Commit | Line | Data |
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057ea7c9 HR |
1 | /* |
2 | * Generic SCSI-3 ALUA SCSI Device Handler | |
3 | * | |
69723d17 | 4 | * Copyright (C) 2007-2010 Hannes Reinecke, SUSE Linux Products GmbH. |
057ea7c9 HR |
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> |
69723d17 | 23 | #include <linux/delay.h> |
acf3368f | 24 | #include <linux/module.h> |
057ea7c9 HR |
25 | #include <scsi/scsi.h> |
26 | #include <scsi/scsi_eh.h> | |
27 | #include <scsi/scsi_dh.h> | |
28 | ||
29 | #define ALUA_DH_NAME "alua" | |
69723d17 | 30 | #define ALUA_DH_VER "1.3" |
057ea7c9 HR |
31 | |
32 | #define TPGS_STATE_OPTIMIZED 0x0 | |
33 | #define TPGS_STATE_NONOPTIMIZED 0x1 | |
34 | #define TPGS_STATE_STANDBY 0x2 | |
35 | #define TPGS_STATE_UNAVAILABLE 0x3 | |
69723d17 | 36 | #define TPGS_STATE_LBA_DEPENDENT 0x4 |
057ea7c9 HR |
37 | #define TPGS_STATE_OFFLINE 0xe |
38 | #define TPGS_STATE_TRANSITIONING 0xf | |
39 | ||
40 | #define TPGS_SUPPORT_NONE 0x00 | |
41 | #define TPGS_SUPPORT_OPTIMIZED 0x01 | |
42 | #define TPGS_SUPPORT_NONOPTIMIZED 0x02 | |
43 | #define TPGS_SUPPORT_STANDBY 0x04 | |
44 | #define TPGS_SUPPORT_UNAVAILABLE 0x08 | |
69723d17 | 45 | #define TPGS_SUPPORT_LBA_DEPENDENT 0x10 |
057ea7c9 HR |
46 | #define TPGS_SUPPORT_OFFLINE 0x40 |
47 | #define TPGS_SUPPORT_TRANSITION 0x80 | |
48 | ||
3588c5a2 RE |
49 | #define RTPG_FMT_MASK 0x70 |
50 | #define RTPG_FMT_EXT_HDR 0x10 | |
51 | ||
057ea7c9 HR |
52 | #define TPGS_MODE_UNINITIALIZED -1 |
53 | #define TPGS_MODE_NONE 0x0 | |
54 | #define TPGS_MODE_IMPLICIT 0x1 | |
55 | #define TPGS_MODE_EXPLICIT 0x2 | |
56 | ||
57 | #define ALUA_INQUIRY_SIZE 36 | |
3588c5a2 | 58 | #define ALUA_FAILOVER_TIMEOUT 60 |
057ea7c9 HR |
59 | #define ALUA_FAILOVER_RETRIES 5 |
60 | ||
4335d092 MB |
61 | /* flags passed from user level */ |
62 | #define ALUA_OPTIMIZE_STPG 1 | |
63 | ||
057ea7c9 HR |
64 | struct alua_dh_data { |
65 | int group_id; | |
66 | int rel_port; | |
67 | int tpgs; | |
68 | int state; | |
dcd3a754 | 69 | int pref; |
4335d092 | 70 | unsigned flags; /* used for optimizing STPG */ |
057ea7c9 HR |
71 | unsigned char inq[ALUA_INQUIRY_SIZE]; |
72 | unsigned char *buff; | |
73 | int bufflen; | |
3588c5a2 | 74 | unsigned char transition_tmo; |
057ea7c9 HR |
75 | unsigned char sense[SCSI_SENSE_BUFFERSIZE]; |
76 | int senselen; | |
96e65865 CS |
77 | struct scsi_device *sdev; |
78 | activate_complete callback_fn; | |
79 | void *callback_data; | |
057ea7c9 HR |
80 | }; |
81 | ||
82 | #define ALUA_POLICY_SWITCH_CURRENT 0 | |
83 | #define ALUA_POLICY_SWITCH_ALL 1 | |
84 | ||
96e65865 CS |
85 | static char print_alua_state(int); |
86 | static int alua_check_sense(struct scsi_device *, struct scsi_sense_hdr *); | |
87 | ||
057ea7c9 HR |
88 | static inline struct alua_dh_data *get_alua_data(struct scsi_device *sdev) |
89 | { | |
90 | struct scsi_dh_data *scsi_dh_data = sdev->scsi_dh_data; | |
91 | BUG_ON(scsi_dh_data == NULL); | |
92 | return ((struct alua_dh_data *) scsi_dh_data->buf); | |
93 | } | |
94 | ||
95 | static int realloc_buffer(struct alua_dh_data *h, unsigned len) | |
96 | { | |
97 | if (h->buff && h->buff != h->inq) | |
98 | kfree(h->buff); | |
99 | ||
100 | h->buff = kmalloc(len, GFP_NOIO); | |
101 | if (!h->buff) { | |
102 | h->buff = h->inq; | |
103 | h->bufflen = ALUA_INQUIRY_SIZE; | |
104 | return 1; | |
105 | } | |
106 | h->bufflen = len; | |
107 | return 0; | |
108 | } | |
109 | ||
110 | static struct request *get_alua_req(struct scsi_device *sdev, | |
111 | void *buffer, unsigned buflen, int rw) | |
112 | { | |
113 | struct request *rq; | |
114 | struct request_queue *q = sdev->request_queue; | |
115 | ||
116 | rq = blk_get_request(q, rw, GFP_NOIO); | |
117 | ||
118 | if (!rq) { | |
119 | sdev_printk(KERN_INFO, sdev, | |
cadbd4a5 | 120 | "%s: blk_get_request failed\n", __func__); |
057ea7c9 HR |
121 | return NULL; |
122 | } | |
123 | ||
124 | if (buflen && blk_rq_map_kern(q, rq, buffer, buflen, GFP_NOIO)) { | |
125 | blk_put_request(rq); | |
126 | sdev_printk(KERN_INFO, sdev, | |
cadbd4a5 | 127 | "%s: blk_rq_map_kern failed\n", __func__); |
057ea7c9 HR |
128 | return NULL; |
129 | } | |
130 | ||
131 | rq->cmd_type = REQ_TYPE_BLOCK_PC; | |
6000a368 | 132 | rq->cmd_flags |= REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT | |
64f84bc1 | 133 | REQ_FAILFAST_DRIVER; |
057ea7c9 | 134 | rq->retries = ALUA_FAILOVER_RETRIES; |
3588c5a2 | 135 | rq->timeout = ALUA_FAILOVER_TIMEOUT * HZ; |
057ea7c9 HR |
136 | |
137 | return rq; | |
138 | } | |
139 | ||
057ea7c9 HR |
140 | /* |
141 | * submit_vpd_inquiry - Issue an INQUIRY VPD page 0x83 command | |
142 | * @sdev: sdev the command should be sent to | |
143 | */ | |
144 | static int submit_vpd_inquiry(struct scsi_device *sdev, struct alua_dh_data *h) | |
145 | { | |
146 | struct request *rq; | |
147 | int err = SCSI_DH_RES_TEMP_UNAVAIL; | |
148 | ||
149 | rq = get_alua_req(sdev, h->buff, h->bufflen, READ); | |
150 | if (!rq) | |
151 | goto done; | |
152 | ||
153 | /* Prepare the command. */ | |
154 | rq->cmd[0] = INQUIRY; | |
155 | rq->cmd[1] = 1; | |
156 | rq->cmd[2] = 0x83; | |
157 | rq->cmd[4] = h->bufflen; | |
158 | rq->cmd_len = COMMAND_SIZE(INQUIRY); | |
159 | ||
160 | rq->sense = h->sense; | |
161 | memset(rq->sense, 0, SCSI_SENSE_BUFFERSIZE); | |
162 | rq->sense_len = h->senselen = 0; | |
163 | ||
164 | err = blk_execute_rq(rq->q, NULL, rq, 1); | |
165 | if (err == -EIO) { | |
166 | sdev_printk(KERN_INFO, sdev, | |
167 | "%s: evpd inquiry failed with %x\n", | |
168 | ALUA_DH_NAME, rq->errors); | |
169 | h->senselen = rq->sense_len; | |
170 | err = SCSI_DH_IO; | |
171 | } | |
172 | blk_put_request(rq); | |
173 | done: | |
174 | return err; | |
175 | } | |
176 | ||
177 | /* | |
178 | * submit_rtpg - Issue a REPORT TARGET GROUP STATES command | |
179 | * @sdev: sdev the command should be sent to | |
180 | */ | |
181 | static unsigned submit_rtpg(struct scsi_device *sdev, struct alua_dh_data *h) | |
182 | { | |
183 | struct request *rq; | |
184 | int err = SCSI_DH_RES_TEMP_UNAVAIL; | |
185 | ||
186 | rq = get_alua_req(sdev, h->buff, h->bufflen, READ); | |
187 | if (!rq) | |
188 | goto done; | |
189 | ||
190 | /* Prepare the command. */ | |
191 | rq->cmd[0] = MAINTENANCE_IN; | |
3588c5a2 | 192 | rq->cmd[1] = MI_REPORT_TARGET_PGS | MI_EXT_HDR_PARAM_FMT; |
057ea7c9 HR |
193 | rq->cmd[6] = (h->bufflen >> 24) & 0xff; |
194 | rq->cmd[7] = (h->bufflen >> 16) & 0xff; | |
195 | rq->cmd[8] = (h->bufflen >> 8) & 0xff; | |
196 | rq->cmd[9] = h->bufflen & 0xff; | |
197 | rq->cmd_len = COMMAND_SIZE(MAINTENANCE_IN); | |
198 | ||
199 | rq->sense = h->sense; | |
200 | memset(rq->sense, 0, SCSI_SENSE_BUFFERSIZE); | |
201 | rq->sense_len = h->senselen = 0; | |
202 | ||
203 | err = blk_execute_rq(rq->q, NULL, rq, 1); | |
204 | if (err == -EIO) { | |
205 | sdev_printk(KERN_INFO, sdev, | |
206 | "%s: rtpg failed with %x\n", | |
207 | ALUA_DH_NAME, rq->errors); | |
208 | h->senselen = rq->sense_len; | |
209 | err = SCSI_DH_IO; | |
210 | } | |
211 | blk_put_request(rq); | |
212 | done: | |
213 | return err; | |
214 | } | |
215 | ||
96e65865 CS |
216 | /* |
217 | * alua_stpg - Evaluate SET TARGET GROUP STATES | |
218 | * @sdev: the device to be evaluated | |
219 | * @state: the new target group state | |
220 | * | |
221 | * Send a SET TARGET GROUP STATES command to the device. | |
222 | * We only have to test here if we should resubmit the command; | |
223 | * any other error is assumed as a failure. | |
224 | */ | |
225 | static void stpg_endio(struct request *req, int error) | |
226 | { | |
227 | struct alua_dh_data *h = req->end_io_data; | |
228 | struct scsi_sense_hdr sense_hdr; | |
9349923d | 229 | unsigned err = SCSI_DH_OK; |
96e65865 CS |
230 | |
231 | if (error || host_byte(req->errors) != DID_OK || | |
9349923d JG |
232 | msg_byte(req->errors) != COMMAND_COMPLETE) { |
233 | err = SCSI_DH_IO; | |
96e65865 | 234 | goto done; |
9349923d | 235 | } |
96e65865 | 236 | |
9349923d | 237 | if (h->senselen > 0) { |
96e65865 CS |
238 | err = scsi_normalize_sense(h->sense, SCSI_SENSE_BUFFERSIZE, |
239 | &sense_hdr); | |
240 | if (!err) { | |
241 | err = SCSI_DH_IO; | |
242 | goto done; | |
243 | } | |
244 | err = alua_check_sense(h->sdev, &sense_hdr); | |
245 | if (err == ADD_TO_MLQUEUE) { | |
246 | err = SCSI_DH_RETRY; | |
247 | goto done; | |
248 | } | |
249 | sdev_printk(KERN_INFO, h->sdev, | |
250 | "%s: stpg sense code: %02x/%02x/%02x\n", | |
251 | ALUA_DH_NAME, sense_hdr.sense_key, | |
252 | sense_hdr.asc, sense_hdr.ascq); | |
253 | err = SCSI_DH_IO; | |
254 | } | |
255 | if (err == SCSI_DH_OK) { | |
256 | h->state = TPGS_STATE_OPTIMIZED; | |
257 | sdev_printk(KERN_INFO, h->sdev, | |
258 | "%s: port group %02x switched to state %c\n", | |
259 | ALUA_DH_NAME, h->group_id, | |
260 | print_alua_state(h->state)); | |
261 | } | |
262 | done: | |
ed0f36bc JG |
263 | req->end_io_data = NULL; |
264 | __blk_put_request(req->q, req); | |
96e65865 CS |
265 | if (h->callback_fn) { |
266 | h->callback_fn(h->callback_data, err); | |
267 | h->callback_fn = h->callback_data = NULL; | |
268 | } | |
269 | return; | |
270 | } | |
271 | ||
057ea7c9 HR |
272 | /* |
273 | * submit_stpg - Issue a SET TARGET GROUP STATES command | |
057ea7c9 HR |
274 | * |
275 | * Currently we're only setting the current target port group state | |
276 | * to 'active/optimized' and let the array firmware figure out | |
277 | * the states of the remaining groups. | |
278 | */ | |
96e65865 | 279 | static unsigned submit_stpg(struct alua_dh_data *h) |
057ea7c9 HR |
280 | { |
281 | struct request *rq; | |
057ea7c9 | 282 | int stpg_len = 8; |
96e65865 | 283 | struct scsi_device *sdev = h->sdev; |
057ea7c9 HR |
284 | |
285 | /* Prepare the data buffer */ | |
286 | memset(h->buff, 0, stpg_len); | |
287 | h->buff[4] = TPGS_STATE_OPTIMIZED & 0x0f; | |
ef3fa8c6 IH |
288 | h->buff[6] = (h->group_id >> 8) & 0xff; |
289 | h->buff[7] = h->group_id & 0xff; | |
057ea7c9 HR |
290 | |
291 | rq = get_alua_req(sdev, h->buff, stpg_len, WRITE); | |
292 | if (!rq) | |
96e65865 | 293 | return SCSI_DH_RES_TEMP_UNAVAIL; |
057ea7c9 HR |
294 | |
295 | /* Prepare the command. */ | |
296 | rq->cmd[0] = MAINTENANCE_OUT; | |
297 | rq->cmd[1] = MO_SET_TARGET_PGS; | |
298 | rq->cmd[6] = (stpg_len >> 24) & 0xff; | |
299 | rq->cmd[7] = (stpg_len >> 16) & 0xff; | |
300 | rq->cmd[8] = (stpg_len >> 8) & 0xff; | |
301 | rq->cmd[9] = stpg_len & 0xff; | |
302 | rq->cmd_len = COMMAND_SIZE(MAINTENANCE_OUT); | |
303 | ||
304 | rq->sense = h->sense; | |
305 | memset(rq->sense, 0, SCSI_SENSE_BUFFERSIZE); | |
306 | rq->sense_len = h->senselen = 0; | |
96e65865 | 307 | rq->end_io_data = h; |
057ea7c9 | 308 | |
96e65865 | 309 | blk_execute_rq_nowait(rq->q, NULL, rq, 1, stpg_endio); |
7c66e9a5 | 310 | return SCSI_DH_OK; |
057ea7c9 HR |
311 | } |
312 | ||
313 | /* | |
d7c48feb | 314 | * alua_check_tpgs - Evaluate TPGS setting |
057ea7c9 HR |
315 | * @sdev: device to be checked |
316 | * | |
d7c48feb | 317 | * Examine the TPGS setting of the sdev to find out if ALUA |
057ea7c9 HR |
318 | * is supported. |
319 | */ | |
d7c48feb | 320 | static int alua_check_tpgs(struct scsi_device *sdev, struct alua_dh_data *h) |
057ea7c9 | 321 | { |
d7c48feb | 322 | int err = SCSI_DH_OK; |
057ea7c9 | 323 | |
d7c48feb | 324 | h->tpgs = scsi_device_tpgs(sdev); |
057ea7c9 HR |
325 | switch (h->tpgs) { |
326 | case TPGS_MODE_EXPLICIT|TPGS_MODE_IMPLICIT: | |
327 | sdev_printk(KERN_INFO, sdev, | |
328 | "%s: supports implicit and explicit TPGS\n", | |
329 | ALUA_DH_NAME); | |
330 | break; | |
331 | case TPGS_MODE_EXPLICIT: | |
332 | sdev_printk(KERN_INFO, sdev, "%s: supports explicit TPGS\n", | |
333 | ALUA_DH_NAME); | |
334 | break; | |
335 | case TPGS_MODE_IMPLICIT: | |
336 | sdev_printk(KERN_INFO, sdev, "%s: supports implicit TPGS\n", | |
337 | ALUA_DH_NAME); | |
338 | break; | |
339 | default: | |
340 | h->tpgs = TPGS_MODE_NONE; | |
341 | sdev_printk(KERN_INFO, sdev, "%s: not supported\n", | |
342 | ALUA_DH_NAME); | |
343 | err = SCSI_DH_DEV_UNSUPP; | |
344 | break; | |
345 | } | |
346 | ||
347 | return err; | |
348 | } | |
349 | ||
350 | /* | |
351 | * alua_vpd_inquiry - Evaluate INQUIRY vpd page 0x83 | |
352 | * @sdev: device to be checked | |
353 | * | |
354 | * Extract the relative target port and the target port group | |
355 | * descriptor from the list of identificators. | |
356 | */ | |
357 | static int alua_vpd_inquiry(struct scsi_device *sdev, struct alua_dh_data *h) | |
358 | { | |
359 | int len; | |
360 | unsigned err; | |
361 | unsigned char *d; | |
362 | ||
363 | retry: | |
364 | err = submit_vpd_inquiry(sdev, h); | |
365 | ||
366 | if (err != SCSI_DH_OK) | |
367 | return err; | |
368 | ||
369 | /* Check if vpd page exceeds initial buffer */ | |
370 | len = (h->buff[2] << 8) + h->buff[3] + 4; | |
371 | if (len > h->bufflen) { | |
372 | /* Resubmit with the correct length */ | |
373 | if (realloc_buffer(h, len)) { | |
374 | sdev_printk(KERN_WARNING, sdev, | |
375 | "%s: kmalloc buffer failed\n", | |
376 | ALUA_DH_NAME); | |
377 | /* Temporary failure, bypass */ | |
378 | return SCSI_DH_DEV_TEMP_BUSY; | |
379 | } | |
380 | goto retry; | |
381 | } | |
382 | ||
383 | /* | |
384 | * Now look for the correct descriptor. | |
385 | */ | |
386 | d = h->buff + 4; | |
387 | while (d < h->buff + len) { | |
388 | switch (d[1] & 0xf) { | |
389 | case 0x4: | |
390 | /* Relative target port */ | |
391 | h->rel_port = (d[6] << 8) + d[7]; | |
392 | break; | |
393 | case 0x5: | |
394 | /* Target port group */ | |
395 | h->group_id = (d[6] << 8) + d[7]; | |
396 | break; | |
397 | default: | |
398 | break; | |
399 | } | |
400 | d += d[3] + 4; | |
401 | } | |
402 | ||
403 | if (h->group_id == -1) { | |
404 | /* | |
405 | * Internal error; TPGS supported but required | |
406 | * VPD identification descriptors not present. | |
407 | * Disable ALUA support | |
408 | */ | |
409 | sdev_printk(KERN_INFO, sdev, | |
410 | "%s: No target port descriptors found\n", | |
411 | ALUA_DH_NAME); | |
412 | h->state = TPGS_STATE_OPTIMIZED; | |
413 | h->tpgs = TPGS_MODE_NONE; | |
414 | err = SCSI_DH_DEV_UNSUPP; | |
415 | } else { | |
416 | sdev_printk(KERN_INFO, sdev, | |
417 | "%s: port group %02x rel port %02x\n", | |
418 | ALUA_DH_NAME, h->group_id, h->rel_port); | |
419 | } | |
420 | ||
421 | return err; | |
422 | } | |
423 | ||
424 | static char print_alua_state(int state) | |
425 | { | |
426 | switch (state) { | |
427 | case TPGS_STATE_OPTIMIZED: | |
428 | return 'A'; | |
429 | case TPGS_STATE_NONOPTIMIZED: | |
430 | return 'N'; | |
431 | case TPGS_STATE_STANDBY: | |
432 | return 'S'; | |
433 | case TPGS_STATE_UNAVAILABLE: | |
434 | return 'U'; | |
69723d17 HR |
435 | case TPGS_STATE_LBA_DEPENDENT: |
436 | return 'L'; | |
057ea7c9 HR |
437 | case TPGS_STATE_OFFLINE: |
438 | return 'O'; | |
439 | case TPGS_STATE_TRANSITIONING: | |
440 | return 'T'; | |
441 | default: | |
442 | return 'X'; | |
443 | } | |
444 | } | |
445 | ||
446 | static int alua_check_sense(struct scsi_device *sdev, | |
447 | struct scsi_sense_hdr *sense_hdr) | |
448 | { | |
449 | switch (sense_hdr->sense_key) { | |
450 | case NOT_READY: | |
451 | if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x0a) | |
452 | /* | |
453 | * LUN Not Accessible - ALUA state transition | |
454 | */ | |
c7dbb627 | 455 | return ADD_TO_MLQUEUE; |
057ea7c9 HR |
456 | if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x0b) |
457 | /* | |
458 | * LUN Not Accessible -- Target port in standby state | |
459 | */ | |
460 | return SUCCESS; | |
461 | if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x0c) | |
462 | /* | |
463 | * LUN Not Accessible -- Target port in unavailable state | |
464 | */ | |
465 | return SUCCESS; | |
466 | if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x12) | |
467 | /* | |
468 | * LUN Not Ready -- Offline | |
469 | */ | |
470 | return SUCCESS; | |
471 | break; | |
472 | case UNIT_ATTENTION: | |
473 | if (sense_hdr->asc == 0x29 && sense_hdr->ascq == 0x00) | |
474 | /* | |
475 | * Power On, Reset, or Bus Device Reset, just retry. | |
476 | */ | |
c7dbb627 | 477 | return ADD_TO_MLQUEUE; |
410f02d8 MB |
478 | if (sense_hdr->asc == 0x2a && sense_hdr->ascq == 0x01) |
479 | /* | |
480 | * Mode Parameters Changed | |
481 | */ | |
482 | return ADD_TO_MLQUEUE; | |
bf81973a | 483 | if (sense_hdr->asc == 0x2a && sense_hdr->ascq == 0x06) |
057ea7c9 HR |
484 | /* |
485 | * ALUA state changed | |
486 | */ | |
c7dbb627 | 487 | return ADD_TO_MLQUEUE; |
bf81973a | 488 | if (sense_hdr->asc == 0x2a && sense_hdr->ascq == 0x07) |
057ea7c9 HR |
489 | /* |
490 | * Implicit ALUA state transition failed | |
491 | */ | |
c7dbb627 | 492 | return ADD_TO_MLQUEUE; |
bf81973a MB |
493 | if (sense_hdr->asc == 0x3f && sense_hdr->ascq == 0x03) |
494 | /* | |
495 | * Inquiry data has changed | |
496 | */ | |
497 | return ADD_TO_MLQUEUE; | |
498 | if (sense_hdr->asc == 0x3f && sense_hdr->ascq == 0x0e) | |
4d086f6b IH |
499 | /* |
500 | * REPORTED_LUNS_DATA_HAS_CHANGED is reported | |
501 | * when switching controllers on targets like | |
502 | * Intel Multi-Flex. We can just retry. | |
503 | */ | |
504 | return ADD_TO_MLQUEUE; | |
057ea7c9 HR |
505 | break; |
506 | } | |
507 | ||
508 | return SCSI_RETURN_NOT_HANDLED; | |
509 | } | |
510 | ||
057ea7c9 HR |
511 | /* |
512 | * alua_rtpg - Evaluate REPORT TARGET GROUP STATES | |
513 | * @sdev: the device to be evaluated. | |
514 | * | |
515 | * Evaluate the Target Port Group State. | |
516 | * Returns SCSI_DH_DEV_OFFLINED if the path is | |
25985edc | 517 | * found to be unusable. |
057ea7c9 HR |
518 | */ |
519 | static int alua_rtpg(struct scsi_device *sdev, struct alua_dh_data *h) | |
520 | { | |
521 | struct scsi_sense_hdr sense_hdr; | |
522 | int len, k, off, valid_states = 0; | |
cfde3fa1 | 523 | unsigned char *ucp; |
057ea7c9 | 524 | unsigned err; |
ab72002b | 525 | unsigned long expiry, interval = 1000; |
3588c5a2 RE |
526 | unsigned int tpg_desc_tbl_off; |
527 | unsigned char orig_transition_tmo; | |
528 | ||
529 | if (!h->transition_tmo) | |
530 | expiry = round_jiffies_up(jiffies + ALUA_FAILOVER_TIMEOUT * HZ); | |
531 | else | |
532 | expiry = round_jiffies_up(jiffies + h->transition_tmo * HZ); | |
057ea7c9 HR |
533 | |
534 | retry: | |
535 | err = submit_rtpg(sdev, h); | |
536 | ||
537 | if (err == SCSI_DH_IO && h->senselen > 0) { | |
538 | err = scsi_normalize_sense(h->sense, SCSI_SENSE_BUFFERSIZE, | |
539 | &sense_hdr); | |
540 | if (!err) | |
541 | return SCSI_DH_IO; | |
542 | ||
543 | err = alua_check_sense(sdev, &sense_hdr); | |
69723d17 | 544 | if (err == ADD_TO_MLQUEUE && time_before(jiffies, expiry)) |
057ea7c9 HR |
545 | goto retry; |
546 | sdev_printk(KERN_INFO, sdev, | |
547 | "%s: rtpg sense code %02x/%02x/%02x\n", | |
548 | ALUA_DH_NAME, sense_hdr.sense_key, | |
549 | sense_hdr.asc, sense_hdr.ascq); | |
550 | err = SCSI_DH_IO; | |
551 | } | |
552 | if (err != SCSI_DH_OK) | |
553 | return err; | |
554 | ||
555 | len = (h->buff[0] << 24) + (h->buff[1] << 16) + | |
556 | (h->buff[2] << 8) + h->buff[3] + 4; | |
557 | ||
558 | if (len > h->bufflen) { | |
559 | /* Resubmit with the correct length */ | |
560 | if (realloc_buffer(h, len)) { | |
561 | sdev_printk(KERN_WARNING, sdev, | |
cadbd4a5 | 562 | "%s: kmalloc buffer failed\n",__func__); |
057ea7c9 HR |
563 | /* Temporary failure, bypass */ |
564 | return SCSI_DH_DEV_TEMP_BUSY; | |
565 | } | |
566 | goto retry; | |
567 | } | |
568 | ||
3588c5a2 RE |
569 | orig_transition_tmo = h->transition_tmo; |
570 | if ((h->buff[4] & RTPG_FMT_MASK) == RTPG_FMT_EXT_HDR && h->buff[5] != 0) | |
571 | h->transition_tmo = h->buff[5]; | |
572 | else | |
573 | h->transition_tmo = ALUA_FAILOVER_TIMEOUT; | |
574 | ||
575 | if (orig_transition_tmo != h->transition_tmo) { | |
576 | sdev_printk(KERN_INFO, sdev, | |
577 | "%s: transition timeout set to %d seconds\n", | |
578 | ALUA_DH_NAME, h->transition_tmo); | |
579 | expiry = jiffies + h->transition_tmo * HZ; | |
580 | } | |
581 | ||
582 | if ((h->buff[4] & RTPG_FMT_MASK) == RTPG_FMT_EXT_HDR) | |
583 | tpg_desc_tbl_off = 8; | |
584 | else | |
585 | tpg_desc_tbl_off = 4; | |
586 | ||
587 | for (k = tpg_desc_tbl_off, ucp = h->buff + tpg_desc_tbl_off; | |
588 | k < len; | |
589 | k += off, ucp += off) { | |
590 | ||
057ea7c9 HR |
591 | if (h->group_id == (ucp[2] << 8) + ucp[3]) { |
592 | h->state = ucp[0] & 0x0f; | |
dcd3a754 | 593 | h->pref = ucp[0] >> 7; |
057ea7c9 HR |
594 | valid_states = ucp[1]; |
595 | } | |
596 | off = 8 + (ucp[7] * 4); | |
597 | } | |
598 | ||
599 | sdev_printk(KERN_INFO, sdev, | |
dcd3a754 | 600 | "%s: port group %02x state %c %s supports %c%c%c%c%c%c%c\n", |
057ea7c9 | 601 | ALUA_DH_NAME, h->group_id, print_alua_state(h->state), |
dcd3a754 | 602 | h->pref ? "preferred" : "non-preferred", |
057ea7c9 HR |
603 | valid_states&TPGS_SUPPORT_TRANSITION?'T':'t', |
604 | valid_states&TPGS_SUPPORT_OFFLINE?'O':'o', | |
69723d17 | 605 | valid_states&TPGS_SUPPORT_LBA_DEPENDENT?'L':'l', |
057ea7c9 HR |
606 | valid_states&TPGS_SUPPORT_UNAVAILABLE?'U':'u', |
607 | valid_states&TPGS_SUPPORT_STANDBY?'S':'s', | |
608 | valid_states&TPGS_SUPPORT_NONOPTIMIZED?'N':'n', | |
609 | valid_states&TPGS_SUPPORT_OPTIMIZED?'A':'a'); | |
610 | ||
69723d17 HR |
611 | switch (h->state) { |
612 | case TPGS_STATE_TRANSITIONING: | |
613 | if (time_before(jiffies, expiry)) { | |
057ea7c9 | 614 | /* State transition, retry */ |
ebd1f645 | 615 | interval *= 2; |
69723d17 | 616 | msleep(interval); |
057ea7c9 | 617 | goto retry; |
057ea7c9 | 618 | } |
69723d17 HR |
619 | /* Transitioning time exceeded, set port to standby */ |
620 | err = SCSI_DH_RETRY; | |
621 | h->state = TPGS_STATE_STANDBY; | |
622 | break; | |
623 | case TPGS_STATE_OFFLINE: | |
624 | case TPGS_STATE_UNAVAILABLE: | |
25985edc | 625 | /* Path unusable for unavailable/offline */ |
69723d17 HR |
626 | err = SCSI_DH_DEV_OFFLINED; |
627 | break; | |
628 | default: | |
629 | /* Useable path if active */ | |
630 | err = SCSI_DH_OK; | |
631 | break; | |
057ea7c9 HR |
632 | } |
633 | return err; | |
634 | } | |
635 | ||
636 | /* | |
637 | * alua_initialize - Initialize ALUA state | |
638 | * @sdev: the device to be initialized | |
639 | * | |
640 | * For the prep_fn to work correctly we have | |
641 | * to initialize the ALUA state for the device. | |
642 | */ | |
643 | static int alua_initialize(struct scsi_device *sdev, struct alua_dh_data *h) | |
644 | { | |
645 | int err; | |
646 | ||
d7c48feb | 647 | err = alua_check_tpgs(sdev, h); |
057ea7c9 HR |
648 | if (err != SCSI_DH_OK) |
649 | goto out; | |
650 | ||
651 | err = alua_vpd_inquiry(sdev, h); | |
652 | if (err != SCSI_DH_OK) | |
653 | goto out; | |
654 | ||
655 | err = alua_rtpg(sdev, h); | |
656 | if (err != SCSI_DH_OK) | |
657 | goto out; | |
658 | ||
659 | out: | |
660 | return err; | |
661 | } | |
4335d092 MB |
662 | /* |
663 | * alua_set_params - set/unset the optimize flag | |
664 | * @sdev: device on the path to be activated | |
665 | * params - parameters in the following format | |
666 | * "no_of_params\0param1\0param2\0param3\0...\0" | |
667 | * For example, to set the flag pass the following parameters | |
668 | * from multipath.conf | |
669 | * hardware_handler "2 alua 1" | |
670 | */ | |
671 | static int alua_set_params(struct scsi_device *sdev, const char *params) | |
672 | { | |
673 | struct alua_dh_data *h = get_alua_data(sdev); | |
674 | unsigned int optimize = 0, argc; | |
675 | const char *p = params; | |
676 | int result = SCSI_DH_OK; | |
677 | ||
678 | if ((sscanf(params, "%u", &argc) != 1) || (argc != 1)) | |
679 | return -EINVAL; | |
680 | ||
681 | while (*p++) | |
682 | ; | |
683 | if ((sscanf(p, "%u", &optimize) != 1) || (optimize > 1)) | |
684 | return -EINVAL; | |
685 | ||
686 | if (optimize) | |
687 | h->flags |= ALUA_OPTIMIZE_STPG; | |
688 | else | |
689 | h->flags &= ~ALUA_OPTIMIZE_STPG; | |
690 | ||
691 | return result; | |
692 | } | |
057ea7c9 HR |
693 | |
694 | /* | |
695 | * alua_activate - activate a path | |
696 | * @sdev: device on the path to be activated | |
697 | * | |
698 | * We're currently switching the port group to be activated only and | |
699 | * let the array figure out the rest. | |
700 | * There may be other arrays which require us to switch all port groups | |
701 | * based on a certain policy. But until we actually encounter them it | |
702 | * should be okay. | |
703 | */ | |
3ae31f6a CS |
704 | static int alua_activate(struct scsi_device *sdev, |
705 | activate_complete fn, void *data) | |
057ea7c9 HR |
706 | { |
707 | struct alua_dh_data *h = get_alua_data(sdev); | |
708 | int err = SCSI_DH_OK; | |
72d9e0f3 | 709 | int stpg = 0; |
057ea7c9 | 710 | |
46ccf6b5 HR |
711 | err = alua_rtpg(sdev, h); |
712 | if (err != SCSI_DH_OK) | |
713 | goto out; | |
057ea7c9 | 714 | |
72d9e0f3 MB |
715 | if (h->tpgs & TPGS_MODE_EXPLICIT) { |
716 | switch (h->state) { | |
717 | case TPGS_STATE_NONOPTIMIZED: | |
718 | stpg = 1; | |
719 | if ((h->flags & ALUA_OPTIMIZE_STPG) && | |
720 | (!h->pref) && | |
721 | (h->tpgs & TPGS_MODE_IMPLICIT)) | |
722 | stpg = 0; | |
723 | break; | |
724 | case TPGS_STATE_STANDBY: | |
725 | stpg = 1; | |
726 | break; | |
727 | case TPGS_STATE_UNAVAILABLE: | |
728 | case TPGS_STATE_OFFLINE: | |
729 | err = SCSI_DH_IO; | |
730 | break; | |
731 | case TPGS_STATE_TRANSITIONING: | |
732 | err = SCSI_DH_RETRY; | |
733 | break; | |
734 | default: | |
735 | break; | |
736 | } | |
737 | } | |
738 | ||
739 | if (stpg) { | |
96e65865 CS |
740 | h->callback_fn = fn; |
741 | h->callback_data = data; | |
742 | err = submit_stpg(h); | |
743 | if (err == SCSI_DH_OK) | |
744 | return 0; | |
745 | h->callback_fn = h->callback_data = NULL; | |
746 | } | |
057ea7c9 HR |
747 | |
748 | out: | |
3ae31f6a CS |
749 | if (fn) |
750 | fn(data, err); | |
751 | return 0; | |
057ea7c9 HR |
752 | } |
753 | ||
754 | /* | |
755 | * alua_prep_fn - request callback | |
756 | * | |
757 | * Fail I/O to all paths not in state | |
758 | * active/optimized or active/non-optimized. | |
759 | */ | |
760 | static int alua_prep_fn(struct scsi_device *sdev, struct request *req) | |
761 | { | |
762 | struct alua_dh_data *h = get_alua_data(sdev); | |
763 | int ret = BLKPREP_OK; | |
764 | ||
69723d17 HR |
765 | if (h->state == TPGS_STATE_TRANSITIONING) |
766 | ret = BLKPREP_DEFER; | |
767 | else if (h->state != TPGS_STATE_OPTIMIZED && | |
768 | h->state != TPGS_STATE_NONOPTIMIZED && | |
769 | h->state != TPGS_STATE_LBA_DEPENDENT) { | |
057ea7c9 HR |
770 | ret = BLKPREP_KILL; |
771 | req->cmd_flags |= REQ_QUIET; | |
772 | } | |
773 | return ret; | |
774 | ||
775 | } | |
776 | ||
6c3633d0 HR |
777 | static bool alua_match(struct scsi_device *sdev) |
778 | { | |
779 | return (scsi_device_tpgs(sdev) != 0); | |
780 | } | |
057ea7c9 HR |
781 | |
782 | static int alua_bus_attach(struct scsi_device *sdev); | |
783 | static void alua_bus_detach(struct scsi_device *sdev); | |
784 | ||
785 | static struct scsi_device_handler alua_dh = { | |
786 | .name = ALUA_DH_NAME, | |
787 | .module = THIS_MODULE, | |
057ea7c9 HR |
788 | .attach = alua_bus_attach, |
789 | .detach = alua_bus_detach, | |
790 | .prep_fn = alua_prep_fn, | |
791 | .check_sense = alua_check_sense, | |
792 | .activate = alua_activate, | |
4335d092 | 793 | .set_params = alua_set_params, |
6c3633d0 | 794 | .match = alua_match, |
057ea7c9 HR |
795 | }; |
796 | ||
797 | /* | |
798 | * alua_bus_attach - Attach device handler | |
799 | * @sdev: device to be attached to | |
800 | */ | |
801 | static int alua_bus_attach(struct scsi_device *sdev) | |
802 | { | |
803 | struct scsi_dh_data *scsi_dh_data; | |
804 | struct alua_dh_data *h; | |
805 | unsigned long flags; | |
806 | int err = SCSI_DH_OK; | |
807 | ||
9dfeb315 | 808 | scsi_dh_data = kzalloc(sizeof(*scsi_dh_data) |
057ea7c9 HR |
809 | + sizeof(*h) , GFP_KERNEL); |
810 | if (!scsi_dh_data) { | |
811 | sdev_printk(KERN_ERR, sdev, "%s: Attach failed\n", | |
812 | ALUA_DH_NAME); | |
813 | return -ENOMEM; | |
814 | } | |
815 | ||
816 | scsi_dh_data->scsi_dh = &alua_dh; | |
817 | h = (struct alua_dh_data *) scsi_dh_data->buf; | |
818 | h->tpgs = TPGS_MODE_UNINITIALIZED; | |
819 | h->state = TPGS_STATE_OPTIMIZED; | |
820 | h->group_id = -1; | |
821 | h->rel_port = -1; | |
822 | h->buff = h->inq; | |
823 | h->bufflen = ALUA_INQUIRY_SIZE; | |
96e65865 | 824 | h->sdev = sdev; |
057ea7c9 HR |
825 | |
826 | err = alua_initialize(sdev, h); | |
c0d289b3 | 827 | if ((err != SCSI_DH_OK) && (err != SCSI_DH_DEV_OFFLINED)) |
057ea7c9 HR |
828 | goto failed; |
829 | ||
830 | if (!try_module_get(THIS_MODULE)) | |
831 | goto failed; | |
832 | ||
833 | spin_lock_irqsave(sdev->request_queue->queue_lock, flags); | |
834 | sdev->scsi_dh_data = scsi_dh_data; | |
835 | spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags); | |
ab72002b | 836 | sdev_printk(KERN_NOTICE, sdev, "%s: Attached\n", ALUA_DH_NAME); |
057ea7c9 HR |
837 | |
838 | return 0; | |
839 | ||
840 | failed: | |
841 | kfree(scsi_dh_data); | |
842 | sdev_printk(KERN_ERR, sdev, "%s: not attached\n", ALUA_DH_NAME); | |
843 | return -EINVAL; | |
844 | } | |
845 | ||
846 | /* | |
847 | * alua_bus_detach - Detach device handler | |
848 | * @sdev: device to be detached from | |
849 | */ | |
850 | static void alua_bus_detach(struct scsi_device *sdev) | |
851 | { | |
852 | struct scsi_dh_data *scsi_dh_data; | |
853 | struct alua_dh_data *h; | |
854 | unsigned long flags; | |
855 | ||
856 | spin_lock_irqsave(sdev->request_queue->queue_lock, flags); | |
857 | scsi_dh_data = sdev->scsi_dh_data; | |
858 | sdev->scsi_dh_data = NULL; | |
859 | spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags); | |
860 | ||
861 | h = (struct alua_dh_data *) scsi_dh_data->buf; | |
862 | if (h->buff && h->inq != h->buff) | |
863 | kfree(h->buff); | |
864 | kfree(scsi_dh_data); | |
865 | module_put(THIS_MODULE); | |
866 | sdev_printk(KERN_NOTICE, sdev, "%s: Detached\n", ALUA_DH_NAME); | |
867 | } | |
868 | ||
869 | static int __init alua_init(void) | |
870 | { | |
871 | int r; | |
872 | ||
873 | r = scsi_register_device_handler(&alua_dh); | |
874 | if (r != 0) | |
875 | printk(KERN_ERR "%s: Failed to register scsi device handler", | |
876 | ALUA_DH_NAME); | |
877 | return r; | |
878 | } | |
879 | ||
880 | static void __exit alua_exit(void) | |
881 | { | |
882 | scsi_unregister_device_handler(&alua_dh); | |
883 | } | |
884 | ||
885 | module_init(alua_init); | |
886 | module_exit(alua_exit); | |
887 | ||
888 | MODULE_DESCRIPTION("DM Multipath ALUA support"); | |
889 | MODULE_AUTHOR("Hannes Reinecke <hare@suse.de>"); | |
890 | MODULE_LICENSE("GPL"); | |
891 | MODULE_VERSION(ALUA_DH_VER); |