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