[PATCH] ide-tape update for 2.6 (Was: PATCH: gets ide-tape working on 2.6)

From: Bartlomiej Zolnierkiewicz
Date: Thu Nov 13 2003 - 17:07:47 EST


[ with changed subject because ide-tape _is_ already working in 2.6 ]

On Thursday 13 of November 2003 16:54, stuart hayes wrote:
> Here's the patch in plain text.
>
> --
>
> Bart (et al),
>
> Here's a patch for ide-tape.c that gets ide-tape working on the 2.6 kernel.
>
> This should be applied after your recent patch that fixed the rq->flags
> stuff in ide-tape.

Current 2.6 -bk tree already contains corrected version of my patch
and fix for ide-tape character device (so no need to use iminor(inode)).

-bk snapshots are at http://www.kernel.org/pub/linux/kernel/v2.6/snapshots/

I've updated your patch accordingly.

> There's nothing in here that will make it more difficult to change the
> rq->flags stuff later if necessary--this will just tweak a few things to
> get the driver functional.
>
> Most of this stuff is just stuff to get the Seagate STT3401A Travan tape
> drive working, as I already submitted for the 2.4 kernel.

I dropped tape->spinlock changes. They are racy, you can't use spin_lock()
for tape->spinlock because this lock can be taken from IRQ context
(i.e. through idetape_pc_intr() -> pc->callback() -> idetape_end_request()).
I moved check for Travan drives outside CONFIG_BLK_DEV_IDEPCI.
I also removed code depending on NO_LONGER_NEEDED define to match 2.4.x
kernel (it was removed in 2.4.21 kernel) and made some cosmetics.

Thanks,
--bartlomiej


[IDE] ide-tape update

From: Stuart Hayes <stuart_hayes@xxxxxxxx>

- Check drive's write protect bit, try to return appropriate
errors when attempting to write a write-protected tape.

- Moved "idetape_read_position" call in idetape_chrdev_open
after the "wait_ready" call.

- Added IDETAPE_MEDIUM_PRESENT flag so driver would know
not to rewind tape after ejecting it.

- Fixed bug with ide_abort_pipeline (it was deleting stages
from tape->next_stage to end, instead of from
new_last_stage->next (tape->next_stage was set to NULL
by idetape_discard_read_pipeline before calling!).

- Made improvements to idetape_wait_ready.

- Added a few comments here and there.

- Made MTOFFL unlock tape drive door before attempting to eject.

- Added fixes to get Seagate STT3401A Travan working:
Handle drives that don't support 0-length reads/writes increased timeout
(retension takes ~10 minutes before irq is returned).
Fixed request mode page packet command byte 3.

Also remove code depending on NO_LONGER_REQUIRED to match 2.4.x (me).

drivers/ide/ide-tape.c | 211 ++++++++++++++++++++++++++++++++++---------------
1 files changed, 147 insertions(+), 64 deletions(-)

diff -puN drivers/ide/ide-tape.c~ide-tape-update drivers/ide/ide-tape.c
--- linux-2.6.0-test9-bk17/drivers/ide/ide-tape.c~ide-tape-update 2003-11-13 18:25:52.537457360 +0100
+++ linux-2.6.0-test9-bk17-root/drivers/ide/ide-tape.c 2003-11-13 22:37:06.768825864 +0100
@@ -1,5 +1,5 @@
/*
- * linux/drivers/ide/ide-tape.c Version 1.17b Oct, 2002
+ * linux/drivers/ide/ide-tape.c Version 1.18 Nov, 2003
*
* Copyright (C) 1995 - 1999 Gadi Oxman <gadio@xxxxxxxxxxxxxxxx>
*
@@ -422,7 +422,7 @@
* sharing a (fast) ATA-2 disk with any (slow) new ATAPI device.
*/

-#define IDETAPE_VERSION "1.17b-ac1"
+#define IDETAPE_VERSION "1.18"

#include <linux/config.h>
#include <linux/module.h>
@@ -450,9 +450,6 @@
#include <asm/unaligned.h>
#include <asm/bitops.h>

-
-#define NO_LONGER_REQUIRED (1)
-
/*
* OnStream support
*/
@@ -652,9 +649,11 @@ typedef struct {
#define IDETAPE_PC_STACK (10 + IDETAPE_MAX_PC_RETRIES)

/*
- * Some tape drives require a long irq timeout
+ * Some drives (for example, Seagate STT3401A Travan) require a very long
+ * timeout, because they don't return an interrupt or clear their busy bit
+ * until after the command completes (even retension commands).
*/
-#define IDETAPE_WAIT_CMD (60*HZ)
+#define IDETAPE_WAIT_CMD (900*HZ)

/*
* The following parameter is used to select the point in the internal
@@ -1032,6 +1031,10 @@ typedef struct {

/* the door is currently locked */
int door_locked;
+ /* the tape hardware is write protected */
+ char drv_write_prot;
+ /* the tape is write protected (hardware or opened as read-only) */
+ char write_prot;

/*
* OnStream flags
@@ -1164,6 +1167,8 @@ typedef struct {
#define IDETAPE_DRQ_INTERRUPT 6 /* DRQ interrupt device */
#define IDETAPE_READ_ERROR 7
#define IDETAPE_PIPELINE_ACTIVE 8 /* pipeline active */
+/* 0 = no tape is loaded, so we don't rewind after ejecting */
+#define IDETAPE_MEDIUM_PRESENT 9

/*
* Supported ATAPI tape drives packet commands
@@ -1665,6 +1670,20 @@ static void idetape_analyze_error (ide_d
idetape_update_buffers(pc);
}

+ /*
+ * If error was the result of a zero-length read or write command,
+ * with sense key=5, asc=0x22, ascq=0, let it slide. Some drives
+ * (i.e. Seagate STT3401A Travan) don't support 0-length read/writes.
+ */
+ if ((pc->c[0] == IDETAPE_READ_CMD || pc->c[0] == IDETAPE_WRITE_CMD)
+ && pc->c[4] == 0 && pc->c[3] == 0 && pc->c[2] == 0) { /* length==0 */
+ if (result->sense_key == 5) {
+ /* don't report an error, everything's ok */
+ pc->error = 0;
+ /* don't retry read/write */
+ set_bit(PC_ABORT, &pc->flags);
+ }
+ }
if (pc->c[0] == IDETAPE_READ_CMD && result->filemark) {
pc->error = IDETAPE_ERROR_FILEMARK;
set_bit(PC_ABORT, &pc->flags);
@@ -1805,10 +1824,15 @@ static void idetape_remove_stage_head (i
}
}

-static void idetape_abort_pipeline (ide_drive_t *drive, idetape_stage_t *last_stage)
+/*
+ * This will free all the pipeline stages starting from new_last_stage->next
+ * to the end of the list, and point tape->last_stage to new_last_stage.
+ */
+static void idetape_abort_pipeline(ide_drive_t *drive,
+ idetape_stage_t *new_last_stage)
{
idetape_tape_t *tape = drive->driver_data;
- idetape_stage_t *stage = tape->next_stage;
+ idetape_stage_t *stage = new_last_stage->next;
idetape_stage_t *nstage;

#if IDETAPE_DEBUG_LOG
@@ -1822,9 +1846,9 @@ static void idetape_abort_pipeline (ide_
--tape->nr_pending_stages;
stage = nstage;
}
- tape->last_stage = last_stage;
- if (last_stage)
- last_stage->next = NULL;
+ if (new_last_stage)
+ new_last_stage->next = NULL;
+ tape->last_stage = new_last_stage;
tape->next_stage = NULL;
}

@@ -2430,7 +2454,14 @@ static void idetape_create_mode_sense_cm
if (page_code != IDETAPE_BLOCK_DESCRIPTOR)
pc->c[1] = 8; /* DBD = 1 - Don't return block descriptors */
pc->c[2] = page_code;
- pc->c[3] = 255; /* Don't limit the returned information */
+ /*
+ * Changed pc->c[3] to 0 (255 will at best return unused info).
+ *
+ * For SCSI this byte is defined as subpage instead of high byte
+ * of length and some IDE drives seem to interpret it this way
+ * and return an error when 255 is used.
+ */
+ pc->c[3] = 0;
pc->c[4] = 255; /* (We will just discard data in that case) */
if (page_code == IDETAPE_BLOCK_DESCRIPTOR)
pc->request_transfer = 12;
@@ -2544,8 +2575,9 @@ static ide_startstop_t idetape_media_acc
if (status.b.dsc) {
if (status.b.check) {
/* Error detected */
- printk(KERN_ERR "ide-tape: %s: I/O error, ",tape->name);
-
+ if (pc->c[0] != IDETAPE_TEST_UNIT_READY_CMD)
+ printk(KERN_ERR "ide-tape: %s: I/O error, ",
+ tape->name);
/* Retry operation */
return idetape_retry_pc(drive);
}
@@ -3295,25 +3327,28 @@ static int idetape_wait_ready(ide_drive_
{
idetape_tape_t *tape = drive->driver_data;
idetape_pc_t pc;
+ int load_attempted = 0;

/*
* Wait for the tape to become ready
*/
+ set_bit(IDETAPE_MEDIUM_PRESENT, &tape->flags);
timeout += jiffies;
while (time_before(jiffies, timeout)) {
idetape_create_test_unit_ready_cmd(&pc);
if (!__idetape_queue_pc_tail(drive, &pc))
return 0;
- if (tape->sense_key == 2 && tape->asc == 4 && tape->ascq == 2) {
+ if ((tape->sense_key == 2 && tape->asc == 4 && tape->ascq == 2)
+ || (tape->asc == 0x3A)) { /* no media */
+ if (load_attempted)
+ return -ENOMEDIUM;
idetape_create_load_unload_cmd(drive, &pc, IDETAPE_LU_LOAD_MASK);
__idetape_queue_pc_tail(drive, &pc);
- idetape_create_test_unit_ready_cmd(&pc);
- if (!__idetape_queue_pc_tail(drive, &pc))
- return 0;
- }
- if (!(tape->sense_key == 2 && tape->asc == 4 &&
- (tape->ascq == 1 || tape->ascq == 8)))
- break;
+ load_attempted = 1;
+ /* not about to be ready */
+ } else if (!(tape->sense_key == 2 && tape->asc == 4 &&
+ (tape->ascq == 1 || tape->ascq == 8)))
+ return -EIO;
current->state = TASK_INTERRUPTIBLE;
schedule_timeout(HZ / 10);
}
@@ -3369,25 +3404,10 @@ static int idetape_read_position (ide_dr
printk(KERN_INFO "ide-tape: Reached idetape_read_position\n");
#endif /* IDETAPE_DEBUG_LOG */

-#ifdef NO_LONGER_REQUIRED
- idetape_flush_tape_buffers(drive);
-#endif
idetape_create_read_position_cmd(&pc);
if (idetape_queue_pc_tail(drive, &pc))
return -1;
position = tape->first_frame_position;
-#ifdef NO_LONGER_REQUIRED
- if (tape->onstream) {
- if ((position != tape->last_frame_position - tape->blocks_in_buffer) &&
- (position != tape->last_frame_position + tape->blocks_in_buffer)) {
- if (tape->blocks_in_buffer == 0) {
- printk("ide-tape: %s: correcting read position %d, %d, %d\n", tape->name, position, tape->last_frame_position, tape->blocks_in_buffer);
- position = tape->last_frame_position;
- tape->first_frame_position = position;
- }
- }
- }
-#endif
return position;
}

@@ -3436,6 +3456,8 @@ static int __idetape_discard_read_pipeli

if (tape->chrdev_direction != idetape_direction_read)
return 0;
+
+ /* Remove merge stage. */
cnt = tape->merge_stage_size / tape->tape_block_size;
if (test_and_clear_bit(IDETAPE_FILEMARK, &tape->flags))
++cnt; /* Filemarks count as 1 sector */
@@ -3444,9 +3466,12 @@ static int __idetape_discard_read_pipeli
__idetape_kfree_stage(tape->merge_stage);
tape->merge_stage = NULL;
}
+
+ /* Clear pipeline flags. */
clear_bit(IDETAPE_PIPELINE_ERROR, &tape->flags);
tape->chrdev_direction = idetape_direction_none;
-
+
+ /* Remove pipeline stages. */
if (tape->first_stage == NULL)
return 0;

@@ -4059,13 +4084,17 @@ static int idetape_initiate_read (ide_dr
* 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 drives (Seagate STT3401A) will return an error.
*/
- bytes_read = idetape_queue_rw_tail(drive, REQ_IDETAPE_READ, 0, tape->merge_stage->bh);
- if (bytes_read < 0) {
- __idetape_kfree_stage(tape->merge_stage);
- tape->merge_stage = NULL;
- tape->chrdev_direction = idetape_direction_none;
- return bytes_read;
+ if (drive->dsc_overlap) {
+ bytes_read = idetape_queue_rw_tail(drive, REQ_IDETAPE_READ, 0, tape->merge_stage->bh);
+ if (bytes_read < 0) {
+ __idetape_kfree_stage(tape->merge_stage);
+ tape->merge_stage = NULL;
+ tape->chrdev_direction = idetape_direction_none;
+ return bytes_read;
+ }
}
}
if (tape->restart_speed_control_req)
@@ -4898,6 +4927,10 @@ static ssize_t idetape_chrdev_write (str
return -ENXIO;
}

+ /* The drive is write protected. */
+ if (tape->write_prot)
+ return -EACCES;
+
#if IDETAPE_DEBUG_LOG
if (tape->debug_level >= 3)
printk(KERN_INFO "ide-tape: Reached idetape_chrdev_write, "
@@ -4979,13 +5012,17 @@ static ssize_t idetape_chrdev_write (str
* 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.
*/
- retval = idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE, 0, tape->merge_stage->bh);
- if (retval < 0) {
- __idetape_kfree_stage(tape->merge_stage);
- tape->merge_stage = NULL;
- tape->chrdev_direction = idetape_direction_none;
- return retval;
+ if (drive->dsc_overlap) {
+ retval = idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE, 0, tape->merge_stage->bh);
+ if (retval < 0) {
+ __idetape_kfree_stage(tape->merge_stage);
+ tape->merge_stage = NULL;
+ tape->chrdev_direction = idetape_direction_none;
+ return retval;
+ }
}
#if ONSTREAM_DEBUG
if (tape->debug_level >= 2)
@@ -5141,7 +5178,7 @@ ok:
* Note:
*
* MTBSF and MTBSFM are not supported when the tape doesn't
- * supports spacing over filemarks in the reverse direction.
+ * support spacing over filemarks in the reverse direction.
* In this case, MTFSFM is also usually not supported (it is
* supported in the rare case in which we crossed the filemark
* during our read-ahead pipelined operation mode).
@@ -5211,6 +5248,8 @@ static int idetape_mtioctop (ide_drive_t
}
switch (mt_op) {
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);
@@ -5231,9 +5270,21 @@ static int idetape_mtioctop (ide_drive_t
return (idetape_queue_pc_tail(drive, &pc));
case MTUNLOAD:
case MTOFFL:
+ /*
+ * If door is locked, attempt to unlock before
+ * attempting to eject.
+ */
+ if (tape->door_locked) {
+ if (idetape_create_prevent_cmd(drive, &pc, 0))
+ 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);
- return (idetape_queue_pc_tail(drive, &pc));
+ retval = idetape_queue_pc_tail(drive, &pc);
+ if (!retval)
+ clear_bit(IDETAPE_MEDIUM_PRESENT, &tape->flags);
+ return retval;
case MTNOP:
idetape_discard_read_pipeline(drive, 0);
return (idetape_flush_tape_buffers(drive));
@@ -5409,6 +5460,8 @@ static int idetape_chrdev_ioctl (struct
mtget.mt_gstat |= GMT_EOD(0xffffffff);
if (position <= OS_DATA_STARTFRAME1)
mtget.mt_gstat |= GMT_BOT(0xffffffff);
+ } else if (tape->drv_write_prot) {
+ mtget.mt_gstat |= GMT_WR_PROT(0xffffffff);
}
if (copy_to_user((char *) arg,(char *) &mtget, sizeof(struct mtget)))
return -EFAULT;
@@ -5530,6 +5583,8 @@ ok:
return 1;
}

+static void idetape_get_blocksize_from_block_descriptor(ide_drive_t *drive);
+
/*
* Our character device open function.
*/
@@ -5539,7 +5594,8 @@ static int idetape_chrdev_open (struct i
ide_drive_t *drive;
idetape_tape_t *tape;
idetape_pc_t pc;
-
+ int retval;
+
#if IDETAPE_DEBUG_LOG
printk(KERN_INFO "ide-tape: Reached idetape_chrdev_open\n");
#endif /* IDETAPE_DEBUG_LOG */
@@ -5552,11 +5608,7 @@ static int idetape_chrdev_open (struct i

if (test_and_set_bit(IDETAPE_BUSY, &tape->flags))
return -EBUSY;
- if (!tape->onstream) {
- idetape_read_position(drive);
- if (!test_bit(IDETAPE_ADDRESS_VALID, &tape->flags))
- (void) idetape_rewind_tape(drive);
- } else {
+ if (tape->onstream) {
if (minor & 64) {
tape->tape_block_size = tape->stage_size = 32768 + 512;
tape->raw = 1;
@@ -5566,16 +5618,42 @@ static int idetape_chrdev_open (struct i
}
idetape_onstream_mode_sense_tape_parameter_page(drive, tape->debug_level);
}
- if (idetape_wait_ready(drive, 60 * HZ)) {
+ retval = idetape_wait_ready(drive, 60 * HZ);
+ if (retval) {
clear_bit(IDETAPE_BUSY, &tape->flags);
printk(KERN_ERR "ide-tape: %s: drive not ready\n", tape->name);
- return -EBUSY;
+ return retval;
}
- if (tape->onstream)
- idetape_read_position(drive);
+
+ idetape_read_position(drive);
+ if (!test_bit(IDETAPE_ADDRESS_VALID, &tape->flags))
+ (void)idetape_rewind_tape(drive);
+
if (tape->chrdev_direction != idetape_direction_read)
clear_bit(IDETAPE_PIPELINE_ERROR, &tape->flags);

+ /* Read block size and write protect status from drive. */
+ idetape_get_blocksize_from_block_descriptor(drive);
+
+ /* Set write protect flag if device is opened as read-only. */
+ if ((filp->f_flags & O_ACCMODE) == O_RDONLY)
+ tape->write_prot = 1;
+ else
+ tape->write_prot = tape->drv_write_prot;
+
+ /* Make sure drive isn't write protected if user wants to write. */
+ if (tape->write_prot) {
+ if ((filp->f_flags & O_ACCMODE) == O_WRONLY ||
+ (filp->f_flags & O_ACCMODE) == O_RDWR) {
+ clear_bit(IDETAPE_BUSY, &tape->flags);
+ return -EROFS;
+ }
+ }
+
+ /*
+ * Lock the tape drive door so user can't eject.
+ * Analyze headers for OnStream drives.
+ */
if (tape->chrdev_direction == idetape_direction_none) {
if (idetape_create_prevent_cmd(drive, &pc, 1)) {
if (!idetape_queue_pc_tail(drive, &pc)) {
@@ -5638,7 +5716,7 @@ static int idetape_chrdev_release (struc
__idetape_kfree_stage(tape->cache_stage);
tape->cache_stage = NULL;
}
- if (minor < 128)
+ if (minor < 128 && test_bit(IDETAPE_MEDIUM_PRESENT, &tape->flags))
(void) idetape_rewind_tape(drive);
if (tape->chrdev_direction == idetape_direction_none) {
if (tape->door_locked == DOOR_LOCKED) {
@@ -6059,6 +6137,8 @@ static void idetape_get_blocksize_from_b
header = (idetape_mode_parameter_header_t *) pc.buffer;
block_descrp = (idetape_parameter_block_descriptor_t *) (pc.buffer + sizeof(idetape_mode_parameter_header_t));
tape->tape_block_size =( block_descrp->length[0]<<16) + (block_descrp->length[1]<<8) + block_descrp->length[2];
+ tape->drv_write_prot = (header->dsp & 0x80) >> 7;
+
#if IDETAPE_DEBUG_INFO
printk(KERN_INFO "ide-tape: Adjusted block size - %d\n", tape->tape_block_size);
#endif /* IDETAPE_DEBUG_INFO */
@@ -6139,6 +6219,9 @@ static void idetape_setup (ide_drive_t *
}
}
#endif /* CONFIG_BLK_DEV_IDEPCI */
+ /* Seagate Travan drives do not support DSC overlap. */
+ if (strstr(drive->id->model, "Seagate STT3401"))
+ drive->dsc_overlap = 0;
tape->drive = drive;
tape->minor = minor;
tape->name[0] = 'h';

_

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