linux/drivers/mtd/ubi/kapi.c
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

788 lines
23 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)
*/
/* This file mostly implements UBI kernel API functions */
#include <linux/module.h>
#include <linux/err.h>
#include <linux/slab.h>
#include <linux/namei.h>
#include <linux/fs.h>
#include <asm/div64.h>
#include "ubi.h"
/**
* ubi_do_get_device_info - get information about UBI device.
* @ubi: UBI device description object
* @di: the information is stored here
*
* This function is the same as 'ubi_get_device_info()', but it assumes the UBI
* device is locked and cannot disappear.
*/
void ubi_do_get_device_info(struct ubi_device *ubi, struct ubi_device_info *di)
{
di->ubi_num = ubi->ubi_num;
di->leb_size = ubi->leb_size;
di->leb_start = ubi->leb_start;
di->min_io_size = ubi->min_io_size;
di->max_write_size = ubi->max_write_size;
di->ro_mode = ubi->ro_mode;
di->cdev = ubi->cdev.dev;
}
EXPORT_SYMBOL_GPL(ubi_do_get_device_info);
/**
* ubi_get_device_info - get information about UBI device.
* @ubi_num: UBI device number
* @di: the information is stored here
*
* This function returns %0 in case of success, %-EINVAL if the UBI device
* number is invalid, and %-ENODEV if there is no such UBI device.
*/
int ubi_get_device_info(int ubi_num, struct ubi_device_info *di)
{
struct ubi_device *ubi;
if (ubi_num < 0 || ubi_num >= UBI_MAX_DEVICES)
return -EINVAL;
ubi = ubi_get_device(ubi_num);
if (!ubi)
return -ENODEV;
ubi_do_get_device_info(ubi, di);
ubi_put_device(ubi);
return 0;
}
EXPORT_SYMBOL_GPL(ubi_get_device_info);
/**
* ubi_do_get_volume_info - get information about UBI volume.
* @ubi: UBI device description object
* @vol: volume description object
* @vi: the information is stored here
*/
void ubi_do_get_volume_info(struct ubi_device *ubi, struct ubi_volume *vol,
struct ubi_volume_info *vi)
{
vi->vol_id = vol->vol_id;
vi->ubi_num = ubi->ubi_num;
vi->size = vol->reserved_pebs;
vi->used_bytes = vol->used_bytes;
vi->vol_type = vol->vol_type;
vi->corrupted = vol->corrupted;
vi->upd_marker = vol->upd_marker;
vi->alignment = vol->alignment;
vi->usable_leb_size = vol->usable_leb_size;
vi->name_len = vol->name_len;
vi->name = vol->name;
vi->cdev = vol->cdev.dev;
}
/**
* ubi_get_volume_info - get information about UBI volume.
* @desc: volume descriptor
* @vi: the information is stored here
*/
void ubi_get_volume_info(struct ubi_volume_desc *desc,
struct ubi_volume_info *vi)
{
ubi_do_get_volume_info(desc->vol->ubi, desc->vol, vi);
}
EXPORT_SYMBOL_GPL(ubi_get_volume_info);
/**
* ubi_open_volume - open UBI volume.
* @ubi_num: UBI device number
* @vol_id: volume ID
* @mode: open mode
*
* The @mode parameter specifies if the volume should be opened in read-only
* mode, read-write mode, or exclusive mode. The exclusive mode guarantees that
* nobody else will be able to open this volume. UBI allows to have many volume
* readers and one writer at a time.
*
* If a static volume is being opened for the first time since boot, it will be
* checked by this function, which means it will be fully read and the CRC
* checksum of each logical eraseblock will be checked.
*
* This function returns volume descriptor in case of success and a negative
* error code in case of failure.
*/
struct ubi_volume_desc *ubi_open_volume(int ubi_num, int vol_id, int mode)
{
int err;
struct ubi_volume_desc *desc;
struct ubi_device *ubi;
struct ubi_volume *vol;
dbg_gen("open device %d, volume %d, mode %d", ubi_num, vol_id, mode);
if (ubi_num < 0 || ubi_num >= UBI_MAX_DEVICES)
return ERR_PTR(-EINVAL);
if (mode != UBI_READONLY && mode != UBI_READWRITE &&
mode != UBI_EXCLUSIVE)
return ERR_PTR(-EINVAL);
/*
* First of all, we have to get the UBI device to prevent its removal.
*/
ubi = ubi_get_device(ubi_num);
if (!ubi)
return ERR_PTR(-ENODEV);
if (vol_id < 0 || vol_id >= ubi->vtbl_slots) {
err = -EINVAL;
goto out_put_ubi;
}
desc = kmalloc(sizeof(struct ubi_volume_desc), GFP_KERNEL);
if (!desc) {
err = -ENOMEM;
goto out_put_ubi;
}
err = -ENODEV;
if (!try_module_get(THIS_MODULE))
goto out_free;
spin_lock(&ubi->volumes_lock);
vol = ubi->volumes[vol_id];
if (!vol)
goto out_unlock;
err = -EBUSY;
switch (mode) {
case UBI_READONLY:
if (vol->exclusive)
goto out_unlock;
vol->readers += 1;
break;
case UBI_READWRITE:
if (vol->exclusive || vol->writers > 0)
goto out_unlock;
vol->writers += 1;
break;
case UBI_EXCLUSIVE:
if (vol->exclusive || vol->writers || vol->readers)
goto out_unlock;
vol->exclusive = 1;
break;
}
get_device(&vol->dev);
vol->ref_count += 1;
spin_unlock(&ubi->volumes_lock);
desc->vol = vol;
desc->mode = mode;
mutex_lock(&ubi->ckvol_mutex);
if (!vol->checked) {
/* This is the first open - check the volume */
err = ubi_check_volume(ubi, vol_id);
if (err < 0) {
mutex_unlock(&ubi->ckvol_mutex);
ubi_close_volume(desc);
return ERR_PTR(err);
}
if (err == 1) {
ubi_warn("volume %d on UBI device %d is corrupted",
vol_id, ubi->ubi_num);
vol->corrupted = 1;
}
vol->checked = 1;
}
mutex_unlock(&ubi->ckvol_mutex);
return desc;
out_unlock:
spin_unlock(&ubi->volumes_lock);
module_put(THIS_MODULE);
out_free:
kfree(desc);
out_put_ubi:
ubi_put_device(ubi);
ubi_err("cannot open device %d, volume %d, error %d",
ubi_num, vol_id, err);
return ERR_PTR(err);
}
EXPORT_SYMBOL_GPL(ubi_open_volume);
/**
* ubi_open_volume_nm - open UBI volume by name.
* @ubi_num: UBI device number
* @name: volume name
* @mode: open mode
*
* This function is similar to 'ubi_open_volume()', but opens a volume by name.
*/
struct ubi_volume_desc *ubi_open_volume_nm(int ubi_num, const char *name,
int mode)
{
int i, vol_id = -1, len;
struct ubi_device *ubi;
struct ubi_volume_desc *ret;
dbg_gen("open device %d, volume %s, mode %d", ubi_num, name, mode);
if (!name)
return ERR_PTR(-EINVAL);
len = strnlen(name, UBI_VOL_NAME_MAX + 1);
if (len > UBI_VOL_NAME_MAX)
return ERR_PTR(-EINVAL);
if (ubi_num < 0 || ubi_num >= UBI_MAX_DEVICES)
return ERR_PTR(-EINVAL);
ubi = ubi_get_device(ubi_num);
if (!ubi)
return ERR_PTR(-ENODEV);
spin_lock(&ubi->volumes_lock);
/* Walk all volumes of this UBI device */
for (i = 0; i < ubi->vtbl_slots; i++) {
struct ubi_volume *vol = ubi->volumes[i];
if (vol && len == vol->name_len && !strcmp(name, vol->name)) {
vol_id = i;
break;
}
}
spin_unlock(&ubi->volumes_lock);
if (vol_id >= 0)
ret = ubi_open_volume(ubi_num, vol_id, mode);
else
ret = ERR_PTR(-ENODEV);
/*
* We should put the UBI device even in case of success, because
* 'ubi_open_volume()' took a reference as well.
*/
ubi_put_device(ubi);
return ret;
}
EXPORT_SYMBOL_GPL(ubi_open_volume_nm);
/**
* ubi_open_volume_path - open UBI volume by its character device node path.
* @pathname: volume character device node path
* @mode: open mode
*
* This function is similar to 'ubi_open_volume()', but opens a volume the path
* to its character device node.
*/
struct ubi_volume_desc *ubi_open_volume_path(const char *pathname, int mode)
{
int error, ubi_num, vol_id, mod;
struct inode *inode;
struct path path;
dbg_gen("open volume %s, mode %d", pathname, mode);
if (!pathname || !*pathname)
return ERR_PTR(-EINVAL);
error = kern_path(pathname, LOOKUP_FOLLOW, &path);
if (error)
return ERR_PTR(error);
inode = path.dentry->d_inode;
mod = inode->i_mode;
ubi_num = ubi_major2num(imajor(inode));
vol_id = iminor(inode) - 1;
path_put(&path);
if (!S_ISCHR(mod))
return ERR_PTR(-EINVAL);
if (vol_id >= 0 && ubi_num >= 0)
return ubi_open_volume(ubi_num, vol_id, mode);
return ERR_PTR(-ENODEV);
}
EXPORT_SYMBOL_GPL(ubi_open_volume_path);
/**
* ubi_close_volume - close UBI volume.
* @desc: volume descriptor
*/
void ubi_close_volume(struct ubi_volume_desc *desc)
{
struct ubi_volume *vol = desc->vol;
struct ubi_device *ubi = vol->ubi;
dbg_gen("close device %d, volume %d, mode %d",
ubi->ubi_num, vol->vol_id, desc->mode);
spin_lock(&ubi->volumes_lock);
switch (desc->mode) {
case UBI_READONLY:
vol->readers -= 1;
break;
case UBI_READWRITE:
vol->writers -= 1;
break;
case UBI_EXCLUSIVE:
vol->exclusive = 0;
}
vol->ref_count -= 1;
spin_unlock(&ubi->volumes_lock);
kfree(desc);
put_device(&vol->dev);
ubi_put_device(ubi);
module_put(THIS_MODULE);
}
EXPORT_SYMBOL_GPL(ubi_close_volume);
/**
* ubi_leb_read - read data.
* @desc: volume descriptor
* @lnum: logical eraseblock number to read from
* @buf: buffer where to store the read data
* @offset: offset within the logical eraseblock to read from
* @len: how many bytes to read
* @check: whether UBI has to check the read data's CRC or not.
*
* This function reads data from offset @offset of logical eraseblock @lnum and
* stores the data at @buf. When reading from static volumes, @check specifies
* whether the data has to be checked or not. If yes, the whole logical
* eraseblock will be read and its CRC checksum will be checked (i.e., the CRC
* checksum is per-eraseblock). So checking may substantially slow down the
* read speed. The @check argument is ignored for dynamic volumes.
*
* In case of success, this function returns zero. In case of failure, this
* function returns a negative error code.
*
* %-EBADMSG error code is returned:
* o for both static and dynamic volumes if MTD driver has detected a data
* integrity problem (unrecoverable ECC checksum mismatch in case of NAND);
* o for static volumes in case of data CRC mismatch.
*
* If the volume is damaged because of an interrupted update this function just
* returns immediately with %-EBADF error code.
*/
int ubi_leb_read(struct ubi_volume_desc *desc, int lnum, char *buf, int offset,
int len, int check)
{
struct ubi_volume *vol = desc->vol;
struct ubi_device *ubi = vol->ubi;
int err, vol_id = vol->vol_id;
dbg_gen("read %d bytes from LEB %d:%d:%d", len, vol_id, lnum, offset);
if (vol_id < 0 || vol_id >= ubi->vtbl_slots || lnum < 0 ||
lnum >= vol->used_ebs || offset < 0 || len < 0 ||
offset + len > vol->usable_leb_size)
return -EINVAL;
if (vol->vol_type == UBI_STATIC_VOLUME) {
if (vol->used_ebs == 0)
/* Empty static UBI volume */
return 0;
if (lnum == vol->used_ebs - 1 &&
offset + len > vol->last_eb_bytes)
return -EINVAL;
}
if (vol->upd_marker)
return -EBADF;
if (len == 0)
return 0;
err = ubi_eba_read_leb(ubi, vol, lnum, buf, offset, len, check);
if (err && mtd_is_eccerr(err) && vol->vol_type == UBI_STATIC_VOLUME) {
ubi_warn("mark volume %d as corrupted", vol_id);
vol->corrupted = 1;
}
return err;
}
EXPORT_SYMBOL_GPL(ubi_leb_read);
/**
* ubi_leb_write - write data.
* @desc: volume descriptor
* @lnum: logical eraseblock number to write to
* @buf: data to write
* @offset: offset within the logical eraseblock where to write
* @len: how many bytes to write
*
* This function writes @len bytes of data from @buf to offset @offset of
* logical eraseblock @lnum.
*
* This function takes care of physical eraseblock write failures. If write to
* the physical eraseblock write operation fails, the logical eraseblock is
* re-mapped to another physical eraseblock, the data is recovered, and the
* write finishes. UBI has a pool of reserved physical eraseblocks for this.
*
* If all the data were successfully written, zero is returned. If an error
* occurred and UBI has not been able to recover from it, this function returns
* a negative error code. Note, in case of an error, it is possible that
* something was still written to the flash media, but that may be some
* garbage.
*
* If the volume is damaged because of an interrupted update this function just
* returns immediately with %-EBADF code.
*/
int ubi_leb_write(struct ubi_volume_desc *desc, int lnum, const void *buf,
int offset, int len)
{
struct ubi_volume *vol = desc->vol;
struct ubi_device *ubi = vol->ubi;
int vol_id = vol->vol_id;
dbg_gen("write %d bytes to LEB %d:%d:%d", len, vol_id, lnum, offset);
if (vol_id < 0 || vol_id >= ubi->vtbl_slots)
return -EINVAL;
if (desc->mode == UBI_READONLY || vol->vol_type == UBI_STATIC_VOLUME)
return -EROFS;
if (lnum < 0 || lnum >= vol->reserved_pebs || offset < 0 || len < 0 ||
offset + len > vol->usable_leb_size ||
offset & (ubi->min_io_size - 1) || len & (ubi->min_io_size - 1))
return -EINVAL;
if (vol->upd_marker)
return -EBADF;
if (len == 0)
return 0;
return ubi_eba_write_leb(ubi, vol, lnum, buf, offset, len);
}
EXPORT_SYMBOL_GPL(ubi_leb_write);
/*
* ubi_leb_change - change logical eraseblock atomically.
* @desc: volume descriptor
* @lnum: logical eraseblock number to change
* @buf: data to write
* @len: how many bytes to write
*
* This function changes the contents of a logical eraseblock atomically. @buf
* has to contain new logical eraseblock data, and @len - the length of the
* data, which has to be aligned. The length may be shorter than the logical
* eraseblock size, ant the logical eraseblock may be appended to more times
* later on. This function guarantees that in case of an unclean reboot the old
* contents is preserved. Returns zero in case of success and a negative error
* code in case of failure.
*/
int ubi_leb_change(struct ubi_volume_desc *desc, int lnum, const void *buf,
int len)
{
struct ubi_volume *vol = desc->vol;
struct ubi_device *ubi = vol->ubi;
int vol_id = vol->vol_id;
dbg_gen("atomically write %d bytes to LEB %d:%d", len, vol_id, lnum);
if (vol_id < 0 || vol_id >= ubi->vtbl_slots)
return -EINVAL;
if (desc->mode == UBI_READONLY || vol->vol_type == UBI_STATIC_VOLUME)
return -EROFS;
if (lnum < 0 || lnum >= vol->reserved_pebs || len < 0 ||
len > vol->usable_leb_size || len & (ubi->min_io_size - 1))
return -EINVAL;
if (vol->upd_marker)
return -EBADF;
if (len == 0)
return 0;
return ubi_eba_atomic_leb_change(ubi, vol, lnum, buf, len);
}
EXPORT_SYMBOL_GPL(ubi_leb_change);
/**
* ubi_leb_erase - erase logical eraseblock.
* @desc: volume descriptor
* @lnum: logical eraseblock number
*
* This function un-maps logical eraseblock @lnum and synchronously erases the
* correspondent physical eraseblock. Returns zero in case of success and a
* negative error code in case of failure.
*
* If the volume is damaged because of an interrupted update this function just
* returns immediately with %-EBADF code.
*/
int ubi_leb_erase(struct ubi_volume_desc *desc, int lnum)
{
struct ubi_volume *vol = desc->vol;
struct ubi_device *ubi = vol->ubi;
int err;
dbg_gen("erase LEB %d:%d", vol->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 (vol->upd_marker)
return -EBADF;
err = ubi_eba_unmap_leb(ubi, vol, lnum);
if (err)
return err;
return ubi_wl_flush(ubi, vol->vol_id, lnum);
}
EXPORT_SYMBOL_GPL(ubi_leb_erase);
/**
* ubi_leb_unmap - un-map logical eraseblock.
* @desc: volume descriptor
* @lnum: logical eraseblock number
*
* This function un-maps logical eraseblock @lnum and schedules the
* corresponding physical eraseblock for erasure, so that it will eventually be
* physically erased in background. This operation is much faster than the
* erase operation.
*
* Unlike erase, the un-map operation does not guarantee that the logical
* eraseblock will contain all 0xFF bytes when UBI is initialized again. For
* example, if several logical eraseblocks are un-mapped, and an unclean reboot
* happens after this, the logical eraseblocks will not necessarily be
* un-mapped again when this MTD device is attached. They may actually be
* mapped to the same physical eraseblocks again. So, this function has to be
* used with care.
*
* In other words, when un-mapping a logical eraseblock, UBI does not store
* any information about this on the flash media, it just marks the logical
* eraseblock as "un-mapped" in RAM. If UBI is detached before the physical
* eraseblock is physically erased, it will be mapped again to the same logical
* eraseblock when the MTD device is attached again.
*
* The main and obvious use-case of this function is when the contents of a
* logical eraseblock has to be re-written. Then it is much more efficient to
* first un-map it, then write new data, rather than first erase it, then write
* new data. Note, once new data has been written to the logical eraseblock,
* UBI guarantees that the old contents has gone forever. In other words, if an
* unclean reboot happens after the logical eraseblock has been un-mapped and
* then written to, it will contain the last written data.
*
* This function returns zero in case of success and a negative error code in
* case of failure. If the volume is damaged because of an interrupted update
* this function just returns immediately with %-EBADF code.
*/
int ubi_leb_unmap(struct ubi_volume_desc *desc, int lnum)
{
struct ubi_volume *vol = desc->vol;
struct ubi_device *ubi = vol->ubi;
dbg_gen("unmap LEB %d:%d", vol->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 (vol->upd_marker)
return -EBADF;
return ubi_eba_unmap_leb(ubi, vol, lnum);
}
EXPORT_SYMBOL_GPL(ubi_leb_unmap);
/**
* ubi_leb_map - map logical eraseblock to a physical eraseblock.
* @desc: volume descriptor
* @lnum: logical eraseblock number
*
* This function maps an un-mapped logical eraseblock @lnum to a physical
* eraseblock. This means, that after a successful 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)
{
struct ubi_volume *vol = desc->vol;
struct ubi_device *ubi = vol->ubi;
dbg_gen("unmap LEB %d:%d", vol->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 (vol->upd_marker)
return -EBADF;
if (vol->eba_tbl[lnum] >= 0)
return -EBADMSG;
return ubi_eba_write_leb(ubi, vol, lnum, NULL, 0, 0);
}
EXPORT_SYMBOL_GPL(ubi_leb_map);
/**
* ubi_is_mapped - check if logical eraseblock is mapped.
* @desc: volume descriptor
* @lnum: logical eraseblock number
*
* This function checks if logical eraseblock @lnum is mapped to a physical
* eraseblock. If a logical eraseblock is un-mapped, this does not necessarily
* mean it will still be un-mapped after the UBI device is re-attached. The
* logical eraseblock may become mapped to the physical eraseblock it was last
* mapped to.
*
* This function returns %1 if the LEB is mapped, %0 if not, and a negative
* error code in case of failure. If the volume is damaged because of an
* interrupted update this function just returns immediately with %-EBADF error
* code.
*/
int ubi_is_mapped(struct ubi_volume_desc *desc, int lnum)
{
struct ubi_volume *vol = desc->vol;
dbg_gen("test LEB %d:%d", vol->vol_id, lnum);
if (lnum < 0 || lnum >= vol->reserved_pebs)
return -EINVAL;
if (vol->upd_marker)
return -EBADF;
return vol->eba_tbl[lnum] >= 0;
}
EXPORT_SYMBOL_GPL(ubi_is_mapped);
/**
* ubi_sync - synchronize UBI device buffers.
* @ubi_num: UBI device to synchronize
*
* The underlying MTD device may cache data in hardware or in software. This
* function ensures the caches are flushed. Returns zero in case of success and
* a negative error code in case of failure.
*/
int ubi_sync(int ubi_num)
{
struct ubi_device *ubi;
ubi = ubi_get_device(ubi_num);
if (!ubi)
return -ENODEV;
mtd_sync(ubi->mtd);
ubi_put_device(ubi);
return 0;
}
EXPORT_SYMBOL_GPL(ubi_sync);
/**
* ubi_flush - flush UBI work queue.
* @ubi_num: UBI device to flush work queue
* @vol_id: volume id to flush for
* @lnum: logical eraseblock number to flush for
*
* This function executes all pending works for a particular volume id / logical
* eraseblock number pair. If either value is set to %UBI_ALL, then it acts as
* a wildcard for all of the corresponding volume numbers or logical
* eraseblock numbers. It returns zero in case of success and a negative error
* code in case of failure.
*/
int ubi_flush(int ubi_num, int vol_id, int lnum)
{
struct ubi_device *ubi;
int err = 0;
ubi = ubi_get_device(ubi_num);
if (!ubi)
return -ENODEV;
err = ubi_wl_flush(ubi, vol_id, lnum);
ubi_put_device(ubi);
return err;
}
EXPORT_SYMBOL_GPL(ubi_flush);
BLOCKING_NOTIFIER_HEAD(ubi_notifiers);
/**
* ubi_register_volume_notifier - register a volume notifier.
* @nb: the notifier description object
* @ignore_existing: if non-zero, do not send "added" notification for all
* already existing volumes
*
* This function registers a volume notifier, which means that
* 'nb->notifier_call()' will be invoked when an UBI volume is created,
* removed, re-sized, re-named, or updated. The first argument of the function
* is the notification type. The second argument is pointer to a
* &struct ubi_notification object which describes the notification event.
* Using UBI API from the volume notifier is prohibited.
*
* This function returns zero in case of success and a negative error code
* in case of failure.
*/
int ubi_register_volume_notifier(struct notifier_block *nb,
int ignore_existing)
{
int err;
err = blocking_notifier_chain_register(&ubi_notifiers, nb);
if (err != 0)
return err;
if (ignore_existing)
return 0;
/*
* We are going to walk all UBI devices and all volumes, and
* notify the user about existing volumes by the %UBI_VOLUME_ADDED
* event. We have to lock the @ubi_devices_mutex to make sure UBI
* devices do not disappear.
*/
mutex_lock(&ubi_devices_mutex);
ubi_enumerate_volumes(nb);
mutex_unlock(&ubi_devices_mutex);
return err;
}
EXPORT_SYMBOL_GPL(ubi_register_volume_notifier);
/**
* ubi_unregister_volume_notifier - unregister the volume notifier.
* @nb: the notifier description object
*
* This function unregisters volume notifier @nm and returns zero in case of
* success and a negative error code in case of failure.
*/
int ubi_unregister_volume_notifier(struct notifier_block *nb)
{
return blocking_notifier_chain_unregister(&ubi_notifiers, nb);
}
EXPORT_SYMBOL_GPL(ubi_unregister_volume_notifier);