Commit eb89580e authored by Artem Bityutskiy's avatar Artem Bityutskiy
Browse files

UBI: introduce a new IO return code 



This patch introduces the %UBI_IO_BAD_HDR_READ return code for
the I/O level function. We will use this code in order to distinguish
between "corrupted header possibly because this is non-ubi data" and
"corrupted header possibly because of real data corruption and ECC error".

So far this patch does not introduce any functional change, just a
preparation.

This patch is pased on a patch from
Sebastian Andrzej Siewior <sebastian@breakpoint.cc>

Signed-off-by: default avatarArtem Bityutskiy <Artem.Bityutskiy@nokia.com>
Reviewed-by: default avatarSebastian Andrzej Siewior <sebastian@breakpoint.cc>
Tested-by: default avatarSebastian Andrzej Siewior <sebastian@breakpoint.cc>
parent 786d7831

drivers/mtd/ubi/eba.c

+3 −2
Original line number Diff line number Diff line
@@ -418,7 +418,8 @@ retry: 
				 * may try to recover data. FIXME: but this is

				 * not implemented.

				 */

				if (err == UBI_IO_BAD_HDR) {

				if (err == UBI_IO_BAD_HDR_READ ||

				    err == UBI_IO_BAD_HDR) {

					ubi_warn("corrupted VID header at PEB "

						 "%d, LEB %d:%d", pnum, vol_id,

						 lnum);
@@ -962,7 +963,7 @@ write_error: 
static int is_error_sane(int err)

{

	if (err == -EIO || err == -ENOMEM || err == UBI_IO_BAD_HDR ||

	    err == -ETIMEDOUT)

	    err == UBI_IO_BAD_HDR_READ || err == -ETIMEDOUT)

		return 0;

	return 1;

}

drivers/mtd/ubi/io.c

+23 −19
Original line number Diff line number Diff line
@@ -515,7 +515,7 @@ static int nor_erase_prepare(struct ubi_device *ubi, int pnum) 
	 * In this case we probably anyway have garbage in this PEB.

	 */

	err1 = ubi_io_read_vid_hdr(ubi, pnum, &vid_hdr, 0);

	if (err1 == UBI_IO_BAD_HDR)

	if (err1 == UBI_IO_BAD_HDR_READ || err1 == UBI_IO_BAD_HDR)

		/*

		 * The VID header is corrupted, so we can safely erase this

		 * PEB and not afraid that it will be treated as a valid PEB in
@@ -736,23 +736,21 @@ int ubi_io_read_ec_hdr(struct ubi_device *ubi, int pnum, 
		 * header is still OK, we just report this as there was a

		 * bit-flip.

		 */

		read_err = err;

		if (err == -EBADMSG)

			read_err = UBI_IO_BAD_HDR_READ;

	}



	magic = be32_to_cpu(ec_hdr->magic);

	if (magic != UBI_EC_HDR_MAGIC) {

		if (read_err)

			return read_err;



		/*

		 * The magic field is wrong. Let's check if we have read all

		 * 0xFF. If yes, this physical eraseblock is assumed to be

		 * empty.

		 *

		 * But if there was a read error, we do not test it for all

		 * 0xFFs. Even if it does contain all 0xFFs, this error

		 * indicates that something is still wrong with this physical

		 * eraseblock and we anyway cannot treat it as empty.

		 */

		if (read_err != -EBADMSG &&

		    check_pattern(ec_hdr, 0xFF, UBI_EC_HDR_SIZE)) {

		if (check_pattern(ec_hdr, 0xFF, UBI_EC_HDR_SIZE)) {

			/* The physical eraseblock is supposedly empty */

			if (verbose)

				ubi_warn("no EC header found at PEB %d, "
@@ -788,7 +786,7 @@ int ubi_io_read_ec_hdr(struct ubi_device *ubi, int pnum, 
		} else if (UBI_IO_DEBUG)

			dbg_msg("bad EC header CRC at PEB %d, calculated "

				"%#08x, read %#08x", pnum, crc, hdr_crc);

		return UBI_IO_BAD_HDR;

		return read_err ?: UBI_IO_BAD_HDR;

	}



	/* And of course validate what has just been read from the media */
@@ -798,6 +796,10 @@ int ubi_io_read_ec_hdr(struct ubi_device *ubi, int pnum, 
		return -EINVAL;

	}



	/*

	 * If there was %-EBADMSG, but the header CRC is still OK, report about

	 * a bit-flip to force scrubbing on this PEB.

	 */

	return read_err ? UBI_IO_BITFLIPS : 0;

}
@@ -1008,22 +1010,20 @@ int ubi_io_read_vid_hdr(struct ubi_device *ubi, int pnum, 
		 * CRC check-sum and we will identify this. If the VID header is

		 * still OK, we just report this as there was a bit-flip.

		 */

		read_err = err;

		if (err == -EBADMSG)

			read_err = UBI_IO_BAD_HDR_READ;

	}



	magic = be32_to_cpu(vid_hdr->magic);

	if (magic != UBI_VID_HDR_MAGIC) {

		if (read_err)

			return read_err;



		/*

		 * If we have read all 0xFF bytes, the VID header probably does

		 * not exist and the physical eraseblock is assumed to be free.

		 *

		 * But if there was a read error, we do not test the data for

		 * 0xFFs. Even if it does contain all 0xFFs, this error

		 * indicates that something is still wrong with this physical

		 * eraseblock and it cannot be regarded as free.

		 */

		if (read_err != -EBADMSG &&

		    check_pattern(vid_hdr, 0xFF, UBI_VID_HDR_SIZE)) {

		if (check_pattern(vid_hdr, 0xFF, UBI_VID_HDR_SIZE)) {

			/* The physical eraseblock is supposedly free */

			if (verbose)

				ubi_warn("no VID header found at PEB %d, "
@@ -1059,7 +1059,7 @@ int ubi_io_read_vid_hdr(struct ubi_device *ubi, int pnum, 
		} else if (UBI_IO_DEBUG)

			dbg_msg("bad CRC at PEB %d, calculated %#08x, "

				"read %#08x", pnum, crc, hdr_crc);

		return UBI_IO_BAD_HDR;

		return read_err ?: UBI_IO_BAD_HDR;

	}



	/* Validate the VID header that we have just read */
@@ -1069,6 +1069,10 @@ int ubi_io_read_vid_hdr(struct ubi_device *ubi, int pnum, 
		return -EINVAL;

	}



	/*

	 * If there was a read error (%-EBADMSG), but the header CRC is still

	 * OK, report about a bit-flip to force scrubbing on this PEB.

	 */

	return read_err ? UBI_IO_BITFLIPS : 0;

}

drivers/mtd/ubi/scan.c

+2 −2
Original line number Diff line number Diff line
@@ -745,7 +745,7 @@ static int process_eb(struct ubi_device *ubi, struct ubi_scan_info *si, 
		bitflips = 1;

	else if (err == UBI_IO_PEB_EMPTY)

		return add_to_list(si, pnum, UBI_SCAN_UNKNOWN_EC, &si->erase);

	else if (err == UBI_IO_BAD_HDR) {

	else if (err == UBI_IO_BAD_HDR_READ || err == UBI_IO_BAD_HDR) {

		/*

		 * We have to also look at the VID header, possibly it is not

		 * corrupted. Set %bitflips flag in order to make this PEB be
@@ -813,7 +813,7 @@ static int process_eb(struct ubi_device *ubi, struct ubi_scan_info *si, 
		return err;

	else if (err == UBI_IO_BITFLIPS)

		bitflips = 1;

	else if (err == UBI_IO_BAD_HDR ||

	else if (err == UBI_IO_BAD_HDR_READ || err == UBI_IO_BAD_HDR ||

		 (err == UBI_IO_PEB_FREE && ec_corr)) {

		/* VID header is corrupted */

		err = add_to_list(si, pnum, ec, &si->corr);

drivers/mtd/ubi/ubi.h

+3 −0
Original line number Diff line number Diff line
@@ -90,12 +90,15 @@ 
 * UBI_IO_PEB_FREE: the physical eraseblock is free, i.e. it contains only a

 *                  valid erase counter header, and the rest are %0xFF bytes

 * UBI_IO_BAD_HDR: the EC or VID header is corrupted (bad magic or CRC)

 * UBI_IO_BAD_HDR_READ: the same as %UBI_IO_BAD_HDR, but also there was a read

 * 			error reported by the flash driver

 * UBI_IO_BITFLIPS: bit-flips were detected and corrected

 */

enum {

	UBI_IO_PEB_EMPTY = 1,

	UBI_IO_PEB_FREE,

	UBI_IO_BAD_HDR,

	UBI_IO_BAD_HDR_READ,

	UBI_IO_BITFLIPS

};

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