[PATCH 03/17] ide-tape: remove idetape_discard_read_pipeline()

[Borislav Petkov <petkovbb@googlemail.com>]

Now that we don't queue any more requests on the pipeline we don't need to
discard it anymore. Also, remove __idetape_discard_read_pipeline() too.

Signed-off-by: Borislav Petkov <petkovbb@gmail.com>
---
 drivers/ide/ide-tape.c |   92 +----------------------------------------------
 1 files changed, 2 insertions(+), 90 deletions(-)

diff --git a/drivers/ide/ide-tape.c b/drivers/ide/ide-tape.c
index 241f596..429fed4 100644
--- a/drivers/ide/ide-tape.c
+++ b/drivers/ide/ide-tape.c
@@ -1875,52 +1875,6 @@ static int idetape_create_prevent_cmd(ide_drive_t *drive,
 	return 1;
 }
 
-static int __idetape_discard_read_pipeline(ide_drive_t *drive)
-{
-	idetape_tape_t *tape = drive->driver_data;
-	unsigned long flags;
-	int cnt;
-
-	if (tape->chrdev_dir != IDETAPE_DIR_READ)
-		return 0;
-
-	/* Remove merge stage. */
-	cnt = tape->merge_stage_size / tape->blk_size;
-	if (test_and_clear_bit(IDETAPE_FLAG_FILEMARK, &tape->flags))
-		++cnt;		/* Filemarks count as 1 sector */
-	tape->merge_stage_size = 0;
-	if (tape->merge_stage != NULL) {
-		__idetape_kfree_stage(tape->merge_stage);
-		tape->merge_stage = NULL;
-	}
-
-	/* Clear pipeline flags. */
-	clear_bit(IDETAPE_FLAG_PIPELINE_ERR, &tape->flags);
-	tape->chrdev_dir = IDETAPE_DIR_NONE;
-
-	/* Remove pipeline stages. */
-	if (tape->first_stage == NULL)
-		return 0;
-
-	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) {
-		struct request *rq_ptr = &tape->first_stage->rq;
-
-		cnt += rq_ptr->nr_sectors - rq_ptr->current_nr_sectors;
-		if (rq_ptr->errors == IDETAPE_ERROR_FILEMARK)
-			++cnt;
-		idetape_remove_stage_head(drive);
-	}
-	tape->nr_pending_stages = 0;
-	tape->max_stages = tape->min_pipeline;
-	return cnt;
-}
-
 /*
  * Position the tape to the requested block using the LOCATE packet command.
  * A READ POSITION command is then issued to check where we are positioned. Like
@@ -1930,12 +1884,9 @@ static int __idetape_discard_read_pipeline(ide_drive_t *drive)
 static int idetape_position_tape(ide_drive_t *drive, unsigned int block,
 		u8 partition, int skip)
 {
-	idetape_tape_t *tape = drive->driver_data;
-	int retval;
 	struct ide_atapi_pc pc;
+	int retval;
 
-	if (tape->chrdev_dir == IDETAPE_DIR_READ)
-		__idetape_discard_read_pipeline(drive);
 	idetape_wait_ready(drive, 60 * 5 * HZ);
 	idetape_create_locate_cmd(drive, &pc, block, partition, skip);
 	retval = idetape_queue_pc_tail(drive, &pc);
@@ -1946,25 +1897,6 @@ static int idetape_position_tape(ide_drive_t *drive, unsigned int block,
 	return (idetape_queue_pc_tail(drive, &pc));
 }
 
-static void idetape_discard_read_pipeline(ide_drive_t *drive,
-					  int restore_position)
-{
-	idetape_tape_t *tape = drive->driver_data;
-	int cnt;
-	int seek, position;
-
-	cnt = __idetape_discard_read_pipeline(drive);
-	if (restore_position) {
-		position = idetape_read_position(drive);
-		seek = position > cnt ? position - cnt : 0;
-		if (idetape_position_tape(drive, seek, 0, 0)) {
-			printk(KERN_INFO "ide-tape: %s: position_tape failed in"
-					 " discard_pipeline()\n", tape->name);
-			return;
-		}
-	}
-}
-
 /*
  * Generate a read/write request for the block device interface and wait for it
  * to be serviced.
@@ -2406,11 +2338,6 @@ static int idetape_space_over_filemarks(ide_drive_t *drive, short mt_op,
 				 * pipeline. There is no point in allowing the
 				 * drive to continue reading any farther, so we
 				 * stop the pipeline.
-				 *
-				 * This section should be moved to a separate
-				 * subroutine because similar operations are
-				 * done in __idetape_discard_read_pipeline(),
-				 * for example.
 				 */
 				tape->next_stage = NULL;
 				spin_unlock_irqrestore(&tape->lock, flags);
@@ -2423,7 +2350,6 @@ static int idetape_space_over_filemarks(ide_drive_t *drive, short mt_op,
 				++count;
 			idetape_remove_stage_head(drive);
 		}
-		idetape_discard_read_pipeline(drive, 0);
 	}
 
 	/*
@@ -2547,8 +2473,6 @@ static ssize_t idetape_chrdev_write(struct file *file, const char __user *buf,
 
 	/* Initialize write operation */
 	if (tape->chrdev_dir != IDETAPE_DIR_WRITE) {
-		if (tape->chrdev_dir == IDETAPE_DIR_READ)
-			idetape_discard_read_pipeline(drive, 1);
 		if (tape->merge_stage || tape->merge_stage_size) {
 			printk(KERN_ERR "ide-tape: merge_stage_size "
 				"should be 0 now\n");
@@ -2675,7 +2599,6 @@ static int idetape_mtioctop(ide_drive_t *drive, short mt_op, int mt_count)
 	case MTWEOF:
 		if (tape->write_prot)
 			return -EACCES;
-		idetape_discard_read_pipeline(drive, 1);
 		for (i = 0; i < mt_count; i++) {
 			retval = idetape_write_filemark(drive);
 			if (retval)
@@ -2683,12 +2606,10 @@ static int idetape_mtioctop(ide_drive_t *drive, short mt_op, int mt_count)
 		}
 		return 0;
 	case MTREW:
-		idetape_discard_read_pipeline(drive, 0);
 		if (idetape_rewind_tape(drive))
 			return -EIO;
 		return 0;
 	case MTLOAD:
-		idetape_discard_read_pipeline(drive, 0);
 		idetape_create_load_unload_cmd(drive, &pc,
 					       IDETAPE_LU_LOAD_MASK);
 		return idetape_queue_pc_tail(drive, &pc);
@@ -2703,7 +2624,6 @@ static int idetape_mtioctop(ide_drive_t *drive, short mt_op, int mt_count)
 				if (!idetape_queue_pc_tail(drive, &pc))
 					tape->door_locked = DOOR_UNLOCKED;
 		}
-		idetape_discard_read_pipeline(drive, 0);
 		idetape_create_load_unload_cmd(drive, &pc,
 					      !IDETAPE_LU_LOAD_MASK);
 		retval = idetape_queue_pc_tail(drive, &pc);
@@ -2711,10 +2631,8 @@ static int idetape_mtioctop(ide_drive_t *drive, short mt_op, int mt_count)
 			clear_bit(IDETAPE_FLAG_MEDIUM_PRESENT, &tape->flags);
 		return retval;
 	case MTNOP:
-		idetape_discard_read_pipeline(drive, 0);
 		return idetape_flush_tape_buffers(drive);
 	case MTRETEN:
-		idetape_discard_read_pipeline(drive, 0);
 		idetape_create_load_unload_cmd(drive, &pc,
 			IDETAPE_LU_RETENSION_MASK | IDETAPE_LU_LOAD_MASK);
 		return idetape_queue_pc_tail(drive, &pc);
@@ -2736,11 +2654,9 @@ static int idetape_mtioctop(ide_drive_t *drive, short mt_op, int mt_count)
 			set_bit(IDETAPE_FLAG_DETECT_BS, &tape->flags);
 		return 0;
 	case MTSEEK:
-		idetape_discard_read_pipeline(drive, 0);
 		return idetape_position_tape(drive,
 			mt_count * tape->user_bs_factor, tape->partition, 0);
 	case MTSETPART:
-		idetape_discard_read_pipeline(drive, 0);
 		return idetape_position_tape(drive, 0, mt_count, 0);
 	case MTFSR:
 	case MTBSR:
@@ -2821,8 +2737,6 @@ static int idetape_chrdev_ioctl(struct inode *inode, struct file *file,
 			return -EFAULT;
 		return 0;
 	default:
-		if (tape->chrdev_dir == IDETAPE_DIR_READ)
-			idetape_discard_read_pipeline(drive, 1);
 		return idetape_blkdev_ioctl(drive, cmd, arg);
 	}
 }
@@ -2966,9 +2880,7 @@ static int idetape_chrdev_release(struct inode *inode, struct file *filp)
 	if (tape->chrdev_dir == IDETAPE_DIR_WRITE)
 		idetape_write_release(drive, minor);
 	if (tape->chrdev_dir == IDETAPE_DIR_READ) {
-		if (minor < 128)
-			idetape_discard_read_pipeline(drive, 1);
-		else
+		if (minor >= 128)
 			idetape_wait_for_pipeline(drive);
 	}
 
-- 
1.5.4.1