kernel-ark/include/linux/mtd/ubi.h
Artem Bityutskiy 866136827b UBI: introduce atomic LEB change ioctl
We have to be able to change individual LEBs for utilities like
ubifsck, ubifstune. For example, ubifsck has to be able to fix
errors on the media, ubifstune has to be able to change the
the superblock, hence this ioctl.

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2008-01-25 16:41:25 +02:00

187 lines
6.8 KiB
C

/*
* Copyright (c) International Business Machines Corp., 2006
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
* the GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* Author: Artem Bityutskiy (Битюцкий Артём)
*/
#ifndef __LINUX_UBI_H__
#define __LINUX_UBI_H__
#include <asm/ioctl.h>
#include <linux/types.h>
#include <mtd/ubi-user.h>
/*
* enum ubi_open_mode - UBI volume open mode constants.
*
* UBI_READONLY: read-only mode
* UBI_READWRITE: read-write mode
* UBI_EXCLUSIVE: exclusive mode
*/
enum {
UBI_READONLY = 1,
UBI_READWRITE,
UBI_EXCLUSIVE
};
/**
* struct ubi_volume_info - UBI volume description data structure.
* @vol_id: volume ID
* @ubi_num: UBI device number this volume belongs to
* @size: how many physical eraseblocks are reserved for this volume
* @used_bytes: how many bytes of data this volume contains
* @used_ebs: how many physical eraseblocks of this volume actually contain any
* data
* @vol_type: volume type (%UBI_DYNAMIC_VOLUME or %UBI_STATIC_VOLUME)
* @corrupted: non-zero if the volume is corrupted (static volumes only)
* @upd_marker: non-zero if the volume has update marker set
* @alignment: volume alignment
* @usable_leb_size: how many bytes are available in logical eraseblocks of
* this volume
* @name_len: volume name length
* @name: volume name
* @cdev: UBI volume character device major and minor numbers
*
* The @corrupted flag is only relevant to static volumes and is always zero
* for dynamic ones. This is because UBI does not care about dynamic volume
* data protection and only cares about protecting static volume data.
*
* The @upd_marker flag is set if the volume update operation was interrupted.
* Before touching the volume data during the update operation, UBI first sets
* the update marker flag for this volume. If the volume update operation was
* further interrupted, the update marker indicates this. If the update marker
* is set, the contents of the volume is certainly damaged and a new volume
* update operation has to be started.
*
* To put it differently, @corrupted and @upd_marker fields have different
* semantics:
* o the @corrupted flag means that this static volume is corrupted for some
* reasons, but not because an interrupted volume update
* o the @upd_marker field means that the volume is damaged because of an
* interrupted update operation.
*
* I.e., the @corrupted flag is never set if the @upd_marker flag is set.
*
* The @used_bytes and @used_ebs fields are only really needed for static
* volumes and contain the number of bytes stored in this static volume and how
* many eraseblock this data occupies. In case of dynamic volumes, the
* @used_bytes field is equivalent to @size*@usable_leb_size, and the @used_ebs
* field is equivalent to @size.
*
* In general, logical eraseblock size is a property of the UBI device, not
* of the UBI volume. Indeed, the logical eraseblock size depends on the
* physical eraseblock size and on how much bytes UBI headers consume. But
* because of the volume alignment (@alignment), the usable size of logical
* eraseblocks if a volume may be less. The following equation is true:
* @usable_leb_size = LEB size - (LEB size mod @alignment),
* where LEB size is the logical eraseblock size defined by the UBI device.
*
* The alignment is multiple to the minimal flash input/output unit size or %1
* if all the available space is used.
*
* To put this differently, alignment may be considered is a way to change
* volume logical eraseblock sizes.
*/
struct ubi_volume_info {
int ubi_num;
int vol_id;
int size;
long long used_bytes;
int used_ebs;
int vol_type;
int corrupted;
int upd_marker;
int alignment;
int usable_leb_size;
int name_len;
const char *name;
dev_t cdev;
};
/**
* struct ubi_device_info - UBI device description data structure.
* @ubi_num: ubi device number
* @leb_size: logical eraseblock size on this UBI device
* @min_io_size: minimal I/O unit size
* @ro_mode: if this device is in read-only mode
* @cdev: UBI character device major and minor numbers
*
* Note, @leb_size is the logical eraseblock size offered by the UBI device.
* Volumes of this UBI device may have smaller logical eraseblock size if their
* alignment is not equivalent to %1.
*/
struct ubi_device_info {
int ubi_num;
int leb_size;
int min_io_size;
int ro_mode;
dev_t cdev;
};
/* UBI descriptor given to users when they open UBI volumes */
struct ubi_volume_desc;
int ubi_get_device_info(int ubi_num, struct ubi_device_info *di);
void ubi_get_volume_info(struct ubi_volume_desc *desc,
struct ubi_volume_info *vi);
struct ubi_volume_desc *ubi_open_volume(int ubi_num, int vol_id, int mode);
struct ubi_volume_desc *ubi_open_volume_nm(int ubi_num, const char *name,
int mode);
void ubi_close_volume(struct ubi_volume_desc *desc);
int ubi_leb_read(struct ubi_volume_desc *desc, int lnum, char *buf, int offset,
int len, int check);
int ubi_leb_write(struct ubi_volume_desc *desc, int lnum, const void *buf,
int offset, int len, int dtype);
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);
/*
* This function is the same as the 'ubi_leb_read()' function, but it does not
* provide the checking capability.
*/
static inline int ubi_read(struct ubi_volume_desc *desc, int lnum, char *buf,
int offset, int len)
{
return ubi_leb_read(desc, lnum, buf, offset, len, 0);
}
/*
* This function is the same as the 'ubi_leb_write()' functions, but it does
* not have the data type argument.
*/
static inline int ubi_write(struct ubi_volume_desc *desc, int lnum,
const void *buf, int offset, int len)
{
return ubi_leb_write(desc, lnum, buf, offset, len, UBI_UNKNOWN);
}
/*
* This function is the same as the 'ubi_leb_change()' functions, but it does
* not have the data type argument.
*/
static inline int ubi_change(struct ubi_volume_desc *desc, int lnum,
const void *buf, int len)
{
return ubi_leb_change(desc, lnum, buf, len, UBI_UNKNOWN);
}
#endif /* !__LINUX_UBI_H__ */