/*
* 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 includes implementation of UBI character device operations.
*
* There are two kinds of character devices in UBI: UBI character devices and
* UBI volume character devices. UBI character devices allow users to
* manipulate whole volumes: create, remove, and re-size them. Volume character
* devices provide volume I/O capabilities.
*
* Major and minor numbers are assigned dynamically to both UBI and volume
* character devices.
*
* Well, there is the third kind of character devices - the UBI control
* character device, which allows to manipulate by UBI devices - create and
* delete them. In other words, it is used for attaching and detaching MTD
* devices.
*/
#include <linux/module.h>
#include <linux/stat.h>
#include <linux/ioctl.h>
#include <linux/capability.h>
#include <mtd/ubi-user.h>
#include <asm/uaccess.h>
#include <asm/div64.h>
#include "ubi.h"
/**
* get_exclusive - get exclusive access to an UBI volume.
* @desc: volume descriptor
*
* This function changes UBI volume open mode to "exclusive". Returns previous
* mode value (positive integer) in case of success and a negative error code
* in case of failure.
*/
static int get_exclusive(struct ubi_volume_desc *desc)
{
int users, err;
struct ubi_volume *vol = desc->vol;
spin_lock(&vol->ubi->volumes_lock);
users = vol->readers + vol->writers + vol->exclusive;
ubi_assert(users > 0);
if (users > 1) {
dbg_err("%d users for volume %d", users, vol->vol_id);
err = -EBUSY;
} else {
vol->readers = vol->writers = 0;
vol->exclusive = 1;
err = desc->mode;
desc->mode = UBI_EXCLUSIVE;
}
spin_unlock(&vol->ubi->volumes_lock);
return err;
}
/**
* revoke_exclusive - revoke exclusive mode.
* @desc: volume descriptor
* @mode: new mode to switch to
*/
static void revoke_exclusive(struct ubi_volume_desc *desc, int mode)
{
struct ubi_volume *vol = desc->vol;
spin_lock(&vol->ubi->volumes_lock);
ubi_assert(vol->readers == 0 && vol->writers == 0);
ubi_assert(vol->exclusive == 1 && desc->mode == UBI_EXCLUSIVE);
vol->exclusive = 0;
if (mode == UBI_READONLY)
vol->readers = 1;
else if (mode == UBI_READWRITE)
vol->writers = 1;
else
vol->exclusive = 1;
spin_unlock(&vol->ubi->volumes_lock);
desc->mode = mode;
}
static int vol_cdev_open(struct inode *inode, struct file *file)
{
struct ubi_volume_desc *desc;
int vol_id = iminor(inode) - 1, mode, ubi_num;
ubi_num = ubi_major2num(imajor(inode));
if (ubi_num < 0)
return ubi_num;
if (file->f_mode & FMODE_WRITE)
mode = UBI_READWRITE;
else
mode = UBI_READONLY;
dbg_msg("open volume %d, mode %d", vol_id, mode);
desc = ubi_open_volume(ubi_num, vol_id, mode);
if (IS_ERR(desc))
return PTR_ERR(desc);
file->private_data = desc;
return 0;
}
static int vol_cdev_release(struct inode *inode, struct file *file)
{
struct ubi_volume_desc *desc = file->private_data;
struct ubi_volume *vol = desc->vol;
dbg_msg("release volume %d, mode %d", vol->vol_id, desc->mode);
if (vol->updating) {
ubi_warn("update of volume %d not finished, volume is damaged",
vol->vol_id);
ubi_assert(!vol->changing_leb);
vol->updating = 0;
vfree(vol->upd_buf);
} else if (vol->changing_leb) {
dbg_msg("only %lld of %lld bytes received for atomic LEB change"
" for volume %d:%d, cancel", vol->upd_received,
vol->upd_bytes, vol->ubi->ubi_num, vol->vol_id);
vol->changing_leb = 0;
vfree(vol->upd_buf);
}
ubi_close_volume(desc);
return 0;
}
static loff_t vol_cdev_llseek(struct file *file, loff_t offset, int origin)
{
struct ubi_volume_desc *desc = file->private_data;
struct ubi_volume *vol = desc->vol;
loff_t new_offset;
if (vol->updating) {
/* Update is in progress, seeking is prohibited */
dbg_err("updating");
return -EBUSY;
}
switch (origin) {
case 0: /* SEEK_SET */
new_offset = offset;
break;
case 1: /* SEEK_CUR */
new_offset = file->f_pos + offset;
break;
case 2: /* SEEK_END */
new_offset = vol->used_bytes + offset;
break;
default:
return -EINVAL;
}
if (new_offset < 0 || new_offset > vol->used_bytes) {
dbg_err("bad seek %lld", new_offset);
return -EINVAL;
}
dbg_msg("seek volume %d, offset %lld, origin %d, new offset %lld",
vol->vol_id, offset, origin, new_offset);
file->f_pos = new_offset;
return new_offset;
}
static ssize_t vol_cdev_read(struct file *file, __user char *buf, size_t count,
loff_t *offp)
{
struct ubi_volume_desc *desc = file->private_data;
struct ubi_volume *vol = desc->vol;
struct ubi_device *ubi = vol->ubi;
int err, lnum, off, len, tbuf_size;
size_t count_save = count;
void *tbuf;
uint64_t tmp;
dbg_msg("read %zd bytes from offset %lld of volume %d",
count, *offp, vol->vol_id);
if (vol->updating) {
dbg_err("updating");
return -EBUSY;
}
if (vol->upd_marker) {
dbg_err("damaged volume, update marker is set");
return -EBADF;
}
if (*offp == vol->used_bytes || count == 0)
return 0;
if (vol->corrupted)
dbg_msg("read from corrupted volume %d", vol->vol_id);
if (*offp + count > vol->used_bytes)
count_save = count = vol->used_bytes - *offp;
tbuf_size = vol->usable_leb_size;
if (count < tbuf_size)
tbuf_size = ALIGN(count, ubi->min_io_size);
tbuf = vmalloc(tbuf_size);
if (!tbuf)
return -ENOMEM;
len = count > tbuf_size ? tbuf_size : count;
tmp = *offp;
off = do_div(tmp, vol->usable_leb_size);
lnum = tmp;
do {
cond_resched();
if (off + len >= vol->usable_leb_size)
len = vol->usable_leb_size - off;
err = ubi_eba_read_leb(ubi, vol, lnum, tbuf, off, len, 0);
if (err)
break;
off += len;
if (off == vol->usable_leb_size) {
lnum += 1;
off -= vol->usable_leb_size;
}
count -= len;
*offp += len;
err = copy_to_user(buf, tbuf, len);
if (err) {
err = -EFAULT;
break;
}
buf += len;
len = count > tbuf_size ? tbuf_size : count;
} while (count);
vfree(tbuf);
return err ? err : count_save - count;
}
#ifdef CONFIG_MTD_UBI_DEBUG_USERSPACE_IO
/*
* This function allows to directly write to dynamic UBI volumes, without
* issuing the volume update operation. Available only as a debugging feature.
* Very useful for testing UBI.
*/
static ssize_t vol_cdev_direct_write(struct file *file, const char __user *buf,
size_t count, loff_t *offp)
{
struct ubi_volume_desc *desc = file->private_data;
struct ubi_volume *vol = desc->vol;
struct ubi_device *ubi = vol->ubi;
int lnum, off, len, tbuf_size, err = 0;
size_t count_save = count;
char *tbuf;
uint64_t tmp;
dbg_msg("requested: write %zd bytes to offset %lld of volume %u",
count, *offp, vol->vol_id);
if (vol->vol_type == UBI_STATIC_VOLUME)
return -EROFS;
tmp = *offp;
off = do_div(tmp, vol->usable_leb_size);
lnum = tmp;
if (off % ubi->min_io_size) {
dbg_err("unaligned position");
return -EINVAL;
}
if (*offp + count > vol->used_bytes)
count_save = count = vol->used_bytes - *offp;
/* We can write only in fractions of the minimum I/O unit */
if (count % ubi->min_io_size) {
dbg_err("unaligned write length");
return -EINVAL;
}
tbuf_size = vol->usable_leb_size;
if (count < tbuf_size)
tbuf_size = ALIGN(count, ubi->min_io_size);
tbuf = vmalloc(tbuf_size);
if (!tbuf)
return -ENOMEM;
len = count > tbuf_size ? tbuf_size : count;
while (count) {
cond_resched();
if (off + len >= vol->usable_leb_size)
len = vol->usable_leb_size - off;
err = copy_from_user(tbuf, buf, len);
if (err) {
err = -EFAULT;
break;
}
err = ubi_eba_write_leb(ubi, vol, lnum, tbuf, off, len,
UBI_UNKNOWN);
if (err)
break;
off += len;
if (off == vol->usable_leb_size) {
lnum += 1;
off -= vol->usable_leb_size;
}
count -= len;
*offp += len;
buf += len;
len = count > tbuf_size ? tbuf_size : count;
}
vfree(tbuf);
return err ? err : count_save - count;
}
#else
#define vol_cdev_direct_write(file, buf, count, offp) -EPERM
#endif /* CONFIG_MTD_UBI_DEBUG_USERSPACE_IO */
static ssize_t vol_cdev_write(struct file *file, const char __user *buf,
size_t count, loff_t *offp)
{
int err = 0;
struct ubi_volume_desc *desc = file->private_data;
struct ubi_volume *vol = desc->vol;
struct ubi_device *ubi = vol->ubi;
if (!vol->updating && !vol->changing_leb)
return vol_cdev_direct_write(file, buf, count, offp);
if (vol->updating)
err = ubi_more_update_data(ubi, vol, buf, count);
else
err = ubi_more_leb_change_data(ubi, vol, buf, count);
if (err < 0) {
ubi_err("cannot accept more %zd bytes of data, error %d",
count, err);
return err;
}
if (err) {
/*
* The operation is finished, @err contains number of actually
* written bytes.
*/
count = err;
if (vol->changing_leb) {
revoke_exclusive(desc, UBI_READWRITE);
return count;
}
err = ubi_check_volume(ubi, vol->vol_id);
if (err < 0)
return err;
if (err) {
ubi_warn("volume %d on UBI device %d is corrupted",
vol->vol_id, ubi->ubi_num);
vol->corrupted = 1;
}
vol->checked = 1;
ubi_gluebi_updated(vol);
revoke_exclusive(desc, UBI_READWRITE);
}
return count;
}
static int vol_cdev_ioctl(struct inode *inode, struct file *file,
unsigned int cmd, unsigned long arg)
{
int err = 0;
struct ubi_volume_desc *desc = file->private_data;
struct ubi_volume *vol = desc->vol;
struct ubi_device *ubi = vol->ubi;
void __user *argp = (void __user *)arg;
switch (cmd) {
/* Volume update command */
case UBI_IOCVOLUP:
{
int64_t bytes, rsvd_bytes;
if (!capable(CAP_SYS_RESOURCE)) {
err = -EPERM;
break;
}
err = copy_from_user(&bytes, argp, sizeof(int64_t));
if (err) {
err = -EFAULT;
break;
}
if (desc->mode == UBI_READONLY) {
err = -EROFS;
break;
}
rsvd_bytes = vol->reserved_pebs * (ubi->leb_size-vol->data_pad);
if (bytes < 0 || bytes > rsvd_bytes) {
err = -EINVAL;
break;
}
err = get_exclusive(desc);
if (err < 0)
break;
err = ubi_start_update(ubi, vol, bytes);
if (bytes == 0)
revoke_exclusive(desc, UBI_READWRITE);
break;
}
/* Atomic logical eraseblock change command */
case UBI_IOCEBCH:
{
struct ubi_leb_change_req req;
err = copy_from_user(&req, argp,
sizeof(struct ubi_leb_change_req));
if (err) {
err = -EFAULT;
break;
}
if (desc->mode == UBI_READONLY ||
vol->vol_type == UBI_STATIC_VOLUME) {
err = -EROFS;
break;
}
/* Validate the request */
err = -EINVAL;
if (req.lnum < 0 || req.lnum >= vol->reserved_pebs ||
req.bytes < 0 || req.lnum >= vol->usable_leb_size)
break;
if (req.dtype != UBI_LONGTERM && req.dtype != UBI_SHORTTERM &&
req.dtype != UBI_UNKNOWN)
break;
err = get_exclusive(desc);
if (err < 0)
break;
err = ubi_start_leb_change(ubi, vol, &req);
if (req.bytes == 0)
revoke_exclusive(desc, UBI_READWRITE);
break;
}
#ifdef CONFIG_MTD_UBI_DEBUG_USERSPACE_IO
/* Logical eraseblock erasure command */
case UBI_IOCEBER:
{
int32_t lnum;
err = get_user(lnum, (__user int32_t *)argp);
if (err) {
err = -EFAULT;
break;
}
if (desc->mode == UBI_READONLY ||
vol->vol_type == UBI_STATIC_VOLUME) {
err = -EROFS;
break;
}
if (lnum < 0 || lnum >= vol->reserved_pebs) {
err = -EINVAL;
break;
}
dbg_msg("erase LEB %d:%d", vol->vol_id, lnum);
err = ubi_eba_unmap_leb(ubi, vol, lnum);
if (err)
break;
err = ubi_wl_flush(ubi);
break;
}
#endif
default:
err = -ENOTTY;
break;
}
return err;
}
/**
* verify_mkvol_req - verify volume creation request.
* @ubi: UBI device description object
* @req: the request to check
*
* This function zero if the request is correct, and %-EINVAL if not.
*/
static int verify_mkvol_req(const struct ubi_device *ubi,
const struct ubi_mkvol_req *req)
{
int n, err = -EINVAL;
if (req->bytes < 0 || req->alignment < 0 || req->vol_type < 0 ||
req->name_len < 0)
goto bad;
if ((req->vol_id < 0 || req->vol_id >= ubi->vtbl_slots) &&
req->vol_id != UBI_VOL_NUM_AUTO)
goto bad;
if (req->alignment == 0)
goto bad;
if (req->bytes == 0)
goto bad;
if (req->vol_type != UBI_DYNAMIC_VOLUME &&
req->vol_type != UBI_STATIC_VOLUME)
goto bad;
if (req->alignment > ubi->leb_size)
goto bad;
n = req->alignment % ubi->min_io_size;
if (req->alignment != 1 && n)
goto bad;
if (req->name_len > UBI_VOL_NAME_MAX) {
err = -ENAMETOOLONG;
goto bad;
}
return 0;
bad:
dbg_err("bad volume creation request");
ubi_dbg_dump_mkvol_req(req);
return err;
}
/**
* verify_rsvol_req - verify volume re-size request.
* @ubi: UBI device description object
* @req: the request to check
*
* This function returns zero if the request is correct, and %-EINVAL if not.
*/
static int verify_rsvol_req(const struct ubi_device *ubi,
const struct ubi_rsvol_req *req)
{
if (req->bytes <= 0)
return -EINVAL;
if (req->vol_id < 0 || req->vol_id >= ubi->vtbl_slots)
return -EINVAL;
return 0;
}
static int ubi_cdev_ioctl(struct inode *inode, struct file *file,
unsigned int cmd, unsigned long arg)
{
int err = 0;
struct ubi_device *ubi;
struct ubi_volume_desc *desc;
void __user *argp = (void __user *)arg;
if (!capable(CAP_SYS_RESOURCE))
return -EPERM;
ubi = ubi_get_by_major(imajor(inode));
if (!ubi)
return -ENODEV;
switch (cmd) {
/* Create volume command */
case UBI_IOCMKVOL:
{
struct ubi_mkvol_req req;
dbg_msg("create volume");
err = copy_from_user(&req, argp, sizeof(struct ubi_mkvol_req));
if (err) {
err = -EFAULT;
break;
}
err = verify_mkvol_req(ubi, &req);
if (err)
break;
req.name[req.name_len] = '\0';
mutex_lock(&ubi->volumes_mutex);
err = ubi_create_volume(ubi, &req);
mutex_unlock(&ubi->volumes_mutex);
if (err)
break;
err = put_user(req.vol_id, (__user int32_t *)argp);
if (err)
err = -EFAULT;
break;
}
/* Remove volume command */
case UBI_IOCRMVOL:
{
int vol_id;
dbg_msg("remove volume");
err = get_user(vol_id, (__user int32_t *)argp);
if (err) {
err = -EFAULT;
break;
}
desc = ubi_open_volume(ubi->ubi_num, vol_id, UBI_EXCLUSIVE);
if (IS_ERR(desc)) {
err = PTR_ERR(desc);
break;
}
mutex_lock(&ubi->volumes_mutex);
err = ubi_remove_volume(desc);
mutex_unlock(&ubi->volumes_mutex);
/*
* The volume is deleted (unless an error occurred), and the
* 'struct ubi_volume' object will be freed when
* 'ubi_close_volume()' will call 'put_device()'.
*/
ubi_close_volume(desc);
break;
}
/* Re-size volume command */
case UBI_IOCRSVOL:
{
int pebs;
uint64_t tmp;
struct ubi_rsvol_req req;
dbg_msg("re-size volume");
err = copy_from_user(&req, argp, sizeof(struct ubi_rsvol_req));
if (err) {
err = -EFAULT;
break;
}
err = verify_rsvol_req(ubi, &req);
if (err)
break;
desc = ubi_open_volume(ubi->ubi_num, req.vol_id, UBI_EXCLUSIVE);
if (IS_ERR(desc)) {
err = PTR_ERR(desc);
break;
}
tmp = req.bytes;
pebs = !!do_div(tmp, desc->vol->usable_leb_size);
pebs += tmp;
mutex_lock(&ubi->volumes_mutex);
err = ubi_resize_volume(desc, pebs);
mutex_unlock(&ubi->volumes_mutex);
ubi_close_volume(desc);
break;
}
default:
err = -ENOTTY;
break;
}
ubi_put_device(ubi);
return err;
}
static int ctrl_cdev_ioctl(struct inode *inode, struct file *file,
unsigned int cmd, unsigned long arg)
{
int err = 0;
void __user *argp = (void __user *)arg;
if (!capable(CAP_SYS_RESOURCE))
return -EPERM;
switch (cmd) {
/* Attach an MTD device command */
case UBI_IOCATT:
{
struct ubi_attach_req req;
struct mtd_info *mtd;
dbg_msg("attach MTD device");
err = copy_from_user(&req, argp, sizeof(struct ubi_attach_req));
if (err) {
err = -EFAULT;
break;
}
if (req.mtd_num < 0 ||
(req.ubi_num < 0 && req.ubi_num != UBI_DEV_NUM_AUTO)) {
err = -EINVAL;
break;
}
mtd = get_mtd_device(NULL, req.mtd_num);
if (IS_ERR(mtd)) {
err = PTR_ERR(mtd);
break;
}
/*
* Note, further request verification is done by
* 'ubi_attach_mtd_dev()'.
*/
mutex_lock(&ubi_devices_mutex);
err = ubi_attach_mtd_dev(mtd, req.ubi_num, req.vid_hdr_offset);
mutex_unlock(&ubi_devices_mutex);
if (err < 0)
put_mtd_device(mtd);
else
/* @err contains UBI device number */
err = put_user(err, (__user int32_t *)argp);
break;
}
/* Detach an MTD device command */
case UBI_IOCDET:
{
int ubi_num;
dbg_msg("dettach MTD device");
err = get_user(ubi_num, (__user int32_t *)argp);
if (err) {
err = -EFAULT;
break;
}
mutex_lock(&ubi_devices_mutex);
err = ubi_detach_mtd_dev(ubi_num, 0);
mutex_unlock(&ubi_devices_mutex);
break;
}
default:
err = -ENOTTY;
break;
}
return err;
}
/* UBI control character device operations */
struct file_operations ubi_ctrl_cdev_operations = {
.ioctl = ctrl_cdev_ioctl,
.owner = THIS_MODULE,
};
/* UBI character device operations */
struct file_operations ubi_cdev_operations = {
.owner = THIS_MODULE,
.ioctl = ubi_cdev_ioctl,
.llseek = no_llseek,
};
/* UBI volume character device operations */
struct file_operations ubi_vol_cdev_operations = {
.owner = THIS_MODULE,
.open = vol_cdev_open,
.release = vol_cdev_release,
.llseek = vol_cdev_llseek,
.read = vol_cdev_read,
.write = vol_cdev_write,
.ioctl = vol_cdev_ioctl,
};
