Commit 88f1b941 authored by Tejun Heo's avatar Tejun Heo
Browse files

ide-tape: unify r/w init paths 



Impact: cleanup

Read and write init paths are almost identical.  Unify them into
idetape_init_rw().

Signed-off-by: default avatarTejun Heo <tj@kernel.org>
parent 963da55c

drivers/ide/ide-tape.c

+46 −64
Original line number Diff line number Diff line
@@ -987,42 +987,50 @@ static void ide_tape_flush_merge_buffer(ide_drive_t *drive) 
	tape->chrdev_dir = IDETAPE_DIR_NONE;

}



static int idetape_init_read(ide_drive_t *drive)

static int idetape_init_rw(ide_drive_t *drive, int dir)

{

	idetape_tape_t *tape = drive->driver_data;

	int bytes_read;

	int rc;



	/* Initialize read operation */

	if (tape->chrdev_dir != IDETAPE_DIR_READ) {

		if (tape->chrdev_dir == IDETAPE_DIR_WRITE) {

	BUG_ON(dir != IDETAPE_DIR_READ && dir != IDETAPE_DIR_WRITE);



	if (tape->chrdev_dir == dir)

		return 0;



	if (tape->chrdev_dir == IDETAPE_DIR_READ)

		ide_tape_discard_merge_buffer(drive, 1);

	else if (tape->chrdev_dir == IDETAPE_DIR_WRITE) {

		ide_tape_flush_merge_buffer(drive);

		idetape_flush_tape_buffers(drive);

	}



	if (tape->buf || tape->valid) {

		printk(KERN_ERR "ide-tape: valid should be 0 now\n");

		tape->valid = 0;

	}



	tape->buf = kmalloc(tape->buffer_size, GFP_KERNEL);

	if (!tape->buf)

		return -ENOMEM;

		tape->chrdev_dir = IDETAPE_DIR_READ;

	tape->chrdev_dir = dir;

	tape->cur = tape->buf;



	/*

		 * Issue a read 0 command to ensure that DSC handshake is

		 * switched from completion mode to buffer available mode.

		 * No point in issuing this if DSC overlap isn't supported, some

	 * Issue a 0 rw command to ensure that DSC handshake is

	 * switched from completion mode to buffer available mode.  No

	 * point in issuing this if DSC overlap isn't supported, some

	 * drives (Seagate STT3401A) will return an error.

	 */

	if (drive->dev_flags & IDE_DFLAG_DSC_OVERLAP) {

			bytes_read = idetape_queue_rw_tail(drive,

							REQ_IDETAPE_READ, 0);

			if (bytes_read < 0) {

		int cmd = dir == IDETAPE_DIR_READ ? REQ_IDETAPE_READ

						  : REQ_IDETAPE_WRITE;



		rc = idetape_queue_rw_tail(drive, cmd, 0);

		if (rc < 0) {

			kfree(tape->buf);

			tape->buf = NULL;

			tape->chrdev_dir = IDETAPE_DIR_NONE;

				return bytes_read;

			}

			return rc;

		}

	}
@@ -1038,7 +1046,7 @@ static int idetape_add_chrdev_read_request(ide_drive_t *drive, int blocks) 
	if (test_bit(IDE_AFLAG_FILEMARK, &drive->atapi_flags))

		return 0;



	idetape_init_read(drive);

	idetape_init_rw(drive, IDETAPE_DIR_READ);



	return idetape_queue_rw_tail(drive, REQ_IDETAPE_READ, blocks);

}
@@ -1195,7 +1203,7 @@ static ssize_t idetape_chrdev_read(struct file *file, char __user *buf, 
			    (count % tape->blk_size) == 0)

				tape->user_bs_factor = count / tape->blk_size;

	}

	rc = idetape_init_read(drive);

	rc = idetape_init_rw(drive, IDETAPE_DIR_READ);

	if (rc < 0)

		return rc;

	if (count == 0)
@@ -1249,6 +1257,7 @@ static ssize_t idetape_chrdev_write(struct file *file, const char __user *buf, 
	ssize_t actually_written = 0;

	ssize_t ret = 0;

	u16 ctl = *(u16 *)&tape->caps[12];

	int rc;



	/* The drive is write protected. */

	if (tape->write_prot)
@@ -1257,36 +1266,9 @@ static ssize_t idetape_chrdev_write(struct file *file, const char __user *buf, 
	debug_log(DBG_CHRDEV, "Enter %s, count %Zd\n", __func__, count);



	/* Initialize write operation */

	if (tape->chrdev_dir != IDETAPE_DIR_WRITE) {

		if (tape->chrdev_dir == IDETAPE_DIR_READ)

			ide_tape_discard_merge_buffer(drive, 1);

		if (tape->buf || tape->valid) {

			printk(KERN_ERR "ide-tape: valid should be 0 now\n");

			tape->valid = 0;

		}

		tape->buf = kmalloc(tape->buffer_size, GFP_KERNEL);

		if (!tape->buf)

			return -ENOMEM;

		tape->chrdev_dir = IDETAPE_DIR_WRITE;

		tape->cur = tape->buf;



		/*

		 * Issue a write 0 command to ensure that DSC handshake is

		 * switched from completion mode to buffer available mode. No

		 * point in issuing this if DSC overlap isn't supported, some

		 * drives (Seagate STT3401A) will return an error.

		 */

		if (drive->dev_flags & IDE_DFLAG_DSC_OVERLAP) {

			ssize_t retval = idetape_queue_rw_tail(drive,

							REQ_IDETAPE_WRITE, 0);

			if (retval < 0) {

				kfree(tape->buf);

				tape->buf = NULL;

				tape->chrdev_dir = IDETAPE_DIR_NONE;

				return retval;

			}

		}

	}

	rc = idetape_init_rw(drive, IDETAPE_DIR_WRITE);

	if (rc < 0)

		return rc;

	if (count == 0)

		return (0);

	if (tape->valid < tape->buffer_size) {