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 | 64 | struct alua_dh_data { |
cd37743f | 65 | struct scsi_dh_data dh_data; |
057ea7c9 HR |
66 | int group_id; |
67 | int rel_port; | |
68 | int tpgs; | |
69 | int state; | |
dcd3a754 | 70 | int pref; |
4335d092 | 71 | unsigned flags; /* used for optimizing STPG */ |
057ea7c9 HR |
72 | unsigned char inq[ALUA_INQUIRY_SIZE]; |
73 | unsigned char *buff; | |
74 | int bufflen; | |
3588c5a2 | 75 | unsigned char transition_tmo; |
057ea7c9 HR |
76 | unsigned char sense[SCSI_SENSE_BUFFERSIZE]; |
77 | int senselen; | |
96e65865 CS |
78 | struct scsi_device *sdev; |
79 | activate_complete callback_fn; | |
80 | void *callback_data; | |
057ea7c9 HR |
81 | }; |
82 | ||
83 | #define ALUA_POLICY_SWITCH_CURRENT 0 | |
84 | #define ALUA_POLICY_SWITCH_ALL 1 | |
85 | ||
96e65865 CS |
86 | static char print_alua_state(int); |
87 | static int alua_check_sense(struct scsi_device *, struct scsi_sense_hdr *); | |
88 | ||
057ea7c9 HR |
89 | static inline struct alua_dh_data *get_alua_data(struct scsi_device *sdev) |
90 | { | |
cd37743f | 91 | return container_of(sdev->scsi_dh_data, struct alua_dh_data, dh_data); |
057ea7c9 HR |
92 | } |
93 | ||
94 | static int realloc_buffer(struct alua_dh_data *h, unsigned len) | |
95 | { | |
96 | if (h->buff && h->buff != h->inq) | |
97 | kfree(h->buff); | |
98 | ||
99 | h->buff = kmalloc(len, GFP_NOIO); | |
100 | if (!h->buff) { | |
101 | h->buff = h->inq; | |
102 | h->bufflen = ALUA_INQUIRY_SIZE; | |
103 | return 1; | |
104 | } | |
105 | h->bufflen = len; | |
106 | return 0; | |
107 | } | |
108 | ||
109 | static struct request *get_alua_req(struct scsi_device *sdev, | |
110 | void *buffer, unsigned buflen, int rw) | |
111 | { | |
112 | struct request *rq; | |
113 | struct request_queue *q = sdev->request_queue; | |
114 | ||
115 | rq = blk_get_request(q, rw, GFP_NOIO); | |
116 | ||
a492f075 | 117 | if (IS_ERR(rq)) { |
057ea7c9 | 118 | sdev_printk(KERN_INFO, sdev, |
cadbd4a5 | 119 | "%s: blk_get_request failed\n", __func__); |
057ea7c9 HR |
120 | return NULL; |
121 | } | |
f27b087b | 122 | blk_rq_set_block_pc(rq); |
057ea7c9 HR |
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 | ||
6000a368 | 131 | rq->cmd_flags |= REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT | |
64f84bc1 | 132 | REQ_FAILFAST_DRIVER; |
057ea7c9 | 133 | rq->retries = ALUA_FAILOVER_RETRIES; |
3588c5a2 | 134 | rq->timeout = ALUA_FAILOVER_TIMEOUT * HZ; |
057ea7c9 HR |
135 | |
136 | return rq; | |
137 | } | |
138 | ||
057ea7c9 HR |
139 | /* |
140 | * submit_vpd_inquiry - Issue an INQUIRY VPD page 0x83 command | |
141 | * @sdev: sdev the command should be sent to | |
142 | */ | |
143 | static int submit_vpd_inquiry(struct scsi_device *sdev, struct alua_dh_data *h) | |
144 | { | |
145 | struct request *rq; | |
146 | int err = SCSI_DH_RES_TEMP_UNAVAIL; | |
147 | ||
148 | rq = get_alua_req(sdev, h->buff, h->bufflen, READ); | |
149 | if (!rq) | |
150 | goto done; | |
151 | ||
152 | /* Prepare the command. */ | |
153 | rq->cmd[0] = INQUIRY; | |
154 | rq->cmd[1] = 1; | |
155 | rq->cmd[2] = 0x83; | |
156 | rq->cmd[4] = h->bufflen; | |
157 | rq->cmd_len = COMMAND_SIZE(INQUIRY); | |
158 | ||
159 | rq->sense = h->sense; | |
160 | memset(rq->sense, 0, SCSI_SENSE_BUFFERSIZE); | |
161 | rq->sense_len = h->senselen = 0; | |
162 | ||
163 | err = blk_execute_rq(rq->q, NULL, rq, 1); | |
164 | if (err == -EIO) { | |
165 | sdev_printk(KERN_INFO, sdev, | |
166 | "%s: evpd inquiry failed with %x\n", | |
167 | ALUA_DH_NAME, rq->errors); | |
168 | h->senselen = rq->sense_len; | |
169 | err = SCSI_DH_IO; | |
170 | } | |
171 | blk_put_request(rq); | |
172 | done: | |
173 | return err; | |
174 | } | |
175 | ||
176 | /* | |
177 | * submit_rtpg - Issue a REPORT TARGET GROUP STATES command | |
178 | * @sdev: sdev the command should be sent to | |
179 | */ | |
8e67ce60 RE |
180 | static unsigned submit_rtpg(struct scsi_device *sdev, struct alua_dh_data *h, |
181 | bool rtpg_ext_hdr_req) | |
057ea7c9 HR |
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; | |
8e67ce60 RE |
192 | if (rtpg_ext_hdr_req) |
193 | rq->cmd[1] = MI_REPORT_TARGET_PGS | MI_EXT_HDR_PARAM_FMT; | |
194 | else | |
195 | rq->cmd[1] = MI_REPORT_TARGET_PGS; | |
057ea7c9 HR |
196 | rq->cmd[6] = (h->bufflen >> 24) & 0xff; |
197 | rq->cmd[7] = (h->bufflen >> 16) & 0xff; | |
198 | rq->cmd[8] = (h->bufflen >> 8) & 0xff; | |
199 | rq->cmd[9] = h->bufflen & 0xff; | |
200 | rq->cmd_len = COMMAND_SIZE(MAINTENANCE_IN); | |
201 | ||
202 | rq->sense = h->sense; | |
203 | memset(rq->sense, 0, SCSI_SENSE_BUFFERSIZE); | |
204 | rq->sense_len = h->senselen = 0; | |
205 | ||
206 | err = blk_execute_rq(rq->q, NULL, rq, 1); | |
207 | if (err == -EIO) { | |
208 | sdev_printk(KERN_INFO, sdev, | |
209 | "%s: rtpg failed with %x\n", | |
210 | ALUA_DH_NAME, rq->errors); | |
211 | h->senselen = rq->sense_len; | |
212 | err = SCSI_DH_IO; | |
213 | } | |
214 | blk_put_request(rq); | |
215 | done: | |
216 | return err; | |
217 | } | |
218 | ||
96e65865 CS |
219 | /* |
220 | * alua_stpg - Evaluate SET TARGET GROUP STATES | |
221 | * @sdev: the device to be evaluated | |
222 | * @state: the new target group state | |
223 | * | |
224 | * Send a SET TARGET GROUP STATES command to the device. | |
225 | * We only have to test here if we should resubmit the command; | |
226 | * any other error is assumed as a failure. | |
227 | */ | |
228 | static void stpg_endio(struct request *req, int error) | |
229 | { | |
230 | struct alua_dh_data *h = req->end_io_data; | |
231 | struct scsi_sense_hdr sense_hdr; | |
9349923d | 232 | unsigned err = SCSI_DH_OK; |
96e65865 | 233 | |
27db682b MC |
234 | if (host_byte(req->errors) != DID_OK || |
235 | msg_byte(req->errors) != COMMAND_COMPLETE) { | |
9349923d | 236 | err = SCSI_DH_IO; |
96e65865 | 237 | goto done; |
9349923d | 238 | } |
96e65865 | 239 | |
27db682b | 240 | if (req->sense_len > 0) { |
96e65865 CS |
241 | err = scsi_normalize_sense(h->sense, SCSI_SENSE_BUFFERSIZE, |
242 | &sense_hdr); | |
243 | if (!err) { | |
244 | err = SCSI_DH_IO; | |
245 | goto done; | |
246 | } | |
247 | err = alua_check_sense(h->sdev, &sense_hdr); | |
248 | if (err == ADD_TO_MLQUEUE) { | |
249 | err = SCSI_DH_RETRY; | |
250 | goto done; | |
251 | } | |
252 | sdev_printk(KERN_INFO, h->sdev, | |
253 | "%s: stpg sense code: %02x/%02x/%02x\n", | |
254 | ALUA_DH_NAME, sense_hdr.sense_key, | |
255 | sense_hdr.asc, sense_hdr.ascq); | |
256 | err = SCSI_DH_IO; | |
27db682b MC |
257 | } else if (error) |
258 | err = SCSI_DH_IO; | |
259 | ||
96e65865 CS |
260 | if (err == SCSI_DH_OK) { |
261 | h->state = TPGS_STATE_OPTIMIZED; | |
262 | sdev_printk(KERN_INFO, h->sdev, | |
263 | "%s: port group %02x switched to state %c\n", | |
264 | ALUA_DH_NAME, h->group_id, | |
265 | print_alua_state(h->state)); | |
266 | } | |
267 | done: | |
ed0f36bc JG |
268 | req->end_io_data = NULL; |
269 | __blk_put_request(req->q, req); | |
96e65865 CS |
270 | if (h->callback_fn) { |
271 | h->callback_fn(h->callback_data, err); | |
272 | h->callback_fn = h->callback_data = NULL; | |
273 | } | |
274 | return; | |
275 | } | |
276 | ||
057ea7c9 HR |
277 | /* |
278 | * submit_stpg - Issue a SET TARGET GROUP STATES command | |
057ea7c9 HR |
279 | * |
280 | * Currently we're only setting the current target port group state | |
281 | * to 'active/optimized' and let the array firmware figure out | |
282 | * the states of the remaining groups. | |
283 | */ | |
96e65865 | 284 | static unsigned submit_stpg(struct alua_dh_data *h) |
057ea7c9 HR |
285 | { |
286 | struct request *rq; | |
057ea7c9 | 287 | int stpg_len = 8; |
96e65865 | 288 | struct scsi_device *sdev = h->sdev; |
057ea7c9 HR |
289 | |
290 | /* Prepare the data buffer */ | |
291 | memset(h->buff, 0, stpg_len); | |
292 | h->buff[4] = TPGS_STATE_OPTIMIZED & 0x0f; | |
ef3fa8c6 IH |
293 | h->buff[6] = (h->group_id >> 8) & 0xff; |
294 | h->buff[7] = h->group_id & 0xff; | |
057ea7c9 HR |
295 | |
296 | rq = get_alua_req(sdev, h->buff, stpg_len, WRITE); | |
297 | if (!rq) | |
96e65865 | 298 | return SCSI_DH_RES_TEMP_UNAVAIL; |
057ea7c9 HR |
299 | |
300 | /* Prepare the command. */ | |
301 | rq->cmd[0] = MAINTENANCE_OUT; | |
302 | rq->cmd[1] = MO_SET_TARGET_PGS; | |
303 | rq->cmd[6] = (stpg_len >> 24) & 0xff; | |
304 | rq->cmd[7] = (stpg_len >> 16) & 0xff; | |
305 | rq->cmd[8] = (stpg_len >> 8) & 0xff; | |
306 | rq->cmd[9] = stpg_len & 0xff; | |
307 | rq->cmd_len = COMMAND_SIZE(MAINTENANCE_OUT); | |
308 | ||
309 | rq->sense = h->sense; | |
310 | memset(rq->sense, 0, SCSI_SENSE_BUFFERSIZE); | |
311 | rq->sense_len = h->senselen = 0; | |
96e65865 | 312 | rq->end_io_data = h; |
057ea7c9 | 313 | |
96e65865 | 314 | blk_execute_rq_nowait(rq->q, NULL, rq, 1, stpg_endio); |
7c66e9a5 | 315 | return SCSI_DH_OK; |
057ea7c9 HR |
316 | } |
317 | ||
318 | /* | |
d7c48feb | 319 | * alua_check_tpgs - Evaluate TPGS setting |
057ea7c9 HR |
320 | * @sdev: device to be checked |
321 | * | |
d7c48feb | 322 | * Examine the TPGS setting of the sdev to find out if ALUA |
057ea7c9 HR |
323 | * is supported. |
324 | */ | |
d7c48feb | 325 | static int alua_check_tpgs(struct scsi_device *sdev, struct alua_dh_data *h) |
057ea7c9 | 326 | { |
d7c48feb | 327 | int err = SCSI_DH_OK; |
057ea7c9 | 328 | |
d7c48feb | 329 | h->tpgs = scsi_device_tpgs(sdev); |
057ea7c9 HR |
330 | switch (h->tpgs) { |
331 | case TPGS_MODE_EXPLICIT|TPGS_MODE_IMPLICIT: | |
332 | sdev_printk(KERN_INFO, sdev, | |
333 | "%s: supports implicit and explicit TPGS\n", | |
334 | ALUA_DH_NAME); | |
335 | break; | |
336 | case TPGS_MODE_EXPLICIT: | |
337 | sdev_printk(KERN_INFO, sdev, "%s: supports explicit TPGS\n", | |
338 | ALUA_DH_NAME); | |
339 | break; | |
340 | case TPGS_MODE_IMPLICIT: | |
341 | sdev_printk(KERN_INFO, sdev, "%s: supports implicit TPGS\n", | |
342 | ALUA_DH_NAME); | |
343 | break; | |
344 | default: | |
345 | h->tpgs = TPGS_MODE_NONE; | |
346 | sdev_printk(KERN_INFO, sdev, "%s: not supported\n", | |
347 | ALUA_DH_NAME); | |
348 | err = SCSI_DH_DEV_UNSUPP; | |
349 | break; | |
350 | } | |
351 | ||
352 | return err; | |
353 | } | |
354 | ||
355 | /* | |
356 | * alua_vpd_inquiry - Evaluate INQUIRY vpd page 0x83 | |
357 | * @sdev: device to be checked | |
358 | * | |
359 | * Extract the relative target port and the target port group | |
360 | * descriptor from the list of identificators. | |
361 | */ | |
362 | static int alua_vpd_inquiry(struct scsi_device *sdev, struct alua_dh_data *h) | |
363 | { | |
364 | int len; | |
365 | unsigned err; | |
366 | unsigned char *d; | |
367 | ||
368 | retry: | |
369 | err = submit_vpd_inquiry(sdev, h); | |
370 | ||
371 | if (err != SCSI_DH_OK) | |
372 | return err; | |
373 | ||
374 | /* Check if vpd page exceeds initial buffer */ | |
375 | len = (h->buff[2] << 8) + h->buff[3] + 4; | |
376 | if (len > h->bufflen) { | |
377 | /* Resubmit with the correct length */ | |
378 | if (realloc_buffer(h, len)) { | |
379 | sdev_printk(KERN_WARNING, sdev, | |
380 | "%s: kmalloc buffer failed\n", | |
381 | ALUA_DH_NAME); | |
382 | /* Temporary failure, bypass */ | |
383 | return SCSI_DH_DEV_TEMP_BUSY; | |
384 | } | |
385 | goto retry; | |
386 | } | |
387 | ||
388 | /* | |
389 | * Now look for the correct descriptor. | |
390 | */ | |
391 | d = h->buff + 4; | |
392 | while (d < h->buff + len) { | |
393 | switch (d[1] & 0xf) { | |
394 | case 0x4: | |
395 | /* Relative target port */ | |
396 | h->rel_port = (d[6] << 8) + d[7]; | |
397 | break; | |
398 | case 0x5: | |
399 | /* Target port group */ | |
400 | h->group_id = (d[6] << 8) + d[7]; | |
401 | break; | |
402 | default: | |
403 | break; | |
404 | } | |
405 | d += d[3] + 4; | |
406 | } | |
407 | ||
408 | if (h->group_id == -1) { | |
409 | /* | |
410 | * Internal error; TPGS supported but required | |
411 | * VPD identification descriptors not present. | |
412 | * Disable ALUA support | |
413 | */ | |
414 | sdev_printk(KERN_INFO, sdev, | |
415 | "%s: No target port descriptors found\n", | |
416 | ALUA_DH_NAME); | |
417 | h->state = TPGS_STATE_OPTIMIZED; | |
418 | h->tpgs = TPGS_MODE_NONE; | |
419 | err = SCSI_DH_DEV_UNSUPP; | |
420 | } else { | |
421 | sdev_printk(KERN_INFO, sdev, | |
422 | "%s: port group %02x rel port %02x\n", | |
423 | ALUA_DH_NAME, h->group_id, h->rel_port); | |
424 | } | |
425 | ||
426 | return err; | |
427 | } | |
428 | ||
429 | static char print_alua_state(int state) | |
430 | { | |
431 | switch (state) { | |
432 | case TPGS_STATE_OPTIMIZED: | |
433 | return 'A'; | |
434 | case TPGS_STATE_NONOPTIMIZED: | |
435 | return 'N'; | |
436 | case TPGS_STATE_STANDBY: | |
437 | return 'S'; | |
438 | case TPGS_STATE_UNAVAILABLE: | |
439 | return 'U'; | |
69723d17 HR |
440 | case TPGS_STATE_LBA_DEPENDENT: |
441 | return 'L'; | |
057ea7c9 HR |
442 | case TPGS_STATE_OFFLINE: |
443 | return 'O'; | |
444 | case TPGS_STATE_TRANSITIONING: | |
445 | return 'T'; | |
446 | default: | |
447 | return 'X'; | |
448 | } | |
449 | } | |
450 | ||
451 | static int alua_check_sense(struct scsi_device *sdev, | |
452 | struct scsi_sense_hdr *sense_hdr) | |
453 | { | |
454 | switch (sense_hdr->sense_key) { | |
455 | case NOT_READY: | |
456 | if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x0a) | |
457 | /* | |
458 | * LUN Not Accessible - ALUA state transition | |
459 | */ | |
c7dbb627 | 460 | return ADD_TO_MLQUEUE; |
057ea7c9 HR |
461 | if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x0b) |
462 | /* | |
463 | * LUN Not Accessible -- Target port in standby state | |
464 | */ | |
465 | return SUCCESS; | |
466 | if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x0c) | |
467 | /* | |
468 | * LUN Not Accessible -- Target port in unavailable state | |
469 | */ | |
470 | return SUCCESS; | |
471 | if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x12) | |
472 | /* | |
473 | * LUN Not Ready -- Offline | |
474 | */ | |
475 | return SUCCESS; | |
333b2448 | 476 | if (sdev->allow_restart && |
477 | sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x02) | |
478 | /* | |
479 | * if the device is not started, we need to wake | |
480 | * the error handler to start the motor | |
481 | */ | |
482 | return FAILED; | |
057ea7c9 HR |
483 | break; |
484 | case UNIT_ATTENTION: | |
485 | if (sense_hdr->asc == 0x29 && sense_hdr->ascq == 0x00) | |
486 | /* | |
487 | * Power On, Reset, or Bus Device Reset, just retry. | |
488 | */ | |
c7dbb627 | 489 | return ADD_TO_MLQUEUE; |
c20ee7b5 SS |
490 | if (sense_hdr->asc == 0x29 && sense_hdr->ascq == 0x04) |
491 | /* | |
492 | * Device internal reset | |
493 | */ | |
494 | return ADD_TO_MLQUEUE; | |
410f02d8 MB |
495 | if (sense_hdr->asc == 0x2a && sense_hdr->ascq == 0x01) |
496 | /* | |
497 | * Mode Parameters Changed | |
498 | */ | |
499 | return ADD_TO_MLQUEUE; | |
bf81973a | 500 | if (sense_hdr->asc == 0x2a && sense_hdr->ascq == 0x06) |
057ea7c9 HR |
501 | /* |
502 | * ALUA state changed | |
503 | */ | |
c7dbb627 | 504 | return ADD_TO_MLQUEUE; |
bf81973a | 505 | if (sense_hdr->asc == 0x2a && sense_hdr->ascq == 0x07) |
057ea7c9 HR |
506 | /* |
507 | * Implicit ALUA state transition failed | |
508 | */ | |
c7dbb627 | 509 | return ADD_TO_MLQUEUE; |
bf81973a MB |
510 | if (sense_hdr->asc == 0x3f && sense_hdr->ascq == 0x03) |
511 | /* | |
512 | * Inquiry data has changed | |
513 | */ | |
514 | return ADD_TO_MLQUEUE; | |
515 | if (sense_hdr->asc == 0x3f && sense_hdr->ascq == 0x0e) | |
4d086f6b IH |
516 | /* |
517 | * REPORTED_LUNS_DATA_HAS_CHANGED is reported | |
518 | * when switching controllers on targets like | |
519 | * Intel Multi-Flex. We can just retry. | |
520 | */ | |
521 | return ADD_TO_MLQUEUE; | |
057ea7c9 HR |
522 | break; |
523 | } | |
524 | ||
525 | return SCSI_RETURN_NOT_HANDLED; | |
526 | } | |
527 | ||
057ea7c9 HR |
528 | /* |
529 | * alua_rtpg - Evaluate REPORT TARGET GROUP STATES | |
530 | * @sdev: the device to be evaluated. | |
a8e5a2d5 | 531 | * @wait_for_transition: if nonzero, wait ALUA_FAILOVER_TIMEOUT seconds for device to exit transitioning state |
057ea7c9 HR |
532 | * |
533 | * Evaluate the Target Port Group State. | |
534 | * Returns SCSI_DH_DEV_OFFLINED if the path is | |
25985edc | 535 | * found to be unusable. |
057ea7c9 | 536 | */ |
a8e5a2d5 | 537 | static int alua_rtpg(struct scsi_device *sdev, struct alua_dh_data *h, int wait_for_transition) |
057ea7c9 HR |
538 | { |
539 | struct scsi_sense_hdr sense_hdr; | |
540 | int len, k, off, valid_states = 0; | |
cfde3fa1 | 541 | unsigned char *ucp; |
057ea7c9 | 542 | unsigned err; |
8e67ce60 | 543 | bool rtpg_ext_hdr_req = 1; |
bc97f4bb | 544 | unsigned long expiry, interval = 0; |
3588c5a2 RE |
545 | unsigned int tpg_desc_tbl_off; |
546 | unsigned char orig_transition_tmo; | |
547 | ||
548 | if (!h->transition_tmo) | |
549 | expiry = round_jiffies_up(jiffies + ALUA_FAILOVER_TIMEOUT * HZ); | |
550 | else | |
551 | expiry = round_jiffies_up(jiffies + h->transition_tmo * HZ); | |
057ea7c9 HR |
552 | |
553 | retry: | |
8e67ce60 | 554 | err = submit_rtpg(sdev, h, rtpg_ext_hdr_req); |
057ea7c9 HR |
555 | |
556 | if (err == SCSI_DH_IO && h->senselen > 0) { | |
557 | err = scsi_normalize_sense(h->sense, SCSI_SENSE_BUFFERSIZE, | |
558 | &sense_hdr); | |
559 | if (!err) | |
560 | return SCSI_DH_IO; | |
561 | ||
8e67ce60 RE |
562 | /* |
563 | * submit_rtpg() has failed on existing arrays | |
564 | * when requesting extended header info, and | |
565 | * the array doesn't support extended headers, | |
566 | * even though it shouldn't according to T10. | |
567 | * The retry without rtpg_ext_hdr_req set | |
568 | * handles this. | |
569 | */ | |
570 | if (rtpg_ext_hdr_req == 1 && | |
571 | sense_hdr.sense_key == ILLEGAL_REQUEST && | |
572 | sense_hdr.asc == 0x24 && sense_hdr.ascq == 0) { | |
573 | rtpg_ext_hdr_req = 0; | |
574 | goto retry; | |
575 | } | |
576 | ||
057ea7c9 | 577 | err = alua_check_sense(sdev, &sense_hdr); |
69723d17 | 578 | if (err == ADD_TO_MLQUEUE && time_before(jiffies, expiry)) |
057ea7c9 HR |
579 | goto retry; |
580 | sdev_printk(KERN_INFO, sdev, | |
581 | "%s: rtpg sense code %02x/%02x/%02x\n", | |
582 | ALUA_DH_NAME, sense_hdr.sense_key, | |
583 | sense_hdr.asc, sense_hdr.ascq); | |
584 | err = SCSI_DH_IO; | |
585 | } | |
586 | if (err != SCSI_DH_OK) | |
587 | return err; | |
588 | ||
589 | len = (h->buff[0] << 24) + (h->buff[1] << 16) + | |
590 | (h->buff[2] << 8) + h->buff[3] + 4; | |
591 | ||
592 | if (len > h->bufflen) { | |
593 | /* Resubmit with the correct length */ | |
594 | if (realloc_buffer(h, len)) { | |
595 | sdev_printk(KERN_WARNING, sdev, | |
cadbd4a5 | 596 | "%s: kmalloc buffer failed\n",__func__); |
057ea7c9 HR |
597 | /* Temporary failure, bypass */ |
598 | return SCSI_DH_DEV_TEMP_BUSY; | |
599 | } | |
600 | goto retry; | |
601 | } | |
602 | ||
3588c5a2 RE |
603 | orig_transition_tmo = h->transition_tmo; |
604 | if ((h->buff[4] & RTPG_FMT_MASK) == RTPG_FMT_EXT_HDR && h->buff[5] != 0) | |
605 | h->transition_tmo = h->buff[5]; | |
606 | else | |
607 | h->transition_tmo = ALUA_FAILOVER_TIMEOUT; | |
608 | ||
a8e5a2d5 | 609 | if (wait_for_transition && (orig_transition_tmo != h->transition_tmo)) { |
3588c5a2 RE |
610 | sdev_printk(KERN_INFO, sdev, |
611 | "%s: transition timeout set to %d seconds\n", | |
612 | ALUA_DH_NAME, h->transition_tmo); | |
613 | expiry = jiffies + h->transition_tmo * HZ; | |
614 | } | |
615 | ||
616 | if ((h->buff[4] & RTPG_FMT_MASK) == RTPG_FMT_EXT_HDR) | |
617 | tpg_desc_tbl_off = 8; | |
618 | else | |
619 | tpg_desc_tbl_off = 4; | |
620 | ||
621 | for (k = tpg_desc_tbl_off, ucp = h->buff + tpg_desc_tbl_off; | |
622 | k < len; | |
623 | k += off, ucp += off) { | |
624 | ||
057ea7c9 HR |
625 | if (h->group_id == (ucp[2] << 8) + ucp[3]) { |
626 | h->state = ucp[0] & 0x0f; | |
dcd3a754 | 627 | h->pref = ucp[0] >> 7; |
057ea7c9 HR |
628 | valid_states = ucp[1]; |
629 | } | |
630 | off = 8 + (ucp[7] * 4); | |
631 | } | |
632 | ||
633 | sdev_printk(KERN_INFO, sdev, | |
dcd3a754 | 634 | "%s: port group %02x state %c %s supports %c%c%c%c%c%c%c\n", |
057ea7c9 | 635 | ALUA_DH_NAME, h->group_id, print_alua_state(h->state), |
dcd3a754 | 636 | h->pref ? "preferred" : "non-preferred", |
057ea7c9 HR |
637 | valid_states&TPGS_SUPPORT_TRANSITION?'T':'t', |
638 | valid_states&TPGS_SUPPORT_OFFLINE?'O':'o', | |
69723d17 | 639 | valid_states&TPGS_SUPPORT_LBA_DEPENDENT?'L':'l', |
057ea7c9 HR |
640 | valid_states&TPGS_SUPPORT_UNAVAILABLE?'U':'u', |
641 | valid_states&TPGS_SUPPORT_STANDBY?'S':'s', | |
642 | valid_states&TPGS_SUPPORT_NONOPTIMIZED?'N':'n', | |
643 | valid_states&TPGS_SUPPORT_OPTIMIZED?'A':'a'); | |
644 | ||
69723d17 HR |
645 | switch (h->state) { |
646 | case TPGS_STATE_TRANSITIONING: | |
a8e5a2d5 SS |
647 | if (wait_for_transition) { |
648 | if (time_before(jiffies, expiry)) { | |
649 | /* State transition, retry */ | |
650 | interval += 2000; | |
651 | msleep(interval); | |
652 | goto retry; | |
653 | } | |
654 | err = SCSI_DH_RETRY; | |
655 | } else { | |
656 | err = SCSI_DH_OK; | |
057ea7c9 | 657 | } |
a8e5a2d5 | 658 | |
69723d17 | 659 | /* Transitioning time exceeded, set port to standby */ |
69723d17 HR |
660 | h->state = TPGS_STATE_STANDBY; |
661 | break; | |
662 | case TPGS_STATE_OFFLINE: | |
e47f8976 | 663 | /* Path unusable */ |
69723d17 HR |
664 | err = SCSI_DH_DEV_OFFLINED; |
665 | break; | |
666 | default: | |
667 | /* Useable path if active */ | |
668 | err = SCSI_DH_OK; | |
669 | break; | |
057ea7c9 HR |
670 | } |
671 | return err; | |
672 | } | |
673 | ||
674 | /* | |
675 | * alua_initialize - Initialize ALUA state | |
676 | * @sdev: the device to be initialized | |
677 | * | |
678 | * For the prep_fn to work correctly we have | |
679 | * to initialize the ALUA state for the device. | |
680 | */ | |
681 | static int alua_initialize(struct scsi_device *sdev, struct alua_dh_data *h) | |
682 | { | |
683 | int err; | |
684 | ||
d7c48feb | 685 | err = alua_check_tpgs(sdev, h); |
057ea7c9 HR |
686 | if (err != SCSI_DH_OK) |
687 | goto out; | |
688 | ||
689 | err = alua_vpd_inquiry(sdev, h); | |
690 | if (err != SCSI_DH_OK) | |
691 | goto out; | |
692 | ||
a8e5a2d5 | 693 | err = alua_rtpg(sdev, h, 0); |
057ea7c9 HR |
694 | if (err != SCSI_DH_OK) |
695 | goto out; | |
696 | ||
697 | out: | |
698 | return err; | |
699 | } | |
4335d092 MB |
700 | /* |
701 | * alua_set_params - set/unset the optimize flag | |
702 | * @sdev: device on the path to be activated | |
703 | * params - parameters in the following format | |
704 | * "no_of_params\0param1\0param2\0param3\0...\0" | |
705 | * For example, to set the flag pass the following parameters | |
706 | * from multipath.conf | |
707 | * hardware_handler "2 alua 1" | |
708 | */ | |
709 | static int alua_set_params(struct scsi_device *sdev, const char *params) | |
710 | { | |
711 | struct alua_dh_data *h = get_alua_data(sdev); | |
712 | unsigned int optimize = 0, argc; | |
713 | const char *p = params; | |
714 | int result = SCSI_DH_OK; | |
715 | ||
716 | if ((sscanf(params, "%u", &argc) != 1) || (argc != 1)) | |
717 | return -EINVAL; | |
718 | ||
719 | while (*p++) | |
720 | ; | |
721 | if ((sscanf(p, "%u", &optimize) != 1) || (optimize > 1)) | |
722 | return -EINVAL; | |
723 | ||
724 | if (optimize) | |
725 | h->flags |= ALUA_OPTIMIZE_STPG; | |
726 | else | |
727 | h->flags &= ~ALUA_OPTIMIZE_STPG; | |
728 | ||
729 | return result; | |
730 | } | |
057ea7c9 | 731 | |
7a3ad392 SS |
732 | static uint optimize_stpg; |
733 | module_param(optimize_stpg, uint, S_IRUGO|S_IWUSR); | |
734 | MODULE_PARM_DESC(optimize_stpg, "Allow use of a non-optimized path, rather than sending a STPG, when implicit TPGS is supported (0=No,1=Yes). Default is 0."); | |
735 | ||
057ea7c9 HR |
736 | /* |
737 | * alua_activate - activate a path | |
738 | * @sdev: device on the path to be activated | |
739 | * | |
740 | * We're currently switching the port group to be activated only and | |
741 | * let the array figure out the rest. | |
742 | * There may be other arrays which require us to switch all port groups | |
743 | * based on a certain policy. But until we actually encounter them it | |
744 | * should be okay. | |
745 | */ | |
3ae31f6a CS |
746 | static int alua_activate(struct scsi_device *sdev, |
747 | activate_complete fn, void *data) | |
057ea7c9 HR |
748 | { |
749 | struct alua_dh_data *h = get_alua_data(sdev); | |
750 | int err = SCSI_DH_OK; | |
72d9e0f3 | 751 | int stpg = 0; |
057ea7c9 | 752 | |
a8e5a2d5 | 753 | err = alua_rtpg(sdev, h, 1); |
46ccf6b5 HR |
754 | if (err != SCSI_DH_OK) |
755 | goto out; | |
057ea7c9 | 756 | |
7a3ad392 SS |
757 | if (optimize_stpg) |
758 | h->flags |= ALUA_OPTIMIZE_STPG; | |
759 | ||
72d9e0f3 MB |
760 | if (h->tpgs & TPGS_MODE_EXPLICIT) { |
761 | switch (h->state) { | |
762 | case TPGS_STATE_NONOPTIMIZED: | |
763 | stpg = 1; | |
764 | if ((h->flags & ALUA_OPTIMIZE_STPG) && | |
765 | (!h->pref) && | |
766 | (h->tpgs & TPGS_MODE_IMPLICIT)) | |
767 | stpg = 0; | |
768 | break; | |
769 | case TPGS_STATE_STANDBY: | |
bb2c94a3 | 770 | case TPGS_STATE_UNAVAILABLE: |
72d9e0f3 MB |
771 | stpg = 1; |
772 | break; | |
72d9e0f3 MB |
773 | case TPGS_STATE_OFFLINE: |
774 | err = SCSI_DH_IO; | |
775 | break; | |
776 | case TPGS_STATE_TRANSITIONING: | |
777 | err = SCSI_DH_RETRY; | |
778 | break; | |
779 | default: | |
780 | break; | |
781 | } | |
782 | } | |
783 | ||
784 | if (stpg) { | |
96e65865 CS |
785 | h->callback_fn = fn; |
786 | h->callback_data = data; | |
787 | err = submit_stpg(h); | |
788 | if (err == SCSI_DH_OK) | |
789 | return 0; | |
790 | h->callback_fn = h->callback_data = NULL; | |
791 | } | |
057ea7c9 HR |
792 | |
793 | out: | |
3ae31f6a CS |
794 | if (fn) |
795 | fn(data, err); | |
796 | return 0; | |
057ea7c9 HR |
797 | } |
798 | ||
799 | /* | |
800 | * alua_prep_fn - request callback | |
801 | * | |
802 | * Fail I/O to all paths not in state | |
803 | * active/optimized or active/non-optimized. | |
804 | */ | |
805 | static int alua_prep_fn(struct scsi_device *sdev, struct request *req) | |
806 | { | |
807 | struct alua_dh_data *h = get_alua_data(sdev); | |
808 | int ret = BLKPREP_OK; | |
809 | ||
69723d17 HR |
810 | if (h->state == TPGS_STATE_TRANSITIONING) |
811 | ret = BLKPREP_DEFER; | |
812 | else if (h->state != TPGS_STATE_OPTIMIZED && | |
813 | h->state != TPGS_STATE_NONOPTIMIZED && | |
814 | h->state != TPGS_STATE_LBA_DEPENDENT) { | |
057ea7c9 HR |
815 | ret = BLKPREP_KILL; |
816 | req->cmd_flags |= REQ_QUIET; | |
817 | } | |
818 | return ret; | |
819 | ||
820 | } | |
821 | ||
6c3633d0 HR |
822 | static bool alua_match(struct scsi_device *sdev) |
823 | { | |
824 | return (scsi_device_tpgs(sdev) != 0); | |
825 | } | |
057ea7c9 | 826 | |
057ea7c9 HR |
827 | /* |
828 | * alua_bus_attach - Attach device handler | |
829 | * @sdev: device to be attached to | |
830 | */ | |
1d520328 | 831 | static struct scsi_dh_data *alua_bus_attach(struct scsi_device *sdev) |
057ea7c9 | 832 | { |
057ea7c9 | 833 | struct alua_dh_data *h; |
1d520328 | 834 | int err; |
057ea7c9 | 835 | |
cd37743f | 836 | h = kzalloc(sizeof(*h) , GFP_KERNEL); |
1d520328 CH |
837 | if (!h) |
838 | return ERR_PTR(-ENOMEM); | |
057ea7c9 HR |
839 | h->tpgs = TPGS_MODE_UNINITIALIZED; |
840 | h->state = TPGS_STATE_OPTIMIZED; | |
841 | h->group_id = -1; | |
842 | h->rel_port = -1; | |
843 | h->buff = h->inq; | |
844 | h->bufflen = ALUA_INQUIRY_SIZE; | |
96e65865 | 845 | h->sdev = sdev; |
057ea7c9 HR |
846 | |
847 | err = alua_initialize(sdev, h); | |
1d520328 | 848 | if (err != SCSI_DH_OK && err != SCSI_DH_DEV_OFFLINED) |
057ea7c9 HR |
849 | goto failed; |
850 | ||
ab72002b | 851 | sdev_printk(KERN_NOTICE, sdev, "%s: Attached\n", ALUA_DH_NAME); |
1d520328 | 852 | return &h->dh_data; |
057ea7c9 | 853 | failed: |
cd37743f | 854 | kfree(h); |
1d520328 | 855 | return ERR_PTR(-EINVAL); |
057ea7c9 HR |
856 | } |
857 | ||
858 | /* | |
859 | * alua_bus_detach - Detach device handler | |
860 | * @sdev: device to be detached from | |
861 | */ | |
862 | static void alua_bus_detach(struct scsi_device *sdev) | |
863 | { | |
cd37743f | 864 | struct alua_dh_data *h = get_alua_data(sdev); |
057ea7c9 | 865 | |
057ea7c9 HR |
866 | if (h->buff && h->inq != h->buff) |
867 | kfree(h->buff); | |
cd37743f | 868 | kfree(h); |
057ea7c9 HR |
869 | } |
870 | ||
1d520328 CH |
871 | static struct scsi_device_handler alua_dh = { |
872 | .name = ALUA_DH_NAME, | |
873 | .module = THIS_MODULE, | |
874 | .attach = alua_bus_attach, | |
875 | .detach = alua_bus_detach, | |
876 | .prep_fn = alua_prep_fn, | |
877 | .check_sense = alua_check_sense, | |
878 | .activate = alua_activate, | |
879 | .set_params = alua_set_params, | |
880 | .match = alua_match, | |
881 | }; | |
882 | ||
057ea7c9 HR |
883 | static int __init alua_init(void) |
884 | { | |
885 | int r; | |
886 | ||
887 | r = scsi_register_device_handler(&alua_dh); | |
888 | if (r != 0) | |
889 | printk(KERN_ERR "%s: Failed to register scsi device handler", | |
890 | ALUA_DH_NAME); | |
891 | return r; | |
892 | } | |
893 | ||
894 | static void __exit alua_exit(void) | |
895 | { | |
896 | scsi_unregister_device_handler(&alua_dh); | |
897 | } | |
898 | ||
899 | module_init(alua_init); | |
900 | module_exit(alua_exit); | |
901 | ||
902 | MODULE_DESCRIPTION("DM Multipath ALUA support"); | |
903 | MODULE_AUTHOR("Hannes Reinecke <hare@suse.de>"); | |
904 | MODULE_LICENSE("GPL"); | |
905 | MODULE_VERSION(ALUA_DH_VER); |