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22#include <linux/slab.h>
23#include <linux/delay.h>
24#include <scsi/scsi.h>
25#include <scsi/scsi_eh.h>
26#include <scsi/scsi_dh.h>
27
28#define ALUA_DH_NAME "alua"
29#define ALUA_DH_VER "1.3"
30
31#define TPGS_STATE_OPTIMIZED 0x0
32#define TPGS_STATE_NONOPTIMIZED 0x1
33#define TPGS_STATE_STANDBY 0x2
34#define TPGS_STATE_UNAVAILABLE 0x3
35#define TPGS_STATE_LBA_DEPENDENT 0x4
36#define TPGS_STATE_OFFLINE 0xe
37#define TPGS_STATE_TRANSITIONING 0xf
38
39#define TPGS_SUPPORT_NONE 0x00
40#define TPGS_SUPPORT_OPTIMIZED 0x01
41#define TPGS_SUPPORT_NONOPTIMIZED 0x02
42#define TPGS_SUPPORT_STANDBY 0x04
43#define TPGS_SUPPORT_UNAVAILABLE 0x08
44#define TPGS_SUPPORT_LBA_DEPENDENT 0x10
45#define TPGS_SUPPORT_OFFLINE 0x40
46#define TPGS_SUPPORT_TRANSITION 0x80
47
48#define TPGS_MODE_UNINITIALIZED -1
49#define TPGS_MODE_NONE 0x0
50#define TPGS_MODE_IMPLICIT 0x1
51#define TPGS_MODE_EXPLICIT 0x2
52
53#define ALUA_INQUIRY_SIZE 36
54#define ALUA_FAILOVER_TIMEOUT (60 * HZ)
55#define ALUA_FAILOVER_RETRIES 5
56
57struct alua_dh_data {
58 int group_id;
59 int rel_port;
60 int tpgs;
61 int state;
62 unsigned char inq[ALUA_INQUIRY_SIZE];
63 unsigned char *buff;
64 int bufflen;
65 unsigned char sense[SCSI_SENSE_BUFFERSIZE];
66 int senselen;
67 struct scsi_device *sdev;
68 activate_complete callback_fn;
69 void *callback_data;
70};
71
72#define ALUA_POLICY_SWITCH_CURRENT 0
73#define ALUA_POLICY_SWITCH_ALL 1
74
75static char print_alua_state(int);
76static int alua_check_sense(struct scsi_device *, struct scsi_sense_hdr *);
77
78static inline struct alua_dh_data *get_alua_data(struct scsi_device *sdev)
79{
80 struct scsi_dh_data *scsi_dh_data = sdev->scsi_dh_data;
81 BUG_ON(scsi_dh_data == NULL);
82 return ((struct alua_dh_data *) scsi_dh_data->buf);
83}
84
85static int realloc_buffer(struct alua_dh_data *h, unsigned len)
86{
87 if (h->buff && h->buff != h->inq)
88 kfree(h->buff);
89
90 h->buff = kmalloc(len, GFP_NOIO);
91 if (!h->buff) {
92 h->buff = h->inq;
93 h->bufflen = ALUA_INQUIRY_SIZE;
94 return 1;
95 }
96 h->bufflen = len;
97 return 0;
98}
99
100static struct request *get_alua_req(struct scsi_device *sdev,
101 void *buffer, unsigned buflen, int rw)
102{
103 struct request *rq;
104 struct request_queue *q = sdev->request_queue;
105
106 rq = blk_get_request(q, rw, GFP_NOIO);
107
108 if (!rq) {
109 sdev_printk(KERN_INFO, sdev,
110 "%s: blk_get_request failed\n", __func__);
111 return NULL;
112 }
113
114 if (buflen && blk_rq_map_kern(q, rq, buffer, buflen, GFP_NOIO)) {
115 blk_put_request(rq);
116 sdev_printk(KERN_INFO, sdev,
117 "%s: blk_rq_map_kern failed\n", __func__);
118 return NULL;
119 }
120
121 rq->cmd_type = REQ_TYPE_BLOCK_PC;
122 rq->cmd_flags |= REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT |
123 REQ_FAILFAST_DRIVER;
124 rq->retries = ALUA_FAILOVER_RETRIES;
125 rq->timeout = ALUA_FAILOVER_TIMEOUT;
126
127 return rq;
128}
129
130
131
132
133
134static int submit_std_inquiry(struct scsi_device *sdev, struct alua_dh_data *h)
135{
136 struct request *rq;
137 int err = SCSI_DH_RES_TEMP_UNAVAIL;
138
139 rq = get_alua_req(sdev, h->inq, ALUA_INQUIRY_SIZE, READ);
140 if (!rq)
141 goto done;
142
143
144 rq->cmd[0] = INQUIRY;
145 rq->cmd[1] = 0;
146 rq->cmd[2] = 0;
147 rq->cmd[4] = ALUA_INQUIRY_SIZE;
148 rq->cmd_len = COMMAND_SIZE(INQUIRY);
149
150 rq->sense = h->sense;
151 memset(rq->sense, 0, SCSI_SENSE_BUFFERSIZE);
152 rq->sense_len = h->senselen = 0;
153
154 err = blk_execute_rq(rq->q, NULL, rq, 1);
155 if (err == -EIO) {
156 sdev_printk(KERN_INFO, sdev,
157 "%s: std inquiry failed with %x\n",
158 ALUA_DH_NAME, rq->errors);
159 h->senselen = rq->sense_len;
160 err = SCSI_DH_IO;
161 }
162 blk_put_request(rq);
163done:
164 return err;
165}
166
167
168
169
170
171static int submit_vpd_inquiry(struct scsi_device *sdev, struct alua_dh_data *h)
172{
173 struct request *rq;
174 int err = SCSI_DH_RES_TEMP_UNAVAIL;
175
176 rq = get_alua_req(sdev, h->buff, h->bufflen, READ);
177 if (!rq)
178 goto done;
179
180
181 rq->cmd[0] = INQUIRY;
182 rq->cmd[1] = 1;
183 rq->cmd[2] = 0x83;
184 rq->cmd[4] = h->bufflen;
185 rq->cmd_len = COMMAND_SIZE(INQUIRY);
186
187 rq->sense = h->sense;
188 memset(rq->sense, 0, SCSI_SENSE_BUFFERSIZE);
189 rq->sense_len = h->senselen = 0;
190
191 err = blk_execute_rq(rq->q, NULL, rq, 1);
192 if (err == -EIO) {
193 sdev_printk(KERN_INFO, sdev,
194 "%s: evpd inquiry failed with %x\n",
195 ALUA_DH_NAME, rq->errors);
196 h->senselen = rq->sense_len;
197 err = SCSI_DH_IO;
198 }
199 blk_put_request(rq);
200done:
201 return err;
202}
203
204
205
206
207
208static unsigned submit_rtpg(struct scsi_device *sdev, struct alua_dh_data *h)
209{
210 struct request *rq;
211 int err = SCSI_DH_RES_TEMP_UNAVAIL;
212
213 rq = get_alua_req(sdev, h->buff, h->bufflen, READ);
214 if (!rq)
215 goto done;
216
217
218 rq->cmd[0] = MAINTENANCE_IN;
219 rq->cmd[1] = MI_REPORT_TARGET_PGS;
220 rq->cmd[6] = (h->bufflen >> 24) & 0xff;
221 rq->cmd[7] = (h->bufflen >> 16) & 0xff;
222 rq->cmd[8] = (h->bufflen >> 8) & 0xff;
223 rq->cmd[9] = h->bufflen & 0xff;
224 rq->cmd_len = COMMAND_SIZE(MAINTENANCE_IN);
225
226 rq->sense = h->sense;
227 memset(rq->sense, 0, SCSI_SENSE_BUFFERSIZE);
228 rq->sense_len = h->senselen = 0;
229
230 err = blk_execute_rq(rq->q, NULL, rq, 1);
231 if (err == -EIO) {
232 sdev_printk(KERN_INFO, sdev,
233 "%s: rtpg failed with %x\n",
234 ALUA_DH_NAME, rq->errors);
235 h->senselen = rq->sense_len;
236 err = SCSI_DH_IO;
237 }
238 blk_put_request(rq);
239done:
240 return err;
241}
242
243
244
245
246
247
248
249
250
251
252static void stpg_endio(struct request *req, int error)
253{
254 struct alua_dh_data *h = req->end_io_data;
255 struct scsi_sense_hdr sense_hdr;
256 unsigned err = SCSI_DH_IO;
257
258 if (error || host_byte(req->errors) != DID_OK ||
259 msg_byte(req->errors) != COMMAND_COMPLETE)
260 goto done;
261
262 if (err == SCSI_DH_IO && h->senselen > 0) {
263 err = scsi_normalize_sense(h->sense, SCSI_SENSE_BUFFERSIZE,
264 &sense_hdr);
265 if (!err) {
266 err = SCSI_DH_IO;
267 goto done;
268 }
269 err = alua_check_sense(h->sdev, &sense_hdr);
270 if (err == ADD_TO_MLQUEUE) {
271 err = SCSI_DH_RETRY;
272 goto done;
273 }
274 sdev_printk(KERN_INFO, h->sdev,
275 "%s: stpg sense code: %02x/%02x/%02x\n",
276 ALUA_DH_NAME, sense_hdr.sense_key,
277 sense_hdr.asc, sense_hdr.ascq);
278 err = SCSI_DH_IO;
279 }
280 if (err == SCSI_DH_OK) {
281 h->state = TPGS_STATE_OPTIMIZED;
282 sdev_printk(KERN_INFO, h->sdev,
283 "%s: port group %02x switched to state %c\n",
284 ALUA_DH_NAME, h->group_id,
285 print_alua_state(h->state));
286 }
287done:
288 blk_put_request(req);
289 if (h->callback_fn) {
290 h->callback_fn(h->callback_data, err);
291 h->callback_fn = h->callback_data = NULL;
292 }
293 return;
294}
295
296
297
298
299
300
301
302
303static unsigned submit_stpg(struct alua_dh_data *h)
304{
305 struct request *rq;
306 int err = SCSI_DH_RES_TEMP_UNAVAIL;
307 int stpg_len = 8;
308 struct scsi_device *sdev = h->sdev;
309
310
311 memset(h->buff, 0, stpg_len);
312 h->buff[4] = TPGS_STATE_OPTIMIZED & 0x0f;
313 h->buff[6] = (h->group_id >> 8) & 0xff;
314 h->buff[7] = h->group_id & 0xff;
315
316 rq = get_alua_req(sdev, h->buff, stpg_len, WRITE);
317 if (!rq)
318 return SCSI_DH_RES_TEMP_UNAVAIL;
319
320
321 rq->cmd[0] = MAINTENANCE_OUT;
322 rq->cmd[1] = MO_SET_TARGET_PGS;
323 rq->cmd[6] = (stpg_len >> 24) & 0xff;
324 rq->cmd[7] = (stpg_len >> 16) & 0xff;
325 rq->cmd[8] = (stpg_len >> 8) & 0xff;
326 rq->cmd[9] = stpg_len & 0xff;
327 rq->cmd_len = COMMAND_SIZE(MAINTENANCE_OUT);
328
329 rq->sense = h->sense;
330 memset(rq->sense, 0, SCSI_SENSE_BUFFERSIZE);
331 rq->sense_len = h->senselen = 0;
332 rq->end_io_data = h;
333
334 blk_execute_rq_nowait(rq->q, NULL, rq, 1, stpg_endio);
335 return err;
336}
337
338
339
340
341
342
343
344
345static int alua_std_inquiry(struct scsi_device *sdev, struct alua_dh_data *h)
346{
347 int err;
348
349 err = submit_std_inquiry(sdev, h);
350
351 if (err != SCSI_DH_OK)
352 return err;
353
354
355 h->tpgs = (h->inq[5] >> 4) & 0x3;
356 switch (h->tpgs) {
357 case TPGS_MODE_EXPLICIT|TPGS_MODE_IMPLICIT:
358 sdev_printk(KERN_INFO, sdev,
359 "%s: supports implicit and explicit TPGS\n",
360 ALUA_DH_NAME);
361 break;
362 case TPGS_MODE_EXPLICIT:
363 sdev_printk(KERN_INFO, sdev, "%s: supports explicit TPGS\n",
364 ALUA_DH_NAME);
365 break;
366 case TPGS_MODE_IMPLICIT:
367 sdev_printk(KERN_INFO, sdev, "%s: supports implicit TPGS\n",
368 ALUA_DH_NAME);
369 break;
370 default:
371 h->tpgs = TPGS_MODE_NONE;
372 sdev_printk(KERN_INFO, sdev, "%s: not supported\n",
373 ALUA_DH_NAME);
374 err = SCSI_DH_DEV_UNSUPP;
375 break;
376 }
377
378 return err;
379}
380
381
382
383
384
385
386
387
388static int alua_vpd_inquiry(struct scsi_device *sdev, struct alua_dh_data *h)
389{
390 int len;
391 unsigned err;
392 unsigned char *d;
393
394 retry:
395 err = submit_vpd_inquiry(sdev, h);
396
397 if (err != SCSI_DH_OK)
398 return err;
399
400
401 len = (h->buff[2] << 8) + h->buff[3] + 4;
402 if (len > h->bufflen) {
403
404 if (realloc_buffer(h, len)) {
405 sdev_printk(KERN_WARNING, sdev,
406 "%s: kmalloc buffer failed\n",
407 ALUA_DH_NAME);
408
409 return SCSI_DH_DEV_TEMP_BUSY;
410 }
411 goto retry;
412 }
413
414
415
416
417 d = h->buff + 4;
418 while (d < h->buff + len) {
419 switch (d[1] & 0xf) {
420 case 0x4:
421
422 h->rel_port = (d[6] << 8) + d[7];
423 break;
424 case 0x5:
425
426 h->group_id = (d[6] << 8) + d[7];
427 break;
428 default:
429 break;
430 }
431 d += d[3] + 4;
432 }
433
434 if (h->group_id == -1) {
435
436
437
438
439
440 sdev_printk(KERN_INFO, sdev,
441 "%s: No target port descriptors found\n",
442 ALUA_DH_NAME);
443 h->state = TPGS_STATE_OPTIMIZED;
444 h->tpgs = TPGS_MODE_NONE;
445 err = SCSI_DH_DEV_UNSUPP;
446 } else {
447 sdev_printk(KERN_INFO, sdev,
448 "%s: port group %02x rel port %02x\n",
449 ALUA_DH_NAME, h->group_id, h->rel_port);
450 }
451
452 return err;
453}
454
455static char print_alua_state(int state)
456{
457 switch (state) {
458 case TPGS_STATE_OPTIMIZED:
459 return 'A';
460 case TPGS_STATE_NONOPTIMIZED:
461 return 'N';
462 case TPGS_STATE_STANDBY:
463 return 'S';
464 case TPGS_STATE_UNAVAILABLE:
465 return 'U';
466 case TPGS_STATE_LBA_DEPENDENT:
467 return 'L';
468 case TPGS_STATE_OFFLINE:
469 return 'O';
470 case TPGS_STATE_TRANSITIONING:
471 return 'T';
472 default:
473 return 'X';
474 }
475}
476
477static int alua_check_sense(struct scsi_device *sdev,
478 struct scsi_sense_hdr *sense_hdr)
479{
480 switch (sense_hdr->sense_key) {
481 case NOT_READY:
482 if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x0a)
483
484
485
486 return ADD_TO_MLQUEUE;
487 if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x0b)
488
489
490
491 return SUCCESS;
492 if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x0c)
493
494
495
496 return SUCCESS;
497 if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x12)
498
499
500
501 return SUCCESS;
502 break;
503 case UNIT_ATTENTION:
504 if (sense_hdr->asc == 0x29 && sense_hdr->ascq == 0x00)
505
506
507
508 return ADD_TO_MLQUEUE;
509 if (sense_hdr->asc == 0x2a && sense_hdr->ascq == 0x06) {
510
511
512
513 return ADD_TO_MLQUEUE;
514 }
515 if (sense_hdr->asc == 0x2a && sense_hdr->ascq == 0x07) {
516
517
518
519 return ADD_TO_MLQUEUE;
520 }
521 if (sense_hdr->asc == 0x3f && sense_hdr->ascq == 0x0e) {
522
523
524
525
526
527 return ADD_TO_MLQUEUE;
528 }
529
530 break;
531 }
532
533 return SCSI_RETURN_NOT_HANDLED;
534}
535
536
537
538
539
540
541
542
543
544static int alua_rtpg(struct scsi_device *sdev, struct alua_dh_data *h)
545{
546 struct scsi_sense_hdr sense_hdr;
547 int len, k, off, valid_states = 0;
548 char *ucp;
549 unsigned err;
550 unsigned long expiry, interval = 10;
551
552 expiry = round_jiffies_up(jiffies + ALUA_FAILOVER_TIMEOUT);
553 retry:
554 err = submit_rtpg(sdev, h);
555
556 if (err == SCSI_DH_IO && h->senselen > 0) {
557 err = scsi_normalize_sense(h->sense, SCSI_SENSE_BUFFERSIZE,
558 &sense_hdr);
559 if (!err)
560 return SCSI_DH_IO;
561
562 err = alua_check_sense(sdev, &sense_hdr);
563 if (err == ADD_TO_MLQUEUE && time_before(jiffies, expiry))
564 goto retry;
565 sdev_printk(KERN_INFO, sdev,
566 "%s: rtpg sense code %02x/%02x/%02x\n",
567 ALUA_DH_NAME, sense_hdr.sense_key,
568 sense_hdr.asc, sense_hdr.ascq);
569 err = SCSI_DH_IO;
570 }
571 if (err != SCSI_DH_OK)
572 return err;
573
574 len = (h->buff[0] << 24) + (h->buff[1] << 16) +
575 (h->buff[2] << 8) + h->buff[3] + 4;
576
577 if (len > h->bufflen) {
578
579 if (realloc_buffer(h, len)) {
580 sdev_printk(KERN_WARNING, sdev,
581 "%s: kmalloc buffer failed\n",__func__);
582
583 return SCSI_DH_DEV_TEMP_BUSY;
584 }
585 goto retry;
586 }
587
588 for (k = 4, ucp = h->buff + 4; k < len; k += off, ucp += off) {
589 if (h->group_id == (ucp[2] << 8) + ucp[3]) {
590 h->state = ucp[0] & 0x0f;
591 valid_states = ucp[1];
592 }
593 off = 8 + (ucp[7] * 4);
594 }
595
596 sdev_printk(KERN_INFO, sdev,
597 "%s: port group %02x state %c supports %c%c%c%c%c%c%c\n",
598 ALUA_DH_NAME, h->group_id, print_alua_state(h->state),
599 valid_states&TPGS_SUPPORT_TRANSITION?'T':'t',
600 valid_states&TPGS_SUPPORT_OFFLINE?'O':'o',
601 valid_states&TPGS_SUPPORT_LBA_DEPENDENT?'L':'l',
602 valid_states&TPGS_SUPPORT_UNAVAILABLE?'U':'u',
603 valid_states&TPGS_SUPPORT_STANDBY?'S':'s',
604 valid_states&TPGS_SUPPORT_NONOPTIMIZED?'N':'n',
605 valid_states&TPGS_SUPPORT_OPTIMIZED?'A':'a');
606
607 switch (h->state) {
608 case TPGS_STATE_TRANSITIONING:
609 if (time_before(jiffies, expiry)) {
610
611 interval *= 10;
612 msleep(interval);
613 goto retry;
614 }
615
616 err = SCSI_DH_RETRY;
617 h->state = TPGS_STATE_STANDBY;
618 break;
619 case TPGS_STATE_OFFLINE:
620 case TPGS_STATE_UNAVAILABLE:
621
622 err = SCSI_DH_DEV_OFFLINED;
623 break;
624 default:
625
626 err = SCSI_DH_OK;
627 break;
628 }
629 return err;
630}
631
632
633
634
635
636
637
638
639static int alua_initialize(struct scsi_device *sdev, struct alua_dh_data *h)
640{
641 int err;
642
643 err = alua_std_inquiry(sdev, h);
644 if (err != SCSI_DH_OK)
645 goto out;
646
647 err = alua_vpd_inquiry(sdev, h);
648 if (err != SCSI_DH_OK)
649 goto out;
650
651 err = alua_rtpg(sdev, h);
652 if (err != SCSI_DH_OK)
653 goto out;
654
655out:
656 return err;
657}
658
659
660
661
662
663
664
665
666
667
668
669static int alua_activate(struct scsi_device *sdev,
670 activate_complete fn, void *data)
671{
672 struct alua_dh_data *h = get_alua_data(sdev);
673 int err = SCSI_DH_OK;
674
675 if (h->group_id != -1) {
676 err = alua_rtpg(sdev, h);
677 if (err != SCSI_DH_OK)
678 goto out;
679 }
680
681 if (h->tpgs & TPGS_MODE_EXPLICIT &&
682 h->state != TPGS_STATE_OPTIMIZED &&
683 h->state != TPGS_STATE_LBA_DEPENDENT) {
684 h->callback_fn = fn;
685 h->callback_data = data;
686 err = submit_stpg(h);
687 if (err == SCSI_DH_OK)
688 return 0;
689 h->callback_fn = h->callback_data = NULL;
690 }
691
692out:
693 if (fn)
694 fn(data, err);
695 return 0;
696}
697
698
699
700
701
702
703
704static int alua_prep_fn(struct scsi_device *sdev, struct request *req)
705{
706 struct alua_dh_data *h = get_alua_data(sdev);
707 int ret = BLKPREP_OK;
708
709 if (h->state == TPGS_STATE_TRANSITIONING)
710 ret = BLKPREP_DEFER;
711 else if (h->state != TPGS_STATE_OPTIMIZED &&
712 h->state != TPGS_STATE_NONOPTIMIZED &&
713 h->state != TPGS_STATE_LBA_DEPENDENT) {
714 ret = BLKPREP_KILL;
715 req->cmd_flags |= REQ_QUIET;
716 }
717 return ret;
718
719}
720
721static const struct scsi_dh_devlist alua_dev_list[] = {
722 {"HP", "MSA VOLUME" },
723 {"HP", "HSV101" },
724 {"HP", "HSV111" },
725 {"HP", "HSV200" },
726 {"HP", "HSV210" },
727 {"HP", "HSV300" },
728 {"IBM", "2107900" },
729 {"IBM", "2145" },
730 {"Pillar", "Axiom" },
731 {"Intel", "Multi-Flex"},
732 {"NETAPP", "LUN"},
733 {"AIX", "NVDISK"},
734 {NULL, NULL}
735};
736
737static int alua_bus_attach(struct scsi_device *sdev);
738static void alua_bus_detach(struct scsi_device *sdev);
739
740static struct scsi_device_handler alua_dh = {
741 .name = ALUA_DH_NAME,
742 .module = THIS_MODULE,
743 .devlist = alua_dev_list,
744 .attach = alua_bus_attach,
745 .detach = alua_bus_detach,
746 .prep_fn = alua_prep_fn,
747 .check_sense = alua_check_sense,
748 .activate = alua_activate,
749};
750
751
752
753
754
755static int alua_bus_attach(struct scsi_device *sdev)
756{
757 struct scsi_dh_data *scsi_dh_data;
758 struct alua_dh_data *h;
759 unsigned long flags;
760 int err = SCSI_DH_OK;
761
762 scsi_dh_data = kzalloc(sizeof(struct scsi_device_handler *)
763 + sizeof(*h) , GFP_KERNEL);
764 if (!scsi_dh_data) {
765 sdev_printk(KERN_ERR, sdev, "%s: Attach failed\n",
766 ALUA_DH_NAME);
767 return -ENOMEM;
768 }
769
770 scsi_dh_data->scsi_dh = &alua_dh;
771 h = (struct alua_dh_data *) scsi_dh_data->buf;
772 h->tpgs = TPGS_MODE_UNINITIALIZED;
773 h->state = TPGS_STATE_OPTIMIZED;
774 h->group_id = -1;
775 h->rel_port = -1;
776 h->buff = h->inq;
777 h->bufflen = ALUA_INQUIRY_SIZE;
778 h->sdev = sdev;
779
780 err = alua_initialize(sdev, h);
781 if (err != SCSI_DH_OK)
782 goto failed;
783
784 if (!try_module_get(THIS_MODULE))
785 goto failed;
786
787 spin_lock_irqsave(sdev->request_queue->queue_lock, flags);
788 sdev->scsi_dh_data = scsi_dh_data;
789 spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags);
790
791 return 0;
792
793failed:
794 kfree(scsi_dh_data);
795 sdev_printk(KERN_ERR, sdev, "%s: not attached\n", ALUA_DH_NAME);
796 return -EINVAL;
797}
798
799
800
801
802
803static void alua_bus_detach(struct scsi_device *sdev)
804{
805 struct scsi_dh_data *scsi_dh_data;
806 struct alua_dh_data *h;
807 unsigned long flags;
808
809 spin_lock_irqsave(sdev->request_queue->queue_lock, flags);
810 scsi_dh_data = sdev->scsi_dh_data;
811 sdev->scsi_dh_data = NULL;
812 spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags);
813
814 h = (struct alua_dh_data *) scsi_dh_data->buf;
815 if (h->buff && h->inq != h->buff)
816 kfree(h->buff);
817 kfree(scsi_dh_data);
818 module_put(THIS_MODULE);
819 sdev_printk(KERN_NOTICE, sdev, "%s: Detached\n", ALUA_DH_NAME);
820}
821
822static int __init alua_init(void)
823{
824 int r;
825
826 r = scsi_register_device_handler(&alua_dh);
827 if (r != 0)
828 printk(KERN_ERR "%s: Failed to register scsi device handler",
829 ALUA_DH_NAME);
830 return r;
831}
832
833static void __exit alua_exit(void)
834{
835 scsi_unregister_device_handler(&alua_dh);
836}
837
838module_init(alua_init);
839module_exit(alua_exit);
840
841MODULE_DESCRIPTION("DM Multipath ALUA support");
842MODULE_AUTHOR("Hannes Reinecke <hare@suse.de>");
843MODULE_LICENSE("GPL");
844MODULE_VERSION(ALUA_DH_VER);
845