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>
49 #ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
50 static int paranoid_check_si(struct ubi_device
*ubi
, struct ubi_scan_info
*si
);
52 #define paranoid_check_si(ubi, si) 0
55 /* Temporary variables used during scanning */
56 static struct ubi_ec_hdr
*ech
;
57 static struct ubi_vid_hdr
*vidh
;
60 * add_to_list - add physical eraseblock to a list.
61 * @si: scanning information
62 * @pnum: physical eraseblock number to add
63 * @ec: erase counter of the physical eraseblock
64 * @list: the list to add to
66 * This function adds physical eraseblock @pnum to free, erase, corrupted or
67 * alien lists. Returns zero in case of success and a negative error code in
70 static int add_to_list(struct ubi_scan_info
*si
, int pnum
, int ec
,
71 struct list_head
*list
)
73 struct ubi_scan_leb
*seb
;
75 if (list
== &si
->free
) {
76 dbg_bld("add to free: PEB %d, EC %d", pnum
, ec
);
77 si
->free_peb_count
+= 1;
78 } else if (list
== &si
->erase
) {
79 dbg_bld("add to erase: PEB %d, EC %d", pnum
, ec
);
80 si
->erase_peb_count
+= 1;
81 } else if (list
== &si
->corr
) {
82 dbg_bld("add to corrupted: PEB %d, EC %d", pnum
, ec
);
83 si
->corr_peb_count
+= 1;
84 } else if (list
== &si
->alien
) {
85 dbg_bld("add to alien: PEB %d, EC %d", pnum
, ec
);
86 si
->alien_peb_count
+= 1;
90 seb
= kmalloc(sizeof(struct ubi_scan_leb
), GFP_KERNEL
);
96 list_add_tail(&seb
->u
.list
, list
);
101 * validate_vid_hdr - check volume identifier header.
102 * @vid_hdr: the volume identifier header to check
103 * @sv: information about the volume this logical eraseblock belongs to
104 * @pnum: physical eraseblock number the VID header came from
106 * This function checks that data stored in @vid_hdr is consistent. Returns
107 * non-zero if an inconsistency was found and zero if not.
109 * Note, UBI does sanity check of everything it reads from the flash media.
110 * Most of the checks are done in the I/O sub-system. Here we check that the
111 * information in the VID header is consistent to the information in other VID
112 * headers of the same volume.
114 static int validate_vid_hdr(const struct ubi_vid_hdr
*vid_hdr
,
115 const struct ubi_scan_volume
*sv
, int pnum
)
117 int vol_type
= vid_hdr
->vol_type
;
118 int vol_id
= be32_to_cpu(vid_hdr
->vol_id
);
119 int used_ebs
= be32_to_cpu(vid_hdr
->used_ebs
);
120 int data_pad
= be32_to_cpu(vid_hdr
->data_pad
);
122 if (sv
->leb_count
!= 0) {
126 * This is not the first logical eraseblock belonging to this
127 * volume. Ensure that the data in its VID header is consistent
128 * to the data in previous logical eraseblock headers.
131 if (vol_id
!= sv
->vol_id
) {
132 dbg_err("inconsistent vol_id");
136 if (sv
->vol_type
== UBI_STATIC_VOLUME
)
137 sv_vol_type
= UBI_VID_STATIC
;
139 sv_vol_type
= UBI_VID_DYNAMIC
;
141 if (vol_type
!= sv_vol_type
) {
142 dbg_err("inconsistent vol_type");
146 if (used_ebs
!= sv
->used_ebs
) {
147 dbg_err("inconsistent used_ebs");
151 if (data_pad
!= sv
->data_pad
) {
152 dbg_err("inconsistent data_pad");
160 ubi_err("inconsistent VID header at PEB %d", pnum
);
161 ubi_dbg_dump_vid_hdr(vid_hdr
);
167 * add_volume - add volume to the scanning information.
168 * @si: scanning information
169 * @vol_id: ID of the volume to add
170 * @pnum: physical eraseblock number
171 * @vid_hdr: volume identifier header
173 * If the volume corresponding to the @vid_hdr logical eraseblock is already
174 * present in the scanning information, this function does nothing. Otherwise
175 * it adds corresponding volume to the scanning information. Returns a pointer
176 * to the scanning volume object in case of success and a negative error code
177 * in case of failure.
179 static struct ubi_scan_volume
*add_volume(struct ubi_scan_info
*si
, int vol_id
,
181 const struct ubi_vid_hdr
*vid_hdr
)
183 struct ubi_scan_volume
*sv
;
184 struct rb_node
**p
= &si
->volumes
.rb_node
, *parent
= NULL
;
186 ubi_assert(vol_id
== be32_to_cpu(vid_hdr
->vol_id
));
188 /* Walk the volume RB-tree to look if this volume is already present */
191 sv
= rb_entry(parent
, struct ubi_scan_volume
, rb
);
193 if (vol_id
== sv
->vol_id
)
196 if (vol_id
> sv
->vol_id
)
202 /* The volume is absent - add it */
203 sv
= kmalloc(sizeof(struct ubi_scan_volume
), GFP_KERNEL
);
205 return ERR_PTR(-ENOMEM
);
207 sv
->highest_lnum
= sv
->leb_count
= 0;
210 sv
->used_ebs
= be32_to_cpu(vid_hdr
->used_ebs
);
211 sv
->data_pad
= be32_to_cpu(vid_hdr
->data_pad
);
212 sv
->compat
= vid_hdr
->compat
;
213 sv
->vol_type
= vid_hdr
->vol_type
== UBI_VID_DYNAMIC
? UBI_DYNAMIC_VOLUME
215 if (vol_id
> si
->highest_vol_id
)
216 si
->highest_vol_id
= vol_id
;
218 rb_link_node(&sv
->rb
, parent
, p
);
219 rb_insert_color(&sv
->rb
, &si
->volumes
);
221 dbg_bld("added volume %d", vol_id
);
226 * compare_lebs - find out which logical eraseblock is newer.
227 * @ubi: UBI device description object
228 * @seb: first logical eraseblock to compare
229 * @pnum: physical eraseblock number of the second logical eraseblock to
231 * @vid_hdr: volume identifier header of the second logical eraseblock
233 * This function compares 2 copies of a LEB and informs which one is newer. In
234 * case of success this function returns a positive value, in case of failure, a
235 * negative error code is returned. The success return codes use the following
237 * o bit 0 is cleared: the first PEB (described by @seb) is newer than the
238 * second PEB (described by @pnum and @vid_hdr);
239 * o bit 0 is set: the second PEB is newer;
240 * o bit 1 is cleared: no bit-flips were detected in the newer LEB;
241 * o bit 1 is set: bit-flips were detected in the newer LEB;
242 * o bit 2 is cleared: the older LEB is not corrupted;
243 * o bit 2 is set: the older LEB is corrupted.
245 static int compare_lebs(struct ubi_device
*ubi
, const struct ubi_scan_leb
*seb
,
246 int pnum
, const struct ubi_vid_hdr
*vid_hdr
)
249 int len
, err
, second_is_newer
, bitflips
= 0, corrupted
= 0;
250 uint32_t data_crc
, crc
;
251 struct ubi_vid_hdr
*vh
= NULL
;
252 unsigned long long sqnum2
= be64_to_cpu(vid_hdr
->sqnum
);
254 if (sqnum2
== seb
->sqnum
) {
256 * This must be a really ancient UBI image which has been
257 * created before sequence numbers support has been added. At
258 * that times we used 32-bit LEB versions stored in logical
259 * eraseblocks. That was before UBI got into mainline. We do not
260 * support these images anymore. Well, those images will work
261 * still work, but only if no unclean reboots happened.
263 ubi_err("unsupported on-flash UBI format\n");
267 /* Obviously the LEB with lower sequence counter is older */
268 second_is_newer
= !!(sqnum2
> seb
->sqnum
);
271 * Now we know which copy is newer. If the copy flag of the PEB with
272 * newer version is not set, then we just return, otherwise we have to
273 * check data CRC. For the second PEB we already have the VID header,
274 * for the first one - we'll need to re-read it from flash.
276 * Note: this may be optimized so that we wouldn't read twice.
279 if (second_is_newer
) {
280 if (!vid_hdr
->copy_flag
) {
281 /* It is not a copy, so it is newer */
282 dbg_bld("second PEB %d is newer, copy_flag is unset",
289 vh
= ubi_zalloc_vid_hdr(ubi
, GFP_KERNEL
);
293 err
= ubi_io_read_vid_hdr(ubi
, pnum
, vh
, 0);
295 if (err
== UBI_IO_BITFLIPS
)
298 dbg_err("VID of PEB %d header is bad, but it "
299 "was OK earlier", pnum
);
307 if (!vh
->copy_flag
) {
308 /* It is not a copy, so it is newer */
309 dbg_bld("first PEB %d is newer, copy_flag is unset",
318 /* Read the data of the copy and check the CRC */
320 len
= be32_to_cpu(vid_hdr
->data_size
);
327 err
= ubi_io_read_data(ubi
, buf
, pnum
, 0, len
);
328 if (err
&& err
!= UBI_IO_BITFLIPS
&& err
!= -EBADMSG
)
331 data_crc
= be32_to_cpu(vid_hdr
->data_crc
);
332 crc
= crc32(UBI_CRC32_INIT
, buf
, len
);
333 if (crc
!= data_crc
) {
334 dbg_bld("PEB %d CRC error: calculated %#08x, must be %#08x",
335 pnum
, crc
, data_crc
);
338 second_is_newer
= !second_is_newer
;
340 dbg_bld("PEB %d CRC is OK", pnum
);
345 ubi_free_vid_hdr(ubi
, vh
);
348 dbg_bld("second PEB %d is newer, copy_flag is set", pnum
);
350 dbg_bld("first PEB %d is newer, copy_flag is set", pnum
);
352 return second_is_newer
| (bitflips
<< 1) | (corrupted
<< 2);
357 ubi_free_vid_hdr(ubi
, vh
);
362 * ubi_scan_add_used - add physical eraseblock to the scanning information.
363 * @ubi: UBI device description object
364 * @si: scanning information
365 * @pnum: the physical eraseblock number
367 * @vid_hdr: the volume identifier header
368 * @bitflips: if bit-flips were detected when this physical eraseblock was read
370 * This function adds information about a used physical eraseblock to the
371 * 'used' tree of the corresponding volume. The function is rather complex
372 * because it has to handle cases when this is not the first physical
373 * eraseblock belonging to the same logical eraseblock, and the newer one has
374 * to be picked, while the older one has to be dropped. This function returns
375 * zero in case of success and a negative error code in case of failure.
377 int ubi_scan_add_used(struct ubi_device
*ubi
, struct ubi_scan_info
*si
,
378 int pnum
, int ec
, const struct ubi_vid_hdr
*vid_hdr
,
381 int err
, vol_id
, lnum
;
382 unsigned long long sqnum
;
383 struct ubi_scan_volume
*sv
;
384 struct ubi_scan_leb
*seb
;
385 struct rb_node
**p
, *parent
= NULL
;
387 vol_id
= be32_to_cpu(vid_hdr
->vol_id
);
388 lnum
= be32_to_cpu(vid_hdr
->lnum
);
389 sqnum
= be64_to_cpu(vid_hdr
->sqnum
);
391 dbg_bld("PEB %d, LEB %d:%d, EC %d, sqnum %llu, bitflips %d",
392 pnum
, vol_id
, lnum
, ec
, sqnum
, bitflips
);
394 sv
= add_volume(si
, vol_id
, pnum
, vid_hdr
);
398 if (si
->max_sqnum
< sqnum
)
399 si
->max_sqnum
= sqnum
;
402 * Walk the RB-tree of logical eraseblocks of volume @vol_id to look
403 * if this is the first instance of this logical eraseblock or not.
405 p
= &sv
->root
.rb_node
;
410 seb
= rb_entry(parent
, struct ubi_scan_leb
, u
.rb
);
411 if (lnum
!= seb
->lnum
) {
412 if (lnum
< seb
->lnum
)
420 * There is already a physical eraseblock describing the same
421 * logical eraseblock present.
424 dbg_bld("this LEB already exists: PEB %d, sqnum %llu, "
425 "EC %d", seb
->pnum
, seb
->sqnum
, seb
->ec
);
428 * Make sure that the logical eraseblocks have different
429 * sequence numbers. Otherwise the image is bad.
431 * However, if the sequence number is zero, we assume it must
432 * be an ancient UBI image from the era when UBI did not have
433 * sequence numbers. We still can attach these images, unless
434 * there is a need to distinguish between old and new
435 * eraseblocks, in which case we'll refuse the image in
436 * 'compare_lebs()'. In other words, we attach old clean
437 * images, but refuse attaching old images with duplicated
438 * logical eraseblocks because there was an unclean reboot.
440 if (seb
->sqnum
== sqnum
&& sqnum
!= 0) {
441 ubi_err("two LEBs with same sequence number %llu",
443 ubi_dbg_dump_seb(seb
, 0);
444 ubi_dbg_dump_vid_hdr(vid_hdr
);
449 * Now we have to drop the older one and preserve the newer
452 cmp_res
= compare_lebs(ubi
, seb
, pnum
, vid_hdr
);
458 * This logical eraseblock is newer than the one
461 err
= validate_vid_hdr(vid_hdr
, sv
, pnum
);
466 err
= add_to_list(si
, seb
->pnum
, seb
->ec
,
469 err
= add_to_list(si
, seb
->pnum
, seb
->ec
,
476 seb
->scrub
= ((cmp_res
& 2) || bitflips
);
479 if (sv
->highest_lnum
== lnum
)
481 be32_to_cpu(vid_hdr
->data_size
);
486 * This logical eraseblock is older than the one found
490 return add_to_list(si
, pnum
, ec
, &si
->corr
);
492 return add_to_list(si
, pnum
, ec
, &si
->erase
);
497 * We've met this logical eraseblock for the first time, add it to the
498 * scanning information.
501 err
= validate_vid_hdr(vid_hdr
, sv
, pnum
);
505 seb
= kmalloc(sizeof(struct ubi_scan_leb
), GFP_KERNEL
);
513 seb
->scrub
= bitflips
;
515 if (sv
->highest_lnum
<= lnum
) {
516 sv
->highest_lnum
= lnum
;
517 sv
->last_data_size
= be32_to_cpu(vid_hdr
->data_size
);
521 rb_link_node(&seb
->u
.rb
, parent
, p
);
522 rb_insert_color(&seb
->u
.rb
, &sv
->root
);
523 si
->used_peb_count
+= 1;
528 * ubi_scan_find_sv - find volume in the scanning information.
529 * @si: scanning information
530 * @vol_id: the requested volume ID
532 * This function returns a pointer to the volume description or %NULL if there
533 * are no data about this volume in the scanning information.
535 struct ubi_scan_volume
*ubi_scan_find_sv(const struct ubi_scan_info
*si
,
538 struct ubi_scan_volume
*sv
;
539 struct rb_node
*p
= si
->volumes
.rb_node
;
542 sv
= rb_entry(p
, struct ubi_scan_volume
, rb
);
544 if (vol_id
== sv
->vol_id
)
547 if (vol_id
> sv
->vol_id
)
557 * ubi_scan_find_seb - find LEB in the volume scanning information.
558 * @sv: a pointer to the volume scanning information
559 * @lnum: the requested logical eraseblock
561 * This function returns a pointer to the scanning logical eraseblock or %NULL
562 * if there are no data about it in the scanning volume information.
564 struct ubi_scan_leb
*ubi_scan_find_seb(const struct ubi_scan_volume
*sv
,
567 struct ubi_scan_leb
*seb
;
568 struct rb_node
*p
= sv
->root
.rb_node
;
571 seb
= rb_entry(p
, struct ubi_scan_leb
, u
.rb
);
573 if (lnum
== seb
->lnum
)
576 if (lnum
> seb
->lnum
)
586 * ubi_scan_rm_volume - delete scanning information about a volume.
587 * @si: scanning information
588 * @sv: the volume scanning information to delete
590 void ubi_scan_rm_volume(struct ubi_scan_info
*si
, struct ubi_scan_volume
*sv
)
593 struct ubi_scan_leb
*seb
;
595 dbg_bld("remove scanning information about volume %d", sv
->vol_id
);
597 while ((rb
= rb_first(&sv
->root
))) {
598 seb
= rb_entry(rb
, struct ubi_scan_leb
, u
.rb
);
599 rb_erase(&seb
->u
.rb
, &sv
->root
);
600 list_add_tail(&seb
->u
.list
, &si
->erase
);
603 rb_erase(&sv
->rb
, &si
->volumes
);
609 * ubi_scan_erase_peb - erase a physical eraseblock.
610 * @ubi: UBI device description object
611 * @si: scanning information
612 * @pnum: physical eraseblock number to erase;
613 * @ec: erase counter value to write (%UBI_SCAN_UNKNOWN_EC if it is unknown)
615 * This function erases physical eraseblock 'pnum', and writes the erase
616 * counter header to it. This function should only be used on UBI device
617 * initialization stages, when the EBA sub-system had not been yet initialized.
618 * This function returns zero in case of success and a negative error code in
621 int ubi_scan_erase_peb(struct ubi_device
*ubi
, const struct ubi_scan_info
*si
,
625 struct ubi_ec_hdr
*ec_hdr
;
627 if ((long long)ec
>= UBI_MAX_ERASECOUNTER
) {
629 * Erase counter overflow. Upgrade UBI and use 64-bit
630 * erase counters internally.
632 ubi_err("erase counter overflow at PEB %d, EC %d", pnum
, ec
);
636 ec_hdr
= kzalloc(ubi
->ec_hdr_alsize
, GFP_KERNEL
);
640 ec_hdr
->ec
= cpu_to_be64(ec
);
642 err
= ubi_io_sync_erase(ubi
, pnum
, 0);
646 err
= ubi_io_write_ec_hdr(ubi
, pnum
, ec_hdr
);
654 * ubi_scan_get_free_peb - get a free physical eraseblock.
655 * @ubi: UBI device description object
656 * @si: scanning information
658 * This function returns a free physical eraseblock. It is supposed to be
659 * called on the UBI initialization stages when the wear-leveling sub-system is
660 * not initialized yet. This function picks a physical eraseblocks from one of
661 * the lists, writes the EC header if it is needed, and removes it from the
664 * This function returns scanning physical eraseblock information in case of
665 * success and an error code in case of failure.
667 struct ubi_scan_leb
*ubi_scan_get_free_peb(struct ubi_device
*ubi
,
668 struct ubi_scan_info
*si
)
671 struct ubi_scan_leb
*seb
;
673 if (!list_empty(&si
->free
)) {
674 seb
= list_entry(si
->free
.next
, struct ubi_scan_leb
, u
.list
);
675 list_del(&seb
->u
.list
);
676 dbg_bld("return free PEB %d, EC %d", seb
->pnum
, seb
->ec
);
680 for (i
= 0; i
< 2; i
++) {
681 struct list_head
*head
;
682 struct ubi_scan_leb
*tmp_seb
;
690 * We try to erase the first physical eraseblock from the @head
691 * list and pick it if we succeed, or try to erase the
692 * next one if not. And so forth. We don't want to take care
693 * about bad eraseblocks here - they'll be handled later.
695 list_for_each_entry_safe(seb
, tmp_seb
, head
, u
.list
) {
696 if (seb
->ec
== UBI_SCAN_UNKNOWN_EC
)
697 seb
->ec
= si
->mean_ec
;
699 err
= ubi_scan_erase_peb(ubi
, si
, seb
->pnum
, seb
->ec
+1);
704 list_del(&seb
->u
.list
);
705 dbg_bld("return PEB %d, EC %d", seb
->pnum
, seb
->ec
);
710 ubi_err("no eraseblocks found");
711 return ERR_PTR(-ENOSPC
);
715 * process_eb - read, check UBI headers, and add them to scanning information.
716 * @ubi: UBI device description object
717 * @si: scanning information
718 * @pnum: the physical eraseblock number
720 * This function returns a zero if the physical eraseblock was successfully
721 * handled and a negative error code in case of failure.
723 static int process_eb(struct ubi_device
*ubi
, struct ubi_scan_info
*si
,
726 long long uninitialized_var(ec
);
727 int err
, bitflips
= 0, vol_id
, ec_corr
= 0;
729 dbg_bld("scan PEB %d", pnum
);
731 /* Skip bad physical eraseblocks */
732 err
= ubi_io_is_bad(ubi
, pnum
);
737 * FIXME: this is actually duty of the I/O sub-system to
738 * initialize this, but MTD does not provide enough
741 si
->bad_peb_count
+= 1;
745 err
= ubi_io_read_ec_hdr(ubi
, pnum
, ech
, 0);
748 else if (err
== UBI_IO_BITFLIPS
)
750 else if (err
== UBI_IO_PEB_EMPTY
)
751 return add_to_list(si
, pnum
, UBI_SCAN_UNKNOWN_EC
, &si
->erase
);
752 else if (err
== UBI_IO_BAD_HDR_READ
|| err
== UBI_IO_BAD_HDR
) {
754 * We have to also look at the VID header, possibly it is not
755 * corrupted. Set %bitflips flag in order to make this PEB be
756 * moved and EC be re-created.
759 ec
= UBI_SCAN_UNKNOWN_EC
;
766 /* Make sure UBI version is OK */
767 if (ech
->version
!= UBI_VERSION
) {
768 ubi_err("this UBI version is %d, image version is %d",
769 UBI_VERSION
, (int)ech
->version
);
773 ec
= be64_to_cpu(ech
->ec
);
774 if (ec
> UBI_MAX_ERASECOUNTER
) {
776 * Erase counter overflow. The EC headers have 64 bits
777 * reserved, but we anyway make use of only 31 bit
778 * values, as this seems to be enough for any existing
779 * flash. Upgrade UBI and use 64-bit erase counters
782 ubi_err("erase counter overflow, max is %d",
783 UBI_MAX_ERASECOUNTER
);
784 ubi_dbg_dump_ec_hdr(ech
);
789 * Make sure that all PEBs have the same image sequence number.
790 * This allows us to detect situations when users flash UBI
791 * images incorrectly, so that the flash has the new UBI image
792 * and leftovers from the old one. This feature was added
793 * relatively recently, and the sequence number was always
794 * zero, because old UBI implementations always set it to zero.
795 * For this reasons, we do not panic if some PEBs have zero
796 * sequence number, while other PEBs have non-zero sequence
799 image_seq
= be32_to_cpu(ech
->image_seq
);
800 if (!ubi
->image_seq
&& image_seq
)
801 ubi
->image_seq
= image_seq
;
802 if (ubi
->image_seq
&& image_seq
&&
803 ubi
->image_seq
!= image_seq
) {
804 ubi_err("bad image sequence number %d in PEB %d, "
805 "expected %d", image_seq
, pnum
, ubi
->image_seq
);
806 ubi_dbg_dump_ec_hdr(ech
);
811 /* OK, we've done with the EC header, let's look at the VID header */
813 err
= ubi_io_read_vid_hdr(ubi
, pnum
, vidh
, 0);
816 else if (err
== UBI_IO_BITFLIPS
)
818 else if (err
== UBI_IO_BAD_HDR_READ
|| err
== UBI_IO_BAD_HDR
||
819 (err
== UBI_IO_PEB_FREE
&& ec_corr
)) {
820 /* VID header is corrupted */
821 if (err
== UBI_IO_BAD_HDR_READ
||
822 ec_corr
== UBI_IO_BAD_HDR_READ
)
823 si
->read_err_count
+= 1;
824 err
= add_to_list(si
, pnum
, ec
, &si
->corr
);
828 } else if (err
== UBI_IO_PEB_FREE
) {
829 /* No VID header - the physical eraseblock is free */
830 err
= add_to_list(si
, pnum
, ec
, &si
->free
);
836 vol_id
= be32_to_cpu(vidh
->vol_id
);
837 if (vol_id
> UBI_MAX_VOLUMES
&& vol_id
!= UBI_LAYOUT_VOLUME_ID
) {
838 int lnum
= be32_to_cpu(vidh
->lnum
);
840 /* Unsupported internal volume */
841 switch (vidh
->compat
) {
842 case UBI_COMPAT_DELETE
:
843 ubi_msg("\"delete\" compatible internal volume %d:%d"
844 " found, remove it", vol_id
, lnum
);
845 err
= add_to_list(si
, pnum
, ec
, &si
->corr
);
851 ubi_msg("read-only compatible internal volume %d:%d"
852 " found, switch to read-only mode",
857 case UBI_COMPAT_PRESERVE
:
858 ubi_msg("\"preserve\" compatible internal volume %d:%d"
859 " found", vol_id
, lnum
);
860 err
= add_to_list(si
, pnum
, ec
, &si
->alien
);
865 case UBI_COMPAT_REJECT
:
866 ubi_err("incompatible internal volume %d:%d found",
873 ubi_warn("valid VID header but corrupted EC header at PEB %d",
875 err
= ubi_scan_add_used(ubi
, si
, pnum
, ec
, vidh
, bitflips
);
893 * check_what_we_have - check what PEB were found by scanning.
894 * @ubi: UBI device description object
895 * @si: scanning information
897 * This is a helper function which takes a look what PEBs were found by
898 * scanning, and decides whether the flash is empty and should be formatted and
899 * whether there are too many corrupted PEBs and we should not attach this
900 * MTD device. Returns zero if we should proceed with attaching the MTD device,
901 * and %-EINVAL if we should not.
903 static int check_what_we_have(const struct ubi_device
*ubi
,
904 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");
960 ubi_err("MTD device possibly contains non-UBI data, "
966 if (si
->corr_peb_count
>= 0)
967 ubi_msg("corrupted PEBs will be formatted");
972 * ubi_scan - scan an MTD device.
973 * @ubi: UBI device description object
975 * This function does full scanning of an MTD device and returns complete
976 * information about it. In case of failure, an error code is returned.
978 struct ubi_scan_info
*ubi_scan(struct ubi_device
*ubi
)
981 struct rb_node
*rb1
, *rb2
;
982 struct ubi_scan_volume
*sv
;
983 struct ubi_scan_leb
*seb
;
984 struct ubi_scan_info
*si
;
986 si
= kzalloc(sizeof(struct ubi_scan_info
), GFP_KERNEL
);
988 return ERR_PTR(-ENOMEM
);
990 INIT_LIST_HEAD(&si
->corr
);
991 INIT_LIST_HEAD(&si
->free
);
992 INIT_LIST_HEAD(&si
->erase
);
993 INIT_LIST_HEAD(&si
->alien
);
994 si
->volumes
= RB_ROOT
;
997 ech
= kzalloc(ubi
->ec_hdr_alsize
, GFP_KERNEL
);
1001 vidh
= ubi_zalloc_vid_hdr(ubi
, GFP_KERNEL
);
1005 for (pnum
= 0; pnum
< ubi
->peb_count
; pnum
++) {
1008 dbg_gen("process PEB %d", pnum
);
1009 err
= process_eb(ubi
, si
, pnum
);
1014 dbg_msg("scanning is finished");
1016 /* Calculate mean erase counter */
1018 si
->mean_ec
= div_u64(si
->ec_sum
, si
->ec_count
);
1020 err
= check_what_we_have(ubi
, si
);
1025 * In case of unknown erase counter we use the mean erase counter
1028 ubi_rb_for_each_entry(rb1
, sv
, &si
->volumes
, rb
) {
1029 ubi_rb_for_each_entry(rb2
, seb
, &sv
->root
, u
.rb
)
1030 if (seb
->ec
== UBI_SCAN_UNKNOWN_EC
)
1031 seb
->ec
= si
->mean_ec
;
1034 list_for_each_entry(seb
, &si
->free
, u
.list
) {
1035 if (seb
->ec
== UBI_SCAN_UNKNOWN_EC
)
1036 seb
->ec
= si
->mean_ec
;
1039 list_for_each_entry(seb
, &si
->corr
, u
.list
)
1040 if (seb
->ec
== UBI_SCAN_UNKNOWN_EC
)
1041 seb
->ec
= si
->mean_ec
;
1043 list_for_each_entry(seb
, &si
->erase
, u
.list
)
1044 if (seb
->ec
== UBI_SCAN_UNKNOWN_EC
)
1045 seb
->ec
= si
->mean_ec
;
1047 err
= paranoid_check_si(ubi
, si
);
1051 ubi_free_vid_hdr(ubi
, vidh
);
1057 ubi_free_vid_hdr(ubi
, vidh
);
1061 ubi_scan_destroy_si(si
);
1062 return ERR_PTR(err
);
1066 * destroy_sv - free the scanning volume information
1067 * @sv: scanning volume information
1069 * This function destroys the volume RB-tree (@sv->root) and the scanning
1070 * volume information.
1072 static void destroy_sv(struct ubi_scan_volume
*sv
)
1074 struct ubi_scan_leb
*seb
;
1075 struct rb_node
*this = sv
->root
.rb_node
;
1079 this = this->rb_left
;
1080 else if (this->rb_right
)
1081 this = this->rb_right
;
1083 seb
= rb_entry(this, struct ubi_scan_leb
, u
.rb
);
1084 this = rb_parent(this);
1086 if (this->rb_left
== &seb
->u
.rb
)
1087 this->rb_left
= NULL
;
1089 this->rb_right
= NULL
;
1099 * ubi_scan_destroy_si - destroy scanning information.
1100 * @si: scanning information
1102 void ubi_scan_destroy_si(struct ubi_scan_info
*si
)
1104 struct ubi_scan_leb
*seb
, *seb_tmp
;
1105 struct ubi_scan_volume
*sv
;
1108 list_for_each_entry_safe(seb
, seb_tmp
, &si
->alien
, u
.list
) {
1109 list_del(&seb
->u
.list
);
1112 list_for_each_entry_safe(seb
, seb_tmp
, &si
->erase
, u
.list
) {
1113 list_del(&seb
->u
.list
);
1116 list_for_each_entry_safe(seb
, seb_tmp
, &si
->corr
, u
.list
) {
1117 list_del(&seb
->u
.list
);
1120 list_for_each_entry_safe(seb
, seb_tmp
, &si
->free
, u
.list
) {
1121 list_del(&seb
->u
.list
);
1125 /* Destroy the volume RB-tree */
1126 rb
= si
->volumes
.rb_node
;
1130 else if (rb
->rb_right
)
1133 sv
= rb_entry(rb
, struct ubi_scan_volume
, rb
);
1137 if (rb
->rb_left
== &sv
->rb
)
1140 rb
->rb_right
= NULL
;
1150 #ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
1153 * paranoid_check_si - check the scanning information.
1154 * @ubi: UBI device description object
1155 * @si: scanning information
1157 * This function returns zero if the scanning information is all right, and a
1158 * negative error code if not or if an error occurred.
1160 static int paranoid_check_si(struct ubi_device
*ubi
, struct ubi_scan_info
*si
)
1162 int pnum
, err
, vols_found
= 0;
1163 struct rb_node
*rb1
, *rb2
;
1164 struct ubi_scan_volume
*sv
;
1165 struct ubi_scan_leb
*seb
, *last_seb
;
1169 * At first, check that scanning information is OK.
1171 ubi_rb_for_each_entry(rb1
, sv
, &si
->volumes
, rb
) {
1179 ubi_err("bad is_empty flag");
1183 if (sv
->vol_id
< 0 || sv
->highest_lnum
< 0 ||
1184 sv
->leb_count
< 0 || sv
->vol_type
< 0 || sv
->used_ebs
< 0 ||
1185 sv
->data_pad
< 0 || sv
->last_data_size
< 0) {
1186 ubi_err("negative values");
1190 if (sv
->vol_id
>= UBI_MAX_VOLUMES
&&
1191 sv
->vol_id
< UBI_INTERNAL_VOL_START
) {
1192 ubi_err("bad vol_id");
1196 if (sv
->vol_id
> si
->highest_vol_id
) {
1197 ubi_err("highest_vol_id is %d, but vol_id %d is there",
1198 si
->highest_vol_id
, sv
->vol_id
);
1202 if (sv
->vol_type
!= UBI_DYNAMIC_VOLUME
&&
1203 sv
->vol_type
!= UBI_STATIC_VOLUME
) {
1204 ubi_err("bad vol_type");
1208 if (sv
->data_pad
> ubi
->leb_size
/ 2) {
1209 ubi_err("bad data_pad");
1214 ubi_rb_for_each_entry(rb2
, seb
, &sv
->root
, u
.rb
) {
1220 if (seb
->pnum
< 0 || seb
->ec
< 0) {
1221 ubi_err("negative values");
1225 if (seb
->ec
< si
->min_ec
) {
1226 ubi_err("bad si->min_ec (%d), %d found",
1227 si
->min_ec
, seb
->ec
);
1231 if (seb
->ec
> si
->max_ec
) {
1232 ubi_err("bad si->max_ec (%d), %d found",
1233 si
->max_ec
, seb
->ec
);
1237 if (seb
->pnum
>= ubi
->peb_count
) {
1238 ubi_err("too high PEB number %d, total PEBs %d",
1239 seb
->pnum
, ubi
->peb_count
);
1243 if (sv
->vol_type
== UBI_STATIC_VOLUME
) {
1244 if (seb
->lnum
>= sv
->used_ebs
) {
1245 ubi_err("bad lnum or used_ebs");
1249 if (sv
->used_ebs
!= 0) {
1250 ubi_err("non-zero used_ebs");
1255 if (seb
->lnum
> sv
->highest_lnum
) {
1256 ubi_err("incorrect highest_lnum or lnum");
1261 if (sv
->leb_count
!= leb_count
) {
1262 ubi_err("bad leb_count, %d objects in the tree",
1272 if (seb
->lnum
!= sv
->highest_lnum
) {
1273 ubi_err("bad highest_lnum");
1278 if (vols_found
!= si
->vols_found
) {
1279 ubi_err("bad si->vols_found %d, should be %d",
1280 si
->vols_found
, vols_found
);
1284 /* Check that scanning information is correct */
1285 ubi_rb_for_each_entry(rb1
, sv
, &si
->volumes
, rb
) {
1287 ubi_rb_for_each_entry(rb2
, seb
, &sv
->root
, u
.rb
) {
1294 err
= ubi_io_read_vid_hdr(ubi
, seb
->pnum
, vidh
, 1);
1295 if (err
&& err
!= UBI_IO_BITFLIPS
) {
1296 ubi_err("VID header is not OK (%d)", err
);
1302 vol_type
= vidh
->vol_type
== UBI_VID_DYNAMIC
?
1303 UBI_DYNAMIC_VOLUME
: UBI_STATIC_VOLUME
;
1304 if (sv
->vol_type
!= vol_type
) {
1305 ubi_err("bad vol_type");
1309 if (seb
->sqnum
!= be64_to_cpu(vidh
->sqnum
)) {
1310 ubi_err("bad sqnum %llu", seb
->sqnum
);
1314 if (sv
->vol_id
!= be32_to_cpu(vidh
->vol_id
)) {
1315 ubi_err("bad vol_id %d", sv
->vol_id
);
1319 if (sv
->compat
!= vidh
->compat
) {
1320 ubi_err("bad compat %d", vidh
->compat
);
1324 if (seb
->lnum
!= be32_to_cpu(vidh
->lnum
)) {
1325 ubi_err("bad lnum %d", seb
->lnum
);
1329 if (sv
->used_ebs
!= be32_to_cpu(vidh
->used_ebs
)) {
1330 ubi_err("bad used_ebs %d", sv
->used_ebs
);
1334 if (sv
->data_pad
!= be32_to_cpu(vidh
->data_pad
)) {
1335 ubi_err("bad data_pad %d", sv
->data_pad
);
1343 if (sv
->highest_lnum
!= be32_to_cpu(vidh
->lnum
)) {
1344 ubi_err("bad highest_lnum %d", sv
->highest_lnum
);
1348 if (sv
->last_data_size
!= be32_to_cpu(vidh
->data_size
)) {
1349 ubi_err("bad last_data_size %d", sv
->last_data_size
);
1355 * Make sure that all the physical eraseblocks are in one of the lists
1358 buf
= kzalloc(ubi
->peb_count
, GFP_KERNEL
);
1362 for (pnum
= 0; pnum
< ubi
->peb_count
; pnum
++) {
1363 err
= ubi_io_is_bad(ubi
, pnum
);
1371 ubi_rb_for_each_entry(rb1
, sv
, &si
->volumes
, rb
)
1372 ubi_rb_for_each_entry(rb2
, seb
, &sv
->root
, u
.rb
)
1375 list_for_each_entry(seb
, &si
->free
, u
.list
)
1378 list_for_each_entry(seb
, &si
->corr
, u
.list
)
1381 list_for_each_entry(seb
, &si
->erase
, u
.list
)
1384 list_for_each_entry(seb
, &si
->alien
, u
.list
)
1388 for (pnum
= 0; pnum
< ubi
->peb_count
; pnum
++)
1390 ubi_err("PEB %d is not referred", pnum
);
1400 ubi_err("bad scanning information about LEB %d", seb
->lnum
);
1401 ubi_dbg_dump_seb(seb
, 0);
1402 ubi_dbg_dump_sv(sv
);
1406 ubi_err("bad scanning information about volume %d", sv
->vol_id
);
1407 ubi_dbg_dump_sv(sv
);
1411 ubi_err("bad scanning information about volume %d", sv
->vol_id
);
1412 ubi_dbg_dump_sv(sv
);
1413 ubi_dbg_dump_vid_hdr(vidh
);
1416 ubi_dbg_dump_stack();
1420 #endif /* CONFIG_MTD_UBI_DEBUG_PARANOID */