pktcdvd.c

Linux块设备驱动源码

	}

	/* Start the write request */
	bio_init(pkt->w_bio);
	pkt->w_bio->bi_max_vecs = PACKET_MAX_SIZE;
	pkt->w_bio->bi_sector = pkt->sector;
	pkt->w_bio->bi_bdev = pd->bdev;
	pkt->w_bio->bi_end_io = pkt_end_io_packet_write;
	pkt->w_bio->bi_private = pkt;
	for (f = 0; f < pkt->frames; f++) {
		if ((f + 1 < pkt->frames) && (pages[f + 1] == pages[f]) &&
		    (offsets[f + 1] = offsets[f] + CD_FRAMESIZE)) {
			if (!bio_add_page(pkt->w_bio, pages[f], CD_FRAMESIZE * 2, offsets[f]))
				BUG();
			f++;
		} else {
			if (!bio_add_page(pkt->w_bio, pages[f], CD_FRAMESIZE, offsets[f]))
				BUG();
		}
	}
	VPRINTK("pktcdvd: vcnt=%d\n", pkt->w_bio->bi_vcnt);

	atomic_set(&pkt->io_wait, 1);
	pkt->w_bio->bi_rw = WRITE;
	pkt_queue_bio(pd, pkt->w_bio);
}

static void pkt_finish_packet(struct packet_data *pkt, int uptodate)
{
	struct bio *bio, *next;

	if (!uptodate)
		pkt->cache_valid = 0;

	/* Finish all bios corresponding to this packet */
	bio = pkt->orig_bios;
	while (bio) {
		next = bio->bi_next;
		bio->bi_next = NULL;
		bio_endio(bio, bio->bi_size, uptodate ? 0 : -EIO);
		bio = next;
	}
	pkt->orig_bios = pkt->orig_bios_tail = NULL;
}

static void pkt_run_state_machine(struct pktcdvd_device *pd, struct packet_data *pkt)
{
	int uptodate;

	VPRINTK("run_state_machine: pkt %d\n", pkt->id);

	for (;;) {
		switch (pkt->state) {
		case PACKET_WAITING_STATE:
			if ((pkt->write_size < pkt->frames) && (pkt->sleep_time > 0))
				return;

			pkt->sleep_time = 0;
			pkt_gather_data(pd, pkt);
			pkt_set_state(pkt, PACKET_READ_WAIT_STATE);
			break;

		case PACKET_READ_WAIT_STATE:
			if (atomic_read(&pkt->io_wait) > 0)
				return;

			if (atomic_read(&pkt->io_errors) > 0) {
				pkt_set_state(pkt, PACKET_RECOVERY_STATE);
			} else {
				pkt_start_write(pd, pkt);
			}
			break;

		case PACKET_WRITE_WAIT_STATE:
			if (atomic_read(&pkt->io_wait) > 0)
				return;

			if (test_bit(BIO_UPTODATE, &pkt->w_bio->bi_flags)) {
				pkt_set_state(pkt, PACKET_FINISHED_STATE);
			} else {
				pkt_set_state(pkt, PACKET_RECOVERY_STATE);
			}
			break;

		case PACKET_RECOVERY_STATE:
			if (pkt_start_recovery(pkt)) {
				pkt_start_write(pd, pkt);
			} else {
				VPRINTK("No recovery possible\n");
				pkt_set_state(pkt, PACKET_FINISHED_STATE);
			}
			break;

		case PACKET_FINISHED_STATE:
			uptodate = test_bit(BIO_UPTODATE, &pkt->w_bio->bi_flags);
			pkt_finish_packet(pkt, uptodate);
			return;

		default:
			BUG();
			break;
		}
	}
}

static void pkt_handle_packets(struct pktcdvd_device *pd)
{
	struct packet_data *pkt, *next;

	VPRINTK("pkt_handle_packets\n");

	/*
	 * Run state machine for active packets
	 */
	list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
		if (atomic_read(&pkt->run_sm) > 0) {
			atomic_set(&pkt->run_sm, 0);
			pkt_run_state_machine(pd, pkt);
		}
	}

	/*
	 * Move no longer active packets to the free list
	 */
	spin_lock(&pd->cdrw.active_list_lock);
	list_for_each_entry_safe(pkt, next, &pd->cdrw.pkt_active_list, list) {
		if (pkt->state == PACKET_FINISHED_STATE) {
			list_del(&pkt->list);
			pkt_put_packet_data(pd, pkt);
			pkt_set_state(pkt, PACKET_IDLE_STATE);
			atomic_set(&pd->scan_queue, 1);
		}
	}
	spin_unlock(&pd->cdrw.active_list_lock);
}

static void pkt_count_states(struct pktcdvd_device *pd, int *states)
{
	struct packet_data *pkt;
	int i;

	for (i = 0; i <= PACKET_NUM_STATES; i++)
		states[i] = 0;

	spin_lock(&pd->cdrw.active_list_lock);
	list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
		states[pkt->state]++;
	}
	spin_unlock(&pd->cdrw.active_list_lock);
}

/*
 * kcdrwd is woken up when writes have been queued for one of our
 * registered devices
 */
static int kcdrwd(void *foobar)
{
	struct pktcdvd_device *pd = foobar;
	struct packet_data *pkt;
	long min_sleep_time, residue;

	set_user_nice(current, -20);

	for (;;) {
		DECLARE_WAITQUEUE(wait, current);

		/*
		 * Wait until there is something to do
		 */
		add_wait_queue(&pd->wqueue, &wait);
		for (;;) {
			set_current_state(TASK_INTERRUPTIBLE);

			/* Check if we need to run pkt_handle_queue */
			if (atomic_read(&pd->scan_queue) > 0)
				goto work_to_do;

			/* Check if we need to run the state machine for some packet */
			list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
				if (atomic_read(&pkt->run_sm) > 0)
					goto work_to_do;
			}

			/* Check if we need to process the iosched queues */
			if (atomic_read(&pd->iosched.attention) != 0)
				goto work_to_do;

			/* Otherwise, go to sleep */
			if (PACKET_DEBUG > 1) {
				int states[PACKET_NUM_STATES];
				pkt_count_states(pd, states);
				VPRINTK("kcdrwd: i:%d ow:%d rw:%d ww:%d rec:%d fin:%d\n",
					states[0], states[1], states[2], states[3],
					states[4], states[5]);
			}

			min_sleep_time = MAX_SCHEDULE_TIMEOUT;
			list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
				if (pkt->sleep_time && pkt->sleep_time < min_sleep_time)
					min_sleep_time = pkt->sleep_time;
			}

			generic_unplug_device(bdev_get_queue(pd->bdev));

			VPRINTK("kcdrwd: sleeping\n");
			residue = schedule_timeout(min_sleep_time);
			VPRINTK("kcdrwd: wake up\n");

			/* make swsusp happy with our thread */
			try_to_freeze();

			list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
				if (!pkt->sleep_time)
					continue;
				pkt->sleep_time -= min_sleep_time - residue;
				if (pkt->sleep_time <= 0) {
					pkt->sleep_time = 0;
					atomic_inc(&pkt->run_sm);
				}
			}

			if (signal_pending(current)) {
				flush_signals(current);
			}
			if (kthread_should_stop())
				break;
		}
work_to_do:
		set_current_state(TASK_RUNNING);
		remove_wait_queue(&pd->wqueue, &wait);

		if (kthread_should_stop())
			break;

		/*
		 * if pkt_handle_queue returns true, we can queue
		 * another request.
		 */
		while (pkt_handle_queue(pd))
			;

		/*
		 * Handle packet state machine
		 */
		pkt_handle_packets(pd);

		/*
		 * Handle iosched queues
		 */
		pkt_iosched_process_queue(pd);
	}

	return 0;
}

static void pkt_print_settings(struct pktcdvd_device *pd)
{
	printk("pktcdvd: %s packets, ", pd->settings.fp ? "Fixed" : "Variable");
	printk("%u blocks, ", pd->settings.size >> 2);
	printk("Mode-%c disc\n", pd->settings.block_mode == 8 ? '1' : '2');
}

static int pkt_mode_sense(struct pktcdvd_device *pd, struct packet_command *cgc, int page_code, int page_control)
{
	memset(cgc->cmd, 0, sizeof(cgc->cmd));

	cgc->cmd[0] = GPCMD_MODE_SENSE_10;
	cgc->cmd[2] = page_code | (page_control << 6);
	cgc->cmd[7] = cgc->buflen >> 8;
	cgc->cmd[8] = cgc->buflen & 0xff;
	cgc->data_direction = CGC_DATA_READ;
	return pkt_generic_packet(pd, cgc);
}

static int pkt_mode_select(struct pktcdvd_device *pd, struct packet_command *cgc)
{
	memset(cgc->cmd, 0, sizeof(cgc->cmd));
	memset(cgc->buffer, 0, 2);
	cgc->cmd[0] = GPCMD_MODE_SELECT_10;
	cgc->cmd[1] = 0x10;		/* PF */
	cgc->cmd[7] = cgc->buflen >> 8;
	cgc->cmd[8] = cgc->buflen & 0xff;
	cgc->data_direction = CGC_DATA_WRITE;
	return pkt_generic_packet(pd, cgc);
}

static int pkt_get_disc_info(struct pktcdvd_device *pd, disc_information *di)
{
	struct packet_command cgc;
	int ret;

	/* set up command and get the disc info */
	init_cdrom_command(&cgc, di, sizeof(*di), CGC_DATA_READ);
	cgc.cmd[0] = GPCMD_READ_DISC_INFO;
	cgc.cmd[8] = cgc.buflen = 2;
	cgc.quiet = 1;

	if ((ret = pkt_generic_packet(pd, &cgc)))
		return ret;

	/* not all drives have the same disc_info length, so requeue
	 * packet with the length the drive tells us it can supply
	 */
	cgc.buflen = be16_to_cpu(di->disc_information_length) +
		     sizeof(di->disc_information_length);

	if (cgc.buflen > sizeof(disc_information))
		cgc.buflen = sizeof(disc_information);

	cgc.cmd[8] = cgc.buflen;
	return pkt_generic_packet(pd, &cgc);
}

static int pkt_get_track_info(struct pktcdvd_device *pd, __u16 track, __u8 type, track_information *ti)
{
	struct packet_command cgc;
	int ret;

	init_cdrom_command(&cgc, ti, 8, CGC_DATA_READ);
	cgc.cmd[0] = GPCMD_READ_TRACK_RZONE_INFO;
	cgc.cmd[1] = type & 3;
	cgc.cmd[4] = (track & 0xff00) >> 8;
	cgc.cmd[5] = track & 0xff;
	cgc.cmd[8] = 8;
	cgc.quiet = 1;

	if ((ret = pkt_generic_packet(pd, &cgc)))
		return ret;

	cgc.buflen = be16_to_cpu(ti->track_information_length) +
		     sizeof(ti->track_information_length);

	if (cgc.buflen > sizeof(track_information))
		cgc.buflen = sizeof(track_information);

	cgc.cmd[8] = cgc.buflen;
	return pkt_generic_packet(pd, &cgc);
}

static int pkt_get_last_written(struct pktcdvd_device *pd, long *last_written)
{
	disc_information di;
	track_information ti;
	__u32 last_track;
	int ret = -1;

	if ((ret = pkt_get_disc_info(pd, &di)))
		return ret;

	last_track = (di.last_track_msb << 8) | di.last_track_lsb;
	if ((ret = pkt_get_track_info(pd, last_track, 1, &ti)))
		return ret;

	/* if this track is blank, try the previous. */
	if (ti.blank) {
		last_track--;
		if ((ret = pkt_get_track_info(pd, last_track, 1, &ti)))
			return ret;
	}

	/* if last recorded field is valid, return it. */
	if (ti.lra_v) {
		*last_written = be32_to_cpu(ti.last_rec_address);
	} else {
		/* make it up instead */
		*last_written = be32_to_cpu(ti.track_start) +
				be32_to_cpu(ti.track_size);
		if (ti.free_blocks)
			*last_written -= (be32_to_cpu(ti.free_blocks) + 7);
	}
	return 0;
}

/*
 * write mode select package based on pd->settings
 */
static int pkt_set_write_settings(struct pktcdvd_device *pd)
{
	struct packet_command cgc;
	struct request_sense sense;
	write_param_page *wp;
	char buffer[128];
	int ret, size;

	/* doesn't apply to DVD+RW or DVD-RAM */
	if ((pd->mmc3_profile == 0x1a) || (pd->mmc3_profile == 0x12))
		return 0;

	memset(buffer, 0, sizeof(buffer));
	init_cdrom_command(&cgc, buffer, sizeof(*wp), CGC_DATA_READ);
	cgc.sense = &sense;
	if ((ret = pkt_mode_sense(pd, &cgc, GPMODE_WRITE_PARMS_PAGE, 0))) {
		pkt_dump_sense(&cgc);
		return ret;
	}

	size = 2 + ((buffer[0] << 8) | (buffer[1] & 0xff));
	pd->mode_offset = (buffer[6] << 8) | (buffer[7] & 0xff);
	if (size > sizeof(buffer))
		size = sizeof(buffer);

	/*
	 * now get it all
	 */
	init_cdrom_command(&cgc, buffer, size, CGC_DATA_READ);
	cgc.sense = &sense;
	if ((ret = pkt_mode_sense(pd, &cgc, GPMODE_WRITE_PARMS_PAGE, 0))) {
		pkt_dump_sense(&cgc);
		return ret;
	}

	/*
	 * write page is offset header + block descriptor length
	 */
	wp = (write_param_page *) &buffer[sizeof(struct mode_page_header) + pd->mode_offset];

	wp->fp = pd->settings.fp;
	wp->track_mode = pd->settings.track_mode;
	wp->write_type = pd->settings.write_type;
	wp->data_block_type = pd->settings.block_mode;

	wp->multi_session = 0;

#ifdef PACKET_USE_LS
	wp->link_size = 7;
	wp->ls_v = 1;
#endif

	if (wp->data_block_type == PACKET_BLOCK_MODE1) {
		wp->session_format = 0;
		wp->subhdr2 = 0x20;
	} else if (wp->data_block_type == PACKET_BLOCK_MODE2) {
		wp->session_format = 0x20;
		wp->subhdr2 = 8;
#if 0
		wp->mcn[0] = 0x80;
		memcpy(&wp->mcn[1], PACKET_MCN, sizeof(wp->mcn) - 1);
#endif
	} else {
		/*
		 * paranoia
		 */
		printk("pktcdvd: write mode wrong %d\n", wp->data_block_type);
		return 1;
	}
	wp->packet_size = cpu_to_be32(pd->settings.size >> 2);

	cgc.buflen = cgc.cmd[8] = size;
	if ((ret = pkt_mode_select(pd, &cgc))) {
		pkt_dump_sense(&cgc);
		return ret;
	}

	pkt_print_settings(pd);
	return 0;
}

/*
 * 0 -- we can write to this track, 1 -- we can't
 */
static int pkt_good_track(track_information *ti)
{
	/*
	 * only good for CD-RW at the moment, not DVD-RW
	 */

	/*
	 * FIXME: only for FP
	 */
	if (ti->fp == 0)
		return 0;

	/*
	 * "good" settings as per Mt Fuji.
	 */
	if (ti->rt == 0 && ti->blank == 0 && ti->packet == 1)
		return 0;

	if (ti->rt == 0 && ti->blank == 1 && ti->packet == 1)
		return 0;

	if (ti->rt == 1 && ti->blank == 0 && ti->packet == 1)
		return 0;

	printk("pktcdvd: bad state %d-%d-%d\n", ti->rt, ti->blank, ti->packet);
	return 1;
}

/*
 * 0 -- we can write to this disc, 1 -- we can't
 */
static int pkt_good_disc(struct pktcdvd_device *pd, disc_information *di)
{
	switch (pd->mmc3_profile) {
		case 0x0a: /* CD-RW */
		case 0xffff: /* MMC3 not supported */
			break;
		case 0x1a: /* DVD+RW */
		case 0x13: /* DVD-RW */
		case 0x12: /* DVD-RAM */
			return 0;
		default:
			printk("pktcdvd: Wrong disc profile (%x)\n", pd->mmc3_profile);
			return 1;
	}

	/*
	 * for disc type 0xff we should probably reserve a new track.
	 * but i'm not sure, should we leave this to user apps? probably.
	 */
	if (di->disc_type == 0xff) {
		printk("pktcdvd: Unknown disc. No track?\n");
		return 1;
	}

	if (di->disc_type != 0x20 && di->disc_type != 0) {
		printk("pktcdvd: Wrong disc type (%x)\n", di->disc_type);
		return 1;
	}

	if (di->erasable == 0) {
		printk("pktcdvd: Disc not erasable\n");
		return 1;
	}

	if (di->border_status == PACKET_SESSION_RESERVED) {