubi, pnum)) {
 434			ubi_err(ubi, "bad PEB in fastmap pool!");
 435			ret = UBI_BAD_FASTMAP;
 436			goto out;
 437		}
 438
 439		err = ubi_io_read_ec_hdr(ubi, pnum, ech, 0);
 440		if (err && err != UBI_IO_BITFLIPS) {
 441			ubi_err(ubi, "unable to read EC header! PEB:%i err:%i",
 442				pnum, err);
 443			ret = err > 0 ? UBI_BAD_FASTMAP : err;
 444			goto out;
 445		} else if (err == UBI_IO_BITFLIPS)
 446			scrub = 1;
 447
 448		/*
 449		 * Older UBI implementations have image_seq set to zero, so
 450		 * we shouldn't fail if image_seq == 0.
 451		 */
 452		image_seq = be32_to_cpu(ech->image_seq);
 453
 454		if (image_seq && (image_seq != ubi->image_seq)) {
 455			ubi_err(ubi, "bad image seq: 0x%x, expected: 0x%x",
 456				be32_to_cpu(ech->image_seq), ubi->image_seq);
 457			ret = UBI_BAD_FASTMAP;
 458			goto out;
 459		}
 460
 461		err = ubi_io_read_vid_hdr(ubi, pnum, vb, 0);
 462		if (err == UBI_IO_FF || err == UBI_IO_FF_BITFLIPS) {
 463			unsigned long long ec = be64_to_cpu(ech->ec);
 464			unmap_peb(ai, pnum);
 465			dbg_bld("Adding PEB to free: %i", pnum);
 466
 467			if (err == UBI_IO_FF_BITFLIPS)
 468				scrub = 1;
 469
 470			ret = add_aeb(ai, free, pnum, ec, scrub);
 471			if (ret)
 472				goto out;
 473			continue;
 474		} else if (err == 0 || err == UBI_IO_BITFLIPS) {
 475			dbg_bld("Found non empty PEB:%i in pool", pnum);
 476
 477			if (err == UBI_IO_BITFLIPS)
 478				scrub = 1;
 479
 480			new_aeb = ubi_alloc_aeb(ai, pnum, be64_to_cpu(ech->ec));
 481			if (!new_aeb) {
 482				ret = -ENOMEM;
 483				goto out;
 484			}
 485
 486			new_aeb->lnum = be32_to_cpu(vh->lnum);
 487			new_aeb->sqnum = be64_to_cpu(vh->sqnum);
 488			new_aeb->copy_flag = vh->copy_flag;
 489			new_aeb->scrub = scrub;
 490
 491			if (*max_sqnum < new_aeb->sqnum)
 492				*max_sqnum = new_aeb->sqnum;
 493
 494			err = process_pool_aeb(ubi, ai, vh, new_aeb);
 495			if (err) {
 496				ret = err > 0 ? UBI_BAD_FASTMAP : err;
 497				goto out;
 498			}
 499		} else {
 500			/* We are paranoid and fall back to scanning mode */
 501			ubi_err(ubi, "fastmap pool PEBs contains damaged PEBs!");
 502			ret = err > 0 ? UBI_BAD_FASTMAP : err;
 503			goto out;
 504		}
 505
 506	}
 507
 508out:
 509	ubi_free_vid_buf(vb);
 510	kfree(ech);
 511	return ret;
 512}
 513
 514/**
 515 * count_fastmap_pebs - Counts the PEBs found by fastmap.
 516 * @ai: The UBI attach info object
 517 */
 518static int count_fastmap_pebs(struct ubi_attach_info *ai)
 519{
 520	struct ubi_ainf_peb *aeb;
 521	struct ubi_ainf_volume *av;
 522	struct rb_node *rb1, *rb2;
 523	int n = 0;
 524
 525	list_for_each_entry(aeb, &ai->erase, u.list)
 526		n++;
 527
 528	list_for_each_entry(aeb, &ai->free, u.list)
 529		n++;
 530
 531	ubi_rb_for_each_entry(rb1, av, &ai->volumes, rb)
 532		ubi_rb_for_each_entry(rb2, aeb, &av->root, u.rb)
 533			n++;
 534
 535	return n;
 536}
 537
 538/**
 539 * ubi_attach_fastmap - creates ubi_attach_info from a fastmap.
 540 * @ubi: UBI device object
 541 * @ai: UBI attach info object
 542 * @fm: the fastmap to be attached
 543 *
 544 * Returns 0 on success, UBI_BAD_FASTMAP if the found fastmap was unusable.
 545 * < 0 indicates an internal error.
 546 */
 547static int ubi_attach_fastmap(struct ubi_device *ubi,
 548			      struct ubi_attach_info *ai,
 549			      struct ubi_fastmap_layout *fm)
 550{
 551	struct list_head used, free;
 552	struct ubi_ainf_volume *av;
 553	struct ubi_ainf_peb *aeb, *tmp_aeb, *_tmp_aeb;
 554	struct ubi_fm_sb *fmsb;
 555	struct ubi_fm_hdr *fmhdr;
 556	struct ubi_fm_scan_pool *fmpl, *fmpl_wl;
 557	struct ubi_fm_ec *fmec;
 558	struct ubi_fm_volhdr *fmvhdr;
 559	struct ubi_fm_eba *fm_eba;
 560	int ret, i, j, pool_size, wl_pool_size;
 561	size_t fm_pos = 0, fm_size = ubi->fm_size;
 562	unsigned long long max_sqnum = 0;
 563	void *fm_raw = ubi->fm_buf;
 564
 565	INIT_LIST_HEAD(&used);
 566	INIT_LIST_HEAD(&free);
 567	ai->min_ec = UBI_MAX_ERASECOUNTER;
 568
 569	fmsb = (struct ubi_fm_sb *)(fm_raw);
 570	ai->max_sqnum = fmsb->sqnum;
 571	fm_pos += sizeof(struct ubi_fm_sb);
 572	if (fm_pos >= fm_size)
 573		goto fail_bad;
 574
 575	fmhdr = (struct ubi_fm_hdr *)(fm_raw + fm_pos);
 576	fm_pos += sizeof(*fmhdr);
 577	if (fm_pos >= fm_size)
 578		goto fail_bad;
 579
 580	if (be32_to_cpu(fmhdr->magic) != UBI_FM_HDR_MAGIC) {
 581		ubi_err(ubi, "bad fastmap header magic: 0x%x, expected: 0x%x",
 582			be32_to_cpu(fmhdr->magic), UBI_FM_HDR_MAGIC);
 583		goto fail_bad;
 584	}
 585
 586	fmpl = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
 587	fm_pos += sizeof(*fmpl);
 588	if (fm_pos >= fm_size)
 589		goto fail_bad;
 590	if (be32_to_cpu(fmpl->magic) != UBI_FM_POOL_MAGIC) {
 591		ubi_err(ubi, "bad fastmap pool magic: 0x%x, expected: 0x%x",
 592			be32_to_cpu(fmpl->magic), UBI_FM_POOL_MAGIC);
 593		goto fail_bad;
 594	}
 595
 596	fmpl_wl = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
 597	fm_pos += sizeof(*fmpl_wl);
 598	if (fm_pos >= fm_size)
 599		goto fail_bad;
 600	if (be32_to_cpu(fmpl_wl->magic) != UBI_FM_POOL_MAGIC) {
 601		ubi_err(ubi, "bad fastmap WL pool magic: 0x%x, expected: 0x%x",
 602			be32_to_cpu(fmpl_wl->magic), UBI_FM_POOL_MAGIC);
 603		goto fail_bad;
 604	}
 605
 606	pool_size = be16_to_cpu(fmpl->size);
 607	wl_pool_size = be16_to_cpu(fmpl_wl->size);
 608	fm->max_pool_size = be16_to_cpu(fmpl->max_size);
 609	fm->max_wl_pool_size = be16_to_cpu(fmpl_wl->max_size);
 610
 611	if (pool_size > UBI_FM_MAX_POOL_SIZE || pool_size < 0) {
 612		ubi_err(ubi, "bad pool size: %i", pool_size);
 613		goto fail_bad;
 614	}
 615
 616	if (wl_pool_size > UBI_FM_MAX_POOL_SIZE || wl_pool_size < 0) {
 617		ubi_err(ubi, "bad WL pool size: %i", wl_pool_size);
 618		goto fail_bad;
 619	}
 620
 621
 622	if (fm->max_pool_size > UBI_FM_MAX_POOL_SIZE ||
 623	    fm->max_pool_size < 0) {
 624		ubi_err(ubi, "bad maximal pool size: %i", fm->max_pool_size);
 625		goto fail_bad;
 626	}
 627
 628	if (fm->max_wl_pool_size > UBI_FM_MAX_POOL_SIZE ||
 629	    fm->max_wl_pool_size < 0) {
 630		ubi_err(ubi, "bad maximal WL pool size: %i",
 631			fm->max_wl_pool_size);
 632		goto fail_bad;
 633	}
 634
 635	/* read EC values from free list */
 636	for (i = 0; i < be32_to_cpu(fmhdr->free_peb_count); i++) {
 637		fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 638		fm_pos += sizeof(*fmec);
 639		if (fm_pos >= fm_size)
 640			goto fail_bad;
 641
 642		ret = add_aeb(ai, &ai->free, be32_to_cpu(fmec->pnum),
 643			      be32_to_cpu(fmec->ec), 0);
 644		if (ret)
 645			goto fail;
 646	}
 647
 648	/* read EC values from used list */
 649	for (i = 0; i < be32_to_cpu(fmhdr->used_peb_count); i++) {
 650		fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 651		fm_pos += sizeof(*fmec);
 652		if (fm_pos >= fm_size)
 653			goto fail_bad;
 654
 655		ret = add_aeb(ai, &used, be32_to_cpu(fmec->pnum),
 656			      be32_to_cpu(fmec->ec), 0);
 657		if (ret)
 658			goto fail;
 659	}
 660
 661	/* read EC values from scrub list */
 662	for (i = 0; i < be32_to_cpu(fmhdr->scrub_peb_count); i++) {
 663		fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 664		fm_pos += sizeof(*fmec);
 665		if (fm_pos >= fm_size)
 666			goto fail_bad;
 667
 668		ret = add_aeb(ai, &used, be32_to_cpu(fmec->pnum),
 669			      be32_to_cpu(fmec->ec), 1);
 670		if (ret)
 671			goto fail;
 672	}
 673
 674	/* read EC values from erase list */
 675	for (i = 0; i < be32_to_cpu(fmhdr->erase_peb_count); i++) {
 676		fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 677		fm_pos += sizeof(*fmec);
 678		if (fm_pos >= fm_size)
 679			goto fail_bad;
 680
 681		ret = add_aeb(ai, &ai->erase, be32_to_cpu(fmec->pnum),
 682			      be32_to_cpu(fmec->ec), 1);
 683		if (ret)
 684			goto fail;
 685	}
 686
 687	ai->mean_ec = div_u64(ai->ec_sum, ai->ec_count);
 688	ai->bad_peb_count = be32_to_cpu(fmhdr->bad_peb_count);
 689
 690	/* Iterate over all volumes and read their EBA table */
 691	for (i = 0; i < be32_to_cpu(fmhdr->vol_count); i++) {
 692		fmvhdr = (struct ubi_fm_volhdr *)(fm_raw + fm_pos);
 693		fm_pos += sizeof(*fmvhdr);
 694		if (fm_pos >= fm_size)
 695			goto fail_bad;
 696
 697		if (be32_to_cpu(fmvhdr->magic) != UBI_FM_VHDR_MAGIC) {
 698			ubi_err(ubi, "bad fastmap vol header magic: 0x%x, expected: 0x%x",
 699				be32_to_cpu(fmvhdr->magic), UBI_FM_VHDR_MAGIC);
 700			goto fail_bad;
 701		}
 702
 703		av = add_vol(ai, be32_to_cpu(fmvhdr->vol_id),
 704			     be32_to_cpu(fmvhdr->used_ebs),
 705			     be32_to_cpu(fmvhdr->data_pad),
 706			     fmvhdr->vol_type,
 707			     be32_to_cpu(fmvhdr->last_eb_bytes));
 708
 709		if (IS_ERR(av)) {
 710			if (PTR_ERR(av) == -EEXIST)
 711				ubi_err(ubi, "volume (ID %i) already exists",
 712					fmvhdr->vol_id);
 713
 714			goto fail_bad;
 715		}
 716
 717		ai->vols_found++;
 718		if (ai->highest_vol_id < be32_to_cpu(fmvhdr->vol_id))
 719			ai->highest_vol_id = be32_to_cpu(fmvhdr->vol_id);
 720
 721		fm_eba = (struct ubi_fm_eba *)(fm_raw + fm_pos);
 722		fm_pos += sizeof(*fm_eba);
 723		fm_pos += (sizeof(__be32) * be32_to_cpu(fm_eba->reserved_pebs));
 724		if (fm_pos >= fm_size)
 725			goto fail_bad;
 726
 727		if (be32_to_cpu(fm_eba->magic) != UBI_FM_EBA_MAGIC) {
 728			ubi_err(ubi, "bad fastmap EBA header magic: 0x%x, expected: 0x%x",
 729				be32_to_cpu(fm_eba->magic), UBI_FM_EBA_MAGIC);
 730			goto fail_bad;
 731		}
 732
 733		for (j = 0; j < be32_to_cpu(fm_eba->reserved_pebs); j++) {
 734			int pnum = be32_to_cpu(fm_eba->pnum[j]);
 735
 736			if (pnum < 0)
 737				continue;
 738
 739			aeb = NULL;
 740			list_for_each_entry(tmp_aeb, &used, u.list) {
 741				if (tmp_aeb->pnum == pnum) {
 742					aeb = tmp_aeb;
 743					break;
 744				}
 745			}
 746
 747			if (!aeb) {
 748				ubi_err(ubi, "PEB %i is in EBA but not in used list", pnum);
 749				goto fail_bad;
 750			}
 751
 752			aeb->lnum = j;
 753
 754			if (av->highest_lnum <= aeb->lnum)
 755				av->highest_lnum = aeb->lnum;
 756
 757			assign_aeb_to_av(ai, aeb, av);
 758
 759			dbg_bld("inserting PEB:%i (LEB %i) to vol %i",
 760				aeb->pnum, aeb->lnum, av->vol_id);
 761		}
 762	}
 763
 764	ret = scan_pool(ubi, ai, fmpl->pebs, pool_size, &max_sqnum, &free);
 765	if (ret)
 766		goto fail;
 767
 768	ret = scan_pool(ubi, ai, fmpl_wl->pebs, wl_pool_size, &max_sqnum, &free);
 769	if (ret)
 770		goto fail;
 771
 772	if (max_sqnum > ai->max_sqnum)
 773		ai->max_sqnum = max_sqnum;
 774
 775	list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &free, u.list)
 776		list_move_tail(&tmp_aeb->u.list, &ai->free);
 777
 778	list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &used, u.list)
 779		list_move_tail(&tmp_aeb->u.list, &ai->erase);
 780
 781	ubi_assert(list_empty(&free));
 782
 783	/*
 784	 * If fastmap is leaking PEBs (must not happen), raise a
 785	 * fat warning and fall back to scanning mode.
 786	 * We do this here because in ubi_wl_init() it's too late
 787	 * and we cannot fall back to scanning.
 788	 */
 789	if (WARN_ON(count_fastmap_pebs(ai) != ubi->peb_count -
 790		    ai->bad_peb_count - fm->used_blocks))
 791		goto fail_bad;
 792
 793	return 0;
 794
 795fail_bad:
 796	ret = UBI_BAD_FASTMAP;
 797fail:
 798	list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &used, u.list) {
 799		list_del(&tmp_aeb->u.list);
 800		ubi_free_aeb(ai, tmp_aeb);
 801	}
 802	list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &free, u.list) {
 803		list_del(&tmp_aeb->u.list);
 804		ubi_free_aeb(ai, tmp_aeb);
 805	}
 806
 807	return ret;
 808}
 809
 810/**
 811 * find_fm_anchor - find the most recent Fastmap superblock (anchor)
 812 * @ai: UBI attach info to be filled
 813 */
 814static int find_fm_anchor(struct ubi_attach_info *ai)
 815{
 816	int ret = -1;
 817	struct ubi_ainf_peb *aeb;
 818	unsigned long long max_sqnum = 0;
 819
 820	list_for_each_entry(aeb, &ai->fastmap, u.list) {
 821		if (aeb->vol_id == UBI_FM_SB_VOLUME_ID && aeb->sqnum > max_sqnum) {
 822			max_sqnum = aeb->sqnum;
 823			ret = aeb->pnum;
 824		}
 825	}
 826
 827	return ret;
 828}
 829
 830static struct ubi_ainf_peb *clone_aeb(struct ubi_attach_info *ai,
 831				      struct ubi_ainf_peb *old)
 832{
 833	struct ubi_ainf_peb *new;
 834
 835	new = ubi_alloc_aeb(ai, old->pnum, old->ec);
 836	if (!new)
 837		return NULL;
 838
 839	new->vol_id = old->vol_id;
 840	new->sqnum = old->sqnum;
 841	new->lnum = old->lnum;
 842	new->scrub = old->scrub;
 843	new->copy_flag = old->copy_flag;
 844
 845	return new;
 846}
 847
 848/**
 849 * ubi_scan_fastmap - scan the fastmap.
 850 * @ubi: UBI device object
 851 * @ai: UBI attach info to be filled
 852 * @scan_ai: UBI attach info from the first 64 PEBs,
 853 *           used to find the most recent Fastmap data structure
 854 *
 855 * Returns 0 on success, UBI_NO_FASTMAP if no fastmap was found,
 856 * UBI_BAD_FASTMAP if one was found but is not usable.
 857 * < 0 indicates an internal error.
 858 */
 859int ubi_scan_fastmap(struct ubi_device *ubi, struct ubi_attach_info *ai,
 860		     struct ubi_attach_info *scan_ai)
 861{
 862	struct ubi_fm_sb *fmsb, *fmsb2;
 863	struct ubi_vid_io_buf *vb;
 864	struct ubi_vid_hdr *vh;
 865	struct ubi_ec_hdr *ech;
 866	struct ubi_fastmap_layout *fm;
 867	struct ubi_ainf_peb *aeb;
 868	int i, used_blocks, pnum, fm_anchor, ret = 0;
 869	size_t fm_size;
 870	__be32 crc, tmp_crc;
 871	unsigned long long sqnum = 0;
 872
 873	fm_anchor = find_fm_anchor(scan_ai);
 874	if (fm_anchor < 0)
 875		return UBI_NO_FASTMAP;
 876
 877	/* Copy all (possible) fastmap blocks into our new attach structure. */
 878	list_for_each_entry(aeb, &scan_ai->fastmap, u.list) {
 879		struct ubi_ainf_peb *new;
 880
 881		new = clone_aeb(ai, aeb);
 882		if (!new)
 883			return -ENOMEM;
 884
 885		list_add(&new->u.list, &ai->fastmap);
 886	}
 887
 888	down_write(&ubi->fm_protect);
 889	memset(ubi->fm_buf, 0, ubi->fm_size);
 890
 891	fmsb = kmalloc(sizeof(*fmsb), GFP_KERNEL);
 892	if (!fmsb) {
 893		ret = -ENOMEM;
 894		goto out;
 895	}
 896
 897	fm = kzalloc(sizeof(*fm), GFP_KERNEL);
 898	if (!fm) {
 899		ret = -ENOMEM;
 900		kfree(fmsb);
 901		goto out;
 902	}
 903
 904	ret = ubi_io_read_data(ubi, fmsb, fm_anchor, 0, sizeof(*fmsb));
 905	if (ret && ret != UBI_IO_BITFLIPS)
 906		goto free_fm_sb;
 907	else if (ret == UBI_IO_BITFLIPS)
 908		fm->to_be_tortured[0] = 1;
 909
 910	if (be32_to_cpu(fmsb->magic) != UBI_FM_SB_MAGIC) {
 911		ubi_err(ubi, "bad super block magic: 0x%x, expected: 0x%x",
 912			be32_to_cpu(fmsb->magic), UBI_FM_SB_MAGIC);
 913		ret = UBI_BAD_FASTMAP;
 914		goto free_fm_sb;
 915	}
 916
 917	if (fmsb->version != UBI_FM_FMT_VERSION) {
 918		ubi_err(ubi, "bad fastmap version: %i, expected: %i",
 919			fmsb->version, UBI_FM_FMT_VERSION);
 920		ret = UBI_BAD_FASTMAP;
 921		goto free_fm_sb;
 922	}
 923
 924	used_blocks = be32_to_cpu(fmsb->used_blocks);
 925	if (used_blocks > UBI_FM_MAX_BLOCKS || used_blocks < 1) {
 926		ubi_err(ubi, "number of fastmap blocks is invalid: %i",
 927			used_blocks);
 928		ret = UBI_BAD_FASTMAP;
 929		goto free_fm_sb;
 930	}
 931
 932	fm_size = ubi->leb_size * used_blocks;
 933	if (fm_size != ubi->fm_size) {
 934		ubi_err(ubi, "bad fastmap size: %zi, expected: %zi",
 935			fm_size, ubi->fm_size);
 936		ret = UBI_BAD_FASTMAP;
 937		goto free_fm_sb;
 938	}
 939
 940	ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
 941	if (!ech) {
 942		ret = -ENOMEM;
 943		goto free_fm_sb;
 944	}
 945
 946	vb = ubi_alloc_vid_buf(ubi, GFP_KERNEL);
 947	if (!vb) {
 948		ret = -ENOMEM;
 949		goto free_hdr;
 950	}
 951
 952	vh = ubi_get_vid_hdr(vb);
 953
 954	for (i = 0; i < used_blocks; i++) {
 955		int image_seq;
 956
 957		pnum = be32_to_cpu(fmsb->block_loc[i]);
 958
 959		if (ubi_io_is_bad(ubi, pnum)) {
 960			ret = UBI_BAD_FASTMAP;
 961			goto free_hdr;
 962		}
 963
 964		if (i == 0 && pnum != fm_anchor) {
 965			ubi_err(ubi, "Fastmap anchor PEB mismatch: PEB: %i vs. %i",
 966				pnum, fm_anchor);
 967			ret = UBI_BAD_FASTMAP;
 968			goto free_hdr;
 969		}
 970
 971		ret = ubi_io_read_ec_hdr(ubi, pnum, ech, 0);
 972		if (ret && ret != UBI_IO_BITFLIPS) {
 973			ubi_err(ubi, "unable to read fastmap block# %i EC (PEB: %i)",
 974				i, pnum);
 975			if (ret > 0)
 976				ret = UBI_BAD_FASTMAP;
 977			goto free_hdr;
 978		} else if (ret == UBI_IO_BITFLIPS)
 979			fm->to_be_tortured[i] = 1;
 980
 981		image_seq = be32_to_cpu(ech->image_seq);
 982		if (!ubi->image_seq)
 983			ubi->image_seq = image_seq;
 984
 985		/*
 986		 * Older UBI implementations have image_seq set to zero, so
 987		 * we shouldn't fail if image_seq == 0.
 988		 */
 989		if (image_seq && (image_seq != ubi->image_seq)) {
 990			ubi_err(ubi, "wrong image seq:%d instead of %d",
 991				be32_to_cpu(ech->image_seq), ubi->image_seq);
 992			ret = UBI_BAD_FASTMAP;
 993			goto free_hdr;
 994		}
 995
 996		ret = ubi_io_read_vid_hdr(ubi, pnum, vb, 0);
 997		if (ret && ret != UBI_IO_BITFLIPS) {
 998			ubi_err(ubi, "unable to read fastmap block# %i (PEB: %i)",
 999				i, pnum);
1000			goto free_hdr;
1001		}
1002
1003		if (i == 0) {
1004			if (be32_to_cpu(vh->vol_id) != UBI_FM_SB_VOLUME_ID) {
1005				ubi_err(ubi, "bad fastmap anchor vol_id: 0x%x, expected: 0x%x",
1006					be32_to_cpu(vh->vol_id),
1007					UBI_FM_SB_VOLUME_ID);
1008				ret = UBI_BAD_FASTMAP;
1009				goto free_hdr;
1010			}
1011		} else {
1012			if (be32_to_cpu(vh->vol_id) != UBI_FM_DATA_VOLUME_ID) {
1013				ubi_err(ubi, "bad fastmap data vol_id: 0x%x, expected: 0x%x",
1014					be32_to_cpu(vh->vol_id),
1015					UBI_FM_DATA_VOLUME_ID);
1016				ret = UBI_BAD_FASTMAP;
1017				goto free_hdr;
1018			}
1019		}
1020
1021		if (sqnum < be64_to_cpu(vh->sqnum))
1022			sqnum = be64_to_cpu(vh->sqnum);
1023
1024		ret = ubi_io_read_data(ubi, ubi->fm_buf + (ubi->leb_size * i),
1025				       pnum, 0, ubi->leb_size);
1026		if (ret && ret != UBI_IO_BITFLIPS) {
1027			ubi_err(ubi, "unable to read fastmap block# %i (PEB: %i, "
1028				"err: %i)", i, pnum, ret);
1029			goto free_hdr;
1030		}
1031	}
1032
1033	kfree(fmsb);
1034	fmsb = NULL;
1035
1036	fmsb2 = (struct ubi_fm_sb *)(ubi->fm_buf);
1037	tmp_crc = be32_to_cpu(fmsb2->data_crc);
1038	fmsb2->data_crc = 0;
1039	crc = crc32(UBI_CRC32_INIT, ubi->fm_buf, fm_size);
1040	if (crc != tmp_crc) {
1041		ubi_err(ubi, "fastmap data CRC is invalid");
1042		ubi_err(ubi, "CRC should be: 0x%x, calc: 0x%x",
1043			tmp_crc, crc);
1044		ret = UBI_BAD_FASTMAP;
1045		goto free_hdr;
1046	}
1047
1048	fmsb2->sqnum = sqnum;
1049
1050	fm->used_blocks = used_blocks;
1051
1052	ret = ubi_attach_fastmap(ubi, ai, fm);
1053	if (ret) {
1054		if (ret > 0)
1055			ret = UBI_BAD_FASTMAP;
1056		goto free_hdr;
1057	}
1058
1059	for (i = 0; i < used_blocks; i++) {
1060		struct ubi_wl_entry *e;
1061
1062		e = kmem_cache_alloc(ubi_wl_entry_slab, GFP_KERNEL);
1063		if (!e) {
1064			while (i--)
1065				kmem_cache_free(ubi_wl_entry_slab, fm->e[i]);
1066
1067			ret = -ENOMEM;
1068			goto free_hdr;
1069		}
1070
1071		e->pnum = be32_to_cpu(fmsb2->block_loc[i]);
1072		e->ec = be32_to_cpu(fmsb2->block_ec[i]);
1073		fm->e[i] = e;
1074	}
1075
1076	ubi->fm = fm;
1077	ubi->fm_pool.max_size = ubi->fm->max_pool_size;
1078	ubi->fm_wl_pool.max_size = ubi->fm->max_wl_pool_size;
1079	ubi_msg(ubi, "attached by fastmap");
1080	ubi_msg(ubi, "fastmap pool size: %d", ubi->fm_pool.max_size);
1081	ubi_msg(ubi, "fastmap WL pool size: %d",
1082		ubi->fm_wl_pool.max_size);
1083	ubi->fm_disabled = 0;
1084	ubi->fast_attach = 1;
1085
1086	ubi_free_vid_buf(vb);
1087	kfree(ech);
1088out:
1089	up_write(&ubi->fm_protect);
1090	if (ret == UBI_BAD_FASTMAP)
1091		ubi_err(ubi, "Attach by fastmap failed, doing a full scan!");
1092	return ret;
1093
1094free_hdr:
1095	ubi_free_vid_buf(vb);
1096	kfree(ech);
1097free_fm_sb:
1098	kfree(fmsb);
1099	kfree(fm);
1100	goto out;
1101}
1102
1103int ubi_fastmap_init_checkmap(struct ubi_volume *vol, int leb_count)
1104{
1105	struct ubi_device *ubi = vol->ubi;
1106
1107	if (!ubi->fast_attach)
1108		return 0;
1109
1110	vol->checkmap = bitmap_zalloc(leb_count, GFP_KERNEL);
1111	if (!vol->checkmap)
1112		return -ENOMEM;
1113
1114	return 0;
1115}
1116
1117void ubi_fastmap_destroy_checkmap(struct ubi_volume *vol)
1118{
1119	bitmap_free(vol->checkmap);
1120}
1121
1122/**
1123 * ubi_write_fastmap - writes a fastmap.
1124 * @ubi: UBI device object
1125 * @new_fm: the to be written fastmap
1126 *
1127 * Returns 0 on success, < 0 indicates an internal error.
1128 */
1129static int ubi_write_fastmap(struct ubi_device *ubi,
1130			     struct ubi_fastmap_layout *new_fm)
1131{
1132	size_t fm_pos = 0;
1133	void *fm_raw;
1134	struct ubi_fm_sb *fmsb;
1135	struct ubi_fm_hdr *fmh;
1136	struct ubi_fm_scan_pool *fmpl, *fmpl_wl;
1137	struct ubi_fm_ec *fec;
1138	struct ubi_fm_volhdr *fvh;
1139	struct ubi_fm_eba *feba;
1140	struct ubi_wl_entry *wl_e;
1141	struct ubi_volume *vol;
1142	struct ubi_vid_io_buf *avbuf, *dvbuf;
1143	struct ubi_vid_hdr *avhdr, *dvhdr;
1144	struct ubi_work *ubi_wrk;
1145	struct rb_node *tmp_rb;
1146	int ret, i, j, free_peb_count, used_peb_count, vol_count;
1147	int scrub_peb_count, erase_peb_count;
1148	unsigned long *seen_pebs;
1149
1150	fm_raw = ubi->fm_buf;
1151	memset(ubi->fm_buf, 0, ubi->fm_size);
1152
1153	avbuf = new_fm_vbuf(ubi, UBI_FM_SB_VOLUME_ID);
1154	if (!avbuf) {
1155		ret = -ENOMEM;
1156		goto out;
1157	}
1158
1159	dvbuf = new_fm_vbuf(ubi, UBI_FM_DATA_VOLUME_ID);
1160	if (!dvbuf) {
1161		ret = -ENOMEM;
1162		goto out_free_avbuf;
1163	}
1164
1165	avhdr = ubi_get_vid_hdr(avbuf);
1166	dvhdr = ubi_get_vid_hdr(dvbuf);
1167
1168	seen_pebs = init_seen(ubi);
1169	if (IS_ERR(seen_pebs)) {
1170		ret = PTR_ERR(seen_pebs);
1171		goto out_free_dvbuf;
1172	}
1173
1174	spin_lock(&ubi->volumes_lock);
1175	spin_lock(&ubi->wl_lock);
1176
1177	fmsb = (struct ubi_fm_sb *)fm_raw;
1178	fm_pos += sizeof(*fmsb);
1179	ubi_assert(fm_pos <= ubi->fm_size);
1180
1181	fmh = (struct ubi_fm_hdr *)(fm_raw + fm_pos);
1182	fm_pos += sizeof(*fmh);
1183	ubi_assert(fm_pos <= ubi->fm_size);
1184
1185	fmsb->magic = cpu_to_be32(UBI_FM_SB_MAGIC);
1186	fmsb->version = UBI_FM_FMT_VERSION;
1187	fmsb->used_blocks = cpu_to_be32(new_fm->used_blocks);
1188	/* the max sqnum will be filled in while *reading* the fastmap */
1189	fmsb->sqnum = 0;
1190
1191	fmh->magic = cpu_to_be32(UBI_FM_HDR_MAGIC);
1192	free_peb_count = 0;
1193	used_peb_count = 0;
1194	scrub_peb_count = 0;
1195	erase_peb_count = 0;
1196	vol_count = 0;
1197
1198	fmpl = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
1199	fm_pos += sizeof(*fmpl);
1200	fmpl->magic = cpu_to_be32(UBI_FM_POOL_MAGIC);
1201	fmpl->size = cpu_to_be16(ubi->fm_pool.size);
1202	fmpl->max_size = cpu_to_be16(ubi->fm_pool.max_size);
1203
1204	for (i = 0; i < ubi->fm_pool.size; i++) {
1205		fmpl->pebs[i] = cpu_to_be32(ubi->fm_pool.pebs[i]);
1206		set_seen(ubi, ubi->fm_pool.pebs[i], seen_pebs);
1207	}
1208
1209	fmpl_wl = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
1210	fm_pos += sizeof(*fmpl_wl);
1211	fmpl_wl->magic = cpu_to_be32(UBI_FM_POOL_MAGIC);
1212	fmpl_wl->size = cpu_to_be16(ubi->fm_wl_pool.size);
1213	fmpl_wl->max_size = cpu_to_be16(ubi->fm_wl_pool.max_size);
1214
1215	for (i = 0; i < ubi->fm_wl_pool.size; i++) {
1216		fmpl_wl->pebs[i] = cpu_to_be32(ubi->fm_wl_pool.pebs[i]);
1217		set_seen(ubi, ubi->fm_wl_pool.pebs[i], seen_pebs);
1218	}
1219
1220	ubi_for_each_free_peb(ubi, wl_e, tmp_rb) {
1221		fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1222
1223		fec->pnum = cpu_to_be32(wl_e->pnum);
1224		set_seen(ubi, wl_e->pnum, seen_pebs);
1225		fec->ec = cpu_to_be32(wl_e->ec);
1226
1227		free_peb_count++;
1228		fm_pos += sizeof(*fec);
1229		ubi_assert(fm_pos <= ubi->fm_size);
1230	}
1231	fmh->free_peb_count = cpu_to_be32(free_peb_count);
1232
1233	ubi_for_each_used_peb(ubi, wl_e, tmp_rb) {
1234		fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1235
1236		fec->pnum = cpu_to_be32(wl_e->pnum);
1237		set_seen(ubi, wl_e->pnum, seen_pebs);
1238		fec->ec = cpu_to_be32(wl_e->ec);
1239
1240		used_peb_count++;
1241		fm_pos += sizeof(*fec);
1242		ubi_assert(fm_pos <= ubi->fm_size);
1243	}
1244
1245	ubi_for_each_protected_peb(ubi, i, wl_e) {
1246		fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1247
1248		fec->pnum = cpu_to_be32(wl_e->pnum);
1249		set_seen(ubi, wl_e->pnum, seen_pebs);
1250		fec->ec = cpu_to_be32(wl_e->ec);
1251
1252		used_peb_count++;
1253		fm_pos += sizeof(*fec);
1254		ubi_assert(fm_pos <= ubi->fm_size);
1255	}
1256	fmh->used_peb_count = cpu_to_be32(used_peb_count);
1257
1258	ubi_for_each_scrub_peb(ubi, wl_e, tmp_rb) {
1259		fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1260
1261		fec->pnum = cpu_to_be32(wl_e->pnum);
1262		set_seen(ubi, wl_e->pnum, seen_pebs);
1263		fec->ec = cpu_to_be32(wl_e->ec);
1264
1265		scrub_peb_count++;
1266		fm_pos += sizeof(*fec);
1267		ubi_assert(fm_pos <= ubi->fm_size);
1268	}
1269	fmh->scrub_peb_count = cpu_to_be32(scrub_peb_count);
1270
1271
1272	list_for_each_entry(ubi_wrk, &ubi->works, list) {
1273		if (ubi_is_erase_work(ubi_wrk)) {
1274			wl_e = ubi_wrk->e;
1275			ubi_assert(wl_e);
1276
1277			fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1278
1279			fec->pnum = cpu_to_be32(wl_e->pnum);
1280			set_seen(ubi, wl_e->pnum, seen_pebs);
1281			fec->ec = cpu_to_be32(wl_e->ec);
1282
1283			erase_peb_count++;
1284			fm_pos += sizeof(*fec);
1285			ubi_assert(fm_pos <= ubi->fm_size);
1286		}
1287	}
1288	fmh->erase_peb_count = cpu_to_be32(erase_peb_count);
1289
1290	for (i = 0; i < UBI_MAX_VOLUMES + UBI_INT_VOL_COUNT; i++) {
1291		vol = ubi->volumes[i];
1292
1293		if (!vol)
1294			continue;
1295
1296		vol_count++;
1297
1298		fvh = (struct ubi_fm_volhdr *)(fm_raw + fm_pos);
1299		fm_pos += sizeof(*fvh);
1300		ubi_assert(fm_pos <= ubi->fm_size);
1301
1302		fvh->magic = cpu_to_be32(UBI_FM_VHDR_MAGIC);
1303		fvh->vol_id = cpu_to_be32(vol->vol_id);
1304		fvh->vol_type = vol->vol_type;
1305		fvh->used_ebs = cpu_to_be32(vol->used_ebs);
1306		fvh->data_pad = cpu_to_be32(vol->data_pad);
1307		fvh->last_eb_bytes = cpu_to_be32(vol->last_eb_bytes);
1308
1309		ubi_assert(vol->vol_type == UBI_DYNAMIC_VOLUME ||
1310			vol->vol_type == UBI_STATIC_VOLUME);
1311
1312		feba = (struct ubi_fm_eba *)(fm_raw + fm_pos);
1313		fm_pos += sizeof(*feba) + (sizeof(__be32) * vol->reserved_pebs);
1314		ubi_assert(fm_pos <= ubi->fm_size);
1315
1316		for (j = 0; j < vol->reserved_pebs; j++) {
1317			struct ubi_eba_leb_desc ldesc;
1318
1319			ubi_eba_get_ldesc(vol, j, &ldesc);
1320			feba->pnum[j] = cpu_to_be32(ldesc.pnum);
1321		}
1322
1323		feba->reserved_pebs = cpu_to_be32(j);
1324		feba->magic = cpu_to_be32(UBI_FM_EBA_MAGIC);
1325	}
1326	fmh->vol_count = cpu_to_be32(vol_count);
1327	fmh->bad_peb_count = cpu_to_be32(ubi->bad_peb_count);
1328
1329	avhdr->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
1330	avhdr->lnum = 0;
1331
1332	spin_unlock(&ubi->wl_lock);
1333	spin_unlock(&ubi->volumes_lock);
1334
1335	dbg_bld("writing fastmap SB to PEB %i", new_fm->e[0]->pnum);
1336	ret = ubi_io_write_vid_hdr(ubi, new_fm->e[0]->pnum, avbuf);
1337	if (ret) {
1338		ubi_err(ubi, "unable to write vid_hdr to fastmap SB!");
1339		goto out_free_seen;
1340	}
1341
1342	for (i = 0; i < new_fm->used_blocks; i++) {
1343		fmsb->block_loc[i] = cpu_to_be32(new_fm->e[i]->pnum);
1344		set_seen(ubi, new_fm->e[i]->pnum, seen_pebs);
1345		fmsb->block_ec[i] = cpu_to_be32(new_fm->e[i]->ec);
1346	}
1347
1348	fmsb->data_crc = 0;
1349	fmsb->data_crc = cpu_to_be32(crc32(UBI_CRC32_INIT, fm_raw,
1350					   ubi->fm_size));
1351
1352	for (i = 1; i < new_fm->used_blocks; i++) {
1353		dvhdr->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
1354		dvhdr->lnum = cpu_to_be32(i);
1355		dbg_bld("writing fastmap data to PEB %i sqnum %llu",
1356			new_fm->e[i]->pnum, be64_to_cpu(dvhdr->sqnum));
1357		ret = ubi_io_write_vid_hdr(ubi, new_fm->e[i]->pnum, dvbuf);
1358		if (ret) {
1359			ubi_err(ubi, "unable to write vid_hdr to PEB %i!",
1360				new_fm->e[i]->pnum);
1361			goto out_free_seen;
1362		}
1363	}
1364
1365	for (i = 0; i < new_fm->used_blocks; i++) {
1366		ret = ubi_io_write_data(ubi, fm_raw + (i * ubi->leb_size),
1367					new_fm->e[i]->pnum, 0, ubi->leb_size);
1368		if (ret) {
1369			ubi_err(ubi, "unable to write fastmap to PEB %i!",
1370				new_fm->e[i]->pnum);
1371			goto out_free_seen;
1372		}
1373	}
1374
1375	ubi_assert(new_fm);
1376	ubi->fm = new_fm;
1377
1378	ret = self_check_seen(ubi, seen_pebs);
1379	dbg_bld("fastmap written!");
1380
1381out_free_seen:
1382	free_seen(seen_pebs);
1383out_free_dvbuf:
1384	ubi_free_vid_buf(dvbuf);
1385out_free_avbuf:
1386	ubi_free_vid_buf(avbuf);
1387
1388out:
1389	return ret;
1390}
1391
1392/**
1393 * invalidate_fastmap - destroys a fastmap.
1394 * @ubi: UBI device object
1395 *
1396 * This function ensures that upon next UBI attach a full scan
1397 * is issued. We need this if UBI is about to write a new fastmap
1398 * but is unable to do so. In this case we have two options:
1399 * a) Make sure that the current fastmap will not be usued upon
1400 * attach time and contine or b) fall back to RO mode to have the
1401 * current fastmap in a valid state.
1402 * Returns 0 on success, < 0 indicates an internal error.
1403 */
1404static int invalidate_fastmap(struct ubi_device *ubi)
1405{
1406	int ret;
1407	struct ubi_fastmap_layout *fm;
1408	struct ubi_wl_entry *e;
1409	struct ubi_vid_io_buf *vb = NULL;
1410	struct ubi_vid_hdr *vh;
1411
1412	if (!ubi->fm)
1413		return 0;
1414
1415	ubi->fm = NULL;
1416
1417	ret = -ENOMEM;
1418	fm = kzalloc(sizeof(*fm), GFP_NOFS);
1419	if (!fm)
1420		goto out;
1421
1422	vb = new_fm_vbuf(ubi, UBI_FM_SB_VOLUME_ID);
1423	if (!vb)
1424		goto out_free_fm;
1425
1426	vh = ubi_get_vid_hdr(vb);
1427
1428	ret = -ENOSPC;
1429	e = ubi_wl_get_fm_peb(ubi, 1);
1430	if (!e)
1431		goto out_free_fm;
1432
1433	/*
1434	 * Create fake fastmap such that UBI will fall back
1435	 * to scanning mode.
1436	 */
1437	vh->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
1438	ret = ubi_io_write_vid_hdr(ubi, e->pnum, vb);
1439	if (ret < 0) {
1440		ubi_wl_put_fm_peb(ubi, e, 0, 0);
1441		goto out_free_fm;
1442	}
1443
1444	fm->used_blocks = 1;
1445	fm->e[0] = e;
1446
1447	ubi->fm = fm;
1448
1449out:
1450	ubi_free_vid_buf(vb);
1451	return ret;
1452
1453out_free_fm:
1454	kfree(fm);
1455	goto out;
1456}
1457
1458/**
1459 * return_fm_pebs - returns all PEBs used by a fastmap back to the
1460 * WL sub-system.
1461 * @ubi: UBI device object
1462 * @fm: fastmap layout object
1463 */
1464static void return_fm_pebs(struct ubi_device *ubi,
1465			   struct ubi_fastmap_layout *fm)
1466{
1467	int i;
1468
1469	if (!fm)
1470		return;
1471
1472	for (i = 0; i < fm->used_blocks; i++) {
1473		if (fm->e[i]) {
1474			ubi_wl_put_fm_peb(ubi, fm->e[i], i,
1475					  fm->to_be_tortured[i]);
1476			fm->e[i] = NULL;
1477		}
1478	}
1479}
1480
1481/**
1482 * ubi_update_fastmap - will be called by UBI if a volume changes or
1483 * a fastmap pool becomes full.
1484 * @ubi: UBI device object
1485 *
1486 * Returns 0 on success, < 0 indicates an internal error.
1487 */
1488int ubi_update_fastmap(struct ubi_device *ubi)
1489{
1490	int ret, i, j;
1491	struct ubi_fastmap_layout *new_fm, *old_fm;
1492	struct ubi_wl_entry *tmp_e;
1493
1494	ubi_refill_pools_and_lock(ubi);
1495
1496	if (ubi->ro_mode || ubi->fm_disabled) {
1497		up_write(&ubi->fm_eba_sem);
1498		up_write(&ubi->work_sem);
1499		up_write(&ubi->fm_protect);
1500		return 0;
1501	}
1502
1503	new_fm = kzalloc(sizeof(*new_fm), GFP_NOFS);
1504	if (!new_fm) {
1505		up_write(&ubi->fm_eba_sem);
1506		up_write(&ubi->work_sem);
1507		up_write(&ubi->fm_protect);
1508		return -ENOMEM;
1509	}
1510
1511	new_fm->used_blocks = ubi->fm_size / ubi->leb_size;
1512	old_fm = ubi->fm;
1513	ubi->fm = NULL;
1514
1515	if (new_fm->used_blocks > UBI_FM_MAX_BLOCKS) {
1516		ubi_err(ubi, "fastmap too large");
1517		ret = -ENOSPC;
1518		goto err;
1519	}
1520
1521	for (i = 1; i < new_fm->used_blocks; i++) {
1522		spin_lock(&ubi->wl_lock);
1523		tmp_e = ubi_wl_get_fm_peb(ubi, 0);
1524		spin_unlock(&ubi->wl_lock);
1525
1526		if (!tmp_e) {
1527			if (old_fm && old_fm->e[i]) {
1528				ret = ubi_sync_erase(ubi, old_fm->e[i], 0);
1529				if (ret < 0) {
1530					ubi_err(ubi, "could not erase old fastmap PEB");
1531
1532					for (j = 1; j < i; j++) {
1533						ubi_wl_put_fm_peb(ubi, new_fm->e[j],
1534								  j, 0);
1535						new_fm->e[j] = NULL;
1536					}
1537					goto err;
1538				}
1539				new_fm->e[i] = old_fm->e[i];
1540				old_fm->e[i] = NULL;
1541			} else {
1542				ubi_err(ubi, "could not get any free erase block");
1543
1544				for (j = 1; j < i; j++) {
1545					ubi_wl_put_fm_peb(ubi, new_fm->e[j], j, 0);
1546					new_fm->e[j] = NULL;
1547				}
1548
1549				ret = -ENOSPC;
1550				goto err;
1551			}
1552		} else {
1553			new_fm->e[i] = tmp_e;
1554
1555			if (old_fm && old_fm->e[i]) {
1556				ubi_wl_put_fm_peb(ubi, old_fm->e[i], i,
1557						  old_fm->to_be_tortured[i]);
1558				old_fm->e[i] = NULL;
1559			}
1560		}
1561	}
1562
1563	/* Old fastmap is larger than the new one */
1564	if (old_fm && new_fm->used_blocks < old_fm->used_blocks) {
1565		for (i = new_fm->used_blocks; i < old_fm->used_blocks; i++) {
1566			ubi_wl_put_fm_peb(ubi, old_fm->e[i], i,
1567					  old_fm->to_be_tortured[i]);
1568			old_fm->e[i] = NULL;
1569		}
1570	}
1571
1572	spin_lock(&ubi->wl_lock);
1573	tmp_e = ubi->fm_anchor;
1574	ubi->fm_anchor = NULL;
1575	spin_unlock(&ubi->wl_lock);
1576
1577	if (old_fm) {
1578		/* no fresh anchor PEB was found, reuse the old one */
1579		if (!tmp_e) {
1580			ret = ubi_sync_erase(ubi, old_fm->e[0], 0);
1581			if (ret < 0) {
1582				ubi_err(ubi, "could not erase old anchor PEB");
1583
1584				for (i = 1; i < new_fm->used_blocks; i++) {
1585					ubi_wl_put_fm_peb(ubi, new_fm->e[i],
1586							  i, 0);
1587					new_fm->e[i] = NULL;
1588				}
1589				goto err;
1590			}
1591			new_fm->e[0] = old_fm->e[0];
1592			old_fm->e[0] = NULL;
1593		} else {
1594			/* we've got a new anchor PEB, return the old one */
1595			ubi_wl_put_fm_peb(ubi, old_fm->e[0], 0,
1596					  old_fm->to_be_tortured[0]);
1597			new_fm->e[0] = tmp_e;
1598			old_fm->e[0] = NULL;
1599		}
1600	} else {
1601		if (!tmp_e) {
1602			ubi_err(ubi, "could not find any anchor PEB");
1603
1604			for (i = 1; i < new_fm->used_blocks; i++) {
1605				ubi_wl_put_fm_peb(ubi, new_fm->e[i], i, 0);
1606				new_fm->e[i] = NULL;
1607			}
1608
1609			ret = -ENOSPC;
1610			goto err;
1611		}
1612		new_fm->e[0] = tmp_e;
1613	}
1614
1615	ret = ubi_write_fastmap(ubi, new_fm);
1616
1617	if (ret)
1618		goto err;
1619
1620out_unlock:
1621	up_write(&ubi->fm_eba_sem);
1622	up_write(&ubi->work_sem);
1623	up_write(&ubi->fm_protect);
1624	kfree(old_fm);
1625
1626	ubi_ensure_anchor_pebs(ubi);
1627
1628	return ret;
1629
1630err:
1631	ubi_warn(ubi, "Unable to write new fastmap, err=%i", ret);
1632
1633	ret = invalidate_fastmap(ubi);
1634	if (ret < 0) {
1635		ubi_err(ubi, "Unable to invalidate current fastmap!");
1636		ubi_ro_mode(ubi);
1637	} else {
1638		return_fm_pebs(ubi, old_fm);
1639		return_fm_pebs(ubi, new_fm);
1640		ret = 0;
1641	}
1642
1643	kfree(new_fm);
1644	goto out_unlock;
1645}