Commit 0aa4b01e authored by Borislav Petkov's avatar Borislav Petkov Committed by Bartlomiej Zolnierkiewicz
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ide-tape: remove remaining pipeline functionality 



The driver is using now solely its own request queue.

- tape->next_stage is always NULL so it is safe to remove
  all code depending on tape->next_stage != NULL

- this patch removes the last place which sets
  IDETAPE_FLAG_PIPELINE_ACTIVE in tape->flags

[bart: add above explanations]

Signed-off-by: default avatarBorislav Petkov <petkovbb@gmail.com>
Signed-off-by: default avatarBartlomiej Zolnierkiewicz <bzolnier@gmail.com>
parent ea1ab3d3

drivers/ide/ide-tape.c

+2 −100
Original line number Diff line number Diff line
@@ -642,28 +642,6 @@ static void idetape_analyze_error(ide_drive_t *drive, u8 *sense) 
	}

}



static void idetape_activate_next_stage(ide_drive_t *drive)

{

	idetape_tape_t *tape = drive->driver_data;

	idetape_stage_t *stage = tape->next_stage;

	struct request *rq = &stage->rq;



	debug_log(DBG_PROCS, "Enter %s\n", __func__);



	if (stage == NULL) {

		printk(KERN_ERR "ide-tape: bug: Trying to activate a non"

				" existing stage\n");

		return;

	}



	rq->rq_disk = tape->disk;

	rq->buffer = NULL;

	rq->special = (void *)stage->bh;

	tape->active_data_rq = rq;

	tape->active_stage = stage;

	tape->next_stage = stage->next;

}



/* Free a stage along with its related buffers completely. */

static void __idetape_kfree_stage(idetape_stage_t *stage)

{
@@ -1546,28 +1524,6 @@ static void idetape_init_merge_stage(idetape_tape_t *tape) 
	}

}



/* Install a completion in a pending request and sleep until it is serviced. The

 * caller should ensure that the request will not be serviced before we install

 * the completion (usually by disabling interrupts).

 */

static void idetape_wait_for_request(ide_drive_t *drive, struct request *rq)

{

	DECLARE_COMPLETION_ONSTACK(wait);

	idetape_tape_t *tape = drive->driver_data;



	if (rq == NULL || !blk_special_request(rq)) {

		printk(KERN_ERR "ide-tape: bug: Trying to sleep on non-valid"

				 " request\n");

		return;

	}

	rq->end_io_data = &wait;

	rq->end_io = blk_end_sync_rq;

	spin_unlock_irq(&tape->lock);

	wait_for_completion(&wait);

	/* The stage and its struct request have been deallocated */

	spin_lock_irq(&tape->lock);

}



static ide_startstop_t idetape_read_position_callback(ide_drive_t *drive)

{

	idetape_tape_t *tape = drive->driver_data;
@@ -1782,8 +1738,6 @@ static int __idetape_discard_read_pipeline(ide_drive_t *drive) 


	spin_lock_irqsave(&tape->lock, flags);

	tape->next_stage = NULL;

	if (test_bit(IDETAPE_FLAG_PIPELINE_ACTIVE, &tape->flags))

		idetape_wait_for_request(drive, tape->active_data_rq);

	spin_unlock_irqrestore(&tape->lock, flags);



	while (tape->first_stage != NULL) {
@@ -1878,19 +1832,6 @@ static int idetape_queue_rw_tail(ide_drive_t *drive, int cmd, int blocks, 
	return (tape->blk_size * (blocks-rq.current_nr_sectors));

}



/* start servicing the pipeline stages, starting from tape->next_stage. */

static void idetape_plug_pipeline(ide_drive_t *drive)

{

	idetape_tape_t *tape = drive->driver_data;



	if (tape->next_stage == NULL)

		return;

	if (!test_and_set_bit(IDETAPE_FLAG_PIPELINE_ACTIVE, &tape->flags)) {

		idetape_activate_next_stage(drive);

		(void) ide_do_drive_cmd(drive, tape->active_data_rq, ide_end);

	}

}



static void idetape_create_inquiry_cmd(struct ide_atapi_pc *pc)

{

	idetape_init_pc(pc);
@@ -1932,46 +1873,12 @@ static void idetape_create_space_cmd(struct ide_atapi_pc *pc, int count, u8 cmd) 
static int idetape_add_chrdev_write_request(ide_drive_t *drive, int blocks)

{

	idetape_tape_t *tape = drive->driver_data;

	unsigned long flags;



	debug_log(DBG_CHRDEV, "Enter %s\n", __func__);



	/* Attempt to allocate a new stage. Beware possible race conditions. */

	while (1) {

		spin_lock_irqsave(&tape->lock, flags);

		if (test_bit(IDETAPE_FLAG_PIPELINE_ACTIVE, &tape->flags)) {

			idetape_wait_for_request(drive, tape->active_data_rq);

			spin_unlock_irqrestore(&tape->lock, flags);

		} else {

			spin_unlock_irqrestore(&tape->lock, flags);

			idetape_plug_pipeline(drive);

			if (test_bit(IDETAPE_FLAG_PIPELINE_ACTIVE,

					&tape->flags))

				continue;

	return idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE,

				     blocks, tape->merge_stage->bh);

}

	}

}



/*

 * Wait until all pending pipeline requests are serviced. Typically called on

 * device close.

 */

static void idetape_wait_for_pipeline(ide_drive_t *drive)

{

	idetape_tape_t *tape = drive->driver_data;

	unsigned long flags;



	while (tape->next_stage || test_bit(IDETAPE_FLAG_PIPELINE_ACTIVE,

						&tape->flags)) {

		idetape_plug_pipeline(drive);

		spin_lock_irqsave(&tape->lock, flags);

		if (test_bit(IDETAPE_FLAG_PIPELINE_ACTIVE, &tape->flags))

			idetape_wait_for_request(drive, tape->active_data_rq);

		spin_unlock_irqrestore(&tape->lock, flags);

	}

}



static void idetape_empty_write_pipeline(ide_drive_t *drive)

{
@@ -2020,7 +1927,6 @@ static void idetape_empty_write_pipeline(ide_drive_t *drive) 
		(void) idetape_add_chrdev_write_request(drive, blocks);

		tape->merge_stage_size = 0;

	}

	idetape_wait_for_pipeline(drive);

	if (tape->merge_stage != NULL) {

		__idetape_kfree_stage(tape->merge_stage);

		tape->merge_stage = NULL;
@@ -2093,7 +1999,6 @@ static int idetape_init_read(ide_drive_t *drive, int max_stages) 
			tape->insert_time = jiffies;

			tape->insert_size = 0;

			tape->insert_speed = 0;

			idetape_plug_pipeline(drive);

		}

	}

	return 0;
@@ -2593,7 +2498,6 @@ static int idetape_chrdev_ioctl(struct inode *inode, struct file *file, 
		idetape_flush_tape_buffers(drive);

	}

	if (cmd == MTIOCGET || cmd == MTIOCPOS) {

		idetape_wait_for_pipeline(drive);

		block_offset = tape->merge_stage_size /

			(tape->blk_size * tape->user_bs_factor);

		position = idetape_read_position(drive);
@@ -2772,8 +2676,6 @@ static int idetape_chrdev_release(struct inode *inode, struct file *filp) 
	if (tape->chrdev_dir == IDETAPE_DIR_READ) {

		if (minor < 128)

			idetape_discard_read_pipeline(drive, 1);

		else

			idetape_wait_for_pipeline(drive);

	}



	if (minor < 128 && test_bit(IDETAPE_FLAG_MEDIUM_PRESENT, &tape->flags))

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