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057ea7c9 HR |
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 | ||
53 | struct 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 | ||
68 | static 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 | ||
75 | static 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 | ||
90 | static 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 | */ | |
123 | static 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); | |
152 | done: | |
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 | */ | |
160 | static 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); | |
189 | done: | |
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 | */ | |
197 | static 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); | |
228 | done: | |
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 | */ | |
240 | static 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); | |
278 | done: | |
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 | */ | |
289 | static 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 | */ | |
332 | static 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 | ||
399 | static 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 | ||
419 | static 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 | */ | |
478 | static 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 | */ | |
521 | static 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 | */ | |
615 | static 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 | ||
631 | out: | |
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 | */ | |
645 | static 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 | ||
659 | out: | |
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 | */ | |
669 | static 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 | ||
683 | const 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 | ||
696 | static int alua_bus_attach(struct scsi_device *sdev); | |
697 | static void alua_bus_detach(struct scsi_device *sdev); | |
698 | ||
699 | static 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 | */ | |
714 | static 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 | ||
751 | failed: | |
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 | */ | |
761 | static 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 | ||
780 | static 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 | ||
791 | static void __exit alua_exit(void) | |
792 | { | |
793 | scsi_unregister_device_handler(&alua_dh); | |
794 | } | |
795 | ||
796 | module_init(alua_init); | |
797 | module_exit(alua_exit); | |
798 | ||
799 | MODULE_DESCRIPTION("DM Multipath ALUA support"); | |
800 | MODULE_AUTHOR("Hannes Reinecke <hare@suse.de>"); | |
801 | MODULE_LICENSE("GPL"); | |
802 | MODULE_VERSION(ALUA_DH_VER); |