From 393852ecfeec575ac78216b0eb58e4fd92f0816c Mon Sep 17 00:00:00 2001 From: Artem Bityutskiy Date: Thu, 6 Dec 2007 18:47:30 +0200 Subject: [PATCH] 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: Artem Bityutskiy --- drivers/mtd/ubi/eba.c | 13 +++++++----- drivers/mtd/ubi/kapi.c | 45 +++++++++++++++++++++++++++++++++++++++++ include/linux/mtd/ubi.h | 1 + 3 files changed, 54 insertions(+), 5 deletions(-) diff --git a/drivers/mtd/ubi/eba.c b/drivers/mtd/ubi/eba.c index 85f50c83cf4..c87db07bcd0 100644 --- a/drivers/mtd/ubi/eba.c +++ b/drivers/mtd/ubi/eba.c @@ -656,11 +656,14 @@ retry: goto write_error; } - 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); - 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); + goto write_error; + } } vol->eba_tbl[lnum] = pnum; diff --git a/drivers/mtd/ubi/kapi.c b/drivers/mtd/ubi/kapi.c index 03c774f4154..e1ef802a03a 100644 --- a/drivers/mtd/ubi/kapi.c +++ b/drivers/mtd/ubi/kapi.c @@ -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 diff --git a/include/linux/mtd/ubi.h b/include/linux/mtd/ubi.h index 3d967b6b120..c4abe035122 100644 --- a/include/linux/mtd/ubi.h +++ b/include/linux/mtd/ubi.h @@ -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); /* -- 2.20.1