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 | 25 | #include <scsi/scsi.h> |
80bd68d6 | 26 | #include <scsi/scsi_dbg.h> |
057ea7c9 HR |
27 | #include <scsi/scsi_eh.h> |
28 | #include <scsi/scsi_dh.h> | |
29 | ||
30 | #define ALUA_DH_NAME "alua" | |
69723d17 | 31 | #define ALUA_DH_VER "1.3" |
057ea7c9 HR |
32 | |
33 | #define TPGS_STATE_OPTIMIZED 0x0 | |
34 | #define TPGS_STATE_NONOPTIMIZED 0x1 | |
35 | #define TPGS_STATE_STANDBY 0x2 | |
36 | #define TPGS_STATE_UNAVAILABLE 0x3 | |
69723d17 | 37 | #define TPGS_STATE_LBA_DEPENDENT 0x4 |
057ea7c9 HR |
38 | #define TPGS_STATE_OFFLINE 0xe |
39 | #define TPGS_STATE_TRANSITIONING 0xf | |
40 | ||
41 | #define TPGS_SUPPORT_NONE 0x00 | |
42 | #define TPGS_SUPPORT_OPTIMIZED 0x01 | |
43 | #define TPGS_SUPPORT_NONOPTIMIZED 0x02 | |
44 | #define TPGS_SUPPORT_STANDBY 0x04 | |
45 | #define TPGS_SUPPORT_UNAVAILABLE 0x08 | |
69723d17 | 46 | #define TPGS_SUPPORT_LBA_DEPENDENT 0x10 |
057ea7c9 HR |
47 | #define TPGS_SUPPORT_OFFLINE 0x40 |
48 | #define TPGS_SUPPORT_TRANSITION 0x80 | |
49 | ||
3588c5a2 RE |
50 | #define RTPG_FMT_MASK 0x70 |
51 | #define RTPG_FMT_EXT_HDR 0x10 | |
52 | ||
057ea7c9 HR |
53 | #define TPGS_MODE_UNINITIALIZED -1 |
54 | #define TPGS_MODE_NONE 0x0 | |
55 | #define TPGS_MODE_IMPLICIT 0x1 | |
56 | #define TPGS_MODE_EXPLICIT 0x2 | |
57 | ||
58 | #define ALUA_INQUIRY_SIZE 36 | |
3588c5a2 | 59 | #define ALUA_FAILOVER_TIMEOUT 60 |
057ea7c9 HR |
60 | #define ALUA_FAILOVER_RETRIES 5 |
61 | ||
6c4fc044 | 62 | /* device handler flags */ |
4335d092 | 63 | #define ALUA_OPTIMIZE_STPG 1 |
6c4fc044 | 64 | #define ALUA_RTPG_EXT_HDR_UNSUPP 2 |
4335d092 | 65 | |
057ea7c9 HR |
66 | struct alua_dh_data { |
67 | int group_id; | |
68 | int rel_port; | |
69 | int tpgs; | |
70 | int state; | |
dcd3a754 | 71 | int pref; |
4335d092 | 72 | unsigned flags; /* used for optimizing STPG */ |
057ea7c9 HR |
73 | unsigned char inq[ALUA_INQUIRY_SIZE]; |
74 | unsigned char *buff; | |
75 | int bufflen; | |
3588c5a2 | 76 | unsigned char transition_tmo; |
057ea7c9 | 77 | unsigned char sense[SCSI_SENSE_BUFFERSIZE]; |
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 int realloc_buffer(struct alua_dh_data *h, unsigned len) |
90 | { | |
91 | if (h->buff && h->buff != h->inq) | |
92 | kfree(h->buff); | |
93 | ||
94 | h->buff = kmalloc(len, GFP_NOIO); | |
95 | if (!h->buff) { | |
96 | h->buff = h->inq; | |
97 | h->bufflen = ALUA_INQUIRY_SIZE; | |
98 | return 1; | |
99 | } | |
100 | h->bufflen = len; | |
101 | return 0; | |
102 | } | |
103 | ||
104 | static struct request *get_alua_req(struct scsi_device *sdev, | |
105 | void *buffer, unsigned buflen, int rw) | |
106 | { | |
107 | struct request *rq; | |
108 | struct request_queue *q = sdev->request_queue; | |
109 | ||
110 | rq = blk_get_request(q, rw, GFP_NOIO); | |
111 | ||
a492f075 | 112 | if (IS_ERR(rq)) { |
057ea7c9 | 113 | sdev_printk(KERN_INFO, sdev, |
cadbd4a5 | 114 | "%s: blk_get_request failed\n", __func__); |
057ea7c9 HR |
115 | return NULL; |
116 | } | |
f27b087b | 117 | blk_rq_set_block_pc(rq); |
057ea7c9 HR |
118 | |
119 | if (buflen && blk_rq_map_kern(q, rq, buffer, buflen, GFP_NOIO)) { | |
120 | blk_put_request(rq); | |
121 | sdev_printk(KERN_INFO, sdev, | |
cadbd4a5 | 122 | "%s: blk_rq_map_kern failed\n", __func__); |
057ea7c9 HR |
123 | return NULL; |
124 | } | |
125 | ||
6000a368 | 126 | rq->cmd_flags |= REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT | |
64f84bc1 | 127 | REQ_FAILFAST_DRIVER; |
057ea7c9 | 128 | rq->retries = ALUA_FAILOVER_RETRIES; |
3588c5a2 | 129 | rq->timeout = ALUA_FAILOVER_TIMEOUT * HZ; |
057ea7c9 HR |
130 | |
131 | return rq; | |
132 | } | |
133 | ||
057ea7c9 HR |
134 | /* |
135 | * submit_rtpg - Issue a REPORT TARGET GROUP STATES command | |
136 | * @sdev: sdev the command should be sent to | |
137 | */ | |
6c4fc044 | 138 | static unsigned submit_rtpg(struct scsi_device *sdev, struct alua_dh_data *h) |
057ea7c9 HR |
139 | { |
140 | struct request *rq; | |
5597cafc | 141 | int err = 0; |
057ea7c9 HR |
142 | |
143 | rq = get_alua_req(sdev, h->buff, h->bufflen, READ); | |
5597cafc HR |
144 | if (!rq) { |
145 | err = DRIVER_BUSY << 24; | |
057ea7c9 | 146 | goto done; |
5597cafc | 147 | } |
057ea7c9 HR |
148 | |
149 | /* Prepare the command. */ | |
150 | rq->cmd[0] = MAINTENANCE_IN; | |
6c4fc044 | 151 | if (!(h->flags & ALUA_RTPG_EXT_HDR_UNSUPP)) |
8e67ce60 RE |
152 | rq->cmd[1] = MI_REPORT_TARGET_PGS | MI_EXT_HDR_PARAM_FMT; |
153 | else | |
154 | rq->cmd[1] = MI_REPORT_TARGET_PGS; | |
057ea7c9 HR |
155 | rq->cmd[6] = (h->bufflen >> 24) & 0xff; |
156 | rq->cmd[7] = (h->bufflen >> 16) & 0xff; | |
157 | rq->cmd[8] = (h->bufflen >> 8) & 0xff; | |
158 | rq->cmd[9] = h->bufflen & 0xff; | |
159 | rq->cmd_len = COMMAND_SIZE(MAINTENANCE_IN); | |
160 | ||
161 | rq->sense = h->sense; | |
162 | memset(rq->sense, 0, SCSI_SENSE_BUFFERSIZE); | |
d3692a3d | 163 | rq->sense_len = 0; |
057ea7c9 | 164 | |
5597cafc HR |
165 | blk_execute_rq(rq->q, NULL, rq, 1); |
166 | if (rq->errors) | |
167 | err = rq->errors; | |
057ea7c9 HR |
168 | blk_put_request(rq); |
169 | done: | |
170 | return err; | |
171 | } | |
172 | ||
96e65865 | 173 | /* |
dac173ee | 174 | * stpg_endio - Evaluate SET TARGET GROUP STATES |
96e65865 CS |
175 | * @sdev: the device to be evaluated |
176 | * @state: the new target group state | |
177 | * | |
dac173ee | 178 | * Evaluate a SET TARGET GROUP STATES command response. |
96e65865 CS |
179 | */ |
180 | static void stpg_endio(struct request *req, int error) | |
181 | { | |
182 | struct alua_dh_data *h = req->end_io_data; | |
183 | struct scsi_sense_hdr sense_hdr; | |
9349923d | 184 | unsigned err = SCSI_DH_OK; |
96e65865 | 185 | |
27db682b MC |
186 | if (host_byte(req->errors) != DID_OK || |
187 | msg_byte(req->errors) != COMMAND_COMPLETE) { | |
9349923d | 188 | err = SCSI_DH_IO; |
96e65865 | 189 | goto done; |
9349923d | 190 | } |
96e65865 | 191 | |
d3692a3d HR |
192 | if (scsi_normalize_sense(h->sense, SCSI_SENSE_BUFFERSIZE, |
193 | &sense_hdr)) { | |
96e65865 CS |
194 | err = alua_check_sense(h->sdev, &sense_hdr); |
195 | if (err == ADD_TO_MLQUEUE) { | |
196 | err = SCSI_DH_RETRY; | |
197 | goto done; | |
198 | } | |
80bd68d6 HR |
199 | sdev_printk(KERN_INFO, h->sdev, "%s: stpg failed\n", |
200 | ALUA_DH_NAME); | |
201 | scsi_print_sense_hdr(h->sdev, ALUA_DH_NAME, &sense_hdr); | |
96e65865 | 202 | err = SCSI_DH_IO; |
27db682b MC |
203 | } else if (error) |
204 | err = SCSI_DH_IO; | |
205 | ||
96e65865 CS |
206 | if (err == SCSI_DH_OK) { |
207 | h->state = TPGS_STATE_OPTIMIZED; | |
208 | sdev_printk(KERN_INFO, h->sdev, | |
209 | "%s: port group %02x switched to state %c\n", | |
210 | ALUA_DH_NAME, h->group_id, | |
211 | print_alua_state(h->state)); | |
212 | } | |
213 | done: | |
ed0f36bc JG |
214 | req->end_io_data = NULL; |
215 | __blk_put_request(req->q, req); | |
96e65865 CS |
216 | if (h->callback_fn) { |
217 | h->callback_fn(h->callback_data, err); | |
218 | h->callback_fn = h->callback_data = NULL; | |
219 | } | |
220 | return; | |
221 | } | |
222 | ||
057ea7c9 HR |
223 | /* |
224 | * submit_stpg - Issue a SET TARGET GROUP STATES command | |
057ea7c9 HR |
225 | * |
226 | * Currently we're only setting the current target port group state | |
227 | * to 'active/optimized' and let the array firmware figure out | |
228 | * the states of the remaining groups. | |
229 | */ | |
96e65865 | 230 | static unsigned submit_stpg(struct alua_dh_data *h) |
057ea7c9 HR |
231 | { |
232 | struct request *rq; | |
057ea7c9 | 233 | int stpg_len = 8; |
96e65865 | 234 | struct scsi_device *sdev = h->sdev; |
057ea7c9 HR |
235 | |
236 | /* Prepare the data buffer */ | |
237 | memset(h->buff, 0, stpg_len); | |
238 | h->buff[4] = TPGS_STATE_OPTIMIZED & 0x0f; | |
ef3fa8c6 IH |
239 | h->buff[6] = (h->group_id >> 8) & 0xff; |
240 | h->buff[7] = h->group_id & 0xff; | |
057ea7c9 HR |
241 | |
242 | rq = get_alua_req(sdev, h->buff, stpg_len, WRITE); | |
243 | if (!rq) | |
96e65865 | 244 | return SCSI_DH_RES_TEMP_UNAVAIL; |
057ea7c9 HR |
245 | |
246 | /* Prepare the command. */ | |
247 | rq->cmd[0] = MAINTENANCE_OUT; | |
248 | rq->cmd[1] = MO_SET_TARGET_PGS; | |
249 | rq->cmd[6] = (stpg_len >> 24) & 0xff; | |
250 | rq->cmd[7] = (stpg_len >> 16) & 0xff; | |
251 | rq->cmd[8] = (stpg_len >> 8) & 0xff; | |
252 | rq->cmd[9] = stpg_len & 0xff; | |
253 | rq->cmd_len = COMMAND_SIZE(MAINTENANCE_OUT); | |
254 | ||
255 | rq->sense = h->sense; | |
256 | memset(rq->sense, 0, SCSI_SENSE_BUFFERSIZE); | |
d3692a3d | 257 | rq->sense_len = 0; |
96e65865 | 258 | rq->end_io_data = h; |
057ea7c9 | 259 | |
96e65865 | 260 | blk_execute_rq_nowait(rq->q, NULL, rq, 1, stpg_endio); |
7c66e9a5 | 261 | return SCSI_DH_OK; |
057ea7c9 HR |
262 | } |
263 | ||
264 | /* | |
d7c48feb | 265 | * alua_check_tpgs - Evaluate TPGS setting |
057ea7c9 HR |
266 | * @sdev: device to be checked |
267 | * | |
d7c48feb | 268 | * Examine the TPGS setting of the sdev to find out if ALUA |
057ea7c9 HR |
269 | * is supported. |
270 | */ | |
d7c48feb | 271 | static int alua_check_tpgs(struct scsi_device *sdev, struct alua_dh_data *h) |
057ea7c9 | 272 | { |
d7c48feb | 273 | int err = SCSI_DH_OK; |
057ea7c9 | 274 | |
db5a6a60 HR |
275 | /* |
276 | * ALUA support for non-disk devices is fraught with | |
277 | * difficulties, so disable it for now. | |
278 | */ | |
279 | if (sdev->type != TYPE_DISK) { | |
280 | h->tpgs = TPGS_MODE_NONE; | |
281 | sdev_printk(KERN_INFO, sdev, | |
282 | "%s: disable for non-disk devices\n", | |
283 | ALUA_DH_NAME); | |
284 | return SCSI_DH_DEV_UNSUPP; | |
285 | } | |
286 | ||
d7c48feb | 287 | h->tpgs = scsi_device_tpgs(sdev); |
057ea7c9 HR |
288 | switch (h->tpgs) { |
289 | case TPGS_MODE_EXPLICIT|TPGS_MODE_IMPLICIT: | |
290 | sdev_printk(KERN_INFO, sdev, | |
291 | "%s: supports implicit and explicit TPGS\n", | |
292 | ALUA_DH_NAME); | |
293 | break; | |
294 | case TPGS_MODE_EXPLICIT: | |
295 | sdev_printk(KERN_INFO, sdev, "%s: supports explicit TPGS\n", | |
296 | ALUA_DH_NAME); | |
297 | break; | |
298 | case TPGS_MODE_IMPLICIT: | |
299 | sdev_printk(KERN_INFO, sdev, "%s: supports implicit TPGS\n", | |
300 | ALUA_DH_NAME); | |
301 | break; | |
6cc05d45 | 302 | case TPGS_MODE_NONE: |
057ea7c9 HR |
303 | sdev_printk(KERN_INFO, sdev, "%s: not supported\n", |
304 | ALUA_DH_NAME); | |
305 | err = SCSI_DH_DEV_UNSUPP; | |
306 | break; | |
6cc05d45 HR |
307 | default: |
308 | sdev_printk(KERN_INFO, sdev, | |
309 | "%s: unsupported TPGS setting %d\n", | |
310 | ALUA_DH_NAME, h->tpgs); | |
311 | h->tpgs = TPGS_MODE_NONE; | |
312 | err = SCSI_DH_DEV_UNSUPP; | |
313 | break; | |
057ea7c9 HR |
314 | } |
315 | ||
316 | return err; | |
317 | } | |
318 | ||
319 | /* | |
9b80dcec | 320 | * alua_check_vpd - Evaluate INQUIRY vpd page 0x83 |
057ea7c9 HR |
321 | * @sdev: device to be checked |
322 | * | |
323 | * Extract the relative target port and the target port group | |
324 | * descriptor from the list of identificators. | |
325 | */ | |
9b80dcec | 326 | static int alua_check_vpd(struct scsi_device *sdev, struct alua_dh_data *h) |
057ea7c9 | 327 | { |
057ea7c9 | 328 | unsigned char *d; |
9b80dcec | 329 | unsigned char __rcu *vpd_pg83; |
057ea7c9 | 330 | |
9b80dcec HR |
331 | rcu_read_lock(); |
332 | if (!rcu_dereference(sdev->vpd_pg83)) { | |
333 | rcu_read_unlock(); | |
334 | return SCSI_DH_DEV_UNSUPP; | |
057ea7c9 HR |
335 | } |
336 | ||
337 | /* | |
9b80dcec | 338 | * Look for the correct descriptor. |
057ea7c9 | 339 | */ |
9b80dcec HR |
340 | vpd_pg83 = rcu_dereference(sdev->vpd_pg83); |
341 | d = vpd_pg83 + 4; | |
342 | while (d < vpd_pg83 + sdev->vpd_pg83_len) { | |
057ea7c9 HR |
343 | switch (d[1] & 0xf) { |
344 | case 0x4: | |
345 | /* Relative target port */ | |
346 | h->rel_port = (d[6] << 8) + d[7]; | |
347 | break; | |
348 | case 0x5: | |
349 | /* Target port group */ | |
350 | h->group_id = (d[6] << 8) + d[7]; | |
351 | break; | |
352 | default: | |
353 | break; | |
354 | } | |
355 | d += d[3] + 4; | |
356 | } | |
9b80dcec | 357 | rcu_read_unlock(); |
057ea7c9 HR |
358 | |
359 | if (h->group_id == -1) { | |
360 | /* | |
361 | * Internal error; TPGS supported but required | |
362 | * VPD identification descriptors not present. | |
363 | * Disable ALUA support | |
364 | */ | |
365 | sdev_printk(KERN_INFO, sdev, | |
366 | "%s: No target port descriptors found\n", | |
367 | ALUA_DH_NAME); | |
368 | h->state = TPGS_STATE_OPTIMIZED; | |
369 | h->tpgs = TPGS_MODE_NONE; | |
9b80dcec | 370 | return SCSI_DH_DEV_UNSUPP; |
057ea7c9 | 371 | } |
9b80dcec HR |
372 | sdev_printk(KERN_INFO, sdev, |
373 | "%s: port group %02x rel port %02x\n", | |
374 | ALUA_DH_NAME, h->group_id, h->rel_port); | |
057ea7c9 | 375 | |
9b80dcec | 376 | return 0; |
057ea7c9 HR |
377 | } |
378 | ||
379 | static char print_alua_state(int state) | |
380 | { | |
381 | switch (state) { | |
382 | case TPGS_STATE_OPTIMIZED: | |
383 | return 'A'; | |
384 | case TPGS_STATE_NONOPTIMIZED: | |
385 | return 'N'; | |
386 | case TPGS_STATE_STANDBY: | |
387 | return 'S'; | |
388 | case TPGS_STATE_UNAVAILABLE: | |
389 | return 'U'; | |
69723d17 HR |
390 | case TPGS_STATE_LBA_DEPENDENT: |
391 | return 'L'; | |
057ea7c9 HR |
392 | case TPGS_STATE_OFFLINE: |
393 | return 'O'; | |
394 | case TPGS_STATE_TRANSITIONING: | |
395 | return 'T'; | |
396 | default: | |
397 | return 'X'; | |
398 | } | |
399 | } | |
400 | ||
401 | static int alua_check_sense(struct scsi_device *sdev, | |
402 | struct scsi_sense_hdr *sense_hdr) | |
403 | { | |
404 | switch (sense_hdr->sense_key) { | |
405 | case NOT_READY: | |
406 | if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x0a) | |
407 | /* | |
408 | * LUN Not Accessible - ALUA state transition | |
409 | */ | |
c7dbb627 | 410 | return ADD_TO_MLQUEUE; |
057ea7c9 HR |
411 | if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x0b) |
412 | /* | |
413 | * LUN Not Accessible -- Target port in standby state | |
414 | */ | |
415 | return SUCCESS; | |
416 | if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x0c) | |
417 | /* | |
418 | * LUN Not Accessible -- Target port in unavailable state | |
419 | */ | |
420 | return SUCCESS; | |
421 | if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x12) | |
422 | /* | |
423 | * LUN Not Ready -- Offline | |
424 | */ | |
425 | return SUCCESS; | |
333b2448 | 426 | if (sdev->allow_restart && |
427 | sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x02) | |
428 | /* | |
429 | * if the device is not started, we need to wake | |
430 | * the error handler to start the motor | |
431 | */ | |
432 | return FAILED; | |
057ea7c9 HR |
433 | break; |
434 | case UNIT_ATTENTION: | |
435 | if (sense_hdr->asc == 0x29 && sense_hdr->ascq == 0x00) | |
436 | /* | |
437 | * Power On, Reset, or Bus Device Reset, just retry. | |
438 | */ | |
c7dbb627 | 439 | return ADD_TO_MLQUEUE; |
c20ee7b5 SS |
440 | if (sense_hdr->asc == 0x29 && sense_hdr->ascq == 0x04) |
441 | /* | |
442 | * Device internal reset | |
443 | */ | |
444 | return ADD_TO_MLQUEUE; | |
410f02d8 MB |
445 | if (sense_hdr->asc == 0x2a && sense_hdr->ascq == 0x01) |
446 | /* | |
447 | * Mode Parameters Changed | |
448 | */ | |
449 | return ADD_TO_MLQUEUE; | |
bf81973a | 450 | if (sense_hdr->asc == 0x2a && sense_hdr->ascq == 0x06) |
057ea7c9 HR |
451 | /* |
452 | * ALUA state changed | |
453 | */ | |
c7dbb627 | 454 | return ADD_TO_MLQUEUE; |
bf81973a | 455 | if (sense_hdr->asc == 0x2a && sense_hdr->ascq == 0x07) |
057ea7c9 HR |
456 | /* |
457 | * Implicit ALUA state transition failed | |
458 | */ | |
c7dbb627 | 459 | return ADD_TO_MLQUEUE; |
bf81973a MB |
460 | if (sense_hdr->asc == 0x3f && sense_hdr->ascq == 0x03) |
461 | /* | |
462 | * Inquiry data has changed | |
463 | */ | |
464 | return ADD_TO_MLQUEUE; | |
465 | if (sense_hdr->asc == 0x3f && sense_hdr->ascq == 0x0e) | |
4d086f6b IH |
466 | /* |
467 | * REPORTED_LUNS_DATA_HAS_CHANGED is reported | |
468 | * when switching controllers on targets like | |
469 | * Intel Multi-Flex. We can just retry. | |
470 | */ | |
471 | return ADD_TO_MLQUEUE; | |
057ea7c9 HR |
472 | break; |
473 | } | |
474 | ||
475 | return SCSI_RETURN_NOT_HANDLED; | |
476 | } | |
477 | ||
057ea7c9 HR |
478 | /* |
479 | * alua_rtpg - Evaluate REPORT TARGET GROUP STATES | |
480 | * @sdev: the device to be evaluated. | |
a8e5a2d5 | 481 | * @wait_for_transition: if nonzero, wait ALUA_FAILOVER_TIMEOUT seconds for device to exit transitioning state |
057ea7c9 HR |
482 | * |
483 | * Evaluate the Target Port Group State. | |
484 | * Returns SCSI_DH_DEV_OFFLINED if the path is | |
25985edc | 485 | * found to be unusable. |
057ea7c9 | 486 | */ |
a8e5a2d5 | 487 | static int alua_rtpg(struct scsi_device *sdev, struct alua_dh_data *h, int wait_for_transition) |
057ea7c9 HR |
488 | { |
489 | struct scsi_sense_hdr sense_hdr; | |
490 | int len, k, off, valid_states = 0; | |
cfde3fa1 | 491 | unsigned char *ucp; |
5597cafc | 492 | unsigned err, retval; |
bc97f4bb | 493 | unsigned long expiry, interval = 0; |
3588c5a2 RE |
494 | unsigned int tpg_desc_tbl_off; |
495 | unsigned char orig_transition_tmo; | |
496 | ||
497 | if (!h->transition_tmo) | |
498 | expiry = round_jiffies_up(jiffies + ALUA_FAILOVER_TIMEOUT * HZ); | |
499 | else | |
500 | expiry = round_jiffies_up(jiffies + h->transition_tmo * HZ); | |
057ea7c9 HR |
501 | |
502 | retry: | |
6c4fc044 | 503 | retval = submit_rtpg(sdev, h); |
5597cafc | 504 | if (retval) { |
d3692a3d | 505 | if (!scsi_normalize_sense(h->sense, SCSI_SENSE_BUFFERSIZE, |
5597cafc HR |
506 | &sense_hdr)) { |
507 | sdev_printk(KERN_INFO, sdev, | |
508 | "%s: rtpg failed, result %d\n", | |
509 | ALUA_DH_NAME, retval); | |
510 | if (driver_byte(retval) == DRIVER_BUSY) | |
511 | return SCSI_DH_DEV_TEMP_BUSY; | |
057ea7c9 | 512 | return SCSI_DH_IO; |
5597cafc | 513 | } |
057ea7c9 | 514 | |
8e67ce60 RE |
515 | /* |
516 | * submit_rtpg() has failed on existing arrays | |
517 | * when requesting extended header info, and | |
518 | * the array doesn't support extended headers, | |
519 | * even though it shouldn't according to T10. | |
520 | * The retry without rtpg_ext_hdr_req set | |
521 | * handles this. | |
522 | */ | |
6c4fc044 | 523 | if (!(h->flags & ALUA_RTPG_EXT_HDR_UNSUPP) && |
8e67ce60 RE |
524 | sense_hdr.sense_key == ILLEGAL_REQUEST && |
525 | sense_hdr.asc == 0x24 && sense_hdr.ascq == 0) { | |
6c4fc044 | 526 | h->flags |= ALUA_RTPG_EXT_HDR_UNSUPP; |
8e67ce60 RE |
527 | goto retry; |
528 | } | |
529 | ||
057ea7c9 | 530 | err = alua_check_sense(sdev, &sense_hdr); |
80bd68d6 HR |
531 | if (err == ADD_TO_MLQUEUE && time_before(jiffies, expiry)) { |
532 | sdev_printk(KERN_ERR, sdev, "%s: rtpg retry\n", | |
533 | ALUA_DH_NAME); | |
534 | scsi_print_sense_hdr(sdev, ALUA_DH_NAME, &sense_hdr); | |
057ea7c9 | 535 | goto retry; |
80bd68d6 HR |
536 | } |
537 | sdev_printk(KERN_ERR, sdev, "%s: rtpg failed\n", | |
538 | ALUA_DH_NAME); | |
539 | scsi_print_sense_hdr(sdev, ALUA_DH_NAME, &sense_hdr); | |
540 | return SCSI_DH_IO; | |
057ea7c9 | 541 | } |
057ea7c9 HR |
542 | |
543 | len = (h->buff[0] << 24) + (h->buff[1] << 16) + | |
544 | (h->buff[2] << 8) + h->buff[3] + 4; | |
545 | ||
546 | if (len > h->bufflen) { | |
547 | /* Resubmit with the correct length */ | |
548 | if (realloc_buffer(h, len)) { | |
549 | sdev_printk(KERN_WARNING, sdev, | |
cadbd4a5 | 550 | "%s: kmalloc buffer failed\n",__func__); |
057ea7c9 HR |
551 | /* Temporary failure, bypass */ |
552 | return SCSI_DH_DEV_TEMP_BUSY; | |
553 | } | |
554 | goto retry; | |
555 | } | |
556 | ||
3588c5a2 RE |
557 | orig_transition_tmo = h->transition_tmo; |
558 | if ((h->buff[4] & RTPG_FMT_MASK) == RTPG_FMT_EXT_HDR && h->buff[5] != 0) | |
559 | h->transition_tmo = h->buff[5]; | |
560 | else | |
561 | h->transition_tmo = ALUA_FAILOVER_TIMEOUT; | |
562 | ||
a8e5a2d5 | 563 | if (wait_for_transition && (orig_transition_tmo != h->transition_tmo)) { |
3588c5a2 RE |
564 | sdev_printk(KERN_INFO, sdev, |
565 | "%s: transition timeout set to %d seconds\n", | |
566 | ALUA_DH_NAME, h->transition_tmo); | |
567 | expiry = jiffies + h->transition_tmo * HZ; | |
568 | } | |
569 | ||
570 | if ((h->buff[4] & RTPG_FMT_MASK) == RTPG_FMT_EXT_HDR) | |
571 | tpg_desc_tbl_off = 8; | |
572 | else | |
573 | tpg_desc_tbl_off = 4; | |
574 | ||
575 | for (k = tpg_desc_tbl_off, ucp = h->buff + tpg_desc_tbl_off; | |
576 | k < len; | |
577 | k += off, ucp += off) { | |
578 | ||
057ea7c9 HR |
579 | if (h->group_id == (ucp[2] << 8) + ucp[3]) { |
580 | h->state = ucp[0] & 0x0f; | |
dcd3a754 | 581 | h->pref = ucp[0] >> 7; |
057ea7c9 HR |
582 | valid_states = ucp[1]; |
583 | } | |
584 | off = 8 + (ucp[7] * 4); | |
585 | } | |
586 | ||
587 | sdev_printk(KERN_INFO, sdev, | |
dcd3a754 | 588 | "%s: port group %02x state %c %s supports %c%c%c%c%c%c%c\n", |
057ea7c9 | 589 | ALUA_DH_NAME, h->group_id, print_alua_state(h->state), |
dcd3a754 | 590 | h->pref ? "preferred" : "non-preferred", |
057ea7c9 HR |
591 | valid_states&TPGS_SUPPORT_TRANSITION?'T':'t', |
592 | valid_states&TPGS_SUPPORT_OFFLINE?'O':'o', | |
69723d17 | 593 | valid_states&TPGS_SUPPORT_LBA_DEPENDENT?'L':'l', |
057ea7c9 HR |
594 | valid_states&TPGS_SUPPORT_UNAVAILABLE?'U':'u', |
595 | valid_states&TPGS_SUPPORT_STANDBY?'S':'s', | |
596 | valid_states&TPGS_SUPPORT_NONOPTIMIZED?'N':'n', | |
597 | valid_states&TPGS_SUPPORT_OPTIMIZED?'A':'a'); | |
598 | ||
69723d17 HR |
599 | switch (h->state) { |
600 | case TPGS_STATE_TRANSITIONING: | |
a8e5a2d5 SS |
601 | if (wait_for_transition) { |
602 | if (time_before(jiffies, expiry)) { | |
603 | /* State transition, retry */ | |
604 | interval += 2000; | |
605 | msleep(interval); | |
606 | goto retry; | |
607 | } | |
608 | err = SCSI_DH_RETRY; | |
609 | } else { | |
610 | err = SCSI_DH_OK; | |
057ea7c9 | 611 | } |
a8e5a2d5 | 612 | |
69723d17 | 613 | /* Transitioning time exceeded, set port to standby */ |
69723d17 HR |
614 | h->state = TPGS_STATE_STANDBY; |
615 | break; | |
616 | case TPGS_STATE_OFFLINE: | |
e47f8976 | 617 | /* Path unusable */ |
69723d17 HR |
618 | err = SCSI_DH_DEV_OFFLINED; |
619 | break; | |
620 | default: | |
621 | /* Useable path if active */ | |
622 | err = SCSI_DH_OK; | |
623 | break; | |
057ea7c9 HR |
624 | } |
625 | return err; | |
626 | } | |
627 | ||
628 | /* | |
629 | * alua_initialize - Initialize ALUA state | |
630 | * @sdev: the device to be initialized | |
631 | * | |
632 | * For the prep_fn to work correctly we have | |
633 | * to initialize the ALUA state for the device. | |
634 | */ | |
635 | static int alua_initialize(struct scsi_device *sdev, struct alua_dh_data *h) | |
636 | { | |
637 | int err; | |
638 | ||
d7c48feb | 639 | err = alua_check_tpgs(sdev, h); |
057ea7c9 HR |
640 | if (err != SCSI_DH_OK) |
641 | goto out; | |
642 | ||
9b80dcec | 643 | err = alua_check_vpd(sdev, h); |
057ea7c9 HR |
644 | if (err != SCSI_DH_OK) |
645 | goto out; | |
646 | ||
a8e5a2d5 | 647 | err = alua_rtpg(sdev, h, 0); |
057ea7c9 HR |
648 | if (err != SCSI_DH_OK) |
649 | goto out; | |
650 | ||
651 | out: | |
652 | return err; | |
653 | } | |
4335d092 MB |
654 | /* |
655 | * alua_set_params - set/unset the optimize flag | |
656 | * @sdev: device on the path to be activated | |
657 | * params - parameters in the following format | |
658 | * "no_of_params\0param1\0param2\0param3\0...\0" | |
659 | * For example, to set the flag pass the following parameters | |
660 | * from multipath.conf | |
661 | * hardware_handler "2 alua 1" | |
662 | */ | |
663 | static int alua_set_params(struct scsi_device *sdev, const char *params) | |
664 | { | |
ee14c674 | 665 | struct alua_dh_data *h = sdev->handler_data; |
4335d092 MB |
666 | unsigned int optimize = 0, argc; |
667 | const char *p = params; | |
668 | int result = SCSI_DH_OK; | |
669 | ||
670 | if ((sscanf(params, "%u", &argc) != 1) || (argc != 1)) | |
671 | return -EINVAL; | |
672 | ||
673 | while (*p++) | |
674 | ; | |
675 | if ((sscanf(p, "%u", &optimize) != 1) || (optimize > 1)) | |
676 | return -EINVAL; | |
677 | ||
678 | if (optimize) | |
679 | h->flags |= ALUA_OPTIMIZE_STPG; | |
680 | else | |
681 | h->flags &= ~ALUA_OPTIMIZE_STPG; | |
682 | ||
683 | return result; | |
684 | } | |
057ea7c9 | 685 | |
7a3ad392 SS |
686 | static uint optimize_stpg; |
687 | module_param(optimize_stpg, uint, S_IRUGO|S_IWUSR); | |
688 | 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."); | |
689 | ||
057ea7c9 HR |
690 | /* |
691 | * alua_activate - activate a path | |
692 | * @sdev: device on the path to be activated | |
693 | * | |
694 | * We're currently switching the port group to be activated only and | |
695 | * let the array figure out the rest. | |
696 | * There may be other arrays which require us to switch all port groups | |
697 | * based on a certain policy. But until we actually encounter them it | |
698 | * should be okay. | |
699 | */ | |
3ae31f6a CS |
700 | static int alua_activate(struct scsi_device *sdev, |
701 | activate_complete fn, void *data) | |
057ea7c9 | 702 | { |
ee14c674 | 703 | struct alua_dh_data *h = sdev->handler_data; |
057ea7c9 | 704 | int err = SCSI_DH_OK; |
72d9e0f3 | 705 | int stpg = 0; |
057ea7c9 | 706 | |
a8e5a2d5 | 707 | err = alua_rtpg(sdev, h, 1); |
46ccf6b5 HR |
708 | if (err != SCSI_DH_OK) |
709 | goto out; | |
057ea7c9 | 710 | |
7a3ad392 SS |
711 | if (optimize_stpg) |
712 | h->flags |= ALUA_OPTIMIZE_STPG; | |
713 | ||
72d9e0f3 MB |
714 | if (h->tpgs & TPGS_MODE_EXPLICIT) { |
715 | switch (h->state) { | |
716 | case TPGS_STATE_NONOPTIMIZED: | |
717 | stpg = 1; | |
718 | if ((h->flags & ALUA_OPTIMIZE_STPG) && | |
719 | (!h->pref) && | |
720 | (h->tpgs & TPGS_MODE_IMPLICIT)) | |
721 | stpg = 0; | |
722 | break; | |
723 | case TPGS_STATE_STANDBY: | |
bb2c94a3 | 724 | case TPGS_STATE_UNAVAILABLE: |
72d9e0f3 MB |
725 | stpg = 1; |
726 | break; | |
72d9e0f3 MB |
727 | case TPGS_STATE_OFFLINE: |
728 | err = SCSI_DH_IO; | |
729 | break; | |
730 | case TPGS_STATE_TRANSITIONING: | |
731 | err = SCSI_DH_RETRY; | |
732 | break; | |
733 | default: | |
734 | break; | |
735 | } | |
736 | } | |
737 | ||
738 | if (stpg) { | |
96e65865 CS |
739 | h->callback_fn = fn; |
740 | h->callback_data = data; | |
741 | err = submit_stpg(h); | |
742 | if (err == SCSI_DH_OK) | |
743 | return 0; | |
744 | h->callback_fn = h->callback_data = NULL; | |
745 | } | |
057ea7c9 HR |
746 | |
747 | out: | |
3ae31f6a CS |
748 | if (fn) |
749 | fn(data, err); | |
750 | return 0; | |
057ea7c9 HR |
751 | } |
752 | ||
753 | /* | |
754 | * alua_prep_fn - request callback | |
755 | * | |
756 | * Fail I/O to all paths not in state | |
757 | * active/optimized or active/non-optimized. | |
758 | */ | |
759 | static int alua_prep_fn(struct scsi_device *sdev, struct request *req) | |
760 | { | |
ee14c674 | 761 | struct alua_dh_data *h = sdev->handler_data; |
057ea7c9 HR |
762 | int ret = BLKPREP_OK; |
763 | ||
69723d17 HR |
764 | if (h->state == TPGS_STATE_TRANSITIONING) |
765 | ret = BLKPREP_DEFER; | |
766 | else if (h->state != TPGS_STATE_OPTIMIZED && | |
767 | h->state != TPGS_STATE_NONOPTIMIZED && | |
768 | h->state != TPGS_STATE_LBA_DEPENDENT) { | |
057ea7c9 HR |
769 | ret = BLKPREP_KILL; |
770 | req->cmd_flags |= REQ_QUIET; | |
771 | } | |
772 | return ret; | |
773 | ||
774 | } | |
775 | ||
057ea7c9 HR |
776 | /* |
777 | * alua_bus_attach - Attach device handler | |
778 | * @sdev: device to be attached to | |
779 | */ | |
ee14c674 | 780 | static int alua_bus_attach(struct scsi_device *sdev) |
057ea7c9 | 781 | { |
057ea7c9 | 782 | struct alua_dh_data *h; |
1d520328 | 783 | int err; |
057ea7c9 | 784 | |
cd37743f | 785 | h = kzalloc(sizeof(*h) , GFP_KERNEL); |
1d520328 | 786 | if (!h) |
ee14c674 | 787 | return -ENOMEM; |
057ea7c9 HR |
788 | h->tpgs = TPGS_MODE_UNINITIALIZED; |
789 | h->state = TPGS_STATE_OPTIMIZED; | |
790 | h->group_id = -1; | |
791 | h->rel_port = -1; | |
792 | h->buff = h->inq; | |
793 | h->bufflen = ALUA_INQUIRY_SIZE; | |
96e65865 | 794 | h->sdev = sdev; |
057ea7c9 HR |
795 | |
796 | err = alua_initialize(sdev, h); | |
1d520328 | 797 | if (err != SCSI_DH_OK && err != SCSI_DH_DEV_OFFLINED) |
057ea7c9 HR |
798 | goto failed; |
799 | ||
ee14c674 CH |
800 | sdev->handler_data = h; |
801 | return 0; | |
057ea7c9 | 802 | failed: |
cd37743f | 803 | kfree(h); |
ee14c674 | 804 | return -EINVAL; |
057ea7c9 HR |
805 | } |
806 | ||
807 | /* | |
808 | * alua_bus_detach - Detach device handler | |
809 | * @sdev: device to be detached from | |
810 | */ | |
811 | static void alua_bus_detach(struct scsi_device *sdev) | |
812 | { | |
ee14c674 | 813 | struct alua_dh_data *h = sdev->handler_data; |
057ea7c9 | 814 | |
057ea7c9 HR |
815 | if (h->buff && h->inq != h->buff) |
816 | kfree(h->buff); | |
ee14c674 | 817 | sdev->handler_data = NULL; |
cd37743f | 818 | kfree(h); |
057ea7c9 HR |
819 | } |
820 | ||
1d520328 CH |
821 | static struct scsi_device_handler alua_dh = { |
822 | .name = ALUA_DH_NAME, | |
823 | .module = THIS_MODULE, | |
824 | .attach = alua_bus_attach, | |
825 | .detach = alua_bus_detach, | |
826 | .prep_fn = alua_prep_fn, | |
827 | .check_sense = alua_check_sense, | |
828 | .activate = alua_activate, | |
829 | .set_params = alua_set_params, | |
1d520328 CH |
830 | }; |
831 | ||
057ea7c9 HR |
832 | static int __init alua_init(void) |
833 | { | |
834 | int r; | |
835 | ||
836 | r = scsi_register_device_handler(&alua_dh); | |
837 | if (r != 0) | |
838 | printk(KERN_ERR "%s: Failed to register scsi device handler", | |
839 | ALUA_DH_NAME); | |
840 | return r; | |
841 | } | |
842 | ||
843 | static void __exit alua_exit(void) | |
844 | { | |
845 | scsi_unregister_device_handler(&alua_dh); | |
846 | } | |
847 | ||
848 | module_init(alua_init); | |
849 | module_exit(alua_exit); | |
850 | ||
851 | MODULE_DESCRIPTION("DM Multipath ALUA support"); | |
852 | MODULE_AUTHOR("Hannes Reinecke <hare@suse.de>"); | |
853 | MODULE_LICENSE("GPL"); | |
854 | MODULE_VERSION(ALUA_DH_VER); |