linux/drivers/scsi/device_handler/scsi_dh_hp_sw.c
Mike Christie 6000a368cd [SCSI] block: separate failfast into multiple bits.
Multipath is best at handling transport errors. If it gets a device
error then there is not much the multipath layer can do. It will just
access the same device but from a different path.

This patch breaks up failfast into device, transport and driver errors.
The multipath layers (md and dm mutlipath) only ask the lower levels to
fast fail transport errors. The user of failfast, read ahead, will ask
to fast fail on all errors.

Note that blk_noretry_request will return true if any failfast bit
is set. This allows drivers that do not support the multipath failfast
bits to continue to fail on any failfast error like before. Drivers
like scsi that are able to fail fast specific errors can check
for the specific fail fast type. In the next patch I will convert
scsi.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Cc: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-10-13 09:28:52 -04:00

382 lines
9.2 KiB
C

/*
* Basic HP/COMPAQ MSA 1000 support. This is only needed if your HW cannot be
* upgraded.
*
* Copyright (C) 2006 Red Hat, Inc. All rights reserved.
* Copyright (C) 2006 Mike Christie
* Copyright (C) 2008 Hannes Reinecke <hare@suse.de>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2, or (at your option)
* any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; see the file COPYING. If not, write to
* the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <scsi/scsi.h>
#include <scsi/scsi_dbg.h>
#include <scsi/scsi_eh.h>
#include <scsi/scsi_dh.h>
#define HP_SW_NAME "hp_sw"
#define HP_SW_TIMEOUT (60 * HZ)
#define HP_SW_RETRIES 3
#define HP_SW_PATH_UNINITIALIZED -1
#define HP_SW_PATH_ACTIVE 0
#define HP_SW_PATH_PASSIVE 1
struct hp_sw_dh_data {
unsigned char sense[SCSI_SENSE_BUFFERSIZE];
int path_state;
int retries;
};
static inline struct hp_sw_dh_data *get_hp_sw_data(struct scsi_device *sdev)
{
struct scsi_dh_data *scsi_dh_data = sdev->scsi_dh_data;
BUG_ON(scsi_dh_data == NULL);
return ((struct hp_sw_dh_data *) scsi_dh_data->buf);
}
/*
* tur_done - Handle TEST UNIT READY return status
* @sdev: sdev the command has been sent to
* @errors: blk error code
*
* Returns SCSI_DH_DEV_OFFLINED if the sdev is on the passive path
*/
static int tur_done(struct scsi_device *sdev, unsigned char *sense)
{
struct scsi_sense_hdr sshdr;
int ret;
ret = scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE, &sshdr);
if (!ret) {
sdev_printk(KERN_WARNING, sdev,
"%s: sending tur failed, no sense available\n",
HP_SW_NAME);
ret = SCSI_DH_IO;
goto done;
}
switch (sshdr.sense_key) {
case UNIT_ATTENTION:
ret = SCSI_DH_IMM_RETRY;
break;
case NOT_READY:
if ((sshdr.asc == 0x04) && (sshdr.ascq == 2)) {
/*
* LUN not ready - Initialization command required
*
* This is the passive path
*/
ret = SCSI_DH_DEV_OFFLINED;
break;
}
/* Fallthrough */
default:
sdev_printk(KERN_WARNING, sdev,
"%s: sending tur failed, sense %x/%x/%x\n",
HP_SW_NAME, sshdr.sense_key, sshdr.asc,
sshdr.ascq);
break;
}
done:
return ret;
}
/*
* hp_sw_tur - Send TEST UNIT READY
* @sdev: sdev command should be sent to
*
* Use the TEST UNIT READY command to determine
* the path state.
*/
static int hp_sw_tur(struct scsi_device *sdev, struct hp_sw_dh_data *h)
{
struct request *req;
int ret;
req = blk_get_request(sdev->request_queue, WRITE, GFP_NOIO);
if (!req)
return SCSI_DH_RES_TEMP_UNAVAIL;
req->cmd_type = REQ_TYPE_BLOCK_PC;
req->cmd_flags |= REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT |
REQ_FAILFAST_DRIVER;
req->cmd_len = COMMAND_SIZE(TEST_UNIT_READY);
req->cmd[0] = TEST_UNIT_READY;
req->timeout = HP_SW_TIMEOUT;
req->sense = h->sense;
memset(req->sense, 0, SCSI_SENSE_BUFFERSIZE);
req->sense_len = 0;
retry:
ret = blk_execute_rq(req->q, NULL, req, 1);
if (ret == -EIO) {
if (req->sense_len > 0) {
ret = tur_done(sdev, h->sense);
} else {
sdev_printk(KERN_WARNING, sdev,
"%s: sending tur failed with %x\n",
HP_SW_NAME, req->errors);
ret = SCSI_DH_IO;
}
} else {
h->path_state = HP_SW_PATH_ACTIVE;
ret = SCSI_DH_OK;
}
if (ret == SCSI_DH_IMM_RETRY)
goto retry;
if (ret == SCSI_DH_DEV_OFFLINED) {
h->path_state = HP_SW_PATH_PASSIVE;
ret = SCSI_DH_OK;
}
blk_put_request(req);
return ret;
}
/*
* start_done - Handle START STOP UNIT return status
* @sdev: sdev the command has been sent to
* @errors: blk error code
*/
static int start_done(struct scsi_device *sdev, unsigned char *sense)
{
struct scsi_sense_hdr sshdr;
int rc;
rc = scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE, &sshdr);
if (!rc) {
sdev_printk(KERN_WARNING, sdev,
"%s: sending start_stop_unit failed, "
"no sense available\n",
HP_SW_NAME);
return SCSI_DH_IO;
}
switch (sshdr.sense_key) {
case NOT_READY:
if ((sshdr.asc == 0x04) && (sshdr.ascq == 3)) {
/*
* LUN not ready - manual intervention required
*
* Switch-over in progress, retry.
*/
rc = SCSI_DH_RETRY;
break;
}
/* fall through */
default:
sdev_printk(KERN_WARNING, sdev,
"%s: sending start_stop_unit failed, sense %x/%x/%x\n",
HP_SW_NAME, sshdr.sense_key, sshdr.asc,
sshdr.ascq);
rc = SCSI_DH_IO;
}
return rc;
}
/*
* hp_sw_start_stop - Send START STOP UNIT command
* @sdev: sdev command should be sent to
*
* Sending START STOP UNIT activates the SP.
*/
static int hp_sw_start_stop(struct scsi_device *sdev, struct hp_sw_dh_data *h)
{
struct request *req;
int ret, retry;
req = blk_get_request(sdev->request_queue, WRITE, GFP_NOIO);
if (!req)
return SCSI_DH_RES_TEMP_UNAVAIL;
req->cmd_type = REQ_TYPE_BLOCK_PC;
req->cmd_flags |= REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT |
REQ_FAILFAST_DRIVER;
req->cmd_len = COMMAND_SIZE(START_STOP);
req->cmd[0] = START_STOP;
req->cmd[4] = 1; /* Start spin cycle */
req->timeout = HP_SW_TIMEOUT;
req->sense = h->sense;
memset(req->sense, 0, SCSI_SENSE_BUFFERSIZE);
req->sense_len = 0;
retry = h->retries;
retry:
ret = blk_execute_rq(req->q, NULL, req, 1);
if (ret == -EIO) {
if (req->sense_len > 0) {
ret = start_done(sdev, h->sense);
} else {
sdev_printk(KERN_WARNING, sdev,
"%s: sending start_stop_unit failed with %x\n",
HP_SW_NAME, req->errors);
ret = SCSI_DH_IO;
}
} else
ret = SCSI_DH_OK;
if (ret == SCSI_DH_RETRY) {
if (--retry)
goto retry;
ret = SCSI_DH_IO;
}
blk_put_request(req);
return ret;
}
static int hp_sw_prep_fn(struct scsi_device *sdev, struct request *req)
{
struct hp_sw_dh_data *h = get_hp_sw_data(sdev);
int ret = BLKPREP_OK;
if (h->path_state != HP_SW_PATH_ACTIVE) {
ret = BLKPREP_KILL;
req->cmd_flags |= REQ_QUIET;
}
return ret;
}
/*
* hp_sw_activate - Activate a path
* @sdev: sdev on the path to be activated
*
* The HP Active/Passive firmware is pretty simple;
* the passive path reports NOT READY with sense codes
* 0x04/0x02; a START STOP UNIT command will then
* activate the passive path (and deactivate the
* previously active one).
*/
static int hp_sw_activate(struct scsi_device *sdev)
{
int ret = SCSI_DH_OK;
struct hp_sw_dh_data *h = get_hp_sw_data(sdev);
ret = hp_sw_tur(sdev, h);
if (ret == SCSI_DH_OK && h->path_state == HP_SW_PATH_PASSIVE) {
ret = hp_sw_start_stop(sdev, h);
if (ret == SCSI_DH_OK)
sdev_printk(KERN_INFO, sdev,
"%s: activated path\n",
HP_SW_NAME);
}
return ret;
}
static const struct scsi_dh_devlist hp_sw_dh_data_list[] = {
{"COMPAQ", "MSA1000 VOLUME"},
{"COMPAQ", "HSV110"},
{"HP", "HSV100"},
{"DEC", "HSG80"},
{NULL, NULL},
};
static int hp_sw_bus_attach(struct scsi_device *sdev);
static void hp_sw_bus_detach(struct scsi_device *sdev);
static struct scsi_device_handler hp_sw_dh = {
.name = HP_SW_NAME,
.module = THIS_MODULE,
.devlist = hp_sw_dh_data_list,
.attach = hp_sw_bus_attach,
.detach = hp_sw_bus_detach,
.activate = hp_sw_activate,
.prep_fn = hp_sw_prep_fn,
};
static int hp_sw_bus_attach(struct scsi_device *sdev)
{
struct scsi_dh_data *scsi_dh_data;
struct hp_sw_dh_data *h;
unsigned long flags;
int ret;
scsi_dh_data = kzalloc(sizeof(struct scsi_device_handler *)
+ sizeof(struct hp_sw_dh_data) , GFP_KERNEL);
if (!scsi_dh_data) {
sdev_printk(KERN_ERR, sdev, "%s: Attach Failed\n",
HP_SW_NAME);
return 0;
}
scsi_dh_data->scsi_dh = &hp_sw_dh;
h = (struct hp_sw_dh_data *) scsi_dh_data->buf;
h->path_state = HP_SW_PATH_UNINITIALIZED;
h->retries = HP_SW_RETRIES;
ret = hp_sw_tur(sdev, h);
if (ret != SCSI_DH_OK || h->path_state == HP_SW_PATH_UNINITIALIZED)
goto failed;
if (!try_module_get(THIS_MODULE))
goto failed;
spin_lock_irqsave(sdev->request_queue->queue_lock, flags);
sdev->scsi_dh_data = scsi_dh_data;
spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags);
sdev_printk(KERN_INFO, sdev, "%s: attached to %s path\n",
HP_SW_NAME, h->path_state == HP_SW_PATH_ACTIVE?
"active":"passive");
return 0;
failed:
kfree(scsi_dh_data);
sdev_printk(KERN_ERR, sdev, "%s: not attached\n",
HP_SW_NAME);
return -EINVAL;
}
static void hp_sw_bus_detach( struct scsi_device *sdev )
{
struct scsi_dh_data *scsi_dh_data;
unsigned long flags;
spin_lock_irqsave(sdev->request_queue->queue_lock, flags);
scsi_dh_data = sdev->scsi_dh_data;
sdev->scsi_dh_data = NULL;
spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags);
module_put(THIS_MODULE);
sdev_printk(KERN_NOTICE, sdev, "%s: Detached\n", HP_SW_NAME);
kfree(scsi_dh_data);
}
static int __init hp_sw_init(void)
{
return scsi_register_device_handler(&hp_sw_dh);
}
static void __exit hp_sw_exit(void)
{
scsi_unregister_device_handler(&hp_sw_dh);
}
module_init(hp_sw_init);
module_exit(hp_sw_exit);
MODULE_DESCRIPTION("HP Active/Passive driver");
MODULE_AUTHOR("Mike Christie <michaelc@cs.wisc.edu");
MODULE_LICENSE("GPL");