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 unit.
25 * This unit provides a uniform way to work with all kinds of the underlying
26 * MTD devices. It also implements handy functions for reading and writing UBI
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 unit
31 * 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 no relevant to the sub-page are 0xFF. So, basically, writing
68 * 4x512 sub-pages is 4 times slower then writing one 2KiB NAND page. Thus, we
69 * prefer to use sub-pages only for EV 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 unit does the following trick in order to avoid this extra copy.
83 * It always allocates a @ubi->vid_hdr_alsize bytes buffer for the VID header
84 * and returns a pointer to offset @ubi->vid_hdr_shift of this buffer. When the
85 * VID header is being written out, it shifts the VID header pointer back and
86 * writes the whole sub-page.
89 #include <linux/crc32.h>
90 #include <linux/err.h>
93 #ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
94 static int paranoid_check_not_bad(const struct ubi_device *ubi, int pnum);
95 static int paranoid_check_peb_ec_hdr(const struct ubi_device *ubi, int pnum);
96 static int paranoid_check_ec_hdr(const struct ubi_device *ubi, int pnum,
97 const struct ubi_ec_hdr *ec_hdr);
98 static int paranoid_check_peb_vid_hdr(const struct ubi_device *ubi, int pnum);
99 static int paranoid_check_vid_hdr(const struct ubi_device *ubi, int pnum,
100 const struct ubi_vid_hdr *vid_hdr);
101 static int paranoid_check_all_ff(const struct ubi_device *ubi, int pnum,
102 int offset, int len);
104 #define paranoid_check_not_bad(ubi, pnum) 0
105 #define paranoid_check_peb_ec_hdr(ubi, pnum) 0
106 #define paranoid_check_ec_hdr(ubi, pnum, ec_hdr) 0
107 #define paranoid_check_peb_vid_hdr(ubi, pnum) 0
108 #define paranoid_check_vid_hdr(ubi, pnum, vid_hdr) 0
109 #define paranoid_check_all_ff(ubi, pnum, offset, len) 0
113 * ubi_io_read - read data from a physical eraseblock.
114 * @ubi: UBI device description object
115 * @buf: buffer where to store the read data
116 * @pnum: physical eraseblock number to read from
117 * @offset: offset within the physical eraseblock from where to read
118 * @len: how many bytes to read
120 * This function reads data from offset @offset of physical eraseblock @pnum
121 * and stores the read data in the @buf buffer. The following return codes are
124 * o %0 if all the requested data were successfully read;
125 * o %UBI_IO_BITFLIPS if all the requested data were successfully read, but
126 * correctable bit-flips were detected; this is harmless but may indicate
127 * that this eraseblock may become bad soon (but do not have to);
128 * o %-EBADMSG if the MTD subsystem reported about data integrity problems, for
129 * example it can be an ECC error in case of NAND; this most probably means
130 * that the data is corrupted;
131 * o %-EIO if some I/O error occurred;
132 * o other negative error codes in case of other errors.
134 int ubi_io_read(const struct ubi_device *ubi, void *buf, int pnum, int offset,
137 int err, retries = 0;
141 dbg_io("read %d bytes from PEB %d:%d", len, pnum, offset);
143 ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
144 ubi_assert(offset >= 0 && offset + len <= ubi->peb_size);
147 err = paranoid_check_not_bad(ubi, pnum);
149 return err > 0 ? -EINVAL : err;
151 addr = (loff_t)pnum * ubi->peb_size + offset;
153 err = ubi->mtd->read(ubi->mtd, addr, len, &read, buf);
155 if (err == -EUCLEAN) {
157 * -EUCLEAN is reported if there was a bit-flip which
158 * was corrected, so this is harmless.
160 ubi_msg("fixable bit-flip detected at PEB %d", pnum);
161 ubi_assert(len == read);
162 return UBI_IO_BITFLIPS;
165 if (read != len && retries++ < UBI_IO_RETRIES) {
166 dbg_io("error %d while reading %d bytes from PEB %d:%d, "
167 "read only %zd bytes, retry",
168 err, len, pnum, offset, read);
173 ubi_err("error %d while reading %d bytes from PEB %d:%d, "
174 "read %zd bytes", err, len, pnum, offset, read);
175 ubi_dbg_dump_stack();
177 ubi_assert(len == read);
179 if (ubi_dbg_is_bitflip()) {
180 dbg_msg("bit-flip (emulated)");
181 err = UBI_IO_BITFLIPS;
189 * ubi_io_write - write data to a physical eraseblock.
190 * @ubi: UBI device description object
191 * @buf: buffer with the data to write
192 * @pnum: physical eraseblock number to write to
193 * @offset: offset within the physical eraseblock where to write
194 * @len: how many bytes to write
196 * This function writes @len bytes of data from buffer @buf to offset @offset
197 * of physical eraseblock @pnum. If all the data were successfully written,
198 * zero is returned. If an error occurred, this function returns a negative
199 * error code. If %-EIO is returned, the physical eraseblock most probably went
202 * Note, in case of an error, it is possible that something was still written
203 * to the flash media, but may be some garbage.
205 int ubi_io_write(const struct ubi_device *ubi, const void *buf, int pnum,
212 dbg_io("write %d bytes to PEB %d:%d", len, pnum, offset);
214 ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
215 ubi_assert(offset >= 0 && offset + len <= ubi->peb_size);
216 ubi_assert(offset % ubi->hdrs_min_io_size == 0);
217 ubi_assert(len > 0 && len % ubi->hdrs_min_io_size == 0);
220 ubi_err("read-only mode");
224 /* The below has to be compiled out if paranoid checks are disabled */
226 err = paranoid_check_not_bad(ubi, pnum);
228 return err > 0 ? -EINVAL : err;
230 /* The area we are writing to has to contain all 0xFF bytes */
231 err = paranoid_check_all_ff(ubi, pnum, offset, len);
233 return err > 0 ? -EINVAL : err;
235 if (offset >= ubi->leb_start) {
237 * We write to the data area of the physical eraseblock. Make
238 * sure it has valid EC and VID headers.
240 err = paranoid_check_peb_ec_hdr(ubi, pnum);
242 return err > 0 ? -EINVAL : err;
243 err = paranoid_check_peb_vid_hdr(ubi, pnum);
245 return err > 0 ? -EINVAL : err;
248 if (ubi_dbg_is_write_failure()) {
249 dbg_err("cannot write %d bytes to PEB %d:%d "
250 "(emulated)", len, pnum, offset);
251 ubi_dbg_dump_stack();
255 addr = (loff_t)pnum * ubi->peb_size + offset;
256 err = ubi->mtd->write(ubi->mtd, addr, len, &written, buf);
258 ubi_err("error %d while writing %d bytes to PEB %d:%d, written"
259 " %zd bytes", err, len, pnum, offset, written);
260 ubi_dbg_dump_stack();
262 ubi_assert(written == len);
268 * erase_callback - MTD erasure call-back.
269 * @ei: MTD erase information object.
271 * Note, even though MTD erase interface is asynchronous, all the current
272 * implementations are synchronous anyway.
274 static void erase_callback(struct erase_info *ei)
276 wake_up_interruptible((wait_queue_head_t *)ei->priv);
280 * do_sync_erase - synchronously erase a physical eraseblock.
281 * @ubi: UBI device description object
282 * @pnum: the physical eraseblock number to erase
284 * This function synchronously erases physical eraseblock @pnum and returns
285 * zero in case of success and a negative error code in case of failure. If
286 * %-EIO is returned, the physical eraseblock most probably went bad.
288 static int do_sync_erase(const struct ubi_device *ubi, int pnum)
290 int err, retries = 0;
291 struct erase_info ei;
292 wait_queue_head_t wq;
294 dbg_io("erase PEB %d", pnum);
297 init_waitqueue_head(&wq);
298 memset(&ei, 0, sizeof(struct erase_info));
301 ei.addr = (loff_t)pnum * ubi->peb_size;
302 ei.len = ubi->peb_size;
303 ei.callback = erase_callback;
304 ei.priv = (unsigned long)&wq;
306 err = ubi->mtd->erase(ubi->mtd, &ei);
308 if (retries++ < UBI_IO_RETRIES) {
309 dbg_io("error %d while erasing PEB %d, retry",
314 ubi_err("cannot erase PEB %d, error %d", pnum, err);
315 ubi_dbg_dump_stack();
319 err = wait_event_interruptible(wq, ei.state == MTD_ERASE_DONE ||
320 ei.state == MTD_ERASE_FAILED);
322 ubi_err("interrupted PEB %d erasure", pnum);
326 if (ei.state == MTD_ERASE_FAILED) {
327 if (retries++ < UBI_IO_RETRIES) {
328 dbg_io("error while erasing PEB %d, retry", pnum);
332 ubi_err("cannot erase PEB %d", pnum);
333 ubi_dbg_dump_stack();
337 err = paranoid_check_all_ff(ubi, pnum, 0, ubi->peb_size);
339 return err > 0 ? -EINVAL : err;
341 if (ubi_dbg_is_erase_failure() && !err) {
342 dbg_err("cannot erase PEB %d (emulated)", pnum);
350 * check_pattern - check if buffer contains only a certain byte pattern.
351 * @buf: buffer to check
352 * @patt: the pattern to check
353 * @size: buffer size in bytes
355 * This function returns %1 in there are only @patt bytes in @buf, and %0 if
356 * something else was also found.
358 static int check_pattern(const void *buf, uint8_t patt, int size)
362 for (i = 0; i < size; i++)
363 if (((const uint8_t *)buf)[i] != patt)
368 /* Patterns to write to a physical eraseblock when torturing it */
369 static uint8_t patterns[] = {0xa5, 0x5a, 0x0};
372 * torture_peb - test a supposedly bad physical eraseblock.
373 * @ubi: UBI device description object
374 * @pnum: the physical eraseblock number to test
376 * This function returns %-EIO if the physical eraseblock did not pass the
377 * test, a positive number of erase operations done if the test was
378 * successfully passed, and other negative error codes in case of other errors.
380 static int torture_peb(const struct ubi_device *ubi, int pnum)
383 int err, i, patt_count;
385 buf = vmalloc(ubi->peb_size);
389 patt_count = ARRAY_SIZE(patterns);
390 ubi_assert(patt_count > 0);
392 for (i = 0; i < patt_count; i++) {
393 err = do_sync_erase(ubi, pnum);
397 /* Make sure the PEB contains only 0xFF bytes */
398 err = ubi_io_read(ubi, buf, pnum, 0, ubi->peb_size);
402 err = check_pattern(buf, 0xFF, ubi->peb_size);
404 ubi_err("erased PEB %d, but a non-0xFF byte found",
410 /* Write a pattern and check it */
411 memset(buf, patterns[i], ubi->peb_size);
412 err = ubi_io_write(ubi, buf, pnum, 0, ubi->peb_size);
416 memset(buf, ~patterns[i], ubi->peb_size);
417 err = ubi_io_read(ubi, buf, pnum, 0, ubi->peb_size);
421 err = check_pattern(buf, patterns[i], ubi->peb_size);
423 ubi_err("pattern %x checking failed for PEB %d",
433 if (err == UBI_IO_BITFLIPS || err == -EBADMSG) {
435 * If a bit-flip or data integrity error was detected, the test
436 * has not passed because it happened on a freshly erased
437 * physical eraseblock which means something is wrong with it.
439 ubi_err("read problems on freshly erased PEB %d, must be bad",
448 * ubi_io_sync_erase - synchronously erase a physical eraseblock.
449 * @ubi: UBI device description object
450 * @pnum: physical eraseblock number to erase
451 * @torture: if this physical eraseblock has to be tortured
453 * This function synchronously erases physical eraseblock @pnum. If @torture
454 * flag is not zero, the physical eraseblock is checked by means of writing
455 * different patterns to it and reading them back. If the torturing is enabled,
456 * the physical eraseblock is erased more then once.
458 * This function returns the number of erasures made in case of success, %-EIO
459 * if the erasure failed or the torturing test failed, and other negative error
460 * codes in case of other errors. Note, %-EIO means that the physical
463 int ubi_io_sync_erase(const struct ubi_device *ubi, int pnum, int torture)
467 ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
469 err = paranoid_check_not_bad(ubi, pnum);
471 return err > 0 ? -EINVAL : err;
474 ubi_err("read-only mode");
479 ret = torture_peb(ubi, pnum);
484 err = do_sync_erase(ubi, pnum);
492 * ubi_io_is_bad - check if a physical eraseblock is bad.
493 * @ubi: UBI device description object
494 * @pnum: the physical eraseblock number to check
496 * This function returns a positive number if the physical eraseblock is bad,
497 * zero if not, and a negative error code if an error occurred.
499 int ubi_io_is_bad(const struct ubi_device *ubi, int pnum)
501 struct mtd_info *mtd = ubi->mtd;
503 ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
505 if (ubi->bad_allowed) {
508 ret = mtd->block_isbad(mtd, (loff_t)pnum * ubi->peb_size);
510 ubi_err("error %d while checking if PEB %d is bad",
513 dbg_io("PEB %d is bad", pnum);
521 * ubi_io_mark_bad - mark a physical eraseblock as bad.
522 * @ubi: UBI device description object
523 * @pnum: the physical eraseblock number to mark
525 * This function returns zero in case of success and a negative error code in
528 int ubi_io_mark_bad(const struct ubi_device *ubi, int pnum)
531 struct mtd_info *mtd = ubi->mtd;
533 ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
536 ubi_err("read-only mode");
540 if (!ubi->bad_allowed)
543 err = mtd->block_markbad(mtd, (loff_t)pnum * ubi->peb_size);
545 ubi_err("cannot mark PEB %d bad, error %d", pnum, err);
550 * validate_ec_hdr - validate an erase counter header.
551 * @ubi: UBI device description object
552 * @ec_hdr: the erase counter header to check
554 * This function returns zero if the erase counter header is OK, and %1 if
557 static int validate_ec_hdr(const struct ubi_device *ubi,
558 const struct ubi_ec_hdr *ec_hdr)
561 int vid_hdr_offset, leb_start;
563 ec = be64_to_cpu(ec_hdr->ec);
564 vid_hdr_offset = be32_to_cpu(ec_hdr->vid_hdr_offset);
565 leb_start = be32_to_cpu(ec_hdr->data_offset);
567 if (ec_hdr->version != UBI_VERSION) {
568 ubi_err("node with incompatible UBI version found: "
569 "this UBI version is %d, image version is %d",
570 UBI_VERSION, (int)ec_hdr->version);
574 if (vid_hdr_offset != ubi->vid_hdr_offset) {
575 ubi_err("bad VID header offset %d, expected %d",
576 vid_hdr_offset, ubi->vid_hdr_offset);
580 if (leb_start != ubi->leb_start) {
581 ubi_err("bad data offset %d, expected %d",
582 leb_start, ubi->leb_start);
586 if (ec < 0 || ec > UBI_MAX_ERASECOUNTER) {
587 ubi_err("bad erase counter %lld", ec);
594 ubi_err("bad EC header");
595 ubi_dbg_dump_ec_hdr(ec_hdr);
596 ubi_dbg_dump_stack();
601 * ubi_io_read_ec_hdr - read and check an erase counter header.
602 * @ubi: UBI device description object
603 * @pnum: physical eraseblock to read from
604 * @ec_hdr: a &struct ubi_ec_hdr object where to store the read erase counter
606 * @verbose: be verbose if the header is corrupted or was not found
608 * This function reads erase counter header from physical eraseblock @pnum and
609 * stores it in @ec_hdr. This function also checks CRC checksum of the read
610 * erase counter header. The following codes may be returned:
612 * o %0 if the CRC checksum is correct and the header was successfully read;
613 * o %UBI_IO_BITFLIPS if the CRC is correct, but bit-flips were detected
614 * and corrected by the flash driver; this is harmless but may indicate that
615 * this eraseblock may become bad soon (but may be not);
616 * o %UBI_IO_BAD_EC_HDR if the erase counter header is corrupted (a CRC error);
617 * o %UBI_IO_PEB_EMPTY if the physical eraseblock is empty;
618 * o a negative error code in case of failure.
620 int ubi_io_read_ec_hdr(const struct ubi_device *ubi, int pnum,
621 struct ubi_ec_hdr *ec_hdr, int verbose)
623 int err, read_err = 0;
624 uint32_t crc, magic, hdr_crc;
626 dbg_io("read EC header from PEB %d", pnum);
627 ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
629 err = ubi_io_read(ubi, ec_hdr, pnum, 0, UBI_EC_HDR_SIZE);
631 if (err != UBI_IO_BITFLIPS && err != -EBADMSG)
635 * We read all the data, but either a correctable bit-flip
636 * occurred, or MTD reported about some data integrity error,
637 * like an ECC error in case of NAND. The former is harmless,
638 * the later may mean that the read data is corrupted. But we
639 * have a CRC check-sum and we will detect this. If the EC
640 * header is still OK, we just report this as there was a
646 magic = be32_to_cpu(ec_hdr->magic);
647 if (magic != UBI_EC_HDR_MAGIC) {
649 * The magic field is wrong. Let's check if we have read all
650 * 0xFF. If yes, this physical eraseblock is assumed to be
653 * But if there was a read error, we do not test it for all
654 * 0xFFs. Even if it does contain all 0xFFs, this error
655 * indicates that something is still wrong with this physical
656 * eraseblock and we anyway cannot treat it as empty.
658 if (read_err != -EBADMSG &&
659 check_pattern(ec_hdr, 0xFF, UBI_EC_HDR_SIZE)) {
660 /* The physical eraseblock is supposedly empty */
663 * The below is just a paranoid check, it has to be
664 * compiled out if paranoid checks are disabled.
666 err = paranoid_check_all_ff(ubi, pnum, 0,
669 return err > 0 ? UBI_IO_BAD_EC_HDR : err;
672 ubi_warn("no EC header found at PEB %d, "
673 "only 0xFF bytes", pnum);
674 return UBI_IO_PEB_EMPTY;
678 * This is not a valid erase counter header, and these are not
679 * 0xFF bytes. Report that the header is corrupted.
682 ubi_warn("bad magic number at PEB %d: %08x instead of "
683 "%08x", pnum, magic, UBI_EC_HDR_MAGIC);
684 ubi_dbg_dump_ec_hdr(ec_hdr);
686 return UBI_IO_BAD_EC_HDR;
689 crc = crc32(UBI_CRC32_INIT, ec_hdr, UBI_EC_HDR_SIZE_CRC);
690 hdr_crc = be32_to_cpu(ec_hdr->hdr_crc);
692 if (hdr_crc != crc) {
694 ubi_warn("bad EC header CRC at PEB %d, calculated %#08x,"
695 " read %#08x", pnum, crc, hdr_crc);
696 ubi_dbg_dump_ec_hdr(ec_hdr);
698 return UBI_IO_BAD_EC_HDR;
701 /* And of course validate what has just been read from the media */
702 err = validate_ec_hdr(ubi, ec_hdr);
704 ubi_err("validation failed for PEB %d", pnum);
708 return read_err ? UBI_IO_BITFLIPS : 0;
712 * ubi_io_write_ec_hdr - write an erase counter header.
713 * @ubi: UBI device description object
714 * @pnum: physical eraseblock to write to
715 * @ec_hdr: the erase counter header to write
717 * This function writes erase counter header described by @ec_hdr to physical
718 * eraseblock @pnum. It also fills most fields of @ec_hdr before writing, so
719 * the caller do not have to fill them. Callers must only fill the @ec_hdr->ec
722 * This function returns zero in case of success and a negative error code in
723 * case of failure. If %-EIO is returned, the physical eraseblock most probably
726 int ubi_io_write_ec_hdr(const struct ubi_device *ubi, int pnum,
727 struct ubi_ec_hdr *ec_hdr)
732 dbg_io("write EC header to PEB %d", pnum);
733 ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
735 ec_hdr->magic = cpu_to_be32(UBI_EC_HDR_MAGIC);
736 ec_hdr->version = UBI_VERSION;
737 ec_hdr->vid_hdr_offset = cpu_to_be32(ubi->vid_hdr_offset);
738 ec_hdr->data_offset = cpu_to_be32(ubi->leb_start);
739 crc = crc32(UBI_CRC32_INIT, ec_hdr, UBI_EC_HDR_SIZE_CRC);
740 ec_hdr->hdr_crc = cpu_to_be32(crc);
742 err = paranoid_check_ec_hdr(ubi, pnum, ec_hdr);
746 err = ubi_io_write(ubi, ec_hdr, pnum, 0, ubi->ec_hdr_alsize);
751 * validate_vid_hdr - validate a volume identifier header.
752 * @ubi: UBI device description object
753 * @vid_hdr: the volume identifier header to check
755 * This function checks that data stored in the volume identifier header
756 * @vid_hdr. Returns zero if the VID header is OK and %1 if not.
758 static int validate_vid_hdr(const struct ubi_device *ubi,
759 const struct ubi_vid_hdr *vid_hdr)
761 int vol_type = vid_hdr->vol_type;
762 int copy_flag = vid_hdr->copy_flag;
763 int vol_id = be32_to_cpu(vid_hdr->vol_id);
764 int lnum = be32_to_cpu(vid_hdr->lnum);
765 int compat = vid_hdr->compat;
766 int data_size = be32_to_cpu(vid_hdr->data_size);
767 int used_ebs = be32_to_cpu(vid_hdr->used_ebs);
768 int data_pad = be32_to_cpu(vid_hdr->data_pad);
769 int data_crc = be32_to_cpu(vid_hdr->data_crc);
770 int usable_leb_size = ubi->leb_size - data_pad;
772 if (copy_flag != 0 && copy_flag != 1) {
773 dbg_err("bad copy_flag");
777 if (vol_id < 0 || lnum < 0 || data_size < 0 || used_ebs < 0 ||
779 dbg_err("negative values");
783 if (vol_id >= UBI_MAX_VOLUMES && vol_id < UBI_INTERNAL_VOL_START) {
784 dbg_err("bad vol_id");
788 if (vol_id < UBI_INTERNAL_VOL_START && compat != 0) {
789 dbg_err("bad compat");
793 if (vol_id >= UBI_INTERNAL_VOL_START && compat != UBI_COMPAT_DELETE &&
794 compat != UBI_COMPAT_RO && compat != UBI_COMPAT_PRESERVE &&
795 compat != UBI_COMPAT_REJECT) {
796 dbg_err("bad compat");
800 if (vol_type != UBI_VID_DYNAMIC && vol_type != UBI_VID_STATIC) {
801 dbg_err("bad vol_type");
805 if (data_pad >= ubi->leb_size / 2) {
806 dbg_err("bad data_pad");
810 if (vol_type == UBI_VID_STATIC) {
812 * Although from high-level point of view static volumes may
813 * contain zero bytes of data, but no VID headers can contain
814 * zero at these fields, because they empty volumes do not have
815 * mapped logical eraseblocks.
818 dbg_err("zero used_ebs");
821 if (data_size == 0) {
822 dbg_err("zero data_size");
825 if (lnum < used_ebs - 1) {
826 if (data_size != usable_leb_size) {
827 dbg_err("bad data_size");
830 } else if (lnum == used_ebs - 1) {
831 if (data_size == 0) {
832 dbg_err("bad data_size at last LEB");
836 dbg_err("too high lnum");
840 if (copy_flag == 0) {
842 dbg_err("non-zero data CRC");
845 if (data_size != 0) {
846 dbg_err("non-zero data_size");
850 if (data_size == 0) {
851 dbg_err("zero data_size of copy");
856 dbg_err("bad used_ebs");
864 ubi_err("bad VID header");
865 ubi_dbg_dump_vid_hdr(vid_hdr);
866 ubi_dbg_dump_stack();
871 * ubi_io_read_vid_hdr - read and check a volume identifier header.
872 * @ubi: UBI device description object
873 * @pnum: physical eraseblock number to read from
874 * @vid_hdr: &struct ubi_vid_hdr object where to store the read volume
876 * @verbose: be verbose if the header is corrupted or wasn't found
878 * This function reads the volume identifier header from physical eraseblock
879 * @pnum and stores it in @vid_hdr. It also checks CRC checksum of the read
880 * volume identifier header. The following codes may be returned:
882 * o %0 if the CRC checksum is correct and the header was successfully read;
883 * o %UBI_IO_BITFLIPS if the CRC is correct, but bit-flips were detected
884 * and corrected by the flash driver; this is harmless but may indicate that
885 * this eraseblock may become bad soon;
886 * o %UBI_IO_BAD_VID_HRD if the volume identifier header is corrupted (a CRC
888 * o %UBI_IO_PEB_FREE if the physical eraseblock is free (i.e., there is no VID
890 * o a negative error code in case of failure.
892 int ubi_io_read_vid_hdr(const struct ubi_device *ubi, int pnum,
893 struct ubi_vid_hdr *vid_hdr, int verbose)
895 int err, read_err = 0;
896 uint32_t crc, magic, hdr_crc;
899 dbg_io("read VID header from PEB %d", pnum);
900 ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
902 p = (char *)vid_hdr - ubi->vid_hdr_shift;
903 err = ubi_io_read(ubi, p, pnum, ubi->vid_hdr_aloffset,
904 ubi->vid_hdr_alsize);
906 if (err != UBI_IO_BITFLIPS && err != -EBADMSG)
910 * We read all the data, but either a correctable bit-flip
911 * occurred, or MTD reported about some data integrity error,
912 * like an ECC error in case of NAND. The former is harmless,
913 * the later may mean the read data is corrupted. But we have a
914 * CRC check-sum and we will identify this. If the VID header is
915 * still OK, we just report this as there was a bit-flip.
920 magic = be32_to_cpu(vid_hdr->magic);
921 if (magic != UBI_VID_HDR_MAGIC) {
923 * If we have read all 0xFF bytes, the VID header probably does
924 * not exist and the physical eraseblock is assumed to be free.
926 * But if there was a read error, we do not test the data for
927 * 0xFFs. Even if it does contain all 0xFFs, this error
928 * indicates that something is still wrong with this physical
929 * eraseblock and it cannot be regarded as free.
931 if (read_err != -EBADMSG &&
932 check_pattern(vid_hdr, 0xFF, UBI_VID_HDR_SIZE)) {
933 /* The physical eraseblock is supposedly free */
936 * The below is just a paranoid check, it has to be
937 * compiled out if paranoid checks are disabled.
939 err = paranoid_check_all_ff(ubi, pnum, ubi->leb_start,
942 return err > 0 ? UBI_IO_BAD_VID_HDR : err;
945 ubi_warn("no VID header found at PEB %d, "
946 "only 0xFF bytes", pnum);
947 return UBI_IO_PEB_FREE;
951 * This is not a valid VID header, and these are not 0xFF
952 * bytes. Report that the header is corrupted.
955 ubi_warn("bad magic number at PEB %d: %08x instead of "
956 "%08x", pnum, magic, UBI_VID_HDR_MAGIC);
957 ubi_dbg_dump_vid_hdr(vid_hdr);
959 return UBI_IO_BAD_VID_HDR;
962 crc = crc32(UBI_CRC32_INIT, vid_hdr, UBI_VID_HDR_SIZE_CRC);
963 hdr_crc = be32_to_cpu(vid_hdr->hdr_crc);
965 if (hdr_crc != crc) {
967 ubi_warn("bad CRC at PEB %d, calculated %#08x, "
968 "read %#08x", pnum, crc, hdr_crc);
969 ubi_dbg_dump_vid_hdr(vid_hdr);
971 return UBI_IO_BAD_VID_HDR;
974 /* Validate the VID header that we have just read */
975 err = validate_vid_hdr(ubi, vid_hdr);
977 ubi_err("validation failed for PEB %d", pnum);
981 return read_err ? UBI_IO_BITFLIPS : 0;
985 * ubi_io_write_vid_hdr - write a volume identifier header.
986 * @ubi: UBI device description object
987 * @pnum: the physical eraseblock number to write to
988 * @vid_hdr: the volume identifier header to write
990 * This function writes the volume identifier header described by @vid_hdr to
991 * physical eraseblock @pnum. This function automatically fills the
992 * @vid_hdr->magic and the @vid_hdr->version fields, as well as calculates
993 * header CRC checksum and stores it at vid_hdr->hdr_crc.
995 * This function returns zero in case of success and a negative error code in
996 * case of failure. If %-EIO is returned, the physical eraseblock probably went
999 int ubi_io_write_vid_hdr(const struct ubi_device *ubi, int pnum,
1000 struct ubi_vid_hdr *vid_hdr)
1006 dbg_io("write VID header to PEB %d", pnum);
1007 ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
1009 err = paranoid_check_peb_ec_hdr(ubi, pnum);
1011 return err > 0 ? -EINVAL: err;
1013 vid_hdr->magic = cpu_to_be32(UBI_VID_HDR_MAGIC);
1014 vid_hdr->version = UBI_VERSION;
1015 crc = crc32(UBI_CRC32_INIT, vid_hdr, UBI_VID_HDR_SIZE_CRC);
1016 vid_hdr->hdr_crc = cpu_to_be32(crc);
1018 err = paranoid_check_vid_hdr(ubi, pnum, vid_hdr);
1022 p = (char *)vid_hdr - ubi->vid_hdr_shift;
1023 err = ubi_io_write(ubi, p, pnum, ubi->vid_hdr_aloffset,
1024 ubi->vid_hdr_alsize);
1028 #ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
1031 * paranoid_check_not_bad - ensure that a physical eraseblock is not bad.
1032 * @ubi: UBI device description object
1033 * @pnum: physical eraseblock number to check
1035 * This function returns zero if the physical eraseblock is good, a positive
1036 * number if it is bad and a negative error code if an error occurred.
1038 static int paranoid_check_not_bad(const struct ubi_device *ubi, int pnum)
1042 err = ubi_io_is_bad(ubi, pnum);
1046 ubi_err("paranoid check failed for PEB %d", pnum);
1047 ubi_dbg_dump_stack();
1052 * paranoid_check_ec_hdr - check if an erase counter header is all right.
1053 * @ubi: UBI device description object
1054 * @pnum: physical eraseblock number the erase counter header belongs to
1055 * @ec_hdr: the erase counter header to check
1057 * This function returns zero if the erase counter header contains valid
1058 * values, and %1 if not.
1060 static int paranoid_check_ec_hdr(const struct ubi_device *ubi, int pnum,
1061 const struct ubi_ec_hdr *ec_hdr)
1066 magic = be32_to_cpu(ec_hdr->magic);
1067 if (magic != UBI_EC_HDR_MAGIC) {
1068 ubi_err("bad magic %#08x, must be %#08x",
1069 magic, UBI_EC_HDR_MAGIC);
1073 err = validate_ec_hdr(ubi, ec_hdr);
1075 ubi_err("paranoid check failed for PEB %d", pnum);
1082 ubi_dbg_dump_ec_hdr(ec_hdr);
1083 ubi_dbg_dump_stack();
1088 * paranoid_check_peb_ec_hdr - check that the erase counter header of a
1089 * physical eraseblock is in-place and is all right.
1090 * @ubi: UBI device description object
1091 * @pnum: the physical eraseblock number to check
1093 * This function returns zero if the erase counter header is all right, %1 if
1094 * not, and a negative error code if an error occurred.
1096 static int paranoid_check_peb_ec_hdr(const struct ubi_device *ubi, int pnum)
1099 uint32_t crc, hdr_crc;
1100 struct ubi_ec_hdr *ec_hdr;
1102 ec_hdr = kzalloc(ubi->ec_hdr_alsize, GFP_NOFS);
1106 err = ubi_io_read(ubi, ec_hdr, pnum, 0, UBI_EC_HDR_SIZE);
1107 if (err && err != UBI_IO_BITFLIPS && err != -EBADMSG)
1110 crc = crc32(UBI_CRC32_INIT, ec_hdr, UBI_EC_HDR_SIZE_CRC);
1111 hdr_crc = be32_to_cpu(ec_hdr->hdr_crc);
1112 if (hdr_crc != crc) {
1113 ubi_err("bad CRC, calculated %#08x, read %#08x", crc, hdr_crc);
1114 ubi_err("paranoid check failed for PEB %d", pnum);
1115 ubi_dbg_dump_ec_hdr(ec_hdr);
1116 ubi_dbg_dump_stack();
1121 err = paranoid_check_ec_hdr(ubi, pnum, ec_hdr);
1129 * paranoid_check_vid_hdr - check that a volume identifier header is all right.
1130 * @ubi: UBI device description object
1131 * @pnum: physical eraseblock number the volume identifier header belongs to
1132 * @vid_hdr: the volume identifier header to check
1134 * This function returns zero if the volume identifier header is all right, and
1137 static int paranoid_check_vid_hdr(const struct ubi_device *ubi, int pnum,
1138 const struct ubi_vid_hdr *vid_hdr)
1143 magic = be32_to_cpu(vid_hdr->magic);
1144 if (magic != UBI_VID_HDR_MAGIC) {
1145 ubi_err("bad VID header magic %#08x at PEB %d, must be %#08x",
1146 magic, pnum, UBI_VID_HDR_MAGIC);
1150 err = validate_vid_hdr(ubi, vid_hdr);
1152 ubi_err("paranoid check failed for PEB %d", pnum);
1159 ubi_err("paranoid check failed for PEB %d", pnum);
1160 ubi_dbg_dump_vid_hdr(vid_hdr);
1161 ubi_dbg_dump_stack();
1167 * paranoid_check_peb_vid_hdr - check that the volume identifier header of a
1168 * physical eraseblock is in-place and is all right.
1169 * @ubi: UBI device description object
1170 * @pnum: the physical eraseblock number to check
1172 * This function returns zero if the volume identifier header is all right,
1173 * %1 if not, and a negative error code if an error occurred.
1175 static int paranoid_check_peb_vid_hdr(const struct ubi_device *ubi, int pnum)
1178 uint32_t crc, hdr_crc;
1179 struct ubi_vid_hdr *vid_hdr;
1182 vid_hdr = ubi_zalloc_vid_hdr(ubi, GFP_NOFS);
1186 p = (char *)vid_hdr - ubi->vid_hdr_shift;
1187 err = ubi_io_read(ubi, p, pnum, ubi->vid_hdr_aloffset,
1188 ubi->vid_hdr_alsize);
1189 if (err && err != UBI_IO_BITFLIPS && err != -EBADMSG)
1192 crc = crc32(UBI_CRC32_INIT, vid_hdr, UBI_EC_HDR_SIZE_CRC);
1193 hdr_crc = be32_to_cpu(vid_hdr->hdr_crc);
1194 if (hdr_crc != crc) {
1195 ubi_err("bad VID header CRC at PEB %d, calculated %#08x, "
1196 "read %#08x", pnum, crc, hdr_crc);
1197 ubi_err("paranoid check failed for PEB %d", pnum);
1198 ubi_dbg_dump_vid_hdr(vid_hdr);
1199 ubi_dbg_dump_stack();
1204 err = paranoid_check_vid_hdr(ubi, pnum, vid_hdr);
1207 ubi_free_vid_hdr(ubi, vid_hdr);
1212 * paranoid_check_all_ff - check that a region of flash is empty.
1213 * @ubi: UBI device description object
1214 * @pnum: the physical eraseblock number to check
1215 * @offset: the starting offset within the physical eraseblock to check
1216 * @len: the length of the region to check
1218 * This function returns zero if only 0xFF bytes are present at offset
1219 * @offset of the physical eraseblock @pnum, %1 if not, and a negative error
1220 * code if an error occurred.
1222 static int paranoid_check_all_ff(const struct ubi_device *ubi, int pnum,
1223 int offset, int len)
1228 loff_t addr = (loff_t)pnum * ubi->peb_size + offset;
1233 memset(buf, 0, len);
1235 err = ubi->mtd->read(ubi->mtd, addr, len, &read, buf);
1236 if (err && err != -EUCLEAN) {
1237 ubi_err("error %d while reading %d bytes from PEB %d:%d, "
1238 "read %zd bytes", err, len, pnum, offset, read);
1242 err = check_pattern(buf, 0xFF, len);
1244 ubi_err("flash region at PEB %d:%d, length %d does not "
1245 "contain all 0xFF bytes", pnum, offset, len);
1253 ubi_err("paranoid check failed for PEB %d", pnum);
1254 dbg_msg("hex dump of the %d-%d region", offset, offset + len);
1255 print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 4, buf, len, 1);
1258 ubi_dbg_dump_stack();
1263 #endif /* CONFIG_MTD_UBI_DEBUG_PARANOID */