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

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
...@@ -656,11 +656,14 @@ retry: ...@@ -656,11 +656,14 @@ retry:
goto write_error; goto write_error;
} }
err = ubi_io_write_data(ubi, buf, pnum, offset, len); if (len) {
if (err) { err = ubi_io_write_data(ubi, buf, pnum, offset, len);
ubi_warn("failed to write %d bytes at offset %d of LEB %d:%d, " if (err) {
"PEB %d", len, offset, vol_id, lnum, pnum); ubi_warn("failed to write %d bytes at offset %d of "
goto write_error; "LEB %d:%d, PEB %d", len, offset, vol_id,
lnum, pnum);
goto write_error;
}
} }
vol->eba_tbl[lnum] = pnum; vol->eba_tbl[lnum] = pnum;
......
...@@ -546,6 +546,51 @@ int ubi_leb_unmap(struct ubi_volume_desc *desc, int lnum) ...@@ -546,6 +546,51 @@ int ubi_leb_unmap(struct ubi_volume_desc *desc, int lnum)
} }
EXPORT_SYMBOL_GPL(ubi_leb_unmap); 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. * ubi_is_mapped - check if logical eraseblock is mapped.
* @desc: volume descriptor * @desc: volume descriptor
......
...@@ -167,6 +167,7 @@ int ubi_leb_change(struct ubi_volume_desc *desc, int lnum, const void *buf, ...@@ -167,6 +167,7 @@ int ubi_leb_change(struct ubi_volume_desc *desc, int lnum, const void *buf,
int len, int dtype); int len, int dtype);
int ubi_leb_erase(struct ubi_volume_desc *desc, int lnum); 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_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); int ubi_is_mapped(struct ubi_volume_desc *desc, int lnum);
/* /*
......
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