2 * Copyright (c) International Business Machines Corp., 2006
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.
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.
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
18 * Author: Artem Bityutskiy (Битюцкий Артём)
22 * UBI scanning sub-system.
24 * This sub-system is responsible for scanning the flash media, checking UBI
25 * headers and providing complete information about the UBI flash image.
27 * The scanning information is represented by a &struct ubi_scan_info' object.
28 * Information about found volumes is represented by &struct ubi_scan_volume
29 * objects which are kept in volume RB-tree with root at the @volumes field.
30 * The RB-tree is indexed by the volume ID.
32 * Found logical eraseblocks are represented by &struct ubi_scan_leb objects.
33 * These objects are kept in per-volume RB-trees with the root at the
34 * corresponding &struct ubi_scan_volume object. To put it differently, we keep
35 * an RB-tree of per-volume objects and each of these objects is the root of
36 * RB-tree of per-eraseblock objects.
38 * Corrupted physical eraseblocks are put to the @corr list, free physical
39 * eraseblocks are put to the @free list and the physical eraseblock to be
40 * erased are put to the @erase list.
43 #include <linux/err.h>
44 #include <linux/slab.h>
45 #include <linux/crc32.h>
46 #include <linux/math64.h>
47 #include <linux/random.h>
50 #ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
51 static int paranoid_check_si(struct ubi_device *ubi, struct ubi_scan_info *si);
53 #define paranoid_check_si(ubi, si) 0
56 /* Temporary variables used during scanning */
57 static struct ubi_ec_hdr *ech;
58 static struct ubi_vid_hdr *vidh;
61 * add_to_list - add physical eraseblock to a list.
62 * @si: scanning information
63 * @pnum: physical eraseblock number to add
64 * @ec: erase counter of the physical eraseblock
65 * @list: the list to add to
67 * This function adds physical eraseblock @pnum to free, erase, corrupted or
68 * alien lists. Returns zero in case of success and a negative error code in
71 static int add_to_list(struct ubi_scan_info *si, int pnum, int ec,
72 struct list_head *list)
74 struct ubi_scan_leb *seb;
76 if (list == &si->free) {
77 dbg_bld("add to free: PEB %d, EC %d", pnum, ec);
78 si->free_peb_count += 1;
79 } else if (list == &si->erase) {
80 dbg_bld("add to erase: PEB %d, EC %d", pnum, ec);
81 si->erase_peb_count += 1;
82 } else if (list == &si->corr) {
83 dbg_bld("add to corrupted: PEB %d, EC %d", pnum, ec);
84 si->corr_peb_count += 1;
85 } else if (list == &si->alien) {
86 dbg_bld("add to alien: PEB %d, EC %d", pnum, ec);
87 si->alien_peb_count += 1;
91 seb = kmalloc(sizeof(struct ubi_scan_leb), GFP_KERNEL);
97 list_add_tail(&seb->u.list, list);
102 * validate_vid_hdr - check volume identifier header.
103 * @vid_hdr: the volume identifier header to check
104 * @sv: information about the volume this logical eraseblock belongs to
105 * @pnum: physical eraseblock number the VID header came from
107 * This function checks that data stored in @vid_hdr is consistent. Returns
108 * non-zero if an inconsistency was found and zero if not.
110 * Note, UBI does sanity check of everything it reads from the flash media.
111 * Most of the checks are done in the I/O sub-system. Here we check that the
112 * information in the VID header is consistent to the information in other VID
113 * headers of the same volume.
115 static int validate_vid_hdr(const struct ubi_vid_hdr *vid_hdr,
116 const struct ubi_scan_volume *sv, int pnum)
118 int vol_type = vid_hdr->vol_type;
119 int vol_id = be32_to_cpu(vid_hdr->vol_id);
120 int used_ebs = be32_to_cpu(vid_hdr->used_ebs);
121 int data_pad = be32_to_cpu(vid_hdr->data_pad);
123 if (sv->leb_count != 0) {
127 * This is not the first logical eraseblock belonging to this
128 * volume. Ensure that the data in its VID header is consistent
129 * to the data in previous logical eraseblock headers.
132 if (vol_id != sv->vol_id) {
133 dbg_err("inconsistent vol_id");
137 if (sv->vol_type == UBI_STATIC_VOLUME)
138 sv_vol_type = UBI_VID_STATIC;
140 sv_vol_type = UBI_VID_DYNAMIC;
142 if (vol_type != sv_vol_type) {
143 dbg_err("inconsistent vol_type");
147 if (used_ebs != sv->used_ebs) {
148 dbg_err("inconsistent used_ebs");
152 if (data_pad != sv->data_pad) {
153 dbg_err("inconsistent data_pad");
161 ubi_err("inconsistent VID header at PEB %d", pnum);
162 ubi_dbg_dump_vid_hdr(vid_hdr);
168 * add_volume - add volume to the scanning information.
169 * @si: scanning information
170 * @vol_id: ID of the volume to add
171 * @pnum: physical eraseblock number
172 * @vid_hdr: volume identifier header
174 * If the volume corresponding to the @vid_hdr logical eraseblock is already
175 * present in the scanning information, this function does nothing. Otherwise
176 * it adds corresponding volume to the scanning information. Returns a pointer
177 * to the scanning volume object in case of success and a negative error code
178 * in case of failure.
180 static struct ubi_scan_volume *add_volume(struct ubi_scan_info *si, int vol_id,
182 const struct ubi_vid_hdr *vid_hdr)
184 struct ubi_scan_volume *sv;
185 struct rb_node **p = &si->volumes.rb_node, *parent = NULL;
187 ubi_assert(vol_id == be32_to_cpu(vid_hdr->vol_id));
189 /* Walk the volume RB-tree to look if this volume is already present */
192 sv = rb_entry(parent, struct ubi_scan_volume, rb);
194 if (vol_id == sv->vol_id)
197 if (vol_id > sv->vol_id)
203 /* The volume is absent - add it */
204 sv = kmalloc(sizeof(struct ubi_scan_volume), GFP_KERNEL);
206 return ERR_PTR(-ENOMEM);
208 sv->highest_lnum = sv->leb_count = 0;
211 sv->used_ebs = be32_to_cpu(vid_hdr->used_ebs);
212 sv->data_pad = be32_to_cpu(vid_hdr->data_pad);
213 sv->compat = vid_hdr->compat;
214 sv->vol_type = vid_hdr->vol_type == UBI_VID_DYNAMIC ? UBI_DYNAMIC_VOLUME
216 if (vol_id > si->highest_vol_id)
217 si->highest_vol_id = vol_id;
219 rb_link_node(&sv->rb, parent, p);
220 rb_insert_color(&sv->rb, &si->volumes);
222 dbg_bld("added volume %d", vol_id);
227 * compare_lebs - find out which logical eraseblock is newer.
228 * @ubi: UBI device description object
229 * @seb: first logical eraseblock to compare
230 * @pnum: physical eraseblock number of the second logical eraseblock to
232 * @vid_hdr: volume identifier header of the second logical eraseblock
234 * This function compares 2 copies of a LEB and informs which one is newer. In
235 * case of success this function returns a positive value, in case of failure, a
236 * negative error code is returned. The success return codes use the following
238 * o bit 0 is cleared: the first PEB (described by @seb) is newer than the
239 * second PEB (described by @pnum and @vid_hdr);
240 * o bit 0 is set: the second PEB is newer;
241 * o bit 1 is cleared: no bit-flips were detected in the newer LEB;
242 * o bit 1 is set: bit-flips were detected in the newer LEB;
243 * o bit 2 is cleared: the older LEB is not corrupted;
244 * o bit 2 is set: the older LEB is corrupted.
246 static int compare_lebs(struct ubi_device *ubi, const struct ubi_scan_leb *seb,
247 int pnum, const struct ubi_vid_hdr *vid_hdr)
250 int len, err, second_is_newer, bitflips = 0, corrupted = 0;
251 uint32_t data_crc, crc;
252 struct ubi_vid_hdr *vh = NULL;
253 unsigned long long sqnum2 = be64_to_cpu(vid_hdr->sqnum);
255 if (sqnum2 == seb->sqnum) {
257 * This must be a really ancient UBI image which has been
258 * created before sequence numbers support has been added. At
259 * that times we used 32-bit LEB versions stored in logical
260 * eraseblocks. That was before UBI got into mainline. We do not
261 * support these images anymore. Well, those images will work
262 * still work, but only if no unclean reboots happened.
264 ubi_err("unsupported on-flash UBI format\n");
268 /* Obviously the LEB with lower sequence counter is older */
269 second_is_newer = !!(sqnum2 > seb->sqnum);
272 * Now we know which copy is newer. If the copy flag of the PEB with
273 * newer version is not set, then we just return, otherwise we have to
274 * check data CRC. For the second PEB we already have the VID header,
275 * for the first one - we'll need to re-read it from flash.
277 * Note: this may be optimized so that we wouldn't read twice.
280 if (second_is_newer) {
281 if (!vid_hdr->copy_flag) {
282 /* It is not a copy, so it is newer */
283 dbg_bld("second PEB %d is newer, copy_flag is unset",
290 vh = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
294 err = ubi_io_read_vid_hdr(ubi, pnum, vh, 0);
296 if (err == UBI_IO_BITFLIPS)
299 dbg_err("VID of PEB %d header is bad, but it "
300 "was OK earlier", pnum);
308 if (!vh->copy_flag) {
309 /* It is not a copy, so it is newer */
310 dbg_bld("first PEB %d is newer, copy_flag is unset",
319 /* Read the data of the copy and check the CRC */
321 len = be32_to_cpu(vid_hdr->data_size);
328 err = ubi_io_read_data(ubi, buf, pnum, 0, len);
329 if (err && err != UBI_IO_BITFLIPS && err != -EBADMSG)
332 data_crc = be32_to_cpu(vid_hdr->data_crc);
333 crc = crc32(UBI_CRC32_INIT, buf, len);
334 if (crc != data_crc) {
335 dbg_bld("PEB %d CRC error: calculated %#08x, must be %#08x",
336 pnum, crc, data_crc);
339 second_is_newer = !second_is_newer;
341 dbg_bld("PEB %d CRC is OK", pnum);
346 ubi_free_vid_hdr(ubi, vh);
349 dbg_bld("second PEB %d is newer, copy_flag is set", pnum);
351 dbg_bld("first PEB %d is newer, copy_flag is set", pnum);
353 return second_is_newer | (bitflips << 1) | (corrupted << 2);
358 ubi_free_vid_hdr(ubi, vh);
363 * ubi_scan_add_used - add physical eraseblock to the scanning information.
364 * @ubi: UBI device description object
365 * @si: scanning information
366 * @pnum: the physical eraseblock number
368 * @vid_hdr: the volume identifier header
369 * @bitflips: if bit-flips were detected when this physical eraseblock was read
371 * This function adds information about a used physical eraseblock to the
372 * 'used' tree of the corresponding volume. The function is rather complex
373 * because it has to handle cases when this is not the first physical
374 * eraseblock belonging to the same logical eraseblock, and the newer one has
375 * to be picked, while the older one has to be dropped. This function returns
376 * zero in case of success and a negative error code in case of failure.
378 int ubi_scan_add_used(struct ubi_device *ubi, struct ubi_scan_info *si,
379 int pnum, int ec, const struct ubi_vid_hdr *vid_hdr,
382 int err, vol_id, lnum;
383 unsigned long long sqnum;
384 struct ubi_scan_volume *sv;
385 struct ubi_scan_leb *seb;
386 struct rb_node **p, *parent = NULL;
388 vol_id = be32_to_cpu(vid_hdr->vol_id);
389 lnum = be32_to_cpu(vid_hdr->lnum);
390 sqnum = be64_to_cpu(vid_hdr->sqnum);
392 dbg_bld("PEB %d, LEB %d:%d, EC %d, sqnum %llu, bitflips %d",
393 pnum, vol_id, lnum, ec, sqnum, bitflips);
395 sv = add_volume(si, vol_id, pnum, vid_hdr);
399 if (si->max_sqnum < sqnum)
400 si->max_sqnum = sqnum;
403 * Walk the RB-tree of logical eraseblocks of volume @vol_id to look
404 * if this is the first instance of this logical eraseblock or not.
406 p = &sv->root.rb_node;
411 seb = rb_entry(parent, struct ubi_scan_leb, u.rb);
412 if (lnum != seb->lnum) {
413 if (lnum < seb->lnum)
421 * There is already a physical eraseblock describing the same
422 * logical eraseblock present.
425 dbg_bld("this LEB already exists: PEB %d, sqnum %llu, "
426 "EC %d", seb->pnum, seb->sqnum, seb->ec);
429 * Make sure that the logical eraseblocks have different
430 * sequence numbers. Otherwise the image is bad.
432 * However, if the sequence number is zero, we assume it must
433 * be an ancient UBI image from the era when UBI did not have
434 * sequence numbers. We still can attach these images, unless
435 * there is a need to distinguish between old and new
436 * eraseblocks, in which case we'll refuse the image in
437 * 'compare_lebs()'. In other words, we attach old clean
438 * images, but refuse attaching old images with duplicated
439 * logical eraseblocks because there was an unclean reboot.
441 if (seb->sqnum == sqnum && sqnum != 0) {
442 ubi_err("two LEBs with same sequence number %llu",
444 ubi_dbg_dump_seb(seb, 0);
445 ubi_dbg_dump_vid_hdr(vid_hdr);
450 * Now we have to drop the older one and preserve the newer
453 cmp_res = compare_lebs(ubi, seb, pnum, vid_hdr);
459 * This logical eraseblock is newer than the one
462 err = validate_vid_hdr(vid_hdr, sv, pnum);
467 err = add_to_list(si, seb->pnum, seb->ec,
470 err = add_to_list(si, seb->pnum, seb->ec,
477 seb->scrub = ((cmp_res & 2) || bitflips);
480 if (sv->highest_lnum == lnum)
482 be32_to_cpu(vid_hdr->data_size);
487 * This logical eraseblock is older than the one found
491 return add_to_list(si, pnum, ec, &si->corr);
493 return add_to_list(si, pnum, ec, &si->erase);
498 * We've met this logical eraseblock for the first time, add it to the
499 * scanning information.
502 err = validate_vid_hdr(vid_hdr, sv, pnum);
506 seb = kmalloc(sizeof(struct ubi_scan_leb), GFP_KERNEL);
514 seb->scrub = bitflips;
516 if (sv->highest_lnum <= lnum) {
517 sv->highest_lnum = lnum;
518 sv->last_data_size = be32_to_cpu(vid_hdr->data_size);
522 rb_link_node(&seb->u.rb, parent, p);
523 rb_insert_color(&seb->u.rb, &sv->root);
524 si->used_peb_count += 1;
529 * ubi_scan_find_sv - find volume in the scanning information.
530 * @si: scanning information
531 * @vol_id: the requested volume ID
533 * This function returns a pointer to the volume description or %NULL if there
534 * are no data about this volume in the scanning information.
536 struct ubi_scan_volume *ubi_scan_find_sv(const struct ubi_scan_info *si,
539 struct ubi_scan_volume *sv;
540 struct rb_node *p = si->volumes.rb_node;
543 sv = rb_entry(p, struct ubi_scan_volume, rb);
545 if (vol_id == sv->vol_id)
548 if (vol_id > sv->vol_id)
558 * ubi_scan_find_seb - find LEB in the volume scanning information.
559 * @sv: a pointer to the volume scanning information
560 * @lnum: the requested logical eraseblock
562 * This function returns a pointer to the scanning logical eraseblock or %NULL
563 * if there are no data about it in the scanning volume information.
565 struct ubi_scan_leb *ubi_scan_find_seb(const struct ubi_scan_volume *sv,
568 struct ubi_scan_leb *seb;
569 struct rb_node *p = sv->root.rb_node;
572 seb = rb_entry(p, struct ubi_scan_leb, u.rb);
574 if (lnum == seb->lnum)
577 if (lnum > seb->lnum)
587 * ubi_scan_rm_volume - delete scanning information about a volume.
588 * @si: scanning information
589 * @sv: the volume scanning information to delete
591 void ubi_scan_rm_volume(struct ubi_scan_info *si, struct ubi_scan_volume *sv)
594 struct ubi_scan_leb *seb;
596 dbg_bld("remove scanning information about volume %d", sv->vol_id);
598 while ((rb = rb_first(&sv->root))) {
599 seb = rb_entry(rb, struct ubi_scan_leb, u.rb);
600 rb_erase(&seb->u.rb, &sv->root);
601 list_add_tail(&seb->u.list, &si->erase);
604 rb_erase(&sv->rb, &si->volumes);
610 * ubi_scan_erase_peb - erase a physical eraseblock.
611 * @ubi: UBI device description object
612 * @si: scanning information
613 * @pnum: physical eraseblock number to erase;
614 * @ec: erase counter value to write (%UBI_SCAN_UNKNOWN_EC if it is unknown)
616 * This function erases physical eraseblock 'pnum', and writes the erase
617 * counter header to it. This function should only be used on UBI device
618 * initialization stages, when the EBA sub-system had not been yet initialized.
619 * This function returns zero in case of success and a negative error code in
622 int ubi_scan_erase_peb(struct ubi_device *ubi, const struct ubi_scan_info *si,
626 struct ubi_ec_hdr *ec_hdr;
628 if ((long long)ec >= UBI_MAX_ERASECOUNTER) {
630 * Erase counter overflow. Upgrade UBI and use 64-bit
631 * erase counters internally.
633 ubi_err("erase counter overflow at PEB %d, EC %d", pnum, ec);
637 ec_hdr = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
641 ec_hdr->ec = cpu_to_be64(ec);
643 err = ubi_io_sync_erase(ubi, pnum, 0);
647 err = ubi_io_write_ec_hdr(ubi, pnum, ec_hdr);
655 * ubi_scan_get_free_peb - get a free physical eraseblock.
656 * @ubi: UBI device description object
657 * @si: scanning information
659 * This function returns a free physical eraseblock. It is supposed to be
660 * called on the UBI initialization stages when the wear-leveling sub-system is
661 * not initialized yet. This function picks a physical eraseblocks from one of
662 * the lists, writes the EC header if it is needed, and removes it from the
665 * This function returns scanning physical eraseblock information in case of
666 * success and an error code in case of failure.
668 struct ubi_scan_leb *ubi_scan_get_free_peb(struct ubi_device *ubi,
669 struct ubi_scan_info *si)
672 struct ubi_scan_leb *seb;
674 if (!list_empty(&si->free)) {
675 seb = list_entry(si->free.next, struct ubi_scan_leb, u.list);
676 list_del(&seb->u.list);
677 dbg_bld("return free PEB %d, EC %d", seb->pnum, seb->ec);
681 for (i = 0; i < 2; i++) {
682 struct list_head *head;
683 struct ubi_scan_leb *tmp_seb;
691 * We try to erase the first physical eraseblock from the @head
692 * list and pick it if we succeed, or try to erase the
693 * next one if not. And so forth. We don't want to take care
694 * about bad eraseblocks here - they'll be handled later.
696 list_for_each_entry_safe(seb, tmp_seb, head, u.list) {
697 if (seb->ec == UBI_SCAN_UNKNOWN_EC)
698 seb->ec = si->mean_ec;
700 err = ubi_scan_erase_peb(ubi, si, seb->pnum, seb->ec+1);
705 list_del(&seb->u.list);
706 dbg_bld("return PEB %d, EC %d", seb->pnum, seb->ec);
711 ubi_err("no eraseblocks found");
712 return ERR_PTR(-ENOSPC);
716 * process_eb - read, check UBI headers, and add them to scanning information.
717 * @ubi: UBI device description object
718 * @si: scanning information
719 * @pnum: the physical eraseblock number
721 * This function returns a zero if the physical eraseblock was successfully
722 * handled and a negative error code in case of failure.
724 static int process_eb(struct ubi_device *ubi, struct ubi_scan_info *si,
727 long long uninitialized_var(ec);
728 int err, bitflips = 0, vol_id, ec_corr = 0;
730 dbg_bld("scan PEB %d", pnum);
732 /* Skip bad physical eraseblocks */
733 err = ubi_io_is_bad(ubi, pnum);
738 * FIXME: this is actually duty of the I/O sub-system to
739 * initialize this, but MTD does not provide enough
742 si->bad_peb_count += 1;
746 err = ubi_io_read_ec_hdr(ubi, pnum, ech, 0);
749 else if (err == UBI_IO_BITFLIPS)
751 else if (err == UBI_IO_PEB_EMPTY)
752 return add_to_list(si, pnum, UBI_SCAN_UNKNOWN_EC, &si->erase);
753 else if (err == UBI_IO_BAD_HDR_READ || err == UBI_IO_BAD_HDR) {
755 * We have to also look at the VID header, possibly it is not
756 * corrupted. Set %bitflips flag in order to make this PEB be
757 * moved and EC be re-created.
760 ec = UBI_SCAN_UNKNOWN_EC;
767 /* Make sure UBI version is OK */
768 if (ech->version != UBI_VERSION) {
769 ubi_err("this UBI version is %d, image version is %d",
770 UBI_VERSION, (int)ech->version);
774 ec = be64_to_cpu(ech->ec);
775 if (ec > UBI_MAX_ERASECOUNTER) {
777 * Erase counter overflow. The EC headers have 64 bits
778 * reserved, but we anyway make use of only 31 bit
779 * values, as this seems to be enough for any existing
780 * flash. Upgrade UBI and use 64-bit erase counters
783 ubi_err("erase counter overflow, max is %d",
784 UBI_MAX_ERASECOUNTER);
785 ubi_dbg_dump_ec_hdr(ech);
790 * Make sure that all PEBs have the same image sequence number.
791 * This allows us to detect situations when users flash UBI
792 * images incorrectly, so that the flash has the new UBI image
793 * and leftovers from the old one. This feature was added
794 * relatively recently, and the sequence number was always
795 * zero, because old UBI implementations always set it to zero.
796 * For this reasons, we do not panic if some PEBs have zero
797 * sequence number, while other PEBs have non-zero sequence
800 image_seq = be32_to_cpu(ech->image_seq);
801 if (!ubi->image_seq && image_seq)
802 ubi->image_seq = image_seq;
803 if (ubi->image_seq && image_seq &&
804 ubi->image_seq != image_seq) {
805 ubi_err("bad image sequence number %d in PEB %d, "
806 "expected %d", image_seq, pnum, ubi->image_seq);
807 ubi_dbg_dump_ec_hdr(ech);
812 /* OK, we've done with the EC header, let's look at the VID header */
814 err = ubi_io_read_vid_hdr(ubi, pnum, vidh, 0);
817 else if (err == UBI_IO_BITFLIPS)
819 else if (err == UBI_IO_BAD_HDR_READ || err == UBI_IO_BAD_HDR ||
820 (err == UBI_IO_PEB_FREE && ec_corr)) {
821 /* VID header is corrupted */
822 if (err == UBI_IO_BAD_HDR_READ ||
823 ec_corr == UBI_IO_BAD_HDR_READ)
824 si->read_err_count += 1;
825 err = add_to_list(si, pnum, ec, &si->corr);
829 } else if (err == UBI_IO_PEB_FREE) {
830 /* No VID header - the physical eraseblock is free */
831 err = add_to_list(si, pnum, ec, &si->free);
837 vol_id = be32_to_cpu(vidh->vol_id);
838 if (vol_id > UBI_MAX_VOLUMES && vol_id != UBI_LAYOUT_VOLUME_ID) {
839 int lnum = be32_to_cpu(vidh->lnum);
841 /* Unsupported internal volume */
842 switch (vidh->compat) {
843 case UBI_COMPAT_DELETE:
844 ubi_msg("\"delete\" compatible internal volume %d:%d"
845 " found, will remove it", vol_id, lnum);
846 err = add_to_list(si, pnum, ec, &si->erase);
852 ubi_msg("read-only compatible internal volume %d:%d"
853 " found, switch to read-only mode",
858 case UBI_COMPAT_PRESERVE:
859 ubi_msg("\"preserve\" compatible internal volume %d:%d"
860 " found", vol_id, lnum);
861 err = add_to_list(si, pnum, ec, &si->alien);
866 case UBI_COMPAT_REJECT:
867 ubi_err("incompatible internal volume %d:%d found",
874 ubi_warn("valid VID header but corrupted EC header at PEB %d",
876 err = ubi_scan_add_used(ubi, si, pnum, ec, vidh, bitflips);
894 * check_what_we_have - check what PEB were found by scanning.
895 * @ubi: UBI device description object
896 * @si: scanning information
898 * This is a helper function which takes a look what PEBs were found by
899 * scanning, and decides whether the flash is empty and should be formatted and
900 * whether there are too many corrupted PEBs and we should not attach this
901 * MTD device. Returns zero if we should proceed with attaching the MTD device,
902 * and %-EINVAL if we should not.
904 static int check_what_we_have(struct ubi_device *ubi, struct ubi_scan_info *si)
906 struct ubi_scan_leb *seb;
909 max_corr = ubi->peb_count - si->bad_peb_count - si->alien_peb_count;
910 max_corr = max_corr / 20 ?: 8;
913 * Few corrupted PEBs are not a problem and may be just a result of
914 * unclean reboots. However, many of them may indicate some problems
915 * with the flash HW or driver.
917 if (si->corr_peb_count >= 8) {
918 ubi_warn("%d PEBs are corrupted", si->corr_peb_count);
919 printk(KERN_WARNING "corrupted PEBs are:");
920 list_for_each_entry(seb, &si->corr, u.list)
921 printk(KERN_CONT " %d", seb->pnum);
922 printk(KERN_CONT "\n");
925 * If too many PEBs are corrupted, we refuse attaching,
926 * otherwise, only print a warning.
928 if (si->corr_peb_count >= max_corr) {
929 ubi_err("too many corrupted PEBs, refusing this device");
934 if (si->free_peb_count + si->used_peb_count +
935 si->alien_peb_count == 0) {
936 /* No UBI-formatted eraseblocks were found */
937 if (si->corr_peb_count == si->read_err_count &&
938 si->corr_peb_count < 8) {
939 /* No or just few corrupted PEBs, and all of them had a
940 * read error. We assume that those are bad PEBs, which
941 * were just not marked as bad so far.
943 * This piece of code basically tries to distinguish
944 * between the following 2 situations:
946 * 1. Flash is empty, but there are few bad PEBs, which
947 * are not marked as bad so far, and which were read
948 * with error. We want to go ahead and format this
949 * flash. While formating, the faulty PEBs will
950 * probably be marked as bad.
952 * 2. Flash probably contains non-UBI data and we do
953 * not want to format it and destroy possibly needed
954 * data (e.g., consider the case when the bootloader
955 * MTD partition was accidentally fed to UBI).
958 ubi_msg("empty MTD device detected");
959 get_random_bytes(&ubi->image_seq, sizeof(ubi->image_seq));
961 ubi_err("MTD device possibly contains non-UBI data, "
967 if (si->corr_peb_count > 0)
968 ubi_msg("corrupted PEBs will be formatted");
973 * ubi_scan - scan an MTD device.
974 * @ubi: UBI device description object
976 * This function does full scanning of an MTD device and returns complete
977 * information about it. In case of failure, an error code is returned.
979 struct ubi_scan_info *ubi_scan(struct ubi_device *ubi)
982 struct rb_node *rb1, *rb2;
983 struct ubi_scan_volume *sv;
984 struct ubi_scan_leb *seb;
985 struct ubi_scan_info *si;
987 si = kzalloc(sizeof(struct ubi_scan_info), GFP_KERNEL);
989 return ERR_PTR(-ENOMEM);
991 INIT_LIST_HEAD(&si->corr);
992 INIT_LIST_HEAD(&si->free);
993 INIT_LIST_HEAD(&si->erase);
994 INIT_LIST_HEAD(&si->alien);
995 si->volumes = RB_ROOT;
998 ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
1002 vidh = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
1006 for (pnum = 0; pnum < ubi->peb_count; pnum++) {
1009 dbg_gen("process PEB %d", pnum);
1010 err = process_eb(ubi, si, pnum);
1015 dbg_msg("scanning is finished");
1017 /* Calculate mean erase counter */
1019 si->mean_ec = div_u64(si->ec_sum, si->ec_count);
1021 err = check_what_we_have(ubi, si);
1026 * In case of unknown erase counter we use the mean erase counter
1029 ubi_rb_for_each_entry(rb1, sv, &si->volumes, rb) {
1030 ubi_rb_for_each_entry(rb2, seb, &sv->root, u.rb)
1031 if (seb->ec == UBI_SCAN_UNKNOWN_EC)
1032 seb->ec = si->mean_ec;
1035 list_for_each_entry(seb, &si->free, u.list) {
1036 if (seb->ec == UBI_SCAN_UNKNOWN_EC)
1037 seb->ec = si->mean_ec;
1040 list_for_each_entry(seb, &si->corr, u.list)
1041 if (seb->ec == UBI_SCAN_UNKNOWN_EC)
1042 seb->ec = si->mean_ec;
1044 list_for_each_entry(seb, &si->erase, u.list)
1045 if (seb->ec == UBI_SCAN_UNKNOWN_EC)
1046 seb->ec = si->mean_ec;
1048 err = paranoid_check_si(ubi, si);
1052 ubi_free_vid_hdr(ubi, vidh);
1058 ubi_free_vid_hdr(ubi, vidh);
1062 ubi_scan_destroy_si(si);
1063 return ERR_PTR(err);
1067 * destroy_sv - free the scanning volume information
1068 * @sv: scanning volume information
1070 * This function destroys the volume RB-tree (@sv->root) and the scanning
1071 * volume information.
1073 static void destroy_sv(struct ubi_scan_volume *sv)
1075 struct ubi_scan_leb *seb;
1076 struct rb_node *this = sv->root.rb_node;
1080 this = this->rb_left;
1081 else if (this->rb_right)
1082 this = this->rb_right;
1084 seb = rb_entry(this, struct ubi_scan_leb, u.rb);
1085 this = rb_parent(this);
1087 if (this->rb_left == &seb->u.rb)
1088 this->rb_left = NULL;
1090 this->rb_right = NULL;
1100 * ubi_scan_destroy_si - destroy scanning information.
1101 * @si: scanning information
1103 void ubi_scan_destroy_si(struct ubi_scan_info *si)
1105 struct ubi_scan_leb *seb, *seb_tmp;
1106 struct ubi_scan_volume *sv;
1109 list_for_each_entry_safe(seb, seb_tmp, &si->alien, u.list) {
1110 list_del(&seb->u.list);
1113 list_for_each_entry_safe(seb, seb_tmp, &si->erase, u.list) {
1114 list_del(&seb->u.list);
1117 list_for_each_entry_safe(seb, seb_tmp, &si->corr, u.list) {
1118 list_del(&seb->u.list);
1121 list_for_each_entry_safe(seb, seb_tmp, &si->free, u.list) {
1122 list_del(&seb->u.list);
1126 /* Destroy the volume RB-tree */
1127 rb = si->volumes.rb_node;
1131 else if (rb->rb_right)
1134 sv = rb_entry(rb, struct ubi_scan_volume, rb);
1138 if (rb->rb_left == &sv->rb)
1141 rb->rb_right = NULL;
1151 #ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
1154 * paranoid_check_si - check the scanning information.
1155 * @ubi: UBI device description object
1156 * @si: scanning information
1158 * This function returns zero if the scanning information is all right, and a
1159 * negative error code if not or if an error occurred.
1161 static int paranoid_check_si(struct ubi_device *ubi, struct ubi_scan_info *si)
1163 int pnum, err, vols_found = 0;
1164 struct rb_node *rb1, *rb2;
1165 struct ubi_scan_volume *sv;
1166 struct ubi_scan_leb *seb, *last_seb;
1170 * At first, check that scanning information is OK.
1172 ubi_rb_for_each_entry(rb1, sv, &si->volumes, rb) {
1180 ubi_err("bad is_empty flag");
1184 if (sv->vol_id < 0 || sv->highest_lnum < 0 ||
1185 sv->leb_count < 0 || sv->vol_type < 0 || sv->used_ebs < 0 ||
1186 sv->data_pad < 0 || sv->last_data_size < 0) {
1187 ubi_err("negative values");
1191 if (sv->vol_id >= UBI_MAX_VOLUMES &&
1192 sv->vol_id < UBI_INTERNAL_VOL_START) {
1193 ubi_err("bad vol_id");
1197 if (sv->vol_id > si->highest_vol_id) {
1198 ubi_err("highest_vol_id is %d, but vol_id %d is there",
1199 si->highest_vol_id, sv->vol_id);
1203 if (sv->vol_type != UBI_DYNAMIC_VOLUME &&
1204 sv->vol_type != UBI_STATIC_VOLUME) {
1205 ubi_err("bad vol_type");
1209 if (sv->data_pad > ubi->leb_size / 2) {
1210 ubi_err("bad data_pad");
1215 ubi_rb_for_each_entry(rb2, seb, &sv->root, u.rb) {
1221 if (seb->pnum < 0 || seb->ec < 0) {
1222 ubi_err("negative values");
1226 if (seb->ec < si->min_ec) {
1227 ubi_err("bad si->min_ec (%d), %d found",
1228 si->min_ec, seb->ec);
1232 if (seb->ec > si->max_ec) {
1233 ubi_err("bad si->max_ec (%d), %d found",
1234 si->max_ec, seb->ec);
1238 if (seb->pnum >= ubi->peb_count) {
1239 ubi_err("too high PEB number %d, total PEBs %d",
1240 seb->pnum, ubi->peb_count);
1244 if (sv->vol_type == UBI_STATIC_VOLUME) {
1245 if (seb->lnum >= sv->used_ebs) {
1246 ubi_err("bad lnum or used_ebs");
1250 if (sv->used_ebs != 0) {
1251 ubi_err("non-zero used_ebs");
1256 if (seb->lnum > sv->highest_lnum) {
1257 ubi_err("incorrect highest_lnum or lnum");
1262 if (sv->leb_count != leb_count) {
1263 ubi_err("bad leb_count, %d objects in the tree",
1273 if (seb->lnum != sv->highest_lnum) {
1274 ubi_err("bad highest_lnum");
1279 if (vols_found != si->vols_found) {
1280 ubi_err("bad si->vols_found %d, should be %d",
1281 si->vols_found, vols_found);
1285 /* Check that scanning information is correct */
1286 ubi_rb_for_each_entry(rb1, sv, &si->volumes, rb) {
1288 ubi_rb_for_each_entry(rb2, seb, &sv->root, u.rb) {
1295 err = ubi_io_read_vid_hdr(ubi, seb->pnum, vidh, 1);
1296 if (err && err != UBI_IO_BITFLIPS) {
1297 ubi_err("VID header is not OK (%d)", err);
1303 vol_type = vidh->vol_type == UBI_VID_DYNAMIC ?
1304 UBI_DYNAMIC_VOLUME : UBI_STATIC_VOLUME;
1305 if (sv->vol_type != vol_type) {
1306 ubi_err("bad vol_type");
1310 if (seb->sqnum != be64_to_cpu(vidh->sqnum)) {
1311 ubi_err("bad sqnum %llu", seb->sqnum);
1315 if (sv->vol_id != be32_to_cpu(vidh->vol_id)) {
1316 ubi_err("bad vol_id %d", sv->vol_id);
1320 if (sv->compat != vidh->compat) {
1321 ubi_err("bad compat %d", vidh->compat);
1325 if (seb->lnum != be32_to_cpu(vidh->lnum)) {
1326 ubi_err("bad lnum %d", seb->lnum);
1330 if (sv->used_ebs != be32_to_cpu(vidh->used_ebs)) {
1331 ubi_err("bad used_ebs %d", sv->used_ebs);
1335 if (sv->data_pad != be32_to_cpu(vidh->data_pad)) {
1336 ubi_err("bad data_pad %d", sv->data_pad);
1344 if (sv->highest_lnum != be32_to_cpu(vidh->lnum)) {
1345 ubi_err("bad highest_lnum %d", sv->highest_lnum);
1349 if (sv->last_data_size != be32_to_cpu(vidh->data_size)) {
1350 ubi_err("bad last_data_size %d", sv->last_data_size);
1356 * Make sure that all the physical eraseblocks are in one of the lists
1359 buf = kzalloc(ubi->peb_count, GFP_KERNEL);
1363 for (pnum = 0; pnum < ubi->peb_count; pnum++) {
1364 err = ubi_io_is_bad(ubi, pnum);
1372 ubi_rb_for_each_entry(rb1, sv, &si->volumes, rb)
1373 ubi_rb_for_each_entry(rb2, seb, &sv->root, u.rb)
1376 list_for_each_entry(seb, &si->free, u.list)
1379 list_for_each_entry(seb, &si->corr, u.list)
1382 list_for_each_entry(seb, &si->erase, u.list)
1385 list_for_each_entry(seb, &si->alien, u.list)
1389 for (pnum = 0; pnum < ubi->peb_count; pnum++)
1391 ubi_err("PEB %d is not referred", pnum);
1401 ubi_err("bad scanning information about LEB %d", seb->lnum);
1402 ubi_dbg_dump_seb(seb, 0);
1403 ubi_dbg_dump_sv(sv);
1407 ubi_err("bad scanning information about volume %d", sv->vol_id);
1408 ubi_dbg_dump_sv(sv);
1412 ubi_err("bad scanning information about volume %d", sv->vol_id);
1413 ubi_dbg_dump_sv(sv);
1414 ubi_dbg_dump_vid_hdr(vidh);
1417 ubi_dbg_dump_stack();
1421 #endif /* CONFIG_MTD_UBI_DEBUG_PARANOID */