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-rw-r--r--drivers/scsi/device_handler/Kconfig8
-rw-r--r--drivers/scsi/device_handler/Makefile1
-rw-r--r--drivers/scsi/device_handler/scsi_dh_alua.c802
3 files changed, 811 insertions, 0 deletions
diff --git a/drivers/scsi/device_handler/Kconfig b/drivers/scsi/device_handler/Kconfig
index 2adc0f666b68..67070257919f 100644
--- a/drivers/scsi/device_handler/Kconfig
+++ b/drivers/scsi/device_handler/Kconfig
@@ -30,3 +30,11 @@ config SCSI_DH_EMC
30 depends on SCSI_DH 30 depends on SCSI_DH
31 help 31 help
32 If you have a EMC CLARiiON select y. Otherwise, say N. 32 If you have a EMC CLARiiON select y. Otherwise, say N.
33
34config SCSI_DH_ALUA
35 tristate "SPC-3 ALUA Device Handler (EXPERIMENTAL)"
36 depends on SCSI_DH && EXPERIMENTAL
37 help
38 SCSI Device handler for generic SPC-3 Asymmetric Logical Unit
39 Access (ALUA).
40
diff --git a/drivers/scsi/device_handler/Makefile b/drivers/scsi/device_handler/Makefile
index 35272e93b1c8..e1d2ea083e15 100644
--- a/drivers/scsi/device_handler/Makefile
+++ b/drivers/scsi/device_handler/Makefile
@@ -5,3 +5,4 @@ obj-$(CONFIG_SCSI_DH) += scsi_dh.o
5obj-$(CONFIG_SCSI_DH_RDAC) += scsi_dh_rdac.o 5obj-$(CONFIG_SCSI_DH_RDAC) += scsi_dh_rdac.o
6obj-$(CONFIG_SCSI_DH_HP_SW) += scsi_dh_hp_sw.o 6obj-$(CONFIG_SCSI_DH_HP_SW) += scsi_dh_hp_sw.o
7obj-$(CONFIG_SCSI_DH_EMC) += scsi_dh_emc.o 7obj-$(CONFIG_SCSI_DH_EMC) += scsi_dh_emc.o
8obj-$(CONFIG_SCSI_DH_ALUA) += scsi_dh_alua.o
diff --git a/drivers/scsi/device_handler/scsi_dh_alua.c b/drivers/scsi/device_handler/scsi_dh_alua.c
new file mode 100644
index 000000000000..6e464488bcab
--- /dev/null
+++ b/drivers/scsi/device_handler/scsi_dh_alua.c
@@ -0,0 +1,802 @@
1/*
2 * Generic SCSI-3 ALUA SCSI Device Handler
3 *
4 * Copyright (C) 2007, 2008 Hannes Reinecke, SUSE Linux Products GmbH.
5 * All rights reserved.
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
20 *
21 */
22#include <scsi/scsi.h>
23#include <scsi/scsi_eh.h>
24#include <scsi/scsi_dh.h>
25
26#define ALUA_DH_NAME "alua"
27#define ALUA_DH_VER "1.2"
28
29#define TPGS_STATE_OPTIMIZED 0x0
30#define TPGS_STATE_NONOPTIMIZED 0x1
31#define TPGS_STATE_STANDBY 0x2
32#define TPGS_STATE_UNAVAILABLE 0x3
33#define TPGS_STATE_OFFLINE 0xe
34#define TPGS_STATE_TRANSITIONING 0xf
35
36#define TPGS_SUPPORT_NONE 0x00
37#define TPGS_SUPPORT_OPTIMIZED 0x01
38#define TPGS_SUPPORT_NONOPTIMIZED 0x02
39#define TPGS_SUPPORT_STANDBY 0x04
40#define TPGS_SUPPORT_UNAVAILABLE 0x08
41#define TPGS_SUPPORT_OFFLINE 0x40
42#define TPGS_SUPPORT_TRANSITION 0x80
43
44#define TPGS_MODE_UNINITIALIZED -1
45#define TPGS_MODE_NONE 0x0
46#define TPGS_MODE_IMPLICIT 0x1
47#define TPGS_MODE_EXPLICIT 0x2
48
49#define ALUA_INQUIRY_SIZE 36
50#define ALUA_FAILOVER_TIMEOUT (60 * HZ)
51#define ALUA_FAILOVER_RETRIES 5
52
53struct alua_dh_data {
54 int group_id;
55 int rel_port;
56 int tpgs;
57 int state;
58 unsigned char inq[ALUA_INQUIRY_SIZE];
59 unsigned char *buff;
60 int bufflen;
61 unsigned char sense[SCSI_SENSE_BUFFERSIZE];
62 int senselen;
63};
64
65#define ALUA_POLICY_SWITCH_CURRENT 0
66#define ALUA_POLICY_SWITCH_ALL 1
67
68static inline struct alua_dh_data *get_alua_data(struct scsi_device *sdev)
69{
70 struct scsi_dh_data *scsi_dh_data = sdev->scsi_dh_data;
71 BUG_ON(scsi_dh_data == NULL);
72 return ((struct alua_dh_data *) scsi_dh_data->buf);
73}
74
75static int realloc_buffer(struct alua_dh_data *h, unsigned len)
76{
77 if (h->buff && h->buff != h->inq)
78 kfree(h->buff);
79
80 h->buff = kmalloc(len, GFP_NOIO);
81 if (!h->buff) {
82 h->buff = h->inq;
83 h->bufflen = ALUA_INQUIRY_SIZE;
84 return 1;
85 }
86 h->bufflen = len;
87 return 0;
88}
89
90static struct request *get_alua_req(struct scsi_device *sdev,
91 void *buffer, unsigned buflen, int rw)
92{
93 struct request *rq;
94 struct request_queue *q = sdev->request_queue;
95
96 rq = blk_get_request(q, rw, GFP_NOIO);
97
98 if (!rq) {
99 sdev_printk(KERN_INFO, sdev,
100 "%s: blk_get_request failed\n", __FUNCTION__);
101 return NULL;
102 }
103
104 if (buflen && blk_rq_map_kern(q, rq, buffer, buflen, GFP_NOIO)) {
105 blk_put_request(rq);
106 sdev_printk(KERN_INFO, sdev,
107 "%s: blk_rq_map_kern failed\n", __FUNCTION__);
108 return NULL;
109 }
110
111 rq->cmd_type = REQ_TYPE_BLOCK_PC;
112 rq->cmd_flags |= REQ_FAILFAST | REQ_NOMERGE;
113 rq->retries = ALUA_FAILOVER_RETRIES;
114 rq->timeout = ALUA_FAILOVER_TIMEOUT;
115
116 return rq;
117}
118
119/*
120 * submit_std_inquiry - Issue a standard INQUIRY command
121 * @sdev: sdev the command should be send to
122 */
123static int submit_std_inquiry(struct scsi_device *sdev, struct alua_dh_data *h)
124{
125 struct request *rq;
126 int err = SCSI_DH_RES_TEMP_UNAVAIL;
127
128 rq = get_alua_req(sdev, h->inq, ALUA_INQUIRY_SIZE, READ);
129 if (!rq)
130 goto done;
131
132 /* Prepare the command. */
133 rq->cmd[0] = INQUIRY;
134 rq->cmd[1] = 0;
135 rq->cmd[2] = 0;
136 rq->cmd[4] = ALUA_INQUIRY_SIZE;
137 rq->cmd_len = COMMAND_SIZE(INQUIRY);
138
139 rq->sense = h->sense;
140 memset(rq->sense, 0, SCSI_SENSE_BUFFERSIZE);
141 rq->sense_len = h->senselen = 0;
142
143 err = blk_execute_rq(rq->q, NULL, rq, 1);
144 if (err == -EIO) {
145 sdev_printk(KERN_INFO, sdev,
146 "%s: std inquiry failed with %x\n",
147 ALUA_DH_NAME, rq->errors);
148 h->senselen = rq->sense_len;
149 err = SCSI_DH_IO;
150 }
151 blk_put_request(rq);
152done:
153 return err;
154}
155
156/*
157 * submit_vpd_inquiry - Issue an INQUIRY VPD page 0x83 command
158 * @sdev: sdev the command should be sent to
159 */
160static int submit_vpd_inquiry(struct scsi_device *sdev, struct alua_dh_data *h)
161{
162 struct request *rq;
163 int err = SCSI_DH_RES_TEMP_UNAVAIL;
164
165 rq = get_alua_req(sdev, h->buff, h->bufflen, READ);
166 if (!rq)
167 goto done;
168
169 /* Prepare the command. */
170 rq->cmd[0] = INQUIRY;
171 rq->cmd[1] = 1;
172 rq->cmd[2] = 0x83;
173 rq->cmd[4] = h->bufflen;
174 rq->cmd_len = COMMAND_SIZE(INQUIRY);
175
176 rq->sense = h->sense;
177 memset(rq->sense, 0, SCSI_SENSE_BUFFERSIZE);
178 rq->sense_len = h->senselen = 0;
179
180 err = blk_execute_rq(rq->q, NULL, rq, 1);
181 if (err == -EIO) {
182 sdev_printk(KERN_INFO, sdev,
183 "%s: evpd inquiry failed with %x\n",
184 ALUA_DH_NAME, rq->errors);
185 h->senselen = rq->sense_len;
186 err = SCSI_DH_IO;
187 }
188 blk_put_request(rq);
189done:
190 return err;
191}
192
193/*
194 * submit_rtpg - Issue a REPORT TARGET GROUP STATES command
195 * @sdev: sdev the command should be sent to
196 */
197static unsigned submit_rtpg(struct scsi_device *sdev, struct alua_dh_data *h)
198{
199 struct request *rq;
200 int err = SCSI_DH_RES_TEMP_UNAVAIL;
201
202 rq = get_alua_req(sdev, h->buff, h->bufflen, READ);
203 if (!rq)
204 goto done;
205
206 /* Prepare the command. */
207 rq->cmd[0] = MAINTENANCE_IN;
208 rq->cmd[1] = MI_REPORT_TARGET_PGS;
209 rq->cmd[6] = (h->bufflen >> 24) & 0xff;
210 rq->cmd[7] = (h->bufflen >> 16) & 0xff;
211 rq->cmd[8] = (h->bufflen >> 8) & 0xff;
212 rq->cmd[9] = h->bufflen & 0xff;
213 rq->cmd_len = COMMAND_SIZE(MAINTENANCE_IN);
214
215 rq->sense = h->sense;
216 memset(rq->sense, 0, SCSI_SENSE_BUFFERSIZE);
217 rq->sense_len = h->senselen = 0;
218
219 err = blk_execute_rq(rq->q, NULL, rq, 1);
220 if (err == -EIO) {
221 sdev_printk(KERN_INFO, sdev,
222 "%s: rtpg failed with %x\n",
223 ALUA_DH_NAME, rq->errors);
224 h->senselen = rq->sense_len;
225 err = SCSI_DH_IO;
226 }
227 blk_put_request(rq);
228done:
229 return err;
230}
231
232/*
233 * submit_stpg - Issue a SET TARGET GROUP STATES command
234 * @sdev: sdev the command should be sent to
235 *
236 * Currently we're only setting the current target port group state
237 * to 'active/optimized' and let the array firmware figure out
238 * the states of the remaining groups.
239 */
240static unsigned submit_stpg(struct scsi_device *sdev, struct alua_dh_data *h)
241{
242 struct request *rq;
243 int err = SCSI_DH_RES_TEMP_UNAVAIL;
244 int stpg_len = 8;
245
246 /* Prepare the data buffer */
247 memset(h->buff, 0, stpg_len);
248 h->buff[4] = TPGS_STATE_OPTIMIZED & 0x0f;
249 h->buff[6] = (h->group_id >> 8) & 0x0f;
250 h->buff[7] = h->group_id & 0x0f;
251
252 rq = get_alua_req(sdev, h->buff, stpg_len, WRITE);
253 if (!rq)
254 goto done;
255
256 /* Prepare the command. */
257 rq->cmd[0] = MAINTENANCE_OUT;
258 rq->cmd[1] = MO_SET_TARGET_PGS;
259 rq->cmd[6] = (stpg_len >> 24) & 0xff;
260 rq->cmd[7] = (stpg_len >> 16) & 0xff;
261 rq->cmd[8] = (stpg_len >> 8) & 0xff;
262 rq->cmd[9] = stpg_len & 0xff;
263 rq->cmd_len = COMMAND_SIZE(MAINTENANCE_OUT);
264
265 rq->sense = h->sense;
266 memset(rq->sense, 0, SCSI_SENSE_BUFFERSIZE);
267 rq->sense_len = h->senselen = 0;
268
269 err = blk_execute_rq(rq->q, NULL, rq, 1);
270 if (err == -EIO) {
271 sdev_printk(KERN_INFO, sdev,
272 "%s: stpg failed with %x\n",
273 ALUA_DH_NAME, rq->errors);
274 h->senselen = rq->sense_len;
275 err = SCSI_DH_IO;
276 }
277 blk_put_request(rq);
278done:
279 return err;
280}
281
282/*
283 * alua_std_inquiry - Evaluate standard INQUIRY command
284 * @sdev: device to be checked
285 *
286 * Just extract the TPGS setting to find out if ALUA
287 * is supported.
288 */
289static int alua_std_inquiry(struct scsi_device *sdev, struct alua_dh_data *h)
290{
291 int err;
292
293 err = submit_std_inquiry(sdev, h);
294
295 if (err != SCSI_DH_OK)
296 return err;
297
298 /* Check TPGS setting */
299 h->tpgs = (h->inq[5] >> 4) & 0x3;
300 switch (h->tpgs) {
301 case TPGS_MODE_EXPLICIT|TPGS_MODE_IMPLICIT:
302 sdev_printk(KERN_INFO, sdev,
303 "%s: supports implicit and explicit TPGS\n",
304 ALUA_DH_NAME);
305 break;
306 case TPGS_MODE_EXPLICIT:
307 sdev_printk(KERN_INFO, sdev, "%s: supports explicit TPGS\n",
308 ALUA_DH_NAME);
309 break;
310 case TPGS_MODE_IMPLICIT:
311 sdev_printk(KERN_INFO, sdev, "%s: supports implicit TPGS\n",
312 ALUA_DH_NAME);
313 break;
314 default:
315 h->tpgs = TPGS_MODE_NONE;
316 sdev_printk(KERN_INFO, sdev, "%s: not supported\n",
317 ALUA_DH_NAME);
318 err = SCSI_DH_DEV_UNSUPP;
319 break;
320 }
321
322 return err;
323}
324
325/*
326 * alua_vpd_inquiry - Evaluate INQUIRY vpd page 0x83
327 * @sdev: device to be checked
328 *
329 * Extract the relative target port and the target port group
330 * descriptor from the list of identificators.
331 */
332static int alua_vpd_inquiry(struct scsi_device *sdev, struct alua_dh_data *h)
333{
334 int len;
335 unsigned err;
336 unsigned char *d;
337
338 retry:
339 err = submit_vpd_inquiry(sdev, h);
340
341 if (err != SCSI_DH_OK)
342 return err;
343
344 /* Check if vpd page exceeds initial buffer */
345 len = (h->buff[2] << 8) + h->buff[3] + 4;
346 if (len > h->bufflen) {
347 /* Resubmit with the correct length */
348 if (realloc_buffer(h, len)) {
349 sdev_printk(KERN_WARNING, sdev,
350 "%s: kmalloc buffer failed\n",
351 ALUA_DH_NAME);
352 /* Temporary failure, bypass */
353 return SCSI_DH_DEV_TEMP_BUSY;
354 }
355 goto retry;
356 }
357
358 /*
359 * Now look for the correct descriptor.
360 */
361 d = h->buff + 4;
362 while (d < h->buff + len) {
363 switch (d[1] & 0xf) {
364 case 0x4:
365 /* Relative target port */
366 h->rel_port = (d[6] << 8) + d[7];
367 break;
368 case 0x5:
369 /* Target port group */
370 h->group_id = (d[6] << 8) + d[7];
371 break;
372 default:
373 break;
374 }
375 d += d[3] + 4;
376 }
377
378 if (h->group_id == -1) {
379 /*
380 * Internal error; TPGS supported but required
381 * VPD identification descriptors not present.
382 * Disable ALUA support
383 */
384 sdev_printk(KERN_INFO, sdev,
385 "%s: No target port descriptors found\n",
386 ALUA_DH_NAME);
387 h->state = TPGS_STATE_OPTIMIZED;
388 h->tpgs = TPGS_MODE_NONE;
389 err = SCSI_DH_DEV_UNSUPP;
390 } else {
391 sdev_printk(KERN_INFO, sdev,
392 "%s: port group %02x rel port %02x\n",
393 ALUA_DH_NAME, h->group_id, h->rel_port);
394 }
395
396 return err;
397}
398
399static char print_alua_state(int state)
400{
401 switch (state) {
402 case TPGS_STATE_OPTIMIZED:
403 return 'A';
404 case TPGS_STATE_NONOPTIMIZED:
405 return 'N';
406 case TPGS_STATE_STANDBY:
407 return 'S';
408 case TPGS_STATE_UNAVAILABLE:
409 return 'U';
410 case TPGS_STATE_OFFLINE:
411 return 'O';
412 case TPGS_STATE_TRANSITIONING:
413 return 'T';
414 default:
415 return 'X';
416 }
417}
418
419static int alua_check_sense(struct scsi_device *sdev,
420 struct scsi_sense_hdr *sense_hdr)
421{
422 switch (sense_hdr->sense_key) {
423 case NOT_READY:
424 if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x0a)
425 /*
426 * LUN Not Accessible - ALUA state transition
427 */
428 return NEEDS_RETRY;
429 if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x0b)
430 /*
431 * LUN Not Accessible -- Target port in standby state
432 */
433 return SUCCESS;
434 if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x0c)
435 /*
436 * LUN Not Accessible -- Target port in unavailable state
437 */
438 return SUCCESS;
439 if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x12)
440 /*
441 * LUN Not Ready -- Offline
442 */
443 return SUCCESS;
444 break;
445 case UNIT_ATTENTION:
446 if (sense_hdr->asc == 0x29 && sense_hdr->ascq == 0x00)
447 /*
448 * Power On, Reset, or Bus Device Reset, just retry.
449 */
450 return NEEDS_RETRY;
451 if (sense_hdr->asc == 0x2a && sense_hdr->ascq == 0x06) {
452 /*
453 * ALUA state changed
454 */
455 return NEEDS_RETRY;
456 }
457 if (sense_hdr->asc == 0x2a && sense_hdr->ascq == 0x07) {
458 /*
459 * Implicit ALUA state transition failed
460 */
461 return NEEDS_RETRY;
462 }
463 break;
464 }
465
466 return SCSI_RETURN_NOT_HANDLED;
467}
468
469/*
470 * alua_stpg - Evaluate SET TARGET GROUP STATES
471 * @sdev: the device to be evaluated
472 * @state: the new target group state
473 *
474 * Send a SET TARGET GROUP STATES command to the device.
475 * We only have to test here if we should resubmit the command;
476 * any other error is assumed as a failure.
477 */
478static int alua_stpg(struct scsi_device *sdev, int state,
479 struct alua_dh_data *h)
480{
481 struct scsi_sense_hdr sense_hdr;
482 unsigned err;
483 int retry = ALUA_FAILOVER_RETRIES;
484
485 retry:
486 err = submit_stpg(sdev, h);
487 if (err == SCSI_DH_IO && h->senselen > 0) {
488 err = scsi_normalize_sense(h->sense, SCSI_SENSE_BUFFERSIZE,
489 &sense_hdr);
490 if (!err)
491 return SCSI_DH_IO;
492 err = alua_check_sense(sdev, &sense_hdr);
493 if (retry > 0 && err == NEEDS_RETRY) {
494 retry--;
495 goto retry;
496 }
497 sdev_printk(KERN_INFO, sdev,
498 "%s: stpg sense code: %02x/%02x/%02x\n",
499 ALUA_DH_NAME, sense_hdr.sense_key,
500 sense_hdr.asc, sense_hdr.ascq);
501 err = SCSI_DH_IO;
502 }
503 if (err == SCSI_DH_OK) {
504 h->state = state;
505 sdev_printk(KERN_INFO, sdev,
506 "%s: port group %02x switched to state %c\n",
507 ALUA_DH_NAME, h->group_id,
508 print_alua_state(h->state) );
509 }
510 return err;
511}
512
513/*
514 * alua_rtpg - Evaluate REPORT TARGET GROUP STATES
515 * @sdev: the device to be evaluated.
516 *
517 * Evaluate the Target Port Group State.
518 * Returns SCSI_DH_DEV_OFFLINED if the path is
519 * found to be unuseable.
520 */
521static int alua_rtpg(struct scsi_device *sdev, struct alua_dh_data *h)
522{
523 struct scsi_sense_hdr sense_hdr;
524 int len, k, off, valid_states = 0;
525 char *ucp;
526 unsigned err;
527
528 retry:
529 err = submit_rtpg(sdev, h);
530
531 if (err == SCSI_DH_IO && h->senselen > 0) {
532 err = scsi_normalize_sense(h->sense, SCSI_SENSE_BUFFERSIZE,
533 &sense_hdr);
534 if (!err)
535 return SCSI_DH_IO;
536
537 err = alua_check_sense(sdev, &sense_hdr);
538 if (err == NEEDS_RETRY)
539 goto retry;
540 sdev_printk(KERN_INFO, sdev,
541 "%s: rtpg sense code %02x/%02x/%02x\n",
542 ALUA_DH_NAME, sense_hdr.sense_key,
543 sense_hdr.asc, sense_hdr.ascq);
544 err = SCSI_DH_IO;
545 }
546 if (err != SCSI_DH_OK)
547 return err;
548
549 len = (h->buff[0] << 24) + (h->buff[1] << 16) +
550 (h->buff[2] << 8) + h->buff[3] + 4;
551
552 if (len > h->bufflen) {
553 /* Resubmit with the correct length */
554 if (realloc_buffer(h, len)) {
555 sdev_printk(KERN_WARNING, sdev,
556 "%s: kmalloc buffer failed\n",__FUNCTION__);
557 /* Temporary failure, bypass */
558 return SCSI_DH_DEV_TEMP_BUSY;
559 }
560 goto retry;
561 }
562
563 for (k = 4, ucp = h->buff + 4; k < len; k += off, ucp += off) {
564 if (h->group_id == (ucp[2] << 8) + ucp[3]) {
565 h->state = ucp[0] & 0x0f;
566 valid_states = ucp[1];
567 }
568 off = 8 + (ucp[7] * 4);
569 }
570
571 sdev_printk(KERN_INFO, sdev,
572 "%s: port group %02x state %c supports %c%c%c%c%c%c\n",
573 ALUA_DH_NAME, h->group_id, print_alua_state(h->state),
574 valid_states&TPGS_SUPPORT_TRANSITION?'T':'t',
575 valid_states&TPGS_SUPPORT_OFFLINE?'O':'o',
576 valid_states&TPGS_SUPPORT_UNAVAILABLE?'U':'u',
577 valid_states&TPGS_SUPPORT_STANDBY?'S':'s',
578 valid_states&TPGS_SUPPORT_NONOPTIMIZED?'N':'n',
579 valid_states&TPGS_SUPPORT_OPTIMIZED?'A':'a');
580
581 if (h->tpgs & TPGS_MODE_EXPLICIT) {
582 switch (h->state) {
583 case TPGS_STATE_TRANSITIONING:
584 /* State transition, retry */
585 goto retry;
586 break;
587 case TPGS_STATE_OFFLINE:
588 /* Path is offline, fail */
589 err = SCSI_DH_DEV_OFFLINED;
590 break;
591 default:
592 break;
593 }
594 } else {
595 /* Only Implicit ALUA support */
596 if (h->state == TPGS_STATE_OPTIMIZED ||
597 h->state == TPGS_STATE_NONOPTIMIZED ||
598 h->state == TPGS_STATE_STANDBY)
599 /* Useable path if active */
600 err = SCSI_DH_OK;
601 else
602 /* Path unuseable for unavailable/offline */
603 err = SCSI_DH_DEV_OFFLINED;
604 }
605 return err;
606}
607
608/*
609 * alua_initialize - Initialize ALUA state
610 * @sdev: the device to be initialized
611 *
612 * For the prep_fn to work correctly we have
613 * to initialize the ALUA state for the device.
614 */
615static int alua_initialize(struct scsi_device *sdev, struct alua_dh_data *h)
616{
617 int err;
618
619 err = alua_std_inquiry(sdev, h);
620 if (err != SCSI_DH_OK)
621 goto out;
622
623 err = alua_vpd_inquiry(sdev, h);
624 if (err != SCSI_DH_OK)
625 goto out;
626
627 err = alua_rtpg(sdev, h);
628 if (err != SCSI_DH_OK)
629 goto out;
630
631out:
632 return err;
633}
634
635/*
636 * alua_activate - activate a path
637 * @sdev: device on the path to be activated
638 *
639 * We're currently switching the port group to be activated only and
640 * let the array figure out the rest.
641 * There may be other arrays which require us to switch all port groups
642 * based on a certain policy. But until we actually encounter them it
643 * should be okay.
644 */
645static int alua_activate(struct scsi_device *sdev)
646{
647 struct alua_dh_data *h = get_alua_data(sdev);
648 int err = SCSI_DH_OK;
649
650 if (h->group_id != -1) {
651 err = alua_rtpg(sdev, h);
652 if (err != SCSI_DH_OK)
653 goto out;
654 }
655
656 if (h->tpgs == TPGS_MODE_EXPLICIT && h->state != TPGS_STATE_OPTIMIZED)
657 err = alua_stpg(sdev, TPGS_STATE_OPTIMIZED, h);
658
659out:
660 return err;
661}
662
663/*
664 * alua_prep_fn - request callback
665 *
666 * Fail I/O to all paths not in state
667 * active/optimized or active/non-optimized.
668 */
669static int alua_prep_fn(struct scsi_device *sdev, struct request *req)
670{
671 struct alua_dh_data *h = get_alua_data(sdev);
672 int ret = BLKPREP_OK;
673
674 if (h->state != TPGS_STATE_OPTIMIZED &&
675 h->state != TPGS_STATE_NONOPTIMIZED) {
676 ret = BLKPREP_KILL;
677 req->cmd_flags |= REQ_QUIET;
678 }
679 return ret;
680
681}
682
683const struct scsi_dh_devlist alua_dev_list[] = {
684 {"HP", "MSA VOLUME" },
685 {"HP", "HSV101" },
686 {"HP", "HSV111" },
687 {"HP", "HSV200" },
688 {"HP", "HSV210" },
689 {"HP", "HSV300" },
690 {"IBM", "2107900" },
691 {"IBM", "2145" },
692 {"Pillar", "Axiom" },
693 {NULL, NULL}
694};
695
696static int alua_bus_attach(struct scsi_device *sdev);
697static void alua_bus_detach(struct scsi_device *sdev);
698
699static struct scsi_device_handler alua_dh = {
700 .name = ALUA_DH_NAME,
701 .module = THIS_MODULE,
702 .devlist = alua_dev_list,
703 .attach = alua_bus_attach,
704 .detach = alua_bus_detach,
705 .prep_fn = alua_prep_fn,
706 .check_sense = alua_check_sense,
707 .activate = alua_activate,
708};
709
710/*
711 * alua_bus_attach - Attach device handler
712 * @sdev: device to be attached to
713 */
714static int alua_bus_attach(struct scsi_device *sdev)
715{
716 struct scsi_dh_data *scsi_dh_data;
717 struct alua_dh_data *h;
718 unsigned long flags;
719 int err = SCSI_DH_OK;
720
721 scsi_dh_data = kzalloc(sizeof(struct scsi_device_handler *)
722 + sizeof(*h) , GFP_KERNEL);
723 if (!scsi_dh_data) {
724 sdev_printk(KERN_ERR, sdev, "%s: Attach failed\n",
725 ALUA_DH_NAME);
726 return -ENOMEM;
727 }
728
729 scsi_dh_data->scsi_dh = &alua_dh;
730 h = (struct alua_dh_data *) scsi_dh_data->buf;
731 h->tpgs = TPGS_MODE_UNINITIALIZED;
732 h->state = TPGS_STATE_OPTIMIZED;
733 h->group_id = -1;
734 h->rel_port = -1;
735 h->buff = h->inq;
736 h->bufflen = ALUA_INQUIRY_SIZE;
737
738 err = alua_initialize(sdev, h);
739 if (err != SCSI_DH_OK)
740 goto failed;
741
742 if (!try_module_get(THIS_MODULE))
743 goto failed;
744
745 spin_lock_irqsave(sdev->request_queue->queue_lock, flags);
746 sdev->scsi_dh_data = scsi_dh_data;
747 spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags);
748
749 return 0;
750
751failed:
752 kfree(scsi_dh_data);
753 sdev_printk(KERN_ERR, sdev, "%s: not attached\n", ALUA_DH_NAME);
754 return -EINVAL;
755}
756
757/*
758 * alua_bus_detach - Detach device handler
759 * @sdev: device to be detached from
760 */
761static void alua_bus_detach(struct scsi_device *sdev)
762{
763 struct scsi_dh_data *scsi_dh_data;
764 struct alua_dh_data *h;
765 unsigned long flags;
766
767 spin_lock_irqsave(sdev->request_queue->queue_lock, flags);
768 scsi_dh_data = sdev->scsi_dh_data;
769 sdev->scsi_dh_data = NULL;
770 spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags);
771
772 h = (struct alua_dh_data *) scsi_dh_data->buf;
773 if (h->buff && h->inq != h->buff)
774 kfree(h->buff);
775 kfree(scsi_dh_data);
776 module_put(THIS_MODULE);
777 sdev_printk(KERN_NOTICE, sdev, "%s: Detached\n", ALUA_DH_NAME);
778}
779
780static int __init alua_init(void)
781{
782 int r;
783
784 r = scsi_register_device_handler(&alua_dh);
785 if (r != 0)
786 printk(KERN_ERR "%s: Failed to register scsi device handler",
787 ALUA_DH_NAME);
788 return r;
789}
790
791static void __exit alua_exit(void)
792{
793 scsi_unregister_device_handler(&alua_dh);
794}
795
796module_init(alua_init);
797module_exit(alua_exit);
798
799MODULE_DESCRIPTION("DM Multipath ALUA support");
800MODULE_AUTHOR("Hannes Reinecke <hare@suse.de>");
801MODULE_LICENSE("GPL");
802MODULE_VERSION(ALUA_DH_VER);
generated by cgit v1.2.2 (git 2.25.0) at 2024-12-24 20:58:33 -0500