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Re: [dm-devel] [PATCH] HP storage works support take 2



I told you I tried this simple fix, without success.

It is not enough, as it still hangs the kernel upon first io submited to
the map.

I verified this even without any hardware, with ram disks.
Here is a sample table :

[root s64p17bibrn mce-dm-sstart]# dmsetup table toto: 0 1000 multipath 1
queue_if_no_path 1 hp_sw 2 1 round-robin 0 1 1 1:2 1000 round-robin 0 1
1 1:2 1000
[root s64p17bibrn mce-dm-sstart]# dd if=/dev/mapper/toto of=/dev/null
bs=512 count=1

<HANG>

Regards,
cvaroqui

On sam, 2005-06-11 at 18:33 -0700, Mike Christie wrote:
> This should fix some bugs.
> 
> 
> 
> diff -Naurp linux-2.6.12-rc5.orig/drivers/md/dm-hp-sw.c linux-2.6.12-rc5/drivers/md/dm-hp-sw.c
> --- linux-2.6.12-rc5.orig/drivers/md/dm-hp-sw.c	1969-12-31 16:00:00.000000000 -0800
> +++ linux-2.6.12-rc5/drivers/md/dm-hp-sw.c	2005-06-10 23:25:01.000000000 -0700
> @@ -0,0 +1,160 @@
> +/*
> + * Copyright (C) 2005 Mike Christie, All rights reserved.
> + *
> + * This file is released under the GPL.
> + *
> + * Basic, very basic, support for HP StorageWorks and FSC FibreCat
> + */
> +#include <scsi/scsi.h>
> +#include <scsi/scsi_cmnd.h>
> +
> +#include "dm.h"
> +#include "dm-hw-handler.h"
> +
> +struct hp_sw_handler {
> +	unsigned char sense[SCSI_SENSE_BUFFERSIZE];
> +};
> +
> +static void hp_sw_endio(struct request *rq)
> +{
> +	struct path *path = rq->end_io_data;
> +
> +	/*
> +	 * TODO: something.. we have the sense and scsi bytes
> +	 */
> +	if (rq->errors) {
> +		DMINFO("hp_sw: START_STOP completed %d", rq->errors);
> +		dm_pg_init_complete(path, MP_FAIL_PATH);
> +	} else
> +		dm_pg_init_complete(path, 0);
> +
> +	blk_put_request(rq);
> +}
> +
> +static struct request *hp_sw_get_request(struct hp_sw_handler *h,
> +					struct path *path)
> +{
> +	struct request *rq;
> +	struct block_device *bdev = path->dev->bdev;
> +	struct request_queue *q = bdev_get_queue(bdev);
> +
> +	rq = blk_get_request(q, READ, __GFP_WAIT);
> +	if (!rq)
> +		return NULL;
> +
> +	rq->end_io = hp_sw_endio;
> +	rq->end_io_data = path;
> +	rq->rq_disk = bdev->bd_contains->bd_disk;
> +	rq->sense = h->sense;
> +	memset(rq->sense, 0, SCSI_SENSE_BUFFERSIZE);
> +	rq->sense_len = 0;
> +	/*
> +	 * TODO: make me configurable
> +	 */
> +	rq->timeout = 30;
> +	rq->flags |= (REQ_BLOCK_PC | REQ_FAILFAST | REQ_NOMERGE);
> +
> +	memset(&rq->cmd, 0, BLK_MAX_CDB);
> +	rq->cmd[0] = START_STOP;
> +	/* Start spin cycle */
> +	rq->cmd[4] = 1;
> +	rq->cmd_len = COMMAND_SIZE(rq->cmd[0]);
> +
> +	return rq;
> +}
> +
> +static void hp_sw_pg_init(struct hw_handler *hwh, unsigned bypassed,
> +			   struct path *path)
> +{
> +	struct request *rq;
> +	struct request_queue *q = bdev_get_queue(path->dev->bdev);
> +
> +	/*
> +	 * We can either blindly init the pg (then look at the sense),
> +	 * or we can send some commands to get the state here (then
> +	 * possibly send the fo cmnd), or we can also have the
> +	 * initial state passed into us and then get an update here.
> +	 */
> +	if (!q) {
> +		DMERR("hp_sw: no queue!");
> +		goto fail_path;
> +	}
> +
> +	if (blk_get_queue(q))
> +		goto fail_path;
> +
> +	rq = hp_sw_get_request(hwh->context, path);
> +	if (!rq) {
> +		DMERR("hp_sw: could not allocate request for START_STOP");
> +		goto rel_queue;
> +	}
> +
> +	DMINFO("hp_sw: queueing START_STOP command");
> +	elv_add_request(q, rq, ELEVATOR_INSERT_FRONT, 1);
> +	blk_put_queue(q);
> +	return;
> +
> +rel_queue:
> +	blk_put_queue(q);
> +fail_path:
> +	dm_pg_init_complete(path, MP_FAIL_PATH);
> +}
> +
> +static int hp_sw_create(struct hw_handler *hwh, unsigned argc, char **argv)
> +{
> +	struct hp_sw_handler *h;
> +
> +	h = kmalloc(sizeof(*h), GFP_KERNEL);
> +	if (!h) {
> +		DMERR("hp_sw: could not allocate hw_handler");
> +		return -ENOMEM;
> +	}
> +
> +	hwh->context = h;
> +	return 0;
> +}
> +
> +static void hp_sw_destroy(struct hw_handler *hwh)
> +{
> +	struct hp_sw_handler *h = hwh->context;
> +
> +	kfree(h);
> +	hwh->context = NULL;
> +}
> +
> +static struct hw_handler_type hp_sw_hwh = {
> +	.name = "hp_sw",
> +	.module = THIS_MODULE,
> +	.create = hp_sw_create,
> +	.destroy = hp_sw_destroy,
> +	.pg_init = hp_sw_pg_init,
> +};
> +
> +static int __init hp_sw_init(void)
> +{
> +	int r;
> +
> +	r = dm_register_hw_handler(&hp_sw_hwh);
> +	if (r < 0)
> +		DMERR("hp_sw: register failed %d", r);
> +
> +	DMINFO("hp_sw version 0.1 loaded");
> +
> +	return r;
> +}
> +
> +static void __exit hp_sw_exit(void)
> +{
> +	int r;
> +
> +	r = dm_unregister_hw_handler(&hp_sw_hwh);
> +	if (r < 0)
> +		DMERR("hp_sw: unregister failed %d", r);
> +}
> +
> +module_init(hp_sw_init);
> +module_exit(hp_sw_exit);
> +
> +MODULE_DESCRIPTION("HP StorageWorks and FSC FibreCat support for dm-multipath");
> +MODULE_AUTHOR("Mike Christie <michaelc cs wisc edu>");
> +MODULE_LICENSE("GPL");
> diff -Naurp linux-2.6.12-rc5.orig/drivers/md/Kconfig linux-2.6.12-rc5/drivers/md/Kconfig
> --- linux-2.6.12-rc5.orig/drivers/md/Kconfig	2005-06-08 19:30:05.000000000 -0700
> +++ linux-2.6.12-rc5/drivers/md/Kconfig	2005-06-10 23:23:31.000000000 -0700
> @@ -236,5 +236,14 @@ config DM_MULTIPATH_EMC
>  	---help---
>  	  Multipath support for EMC CX/AX series hardware.
>  
> +config DM_MULTIPATH_HP_SW
> +	tristate "HP StorageWorks and FSC FibreCat (EXPERIMENTAL)"
> +	depends on DM_MULTIPATH && BLK_DEV_DM && EXPERIMENTAL
> +	---help---
> +	  Multipath support for HP StorageWorks and FSC FibreCat.
> +          This was created with no knowledge of the HW other than
> +          that it uses a START_STOP command for failover so it
> +          is marked EXPERIMENTAL.
> +
>  endmenu
>  
> diff -Naurp linux-2.6.12-rc5.orig/drivers/md/Makefile linux-2.6.12-rc5/drivers/md/Makefile
> --- linux-2.6.12-rc5.orig/drivers/md/Makefile	2005-06-08 19:30:05.000000000 -0700
> +++ linux-2.6.12-rc5/drivers/md/Makefile	2005-06-10 23:23:31.000000000 -0700
> @@ -33,6 +33,7 @@ obj-$(CONFIG_BLK_DEV_DM)	+= dm-mod.o
>  obj-$(CONFIG_DM_CRYPT)		+= dm-crypt.o
>  obj-$(CONFIG_DM_MULTIPATH)	+= dm-multipath.o dm-round-robin.o
>  obj-$(CONFIG_DM_MULTIPATH_EMC)	+= dm-emc.o
> +obj-$(CONFIG_DM_MULTIPATH_HP_SW) += dm-hp-sw.o
>  obj-$(CONFIG_DM_SNAPSHOT)	+= dm-snapshot.o
>  obj-$(CONFIG_DM_MIRROR)		+= dm-mirror.o
>  obj-$(CONFIG_DM_ZERO)		+= dm-zero.o
> 
> 
> --
> dm-devel mailing list
> dm-devel redhat com
> https://www.redhat.com/mailman/listinfo/dm-devel
-- 
christophe varoqui <christophe varoqui free fr>



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