*/
/*
- * This file includes UBI initialization and building of UBI devices. At the
- * moment UBI devices may only be added while UBI is initialized, but dynamic
- * device add/remove functionality is planned. Also, 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.
+ * 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/moduleparam.h>
#include <linux/stringify.h>
#include <linux/stat.h>
+#include <linux/miscdevice.h>
#include <linux/log2.h>
+#include <linux/kthread.h>
+#include <linux/reboot.h>
#include "ubi.h"
/* Maximum length of the 'mtd=' parameter */
* struct mtd_dev_param - MTD device parameter description data structure.
* @name: MTD device name or number string
* @vid_hdr_offs: VID header offset
- * @data_offs: data offset
*/
-struct mtd_dev_param
-{
+struct mtd_dev_param {
char name[MTD_PARAM_LEN_MAX];
int vid_hdr_offs;
- int data_offs;
};
/* Numbers of elements set in the @mtd_dev_param array */
-static int mtd_devs = 0;
+static int mtd_devs;
/* MTD devices specification parameters */
static struct mtd_dev_param mtd_dev_param[UBI_MAX_DEVICES];
-/* Number of UBI devices in system */
-int ubi_devices_cnt;
+/* 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 */
-struct ubi_device *ubi_devices[UBI_MAX_DEVICES];
+static struct ubi_device *ubi_devices[UBI_MAX_DEVICES];
-/* Root UBI "class" object (corresponds to '/<sysfs>/class/ubi/') */
-struct class *ubi_class;
+/* 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)
__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_volume_notify - send a volume change notification.
+ * @ubi: UBI device description object
+ * @vol: volume description object of the changed volume
+ * @ntype: notification type to send (%UBI_VOLUME_ADDED, etc)
+ *
+ * This is a helper function which notifies all subscribers about a volume
+ * change event (creation, removal, re-sizing, re-naming, updating). Returns
+ * zero in case of success and a negative error code in case of failure.
+ */
+int ubi_volume_notify(struct ubi_device *ubi, struct ubi_volume *vol, int ntype)
+{
+ struct ubi_notification nt;
+
+ ubi_do_get_device_info(ubi, &nt.di);
+ ubi_do_get_volume_info(ubi, vol, &nt.vi);
+ return blocking_notifier_call_chain(&ubi_notifiers, ntype, &nt);
+}
+
+/**
+ * ubi_notify_all - send a notification to all volumes.
+ * @ubi: UBI device description object
+ * @ntype: notification type to send (%UBI_VOLUME_ADDED, etc)
+ * @nb: the notifier to call
+ *
+ * This function walks all volumes of UBI device @ubi and sends the @ntype
+ * notification for each volume. If @nb is %NULL, then all registered notifiers
+ * are called, otherwise only the @nb notifier is called. Returns the number of
+ * sent notifications.
+ */
+int ubi_notify_all(struct ubi_device *ubi, int ntype, struct notifier_block *nb)
+{
+ struct ubi_notification nt;
+ int i, count = 0;
+
+ ubi_do_get_device_info(ubi, &nt.di);
+
+ mutex_lock(&ubi->device_mutex);
+ for (i = 0; i < ubi->vtbl_slots; i++) {
+ /*
+ * Since the @ubi->device is locked, and we are not going to
+ * change @ubi->volumes, we do not have to lock
+ * @ubi->volumes_lock.
+ */
+ if (!ubi->volumes[i])
+ continue;
+
+ ubi_do_get_volume_info(ubi, ubi->volumes[i], &nt.vi);
+ if (nb)
+ nb->notifier_call(nb, ntype, &nt);
+ else
+ blocking_notifier_call_chain(&ubi_notifiers, ntype,
+ &nt);
+ count += 1;
+ }
+ mutex_unlock(&ubi->device_mutex);
+
+ return count;
+}
+
+/**
+ * ubi_enumerate_volumes - send "add" notification for all existing volumes.
+ * @nb: the notifier to call
+ *
+ * This function walks all UBI devices and volumes and sends the
+ * %UBI_VOLUME_ADDED notification for each volume. If @nb is %NULL, then all
+ * registered notifiers are called, otherwise only the @nb notifier is called.
+ * Returns the number of sent notifications.
+ */
+int ubi_enumerate_volumes(struct notifier_block *nb)
+{
+ int i, count = 0;
+
+ /*
+ * Since the @ubi_devices_mutex is locked, and we are not going to
+ * change @ubi_devices, we do not have to lock @ubi_devices_lock.
+ */
+ for (i = 0; i < UBI_MAX_DEVICES; i++) {
+ struct ubi_device *ubi = ubi_devices[i];
+
+ if (!ubi)
+ continue;
+ count += ubi_notify_all(ubi, UBI_VOLUME_ADDED, nb);
+ }
+
+ return count;
+}
+
+/**
+ * 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)
{
- const struct ubi_device *ubi;
+ 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)
- return sprintf(buf, "%d\n", ubi->leb_size);
+ ret = sprintf(buf, "%d\n", ubi->leb_size);
else if (attr == &dev_avail_eraseblocks)
- return sprintf(buf, "%d\n", ubi->avail_pebs);
+ ret = sprintf(buf, "%d\n", ubi->avail_pebs);
else if (attr == &dev_total_eraseblocks)
- return sprintf(buf, "%d\n", ubi->good_peb_count);
+ ret = sprintf(buf, "%d\n", ubi->good_peb_count);
else if (attr == &dev_volumes_count)
- return sprintf(buf, "%d\n", ubi->vol_count);
+ ret = sprintf(buf, "%d\n", ubi->vol_count - UBI_INT_VOL_COUNT);
else if (attr == &dev_max_ec)
- return sprintf(buf, "%d\n", ubi->max_ec);
+ ret = sprintf(buf, "%d\n", ubi->max_ec);
else if (attr == &dev_reserved_for_bad)
- return sprintf(buf, "%d\n", ubi->beb_rsvd_pebs);
+ ret = sprintf(buf, "%d\n", ubi->beb_rsvd_pebs);
else if (attr == &dev_bad_peb_count)
- return sprintf(buf, "%d\n", ubi->bad_peb_count);
+ ret = sprintf(buf, "%d\n", ubi->bad_peb_count);
else if (attr == &dev_max_vol_count)
- return sprintf(buf, "%d\n", ubi->vtbl_slots);
+ ret = sprintf(buf, "%d\n", ubi->vtbl_slots);
else if (attr == &dev_min_io_size)
- return sprintf(buf, "%d\n", ubi->min_io_size);
+ ret = sprintf(buf, "%d\n", ubi->min_io_size);
else if (attr == &dev_bgt_enabled)
- return sprintf(buf, "%d\n", ubi->thread_enabled);
+ ret = sprintf(buf, "%d\n", ubi->thread_enabled);
+ else if (attr == &dev_mtd_num)
+ ret = sprintf(buf, "%d\n", ubi->mtd->index);
else
- BUG();
+ ret = -EINVAL;
- return 0;
+ ubi_put_device(ubi);
+ return ret;
}
-/* Fake "release" method for UBI devices */
-static void dev_release(struct device *dev) { }
+static void dev_release(struct device *dev)
+{
+ struct ubi_device *ubi = container_of(dev, struct ubi_device, dev);
+
+ kfree(ubi);
+}
/**
* ubi_sysfs_init - initialize sysfs for an UBI device.
int err;
ubi->dev.release = dev_release;
- ubi->dev.devt = MKDEV(ubi->major, 0);
+ ubi->dev.devt = ubi->cdev.dev;
ubi->dev.class = ubi_class;
- sprintf(&ubi->dev.bus_id[0], UBI_NAME_STR"%d", ubi->ubi_num);
+ dev_set_name(&ubi->dev, UBI_NAME_STR"%d", ubi->ubi_num);
err = device_register(&ubi->dev);
if (err)
- goto out;
+ return err;
err = device_create_file(&ubi->dev, &dev_eraseblock_size);
if (err)
- goto out_unregister;
+ return err;
err = device_create_file(&ubi->dev, &dev_avail_eraseblocks);
if (err)
- goto out_eraseblock_size;
+ return err;
err = device_create_file(&ubi->dev, &dev_total_eraseblocks);
if (err)
- goto out_avail_eraseblocks;
+ return err;
err = device_create_file(&ubi->dev, &dev_volumes_count);
if (err)
- goto out_total_eraseblocks;
+ return err;
err = device_create_file(&ubi->dev, &dev_max_ec);
if (err)
- goto out_volumes_count;
+ return err;
err = device_create_file(&ubi->dev, &dev_reserved_for_bad);
if (err)
- goto out_volumes_max_ec;
+ return err;
err = device_create_file(&ubi->dev, &dev_bad_peb_count);
if (err)
- goto out_reserved_for_bad;
+ return err;
err = device_create_file(&ubi->dev, &dev_max_vol_count);
if (err)
- goto out_bad_peb_count;
+ return err;
err = device_create_file(&ubi->dev, &dev_min_io_size);
if (err)
- goto out_max_vol_count;
+ return err;
err = device_create_file(&ubi->dev, &dev_bgt_enabled);
if (err)
- goto out_min_io_size;
-
- return 0;
-
-out_min_io_size:
- device_remove_file(&ubi->dev, &dev_min_io_size);
-out_max_vol_count:
- device_remove_file(&ubi->dev, &dev_max_vol_count);
-out_bad_peb_count:
- device_remove_file(&ubi->dev, &dev_bad_peb_count);
-out_reserved_for_bad:
- device_remove_file(&ubi->dev, &dev_reserved_for_bad);
-out_volumes_max_ec:
- device_remove_file(&ubi->dev, &dev_max_ec);
-out_volumes_count:
- device_remove_file(&ubi->dev, &dev_volumes_count);
-out_total_eraseblocks:
- device_remove_file(&ubi->dev, &dev_total_eraseblocks);
-out_avail_eraseblocks:
- device_remove_file(&ubi->dev, &dev_avail_eraseblocks);
-out_eraseblock_size:
- device_remove_file(&ubi->dev, &dev_eraseblock_size);
-out_unregister:
- device_unregister(&ubi->dev);
-out:
- ubi_err("failed to initialize sysfs for %s", ubi->ubi_name);
+ return err;
+ err = device_create_file(&ubi->dev, &dev_mtd_num);
return err;
}
*/
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);
for (i = 0; i < ubi->vtbl_slots; i++)
if (ubi->volumes[i])
- ubi_free_volume(ubi, 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]);
+ }
}
/**
* @ubi: UBI device description object
*
* This function returns zero in case of success and a negative error code in
- * case of failure.
+ * case of failure. Note, this function destroys all volumes if it fails.
*/
static int uif_init(struct ubi_device *ubi)
{
int i, err;
dev_t dev;
- mutex_init(&ubi->vtbl_mutex);
- spin_lock_init(&ubi->volumes_lock);
-
sprintf(ubi->ubi_name, UBI_NAME_STR "%d", ubi->ubi_num);
/*
return err;
}
+ ubi_assert(MINOR(dev) == 0);
cdev_init(&ubi->cdev, &ubi_cdev_operations);
- ubi->major = MAJOR(dev);
- dbg_msg("%s major is %u", ubi->ubi_name, ubi->major);
+ dbg_gen("%s major is %u", ubi->ubi_name, MAJOR(dev));
ubi->cdev.owner = THIS_MODULE;
- dev = MKDEV(ubi->major, 0);
err = cdev_add(&ubi->cdev, dev, 1);
if (err) {
- ubi_err("cannot add character device %s", ubi->ubi_name);
+ ubi_err("cannot add character device");
goto out_unreg;
}
err = ubi_sysfs_init(ubi);
if (err)
- goto out_cdev;
+ goto out_sysfs;
for (i = 0; i < ubi->vtbl_slots; i++)
if (ubi->volumes[i]) {
- err = ubi_add_volume(ubi, i);
- if (err)
+ 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);
+out_sysfs:
ubi_sysfs_close(ubi);
-out_cdev:
cdev_del(&ubi->cdev);
out_unreg:
- unregister_chrdev_region(MKDEV(ubi->major, 0),
- ubi->vtbl_slots + 1);
+ 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(MKDEV(ubi->major, 0), ubi->vtbl_slots + 1);
+ 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]);
+ }
}
/**
out_wl:
ubi_wl_close(ubi);
out_vtbl:
+ free_internal_volumes(ubi);
vfree(ubi->vtbl);
out_si:
ubi_scan_destroy_si(si);
}
/**
- * io_init - initialize I/O unit for a given UBI device.
+ * 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;
+ * 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
+ * @io->min_io_size
*
* This function returns zero in case of success and a negative error code in
* case of failure.
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->peb_count = mtd_div_by_eb(ubi->mtd->size, ubi->mtd);
ubi->flash_size = ubi->mtd->size;
if (ubi->mtd->block_isbad && ubi->mtd->block_markbad)
ubi->bad_allowed = 1;
+ if (ubi->mtd->type == MTD_NORFLASH) {
+ ubi_assert(ubi->mtd->writesize == 1);
+ ubi->nor_flash = 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 */
+ /*
+ * 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("bad min. I/O unit");
+ ubi_err("min. I/O unit (%d) is not power of 2",
+ ubi->min_io_size);
return -EINVAL;
}
}
/* Similar for the data offset */
- if (ubi->leb_start == 0) {
- ubi->leb_start = ubi->vid_hdr_offset + ubi->vid_hdr_alsize;
- ubi->leb_start = ALIGN(ubi->leb_start, ubi->min_io_size);
- }
+ 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);
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) {
+ 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;
}
/*
+ * Set maximum amount of physical erroneous eraseblocks to be 10%.
+ * Erroneous PEB are those which have read errors.
+ */
+ ubi->max_erroneous = ubi->peb_count / 10;
+ if (ubi->max_erroneous < 16)
+ ubi->max_erroneous = 16;
+ dbg_msg("max_erroneous %d", ubi->max_erroneous);
+
+ /*
* 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.
ubi->ro_mode = 1;
}
- dbg_msg("leb_size %d", ubi->leb_size);
- dbg_msg("ro_mode %d", ubi->ro_mode);
+ 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
}
/**
- * attach_mtd_dev - attach an MTD device.
- * @mtd_dev: MTD device name or number string
- * @vid_hdr_offset: VID header offset
- * @data_offset: data offset
+ * 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 attaches an MTD device to UBI. It first treats @mtd_dev as the
- * MTD device name, and tries to open it by this name. If it is unable to open,
- * it tries to convert @mtd_dev to an integer and open the MTD device by its
- * number. Returns zero in case of success and a negative error code in case of
- * failure.
+ * 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 attach_mtd_dev(const char *mtd_dev, int vid_hdr_offset,
- int data_offset)
+static int autoresize(struct ubi_device *ubi, int vol_id)
{
- struct ubi_device *ubi;
- struct mtd_info *mtd;
- int i, err;
+ struct ubi_volume_desc desc;
+ struct ubi_volume *vol = ubi->volumes[vol_id];
+ int err, old_reserved_pebs = vol->reserved_pebs;
- mtd = get_mtd_device_nm(mtd_dev);
- if (IS_ERR(mtd)) {
- int mtd_num;
- char *endp;
+ /*
+ * 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 (PTR_ERR(mtd) != -ENODEV)
- return PTR_ERR(mtd);
+ if (ubi->avail_pebs == 0) {
+ struct ubi_vtbl_record vtbl_rec;
/*
- * Probably this is not MTD device name but MTD device number -
- * check this out.
+ * No available PEBs to re-size the volume, clear the flag on
+ * flash and exit.
*/
- mtd_num = simple_strtoul(mtd_dev, &endp, 0);
- if (*endp != '\0' || mtd_dev == endp) {
- ubi_err("incorrect MTD device: \"%s\"", mtd_dev);
- return -ENODEV;
- }
-
- mtd = get_mtd_device(NULL, mtd_num);
- if (IS_ERR(mtd))
- return PTR_ERR(mtd);
+ 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);
}
- /* Check if we already have the same MTD device attached */
- for (i = 0; i < ubi_devices_cnt; i++)
- if (ubi_devices[i]->mtd->index == mtd->index) {
- ubi_err("mtd%d is already attached to ubi%d",
+ 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_reboot_notifier - halt UBI transactions immediately prior to a reboot.
+ * @n: reboot notifier object
+ * @state: SYS_RESTART, SYS_HALT, or SYS_POWER_OFF
+ * @cmd: pointer to command string for RESTART2
+ *
+ * This function stops the UBI background thread so that the flash device
+ * remains quiescent when Linux restarts the system. Any queued work will be
+ * discarded, but this function will block until do_work() finishes if an
+ * operation is already in progress.
+ *
+ * This function solves a real-life problem observed on NOR flashes when an
+ * PEB erase operation starts, then the system is rebooted before the erase is
+ * finishes, and the boot loader gets confused and dies. So we prefer to finish
+ * the ongoing operation before rebooting.
+ */
+static int ubi_reboot_notifier(struct notifier_block *n, unsigned long state,
+ void *cmd)
+{
+ struct ubi_device *ubi;
+
+ ubi = container_of(n, struct ubi_device, reboot_notifier);
+ if (ubi->bgt_thread)
+ kthread_stop(ubi->bgt_thread);
+ ubi_sync(ubi->ubi_num);
+ return NOTIFY_DONE;
+}
+
+/**
+ * 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);
- err = -EINVAL;
- goto out_mtd;
+ 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;
+ }
- ubi = ubi_devices[ubi_devices_cnt] = kzalloc(sizeof(struct ubi_device),
- GFP_KERNEL);
- if (!ubi) {
- err = -ENOMEM;
- goto out_mtd;
+ 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->ubi_num = ubi_devices_cnt;
+ 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->device_mutex);
+ spin_lock_init(&ubi->volumes_lock);
- dbg_msg("attaching mtd%d to ubi%d: VID header offset %d data offset %d",
- ubi->mtd->index, ubi_devices_cnt, vid_hdr_offset, data_offset);
+ ubi_msg("attaching mtd%d to ubi%d", mtd->index, ubi_num);
- ubi->vid_hdr_offset = vid_hdr_offset;
- ubi->leb_start = data_offset;
err = io_init(ubi);
if (err)
goto out_free;
+ err = -ENOMEM;
+ 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_PARANOID
+ 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_detach;
+ 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", ubi->mtd->index, ubi_devices_cnt);
- ubi_msg("MTD device name: \"%s\"", ubi->mtd->name);
+ 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("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("number of good PEBs: %d", ubi->good_peb_count);
ubi_msg("number of bad PEBs: %d", ubi->bad_peb_count);
- ubi_msg("smallest flash I/O unit: %d", ubi->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);
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 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);
+ ubi_msg("image sequence number: %d", ubi->image_seq);
- /* Enable the background thread */
- if (!DBG_DISABLE_BGT) {
+ /*
+ * The below lock makes sure we do not race with 'ubi_thread()' which
+ * checks @ubi->thread_enabled. Otherwise we may fail to wake it up.
+ */
+ spin_lock(&ubi->wl_lock);
+ if (!DBG_DISABLE_BGT)
ubi->thread_enabled = 1;
- wake_up_process(ubi->bgt_thread);
- }
+ wake_up_process(ubi->bgt_thread);
+ spin_unlock(&ubi->wl_lock);
- ubi_devices_cnt += 1;
- return 0;
+ /* Flash device priority is 0 - UBI needs to shut down first */
+ ubi->reboot_notifier.priority = 1;
+ ubi->reboot_notifier.notifier_call = ubi_reboot_notifier;
+ register_reboot_notifier(&ubi->reboot_notifier);
+ ubi_devices[ubi_num] = ubi;
+ ubi_notify_all(ubi, UBI_VOLUME_ADDED, NULL);
+ return ubi_num;
+
+out_uif:
+ uif_close(ubi);
+out_nofree:
+ do_free = 0;
out_detach:
- ubi_eba_close(ubi);
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_PARANOID
+ vfree(ubi->dbg_peb_buf);
+#endif
kfree(ubi);
-out_mtd:
- put_mtd_device(mtd);
- ubi_devices[ubi_devices_cnt] = NULL;
return err;
}
/**
- * detach_mtd_dev - detach an MTD device.
- * @ubi: UBI device description object
+ * 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.
*/
-static void detach_mtd_dev(struct ubi_device *ubi)
+int ubi_detach_mtd_dev(int ubi_num, int anyway)
{
- int ubi_num = ubi->ubi_num, mtd_num = ubi->mtd->index;
+ struct ubi_device *ubi;
+
+ if (ubi_num < 0 || ubi_num >= UBI_MAX_DEVICES)
+ return -EINVAL;
+
+ ubi = ubi_get_device(ubi_num);
+ if (!ubi)
+ return -EINVAL;
+
+ spin_lock(&ubi_devices_lock);
+ put_device(&ubi->dev);
+ ubi->ref_count -= 1;
+ 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);
+ ubi_notify_all(ubi, UBI_VOLUME_REMOVED, NULL);
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.
+ */
+ unregister_reboot_notifier(&ubi->reboot_notifier);
+ if (ubi->bgt_thread)
+ kthread_stop(ubi->bgt_thread);
+
+ /*
+ * Get a reference to the device in order to prevent 'dev_release()'
+ * from freeing @ubi object.
+ */
+ get_device(&ubi->dev);
+
uif_close(ubi);
- ubi_eba_close(ubi);
ubi_wl_close(ubi);
+ free_internal_volumes(ubi);
vfree(ubi->vtbl);
put_mtd_device(ubi->mtd);
- kfree(ubi_devices[ubi_num]);
- ubi_devices[ubi_num] = NULL;
- ubi_devices_cnt -= 1;
- ubi_assert(ubi_devices_cnt >= 0);
- ubi_msg("mtd%d is detached from ubi%d", mtd_num, ubi_num);
+ vfree(ubi->peb_buf1);
+ vfree(ubi->peb_buf2);
+#ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
+ vfree(ubi->dbg_peb_buf);
+#endif
+ ubi_msg("mtd%d is detached from ubi%d", ubi->mtd->index, ubi->ubi_num);
+ put_device(&ubi->dev);
+ 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)
BUILD_BUG_ON(sizeof(struct ubi_vid_hdr) != 64);
if (mtd_devs > UBI_MAX_DEVICES) {
- printk("UBI error: too many MTD devices, maximum is %d\n",
- 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))
- return PTR_ERR(ubi_class);
+ 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)
+ 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();
- err = attach_mtd_dev(p->name, p->vid_hdr_offs, p->data_offs);
- if (err)
+
+ 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++)
- detach_mtd_dev(ubi_devices[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, n = ubi_devices_cnt;
+ int i;
- for (i = 0; i < n; i++)
- detach_mtd_dev(ubi_devices[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 string representing number of bytes to an
- * integer.
+ * 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
result = simple_strtoul(str, &endp, 0);
if (str == endp || result < 0) {
- printk("UBI error: incorrect bytes count: \"%s\"\n", str);
+ printk(KERN_ERR "UBI error: incorrect bytes count: \"%s\"\n",
+ str);
return -EINVAL;
}
case 'M':
result *= 1024;
case 'K':
- case 'k':
result *= 1024;
- if (endp[1] == 'i' && (endp[2] == '\0' ||
- endp[2] == 'B' || endp[2] == 'b'))
+ if (endp[1] == 'i' && endp[2] == 'B')
endp += 2;
case '\0':
break;
default:
- printk("UBI error: incorrect bytes count: \"%s\"\n", str);
+ printk(KERN_ERR "UBI error: incorrect bytes count: \"%s\"\n",
+ str);
return -EINVAL;
}
struct mtd_dev_param *p;
char buf[MTD_PARAM_LEN_MAX];
char *pbuf = &buf[0];
- char *tokens[3] = {NULL, NULL, NULL};
+ char *tokens[2] = {NULL, NULL};
+
+ if (!val)
+ return -EINVAL;
if (mtd_devs == UBI_MAX_DEVICES) {
- printk("UBI error: too many parameters, max. is %d\n",
+ 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("UBI error: parameter \"%s\" is too long, max. is %d\n",
- val, 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("UBI warning: empty 'mtd=' parameter - ignored\n");
+ printk(KERN_WARNING "UBI warning: empty 'mtd=' parameter - "
+ "ignored\n");
return 0;
}
if (buf[len - 1] == '\n')
buf[len - 1] = '\0';
- for (i = 0; i < 3; i++)
+ for (i = 0; i < 2; i++)
tokens[i] = strsep(&pbuf, ",");
if (pbuf) {
- printk("UBI error: too many arguments at \"%s\"\n", val);
+ printk(KERN_ERR "UBI error: too many arguments at \"%s\"\n",
+ val);
return -EINVAL;
}
if (tokens[1])
p->vid_hdr_offs = bytes_str_to_int(tokens[1]);
- if (tokens[2])
- p->data_offs = bytes_str_to_int(tokens[2]);
if (p->vid_hdr_offs < 0)
return p->vid_hdr_offs;
- if (p->data_offs < 0)
- return p->data_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>,<data_offs>]. "
+ "mtd=<name|num>[,<vid_hdr_offs>].\n"
"Multiple \"mtd\" parameters may be specified.\n"
- "MTD devices may be specified by their number or name. "
- "Optional \"vid_hdr_offs\" and \"data_offs\" parameters "
- "specify UBI VID header position and data starting "
- "position to be used by UBI.\n"
- "Example: mtd=content,1984,2048 mtd=4 - attach MTD device"
- "with name content using VID header offset 1984 and data "
- "start 2048, and MTD device number 4 using default "
- "offsets");
+ "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");
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff