1/*
   2 * Copyright (c) International Business Machines Corp., 2006
   3 *
   4 * This program is free software; you can redistribute it and/or modify
   5 * it under the terms of the GNU General Public License as published by
   6 * the Free Software Foundation; either version 2 of the License, or
   7 * (at your option) any later version.
   8 *
   9 * This program is distributed in the hope that it will be useful,
  10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
  12 * the GNU General Public License for more details.
  13 *
  14 * You should have received a copy of the GNU General Public License
  15 * along with this program; if not, write to the Free Software
  16 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  17 *
  18 * Author: Artem Bityutskiy (Битюцкий Артём)
  19 */
  20
  21/*
  22 * The UBI Eraseblock Association (EBA) sub-system.
  23 *
  24 * This sub-system is responsible for I/O to/from logical eraseblock.
  25 *
  26 * Although in this implementation the EBA table is fully kept and managed in
  27 * RAM, which assumes poor scalability, it might be (partially) maintained on
  28 * flash in future implementations.
  29 *
  30 * The EBA sub-system implements per-logical eraseblock locking. Before
  31 * accessing a logical eraseblock it is locked for reading or writing. The
  32 * per-logical eraseblock locking is implemented by means of the lock tree. The
  33 * lock tree is an RB-tree which refers all the currently locked logical
  34 * eraseblocks. The lock tree elements are &struct ubi_ltree_entry objects.
  35 * They are indexed by (@vol_id, @lnum) pairs.
  36 *
  37 * EBA also maintains the global sequence counter which is incremented each
  38 * time a logical eraseblock is mapped to a physical eraseblock and it is
  39 * stored in the volume identifier header. This means that each VID header has
  40 * a unique sequence number. The sequence number is only increased an we assume
  41 * 64 bits is enough to never overflow.
  42 */
  43
  44#include <linux/slab.h>
  45#include <linux/crc32.h>
  46#include <linux/err.h>
  47#include "ubi.h"
  48
  49/* Number of physical eraseblocks reserved for atomic LEB change operation */
  50#define EBA_RESERVED_PEBS 1
  51
  52/**
  53 * next_sqnum - get next sequence number.
  54 * @ubi: UBI device description object
  55 *
  56 * This function returns next sequence number to use, which is just the current
  57 * global sequence counter value. It also increases the global sequence
  58 * counter.
  59 */
  60static unsigned long long next_sqnum(struct ubi_device *ubi)
  61{
  62	unsigned long long sqnum;
  63
  64	spin_lock(&ubi->ltree_lock);
  65	sqnum = ubi->global_sqnum++;
  66	spin_unlock(&ubi->ltree_lock);
  67
  68	return sqnum;
  69}
  70
  71/**
  72 * ubi_get_compat - get compatibility flags of a volume.
  73 * @ubi: UBI device description object
  74 * @vol_id: volume ID
  75 *
  76 * This function returns compatibility flags for an internal volume. User
  77 * volumes have no compatibility flags, so %0 is returned.
  78 */
  79static int ubi_get_compat(const struct ubi_device *ubi, int vol_id)
  80{
  81	if (vol_id == UBI_LAYOUT_VOLUME_ID)
  82		return UBI_LAYOUT_VOLUME_COMPAT;
  83	return 0;
  84}
  85
  86/**
  87 * ltree_lookup - look up the lock tree.
  88 * @ubi: UBI device description object
  89 * @vol_id: volume ID
  90 * @lnum: logical eraseblock number
  91 *
  92 * This function returns a pointer to the corresponding &struct ubi_ltree_entry
  93 * object if the logical eraseblock is locked and %NULL if it is not.
  94 * @ubi->ltree_lock has to be locked.
  95 */
  96static struct ubi_ltree_entry *ltree_lookup(struct ubi_device *ubi, int vol_id,
  97					    int lnum)
  98{
  99	struct rb_node *p;
 100
 101	p = ubi->ltree.rb_node;
 102	while (p) {
 103		struct ubi_ltree_entry *le;
 104
 105		le = rb_entry(p, struct ubi_ltree_entry, rb);
 106
 107		if (vol_id < le->vol_id)
 108			p = p->rb_left;
 109		else if (vol_id > le->vol_id)
 110			p = p->rb_right;
 111		else {
 112			if (lnum < le->lnum)
 113				p = p->rb_left;
 114			else if (lnum > le->lnum)
 115				p = p->rb_right;
 116			else
 117				return le;
 118		}
 119	}
 120
 121	return NULL;
 122}
 123
 124/**
 125 * ltree_add_entry - add new entry to the lock tree.
 126 * @ubi: UBI device description object
 127 * @vol_id: volume ID
 128 * @lnum: logical eraseblock number
 129 *
 130 * This function adds new entry for logical eraseblock (@vol_id, @lnum) to the
 131 * lock tree. If such entry is already there, its usage counter is increased.
 132 * Returns pointer to the lock tree entry or %-ENOMEM if memory allocation
 133 * failed.
 134 */
 135static struct ubi_ltree_entry *ltree_add_entry(struct ubi_device *ubi,
 136					       int vol_id, int lnum)
 137{
 138	struct ubi_ltree_entry *le, *le1, *le_free;
 139
 140	le = kmalloc(sizeof(struct ubi_ltree_entry), GFP_NOFS);
 141	if (!le)
 142		return ERR_PTR(-ENOMEM);
 143
 144	le->users = 0;
 145	init_rwsem(&le->mutex);
 146	le->vol_id = vol_id;
 147	le->lnum = lnum;
 148
 149	spin_lock(&ubi->ltree_lock);
 150	le1 = ltree_lookup(ubi, vol_id, lnum);
 151
 152	if (le1) {
 153		/*
 154		 * This logical eraseblock is already locked. The newly
 155		 * allocated lock entry is not needed.
 156		 */
 157		le_free = le;
 158		le = le1;
 159	} else {
 160		struct rb_node **p, *parent = NULL;
 161
 162		/*
 163		 * No lock entry, add the newly allocated one to the
 164		 * @ubi->ltree RB-tree.
 165		 */
 166		le_free = NULL;
 167
 168		p = &ubi->ltree.rb_node;
 169		while (*p) {
 170			parent = *p;
 171			le1 = rb_entry(parent, struct ubi_ltree_entry, rb);
 172
 173			if (vol_id < le1->vol_id)
 174				p = &(*p)->rb_left;
 175			else if (vol_id > le1->vol_id)
 176				p = &(*p)->rb_right;
 177			else {
 178				ubi_assert(lnum != le1->lnum);
 179				if (lnum < le1->lnum)
 180					p = &(*p)->rb_left;
 181				else
 182					p = &(*p)->rb_right;
 183			}
 184		}
 185
 186		rb_link_node(&le->rb, parent, p);
 187		rb_insert_color(&le->rb, &ubi->ltree);
 188	}
 189	le->users += 1;
 190	spin_unlock(&ubi->ltree_lock);
 191
 192	kfree(le_free);
 193	return le;
 194}
 195
 196/**
 197 * leb_read_lock - lock logical eraseblock for reading.
 198 * @ubi: UBI device description object
 199 * @vol_id: volume ID
 200 * @lnum: logical eraseblock number
 201 *
 202 * This function locks a logical eraseblock for reading. Returns zero in case
 203 * of success and a negative error code in case of failure.
 204 */
 205static int leb_read_lock(struct ubi_device *ubi, int vol_id, int lnum)
 206{
 207	struct ubi_ltree_entry *le;
 208
 209	le = ltree_add_entry(ubi, vol_id, lnum);
 210	if (IS_ERR(le))
 211		return PTR_ERR(le);
 212	down_read(&le->mutex);
 213	return 0;
 214}
 215
 216/**
 217 * leb_read_unlock - unlock logical eraseblock.
 218 * @ubi: UBI device description object
 219 * @vol_id: volume ID
 220 * @lnum: logical eraseblock number
 221 */
 222static void leb_read_unlock(struct ubi_device *ubi, int vol_id, int lnum)
 223{
 224	struct ubi_ltree_entry *le;
 225
 226	spin_lock(&ubi->ltree_lock);
 227	le = ltree_lookup(ubi, vol_id, lnum);
 228	le->users -= 1;
 229	ubi_assert(le->users >= 0);
 230	up_read(&le->mutex);
 231	if (le->users == 0) {
 232		rb_erase(&le->rb, &ubi->ltree);
 233		kfree(le);
 234	}
 235	spin_unlock(&ubi->ltree_lock);
 236}
 237
 238/**
 239 * leb_write_lock - lock logical eraseblock for writing.
 240 * @ubi: UBI device description object
 241 * @vol_id: volume ID
 242 * @lnum: logical eraseblock number
 243 *
 244 * This function locks a logical eraseblock for writing. Returns zero in case
 245 * of success and a negative error code in case of failure.
 246 */
 247static int leb_write_lock(struct ubi_device *ubi, int vol_id, int lnum)
 248{
 249	struct ubi_ltree_entry *le;
 250
 251	le = ltree_add_entry(ubi, vol_id, lnum);
 252	if (IS_ERR(le))
 253		return PTR_ERR(le);
 254	down_write(&le->mutex);
 255	return 0;
 256}
 257
 258/**
 259 * leb_write_lock - lock logical eraseblock for writing.
 260 * @ubi: UBI device description object
 261 * @vol_id: volume ID
 262 * @lnum: logical eraseblock number
 263 *
 264 * This function locks a logical eraseblock for writing if there is no
 265 * contention and does nothing if there is contention. Returns %0 in case of
 266 * success, %1 in case of contention, and and a negative error code in case of
 267 * failure.
 268 */
 269static int leb_write_trylock(struct ubi_device *ubi, int vol_id, int lnum)
 270{
 271	struct ubi_ltree_entry *le;
 272
 273	le = ltree_add_entry(ubi, vol_id, lnum);
 274	if (IS_ERR(le))
 275		return PTR_ERR(le);
 276	if (down_write_trylock(&le->mutex))
 277		return 0;
 278
 279	/* Contention, cancel */
 280	spin_lock(&ubi->ltree_lock);
 281	le->users -= 1;
 282	ubi_assert(le->users >= 0);
 283	if (le->users == 0) {
 284		rb_erase(&le->rb, &ubi->ltree);
 285		kfree(le);
 286	}
 287	spin_unlock(&ubi->ltree_lock);
 288
 289	return 1;
 290}
 291
 292/**
 293 * leb_write_unlock - unlock logical eraseblock.
 294 * @ubi: UBI device description object
 295 * @vol_id: volume ID
 296 * @lnum: logical eraseblock number
 297 */
 298static void leb_write_unlock(struct ubi_device *ubi, int vol_id, int lnum)
 299{
 300	struct ubi_ltree_entry *le;
 301
 302	spin_lock(&ubi->ltree_lock);
 303	le = ltree_lookup(ubi, vol_id, lnum);
 304	le->users -= 1;
 305	ubi_assert(le->users >= 0);
 306	up_write(&le->mutex);
 307	if (le->users == 0) {
 308		rb_erase(&le->rb, &ubi->ltree);
 309		kfree(le);
 310	}
 311	spin_unlock(&ubi->ltree_lock);
 312}
 313
 314/**
 315 * ubi_eba_unmap_leb - un-map logical eraseblock.
 316 * @ubi: UBI device description object
 317 * @vol: volume description object
 318 * @lnum: logical eraseblock number
 319 *
 320 * This function un-maps logical eraseblock @lnum and schedules corresponding
 321 * physical eraseblock for erasure. Returns zero in case of success and a
 322 * negative error code in case of failure.
 323 */
 324int ubi_eba_unmap_leb(struct ubi_device *ubi, struct ubi_volume *vol,
 325		      int lnum)
 326{
 327	int err, pnum, vol_id = vol->vol_id;
 328
 329	if (ubi->ro_mode)
 330		return -EROFS;
 331
 332	err = leb_write_lock(ubi, vol_id, lnum);
 333	if (err)
 334		return err;
 335
 336	pnum = vol->eba_tbl[lnum];
 337	if (pnum < 0)
 338		/* This logical eraseblock is already unmapped */
 339		goto out_unlock;
 340
 341	dbg_eba("erase LEB %d:%d, PEB %d", vol_id, lnum, pnum);
 342
 343	vol->eba_tbl[lnum] = UBI_LEB_UNMAPPED;
 344	err = ubi_wl_put_peb(ubi, pnum, 0);
 345
 346out_unlock:
 347	leb_write_unlock(ubi, vol_id, lnum);
 348	return err;
 349}
 350
 351/**
 352 * ubi_eba_read_leb - read data.
 353 * @ubi: UBI device description object
 354 * @vol: volume description object
 355 * @lnum: logical eraseblock number
 356 * @buf: buffer to store the read data
 357 * @offset: offset from where to read
 358 * @len: how many bytes to read
 359 * @check: data CRC check flag
 360 *
 361 * If the logical eraseblock @lnum is unmapped, @buf is filled with 0xFF
 362 * bytes. The @check flag only makes sense for static volumes and forces
 363 * eraseblock data CRC checking.
 364 *
 365 * In case of success this function returns zero. In case of a static volume,
 366 * if data CRC mismatches - %-EBADMSG is returned. %-EBADMSG may also be
 367 * returned for any volume type if an ECC error was detected by the MTD device
 368 * driver. Other negative error cored may be returned in case of other errors.
 369 */
 370int ubi_eba_read_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum,
 371		     void *buf, int offset, int len, int check)
 372{
 373	int err, pnum, scrub = 0, vol_id = vol->vol_id;
 374	struct ubi_vid_hdr *vid_hdr;
 375	uint32_t uninitialized_var(crc);
 376
 377	err = leb_read_lock(ubi, vol_id, lnum);
 378	if (err)
 379		return err;
 380
 381	pnum = vol->eba_tbl[lnum];
 382	if (pnum < 0) {
 383		/*
 384		 * The logical eraseblock is not mapped, fill the whole buffer
 385		 * with 0xFF bytes. The exception is static volumes for which
 386		 * it is an error to read unmapped logical eraseblocks.
 387		 */
 388		dbg_eba("read %d bytes from offset %d of LEB %d:%d (unmapped)",
 389			len, offset, vol_id, lnum);
 390		leb_read_unlock(ubi, vol_id, lnum);
 391		ubi_assert(vol->vol_type != UBI_STATIC_VOLUME);
 392		memset(buf, 0xFF, len);
 393		return 0;
 394	}
 395
 396	dbg_eba("read %d bytes from offset %d of LEB %d:%d, PEB %d",
 397		len, offset, vol_id, lnum, pnum);
 398
 399	if (vol->vol_type == UBI_DYNAMIC_VOLUME)
 400		check = 0;
 401
 402retry:
 403	if (check) {
 404		vid_hdr = ubi_zalloc_vid_hdr(ubi, GFP_NOFS);
 405		if (!vid_hdr) {
 406			err = -ENOMEM;
 407			goto out_unlock;
 408		}
 409
 410		err = ubi_io_read_vid_hdr(ubi, pnum, vid_hdr, 1);
 411		if (err && err != UBI_IO_BITFLIPS) {
 412			if (err > 0) {
 413				/*
 414				 * The header is either absent or corrupted.
 415				 * The former case means there is a bug -
 416				 * switch to read-only mode just in case.
 417				 * The latter case means a real corruption - we
 418				 * may try to recover data. FIXME: but this is
 419				 * not implemented.
 420				 */
 421				if (err == UBI_IO_BAD_HDR_EBADMSG ||
 422				    err == UBI_IO_BAD_HDR) {
 423					ubi_warn("corrupted VID header at PEB "
 424						 "%d, LEB %d:%d", pnum, vol_id,
 425						 lnum);
 426					err = -EBADMSG;
 427				} else
 428					ubi_ro_mode(ubi);
 429			}
 430			goto out_free;
 431		} else if (err == UBI_IO_BITFLIPS)
 432			scrub = 1;
 433
 434		ubi_assert(lnum < be32_to_cpu(vid_hdr->used_ebs));
 435		ubi_assert(len == be32_to_cpu(vid_hdr->data_size));
 436
 437		crc = be32_to_cpu(vid_hdr->data_crc);
 438		ubi_free_vid_hdr(ubi, vid_hdr);
 439	}
 440
 441	err = ubi_io_read_data(ubi, buf, pnum, offset, len);
 442	if (err) {
 443		if (err == UBI_IO_BITFLIPS) {
 444			scrub = 1;
 445			err = 0;
 446		} else if (err == -EBADMSG) {
 447			if (vol->vol_type == UBI_DYNAMIC_VOLUME)
 448				goto out_unlock;
 449			scrub = 1;
 450			if (!check) {
 451				ubi_msg("force data checking");
 452				check = 1;
 453				goto retry;
 454			}
 455		} else
 456			goto out_unlock;
 457	}
 458
 459	if (check) {
 460		uint32_t crc1 = crc32(UBI_CRC32_INIT, buf, len);
 461		if (crc1 != crc) {
 462			ubi_warn("CRC error: calculated %#08x, must be %#08x",
 463				 crc1, crc);
 464			err = -EBADMSG;
 465			goto out_unlock;
 466		}
 467	}
 468
 469	if (scrub)
 470		err = ubi_wl_scrub_peb(ubi, pnum);
 471
 472	leb_read_unlock(ubi, vol_id, lnum);
 473	return err;
 474
 475out_free:
 476	ubi_free_vid_hdr(ubi, vid_hdr);
 477out_unlock:
 478	leb_read_unlock(ubi, vol_id, lnum);
 479	return err;
 480}
 481
 482/**
 483 * recover_peb - recover from write failure.
 484 * @ubi: UBI device description object
 485 * @pnum: the physical eraseblock to recover
 486 * @vol_id: volume ID
 487 * @lnum: logical eraseblock number
 488 * @buf: data which was not written because of the write failure
 489 * @offset: offset of the failed write
 490 * @len: how many bytes should have been written
 491 *
 492 * This function is called in case of a write failure and moves all good data
 493 * from the potentially bad physical eraseblock to a good physical eraseblock.
 494 * This function also writes the data which was not written due to the failure.
 495 * Returns new physical eraseblock number in case of success, and a negative
 496 * error code in case of failure.
 497 */
 498static int recover_peb(struct ubi_device *ubi, int pnum, int vol_id, int lnum,
 499		       const void *buf, int offset, int len)
 500{
 501	int err, idx = vol_id2idx(ubi, vol_id), new_pnum, data_size, tries = 0;
 502	struct ubi_volume *vol = ubi->volumes[idx];
 503	struct ubi_vid_hdr *vid_hdr;
 504
 505	vid_hdr = ubi_zalloc_vid_hdr(ubi, GFP_NOFS);
 506	if (!vid_hdr)
 507		return -ENOMEM;
 508
 509retry:
 510	new_pnum = ubi_wl_get_peb(ubi, UBI_UNKNOWN);
 511	if (new_pnum < 0) {
 512		ubi_free_vid_hdr(ubi, vid_hdr);
 513		return new_pnum;
 514	}
 515
 516	ubi_msg("recover PEB %d, move data to PEB %d", pnum, new_pnum);
 517
 518	err = ubi_io_read_vid_hdr(ubi, pnum, vid_hdr, 1);
 519	if (err && err != UBI_IO_BITFLIPS) {
 520		if (err > 0)
 521			err = -EIO;
 522		goto out_put;
 523	}
 524
 525	vid_hdr->sqnum = cpu_to_be64(next_sqnum(ubi));
 526	err = ubi_io_write_vid_hdr(ubi, new_pnum, vid_hdr);
 527	if (err)
 528		goto write_error;
 529
 530	data_size = offset + len;
 531	mutex_lock(&ubi->buf_mutex);
 532	memset(ubi->peb_buf1 + offset, 0xFF, len);
 533
 534	/* Read everything before the area where the write failure happened */
 535	if (offset > 0) {
 536		err = ubi_io_read_data(ubi, ubi->peb_buf1, pnum, 0, offset);
 537		if (err && err != UBI_IO_BITFLIPS)
 538			goto out_unlock;
 539	}
 540
 541	memcpy(ubi->peb_buf1 + offset, buf, len);
 542
 543	err = ubi_io_write_data(ubi, ubi->peb_buf1, new_pnum, 0, data_size);
 544	if (err) {
 545		mutex_unlock(&ubi->buf_mutex);
 546		goto write_error;
 547	}
 548
 549	mutex_unlock(&ubi->buf_mutex);
 550	ubi_free_vid_hdr(ubi, vid_hdr);
 551
 552	vol->eba_tbl[lnum] = new_pnum;
 553	ubi_wl_put_peb(ubi, pnum, 1);
 554
 555	ubi_msg("data was successfully recovered");
 556	return 0;
 557
 558out_unlock:
 559	mutex_unlock(&ubi->buf_mutex);
 560out_put:
 561	ubi_wl_put_peb(ubi, new_pnum, 1);
 562	ubi_free_vid_hdr(ubi, vid_hdr);
 563	return err;
 564
 565write_error:
 566	/*
 567	 * Bad luck? This physical eraseblock is bad too? Crud. Let's try to
 568	 * get another one.
 569	 */
 570	ubi_warn("failed to write to PEB %d", new_pnum);
 571	ubi_wl_put_peb(ubi, new_pnum, 1);
 572	if (++tries > UBI_IO_RETRIES) {
 573		ubi_free_vid_hdr(ubi, vid_hdr);
 574		return err;
 575	}
 576	ubi_msg("try again");
 577	goto retry;
 578}
 579
 580/**
 581 * ubi_eba_write_leb - write data to dynamic volume.
 582 * @ubi: UBI device description object
 583 * @vol: volume description object
 584 * @lnum: logical eraseblock number
 585 * @buf: the data to write
 586 * @offset: offset within the logical eraseblock where to write
 587 * @len: how many bytes to write
 588 * @dtype: data type
 589 *
 590 * This function writes data to logical eraseblock @lnum of a dynamic volume
 591 * @vol. Returns zero in case of success and a negative error code in case
 592 * of failure. In case of error, it is possible that something was still
 593 * written to the flash media, but may be some garbage.
 594 */
 595int ubi_eba_write_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum,
 596		      const void *buf, int offset, int len, int dtype)
 597{
 598	int err, pnum, tries = 0, vol_id = vol->vol_id;
 599	struct ubi_vid_hdr *vid_hdr;
 600
 601	if (ubi->ro_mode)
 602		return -EROFS;
 603
 604	err = leb_write_lock(ubi, vol_id, lnum);
 605	if (err)
 606		return err;
 607
 608	pnum = vol->eba_tbl[lnum];
 609	if (pnum >= 0) {
 610		dbg_eba("write %d bytes at offset %d of LEB %d:%d, PEB %d",
 611			len, offset, vol_id, lnum, pnum);
 612
 613		err = ubi_io_write_data(ubi, buf, pnum, offset, len);
 614		if (err) {
 615			ubi_warn("failed to write data to PEB %d", pnum);
 616			if (err == -EIO && ubi->bad_allowed)
 617				err = recover_peb(ubi, pnum, vol_id, lnum, buf,
 618						  offset, len);
 619			if (err)
 620				ubi_ro_mode(ubi);
 621		}
 622		leb_write_unlock(ubi, vol_id, lnum);
 623		return err;
 624	}
 625
 626	/*
 627	 * The logical eraseblock is not mapped. We have to get a free physical
 628	 * eraseblock and write the volume identifier header there first.
 629	 */
 630	vid_hdr = ubi_zalloc_vid_hdr(ubi, GFP_NOFS);
 631	if (!vid_hdr) {
 632		leb_write_unlock(ubi, vol_id, lnum);
 633		return -ENOMEM;
 634	}
 635
 636	vid_hdr->vol_type = UBI_VID_DYNAMIC;
 637	vid_hdr->sqnum = cpu_to_be64(next_sqnum(ubi));
 638	vid_hdr->vol_id = cpu_to_be32(vol_id);
 639	vid_hdr->lnum = cpu_to_be32(lnum);
 640	vid_hdr->compat = ubi_get_compat(ubi, vol_id);
 641	vid_hdr->data_pad = cpu_to_be32(vol->data_pad);
 642
 643retry:
 644	pnum = ubi_wl_get_peb(ubi, dtype);
 645	if (pnum < 0) {
 646		ubi_free_vid_hdr(ubi, vid_hdr);
 647		leb_write_unlock(ubi, vol_id, lnum);
 648		return pnum;
 649	}
 650
 651	dbg_eba("write VID hdr and %d bytes at offset %d of LEB %d:%d, PEB %d",
 652		len, offset, vol_id, lnum, pnum);
 653
 654	err = ubi_io_write_vid_hdr(ubi, pnum, vid_hdr);
 655	if (err) {
 656		ubi_warn("failed to write VID header to LEB %d:%d, PEB %d",
 657			 vol_id, lnum, pnum);
 658		goto write_error;
 659	}
 660
 661	if (len) {
 662		err = ubi_io_write_data(ubi, buf, pnum, offset, len);
 663		if (err) {
 664			ubi_warn("failed to write %d bytes at offset %d of "
 665				 "LEB %d:%d, PEB %d", len, offset, vol_id,
 666				 lnum, pnum);
 667			goto write_error;
 668		}
 669	}
 670
 671	vol->eba_tbl[lnum] = pnum;
 672
 673	leb_write_unlock(ubi, vol_id, lnum);
 674	ubi_free_vid_hdr(ubi, vid_hdr);
 675	return 0;
 676
 677write_error:
 678	if (err != -EIO || !ubi->bad_allowed) {
 679		ubi_ro_mode(ubi);
 680		leb_write_unlock(ubi, vol_id, lnum);
 681		ubi_free_vid_hdr(ubi, vid_hdr);
 682		return err;
 683	}
 684
 685	/*
 686	 * Fortunately, this is the first write operation to this physical
 687	 * eraseblock, so just put it and request a new one. We assume that if
 688	 * this physical eraseblock went bad, the erase code will handle that.
 689	 */
 690	err = ubi_wl_put_peb(ubi, pnum, 1);
 691	if (err || ++tries > UBI_IO_RETRIES) {
 692		ubi_ro_mode(ubi);
 693		leb_write_unlock(ubi, vol_id, lnum);
 694		ubi_free_vid_hdr(ubi, vid_hdr);
 695		return err;
 696	}
 697
 698	vid_hdr->sqnum = cpu_to_be64(next_sqnum(ubi));
 699	ubi_msg("try another PEB");
 700	goto retry;
 701}
 702
 703/**
 704 * ubi_eba_write_leb_st - write data to static volume.
 705 * @ubi: UBI device description object
 706 * @vol: volume description object
 707 * @lnum: logical eraseblock number
 708 * @buf: data to write
 709 * @len: how many bytes to write
 710 * @dtype: data type
 711 * @used_ebs: how many logical eraseblocks will this volume contain
 712 *
 713 * This function writes data to logical eraseblock @lnum of static volume
 714 * @vol. The @used_ebs argument should contain total number of logical
 715 * eraseblock in this static volume.
 716 *
 717 * When writing to the last logical eraseblock, the @len argument doesn't have
 718 * to be aligned to the minimal I/O unit size. Instead, it has to be equivalent
 719 * to the real data size, although the @buf buffer has to contain the
 720 * alignment. In all other cases, @len has to be aligned.
 721 *
 722 * It is prohibited to write more than once to logical eraseblocks of static
 723 * volumes. This function returns zero in case of success and a negative error
 724 * code in case of failure.
 725 */
 726int ubi_eba_write_leb_st(struct ubi_device *ubi, struct ubi_volume *vol,
 727			 int lnum, const void *buf, int len, int dtype,
 728			 int used_ebs)
 729{
 730	int err, pnum, tries = 0, data_size = len, vol_id = vol->vol_id;
 731	struct ubi_vid_hdr *vid_hdr;
 732	uint32_t crc;
 733
 734	if (ubi->ro_mode)
 735		return -EROFS;
 736
 737	if (lnum == used_ebs - 1)
 738		/* If this is the last LEB @len may be unaligned */
 739		len = ALIGN(data_size, ubi->min_io_size);
 740	else
 741		ubi_assert(!(len & (ubi->min_io_size - 1)));
 742
 743	vid_hdr = ubi_zalloc_vid_hdr(ubi, GFP_NOFS);
 744	if (!vid_hdr)
 745		return -ENOMEM;
 746
 747	err = leb_write_lock(ubi, vol_id, lnum);
 748	if (err) {
 749		ubi_free_vid_hdr(ubi, vid_hdr);
 750		return err;
 751	}
 752
 753	vid_hdr->sqnum = cpu_to_be64(next_sqnum(ubi));
 754	vid_hdr->vol_id = cpu_to_be32(vol_id);
 755	vid_hdr->lnum = cpu_to_be32(lnum);
 756	vid_hdr->compat = ubi_get_compat(ubi, vol_id);
 757	vid_hdr->data_pad = cpu_to_be32(vol->data_pad);
 758
 759	crc = crc32(UBI_CRC32_INIT, buf, data_size);
 760	vid_hdr->vol_type = UBI_VID_STATIC;
 761	vid_hdr->data_size = cpu_to_be32(data_size);
 762	vid_hdr->used_ebs = cpu_to_be32(used_ebs);
 763	vid_hdr->data_crc = cpu_to_be32(crc);
 764
 765retry:
 766	pnum = ubi_wl_get_peb(ubi, dtype);
 767	if (pnum < 0) {
 768		ubi_free_vid_hdr(ubi, vid_hdr);
 769		leb_write_unlock(ubi, vol_id, lnum);
 770		return pnum;
 771	}
 772
 773	dbg_eba("write VID hdr and %d bytes at LEB %d:%d, PEB %d, used_ebs %d",
 774		len, vol_id, lnum, pnum, used_ebs);
 775
 776	err = ubi_io_write_vid_hdr(ubi, pnum, vid_hdr);
 777	if (err) {
 778		ubi_warn("failed to write VID header to LEB %d:%d, PEB %d",
 779			 vol_id, lnum, pnum);
 780		goto write_error;
 781	}
 782
 783	err = ubi_io_write_data(ubi, buf, pnum, 0, len);
 784	if (err) {
 785		ubi_warn("failed to write %d bytes of data to PEB %d",
 786			 len, pnum);
 787		goto write_error;
 788	}
 789
 790	ubi_assert(vol->eba_tbl[lnum] < 0);
 791	vol->eba_tbl[lnum] = pnum;
 792
 793	leb_write_unlock(ubi, vol_id, lnum);
 794	ubi_free_vid_hdr(ubi, vid_hdr);
 795	return 0;
 796
 797write_error:
 798	if (err != -EIO || !ubi->bad_allowed) {
 799		/*
 800		 * This flash device does not admit of bad eraseblocks or
 801		 * something nasty and unexpected happened. Switch to read-only
 802		 * mode just in case.
 803		 */
 804		ubi_ro_mode(ubi);
 805		leb_write_unlock(ubi, vol_id, lnum);
 806		ubi_free_vid_hdr(ubi, vid_hdr);
 807		return err;
 808	}
 809
 810	err = ubi_wl_put_peb(ubi, pnum, 1);
 811	if (err || ++tries > UBI_IO_RETRIES) {
 812		ubi_ro_mode(ubi);
 813		leb_write_unlock(ubi, vol_id, lnum);
 814		ubi_free_vid_hdr(ubi, vid_hdr);
 815		return err;
 816	}
 817
 818	vid_hdr->sqnum = cpu_to_be64(next_sqnum(ubi));
 819	ubi_msg("try another PEB");
 820	goto retry;
 821}
 822
 823/*
 824 * ubi_eba_atomic_leb_change - change logical eraseblock atomically.
 825 * @ubi: UBI device description object
 826 * @vol: volume description object
 827 * @lnum: logical eraseblock number
 828 * @buf: data to write
 829 * @len: how many bytes to write
 830 * @dtype: data type
 831 *
 832 * This function changes the contents of a logical eraseblock atomically. @buf
 833 * has to contain new logical eraseblock data, and @len - the length of the
 834 * data, which has to be aligned. This function guarantees that in case of an
 835 * unclean reboot the old contents is preserved. Returns zero in case of
 836 * success and a negative error code in case of failure.
 837 *
 838 * UBI reserves one LEB for the "atomic LEB change" operation, so only one
 839 * LEB change may be done at a time. This is ensured by @ubi->alc_mutex.
 840 */
 841int ubi_eba_atomic_leb_change(struct ubi_device *ubi, struct ubi_volume *vol,
 842			      int lnum, const void *buf, int len, int dtype)
 843{
 844	int err, pnum, tries = 0, vol_id = vol->vol_id;
 845	struct ubi_vid_hdr *vid_hdr;
 846	uint32_t crc;
 847
 848	if (ubi->ro_mode)
 849		return -EROFS;
 850
 851	if (len == 0) {
 852		/*
 853		 * Special case when data length is zero. In this case the LEB
 854		 * has to be unmapped and mapped somewhere else.
 855		 */
 856		err = ubi_eba_unmap_leb(ubi, vol, lnum);
 857		if (err)
 858			return err;
 859		return ubi_eba_write_leb(ubi, vol, lnum, NULL, 0, 0, dtype);
 860	}
 861
 862	vid_hdr = ubi_zalloc_vid_hdr(ubi, GFP_NOFS);
 863	if (!vid_hdr)
 864		return -ENOMEM;
 865
 866	mutex_lock(&ubi->alc_mutex);
 867	err = leb_write_lock(ubi, vol_id, lnum);
 868	if (err)
 869		goto out_mutex;
 870
 871	vid_hdr->sqnum = cpu_to_be64(next_sqnum(ubi));
 872	vid_hdr->vol_id = cpu_to_be32(vol_id);
 873	vid_hdr->lnum = cpu_to_be32(lnum);
 874	vid_hdr->compat = ubi_get_compat(ubi, vol_id);
 875	vid_hdr->data_pad = cpu_to_be32(vol->data_pad);
 876
 877	crc = crc32(UBI_CRC32_INIT, buf, len);
 878	vid_hdr->vol_type = UBI_VID_DYNAMIC;
 879	vid_hdr->data_size = cpu_to_be32(len);
 880	vid_hdr->copy_flag = 1;
 881	vid_hdr->data_crc = cpu_to_be32(crc);
 882
 883retry:
 884	pnum = ubi_wl_get_peb(ubi, dtype);
 885	if (pnum < 0) {
 886		err = pnum;
 887		goto out_leb_unlock;
 888	}
 889
 890	dbg_eba("change LEB %d:%d, PEB %d, write VID hdr to PEB %d",
 891		vol_id, lnum, vol->eba_tbl[lnum], pnum);
 892
 893	err = ubi_io_write_vid_hdr(ubi, pnum, vid_hdr);
 894	if (err) {
 895		ubi_warn("failed to write VID header to LEB %d:%d, PEB %d",
 896			 vol_id, lnum, pnum);
 897		goto write_error;
 898	}
 899
 900	err = ubi_io_write_data(ubi, buf, pnum, 0, len);
 901	if (err) {
 902		ubi_warn("failed to write %d bytes of data to PEB %d",
 903			 len, pnum);
 904		goto write_error;
 905	}
 906
 907	if (vol->eba_tbl[lnum] >= 0) {
 908		err = ubi_wl_put_peb(ubi, vol->eba_tbl[lnum], 0);
 909		if (err)
 910			goto out_leb_unlock;
 911	}
 912
 913	vol->eba_tbl[lnum] = pnum;
 914
 915out_leb_unlock:
 916	leb_write_unlock(ubi, vol_id, lnum);
 917out_mutex:
 918	mutex_unlock(&ubi->alc_mutex);
 919	ubi_free_vid_hdr(ubi, vid_hdr);
 920	return err;
 921
 922write_error:
 923	if (err != -EIO || !ubi->bad_allowed) {
 924		/*
 925		 * This flash device does not admit of bad eraseblocks or
 926		 * something nasty and unexpected happened. Switch to read-only
 927		 * mode just in case.
 928		 */
 929		ubi_ro_mode(ubi);
 930		goto out_leb_unlock;
 931	}
 932
 933	err = ubi_wl_put_peb(ubi, pnum, 1);
 934	if (err || ++tries > UBI_IO_RETRIES) {
 935		ubi_ro_mode(ubi);
 936		goto out_leb_unlock;
 937	}
 938
 939	vid_hdr->sqnum = cpu_to_be64(next_sqnum(ubi));
 940	ubi_msg("try another PEB");
 941	goto retry;
 942}
 943
 944/**
 945 * is_error_sane - check whether a read error is sane.
 946 * @err: code of the error happened during reading
 947 *
 948 * This is a helper function for 'ubi_eba_copy_leb()' which is called when we
 949 * cannot read data from the target PEB (an error @err happened). If the error
 950 * code is sane, then we treat this error as non-fatal. Otherwise the error is
 951 * fatal and UBI will be switched to R/O mode later.
 952 *
 953 * The idea is that we try not to switch to R/O mode if the read error is
 954 * something which suggests there was a real read problem. E.g., %-EIO. Or a
 955 * memory allocation failed (-%ENOMEM). Otherwise, it is safer to switch to R/O
 956 * mode, simply because we do not know what happened at the MTD level, and we
 957 * cannot handle this. E.g., the underlying driver may have become crazy, and
 958 * it is safer to switch to R/O mode to preserve the data.
 959 *
 960 * And bear in mind, this is about reading from the target PEB, i.e. the PEB
 961 * which we have just written.
 962 */
 963static int is_error_sane(int err)
 964{
 965	if (err == -EIO || err == -ENOMEM || err == UBI_IO_BAD_HDR ||
 966	    err == UBI_IO_BAD_HDR_EBADMSG || err == -ETIMEDOUT)
 967		return 0;
 968	return 1;
 969}
 970
 971/**
 972 * ubi_eba_copy_leb - copy logical eraseblock.
 973 * @ubi: UBI device description object
 974 * @from: physical eraseblock number from where to copy
 975 * @to: physical eraseblock number where to copy
 976 * @vid_hdr: VID header of the @from physical eraseblock
 977 *
 978 * This function copies logical eraseblock from physical eraseblock @from to
 979 * physical eraseblock @to. The @vid_hdr buffer may be changed by this
 980 * function. Returns:
 981 *   o %0 in case of success;
 982 *   o %MOVE_CANCEL_RACE, %MOVE_TARGET_WR_ERR, %MOVE_CANCEL_BITFLIPS, etc;
 983 *   o a negative error code in case of failure.
 984 */
 985int ubi_eba_copy_leb(struct ubi_device *ubi, int from, int to,
 986		     struct ubi_vid_hdr *vid_hdr)
 987{
 988	int err, vol_id, lnum, data_size, aldata_size, idx;
 989	struct ubi_volume *vol;
 990	uint32_t crc;
 991
 992	vol_id = be32_to_cpu(vid_hdr->vol_id);
 993	lnum = be32_to_cpu(vid_hdr->lnum);
 994
 995	dbg_wl("copy LEB %d:%d, PEB %d to PEB %d", vol_id, lnum, from, to);
 996
 997	if (vid_hdr->vol_type == UBI_VID_STATIC) {
 998		data_size = be32_to_cpu(vid_hdr->data_size);
 999		aldata_size = ALIGN(data_size, ubi->min_io_size);
1000	} else
1001		data_size = aldata_size =
1002			    ubi->leb_size - be32_to_cpu(vid_hdr->data_pad);
1003
1004	idx = vol_id2idx(ubi, vol_id);
1005	spin_lock(&ubi->volumes_lock);
1006	/*
1007	 * Note, we may race with volume deletion, which means that the volume
1008	 * this logical eraseblock belongs to might be being deleted. Since the
1009	 * volume deletion un-maps all the volume's logical eraseblocks, it will
1010	 * be locked in 'ubi_wl_put_peb()' and wait for the WL worker to finish.
1011	 */
1012	vol = ubi->volumes[idx];
1013	spin_unlock(&ubi->volumes_lock);
1014	if (!vol) {
1015		/* No need to do further work, cancel */
1016		dbg_wl("volume %d is being removed, cancel", vol_id);
1017		return MOVE_CANCEL_RACE;
1018	}
1019
1020	/*
1021	 * We do not want anybody to write to this logical eraseblock while we
1022	 * are moving it, so lock it.
1023	 *
1024	 * Note, we are using non-waiting locking here, because we cannot sleep
1025	 * on the LEB, since it may cause deadlocks. Indeed, imagine a task is
1026	 * unmapping the LEB which is mapped to the PEB we are going to move
1027	 * (@from). This task locks the LEB and goes sleep in the
1028	 * 'ubi_wl_put_peb()' function on the @ubi->move_mutex. In turn, we are
1029	 * holding @ubi->move_mutex and go sleep on the LEB lock. So, if the
1030	 * LEB is already locked, we just do not move it and return
1031	 * %MOVE_CANCEL_RACE, which means that UBI will re-try, but later.
 
 
1032	 */
1033	err = leb_write_trylock(ubi, vol_id, lnum);
1034	if (err) {
1035		dbg_wl("contention on LEB %d:%d, cancel", vol_id, lnum);
1036		return MOVE_CANCEL_RACE;
1037	}
1038
1039	/*
1040	 * The LEB might have been put meanwhile, and the task which put it is
1041	 * probably waiting on @ubi->move_mutex. No need to continue the work,
1042	 * cancel it.
1043	 */
1044	if (vol->eba_tbl[lnum] != from) {
1045		dbg_wl("LEB %d:%d is no longer mapped to PEB %d, mapped to "
1046		       "PEB %d, cancel", vol_id, lnum, from,
1047		       vol->eba_tbl[lnum]);
1048		err = MOVE_CANCEL_RACE;
1049		goto out_unlock_leb;
1050	}
1051
1052	/*
1053	 * OK, now the LEB is locked and we can safely start moving it. Since
1054	 * this function utilizes the @ubi->peb_buf1 buffer which is shared
1055	 * with some other functions - we lock the buffer by taking the
1056	 * @ubi->buf_mutex.
1057	 */
1058	mutex_lock(&ubi->buf_mutex);
1059	dbg_wl("read %d bytes of data", aldata_size);
1060	err = ubi_io_read_data(ubi, ubi->peb_buf1, from, 0, aldata_size);
1061	if (err && err != UBI_IO_BITFLIPS) {
1062		ubi_warn("error %d while reading data from PEB %d",
1063			 err, from);
1064		err = MOVE_SOURCE_RD_ERR;
1065		goto out_unlock_buf;
1066	}
1067
1068	/*
1069	 * Now we have got to calculate how much data we have to copy. In
1070	 * case of a static volume it is fairly easy - the VID header contains
1071	 * the data size. In case of a dynamic volume it is more difficult - we
1072	 * have to read the contents, cut 0xFF bytes from the end and copy only
1073	 * the first part. We must do this to avoid writing 0xFF bytes as it
1074	 * may have some side-effects. And not only this. It is important not
1075	 * to include those 0xFFs to CRC because later the they may be filled
1076	 * by data.
1077	 */
1078	if (vid_hdr->vol_type == UBI_VID_DYNAMIC)
1079		aldata_size = data_size =
1080			ubi_calc_data_len(ubi, ubi->peb_buf1, data_size);
1081
1082	cond_resched();
1083	crc = crc32(UBI_CRC32_INIT, ubi->peb_buf1, data_size);
1084	cond_resched();
1085
1086	/*
1087	 * It may turn out to be that the whole @from physical eraseblock
1088	 * contains only 0xFF bytes. Then we have to only write the VID header
1089	 * and do not write any data. This also means we should not set
1090	 * @vid_hdr->copy_flag, @vid_hdr->data_size, and @vid_hdr->data_crc.
1091	 */
1092	if (data_size > 0) {
1093		vid_hdr->copy_flag = 1;
1094		vid_hdr->data_size = cpu_to_be32(data_size);
1095		vid_hdr->data_crc = cpu_to_be32(crc);
1096	}
1097	vid_hdr->sqnum = cpu_to_be64(next_sqnum(ubi));
1098
1099	err = ubi_io_write_vid_hdr(ubi, to, vid_hdr);
1100	if (err) {
1101		if (err == -EIO)
1102			err = MOVE_TARGET_WR_ERR;
1103		goto out_unlock_buf;
1104	}
1105
1106	cond_resched();
1107
1108	/* Read the VID header back and check if it was written correctly */
1109	err = ubi_io_read_vid_hdr(ubi, to, vid_hdr, 1);
1110	if (err) {
1111		if (err != UBI_IO_BITFLIPS) {
1112			ubi_warn("error %d while reading VID header back from "
1113				  "PEB %d", err, to);
1114			if (is_error_sane(err))
1115				err = MOVE_TARGET_RD_ERR;
1116		} else
1117			err = MOVE_CANCEL_BITFLIPS;
1118		goto out_unlock_buf;
1119	}
1120
1121	if (data_size > 0) {
1122		err = ubi_io_write_data(ubi, ubi->peb_buf1, to, 0, aldata_size);
1123		if (err) {
1124			if (err == -EIO)
1125				err = MOVE_TARGET_WR_ERR;
1126			goto out_unlock_buf;
1127		}
1128
1129		cond_resched();
1130
1131		/*
1132		 * We've written the data and are going to read it back to make
1133		 * sure it was written correctly.
1134		 */
1135
1136		err = ubi_io_read_data(ubi, ubi->peb_buf2, to, 0, aldata_size);
1137		if (err) {
1138			if (err != UBI_IO_BITFLIPS) {
1139				ubi_warn("error %d while reading data back "
1140					 "from PEB %d", err, to);
1141				if (is_error_sane(err))
1142					err = MOVE_TARGET_RD_ERR;
1143			} else
1144				err = MOVE_CANCEL_BITFLIPS;
1145			goto out_unlock_buf;
1146		}
1147
1148		cond_resched();
1149
1150		if (memcmp(ubi->peb_buf1, ubi->peb_buf2, aldata_size)) {
1151			ubi_warn("read data back from PEB %d and it is "
1152				 "different", to);
1153			err = -EINVAL;
1154			goto out_unlock_buf;
1155		}
1156	}
1157
1158	ubi_assert(vol->eba_tbl[lnum] == from);
1159	vol->eba_tbl[lnum] = to;
1160
1161out_unlock_buf:
1162	mutex_unlock(&ubi->buf_mutex);
1163out_unlock_leb:
1164	leb_write_unlock(ubi, vol_id, lnum);
1165	return err;
1166}
1167
1168/**
1169 * print_rsvd_warning - warn about not having enough reserved PEBs.
1170 * @ubi: UBI device description object
1171 *
1172 * This is a helper function for 'ubi_eba_init_scan()' which is called when UBI
1173 * cannot reserve enough PEBs for bad block handling. This function makes a
1174 * decision whether we have to print a warning or not. The algorithm is as
1175 * follows:
1176 *   o if this is a new UBI image, then just print the warning
1177 *   o if this is an UBI image which has already been used for some time, print
1178 *     a warning only if we can reserve less than 10% of the expected amount of
1179 *     the reserved PEB.
1180 *
1181 * The idea is that when UBI is used, PEBs become bad, and the reserved pool
1182 * of PEBs becomes smaller, which is normal and we do not want to scare users
1183 * with a warning every time they attach the MTD device. This was an issue
1184 * reported by real users.
1185 */
1186static void print_rsvd_warning(struct ubi_device *ubi,
1187			       struct ubi_scan_info *si)
1188{
1189	/*
1190	 * The 1 << 18 (256KiB) number is picked randomly, just a reasonably
1191	 * large number to distinguish between newly flashed and used images.
1192	 */
1193	if (si->max_sqnum > (1 << 18)) {
1194		int min = ubi->beb_rsvd_level / 10;
1195
1196		if (!min)
1197			min = 1;
1198		if (ubi->beb_rsvd_pebs > min)
1199			return;
1200	}
1201
1202	ubi_warn("cannot reserve enough PEBs for bad PEB handling, reserved %d,"
1203		 " need %d", ubi->beb_rsvd_pebs, ubi->beb_rsvd_level);
1204	if (ubi->corr_peb_count)
1205		ubi_warn("%d PEBs are corrupted and not used",
1206			ubi->corr_peb_count);
1207}
1208
1209/**
1210 * ubi_eba_init_scan - initialize the EBA sub-system using scanning information.
1211 * @ubi: UBI device description object
1212 * @si: scanning information
1213 *
1214 * This function returns zero in case of success and a negative error code in
1215 * case of failure.
1216 */
1217int ubi_eba_init_scan(struct ubi_device *ubi, struct ubi_scan_info *si)
1218{
1219	int i, j, err, num_volumes;
1220	struct ubi_scan_volume *sv;
1221	struct ubi_volume *vol;
1222	struct ubi_scan_leb *seb;
1223	struct rb_node *rb;
1224
1225	dbg_eba("initialize EBA sub-system");
1226
1227	spin_lock_init(&ubi->ltree_lock);
1228	mutex_init(&ubi->alc_mutex);
1229	ubi->ltree = RB_ROOT;
1230
1231	ubi->global_sqnum = si->max_sqnum + 1;
1232	num_volumes = ubi->vtbl_slots + UBI_INT_VOL_COUNT;
1233
1234	for (i = 0; i < num_volumes; i++) {
1235		vol = ubi->volumes[i];
1236		if (!vol)
1237			continue;
1238
1239		cond_resched();
1240
1241		vol->eba_tbl = kmalloc(vol->reserved_pebs * sizeof(int),
1242				       GFP_KERNEL);
1243		if (!vol->eba_tbl) {
1244			err = -ENOMEM;
1245			goto out_free;
1246		}
1247
1248		for (j = 0; j < vol->reserved_pebs; j++)
1249			vol->eba_tbl[j] = UBI_LEB_UNMAPPED;
1250
1251		sv = ubi_scan_find_sv(si, idx2vol_id(ubi, i));
1252		if (!sv)
1253			continue;
1254
1255		ubi_rb_for_each_entry(rb, seb, &sv->root, u.rb) {
1256			if (seb->lnum >= vol->reserved_pebs)
1257				/*
1258				 * This may happen in case of an unclean reboot
1259				 * during re-size.
1260				 */
1261				ubi_scan_move_to_list(sv, seb, &si->erase);
1262			vol->eba_tbl[seb->lnum] = seb->pnum;
1263		}
1264	}
1265
1266	if (ubi->avail_pebs < EBA_RESERVED_PEBS) {
1267		ubi_err("no enough physical eraseblocks (%d, need %d)",
1268			ubi->avail_pebs, EBA_RESERVED_PEBS);
1269		if (ubi->corr_peb_count)
1270			ubi_err("%d PEBs are corrupted and not used",
1271				ubi->corr_peb_count);
1272		err = -ENOSPC;
1273		goto out_free;
1274	}
1275	ubi->avail_pebs -= EBA_RESERVED_PEBS;
1276	ubi->rsvd_pebs += EBA_RESERVED_PEBS;
1277
1278	if (ubi->bad_allowed) {
1279		ubi_calculate_reserved(ubi);
1280
1281		if (ubi->avail_pebs < ubi->beb_rsvd_level) {
1282			/* No enough free physical eraseblocks */
1283			ubi->beb_rsvd_pebs = ubi->avail_pebs;
1284			print_rsvd_warning(ubi, si);
1285		} else
1286			ubi->beb_rsvd_pebs = ubi->beb_rsvd_level;
1287
1288		ubi->avail_pebs -= ubi->beb_rsvd_pebs;
1289		ubi->rsvd_pebs  += ubi->beb_rsvd_pebs;
1290	}
1291
1292	dbg_eba("EBA sub-system is initialized");
1293	return 0;
1294
1295out_free:
1296	for (i = 0; i < num_volumes; i++) {
1297		if (!ubi->volumes[i])
1298			continue;
1299		kfree(ubi->volumes[i]->eba_tbl);
1300		ubi->volumes[i]->eba_tbl = NULL;
1301	}
1302	return err;
1303}