Commit 393852ec authored by Artem Bityutskiy's avatar Artem Bityutskiy
Browse files

UBI: add ubi_leb_map interface 



The idea of this interface belongs to Adrian Hunter. The
interface is extremely useful when one has to have a guarantee
that an LEB will contain all 0xFFs even in case of an unclean
reboot. UBI does have an 'ubi_leb_erase()' call which may do
this, but it is stupid and ineffecient, because it flushes whole
queue. I should be re-worked to just be a pair of unmap,
map calls.

The user of the interfaci is UBIFS at the moment.

Signed-off-by: default avatarArtem Bityutskiy <Artem.Bityutskiy@nokia.com>
parent 94780d4d

drivers/mtd/ubi/eba.c

+8 −5
Original line number Diff line number Diff line
@@ -656,12 +656,15 @@ retry: 
		goto write_error;

	}



	if (len) {

		err = ubi_io_write_data(ubi, buf, pnum, offset, len);

		if (err) {

		ubi_warn("failed to write %d bytes at offset %d of LEB %d:%d, "

			 "PEB %d", len, offset, vol_id, lnum, pnum);

			ubi_warn("failed to write %d bytes at offset %d of "

				 "LEB %d:%d, PEB %d", len, offset, vol_id,

				 lnum, pnum);

			goto write_error;

		}

	}



	vol->eba_tbl[lnum] = pnum;

drivers/mtd/ubi/kapi.c

+45 −0
Original line number Diff line number Diff line
@@ -546,6 +546,51 @@ int ubi_leb_unmap(struct ubi_volume_desc *desc, int lnum) 
}

EXPORT_SYMBOL_GPL(ubi_leb_unmap);



/**

 * ubi_leb_map - map logical erasblock to a physical eraseblock.

 * @desc: volume descriptor

 * @lnum: logical eraseblock number

 * @dtype: expected data type

 *

 * This function maps an un-mapped logical eraseblock @lnum to a physical

 * eraseblock. This means, that after a successfull invocation of this

 * function the logical eraseblock @lnum will be empty (contain only %0xFF

 * bytes) and be mapped to a physical eraseblock, even if an unclean reboot

 * happens.

 *

 * This function returns zero in case of success, %-EBADF if the volume is

 * damaged because of an interrupted update, %-EBADMSG if the logical

 * eraseblock is already mapped, and other negative error codes in case of

 * other failures.

 */

int ubi_leb_map(struct ubi_volume_desc *desc, int lnum, int dtype)

{

	struct ubi_volume *vol = desc->vol;

	struct ubi_device *ubi = vol->ubi;

	int vol_id = vol->vol_id;



	dbg_msg("unmap LEB %d:%d", vol_id, lnum);



	if (desc->mode == UBI_READONLY || vol->vol_type == UBI_STATIC_VOLUME)

		return -EROFS;



	if (lnum < 0 || lnum >= vol->reserved_pebs)

		return -EINVAL;



	if (dtype != UBI_LONGTERM && dtype != UBI_SHORTTERM &&

	    dtype != UBI_UNKNOWN)

		return -EINVAL;



	if (vol->upd_marker)

		return -EBADF;



	if (vol->eba_tbl[lnum] >= 0)

		return -EBADMSG;



	return ubi_eba_write_leb(ubi, vol_id, lnum, NULL, 0, 0, dtype);

}

EXPORT_SYMBOL_GPL(ubi_leb_map);



/**

 * ubi_is_mapped - check if logical eraseblock is mapped.

 * @desc: volume descriptor

include/linux/mtd/ubi.h

+1 −0
Original line number Diff line number Diff line
@@ -167,6 +167,7 @@ int ubi_leb_change(struct ubi_volume_desc *desc, int lnum, const void *buf, 
		   int len, int dtype);

int ubi_leb_erase(struct ubi_volume_desc *desc, int lnum);

int ubi_leb_unmap(struct ubi_volume_desc *desc, int lnum);

int ubi_leb_map(struct ubi_volume_desc *desc, int lnum, int dtype);

int ubi_is_mapped(struct ubi_volume_desc *desc, int lnum);



/*

CRA Git | Maintained and supported by SUSTech CRA and CCSE