vmt.c

基于linux-2.6.28的mtd驱动

			goto out_err;
	}

	cdev_del(&vol->cdev);
	volume_sysfs_close(vol);

	spin_lock(&ubi->volumes_lock);
	ubi->rsvd_pebs -= reserved_pebs;
	ubi->avail_pebs += reserved_pebs;
	i = ubi->beb_rsvd_level - ubi->beb_rsvd_pebs;
	if (i > 0) {
		i = ubi->avail_pebs >= i ? i : ubi->avail_pebs;
		ubi->avail_pebs -= i;
		ubi->rsvd_pebs += i;
		ubi->beb_rsvd_pebs += i;
		if (i > 0)
			ubi_msg("reserve more %d PEBs", i);
	}
	ubi->vol_count -= 1;
	spin_unlock(&ubi->volumes_lock);

	if (!no_vtbl)
		err = paranoid_check_volumes(ubi);
	return err;

out_err:
	ubi_err("cannot remove volume %d, error %d", vol_id, err);
	spin_lock(&ubi->volumes_lock);
	ubi->volumes[vol_id] = vol;
out_unlock:
	spin_unlock(&ubi->volumes_lock);
	return err;
}

/**
 * ubi_resize_volume - re-size volume.
 * @desc: volume descriptor
 * @reserved_pebs: new size in physical eraseblocks
 *
 * This function re-sizes the volume and returns zero in case of success, and a
 * negative error code in case of failure. The caller has to have the
 * @ubi->volumes_mutex locked.
 */
int ubi_resize_volume(struct ubi_volume_desc *desc, int reserved_pebs)
{
	int i, err, pebs, *new_mapping;
	struct ubi_volume *vol = desc->vol;
	struct ubi_device *ubi = vol->ubi;
	struct ubi_vtbl_record vtbl_rec;
	int vol_id = vol->vol_id;

	if (ubi->ro_mode)
		return -EROFS;

	dbg_gen("re-size volume %d to from %d to %d PEBs",
		vol_id, vol->reserved_pebs, reserved_pebs);

	if (vol->vol_type == UBI_STATIC_VOLUME &&
	    reserved_pebs < vol->used_ebs) {
		dbg_err("too small size %d, %d LEBs contain data",
			reserved_pebs, vol->used_ebs);
		return -EINVAL;
	}

	/* If the size is the same, we have nothing to do */
	if (reserved_pebs == vol->reserved_pebs)
		return 0;

	new_mapping = kmalloc(reserved_pebs * sizeof(int), GFP_KERNEL);
	if (!new_mapping)
		return -ENOMEM;

	for (i = 0; i < reserved_pebs; i++)
		new_mapping[i] = UBI_LEB_UNMAPPED;

	spin_lock(&ubi->volumes_lock);
	if (vol->ref_count > 1) {
		spin_unlock(&ubi->volumes_lock);
		err = -EBUSY;
		goto out_free;
	}
	spin_unlock(&ubi->volumes_lock);

	/* Reserve physical eraseblocks */
	pebs = reserved_pebs - vol->reserved_pebs;
	if (pebs > 0) {
		spin_lock(&ubi->volumes_lock);
		if (pebs > ubi->avail_pebs) {
			dbg_err("not enough PEBs: requested %d, available %d",
				pebs, ubi->avail_pebs);
			spin_unlock(&ubi->volumes_lock);
			err = -ENOSPC;
			goto out_free;
		}
		ubi->avail_pebs -= pebs;
		ubi->rsvd_pebs += pebs;
		for (i = 0; i < vol->reserved_pebs; i++)
			new_mapping[i] = vol->eba_tbl[i];
		kfree(vol->eba_tbl);
		vol->eba_tbl = new_mapping;
		spin_unlock(&ubi->volumes_lock);
	}

	/* Change volume table record */
	memcpy(&vtbl_rec, &ubi->vtbl[vol_id], sizeof(struct ubi_vtbl_record));
	vtbl_rec.reserved_pebs = cpu_to_be32(reserved_pebs);
	err = ubi_change_vtbl_record(ubi, vol_id, &vtbl_rec);
	if (err)
		goto out_acc;

	if (pebs < 0) {
		for (i = 0; i < -pebs; i++) {
			err = ubi_eba_unmap_leb(ubi, vol, reserved_pebs + i);
			if (err)
				goto out_acc;
		}
		spin_lock(&ubi->volumes_lock);
		ubi->rsvd_pebs += pebs;
		ubi->avail_pebs -= pebs;
		pebs = ubi->beb_rsvd_level - ubi->beb_rsvd_pebs;
		if (pebs > 0) {
			pebs = ubi->avail_pebs >= pebs ? pebs : ubi->avail_pebs;
			ubi->avail_pebs -= pebs;
			ubi->rsvd_pebs += pebs;
			ubi->beb_rsvd_pebs += pebs;
			if (pebs > 0)
				ubi_msg("reserve more %d PEBs", pebs);
		}
		for (i = 0; i < reserved_pebs; i++)
			new_mapping[i] = vol->eba_tbl[i];
		kfree(vol->eba_tbl);
		vol->eba_tbl = new_mapping;
		spin_unlock(&ubi->volumes_lock);
	}

	vol->reserved_pebs = reserved_pebs;
	if (vol->vol_type == UBI_DYNAMIC_VOLUME) {
		vol->used_ebs = reserved_pebs;
		vol->last_eb_bytes = vol->usable_leb_size;
		vol->used_bytes =
			(long long)vol->used_ebs * vol->usable_leb_size;
	}

	err = paranoid_check_volumes(ubi);
	return err;

out_acc:
	if (pebs > 0) {
		spin_lock(&ubi->volumes_lock);
		ubi->rsvd_pebs -= pebs;
		ubi->avail_pebs += pebs;
		spin_unlock(&ubi->volumes_lock);
	}
out_free:
	kfree(new_mapping);
	return err;
}

/**
 * ubi_rename_volumes - re-name UBI volumes.
 * @ubi: UBI device description object
 * @rename_list: list of &struct ubi_rename_entry objects
 *
 * This function re-names or removes volumes specified in the re-name list.
 * Returns zero in case of success and a negative error code in case of
 * failure.
 */
int ubi_rename_volumes(struct ubi_device *ubi, struct list_head *rename_list)
{
	int err;
	struct ubi_rename_entry *re;

	err = ubi_vtbl_rename_volumes(ubi, rename_list);
	if (err)
		return err;

	list_for_each_entry(re, rename_list, list) {
		if (re->remove) {
			err = ubi_remove_volume(re->desc, 1);
			if (err)
				break;
		} else {
			struct ubi_volume *vol = re->desc->vol;

			spin_lock(&ubi->volumes_lock);
			vol->name_len = re->new_name_len;
			memcpy(vol->name, re->new_name, re->new_name_len + 1);
			spin_unlock(&ubi->volumes_lock);
		}
	}

	if (!err)
		err = paranoid_check_volumes(ubi);
	return err;
}

/**
 * ubi_add_volume - add volume.
 * @ubi: UBI device description object
 * @vol: volume description object
 *
 * This function adds an existing volume and initializes all its data
 * structures. Returns zero in case of success and a negative error code in
 * case of failure.
 */
int ubi_add_volume(struct ubi_device *ubi, struct ubi_volume *vol)
{
	int err, vol_id = vol->vol_id;
	dev_t dev;

	dbg_gen("add volume %d", vol_id);

	/* Register character device for the volume */
	cdev_init(&vol->cdev, &ubi_vol_cdev_operations);
	vol->cdev.owner = THIS_MODULE;
	dev = MKDEV(MAJOR(ubi->cdev.dev), vol->vol_id + 1);
	err = cdev_add(&vol->cdev, dev, 1);
	if (err) {
		ubi_err("cannot add character device for volume %d, error %d",
			vol_id, err);
		return err;
	}

	err = ubi_create_gluebi(ubi, vol);
	if (err)
		goto out_cdev;

	vol->dev.release = vol_release;
	vol->dev.parent = &ubi->dev;
	vol->dev.devt = dev;
	vol->dev.class = ubi_class;
	sprintf(&vol->dev.bus_id[0], "%s_%d", ubi->ubi_name, vol->vol_id);
	err = device_register(&vol->dev);
	if (err)
		goto out_gluebi;

	err = volume_sysfs_init(ubi, vol);
	if (err) {
		cdev_del(&vol->cdev);
		err = ubi_destroy_gluebi(vol);
		volume_sysfs_close(vol);
		return err;
	}

	err = paranoid_check_volumes(ubi);
	return err;

out_gluebi:
	err = ubi_destroy_gluebi(vol);
out_cdev:
	cdev_del(&vol->cdev);
	return err;
}

/**
 * ubi_free_volume - free volume.
 * @ubi: UBI device description object
 * @vol: volume description object
 *
 * This function frees all resources for volume @vol but does not remove it.
 * Used only when the UBI device is detached.
 */
void ubi_free_volume(struct ubi_device *ubi, struct ubi_volume *vol)
{
	int err;

	dbg_gen("free volume %d", vol->vol_id);

	ubi->volumes[vol->vol_id] = NULL;
	err = ubi_destroy_gluebi(vol);
	cdev_del(&vol->cdev);
	volume_sysfs_close(vol);
}

#ifdef CONFIG_MTD_UBI_DEBUG_PARANOID

/**
 * paranoid_check_volume - check volume information.
 * @ubi: UBI device description object
 * @vol_id: volume ID
 *
 * Returns zero if volume is all right and a a negative error code if not.
 */
static int paranoid_check_volume(struct ubi_device *ubi, int vol_id)
{
	int idx = vol_id2idx(ubi, vol_id);
	int reserved_pebs, alignment, data_pad, vol_type, name_len, upd_marker;
	const struct ubi_volume *vol;
	long long n;
	const char *name;

	spin_lock(&ubi->volumes_lock);
	reserved_pebs = be32_to_cpu(ubi->vtbl[vol_id].reserved_pebs);
	vol = ubi->volumes[idx];

	if (!vol) {
		if (reserved_pebs) {
			ubi_err("no volume info, but volume exists");
			goto fail;
		}
		spin_unlock(&ubi->volumes_lock);
		return 0;
	}

	if (vol->reserved_pebs < 0 || vol->alignment < 0 || vol->data_pad < 0 ||
	    vol->name_len < 0) {
		ubi_err("negative values");
		goto fail;
	}
	if (vol->alignment > ubi->leb_size || vol->alignment == 0) {
		ubi_err("bad alignment");
		goto fail;
	}

	n = vol->alignment & (ubi->min_io_size - 1);
	if (vol->alignment != 1 && n) {
		ubi_err("alignment is not multiple of min I/O unit");
		goto fail;
	}

	n = ubi->leb_size % vol->alignment;
	if (vol->data_pad != n) {
		ubi_err("bad data_pad, has to be %lld", n);
		goto fail;
	}

	if (vol->vol_type != UBI_DYNAMIC_VOLUME &&
	    vol->vol_type != UBI_STATIC_VOLUME) {
		ubi_err("bad vol_type");
		goto fail;
	}

	if (vol->upd_marker && vol->corrupted) {
		dbg_err("update marker and corrupted simultaneously");
		goto fail;
	}

	if (vol->reserved_pebs > ubi->good_peb_count) {
		ubi_err("too large reserved_pebs");
		goto fail;
	}

	n = ubi->leb_size - vol->data_pad;
	if (vol->usable_leb_size != ubi->leb_size - vol->data_pad) {
		ubi_err("bad usable_leb_size, has to be %lld", n);
		goto fail;
	}

	if (vol->name_len > UBI_VOL_NAME_MAX) {
		ubi_err("too long volume name, max is %d", UBI_VOL_NAME_MAX);
		goto fail;
	}

	if (!vol->name) {
		ubi_err("NULL volume name");
		goto fail;
	}

	n = strnlen(vol->name, vol->name_len + 1);
	if (n != vol->name_len) {
		ubi_err("bad name_len %lld", n);
		goto fail;
	}

	n = (long long)vol->used_ebs * vol->usable_leb_size;
	if (vol->vol_type == UBI_DYNAMIC_VOLUME) {
		if (vol->corrupted) {
			ubi_err("corrupted dynamic volume");
			goto fail;
		}
		if (vol->used_ebs != vol->reserved_pebs) {
			ubi_err("bad used_ebs");
			goto fail;
		}
		if (vol->last_eb_bytes != vol->usable_leb_size) {
			ubi_err("bad last_eb_bytes");
			goto fail;
		}
		if (vol->used_bytes != n) {
			ubi_err("bad used_bytes");
			goto fail;
		}
	} else {
		if (vol->used_ebs < 0 || vol->used_ebs > vol->reserved_pebs) {
			ubi_err("bad used_ebs");
			goto fail;
		}
		if (vol->last_eb_bytes < 0 ||
		    vol->last_eb_bytes > vol->usable_leb_size) {
			ubi_err("bad last_eb_bytes");
			goto fail;
		}
		if (vol->used_bytes < 0 || vol->used_bytes > n ||
		    vol->used_bytes < n - vol->usable_leb_size) {
			ubi_err("bad used_bytes");
			goto fail;
		}
	}

	alignment  = be32_to_cpu(ubi->vtbl[vol_id].alignment);
	data_pad   = be32_to_cpu(ubi->vtbl[vol_id].data_pad);
	name_len   = be16_to_cpu(ubi->vtbl[vol_id].name_len);
	upd_marker = ubi->vtbl[vol_id].upd_marker;
	name       = &ubi->vtbl[vol_id].name[0];
	if (ubi->vtbl[vol_id].vol_type == UBI_VID_DYNAMIC)
		vol_type = UBI_DYNAMIC_VOLUME;
	else
		vol_type = UBI_STATIC_VOLUME;

	if (alignment != vol->alignment || data_pad != vol->data_pad ||
	    upd_marker != vol->upd_marker || vol_type != vol->vol_type ||
	    name_len != vol->name_len || strncmp(name, vol->name, name_len)) {
		ubi_err("volume info is different");
		goto fail;
	}

	spin_unlock(&ubi->volumes_lock);
	return 0;

fail:
	ubi_err("paranoid check failed for volume %d", vol_id);
	if (vol)
		ubi_dbg_dump_vol_info(vol);
	ubi_dbg_dump_vtbl_record(&ubi->vtbl[vol_id], vol_id);
	spin_unlock(&ubi->volumes_lock);
	return -EINVAL;
}

/**
 * paranoid_check_volumes - check information about all volumes.
 * @ubi: UBI device description object
 *
 * Returns zero if volumes are all right and a a negative error code if not.
 */
static int paranoid_check_volumes(struct ubi_device *ubi)
{
	int i, err = 0;

	for (i = 0; i < ubi->vtbl_slots; i++) {
		err = paranoid_check_volume(ubi, i);
		if (err)
			break;
	}

	return err;
}
#endif