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/crc32.h>
45 #include <linux/math64.h>
48 #ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
49 static int paranoid_check_si(struct ubi_device *ubi, struct ubi_scan_info *si);
51 #define paranoid_check_si(ubi, si) 0
54 /* Temporary variables used during scanning */
55 static struct ubi_ec_hdr *ech;
56 static struct ubi_vid_hdr *vidh;
59 * add_to_list - add physical eraseblock to a list.
60 * @si: scanning information
61 * @pnum: physical eraseblock number to add
62 * @ec: erase counter of the physical eraseblock
63 * @list: the list to add to
65 * This function adds physical eraseblock @pnum to free, erase, corrupted or
66 * alien lists. Returns zero in case of success and a negative error code in
69 static int add_to_list(struct ubi_scan_info *si, int pnum, int ec,
70 struct list_head *list)
72 struct ubi_scan_leb *seb;
74 if (list == &si->free)
75 dbg_bld("add to free: PEB %d, EC %d", pnum, ec);
76 else if (list == &si->erase)
77 dbg_bld("add to erase: PEB %d, EC %d", pnum, ec);
78 else if (list == &si->corr) {
79 dbg_bld("add to corrupted: PEB %d, EC %d", pnum, ec);
81 } else if (list == &si->alien)
82 dbg_bld("add to alien: PEB %d, EC %d", pnum, ec);
86 seb = kmalloc(sizeof(struct ubi_scan_leb), GFP_KERNEL);
92 list_add_tail(&seb->u.list, list);
97 * validate_vid_hdr - check volume identifier header.
98 * @vid_hdr: the volume identifier header to check
99 * @sv: information about the volume this logical eraseblock belongs to
100 * @pnum: physical eraseblock number the VID header came from
102 * This function checks that data stored in @vid_hdr is consistent. Returns
103 * non-zero if an inconsistency was found and zero if not.
105 * Note, UBI does sanity check of everything it reads from the flash media.
106 * Most of the checks are done in the I/O sub-system. Here we check that the
107 * information in the VID header is consistent to the information in other VID
108 * headers of the same volume.
110 static int validate_vid_hdr(const struct ubi_vid_hdr *vid_hdr,
111 const struct ubi_scan_volume *sv, int pnum)
113 int vol_type = vid_hdr->vol_type;
114 int vol_id = be32_to_cpu(vid_hdr->vol_id);
115 int used_ebs = be32_to_cpu(vid_hdr->used_ebs);
116 int data_pad = be32_to_cpu(vid_hdr->data_pad);
118 if (sv->leb_count != 0) {
122 * This is not the first logical eraseblock belonging to this
123 * volume. Ensure that the data in its VID header is consistent
124 * to the data in previous logical eraseblock headers.
127 if (vol_id != sv->vol_id) {
128 dbg_err("inconsistent vol_id");
132 if (sv->vol_type == UBI_STATIC_VOLUME)
133 sv_vol_type = UBI_VID_STATIC;
135 sv_vol_type = UBI_VID_DYNAMIC;
137 if (vol_type != sv_vol_type) {
138 dbg_err("inconsistent vol_type");
142 if (used_ebs != sv->used_ebs) {
143 dbg_err("inconsistent used_ebs");
147 if (data_pad != sv->data_pad) {
148 dbg_err("inconsistent data_pad");
156 ubi_err("inconsistent VID header at PEB %d", pnum);
157 ubi_dbg_dump_vid_hdr(vid_hdr);
163 * add_volume - add volume to the scanning information.
164 * @si: scanning information
165 * @vol_id: ID of the volume to add
166 * @pnum: physical eraseblock number
167 * @vid_hdr: volume identifier header
169 * If the volume corresponding to the @vid_hdr logical eraseblock is already
170 * present in the scanning information, this function does nothing. Otherwise
171 * it adds corresponding volume to the scanning information. Returns a pointer
172 * to the scanning volume object in case of success and a negative error code
173 * in case of failure.
175 static struct ubi_scan_volume *add_volume(struct ubi_scan_info *si, int vol_id,
177 const struct ubi_vid_hdr *vid_hdr)
179 struct ubi_scan_volume *sv;
180 struct rb_node **p = &si->volumes.rb_node, *parent = NULL;
182 ubi_assert(vol_id == be32_to_cpu(vid_hdr->vol_id));
184 /* Walk the volume RB-tree to look if this volume is already present */
187 sv = rb_entry(parent, struct ubi_scan_volume, rb);
189 if (vol_id == sv->vol_id)
192 if (vol_id > sv->vol_id)
198 /* The volume is absent - add it */
199 sv = kmalloc(sizeof(struct ubi_scan_volume), GFP_KERNEL);
201 return ERR_PTR(-ENOMEM);
203 sv->highest_lnum = sv->leb_count = 0;
206 sv->used_ebs = be32_to_cpu(vid_hdr->used_ebs);
207 sv->data_pad = be32_to_cpu(vid_hdr->data_pad);
208 sv->compat = vid_hdr->compat;
209 sv->vol_type = vid_hdr->vol_type == UBI_VID_DYNAMIC ? UBI_DYNAMIC_VOLUME
211 if (vol_id > si->highest_vol_id)
212 si->highest_vol_id = vol_id;
214 rb_link_node(&sv->rb, parent, p);
215 rb_insert_color(&sv->rb, &si->volumes);
217 dbg_bld("added volume %d", vol_id);
222 * compare_lebs - find out which logical eraseblock is newer.
223 * @ubi: UBI device description object
224 * @seb: first logical eraseblock to compare
225 * @pnum: physical eraseblock number of the second logical eraseblock to
227 * @vid_hdr: volume identifier header of the second logical eraseblock
229 * This function compares 2 copies of a LEB and informs which one is newer. In
230 * case of success this function returns a positive value, in case of failure, a
231 * negative error code is returned. The success return codes use the following
233 * o bit 0 is cleared: the first PEB (described by @seb) is newer then the
234 * second PEB (described by @pnum and @vid_hdr);
235 * o bit 0 is set: the second PEB is newer;
236 * o bit 1 is cleared: no bit-flips were detected in the newer LEB;
237 * o bit 1 is set: bit-flips were detected in the newer LEB;
238 * o bit 2 is cleared: the older LEB is not corrupted;
239 * o bit 2 is set: the older LEB is corrupted.
241 static int compare_lebs(struct ubi_device *ubi, const struct ubi_scan_leb *seb,
242 int pnum, const struct ubi_vid_hdr *vid_hdr)
245 int len, err, second_is_newer, bitflips = 0, corrupted = 0;
246 uint32_t data_crc, crc;
247 struct ubi_vid_hdr *vh = NULL;
248 unsigned long long sqnum2 = be64_to_cpu(vid_hdr->sqnum);
250 if (sqnum2 == seb->sqnum) {
252 * This must be a really ancient UBI image which has been
253 * created before sequence numbers support has been added. At
254 * that times we used 32-bit LEB versions stored in logical
255 * eraseblocks. That was before UBI got into mainline. We do not
256 * support these images anymore. Well, those images will work
257 * still work, but only if no unclean reboots happened.
259 ubi_err("unsupported on-flash UBI format\n");
263 /* Obviously the LEB with lower sequence counter is older */
264 second_is_newer = !!(sqnum2 > seb->sqnum);
267 * Now we know which copy is newer. If the copy flag of the PEB with
268 * newer version is not set, then we just return, otherwise we have to
269 * check data CRC. For the second PEB we already have the VID header,
270 * for the first one - we'll need to re-read it from flash.
272 * Note: this may be optimized so that we wouldn't read twice.
275 if (second_is_newer) {
276 if (!vid_hdr->copy_flag) {
277 /* It is not a copy, so it is newer */
278 dbg_bld("second PEB %d is newer, copy_flag is unset",
285 vh = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
289 err = ubi_io_read_vid_hdr(ubi, pnum, vh, 0);
291 if (err == UBI_IO_BITFLIPS)
294 dbg_err("VID of PEB %d header is bad, but it "
295 "was OK earlier", pnum);
303 if (!vh->copy_flag) {
304 /* It is not a copy, so it is newer */
305 dbg_bld("first PEB %d is newer, copy_flag is unset",
314 /* Read the data of the copy and check the CRC */
316 len = be32_to_cpu(vid_hdr->data_size);
323 err = ubi_io_read_data(ubi, buf, pnum, 0, len);
324 if (err && err != UBI_IO_BITFLIPS && err != -EBADMSG)
327 data_crc = be32_to_cpu(vid_hdr->data_crc);
328 crc = crc32(UBI_CRC32_INIT, buf, len);
329 if (crc != data_crc) {
330 dbg_bld("PEB %d CRC error: calculated %#08x, must be %#08x",
331 pnum, crc, data_crc);
334 second_is_newer = !second_is_newer;
336 dbg_bld("PEB %d CRC is OK", pnum);
341 ubi_free_vid_hdr(ubi, vh);
344 dbg_bld("second PEB %d is newer, copy_flag is set", pnum);
346 dbg_bld("first PEB %d is newer, copy_flag is set", pnum);
348 return second_is_newer | (bitflips << 1) | (corrupted << 2);
353 ubi_free_vid_hdr(ubi, vh);
358 * ubi_scan_add_used - add physical eraseblock to the scanning information.
359 * @ubi: UBI device description object
360 * @si: scanning information
361 * @pnum: the physical eraseblock number
363 * @vid_hdr: the volume identifier header
364 * @bitflips: if bit-flips were detected when this physical eraseblock was read
366 * This function adds information about a used physical eraseblock to the
367 * 'used' tree of the corresponding volume. The function is rather complex
368 * because it has to handle cases when this is not the first physical
369 * eraseblock belonging to the same logical eraseblock, and the newer one has
370 * to be picked, while the older one has to be dropped. This function returns
371 * zero in case of success and a negative error code in case of failure.
373 int ubi_scan_add_used(struct ubi_device *ubi, struct ubi_scan_info *si,
374 int pnum, int ec, const struct ubi_vid_hdr *vid_hdr,
377 int err, vol_id, lnum;
378 unsigned long long sqnum;
379 struct ubi_scan_volume *sv;
380 struct ubi_scan_leb *seb;
381 struct rb_node **p, *parent = NULL;
383 vol_id = be32_to_cpu(vid_hdr->vol_id);
384 lnum = be32_to_cpu(vid_hdr->lnum);
385 sqnum = be64_to_cpu(vid_hdr->sqnum);
387 dbg_bld("PEB %d, LEB %d:%d, EC %d, sqnum %llu, bitflips %d",
388 pnum, vol_id, lnum, ec, sqnum, bitflips);
390 sv = add_volume(si, vol_id, pnum, vid_hdr);
394 if (si->max_sqnum < sqnum)
395 si->max_sqnum = sqnum;
398 * Walk the RB-tree of logical eraseblocks of volume @vol_id to look
399 * if this is the first instance of this logical eraseblock or not.
401 p = &sv->root.rb_node;
406 seb = rb_entry(parent, struct ubi_scan_leb, u.rb);
407 if (lnum != seb->lnum) {
408 if (lnum < seb->lnum)
416 * There is already a physical eraseblock describing the same
417 * logical eraseblock present.
420 dbg_bld("this LEB already exists: PEB %d, sqnum %llu, "
421 "EC %d", seb->pnum, seb->sqnum, seb->ec);
424 * Make sure that the logical eraseblocks have different
425 * sequence numbers. Otherwise the image is bad.
427 * However, if the sequence number is zero, we assume it must
428 * be an ancient UBI image from the era when UBI did not have
429 * sequence numbers. We still can attach these images, unless
430 * there is a need to distinguish between old and new
431 * eraseblocks, in which case we'll refuse the image in
432 * 'compare_lebs()'. In other words, we attach old clean
433 * images, but refuse attaching old images with duplicated
434 * logical eraseblocks because there was an unclean reboot.
436 if (seb->sqnum == sqnum && sqnum != 0) {
437 ubi_err("two LEBs with same sequence number %llu",
439 ubi_dbg_dump_seb(seb, 0);
440 ubi_dbg_dump_vid_hdr(vid_hdr);
445 * Now we have to drop the older one and preserve the newer
448 cmp_res = compare_lebs(ubi, seb, pnum, vid_hdr);
454 * This logical eraseblock is newer then the one
457 err = validate_vid_hdr(vid_hdr, sv, pnum);
462 err = add_to_list(si, seb->pnum, seb->ec,
465 err = add_to_list(si, seb->pnum, seb->ec,
472 seb->scrub = ((cmp_res & 2) || bitflips);
475 if (sv->highest_lnum == lnum)
477 be32_to_cpu(vid_hdr->data_size);
482 * This logical eraseblock is older than the one found
486 return add_to_list(si, pnum, ec, &si->corr);
488 return add_to_list(si, pnum, ec, &si->erase);
493 * We've met this logical eraseblock for the first time, add it to the
494 * scanning information.
497 err = validate_vid_hdr(vid_hdr, sv, pnum);
501 seb = kmalloc(sizeof(struct ubi_scan_leb), GFP_KERNEL);
509 seb->scrub = bitflips;
511 if (sv->highest_lnum <= lnum) {
512 sv->highest_lnum = lnum;
513 sv->last_data_size = be32_to_cpu(vid_hdr->data_size);
517 rb_link_node(&seb->u.rb, parent, p);
518 rb_insert_color(&seb->u.rb, &sv->root);
523 * ubi_scan_find_sv - find volume in the scanning information.
524 * @si: scanning information
525 * @vol_id: the requested volume ID
527 * This function returns a pointer to the volume description or %NULL if there
528 * are no data about this volume in the scanning information.
530 struct ubi_scan_volume *ubi_scan_find_sv(const struct ubi_scan_info *si,
533 struct ubi_scan_volume *sv;
534 struct rb_node *p = si->volumes.rb_node;
537 sv = rb_entry(p, struct ubi_scan_volume, rb);
539 if (vol_id == sv->vol_id)
542 if (vol_id > sv->vol_id)
552 * ubi_scan_find_seb - find LEB in the volume scanning information.
553 * @sv: a pointer to the volume scanning information
554 * @lnum: the requested logical eraseblock
556 * This function returns a pointer to the scanning logical eraseblock or %NULL
557 * if there are no data about it in the scanning volume information.
559 struct ubi_scan_leb *ubi_scan_find_seb(const struct ubi_scan_volume *sv,
562 struct ubi_scan_leb *seb;
563 struct rb_node *p = sv->root.rb_node;
566 seb = rb_entry(p, struct ubi_scan_leb, u.rb);
568 if (lnum == seb->lnum)
571 if (lnum > seb->lnum)
581 * ubi_scan_rm_volume - delete scanning information about a volume.
582 * @si: scanning information
583 * @sv: the volume scanning information to delete
585 void ubi_scan_rm_volume(struct ubi_scan_info *si, struct ubi_scan_volume *sv)
588 struct ubi_scan_leb *seb;
590 dbg_bld("remove scanning information about volume %d", sv->vol_id);
592 while ((rb = rb_first(&sv->root))) {
593 seb = rb_entry(rb, struct ubi_scan_leb, u.rb);
594 rb_erase(&seb->u.rb, &sv->root);
595 list_add_tail(&seb->u.list, &si->erase);
598 rb_erase(&sv->rb, &si->volumes);
604 * ubi_scan_erase_peb - erase a physical eraseblock.
605 * @ubi: UBI device description object
606 * @si: scanning information
607 * @pnum: physical eraseblock number to erase;
608 * @ec: erase counter value to write (%UBI_SCAN_UNKNOWN_EC if it is unknown)
610 * This function erases physical eraseblock 'pnum', and writes the erase
611 * counter header to it. This function should only be used on UBI device
612 * initialization stages, when the EBA sub-system had not been yet initialized.
613 * This function returns zero in case of success and a negative error code in
616 int ubi_scan_erase_peb(struct ubi_device *ubi, const struct ubi_scan_info *si,
620 struct ubi_ec_hdr *ec_hdr;
622 if ((long long)ec >= UBI_MAX_ERASECOUNTER) {
624 * Erase counter overflow. Upgrade UBI and use 64-bit
625 * erase counters internally.
627 ubi_err("erase counter overflow at PEB %d, EC %d", pnum, ec);
631 ec_hdr = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
635 ec_hdr->ec = cpu_to_be64(ec);
637 err = ubi_io_sync_erase(ubi, pnum, 0);
641 err = ubi_io_write_ec_hdr(ubi, pnum, ec_hdr);
649 * ubi_scan_get_free_peb - get a free physical eraseblock.
650 * @ubi: UBI device description object
651 * @si: scanning information
653 * This function returns a free physical eraseblock. It is supposed to be
654 * called on the UBI initialization stages when the wear-leveling sub-system is
655 * not initialized yet. This function picks a physical eraseblocks from one of
656 * the lists, writes the EC header if it is needed, and removes it from the
659 * This function returns scanning physical eraseblock information in case of
660 * success and an error code in case of failure.
662 struct ubi_scan_leb *ubi_scan_get_free_peb(struct ubi_device *ubi,
663 struct ubi_scan_info *si)
666 struct ubi_scan_leb *seb;
668 if (!list_empty(&si->free)) {
669 seb = list_entry(si->free.next, struct ubi_scan_leb, u.list);
670 list_del(&seb->u.list);
671 dbg_bld("return free PEB %d, EC %d", seb->pnum, seb->ec);
675 for (i = 0; i < 2; i++) {
676 struct list_head *head;
677 struct ubi_scan_leb *tmp_seb;
685 * We try to erase the first physical eraseblock from the @head
686 * list and pick it if we succeed, or try to erase the
687 * next one if not. And so forth. We don't want to take care
688 * about bad eraseblocks here - they'll be handled later.
690 list_for_each_entry_safe(seb, tmp_seb, head, u.list) {
691 if (seb->ec == UBI_SCAN_UNKNOWN_EC)
692 seb->ec = si->mean_ec;
694 err = ubi_scan_erase_peb(ubi, si, seb->pnum, seb->ec+1);
699 list_del(&seb->u.list);
700 dbg_bld("return PEB %d, EC %d", seb->pnum, seb->ec);
705 ubi_err("no eraseblocks found");
706 return ERR_PTR(-ENOSPC);
710 * process_eb - read, check UBI headers, and add them to scanning information.
711 * @ubi: UBI device description object
712 * @si: scanning information
713 * @pnum: the physical eraseblock number
715 * This function returns a zero if the physical eraseblock was successfully
716 * handled and a negative error code in case of failure.
718 static int process_eb(struct ubi_device *ubi, struct ubi_scan_info *si,
721 long long uninitialized_var(ec);
722 int err, bitflips = 0, vol_id, ec_corr = 0;
724 dbg_bld("scan PEB %d", pnum);
726 /* Skip bad physical eraseblocks */
727 err = ubi_io_is_bad(ubi, pnum);
732 * FIXME: this is actually duty of the I/O sub-system to
733 * initialize this, but MTD does not provide enough
736 si->bad_peb_count += 1;
740 err = ubi_io_read_ec_hdr(ubi, pnum, ech, 0);
743 else if (err == UBI_IO_BITFLIPS)
745 else if (err == UBI_IO_PEB_EMPTY)
746 return add_to_list(si, pnum, UBI_SCAN_UNKNOWN_EC, &si->erase);
747 else if (err == UBI_IO_BAD_EC_HDR) {
749 * We have to also look at the VID header, possibly it is not
750 * corrupted. Set %bitflips flag in order to make this PEB be
751 * moved and EC be re-created.
754 ec = UBI_SCAN_UNKNOWN_EC;
763 /* Make sure UBI version is OK */
764 if (ech->version != UBI_VERSION) {
765 ubi_err("this UBI version is %d, image version is %d",
766 UBI_VERSION, (int)ech->version);
770 ec = be64_to_cpu(ech->ec);
771 if (ec > UBI_MAX_ERASECOUNTER) {
773 * Erase counter overflow. The EC headers have 64 bits
774 * reserved, but we anyway make use of only 31 bit
775 * values, as this seems to be enough for any existing
776 * flash. Upgrade UBI and use 64-bit erase counters
779 ubi_err("erase counter overflow, max is %d",
780 UBI_MAX_ERASECOUNTER);
781 ubi_dbg_dump_ec_hdr(ech);
786 * Make sure that all PEBs have the same image sequence number.
787 * This allows us to detect situations when users flash UBI
788 * images incorrectly, so that the flash has the new UBI image
789 * and leftovers from the old one. This feature was added
790 * relatively recently, and the sequence number was always
791 * zero, because old UBI implementations always set it to zero.
792 * For this reasons, we do not panic if some PEBs have zero
793 * sequence number, while other PEBs have non-zero sequence
796 image_seq = be32_to_cpu(ech->image_seq);
797 if (!si->image_seq_set) {
798 ubi->image_seq = image_seq;
799 si->image_seq_set = 1;
800 } else if (ubi->image_seq && ubi->image_seq != image_seq) {
801 ubi_err("bad image sequence number %d in PEB %d, "
802 "expected %d", image_seq, pnum, ubi->image_seq);
803 ubi_dbg_dump_ec_hdr(ech);
809 /* OK, we've done with the EC header, let's look at the VID header */
811 err = ubi_io_read_vid_hdr(ubi, pnum, vidh, 0);
814 else if (err == UBI_IO_BITFLIPS)
816 else if (err == UBI_IO_BAD_VID_HDR ||
817 (err == UBI_IO_PEB_FREE && ec_corr)) {
818 /* VID header is corrupted */
819 err = add_to_list(si, pnum, ec, &si->corr);
823 } else if (err == UBI_IO_PEB_FREE) {
824 /* No VID header - the physical eraseblock is free */
825 err = add_to_list(si, pnum, ec, &si->free);
831 vol_id = be32_to_cpu(vidh->vol_id);
832 if (vol_id > UBI_MAX_VOLUMES && vol_id != UBI_LAYOUT_VOLUME_ID) {
833 int lnum = be32_to_cpu(vidh->lnum);
835 /* Unsupported internal volume */
836 switch (vidh->compat) {
837 case UBI_COMPAT_DELETE:
838 ubi_msg("\"delete\" compatible internal volume %d:%d"
839 " found, remove it", vol_id, lnum);
840 err = add_to_list(si, pnum, ec, &si->corr);
846 ubi_msg("read-only compatible internal volume %d:%d"
847 " found, switch to read-only mode",
852 case UBI_COMPAT_PRESERVE:
853 ubi_msg("\"preserve\" compatible internal volume %d:%d"
854 " found", vol_id, lnum);
855 err = add_to_list(si, pnum, ec, &si->alien);
858 si->alien_peb_count += 1;
861 case UBI_COMPAT_REJECT:
862 ubi_err("incompatible internal volume %d:%d found",
869 ubi_warn("valid VID header but corrupted EC header at PEB %d",
871 err = ubi_scan_add_used(ubi, si, pnum, ec, vidh, bitflips);
889 * ubi_scan - scan an MTD device.
890 * @ubi: UBI device description object
892 * This function does full scanning of an MTD device and returns complete
893 * information about it. In case of failure, an error code is returned.
895 struct ubi_scan_info *ubi_scan(struct ubi_device *ubi)
898 struct rb_node *rb1, *rb2;
899 struct ubi_scan_volume *sv;
900 struct ubi_scan_leb *seb;
901 struct ubi_scan_info *si;
903 si = kzalloc(sizeof(struct ubi_scan_info), GFP_KERNEL);
905 return ERR_PTR(-ENOMEM);
907 INIT_LIST_HEAD(&si->corr);
908 INIT_LIST_HEAD(&si->free);
909 INIT_LIST_HEAD(&si->erase);
910 INIT_LIST_HEAD(&si->alien);
911 si->volumes = RB_ROOT;
915 ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
919 vidh = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
923 for (pnum = 0; pnum < ubi->peb_count; pnum++) {
926 dbg_gen("process PEB %d", pnum);
927 err = process_eb(ubi, si, pnum);
932 dbg_msg("scanning is finished");
934 /* Calculate mean erase counter */
936 si->mean_ec = div_u64(si->ec_sum, si->ec_count);
939 ubi_msg("empty MTD device detected");
942 * Few corrupted PEBs are not a problem and may be just a result of
943 * unclean reboots. However, many of them may indicate some problems
944 * with the flash HW or driver. Print a warning in this case.
946 if (si->corr_count >= 8 || si->corr_count >= ubi->peb_count / 4) {
947 ubi_warn("%d PEBs are corrupted", si->corr_count);
948 printk(KERN_WARNING "corrupted PEBs are:");
949 list_for_each_entry(seb, &si->corr, u.list)
950 printk(KERN_CONT " %d", seb->pnum);
951 printk(KERN_CONT "\n");
955 * In case of unknown erase counter we use the mean erase counter
958 ubi_rb_for_each_entry(rb1, sv, &si->volumes, rb) {
959 ubi_rb_for_each_entry(rb2, seb, &sv->root, u.rb)
960 if (seb->ec == UBI_SCAN_UNKNOWN_EC)
961 seb->ec = si->mean_ec;
964 list_for_each_entry(seb, &si->free, u.list) {
965 if (seb->ec == UBI_SCAN_UNKNOWN_EC)
966 seb->ec = si->mean_ec;
969 list_for_each_entry(seb, &si->corr, u.list)
970 if (seb->ec == UBI_SCAN_UNKNOWN_EC)
971 seb->ec = si->mean_ec;
973 list_for_each_entry(seb, &si->erase, u.list)
974 if (seb->ec == UBI_SCAN_UNKNOWN_EC)
975 seb->ec = si->mean_ec;
977 err = paranoid_check_si(ubi, si);
984 ubi_free_vid_hdr(ubi, vidh);
990 ubi_free_vid_hdr(ubi, vidh);
994 ubi_scan_destroy_si(si);
999 * destroy_sv - free the scanning volume information
1000 * @sv: scanning volume information
1002 * This function destroys the volume RB-tree (@sv->root) and the scanning
1003 * volume information.
1005 static void destroy_sv(struct ubi_scan_volume *sv)
1007 struct ubi_scan_leb *seb;
1008 struct rb_node *this = sv->root.rb_node;
1012 this = this->rb_left;
1013 else if (this->rb_right)
1014 this = this->rb_right;
1016 seb = rb_entry(this, struct ubi_scan_leb, u.rb);
1017 this = rb_parent(this);
1019 if (this->rb_left == &seb->u.rb)
1020 this->rb_left = NULL;
1022 this->rb_right = NULL;
1032 * ubi_scan_destroy_si - destroy scanning information.
1033 * @si: scanning information
1035 void ubi_scan_destroy_si(struct ubi_scan_info *si)
1037 struct ubi_scan_leb *seb, *seb_tmp;
1038 struct ubi_scan_volume *sv;
1041 list_for_each_entry_safe(seb, seb_tmp, &si->alien, u.list) {
1042 list_del(&seb->u.list);
1045 list_for_each_entry_safe(seb, seb_tmp, &si->erase, u.list) {
1046 list_del(&seb->u.list);
1049 list_for_each_entry_safe(seb, seb_tmp, &si->corr, u.list) {
1050 list_del(&seb->u.list);
1053 list_for_each_entry_safe(seb, seb_tmp, &si->free, u.list) {
1054 list_del(&seb->u.list);
1058 /* Destroy the volume RB-tree */
1059 rb = si->volumes.rb_node;
1063 else if (rb->rb_right)
1066 sv = rb_entry(rb, struct ubi_scan_volume, rb);
1070 if (rb->rb_left == &sv->rb)
1073 rb->rb_right = NULL;
1083 #ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
1086 * paranoid_check_si - check the scanning information.
1087 * @ubi: UBI device description object
1088 * @si: scanning information
1090 * This function returns zero if the scanning information is all right, %1 if
1091 * not and a negative error code if an error occurred.
1093 static int paranoid_check_si(struct ubi_device *ubi, struct ubi_scan_info *si)
1095 int pnum, err, vols_found = 0;
1096 struct rb_node *rb1, *rb2;
1097 struct ubi_scan_volume *sv;
1098 struct ubi_scan_leb *seb, *last_seb;
1102 * At first, check that scanning information is OK.
1104 ubi_rb_for_each_entry(rb1, sv, &si->volumes, rb) {
1112 ubi_err("bad is_empty flag");
1116 if (sv->vol_id < 0 || sv->highest_lnum < 0 ||
1117 sv->leb_count < 0 || sv->vol_type < 0 || sv->used_ebs < 0 ||
1118 sv->data_pad < 0 || sv->last_data_size < 0) {
1119 ubi_err("negative values");
1123 if (sv->vol_id >= UBI_MAX_VOLUMES &&
1124 sv->vol_id < UBI_INTERNAL_VOL_START) {
1125 ubi_err("bad vol_id");
1129 if (sv->vol_id > si->highest_vol_id) {
1130 ubi_err("highest_vol_id is %d, but vol_id %d is there",
1131 si->highest_vol_id, sv->vol_id);
1135 if (sv->vol_type != UBI_DYNAMIC_VOLUME &&
1136 sv->vol_type != UBI_STATIC_VOLUME) {
1137 ubi_err("bad vol_type");
1141 if (sv->data_pad > ubi->leb_size / 2) {
1142 ubi_err("bad data_pad");
1147 ubi_rb_for_each_entry(rb2, seb, &sv->root, u.rb) {
1153 if (seb->pnum < 0 || seb->ec < 0) {
1154 ubi_err("negative values");
1158 if (seb->ec < si->min_ec) {
1159 ubi_err("bad si->min_ec (%d), %d found",
1160 si->min_ec, seb->ec);
1164 if (seb->ec > si->max_ec) {
1165 ubi_err("bad si->max_ec (%d), %d found",
1166 si->max_ec, seb->ec);
1170 if (seb->pnum >= ubi->peb_count) {
1171 ubi_err("too high PEB number %d, total PEBs %d",
1172 seb->pnum, ubi->peb_count);
1176 if (sv->vol_type == UBI_STATIC_VOLUME) {
1177 if (seb->lnum >= sv->used_ebs) {
1178 ubi_err("bad lnum or used_ebs");
1182 if (sv->used_ebs != 0) {
1183 ubi_err("non-zero used_ebs");
1188 if (seb->lnum > sv->highest_lnum) {
1189 ubi_err("incorrect highest_lnum or lnum");
1194 if (sv->leb_count != leb_count) {
1195 ubi_err("bad leb_count, %d objects in the tree",
1205 if (seb->lnum != sv->highest_lnum) {
1206 ubi_err("bad highest_lnum");
1211 if (vols_found != si->vols_found) {
1212 ubi_err("bad si->vols_found %d, should be %d",
1213 si->vols_found, vols_found);
1217 /* Check that scanning information is correct */
1218 ubi_rb_for_each_entry(rb1, sv, &si->volumes, rb) {
1220 ubi_rb_for_each_entry(rb2, seb, &sv->root, u.rb) {
1227 err = ubi_io_read_vid_hdr(ubi, seb->pnum, vidh, 1);
1228 if (err && err != UBI_IO_BITFLIPS) {
1229 ubi_err("VID header is not OK (%d)", err);
1235 vol_type = vidh->vol_type == UBI_VID_DYNAMIC ?
1236 UBI_DYNAMIC_VOLUME : UBI_STATIC_VOLUME;
1237 if (sv->vol_type != vol_type) {
1238 ubi_err("bad vol_type");
1242 if (seb->sqnum != be64_to_cpu(vidh->sqnum)) {
1243 ubi_err("bad sqnum %llu", seb->sqnum);
1247 if (sv->vol_id != be32_to_cpu(vidh->vol_id)) {
1248 ubi_err("bad vol_id %d", sv->vol_id);
1252 if (sv->compat != vidh->compat) {
1253 ubi_err("bad compat %d", vidh->compat);
1257 if (seb->lnum != be32_to_cpu(vidh->lnum)) {
1258 ubi_err("bad lnum %d", seb->lnum);
1262 if (sv->used_ebs != be32_to_cpu(vidh->used_ebs)) {
1263 ubi_err("bad used_ebs %d", sv->used_ebs);
1267 if (sv->data_pad != be32_to_cpu(vidh->data_pad)) {
1268 ubi_err("bad data_pad %d", sv->data_pad);
1276 if (sv->highest_lnum != be32_to_cpu(vidh->lnum)) {
1277 ubi_err("bad highest_lnum %d", sv->highest_lnum);
1281 if (sv->last_data_size != be32_to_cpu(vidh->data_size)) {
1282 ubi_err("bad last_data_size %d", sv->last_data_size);
1288 * Make sure that all the physical eraseblocks are in one of the lists
1291 buf = kzalloc(ubi->peb_count, GFP_KERNEL);
1295 for (pnum = 0; pnum < ubi->peb_count; pnum++) {
1296 err = ubi_io_is_bad(ubi, pnum);
1304 ubi_rb_for_each_entry(rb1, sv, &si->volumes, rb)
1305 ubi_rb_for_each_entry(rb2, seb, &sv->root, u.rb)
1308 list_for_each_entry(seb, &si->free, u.list)
1311 list_for_each_entry(seb, &si->corr, u.list)
1314 list_for_each_entry(seb, &si->erase, u.list)
1317 list_for_each_entry(seb, &si->alien, u.list)
1321 for (pnum = 0; pnum < ubi->peb_count; pnum++)
1323 ubi_err("PEB %d is not referred", pnum);
1333 ubi_err("bad scanning information about LEB %d", seb->lnum);
1334 ubi_dbg_dump_seb(seb, 0);
1335 ubi_dbg_dump_sv(sv);
1339 ubi_err("bad scanning information about volume %d", sv->vol_id);
1340 ubi_dbg_dump_sv(sv);
1344 ubi_err("bad scanning information about volume %d", sv->vol_id);
1345 ubi_dbg_dump_sv(sv);
1346 ubi_dbg_dump_vid_hdr(vidh);
1349 ubi_dbg_dump_stack();
1353 #endif /* CONFIG_MTD_UBI_DEBUG_PARANOID */