linux-kernel - [PATCH 04/17] ide-tape: remove idetape_empty_write

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Date:	Mon, 17 Mar 2008 07:41:17 +0100
From:	Borislav Petkov <petkovbb@...glemail.com>
To:	<bzolnier@...il.com>
Cc:	linux-kernel@...r.kernel.org, linux-ide@...r.kernel.org,
	Borislav Petkov <petkovbb@...il.com>
Subject: [PATCH 04/17] ide-tape: remove idetape_empty_write_pipeline()

In order _not_ to skip over some pipeline stages left, we carefully flush any
remaining ones. Nevertheless, this is only a temporary measure (git-bisect)
before removing pipeline functionality completely.

Signed-off-by: Borislav Petkov <petkovbb@...il.com>
---
 drivers/ide/ide-tape.c |   80 ++----------------------------------------------
 1 files changed, 3 insertions(+), 77 deletions(-)

diff --git a/drivers/ide/ide-tape.c b/drivers/ide/ide-tape.c
index 429fed4..d4a94d5 100644
--- a/drivers/ide/ide-tape.c
+++ b/drivers/ide/ide-tape.c
@@ -2041,80 +2041,6 @@ static void idetape_wait_for_pipeline(ide_drive_t *drive)
 	}
 }
 
-static void idetape_empty_write_pipeline(ide_drive_t *drive)
-{
-	idetape_tape_t *tape = drive->driver_data;
-	int blocks, min;
-	struct idetape_bh *bh;
-
-	if (tape->chrdev_dir != IDETAPE_DIR_WRITE) {
-		printk(KERN_ERR "ide-tape: bug: Trying to empty write pipeline,"
-				" but we are not writing.\n");
-		return;
-	}
-	if (tape->merge_stage_size > tape->stage_size) {
-		printk(KERN_ERR "ide-tape: bug: merge_buffer too big\n");
-		tape->merge_stage_size = tape->stage_size;
-	}
-	if (tape->merge_stage_size) {
-		blocks = tape->merge_stage_size / tape->blk_size;
-		if (tape->merge_stage_size % tape->blk_size) {
-			unsigned int i;
-
-			blocks++;
-			i = tape->blk_size - tape->merge_stage_size %
-				tape->blk_size;
-			bh = tape->bh->b_reqnext;
-			while (bh) {
-				atomic_set(&bh->b_count, 0);
-				bh = bh->b_reqnext;
-			}
-			bh = tape->bh;
-			while (i) {
-				if (bh == NULL) {
-					printk(KERN_INFO "ide-tape: bug,"
-							 " bh NULL\n");
-					break;
-				}
-				min = min(i, (unsigned int)(bh->b_size -
-						atomic_read(&bh->b_count)));
-				memset(bh->b_data + atomic_read(&bh->b_count),
-						0, min);
-				atomic_add(min, &bh->b_count);
-				i -= min;
-				bh = bh->b_reqnext;
-			}
-		}
-		(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;
-	}
-	clear_bit(IDETAPE_FLAG_PIPELINE_ERR, &tape->flags);
-	tape->chrdev_dir = IDETAPE_DIR_NONE;
-
-	/*
-	 * On the next backup, perform the feedback loop again. (I don't want to
-	 * keep sense information between backups, as some systems are
-	 * constantly on, and the system load can be totally different on the
-	 * next backup).
-	 */
-	tape->max_stages = tape->min_pipeline;
-	if (tape->first_stage != NULL ||
-	    tape->next_stage != NULL ||
-	    tape->last_stage != NULL ||
-	    tape->nr_stages != 0) {
-		printk(KERN_ERR "ide-tape: ide-tape pipeline bug, "
-			"first_stage %p, next_stage %p, "
-			"last_stage %p, nr_stages %d\n",
-			tape->first_stage, tape->next_stage,
-			tape->last_stage, tape->nr_stages);
-	}
-}
-
 static int idetape_init_read(ide_drive_t *drive, int max_stages)
 {
 	idetape_tape_t *tape = drive->driver_data;
@@ -2123,7 +2049,7 @@ static int idetape_init_read(ide_drive_t *drive, int max_stages)
 	/* Initialize read operation */
 	if (tape->chrdev_dir != IDETAPE_DIR_READ) {
 		if (tape->chrdev_dir == IDETAPE_DIR_WRITE) {
-			idetape_empty_write_pipeline(drive);
+			idetape_wait_for_pipeline(drive);
 			idetape_flush_tape_buffers(drive);
 		}
 		if (tape->merge_stage || tape->merge_stage_size) {
@@ -2702,7 +2628,7 @@ static int idetape_chrdev_ioctl(struct inode *inode, struct file *file,
 	debug_log(DBG_CHRDEV, "Enter %s, cmd=%u\n", __func__, cmd);
 
 	if (tape->chrdev_dir == IDETAPE_DIR_WRITE) {
-		idetape_empty_write_pipeline(drive);
+		idetape_wait_for_pipeline(drive);
 		idetape_flush_tape_buffers(drive);
 	}
 	if (cmd == MTIOCGET || cmd == MTIOCPOS) {
@@ -2852,7 +2778,7 @@ static void idetape_write_release(ide_drive_t *drive, unsigned int minor)
 {
 	idetape_tape_t *tape = drive->driver_data;
 
-	idetape_empty_write_pipeline(drive);
+	idetape_wait_for_pipeline(drive);
 	tape->merge_stage = __idetape_kmalloc_stage(tape, 1, 0);
 	if (tape->merge_stage != NULL) {
 		idetape_pad_zeros(drive, tape->blk_size *
-- 
1.5.4.1

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