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.
73 #include <linux/err.h>
74 #include <linux/slab.h>
75 #include <linux/crc32.h>
76 #include <linux/random.h>
79 #include <linux/err.h>
82 #include <linux/math64.h>
84 #include <ubi_uboot.h>
87 static int self_check_ai(struct ubi_device *ubi, struct ubi_attach_info *ai);
89 /* Temporary variables used during scanning */
90 static struct ubi_ec_hdr *ech;
91 static struct ubi_vid_hdr *vidh;
94 * add_to_list - add physical eraseblock to a list.
95 * @ai: attaching information
96 * @pnum: physical eraseblock number to add
97 * @vol_id: the last used volume id for the PEB
98 * @lnum: the last used LEB number for the PEB
99 * @ec: erase counter of the physical eraseblock
100 * @to_head: if not zero, add to the head of the list
101 * @list: the list to add to
103 * This function allocates a 'struct ubi_ainf_peb' object for physical
104 * eraseblock @pnum and adds it to the "free", "erase", or "alien" lists.
105 * It stores the @lnum and @vol_id alongside, which can both be
106 * %UBI_UNKNOWN if they are not available, not readable, or not assigned.
107 * If @to_head is not zero, PEB will be added to the head of the list, which
108 * basically means it will be processed first later. E.g., we add corrupted
109 * PEBs (corrupted due to power cuts) to the head of the erase list to make
110 * sure we erase them first and get rid of corruptions ASAP. This function
111 * returns zero in case of success and a negative error code in case of
114 static int add_to_list(struct ubi_attach_info *ai, int pnum, int vol_id,
115 int lnum, int ec, int to_head, struct list_head *list)
117 struct ubi_ainf_peb *aeb;
119 if (list == &ai->free) {
120 dbg_bld("add to free: PEB %d, EC %d", pnum, ec);
121 } else if (list == &ai->erase) {
122 dbg_bld("add to erase: PEB %d, EC %d", pnum, ec);
123 } else if (list == &ai->alien) {
124 dbg_bld("add to alien: PEB %d, EC %d", pnum, ec);
125 ai->alien_peb_count += 1;
129 aeb = kmem_cache_alloc(ai->aeb_slab_cache, GFP_KERNEL);
134 aeb->vol_id = vol_id;
138 list_add(&aeb->u.list, list);
140 list_add_tail(&aeb->u.list, list);
145 * add_corrupted - add a corrupted physical eraseblock.
146 * @ai: attaching information
147 * @pnum: physical eraseblock number to add
148 * @ec: erase counter of the physical eraseblock
150 * This function allocates a 'struct ubi_ainf_peb' object for a corrupted
151 * physical eraseblock @pnum and adds it to the 'corr' list. The corruption
152 * was presumably not caused by a power cut. Returns zero in case of success
153 * and a negative error code in case of failure.
155 static int add_corrupted(struct ubi_attach_info *ai, int pnum, int ec)
157 struct ubi_ainf_peb *aeb;
159 dbg_bld("add to corrupted: PEB %d, EC %d", pnum, ec);
161 aeb = kmem_cache_alloc(ai->aeb_slab_cache, GFP_KERNEL);
165 ai->corr_peb_count += 1;
168 list_add(&aeb->u.list, &ai->corr);
173 * validate_vid_hdr - check volume identifier header.
174 * @ubi: UBI device description object
175 * @vid_hdr: the volume identifier header to check
176 * @av: information about the volume this logical eraseblock belongs to
177 * @pnum: physical eraseblock number the VID header came from
179 * This function checks that data stored in @vid_hdr is consistent. Returns
180 * non-zero if an inconsistency was found and zero if not.
182 * Note, UBI does sanity check of everything it reads from the flash media.
183 * Most of the checks are done in the I/O sub-system. Here we check that the
184 * information in the VID header is consistent to the information in other VID
185 * headers of the same volume.
187 static int validate_vid_hdr(const struct ubi_device *ubi,
188 const struct ubi_vid_hdr *vid_hdr,
189 const struct ubi_ainf_volume *av, int pnum)
191 int vol_type = vid_hdr->vol_type;
192 int vol_id = be32_to_cpu(vid_hdr->vol_id);
193 int used_ebs = be32_to_cpu(vid_hdr->used_ebs);
194 int data_pad = be32_to_cpu(vid_hdr->data_pad);
196 if (av->leb_count != 0) {
200 * This is not the first logical eraseblock belonging to this
201 * volume. Ensure that the data in its VID header is consistent
202 * to the data in previous logical eraseblock headers.
205 if (vol_id != av->vol_id) {
206 ubi_err(ubi, "inconsistent vol_id");
210 if (av->vol_type == UBI_STATIC_VOLUME)
211 av_vol_type = UBI_VID_STATIC;
213 av_vol_type = UBI_VID_DYNAMIC;
215 if (vol_type != av_vol_type) {
216 ubi_err(ubi, "inconsistent vol_type");
220 if (used_ebs != av->used_ebs) {
221 ubi_err(ubi, "inconsistent used_ebs");
225 if (data_pad != av->data_pad) {
226 ubi_err(ubi, "inconsistent data_pad");
234 ubi_err(ubi, "inconsistent VID header at PEB %d", pnum);
235 ubi_dump_vid_hdr(vid_hdr);
241 * add_volume - add volume to the attaching information.
242 * @ai: attaching information
243 * @vol_id: ID of the volume to add
244 * @pnum: physical eraseblock number
245 * @vid_hdr: volume identifier header
247 * If the volume corresponding to the @vid_hdr logical eraseblock is already
248 * present in the attaching information, this function does nothing. Otherwise
249 * it adds corresponding volume to the attaching information. Returns a pointer
250 * to the allocated "av" object in case of success and a negative error code in
253 static struct ubi_ainf_volume *add_volume(struct ubi_attach_info *ai,
254 int vol_id, int pnum,
255 const struct ubi_vid_hdr *vid_hdr)
257 struct ubi_ainf_volume *av;
258 struct rb_node **p = &ai->volumes.rb_node, *parent = NULL;
260 ubi_assert(vol_id == be32_to_cpu(vid_hdr->vol_id));
262 /* Walk the volume RB-tree to look if this volume is already present */
265 av = rb_entry(parent, struct ubi_ainf_volume, rb);
267 if (vol_id == av->vol_id)
270 if (vol_id > av->vol_id)
276 /* The volume is absent - add it */
277 av = kmalloc(sizeof(struct ubi_ainf_volume), GFP_KERNEL);
279 return ERR_PTR(-ENOMEM);
281 av->highest_lnum = av->leb_count = 0;
284 av->used_ebs = be32_to_cpu(vid_hdr->used_ebs);
285 av->data_pad = be32_to_cpu(vid_hdr->data_pad);
286 av->compat = vid_hdr->compat;
287 av->vol_type = vid_hdr->vol_type == UBI_VID_DYNAMIC ? UBI_DYNAMIC_VOLUME
289 if (vol_id > ai->highest_vol_id)
290 ai->highest_vol_id = vol_id;
292 rb_link_node(&av->rb, parent, p);
293 rb_insert_color(&av->rb, &ai->volumes);
295 dbg_bld("added volume %d", vol_id);
300 * ubi_compare_lebs - find out which logical eraseblock is newer.
301 * @ubi: UBI device description object
302 * @aeb: first logical eraseblock to compare
303 * @pnum: physical eraseblock number of the second logical eraseblock to
305 * @vid_hdr: volume identifier header of the second logical eraseblock
307 * This function compares 2 copies of a LEB and informs which one is newer. In
308 * case of success this function returns a positive value, in case of failure, a
309 * negative error code is returned. The success return codes use the following
311 * o bit 0 is cleared: the first PEB (described by @aeb) is newer than the
312 * second PEB (described by @pnum and @vid_hdr);
313 * o bit 0 is set: the second PEB is newer;
314 * o bit 1 is cleared: no bit-flips were detected in the newer LEB;
315 * o bit 1 is set: bit-flips were detected in the newer LEB;
316 * o bit 2 is cleared: the older LEB is not corrupted;
317 * o bit 2 is set: the older LEB is corrupted.
319 int ubi_compare_lebs(struct ubi_device *ubi, const struct ubi_ainf_peb *aeb,
320 int pnum, const struct ubi_vid_hdr *vid_hdr)
322 int len, err, second_is_newer, bitflips = 0, corrupted = 0;
323 uint32_t data_crc, crc;
324 struct ubi_vid_hdr *vh = NULL;
325 unsigned long long sqnum2 = be64_to_cpu(vid_hdr->sqnum);
327 if (sqnum2 == aeb->sqnum) {
329 * This must be a really ancient UBI image which has been
330 * created before sequence numbers support has been added. At
331 * that times we used 32-bit LEB versions stored in logical
332 * eraseblocks. That was before UBI got into mainline. We do not
333 * support these images anymore. Well, those images still work,
334 * but only if no unclean reboots happened.
336 ubi_err(ubi, "unsupported on-flash UBI format");
340 /* Obviously the LEB with lower sequence counter is older */
341 second_is_newer = (sqnum2 > aeb->sqnum);
344 * Now we know which copy is newer. If the copy flag of the PEB with
345 * newer version is not set, then we just return, otherwise we have to
346 * check data CRC. For the second PEB we already have the VID header,
347 * for the first one - we'll need to re-read it from flash.
349 * Note: this may be optimized so that we wouldn't read twice.
352 if (second_is_newer) {
353 if (!vid_hdr->copy_flag) {
354 /* It is not a copy, so it is newer */
355 dbg_bld("second PEB %d is newer, copy_flag is unset",
360 if (!aeb->copy_flag) {
361 /* It is not a copy, so it is newer */
362 dbg_bld("first PEB %d is newer, copy_flag is unset",
364 return bitflips << 1;
367 vh = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
372 err = ubi_io_read_vid_hdr(ubi, pnum, vh, 0);
374 if (err == UBI_IO_BITFLIPS)
377 ubi_err(ubi, "VID of PEB %d header is bad, but it was OK earlier, err %d",
389 /* Read the data of the copy and check the CRC */
391 len = be32_to_cpu(vid_hdr->data_size);
393 mutex_lock(&ubi->buf_mutex);
394 err = ubi_io_read_data(ubi, ubi->peb_buf, pnum, 0, len);
395 if (err && err != UBI_IO_BITFLIPS && !mtd_is_eccerr(err))
398 data_crc = be32_to_cpu(vid_hdr->data_crc);
399 crc = crc32(UBI_CRC32_INIT, ubi->peb_buf, len);
400 if (crc != data_crc) {
401 dbg_bld("PEB %d CRC error: calculated %#08x, must be %#08x",
402 pnum, crc, data_crc);
405 second_is_newer = !second_is_newer;
407 dbg_bld("PEB %d CRC is OK", pnum);
410 mutex_unlock(&ubi->buf_mutex);
412 ubi_free_vid_hdr(ubi, vh);
415 dbg_bld("second PEB %d is newer, copy_flag is set", pnum);
417 dbg_bld("first PEB %d is newer, copy_flag is set", pnum);
419 return second_is_newer | (bitflips << 1) | (corrupted << 2);
422 mutex_unlock(&ubi->buf_mutex);
424 ubi_free_vid_hdr(ubi, vh);
429 * ubi_add_to_av - add used physical eraseblock to the attaching information.
430 * @ubi: UBI device description object
431 * @ai: attaching information
432 * @pnum: the physical eraseblock number
434 * @vid_hdr: the volume identifier header
435 * @bitflips: if bit-flips were detected when this physical eraseblock was read
437 * This function adds information about a used physical eraseblock to the
438 * 'used' tree of the corresponding volume. The function is rather complex
439 * because it has to handle cases when this is not the first physical
440 * eraseblock belonging to the same logical eraseblock, and the newer one has
441 * to be picked, while the older one has to be dropped. This function returns
442 * zero in case of success and a negative error code in case of failure.
444 int ubi_add_to_av(struct ubi_device *ubi, struct ubi_attach_info *ai, int pnum,
445 int ec, const struct ubi_vid_hdr *vid_hdr, int bitflips)
447 int err, vol_id, lnum;
448 unsigned long long sqnum;
449 struct ubi_ainf_volume *av;
450 struct ubi_ainf_peb *aeb;
451 struct rb_node **p, *parent = NULL;
453 vol_id = be32_to_cpu(vid_hdr->vol_id);
454 lnum = be32_to_cpu(vid_hdr->lnum);
455 sqnum = be64_to_cpu(vid_hdr->sqnum);
457 dbg_bld("PEB %d, LEB %d:%d, EC %d, sqnum %llu, bitflips %d",
458 pnum, vol_id, lnum, ec, sqnum, bitflips);
460 av = add_volume(ai, vol_id, pnum, vid_hdr);
464 if (ai->max_sqnum < sqnum)
465 ai->max_sqnum = sqnum;
468 * Walk the RB-tree of logical eraseblocks of volume @vol_id to look
469 * if this is the first instance of this logical eraseblock or not.
471 p = &av->root.rb_node;
476 aeb = rb_entry(parent, struct ubi_ainf_peb, u.rb);
477 if (lnum != aeb->lnum) {
478 if (lnum < aeb->lnum)
486 * There is already a physical eraseblock describing the same
487 * logical eraseblock present.
490 dbg_bld("this LEB already exists: PEB %d, sqnum %llu, EC %d",
491 aeb->pnum, aeb->sqnum, aeb->ec);
494 * Make sure that the logical eraseblocks have different
495 * sequence numbers. Otherwise the image is bad.
497 * However, if the sequence number is zero, we assume it must
498 * be an ancient UBI image from the era when UBI did not have
499 * sequence numbers. We still can attach these images, unless
500 * there is a need to distinguish between old and new
501 * eraseblocks, in which case we'll refuse the image in
502 * 'ubi_compare_lebs()'. In other words, we attach old clean
503 * images, but refuse attaching old images with duplicated
504 * logical eraseblocks because there was an unclean reboot.
506 if (aeb->sqnum == sqnum && sqnum != 0) {
507 ubi_err(ubi, "two LEBs with same sequence number %llu",
509 ubi_dump_aeb(aeb, 0);
510 ubi_dump_vid_hdr(vid_hdr);
515 * Now we have to drop the older one and preserve the newer
518 cmp_res = ubi_compare_lebs(ubi, aeb, pnum, vid_hdr);
524 * This logical eraseblock is newer than the one
527 err = validate_vid_hdr(ubi, vid_hdr, av, pnum);
531 err = add_to_list(ai, aeb->pnum, aeb->vol_id,
532 aeb->lnum, aeb->ec, cmp_res & 4,
539 aeb->vol_id = vol_id;
541 aeb->scrub = ((cmp_res & 2) || bitflips);
542 aeb->copy_flag = vid_hdr->copy_flag;
545 if (av->highest_lnum == lnum)
547 be32_to_cpu(vid_hdr->data_size);
552 * This logical eraseblock is older than the one found
555 return add_to_list(ai, pnum, vol_id, lnum, ec,
556 cmp_res & 4, &ai->erase);
561 * We've met this logical eraseblock for the first time, add it to the
562 * attaching information.
565 err = validate_vid_hdr(ubi, vid_hdr, av, pnum);
569 aeb = kmem_cache_alloc(ai->aeb_slab_cache, GFP_KERNEL);
575 aeb->vol_id = vol_id;
577 aeb->scrub = bitflips;
578 aeb->copy_flag = vid_hdr->copy_flag;
581 if (av->highest_lnum <= lnum) {
582 av->highest_lnum = lnum;
583 av->last_data_size = be32_to_cpu(vid_hdr->data_size);
587 rb_link_node(&aeb->u.rb, parent, p);
588 rb_insert_color(&aeb->u.rb, &av->root);
593 * ubi_find_av - find volume in the attaching information.
594 * @ai: attaching information
595 * @vol_id: the requested volume ID
597 * This function returns a pointer to the volume description or %NULL if there
598 * are no data about this volume in the attaching information.
600 struct ubi_ainf_volume *ubi_find_av(const struct ubi_attach_info *ai,
603 struct ubi_ainf_volume *av;
604 struct rb_node *p = ai->volumes.rb_node;
607 av = rb_entry(p, struct ubi_ainf_volume, rb);
609 if (vol_id == av->vol_id)
612 if (vol_id > av->vol_id)
622 * ubi_remove_av - delete attaching information about a volume.
623 * @ai: attaching information
624 * @av: the volume attaching information to delete
626 void ubi_remove_av(struct ubi_attach_info *ai, struct ubi_ainf_volume *av)
629 struct ubi_ainf_peb *aeb;
631 dbg_bld("remove attaching information about volume %d", av->vol_id);
633 while ((rb = rb_first(&av->root))) {
634 aeb = rb_entry(rb, struct ubi_ainf_peb, u.rb);
635 rb_erase(&aeb->u.rb, &av->root);
636 list_add_tail(&aeb->u.list, &ai->erase);
639 rb_erase(&av->rb, &ai->volumes);
645 * early_erase_peb - erase a physical eraseblock.
646 * @ubi: UBI device description object
647 * @ai: attaching information
648 * @pnum: physical eraseblock number to erase;
649 * @ec: erase counter value to write (%UBI_UNKNOWN if it is unknown)
651 * This function erases physical eraseblock 'pnum', and writes the erase
652 * counter header to it. This function should only be used on UBI device
653 * initialization stages, when the EBA sub-system had not been yet initialized.
654 * This function returns zero in case of success and a negative error code in
657 static int early_erase_peb(struct ubi_device *ubi,
658 const struct ubi_attach_info *ai, int pnum, int ec)
661 struct ubi_ec_hdr *ec_hdr;
663 if ((long long)ec >= UBI_MAX_ERASECOUNTER) {
665 * Erase counter overflow. Upgrade UBI and use 64-bit
666 * erase counters internally.
668 ubi_err(ubi, "erase counter overflow at PEB %d, EC %d",
673 ec_hdr = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
677 ec_hdr->ec = cpu_to_be64(ec);
679 err = ubi_io_sync_erase(ubi, pnum, 0);
683 err = ubi_io_write_ec_hdr(ubi, pnum, ec_hdr);
691 * ubi_early_get_peb - get a free physical eraseblock.
692 * @ubi: UBI device description object
693 * @ai: attaching information
695 * This function returns a free physical eraseblock. It is supposed to be
696 * called on the UBI initialization stages when the wear-leveling sub-system is
697 * not initialized yet. This function picks a physical eraseblocks from one of
698 * the lists, writes the EC header if it is needed, and removes it from the
701 * This function returns a pointer to the "aeb" of the found free PEB in case
702 * of success and an error code in case of failure.
704 struct ubi_ainf_peb *ubi_early_get_peb(struct ubi_device *ubi,
705 struct ubi_attach_info *ai)
708 struct ubi_ainf_peb *aeb, *tmp_aeb;
710 if (!list_empty(&ai->free)) {
711 aeb = list_entry(ai->free.next, struct ubi_ainf_peb, u.list);
712 list_del(&aeb->u.list);
713 dbg_bld("return free PEB %d, EC %d", aeb->pnum, aeb->ec);
718 * We try to erase the first physical eraseblock from the erase list
719 * and pick it if we succeed, or try to erase the next one if not. And
720 * so forth. We don't want to take care about bad eraseblocks here -
721 * they'll be handled later.
723 list_for_each_entry_safe(aeb, tmp_aeb, &ai->erase, u.list) {
724 if (aeb->ec == UBI_UNKNOWN)
725 aeb->ec = ai->mean_ec;
727 err = early_erase_peb(ubi, ai, aeb->pnum, aeb->ec+1);
732 list_del(&aeb->u.list);
733 dbg_bld("return PEB %d, EC %d", aeb->pnum, aeb->ec);
737 ubi_err(ubi, "no free eraseblocks");
738 return ERR_PTR(-ENOSPC);
742 * check_corruption - check the data area of PEB.
743 * @ubi: UBI device description object
744 * @vid_hdr: the (corrupted) VID header of this PEB
745 * @pnum: the physical eraseblock number to check
747 * This is a helper function which is used to distinguish between VID header
748 * corruptions caused by power cuts and other reasons. If the PEB contains only
749 * 0xFF bytes in the data area, the VID header is most probably corrupted
750 * because of a power cut (%0 is returned in this case). Otherwise, it was
751 * probably corrupted for some other reasons (%1 is returned in this case). A
752 * negative error code is returned if a read error occurred.
754 * If the corruption reason was a power cut, UBI can safely erase this PEB.
755 * Otherwise, it should preserve it to avoid possibly destroying important
758 static int check_corruption(struct ubi_device *ubi, struct ubi_vid_hdr *vid_hdr,
763 mutex_lock(&ubi->buf_mutex);
764 memset(ubi->peb_buf, 0x00, ubi->leb_size);
766 err = ubi_io_read(ubi, ubi->peb_buf, pnum, ubi->leb_start,
768 if (err == UBI_IO_BITFLIPS || mtd_is_eccerr(err)) {
770 * Bit-flips or integrity errors while reading the data area.
771 * It is difficult to say for sure what type of corruption is
772 * this, but presumably a power cut happened while this PEB was
773 * erased, so it became unstable and corrupted, and should be
783 if (ubi_check_pattern(ubi->peb_buf, 0xFF, ubi->leb_size))
786 ubi_err(ubi, "PEB %d contains corrupted VID header, and the data does not contain all 0xFF",
788 ubi_err(ubi, "this may be a non-UBI PEB or a severe VID header corruption which requires manual inspection");
789 ubi_dump_vid_hdr(vid_hdr);
790 pr_err("hexdump of PEB %d offset %d, length %d",
791 pnum, ubi->leb_start, ubi->leb_size);
792 ubi_dbg_print_hex_dump("", DUMP_PREFIX_OFFSET, 32, 1,
793 ubi->peb_buf, ubi->leb_size, 1);
797 mutex_unlock(&ubi->buf_mutex);
802 * scan_peb - scan and process UBI headers of a PEB.
803 * @ubi: UBI device description object
804 * @ai: attaching information
805 * @pnum: the physical eraseblock number
806 * @vid: The volume ID of the found volume will be stored in this pointer
807 * @sqnum: The sqnum of the found volume will be stored in this pointer
809 * This function reads UBI headers of PEB @pnum, checks them, and adds
810 * information about this PEB to the corresponding list or RB-tree in the
811 * "attaching info" structure. Returns zero if the physical eraseblock was
812 * successfully handled and a negative error code in case of failure.
814 static int scan_peb(struct ubi_device *ubi, struct ubi_attach_info *ai,
815 int pnum, int *vid, unsigned long long *sqnum)
817 long long uninitialized_var(ec);
818 int err, bitflips = 0, vol_id = -1, ec_err = 0;
820 dbg_bld("scan PEB %d", pnum);
822 /* Skip bad physical eraseblocks */
823 err = ubi_io_is_bad(ubi, pnum);
827 ai->bad_peb_count += 1;
831 err = ubi_io_read_ec_hdr(ubi, pnum, ech, 0);
837 case UBI_IO_BITFLIPS:
841 ai->empty_peb_count += 1;
842 return add_to_list(ai, pnum, UBI_UNKNOWN, UBI_UNKNOWN,
843 UBI_UNKNOWN, 0, &ai->erase);
844 case UBI_IO_FF_BITFLIPS:
845 ai->empty_peb_count += 1;
846 return add_to_list(ai, pnum, UBI_UNKNOWN, UBI_UNKNOWN,
847 UBI_UNKNOWN, 1, &ai->erase);
848 case UBI_IO_BAD_HDR_EBADMSG:
851 * We have to also look at the VID header, possibly it is not
852 * corrupted. Set %bitflips flag in order to make this PEB be
853 * moved and EC be re-created.
860 ubi_err(ubi, "'ubi_io_read_ec_hdr()' returned unknown code %d",
868 /* Make sure UBI version is OK */
869 if (ech->version != UBI_VERSION) {
870 ubi_err(ubi, "this UBI version is %d, image version is %d",
871 UBI_VERSION, (int)ech->version);
875 ec = be64_to_cpu(ech->ec);
876 if (ec > UBI_MAX_ERASECOUNTER) {
878 * Erase counter overflow. The EC headers have 64 bits
879 * reserved, but we anyway make use of only 31 bit
880 * values, as this seems to be enough for any existing
881 * flash. Upgrade UBI and use 64-bit erase counters
884 ubi_err(ubi, "erase counter overflow, max is %d",
885 UBI_MAX_ERASECOUNTER);
886 ubi_dump_ec_hdr(ech);
891 * Make sure that all PEBs have the same image sequence number.
892 * This allows us to detect situations when users flash UBI
893 * images incorrectly, so that the flash has the new UBI image
894 * and leftovers from the old one. This feature was added
895 * relatively recently, and the sequence number was always
896 * zero, because old UBI implementations always set it to zero.
897 * For this reasons, we do not panic if some PEBs have zero
898 * sequence number, while other PEBs have non-zero sequence
901 image_seq = be32_to_cpu(ech->image_seq);
903 ubi->image_seq = image_seq;
904 if (image_seq && ubi->image_seq != image_seq) {
905 ubi_err(ubi, "bad image sequence number %d in PEB %d, expected %d",
906 image_seq, pnum, ubi->image_seq);
907 ubi_dump_ec_hdr(ech);
912 /* OK, we've done with the EC header, let's look at the VID header */
914 err = ubi_io_read_vid_hdr(ubi, pnum, vidh, 0);
920 case UBI_IO_BITFLIPS:
923 case UBI_IO_BAD_HDR_EBADMSG:
924 if (ec_err == UBI_IO_BAD_HDR_EBADMSG)
926 * Both EC and VID headers are corrupted and were read
927 * with data integrity error, probably this is a bad
928 * PEB, bit it is not marked as bad yet. This may also
929 * be a result of power cut during erasure.
931 ai->maybe_bad_peb_count += 1;
935 * Both headers are corrupted. There is a possibility
936 * that this a valid UBI PEB which has corresponding
937 * LEB, but the headers are corrupted. However, it is
938 * impossible to distinguish it from a PEB which just
939 * contains garbage because of a power cut during erase
940 * operation. So we just schedule this PEB for erasure.
942 * Besides, in case of NOR flash, we deliberately
943 * corrupt both headers because NOR flash erasure is
944 * slow and can start from the end.
949 * The EC was OK, but the VID header is corrupted. We
950 * have to check what is in the data area.
952 err = check_corruption(ubi, vidh, pnum);
957 /* This corruption is caused by a power cut */
958 err = add_to_list(ai, pnum, UBI_UNKNOWN,
959 UBI_UNKNOWN, ec, 1, &ai->erase);
961 /* This is an unexpected corruption */
962 err = add_corrupted(ai, pnum, ec);
966 case UBI_IO_FF_BITFLIPS:
967 err = add_to_list(ai, pnum, UBI_UNKNOWN, UBI_UNKNOWN,
973 if (ec_err || bitflips)
974 err = add_to_list(ai, pnum, UBI_UNKNOWN,
975 UBI_UNKNOWN, ec, 1, &ai->erase);
977 err = add_to_list(ai, pnum, UBI_UNKNOWN,
978 UBI_UNKNOWN, ec, 0, &ai->free);
983 ubi_err(ubi, "'ubi_io_read_vid_hdr()' returned unknown code %d",
988 vol_id = be32_to_cpu(vidh->vol_id);
992 *sqnum = be64_to_cpu(vidh->sqnum);
993 if (vol_id > UBI_MAX_VOLUMES && vol_id != UBI_LAYOUT_VOLUME_ID) {
994 int lnum = be32_to_cpu(vidh->lnum);
996 /* Unsupported internal volume */
997 switch (vidh->compat) {
998 case UBI_COMPAT_DELETE:
999 if (vol_id != UBI_FM_SB_VOLUME_ID
1000 && vol_id != UBI_FM_DATA_VOLUME_ID) {
1001 ubi_msg(ubi, "\"delete\" compatible internal volume %d:%d found, will remove it",
1004 err = add_to_list(ai, pnum, vol_id, lnum,
1011 ubi_msg(ubi, "read-only compatible internal volume %d:%d found, switch to read-only mode",
1016 case UBI_COMPAT_PRESERVE:
1017 ubi_msg(ubi, "\"preserve\" compatible internal volume %d:%d found",
1019 err = add_to_list(ai, pnum, vol_id, lnum,
1025 case UBI_COMPAT_REJECT:
1026 ubi_err(ubi, "incompatible internal volume %d:%d found",
1033 ubi_warn(ubi, "valid VID header but corrupted EC header at PEB %d",
1035 err = ubi_add_to_av(ubi, ai, pnum, ec, vidh, bitflips);
1043 if (ec > ai->max_ec)
1045 if (ec < ai->min_ec)
1053 * late_analysis - analyze the overall situation with PEB.
1054 * @ubi: UBI device description object
1055 * @ai: attaching information
1057 * This is a helper function which takes a look what PEBs we have after we
1058 * gather information about all of them ("ai" is compete). It decides whether
1059 * the flash is empty and should be formatted of whether there are too many
1060 * corrupted PEBs and we should not attach this MTD device. Returns zero if we
1061 * should proceed with attaching the MTD device, and %-EINVAL if we should not.
1063 static int late_analysis(struct ubi_device *ubi, struct ubi_attach_info *ai)
1065 struct ubi_ainf_peb *aeb;
1066 int max_corr, peb_count;
1068 peb_count = ubi->peb_count - ai->bad_peb_count - ai->alien_peb_count;
1069 max_corr = peb_count / 20 ?: 8;
1072 * Few corrupted PEBs is not a problem and may be just a result of
1073 * unclean reboots. However, many of them may indicate some problems
1074 * with the flash HW or driver.
1076 if (ai->corr_peb_count) {
1077 ubi_err(ubi, "%d PEBs are corrupted and preserved",
1078 ai->corr_peb_count);
1079 pr_err("Corrupted PEBs are:");
1080 list_for_each_entry(aeb, &ai->corr, u.list)
1081 pr_cont(" %d", aeb->pnum);
1085 * If too many PEBs are corrupted, we refuse attaching,
1086 * otherwise, only print a warning.
1088 if (ai->corr_peb_count >= max_corr) {
1089 ubi_err(ubi, "too many corrupted PEBs, refusing");
1094 if (ai->empty_peb_count + ai->maybe_bad_peb_count == peb_count) {
1096 * All PEBs are empty, or almost all - a couple PEBs look like
1097 * they may be bad PEBs which were not marked as bad yet.
1099 * This piece of code basically tries to distinguish between
1100 * the following situations:
1102 * 1. Flash is empty, but there are few bad PEBs, which are not
1103 * marked as bad so far, and which were read with error. We
1104 * want to go ahead and format this flash. While formatting,
1105 * the faulty PEBs will probably be marked as bad.
1107 * 2. Flash contains non-UBI data and we do not want to format
1108 * it and destroy possibly important information.
1110 if (ai->maybe_bad_peb_count <= 2) {
1112 ubi_msg(ubi, "empty MTD device detected");
1113 get_random_bytes(&ubi->image_seq,
1114 sizeof(ubi->image_seq));
1116 ubi_err(ubi, "MTD device is not UBI-formatted and possibly contains non-UBI data - refusing it");
1126 * destroy_av - free volume attaching information.
1127 * @av: volume attaching information
1128 * @ai: attaching information
1130 * This function destroys the volume attaching information.
1132 static void destroy_av(struct ubi_attach_info *ai, struct ubi_ainf_volume *av)
1134 struct ubi_ainf_peb *aeb;
1135 struct rb_node *this = av->root.rb_node;
1139 this = this->rb_left;
1140 else if (this->rb_right)
1141 this = this->rb_right;
1143 aeb = rb_entry(this, struct ubi_ainf_peb, u.rb);
1144 this = rb_parent(this);
1146 if (this->rb_left == &aeb->u.rb)
1147 this->rb_left = NULL;
1149 this->rb_right = NULL;
1152 kmem_cache_free(ai->aeb_slab_cache, aeb);
1159 * destroy_ai - destroy attaching information.
1160 * @ai: attaching information
1162 static void destroy_ai(struct ubi_attach_info *ai)
1164 struct ubi_ainf_peb *aeb, *aeb_tmp;
1165 struct ubi_ainf_volume *av;
1168 list_for_each_entry_safe(aeb, aeb_tmp, &ai->alien, u.list) {
1169 list_del(&aeb->u.list);
1170 kmem_cache_free(ai->aeb_slab_cache, aeb);
1172 list_for_each_entry_safe(aeb, aeb_tmp, &ai->erase, u.list) {
1173 list_del(&aeb->u.list);
1174 kmem_cache_free(ai->aeb_slab_cache, aeb);
1176 list_for_each_entry_safe(aeb, aeb_tmp, &ai->corr, u.list) {
1177 list_del(&aeb->u.list);
1178 kmem_cache_free(ai->aeb_slab_cache, aeb);
1180 list_for_each_entry_safe(aeb, aeb_tmp, &ai->free, u.list) {
1181 list_del(&aeb->u.list);
1182 kmem_cache_free(ai->aeb_slab_cache, aeb);
1185 /* Destroy the volume RB-tree */
1186 rb = ai->volumes.rb_node;
1190 else if (rb->rb_right)
1193 av = rb_entry(rb, struct ubi_ainf_volume, rb);
1197 if (rb->rb_left == &av->rb)
1200 rb->rb_right = NULL;
1207 kmem_cache_destroy(ai->aeb_slab_cache);
1213 * scan_all - scan entire MTD device.
1214 * @ubi: UBI device description object
1215 * @ai: attach info object
1216 * @start: start scanning at this PEB
1218 * This function does full scanning of an MTD device and returns complete
1219 * information about it in form of a "struct ubi_attach_info" object. In case
1220 * of failure, an error code is returned.
1222 static int scan_all(struct ubi_device *ubi, struct ubi_attach_info *ai,
1226 struct rb_node *rb1, *rb2;
1227 struct ubi_ainf_volume *av;
1228 struct ubi_ainf_peb *aeb;
1232 ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
1236 vidh = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
1240 for (pnum = start; pnum < ubi->peb_count; pnum++) {
1243 dbg_gen("process PEB %d", pnum);
1244 err = scan_peb(ubi, ai, pnum, NULL, NULL);
1249 ubi_msg(ubi, "scanning is finished");
1251 /* Calculate mean erase counter */
1253 ai->mean_ec = div_u64(ai->ec_sum, ai->ec_count);
1255 err = late_analysis(ubi, ai);
1260 * In case of unknown erase counter we use the mean erase counter
1263 ubi_rb_for_each_entry(rb1, av, &ai->volumes, rb) {
1264 ubi_rb_for_each_entry(rb2, aeb, &av->root, u.rb)
1265 if (aeb->ec == UBI_UNKNOWN)
1266 aeb->ec = ai->mean_ec;
1269 list_for_each_entry(aeb, &ai->free, u.list) {
1270 if (aeb->ec == UBI_UNKNOWN)
1271 aeb->ec = ai->mean_ec;
1274 list_for_each_entry(aeb, &ai->corr, u.list)
1275 if (aeb->ec == UBI_UNKNOWN)
1276 aeb->ec = ai->mean_ec;
1278 list_for_each_entry(aeb, &ai->erase, u.list)
1279 if (aeb->ec == UBI_UNKNOWN)
1280 aeb->ec = ai->mean_ec;
1282 err = self_check_ai(ubi, ai);
1286 ubi_free_vid_hdr(ubi, vidh);
1292 ubi_free_vid_hdr(ubi, vidh);
1298 static struct ubi_attach_info *alloc_ai(void)
1300 struct ubi_attach_info *ai;
1302 ai = kzalloc(sizeof(struct ubi_attach_info), GFP_KERNEL);
1306 INIT_LIST_HEAD(&ai->corr);
1307 INIT_LIST_HEAD(&ai->free);
1308 INIT_LIST_HEAD(&ai->erase);
1309 INIT_LIST_HEAD(&ai->alien);
1310 ai->volumes = RB_ROOT;
1311 ai->aeb_slab_cache = kmem_cache_create("ubi_aeb_slab_cache",
1312 sizeof(struct ubi_ainf_peb),
1314 if (!ai->aeb_slab_cache) {
1322 #ifdef CONFIG_MTD_UBI_FASTMAP
1325 * scan_fastmap - try to find a fastmap and attach from it.
1326 * @ubi: UBI device description object
1327 * @ai: attach info object
1329 * Returns 0 on success, negative return values indicate an internal
1331 * UBI_NO_FASTMAP denotes that no fastmap was found.
1332 * UBI_BAD_FASTMAP denotes that the found fastmap was invalid.
1334 static int scan_fast(struct ubi_device *ubi, struct ubi_attach_info **ai)
1336 int err, pnum, fm_anchor = -1;
1337 unsigned long long max_sqnum = 0;
1341 ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
1345 vidh = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
1349 for (pnum = 0; pnum < UBI_FM_MAX_START; pnum++) {
1351 unsigned long long sqnum = -1;
1354 dbg_gen("process PEB %d", pnum);
1355 err = scan_peb(ubi, *ai, pnum, &vol_id, &sqnum);
1359 if (vol_id == UBI_FM_SB_VOLUME_ID && sqnum > max_sqnum) {
1365 ubi_free_vid_hdr(ubi, vidh);
1369 return UBI_NO_FASTMAP;
1376 return ubi_scan_fastmap(ubi, *ai, fm_anchor);
1379 ubi_free_vid_hdr(ubi, vidh);
1389 * ubi_attach - attach an MTD device.
1390 * @ubi: UBI device descriptor
1391 * @force_scan: if set to non-zero attach by scanning
1393 * This function returns zero in case of success and a negative error code in
1396 int ubi_attach(struct ubi_device *ubi, int force_scan)
1399 struct ubi_attach_info *ai;
1405 #ifdef CONFIG_MTD_UBI_FASTMAP
1406 /* On small flash devices we disable fastmap in any case. */
1407 if ((int)mtd_div_by_eb(ubi->mtd->size, ubi->mtd) <= UBI_FM_MAX_START) {
1408 ubi->fm_disabled = 1;
1413 err = scan_all(ubi, ai, 0);
1415 err = scan_fast(ubi, &ai);
1416 if (err > 0 || mtd_is_eccerr(err)) {
1417 if (err != UBI_NO_FASTMAP) {
1423 err = scan_all(ubi, ai, 0);
1425 err = scan_all(ubi, ai, UBI_FM_MAX_START);
1430 err = scan_all(ubi, ai, 0);
1435 ubi->bad_peb_count = ai->bad_peb_count;
1436 ubi->good_peb_count = ubi->peb_count - ubi->bad_peb_count;
1437 ubi->corr_peb_count = ai->corr_peb_count;
1438 ubi->max_ec = ai->max_ec;
1439 ubi->mean_ec = ai->mean_ec;
1440 dbg_gen("max. sequence number: %llu", ai->max_sqnum);
1442 err = ubi_read_volume_table(ubi, ai);
1446 err = ubi_wl_init(ubi, ai);
1450 err = ubi_eba_init(ubi, ai);
1454 #ifdef CONFIG_MTD_UBI_FASTMAP
1455 if (ubi->fm && ubi_dbg_chk_fastmap(ubi)) {
1456 struct ubi_attach_info *scan_ai;
1458 scan_ai = alloc_ai();
1464 err = scan_all(ubi, scan_ai, 0);
1466 destroy_ai(scan_ai);
1470 err = self_check_eba(ubi, ai, scan_ai);
1471 destroy_ai(scan_ai);
1484 ubi_free_internal_volumes(ubi);
1492 * self_check_ai - check the attaching information.
1493 * @ubi: UBI device description object
1494 * @ai: attaching information
1496 * This function returns zero if the attaching information is all right, and a
1497 * negative error code if not or if an error occurred.
1499 static int self_check_ai(struct ubi_device *ubi, struct ubi_attach_info *ai)
1501 int pnum, err, vols_found = 0;
1502 struct rb_node *rb1, *rb2;
1503 struct ubi_ainf_volume *av;
1504 struct ubi_ainf_peb *aeb, *last_aeb;
1507 if (!ubi_dbg_chk_gen(ubi))
1511 * At first, check that attaching information is OK.
1513 ubi_rb_for_each_entry(rb1, av, &ai->volumes, rb) {
1521 ubi_err(ubi, "bad is_empty flag");
1525 if (av->vol_id < 0 || av->highest_lnum < 0 ||
1526 av->leb_count < 0 || av->vol_type < 0 || av->used_ebs < 0 ||
1527 av->data_pad < 0 || av->last_data_size < 0) {
1528 ubi_err(ubi, "negative values");
1532 if (av->vol_id >= UBI_MAX_VOLUMES &&
1533 av->vol_id < UBI_INTERNAL_VOL_START) {
1534 ubi_err(ubi, "bad vol_id");
1538 if (av->vol_id > ai->highest_vol_id) {
1539 ubi_err(ubi, "highest_vol_id is %d, but vol_id %d is there",
1540 ai->highest_vol_id, av->vol_id);
1544 if (av->vol_type != UBI_DYNAMIC_VOLUME &&
1545 av->vol_type != UBI_STATIC_VOLUME) {
1546 ubi_err(ubi, "bad vol_type");
1550 if (av->data_pad > ubi->leb_size / 2) {
1551 ubi_err(ubi, "bad data_pad");
1556 ubi_rb_for_each_entry(rb2, aeb, &av->root, u.rb) {
1562 if (aeb->pnum < 0 || aeb->ec < 0) {
1563 ubi_err(ubi, "negative values");
1567 if (aeb->ec < ai->min_ec) {
1568 ubi_err(ubi, "bad ai->min_ec (%d), %d found",
1569 ai->min_ec, aeb->ec);
1573 if (aeb->ec > ai->max_ec) {
1574 ubi_err(ubi, "bad ai->max_ec (%d), %d found",
1575 ai->max_ec, aeb->ec);
1579 if (aeb->pnum >= ubi->peb_count) {
1580 ubi_err(ubi, "too high PEB number %d, total PEBs %d",
1581 aeb->pnum, ubi->peb_count);
1585 if (av->vol_type == UBI_STATIC_VOLUME) {
1586 if (aeb->lnum >= av->used_ebs) {
1587 ubi_err(ubi, "bad lnum or used_ebs");
1591 if (av->used_ebs != 0) {
1592 ubi_err(ubi, "non-zero used_ebs");
1597 if (aeb->lnum > av->highest_lnum) {
1598 ubi_err(ubi, "incorrect highest_lnum or lnum");
1603 if (av->leb_count != leb_count) {
1604 ubi_err(ubi, "bad leb_count, %d objects in the tree",
1614 if (aeb->lnum != av->highest_lnum) {
1615 ubi_err(ubi, "bad highest_lnum");
1620 if (vols_found != ai->vols_found) {
1621 ubi_err(ubi, "bad ai->vols_found %d, should be %d",
1622 ai->vols_found, vols_found);
1626 /* Check that attaching information is correct */
1627 ubi_rb_for_each_entry(rb1, av, &ai->volumes, rb) {
1629 ubi_rb_for_each_entry(rb2, aeb, &av->root, u.rb) {
1636 err = ubi_io_read_vid_hdr(ubi, aeb->pnum, vidh, 1);
1637 if (err && err != UBI_IO_BITFLIPS) {
1638 ubi_err(ubi, "VID header is not OK (%d)",
1645 vol_type = vidh->vol_type == UBI_VID_DYNAMIC ?
1646 UBI_DYNAMIC_VOLUME : UBI_STATIC_VOLUME;
1647 if (av->vol_type != vol_type) {
1648 ubi_err(ubi, "bad vol_type");
1652 if (aeb->sqnum != be64_to_cpu(vidh->sqnum)) {
1653 ubi_err(ubi, "bad sqnum %llu", aeb->sqnum);
1657 if (av->vol_id != be32_to_cpu(vidh->vol_id)) {
1658 ubi_err(ubi, "bad vol_id %d", av->vol_id);
1662 if (av->compat != vidh->compat) {
1663 ubi_err(ubi, "bad compat %d", vidh->compat);
1667 if (aeb->lnum != be32_to_cpu(vidh->lnum)) {
1668 ubi_err(ubi, "bad lnum %d", aeb->lnum);
1672 if (av->used_ebs != be32_to_cpu(vidh->used_ebs)) {
1673 ubi_err(ubi, "bad used_ebs %d", av->used_ebs);
1677 if (av->data_pad != be32_to_cpu(vidh->data_pad)) {
1678 ubi_err(ubi, "bad data_pad %d", av->data_pad);
1686 if (av->highest_lnum != be32_to_cpu(vidh->lnum)) {
1687 ubi_err(ubi, "bad highest_lnum %d", av->highest_lnum);
1691 if (av->last_data_size != be32_to_cpu(vidh->data_size)) {
1692 ubi_err(ubi, "bad last_data_size %d",
1693 av->last_data_size);
1699 * Make sure that all the physical eraseblocks are in one of the lists
1702 buf = kzalloc(ubi->peb_count, GFP_KERNEL);
1706 for (pnum = 0; pnum < ubi->peb_count; pnum++) {
1707 err = ubi_io_is_bad(ubi, pnum);
1715 ubi_rb_for_each_entry(rb1, av, &ai->volumes, rb)
1716 ubi_rb_for_each_entry(rb2, aeb, &av->root, u.rb)
1719 list_for_each_entry(aeb, &ai->free, u.list)
1722 list_for_each_entry(aeb, &ai->corr, u.list)
1725 list_for_each_entry(aeb, &ai->erase, u.list)
1728 list_for_each_entry(aeb, &ai->alien, u.list)
1732 for (pnum = 0; pnum < ubi->peb_count; pnum++)
1734 ubi_err(ubi, "PEB %d is not referred", pnum);
1744 ubi_err(ubi, "bad attaching information about LEB %d", aeb->lnum);
1745 ubi_dump_aeb(aeb, 0);
1750 ubi_err(ubi, "bad attaching information about volume %d", av->vol_id);
1755 ubi_err(ubi, "bad attaching information about volume %d", av->vol_id);
1757 ubi_dump_vid_hdr(vidh);