[mirror_ubuntu-eoan-kernel.git] / drivers / scsi / scsi_dh.c

/*
 * SCSI device handler infrastruture.
 *
 * 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 of the License, 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; if not, write to the Free Software Foundation, Inc.,
 * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 *
 * Copyright IBM Corporation, 2007
 *      Authors:
 *               Chandra Seetharaman <sekharan@us.ibm.com>
 *               Mike Anderson <andmike@linux.vnet.ibm.com>
 */

#include <linux/slab.h>
#include <linux/module.h>
#include <scsi/scsi_dh.h>
#include "scsi_priv.h"

static DEFINE_SPINLOCK(list_lock);
static LIST_HEAD(scsi_dh_list);

struct scsi_dh_blist {
	const char *vendor;
	const char *model;
	const char *driver;
};

static const struct scsi_dh_blist scsi_dh_blist[] = {
	{"DGC", "RAID",			"emc" },
	{"DGC", "DISK",			"emc" },
	{"DGC", "VRAID",		"emc" },

	{"COMPAQ", "MSA1000 VOLUME",	"hp_sw" },
	{"COMPAQ", "HSV110",		"hp_sw" },
	{"HP", "HSV100",		"hp_sw"},
	{"DEC", "HSG80",		"hp_sw"},

	{"IBM", "1722",			"rdac", },
	{"IBM", "1724",			"rdac", },
	{"IBM", "1726",			"rdac", },
	{"IBM", "1742",			"rdac", },
	{"IBM", "1745",			"rdac", },
	{"IBM", "1746",			"rdac", },
	{"IBM", "1813",			"rdac", },
	{"IBM", "1814",			"rdac", },
	{"IBM", "1815",			"rdac", },
	{"IBM", "1818",			"rdac", },
	{"IBM", "3526",			"rdac", },
	{"IBM", "3542",			"rdac", },
	{"IBM", "3552",			"rdac", },
	{"SGI", "TP9300",		"rdac", },
	{"SGI", "TP9400",		"rdac", },
	{"SGI", "TP9500",		"rdac", },
	{"SGI", "TP9700",		"rdac", },
	{"SGI", "IS",			"rdac", },
	{"STK", "OPENstorage",		"rdac", },
	{"STK", "FLEXLINE 380",		"rdac", },
	{"STK", "BladeCtlr",		"rdac", },
	{"SUN", "CSM",			"rdac", },
	{"SUN", "LCSM100",		"rdac", },
	{"SUN", "STK6580_6780",		"rdac", },
	{"SUN", "SUN_6180",		"rdac", },
	{"SUN", "ArrayStorage",		"rdac", },
	{"DELL", "MD3",			"rdac", },
	{"NETAPP", "INF-01-00",		"rdac", },
	{"LSI", "INF-01-00",		"rdac", },
	{"ENGENIO", "INF-01-00",	"rdac", },
	{NULL, NULL,			NULL },
};

static const char *
scsi_dh_find_driver(struct scsi_device *sdev)
{
	const struct scsi_dh_blist *b;

	if (scsi_device_tpgs(sdev))
		return "alua";

	for (b = scsi_dh_blist; b->vendor; b++) {
		if (!strncmp(sdev->vendor, b->vendor, strlen(b->vendor)) &&
		    !strncmp(sdev->model, b->model, strlen(b->model))) {
			return b->driver;
		}
	}
	return NULL;
}


static struct scsi_device_handler *__scsi_dh_lookup(const char *name)
{
	struct scsi_device_handler *tmp, *found = NULL;

	spin_lock(&list_lock);
	list_for_each_entry(tmp, &scsi_dh_list, list) {
		if (!strncmp(tmp->name, name, strlen(tmp->name))) {
			found = tmp;
			break;
		}
	}
	spin_unlock(&list_lock);
	return found;
}

static struct scsi_device_handler *scsi_dh_lookup(const char *name)
{
	struct scsi_device_handler *dh;

	if (!name || strlen(name) == 0)
		return NULL;

	dh = __scsi_dh_lookup(name);
	if (!dh) {
		request_module("scsi_dh_%s", name);
		dh = __scsi_dh_lookup(name);
	}

	return dh;
}

/*
 * scsi_dh_handler_attach - Attach a device handler to a device
 * @sdev - SCSI device the device handler should attach to
 * @scsi_dh - The device handler to attach
 */
static int scsi_dh_handler_attach(struct scsi_device *sdev,
				  struct scsi_device_handler *scsi_dh)
{
	int error, ret = 0;

	if (!try_module_get(scsi_dh->module))
		return -EINVAL;

	error = scsi_dh->attach(sdev);
	if (error != SCSI_DH_OK) {
		switch (error) {
		case SCSI_DH_NOMEM:
			ret = -ENOMEM;
			break;
		case SCSI_DH_RES_TEMP_UNAVAIL:
			ret = -EAGAIN;
			break;
		case SCSI_DH_DEV_UNSUPP:
		case SCSI_DH_NOSYS:
			ret = -ENODEV;
			break;
		default:
			ret = -EINVAL;
			break;
		}
		if (ret != -ENODEV)
			sdev_printk(KERN_ERR, sdev, "%s: Attach failed (%d)\n",
				    scsi_dh->name, error);
		module_put(scsi_dh->module);
	} else
		sdev->handler = scsi_dh;

	return ret;
}

/*
 * scsi_dh_handler_detach - Detach a device handler from a device
 * @sdev - SCSI device the device handler should be detached from
 */
static void scsi_dh_handler_detach(struct scsi_device *sdev)
{
	sdev->handler->detach(sdev);
	sdev_printk(KERN_NOTICE, sdev, "%s: Detached\n", sdev->handler->name);
	module_put(sdev->handler->module);
}

void scsi_dh_add_device(struct scsi_device *sdev)
{
	struct scsi_device_handler *devinfo = NULL;
	const char *drv;

	drv = scsi_dh_find_driver(sdev);
	if (drv)
		devinfo = __scsi_dh_lookup(drv);
	/*
	 * device_handler is optional, so ignore errors
	 * from scsi_dh_handler_attach()
	 */
	if (devinfo)
		(void)scsi_dh_handler_attach(sdev, devinfo);
}

void scsi_dh_release_device(struct scsi_device *sdev)
{
	if (sdev->handler)
		scsi_dh_handler_detach(sdev);
}

/*
 * scsi_register_device_handler - register a device handler personality
 *      module.
 * @scsi_dh - device handler to be registered.
 *
 * Returns 0 on success, -EBUSY if handler already registered.
 */
int scsi_register_device_handler(struct scsi_device_handler *scsi_dh)
{
	if (__scsi_dh_lookup(scsi_dh->name))
		return -EBUSY;

	if (!scsi_dh->attach || !scsi_dh->detach)
		return -EINVAL;

	spin_lock(&list_lock);
	list_add(&scsi_dh->list, &scsi_dh_list);
	spin_unlock(&list_lock);

	printk(KERN_INFO "%s: device handler registered\n", scsi_dh->name);

	return SCSI_DH_OK;
}
EXPORT_SYMBOL_GPL(scsi_register_device_handler);

/*
 * scsi_unregister_device_handler - register a device handler personality
 *      module.
 * @scsi_dh - device handler to be unregistered.
 *
 * Returns 0 on success, -ENODEV if handler not registered.
 */
int scsi_unregister_device_handler(struct scsi_device_handler *scsi_dh)
{
	if (!__scsi_dh_lookup(scsi_dh->name))
		return -ENODEV;

	spin_lock(&list_lock);
	list_del(&scsi_dh->list);
	spin_unlock(&list_lock);
	printk(KERN_INFO "%s: device handler unregistered\n", scsi_dh->name);

	return SCSI_DH_OK;
}
EXPORT_SYMBOL_GPL(scsi_unregister_device_handler);

/*
 * scsi_dh_activate - activate the path associated with the scsi_device
 *      corresponding to the given request queue.
 *     Returns immediately without waiting for activation to be completed.
 * @q    - Request queue that is associated with the scsi_device to be
 *         activated.
 * @fn   - Function to be called upon completion of the activation.
 *         Function fn is called with data (below) and the error code.
 *         Function fn may be called from the same calling context. So,
 *         do not hold the lock in the caller which may be needed in fn.
 * @data - data passed to the function fn upon completion.
 *
 */
int scsi_dh_activate(struct request_queue *q, activate_complete fn, void *data)
{
	struct scsi_device *sdev;
	int err = SCSI_DH_NOSYS;

	sdev = scsi_device_from_queue(q);
	if (!sdev) {
		if (fn)
			fn(data, err);
		return err;
	}

	if (!sdev->handler)
		goto out_fn;
	err = SCSI_DH_NOTCONN;
	if (sdev->sdev_state == SDEV_CANCEL ||
	    sdev->sdev_state == SDEV_DEL)
		goto out_fn;

	err = SCSI_DH_DEV_OFFLINED;
	if (sdev->sdev_state == SDEV_OFFLINE)
		goto out_fn;

	if (sdev->handler->activate)
		err = sdev->handler->activate(sdev, fn, data);

out_put_device:
	put_device(&sdev->sdev_gendev);
	return err;

out_fn:
	if (fn)
		fn(data, err);
	goto out_put_device;
}
EXPORT_SYMBOL_GPL(scsi_dh_activate);

/*
 * scsi_dh_set_params - set the parameters for the device as per the
 *      string specified in params.
 * @q - Request queue that is associated with the scsi_device for
 *      which the parameters to be set.
 * @params - parameters in the following format
 *      "no_of_params\0param1\0param2\0param3\0...\0"
 *      for example, string for 2 parameters with value 10 and 21
 *      is specified as "2\010\021\0".
 */
int scsi_dh_set_params(struct request_queue *q, const char *params)
{
	struct scsi_device *sdev;
	int err = -SCSI_DH_NOSYS;

	sdev = scsi_device_from_queue(q);
	if (!sdev)
		return err;

	if (sdev->handler && sdev->handler->set_params)
		err = sdev->handler->set_params(sdev, params);
	put_device(&sdev->sdev_gendev);
	return err;
}
EXPORT_SYMBOL_GPL(scsi_dh_set_params);

/*
 * scsi_dh_attach - Attach device handler
 * @q - Request queue that is associated with the scsi_device
 *      the handler should be attached to
 * @name - name of the handler to attach
 */
int scsi_dh_attach(struct request_queue *q, const char *name)
{
	struct scsi_device *sdev;
	struct scsi_device_handler *scsi_dh;
	int err = 0;

	sdev = scsi_device_from_queue(q);
	if (!sdev)
		return -ENODEV;

	scsi_dh = scsi_dh_lookup(name);
	if (!scsi_dh) {
		err = -EINVAL;
		goto out_put_device;
	}

	if (sdev->handler) {
		if (sdev->handler != scsi_dh)
			err = -EBUSY;
		goto out_put_device;
	}

	err = scsi_dh_handler_attach(sdev, scsi_dh);

out_put_device:
	put_device(&sdev->sdev_gendev);
	return err;
}
EXPORT_SYMBOL_GPL(scsi_dh_attach);

/*
 * scsi_dh_attached_handler_name - Get attached device handler's name
 * @q - Request queue that is associated with the scsi_device
 *      that may have a device handler attached
 * @gfp - the GFP mask used in the kmalloc() call when allocating memory
 *
 * Returns name of attached handler, NULL if no handler is attached.
 * Caller must take care to free the returned string.
 */
const char *scsi_dh_attached_handler_name(struct request_queue *q, gfp_t gfp)
{
	struct scsi_device *sdev;
	const char *handler_name = NULL;

	sdev = scsi_device_from_queue(q);
	if (!sdev)
		return NULL;

	if (sdev->handler)
		handler_name = kstrdup(sdev->handler->name, gfp);
	put_device(&sdev->sdev_gendev);
	return handler_name;
}
EXPORT_SYMBOL_GPL(scsi_dh_attached_handler_name);
Commit	Line	Data
a6a8d9f8 CS	1	/*
	2	* SCSI device handler infrastruture.
	3	*
	4	* This program is free software; you can redistribute it and/or modify it
	5	* under the terms of the GNU General Public License as published by the
	6	* Free Software Foundation; either version 2 of the License, or (at your
	7	* option) any later version.
	8	*
	9	* This program is distributed in the hope that it will be useful, but
	10	* WITHOUT ANY WARRANTY; without even the implied warranty of
	11	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	12	* General Public License for more details.
	13	*
	14	* You should have received a copy of the GNU General Public License along
	15	* with this program; if not, write to the Free Software Foundation, Inc.,
	16	* 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
	17	*
	18	* Copyright IBM Corporation, 2007
	19	* Authors:
	20	* Chandra Seetharaman <sekharan@us.ibm.com>
	21	* Mike Anderson <andmike@linux.vnet.ibm.com>
	22	*/
	23
5a0e3ad6	24	#include <linux/slab.h>
acf3368f	25	#include <linux/module.h>
a6a8d9f8	26	#include <scsi/scsi_dh.h>
daaa858b	27	#include "scsi_priv.h"
a6a8d9f8 CS	28
	29	static DEFINE_SPINLOCK(list_lock);
	30	static LIST_HEAD(scsi_dh_list);
	31
d95dbff2 CH	32	struct scsi_dh_blist {
	33	const char *vendor;
	34	const char *model;
	35	const char *driver;
	36	};
	37
	38	static const struct scsi_dh_blist scsi_dh_blist[] = {
0ba43a81 XVP	39	{"DGC", "RAID", "emc" },
	40	{"DGC", "DISK", "emc" },
	41	{"DGC", "VRAID", "emc" },
d95dbff2 CH	42
	43	{"COMPAQ", "MSA1000 VOLUME", "hp_sw" },
	44	{"COMPAQ", "HSV110", "hp_sw" },
	45	{"HP", "HSV100", "hp_sw"},
	46	{"DEC", "HSG80", "hp_sw"},
	47
	48	{"IBM", "1722", "rdac", },
	49	{"IBM", "1724", "rdac", },
	50	{"IBM", "1726", "rdac", },
	51	{"IBM", "1742", "rdac", },
	52	{"IBM", "1745", "rdac", },
	53	{"IBM", "1746", "rdac", },
	54	{"IBM", "1813", "rdac", },
	55	{"IBM", "1814", "rdac", },
	56	{"IBM", "1815", "rdac", },
	57	{"IBM", "1818", "rdac", },
	58	{"IBM", "3526", "rdac", },
4b3aec2b XVP	59	{"IBM", "3542", "rdac", },
4b3aec2b XVP	60	{"IBM", "3552", "rdac", },
37b37d26 XVP	61	{"SGI", "TP9300", "rdac", },
	62	{"SGI", "TP9400", "rdac", },
	63	{"SGI", "TP9500", "rdac", },
	64	{"SGI", "TP9700", "rdac", },
d95dbff2	65	{"SGI", "IS", "rdac", },
4b3aec2b	66	{"STK", "OPENstorage", "rdac", },
d95dbff2	67	{"STK", "FLEXLINE 380", "rdac", },
4b3aec2b	68	{"STK", "BladeCtlr", "rdac", },
d95dbff2 CH	69	{"SUN", "CSM", "rdac", },
	70	{"SUN", "LCSM100", "rdac", },
	71	{"SUN", "STK6580_6780", "rdac", },
	72	{"SUN", "SUN_6180", "rdac", },
	73	{"SUN", "ArrayStorage", "rdac", },
	74	{"DELL", "MD3", "rdac", },
	75	{"NETAPP", "INF-01-00", "rdac", },
	76	{"LSI", "INF-01-00", "rdac", },
	77	{"ENGENIO", "INF-01-00", "rdac", },
	78	{NULL, NULL, NULL },
	79	};
	80
	81	static const char *
	82	scsi_dh_find_driver(struct scsi_device *sdev)
	83	{
	84	const struct scsi_dh_blist *b;
	85
	86	if (scsi_device_tpgs(sdev))
	87	return "alua";
	88
	89	for (b = scsi_dh_blist; b->vendor; b++) {
	90	if (!strncmp(sdev->vendor, b->vendor, strlen(b->vendor)) &&
	91	!strncmp(sdev->model, b->model, strlen(b->model))) {
	92	return b->driver;
	93	}
	94	}
	95	return NULL;
	96	}
	97
	98
566079c8	99	static struct scsi_device_handler __scsi_dh_lookup(const char name)
a6a8d9f8 CS	100	{
	101	struct scsi_device_handler tmp, found = NULL;
	102
	103	spin_lock(&list_lock);
	104	list_for_each_entry(tmp, &scsi_dh_list, list) {
765cbc6d	105	if (!strncmp(tmp->name, name, strlen(tmp->name))) {
a6a8d9f8 CS	106	found = tmp;
	107	break;
	108	}
	109	}
	110	spin_unlock(&list_lock);
	111	return found;
	112	}
	113
566079c8 CH	114	static struct scsi_device_handler scsi_dh_lookup(const char name)
	115	{
	116	struct scsi_device_handler *dh;
	117
2ee5671e JT	118	if (!name \|\| strlen(name) == 0)
	119	return NULL;
	120
566079c8 CH	121	dh = __scsi_dh_lookup(name);
566079c8 CH	122	if (!dh) {
1378889c	123	request_module("scsi_dh_%s", name);
566079c8 CH	124	dh = __scsi_dh_lookup(name);
	125	}
	126
	127	return dh;
	128	}
	129
a6a8d9f8	130	/*
765cbc6d HR	131	* scsi_dh_handler_attach - Attach a device handler to a device
	132	* @sdev - SCSI device the device handler should attach to
	133	* @scsi_dh - The device handler to attach
	134	*/
	135	static int scsi_dh_handler_attach(struct scsi_device *sdev,
	136	struct scsi_device_handler *scsi_dh)
	137	{
2a8f7a03	138	int error, ret = 0;
765cbc6d	139
1f12ffa5 CH	140	if (!try_module_get(scsi_dh->module))
1f12ffa5 CH	141	return -EINVAL;
27c888f0	142
ee14c674	143	error = scsi_dh->attach(sdev);
2a8f7a03 HR	144	if (error != SCSI_DH_OK) {
	145	switch (error) {
	146	case SCSI_DH_NOMEM:
	147	ret = -ENOMEM;
	148	break;
	149	case SCSI_DH_RES_TEMP_UNAVAIL:
	150	ret = -EAGAIN;
	151	break;
2930f817 HR	152	case SCSI_DH_DEV_UNSUPP:
	153	case SCSI_DH_NOSYS:
	154	ret = -ENODEV;
	155	break;
2a8f7a03 HR	156	default:
	157	ret = -EINVAL;
	158	break;
	159	}
2930f817 HR	160	if (ret != -ENODEV)
	161	sdev_printk(KERN_ERR, sdev, "%s: Attach failed (%d)\n",
	162	scsi_dh->name, error);
1f12ffa5	163	module_put(scsi_dh->module);
ee14c674 CH	164	} else
ee14c674 CH	165	sdev->handler = scsi_dh;
1d520328	166
2a8f7a03	167	return ret;
765cbc6d HR	168	}
765cbc6d HR	169
1bab0de0 CH	170	/*
	171	* scsi_dh_handler_detach - Detach a device handler from a device
	172	* @sdev - SCSI device the device handler should be detached from
	173	*/
	174	static void scsi_dh_handler_detach(struct scsi_device *sdev)
6c10db72	175	{
ee14c674 CH	176	sdev->handler->detach(sdev);
	177	sdev_printk(KERN_NOTICE, sdev, "%s: Detached\n", sdev->handler->name);
	178	module_put(sdev->handler->module);
6c10db72 CS	179	}
6c10db72 CS	180
2930f817	181	void scsi_dh_add_device(struct scsi_device *sdev)
4c05ae52	182	{
d95dbff2 CH	183	struct scsi_device_handler *devinfo = NULL;
d95dbff2 CH	184	const char *drv;
4c05ae52	185
d95dbff2 CH	186	drv = scsi_dh_find_driver(sdev);
d95dbff2 CH	187	if (drv)
d6a32b98	188	devinfo = __scsi_dh_lookup(drv);
2930f817 HR	189	/*
	190	* device_handler is optional, so ignore errors
	191	* from scsi_dh_handler_attach()
	192	*/
086b91d0	193	if (devinfo)
2930f817	194	(void)scsi_dh_handler_attach(sdev, devinfo);
a6a8d9f8	195	}
a6a8d9f8	196
23695e41	197	void scsi_dh_release_device(struct scsi_device *sdev)
765cbc6d	198	{
ee14c674	199	if (sdev->handler)
1bab0de0	200	scsi_dh_handler_detach(sdev);
23695e41 JN	201	}
23695e41 JN	202
765cbc6d HR	203	/*
	204	* scsi_register_device_handler - register a device handler personality
	205	* module.
	206	* @scsi_dh - device handler to be registered.
	207	*
	208	* Returns 0 on success, -EBUSY if handler already registered.
	209	*/
	210	int scsi_register_device_handler(struct scsi_device_handler *scsi_dh)
	211	{
566079c8	212	if (__scsi_dh_lookup(scsi_dh->name))
765cbc6d HR	213	return -EBUSY;
765cbc6d HR	214
1f12ffa5 CH	215	if (!scsi_dh->attach \|\| !scsi_dh->detach)
	216	return -EINVAL;
	217
765cbc6d HR	218	spin_lock(&list_lock);
	219	list_add(&scsi_dh->list, &scsi_dh_list);
	220	spin_unlock(&list_lock);
940d7faa	221
765cbc6d HR	222	printk(KERN_INFO "%s: device handler registered\n", scsi_dh->name);
	223
	224	return SCSI_DH_OK;
	225	}
	226	EXPORT_SYMBOL_GPL(scsi_register_device_handler);
	227
a6a8d9f8 CS	228	/*
	229	* scsi_unregister_device_handler - register a device handler personality
	230	* module.
	231	* @scsi_dh - device handler to be unregistered.
	232	*
	233	* Returns 0 on success, -ENODEV if handler not registered.
	234	*/
	235	int scsi_unregister_device_handler(struct scsi_device_handler *scsi_dh)
	236	{
566079c8	237	if (!__scsi_dh_lookup(scsi_dh->name))
765cbc6d	238	return -ENODEV;
a6a8d9f8	239
a6a8d9f8 CS	240	spin_lock(&list_lock);
	241	list_del(&scsi_dh->list);
	242	spin_unlock(&list_lock);
765cbc6d	243	printk(KERN_INFO "%s: device handler unregistered\n", scsi_dh->name);
a6a8d9f8	244
765cbc6d	245	return SCSI_DH_OK;
a6a8d9f8 CS	246	}
	247	EXPORT_SYMBOL_GPL(scsi_unregister_device_handler);
	248
	249	/*
	250	* scsi_dh_activate - activate the path associated with the scsi_device
	251	* corresponding to the given request queue.
3ae31f6a CS	252	* Returns immediately without waiting for activation to be completed.
	253	* @q - Request queue that is associated with the scsi_device to be
	254	* activated.
	255	* @fn - Function to be called upon completion of the activation.
	256	* Function fn is called with data (below) and the error code.
	257	* Function fn may be called from the same calling context. So,
	258	* do not hold the lock in the caller which may be needed in fn.
	259	* @data - data passed to the function fn upon completion.
	260	*
a6a8d9f8	261	*/
3ae31f6a	262	int scsi_dh_activate(struct request_queue q, activate_complete fn, void data)
a6a8d9f8	263	{
a6a8d9f8	264	struct scsi_device *sdev;
e959ed9a	265	int err = SCSI_DH_NOSYS;
a6a8d9f8	266
857de6e0	267	sdev = scsi_device_from_queue(q);
a18a920c	268	if (!sdev) {
a18a920c MB	269	if (fn)
	270	fn(data, err);
	271	return err;
	272	}
	273
e959ed9a CH	274	if (!sdev->handler)
e959ed9a CH	275	goto out_fn;
710105fd	276	err = SCSI_DH_NOTCONN;
e959ed9a	277	if (sdev->sdev_state == SDEV_CANCEL \|\|
db422318	278	sdev->sdev_state == SDEV_DEL)
e959ed9a	279	goto out_fn;
a6a8d9f8	280
e959ed9a CH	281	err = SCSI_DH_DEV_OFFLINED;
	282	if (sdev->sdev_state == SDEV_OFFLINE)
	283	goto out_fn;
a6a8d9f8	284
ee14c674 CH	285	if (sdev->handler->activate)
ee14c674 CH	286	err = sdev->handler->activate(sdev, fn, data);
e959ed9a CH	287
	288	out_put_device:
	289	put_device(&sdev->sdev_gendev);
a6a8d9f8	290	return err;
e959ed9a CH	291
	292	out_fn:
	293	if (fn)
	294	fn(data, err);
	295	goto out_put_device;
a6a8d9f8 CS	296	}
	297	EXPORT_SYMBOL_GPL(scsi_dh_activate);
	298
18ee70c9 CS	299	/*
	300	* scsi_dh_set_params - set the parameters for the device as per the
	301	* string specified in params.
	302	* @q - Request queue that is associated with the scsi_device for
	303	* which the parameters to be set.
	304	* @params - parameters in the following format
	305	* "no_of_params\0param1\0param2\0param3\0...\0"
	306	* for example, string for 2 parameters with value 10 and 21
	307	* is specified as "2\010\021\0".
	308	*/
	309	int scsi_dh_set_params(struct request_queue q, const char params)
	310	{
18ee70c9	311	struct scsi_device *sdev;
e959ed9a	312	int err = -SCSI_DH_NOSYS;
18ee70c9	313
857de6e0	314	sdev = scsi_device_from_queue(q);
e959ed9a	315	if (!sdev)
18ee70c9	316	return err;
e959ed9a CH	317
	318	if (sdev->handler && sdev->handler->set_params)
	319	err = sdev->handler->set_params(sdev, params);
18ee70c9 CS	320	put_device(&sdev->sdev_gendev);
	321	return err;
	322	}
	323	EXPORT_SYMBOL_GPL(scsi_dh_set_params);
	324
ae11b1b3	325	/*
2a9ab40f	326	* scsi_dh_attach - Attach device handler
7e8a74b1 MS	327	* @q - Request queue that is associated with the scsi_device
7e8a74b1 MS	328	* the handler should be attached to
ae11b1b3 HR	329	* @name - name of the handler to attach
	330	*/
	331	int scsi_dh_attach(struct request_queue q, const char name)
	332	{
ae11b1b3 HR	333	struct scsi_device *sdev;
	334	struct scsi_device_handler *scsi_dh;
	335	int err = 0;
	336
857de6e0	337	sdev = scsi_device_from_queue(q);
e959ed9a CH	338	if (!sdev)
e959ed9a CH	339	return -ENODEV;
ae11b1b3	340
e959ed9a CH	341	scsi_dh = scsi_dh_lookup(name);
	342	if (!scsi_dh) {
	343	err = -EINVAL;
	344	goto out_put_device;
	345	}
ae11b1b3	346
ee14c674 CH	347	if (sdev->handler) {
ee14c674 CH	348	if (sdev->handler != scsi_dh)
1bab0de0 CH	349	err = -EBUSY;
1bab0de0 CH	350	goto out_put_device;
ae11b1b3	351	}
1bab0de0 CH	352
	353	err = scsi_dh_handler_attach(sdev, scsi_dh);
	354
	355	out_put_device:
ae11b1b3	356	put_device(&sdev->sdev_gendev);
1bab0de0	357	return err;
ae11b1b3	358	}
1bab0de0	359	EXPORT_SYMBOL_GPL(scsi_dh_attach);
ae11b1b3	360
7e8a74b1 MS	361	/*
	362	* scsi_dh_attached_handler_name - Get attached device handler's name
	363	* @q - Request queue that is associated with the scsi_device
	364	* that may have a device handler attached
	365	* @gfp - the GFP mask used in the kmalloc() call when allocating memory
	366	*
	367	* Returns name of attached handler, NULL if no handler is attached.
	368	* Caller must take care to free the returned string.
	369	*/
	370	const char scsi_dh_attached_handler_name(struct request_queue q, gfp_t gfp)
	371	{
7e8a74b1 MS	372	struct scsi_device *sdev;
	373	const char *handler_name = NULL;
	374
857de6e0	375	sdev = scsi_device_from_queue(q);
7e8a74b1 MS	376	if (!sdev)
	377	return NULL;
	378
ee14c674 CH	379	if (sdev->handler)
ee14c674 CH	380	handler_name = kstrdup(sdev->handler->name, gfp);
7e8a74b1 MS	381	put_device(&sdev->sdev_gendev);
	382	return handler_name;
	383	}
	384	EXPORT_SYMBOL_GPL(scsi_dh_attached_handler_name);