1 /*
2  * Target driver for EMC CLARiiON AX/CX-series hardware.
3  * Based on code from Lars Marowsky-Bree <lmb@suse.de>
4  * and Ed Goggin <egoggin@emc.com>.
5  *
6  * Copyright (C) 2006 Red Hat, Inc.  All rights reserved.
7  * Copyright (C) 2006 Mike Christie
8  *
9  * This program is free software; you can redistribute it and/or modify
10  * it under the terms of the GNU General Public License as published by
11  * the Free Software Foundation; either version 2, or (at your option)
12  * any later version.
13  *
14  * This program is distributed in the hope that it will be useful,
15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17  * GNU General Public License for more details.
18  *
19  * You should have received a copy of the GNU General Public License
20  * along with this program; see the file COPYING.  If not, write to
21  * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
22  */
23 #include <scsi/scsi.h>
24 #include <scsi/scsi_eh.h>
25 #include <scsi/scsi_dh.h>
26 #include <scsi/scsi_device.h>
27 
28 #define CLARIION_NAME			"emc"
29 
30 #define CLARIION_TRESPASS_PAGE		0x22
31 #define CLARIION_BUFFER_SIZE		0xFC
32 #define CLARIION_TIMEOUT		(60 * HZ)
33 #define CLARIION_RETRIES		3
34 #define CLARIION_UNBOUND_LU		-1
35 #define CLARIION_SP_A			0
36 #define CLARIION_SP_B			1
37 
38 /* Flags */
39 #define CLARIION_SHORT_TRESPASS		1
40 #define CLARIION_HONOR_RESERVATIONS	2
41 
42 /* LUN states */
43 #define CLARIION_LUN_UNINITIALIZED	-1
44 #define CLARIION_LUN_UNBOUND		0
45 #define CLARIION_LUN_BOUND		1
46 #define CLARIION_LUN_OWNED		2
47 
48 static unsigned char long_trespass[] = {
49 	0, 0, 0, 0, 0, 0, 0, 0,
50 	CLARIION_TRESPASS_PAGE,	/* Page code */
51 	0x09,			/* Page length - 2 */
52 	0x01,			/* Trespass code */
53 	0xff, 0xff,		/* Trespass target */
54 	0, 0, 0, 0, 0, 0	/* Reserved bytes / unknown */
55 };
56 
57 static unsigned char short_trespass[] = {
58 	0, 0, 0, 0,
59 	CLARIION_TRESPASS_PAGE,	/* Page code */
60 	0x02,			/* Page length - 2 */
61 	0x01,			/* Trespass code */
62 	0xff,			/* Trespass target */
63 };
64 
65 static const char * lun_state[] =
66 {
67     "not bound",
68     "bound",
69     "owned",
70 };
71 
72 struct clariion_dh_data {
73 	/*
74 	 * Flags:
75 	 *  CLARIION_SHORT_TRESPASS
76 	 * Use short trespass command (FC-series) or the long version
77 	 * (default for AX/CX CLARiiON arrays).
78 	 *
79 	 *  CLARIION_HONOR_RESERVATIONS
80 	 * Whether or not (default) to honor SCSI reservations when
81 	 * initiating a switch-over.
82 	 */
83 	unsigned flags;
84 	/*
85 	 * I/O buffer for both MODE_SELECT and INQUIRY commands.
86 	 */
87 	unsigned char buffer[CLARIION_BUFFER_SIZE];
88 	/*
89 	 * SCSI sense buffer for commands -- assumes serial issuance
90 	 * and completion sequence of all commands for same multipath.
91 	 */
92 	unsigned char sense[SCSI_SENSE_BUFFERSIZE];
93 	unsigned int senselen;
94 	/*
95 	 * LUN state
96 	 */
97 	int lun_state;
98 	/*
99 	 * SP Port number
100 	 */
101 	int port;
102 	/*
103 	 * which SP (A=0,B=1,UNBOUND=-1) is the default SP for this
104 	 * path's mapped LUN
105 	 */
106 	int default_sp;
107 	/*
108 	 * which SP (A=0,B=1,UNBOUND=-1) is the active SP for this
109 	 * path's mapped LUN
110 	 */
111 	int current_sp;
112 };
113 
114 static inline struct clariion_dh_data
115 			*get_clariion_data(struct scsi_device *sdev)
116 {
117 	struct scsi_dh_data *scsi_dh_data = sdev->scsi_dh_data;
118 	BUG_ON(scsi_dh_data == NULL);
119 	return ((struct clariion_dh_data *) scsi_dh_data->buf);
120 }
121 
122 /*
123  * Parse MODE_SELECT cmd reply.
124  */
125 static int trespass_endio(struct scsi_device *sdev, char *sense)
126 {
127 	int err = SCSI_DH_IO;
128 	struct scsi_sense_hdr sshdr;
129 
130 	if (!scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE, &sshdr)) {
131 		sdev_printk(KERN_ERR, sdev, "%s: Found valid sense data 0x%2x, "
132 			    "0x%2x, 0x%2x while sending CLARiiON trespass "
133 			    "command.\n", CLARIION_NAME, sshdr.sense_key,
134 			    sshdr.asc, sshdr.ascq);
135 
136 		if ((sshdr.sense_key == 0x05) && (sshdr.asc == 0x04) &&
137 		     (sshdr.ascq == 0x00)) {
138 			/*
139 			 * Array based copy in progress -- do not send
140 			 * mode_select or copy will be aborted mid-stream.
141 			 */
142 			sdev_printk(KERN_INFO, sdev, "%s: Array Based Copy in "
143 				    "progress while sending CLARiiON trespass "
144 				    "command.\n", CLARIION_NAME);
145 			err = SCSI_DH_DEV_TEMP_BUSY;
146 		} else if ((sshdr.sense_key == 0x02) && (sshdr.asc == 0x04) &&
147 			    (sshdr.ascq == 0x03)) {
148 			/*
149 			 * LUN Not Ready - Manual Intervention Required
150 			 * indicates in-progress ucode upgrade (NDU).
151 			 */
152 			sdev_printk(KERN_INFO, sdev, "%s: Detected in-progress "
153 				    "ucode upgrade NDU operation while sending "
154 				    "CLARiiON trespass command.\n", CLARIION_NAME);
155 			err = SCSI_DH_DEV_TEMP_BUSY;
156 		} else
157 			err = SCSI_DH_DEV_FAILED;
158 	} else {
159 		sdev_printk(KERN_INFO, sdev,
160 			    "%s: failed to send MODE SELECT, no sense available\n",
161 			    CLARIION_NAME);
162 	}
163 	return err;
164 }
165 
166 static int parse_sp_info_reply(struct scsi_device *sdev,
167 			       struct clariion_dh_data *csdev)
168 {
169 	int err = SCSI_DH_OK;
170 
171 	/* check for in-progress ucode upgrade (NDU) */
172 	if (csdev->buffer[48] != 0) {
173 		sdev_printk(KERN_NOTICE, sdev, "%s: Detected in-progress "
174 			    "ucode upgrade NDU operation while finding "
175 			    "current active SP.", CLARIION_NAME);
176 		err = SCSI_DH_DEV_TEMP_BUSY;
177 		goto out;
178 	}
179 	if (csdev->buffer[4] > 2) {
180 		/* Invalid buffer format */
181 		sdev_printk(KERN_NOTICE, sdev,
182 			    "%s: invalid VPD page 0xC0 format\n",
183 			    CLARIION_NAME);
184 		err = SCSI_DH_NOSYS;
185 		goto out;
186 	}
187 	switch (csdev->buffer[28] & 0x0f) {
188 	case 6:
189 		sdev_printk(KERN_NOTICE, sdev,
190 			    "%s: ALUA failover mode detected\n",
191 			    CLARIION_NAME);
192 		break;
193 	case 4:
194 		/* Linux failover */
195 		break;
196 	default:
197 		sdev_printk(KERN_WARNING, sdev,
198 			    "%s: Invalid failover mode %d\n",
199 			    CLARIION_NAME, csdev->buffer[28] & 0x0f);
200 		err = SCSI_DH_NOSYS;
201 		goto out;
202 	}
203 
204 	csdev->default_sp = csdev->buffer[5];
205 	csdev->lun_state = csdev->buffer[4];
206 	csdev->current_sp = csdev->buffer[8];
207 	csdev->port = csdev->buffer[7];
208 
209 out:
210 	return err;
211 }
212 
213 #define emc_default_str "FC (Legacy)"
214 
215 static char * parse_sp_model(struct scsi_device *sdev, unsigned char *buffer)
216 {
217 	unsigned char len = buffer[4] + 5;
218 	char *sp_model = NULL;
219 	unsigned char sp_len, serial_len;
220 
221 	if (len < 160) {
222 		sdev_printk(KERN_WARNING, sdev,
223 			    "%s: Invalid information section length %d\n",
224 			    CLARIION_NAME, len);
225 		/* Check for old FC arrays */
226 		if (!strncmp(buffer + 8, "DGC", 3)) {
227 			/* Old FC array, not supporting extended information */
228 			sp_model = emc_default_str;
229 		}
230 		goto out;
231 	}
232 
233 	/*
234 	 * Parse extended information for SP model number
235 	 */
236 	serial_len = buffer[160];
237 	if (serial_len == 0 || serial_len + 161 > len) {
238 		sdev_printk(KERN_WARNING, sdev,
239 			    "%s: Invalid array serial number length %d\n",
240 			    CLARIION_NAME, serial_len);
241 		goto out;
242 	}
243 	sp_len = buffer[99];
244 	if (sp_len == 0 || serial_len + sp_len + 161 > len) {
245 		sdev_printk(KERN_WARNING, sdev,
246 			    "%s: Invalid model number length %d\n",
247 			    CLARIION_NAME, sp_len);
248 		goto out;
249 	}
250 	sp_model = &buffer[serial_len + 161];
251 	/* Strip whitespace at the end */
252 	while (sp_len > 1 && sp_model[sp_len - 1] == ' ')
253 		sp_len--;
254 
255 	sp_model[sp_len] = '\0';
256 
257 out:
258 	return sp_model;
259 }
260 
261 /*
262  * Get block request for REQ_BLOCK_PC command issued to path.  Currently
263  * limited to MODE_SELECT (trespass) and INQUIRY (VPD page 0xC0) commands.
264  *
265  * Uses data and sense buffers in hardware handler context structure and
266  * assumes serial servicing of commands, both issuance and completion.
267  */
268 static struct request *get_req(struct scsi_device *sdev, int cmd,
269 				unsigned char *buffer)
270 {
271 	struct request *rq;
272 	int len = 0;
273 
274 	rq = blk_get_request(sdev->request_queue,
275 			(cmd == MODE_SELECT) ? WRITE : READ, GFP_NOIO);
276 	if (!rq) {
277 		sdev_printk(KERN_INFO, sdev, "get_req: blk_get_request failed");
278 		return NULL;
279 	}
280 
281 	rq->cmd_len = COMMAND_SIZE(cmd);
282 	rq->cmd[0] = cmd;
283 
284 	switch (cmd) {
285 	case MODE_SELECT:
286 		len = sizeof(short_trespass);
287 		rq->cmd_flags |= REQ_RW;
288 		rq->cmd[1] = 0x10;
289 		break;
290 	case MODE_SELECT_10:
291 		len = sizeof(long_trespass);
292 		rq->cmd_flags |= REQ_RW;
293 		rq->cmd[1] = 0x10;
294 		break;
295 	case INQUIRY:
296 		len = CLARIION_BUFFER_SIZE;
297 		memset(buffer, 0, len);
298 		break;
299 	default:
300 		BUG_ON(1);
301 		break;
302 	}
303 
304 	rq->cmd[4] = len;
305 	rq->cmd_type = REQ_TYPE_BLOCK_PC;
306 	rq->cmd_flags |= REQ_FAILFAST;
307 	rq->timeout = CLARIION_TIMEOUT;
308 	rq->retries = CLARIION_RETRIES;
309 
310 	if (blk_rq_map_kern(rq->q, rq, buffer, len, GFP_NOIO)) {
311 		blk_put_request(rq);
312 		return NULL;
313 	}
314 
315 	return rq;
316 }
317 
318 static int send_inquiry_cmd(struct scsi_device *sdev, int page,
319 			    struct clariion_dh_data *csdev)
320 {
321 	struct request *rq = get_req(sdev, INQUIRY, csdev->buffer);
322 	int err;
323 
324 	if (!rq)
325 		return SCSI_DH_RES_TEMP_UNAVAIL;
326 
327 	rq->sense = csdev->sense;
328 	memset(rq->sense, 0, SCSI_SENSE_BUFFERSIZE);
329 	rq->sense_len = csdev->senselen = 0;
330 
331 	rq->cmd[0] = INQUIRY;
332 	if (page != 0) {
333 		rq->cmd[1] = 1;
334 		rq->cmd[2] = page;
335 	}
336 	err = blk_execute_rq(sdev->request_queue, NULL, rq, 1);
337 	if (err == -EIO) {
338 		sdev_printk(KERN_INFO, sdev,
339 			    "%s: failed to send %s INQUIRY: %x\n",
340 			    CLARIION_NAME, page?"EVPD":"standard",
341 			    rq->errors);
342 		csdev->senselen = rq->sense_len;
343 		err = SCSI_DH_IO;
344 	}
345 
346 	blk_put_request(rq);
347 
348 	return err;
349 }
350 
351 static int send_trespass_cmd(struct scsi_device *sdev,
352 			    struct clariion_dh_data *csdev)
353 {
354 	struct request *rq;
355 	unsigned char *page22;
356 	int err, len, cmd;
357 
358 	if (csdev->flags & CLARIION_SHORT_TRESPASS) {
359 		page22 = short_trespass;
360 		if (!(csdev->flags & CLARIION_HONOR_RESERVATIONS))
361 			/* Set Honor Reservations bit */
362 			page22[6] |= 0x80;
363 		len = sizeof(short_trespass);
364 		cmd = MODE_SELECT;
365 	} else {
366 		page22 = long_trespass;
367 		if (!(csdev->flags & CLARIION_HONOR_RESERVATIONS))
368 			/* Set Honor Reservations bit */
369 			page22[10] |= 0x80;
370 		len = sizeof(long_trespass);
371 		cmd = MODE_SELECT_10;
372 	}
373 	BUG_ON((len > CLARIION_BUFFER_SIZE));
374 	memcpy(csdev->buffer, page22, len);
375 
376 	rq = get_req(sdev, cmd, csdev->buffer);
377 	if (!rq)
378 		return SCSI_DH_RES_TEMP_UNAVAIL;
379 
380 	rq->sense = csdev->sense;
381 	memset(rq->sense, 0, SCSI_SENSE_BUFFERSIZE);
382 	rq->sense_len = csdev->senselen = 0;
383 
384 	err = blk_execute_rq(sdev->request_queue, NULL, rq, 1);
385 	if (err == -EIO) {
386 		if (rq->sense_len) {
387 			err = trespass_endio(sdev, csdev->sense);
388 		} else {
389 			sdev_printk(KERN_INFO, sdev,
390 				    "%s: failed to send MODE SELECT: %x\n",
391 				    CLARIION_NAME, rq->errors);
392 		}
393 	}
394 
395 	blk_put_request(rq);
396 
397 	return err;
398 }
399 
400 static int clariion_check_sense(struct scsi_device *sdev,
401 				struct scsi_sense_hdr *sense_hdr)
402 {
403 	switch (sense_hdr->sense_key) {
404 	case NOT_READY:
405 		if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x03)
406 			/*
407 			 * LUN Not Ready - Manual Intervention Required
408 			 * indicates this is a passive path.
409 			 *
410 			 * FIXME: However, if this is seen and EVPD C0
411 			 * indicates that this is due to a NDU in
412 			 * progress, we should set FAIL_PATH too.
413 			 * This indicates we might have to do a SCSI
414 			 * inquiry in the end_io path. Ugh.
415 			 *
416 			 * Can return FAILED only when we want the error
417 			 * recovery process to kick in.
418 			 */
419 			return SUCCESS;
420 		break;
421 	case ILLEGAL_REQUEST:
422 		if (sense_hdr->asc == 0x25 && sense_hdr->ascq == 0x01)
423 			/*
424 			 * An array based copy is in progress. Do not
425 			 * fail the path, do not bypass to another PG,
426 			 * do not retry. Fail the IO immediately.
427 			 * (Actually this is the same conclusion as in
428 			 * the default handler, but lets make sure.)
429 			 *
430 			 * Can return FAILED only when we want the error
431 			 * recovery process to kick in.
432 			 */
433 			return SUCCESS;
434 		break;
435 	case UNIT_ATTENTION:
436 		if (sense_hdr->asc == 0x29 && sense_hdr->ascq == 0x00)
437 			/*
438 			 * Unit Attention Code. This is the first IO
439 			 * to the new path, so just retry.
440 			 */
441 			return ADD_TO_MLQUEUE;
442 		break;
443 	}
444 
445 	return SCSI_RETURN_NOT_HANDLED;
446 }
447 
448 static int clariion_prep_fn(struct scsi_device *sdev, struct request *req)
449 {
450 	struct clariion_dh_data *h = get_clariion_data(sdev);
451 	int ret = BLKPREP_OK;
452 
453 	if (h->lun_state != CLARIION_LUN_OWNED) {
454 		ret = BLKPREP_KILL;
455 		req->cmd_flags |= REQ_QUIET;
456 	}
457 	return ret;
458 
459 }
460 
461 static int clariion_std_inquiry(struct scsi_device *sdev,
462 				struct clariion_dh_data *csdev)
463 {
464 	int err;
465 	char *sp_model;
466 
467 	err = send_inquiry_cmd(sdev, 0, csdev);
468 	if (err != SCSI_DH_OK && csdev->senselen) {
469 		struct scsi_sense_hdr sshdr;
470 
471 		if (scsi_normalize_sense(csdev->sense, SCSI_SENSE_BUFFERSIZE,
472 					 &sshdr)) {
473 			sdev_printk(KERN_ERR, sdev, "%s: INQUIRY sense code "
474 				    "%02x/%02x/%02x\n", CLARIION_NAME,
475 				    sshdr.sense_key, sshdr.asc, sshdr.ascq);
476 		}
477 		err = SCSI_DH_IO;
478 		goto out;
479 	}
480 
481 	sp_model = parse_sp_model(sdev, csdev->buffer);
482 	if (!sp_model) {
483 		err = SCSI_DH_DEV_UNSUPP;
484 		goto out;
485 	}
486 
487 	/*
488 	 * FC Series arrays do not support long trespass
489 	 */
490 	if (!strlen(sp_model) || !strncmp(sp_model, "FC",2))
491 		csdev->flags |= CLARIION_SHORT_TRESPASS;
492 
493 	sdev_printk(KERN_INFO, sdev,
494 		    "%s: detected Clariion %s, flags %x\n",
495 		    CLARIION_NAME, sp_model, csdev->flags);
496 out:
497 	return err;
498 }
499 
500 static int clariion_send_inquiry(struct scsi_device *sdev,
501 				 struct clariion_dh_data *csdev)
502 {
503 	int err, retry = CLARIION_RETRIES;
504 
505 retry:
506 	err = send_inquiry_cmd(sdev, 0xC0, csdev);
507 	if (err != SCSI_DH_OK && csdev->senselen) {
508 		struct scsi_sense_hdr sshdr;
509 
510 		err = scsi_normalize_sense(csdev->sense, SCSI_SENSE_BUFFERSIZE,
511 					   &sshdr);
512 		if (!err)
513 			return SCSI_DH_IO;
514 
515 		err = clariion_check_sense(sdev, &sshdr);
516 		if (retry > 0 && err == ADD_TO_MLQUEUE) {
517 			retry--;
518 			goto retry;
519 		}
520 		sdev_printk(KERN_ERR, sdev, "%s: INQUIRY sense code "
521 			    "%02x/%02x/%02x\n", CLARIION_NAME,
522 			      sshdr.sense_key, sshdr.asc, sshdr.ascq);
523 		err = SCSI_DH_IO;
524 	} else {
525 		err = parse_sp_info_reply(sdev, csdev);
526 	}
527 	return err;
528 }
529 
530 static int clariion_activate(struct scsi_device *sdev)
531 {
532 	struct clariion_dh_data *csdev = get_clariion_data(sdev);
533 	int result;
534 
535 	result = clariion_send_inquiry(sdev, csdev);
536 	if (result != SCSI_DH_OK)
537 		goto done;
538 
539 	if (csdev->lun_state == CLARIION_LUN_OWNED)
540 		goto done;
541 
542 	result = send_trespass_cmd(sdev, csdev);
543 	if (result != SCSI_DH_OK)
544 		goto done;
545 	sdev_printk(KERN_INFO, sdev,"%s: %s trespass command sent\n",
546 		    CLARIION_NAME,
547 		    csdev->flags&CLARIION_SHORT_TRESPASS?"short":"long" );
548 
549 	/* Update status */
550 	result = clariion_send_inquiry(sdev, csdev);
551 	if (result != SCSI_DH_OK)
552 		goto done;
553 
554 done:
555 	sdev_printk(KERN_INFO, sdev,
556 		    "%s: at SP %c Port %d (%s, default SP %c)\n",
557 		    CLARIION_NAME, csdev->current_sp + 'A',
558 		    csdev->port, lun_state[csdev->lun_state],
559 		    csdev->default_sp + 'A');
560 
561 	return result;
562 }
563 
564 static const struct scsi_dh_devlist clariion_dev_list[] = {
565 	{"DGC", "RAID"},
566 	{"DGC", "DISK"},
567 	{"DGC", "VRAID"},
568 	{NULL, NULL},
569 };
570 
571 static int clariion_bus_attach(struct scsi_device *sdev);
572 static void clariion_bus_detach(struct scsi_device *sdev);
573 
574 static struct scsi_device_handler clariion_dh = {
575 	.name		= CLARIION_NAME,
576 	.module		= THIS_MODULE,
577 	.devlist	= clariion_dev_list,
578 	.attach		= clariion_bus_attach,
579 	.detach		= clariion_bus_detach,
580 	.check_sense	= clariion_check_sense,
581 	.activate	= clariion_activate,
582 	.prep_fn	= clariion_prep_fn,
583 };
584 
585 /*
586  * TODO: need some interface so we can set trespass values
587  */
588 static int clariion_bus_attach(struct scsi_device *sdev)
589 {
590 	struct scsi_dh_data *scsi_dh_data;
591 	struct clariion_dh_data *h;
592 	unsigned long flags;
593 	int err;
594 
595 	scsi_dh_data = kzalloc(sizeof(struct scsi_device_handler *)
596 			       + sizeof(*h) , GFP_KERNEL);
597 	if (!scsi_dh_data) {
598 		sdev_printk(KERN_ERR, sdev, "%s: Attach failed\n",
599 			    CLARIION_NAME);
600 		return -ENOMEM;
601 	}
602 
603 	scsi_dh_data->scsi_dh = &clariion_dh;
604 	h = (struct clariion_dh_data *) scsi_dh_data->buf;
605 	h->lun_state = CLARIION_LUN_UNINITIALIZED;
606 	h->default_sp = CLARIION_UNBOUND_LU;
607 	h->current_sp = CLARIION_UNBOUND_LU;
608 
609 	err = clariion_std_inquiry(sdev, h);
610 	if (err != SCSI_DH_OK)
611 		goto failed;
612 
613 	err = clariion_send_inquiry(sdev, h);
614 	if (err != SCSI_DH_OK)
615 		goto failed;
616 
617 	if (!try_module_get(THIS_MODULE))
618 		goto failed;
619 
620 	spin_lock_irqsave(sdev->request_queue->queue_lock, flags);
621 	sdev->scsi_dh_data = scsi_dh_data;
622 	spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags);
623 
624 	sdev_printk(KERN_INFO, sdev,
625 		    "%s: connected to SP %c Port %d (%s, default SP %c)\n",
626 		    CLARIION_NAME, h->current_sp + 'A',
627 		    h->port, lun_state[h->lun_state],
628 		    h->default_sp + 'A');
629 
630 	return 0;
631 
632 failed:
633 	kfree(scsi_dh_data);
634 	sdev_printk(KERN_ERR, sdev, "%s: not attached\n",
635 		    CLARIION_NAME);
636 	return -EINVAL;
637 }
638 
639 static void clariion_bus_detach(struct scsi_device *sdev)
640 {
641 	struct scsi_dh_data *scsi_dh_data;
642 	unsigned long flags;
643 
644 	spin_lock_irqsave(sdev->request_queue->queue_lock, flags);
645 	scsi_dh_data = sdev->scsi_dh_data;
646 	sdev->scsi_dh_data = NULL;
647 	spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags);
648 
649 	sdev_printk(KERN_NOTICE, sdev, "%s: Detached\n",
650 		    CLARIION_NAME);
651 
652 	kfree(scsi_dh_data);
653 	module_put(THIS_MODULE);
654 }
655 
656 static int __init clariion_init(void)
657 {
658 	int r;
659 
660 	r = scsi_register_device_handler(&clariion_dh);
661 	if (r != 0)
662 		printk(KERN_ERR "%s: Failed to register scsi device handler.",
663 			CLARIION_NAME);
664 	return r;
665 }
666 
667 static void __exit clariion_exit(void)
668 {
669 	scsi_unregister_device_handler(&clariion_dh);
670 }
671 
672 module_init(clariion_init);
673 module_exit(clariion_exit);
674 
675 MODULE_DESCRIPTION("EMC CX/AX/FC-family driver");
676 MODULE_AUTHOR("Mike Christie <michaelc@cs.wisc.edu>, Chandra Seetharaman <sekharan@us.ibm.com>");
677 MODULE_LICENSE("GPL");
678