linux/drivers/mtd/ubi/build.c
Artem Bityutskiy d37e6bf68f UBI: always start the background thread
This fix only affects UBI debugging.

If the the background thread is disabled for debugging purposes,
start it anyway, because otherwise we see tonns of kernel debugging
complaints like this:

INFO: task ubi_bgt0d:26857 blocked for more than 120 seconds.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
ubi_bgt0d     D dd37bf94     0 26857      2
       dd37bfcc 00000086 f8e17cea dd37bf94 00000046 00000000 00000000 f5c62430
       f5c62430 f5c62590 c2a09c80 f6cbd498 dd8e9cbc 00000296 dd37bfb0 00000296
       dd8e9cb8 dd8e9cbc dd37bfcc c0119774 00000000 00000000 c0132e89 f6961560
Call Trace:
 [<f8e17cea>] ? ubi_thread+0x0/0x127 [ubi]
 [<c0119774>] ? complete+0x43/0x4b
 [<c0132e89>] ? kthread+0x0/0x5b
 [<f8e17cea>] ? ubi_thread+0x0/0x127 [ubi]
 [<c0132eae>] kthread+0x25/0x5b
 [<c0132e89>] ? kthread+0x0/0x5b
 [<c0104953>] kernel_thread_helper+0x7/0x14
 =======================

So start it, and go sleep inside it, instead of creating it and never
start.

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2008-07-25 11:35:15 +03:00

1215 lines
34 KiB
C

/*
* Copyright (c) International Business Machines Corp., 2006
* Copyright (c) Nokia Corporation, 2007
*
* 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),
* Frank Haverkamp
*/
/*
* This file includes UBI initialization and building of UBI devices.
*
* When UBI is initialized, it attaches all the MTD devices specified as the
* module load parameters or the kernel boot parameters. If MTD devices were
* specified, UBI does not attach any MTD device, but it is possible to do
* later using the "UBI control device".
*
* At the moment we only attach UBI devices by scanning, which will become a
* bottleneck when flashes reach certain large size. Then one may improve UBI
* and add other methods, although it does not seem to be easy to do.
*/
#include <linux/err.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/stringify.h>
#include <linux/stat.h>
#include <linux/miscdevice.h>
#include <linux/log2.h>
#include <linux/kthread.h>
#include "ubi.h"
/* Maximum length of the 'mtd=' parameter */
#define MTD_PARAM_LEN_MAX 64
/**
* struct mtd_dev_param - MTD device parameter description data structure.
* @name: MTD device name or number string
* @vid_hdr_offs: VID header offset
*/
struct mtd_dev_param {
char name[MTD_PARAM_LEN_MAX];
int vid_hdr_offs;
};
/* Numbers of elements set in the @mtd_dev_param array */
static int mtd_devs;
/* MTD devices specification parameters */
static struct mtd_dev_param mtd_dev_param[UBI_MAX_DEVICES];
/* Root UBI "class" object (corresponds to '/<sysfs>/class/ubi/') */
struct class *ubi_class;
/* Slab cache for wear-leveling entries */
struct kmem_cache *ubi_wl_entry_slab;
/* UBI control character device */
static struct miscdevice ubi_ctrl_cdev = {
.minor = MISC_DYNAMIC_MINOR,
.name = "ubi_ctrl",
.fops = &ubi_ctrl_cdev_operations,
};
/* All UBI devices in system */
static struct ubi_device *ubi_devices[UBI_MAX_DEVICES];
/* Serializes UBI devices creations and removals */
DEFINE_MUTEX(ubi_devices_mutex);
/* Protects @ubi_devices and @ubi->ref_count */
static DEFINE_SPINLOCK(ubi_devices_lock);
/* "Show" method for files in '/<sysfs>/class/ubi/' */
static ssize_t ubi_version_show(struct class *class, char *buf)
{
return sprintf(buf, "%d\n", UBI_VERSION);
}
/* UBI version attribute ('/<sysfs>/class/ubi/version') */
static struct class_attribute ubi_version =
__ATTR(version, S_IRUGO, ubi_version_show, NULL);
static ssize_t dev_attribute_show(struct device *dev,
struct device_attribute *attr, char *buf);
/* UBI device attributes (correspond to files in '/<sysfs>/class/ubi/ubiX') */
static struct device_attribute dev_eraseblock_size =
__ATTR(eraseblock_size, S_IRUGO, dev_attribute_show, NULL);
static struct device_attribute dev_avail_eraseblocks =
__ATTR(avail_eraseblocks, S_IRUGO, dev_attribute_show, NULL);
static struct device_attribute dev_total_eraseblocks =
__ATTR(total_eraseblocks, S_IRUGO, dev_attribute_show, NULL);
static struct device_attribute dev_volumes_count =
__ATTR(volumes_count, S_IRUGO, dev_attribute_show, NULL);
static struct device_attribute dev_max_ec =
__ATTR(max_ec, S_IRUGO, dev_attribute_show, NULL);
static struct device_attribute dev_reserved_for_bad =
__ATTR(reserved_for_bad, S_IRUGO, dev_attribute_show, NULL);
static struct device_attribute dev_bad_peb_count =
__ATTR(bad_peb_count, S_IRUGO, dev_attribute_show, NULL);
static struct device_attribute dev_max_vol_count =
__ATTR(max_vol_count, S_IRUGO, dev_attribute_show, NULL);
static struct device_attribute dev_min_io_size =
__ATTR(min_io_size, S_IRUGO, dev_attribute_show, NULL);
static struct device_attribute dev_bgt_enabled =
__ATTR(bgt_enabled, S_IRUGO, dev_attribute_show, NULL);
static struct device_attribute dev_mtd_num =
__ATTR(mtd_num, S_IRUGO, dev_attribute_show, NULL);
/**
* ubi_get_device - get UBI device.
* @ubi_num: UBI device number
*
* This function returns UBI device description object for UBI device number
* @ubi_num, or %NULL if the device does not exist. This function increases the
* device reference count to prevent removal of the device. In other words, the
* device cannot be removed if its reference count is not zero.
*/
struct ubi_device *ubi_get_device(int ubi_num)
{
struct ubi_device *ubi;
spin_lock(&ubi_devices_lock);
ubi = ubi_devices[ubi_num];
if (ubi) {
ubi_assert(ubi->ref_count >= 0);
ubi->ref_count += 1;
get_device(&ubi->dev);
}
spin_unlock(&ubi_devices_lock);
return ubi;
}
/**
* ubi_put_device - drop an UBI device reference.
* @ubi: UBI device description object
*/
void ubi_put_device(struct ubi_device *ubi)
{
spin_lock(&ubi_devices_lock);
ubi->ref_count -= 1;
put_device(&ubi->dev);
spin_unlock(&ubi_devices_lock);
}
/**
* ubi_get_by_major - get UBI device by character device major number.
* @major: major number
*
* This function is similar to 'ubi_get_device()', but it searches the device
* by its major number.
*/
struct ubi_device *ubi_get_by_major(int major)
{
int i;
struct ubi_device *ubi;
spin_lock(&ubi_devices_lock);
for (i = 0; i < UBI_MAX_DEVICES; i++) {
ubi = ubi_devices[i];
if (ubi && MAJOR(ubi->cdev.dev) == major) {
ubi_assert(ubi->ref_count >= 0);
ubi->ref_count += 1;
get_device(&ubi->dev);
spin_unlock(&ubi_devices_lock);
return ubi;
}
}
spin_unlock(&ubi_devices_lock);
return NULL;
}
/**
* ubi_major2num - get UBI device number by character device major number.
* @major: major number
*
* This function searches UBI device number object by its major number. If UBI
* device was not found, this function returns -ENODEV, otherwise the UBI device
* number is returned.
*/
int ubi_major2num(int major)
{
int i, ubi_num = -ENODEV;
spin_lock(&ubi_devices_lock);
for (i = 0; i < UBI_MAX_DEVICES; i++) {
struct ubi_device *ubi = ubi_devices[i];
if (ubi && MAJOR(ubi->cdev.dev) == major) {
ubi_num = ubi->ubi_num;
break;
}
}
spin_unlock(&ubi_devices_lock);
return ubi_num;
}
/* "Show" method for files in '/<sysfs>/class/ubi/ubiX/' */
static ssize_t dev_attribute_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
ssize_t ret;
struct ubi_device *ubi;
/*
* The below code looks weird, but it actually makes sense. We get the
* UBI device reference from the contained 'struct ubi_device'. But it
* is unclear if the device was removed or not yet. Indeed, if the
* device was removed before we increased its reference count,
* 'ubi_get_device()' will return -ENODEV and we fail.
*
* Remember, 'struct ubi_device' is freed in the release function, so
* we still can use 'ubi->ubi_num'.
*/
ubi = container_of(dev, struct ubi_device, dev);
ubi = ubi_get_device(ubi->ubi_num);
if (!ubi)
return -ENODEV;
if (attr == &dev_eraseblock_size)
ret = sprintf(buf, "%d\n", ubi->leb_size);
else if (attr == &dev_avail_eraseblocks)
ret = sprintf(buf, "%d\n", ubi->avail_pebs);
else if (attr == &dev_total_eraseblocks)
ret = sprintf(buf, "%d\n", ubi->good_peb_count);
else if (attr == &dev_volumes_count)
ret = sprintf(buf, "%d\n", ubi->vol_count - UBI_INT_VOL_COUNT);
else if (attr == &dev_max_ec)
ret = sprintf(buf, "%d\n", ubi->max_ec);
else if (attr == &dev_reserved_for_bad)
ret = sprintf(buf, "%d\n", ubi->beb_rsvd_pebs);
else if (attr == &dev_bad_peb_count)
ret = sprintf(buf, "%d\n", ubi->bad_peb_count);
else if (attr == &dev_max_vol_count)
ret = sprintf(buf, "%d\n", ubi->vtbl_slots);
else if (attr == &dev_min_io_size)
ret = sprintf(buf, "%d\n", ubi->min_io_size);
else if (attr == &dev_bgt_enabled)
ret = sprintf(buf, "%d\n", ubi->thread_enabled);
else if (attr == &dev_mtd_num)
ret = sprintf(buf, "%d\n", ubi->mtd->index);
else
ret = -EINVAL;
ubi_put_device(ubi);
return ret;
}
/* Fake "release" method for UBI devices */
static void dev_release(struct device *dev) { }
/**
* ubi_sysfs_init - initialize sysfs for an UBI device.
* @ubi: UBI device description object
*
* This function returns zero in case of success and a negative error code in
* case of failure.
*/
static int ubi_sysfs_init(struct ubi_device *ubi)
{
int err;
ubi->dev.release = dev_release;
ubi->dev.devt = ubi->cdev.dev;
ubi->dev.class = ubi_class;
sprintf(&ubi->dev.bus_id[0], UBI_NAME_STR"%d", ubi->ubi_num);
err = device_register(&ubi->dev);
if (err)
return err;
err = device_create_file(&ubi->dev, &dev_eraseblock_size);
if (err)
return err;
err = device_create_file(&ubi->dev, &dev_avail_eraseblocks);
if (err)
return err;
err = device_create_file(&ubi->dev, &dev_total_eraseblocks);
if (err)
return err;
err = device_create_file(&ubi->dev, &dev_volumes_count);
if (err)
return err;
err = device_create_file(&ubi->dev, &dev_max_ec);
if (err)
return err;
err = device_create_file(&ubi->dev, &dev_reserved_for_bad);
if (err)
return err;
err = device_create_file(&ubi->dev, &dev_bad_peb_count);
if (err)
return err;
err = device_create_file(&ubi->dev, &dev_max_vol_count);
if (err)
return err;
err = device_create_file(&ubi->dev, &dev_min_io_size);
if (err)
return err;
err = device_create_file(&ubi->dev, &dev_bgt_enabled);
if (err)
return err;
err = device_create_file(&ubi->dev, &dev_mtd_num);
return err;
}
/**
* ubi_sysfs_close - close sysfs for an UBI device.
* @ubi: UBI device description object
*/
static void ubi_sysfs_close(struct ubi_device *ubi)
{
device_remove_file(&ubi->dev, &dev_mtd_num);
device_remove_file(&ubi->dev, &dev_bgt_enabled);
device_remove_file(&ubi->dev, &dev_min_io_size);
device_remove_file(&ubi->dev, &dev_max_vol_count);
device_remove_file(&ubi->dev, &dev_bad_peb_count);
device_remove_file(&ubi->dev, &dev_reserved_for_bad);
device_remove_file(&ubi->dev, &dev_max_ec);
device_remove_file(&ubi->dev, &dev_volumes_count);
device_remove_file(&ubi->dev, &dev_total_eraseblocks);
device_remove_file(&ubi->dev, &dev_avail_eraseblocks);
device_remove_file(&ubi->dev, &dev_eraseblock_size);
device_unregister(&ubi->dev);
}
/**
* kill_volumes - destroy all volumes.
* @ubi: UBI device description object
*/
static void kill_volumes(struct ubi_device *ubi)
{
int i;
for (i = 0; i < ubi->vtbl_slots; i++)
if (ubi->volumes[i])
ubi_free_volume(ubi, ubi->volumes[i]);
}
/**
* free_user_volumes - free all user volumes.
* @ubi: UBI device description object
*
* Normally the volumes are freed at the release function of the volume device
* objects. However, on error paths the volumes have to be freed before the
* device objects have been initialized.
*/
static void free_user_volumes(struct ubi_device *ubi)
{
int i;
for (i = 0; i < ubi->vtbl_slots; i++)
if (ubi->volumes[i]) {
kfree(ubi->volumes[i]->eba_tbl);
kfree(ubi->volumes[i]);
}
}
/**
* uif_init - initialize user interfaces for an UBI device.
* @ubi: UBI device description object
*
* This function returns zero in case of success and a negative error code in
* case of failure. Note, this function destroys all volumes if it failes.
*/
static int uif_init(struct ubi_device *ubi)
{
int i, err, do_free = 0;
dev_t dev;
sprintf(ubi->ubi_name, UBI_NAME_STR "%d", ubi->ubi_num);
/*
* Major numbers for the UBI character devices are allocated
* dynamically. Major numbers of volume character devices are
* equivalent to ones of the corresponding UBI character device. Minor
* numbers of UBI character devices are 0, while minor numbers of
* volume character devices start from 1. Thus, we allocate one major
* number and ubi->vtbl_slots + 1 minor numbers.
*/
err = alloc_chrdev_region(&dev, 0, ubi->vtbl_slots + 1, ubi->ubi_name);
if (err) {
ubi_err("cannot register UBI character devices");
return err;
}
ubi_assert(MINOR(dev) == 0);
cdev_init(&ubi->cdev, &ubi_cdev_operations);
dbg_gen("%s major is %u", ubi->ubi_name, MAJOR(dev));
ubi->cdev.owner = THIS_MODULE;
err = cdev_add(&ubi->cdev, dev, 1);
if (err) {
ubi_err("cannot add character device");
goto out_unreg;
}
err = ubi_sysfs_init(ubi);
if (err)
goto out_sysfs;
for (i = 0; i < ubi->vtbl_slots; i++)
if (ubi->volumes[i]) {
err = ubi_add_volume(ubi, ubi->volumes[i]);
if (err) {
ubi_err("cannot add volume %d", i);
goto out_volumes;
}
}
return 0;
out_volumes:
kill_volumes(ubi);
do_free = 0;
out_sysfs:
ubi_sysfs_close(ubi);
cdev_del(&ubi->cdev);
out_unreg:
if (do_free)
free_user_volumes(ubi);
unregister_chrdev_region(ubi->cdev.dev, ubi->vtbl_slots + 1);
ubi_err("cannot initialize UBI %s, error %d", ubi->ubi_name, err);
return err;
}
/**
* uif_close - close user interfaces for an UBI device.
* @ubi: UBI device description object
*
* Note, since this function un-registers UBI volume device objects (@vol->dev),
* the memory allocated voe the volumes is freed as well (in the release
* function).
*/
static void uif_close(struct ubi_device *ubi)
{
kill_volumes(ubi);
ubi_sysfs_close(ubi);
cdev_del(&ubi->cdev);
unregister_chrdev_region(ubi->cdev.dev, ubi->vtbl_slots + 1);
}
/**
* free_internal_volumes - free internal volumes.
* @ubi: UBI device description object
*/
static void free_internal_volumes(struct ubi_device *ubi)
{
int i;
for (i = ubi->vtbl_slots;
i < ubi->vtbl_slots + UBI_INT_VOL_COUNT; i++) {
kfree(ubi->volumes[i]->eba_tbl);
kfree(ubi->volumes[i]);
}
}
/**
* attach_by_scanning - attach an MTD device using scanning method.
* @ubi: UBI device descriptor
*
* This function returns zero in case of success and a negative error code in
* case of failure.
*
* Note, currently this is the only method to attach UBI devices. Hopefully in
* the future we'll have more scalable attaching methods and avoid full media
* scanning. But even in this case scanning will be needed as a fall-back
* attaching method if there are some on-flash table corruptions.
*/
static int attach_by_scanning(struct ubi_device *ubi)
{
int err;
struct ubi_scan_info *si;
si = ubi_scan(ubi);
if (IS_ERR(si))
return PTR_ERR(si);
ubi->bad_peb_count = si->bad_peb_count;
ubi->good_peb_count = ubi->peb_count - ubi->bad_peb_count;
ubi->max_ec = si->max_ec;
ubi->mean_ec = si->mean_ec;
err = ubi_read_volume_table(ubi, si);
if (err)
goto out_si;
err = ubi_wl_init_scan(ubi, si);
if (err)
goto out_vtbl;
err = ubi_eba_init_scan(ubi, si);
if (err)
goto out_wl;
ubi_scan_destroy_si(si);
return 0;
out_wl:
ubi_wl_close(ubi);
out_vtbl:
free_internal_volumes(ubi);
vfree(ubi->vtbl);
out_si:
ubi_scan_destroy_si(si);
return err;
}
/**
* io_init - initialize I/O sub-system for a given UBI device.
* @ubi: UBI device description object
*
* If @ubi->vid_hdr_offset or @ubi->leb_start is zero, default offsets are
* assumed:
* o EC header is always at offset zero - this cannot be changed;
* o VID header starts just after the EC header at the closest address
* aligned to @io->hdrs_min_io_size;
* o data starts just after the VID header at the closest address aligned to
* @io->min_io_size
*
* This function returns zero in case of success and a negative error code in
* case of failure.
*/
static int io_init(struct ubi_device *ubi)
{
if (ubi->mtd->numeraseregions != 0) {
/*
* Some flashes have several erase regions. Different regions
* may have different eraseblock size and other
* characteristics. It looks like mostly multi-region flashes
* have one "main" region and one or more small regions to
* store boot loader code or boot parameters or whatever. I
* guess we should just pick the largest region. But this is
* not implemented.
*/
ubi_err("multiple regions, not implemented");
return -EINVAL;
}
if (ubi->vid_hdr_offset < 0)
return -EINVAL;
/*
* Note, in this implementation we support MTD devices with 0x7FFFFFFF
* physical eraseblocks maximum.
*/
ubi->peb_size = ubi->mtd->erasesize;
ubi->peb_count = ubi->mtd->size / ubi->mtd->erasesize;
ubi->flash_size = ubi->mtd->size;
if (ubi->mtd->block_isbad && ubi->mtd->block_markbad)
ubi->bad_allowed = 1;
ubi->min_io_size = ubi->mtd->writesize;
ubi->hdrs_min_io_size = ubi->mtd->writesize >> ubi->mtd->subpage_sft;
/*
* Make sure minimal I/O unit is power of 2. Note, there is no
* fundamental reason for this assumption. It is just an optimization
* which allows us to avoid costly division operations.
*/
if (!is_power_of_2(ubi->min_io_size)) {
ubi_err("min. I/O unit (%d) is not power of 2",
ubi->min_io_size);
return -EINVAL;
}
ubi_assert(ubi->hdrs_min_io_size > 0);
ubi_assert(ubi->hdrs_min_io_size <= ubi->min_io_size);
ubi_assert(ubi->min_io_size % ubi->hdrs_min_io_size == 0);
/* Calculate default aligned sizes of EC and VID headers */
ubi->ec_hdr_alsize = ALIGN(UBI_EC_HDR_SIZE, ubi->hdrs_min_io_size);
ubi->vid_hdr_alsize = ALIGN(UBI_VID_HDR_SIZE, ubi->hdrs_min_io_size);
dbg_msg("min_io_size %d", ubi->min_io_size);
dbg_msg("hdrs_min_io_size %d", ubi->hdrs_min_io_size);
dbg_msg("ec_hdr_alsize %d", ubi->ec_hdr_alsize);
dbg_msg("vid_hdr_alsize %d", ubi->vid_hdr_alsize);
if (ubi->vid_hdr_offset == 0)
/* Default offset */
ubi->vid_hdr_offset = ubi->vid_hdr_aloffset =
ubi->ec_hdr_alsize;
else {
ubi->vid_hdr_aloffset = ubi->vid_hdr_offset &
~(ubi->hdrs_min_io_size - 1);
ubi->vid_hdr_shift = ubi->vid_hdr_offset -
ubi->vid_hdr_aloffset;
}
/* Similar for the data offset */
ubi->leb_start = ubi->vid_hdr_offset + UBI_EC_HDR_SIZE;
ubi->leb_start = ALIGN(ubi->leb_start, ubi->min_io_size);
dbg_msg("vid_hdr_offset %d", ubi->vid_hdr_offset);
dbg_msg("vid_hdr_aloffset %d", ubi->vid_hdr_aloffset);
dbg_msg("vid_hdr_shift %d", ubi->vid_hdr_shift);
dbg_msg("leb_start %d", ubi->leb_start);
/* The shift must be aligned to 32-bit boundary */
if (ubi->vid_hdr_shift % 4) {
ubi_err("unaligned VID header shift %d",
ubi->vid_hdr_shift);
return -EINVAL;
}
/* Check sanity */
if (ubi->vid_hdr_offset < UBI_EC_HDR_SIZE ||
ubi->leb_start < ubi->vid_hdr_offset + UBI_VID_HDR_SIZE ||
ubi->leb_start > ubi->peb_size - UBI_VID_HDR_SIZE ||
ubi->leb_start & (ubi->min_io_size - 1)) {
ubi_err("bad VID header (%d) or data offsets (%d)",
ubi->vid_hdr_offset, ubi->leb_start);
return -EINVAL;
}
/*
* It may happen that EC and VID headers are situated in one minimal
* I/O unit. In this case we can only accept this UBI image in
* read-only mode.
*/
if (ubi->vid_hdr_offset + UBI_VID_HDR_SIZE <= ubi->hdrs_min_io_size) {
ubi_warn("EC and VID headers are in the same minimal I/O unit, "
"switch to read-only mode");
ubi->ro_mode = 1;
}
ubi->leb_size = ubi->peb_size - ubi->leb_start;
if (!(ubi->mtd->flags & MTD_WRITEABLE)) {
ubi_msg("MTD device %d is write-protected, attach in "
"read-only mode", ubi->mtd->index);
ubi->ro_mode = 1;
}
ubi_msg("physical eraseblock size: %d bytes (%d KiB)",
ubi->peb_size, ubi->peb_size >> 10);
ubi_msg("logical eraseblock size: %d bytes", ubi->leb_size);
ubi_msg("smallest flash I/O unit: %d", ubi->min_io_size);
if (ubi->hdrs_min_io_size != ubi->min_io_size)
ubi_msg("sub-page size: %d",
ubi->hdrs_min_io_size);
ubi_msg("VID header offset: %d (aligned %d)",
ubi->vid_hdr_offset, ubi->vid_hdr_aloffset);
ubi_msg("data offset: %d", ubi->leb_start);
/*
* Note, ideally, we have to initialize ubi->bad_peb_count here. But
* unfortunately, MTD does not provide this information. We should loop
* over all physical eraseblocks and invoke mtd->block_is_bad() for
* each physical eraseblock. So, we skip ubi->bad_peb_count
* uninitialized and initialize it after scanning.
*/
return 0;
}
/**
* autoresize - re-size the volume which has the "auto-resize" flag set.
* @ubi: UBI device description object
* @vol_id: ID of the volume to re-size
*
* This function re-sizes the volume marked by the @UBI_VTBL_AUTORESIZE_FLG in
* the volume table to the largest possible size. See comments in ubi-header.h
* for more description of the flag. Returns zero in case of success and a
* negative error code in case of failure.
*/
static int autoresize(struct ubi_device *ubi, int vol_id)
{
struct ubi_volume_desc desc;
struct ubi_volume *vol = ubi->volumes[vol_id];
int err, old_reserved_pebs = vol->reserved_pebs;
/*
* Clear the auto-resize flag in the volume in-memory copy of the
* volume table, and 'ubi_resize_volume()' will propagate this change
* to the flash.
*/
ubi->vtbl[vol_id].flags &= ~UBI_VTBL_AUTORESIZE_FLG;
if (ubi->avail_pebs == 0) {
struct ubi_vtbl_record vtbl_rec;
/*
* No available PEBs to re-size the volume, clear the flag on
* flash and exit.
*/
memcpy(&vtbl_rec, &ubi->vtbl[vol_id],
sizeof(struct ubi_vtbl_record));
err = ubi_change_vtbl_record(ubi, vol_id, &vtbl_rec);
if (err)
ubi_err("cannot clean auto-resize flag for volume %d",
vol_id);
} else {
desc.vol = vol;
err = ubi_resize_volume(&desc,
old_reserved_pebs + ubi->avail_pebs);
if (err)
ubi_err("cannot auto-resize volume %d", vol_id);
}
if (err)
return err;
ubi_msg("volume %d (\"%s\") re-sized from %d to %d LEBs", vol_id,
vol->name, old_reserved_pebs, vol->reserved_pebs);
return 0;
}
/**
* ubi_attach_mtd_dev - attach an MTD device.
* @mtd: MTD device description object
* @ubi_num: number to assign to the new UBI device
* @vid_hdr_offset: VID header offset
*
* This function attaches MTD device @mtd_dev to UBI and assign @ubi_num number
* to the newly created UBI device, unless @ubi_num is %UBI_DEV_NUM_AUTO, in
* which case this function finds a vacant device number and assigns it
* automatically. Returns the new UBI device number in case of success and a
* negative error code in case of failure.
*
* Note, the invocations of this function has to be serialized by the
* @ubi_devices_mutex.
*/
int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num, int vid_hdr_offset)
{
struct ubi_device *ubi;
int i, err, do_free = 1;
/*
* Check if we already have the same MTD device attached.
*
* Note, this function assumes that UBI devices creations and deletions
* are serialized, so it does not take the &ubi_devices_lock.
*/
for (i = 0; i < UBI_MAX_DEVICES; i++) {
ubi = ubi_devices[i];
if (ubi && mtd->index == ubi->mtd->index) {
dbg_err("mtd%d is already attached to ubi%d",
mtd->index, i);
return -EEXIST;
}
}
/*
* Make sure this MTD device is not emulated on top of an UBI volume
* already. Well, generally this recursion works fine, but there are
* different problems like the UBI module takes a reference to itself
* by attaching (and thus, opening) the emulated MTD device. This
* results in inability to unload the module. And in general it makes
* no sense to attach emulated MTD devices, so we prohibit this.
*/
if (mtd->type == MTD_UBIVOLUME) {
ubi_err("refuse attaching mtd%d - it is already emulated on "
"top of UBI", mtd->index);
return -EINVAL;
}
if (ubi_num == UBI_DEV_NUM_AUTO) {
/* Search for an empty slot in the @ubi_devices array */
for (ubi_num = 0; ubi_num < UBI_MAX_DEVICES; ubi_num++)
if (!ubi_devices[ubi_num])
break;
if (ubi_num == UBI_MAX_DEVICES) {
dbg_err("only %d UBI devices may be created",
UBI_MAX_DEVICES);
return -ENFILE;
}
} else {
if (ubi_num >= UBI_MAX_DEVICES)
return -EINVAL;
/* Make sure ubi_num is not busy */
if (ubi_devices[ubi_num]) {
dbg_err("ubi%d already exists", ubi_num);
return -EEXIST;
}
}
ubi = kzalloc(sizeof(struct ubi_device), GFP_KERNEL);
if (!ubi)
return -ENOMEM;
ubi->mtd = mtd;
ubi->ubi_num = ubi_num;
ubi->vid_hdr_offset = vid_hdr_offset;
ubi->autoresize_vol_id = -1;
mutex_init(&ubi->buf_mutex);
mutex_init(&ubi->ckvol_mutex);
mutex_init(&ubi->mult_mutex);
mutex_init(&ubi->volumes_mutex);
spin_lock_init(&ubi->volumes_lock);
ubi_msg("attaching mtd%d to ubi%d", mtd->index, ubi_num);
err = io_init(ubi);
if (err)
goto out_free;
ubi->peb_buf1 = vmalloc(ubi->peb_size);
if (!ubi->peb_buf1)
goto out_free;
ubi->peb_buf2 = vmalloc(ubi->peb_size);
if (!ubi->peb_buf2)
goto out_free;
#ifdef CONFIG_MTD_UBI_DEBUG
mutex_init(&ubi->dbg_buf_mutex);
ubi->dbg_peb_buf = vmalloc(ubi->peb_size);
if (!ubi->dbg_peb_buf)
goto out_free;
#endif
err = attach_by_scanning(ubi);
if (err) {
dbg_err("failed to attach by scanning, error %d", err);
goto out_free;
}
if (ubi->autoresize_vol_id != -1) {
err = autoresize(ubi, ubi->autoresize_vol_id);
if (err)
goto out_detach;
}
err = uif_init(ubi);
if (err)
goto out_nofree;
ubi->bgt_thread = kthread_create(ubi_thread, ubi, ubi->bgt_name);
if (IS_ERR(ubi->bgt_thread)) {
err = PTR_ERR(ubi->bgt_thread);
ubi_err("cannot spawn \"%s\", error %d", ubi->bgt_name,
err);
goto out_uif;
}
ubi_msg("attached mtd%d to ubi%d", mtd->index, ubi_num);
ubi_msg("MTD device name: \"%s\"", mtd->name);
ubi_msg("MTD device size: %llu MiB", ubi->flash_size >> 20);
ubi_msg("number of good PEBs: %d", ubi->good_peb_count);
ubi_msg("number of bad PEBs: %d", ubi->bad_peb_count);
ubi_msg("max. allowed volumes: %d", ubi->vtbl_slots);
ubi_msg("wear-leveling threshold: %d", CONFIG_MTD_UBI_WL_THRESHOLD);
ubi_msg("number of internal volumes: %d", UBI_INT_VOL_COUNT);
ubi_msg("number of user volumes: %d",
ubi->vol_count - UBI_INT_VOL_COUNT);
ubi_msg("available PEBs: %d", ubi->avail_pebs);
ubi_msg("total number of reserved PEBs: %d", ubi->rsvd_pebs);
ubi_msg("number of PEBs reserved for bad PEB handling: %d",
ubi->beb_rsvd_pebs);
ubi_msg("max/mean erase counter: %d/%d", ubi->max_ec, ubi->mean_ec);
if (!DBG_DISABLE_BGT)
ubi->thread_enabled = 1;
wake_up_process(ubi->bgt_thread);
ubi_devices[ubi_num] = ubi;
return ubi_num;
out_uif:
uif_close(ubi);
out_nofree:
do_free = 0;
out_detach:
ubi_wl_close(ubi);
if (do_free)
free_user_volumes(ubi);
free_internal_volumes(ubi);
vfree(ubi->vtbl);
out_free:
vfree(ubi->peb_buf1);
vfree(ubi->peb_buf2);
#ifdef CONFIG_MTD_UBI_DEBUG
vfree(ubi->dbg_peb_buf);
#endif
kfree(ubi);
return err;
}
/**
* ubi_detach_mtd_dev - detach an MTD device.
* @ubi_num: UBI device number to detach from
* @anyway: detach MTD even if device reference count is not zero
*
* This function destroys an UBI device number @ubi_num and detaches the
* underlying MTD device. Returns zero in case of success and %-EBUSY if the
* UBI device is busy and cannot be destroyed, and %-EINVAL if it does not
* exist.
*
* Note, the invocations of this function has to be serialized by the
* @ubi_devices_mutex.
*/
int ubi_detach_mtd_dev(int ubi_num, int anyway)
{
struct ubi_device *ubi;
if (ubi_num < 0 || ubi_num >= UBI_MAX_DEVICES)
return -EINVAL;
spin_lock(&ubi_devices_lock);
ubi = ubi_devices[ubi_num];
if (!ubi) {
spin_unlock(&ubi_devices_lock);
return -EINVAL;
}
if (ubi->ref_count) {
if (!anyway) {
spin_unlock(&ubi_devices_lock);
return -EBUSY;
}
/* This may only happen if there is a bug */
ubi_err("%s reference count %d, destroy anyway",
ubi->ubi_name, ubi->ref_count);
}
ubi_devices[ubi_num] = NULL;
spin_unlock(&ubi_devices_lock);
ubi_assert(ubi_num == ubi->ubi_num);
dbg_msg("detaching mtd%d from ubi%d", ubi->mtd->index, ubi_num);
/*
* Before freeing anything, we have to stop the background thread to
* prevent it from doing anything on this device while we are freeing.
*/
if (ubi->bgt_thread)
kthread_stop(ubi->bgt_thread);
uif_close(ubi);
ubi_wl_close(ubi);
free_internal_volumes(ubi);
vfree(ubi->vtbl);
put_mtd_device(ubi->mtd);
vfree(ubi->peb_buf1);
vfree(ubi->peb_buf2);
#ifdef CONFIG_MTD_UBI_DEBUG
vfree(ubi->dbg_peb_buf);
#endif
ubi_msg("mtd%d is detached from ubi%d", ubi->mtd->index, ubi->ubi_num);
kfree(ubi);
return 0;
}
/**
* find_mtd_device - open an MTD device by its name or number.
* @mtd_dev: name or number of the device
*
* This function tries to open and MTD device described by @mtd_dev string,
* which is first treated as an ASCII number, and if it is not true, it is
* treated as MTD device name. Returns MTD device description object in case of
* success and a negative error code in case of failure.
*/
static struct mtd_info * __init open_mtd_device(const char *mtd_dev)
{
struct mtd_info *mtd;
int mtd_num;
char *endp;
mtd_num = simple_strtoul(mtd_dev, &endp, 0);
if (*endp != '\0' || mtd_dev == endp) {
/*
* This does not look like an ASCII integer, probably this is
* MTD device name.
*/
mtd = get_mtd_device_nm(mtd_dev);
} else
mtd = get_mtd_device(NULL, mtd_num);
return mtd;
}
static int __init ubi_init(void)
{
int err, i, k;
/* Ensure that EC and VID headers have correct size */
BUILD_BUG_ON(sizeof(struct ubi_ec_hdr) != 64);
BUILD_BUG_ON(sizeof(struct ubi_vid_hdr) != 64);
if (mtd_devs > UBI_MAX_DEVICES) {
ubi_err("too many MTD devices, maximum is %d", UBI_MAX_DEVICES);
return -EINVAL;
}
/* Create base sysfs directory and sysfs files */
ubi_class = class_create(THIS_MODULE, UBI_NAME_STR);
if (IS_ERR(ubi_class)) {
err = PTR_ERR(ubi_class);
ubi_err("cannot create UBI class");
goto out;
}
err = class_create_file(ubi_class, &ubi_version);
if (err) {
ubi_err("cannot create sysfs file");
goto out_class;
}
err = misc_register(&ubi_ctrl_cdev);
if (err) {
ubi_err("cannot register device");
goto out_version;
}
ubi_wl_entry_slab = kmem_cache_create("ubi_wl_entry_slab",
sizeof(struct ubi_wl_entry),
0, 0, NULL);
if (!ubi_wl_entry_slab)
goto out_dev_unreg;
/* Attach MTD devices */
for (i = 0; i < mtd_devs; i++) {
struct mtd_dev_param *p = &mtd_dev_param[i];
struct mtd_info *mtd;
cond_resched();
mtd = open_mtd_device(p->name);
if (IS_ERR(mtd)) {
err = PTR_ERR(mtd);
goto out_detach;
}
mutex_lock(&ubi_devices_mutex);
err = ubi_attach_mtd_dev(mtd, UBI_DEV_NUM_AUTO,
p->vid_hdr_offs);
mutex_unlock(&ubi_devices_mutex);
if (err < 0) {
put_mtd_device(mtd);
ubi_err("cannot attach mtd%d", mtd->index);
goto out_detach;
}
}
return 0;
out_detach:
for (k = 0; k < i; k++)
if (ubi_devices[k]) {
mutex_lock(&ubi_devices_mutex);
ubi_detach_mtd_dev(ubi_devices[k]->ubi_num, 1);
mutex_unlock(&ubi_devices_mutex);
}
kmem_cache_destroy(ubi_wl_entry_slab);
out_dev_unreg:
misc_deregister(&ubi_ctrl_cdev);
out_version:
class_remove_file(ubi_class, &ubi_version);
out_class:
class_destroy(ubi_class);
out:
ubi_err("UBI error: cannot initialize UBI, error %d", err);
return err;
}
module_init(ubi_init);
static void __exit ubi_exit(void)
{
int i;
for (i = 0; i < UBI_MAX_DEVICES; i++)
if (ubi_devices[i]) {
mutex_lock(&ubi_devices_mutex);
ubi_detach_mtd_dev(ubi_devices[i]->ubi_num, 1);
mutex_unlock(&ubi_devices_mutex);
}
kmem_cache_destroy(ubi_wl_entry_slab);
misc_deregister(&ubi_ctrl_cdev);
class_remove_file(ubi_class, &ubi_version);
class_destroy(ubi_class);
}
module_exit(ubi_exit);
/**
* bytes_str_to_int - convert a number of bytes string into an integer.
* @str: the string to convert
*
* This function returns positive resulting integer in case of success and a
* negative error code in case of failure.
*/
static int __init bytes_str_to_int(const char *str)
{
char *endp;
unsigned long result;
result = simple_strtoul(str, &endp, 0);
if (str == endp || result < 0) {
printk(KERN_ERR "UBI error: incorrect bytes count: \"%s\"\n",
str);
return -EINVAL;
}
switch (*endp) {
case 'G':
result *= 1024;
case 'M':
result *= 1024;
case 'K':
result *= 1024;
if (endp[1] == 'i' && endp[2] == 'B')
endp += 2;
case '\0':
break;
default:
printk(KERN_ERR "UBI error: incorrect bytes count: \"%s\"\n",
str);
return -EINVAL;
}
return result;
}
/**
* ubi_mtd_param_parse - parse the 'mtd=' UBI parameter.
* @val: the parameter value to parse
* @kp: not used
*
* This function returns zero in case of success and a negative error code in
* case of error.
*/
static int __init ubi_mtd_param_parse(const char *val, struct kernel_param *kp)
{
int i, len;
struct mtd_dev_param *p;
char buf[MTD_PARAM_LEN_MAX];
char *pbuf = &buf[0];
char *tokens[2] = {NULL, NULL};
if (!val)
return -EINVAL;
if (mtd_devs == UBI_MAX_DEVICES) {
printk(KERN_ERR "UBI error: too many parameters, max. is %d\n",
UBI_MAX_DEVICES);
return -EINVAL;
}
len = strnlen(val, MTD_PARAM_LEN_MAX);
if (len == MTD_PARAM_LEN_MAX) {
printk(KERN_ERR "UBI error: parameter \"%s\" is too long, "
"max. is %d\n", val, MTD_PARAM_LEN_MAX);
return -EINVAL;
}
if (len == 0) {
printk(KERN_WARNING "UBI warning: empty 'mtd=' parameter - "
"ignored\n");
return 0;
}
strcpy(buf, val);
/* Get rid of the final newline */
if (buf[len - 1] == '\n')
buf[len - 1] = '\0';
for (i = 0; i < 2; i++)
tokens[i] = strsep(&pbuf, ",");
if (pbuf) {
printk(KERN_ERR "UBI error: too many arguments at \"%s\"\n",
val);
return -EINVAL;
}
p = &mtd_dev_param[mtd_devs];
strcpy(&p->name[0], tokens[0]);
if (tokens[1])
p->vid_hdr_offs = bytes_str_to_int(tokens[1]);
if (p->vid_hdr_offs < 0)
return p->vid_hdr_offs;
mtd_devs += 1;
return 0;
}
module_param_call(mtd, ubi_mtd_param_parse, NULL, NULL, 000);
MODULE_PARM_DESC(mtd, "MTD devices to attach. Parameter format: "
"mtd=<name|num>[,<vid_hdr_offs>].\n"
"Multiple \"mtd\" parameters may be specified.\n"
"MTD devices may be specified by their number or name.\n"
"Optional \"vid_hdr_offs\" parameter specifies UBI VID "
"header position and data starting position to be used "
"by UBI.\n"
"Example: mtd=content,1984 mtd=4 - attach MTD device"
"with name \"content\" using VID header offset 1984, and "
"MTD device number 4 with default VID header offset.");
MODULE_VERSION(__stringify(UBI_VERSION));
MODULE_DESCRIPTION("UBI - Unsorted Block Images");
MODULE_AUTHOR("Artem Bityutskiy");
MODULE_LICENSE("GPL");