kernel-ark/include/linux/mtd/ubi.h
Joel Reardon 62f384552b UBI: modify ubi_wl_flush function to clear work queue for a lnum
This patch modifies ubi_wl_flush to force the erasure of
particular volume id / logical eraseblock number pairs. Previous functionality
is preserved when passing UBI_ALL for both values. The locations where ubi_wl_flush
were called are appropriately changed: ubi_leb_erase only flushes for the
erased LEB, and ubi_create_volume forces only flushing for its volume id.
External code can call this new feature via the new function ubi_flush() added
to kapi.c, which simply passes through to ubi_wl_flush().

This was tested by disabling the call to do_work in ubi thread, which results
in the work queue remaining unless explicitly called to remove. UBIFS was
changed to call ubifs_leb_change 50 times for four different LEBs. Then the
new function was called to clear the queue: passing wrong volume ids / lnum,
correct ones, and finally UBI_ALL for both to ensure it was finally all
cleard. The work queue was dumped each time and the selective removal
of the particular LEB numbers was observed. Extra checks were enabled and
ubifs's integck was also run. Finally, the drive was repeatedly filled and
emptied to ensure that the queue was cleared normally.

Artem: amended the patch.

Signed-off-by: Joel Reardon <reardonj@inf.ethz.ch>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
2012-05-21 11:34:41 +03:00

234 lines
8.8 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 <linux/ioctl.h>
#include <linux/types.h>
#include <mtd/ubi-user.h>
/* All voumes/LEBs */
#define UBI_ALL -1
/*
* 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
* @leb_start: starting offset of logical eraseblocks within physical
* eraseblocks
* @min_io_size: minimal I/O unit size
* @max_write_size: maximum amount of bytes the underlying flash can write at a
* time (MTD write buffer 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.
*
* The @max_write_size field describes flash write maximum write unit. For
* example, NOR flash allows for changing individual bytes, so @min_io_size is
* %1. However, it does not mean than NOR flash has to write data byte-by-byte.
* Instead, CFI NOR flashes have a write-buffer of, e.g., 64 bytes, and when
* writing large chunks of data, they write 64-bytes at a time. Obviously, this
* improves write throughput.
*
* Also, the MTD device may have N interleaved (striped) flash chips
* underneath, in which case @min_io_size can be physical min. I/O size of
* single flash chip, while @max_write_size can be N * @min_io_size.
*
* The @max_write_size field is always greater or equivalent to @min_io_size.
* E.g., some NOR flashes may have (@min_io_size = 1, @max_write_size = 64). In
* contrast, NAND flashes usually have @min_io_size = @max_write_size = NAND
* page size.
*/
struct ubi_device_info {
int ubi_num;
int leb_size;
int leb_start;
int min_io_size;
int max_write_size;
int ro_mode;
dev_t cdev;
};
/*
* Volume notification types.
* @UBI_VOLUME_ADDED: a volume has been added (an UBI device was attached or a
* volume was created)
* @UBI_VOLUME_REMOVED: a volume has been removed (an UBI device was detached
* or a volume was removed)
* @UBI_VOLUME_RESIZED: a volume has been re-sized
* @UBI_VOLUME_RENAMED: a volume has been re-named
* @UBI_VOLUME_UPDATED: data has been written to a volume
*
* These constants define which type of event has happened when a volume
* notification function is invoked.
*/
enum {
UBI_VOLUME_ADDED,
UBI_VOLUME_REMOVED,
UBI_VOLUME_RESIZED,
UBI_VOLUME_RENAMED,
UBI_VOLUME_UPDATED,
};
/*
* struct ubi_notification - UBI notification description structure.
* @di: UBI device description object
* @vi: UBI volume description object
*
* UBI notifiers are called with a pointer to an object of this type. The
* object describes the notification. Namely, it provides a description of the
* UBI device and UBI volume the notification informs about.
*/
struct ubi_notification {
struct ubi_device_info di;
struct ubi_volume_info vi;
};
/* 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);
struct ubi_volume_desc *ubi_open_volume_path(const char *pathname, int mode);
int ubi_register_volume_notifier(struct notifier_block *nb,
int ignore_existing);
int ubi_unregister_volume_notifier(struct notifier_block *nb);
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 ubi_leb_change(struct ubi_volume_desc *desc, int lnum, const void *buf,
int len);
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 ubi_is_mapped(struct ubi_volume_desc *desc, int lnum);
int ubi_sync(int ubi_num);
int ubi_flush(int ubi_num, int vol_id, 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);
}
#endif /* !__LINUX_UBI_H__ */