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 | 75 | unsigned char sense[SCSI_SENSE_BUFFERSIZE]; |
96e65865 CS |
76 | struct scsi_device *sdev; |
77 | activate_complete callback_fn; | |
78 | void *callback_data; | |
057ea7c9 HR |
79 | }; |
80 | ||
81 | #define ALUA_POLICY_SWITCH_CURRENT 0 | |
82 | #define ALUA_POLICY_SWITCH_ALL 1 | |
83 | ||
96e65865 CS |
84 | static char print_alua_state(int); |
85 | static int alua_check_sense(struct scsi_device *, struct scsi_sense_hdr *); | |
86 | ||
057ea7c9 HR |
87 | static int realloc_buffer(struct alua_dh_data *h, unsigned len) |
88 | { | |
89 | if (h->buff && h->buff != h->inq) | |
90 | kfree(h->buff); | |
91 | ||
92 | h->buff = kmalloc(len, GFP_NOIO); | |
93 | if (!h->buff) { | |
94 | h->buff = h->inq; | |
95 | h->bufflen = ALUA_INQUIRY_SIZE; | |
96 | return 1; | |
97 | } | |
98 | h->bufflen = len; | |
99 | return 0; | |
100 | } | |
101 | ||
102 | static struct request *get_alua_req(struct scsi_device *sdev, | |
103 | void *buffer, unsigned buflen, int rw) | |
104 | { | |
105 | struct request *rq; | |
106 | struct request_queue *q = sdev->request_queue; | |
107 | ||
108 | rq = blk_get_request(q, rw, GFP_NOIO); | |
109 | ||
a492f075 | 110 | if (IS_ERR(rq)) { |
057ea7c9 | 111 | sdev_printk(KERN_INFO, sdev, |
cadbd4a5 | 112 | "%s: blk_get_request failed\n", __func__); |
057ea7c9 HR |
113 | return NULL; |
114 | } | |
f27b087b | 115 | blk_rq_set_block_pc(rq); |
057ea7c9 HR |
116 | |
117 | if (buflen && blk_rq_map_kern(q, rq, buffer, buflen, GFP_NOIO)) { | |
118 | blk_put_request(rq); | |
119 | sdev_printk(KERN_INFO, sdev, | |
cadbd4a5 | 120 | "%s: blk_rq_map_kern failed\n", __func__); |
057ea7c9 HR |
121 | return NULL; |
122 | } | |
123 | ||
6000a368 | 124 | rq->cmd_flags |= REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT | |
64f84bc1 | 125 | REQ_FAILFAST_DRIVER; |
057ea7c9 | 126 | rq->retries = ALUA_FAILOVER_RETRIES; |
3588c5a2 | 127 | rq->timeout = ALUA_FAILOVER_TIMEOUT * HZ; |
057ea7c9 HR |
128 | |
129 | return rq; | |
130 | } | |
131 | ||
057ea7c9 HR |
132 | /* |
133 | * submit_rtpg - Issue a REPORT TARGET GROUP STATES command | |
134 | * @sdev: sdev the command should be sent to | |
135 | */ | |
8e67ce60 RE |
136 | static unsigned submit_rtpg(struct scsi_device *sdev, struct alua_dh_data *h, |
137 | bool rtpg_ext_hdr_req) | |
057ea7c9 HR |
138 | { |
139 | struct request *rq; | |
140 | int err = SCSI_DH_RES_TEMP_UNAVAIL; | |
141 | ||
142 | rq = get_alua_req(sdev, h->buff, h->bufflen, READ); | |
143 | if (!rq) | |
144 | goto done; | |
145 | ||
146 | /* Prepare the command. */ | |
147 | rq->cmd[0] = MAINTENANCE_IN; | |
8e67ce60 RE |
148 | if (rtpg_ext_hdr_req) |
149 | rq->cmd[1] = MI_REPORT_TARGET_PGS | MI_EXT_HDR_PARAM_FMT; | |
150 | else | |
151 | rq->cmd[1] = MI_REPORT_TARGET_PGS; | |
057ea7c9 HR |
152 | rq->cmd[6] = (h->bufflen >> 24) & 0xff; |
153 | rq->cmd[7] = (h->bufflen >> 16) & 0xff; | |
154 | rq->cmd[8] = (h->bufflen >> 8) & 0xff; | |
155 | rq->cmd[9] = h->bufflen & 0xff; | |
156 | rq->cmd_len = COMMAND_SIZE(MAINTENANCE_IN); | |
157 | ||
158 | rq->sense = h->sense; | |
159 | memset(rq->sense, 0, SCSI_SENSE_BUFFERSIZE); | |
d3692a3d | 160 | rq->sense_len = 0; |
057ea7c9 HR |
161 | |
162 | err = blk_execute_rq(rq->q, NULL, rq, 1); | |
163 | if (err == -EIO) { | |
164 | sdev_printk(KERN_INFO, sdev, | |
165 | "%s: rtpg failed with %x\n", | |
166 | ALUA_DH_NAME, rq->errors); | |
057ea7c9 HR |
167 | err = SCSI_DH_IO; |
168 | } | |
169 | blk_put_request(rq); | |
170 | done: | |
171 | return err; | |
172 | } | |
173 | ||
96e65865 CS |
174 | /* |
175 | * alua_stpg - Evaluate SET TARGET GROUP STATES | |
176 | * @sdev: the device to be evaluated | |
177 | * @state: the new target group state | |
178 | * | |
179 | * Send a SET TARGET GROUP STATES command to the device. | |
180 | * We only have to test here if we should resubmit the command; | |
181 | * any other error is assumed as a failure. | |
182 | */ | |
183 | static void stpg_endio(struct request *req, int error) | |
184 | { | |
185 | struct alua_dh_data *h = req->end_io_data; | |
186 | struct scsi_sense_hdr sense_hdr; | |
9349923d | 187 | unsigned err = SCSI_DH_OK; |
96e65865 | 188 | |
27db682b MC |
189 | if (host_byte(req->errors) != DID_OK || |
190 | msg_byte(req->errors) != COMMAND_COMPLETE) { | |
9349923d | 191 | err = SCSI_DH_IO; |
96e65865 | 192 | goto done; |
9349923d | 193 | } |
96e65865 | 194 | |
d3692a3d HR |
195 | if (scsi_normalize_sense(h->sense, SCSI_SENSE_BUFFERSIZE, |
196 | &sense_hdr)) { | |
96e65865 CS |
197 | if (!err) { |
198 | err = SCSI_DH_IO; | |
199 | goto done; | |
200 | } | |
201 | err = alua_check_sense(h->sdev, &sense_hdr); | |
202 | if (err == ADD_TO_MLQUEUE) { | |
203 | err = SCSI_DH_RETRY; | |
204 | goto done; | |
205 | } | |
206 | sdev_printk(KERN_INFO, h->sdev, | |
207 | "%s: stpg sense code: %02x/%02x/%02x\n", | |
208 | ALUA_DH_NAME, sense_hdr.sense_key, | |
209 | sense_hdr.asc, sense_hdr.ascq); | |
210 | err = SCSI_DH_IO; | |
27db682b MC |
211 | } else if (error) |
212 | err = SCSI_DH_IO; | |
213 | ||
96e65865 CS |
214 | if (err == SCSI_DH_OK) { |
215 | h->state = TPGS_STATE_OPTIMIZED; | |
216 | sdev_printk(KERN_INFO, h->sdev, | |
217 | "%s: port group %02x switched to state %c\n", | |
218 | ALUA_DH_NAME, h->group_id, | |
219 | print_alua_state(h->state)); | |
220 | } | |
221 | done: | |
ed0f36bc JG |
222 | req->end_io_data = NULL; |
223 | __blk_put_request(req->q, req); | |
96e65865 CS |
224 | if (h->callback_fn) { |
225 | h->callback_fn(h->callback_data, err); | |
226 | h->callback_fn = h->callback_data = NULL; | |
227 | } | |
228 | return; | |
229 | } | |
230 | ||
057ea7c9 HR |
231 | /* |
232 | * submit_stpg - Issue a SET TARGET GROUP STATES command | |
057ea7c9 HR |
233 | * |
234 | * Currently we're only setting the current target port group state | |
235 | * to 'active/optimized' and let the array firmware figure out | |
236 | * the states of the remaining groups. | |
237 | */ | |
96e65865 | 238 | static unsigned submit_stpg(struct alua_dh_data *h) |
057ea7c9 HR |
239 | { |
240 | struct request *rq; | |
057ea7c9 | 241 | int stpg_len = 8; |
96e65865 | 242 | struct scsi_device *sdev = h->sdev; |
057ea7c9 HR |
243 | |
244 | /* Prepare the data buffer */ | |
245 | memset(h->buff, 0, stpg_len); | |
246 | h->buff[4] = TPGS_STATE_OPTIMIZED & 0x0f; | |
ef3fa8c6 IH |
247 | h->buff[6] = (h->group_id >> 8) & 0xff; |
248 | h->buff[7] = h->group_id & 0xff; | |
057ea7c9 HR |
249 | |
250 | rq = get_alua_req(sdev, h->buff, stpg_len, WRITE); | |
251 | if (!rq) | |
96e65865 | 252 | return SCSI_DH_RES_TEMP_UNAVAIL; |
057ea7c9 HR |
253 | |
254 | /* Prepare the command. */ | |
255 | rq->cmd[0] = MAINTENANCE_OUT; | |
256 | rq->cmd[1] = MO_SET_TARGET_PGS; | |
257 | rq->cmd[6] = (stpg_len >> 24) & 0xff; | |
258 | rq->cmd[7] = (stpg_len >> 16) & 0xff; | |
259 | rq->cmd[8] = (stpg_len >> 8) & 0xff; | |
260 | rq->cmd[9] = stpg_len & 0xff; | |
261 | rq->cmd_len = COMMAND_SIZE(MAINTENANCE_OUT); | |
262 | ||
263 | rq->sense = h->sense; | |
264 | memset(rq->sense, 0, SCSI_SENSE_BUFFERSIZE); | |
d3692a3d | 265 | rq->sense_len = 0; |
96e65865 | 266 | rq->end_io_data = h; |
057ea7c9 | 267 | |
96e65865 | 268 | blk_execute_rq_nowait(rq->q, NULL, rq, 1, stpg_endio); |
7c66e9a5 | 269 | return SCSI_DH_OK; |
057ea7c9 HR |
270 | } |
271 | ||
272 | /* | |
d7c48feb | 273 | * alua_check_tpgs - Evaluate TPGS setting |
057ea7c9 HR |
274 | * @sdev: device to be checked |
275 | * | |
d7c48feb | 276 | * Examine the TPGS setting of the sdev to find out if ALUA |
057ea7c9 HR |
277 | * is supported. |
278 | */ | |
d7c48feb | 279 | static int alua_check_tpgs(struct scsi_device *sdev, struct alua_dh_data *h) |
057ea7c9 | 280 | { |
d7c48feb | 281 | int err = SCSI_DH_OK; |
057ea7c9 | 282 | |
db5a6a60 HR |
283 | /* |
284 | * ALUA support for non-disk devices is fraught with | |
285 | * difficulties, so disable it for now. | |
286 | */ | |
287 | if (sdev->type != TYPE_DISK) { | |
288 | h->tpgs = TPGS_MODE_NONE; | |
289 | sdev_printk(KERN_INFO, sdev, | |
290 | "%s: disable for non-disk devices\n", | |
291 | ALUA_DH_NAME); | |
292 | return SCSI_DH_DEV_UNSUPP; | |
293 | } | |
294 | ||
d7c48feb | 295 | h->tpgs = scsi_device_tpgs(sdev); |
057ea7c9 HR |
296 | switch (h->tpgs) { |
297 | case TPGS_MODE_EXPLICIT|TPGS_MODE_IMPLICIT: | |
298 | sdev_printk(KERN_INFO, sdev, | |
299 | "%s: supports implicit and explicit TPGS\n", | |
300 | ALUA_DH_NAME); | |
301 | break; | |
302 | case TPGS_MODE_EXPLICIT: | |
303 | sdev_printk(KERN_INFO, sdev, "%s: supports explicit TPGS\n", | |
304 | ALUA_DH_NAME); | |
305 | break; | |
306 | case TPGS_MODE_IMPLICIT: | |
307 | sdev_printk(KERN_INFO, sdev, "%s: supports implicit TPGS\n", | |
308 | ALUA_DH_NAME); | |
309 | break; | |
6cc05d45 | 310 | case TPGS_MODE_NONE: |
057ea7c9 HR |
311 | sdev_printk(KERN_INFO, sdev, "%s: not supported\n", |
312 | ALUA_DH_NAME); | |
313 | err = SCSI_DH_DEV_UNSUPP; | |
314 | break; | |
6cc05d45 HR |
315 | default: |
316 | sdev_printk(KERN_INFO, sdev, | |
317 | "%s: unsupported TPGS setting %d\n", | |
318 | ALUA_DH_NAME, h->tpgs); | |
319 | h->tpgs = TPGS_MODE_NONE; | |
320 | err = SCSI_DH_DEV_UNSUPP; | |
321 | break; | |
057ea7c9 HR |
322 | } |
323 | ||
324 | return err; | |
325 | } | |
326 | ||
327 | /* | |
9b80dcec | 328 | * alua_check_vpd - Evaluate INQUIRY vpd page 0x83 |
057ea7c9 HR |
329 | * @sdev: device to be checked |
330 | * | |
331 | * Extract the relative target port and the target port group | |
332 | * descriptor from the list of identificators. | |
333 | */ | |
9b80dcec | 334 | static int alua_check_vpd(struct scsi_device *sdev, struct alua_dh_data *h) |
057ea7c9 | 335 | { |
057ea7c9 | 336 | unsigned char *d; |
9b80dcec | 337 | unsigned char __rcu *vpd_pg83; |
057ea7c9 | 338 | |
9b80dcec HR |
339 | rcu_read_lock(); |
340 | if (!rcu_dereference(sdev->vpd_pg83)) { | |
341 | rcu_read_unlock(); | |
342 | return SCSI_DH_DEV_UNSUPP; | |
057ea7c9 HR |
343 | } |
344 | ||
345 | /* | |
9b80dcec | 346 | * Look for the correct descriptor. |
057ea7c9 | 347 | */ |
9b80dcec HR |
348 | vpd_pg83 = rcu_dereference(sdev->vpd_pg83); |
349 | d = vpd_pg83 + 4; | |
350 | while (d < vpd_pg83 + sdev->vpd_pg83_len) { | |
057ea7c9 HR |
351 | switch (d[1] & 0xf) { |
352 | case 0x4: | |
353 | /* Relative target port */ | |
354 | h->rel_port = (d[6] << 8) + d[7]; | |
355 | break; | |
356 | case 0x5: | |
357 | /* Target port group */ | |
358 | h->group_id = (d[6] << 8) + d[7]; | |
359 | break; | |
360 | default: | |
361 | break; | |
362 | } | |
363 | d += d[3] + 4; | |
364 | } | |
9b80dcec | 365 | rcu_read_unlock(); |
057ea7c9 HR |
366 | |
367 | if (h->group_id == -1) { | |
368 | /* | |
369 | * Internal error; TPGS supported but required | |
370 | * VPD identification descriptors not present. | |
371 | * Disable ALUA support | |
372 | */ | |
373 | sdev_printk(KERN_INFO, sdev, | |
374 | "%s: No target port descriptors found\n", | |
375 | ALUA_DH_NAME); | |
376 | h->state = TPGS_STATE_OPTIMIZED; | |
377 | h->tpgs = TPGS_MODE_NONE; | |
9b80dcec | 378 | return SCSI_DH_DEV_UNSUPP; |
057ea7c9 | 379 | } |
9b80dcec HR |
380 | sdev_printk(KERN_INFO, sdev, |
381 | "%s: port group %02x rel port %02x\n", | |
382 | ALUA_DH_NAME, h->group_id, h->rel_port); | |
057ea7c9 | 383 | |
9b80dcec | 384 | return 0; |
057ea7c9 HR |
385 | } |
386 | ||
387 | static char print_alua_state(int state) | |
388 | { | |
389 | switch (state) { | |
390 | case TPGS_STATE_OPTIMIZED: | |
391 | return 'A'; | |
392 | case TPGS_STATE_NONOPTIMIZED: | |
393 | return 'N'; | |
394 | case TPGS_STATE_STANDBY: | |
395 | return 'S'; | |
396 | case TPGS_STATE_UNAVAILABLE: | |
397 | return 'U'; | |
69723d17 HR |
398 | case TPGS_STATE_LBA_DEPENDENT: |
399 | return 'L'; | |
057ea7c9 HR |
400 | case TPGS_STATE_OFFLINE: |
401 | return 'O'; | |
402 | case TPGS_STATE_TRANSITIONING: | |
403 | return 'T'; | |
404 | default: | |
405 | return 'X'; | |
406 | } | |
407 | } | |
408 | ||
409 | static int alua_check_sense(struct scsi_device *sdev, | |
410 | struct scsi_sense_hdr *sense_hdr) | |
411 | { | |
412 | switch (sense_hdr->sense_key) { | |
413 | case NOT_READY: | |
414 | if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x0a) | |
415 | /* | |
416 | * LUN Not Accessible - ALUA state transition | |
417 | */ | |
c7dbb627 | 418 | return ADD_TO_MLQUEUE; |
057ea7c9 HR |
419 | if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x0b) |
420 | /* | |
421 | * LUN Not Accessible -- Target port in standby state | |
422 | */ | |
423 | return SUCCESS; | |
424 | if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x0c) | |
425 | /* | |
426 | * LUN Not Accessible -- Target port in unavailable state | |
427 | */ | |
428 | return SUCCESS; | |
429 | if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x12) | |
430 | /* | |
431 | * LUN Not Ready -- Offline | |
432 | */ | |
433 | return SUCCESS; | |
333b2448 | 434 | if (sdev->allow_restart && |
435 | sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x02) | |
436 | /* | |
437 | * if the device is not started, we need to wake | |
438 | * the error handler to start the motor | |
439 | */ | |
440 | return FAILED; | |
057ea7c9 HR |
441 | break; |
442 | case UNIT_ATTENTION: | |
443 | if (sense_hdr->asc == 0x29 && sense_hdr->ascq == 0x00) | |
444 | /* | |
445 | * Power On, Reset, or Bus Device Reset, just retry. | |
446 | */ | |
c7dbb627 | 447 | return ADD_TO_MLQUEUE; |
c20ee7b5 SS |
448 | if (sense_hdr->asc == 0x29 && sense_hdr->ascq == 0x04) |
449 | /* | |
450 | * Device internal reset | |
451 | */ | |
452 | return ADD_TO_MLQUEUE; | |
410f02d8 MB |
453 | if (sense_hdr->asc == 0x2a && sense_hdr->ascq == 0x01) |
454 | /* | |
455 | * Mode Parameters Changed | |
456 | */ | |
457 | return ADD_TO_MLQUEUE; | |
bf81973a | 458 | if (sense_hdr->asc == 0x2a && sense_hdr->ascq == 0x06) |
057ea7c9 HR |
459 | /* |
460 | * ALUA state changed | |
461 | */ | |
c7dbb627 | 462 | return ADD_TO_MLQUEUE; |
bf81973a | 463 | if (sense_hdr->asc == 0x2a && sense_hdr->ascq == 0x07) |
057ea7c9 HR |
464 | /* |
465 | * Implicit ALUA state transition failed | |
466 | */ | |
c7dbb627 | 467 | return ADD_TO_MLQUEUE; |
bf81973a MB |
468 | if (sense_hdr->asc == 0x3f && sense_hdr->ascq == 0x03) |
469 | /* | |
470 | * Inquiry data has changed | |
471 | */ | |
472 | return ADD_TO_MLQUEUE; | |
473 | if (sense_hdr->asc == 0x3f && sense_hdr->ascq == 0x0e) | |
4d086f6b IH |
474 | /* |
475 | * REPORTED_LUNS_DATA_HAS_CHANGED is reported | |
476 | * when switching controllers on targets like | |
477 | * Intel Multi-Flex. We can just retry. | |
478 | */ | |
479 | return ADD_TO_MLQUEUE; | |
057ea7c9 HR |
480 | break; |
481 | } | |
482 | ||
483 | return SCSI_RETURN_NOT_HANDLED; | |
484 | } | |
485 | ||
057ea7c9 HR |
486 | /* |
487 | * alua_rtpg - Evaluate REPORT TARGET GROUP STATES | |
488 | * @sdev: the device to be evaluated. | |
a8e5a2d5 | 489 | * @wait_for_transition: if nonzero, wait ALUA_FAILOVER_TIMEOUT seconds for device to exit transitioning state |
057ea7c9 HR |
490 | * |
491 | * Evaluate the Target Port Group State. | |
492 | * Returns SCSI_DH_DEV_OFFLINED if the path is | |
25985edc | 493 | * found to be unusable. |
057ea7c9 | 494 | */ |
a8e5a2d5 | 495 | static int alua_rtpg(struct scsi_device *sdev, struct alua_dh_data *h, int wait_for_transition) |
057ea7c9 HR |
496 | { |
497 | struct scsi_sense_hdr sense_hdr; | |
498 | int len, k, off, valid_states = 0; | |
cfde3fa1 | 499 | unsigned char *ucp; |
057ea7c9 | 500 | unsigned err; |
8e67ce60 | 501 | bool rtpg_ext_hdr_req = 1; |
bc97f4bb | 502 | unsigned long expiry, interval = 0; |
3588c5a2 RE |
503 | unsigned int tpg_desc_tbl_off; |
504 | unsigned char orig_transition_tmo; | |
505 | ||
506 | if (!h->transition_tmo) | |
507 | expiry = round_jiffies_up(jiffies + ALUA_FAILOVER_TIMEOUT * HZ); | |
508 | else | |
509 | expiry = round_jiffies_up(jiffies + h->transition_tmo * HZ); | |
057ea7c9 HR |
510 | |
511 | retry: | |
8e67ce60 | 512 | err = submit_rtpg(sdev, h, rtpg_ext_hdr_req); |
057ea7c9 | 513 | |
d3692a3d HR |
514 | if (err == SCSI_DH_IO) { |
515 | if (!scsi_normalize_sense(h->sense, SCSI_SENSE_BUFFERSIZE, | |
516 | &sense_hdr)) | |
057ea7c9 HR |
517 | return SCSI_DH_IO; |
518 | ||
8e67ce60 RE |
519 | /* |
520 | * submit_rtpg() has failed on existing arrays | |
521 | * when requesting extended header info, and | |
522 | * the array doesn't support extended headers, | |
523 | * even though it shouldn't according to T10. | |
524 | * The retry without rtpg_ext_hdr_req set | |
525 | * handles this. | |
526 | */ | |
527 | if (rtpg_ext_hdr_req == 1 && | |
528 | sense_hdr.sense_key == ILLEGAL_REQUEST && | |
529 | sense_hdr.asc == 0x24 && sense_hdr.ascq == 0) { | |
530 | rtpg_ext_hdr_req = 0; | |
531 | goto retry; | |
532 | } | |
533 | ||
057ea7c9 | 534 | err = alua_check_sense(sdev, &sense_hdr); |
69723d17 | 535 | if (err == ADD_TO_MLQUEUE && time_before(jiffies, expiry)) |
057ea7c9 HR |
536 | goto retry; |
537 | sdev_printk(KERN_INFO, sdev, | |
538 | "%s: rtpg sense code %02x/%02x/%02x\n", | |
539 | ALUA_DH_NAME, sense_hdr.sense_key, | |
540 | sense_hdr.asc, sense_hdr.ascq); | |
541 | err = SCSI_DH_IO; | |
542 | } | |
543 | if (err != SCSI_DH_OK) | |
544 | return err; | |
545 | ||
546 | len = (h->buff[0] << 24) + (h->buff[1] << 16) + | |
547 | (h->buff[2] << 8) + h->buff[3] + 4; | |
548 | ||
549 | if (len > h->bufflen) { | |
550 | /* Resubmit with the correct length */ | |
551 | if (realloc_buffer(h, len)) { | |
552 | sdev_printk(KERN_WARNING, sdev, | |
cadbd4a5 | 553 | "%s: kmalloc buffer failed\n",__func__); |
057ea7c9 HR |
554 | /* Temporary failure, bypass */ |
555 | return SCSI_DH_DEV_TEMP_BUSY; | |
556 | } | |
557 | goto retry; | |
558 | } | |
559 | ||
3588c5a2 RE |
560 | orig_transition_tmo = h->transition_tmo; |
561 | if ((h->buff[4] & RTPG_FMT_MASK) == RTPG_FMT_EXT_HDR && h->buff[5] != 0) | |
562 | h->transition_tmo = h->buff[5]; | |
563 | else | |
564 | h->transition_tmo = ALUA_FAILOVER_TIMEOUT; | |
565 | ||
a8e5a2d5 | 566 | if (wait_for_transition && (orig_transition_tmo != h->transition_tmo)) { |
3588c5a2 RE |
567 | sdev_printk(KERN_INFO, sdev, |
568 | "%s: transition timeout set to %d seconds\n", | |
569 | ALUA_DH_NAME, h->transition_tmo); | |
570 | expiry = jiffies + h->transition_tmo * HZ; | |
571 | } | |
572 | ||
573 | if ((h->buff[4] & RTPG_FMT_MASK) == RTPG_FMT_EXT_HDR) | |
574 | tpg_desc_tbl_off = 8; | |
575 | else | |
576 | tpg_desc_tbl_off = 4; | |
577 | ||
578 | for (k = tpg_desc_tbl_off, ucp = h->buff + tpg_desc_tbl_off; | |
579 | k < len; | |
580 | k += off, ucp += off) { | |
581 | ||
057ea7c9 HR |
582 | if (h->group_id == (ucp[2] << 8) + ucp[3]) { |
583 | h->state = ucp[0] & 0x0f; | |
dcd3a754 | 584 | h->pref = ucp[0] >> 7; |
057ea7c9 HR |
585 | valid_states = ucp[1]; |
586 | } | |
587 | off = 8 + (ucp[7] * 4); | |
588 | } | |
589 | ||
590 | sdev_printk(KERN_INFO, sdev, | |
dcd3a754 | 591 | "%s: port group %02x state %c %s supports %c%c%c%c%c%c%c\n", |
057ea7c9 | 592 | ALUA_DH_NAME, h->group_id, print_alua_state(h->state), |
dcd3a754 | 593 | h->pref ? "preferred" : "non-preferred", |
057ea7c9 HR |
594 | valid_states&TPGS_SUPPORT_TRANSITION?'T':'t', |
595 | valid_states&TPGS_SUPPORT_OFFLINE?'O':'o', | |
69723d17 | 596 | valid_states&TPGS_SUPPORT_LBA_DEPENDENT?'L':'l', |
057ea7c9 HR |
597 | valid_states&TPGS_SUPPORT_UNAVAILABLE?'U':'u', |
598 | valid_states&TPGS_SUPPORT_STANDBY?'S':'s', | |
599 | valid_states&TPGS_SUPPORT_NONOPTIMIZED?'N':'n', | |
600 | valid_states&TPGS_SUPPORT_OPTIMIZED?'A':'a'); | |
601 | ||
69723d17 HR |
602 | switch (h->state) { |
603 | case TPGS_STATE_TRANSITIONING: | |
a8e5a2d5 SS |
604 | if (wait_for_transition) { |
605 | if (time_before(jiffies, expiry)) { | |
606 | /* State transition, retry */ | |
607 | interval += 2000; | |
608 | msleep(interval); | |
609 | goto retry; | |
610 | } | |
611 | err = SCSI_DH_RETRY; | |
612 | } else { | |
613 | err = SCSI_DH_OK; | |
057ea7c9 | 614 | } |
a8e5a2d5 | 615 | |
69723d17 | 616 | /* Transitioning time exceeded, set port to standby */ |
69723d17 HR |
617 | h->state = TPGS_STATE_STANDBY; |
618 | break; | |
619 | case TPGS_STATE_OFFLINE: | |
e47f8976 | 620 | /* Path unusable */ |
69723d17 HR |
621 | err = SCSI_DH_DEV_OFFLINED; |
622 | break; | |
623 | default: | |
624 | /* Useable path if active */ | |
625 | err = SCSI_DH_OK; | |
626 | break; | |
057ea7c9 HR |
627 | } |
628 | return err; | |
629 | } | |
630 | ||
631 | /* | |
632 | * alua_initialize - Initialize ALUA state | |
633 | * @sdev: the device to be initialized | |
634 | * | |
635 | * For the prep_fn to work correctly we have | |
636 | * to initialize the ALUA state for the device. | |
637 | */ | |
638 | static int alua_initialize(struct scsi_device *sdev, struct alua_dh_data *h) | |
639 | { | |
640 | int err; | |
641 | ||
d7c48feb | 642 | err = alua_check_tpgs(sdev, h); |
057ea7c9 HR |
643 | if (err != SCSI_DH_OK) |
644 | goto out; | |
645 | ||
9b80dcec | 646 | err = alua_check_vpd(sdev, h); |
057ea7c9 HR |
647 | if (err != SCSI_DH_OK) |
648 | goto out; | |
649 | ||
a8e5a2d5 | 650 | err = alua_rtpg(sdev, h, 0); |
057ea7c9 HR |
651 | if (err != SCSI_DH_OK) |
652 | goto out; | |
653 | ||
654 | out: | |
655 | return err; | |
656 | } | |
4335d092 MB |
657 | /* |
658 | * alua_set_params - set/unset the optimize flag | |
659 | * @sdev: device on the path to be activated | |
660 | * params - parameters in the following format | |
661 | * "no_of_params\0param1\0param2\0param3\0...\0" | |
662 | * For example, to set the flag pass the following parameters | |
663 | * from multipath.conf | |
664 | * hardware_handler "2 alua 1" | |
665 | */ | |
666 | static int alua_set_params(struct scsi_device *sdev, const char *params) | |
667 | { | |
ee14c674 | 668 | struct alua_dh_data *h = sdev->handler_data; |
4335d092 MB |
669 | unsigned int optimize = 0, argc; |
670 | const char *p = params; | |
671 | int result = SCSI_DH_OK; | |
672 | ||
673 | if ((sscanf(params, "%u", &argc) != 1) || (argc != 1)) | |
674 | return -EINVAL; | |
675 | ||
676 | while (*p++) | |
677 | ; | |
678 | if ((sscanf(p, "%u", &optimize) != 1) || (optimize > 1)) | |
679 | return -EINVAL; | |
680 | ||
681 | if (optimize) | |
682 | h->flags |= ALUA_OPTIMIZE_STPG; | |
683 | else | |
684 | h->flags &= ~ALUA_OPTIMIZE_STPG; | |
685 | ||
686 | return result; | |
687 | } | |
057ea7c9 | 688 | |
7a3ad392 SS |
689 | static uint optimize_stpg; |
690 | module_param(optimize_stpg, uint, S_IRUGO|S_IWUSR); | |
691 | 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."); | |
692 | ||
057ea7c9 HR |
693 | /* |
694 | * alua_activate - activate a path | |
695 | * @sdev: device on the path to be activated | |
696 | * | |
697 | * We're currently switching the port group to be activated only and | |
698 | * let the array figure out the rest. | |
699 | * There may be other arrays which require us to switch all port groups | |
700 | * based on a certain policy. But until we actually encounter them it | |
701 | * should be okay. | |
702 | */ | |
3ae31f6a CS |
703 | static int alua_activate(struct scsi_device *sdev, |
704 | activate_complete fn, void *data) | |
057ea7c9 | 705 | { |
ee14c674 | 706 | struct alua_dh_data *h = sdev->handler_data; |
057ea7c9 | 707 | int err = SCSI_DH_OK; |
72d9e0f3 | 708 | int stpg = 0; |
057ea7c9 | 709 | |
a8e5a2d5 | 710 | err = alua_rtpg(sdev, h, 1); |
46ccf6b5 HR |
711 | if (err != SCSI_DH_OK) |
712 | goto out; | |
057ea7c9 | 713 | |
7a3ad392 SS |
714 | if (optimize_stpg) |
715 | h->flags |= ALUA_OPTIMIZE_STPG; | |
716 | ||
72d9e0f3 MB |
717 | if (h->tpgs & TPGS_MODE_EXPLICIT) { |
718 | switch (h->state) { | |
719 | case TPGS_STATE_NONOPTIMIZED: | |
720 | stpg = 1; | |
721 | if ((h->flags & ALUA_OPTIMIZE_STPG) && | |
722 | (!h->pref) && | |
723 | (h->tpgs & TPGS_MODE_IMPLICIT)) | |
724 | stpg = 0; | |
725 | break; | |
726 | case TPGS_STATE_STANDBY: | |
bb2c94a3 | 727 | case TPGS_STATE_UNAVAILABLE: |
72d9e0f3 MB |
728 | stpg = 1; |
729 | break; | |
72d9e0f3 MB |
730 | case TPGS_STATE_OFFLINE: |
731 | err = SCSI_DH_IO; | |
732 | break; | |
733 | case TPGS_STATE_TRANSITIONING: | |
734 | err = SCSI_DH_RETRY; | |
735 | break; | |
736 | default: | |
737 | break; | |
738 | } | |
739 | } | |
740 | ||
741 | if (stpg) { | |
96e65865 CS |
742 | h->callback_fn = fn; |
743 | h->callback_data = data; | |
744 | err = submit_stpg(h); | |
745 | if (err == SCSI_DH_OK) | |
746 | return 0; | |
747 | h->callback_fn = h->callback_data = NULL; | |
748 | } | |
057ea7c9 HR |
749 | |
750 | out: | |
3ae31f6a CS |
751 | if (fn) |
752 | fn(data, err); | |
753 | return 0; | |
057ea7c9 HR |
754 | } |
755 | ||
756 | /* | |
757 | * alua_prep_fn - request callback | |
758 | * | |
759 | * Fail I/O to all paths not in state | |
760 | * active/optimized or active/non-optimized. | |
761 | */ | |
762 | static int alua_prep_fn(struct scsi_device *sdev, struct request *req) | |
763 | { | |
ee14c674 | 764 | struct alua_dh_data *h = sdev->handler_data; |
057ea7c9 HR |
765 | int ret = BLKPREP_OK; |
766 | ||
69723d17 HR |
767 | if (h->state == TPGS_STATE_TRANSITIONING) |
768 | ret = BLKPREP_DEFER; | |
769 | else if (h->state != TPGS_STATE_OPTIMIZED && | |
770 | h->state != TPGS_STATE_NONOPTIMIZED && | |
771 | h->state != TPGS_STATE_LBA_DEPENDENT) { | |
057ea7c9 HR |
772 | ret = BLKPREP_KILL; |
773 | req->cmd_flags |= REQ_QUIET; | |
774 | } | |
775 | return ret; | |
776 | ||
777 | } | |
778 | ||
057ea7c9 HR |
779 | /* |
780 | * alua_bus_attach - Attach device handler | |
781 | * @sdev: device to be attached to | |
782 | */ | |
ee14c674 | 783 | static int alua_bus_attach(struct scsi_device *sdev) |
057ea7c9 | 784 | { |
057ea7c9 | 785 | struct alua_dh_data *h; |
1d520328 | 786 | int err; |
057ea7c9 | 787 | |
cd37743f | 788 | h = kzalloc(sizeof(*h) , GFP_KERNEL); |
1d520328 | 789 | if (!h) |
ee14c674 | 790 | return -ENOMEM; |
057ea7c9 HR |
791 | h->tpgs = TPGS_MODE_UNINITIALIZED; |
792 | h->state = TPGS_STATE_OPTIMIZED; | |
793 | h->group_id = -1; | |
794 | h->rel_port = -1; | |
795 | h->buff = h->inq; | |
796 | h->bufflen = ALUA_INQUIRY_SIZE; | |
96e65865 | 797 | h->sdev = sdev; |
057ea7c9 HR |
798 | |
799 | err = alua_initialize(sdev, h); | |
1d520328 | 800 | if (err != SCSI_DH_OK && err != SCSI_DH_DEV_OFFLINED) |
057ea7c9 HR |
801 | goto failed; |
802 | ||
ee14c674 CH |
803 | sdev->handler_data = h; |
804 | return 0; | |
057ea7c9 | 805 | failed: |
cd37743f | 806 | kfree(h); |
ee14c674 | 807 | return -EINVAL; |
057ea7c9 HR |
808 | } |
809 | ||
810 | /* | |
811 | * alua_bus_detach - Detach device handler | |
812 | * @sdev: device to be detached from | |
813 | */ | |
814 | static void alua_bus_detach(struct scsi_device *sdev) | |
815 | { | |
ee14c674 | 816 | struct alua_dh_data *h = sdev->handler_data; |
057ea7c9 | 817 | |
057ea7c9 HR |
818 | if (h->buff && h->inq != h->buff) |
819 | kfree(h->buff); | |
ee14c674 | 820 | sdev->handler_data = NULL; |
cd37743f | 821 | kfree(h); |
057ea7c9 HR |
822 | } |
823 | ||
1d520328 CH |
824 | static struct scsi_device_handler alua_dh = { |
825 | .name = ALUA_DH_NAME, | |
826 | .module = THIS_MODULE, | |
827 | .attach = alua_bus_attach, | |
828 | .detach = alua_bus_detach, | |
829 | .prep_fn = alua_prep_fn, | |
830 | .check_sense = alua_check_sense, | |
831 | .activate = alua_activate, | |
832 | .set_params = alua_set_params, | |
1d520328 CH |
833 | }; |
834 | ||
057ea7c9 HR |
835 | static int __init alua_init(void) |
836 | { | |
837 | int r; | |
838 | ||
839 | r = scsi_register_device_handler(&alua_dh); | |
840 | if (r != 0) | |
841 | printk(KERN_ERR "%s: Failed to register scsi device handler", | |
842 | ALUA_DH_NAME); | |
843 | return r; | |
844 | } | |
845 | ||
846 | static void __exit alua_exit(void) | |
847 | { | |
848 | scsi_unregister_device_handler(&alua_dh); | |
849 | } | |
850 | ||
851 | module_init(alua_init); | |
852 | module_exit(alua_exit); | |
853 | ||
854 | MODULE_DESCRIPTION("DM Multipath ALUA support"); | |
855 | MODULE_AUTHOR("Hannes Reinecke <hare@suse.de>"); | |
856 | MODULE_LICENSE("GPL"); | |
857 | MODULE_VERSION(ALUA_DH_VER); |