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Commit 688864e2 authored by Chandra Seetharaman's avatar Chandra Seetharaman Committed by James Bottomley
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[SCSI] scsi_dh: Remove hardware handler infrastructure from dm 



This patch just removes infrastructure that provided support for hardware
handlers in the dm layer as it is not needed anymore.

Signed-off-by: default avatarChandra Seetharaman <sekharan@us.ibm.com>
Acked-by: default avatarAlasdair G Kergon <agk@redhat.com>
Signed-off-by: default avatarJames Bottomley <James.Bottomley@HansenPartnership.com>
parent cb520223

drivers/md/Makefile

+1 −1
Original line number Diff line number Diff line
@@ -4,7 +4,7 @@ 


dm-mod-objs	:= dm.o dm-table.o dm-target.o dm-linear.o dm-stripe.o \

		   dm-ioctl.o dm-io.o dm-kcopyd.o

dm-multipath-objs := dm-hw-handler.o dm-path-selector.o dm-mpath.o

dm-multipath-objs := dm-path-selector.o dm-mpath.o

dm-snapshot-objs := dm-snap.o dm-exception-store.o

dm-mirror-objs	:= dm-raid1.o

md-mod-objs     := md.o bitmap.o

drivers/md/dm-hw-handler.c

deleted100644 → 0
+0 −213
Original line number Diff line number Diff line 
/*

 * Copyright (C) 2004 Red Hat, Inc. All rights reserved.

 *

 * This file is released under the GPL.

 *

 * Multipath hardware handler registration.

 */



#include "dm.h"

#include "dm-hw-handler.h"



#include <linux/slab.h>



struct hwh_internal {

	struct hw_handler_type hwht;



	struct list_head list;

	long use;

};



#define hwht_to_hwhi(__hwht) container_of((__hwht), struct hwh_internal, hwht)



static LIST_HEAD(_hw_handlers);

static DECLARE_RWSEM(_hwh_lock);



static struct hwh_internal *__find_hw_handler_type(const char *name)

{

	struct hwh_internal *hwhi;



	list_for_each_entry(hwhi, &_hw_handlers, list) {

		if (!strcmp(name, hwhi->hwht.name))

			return hwhi;

	}



	return NULL;

}



static struct hwh_internal *get_hw_handler(const char *name)

{

	struct hwh_internal *hwhi;



	down_read(&_hwh_lock);

	hwhi = __find_hw_handler_type(name);

	if (hwhi) {

		if ((hwhi->use == 0) && !try_module_get(hwhi->hwht.module))

			hwhi = NULL;

		else

			hwhi->use++;

	}

	up_read(&_hwh_lock);



	return hwhi;

}



struct hw_handler_type *dm_get_hw_handler(const char *name)

{

	struct hwh_internal *hwhi;



	if (!name)

		return NULL;



	hwhi = get_hw_handler(name);

	if (!hwhi) {

		request_module("dm-%s", name);

		hwhi = get_hw_handler(name);

	}



	return hwhi ? &hwhi->hwht : NULL;

}



void dm_put_hw_handler(struct hw_handler_type *hwht)

{

	struct hwh_internal *hwhi;



	if (!hwht)

		return;



	down_read(&_hwh_lock);

	hwhi = __find_hw_handler_type(hwht->name);

	if (!hwhi)

		goto out;



	if (--hwhi->use == 0)

		module_put(hwhi->hwht.module);



	BUG_ON(hwhi->use < 0);



      out:

	up_read(&_hwh_lock);

}



static struct hwh_internal *_alloc_hw_handler(struct hw_handler_type *hwht)

{

	struct hwh_internal *hwhi = kzalloc(sizeof(*hwhi), GFP_KERNEL);



	if (hwhi)

		hwhi->hwht = *hwht;



	return hwhi;

}



int dm_register_hw_handler(struct hw_handler_type *hwht)

{

	int r = 0;

	struct hwh_internal *hwhi = _alloc_hw_handler(hwht);



	if (!hwhi)

		return -ENOMEM;



	down_write(&_hwh_lock);



	if (__find_hw_handler_type(hwht->name)) {

		kfree(hwhi);

		r = -EEXIST;

	} else

		list_add(&hwhi->list, &_hw_handlers);



	up_write(&_hwh_lock);



	return r;

}



int dm_unregister_hw_handler(struct hw_handler_type *hwht)

{

	struct hwh_internal *hwhi;



	down_write(&_hwh_lock);



	hwhi = __find_hw_handler_type(hwht->name);

	if (!hwhi) {

		up_write(&_hwh_lock);

		return -EINVAL;

	}



	if (hwhi->use) {

		up_write(&_hwh_lock);

		return -ETXTBSY;

	}



	list_del(&hwhi->list);



	up_write(&_hwh_lock);



	kfree(hwhi);



	return 0;

}



unsigned dm_scsi_err_handler(struct hw_handler *hwh, struct bio *bio)

{

#if 0

	int sense_key, asc, ascq;



	if (bio->bi_error & BIO_SENSE) {

		/* FIXME: This is just an initial guess. */

		/* key / asc / ascq */

		sense_key = (bio->bi_error >> 16) & 0xff;

		asc = (bio->bi_error >> 8) & 0xff;

		ascq = bio->bi_error & 0xff;



		switch (sense_key) {

			/* This block as a whole comes from the device.

			 * So no point retrying on another path. */

		case 0x03:	/* Medium error */

		case 0x05:	/* Illegal request */

		case 0x07:	/* Data protect */

		case 0x08:	/* Blank check */

		case 0x0a:	/* copy aborted */

		case 0x0c:	/* obsolete - no clue ;-) */

		case 0x0d:	/* volume overflow */

		case 0x0e:	/* data miscompare */

		case 0x0f:	/* reserved - no idea either. */

			return MP_ERROR_IO;



			/* For these errors it's unclear whether they

			 * come from the device or the controller.

			 * So just lets try a different path, and if

			 * it eventually succeeds, user-space will clear

			 * the paths again... */

		case 0x02:	/* Not ready */

		case 0x04:	/* Hardware error */

		case 0x09:	/* vendor specific */

		case 0x0b:	/* Aborted command */

			return MP_FAIL_PATH;



		case 0x06:	/* Unit attention - might want to decode */

			if (asc == 0x04 && ascq == 0x01)

				/* "Unit in the process of

				 * becoming ready" */

				return 0;

			return MP_FAIL_PATH;



			/* FIXME: For Unit Not Ready we may want

			 * to have a generic pg activation

			 * feature (START_UNIT). */



			/* Should these two ever end up in the

			 * error path? I don't think so. */

		case 0x00:	/* No sense */

		case 0x01:	/* Recovered error */

			return 0;

		}

	}

#endif



	/* We got no idea how to decode the other kinds of errors ->

	 * assume generic error condition. */

	return MP_FAIL_PATH;

}



EXPORT_SYMBOL_GPL(dm_register_hw_handler);

EXPORT_SYMBOL_GPL(dm_unregister_hw_handler);

EXPORT_SYMBOL_GPL(dm_scsi_err_handler);

drivers/md/dm-hw-handler.h

deleted100644 → 0
+0 −63
Original line number Diff line number Diff line 
/*

 * Copyright (C) 2004 Red Hat, Inc. All rights reserved.

 *

 * This file is released under the GPL.

 *

 * Multipath hardware handler registration.

 */



#ifndef	DM_HW_HANDLER_H

#define	DM_HW_HANDLER_H



#include <linux/device-mapper.h>



#include "dm-mpath.h"



struct hw_handler_type;

struct hw_handler {

	struct hw_handler_type *type;

	struct mapped_device *md;

	void *context;

};



/*

 * Constructs a hardware handler object, takes custom arguments

 */

/* Information about a hardware handler type */

struct hw_handler_type {

	char *name;

	struct module *module;



	int (*create) (struct hw_handler *handler, unsigned int argc,

		       char **argv);

	void (*destroy) (struct hw_handler *hwh);



	void (*pg_init) (struct hw_handler *hwh, unsigned bypassed,

			 struct dm_path *path);

	unsigned (*error) (struct hw_handler *hwh, struct bio *bio);

	int (*status) (struct hw_handler *hwh, status_type_t type,

		       char *result, unsigned int maxlen);

};



/* Register a hardware handler */

int dm_register_hw_handler(struct hw_handler_type *type);



/* Unregister a hardware handler */

int dm_unregister_hw_handler(struct hw_handler_type *type);



/* Returns a registered hardware handler type */

struct hw_handler_type *dm_get_hw_handler(const char *name);



/* Releases a hardware handler  */

void dm_put_hw_handler(struct hw_handler_type *hwht);



/* Default err function */

unsigned dm_scsi_err_handler(struct hw_handler *hwh, struct bio *bio);



/* Error flags for err and dm_pg_init_complete */

#define MP_FAIL_PATH 1

#define MP_BYPASS_PG 2

#define MP_ERROR_IO  4	/* Don't retry this I/O */

#define MP_RETRY 8



#endif

drivers/md/dm-mpath.h

+0 −1
Original line number Diff line number Diff line
@@ -16,7 +16,6 @@ struct dm_path { 
	unsigned is_active;	/* Read-only */



	void *pscontext;	/* For path-selector use */

	void *hwhcontext;	/* For hw-handler use */

};



/* Callback for hwh_pg_init_fn to use when complete */