2 * Copyright (c) International Business Machines Corp., 2006
3 * Copyright (c) Nokia Corporation, 2006, 2007
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
13 * the GNU General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19 * Author: Artem Bityutskiy (Битюцкий Артём)
23 * UBI input/output sub-system.
25 * This sub-system provides a uniform way to work with all kinds of the
26 * underlying MTD devices. It also implements handy functions for reading and
27 * writing UBI headers.
29 * We are trying to have a paranoid mindset and not to trust to what we read
30 * from the flash media in order to be more secure and robust. So this
31 * sub-system validates every single header it reads from the flash media.
33 * Some words about how the eraseblock headers are stored.
35 * The erase counter header is always stored at offset zero. By default, the
36 * VID header is stored after the EC header at the closest aligned offset
37 * (i.e. aligned to the minimum I/O unit size). Data starts next to the VID
38 * header at the closest aligned offset. But this default layout may be
39 * changed. For example, for different reasons (e.g., optimization) UBI may be
40 * asked to put the VID header at further offset, and even at an unaligned
41 * offset. Of course, if the offset of the VID header is unaligned, UBI adds
42 * proper padding in front of it. Data offset may also be changed but it has to
45 * About minimal I/O units. In general, UBI assumes flash device model where
46 * there is only one minimal I/O unit size. E.g., in case of NOR flash it is 1,
47 * in case of NAND flash it is a NAND page, etc. This is reported by MTD in the
48 * @ubi->mtd->writesize field. But as an exception, UBI admits of using another
49 * (smaller) minimal I/O unit size for EC and VID headers to make it possible
50 * to do different optimizations.
52 * This is extremely useful in case of NAND flashes which admit of several
53 * write operations to one NAND page. In this case UBI can fit EC and VID
54 * headers at one NAND page. Thus, UBI may use "sub-page" size as the minimal
55 * I/O unit for the headers (the @ubi->hdrs_min_io_size field). But it still
56 * reports NAND page size (@ubi->min_io_size) as a minimal I/O unit for the UBI
59 * Example: some Samsung NANDs with 2KiB pages allow 4x 512-byte writes, so
60 * although the minimal I/O unit is 2K, UBI uses 512 bytes for EC and VID
63 * Q: why not just to treat sub-page as a minimal I/O unit of this flash
64 * device, e.g., make @ubi->min_io_size = 512 in the example above?
66 * A: because when writing a sub-page, MTD still writes a full 2K page but the
67 * bytes which are not relevant to the sub-page are 0xFF. So, basically,
68 * writing 4x512 sub-pages is 4 times slower than writing one 2KiB NAND page.
69 * Thus, we prefer to use sub-pages only for EC and VID headers.
71 * As it was noted above, the VID header may start at a non-aligned offset.
72 * For example, in case of a 2KiB page NAND flash with a 512 bytes sub-page,
73 * the VID header may reside at offset 1984 which is the last 64 bytes of the
74 * last sub-page (EC header is always at offset zero). This causes some
75 * difficulties when reading and writing VID headers.
77 * Suppose we have a 64-byte buffer and we read a VID header at it. We change
78 * the data and want to write this VID header out. As we can only write in
79 * 512-byte chunks, we have to allocate one more buffer and copy our VID header
80 * to offset 448 of this buffer.
82 * The I/O sub-system does the following trick in order to avoid this extra
83 * copy. It always allocates a @ubi->vid_hdr_alsize bytes buffer for the VID
84 * header and returns a pointer to offset @ubi->vid_hdr_shift of this buffer.
85 * When the VID header is being written out, it shifts the VID header pointer
86 * back and writes the whole sub-page.
89 #include <linux/crc32.h>
90 #include <linux/err.h>
91 #include <linux/slab.h>
94 #ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
95 static int paranoid_check_not_bad(const struct ubi_device
*ubi
, int pnum
);
96 static int paranoid_check_peb_ec_hdr(const struct ubi_device
*ubi
, int pnum
);
97 static int paranoid_check_ec_hdr(const struct ubi_device
*ubi
, int pnum
,
98 const struct ubi_ec_hdr
*ec_hdr
);
99 static int paranoid_check_peb_vid_hdr(const struct ubi_device
*ubi
, int pnum
);
100 static int paranoid_check_vid_hdr(const struct ubi_device
*ubi
, int pnum
,
101 const struct ubi_vid_hdr
*vid_hdr
);
103 #define paranoid_check_not_bad(ubi, pnum) 0
104 #define paranoid_check_peb_ec_hdr(ubi, pnum) 0
105 #define paranoid_check_ec_hdr(ubi, pnum, ec_hdr) 0
106 #define paranoid_check_peb_vid_hdr(ubi, pnum) 0
107 #define paranoid_check_vid_hdr(ubi, pnum, vid_hdr) 0
111 * ubi_io_read - read data from a physical eraseblock.
112 * @ubi: UBI device description object
113 * @buf: buffer where to store the read data
114 * @pnum: physical eraseblock number to read from
115 * @offset: offset within the physical eraseblock from where to read
116 * @len: how many bytes to read
118 * This function reads data from offset @offset of physical eraseblock @pnum
119 * and stores the read data in the @buf buffer. The following return codes are
122 * o %0 if all the requested data were successfully read;
123 * o %UBI_IO_BITFLIPS if all the requested data were successfully read, but
124 * correctable bit-flips were detected; this is harmless but may indicate
125 * that this eraseblock may become bad soon (but do not have to);
126 * o %-EBADMSG if the MTD subsystem reported about data integrity problems, for
127 * example it can be an ECC error in case of NAND; this most probably means
128 * that the data is corrupted;
129 * o %-EIO if some I/O error occurred;
130 * o other negative error codes in case of other errors.
132 int ubi_io_read(const struct ubi_device
*ubi
, void *buf
, int pnum
, int offset
,
135 int err
, retries
= 0;
139 dbg_io("read %d bytes from PEB %d:%d", len
, pnum
, offset
);
141 ubi_assert(pnum
>= 0 && pnum
< ubi
->peb_count
);
142 ubi_assert(offset
>= 0 && offset
+ len
<= ubi
->peb_size
);
145 err
= paranoid_check_not_bad(ubi
, pnum
);
149 addr
= (loff_t
)pnum
* ubi
->peb_size
+ offset
;
151 err
= ubi
->mtd
->read(ubi
->mtd
, addr
, len
, &read
, buf
);
153 const char *errstr
= (err
== -EBADMSG
) ? " (ECC error)" : "";
155 if (err
== -EUCLEAN
) {
157 * -EUCLEAN is reported if there was a bit-flip which
158 * was corrected, so this is harmless.
160 * We do not report about it here unless debugging is
161 * enabled. A corresponding message will be printed
162 * later, when it is has been scrubbed.
164 dbg_msg("fixable bit-flip detected at PEB %d", pnum
);
165 ubi_assert(len
== read
);
166 return UBI_IO_BITFLIPS
;
169 if (read
!= len
&& retries
++ < UBI_IO_RETRIES
) {
170 dbg_io("error %d%s while reading %d bytes from PEB %d:%d,"
171 " read only %zd bytes, retry",
172 err
, errstr
, len
, pnum
, offset
, read
);
177 ubi_err("error %d%s while reading %d bytes from PEB %d:%d, "
178 "read %zd bytes", err
, errstr
, len
, pnum
, offset
, read
);
179 ubi_dbg_dump_stack();
182 * The driver should never return -EBADMSG if it failed to read
183 * all the requested data. But some buggy drivers might do
184 * this, so we change it to -EIO.
186 if (read
!= len
&& err
== -EBADMSG
) {
191 ubi_assert(len
== read
);
193 if (ubi_dbg_is_bitflip()) {
194 dbg_gen("bit-flip (emulated)");
195 err
= UBI_IO_BITFLIPS
;
203 * ubi_io_write - write data to a physical eraseblock.
204 * @ubi: UBI device description object
205 * @buf: buffer with the data to write
206 * @pnum: physical eraseblock number to write to
207 * @offset: offset within the physical eraseblock where to write
208 * @len: how many bytes to write
210 * This function writes @len bytes of data from buffer @buf to offset @offset
211 * of physical eraseblock @pnum. If all the data were successfully written,
212 * zero is returned. If an error occurred, this function returns a negative
213 * error code. If %-EIO is returned, the physical eraseblock most probably went
216 * Note, in case of an error, it is possible that something was still written
217 * to the flash media, but may be some garbage.
219 int ubi_io_write(struct ubi_device
*ubi
, const void *buf
, int pnum
, int offset
,
226 dbg_io("write %d bytes to PEB %d:%d", len
, pnum
, offset
);
228 ubi_assert(pnum
>= 0 && pnum
< ubi
->peb_count
);
229 ubi_assert(offset
>= 0 && offset
+ len
<= ubi
->peb_size
);
230 ubi_assert(offset
% ubi
->hdrs_min_io_size
== 0);
231 ubi_assert(len
> 0 && len
% ubi
->hdrs_min_io_size
== 0);
234 ubi_err("read-only mode");
238 /* The below has to be compiled out if paranoid checks are disabled */
240 err
= paranoid_check_not_bad(ubi
, pnum
);
244 /* The area we are writing to has to contain all 0xFF bytes */
245 err
= ubi_dbg_check_all_ff(ubi
, pnum
, offset
, len
);
249 if (offset
>= ubi
->leb_start
) {
251 * We write to the data area of the physical eraseblock. Make
252 * sure it has valid EC and VID headers.
254 err
= paranoid_check_peb_ec_hdr(ubi
, pnum
);
257 err
= paranoid_check_peb_vid_hdr(ubi
, pnum
);
262 if (ubi_dbg_is_write_failure()) {
263 dbg_err("cannot write %d bytes to PEB %d:%d "
264 "(emulated)", len
, pnum
, offset
);
265 ubi_dbg_dump_stack();
269 addr
= (loff_t
)pnum
* ubi
->peb_size
+ offset
;
270 err
= ubi
->mtd
->write(ubi
->mtd
, addr
, len
, &written
, buf
);
272 ubi_err("error %d while writing %d bytes to PEB %d:%d, written "
273 "%zd bytes", err
, len
, pnum
, offset
, written
);
274 ubi_dbg_dump_stack();
275 ubi_dbg_dump_flash(ubi
, pnum
, offset
, len
);
277 ubi_assert(written
== len
);
280 err
= ubi_dbg_check_write(ubi
, buf
, pnum
, offset
, len
);
285 * Since we always write sequentially, the rest of the PEB has
286 * to contain only 0xFF bytes.
289 len
= ubi
->peb_size
- offset
;
291 err
= ubi_dbg_check_all_ff(ubi
, pnum
, offset
, len
);
298 * erase_callback - MTD erasure call-back.
299 * @ei: MTD erase information object.
301 * Note, even though MTD erase interface is asynchronous, all the current
302 * implementations are synchronous anyway.
304 static void erase_callback(struct erase_info
*ei
)
306 wake_up_interruptible((wait_queue_head_t
*)ei
->priv
);
310 * do_sync_erase - synchronously erase a physical eraseblock.
311 * @ubi: UBI device description object
312 * @pnum: the physical eraseblock number to erase
314 * This function synchronously erases physical eraseblock @pnum and returns
315 * zero in case of success and a negative error code in case of failure. If
316 * %-EIO is returned, the physical eraseblock most probably went bad.
318 static int do_sync_erase(struct ubi_device
*ubi
, int pnum
)
320 int err
, retries
= 0;
321 struct erase_info ei
;
322 wait_queue_head_t wq
;
324 dbg_io("erase PEB %d", pnum
);
327 init_waitqueue_head(&wq
);
328 memset(&ei
, 0, sizeof(struct erase_info
));
331 ei
.addr
= (loff_t
)pnum
* ubi
->peb_size
;
332 ei
.len
= ubi
->peb_size
;
333 ei
.callback
= erase_callback
;
334 ei
.priv
= (unsigned long)&wq
;
336 err
= ubi
->mtd
->erase(ubi
->mtd
, &ei
);
338 if (retries
++ < UBI_IO_RETRIES
) {
339 dbg_io("error %d while erasing PEB %d, retry",
344 ubi_err("cannot erase PEB %d, error %d", pnum
, err
);
345 ubi_dbg_dump_stack();
349 err
= wait_event_interruptible(wq
, ei
.state
== MTD_ERASE_DONE
||
350 ei
.state
== MTD_ERASE_FAILED
);
352 ubi_err("interrupted PEB %d erasure", pnum
);
356 if (ei
.state
== MTD_ERASE_FAILED
) {
357 if (retries
++ < UBI_IO_RETRIES
) {
358 dbg_io("error while erasing PEB %d, retry", pnum
);
362 ubi_err("cannot erase PEB %d", pnum
);
363 ubi_dbg_dump_stack();
367 err
= ubi_dbg_check_all_ff(ubi
, pnum
, 0, ubi
->peb_size
);
371 if (ubi_dbg_is_erase_failure() && !err
) {
372 dbg_err("cannot erase PEB %d (emulated)", pnum
);
380 * check_pattern - check if buffer contains only a certain byte pattern.
381 * @buf: buffer to check
382 * @patt: the pattern to check
383 * @size: buffer size in bytes
385 * This function returns %1 in there are only @patt bytes in @buf, and %0 if
386 * something else was also found.
388 static int check_pattern(const void *buf
, uint8_t patt
, int size
)
392 for (i
= 0; i
< size
; i
++)
393 if (((const uint8_t *)buf
)[i
] != patt
)
398 /* Patterns to write to a physical eraseblock when torturing it */
399 static uint8_t patterns
[] = {0xa5, 0x5a, 0x0};
402 * torture_peb - test a supposedly bad physical eraseblock.
403 * @ubi: UBI device description object
404 * @pnum: the physical eraseblock number to test
406 * This function returns %-EIO if the physical eraseblock did not pass the
407 * test, a positive number of erase operations done if the test was
408 * successfully passed, and other negative error codes in case of other errors.
410 static int torture_peb(struct ubi_device
*ubi
, int pnum
)
412 int err
, i
, patt_count
;
414 ubi_msg("run torture test for PEB %d", pnum
);
415 patt_count
= ARRAY_SIZE(patterns
);
416 ubi_assert(patt_count
> 0);
418 mutex_lock(&ubi
->buf_mutex
);
419 for (i
= 0; i
< patt_count
; i
++) {
420 err
= do_sync_erase(ubi
, pnum
);
424 /* Make sure the PEB contains only 0xFF bytes */
425 err
= ubi_io_read(ubi
, ubi
->peb_buf1
, pnum
, 0, ubi
->peb_size
);
429 err
= check_pattern(ubi
->peb_buf1
, 0xFF, ubi
->peb_size
);
431 ubi_err("erased PEB %d, but a non-0xFF byte found",
437 /* Write a pattern and check it */
438 memset(ubi
->peb_buf1
, patterns
[i
], ubi
->peb_size
);
439 err
= ubi_io_write(ubi
, ubi
->peb_buf1
, pnum
, 0, ubi
->peb_size
);
443 memset(ubi
->peb_buf1
, ~patterns
[i
], ubi
->peb_size
);
444 err
= ubi_io_read(ubi
, ubi
->peb_buf1
, pnum
, 0, ubi
->peb_size
);
448 err
= check_pattern(ubi
->peb_buf1
, patterns
[i
], ubi
->peb_size
);
450 ubi_err("pattern %x checking failed for PEB %d",
458 ubi_msg("PEB %d passed torture test, do not mark it a bad", pnum
);
461 mutex_unlock(&ubi
->buf_mutex
);
462 if (err
== UBI_IO_BITFLIPS
|| err
== -EBADMSG
) {
464 * If a bit-flip or data integrity error was detected, the test
465 * has not passed because it happened on a freshly erased
466 * physical eraseblock which means something is wrong with it.
468 ubi_err("read problems on freshly erased PEB %d, must be bad",
476 * nor_erase_prepare - prepare a NOR flash PEB for erasure.
477 * @ubi: UBI device description object
478 * @pnum: physical eraseblock number to prepare
480 * NOR flash, or at least some of them, have peculiar embedded PEB erasure
481 * algorithm: the PEB is first filled with zeroes, then it is erased. And
482 * filling with zeroes starts from the end of the PEB. This was observed with
483 * Spansion S29GL512N NOR flash.
485 * This means that in case of a power cut we may end up with intact data at the
486 * beginning of the PEB, and all zeroes at the end of PEB. In other words, the
487 * EC and VID headers are OK, but a large chunk of data at the end of PEB is
488 * zeroed. This makes UBI mistakenly treat this PEB as used and associate it
489 * with an LEB, which leads to subsequent failures (e.g., UBIFS fails).
491 * This function is called before erasing NOR PEBs and it zeroes out EC and VID
492 * magic numbers in order to invalidate them and prevent the failures. Returns
493 * zero in case of success and a negative error code in case of failure.
495 static int nor_erase_prepare(struct ubi_device
*ubi
, int pnum
)
501 struct ubi_vid_hdr vid_hdr
;
503 addr
= (loff_t
)pnum
* ubi
->peb_size
+ ubi
->vid_hdr_aloffset
;
504 err
= ubi
->mtd
->write(ubi
->mtd
, addr
, 4, &written
, (void *)&data
);
506 addr
-= ubi
->vid_hdr_aloffset
;
507 err
= ubi
->mtd
->write(ubi
->mtd
, addr
, 4, &written
,
514 * We failed to write to the media. This was observed with Spansion
515 * S29GL512N NOR flash. Most probably the eraseblock erasure was
516 * interrupted at a very inappropriate moment, so it became unwritable.
517 * In this case we probably anyway have garbage in this PEB.
519 err1
= ubi_io_read_vid_hdr(ubi
, pnum
, &vid_hdr
, 0);
520 if (err1
== UBI_IO_BAD_HDR_EBADMSG
|| err1
== UBI_IO_BAD_HDR
)
522 * The VID header is corrupted, so we can safely erase this
523 * PEB and not afraid that it will be treated as a valid PEB in
524 * case of an unclean reboot.
529 * The PEB contains a valid VID header, but we cannot invalidate it.
530 * Supposedly the flash media or the driver is screwed up, so return an
533 ubi_err("cannot invalidate PEB %d, write returned %d read returned %d",
535 ubi_dbg_dump_flash(ubi
, pnum
, 0, ubi
->peb_size
);
540 * ubi_io_sync_erase - synchronously erase a physical eraseblock.
541 * @ubi: UBI device description object
542 * @pnum: physical eraseblock number to erase
543 * @torture: if this physical eraseblock has to be tortured
545 * This function synchronously erases physical eraseblock @pnum. If @torture
546 * flag is not zero, the physical eraseblock is checked by means of writing
547 * different patterns to it and reading them back. If the torturing is enabled,
548 * the physical eraseblock is erased more than once.
550 * This function returns the number of erasures made in case of success, %-EIO
551 * if the erasure failed or the torturing test failed, and other negative error
552 * codes in case of other errors. Note, %-EIO means that the physical
555 int ubi_io_sync_erase(struct ubi_device
*ubi
, int pnum
, int torture
)
559 ubi_assert(pnum
>= 0 && pnum
< ubi
->peb_count
);
561 err
= paranoid_check_not_bad(ubi
, pnum
);
566 ubi_err("read-only mode");
570 if (ubi
->nor_flash
) {
571 err
= nor_erase_prepare(ubi
, pnum
);
577 ret
= torture_peb(ubi
, pnum
);
582 err
= do_sync_erase(ubi
, pnum
);
590 * ubi_io_is_bad - check if a physical eraseblock is bad.
591 * @ubi: UBI device description object
592 * @pnum: the physical eraseblock number to check
594 * This function returns a positive number if the physical eraseblock is bad,
595 * zero if not, and a negative error code if an error occurred.
597 int ubi_io_is_bad(const struct ubi_device
*ubi
, int pnum
)
599 struct mtd_info
*mtd
= ubi
->mtd
;
601 ubi_assert(pnum
>= 0 && pnum
< ubi
->peb_count
);
603 if (ubi
->bad_allowed
) {
606 ret
= mtd
->block_isbad(mtd
, (loff_t
)pnum
* ubi
->peb_size
);
608 ubi_err("error %d while checking if PEB %d is bad",
611 dbg_io("PEB %d is bad", pnum
);
619 * ubi_io_mark_bad - mark a physical eraseblock as bad.
620 * @ubi: UBI device description object
621 * @pnum: the physical eraseblock number to mark
623 * This function returns zero in case of success and a negative error code in
626 int ubi_io_mark_bad(const struct ubi_device
*ubi
, int pnum
)
629 struct mtd_info
*mtd
= ubi
->mtd
;
631 ubi_assert(pnum
>= 0 && pnum
< ubi
->peb_count
);
634 ubi_err("read-only mode");
638 if (!ubi
->bad_allowed
)
641 err
= mtd
->block_markbad(mtd
, (loff_t
)pnum
* ubi
->peb_size
);
643 ubi_err("cannot mark PEB %d bad, error %d", pnum
, err
);
648 * validate_ec_hdr - validate an erase counter header.
649 * @ubi: UBI device description object
650 * @ec_hdr: the erase counter header to check
652 * This function returns zero if the erase counter header is OK, and %1 if
655 static int validate_ec_hdr(const struct ubi_device
*ubi
,
656 const struct ubi_ec_hdr
*ec_hdr
)
659 int vid_hdr_offset
, leb_start
;
661 ec
= be64_to_cpu(ec_hdr
->ec
);
662 vid_hdr_offset
= be32_to_cpu(ec_hdr
->vid_hdr_offset
);
663 leb_start
= be32_to_cpu(ec_hdr
->data_offset
);
665 if (ec_hdr
->version
!= UBI_VERSION
) {
666 ubi_err("node with incompatible UBI version found: "
667 "this UBI version is %d, image version is %d",
668 UBI_VERSION
, (int)ec_hdr
->version
);
672 if (vid_hdr_offset
!= ubi
->vid_hdr_offset
) {
673 ubi_err("bad VID header offset %d, expected %d",
674 vid_hdr_offset
, ubi
->vid_hdr_offset
);
678 if (leb_start
!= ubi
->leb_start
) {
679 ubi_err("bad data offset %d, expected %d",
680 leb_start
, ubi
->leb_start
);
684 if (ec
< 0 || ec
> UBI_MAX_ERASECOUNTER
) {
685 ubi_err("bad erase counter %lld", ec
);
692 ubi_err("bad EC header");
693 ubi_dbg_dump_ec_hdr(ec_hdr
);
694 ubi_dbg_dump_stack();
699 * ubi_io_read_ec_hdr - read and check an erase counter header.
700 * @ubi: UBI device description object
701 * @pnum: physical eraseblock to read from
702 * @ec_hdr: a &struct ubi_ec_hdr object where to store the read erase counter
704 * @verbose: be verbose if the header is corrupted or was not found
706 * This function reads erase counter header from physical eraseblock @pnum and
707 * stores it in @ec_hdr. This function also checks CRC checksum of the read
708 * erase counter header. The following codes may be returned:
710 * o %0 if the CRC checksum is correct and the header was successfully read;
711 * o %UBI_IO_BITFLIPS if the CRC is correct, but bit-flips were detected
712 * and corrected by the flash driver; this is harmless but may indicate that
713 * this eraseblock may become bad soon (but may be not);
714 * o %UBI_IO_BAD_HDR if the erase counter header is corrupted (a CRC error);
715 * o %UBI_IO_BAD_HDR_EBADMSG is the same as %UBI_IO_BAD_HDR, but there also was
716 * a data integrity error (uncorrectable ECC error in case of NAND);
717 * o %UBI_IO_PEB_EMPTY if the physical eraseblock is empty;
718 * o a negative error code in case of failure.
720 int ubi_io_read_ec_hdr(struct ubi_device
*ubi
, int pnum
,
721 struct ubi_ec_hdr
*ec_hdr
, int verbose
)
723 int err
, read_err
= 0;
724 uint32_t crc
, magic
, hdr_crc
;
726 dbg_io("read EC header from PEB %d", pnum
);
727 ubi_assert(pnum
>= 0 && pnum
< ubi
->peb_count
);
729 err
= ubi_io_read(ubi
, ec_hdr
, pnum
, 0, UBI_EC_HDR_SIZE
);
731 if (err
!= UBI_IO_BITFLIPS
&& err
!= -EBADMSG
)
735 * We read all the data, but either a correctable bit-flip
736 * occurred, or MTD reported a data integrity error
737 * (uncorrectable ECC error in case of NAND). The former is
738 * harmless, the later may mean that the read data is
739 * corrupted. But we have a CRC check-sum and we will detect
740 * this. If the EC header is still OK, we just report this as
741 * there was a bit-flip, to force scrubbing.
744 read_err
= UBI_IO_BAD_HDR_EBADMSG
;
747 magic
= be32_to_cpu(ec_hdr
->magic
);
748 if (magic
!= UBI_EC_HDR_MAGIC
) {
753 * The magic field is wrong. Let's check if we have read all
754 * 0xFF. If yes, this physical eraseblock is assumed to be
757 if (check_pattern(ec_hdr
, 0xFF, UBI_EC_HDR_SIZE
)) {
758 /* The physical eraseblock is supposedly empty */
760 ubi_warn("no EC header found at PEB %d, "
761 "only 0xFF bytes", pnum
);
762 else if (UBI_IO_DEBUG
)
763 dbg_msg("no EC header found at PEB %d, "
764 "only 0xFF bytes", pnum
);
765 return UBI_IO_PEB_EMPTY
;
769 * This is not a valid erase counter header, and these are not
770 * 0xFF bytes. Report that the header is corrupted.
773 ubi_warn("bad magic number at PEB %d: %08x instead of "
774 "%08x", pnum
, magic
, UBI_EC_HDR_MAGIC
);
775 ubi_dbg_dump_ec_hdr(ec_hdr
);
776 } else if (UBI_IO_DEBUG
)
777 dbg_msg("bad magic number at PEB %d: %08x instead of "
778 "%08x", pnum
, magic
, UBI_EC_HDR_MAGIC
);
779 return UBI_IO_BAD_HDR
;
782 crc
= crc32(UBI_CRC32_INIT
, ec_hdr
, UBI_EC_HDR_SIZE_CRC
);
783 hdr_crc
= be32_to_cpu(ec_hdr
->hdr_crc
);
785 if (hdr_crc
!= crc
) {
787 ubi_warn("bad EC header CRC at PEB %d, calculated "
788 "%#08x, read %#08x", pnum
, crc
, hdr_crc
);
789 ubi_dbg_dump_ec_hdr(ec_hdr
);
790 } else if (UBI_IO_DEBUG
)
791 dbg_msg("bad EC header CRC at PEB %d, calculated "
792 "%#08x, read %#08x", pnum
, crc
, hdr_crc
);
793 return read_err
?: UBI_IO_BAD_HDR
;
796 /* And of course validate what has just been read from the media */
797 err
= validate_ec_hdr(ubi
, ec_hdr
);
799 ubi_err("validation failed for PEB %d", pnum
);
804 * If there was %-EBADMSG, but the header CRC is still OK, report about
805 * a bit-flip to force scrubbing on this PEB.
807 return read_err
? UBI_IO_BITFLIPS
: 0;
811 * ubi_io_write_ec_hdr - write an erase counter header.
812 * @ubi: UBI device description object
813 * @pnum: physical eraseblock to write to
814 * @ec_hdr: the erase counter header to write
816 * This function writes erase counter header described by @ec_hdr to physical
817 * eraseblock @pnum. It also fills most fields of @ec_hdr before writing, so
818 * the caller do not have to fill them. Callers must only fill the @ec_hdr->ec
821 * This function returns zero in case of success and a negative error code in
822 * case of failure. If %-EIO is returned, the physical eraseblock most probably
825 int ubi_io_write_ec_hdr(struct ubi_device
*ubi
, int pnum
,
826 struct ubi_ec_hdr
*ec_hdr
)
831 dbg_io("write EC header to PEB %d", pnum
);
832 ubi_assert(pnum
>= 0 && pnum
< ubi
->peb_count
);
834 ec_hdr
->magic
= cpu_to_be32(UBI_EC_HDR_MAGIC
);
835 ec_hdr
->version
= UBI_VERSION
;
836 ec_hdr
->vid_hdr_offset
= cpu_to_be32(ubi
->vid_hdr_offset
);
837 ec_hdr
->data_offset
= cpu_to_be32(ubi
->leb_start
);
838 ec_hdr
->image_seq
= cpu_to_be32(ubi
->image_seq
);
839 crc
= crc32(UBI_CRC32_INIT
, ec_hdr
, UBI_EC_HDR_SIZE_CRC
);
840 ec_hdr
->hdr_crc
= cpu_to_be32(crc
);
842 err
= paranoid_check_ec_hdr(ubi
, pnum
, ec_hdr
);
846 err
= ubi_io_write(ubi
, ec_hdr
, pnum
, 0, ubi
->ec_hdr_alsize
);
851 * validate_vid_hdr - validate a volume identifier header.
852 * @ubi: UBI device description object
853 * @vid_hdr: the volume identifier header to check
855 * This function checks that data stored in the volume identifier header
856 * @vid_hdr. Returns zero if the VID header is OK and %1 if not.
858 static int validate_vid_hdr(const struct ubi_device
*ubi
,
859 const struct ubi_vid_hdr
*vid_hdr
)
861 int vol_type
= vid_hdr
->vol_type
;
862 int copy_flag
= vid_hdr
->copy_flag
;
863 int vol_id
= be32_to_cpu(vid_hdr
->vol_id
);
864 int lnum
= be32_to_cpu(vid_hdr
->lnum
);
865 int compat
= vid_hdr
->compat
;
866 int data_size
= be32_to_cpu(vid_hdr
->data_size
);
867 int used_ebs
= be32_to_cpu(vid_hdr
->used_ebs
);
868 int data_pad
= be32_to_cpu(vid_hdr
->data_pad
);
869 int data_crc
= be32_to_cpu(vid_hdr
->data_crc
);
870 int usable_leb_size
= ubi
->leb_size
- data_pad
;
872 if (copy_flag
!= 0 && copy_flag
!= 1) {
873 dbg_err("bad copy_flag");
877 if (vol_id
< 0 || lnum
< 0 || data_size
< 0 || used_ebs
< 0 ||
879 dbg_err("negative values");
883 if (vol_id
>= UBI_MAX_VOLUMES
&& vol_id
< UBI_INTERNAL_VOL_START
) {
884 dbg_err("bad vol_id");
888 if (vol_id
< UBI_INTERNAL_VOL_START
&& compat
!= 0) {
889 dbg_err("bad compat");
893 if (vol_id
>= UBI_INTERNAL_VOL_START
&& compat
!= UBI_COMPAT_DELETE
&&
894 compat
!= UBI_COMPAT_RO
&& compat
!= UBI_COMPAT_PRESERVE
&&
895 compat
!= UBI_COMPAT_REJECT
) {
896 dbg_err("bad compat");
900 if (vol_type
!= UBI_VID_DYNAMIC
&& vol_type
!= UBI_VID_STATIC
) {
901 dbg_err("bad vol_type");
905 if (data_pad
>= ubi
->leb_size
/ 2) {
906 dbg_err("bad data_pad");
910 if (vol_type
== UBI_VID_STATIC
) {
912 * Although from high-level point of view static volumes may
913 * contain zero bytes of data, but no VID headers can contain
914 * zero at these fields, because they empty volumes do not have
915 * mapped logical eraseblocks.
918 dbg_err("zero used_ebs");
921 if (data_size
== 0) {
922 dbg_err("zero data_size");
925 if (lnum
< used_ebs
- 1) {
926 if (data_size
!= usable_leb_size
) {
927 dbg_err("bad data_size");
930 } else if (lnum
== used_ebs
- 1) {
931 if (data_size
== 0) {
932 dbg_err("bad data_size at last LEB");
936 dbg_err("too high lnum");
940 if (copy_flag
== 0) {
942 dbg_err("non-zero data CRC");
945 if (data_size
!= 0) {
946 dbg_err("non-zero data_size");
950 if (data_size
== 0) {
951 dbg_err("zero data_size of copy");
956 dbg_err("bad used_ebs");
964 ubi_err("bad VID header");
965 ubi_dbg_dump_vid_hdr(vid_hdr
);
966 ubi_dbg_dump_stack();
971 * ubi_io_read_vid_hdr - read and check a volume identifier header.
972 * @ubi: UBI device description object
973 * @pnum: physical eraseblock number to read from
974 * @vid_hdr: &struct ubi_vid_hdr object where to store the read volume
976 * @verbose: be verbose if the header is corrupted or wasn't found
978 * This function reads the volume identifier header from physical eraseblock
979 * @pnum and stores it in @vid_hdr. It also checks CRC checksum of the read
980 * volume identifier header. The following codes may be returned:
982 * o %0 if the CRC checksum is correct and the header was successfully read;
983 * o %UBI_IO_BITFLIPS if the CRC is correct, but bit-flips were detected
984 * and corrected by the flash driver; this is harmless but may indicate that
985 * this eraseblock may become bad soon;
986 * o %UBI_IO_BAD_HDR if the volume identifier header is corrupted (a CRC
988 * o %UBI_IO_BAD_HDR_EBADMSG is the same as %UBI_IO_BAD_HDR, but there also was
989 * a data integrity error (uncorrectable ECC error in case of NAND);
990 * o %UBI_IO_PEB_FREE if the physical eraseblock is free (i.e., there is no VID
992 * o a negative error code in case of failure.
994 int ubi_io_read_vid_hdr(struct ubi_device
*ubi
, int pnum
,
995 struct ubi_vid_hdr
*vid_hdr
, int verbose
)
997 int err
, read_err
= 0;
998 uint32_t crc
, magic
, hdr_crc
;
1001 dbg_io("read VID header from PEB %d", pnum
);
1002 ubi_assert(pnum
>= 0 && pnum
< ubi
->peb_count
);
1004 p
= (char *)vid_hdr
- ubi
->vid_hdr_shift
;
1005 err
= ubi_io_read(ubi
, p
, pnum
, ubi
->vid_hdr_aloffset
,
1006 ubi
->vid_hdr_alsize
);
1008 if (err
!= UBI_IO_BITFLIPS
&& err
!= -EBADMSG
)
1012 * We read all the data, but either a correctable bit-flip
1013 * occurred, or MTD reported a data integrity error
1014 * (uncorrectable ECC error in case of NAND). The former is
1015 * harmless, the later may mean that the read data is
1016 * corrupted. But we have a CRC check-sum and we will detect
1017 * this. If the VID header is still OK, we just report this as
1018 * there was a bit-flip, to force scrubbing.
1020 if (err
== -EBADMSG
)
1021 read_err
= UBI_IO_BAD_HDR_EBADMSG
;
1024 magic
= be32_to_cpu(vid_hdr
->magic
);
1025 if (magic
!= UBI_VID_HDR_MAGIC
) {
1030 * If we have read all 0xFF bytes, the VID header probably does
1031 * not exist and the physical eraseblock is assumed to be free.
1033 if (check_pattern(vid_hdr
, 0xFF, UBI_VID_HDR_SIZE
)) {
1034 /* The physical eraseblock is supposedly free */
1036 ubi_warn("no VID header found at PEB %d, "
1037 "only 0xFF bytes", pnum
);
1038 else if (UBI_IO_DEBUG
)
1039 dbg_msg("no VID header found at PEB %d, "
1040 "only 0xFF bytes", pnum
);
1041 return UBI_IO_PEB_FREE
;
1045 * This is not a valid VID header, and these are not 0xFF
1046 * bytes. Report that the header is corrupted.
1049 ubi_warn("bad magic number at PEB %d: %08x instead of "
1050 "%08x", pnum
, magic
, UBI_VID_HDR_MAGIC
);
1051 ubi_dbg_dump_vid_hdr(vid_hdr
);
1052 } else if (UBI_IO_DEBUG
)
1053 dbg_msg("bad magic number at PEB %d: %08x instead of "
1054 "%08x", pnum
, magic
, UBI_VID_HDR_MAGIC
);
1055 return UBI_IO_BAD_HDR
;
1058 crc
= crc32(UBI_CRC32_INIT
, vid_hdr
, UBI_VID_HDR_SIZE_CRC
);
1059 hdr_crc
= be32_to_cpu(vid_hdr
->hdr_crc
);
1061 if (hdr_crc
!= crc
) {
1063 ubi_warn("bad CRC at PEB %d, calculated %#08x, "
1064 "read %#08x", pnum
, crc
, hdr_crc
);
1065 ubi_dbg_dump_vid_hdr(vid_hdr
);
1066 } else if (UBI_IO_DEBUG
)
1067 dbg_msg("bad CRC at PEB %d, calculated %#08x, "
1068 "read %#08x", pnum
, crc
, hdr_crc
);
1069 return read_err
?: UBI_IO_BAD_HDR
;
1072 /* Validate the VID header that we have just read */
1073 err
= validate_vid_hdr(ubi
, vid_hdr
);
1075 ubi_err("validation failed for PEB %d", pnum
);
1080 * If there was a read error (%-EBADMSG), but the header CRC is still
1081 * OK, report about a bit-flip to force scrubbing on this PEB.
1083 return read_err
? UBI_IO_BITFLIPS
: 0;
1087 * ubi_io_write_vid_hdr - write a volume identifier header.
1088 * @ubi: UBI device description object
1089 * @pnum: the physical eraseblock number to write to
1090 * @vid_hdr: the volume identifier header to write
1092 * This function writes the volume identifier header described by @vid_hdr to
1093 * physical eraseblock @pnum. This function automatically fills the
1094 * @vid_hdr->magic and the @vid_hdr->version fields, as well as calculates
1095 * header CRC checksum and stores it at vid_hdr->hdr_crc.
1097 * This function returns zero in case of success and a negative error code in
1098 * case of failure. If %-EIO is returned, the physical eraseblock probably went
1101 int ubi_io_write_vid_hdr(struct ubi_device
*ubi
, int pnum
,
1102 struct ubi_vid_hdr
*vid_hdr
)
1108 dbg_io("write VID header to PEB %d", pnum
);
1109 ubi_assert(pnum
>= 0 && pnum
< ubi
->peb_count
);
1111 err
= paranoid_check_peb_ec_hdr(ubi
, pnum
);
1115 vid_hdr
->magic
= cpu_to_be32(UBI_VID_HDR_MAGIC
);
1116 vid_hdr
->version
= UBI_VERSION
;
1117 crc
= crc32(UBI_CRC32_INIT
, vid_hdr
, UBI_VID_HDR_SIZE_CRC
);
1118 vid_hdr
->hdr_crc
= cpu_to_be32(crc
);
1120 err
= paranoid_check_vid_hdr(ubi
, pnum
, vid_hdr
);
1124 p
= (char *)vid_hdr
- ubi
->vid_hdr_shift
;
1125 err
= ubi_io_write(ubi
, p
, pnum
, ubi
->vid_hdr_aloffset
,
1126 ubi
->vid_hdr_alsize
);
1130 #ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
1133 * paranoid_check_not_bad - ensure that a physical eraseblock is not bad.
1134 * @ubi: UBI device description object
1135 * @pnum: physical eraseblock number to check
1137 * This function returns zero if the physical eraseblock is good, %-EINVAL if
1138 * it is bad and a negative error code if an error occurred.
1140 static int paranoid_check_not_bad(const struct ubi_device
*ubi
, int pnum
)
1144 err
= ubi_io_is_bad(ubi
, pnum
);
1148 ubi_err("paranoid check failed for PEB %d", pnum
);
1149 ubi_dbg_dump_stack();
1150 return err
> 0 ? -EINVAL
: err
;
1154 * paranoid_check_ec_hdr - check if an erase counter header is all right.
1155 * @ubi: UBI device description object
1156 * @pnum: physical eraseblock number the erase counter header belongs to
1157 * @ec_hdr: the erase counter header to check
1159 * This function returns zero if the erase counter header contains valid
1160 * values, and %-EINVAL if not.
1162 static int paranoid_check_ec_hdr(const struct ubi_device
*ubi
, int pnum
,
1163 const struct ubi_ec_hdr
*ec_hdr
)
1168 magic
= be32_to_cpu(ec_hdr
->magic
);
1169 if (magic
!= UBI_EC_HDR_MAGIC
) {
1170 ubi_err("bad magic %#08x, must be %#08x",
1171 magic
, UBI_EC_HDR_MAGIC
);
1175 err
= validate_ec_hdr(ubi
, ec_hdr
);
1177 ubi_err("paranoid check failed for PEB %d", pnum
);
1184 ubi_dbg_dump_ec_hdr(ec_hdr
);
1185 ubi_dbg_dump_stack();
1190 * paranoid_check_peb_ec_hdr - check erase counter header.
1191 * @ubi: UBI device description object
1192 * @pnum: the physical eraseblock number to check
1194 * This function returns zero if the erase counter header is all right and and
1195 * a negative error code if not or if an error occurred.
1197 static int paranoid_check_peb_ec_hdr(const struct ubi_device
*ubi
, int pnum
)
1200 uint32_t crc
, hdr_crc
;
1201 struct ubi_ec_hdr
*ec_hdr
;
1203 ec_hdr
= kzalloc(ubi
->ec_hdr_alsize
, GFP_NOFS
);
1207 err
= ubi_io_read(ubi
, ec_hdr
, pnum
, 0, UBI_EC_HDR_SIZE
);
1208 if (err
&& err
!= UBI_IO_BITFLIPS
&& err
!= -EBADMSG
)
1211 crc
= crc32(UBI_CRC32_INIT
, ec_hdr
, UBI_EC_HDR_SIZE_CRC
);
1212 hdr_crc
= be32_to_cpu(ec_hdr
->hdr_crc
);
1213 if (hdr_crc
!= crc
) {
1214 ubi_err("bad CRC, calculated %#08x, read %#08x", crc
, hdr_crc
);
1215 ubi_err("paranoid check failed for PEB %d", pnum
);
1216 ubi_dbg_dump_ec_hdr(ec_hdr
);
1217 ubi_dbg_dump_stack();
1222 err
= paranoid_check_ec_hdr(ubi
, pnum
, ec_hdr
);
1230 * paranoid_check_vid_hdr - check that a volume identifier header is all right.
1231 * @ubi: UBI device description object
1232 * @pnum: physical eraseblock number the volume identifier header belongs to
1233 * @vid_hdr: the volume identifier header to check
1235 * This function returns zero if the volume identifier header is all right, and
1238 static int paranoid_check_vid_hdr(const struct ubi_device
*ubi
, int pnum
,
1239 const struct ubi_vid_hdr
*vid_hdr
)
1244 magic
= be32_to_cpu(vid_hdr
->magic
);
1245 if (magic
!= UBI_VID_HDR_MAGIC
) {
1246 ubi_err("bad VID header magic %#08x at PEB %d, must be %#08x",
1247 magic
, pnum
, UBI_VID_HDR_MAGIC
);
1251 err
= validate_vid_hdr(ubi
, vid_hdr
);
1253 ubi_err("paranoid check failed for PEB %d", pnum
);
1260 ubi_err("paranoid check failed for PEB %d", pnum
);
1261 ubi_dbg_dump_vid_hdr(vid_hdr
);
1262 ubi_dbg_dump_stack();
1268 * paranoid_check_peb_vid_hdr - check volume identifier header.
1269 * @ubi: UBI device description object
1270 * @pnum: the physical eraseblock number to check
1272 * This function returns zero if the volume identifier header is all right,
1273 * and a negative error code if not or if an error occurred.
1275 static int paranoid_check_peb_vid_hdr(const struct ubi_device
*ubi
, int pnum
)
1278 uint32_t crc
, hdr_crc
;
1279 struct ubi_vid_hdr
*vid_hdr
;
1282 vid_hdr
= ubi_zalloc_vid_hdr(ubi
, GFP_NOFS
);
1286 p
= (char *)vid_hdr
- ubi
->vid_hdr_shift
;
1287 err
= ubi_io_read(ubi
, p
, pnum
, ubi
->vid_hdr_aloffset
,
1288 ubi
->vid_hdr_alsize
);
1289 if (err
&& err
!= UBI_IO_BITFLIPS
&& err
!= -EBADMSG
)
1292 crc
= crc32(UBI_CRC32_INIT
, vid_hdr
, UBI_EC_HDR_SIZE_CRC
);
1293 hdr_crc
= be32_to_cpu(vid_hdr
->hdr_crc
);
1294 if (hdr_crc
!= crc
) {
1295 ubi_err("bad VID header CRC at PEB %d, calculated %#08x, "
1296 "read %#08x", pnum
, crc
, hdr_crc
);
1297 ubi_err("paranoid check failed for PEB %d", pnum
);
1298 ubi_dbg_dump_vid_hdr(vid_hdr
);
1299 ubi_dbg_dump_stack();
1304 err
= paranoid_check_vid_hdr(ubi
, pnum
, vid_hdr
);
1307 ubi_free_vid_hdr(ubi
, vid_hdr
);
1312 * ubi_dbg_check_write - make sure write succeeded.
1313 * @ubi: UBI device description object
1314 * @buf: buffer with data which were written
1315 * @pnum: physical eraseblock number the data were written to
1316 * @offset: offset within the physical eraseblock the data were written to
1317 * @len: how many bytes were written
1319 * This functions reads data which were recently written and compares it with
1320 * the original data buffer - the data have to match. Returns zero if the data
1321 * match and a negative error code if not or in case of failure.
1323 int ubi_dbg_check_write(struct ubi_device
*ubi
, const void *buf
, int pnum
,
1324 int offset
, int len
)
1328 mutex_lock(&ubi
->dbg_buf_mutex
);
1329 err
= ubi_io_read(ubi
, ubi
->dbg_peb_buf
, pnum
, offset
, len
);
1333 for (i
= 0; i
< len
; i
++) {
1334 uint8_t c
= ((uint8_t *)buf
)[i
];
1335 uint8_t c1
= ((uint8_t *)ubi
->dbg_peb_buf
)[i
];
1341 ubi_err("paranoid check failed for PEB %d:%d, len %d",
1343 ubi_msg("data differ at position %d", i
);
1344 dump_len
= max_t(int, 128, len
- i
);
1345 ubi_msg("hex dump of the original buffer from %d to %d",
1347 print_hex_dump(KERN_DEBUG
, "", DUMP_PREFIX_OFFSET
, 32, 1,
1348 buf
+ i
, dump_len
, 1);
1349 ubi_msg("hex dump of the read buffer from %d to %d",
1351 print_hex_dump(KERN_DEBUG
, "", DUMP_PREFIX_OFFSET
, 32, 1,
1352 ubi
->dbg_peb_buf
+ i
, dump_len
, 1);
1353 ubi_dbg_dump_stack();
1357 mutex_unlock(&ubi
->dbg_buf_mutex
);
1362 mutex_unlock(&ubi
->dbg_buf_mutex
);
1367 * ubi_dbg_check_all_ff - check that a region of flash is empty.
1368 * @ubi: UBI device description object
1369 * @pnum: the physical eraseblock number to check
1370 * @offset: the starting offset within the physical eraseblock to check
1371 * @len: the length of the region to check
1373 * This function returns zero if only 0xFF bytes are present at offset
1374 * @offset of the physical eraseblock @pnum, and a negative error code if not
1375 * or if an error occurred.
1377 int ubi_dbg_check_all_ff(struct ubi_device
*ubi
, int pnum
, int offset
, int len
)
1381 loff_t addr
= (loff_t
)pnum
* ubi
->peb_size
+ offset
;
1383 mutex_lock(&ubi
->dbg_buf_mutex
);
1384 err
= ubi
->mtd
->read(ubi
->mtd
, addr
, len
, &read
, ubi
->dbg_peb_buf
);
1385 if (err
&& err
!= -EUCLEAN
) {
1386 ubi_err("error %d while reading %d bytes from PEB %d:%d, "
1387 "read %zd bytes", err
, len
, pnum
, offset
, read
);
1391 err
= check_pattern(ubi
->dbg_peb_buf
, 0xFF, len
);
1393 ubi_err("flash region at PEB %d:%d, length %d does not "
1394 "contain all 0xFF bytes", pnum
, offset
, len
);
1397 mutex_unlock(&ubi
->dbg_buf_mutex
);
1402 ubi_err("paranoid check failed for PEB %d", pnum
);
1403 ubi_msg("hex dump of the %d-%d region", offset
, offset
+ len
);
1404 print_hex_dump(KERN_DEBUG
, "", DUMP_PREFIX_OFFSET
, 32, 1,
1405 ubi
->dbg_peb_buf
, len
, 1);
1408 ubi_dbg_dump_stack();
1409 mutex_unlock(&ubi
->dbg_buf_mutex
);
1413 #endif /* CONFIG_MTD_UBI_DEBUG_PARANOID */
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