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> |
a7089770 | 25 | #include <asm/unaligned.h> |
057ea7c9 | 26 | #include <scsi/scsi.h> |
80bd68d6 | 27 | #include <scsi/scsi_dbg.h> |
057ea7c9 HR |
28 | #include <scsi/scsi_eh.h> |
29 | #include <scsi/scsi_dh.h> | |
30 | ||
31 | #define ALUA_DH_NAME "alua" | |
69723d17 | 32 | #define ALUA_DH_VER "1.3" |
057ea7c9 HR |
33 | |
34 | #define TPGS_STATE_OPTIMIZED 0x0 | |
35 | #define TPGS_STATE_NONOPTIMIZED 0x1 | |
36 | #define TPGS_STATE_STANDBY 0x2 | |
37 | #define TPGS_STATE_UNAVAILABLE 0x3 | |
69723d17 | 38 | #define TPGS_STATE_LBA_DEPENDENT 0x4 |
057ea7c9 HR |
39 | #define TPGS_STATE_OFFLINE 0xe |
40 | #define TPGS_STATE_TRANSITIONING 0xf | |
41 | ||
42 | #define TPGS_SUPPORT_NONE 0x00 | |
43 | #define TPGS_SUPPORT_OPTIMIZED 0x01 | |
44 | #define TPGS_SUPPORT_NONOPTIMIZED 0x02 | |
45 | #define TPGS_SUPPORT_STANDBY 0x04 | |
46 | #define TPGS_SUPPORT_UNAVAILABLE 0x08 | |
69723d17 | 47 | #define TPGS_SUPPORT_LBA_DEPENDENT 0x10 |
057ea7c9 HR |
48 | #define TPGS_SUPPORT_OFFLINE 0x40 |
49 | #define TPGS_SUPPORT_TRANSITION 0x80 | |
50 | ||
3588c5a2 RE |
51 | #define RTPG_FMT_MASK 0x70 |
52 | #define RTPG_FMT_EXT_HDR 0x10 | |
53 | ||
057ea7c9 HR |
54 | #define TPGS_MODE_UNINITIALIZED -1 |
55 | #define TPGS_MODE_NONE 0x0 | |
56 | #define TPGS_MODE_IMPLICIT 0x1 | |
57 | #define TPGS_MODE_EXPLICIT 0x2 | |
58 | ||
59 | #define ALUA_INQUIRY_SIZE 36 | |
3588c5a2 | 60 | #define ALUA_FAILOVER_TIMEOUT 60 |
057ea7c9 HR |
61 | #define ALUA_FAILOVER_RETRIES 5 |
62 | ||
6c4fc044 | 63 | /* device handler flags */ |
4335d092 | 64 | #define ALUA_OPTIMIZE_STPG 1 |
6c4fc044 | 65 | #define ALUA_RTPG_EXT_HDR_UNSUPP 2 |
4335d092 | 66 | |
057ea7c9 HR |
67 | struct alua_dh_data { |
68 | int group_id; | |
69 | int rel_port; | |
70 | int tpgs; | |
71 | int state; | |
dcd3a754 | 72 | int pref; |
4335d092 | 73 | unsigned flags; /* used for optimizing STPG */ |
057ea7c9 HR |
74 | unsigned char inq[ALUA_INQUIRY_SIZE]; |
75 | unsigned char *buff; | |
76 | int bufflen; | |
3588c5a2 | 77 | unsigned char transition_tmo; |
057ea7c9 | 78 | unsigned char sense[SCSI_SENSE_BUFFERSIZE]; |
96e65865 CS |
79 | struct scsi_device *sdev; |
80 | activate_complete callback_fn; | |
81 | void *callback_data; | |
057ea7c9 HR |
82 | }; |
83 | ||
84 | #define ALUA_POLICY_SWITCH_CURRENT 0 | |
85 | #define ALUA_POLICY_SWITCH_ALL 1 | |
86 | ||
96e65865 | 87 | static char print_alua_state(int); |
96e65865 | 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; | |
a7089770 | 155 | put_unaligned_be32(h->bufflen, &rq->cmd[6]); |
057ea7c9 HR |
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 | 161 | |
5597cafc HR |
162 | blk_execute_rq(rq->q, NULL, rq, 1); |
163 | if (rq->errors) | |
164 | err = rq->errors; | |
057ea7c9 HR |
165 | blk_put_request(rq); |
166 | done: | |
167 | return err; | |
168 | } | |
169 | ||
96e65865 | 170 | /* |
dac173ee | 171 | * stpg_endio - Evaluate SET TARGET GROUP STATES |
96e65865 CS |
172 | * @sdev: the device to be evaluated |
173 | * @state: the new target group state | |
174 | * | |
dac173ee | 175 | * Evaluate a SET TARGET GROUP STATES command response. |
96e65865 CS |
176 | */ |
177 | static void stpg_endio(struct request *req, int error) | |
178 | { | |
179 | struct alua_dh_data *h = req->end_io_data; | |
180 | struct scsi_sense_hdr sense_hdr; | |
9349923d | 181 | unsigned err = SCSI_DH_OK; |
96e65865 | 182 | |
27db682b MC |
183 | if (host_byte(req->errors) != DID_OK || |
184 | msg_byte(req->errors) != COMMAND_COMPLETE) { | |
9349923d | 185 | err = SCSI_DH_IO; |
96e65865 | 186 | goto done; |
9349923d | 187 | } |
96e65865 | 188 | |
d3692a3d HR |
189 | if (scsi_normalize_sense(h->sense, SCSI_SENSE_BUFFERSIZE, |
190 | &sense_hdr)) { | |
e2d817db HR |
191 | if (sense_hdr.sense_key == NOT_READY && |
192 | sense_hdr.asc == 0x04 && sense_hdr.ascq == 0x0a) { | |
193 | /* ALUA state transition already in progress */ | |
194 | err = SCSI_DH_OK; | |
195 | goto done; | |
196 | } | |
197 | if (sense_hdr.sense_key == UNIT_ATTENTION) { | |
96e65865 CS |
198 | err = SCSI_DH_RETRY; |
199 | goto done; | |
200 | } | |
80bd68d6 HR |
201 | sdev_printk(KERN_INFO, h->sdev, "%s: stpg failed\n", |
202 | ALUA_DH_NAME); | |
203 | scsi_print_sense_hdr(h->sdev, ALUA_DH_NAME, &sense_hdr); | |
96e65865 | 204 | err = SCSI_DH_IO; |
27db682b MC |
205 | } else if (error) |
206 | err = SCSI_DH_IO; | |
207 | ||
96e65865 CS |
208 | if (err == SCSI_DH_OK) { |
209 | h->state = TPGS_STATE_OPTIMIZED; | |
210 | sdev_printk(KERN_INFO, h->sdev, | |
211 | "%s: port group %02x switched to state %c\n", | |
212 | ALUA_DH_NAME, h->group_id, | |
213 | print_alua_state(h->state)); | |
214 | } | |
215 | done: | |
ed0f36bc JG |
216 | req->end_io_data = NULL; |
217 | __blk_put_request(req->q, req); | |
96e65865 CS |
218 | if (h->callback_fn) { |
219 | h->callback_fn(h->callback_data, err); | |
220 | h->callback_fn = h->callback_data = NULL; | |
221 | } | |
222 | return; | |
223 | } | |
224 | ||
057ea7c9 HR |
225 | /* |
226 | * submit_stpg - Issue a SET TARGET GROUP STATES command | |
057ea7c9 HR |
227 | * |
228 | * Currently we're only setting the current target port group state | |
229 | * to 'active/optimized' and let the array firmware figure out | |
230 | * the states of the remaining groups. | |
231 | */ | |
96e65865 | 232 | static unsigned submit_stpg(struct alua_dh_data *h) |
057ea7c9 HR |
233 | { |
234 | struct request *rq; | |
057ea7c9 | 235 | int stpg_len = 8; |
96e65865 | 236 | struct scsi_device *sdev = h->sdev; |
057ea7c9 HR |
237 | |
238 | /* Prepare the data buffer */ | |
239 | memset(h->buff, 0, stpg_len); | |
240 | h->buff[4] = TPGS_STATE_OPTIMIZED & 0x0f; | |
a7089770 | 241 | put_unaligned_be16(h->group_id, &h->buff[6]); |
057ea7c9 HR |
242 | |
243 | rq = get_alua_req(sdev, h->buff, stpg_len, WRITE); | |
244 | if (!rq) | |
96e65865 | 245 | return SCSI_DH_RES_TEMP_UNAVAIL; |
057ea7c9 HR |
246 | |
247 | /* Prepare the command. */ | |
248 | rq->cmd[0] = MAINTENANCE_OUT; | |
249 | rq->cmd[1] = MO_SET_TARGET_PGS; | |
a7089770 | 250 | put_unaligned_be32(stpg_len, &rq->cmd[6]); |
057ea7c9 HR |
251 | rq->cmd_len = COMMAND_SIZE(MAINTENANCE_OUT); |
252 | ||
253 | rq->sense = h->sense; | |
254 | memset(rq->sense, 0, SCSI_SENSE_BUFFERSIZE); | |
d3692a3d | 255 | rq->sense_len = 0; |
96e65865 | 256 | rq->end_io_data = h; |
057ea7c9 | 257 | |
96e65865 | 258 | blk_execute_rq_nowait(rq->q, NULL, rq, 1, stpg_endio); |
7c66e9a5 | 259 | return SCSI_DH_OK; |
057ea7c9 HR |
260 | } |
261 | ||
262 | /* | |
d7c48feb | 263 | * alua_check_tpgs - Evaluate TPGS setting |
057ea7c9 HR |
264 | * @sdev: device to be checked |
265 | * | |
d7c48feb | 266 | * Examine the TPGS setting of the sdev to find out if ALUA |
057ea7c9 HR |
267 | * is supported. |
268 | */ | |
ad0ea64c | 269 | static int alua_check_tpgs(struct scsi_device *sdev) |
057ea7c9 | 270 | { |
ad0ea64c | 271 | int tpgs = TPGS_MODE_NONE; |
057ea7c9 | 272 | |
db5a6a60 HR |
273 | /* |
274 | * ALUA support for non-disk devices is fraught with | |
275 | * difficulties, so disable it for now. | |
276 | */ | |
277 | if (sdev->type != TYPE_DISK) { | |
db5a6a60 HR |
278 | sdev_printk(KERN_INFO, sdev, |
279 | "%s: disable for non-disk devices\n", | |
280 | ALUA_DH_NAME); | |
ad0ea64c | 281 | return tpgs; |
db5a6a60 HR |
282 | } |
283 | ||
ad0ea64c HR |
284 | tpgs = scsi_device_tpgs(sdev); |
285 | switch (tpgs) { | |
057ea7c9 HR |
286 | case TPGS_MODE_EXPLICIT|TPGS_MODE_IMPLICIT: |
287 | sdev_printk(KERN_INFO, sdev, | |
288 | "%s: supports implicit and explicit TPGS\n", | |
289 | ALUA_DH_NAME); | |
290 | break; | |
291 | case TPGS_MODE_EXPLICIT: | |
292 | sdev_printk(KERN_INFO, sdev, "%s: supports explicit TPGS\n", | |
293 | ALUA_DH_NAME); | |
294 | break; | |
295 | case TPGS_MODE_IMPLICIT: | |
296 | sdev_printk(KERN_INFO, sdev, "%s: supports implicit TPGS\n", | |
297 | ALUA_DH_NAME); | |
298 | break; | |
6cc05d45 | 299 | case TPGS_MODE_NONE: |
057ea7c9 HR |
300 | sdev_printk(KERN_INFO, sdev, "%s: not supported\n", |
301 | ALUA_DH_NAME); | |
057ea7c9 | 302 | break; |
6cc05d45 HR |
303 | default: |
304 | sdev_printk(KERN_INFO, sdev, | |
305 | "%s: unsupported TPGS setting %d\n", | |
ad0ea64c HR |
306 | ALUA_DH_NAME, tpgs); |
307 | tpgs = TPGS_MODE_NONE; | |
6cc05d45 | 308 | break; |
057ea7c9 HR |
309 | } |
310 | ||
ad0ea64c | 311 | return tpgs; |
057ea7c9 HR |
312 | } |
313 | ||
314 | /* | |
9b80dcec | 315 | * alua_check_vpd - Evaluate INQUIRY vpd page 0x83 |
057ea7c9 HR |
316 | * @sdev: device to be checked |
317 | * | |
318 | * Extract the relative target port and the target port group | |
319 | * descriptor from the list of identificators. | |
320 | */ | |
9b80dcec | 321 | static int alua_check_vpd(struct scsi_device *sdev, struct alua_dh_data *h) |
057ea7c9 | 322 | { |
83ea0e5e | 323 | int rel_port = -1, group_id; |
057ea7c9 | 324 | |
83ea0e5e HR |
325 | group_id = scsi_vpd_tpg_id(sdev, &rel_port); |
326 | if (group_id < 0) { | |
057ea7c9 HR |
327 | /* |
328 | * Internal error; TPGS supported but required | |
329 | * VPD identification descriptors not present. | |
330 | * Disable ALUA support | |
331 | */ | |
332 | sdev_printk(KERN_INFO, sdev, | |
333 | "%s: No target port descriptors found\n", | |
334 | ALUA_DH_NAME); | |
9b80dcec | 335 | return SCSI_DH_DEV_UNSUPP; |
057ea7c9 | 336 | } |
83ea0e5e HR |
337 | h->state = TPGS_STATE_OPTIMIZED; |
338 | h->group_id = group_id; | |
339 | ||
9b80dcec HR |
340 | sdev_printk(KERN_INFO, sdev, |
341 | "%s: port group %02x rel port %02x\n", | |
342 | ALUA_DH_NAME, h->group_id, h->rel_port); | |
057ea7c9 | 343 | |
9b80dcec | 344 | return 0; |
057ea7c9 HR |
345 | } |
346 | ||
347 | static char print_alua_state(int state) | |
348 | { | |
349 | switch (state) { | |
350 | case TPGS_STATE_OPTIMIZED: | |
351 | return 'A'; | |
352 | case TPGS_STATE_NONOPTIMIZED: | |
353 | return 'N'; | |
354 | case TPGS_STATE_STANDBY: | |
355 | return 'S'; | |
356 | case TPGS_STATE_UNAVAILABLE: | |
357 | return 'U'; | |
69723d17 HR |
358 | case TPGS_STATE_LBA_DEPENDENT: |
359 | return 'L'; | |
057ea7c9 HR |
360 | case TPGS_STATE_OFFLINE: |
361 | return 'O'; | |
362 | case TPGS_STATE_TRANSITIONING: | |
363 | return 'T'; | |
364 | default: | |
365 | return 'X'; | |
366 | } | |
367 | } | |
368 | ||
369 | static int alua_check_sense(struct scsi_device *sdev, | |
370 | struct scsi_sense_hdr *sense_hdr) | |
371 | { | |
372 | switch (sense_hdr->sense_key) { | |
373 | case NOT_READY: | |
374 | if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x0a) | |
375 | /* | |
376 | * LUN Not Accessible - ALUA state transition | |
377 | */ | |
c7dbb627 | 378 | return ADD_TO_MLQUEUE; |
057ea7c9 HR |
379 | break; |
380 | case UNIT_ATTENTION: | |
381 | if (sense_hdr->asc == 0x29 && sense_hdr->ascq == 0x00) | |
382 | /* | |
383 | * Power On, Reset, or Bus Device Reset, just retry. | |
384 | */ | |
c7dbb627 | 385 | return ADD_TO_MLQUEUE; |
c20ee7b5 SS |
386 | if (sense_hdr->asc == 0x29 && sense_hdr->ascq == 0x04) |
387 | /* | |
388 | * Device internal reset | |
389 | */ | |
390 | return ADD_TO_MLQUEUE; | |
410f02d8 MB |
391 | if (sense_hdr->asc == 0x2a && sense_hdr->ascq == 0x01) |
392 | /* | |
393 | * Mode Parameters Changed | |
394 | */ | |
395 | return ADD_TO_MLQUEUE; | |
bf81973a | 396 | if (sense_hdr->asc == 0x2a && sense_hdr->ascq == 0x06) |
057ea7c9 HR |
397 | /* |
398 | * ALUA state changed | |
399 | */ | |
c7dbb627 | 400 | return ADD_TO_MLQUEUE; |
bf81973a | 401 | if (sense_hdr->asc == 0x2a && sense_hdr->ascq == 0x07) |
057ea7c9 HR |
402 | /* |
403 | * Implicit ALUA state transition failed | |
404 | */ | |
c7dbb627 | 405 | return ADD_TO_MLQUEUE; |
bf81973a MB |
406 | if (sense_hdr->asc == 0x3f && sense_hdr->ascq == 0x03) |
407 | /* | |
408 | * Inquiry data has changed | |
409 | */ | |
410 | return ADD_TO_MLQUEUE; | |
411 | if (sense_hdr->asc == 0x3f && sense_hdr->ascq == 0x0e) | |
4d086f6b IH |
412 | /* |
413 | * REPORTED_LUNS_DATA_HAS_CHANGED is reported | |
414 | * when switching controllers on targets like | |
415 | * Intel Multi-Flex. We can just retry. | |
416 | */ | |
417 | return ADD_TO_MLQUEUE; | |
057ea7c9 HR |
418 | break; |
419 | } | |
420 | ||
421 | return SCSI_RETURN_NOT_HANDLED; | |
422 | } | |
423 | ||
057ea7c9 HR |
424 | /* |
425 | * alua_rtpg - Evaluate REPORT TARGET GROUP STATES | |
426 | * @sdev: the device to be evaluated. | |
a8e5a2d5 | 427 | * @wait_for_transition: if nonzero, wait ALUA_FAILOVER_TIMEOUT seconds for device to exit transitioning state |
057ea7c9 HR |
428 | * |
429 | * Evaluate the Target Port Group State. | |
430 | * Returns SCSI_DH_DEV_OFFLINED if the path is | |
25985edc | 431 | * found to be unusable. |
057ea7c9 | 432 | */ |
a8e5a2d5 | 433 | static int alua_rtpg(struct scsi_device *sdev, struct alua_dh_data *h, int wait_for_transition) |
057ea7c9 HR |
434 | { |
435 | struct scsi_sense_hdr sense_hdr; | |
436 | int len, k, off, valid_states = 0; | |
cfde3fa1 | 437 | unsigned char *ucp; |
5597cafc | 438 | unsigned err, retval; |
bc97f4bb | 439 | unsigned long expiry, interval = 0; |
3588c5a2 RE |
440 | unsigned int tpg_desc_tbl_off; |
441 | unsigned char orig_transition_tmo; | |
442 | ||
443 | if (!h->transition_tmo) | |
444 | expiry = round_jiffies_up(jiffies + ALUA_FAILOVER_TIMEOUT * HZ); | |
445 | else | |
446 | expiry = round_jiffies_up(jiffies + h->transition_tmo * HZ); | |
057ea7c9 HR |
447 | |
448 | retry: | |
6c4fc044 | 449 | retval = submit_rtpg(sdev, h); |
5597cafc | 450 | if (retval) { |
d3692a3d | 451 | if (!scsi_normalize_sense(h->sense, SCSI_SENSE_BUFFERSIZE, |
5597cafc HR |
452 | &sense_hdr)) { |
453 | sdev_printk(KERN_INFO, sdev, | |
454 | "%s: rtpg failed, result %d\n", | |
455 | ALUA_DH_NAME, retval); | |
456 | if (driver_byte(retval) == DRIVER_BUSY) | |
457 | return SCSI_DH_DEV_TEMP_BUSY; | |
057ea7c9 | 458 | return SCSI_DH_IO; |
5597cafc | 459 | } |
057ea7c9 | 460 | |
8e67ce60 RE |
461 | /* |
462 | * submit_rtpg() has failed on existing arrays | |
463 | * when requesting extended header info, and | |
464 | * the array doesn't support extended headers, | |
465 | * even though it shouldn't according to T10. | |
466 | * The retry without rtpg_ext_hdr_req set | |
467 | * handles this. | |
468 | */ | |
6c4fc044 | 469 | if (!(h->flags & ALUA_RTPG_EXT_HDR_UNSUPP) && |
8e67ce60 RE |
470 | sense_hdr.sense_key == ILLEGAL_REQUEST && |
471 | sense_hdr.asc == 0x24 && sense_hdr.ascq == 0) { | |
6c4fc044 | 472 | h->flags |= ALUA_RTPG_EXT_HDR_UNSUPP; |
8e67ce60 RE |
473 | goto retry; |
474 | } | |
e2d817db HR |
475 | /* |
476 | * Retry on ALUA state transition or if any | |
477 | * UNIT ATTENTION occurred. | |
478 | */ | |
479 | if (sense_hdr.sense_key == NOT_READY && | |
480 | sense_hdr.asc == 0x04 && sense_hdr.ascq == 0x0a) | |
481 | err = SCSI_DH_RETRY; | |
482 | else if (sense_hdr.sense_key == UNIT_ATTENTION) | |
483 | err = SCSI_DH_RETRY; | |
484 | if (err == SCSI_DH_RETRY && time_before(jiffies, expiry)) { | |
80bd68d6 HR |
485 | sdev_printk(KERN_ERR, sdev, "%s: rtpg retry\n", |
486 | ALUA_DH_NAME); | |
487 | scsi_print_sense_hdr(sdev, ALUA_DH_NAME, &sense_hdr); | |
057ea7c9 | 488 | goto retry; |
80bd68d6 HR |
489 | } |
490 | sdev_printk(KERN_ERR, sdev, "%s: rtpg failed\n", | |
491 | ALUA_DH_NAME); | |
492 | scsi_print_sense_hdr(sdev, ALUA_DH_NAME, &sense_hdr); | |
493 | return SCSI_DH_IO; | |
057ea7c9 | 494 | } |
057ea7c9 | 495 | |
a7089770 | 496 | len = get_unaligned_be32(&h->buff[0]) + 4; |
057ea7c9 HR |
497 | |
498 | if (len > h->bufflen) { | |
499 | /* Resubmit with the correct length */ | |
500 | if (realloc_buffer(h, len)) { | |
501 | sdev_printk(KERN_WARNING, sdev, | |
cadbd4a5 | 502 | "%s: kmalloc buffer failed\n",__func__); |
057ea7c9 HR |
503 | /* Temporary failure, bypass */ |
504 | return SCSI_DH_DEV_TEMP_BUSY; | |
505 | } | |
506 | goto retry; | |
507 | } | |
508 | ||
3588c5a2 RE |
509 | orig_transition_tmo = h->transition_tmo; |
510 | if ((h->buff[4] & RTPG_FMT_MASK) == RTPG_FMT_EXT_HDR && h->buff[5] != 0) | |
511 | h->transition_tmo = h->buff[5]; | |
512 | else | |
513 | h->transition_tmo = ALUA_FAILOVER_TIMEOUT; | |
514 | ||
a8e5a2d5 | 515 | if (wait_for_transition && (orig_transition_tmo != h->transition_tmo)) { |
3588c5a2 RE |
516 | sdev_printk(KERN_INFO, sdev, |
517 | "%s: transition timeout set to %d seconds\n", | |
518 | ALUA_DH_NAME, h->transition_tmo); | |
519 | expiry = jiffies + h->transition_tmo * HZ; | |
520 | } | |
521 | ||
522 | if ((h->buff[4] & RTPG_FMT_MASK) == RTPG_FMT_EXT_HDR) | |
523 | tpg_desc_tbl_off = 8; | |
524 | else | |
525 | tpg_desc_tbl_off = 4; | |
526 | ||
527 | for (k = tpg_desc_tbl_off, ucp = h->buff + tpg_desc_tbl_off; | |
528 | k < len; | |
529 | k += off, ucp += off) { | |
530 | ||
a7089770 | 531 | if (h->group_id == get_unaligned_be16(&ucp[2])) { |
057ea7c9 | 532 | h->state = ucp[0] & 0x0f; |
dcd3a754 | 533 | h->pref = ucp[0] >> 7; |
057ea7c9 HR |
534 | valid_states = ucp[1]; |
535 | } | |
536 | off = 8 + (ucp[7] * 4); | |
537 | } | |
538 | ||
539 | sdev_printk(KERN_INFO, sdev, | |
dcd3a754 | 540 | "%s: port group %02x state %c %s supports %c%c%c%c%c%c%c\n", |
057ea7c9 | 541 | ALUA_DH_NAME, h->group_id, print_alua_state(h->state), |
dcd3a754 | 542 | h->pref ? "preferred" : "non-preferred", |
057ea7c9 HR |
543 | valid_states&TPGS_SUPPORT_TRANSITION?'T':'t', |
544 | valid_states&TPGS_SUPPORT_OFFLINE?'O':'o', | |
69723d17 | 545 | valid_states&TPGS_SUPPORT_LBA_DEPENDENT?'L':'l', |
057ea7c9 HR |
546 | valid_states&TPGS_SUPPORT_UNAVAILABLE?'U':'u', |
547 | valid_states&TPGS_SUPPORT_STANDBY?'S':'s', | |
548 | valid_states&TPGS_SUPPORT_NONOPTIMIZED?'N':'n', | |
549 | valid_states&TPGS_SUPPORT_OPTIMIZED?'A':'a'); | |
550 | ||
69723d17 HR |
551 | switch (h->state) { |
552 | case TPGS_STATE_TRANSITIONING: | |
a8e5a2d5 SS |
553 | if (wait_for_transition) { |
554 | if (time_before(jiffies, expiry)) { | |
555 | /* State transition, retry */ | |
556 | interval += 2000; | |
557 | msleep(interval); | |
558 | goto retry; | |
559 | } | |
560 | err = SCSI_DH_RETRY; | |
561 | } else { | |
562 | err = SCSI_DH_OK; | |
057ea7c9 | 563 | } |
a8e5a2d5 | 564 | |
69723d17 | 565 | /* Transitioning time exceeded, set port to standby */ |
69723d17 HR |
566 | h->state = TPGS_STATE_STANDBY; |
567 | break; | |
568 | case TPGS_STATE_OFFLINE: | |
e47f8976 | 569 | /* Path unusable */ |
69723d17 HR |
570 | err = SCSI_DH_DEV_OFFLINED; |
571 | break; | |
572 | default: | |
573 | /* Useable path if active */ | |
574 | err = SCSI_DH_OK; | |
575 | break; | |
057ea7c9 HR |
576 | } |
577 | return err; | |
578 | } | |
579 | ||
580 | /* | |
581 | * alua_initialize - Initialize ALUA state | |
582 | * @sdev: the device to be initialized | |
583 | * | |
584 | * For the prep_fn to work correctly we have | |
585 | * to initialize the ALUA state for the device. | |
586 | */ | |
587 | static int alua_initialize(struct scsi_device *sdev, struct alua_dh_data *h) | |
588 | { | |
ad0ea64c | 589 | int err = SCSI_DH_DEV_UNSUPP; |
057ea7c9 | 590 | |
ad0ea64c HR |
591 | h->tpgs = alua_check_tpgs(sdev); |
592 | if (h->tpgs == TPGS_MODE_NONE) | |
057ea7c9 HR |
593 | goto out; |
594 | ||
9b80dcec | 595 | err = alua_check_vpd(sdev, h); |
057ea7c9 HR |
596 | if (err != SCSI_DH_OK) |
597 | goto out; | |
598 | ||
a8e5a2d5 | 599 | err = alua_rtpg(sdev, h, 0); |
057ea7c9 HR |
600 | if (err != SCSI_DH_OK) |
601 | goto out; | |
602 | ||
603 | out: | |
604 | return err; | |
605 | } | |
4335d092 MB |
606 | /* |
607 | * alua_set_params - set/unset the optimize flag | |
608 | * @sdev: device on the path to be activated | |
609 | * params - parameters in the following format | |
610 | * "no_of_params\0param1\0param2\0param3\0...\0" | |
611 | * For example, to set the flag pass the following parameters | |
612 | * from multipath.conf | |
613 | * hardware_handler "2 alua 1" | |
614 | */ | |
615 | static int alua_set_params(struct scsi_device *sdev, const char *params) | |
616 | { | |
ee14c674 | 617 | struct alua_dh_data *h = sdev->handler_data; |
4335d092 MB |
618 | unsigned int optimize = 0, argc; |
619 | const char *p = params; | |
620 | int result = SCSI_DH_OK; | |
621 | ||
622 | if ((sscanf(params, "%u", &argc) != 1) || (argc != 1)) | |
623 | return -EINVAL; | |
624 | ||
625 | while (*p++) | |
626 | ; | |
627 | if ((sscanf(p, "%u", &optimize) != 1) || (optimize > 1)) | |
628 | return -EINVAL; | |
629 | ||
630 | if (optimize) | |
631 | h->flags |= ALUA_OPTIMIZE_STPG; | |
632 | else | |
633 | h->flags &= ~ALUA_OPTIMIZE_STPG; | |
634 | ||
635 | return result; | |
636 | } | |
057ea7c9 | 637 | |
7a3ad392 SS |
638 | static uint optimize_stpg; |
639 | module_param(optimize_stpg, uint, S_IRUGO|S_IWUSR); | |
640 | 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."); | |
641 | ||
057ea7c9 HR |
642 | /* |
643 | * alua_activate - activate a path | |
644 | * @sdev: device on the path to be activated | |
645 | * | |
646 | * We're currently switching the port group to be activated only and | |
647 | * let the array figure out the rest. | |
648 | * There may be other arrays which require us to switch all port groups | |
649 | * based on a certain policy. But until we actually encounter them it | |
650 | * should be okay. | |
651 | */ | |
3ae31f6a CS |
652 | static int alua_activate(struct scsi_device *sdev, |
653 | activate_complete fn, void *data) | |
057ea7c9 | 654 | { |
ee14c674 | 655 | struct alua_dh_data *h = sdev->handler_data; |
057ea7c9 | 656 | int err = SCSI_DH_OK; |
72d9e0f3 | 657 | int stpg = 0; |
057ea7c9 | 658 | |
a8e5a2d5 | 659 | err = alua_rtpg(sdev, h, 1); |
46ccf6b5 HR |
660 | if (err != SCSI_DH_OK) |
661 | goto out; | |
057ea7c9 | 662 | |
7a3ad392 SS |
663 | if (optimize_stpg) |
664 | h->flags |= ALUA_OPTIMIZE_STPG; | |
665 | ||
72d9e0f3 MB |
666 | if (h->tpgs & TPGS_MODE_EXPLICIT) { |
667 | switch (h->state) { | |
668 | case TPGS_STATE_NONOPTIMIZED: | |
669 | stpg = 1; | |
670 | if ((h->flags & ALUA_OPTIMIZE_STPG) && | |
671 | (!h->pref) && | |
672 | (h->tpgs & TPGS_MODE_IMPLICIT)) | |
673 | stpg = 0; | |
674 | break; | |
675 | case TPGS_STATE_STANDBY: | |
bb2c94a3 | 676 | case TPGS_STATE_UNAVAILABLE: |
72d9e0f3 MB |
677 | stpg = 1; |
678 | break; | |
72d9e0f3 MB |
679 | case TPGS_STATE_OFFLINE: |
680 | err = SCSI_DH_IO; | |
681 | break; | |
682 | case TPGS_STATE_TRANSITIONING: | |
683 | err = SCSI_DH_RETRY; | |
684 | break; | |
685 | default: | |
686 | break; | |
687 | } | |
688 | } | |
689 | ||
690 | if (stpg) { | |
96e65865 CS |
691 | h->callback_fn = fn; |
692 | h->callback_data = data; | |
693 | err = submit_stpg(h); | |
694 | if (err == SCSI_DH_OK) | |
695 | return 0; | |
696 | h->callback_fn = h->callback_data = NULL; | |
697 | } | |
057ea7c9 HR |
698 | |
699 | out: | |
3ae31f6a CS |
700 | if (fn) |
701 | fn(data, err); | |
702 | return 0; | |
057ea7c9 HR |
703 | } |
704 | ||
705 | /* | |
706 | * alua_prep_fn - request callback | |
707 | * | |
708 | * Fail I/O to all paths not in state | |
709 | * active/optimized or active/non-optimized. | |
710 | */ | |
711 | static int alua_prep_fn(struct scsi_device *sdev, struct request *req) | |
712 | { | |
ee14c674 | 713 | struct alua_dh_data *h = sdev->handler_data; |
057ea7c9 HR |
714 | int ret = BLKPREP_OK; |
715 | ||
69723d17 HR |
716 | if (h->state == TPGS_STATE_TRANSITIONING) |
717 | ret = BLKPREP_DEFER; | |
718 | else if (h->state != TPGS_STATE_OPTIMIZED && | |
719 | h->state != TPGS_STATE_NONOPTIMIZED && | |
720 | h->state != TPGS_STATE_LBA_DEPENDENT) { | |
057ea7c9 HR |
721 | ret = BLKPREP_KILL; |
722 | req->cmd_flags |= REQ_QUIET; | |
723 | } | |
724 | return ret; | |
725 | ||
726 | } | |
727 | ||
057ea7c9 HR |
728 | /* |
729 | * alua_bus_attach - Attach device handler | |
730 | * @sdev: device to be attached to | |
731 | */ | |
ee14c674 | 732 | static int alua_bus_attach(struct scsi_device *sdev) |
057ea7c9 | 733 | { |
057ea7c9 | 734 | struct alua_dh_data *h; |
1d520328 | 735 | int err; |
057ea7c9 | 736 | |
cd37743f | 737 | h = kzalloc(sizeof(*h) , GFP_KERNEL); |
1d520328 | 738 | if (!h) |
ee14c674 | 739 | return -ENOMEM; |
057ea7c9 HR |
740 | h->tpgs = TPGS_MODE_UNINITIALIZED; |
741 | h->state = TPGS_STATE_OPTIMIZED; | |
742 | h->group_id = -1; | |
743 | h->rel_port = -1; | |
744 | h->buff = h->inq; | |
745 | h->bufflen = ALUA_INQUIRY_SIZE; | |
96e65865 | 746 | h->sdev = sdev; |
057ea7c9 HR |
747 | |
748 | err = alua_initialize(sdev, h); | |
1d520328 | 749 | if (err != SCSI_DH_OK && err != SCSI_DH_DEV_OFFLINED) |
057ea7c9 HR |
750 | goto failed; |
751 | ||
ee14c674 CH |
752 | sdev->handler_data = h; |
753 | return 0; | |
057ea7c9 | 754 | failed: |
cd37743f | 755 | kfree(h); |
ee14c674 | 756 | return -EINVAL; |
057ea7c9 HR |
757 | } |
758 | ||
759 | /* | |
760 | * alua_bus_detach - Detach device handler | |
761 | * @sdev: device to be detached from | |
762 | */ | |
763 | static void alua_bus_detach(struct scsi_device *sdev) | |
764 | { | |
ee14c674 | 765 | struct alua_dh_data *h = sdev->handler_data; |
057ea7c9 | 766 | |
057ea7c9 HR |
767 | if (h->buff && h->inq != h->buff) |
768 | kfree(h->buff); | |
ee14c674 | 769 | sdev->handler_data = NULL; |
cd37743f | 770 | kfree(h); |
057ea7c9 HR |
771 | } |
772 | ||
1d520328 CH |
773 | static struct scsi_device_handler alua_dh = { |
774 | .name = ALUA_DH_NAME, | |
775 | .module = THIS_MODULE, | |
776 | .attach = alua_bus_attach, | |
777 | .detach = alua_bus_detach, | |
778 | .prep_fn = alua_prep_fn, | |
779 | .check_sense = alua_check_sense, | |
780 | .activate = alua_activate, | |
781 | .set_params = alua_set_params, | |
1d520328 CH |
782 | }; |
783 | ||
057ea7c9 HR |
784 | static int __init alua_init(void) |
785 | { | |
786 | int r; | |
787 | ||
788 | r = scsi_register_device_handler(&alua_dh); | |
789 | if (r != 0) | |
790 | printk(KERN_ERR "%s: Failed to register scsi device handler", | |
791 | ALUA_DH_NAME); | |
792 | return r; | |
793 | } | |
794 | ||
795 | static void __exit alua_exit(void) | |
796 | { | |
797 | scsi_unregister_device_handler(&alua_dh); | |
798 | } | |
799 | ||
800 | module_init(alua_init); | |
801 | module_exit(alua_exit); | |
802 | ||
803 | MODULE_DESCRIPTION("DM Multipath ALUA support"); | |
804 | MODULE_AUTHOR("Hannes Reinecke <hare@suse.de>"); | |
805 | MODULE_LICENSE("GPL"); | |
806 | MODULE_VERSION(ALUA_DH_VER); |