1 // SPDX-License-Identifier: GPL-2.0+
3 * Copyright (c) International Business Machines Corp., 2006
5 * Author: Artem Bityutskiy (Битюцкий Артём)
9 * UBI attaching sub-system.
11 * This sub-system is responsible for attaching MTD devices and it also
12 * implements flash media scanning.
14 * The attaching information is represented by a &struct ubi_attach_info'
15 * object. Information about volumes is represented by &struct ubi_ainf_volume
16 * objects which are kept in volume RB-tree with root at the @volumes field.
17 * The RB-tree is indexed by the volume ID.
19 * Logical eraseblocks are represented by &struct ubi_ainf_peb objects. These
20 * objects are kept in per-volume RB-trees with the root at the corresponding
21 * &struct ubi_ainf_volume object. To put it differently, we keep an RB-tree of
22 * per-volume objects and each of these objects is the root of RB-tree of
25 * Corrupted physical eraseblocks are put to the @corr list, free physical
26 * eraseblocks are put to the @free list and the physical eraseblock to be
27 * erased are put to the @erase list.
32 * UBI protects EC and VID headers with CRC-32 checksums, so it can detect
33 * whether the headers are corrupted or not. Sometimes UBI also protects the
34 * data with CRC-32, e.g., when it executes the atomic LEB change operation, or
35 * when it moves the contents of a PEB for wear-leveling purposes.
37 * UBI tries to distinguish between 2 types of corruptions.
39 * 1. Corruptions caused by power cuts. These are expected corruptions and UBI
40 * tries to handle them gracefully, without printing too many warnings and
41 * error messages. The idea is that we do not lose important data in these
42 * cases - we may lose only the data which were being written to the media just
43 * before the power cut happened, and the upper layers (e.g., UBIFS) are
44 * supposed to handle such data losses (e.g., by using the FS journal).
46 * When UBI detects a corruption (CRC-32 mismatch) in a PEB, and it looks like
47 * the reason is a power cut, UBI puts this PEB to the @erase list, and all
48 * PEBs in the @erase list are scheduled for erasure later.
50 * 2. Unexpected corruptions which are not caused by power cuts. During
51 * attaching, such PEBs are put to the @corr list and UBI preserves them.
52 * Obviously, this lessens the amount of available PEBs, and if at some point
53 * UBI runs out of free PEBs, it switches to R/O mode. UBI also loudly informs
54 * about such PEBs every time the MTD device is attached.
56 * However, it is difficult to reliably distinguish between these types of
57 * corruptions and UBI's strategy is as follows (in case of attaching by
58 * scanning). UBI assumes corruption type 2 if the VID header is corrupted and
59 * the data area does not contain all 0xFFs, and there were no bit-flips or
60 * integrity errors (e.g., ECC errors in case of NAND) while reading the data
61 * area. Otherwise UBI assumes corruption type 1. So the decision criteria
63 * o If the data area contains only 0xFFs, there are no data, and it is safe
64 * to just erase this PEB - this is corruption type 1.
65 * o If the data area has bit-flips or data integrity errors (ECC errors on
66 * NAND), it is probably a PEB which was being erased when power cut
67 * happened, so this is corruption type 1. However, this is just a guess,
68 * which might be wrong.
69 * o Otherwise this is corruption type 2.
74 #include <dm/devres.h>
75 #include <linux/err.h>
76 #include <linux/slab.h>
77 #include <linux/crc32.h>
78 #include <linux/random.h>
79 #include <u-boot/crc.h>
82 #include <linux/err.h>
85 #include <linux/math64.h>
87 #include <ubi_uboot.h>
90 static int self_check_ai(struct ubi_device *ubi, struct ubi_attach_info *ai);
92 /* Temporary variables used during scanning */
93 static struct ubi_ec_hdr *ech;
94 static struct ubi_vid_hdr *vidh;
97 * add_to_list - add physical eraseblock to a list.
98 * @ai: attaching information
99 * @pnum: physical eraseblock number to add
100 * @vol_id: the last used volume id for the PEB
101 * @lnum: the last used LEB number for the PEB
102 * @ec: erase counter of the physical eraseblock
103 * @to_head: if not zero, add to the head of the list
104 * @list: the list to add to
106 * This function allocates a 'struct ubi_ainf_peb' object for physical
107 * eraseblock @pnum and adds it to the "free", "erase", or "alien" lists.
108 * It stores the @lnum and @vol_id alongside, which can both be
109 * %UBI_UNKNOWN if they are not available, not readable, or not assigned.
110 * If @to_head is not zero, PEB will be added to the head of the list, which
111 * basically means it will be processed first later. E.g., we add corrupted
112 * PEBs (corrupted due to power cuts) to the head of the erase list to make
113 * sure we erase them first and get rid of corruptions ASAP. This function
114 * returns zero in case of success and a negative error code in case of
117 static int add_to_list(struct ubi_attach_info *ai, int pnum, int vol_id,
118 int lnum, int ec, int to_head, struct list_head *list)
120 struct ubi_ainf_peb *aeb;
122 if (list == &ai->free) {
123 dbg_bld("add to free: PEB %d, EC %d", pnum, ec);
124 } else if (list == &ai->erase) {
125 dbg_bld("add to erase: PEB %d, EC %d", pnum, ec);
126 } else if (list == &ai->alien) {
127 dbg_bld("add to alien: PEB %d, EC %d", pnum, ec);
128 ai->alien_peb_count += 1;
132 aeb = kmem_cache_alloc(ai->aeb_slab_cache, GFP_KERNEL);
137 aeb->vol_id = vol_id;
141 list_add(&aeb->u.list, list);
143 list_add_tail(&aeb->u.list, list);
148 * add_corrupted - add a corrupted physical eraseblock.
149 * @ai: attaching information
150 * @pnum: physical eraseblock number to add
151 * @ec: erase counter of the physical eraseblock
153 * This function allocates a 'struct ubi_ainf_peb' object for a corrupted
154 * physical eraseblock @pnum and adds it to the 'corr' list. The corruption
155 * was presumably not caused by a power cut. Returns zero in case of success
156 * and a negative error code in case of failure.
158 static int add_corrupted(struct ubi_attach_info *ai, int pnum, int ec)
160 struct ubi_ainf_peb *aeb;
162 dbg_bld("add to corrupted: PEB %d, EC %d", pnum, ec);
164 aeb = kmem_cache_alloc(ai->aeb_slab_cache, GFP_KERNEL);
168 ai->corr_peb_count += 1;
171 list_add(&aeb->u.list, &ai->corr);
176 * validate_vid_hdr - check volume identifier header.
177 * @ubi: UBI device description object
178 * @vid_hdr: the volume identifier header to check
179 * @av: information about the volume this logical eraseblock belongs to
180 * @pnum: physical eraseblock number the VID header came from
182 * This function checks that data stored in @vid_hdr is consistent. Returns
183 * non-zero if an inconsistency was found and zero if not.
185 * Note, UBI does sanity check of everything it reads from the flash media.
186 * Most of the checks are done in the I/O sub-system. Here we check that the
187 * information in the VID header is consistent to the information in other VID
188 * headers of the same volume.
190 static int validate_vid_hdr(const struct ubi_device *ubi,
191 const struct ubi_vid_hdr *vid_hdr,
192 const struct ubi_ainf_volume *av, int pnum)
194 int vol_type = vid_hdr->vol_type;
195 int vol_id = be32_to_cpu(vid_hdr->vol_id);
196 int used_ebs = be32_to_cpu(vid_hdr->used_ebs);
197 int data_pad = be32_to_cpu(vid_hdr->data_pad);
199 if (av->leb_count != 0) {
203 * This is not the first logical eraseblock belonging to this
204 * volume. Ensure that the data in its VID header is consistent
205 * to the data in previous logical eraseblock headers.
208 if (vol_id != av->vol_id) {
209 ubi_err(ubi, "inconsistent vol_id");
213 if (av->vol_type == UBI_STATIC_VOLUME)
214 av_vol_type = UBI_VID_STATIC;
216 av_vol_type = UBI_VID_DYNAMIC;
218 if (vol_type != av_vol_type) {
219 ubi_err(ubi, "inconsistent vol_type");
223 if (used_ebs != av->used_ebs) {
224 ubi_err(ubi, "inconsistent used_ebs");
228 if (data_pad != av->data_pad) {
229 ubi_err(ubi, "inconsistent data_pad");
237 ubi_err(ubi, "inconsistent VID header at PEB %d", pnum);
238 ubi_dump_vid_hdr(vid_hdr);
244 * add_volume - add volume to the attaching information.
245 * @ai: attaching information
246 * @vol_id: ID of the volume to add
247 * @pnum: physical eraseblock number
248 * @vid_hdr: volume identifier header
250 * If the volume corresponding to the @vid_hdr logical eraseblock is already
251 * present in the attaching information, this function does nothing. Otherwise
252 * it adds corresponding volume to the attaching information. Returns a pointer
253 * to the allocated "av" object in case of success and a negative error code in
256 static struct ubi_ainf_volume *add_volume(struct ubi_attach_info *ai,
257 int vol_id, int pnum,
258 const struct ubi_vid_hdr *vid_hdr)
260 struct ubi_ainf_volume *av;
261 struct rb_node **p = &ai->volumes.rb_node, *parent = NULL;
263 ubi_assert(vol_id == be32_to_cpu(vid_hdr->vol_id));
265 /* Walk the volume RB-tree to look if this volume is already present */
268 av = rb_entry(parent, struct ubi_ainf_volume, rb);
270 if (vol_id == av->vol_id)
273 if (vol_id > av->vol_id)
279 /* The volume is absent - add it */
280 av = kmalloc(sizeof(struct ubi_ainf_volume), GFP_KERNEL);
282 return ERR_PTR(-ENOMEM);
284 av->highest_lnum = av->leb_count = 0;
287 av->used_ebs = be32_to_cpu(vid_hdr->used_ebs);
288 av->data_pad = be32_to_cpu(vid_hdr->data_pad);
289 av->compat = vid_hdr->compat;
290 av->vol_type = vid_hdr->vol_type == UBI_VID_DYNAMIC ? UBI_DYNAMIC_VOLUME
292 if (vol_id > ai->highest_vol_id)
293 ai->highest_vol_id = vol_id;
295 rb_link_node(&av->rb, parent, p);
296 rb_insert_color(&av->rb, &ai->volumes);
298 dbg_bld("added volume %d", vol_id);
303 * ubi_compare_lebs - find out which logical eraseblock is newer.
304 * @ubi: UBI device description object
305 * @aeb: first logical eraseblock to compare
306 * @pnum: physical eraseblock number of the second logical eraseblock to
308 * @vid_hdr: volume identifier header of the second logical eraseblock
310 * This function compares 2 copies of a LEB and informs which one is newer. In
311 * case of success this function returns a positive value, in case of failure, a
312 * negative error code is returned. The success return codes use the following
314 * o bit 0 is cleared: the first PEB (described by @aeb) is newer than the
315 * second PEB (described by @pnum and @vid_hdr);
316 * o bit 0 is set: the second PEB is newer;
317 * o bit 1 is cleared: no bit-flips were detected in the newer LEB;
318 * o bit 1 is set: bit-flips were detected in the newer LEB;
319 * o bit 2 is cleared: the older LEB is not corrupted;
320 * o bit 2 is set: the older LEB is corrupted.
322 int ubi_compare_lebs(struct ubi_device *ubi, const struct ubi_ainf_peb *aeb,
323 int pnum, const struct ubi_vid_hdr *vid_hdr)
325 int len, err, second_is_newer, bitflips = 0, corrupted = 0;
326 uint32_t data_crc, crc;
327 struct ubi_vid_hdr *vh = NULL;
328 unsigned long long sqnum2 = be64_to_cpu(vid_hdr->sqnum);
330 if (sqnum2 == aeb->sqnum) {
332 * This must be a really ancient UBI image which has been
333 * created before sequence numbers support has been added. At
334 * that times we used 32-bit LEB versions stored in logical
335 * eraseblocks. That was before UBI got into mainline. We do not
336 * support these images anymore. Well, those images still work,
337 * but only if no unclean reboots happened.
339 ubi_err(ubi, "unsupported on-flash UBI format");
343 /* Obviously the LEB with lower sequence counter is older */
344 second_is_newer = (sqnum2 > aeb->sqnum);
347 * Now we know which copy is newer. If the copy flag of the PEB with
348 * newer version is not set, then we just return, otherwise we have to
349 * check data CRC. For the second PEB we already have the VID header,
350 * for the first one - we'll need to re-read it from flash.
352 * Note: this may be optimized so that we wouldn't read twice.
355 if (second_is_newer) {
356 if (!vid_hdr->copy_flag) {
357 /* It is not a copy, so it is newer */
358 dbg_bld("second PEB %d is newer, copy_flag is unset",
363 if (!aeb->copy_flag) {
364 /* It is not a copy, so it is newer */
365 dbg_bld("first PEB %d is newer, copy_flag is unset",
367 return bitflips << 1;
370 vh = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
375 err = ubi_io_read_vid_hdr(ubi, pnum, vh, 0);
377 if (err == UBI_IO_BITFLIPS)
380 ubi_err(ubi, "VID of PEB %d header is bad, but it was OK earlier, err %d",
392 /* Read the data of the copy and check the CRC */
394 len = be32_to_cpu(vid_hdr->data_size);
396 mutex_lock(&ubi->buf_mutex);
397 err = ubi_io_read_data(ubi, ubi->peb_buf, pnum, 0, len);
398 if (err && err != UBI_IO_BITFLIPS && !mtd_is_eccerr(err))
401 data_crc = be32_to_cpu(vid_hdr->data_crc);
402 crc = crc32(UBI_CRC32_INIT, ubi->peb_buf, len);
403 if (crc != data_crc) {
404 dbg_bld("PEB %d CRC error: calculated %#08x, must be %#08x",
405 pnum, crc, data_crc);
408 second_is_newer = !second_is_newer;
410 dbg_bld("PEB %d CRC is OK", pnum);
413 mutex_unlock(&ubi->buf_mutex);
415 ubi_free_vid_hdr(ubi, vh);
418 dbg_bld("second PEB %d is newer, copy_flag is set", pnum);
420 dbg_bld("first PEB %d is newer, copy_flag is set", pnum);
422 return second_is_newer | (bitflips << 1) | (corrupted << 2);
425 mutex_unlock(&ubi->buf_mutex);
427 ubi_free_vid_hdr(ubi, vh);
432 * ubi_add_to_av - add used physical eraseblock to the attaching information.
433 * @ubi: UBI device description object
434 * @ai: attaching information
435 * @pnum: the physical eraseblock number
437 * @vid_hdr: the volume identifier header
438 * @bitflips: if bit-flips were detected when this physical eraseblock was read
440 * This function adds information about a used physical eraseblock to the
441 * 'used' tree of the corresponding volume. The function is rather complex
442 * because it has to handle cases when this is not the first physical
443 * eraseblock belonging to the same logical eraseblock, and the newer one has
444 * to be picked, while the older one has to be dropped. This function returns
445 * zero in case of success and a negative error code in case of failure.
447 int ubi_add_to_av(struct ubi_device *ubi, struct ubi_attach_info *ai, int pnum,
448 int ec, const struct ubi_vid_hdr *vid_hdr, int bitflips)
450 int err, vol_id, lnum;
451 unsigned long long sqnum;
452 struct ubi_ainf_volume *av;
453 struct ubi_ainf_peb *aeb;
454 struct rb_node **p, *parent = NULL;
456 vol_id = be32_to_cpu(vid_hdr->vol_id);
457 lnum = be32_to_cpu(vid_hdr->lnum);
458 sqnum = be64_to_cpu(vid_hdr->sqnum);
460 dbg_bld("PEB %d, LEB %d:%d, EC %d, sqnum %llu, bitflips %d",
461 pnum, vol_id, lnum, ec, sqnum, bitflips);
463 av = add_volume(ai, vol_id, pnum, vid_hdr);
467 if (ai->max_sqnum < sqnum)
468 ai->max_sqnum = sqnum;
471 * Walk the RB-tree of logical eraseblocks of volume @vol_id to look
472 * if this is the first instance of this logical eraseblock or not.
474 p = &av->root.rb_node;
479 aeb = rb_entry(parent, struct ubi_ainf_peb, u.rb);
480 if (lnum != aeb->lnum) {
481 if (lnum < aeb->lnum)
489 * There is already a physical eraseblock describing the same
490 * logical eraseblock present.
493 dbg_bld("this LEB already exists: PEB %d, sqnum %llu, EC %d",
494 aeb->pnum, aeb->sqnum, aeb->ec);
497 * Make sure that the logical eraseblocks have different
498 * sequence numbers. Otherwise the image is bad.
500 * However, if the sequence number is zero, we assume it must
501 * be an ancient UBI image from the era when UBI did not have
502 * sequence numbers. We still can attach these images, unless
503 * there is a need to distinguish between old and new
504 * eraseblocks, in which case we'll refuse the image in
505 * 'ubi_compare_lebs()'. In other words, we attach old clean
506 * images, but refuse attaching old images with duplicated
507 * logical eraseblocks because there was an unclean reboot.
509 if (aeb->sqnum == sqnum && sqnum != 0) {
510 ubi_err(ubi, "two LEBs with same sequence number %llu",
512 ubi_dump_aeb(aeb, 0);
513 ubi_dump_vid_hdr(vid_hdr);
518 * Now we have to drop the older one and preserve the newer
521 cmp_res = ubi_compare_lebs(ubi, aeb, pnum, vid_hdr);
527 * This logical eraseblock is newer than the one
530 err = validate_vid_hdr(ubi, vid_hdr, av, pnum);
534 err = add_to_list(ai, aeb->pnum, aeb->vol_id,
535 aeb->lnum, aeb->ec, cmp_res & 4,
542 aeb->vol_id = vol_id;
544 aeb->scrub = ((cmp_res & 2) || bitflips);
545 aeb->copy_flag = vid_hdr->copy_flag;
548 if (av->highest_lnum == lnum)
550 be32_to_cpu(vid_hdr->data_size);
555 * This logical eraseblock is older than the one found
558 return add_to_list(ai, pnum, vol_id, lnum, ec,
559 cmp_res & 4, &ai->erase);
564 * We've met this logical eraseblock for the first time, add it to the
565 * attaching information.
568 err = validate_vid_hdr(ubi, vid_hdr, av, pnum);
572 aeb = kmem_cache_alloc(ai->aeb_slab_cache, GFP_KERNEL);
578 aeb->vol_id = vol_id;
580 aeb->scrub = bitflips;
581 aeb->copy_flag = vid_hdr->copy_flag;
584 if (av->highest_lnum <= lnum) {
585 av->highest_lnum = lnum;
586 av->last_data_size = be32_to_cpu(vid_hdr->data_size);
590 rb_link_node(&aeb->u.rb, parent, p);
591 rb_insert_color(&aeb->u.rb, &av->root);
596 * ubi_find_av - find volume in the attaching information.
597 * @ai: attaching information
598 * @vol_id: the requested volume ID
600 * This function returns a pointer to the volume description or %NULL if there
601 * are no data about this volume in the attaching information.
603 struct ubi_ainf_volume *ubi_find_av(const struct ubi_attach_info *ai,
606 struct ubi_ainf_volume *av;
607 struct rb_node *p = ai->volumes.rb_node;
610 av = rb_entry(p, struct ubi_ainf_volume, rb);
612 if (vol_id == av->vol_id)
615 if (vol_id > av->vol_id)
625 * ubi_remove_av - delete attaching information about a volume.
626 * @ai: attaching information
627 * @av: the volume attaching information to delete
629 void ubi_remove_av(struct ubi_attach_info *ai, struct ubi_ainf_volume *av)
632 struct ubi_ainf_peb *aeb;
634 dbg_bld("remove attaching information about volume %d", av->vol_id);
636 while ((rb = rb_first(&av->root))) {
637 aeb = rb_entry(rb, struct ubi_ainf_peb, u.rb);
638 rb_erase(&aeb->u.rb, &av->root);
639 list_add_tail(&aeb->u.list, &ai->erase);
642 rb_erase(&av->rb, &ai->volumes);
648 * early_erase_peb - erase a physical eraseblock.
649 * @ubi: UBI device description object
650 * @ai: attaching information
651 * @pnum: physical eraseblock number to erase;
652 * @ec: erase counter value to write (%UBI_UNKNOWN if it is unknown)
654 * This function erases physical eraseblock 'pnum', and writes the erase
655 * counter header to it. This function should only be used on UBI device
656 * initialization stages, when the EBA sub-system had not been yet initialized.
657 * This function returns zero in case of success and a negative error code in
660 static int early_erase_peb(struct ubi_device *ubi,
661 const struct ubi_attach_info *ai, int pnum, int ec)
664 struct ubi_ec_hdr *ec_hdr;
666 if ((long long)ec >= UBI_MAX_ERASECOUNTER) {
668 * Erase counter overflow. Upgrade UBI and use 64-bit
669 * erase counters internally.
671 ubi_err(ubi, "erase counter overflow at PEB %d, EC %d",
676 ec_hdr = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
680 ec_hdr->ec = cpu_to_be64(ec);
682 err = ubi_io_sync_erase(ubi, pnum, 0);
686 err = ubi_io_write_ec_hdr(ubi, pnum, ec_hdr);
694 * ubi_early_get_peb - get a free physical eraseblock.
695 * @ubi: UBI device description object
696 * @ai: attaching information
698 * This function returns a free physical eraseblock. It is supposed to be
699 * called on the UBI initialization stages when the wear-leveling sub-system is
700 * not initialized yet. This function picks a physical eraseblocks from one of
701 * the lists, writes the EC header if it is needed, and removes it from the
704 * This function returns a pointer to the "aeb" of the found free PEB in case
705 * of success and an error code in case of failure.
707 struct ubi_ainf_peb *ubi_early_get_peb(struct ubi_device *ubi,
708 struct ubi_attach_info *ai)
711 struct ubi_ainf_peb *aeb, *tmp_aeb;
713 if (!list_empty(&ai->free)) {
714 aeb = list_entry(ai->free.next, struct ubi_ainf_peb, u.list);
715 list_del(&aeb->u.list);
716 dbg_bld("return free PEB %d, EC %d", aeb->pnum, aeb->ec);
721 * We try to erase the first physical eraseblock from the erase list
722 * and pick it if we succeed, or try to erase the next one if not. And
723 * so forth. We don't want to take care about bad eraseblocks here -
724 * they'll be handled later.
726 list_for_each_entry_safe(aeb, tmp_aeb, &ai->erase, u.list) {
727 if (aeb->ec == UBI_UNKNOWN)
728 aeb->ec = ai->mean_ec;
730 err = early_erase_peb(ubi, ai, aeb->pnum, aeb->ec+1);
735 list_del(&aeb->u.list);
736 dbg_bld("return PEB %d, EC %d", aeb->pnum, aeb->ec);
740 ubi_err(ubi, "no free eraseblocks");
741 return ERR_PTR(-ENOSPC);
745 * check_corruption - check the data area of PEB.
746 * @ubi: UBI device description object
747 * @vid_hdr: the (corrupted) VID header of this PEB
748 * @pnum: the physical eraseblock number to check
750 * This is a helper function which is used to distinguish between VID header
751 * corruptions caused by power cuts and other reasons. If the PEB contains only
752 * 0xFF bytes in the data area, the VID header is most probably corrupted
753 * because of a power cut (%0 is returned in this case). Otherwise, it was
754 * probably corrupted for some other reasons (%1 is returned in this case). A
755 * negative error code is returned if a read error occurred.
757 * If the corruption reason was a power cut, UBI can safely erase this PEB.
758 * Otherwise, it should preserve it to avoid possibly destroying important
761 static int check_corruption(struct ubi_device *ubi, struct ubi_vid_hdr *vid_hdr,
766 mutex_lock(&ubi->buf_mutex);
767 memset(ubi->peb_buf, 0x00, ubi->leb_size);
769 err = ubi_io_read(ubi, ubi->peb_buf, pnum, ubi->leb_start,
771 if (err == UBI_IO_BITFLIPS || mtd_is_eccerr(err)) {
773 * Bit-flips or integrity errors while reading the data area.
774 * It is difficult to say for sure what type of corruption is
775 * this, but presumably a power cut happened while this PEB was
776 * erased, so it became unstable and corrupted, and should be
786 if (ubi_check_pattern(ubi->peb_buf, 0xFF, ubi->leb_size))
789 ubi_err(ubi, "PEB %d contains corrupted VID header, and the data does not contain all 0xFF",
791 ubi_err(ubi, "this may be a non-UBI PEB or a severe VID header corruption which requires manual inspection");
792 ubi_dump_vid_hdr(vid_hdr);
793 pr_err("hexdump of PEB %d offset %d, length %d",
794 pnum, ubi->leb_start, ubi->leb_size);
795 ubi_dbg_print_hex_dump("", DUMP_PREFIX_OFFSET, 32, 1,
796 ubi->peb_buf, ubi->leb_size, 1);
800 mutex_unlock(&ubi->buf_mutex);
805 * scan_peb - scan and process UBI headers of a PEB.
806 * @ubi: UBI device description object
807 * @ai: attaching information
808 * @pnum: the physical eraseblock number
809 * @vid: The volume ID of the found volume will be stored in this pointer
810 * @sqnum: The sqnum of the found volume will be stored in this pointer
812 * This function reads UBI headers of PEB @pnum, checks them, and adds
813 * information about this PEB to the corresponding list or RB-tree in the
814 * "attaching info" structure. Returns zero if the physical eraseblock was
815 * successfully handled and a negative error code in case of failure.
817 static int scan_peb(struct ubi_device *ubi, struct ubi_attach_info *ai,
818 int pnum, int *vid, unsigned long long *sqnum)
820 long long uninitialized_var(ec);
821 int err, bitflips = 0, vol_id = -1, ec_err = 0;
823 dbg_bld("scan PEB %d", pnum);
825 /* Skip bad physical eraseblocks */
826 err = ubi_io_is_bad(ubi, pnum);
830 ai->bad_peb_count += 1;
834 err = ubi_io_read_ec_hdr(ubi, pnum, ech, 0);
840 case UBI_IO_BITFLIPS:
844 ai->empty_peb_count += 1;
845 return add_to_list(ai, pnum, UBI_UNKNOWN, UBI_UNKNOWN,
846 UBI_UNKNOWN, 0, &ai->erase);
847 case UBI_IO_FF_BITFLIPS:
848 ai->empty_peb_count += 1;
849 return add_to_list(ai, pnum, UBI_UNKNOWN, UBI_UNKNOWN,
850 UBI_UNKNOWN, 1, &ai->erase);
851 case UBI_IO_BAD_HDR_EBADMSG:
854 * We have to also look at the VID header, possibly it is not
855 * corrupted. Set %bitflips flag in order to make this PEB be
856 * moved and EC be re-created.
863 ubi_err(ubi, "'ubi_io_read_ec_hdr()' returned unknown code %d",
871 /* Make sure UBI version is OK */
872 if (ech->version != UBI_VERSION) {
873 ubi_err(ubi, "this UBI version is %d, image version is %d",
874 UBI_VERSION, (int)ech->version);
878 ec = be64_to_cpu(ech->ec);
879 if (ec > UBI_MAX_ERASECOUNTER) {
881 * Erase counter overflow. The EC headers have 64 bits
882 * reserved, but we anyway make use of only 31 bit
883 * values, as this seems to be enough for any existing
884 * flash. Upgrade UBI and use 64-bit erase counters
887 ubi_err(ubi, "erase counter overflow, max is %d",
888 UBI_MAX_ERASECOUNTER);
889 ubi_dump_ec_hdr(ech);
894 * Make sure that all PEBs have the same image sequence number.
895 * This allows us to detect situations when users flash UBI
896 * images incorrectly, so that the flash has the new UBI image
897 * and leftovers from the old one. This feature was added
898 * relatively recently, and the sequence number was always
899 * zero, because old UBI implementations always set it to zero.
900 * For this reasons, we do not panic if some PEBs have zero
901 * sequence number, while other PEBs have non-zero sequence
904 image_seq = be32_to_cpu(ech->image_seq);
906 ubi->image_seq = image_seq;
907 if (image_seq && ubi->image_seq != image_seq) {
908 ubi_err(ubi, "bad image sequence number %d in PEB %d, expected %d",
909 image_seq, pnum, ubi->image_seq);
910 ubi_dump_ec_hdr(ech);
915 /* OK, we've done with the EC header, let's look at the VID header */
917 err = ubi_io_read_vid_hdr(ubi, pnum, vidh, 0);
923 case UBI_IO_BITFLIPS:
926 case UBI_IO_BAD_HDR_EBADMSG:
927 if (ec_err == UBI_IO_BAD_HDR_EBADMSG)
929 * Both EC and VID headers are corrupted and were read
930 * with data integrity error, probably this is a bad
931 * PEB, bit it is not marked as bad yet. This may also
932 * be a result of power cut during erasure.
934 ai->maybe_bad_peb_count += 1;
938 * Both headers are corrupted. There is a possibility
939 * that this a valid UBI PEB which has corresponding
940 * LEB, but the headers are corrupted. However, it is
941 * impossible to distinguish it from a PEB which just
942 * contains garbage because of a power cut during erase
943 * operation. So we just schedule this PEB for erasure.
945 * Besides, in case of NOR flash, we deliberately
946 * corrupt both headers because NOR flash erasure is
947 * slow and can start from the end.
952 * The EC was OK, but the VID header is corrupted. We
953 * have to check what is in the data area.
955 err = check_corruption(ubi, vidh, pnum);
960 /* This corruption is caused by a power cut */
961 err = add_to_list(ai, pnum, UBI_UNKNOWN,
962 UBI_UNKNOWN, ec, 1, &ai->erase);
964 /* This is an unexpected corruption */
965 err = add_corrupted(ai, pnum, ec);
969 case UBI_IO_FF_BITFLIPS:
970 err = add_to_list(ai, pnum, UBI_UNKNOWN, UBI_UNKNOWN,
976 if (ec_err || bitflips)
977 err = add_to_list(ai, pnum, UBI_UNKNOWN,
978 UBI_UNKNOWN, ec, 1, &ai->erase);
980 err = add_to_list(ai, pnum, UBI_UNKNOWN,
981 UBI_UNKNOWN, ec, 0, &ai->free);
986 ubi_err(ubi, "'ubi_io_read_vid_hdr()' returned unknown code %d",
991 vol_id = be32_to_cpu(vidh->vol_id);
995 *sqnum = be64_to_cpu(vidh->sqnum);
996 if (vol_id > UBI_MAX_VOLUMES && vol_id != UBI_LAYOUT_VOLUME_ID) {
997 int lnum = be32_to_cpu(vidh->lnum);
999 /* Unsupported internal volume */
1000 switch (vidh->compat) {
1001 case UBI_COMPAT_DELETE:
1002 if (vol_id != UBI_FM_SB_VOLUME_ID
1003 && vol_id != UBI_FM_DATA_VOLUME_ID) {
1004 ubi_msg(ubi, "\"delete\" compatible internal volume %d:%d found, will remove it",
1007 err = add_to_list(ai, pnum, vol_id, lnum,
1014 ubi_msg(ubi, "read-only compatible internal volume %d:%d found, switch to read-only mode",
1019 case UBI_COMPAT_PRESERVE:
1020 ubi_msg(ubi, "\"preserve\" compatible internal volume %d:%d found",
1022 err = add_to_list(ai, pnum, vol_id, lnum,
1028 case UBI_COMPAT_REJECT:
1029 ubi_err(ubi, "incompatible internal volume %d:%d found",
1036 ubi_warn(ubi, "valid VID header but corrupted EC header at PEB %d",
1038 err = ubi_add_to_av(ubi, ai, pnum, ec, vidh, bitflips);
1046 if (ec > ai->max_ec)
1048 if (ec < ai->min_ec)
1056 * late_analysis - analyze the overall situation with PEB.
1057 * @ubi: UBI device description object
1058 * @ai: attaching information
1060 * This is a helper function which takes a look what PEBs we have after we
1061 * gather information about all of them ("ai" is compete). It decides whether
1062 * the flash is empty and should be formatted of whether there are too many
1063 * corrupted PEBs and we should not attach this MTD device. Returns zero if we
1064 * should proceed with attaching the MTD device, and %-EINVAL if we should not.
1066 static int late_analysis(struct ubi_device *ubi, struct ubi_attach_info *ai)
1068 struct ubi_ainf_peb *aeb;
1069 int max_corr, peb_count;
1071 peb_count = ubi->peb_count - ai->bad_peb_count - ai->alien_peb_count;
1072 max_corr = peb_count / 20 ?: 8;
1075 * Few corrupted PEBs is not a problem and may be just a result of
1076 * unclean reboots. However, many of them may indicate some problems
1077 * with the flash HW or driver.
1079 if (ai->corr_peb_count) {
1080 ubi_err(ubi, "%d PEBs are corrupted and preserved",
1081 ai->corr_peb_count);
1082 pr_err("Corrupted PEBs are:");
1083 list_for_each_entry(aeb, &ai->corr, u.list)
1084 pr_cont(" %d", aeb->pnum);
1088 * If too many PEBs are corrupted, we refuse attaching,
1089 * otherwise, only print a warning.
1091 if (ai->corr_peb_count >= max_corr) {
1092 ubi_err(ubi, "too many corrupted PEBs, refusing");
1097 if (ai->empty_peb_count + ai->maybe_bad_peb_count == peb_count) {
1099 * All PEBs are empty, or almost all - a couple PEBs look like
1100 * they may be bad PEBs which were not marked as bad yet.
1102 * This piece of code basically tries to distinguish between
1103 * the following situations:
1105 * 1. Flash is empty, but there are few bad PEBs, which are not
1106 * marked as bad so far, and which were read with error. We
1107 * want to go ahead and format this flash. While formatting,
1108 * the faulty PEBs will probably be marked as bad.
1110 * 2. Flash contains non-UBI data and we do not want to format
1111 * it and destroy possibly important information.
1113 if (ai->maybe_bad_peb_count <= 2) {
1115 ubi_msg(ubi, "empty MTD device detected");
1116 get_random_bytes(&ubi->image_seq,
1117 sizeof(ubi->image_seq));
1119 ubi_err(ubi, "MTD device is not UBI-formatted and possibly contains non-UBI data - refusing it");
1129 * destroy_av - free volume attaching information.
1130 * @av: volume attaching information
1131 * @ai: attaching information
1133 * This function destroys the volume attaching information.
1135 static void destroy_av(struct ubi_attach_info *ai, struct ubi_ainf_volume *av)
1137 struct ubi_ainf_peb *aeb;
1138 struct rb_node *this = av->root.rb_node;
1142 this = this->rb_left;
1143 else if (this->rb_right)
1144 this = this->rb_right;
1146 aeb = rb_entry(this, struct ubi_ainf_peb, u.rb);
1147 this = rb_parent(this);
1149 if (this->rb_left == &aeb->u.rb)
1150 this->rb_left = NULL;
1152 this->rb_right = NULL;
1155 kmem_cache_free(ai->aeb_slab_cache, aeb);
1162 * destroy_ai - destroy attaching information.
1163 * @ai: attaching information
1165 static void destroy_ai(struct ubi_attach_info *ai)
1167 struct ubi_ainf_peb *aeb, *aeb_tmp;
1168 struct ubi_ainf_volume *av;
1171 list_for_each_entry_safe(aeb, aeb_tmp, &ai->alien, u.list) {
1172 list_del(&aeb->u.list);
1173 kmem_cache_free(ai->aeb_slab_cache, aeb);
1175 list_for_each_entry_safe(aeb, aeb_tmp, &ai->erase, u.list) {
1176 list_del(&aeb->u.list);
1177 kmem_cache_free(ai->aeb_slab_cache, aeb);
1179 list_for_each_entry_safe(aeb, aeb_tmp, &ai->corr, u.list) {
1180 list_del(&aeb->u.list);
1181 kmem_cache_free(ai->aeb_slab_cache, aeb);
1183 list_for_each_entry_safe(aeb, aeb_tmp, &ai->free, u.list) {
1184 list_del(&aeb->u.list);
1185 kmem_cache_free(ai->aeb_slab_cache, aeb);
1188 /* Destroy the volume RB-tree */
1189 rb = ai->volumes.rb_node;
1193 else if (rb->rb_right)
1196 av = rb_entry(rb, struct ubi_ainf_volume, rb);
1200 if (rb->rb_left == &av->rb)
1203 rb->rb_right = NULL;
1210 kmem_cache_destroy(ai->aeb_slab_cache);
1216 * scan_all - scan entire MTD device.
1217 * @ubi: UBI device description object
1218 * @ai: attach info object
1219 * @start: start scanning at this PEB
1221 * This function does full scanning of an MTD device and returns complete
1222 * information about it in form of a "struct ubi_attach_info" object. In case
1223 * of failure, an error code is returned.
1225 static int scan_all(struct ubi_device *ubi, struct ubi_attach_info *ai,
1229 struct rb_node *rb1, *rb2;
1230 struct ubi_ainf_volume *av;
1231 struct ubi_ainf_peb *aeb;
1235 ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
1239 vidh = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
1243 for (pnum = start; pnum < ubi->peb_count; pnum++) {
1246 dbg_gen("process PEB %d", pnum);
1247 err = scan_peb(ubi, ai, pnum, NULL, NULL);
1252 ubi_msg(ubi, "scanning is finished");
1254 /* Calculate mean erase counter */
1256 ai->mean_ec = div_u64(ai->ec_sum, ai->ec_count);
1258 err = late_analysis(ubi, ai);
1263 * In case of unknown erase counter we use the mean erase counter
1266 ubi_rb_for_each_entry(rb1, av, &ai->volumes, rb) {
1267 ubi_rb_for_each_entry(rb2, aeb, &av->root, u.rb)
1268 if (aeb->ec == UBI_UNKNOWN)
1269 aeb->ec = ai->mean_ec;
1272 list_for_each_entry(aeb, &ai->free, u.list) {
1273 if (aeb->ec == UBI_UNKNOWN)
1274 aeb->ec = ai->mean_ec;
1277 list_for_each_entry(aeb, &ai->corr, u.list)
1278 if (aeb->ec == UBI_UNKNOWN)
1279 aeb->ec = ai->mean_ec;
1281 list_for_each_entry(aeb, &ai->erase, u.list)
1282 if (aeb->ec == UBI_UNKNOWN)
1283 aeb->ec = ai->mean_ec;
1285 err = self_check_ai(ubi, ai);
1289 ubi_free_vid_hdr(ubi, vidh);
1295 ubi_free_vid_hdr(ubi, vidh);
1301 static struct ubi_attach_info *alloc_ai(void)
1303 struct ubi_attach_info *ai;
1305 ai = kzalloc(sizeof(struct ubi_attach_info), GFP_KERNEL);
1309 INIT_LIST_HEAD(&ai->corr);
1310 INIT_LIST_HEAD(&ai->free);
1311 INIT_LIST_HEAD(&ai->erase);
1312 INIT_LIST_HEAD(&ai->alien);
1313 ai->volumes = RB_ROOT;
1314 ai->aeb_slab_cache = kmem_cache_create("ubi_aeb_slab_cache",
1315 sizeof(struct ubi_ainf_peb),
1317 if (!ai->aeb_slab_cache) {
1325 #ifdef CONFIG_MTD_UBI_FASTMAP
1328 * scan_fastmap - try to find a fastmap and attach from it.
1329 * @ubi: UBI device description object
1330 * @ai: attach info object
1332 * Returns 0 on success, negative return values indicate an internal
1334 * UBI_NO_FASTMAP denotes that no fastmap was found.
1335 * UBI_BAD_FASTMAP denotes that the found fastmap was invalid.
1337 static int scan_fast(struct ubi_device *ubi, struct ubi_attach_info **ai)
1339 int err, pnum, fm_anchor = -1;
1340 unsigned long long max_sqnum = 0;
1344 ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
1348 vidh = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
1352 for (pnum = 0; pnum < UBI_FM_MAX_START; pnum++) {
1354 unsigned long long sqnum = -1;
1357 dbg_gen("process PEB %d", pnum);
1358 err = scan_peb(ubi, *ai, pnum, &vol_id, &sqnum);
1362 if (vol_id == UBI_FM_SB_VOLUME_ID && sqnum > max_sqnum) {
1368 ubi_free_vid_hdr(ubi, vidh);
1372 return UBI_NO_FASTMAP;
1379 return ubi_scan_fastmap(ubi, *ai, fm_anchor);
1382 ubi_free_vid_hdr(ubi, vidh);
1392 * ubi_attach - attach an MTD device.
1393 * @ubi: UBI device descriptor
1394 * @force_scan: if set to non-zero attach by scanning
1396 * This function returns zero in case of success and a negative error code in
1399 int ubi_attach(struct ubi_device *ubi, int force_scan)
1402 struct ubi_attach_info *ai;
1408 #ifdef CONFIG_MTD_UBI_FASTMAP
1409 /* On small flash devices we disable fastmap in any case. */
1410 if ((int)mtd_div_by_eb(ubi->mtd->size, ubi->mtd) <= UBI_FM_MAX_START) {
1411 ubi->fm_disabled = 1;
1416 err = scan_all(ubi, ai, 0);
1418 err = scan_fast(ubi, &ai);
1419 if (err > 0 || mtd_is_eccerr(err)) {
1420 if (err != UBI_NO_FASTMAP) {
1426 err = scan_all(ubi, ai, 0);
1428 err = scan_all(ubi, ai, UBI_FM_MAX_START);
1433 err = scan_all(ubi, ai, 0);
1438 ubi->bad_peb_count = ai->bad_peb_count;
1439 ubi->good_peb_count = ubi->peb_count - ubi->bad_peb_count;
1440 ubi->corr_peb_count = ai->corr_peb_count;
1441 ubi->max_ec = ai->max_ec;
1442 ubi->mean_ec = ai->mean_ec;
1443 dbg_gen("max. sequence number: %llu", ai->max_sqnum);
1445 err = ubi_read_volume_table(ubi, ai);
1449 err = ubi_wl_init(ubi, ai);
1453 err = ubi_eba_init(ubi, ai);
1457 #ifdef CONFIG_MTD_UBI_FASTMAP
1458 if (ubi->fm && ubi_dbg_chk_fastmap(ubi)) {
1459 struct ubi_attach_info *scan_ai;
1461 scan_ai = alloc_ai();
1467 err = scan_all(ubi, scan_ai, 0);
1469 destroy_ai(scan_ai);
1473 err = self_check_eba(ubi, ai, scan_ai);
1474 destroy_ai(scan_ai);
1487 ubi_free_internal_volumes(ubi);
1495 * self_check_ai - check the attaching information.
1496 * @ubi: UBI device description object
1497 * @ai: attaching information
1499 * This function returns zero if the attaching information is all right, and a
1500 * negative error code if not or if an error occurred.
1502 static int self_check_ai(struct ubi_device *ubi, struct ubi_attach_info *ai)
1504 int pnum, err, vols_found = 0;
1505 struct rb_node *rb1, *rb2;
1506 struct ubi_ainf_volume *av;
1507 struct ubi_ainf_peb *aeb, *last_aeb;
1510 if (!ubi_dbg_chk_gen(ubi))
1514 * At first, check that attaching information is OK.
1516 ubi_rb_for_each_entry(rb1, av, &ai->volumes, rb) {
1524 ubi_err(ubi, "bad is_empty flag");
1528 if (av->vol_id < 0 || av->highest_lnum < 0 ||
1529 av->leb_count < 0 || av->vol_type < 0 || av->used_ebs < 0 ||
1530 av->data_pad < 0 || av->last_data_size < 0) {
1531 ubi_err(ubi, "negative values");
1535 if (av->vol_id >= UBI_MAX_VOLUMES &&
1536 av->vol_id < UBI_INTERNAL_VOL_START) {
1537 ubi_err(ubi, "bad vol_id");
1541 if (av->vol_id > ai->highest_vol_id) {
1542 ubi_err(ubi, "highest_vol_id is %d, but vol_id %d is there",
1543 ai->highest_vol_id, av->vol_id);
1547 if (av->vol_type != UBI_DYNAMIC_VOLUME &&
1548 av->vol_type != UBI_STATIC_VOLUME) {
1549 ubi_err(ubi, "bad vol_type");
1553 if (av->data_pad > ubi->leb_size / 2) {
1554 ubi_err(ubi, "bad data_pad");
1559 ubi_rb_for_each_entry(rb2, aeb, &av->root, u.rb) {
1565 if (aeb->pnum < 0 || aeb->ec < 0) {
1566 ubi_err(ubi, "negative values");
1570 if (aeb->ec < ai->min_ec) {
1571 ubi_err(ubi, "bad ai->min_ec (%d), %d found",
1572 ai->min_ec, aeb->ec);
1576 if (aeb->ec > ai->max_ec) {
1577 ubi_err(ubi, "bad ai->max_ec (%d), %d found",
1578 ai->max_ec, aeb->ec);
1582 if (aeb->pnum >= ubi->peb_count) {
1583 ubi_err(ubi, "too high PEB number %d, total PEBs %d",
1584 aeb->pnum, ubi->peb_count);
1588 if (av->vol_type == UBI_STATIC_VOLUME) {
1589 if (aeb->lnum >= av->used_ebs) {
1590 ubi_err(ubi, "bad lnum or used_ebs");
1594 if (av->used_ebs != 0) {
1595 ubi_err(ubi, "non-zero used_ebs");
1600 if (aeb->lnum > av->highest_lnum) {
1601 ubi_err(ubi, "incorrect highest_lnum or lnum");
1606 if (av->leb_count != leb_count) {
1607 ubi_err(ubi, "bad leb_count, %d objects in the tree",
1617 if (aeb->lnum != av->highest_lnum) {
1618 ubi_err(ubi, "bad highest_lnum");
1623 if (vols_found != ai->vols_found) {
1624 ubi_err(ubi, "bad ai->vols_found %d, should be %d",
1625 ai->vols_found, vols_found);
1629 /* Check that attaching information is correct */
1630 ubi_rb_for_each_entry(rb1, av, &ai->volumes, rb) {
1632 ubi_rb_for_each_entry(rb2, aeb, &av->root, u.rb) {
1639 err = ubi_io_read_vid_hdr(ubi, aeb->pnum, vidh, 1);
1640 if (err && err != UBI_IO_BITFLIPS) {
1641 ubi_err(ubi, "VID header is not OK (%d)",
1648 vol_type = vidh->vol_type == UBI_VID_DYNAMIC ?
1649 UBI_DYNAMIC_VOLUME : UBI_STATIC_VOLUME;
1650 if (av->vol_type != vol_type) {
1651 ubi_err(ubi, "bad vol_type");
1655 if (aeb->sqnum != be64_to_cpu(vidh->sqnum)) {
1656 ubi_err(ubi, "bad sqnum %llu", aeb->sqnum);
1660 if (av->vol_id != be32_to_cpu(vidh->vol_id)) {
1661 ubi_err(ubi, "bad vol_id %d", av->vol_id);
1665 if (av->compat != vidh->compat) {
1666 ubi_err(ubi, "bad compat %d", vidh->compat);
1670 if (aeb->lnum != be32_to_cpu(vidh->lnum)) {
1671 ubi_err(ubi, "bad lnum %d", aeb->lnum);
1675 if (av->used_ebs != be32_to_cpu(vidh->used_ebs)) {
1676 ubi_err(ubi, "bad used_ebs %d", av->used_ebs);
1680 if (av->data_pad != be32_to_cpu(vidh->data_pad)) {
1681 ubi_err(ubi, "bad data_pad %d", av->data_pad);
1689 if (av->highest_lnum != be32_to_cpu(vidh->lnum)) {
1690 ubi_err(ubi, "bad highest_lnum %d", av->highest_lnum);
1694 if (av->last_data_size != be32_to_cpu(vidh->data_size)) {
1695 ubi_err(ubi, "bad last_data_size %d",
1696 av->last_data_size);
1702 * Make sure that all the physical eraseblocks are in one of the lists
1705 buf = kzalloc(ubi->peb_count, GFP_KERNEL);
1709 for (pnum = 0; pnum < ubi->peb_count; pnum++) {
1710 err = ubi_io_is_bad(ubi, pnum);
1718 ubi_rb_for_each_entry(rb1, av, &ai->volumes, rb)
1719 ubi_rb_for_each_entry(rb2, aeb, &av->root, u.rb)
1722 list_for_each_entry(aeb, &ai->free, u.list)
1725 list_for_each_entry(aeb, &ai->corr, u.list)
1728 list_for_each_entry(aeb, &ai->erase, u.list)
1731 list_for_each_entry(aeb, &ai->alien, u.list)
1735 for (pnum = 0; pnum < ubi->peb_count; pnum++)
1737 ubi_err(ubi, "PEB %d is not referred", pnum);
1747 ubi_err(ubi, "bad attaching information about LEB %d", aeb->lnum);
1748 ubi_dump_aeb(aeb, 0);
1753 ubi_err(ubi, "bad attaching information about volume %d", av->vol_id);
1758 ubi_err(ubi, "bad attaching information about volume %d", av->vol_id);
1760 ubi_dump_vid_hdr(vidh);