[PATCH] ide: no partial completions for PIO (CONFIG_IDE_TASKFILE_IO=y)

Don't do partial completions but instead acknowledge already transferred
sectors with verified good status on error.  This allows us to complete
"good" sectors to block layer even if bio they belong to wasn't finished
and simplifies code.
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@elka.pw.edu.pl>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

drivers/ide/ide-taskfile.c

@@ -532,6 +532,18 @@ static u8 wait_drive_not_busy(ide_drive_t *drive)
 	return stat;
 }
 
+static ide_startstop_t task_error(ide_drive_t *drive, struct request *rq,
+				  const char *s, u8 stat, unsigned cur_bad)
+{
+	if (rq->bio) {
+		int sectors = rq->hard_nr_sectors - rq->nr_sectors - cur_bad;
+
+		if (sectors > 0)
+			drive->driver->end_request(drive, 1, sectors);
+	}
+	return drive->driver->error(drive, s, stat);
+}
+
 /*
  * Handler for command with PIO data-in phase (Read).
  */
@@ -542,24 +554,11 @@ ide_startstop_t task_in_intr (ide_drive_t *drive)
 
 	if (!OK_STAT(stat, DATA_READY, BAD_R_STAT)) {
 		if (stat & (ERR_STAT | DRQ_STAT))
-			return DRIVER(drive)->error(drive, __FUNCTION__, stat);
+			return task_error(drive, rq, __FUNCTION__, stat, 0);
 		/* BUSY_STAT: No data yet, so wait for another IRQ. */
 		ide_set_handler(drive, &task_in_intr, WAIT_WORSTCASE, NULL);
 		return ide_started;
 	}
-finish_rq:
-	/*
-	 * Complete previously submitted bios (if any).
-	 * Status was already verifyied.
-	 */
-	while (rq->bio != rq->cbio)
-		if (!DRIVER(drive)->end_request(drive, 1, bio_sectors(rq->bio)))
-			return ide_stopped;
-	/* Complete rq->buffer based request (ioctls). */
-	if (!rq->bio && !rq->nr_sectors) {
-		DRIVER(drive)->end_request(drive, 1, 0);
-		return ide_stopped;
-	}
 
 	task_sectors(drive, rq, 1, IDE_PIO_IN);
 
@@ -567,8 +566,9 @@ ide_startstop_t task_in_intr (ide_drive_t *drive)
 	if (!rq->nr_sectors) {
 		stat = wait_drive_not_busy(drive);
 		if (!OK_STAT(stat, 0, BAD_R_STAT))
-			return DRIVER(drive)->error(drive, __FUNCTION__, stat);
-		goto finish_rq;
+			return task_error(drive, rq, __FUNCTION__, stat, 1);
+		drive->driver->end_request(drive, 1, rq->hard_nr_sectors);
+		return ide_stopped;
 	}
 
 	/* Still data left to transfer. */
@@ -588,24 +588,11 @@ ide_startstop_t task_mulin_intr (ide_drive_t *drive)
 
 	if (!OK_STAT(stat, DATA_READY, BAD_R_STAT)) {
 		if (stat & (ERR_STAT | DRQ_STAT))
-			return DRIVER(drive)->error(drive, __FUNCTION__, stat);
+			return task_error(drive, rq, __FUNCTION__, stat, 0);
 		/* BUSY_STAT: No data yet, so wait for another IRQ. */
 		ide_set_handler(drive, &task_mulin_intr, WAIT_WORSTCASE, NULL);
 		return ide_started;
 	}
-finish_rq:
-	/*
-	 * Complete previously submitted bios (if any).
-	 * Status was already verifyied.
-	 */
-	while (rq->bio != rq->cbio)
-		if (!DRIVER(drive)->end_request(drive, 1, bio_sectors(rq->bio)))
-			return ide_stopped;
-	/* Complete rq->buffer based request (ioctls). */
-	if (!rq->bio && !rq->nr_sectors) {
-		DRIVER(drive)->end_request(drive, 1, 0);
-		return ide_stopped;
-	}
 
 	task_multi_sectors(drive, rq, IDE_PIO_IN);
 
@@ -613,8 +600,9 @@ ide_startstop_t task_mulin_intr (ide_drive_t *drive)
 	if (!rq->nr_sectors) {
 		stat = wait_drive_not_busy(drive);
 		if (!OK_STAT(stat, 0, BAD_R_STAT))
-			return DRIVER(drive)->error(drive, __FUNCTION__, stat);
-		goto finish_rq;
+			return task_error(drive, rq, __FUNCTION__, stat, drive->mult_count);
+		drive->driver->end_request(drive, 1, rq->hard_nr_sectors);
+		return ide_stopped;
 	}
 
 	/* Still data left to transfer. */
@@ -634,23 +622,15 @@ ide_startstop_t task_out_intr (ide_drive_t *drive)
 
 	stat = HWIF(drive)->INB(IDE_STATUS_REG);
 	if (!OK_STAT(stat, DRIVE_READY, drive->bad_wstat))
-		return DRIVER(drive)->error(drive, __FUNCTION__, stat);
+		return task_error(drive, rq, __FUNCTION__, stat, 1);
 
 	/* Deal with unexpected ATA data phase. */
 	if ((!(stat & DATA_READY) && rq->nr_sectors) ||
 	    ((stat & DATA_READY) && !rq->nr_sectors))
-		return DRIVER(drive)->error(drive, __FUNCTION__, stat);
+		return task_error(drive, rq, __FUNCTION__, stat, 1);
 
-	/* 
-	 * Complete previously submitted bios (if any).
-	 * Status was already verifyied.
-	 */
-	while (rq->bio != rq->cbio)
-		if (!DRIVER(drive)->end_request(drive, 1, bio_sectors(rq->bio)))
-			return ide_stopped;
-	/* Complete rq->buffer based request (ioctls). */
-	if (!rq->bio && !rq->nr_sectors) {
-		DRIVER(drive)->end_request(drive, 1, 0);
+	if (!rq->nr_sectors) {
+		drive->driver->end_request(drive, 1, rq->hard_nr_sectors);
 		return ide_stopped;
 	}
 
@@ -694,23 +674,15 @@ ide_startstop_t task_mulout_intr (ide_drive_t *drive)
 
 	stat = HWIF(drive)->INB(IDE_STATUS_REG);
 	if (!OK_STAT(stat, DRIVE_READY, drive->bad_wstat))
-		return DRIVER(drive)->error(drive, __FUNCTION__, stat);
+		return task_error(drive, rq, __FUNCTION__, stat, drive->mult_count);
 
 	/* Deal with unexpected ATA data phase. */
 	if ((!(stat & DATA_READY) && rq->nr_sectors) ||
 	    ((stat & DATA_READY) && !rq->nr_sectors))
-		return DRIVER(drive)->error(drive, __FUNCTION__, stat);
+		return task_error(drive, rq, __FUNCTION__, stat, drive->mult_count);
 
-	/* 
-	 * Complete previously submitted bios (if any).
-	 * Status was already verifyied.
-	 */
-	while (rq->bio != rq->cbio)
-		if (!DRIVER(drive)->end_request(drive, 1, bio_sectors(rq->bio)))
-			return ide_stopped;
-	/* Complete rq->buffer based request (ioctls). */
-	if (!rq->bio && !rq->nr_sectors) {
-		DRIVER(drive)->end_request(drive, 1, 0);
+	if (!rq->nr_sectors) {
+		drive->driver->end_request(drive, 1, rq->hard_nr_sectors);
 		return ide_stopped;
 	}