Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 077e3bdb authored by Borislav Petkov's avatar Borislav Petkov Committed by Bartlomiej Zolnierkiewicz
Browse files

ide-tape: remove tape->merge_stage 



Get rid of the pipeline merge stage but retain the chrdev req caching
functionality by using a merge buffer tape->merge_bh which is flushed in chunks
of several blocks at a time. Also, remove last references to pipelining, e.g.
typedef idetape_stage_s.

Signed-off-by: default avatarBorislav Petkov <petkovbb@gmail.com>
Signed-off-by: default avatarBartlomiej Zolnierkiewicz <bzolnier@gmail.com>
parent 01a63aeb

drivers/ide/ide-tape.c

+46 −61
Original line number Diff line number Diff line
@@ -215,13 +215,6 @@ enum { 
	IDETAPE_FLAG_MEDIUM_PRESENT	= (1 << 6),

};



/* A pipeline stage. */

typedef struct idetape_stage_s {

	struct request rq;			/* The corresponding request */

	struct idetape_bh *bh;			/* The data buffers */

	struct idetape_stage_s *next;		/* Pointer to the next stage */

} idetape_stage_t;



/*

 * Most of our global data which we need to save even as we leave the driver due

 * to an interrupt or a timer event is stored in the struct defined below.
@@ -309,9 +302,11 @@ typedef struct ide_tape_obj { 


	/* Data buffer size chosen based on the tape's recommendation */

	int buffer_size;

	idetape_stage_t *merge_stage;

	/* merge buffer */

	struct idetape_bh *merge_bh;

	/* size of the merge buffer */

	int merge_bh_size;

	/* pointer to current buffer head within the merge buffer */

	struct idetape_bh *bh;

	char *b_data;

	int b_count;
@@ -585,9 +580,9 @@ static void idetape_analyze_error(ide_drive_t *drive, u8 *sense) 
}



/* Free data buffers completely. */

static void ide_tape_kfree_buffer(idetape_stage_t *stage)

static void ide_tape_kfree_buffer(idetape_tape_t *tape)

{

	struct idetape_bh *prev_bh, *bh = stage->bh;

	struct idetape_bh *prev_bh, *bh = tape->merge_bh;



	while (bh) {

		u32 size = bh->b_size;
@@ -605,7 +600,7 @@ static void ide_tape_kfree_buffer(idetape_stage_t *stage) 
		bh = bh->b_reqnext;

		kfree(prev_bh);

	}

	kfree(stage);

	kfree(tape->merge_bh);

}



static int idetape_end_request(ide_drive_t *drive, int uptodate, int nr_sects)
@@ -1299,22 +1294,16 @@ static ide_startstop_t idetape_do_request(ide_drive_t *drive, 
 * It returns a pointer to the newly allocated buffer, or NULL in case of

 * failure.

 */

static idetape_stage_t *ide_tape_kmalloc_buffer(idetape_tape_t *tape, int full,

						int clear)

static struct idetape_bh *ide_tape_kmalloc_buffer(idetape_tape_t *tape,

						  int full, int clear)

{

	idetape_stage_t *stage;

	struct idetape_bh *prev_bh, *bh;

	struct idetape_bh *prev_bh, *bh, *merge_bh;

	int pages = tape->pages_per_buffer;

	unsigned int order, b_allocd;

	char *b_data = NULL;



	stage = kmalloc(sizeof(idetape_stage_t), GFP_KERNEL);

	if (!stage)

		return NULL;

	stage->next = NULL;



	stage->bh = kmalloc(sizeof(struct idetape_bh), GFP_KERNEL);

	bh = stage->bh;

	merge_bh = kmalloc(sizeof(struct idetape_bh), GFP_KERNEL);

	bh = merge_bh;

	if (bh == NULL)

		goto abort;
@@ -1374,9 +1363,9 @@ static idetape_stage_t *ide_tape_kmalloc_buffer(idetape_tape_t *tape, int full, 
	bh->b_size -= tape->excess_bh_size;

	if (full)

		atomic_sub(tape->excess_bh_size, &bh->b_count);

	return stage;

	return merge_bh;

abort:

	ide_tape_kfree_buffer(stage);

	ide_tape_kfree_buffer(tape);

	return NULL;

}
@@ -1444,11 +1433,11 @@ static int idetape_copy_stage_to_user(idetape_tape_t *tape, char __user *buf, 
	return ret;

}



static void idetape_init_merge_stage(idetape_tape_t *tape)

static void idetape_init_merge_buffer(idetape_tape_t *tape)

{

	struct idetape_bh *bh = tape->merge_stage->bh;

	struct idetape_bh *bh = tape->merge_bh;

	tape->bh = tape->merge_bh;



	tape->bh = bh;

	if (tape->chrdev_dir == IDETAPE_DIR_WRITE)

		atomic_set(&bh->b_count, 0);

	else {
@@ -1651,9 +1640,9 @@ static void __ide_tape_discard_merge_buffer(ide_drive_t *drive) 


	clear_bit(IDETAPE_FLAG_FILEMARK, &tape->flags);

	tape->merge_bh_size = 0;

	if (tape->merge_stage != NULL) {

		ide_tape_kfree_buffer(tape->merge_stage);

		tape->merge_stage = NULL;

	if (tape->merge_bh != NULL) {

		ide_tape_kfree_buffer(tape);

		tape->merge_bh = NULL;

	}



	tape->chrdev_dir = IDETAPE_DIR_NONE;
@@ -1725,8 +1714,8 @@ static int idetape_queue_rw_tail(ide_drive_t *drive, int cmd, int blocks, 
	if ((cmd & (REQ_IDETAPE_READ | REQ_IDETAPE_WRITE)) == 0)

		return 0;



	if (tape->merge_stage)

		idetape_init_merge_stage(tape);

	if (tape->merge_bh)

		idetape_init_merge_buffer(tape);

	if (rq.errors == IDETAPE_ERROR_GENERAL)

		return -EIO;

	return (tape->blk_size * (blocks-rq.current_nr_sectors));
@@ -1777,7 +1766,7 @@ static int idetape_add_chrdev_write_request(ide_drive_t *drive, int blocks) 
	debug_log(DBG_CHRDEV, "Enter %s\n", __func__);



	return idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE,

				     blocks, tape->merge_stage->bh);

				     blocks, tape->merge_bh);

}



static void ide_tape_flush_merge_buffer(ide_drive_t *drive)
@@ -1787,7 +1776,7 @@ static void ide_tape_flush_merge_buffer(ide_drive_t *drive) 
	struct idetape_bh *bh;



	if (tape->chrdev_dir != IDETAPE_DIR_WRITE) {

		printk(KERN_ERR "ide-tape: bug: Trying to empty write pipeline,"

		printk(KERN_ERR "ide-tape: bug: Trying to empty merge buffer"

				" but we are not writing.\n");

		return;

	}
@@ -1827,9 +1816,9 @@ static void ide_tape_flush_merge_buffer(ide_drive_t *drive) 
		(void) idetape_add_chrdev_write_request(drive, blocks);

		tape->merge_bh_size = 0;

	}

	if (tape->merge_stage != NULL) {

		ide_tape_kfree_buffer(tape->merge_stage);

		tape->merge_stage = NULL;

	if (tape->merge_bh != NULL) {

		ide_tape_kfree_buffer(tape);

		tape->merge_bh = NULL;

	}

	tape->chrdev_dir = IDETAPE_DIR_NONE;

}
@@ -1845,13 +1834,13 @@ static int idetape_init_read(ide_drive_t *drive) 
			ide_tape_flush_merge_buffer(drive);

			idetape_flush_tape_buffers(drive);

		}

		if (tape->merge_stage || tape->merge_bh_size) {

		if (tape->merge_bh || tape->merge_bh_size) {

			printk(KERN_ERR "ide-tape: merge_bh_size should be"

					 " 0 now\n");

			tape->merge_bh_size = 0;

		}

		tape->merge_stage = ide_tape_kmalloc_buffer(tape, 0, 0);

		if (!tape->merge_stage)

		tape->merge_bh = ide_tape_kmalloc_buffer(tape, 0, 0);

		if (!tape->merge_bh)

			return -ENOMEM;

		tape->chrdev_dir = IDETAPE_DIR_READ;
@@ -1864,10 +1853,10 @@ static int idetape_init_read(ide_drive_t *drive) 
		if (drive->dsc_overlap) {

			bytes_read = idetape_queue_rw_tail(drive,

							REQ_IDETAPE_READ, 0,

							tape->merge_stage->bh);

							tape->merge_bh);

			if (bytes_read < 0) {

				ide_tape_kfree_buffer(tape->merge_stage);

				tape->merge_stage = NULL;

				ide_tape_kfree_buffer(tape);

				tape->merge_bh = NULL;

				tape->chrdev_dir = IDETAPE_DIR_NONE;

				return bytes_read;

			}
@@ -1891,7 +1880,7 @@ static int idetape_add_chrdev_read_request(ide_drive_t *drive, int blocks) 
	idetape_init_read(drive);



	return idetape_queue_rw_tail(drive, REQ_IDETAPE_READ, blocks,

				     tape->merge_stage->bh);

				     tape->merge_bh);

}



static void idetape_pad_zeros(ide_drive_t *drive, int bcount)
@@ -1903,7 +1892,7 @@ static void idetape_pad_zeros(ide_drive_t *drive, int bcount) 
	while (bcount) {

		unsigned int count;



		bh = tape->merge_stage->bh;

		bh = tape->merge_bh;

		count = min(tape->buffer_size, bcount);

		bcount -= count;

		blocks = count / tape->blk_size;
@@ -1915,7 +1904,7 @@ static void idetape_pad_zeros(ide_drive_t *drive, int bcount) 
			bh = bh->b_reqnext;

		}

		idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE, blocks,

				      tape->merge_stage->bh);

				      tape->merge_bh);

	}

}
@@ -2000,10 +1989,6 @@ static int idetape_space_over_filemarks(ide_drive_t *drive, short mt_op, 
		ide_tape_discard_merge_buffer(drive, 0);

	}



	/*

	 * The filemark was not found in our internal pipeline;	now we can issue

	 * the space command.

	 */

	switch (mt_op) {

	case MTFSF:

	case MTBSF:
@@ -2123,16 +2108,16 @@ static ssize_t idetape_chrdev_write(struct file *file, const char __user *buf, 
	if (tape->chrdev_dir != IDETAPE_DIR_WRITE) {

		if (tape->chrdev_dir == IDETAPE_DIR_READ)

			ide_tape_discard_merge_buffer(drive, 1);

		if (tape->merge_stage || tape->merge_bh_size) {

		if (tape->merge_bh || tape->merge_bh_size) {

			printk(KERN_ERR "ide-tape: merge_bh_size "

				"should be 0 now\n");

			tape->merge_bh_size = 0;

		}

		tape->merge_stage = ide_tape_kmalloc_buffer(tape, 0, 0);

		if (!tape->merge_stage)

		tape->merge_bh = ide_tape_kmalloc_buffer(tape, 0, 0);

		if (!tape->merge_bh)

			return -ENOMEM;

		tape->chrdev_dir = IDETAPE_DIR_WRITE;

		idetape_init_merge_stage(tape);

		idetape_init_merge_buffer(tape);



		/*

		 * Issue a write 0 command to ensure that DSC handshake is
@@ -2143,10 +2128,10 @@ static ssize_t idetape_chrdev_write(struct file *file, const char __user *buf, 
		if (drive->dsc_overlap) {

			ssize_t retval = idetape_queue_rw_tail(drive,

							REQ_IDETAPE_WRITE, 0,

							tape->merge_stage->bh);

							tape->merge_bh);

			if (retval < 0) {

				ide_tape_kfree_buffer(tape->merge_stage);

				tape->merge_stage = NULL;

				ide_tape_kfree_buffer(tape);

				tape->merge_bh = NULL;

				tape->chrdev_dir = IDETAPE_DIR_NONE;

				return retval;

			}
@@ -2508,12 +2493,12 @@ static void idetape_write_release(ide_drive_t *drive, unsigned int minor) 
	idetape_tape_t *tape = drive->driver_data;



	ide_tape_flush_merge_buffer(drive);

	tape->merge_stage = ide_tape_kmalloc_buffer(tape, 1, 0);

	if (tape->merge_stage != NULL) {

	tape->merge_bh = ide_tape_kmalloc_buffer(tape, 1, 0);

	if (tape->merge_bh != NULL) {

		idetape_pad_zeros(drive, tape->blk_size *

				(tape->user_bs_factor - 1));

		ide_tape_kfree_buffer(tape->merge_stage);

		tape->merge_stage = NULL;

		ide_tape_kfree_buffer(tape);

		tape->merge_bh = NULL;

	}

	idetape_write_filemark(drive);

	idetape_flush_tape_buffers(drive);