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