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Commit d6be791c authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'linux-next' of git://git.infradead.org/ubi-2.6 

* 'linux-next' of git://git.infradead.org/ubi-2.6:
  UBI: fix compilation warnings
  UBI: fix NOR flash recovery
  UBI: nicify image sequence number handling
  UBI: add image sequence number to EC header
  UBI: remove bogus debugging checks
  UBI: add empty eraseblocks verification
parents 44c695b1 83c2099f

drivers/mtd/ubi/build.c

+6 −0
Original line number Diff line number Diff line
@@ -657,6 +657,11 @@ static int io_init(struct ubi_device *ubi) 
	if (ubi->mtd->block_isbad && ubi->mtd->block_markbad)

		ubi->bad_allowed = 1;



	if (ubi->mtd->type == MTD_NORFLASH) {

		ubi_assert(ubi->mtd->writesize == 1);

		ubi->nor_flash = 1;

	}



	ubi->min_io_size = ubi->mtd->writesize;

	ubi->hdrs_min_io_size = ubi->mtd->writesize >> ubi->mtd->subpage_sft;
@@ -996,6 +1001,7 @@ int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num, int vid_hdr_offset) 
	ubi_msg("number of PEBs reserved for bad PEB handling: %d",

		ubi->beb_rsvd_pebs);

	ubi_msg("max/mean erase counter: %d/%d", ubi->max_ec, ubi->mean_ec);

	ubi_msg("image sequence number: %d", ubi->image_seq);



	/*

	 * The below lock makes sure we do not race with 'ubi_thread()' which

drivers/mtd/ubi/debug.c

+2 −0
Original line number Diff line number Diff line
@@ -44,6 +44,8 @@ void ubi_dbg_dump_ec_hdr(const struct ubi_ec_hdr *ec_hdr) 
	       be32_to_cpu(ec_hdr->vid_hdr_offset));

	printk(KERN_DEBUG "\tdata_offset    %d\n",

	       be32_to_cpu(ec_hdr->data_offset));

	printk(KERN_DEBUG "\timage_seq      %d\n",

	       be32_to_cpu(ec_hdr->image_seq));

	printk(KERN_DEBUG "\thdr_crc        %#08x\n",

	       be32_to_cpu(ec_hdr->hdr_crc));

	printk(KERN_DEBUG "erase counter header hexdump:\n");

drivers/mtd/ubi/debug.h

+7 −0
Original line number Diff line number Diff line
@@ -93,6 +93,12 @@ void ubi_dbg_dump_mkvol_req(const struct ubi_mkvol_req *req); 
#define UBI_IO_DEBUG 0

#endif



#ifdef CONFIG_MTD_UBI_DEBUG_PARANOID

int ubi_dbg_check_all_ff(struct ubi_device *ubi, int pnum, int offset, int len);

#else

#define ubi_dbg_check_all_ff(ubi, pnum, offset, len) 0

#endif



#ifdef CONFIG_MTD_UBI_DEBUG_DISABLE_BGT

#define DBG_DISABLE_BGT 1

#else
@@ -167,6 +173,7 @@ static inline int ubi_dbg_is_erase_failure(void) 
#define ubi_dbg_is_bitflip()       0

#define ubi_dbg_is_write_failure() 0

#define ubi_dbg_is_erase_failure() 0

#define ubi_dbg_check_all_ff(ubi, pnum, offset, len) 0



#endif /* !CONFIG_MTD_UBI_DEBUG */

#endif /* !__UBI_DEBUG_H__ */

drivers/mtd/ubi/io.c

+61 −96
Original line number Diff line number Diff line
@@ -98,17 +98,12 @@ static int paranoid_check_ec_hdr(const struct ubi_device *ubi, int pnum, 
static int paranoid_check_peb_vid_hdr(const struct ubi_device *ubi, int pnum);

static int paranoid_check_vid_hdr(const struct ubi_device *ubi, int pnum,

				  const struct ubi_vid_hdr *vid_hdr);

static int paranoid_check_all_ff(struct ubi_device *ubi, int pnum, int offset,

				 int len);

static int paranoid_check_empty(struct ubi_device *ubi, int pnum);

#else

#define paranoid_check_not_bad(ubi, pnum) 0

#define paranoid_check_peb_ec_hdr(ubi, pnum)  0

#define paranoid_check_ec_hdr(ubi, pnum, ec_hdr)  0

#define paranoid_check_peb_vid_hdr(ubi, pnum) 0

#define paranoid_check_vid_hdr(ubi, pnum, vid_hdr) 0

#define paranoid_check_all_ff(ubi, pnum, offset, len) 0

#define paranoid_check_empty(ubi, pnum) 0

#endif



/**
@@ -244,7 +239,7 @@ int ubi_io_write(struct ubi_device *ubi, const void *buf, int pnum, int offset, 
		return err > 0 ? -EINVAL : err;



	/* The area we are writing to has to contain all 0xFF bytes */

	err = paranoid_check_all_ff(ubi, pnum, offset, len);

	err = ubi_dbg_check_all_ff(ubi, pnum, offset, len);

	if (err)

		return err > 0 ? -EINVAL : err;
@@ -350,7 +345,7 @@ static int do_sync_erase(struct ubi_device *ubi, int pnum) 
		return -EIO;

	}



	err = paranoid_check_all_ff(ubi, pnum, 0, ubi->peb_size);

	err = ubi_dbg_check_all_ff(ubi, pnum, 0, ubi->peb_size);

	if (err)

		return err > 0 ? -EINVAL : err;
@@ -458,6 +453,54 @@ static int torture_peb(struct ubi_device *ubi, int pnum) 
	return err;

}



/**

 * nor_erase_prepare - prepare a NOR flash PEB for erasure.

 * @ubi: UBI device description object

 * @pnum: physical eraseblock number to prepare

 *

 * NOR flash, or at least some of them, have peculiar embedded PEB erasure

 * algorithm: the PEB is first filled with zeroes, then it is erased. And

 * filling with zeroes starts from the end of the PEB. This was observed with

 * Spansion S29GL512N NOR flash.

 *

 * This means that in case of a power cut we may end up with intact data at the

 * beginning of the PEB, and all zeroes at the end of PEB. In other words, the

 * EC and VID headers are OK, but a large chunk of data at the end of PEB is

 * zeroed. This makes UBI mistakenly treat this PEB as used and associate it

 * with an LEB, which leads to subsequent failures (e.g., UBIFS fails).

 *

 * This function is called before erasing NOR PEBs and it zeroes out EC and VID

 * magic numbers in order to invalidate them and prevent the failures. Returns

 * zero in case of success and a negative error code in case of failure.

 */

static int nor_erase_prepare(struct ubi_device *ubi, int pnum)

{

	int err;

	size_t written;

	loff_t addr;

	uint32_t data = 0;



	addr = (loff_t)pnum * ubi->peb_size;

	err = ubi->mtd->write(ubi->mtd, addr, 4, &written, (void *)&data);

	if (err) {

		ubi_err("error %d while writing 4 bytes to PEB %d:%d, written "

			"%zd bytes", err, pnum, 0, written);

		ubi_dbg_dump_stack();

		return err;

	}



	addr += ubi->vid_hdr_aloffset;

	err = ubi->mtd->write(ubi->mtd, addr, 4, &written, (void *)&data);

	if (err) {

		ubi_err("error %d while writing 4 bytes to PEB %d:%d, written "

			"%zd bytes", err, pnum, ubi->vid_hdr_aloffset, written);

		ubi_dbg_dump_stack();

		return err;

	}



	return 0;

}



/**

 * ubi_io_sync_erase - synchronously erase a physical eraseblock.

 * @ubi: UBI device description object
@@ -489,6 +532,12 @@ int ubi_io_sync_erase(struct ubi_device *ubi, int pnum, int torture) 
		return -EROFS;

	}



	if (ubi->nor_flash) {

		err = nor_erase_prepare(ubi, pnum);

		if (err)

			return err;

	}



	if (torture) {

		ret = torture_peb(ubi, pnum);

		if (ret < 0)
@@ -672,11 +721,6 @@ int ubi_io_read_ec_hdr(struct ubi_device *ubi, int pnum, 
		if (read_err != -EBADMSG &&

		    check_pattern(ec_hdr, 0xFF, UBI_EC_HDR_SIZE)) {

			/* The physical eraseblock is supposedly empty */

			err = paranoid_check_all_ff(ubi, pnum, 0,

						    ubi->peb_size);

			if (err)

				return err > 0 ? UBI_IO_BAD_EC_HDR : err;



			if (verbose)

				ubi_warn("no EC header found at PEB %d, "

					 "only 0xFF bytes", pnum);
@@ -752,6 +796,7 @@ int ubi_io_write_ec_hdr(struct ubi_device *ubi, int pnum, 
	ec_hdr->version = UBI_VERSION;

	ec_hdr->vid_hdr_offset = cpu_to_be32(ubi->vid_hdr_offset);

	ec_hdr->data_offset = cpu_to_be32(ubi->leb_start);

	ec_hdr->image_seq = cpu_to_be32(ubi->image_seq);

	crc = crc32(UBI_CRC32_INIT, ec_hdr, UBI_EC_HDR_SIZE_CRC);

	ec_hdr->hdr_crc = cpu_to_be32(crc);
@@ -947,15 +992,6 @@ int ubi_io_read_vid_hdr(struct ubi_device *ubi, int pnum, 
		if (read_err != -EBADMSG &&

		    check_pattern(vid_hdr, 0xFF, UBI_VID_HDR_SIZE)) {

			/* The physical eraseblock is supposedly free */



			/*

			 * The below is just a paranoid check, it has to be

			 * compiled out if paranoid checks are disabled.

			 */

			err = paranoid_check_empty(ubi, pnum);

			if (err)

				return err > 0 ? UBI_IO_BAD_VID_HDR : err;



			if (verbose)

				ubi_warn("no VID header found at PEB %d, "

					 "only 0xFF bytes", pnum);
@@ -1229,7 +1265,7 @@ static int paranoid_check_peb_vid_hdr(const struct ubi_device *ubi, int pnum) 
}



/**

 * paranoid_check_all_ff - check that a region of flash is empty.

 * ubi_dbg_check_all_ff - check that a region of flash is empty.

 * @ubi: UBI device description object

 * @pnum: the physical eraseblock number to check

 * @offset: the starting offset within the physical eraseblock to check
@@ -1239,8 +1275,7 @@ static int paranoid_check_peb_vid_hdr(const struct ubi_device *ubi, int pnum) 
 * @offset of the physical eraseblock @pnum, %1 if not, and a negative error

 * code if an error occurred.

 */

static int paranoid_check_all_ff(struct ubi_device *ubi, int pnum, int offset,

				 int len)

int ubi_dbg_check_all_ff(struct ubi_device *ubi, int pnum, int offset, int len)

{

	size_t read;

	int err;
@@ -1276,74 +1311,4 @@ static int paranoid_check_all_ff(struct ubi_device *ubi, int pnum, int offset, 
	return err;

}



/**

 * paranoid_check_empty - whether a PEB is empty.

 * @ubi: UBI device description object

 * @pnum: the physical eraseblock number to check

 *

 * This function makes sure PEB @pnum is empty, which means it contains only

 * %0xFF data bytes. Returns zero if the PEB is empty, %1 if not, and a

 * negative error code in case of failure.

 *

 * Empty PEBs have the EC header, and do not have the VID header. The caller of

 * this function should have already made sure the PEB does not have the VID

 * header. However, this function re-checks that, because it is possible that

 * the header and data has already been written to the PEB.

 *

 * Let's consider a possible scenario. Suppose there are 2 tasks - A and B.

 * Task A is in 'wear_leveling_worker()'. It is reading VID header of PEB X to

 * find which LEB it corresponds to. PEB X is currently unmapped, and has no

 * VID header. Task B is trying to write to PEB X.

 *

 * Task A: in 'ubi_io_read_vid_hdr()': reads the VID header from PEB X. The

 *         read data contain all 0xFF bytes;

 * Task B: writes VID header and some data to PEB X;

 * Task A: assumes PEB X is empty, calls 'paranoid_check_empty()'. And if we

 *         do not re-read the VID header, and do not cancel the checking if it

 *         is there, we fail.

 */

static int paranoid_check_empty(struct ubi_device *ubi, int pnum)

{

	int err, offs = ubi->vid_hdr_aloffset, len = ubi->vid_hdr_alsize;

	size_t read;

	uint32_t magic;

	const struct ubi_vid_hdr *vid_hdr;



	mutex_lock(&ubi->dbg_buf_mutex);

	err = ubi->mtd->read(ubi->mtd, offs, len, &read, ubi->dbg_peb_buf);

	if (err && err != -EUCLEAN) {

		ubi_err("error %d while reading %d bytes from PEB %d:%d, "

			"read %zd bytes", err, len, pnum, offs, read);

		goto error;

	}



	vid_hdr = ubi->dbg_peb_buf;

	magic = be32_to_cpu(vid_hdr->magic);

	if (magic == UBI_VID_HDR_MAGIC)

		/* The PEB contains VID header, so it is not empty */

		goto out;



	err = check_pattern(ubi->dbg_peb_buf, 0xFF, len);

	if (err == 0) {

		ubi_err("flash region at PEB %d:%d, length %d does not "

			"contain all 0xFF bytes", pnum, offs, len);

		goto fail;

	}



out:

	mutex_unlock(&ubi->dbg_buf_mutex);

	return 0;



fail:

	ubi_err("paranoid check failed for PEB %d", pnum);

	ubi_msg("hex dump of the %d-%d region", offs, offs + len);

	print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 1,

		       ubi->dbg_peb_buf, len, 1);

	err = 1;

error:

	ubi_dbg_dump_stack();

	mutex_unlock(&ubi->dbg_buf_mutex);

	return err;

}



#endif /* CONFIG_MTD_UBI_DEBUG_PARANOID */

drivers/mtd/ubi/scan.c

+14 −0
Original line number Diff line number Diff line
@@ -757,6 +757,8 @@ static int process_eb(struct ubi_device *ubi, struct ubi_scan_info *si, 
	si->is_empty = 0;



	if (!ec_corr) {

		int image_seq;



		/* Make sure UBI version is OK */

		if (ech->version != UBI_VERSION) {

			ubi_err("this UBI version is %d, image version is %d",
@@ -778,6 +780,18 @@ static int process_eb(struct ubi_device *ubi, struct ubi_scan_info *si, 
			ubi_dbg_dump_ec_hdr(ech);

			return -EINVAL;

		}



		image_seq = be32_to_cpu(ech->ec);

		if (!si->image_seq_set) {

			ubi->image_seq = image_seq;

			si->image_seq_set = 1;

		} else if (ubi->image_seq != image_seq) {

			ubi_err("bad image sequence number %d in PEB %d, "

				"expected %d", image_seq, pnum, ubi->image_seq);

			ubi_dbg_dump_ec_hdr(ech);

			return -EINVAL;

		}



	}



	/* OK, we've done with the EC header, let's look at the VID header */