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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 | */ | |
5a0e3ad6 | 22 | #include <linux/slab.h> |
057ea7c9 HR |
23 | #include <scsi/scsi.h> |
24 | #include <scsi/scsi_eh.h> | |
25 | #include <scsi/scsi_dh.h> | |
26 | ||
27 | #define ALUA_DH_NAME "alua" | |
28 | #define ALUA_DH_VER "1.2" | |
29 | ||
30 | #define TPGS_STATE_OPTIMIZED 0x0 | |
31 | #define TPGS_STATE_NONOPTIMIZED 0x1 | |
32 | #define TPGS_STATE_STANDBY 0x2 | |
33 | #define TPGS_STATE_UNAVAILABLE 0x3 | |
34 | #define TPGS_STATE_OFFLINE 0xe | |
35 | #define TPGS_STATE_TRANSITIONING 0xf | |
36 | ||
37 | #define TPGS_SUPPORT_NONE 0x00 | |
38 | #define TPGS_SUPPORT_OPTIMIZED 0x01 | |
39 | #define TPGS_SUPPORT_NONOPTIMIZED 0x02 | |
40 | #define TPGS_SUPPORT_STANDBY 0x04 | |
41 | #define TPGS_SUPPORT_UNAVAILABLE 0x08 | |
42 | #define TPGS_SUPPORT_OFFLINE 0x40 | |
43 | #define TPGS_SUPPORT_TRANSITION 0x80 | |
44 | ||
45 | #define TPGS_MODE_UNINITIALIZED -1 | |
46 | #define TPGS_MODE_NONE 0x0 | |
47 | #define TPGS_MODE_IMPLICIT 0x1 | |
48 | #define TPGS_MODE_EXPLICIT 0x2 | |
49 | ||
50 | #define ALUA_INQUIRY_SIZE 36 | |
51 | #define ALUA_FAILOVER_TIMEOUT (60 * HZ) | |
52 | #define ALUA_FAILOVER_RETRIES 5 | |
53 | ||
54 | struct alua_dh_data { | |
55 | int group_id; | |
56 | int rel_port; | |
57 | int tpgs; | |
58 | int state; | |
59 | unsigned char inq[ALUA_INQUIRY_SIZE]; | |
60 | unsigned char *buff; | |
61 | int bufflen; | |
62 | unsigned char sense[SCSI_SENSE_BUFFERSIZE]; | |
63 | int senselen; | |
96e65865 CS |
64 | struct scsi_device *sdev; |
65 | activate_complete callback_fn; | |
66 | void *callback_data; | |
057ea7c9 HR |
67 | }; |
68 | ||
69 | #define ALUA_POLICY_SWITCH_CURRENT 0 | |
70 | #define ALUA_POLICY_SWITCH_ALL 1 | |
71 | ||
96e65865 CS |
72 | static char print_alua_state(int); |
73 | static int alua_check_sense(struct scsi_device *, struct scsi_sense_hdr *); | |
74 | ||
057ea7c9 HR |
75 | static inline struct alua_dh_data *get_alua_data(struct scsi_device *sdev) |
76 | { | |
77 | struct scsi_dh_data *scsi_dh_data = sdev->scsi_dh_data; | |
78 | BUG_ON(scsi_dh_data == NULL); | |
79 | return ((struct alua_dh_data *) scsi_dh_data->buf); | |
80 | } | |
81 | ||
82 | static int realloc_buffer(struct alua_dh_data *h, unsigned len) | |
83 | { | |
84 | if (h->buff && h->buff != h->inq) | |
85 | kfree(h->buff); | |
86 | ||
87 | h->buff = kmalloc(len, GFP_NOIO); | |
88 | if (!h->buff) { | |
89 | h->buff = h->inq; | |
90 | h->bufflen = ALUA_INQUIRY_SIZE; | |
91 | return 1; | |
92 | } | |
93 | h->bufflen = len; | |
94 | return 0; | |
95 | } | |
96 | ||
97 | static struct request *get_alua_req(struct scsi_device *sdev, | |
98 | void *buffer, unsigned buflen, int rw) | |
99 | { | |
100 | struct request *rq; | |
101 | struct request_queue *q = sdev->request_queue; | |
102 | ||
103 | rq = blk_get_request(q, rw, GFP_NOIO); | |
104 | ||
105 | if (!rq) { | |
106 | sdev_printk(KERN_INFO, sdev, | |
cadbd4a5 | 107 | "%s: blk_get_request failed\n", __func__); |
057ea7c9 HR |
108 | return NULL; |
109 | } | |
110 | ||
111 | if (buflen && blk_rq_map_kern(q, rq, buffer, buflen, GFP_NOIO)) { | |
112 | blk_put_request(rq); | |
113 | sdev_printk(KERN_INFO, sdev, | |
cadbd4a5 | 114 | "%s: blk_rq_map_kern failed\n", __func__); |
057ea7c9 HR |
115 | return NULL; |
116 | } | |
117 | ||
118 | rq->cmd_type = REQ_TYPE_BLOCK_PC; | |
6000a368 | 119 | rq->cmd_flags |= REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT | |
64f84bc1 | 120 | REQ_FAILFAST_DRIVER; |
057ea7c9 HR |
121 | rq->retries = ALUA_FAILOVER_RETRIES; |
122 | rq->timeout = ALUA_FAILOVER_TIMEOUT; | |
123 | ||
124 | return rq; | |
125 | } | |
126 | ||
127 | /* | |
128 | * submit_std_inquiry - Issue a standard INQUIRY command | |
129 | * @sdev: sdev the command should be send to | |
130 | */ | |
131 | static int submit_std_inquiry(struct scsi_device *sdev, struct alua_dh_data *h) | |
132 | { | |
133 | struct request *rq; | |
134 | int err = SCSI_DH_RES_TEMP_UNAVAIL; | |
135 | ||
136 | rq = get_alua_req(sdev, h->inq, ALUA_INQUIRY_SIZE, READ); | |
137 | if (!rq) | |
138 | goto done; | |
139 | ||
140 | /* Prepare the command. */ | |
141 | rq->cmd[0] = INQUIRY; | |
142 | rq->cmd[1] = 0; | |
143 | rq->cmd[2] = 0; | |
144 | rq->cmd[4] = ALUA_INQUIRY_SIZE; | |
145 | rq->cmd_len = COMMAND_SIZE(INQUIRY); | |
146 | ||
147 | rq->sense = h->sense; | |
148 | memset(rq->sense, 0, SCSI_SENSE_BUFFERSIZE); | |
149 | rq->sense_len = h->senselen = 0; | |
150 | ||
151 | err = blk_execute_rq(rq->q, NULL, rq, 1); | |
152 | if (err == -EIO) { | |
153 | sdev_printk(KERN_INFO, sdev, | |
154 | "%s: std inquiry failed with %x\n", | |
155 | ALUA_DH_NAME, rq->errors); | |
156 | h->senselen = rq->sense_len; | |
157 | err = SCSI_DH_IO; | |
158 | } | |
159 | blk_put_request(rq); | |
160 | done: | |
161 | return err; | |
162 | } | |
163 | ||
164 | /* | |
165 | * submit_vpd_inquiry - Issue an INQUIRY VPD page 0x83 command | |
166 | * @sdev: sdev the command should be sent to | |
167 | */ | |
168 | static int submit_vpd_inquiry(struct scsi_device *sdev, struct alua_dh_data *h) | |
169 | { | |
170 | struct request *rq; | |
171 | int err = SCSI_DH_RES_TEMP_UNAVAIL; | |
172 | ||
173 | rq = get_alua_req(sdev, h->buff, h->bufflen, READ); | |
174 | if (!rq) | |
175 | goto done; | |
176 | ||
177 | /* Prepare the command. */ | |
178 | rq->cmd[0] = INQUIRY; | |
179 | rq->cmd[1] = 1; | |
180 | rq->cmd[2] = 0x83; | |
181 | rq->cmd[4] = h->bufflen; | |
182 | rq->cmd_len = COMMAND_SIZE(INQUIRY); | |
183 | ||
184 | rq->sense = h->sense; | |
185 | memset(rq->sense, 0, SCSI_SENSE_BUFFERSIZE); | |
186 | rq->sense_len = h->senselen = 0; | |
187 | ||
188 | err = blk_execute_rq(rq->q, NULL, rq, 1); | |
189 | if (err == -EIO) { | |
190 | sdev_printk(KERN_INFO, sdev, | |
191 | "%s: evpd inquiry failed with %x\n", | |
192 | ALUA_DH_NAME, rq->errors); | |
193 | h->senselen = rq->sense_len; | |
194 | err = SCSI_DH_IO; | |
195 | } | |
196 | blk_put_request(rq); | |
197 | done: | |
198 | return err; | |
199 | } | |
200 | ||
201 | /* | |
202 | * submit_rtpg - Issue a REPORT TARGET GROUP STATES command | |
203 | * @sdev: sdev the command should be sent to | |
204 | */ | |
205 | static unsigned submit_rtpg(struct scsi_device *sdev, struct alua_dh_data *h) | |
206 | { | |
207 | struct request *rq; | |
208 | int err = SCSI_DH_RES_TEMP_UNAVAIL; | |
209 | ||
210 | rq = get_alua_req(sdev, h->buff, h->bufflen, READ); | |
211 | if (!rq) | |
212 | goto done; | |
213 | ||
214 | /* Prepare the command. */ | |
215 | rq->cmd[0] = MAINTENANCE_IN; | |
216 | rq->cmd[1] = MI_REPORT_TARGET_PGS; | |
217 | rq->cmd[6] = (h->bufflen >> 24) & 0xff; | |
218 | rq->cmd[7] = (h->bufflen >> 16) & 0xff; | |
219 | rq->cmd[8] = (h->bufflen >> 8) & 0xff; | |
220 | rq->cmd[9] = h->bufflen & 0xff; | |
221 | rq->cmd_len = COMMAND_SIZE(MAINTENANCE_IN); | |
222 | ||
223 | rq->sense = h->sense; | |
224 | memset(rq->sense, 0, SCSI_SENSE_BUFFERSIZE); | |
225 | rq->sense_len = h->senselen = 0; | |
226 | ||
227 | err = blk_execute_rq(rq->q, NULL, rq, 1); | |
228 | if (err == -EIO) { | |
229 | sdev_printk(KERN_INFO, sdev, | |
230 | "%s: rtpg failed with %x\n", | |
231 | ALUA_DH_NAME, rq->errors); | |
232 | h->senselen = rq->sense_len; | |
233 | err = SCSI_DH_IO; | |
234 | } | |
235 | blk_put_request(rq); | |
236 | done: | |
237 | return err; | |
238 | } | |
239 | ||
96e65865 CS |
240 | /* |
241 | * alua_stpg - Evaluate SET TARGET GROUP STATES | |
242 | * @sdev: the device to be evaluated | |
243 | * @state: the new target group state | |
244 | * | |
245 | * Send a SET TARGET GROUP STATES command to the device. | |
246 | * We only have to test here if we should resubmit the command; | |
247 | * any other error is assumed as a failure. | |
248 | */ | |
249 | static void stpg_endio(struct request *req, int error) | |
250 | { | |
251 | struct alua_dh_data *h = req->end_io_data; | |
252 | struct scsi_sense_hdr sense_hdr; | |
253 | unsigned err = SCSI_DH_IO; | |
254 | ||
255 | if (error || host_byte(req->errors) != DID_OK || | |
256 | msg_byte(req->errors) != COMMAND_COMPLETE) | |
257 | goto done; | |
258 | ||
259 | if (err == SCSI_DH_IO && h->senselen > 0) { | |
260 | err = scsi_normalize_sense(h->sense, SCSI_SENSE_BUFFERSIZE, | |
261 | &sense_hdr); | |
262 | if (!err) { | |
263 | err = SCSI_DH_IO; | |
264 | goto done; | |
265 | } | |
266 | err = alua_check_sense(h->sdev, &sense_hdr); | |
267 | if (err == ADD_TO_MLQUEUE) { | |
268 | err = SCSI_DH_RETRY; | |
269 | goto done; | |
270 | } | |
271 | sdev_printk(KERN_INFO, h->sdev, | |
272 | "%s: stpg sense code: %02x/%02x/%02x\n", | |
273 | ALUA_DH_NAME, sense_hdr.sense_key, | |
274 | sense_hdr.asc, sense_hdr.ascq); | |
275 | err = SCSI_DH_IO; | |
276 | } | |
277 | if (err == SCSI_DH_OK) { | |
278 | h->state = TPGS_STATE_OPTIMIZED; | |
279 | sdev_printk(KERN_INFO, h->sdev, | |
280 | "%s: port group %02x switched to state %c\n", | |
281 | ALUA_DH_NAME, h->group_id, | |
282 | print_alua_state(h->state)); | |
283 | } | |
284 | done: | |
285 | blk_put_request(req); | |
286 | if (h->callback_fn) { | |
287 | h->callback_fn(h->callback_data, err); | |
288 | h->callback_fn = h->callback_data = NULL; | |
289 | } | |
290 | return; | |
291 | } | |
292 | ||
057ea7c9 HR |
293 | /* |
294 | * submit_stpg - Issue a SET TARGET GROUP STATES command | |
057ea7c9 HR |
295 | * |
296 | * Currently we're only setting the current target port group state | |
297 | * to 'active/optimized' and let the array firmware figure out | |
298 | * the states of the remaining groups. | |
299 | */ | |
96e65865 | 300 | static unsigned submit_stpg(struct alua_dh_data *h) |
057ea7c9 HR |
301 | { |
302 | struct request *rq; | |
303 | int err = SCSI_DH_RES_TEMP_UNAVAIL; | |
304 | int stpg_len = 8; | |
96e65865 | 305 | struct scsi_device *sdev = h->sdev; |
057ea7c9 HR |
306 | |
307 | /* Prepare the data buffer */ | |
308 | memset(h->buff, 0, stpg_len); | |
309 | h->buff[4] = TPGS_STATE_OPTIMIZED & 0x0f; | |
ef3fa8c6 IH |
310 | h->buff[6] = (h->group_id >> 8) & 0xff; |
311 | h->buff[7] = h->group_id & 0xff; | |
057ea7c9 HR |
312 | |
313 | rq = get_alua_req(sdev, h->buff, stpg_len, WRITE); | |
314 | if (!rq) | |
96e65865 | 315 | return SCSI_DH_RES_TEMP_UNAVAIL; |
057ea7c9 HR |
316 | |
317 | /* Prepare the command. */ | |
318 | rq->cmd[0] = MAINTENANCE_OUT; | |
319 | rq->cmd[1] = MO_SET_TARGET_PGS; | |
320 | rq->cmd[6] = (stpg_len >> 24) & 0xff; | |
321 | rq->cmd[7] = (stpg_len >> 16) & 0xff; | |
322 | rq->cmd[8] = (stpg_len >> 8) & 0xff; | |
323 | rq->cmd[9] = stpg_len & 0xff; | |
324 | rq->cmd_len = COMMAND_SIZE(MAINTENANCE_OUT); | |
325 | ||
326 | rq->sense = h->sense; | |
327 | memset(rq->sense, 0, SCSI_SENSE_BUFFERSIZE); | |
328 | rq->sense_len = h->senselen = 0; | |
96e65865 | 329 | rq->end_io_data = h; |
057ea7c9 | 330 | |
96e65865 | 331 | blk_execute_rq_nowait(rq->q, NULL, rq, 1, stpg_endio); |
057ea7c9 HR |
332 | return err; |
333 | } | |
334 | ||
335 | /* | |
336 | * alua_std_inquiry - Evaluate standard INQUIRY command | |
337 | * @sdev: device to be checked | |
338 | * | |
339 | * Just extract the TPGS setting to find out if ALUA | |
340 | * is supported. | |
341 | */ | |
342 | static int alua_std_inquiry(struct scsi_device *sdev, struct alua_dh_data *h) | |
343 | { | |
344 | int err; | |
345 | ||
346 | err = submit_std_inquiry(sdev, h); | |
347 | ||
348 | if (err != SCSI_DH_OK) | |
349 | return err; | |
350 | ||
351 | /* Check TPGS setting */ | |
352 | h->tpgs = (h->inq[5] >> 4) & 0x3; | |
353 | switch (h->tpgs) { | |
354 | case TPGS_MODE_EXPLICIT|TPGS_MODE_IMPLICIT: | |
355 | sdev_printk(KERN_INFO, sdev, | |
356 | "%s: supports implicit and explicit TPGS\n", | |
357 | ALUA_DH_NAME); | |
358 | break; | |
359 | case TPGS_MODE_EXPLICIT: | |
360 | sdev_printk(KERN_INFO, sdev, "%s: supports explicit TPGS\n", | |
361 | ALUA_DH_NAME); | |
362 | break; | |
363 | case TPGS_MODE_IMPLICIT: | |
364 | sdev_printk(KERN_INFO, sdev, "%s: supports implicit TPGS\n", | |
365 | ALUA_DH_NAME); | |
366 | break; | |
367 | default: | |
368 | h->tpgs = TPGS_MODE_NONE; | |
369 | sdev_printk(KERN_INFO, sdev, "%s: not supported\n", | |
370 | ALUA_DH_NAME); | |
371 | err = SCSI_DH_DEV_UNSUPP; | |
372 | break; | |
373 | } | |
374 | ||
375 | return err; | |
376 | } | |
377 | ||
378 | /* | |
379 | * alua_vpd_inquiry - Evaluate INQUIRY vpd page 0x83 | |
380 | * @sdev: device to be checked | |
381 | * | |
382 | * Extract the relative target port and the target port group | |
383 | * descriptor from the list of identificators. | |
384 | */ | |
385 | static int alua_vpd_inquiry(struct scsi_device *sdev, struct alua_dh_data *h) | |
386 | { | |
387 | int len; | |
388 | unsigned err; | |
389 | unsigned char *d; | |
390 | ||
391 | retry: | |
392 | err = submit_vpd_inquiry(sdev, h); | |
393 | ||
394 | if (err != SCSI_DH_OK) | |
395 | return err; | |
396 | ||
397 | /* Check if vpd page exceeds initial buffer */ | |
398 | len = (h->buff[2] << 8) + h->buff[3] + 4; | |
399 | if (len > h->bufflen) { | |
400 | /* Resubmit with the correct length */ | |
401 | if (realloc_buffer(h, len)) { | |
402 | sdev_printk(KERN_WARNING, sdev, | |
403 | "%s: kmalloc buffer failed\n", | |
404 | ALUA_DH_NAME); | |
405 | /* Temporary failure, bypass */ | |
406 | return SCSI_DH_DEV_TEMP_BUSY; | |
407 | } | |
408 | goto retry; | |
409 | } | |
410 | ||
411 | /* | |
412 | * Now look for the correct descriptor. | |
413 | */ | |
414 | d = h->buff + 4; | |
415 | while (d < h->buff + len) { | |
416 | switch (d[1] & 0xf) { | |
417 | case 0x4: | |
418 | /* Relative target port */ | |
419 | h->rel_port = (d[6] << 8) + d[7]; | |
420 | break; | |
421 | case 0x5: | |
422 | /* Target port group */ | |
423 | h->group_id = (d[6] << 8) + d[7]; | |
424 | break; | |
425 | default: | |
426 | break; | |
427 | } | |
428 | d += d[3] + 4; | |
429 | } | |
430 | ||
431 | if (h->group_id == -1) { | |
432 | /* | |
433 | * Internal error; TPGS supported but required | |
434 | * VPD identification descriptors not present. | |
435 | * Disable ALUA support | |
436 | */ | |
437 | sdev_printk(KERN_INFO, sdev, | |
438 | "%s: No target port descriptors found\n", | |
439 | ALUA_DH_NAME); | |
440 | h->state = TPGS_STATE_OPTIMIZED; | |
441 | h->tpgs = TPGS_MODE_NONE; | |
442 | err = SCSI_DH_DEV_UNSUPP; | |
443 | } else { | |
444 | sdev_printk(KERN_INFO, sdev, | |
445 | "%s: port group %02x rel port %02x\n", | |
446 | ALUA_DH_NAME, h->group_id, h->rel_port); | |
447 | } | |
448 | ||
449 | return err; | |
450 | } | |
451 | ||
452 | static char print_alua_state(int state) | |
453 | { | |
454 | switch (state) { | |
455 | case TPGS_STATE_OPTIMIZED: | |
456 | return 'A'; | |
457 | case TPGS_STATE_NONOPTIMIZED: | |
458 | return 'N'; | |
459 | case TPGS_STATE_STANDBY: | |
460 | return 'S'; | |
461 | case TPGS_STATE_UNAVAILABLE: | |
462 | return 'U'; | |
463 | case TPGS_STATE_OFFLINE: | |
464 | return 'O'; | |
465 | case TPGS_STATE_TRANSITIONING: | |
466 | return 'T'; | |
467 | default: | |
468 | return 'X'; | |
469 | } | |
470 | } | |
471 | ||
472 | static int alua_check_sense(struct scsi_device *sdev, | |
473 | struct scsi_sense_hdr *sense_hdr) | |
474 | { | |
475 | switch (sense_hdr->sense_key) { | |
476 | case NOT_READY: | |
477 | if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x0a) | |
478 | /* | |
479 | * LUN Not Accessible - ALUA state transition | |
480 | */ | |
c7dbb627 | 481 | return ADD_TO_MLQUEUE; |
057ea7c9 HR |
482 | if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x0b) |
483 | /* | |
484 | * LUN Not Accessible -- Target port in standby state | |
485 | */ | |
486 | return SUCCESS; | |
487 | if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x0c) | |
488 | /* | |
489 | * LUN Not Accessible -- Target port in unavailable state | |
490 | */ | |
491 | return SUCCESS; | |
492 | if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x12) | |
493 | /* | |
494 | * LUN Not Ready -- Offline | |
495 | */ | |
496 | return SUCCESS; | |
497 | break; | |
498 | case UNIT_ATTENTION: | |
499 | if (sense_hdr->asc == 0x29 && sense_hdr->ascq == 0x00) | |
500 | /* | |
501 | * Power On, Reset, or Bus Device Reset, just retry. | |
502 | */ | |
c7dbb627 | 503 | return ADD_TO_MLQUEUE; |
057ea7c9 HR |
504 | if (sense_hdr->asc == 0x2a && sense_hdr->ascq == 0x06) { |
505 | /* | |
506 | * ALUA state changed | |
507 | */ | |
c7dbb627 | 508 | return ADD_TO_MLQUEUE; |
057ea7c9 HR |
509 | } |
510 | if (sense_hdr->asc == 0x2a && sense_hdr->ascq == 0x07) { | |
511 | /* | |
512 | * Implicit ALUA state transition failed | |
513 | */ | |
c7dbb627 | 514 | return ADD_TO_MLQUEUE; |
057ea7c9 | 515 | } |
4d086f6b IH |
516 | if (sense_hdr->asc == 0x3f && sense_hdr->ascq == 0x0e) { |
517 | /* | |
518 | * REPORTED_LUNS_DATA_HAS_CHANGED is reported | |
519 | * when switching controllers on targets like | |
520 | * Intel Multi-Flex. We can just retry. | |
521 | */ | |
522 | return ADD_TO_MLQUEUE; | |
523 | } | |
524 | ||
057ea7c9 HR |
525 | break; |
526 | } | |
527 | ||
528 | return SCSI_RETURN_NOT_HANDLED; | |
529 | } | |
530 | ||
057ea7c9 HR |
531 | /* |
532 | * alua_rtpg - Evaluate REPORT TARGET GROUP STATES | |
533 | * @sdev: the device to be evaluated. | |
534 | * | |
535 | * Evaluate the Target Port Group State. | |
536 | * Returns SCSI_DH_DEV_OFFLINED if the path is | |
537 | * found to be unuseable. | |
538 | */ | |
539 | static int alua_rtpg(struct scsi_device *sdev, struct alua_dh_data *h) | |
540 | { | |
541 | struct scsi_sense_hdr sense_hdr; | |
542 | int len, k, off, valid_states = 0; | |
543 | char *ucp; | |
544 | unsigned err; | |
545 | ||
546 | retry: | |
547 | err = submit_rtpg(sdev, h); | |
548 | ||
549 | if (err == SCSI_DH_IO && h->senselen > 0) { | |
550 | err = scsi_normalize_sense(h->sense, SCSI_SENSE_BUFFERSIZE, | |
551 | &sense_hdr); | |
552 | if (!err) | |
553 | return SCSI_DH_IO; | |
554 | ||
555 | err = alua_check_sense(sdev, &sense_hdr); | |
c7dbb627 | 556 | if (err == ADD_TO_MLQUEUE) |
057ea7c9 HR |
557 | goto retry; |
558 | sdev_printk(KERN_INFO, sdev, | |
559 | "%s: rtpg sense code %02x/%02x/%02x\n", | |
560 | ALUA_DH_NAME, sense_hdr.sense_key, | |
561 | sense_hdr.asc, sense_hdr.ascq); | |
562 | err = SCSI_DH_IO; | |
563 | } | |
564 | if (err != SCSI_DH_OK) | |
565 | return err; | |
566 | ||
567 | len = (h->buff[0] << 24) + (h->buff[1] << 16) + | |
568 | (h->buff[2] << 8) + h->buff[3] + 4; | |
569 | ||
570 | if (len > h->bufflen) { | |
571 | /* Resubmit with the correct length */ | |
572 | if (realloc_buffer(h, len)) { | |
573 | sdev_printk(KERN_WARNING, sdev, | |
cadbd4a5 | 574 | "%s: kmalloc buffer failed\n",__func__); |
057ea7c9 HR |
575 | /* Temporary failure, bypass */ |
576 | return SCSI_DH_DEV_TEMP_BUSY; | |
577 | } | |
578 | goto retry; | |
579 | } | |
580 | ||
581 | for (k = 4, ucp = h->buff + 4; k < len; k += off, ucp += off) { | |
582 | if (h->group_id == (ucp[2] << 8) + ucp[3]) { | |
583 | h->state = ucp[0] & 0x0f; | |
584 | valid_states = ucp[1]; | |
585 | } | |
586 | off = 8 + (ucp[7] * 4); | |
587 | } | |
588 | ||
589 | sdev_printk(KERN_INFO, sdev, | |
590 | "%s: port group %02x state %c supports %c%c%c%c%c%c\n", | |
591 | ALUA_DH_NAME, h->group_id, print_alua_state(h->state), | |
592 | valid_states&TPGS_SUPPORT_TRANSITION?'T':'t', | |
593 | valid_states&TPGS_SUPPORT_OFFLINE?'O':'o', | |
594 | valid_states&TPGS_SUPPORT_UNAVAILABLE?'U':'u', | |
595 | valid_states&TPGS_SUPPORT_STANDBY?'S':'s', | |
596 | valid_states&TPGS_SUPPORT_NONOPTIMIZED?'N':'n', | |
597 | valid_states&TPGS_SUPPORT_OPTIMIZED?'A':'a'); | |
598 | ||
599 | if (h->tpgs & TPGS_MODE_EXPLICIT) { | |
600 | switch (h->state) { | |
601 | case TPGS_STATE_TRANSITIONING: | |
602 | /* State transition, retry */ | |
603 | goto retry; | |
604 | break; | |
605 | case TPGS_STATE_OFFLINE: | |
606 | /* Path is offline, fail */ | |
607 | err = SCSI_DH_DEV_OFFLINED; | |
608 | break; | |
609 | default: | |
610 | break; | |
611 | } | |
612 | } else { | |
613 | /* Only Implicit ALUA support */ | |
614 | if (h->state == TPGS_STATE_OPTIMIZED || | |
615 | h->state == TPGS_STATE_NONOPTIMIZED || | |
616 | h->state == TPGS_STATE_STANDBY) | |
617 | /* Useable path if active */ | |
618 | err = SCSI_DH_OK; | |
619 | else | |
620 | /* Path unuseable for unavailable/offline */ | |
621 | err = SCSI_DH_DEV_OFFLINED; | |
622 | } | |
623 | return err; | |
624 | } | |
625 | ||
626 | /* | |
627 | * alua_initialize - Initialize ALUA state | |
628 | * @sdev: the device to be initialized | |
629 | * | |
630 | * For the prep_fn to work correctly we have | |
631 | * to initialize the ALUA state for the device. | |
632 | */ | |
633 | static int alua_initialize(struct scsi_device *sdev, struct alua_dh_data *h) | |
634 | { | |
635 | int err; | |
636 | ||
637 | err = alua_std_inquiry(sdev, h); | |
638 | if (err != SCSI_DH_OK) | |
639 | goto out; | |
640 | ||
641 | err = alua_vpd_inquiry(sdev, h); | |
642 | if (err != SCSI_DH_OK) | |
643 | goto out; | |
644 | ||
645 | err = alua_rtpg(sdev, h); | |
646 | if (err != SCSI_DH_OK) | |
647 | goto out; | |
648 | ||
649 | out: | |
650 | return err; | |
651 | } | |
652 | ||
653 | /* | |
654 | * alua_activate - activate a path | |
655 | * @sdev: device on the path to be activated | |
656 | * | |
657 | * We're currently switching the port group to be activated only and | |
658 | * let the array figure out the rest. | |
659 | * There may be other arrays which require us to switch all port groups | |
660 | * based on a certain policy. But until we actually encounter them it | |
661 | * should be okay. | |
662 | */ | |
3ae31f6a CS |
663 | static int alua_activate(struct scsi_device *sdev, |
664 | activate_complete fn, void *data) | |
057ea7c9 HR |
665 | { |
666 | struct alua_dh_data *h = get_alua_data(sdev); | |
667 | int err = SCSI_DH_OK; | |
668 | ||
669 | if (h->group_id != -1) { | |
670 | err = alua_rtpg(sdev, h); | |
671 | if (err != SCSI_DH_OK) | |
672 | goto out; | |
673 | } | |
674 | ||
96e65865 CS |
675 | if (h->tpgs & TPGS_MODE_EXPLICIT && h->state != TPGS_STATE_OPTIMIZED) { |
676 | h->callback_fn = fn; | |
677 | h->callback_data = data; | |
678 | err = submit_stpg(h); | |
679 | if (err == SCSI_DH_OK) | |
680 | return 0; | |
681 | h->callback_fn = h->callback_data = NULL; | |
682 | } | |
057ea7c9 HR |
683 | |
684 | out: | |
3ae31f6a CS |
685 | if (fn) |
686 | fn(data, err); | |
687 | return 0; | |
057ea7c9 HR |
688 | } |
689 | ||
690 | /* | |
691 | * alua_prep_fn - request callback | |
692 | * | |
693 | * Fail I/O to all paths not in state | |
694 | * active/optimized or active/non-optimized. | |
695 | */ | |
696 | static int alua_prep_fn(struct scsi_device *sdev, struct request *req) | |
697 | { | |
698 | struct alua_dh_data *h = get_alua_data(sdev); | |
699 | int ret = BLKPREP_OK; | |
700 | ||
701 | if (h->state != TPGS_STATE_OPTIMIZED && | |
702 | h->state != TPGS_STATE_NONOPTIMIZED) { | |
703 | ret = BLKPREP_KILL; | |
704 | req->cmd_flags |= REQ_QUIET; | |
705 | } | |
706 | return ret; | |
707 | ||
708 | } | |
709 | ||
f08c0761 | 710 | static const struct scsi_dh_devlist alua_dev_list[] = { |
057ea7c9 HR |
711 | {"HP", "MSA VOLUME" }, |
712 | {"HP", "HSV101" }, | |
713 | {"HP", "HSV111" }, | |
714 | {"HP", "HSV200" }, | |
715 | {"HP", "HSV210" }, | |
716 | {"HP", "HSV300" }, | |
717 | {"IBM", "2107900" }, | |
718 | {"IBM", "2145" }, | |
719 | {"Pillar", "Axiom" }, | |
49baef0a | 720 | {"Intel", "Multi-Flex"}, |
cd4a8814 | 721 | {"NETAPP", "LUN"}, |
22963a37 | 722 | {"AIX", "NVDISK"}, |
057ea7c9 HR |
723 | {NULL, NULL} |
724 | }; | |
725 | ||
726 | static int alua_bus_attach(struct scsi_device *sdev); | |
727 | static void alua_bus_detach(struct scsi_device *sdev); | |
728 | ||
729 | static struct scsi_device_handler alua_dh = { | |
730 | .name = ALUA_DH_NAME, | |
731 | .module = THIS_MODULE, | |
732 | .devlist = alua_dev_list, | |
733 | .attach = alua_bus_attach, | |
734 | .detach = alua_bus_detach, | |
735 | .prep_fn = alua_prep_fn, | |
736 | .check_sense = alua_check_sense, | |
737 | .activate = alua_activate, | |
738 | }; | |
739 | ||
740 | /* | |
741 | * alua_bus_attach - Attach device handler | |
742 | * @sdev: device to be attached to | |
743 | */ | |
744 | static int alua_bus_attach(struct scsi_device *sdev) | |
745 | { | |
746 | struct scsi_dh_data *scsi_dh_data; | |
747 | struct alua_dh_data *h; | |
748 | unsigned long flags; | |
749 | int err = SCSI_DH_OK; | |
750 | ||
751 | scsi_dh_data = kzalloc(sizeof(struct scsi_device_handler *) | |
752 | + sizeof(*h) , GFP_KERNEL); | |
753 | if (!scsi_dh_data) { | |
754 | sdev_printk(KERN_ERR, sdev, "%s: Attach failed\n", | |
755 | ALUA_DH_NAME); | |
756 | return -ENOMEM; | |
757 | } | |
758 | ||
759 | scsi_dh_data->scsi_dh = &alua_dh; | |
760 | h = (struct alua_dh_data *) scsi_dh_data->buf; | |
761 | h->tpgs = TPGS_MODE_UNINITIALIZED; | |
762 | h->state = TPGS_STATE_OPTIMIZED; | |
763 | h->group_id = -1; | |
764 | h->rel_port = -1; | |
765 | h->buff = h->inq; | |
766 | h->bufflen = ALUA_INQUIRY_SIZE; | |
96e65865 | 767 | h->sdev = sdev; |
057ea7c9 HR |
768 | |
769 | err = alua_initialize(sdev, h); | |
770 | if (err != SCSI_DH_OK) | |
771 | goto failed; | |
772 | ||
773 | if (!try_module_get(THIS_MODULE)) | |
774 | goto failed; | |
775 | ||
776 | spin_lock_irqsave(sdev->request_queue->queue_lock, flags); | |
777 | sdev->scsi_dh_data = scsi_dh_data; | |
778 | spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags); | |
779 | ||
780 | return 0; | |
781 | ||
782 | failed: | |
783 | kfree(scsi_dh_data); | |
784 | sdev_printk(KERN_ERR, sdev, "%s: not attached\n", ALUA_DH_NAME); | |
785 | return -EINVAL; | |
786 | } | |
787 | ||
788 | /* | |
789 | * alua_bus_detach - Detach device handler | |
790 | * @sdev: device to be detached from | |
791 | */ | |
792 | static void alua_bus_detach(struct scsi_device *sdev) | |
793 | { | |
794 | struct scsi_dh_data *scsi_dh_data; | |
795 | struct alua_dh_data *h; | |
796 | unsigned long flags; | |
797 | ||
798 | spin_lock_irqsave(sdev->request_queue->queue_lock, flags); | |
799 | scsi_dh_data = sdev->scsi_dh_data; | |
800 | sdev->scsi_dh_data = NULL; | |
801 | spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags); | |
802 | ||
803 | h = (struct alua_dh_data *) scsi_dh_data->buf; | |
804 | if (h->buff && h->inq != h->buff) | |
805 | kfree(h->buff); | |
806 | kfree(scsi_dh_data); | |
807 | module_put(THIS_MODULE); | |
808 | sdev_printk(KERN_NOTICE, sdev, "%s: Detached\n", ALUA_DH_NAME); | |
809 | } | |
810 | ||
811 | static int __init alua_init(void) | |
812 | { | |
813 | int r; | |
814 | ||
815 | r = scsi_register_device_handler(&alua_dh); | |
816 | if (r != 0) | |
817 | printk(KERN_ERR "%s: Failed to register scsi device handler", | |
818 | ALUA_DH_NAME); | |
819 | return r; | |
820 | } | |
821 | ||
822 | static void __exit alua_exit(void) | |
823 | { | |
824 | scsi_unregister_device_handler(&alua_dh); | |
825 | } | |
826 | ||
827 | module_init(alua_init); | |
828 | module_exit(alua_exit); | |
829 | ||
830 | MODULE_DESCRIPTION("DM Multipath ALUA support"); | |
831 | MODULE_AUTHOR("Hannes Reinecke <hare@suse.de>"); | |
832 | MODULE_LICENSE("GPL"); | |
833 | MODULE_VERSION(ALUA_DH_VER); |