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 | ||
c49c8345 | 59 | #define ALUA_RTPG_SIZE 128 |
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 */ |
3588c5a2 | 74 | unsigned char transition_tmo; |
96e65865 CS |
75 | struct scsi_device *sdev; |
76 | activate_complete callback_fn; | |
77 | void *callback_data; | |
057ea7c9 HR |
78 | }; |
79 | ||
80 | #define ALUA_POLICY_SWITCH_CURRENT 0 | |
81 | #define ALUA_POLICY_SWITCH_ALL 1 | |
82 | ||
96e65865 | 83 | static char print_alua_state(int); |
96e65865 | 84 | |
057ea7c9 HR |
85 | /* |
86 | * submit_rtpg - Issue a REPORT TARGET GROUP STATES command | |
87 | * @sdev: sdev the command should be sent to | |
88 | */ | |
40bb61a7 HR |
89 | static int submit_rtpg(struct scsi_device *sdev, unsigned char *buff, |
90 | int bufflen, struct scsi_sense_hdr *sshdr, int flags) | |
057ea7c9 | 91 | { |
40bb61a7 HR |
92 | u8 cdb[COMMAND_SIZE(MAINTENANCE_IN)]; |
93 | int req_flags = REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT | | |
94 | REQ_FAILFAST_DRIVER; | |
057ea7c9 HR |
95 | |
96 | /* Prepare the command. */ | |
40bb61a7 HR |
97 | memset(cdb, 0x0, COMMAND_SIZE(MAINTENANCE_IN)); |
98 | cdb[0] = MAINTENANCE_IN; | |
d42ae5f3 | 99 | if (!(flags & ALUA_RTPG_EXT_HDR_UNSUPP)) |
40bb61a7 | 100 | cdb[1] = MI_REPORT_TARGET_PGS | MI_EXT_HDR_PARAM_FMT; |
8e67ce60 | 101 | else |
40bb61a7 HR |
102 | cdb[1] = MI_REPORT_TARGET_PGS; |
103 | put_unaligned_be32(bufflen, &cdb[6]); | |
104 | ||
105 | return scsi_execute_req_flags(sdev, cdb, DMA_FROM_DEVICE, | |
106 | buff, bufflen, sshdr, | |
107 | ALUA_FAILOVER_TIMEOUT * HZ, | |
108 | ALUA_FAILOVER_RETRIES, NULL, req_flags); | |
057ea7c9 HR |
109 | } |
110 | ||
96e65865 | 111 | /* |
b2460756 | 112 | * submit_stpg - Issue a SET TARGET PORT GROUP command |
057ea7c9 HR |
113 | * |
114 | * Currently we're only setting the current target port group state | |
115 | * to 'active/optimized' and let the array firmware figure out | |
116 | * the states of the remaining groups. | |
117 | */ | |
40bb61a7 HR |
118 | static int submit_stpg(struct scsi_device *sdev, int group_id, |
119 | struct scsi_sense_hdr *sshdr) | |
057ea7c9 | 120 | { |
40bb61a7 | 121 | u8 cdb[COMMAND_SIZE(MAINTENANCE_OUT)]; |
b2460756 | 122 | unsigned char stpg_data[8]; |
057ea7c9 | 123 | int stpg_len = 8; |
40bb61a7 HR |
124 | int req_flags = REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT | |
125 | REQ_FAILFAST_DRIVER; | |
057ea7c9 HR |
126 | |
127 | /* Prepare the data buffer */ | |
b2460756 HR |
128 | memset(stpg_data, 0, stpg_len); |
129 | stpg_data[4] = TPGS_STATE_OPTIMIZED & 0x0f; | |
130 | put_unaligned_be16(group_id, &stpg_data[6]); | |
057ea7c9 | 131 | |
057ea7c9 | 132 | /* Prepare the command. */ |
40bb61a7 HR |
133 | memset(cdb, 0x0, COMMAND_SIZE(MAINTENANCE_OUT)); |
134 | cdb[0] = MAINTENANCE_OUT; | |
135 | cdb[1] = MO_SET_TARGET_PGS; | |
136 | put_unaligned_be32(stpg_len, &cdb[6]); | |
137 | ||
138 | return scsi_execute_req_flags(sdev, cdb, DMA_TO_DEVICE, | |
139 | stpg_data, stpg_len, | |
140 | sshdr, ALUA_FAILOVER_TIMEOUT * HZ, | |
141 | ALUA_FAILOVER_RETRIES, NULL, req_flags); | |
057ea7c9 HR |
142 | } |
143 | ||
144 | /* | |
d7c48feb | 145 | * alua_check_tpgs - Evaluate TPGS setting |
057ea7c9 HR |
146 | * @sdev: device to be checked |
147 | * | |
d7c48feb | 148 | * Examine the TPGS setting of the sdev to find out if ALUA |
057ea7c9 HR |
149 | * is supported. |
150 | */ | |
ad0ea64c | 151 | static int alua_check_tpgs(struct scsi_device *sdev) |
057ea7c9 | 152 | { |
ad0ea64c | 153 | int tpgs = TPGS_MODE_NONE; |
057ea7c9 | 154 | |
db5a6a60 HR |
155 | /* |
156 | * ALUA support for non-disk devices is fraught with | |
157 | * difficulties, so disable it for now. | |
158 | */ | |
159 | if (sdev->type != TYPE_DISK) { | |
db5a6a60 HR |
160 | sdev_printk(KERN_INFO, sdev, |
161 | "%s: disable for non-disk devices\n", | |
162 | ALUA_DH_NAME); | |
ad0ea64c | 163 | return tpgs; |
db5a6a60 HR |
164 | } |
165 | ||
ad0ea64c HR |
166 | tpgs = scsi_device_tpgs(sdev); |
167 | switch (tpgs) { | |
057ea7c9 HR |
168 | case TPGS_MODE_EXPLICIT|TPGS_MODE_IMPLICIT: |
169 | sdev_printk(KERN_INFO, sdev, | |
170 | "%s: supports implicit and explicit TPGS\n", | |
171 | ALUA_DH_NAME); | |
172 | break; | |
173 | case TPGS_MODE_EXPLICIT: | |
174 | sdev_printk(KERN_INFO, sdev, "%s: supports explicit TPGS\n", | |
175 | ALUA_DH_NAME); | |
176 | break; | |
177 | case TPGS_MODE_IMPLICIT: | |
178 | sdev_printk(KERN_INFO, sdev, "%s: supports implicit TPGS\n", | |
179 | ALUA_DH_NAME); | |
180 | break; | |
6cc05d45 | 181 | case TPGS_MODE_NONE: |
057ea7c9 HR |
182 | sdev_printk(KERN_INFO, sdev, "%s: not supported\n", |
183 | ALUA_DH_NAME); | |
057ea7c9 | 184 | break; |
6cc05d45 HR |
185 | default: |
186 | sdev_printk(KERN_INFO, sdev, | |
187 | "%s: unsupported TPGS setting %d\n", | |
ad0ea64c HR |
188 | ALUA_DH_NAME, tpgs); |
189 | tpgs = TPGS_MODE_NONE; | |
6cc05d45 | 190 | break; |
057ea7c9 HR |
191 | } |
192 | ||
ad0ea64c | 193 | return tpgs; |
057ea7c9 HR |
194 | } |
195 | ||
196 | /* | |
9b80dcec | 197 | * alua_check_vpd - Evaluate INQUIRY vpd page 0x83 |
057ea7c9 HR |
198 | * @sdev: device to be checked |
199 | * | |
200 | * Extract the relative target port and the target port group | |
201 | * descriptor from the list of identificators. | |
202 | */ | |
9b80dcec | 203 | static int alua_check_vpd(struct scsi_device *sdev, struct alua_dh_data *h) |
057ea7c9 | 204 | { |
83ea0e5e | 205 | int rel_port = -1, group_id; |
057ea7c9 | 206 | |
83ea0e5e HR |
207 | group_id = scsi_vpd_tpg_id(sdev, &rel_port); |
208 | if (group_id < 0) { | |
057ea7c9 HR |
209 | /* |
210 | * Internal error; TPGS supported but required | |
211 | * VPD identification descriptors not present. | |
212 | * Disable ALUA support | |
213 | */ | |
214 | sdev_printk(KERN_INFO, sdev, | |
215 | "%s: No target port descriptors found\n", | |
216 | ALUA_DH_NAME); | |
9b80dcec | 217 | return SCSI_DH_DEV_UNSUPP; |
057ea7c9 | 218 | } |
83ea0e5e HR |
219 | h->state = TPGS_STATE_OPTIMIZED; |
220 | h->group_id = group_id; | |
221 | ||
9b80dcec HR |
222 | sdev_printk(KERN_INFO, sdev, |
223 | "%s: port group %02x rel port %02x\n", | |
224 | ALUA_DH_NAME, h->group_id, h->rel_port); | |
057ea7c9 | 225 | |
9b80dcec | 226 | return 0; |
057ea7c9 HR |
227 | } |
228 | ||
229 | static char print_alua_state(int state) | |
230 | { | |
231 | switch (state) { | |
232 | case TPGS_STATE_OPTIMIZED: | |
233 | return 'A'; | |
234 | case TPGS_STATE_NONOPTIMIZED: | |
235 | return 'N'; | |
236 | case TPGS_STATE_STANDBY: | |
237 | return 'S'; | |
238 | case TPGS_STATE_UNAVAILABLE: | |
239 | return 'U'; | |
69723d17 HR |
240 | case TPGS_STATE_LBA_DEPENDENT: |
241 | return 'L'; | |
057ea7c9 HR |
242 | case TPGS_STATE_OFFLINE: |
243 | return 'O'; | |
244 | case TPGS_STATE_TRANSITIONING: | |
245 | return 'T'; | |
246 | default: | |
247 | return 'X'; | |
248 | } | |
249 | } | |
250 | ||
251 | static int alua_check_sense(struct scsi_device *sdev, | |
252 | struct scsi_sense_hdr *sense_hdr) | |
253 | { | |
254 | switch (sense_hdr->sense_key) { | |
255 | case NOT_READY: | |
256 | if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x0a) | |
257 | /* | |
258 | * LUN Not Accessible - ALUA state transition | |
259 | */ | |
c7dbb627 | 260 | return ADD_TO_MLQUEUE; |
057ea7c9 HR |
261 | break; |
262 | case UNIT_ATTENTION: | |
263 | if (sense_hdr->asc == 0x29 && sense_hdr->ascq == 0x00) | |
264 | /* | |
265 | * Power On, Reset, or Bus Device Reset, just retry. | |
266 | */ | |
c7dbb627 | 267 | return ADD_TO_MLQUEUE; |
c20ee7b5 SS |
268 | if (sense_hdr->asc == 0x29 && sense_hdr->ascq == 0x04) |
269 | /* | |
270 | * Device internal reset | |
271 | */ | |
272 | return ADD_TO_MLQUEUE; | |
410f02d8 MB |
273 | if (sense_hdr->asc == 0x2a && sense_hdr->ascq == 0x01) |
274 | /* | |
275 | * Mode Parameters Changed | |
276 | */ | |
277 | return ADD_TO_MLQUEUE; | |
bf81973a | 278 | if (sense_hdr->asc == 0x2a && sense_hdr->ascq == 0x06) |
057ea7c9 HR |
279 | /* |
280 | * ALUA state changed | |
281 | */ | |
c7dbb627 | 282 | return ADD_TO_MLQUEUE; |
bf81973a | 283 | if (sense_hdr->asc == 0x2a && sense_hdr->ascq == 0x07) |
057ea7c9 HR |
284 | /* |
285 | * Implicit ALUA state transition failed | |
286 | */ | |
c7dbb627 | 287 | return ADD_TO_MLQUEUE; |
bf81973a MB |
288 | if (sense_hdr->asc == 0x3f && sense_hdr->ascq == 0x03) |
289 | /* | |
290 | * Inquiry data has changed | |
291 | */ | |
292 | return ADD_TO_MLQUEUE; | |
293 | if (sense_hdr->asc == 0x3f && sense_hdr->ascq == 0x0e) | |
4d086f6b IH |
294 | /* |
295 | * REPORTED_LUNS_DATA_HAS_CHANGED is reported | |
296 | * when switching controllers on targets like | |
297 | * Intel Multi-Flex. We can just retry. | |
298 | */ | |
299 | return ADD_TO_MLQUEUE; | |
057ea7c9 HR |
300 | break; |
301 | } | |
302 | ||
303 | return SCSI_RETURN_NOT_HANDLED; | |
304 | } | |
305 | ||
057ea7c9 HR |
306 | /* |
307 | * alua_rtpg - Evaluate REPORT TARGET GROUP STATES | |
308 | * @sdev: the device to be evaluated. | |
a8e5a2d5 | 309 | * @wait_for_transition: if nonzero, wait ALUA_FAILOVER_TIMEOUT seconds for device to exit transitioning state |
057ea7c9 HR |
310 | * |
311 | * Evaluate the Target Port Group State. | |
312 | * Returns SCSI_DH_DEV_OFFLINED if the path is | |
25985edc | 313 | * found to be unusable. |
057ea7c9 | 314 | */ |
a8e5a2d5 | 315 | static int alua_rtpg(struct scsi_device *sdev, struct alua_dh_data *h, int wait_for_transition) |
057ea7c9 HR |
316 | { |
317 | struct scsi_sense_hdr sense_hdr; | |
c49c8345 HR |
318 | int len, k, off, valid_states = 0, bufflen = ALUA_RTPG_SIZE; |
319 | unsigned char *ucp, *buff; | |
5597cafc | 320 | unsigned err, retval; |
bc97f4bb | 321 | unsigned long expiry, interval = 0; |
3588c5a2 RE |
322 | unsigned int tpg_desc_tbl_off; |
323 | unsigned char orig_transition_tmo; | |
324 | ||
325 | if (!h->transition_tmo) | |
326 | expiry = round_jiffies_up(jiffies + ALUA_FAILOVER_TIMEOUT * HZ); | |
327 | else | |
328 | expiry = round_jiffies_up(jiffies + h->transition_tmo * HZ); | |
057ea7c9 | 329 | |
c49c8345 HR |
330 | buff = kzalloc(bufflen, GFP_KERNEL); |
331 | if (!buff) | |
332 | return SCSI_DH_DEV_TEMP_BUSY; | |
333 | ||
057ea7c9 | 334 | retry: |
c49c8345 | 335 | retval = submit_rtpg(sdev, buff, bufflen, &sense_hdr, h->flags); |
40bb61a7 | 336 | |
5597cafc | 337 | if (retval) { |
40bb61a7 | 338 | if (!scsi_sense_valid(&sense_hdr)) { |
5597cafc HR |
339 | sdev_printk(KERN_INFO, sdev, |
340 | "%s: rtpg failed, result %d\n", | |
341 | ALUA_DH_NAME, retval); | |
c49c8345 | 342 | kfree(buff); |
40bb61a7 | 343 | if (driver_byte(retval) == DRIVER_ERROR) |
5597cafc | 344 | return SCSI_DH_DEV_TEMP_BUSY; |
057ea7c9 | 345 | return SCSI_DH_IO; |
5597cafc | 346 | } |
057ea7c9 | 347 | |
8e67ce60 RE |
348 | /* |
349 | * submit_rtpg() has failed on existing arrays | |
350 | * when requesting extended header info, and | |
351 | * the array doesn't support extended headers, | |
352 | * even though it shouldn't according to T10. | |
353 | * The retry without rtpg_ext_hdr_req set | |
354 | * handles this. | |
355 | */ | |
6c4fc044 | 356 | if (!(h->flags & ALUA_RTPG_EXT_HDR_UNSUPP) && |
8e67ce60 RE |
357 | sense_hdr.sense_key == ILLEGAL_REQUEST && |
358 | sense_hdr.asc == 0x24 && sense_hdr.ascq == 0) { | |
6c4fc044 | 359 | h->flags |= ALUA_RTPG_EXT_HDR_UNSUPP; |
8e67ce60 RE |
360 | goto retry; |
361 | } | |
e2d817db HR |
362 | /* |
363 | * Retry on ALUA state transition or if any | |
364 | * UNIT ATTENTION occurred. | |
365 | */ | |
366 | if (sense_hdr.sense_key == NOT_READY && | |
367 | sense_hdr.asc == 0x04 && sense_hdr.ascq == 0x0a) | |
368 | err = SCSI_DH_RETRY; | |
369 | else if (sense_hdr.sense_key == UNIT_ATTENTION) | |
370 | err = SCSI_DH_RETRY; | |
371 | if (err == SCSI_DH_RETRY && time_before(jiffies, expiry)) { | |
80bd68d6 HR |
372 | sdev_printk(KERN_ERR, sdev, "%s: rtpg retry\n", |
373 | ALUA_DH_NAME); | |
374 | scsi_print_sense_hdr(sdev, ALUA_DH_NAME, &sense_hdr); | |
057ea7c9 | 375 | goto retry; |
80bd68d6 HR |
376 | } |
377 | sdev_printk(KERN_ERR, sdev, "%s: rtpg failed\n", | |
378 | ALUA_DH_NAME); | |
379 | scsi_print_sense_hdr(sdev, ALUA_DH_NAME, &sense_hdr); | |
c49c8345 | 380 | kfree(buff); |
80bd68d6 | 381 | return SCSI_DH_IO; |
057ea7c9 | 382 | } |
057ea7c9 | 383 | |
c49c8345 | 384 | len = get_unaligned_be32(&buff[0]) + 4; |
057ea7c9 | 385 | |
c49c8345 | 386 | if (len > bufflen) { |
057ea7c9 | 387 | /* Resubmit with the correct length */ |
c49c8345 HR |
388 | kfree(buff); |
389 | bufflen = len; | |
390 | buff = kmalloc(bufflen, GFP_KERNEL); | |
391 | if (!buff) { | |
057ea7c9 | 392 | sdev_printk(KERN_WARNING, sdev, |
cadbd4a5 | 393 | "%s: kmalloc buffer failed\n",__func__); |
057ea7c9 HR |
394 | /* Temporary failure, bypass */ |
395 | return SCSI_DH_DEV_TEMP_BUSY; | |
396 | } | |
397 | goto retry; | |
398 | } | |
399 | ||
3588c5a2 | 400 | orig_transition_tmo = h->transition_tmo; |
c49c8345 HR |
401 | if ((buff[4] & RTPG_FMT_MASK) == RTPG_FMT_EXT_HDR && buff[5] != 0) |
402 | h->transition_tmo = buff[5]; | |
3588c5a2 RE |
403 | else |
404 | h->transition_tmo = ALUA_FAILOVER_TIMEOUT; | |
405 | ||
c49c8345 HR |
406 | if (wait_for_transition && |
407 | (orig_transition_tmo != h->transition_tmo)) { | |
3588c5a2 RE |
408 | sdev_printk(KERN_INFO, sdev, |
409 | "%s: transition timeout set to %d seconds\n", | |
410 | ALUA_DH_NAME, h->transition_tmo); | |
411 | expiry = jiffies + h->transition_tmo * HZ; | |
412 | } | |
413 | ||
c49c8345 | 414 | if ((buff[4] & RTPG_FMT_MASK) == RTPG_FMT_EXT_HDR) |
3588c5a2 RE |
415 | tpg_desc_tbl_off = 8; |
416 | else | |
417 | tpg_desc_tbl_off = 4; | |
418 | ||
c49c8345 | 419 | for (k = tpg_desc_tbl_off, ucp = buff + tpg_desc_tbl_off; |
3588c5a2 RE |
420 | k < len; |
421 | k += off, ucp += off) { | |
422 | ||
a7089770 | 423 | if (h->group_id == get_unaligned_be16(&ucp[2])) { |
057ea7c9 | 424 | h->state = ucp[0] & 0x0f; |
dcd3a754 | 425 | h->pref = ucp[0] >> 7; |
057ea7c9 HR |
426 | valid_states = ucp[1]; |
427 | } | |
428 | off = 8 + (ucp[7] * 4); | |
429 | } | |
430 | ||
431 | sdev_printk(KERN_INFO, sdev, | |
dcd3a754 | 432 | "%s: port group %02x state %c %s supports %c%c%c%c%c%c%c\n", |
057ea7c9 | 433 | ALUA_DH_NAME, h->group_id, print_alua_state(h->state), |
dcd3a754 | 434 | h->pref ? "preferred" : "non-preferred", |
057ea7c9 HR |
435 | valid_states&TPGS_SUPPORT_TRANSITION?'T':'t', |
436 | valid_states&TPGS_SUPPORT_OFFLINE?'O':'o', | |
69723d17 | 437 | valid_states&TPGS_SUPPORT_LBA_DEPENDENT?'L':'l', |
057ea7c9 HR |
438 | valid_states&TPGS_SUPPORT_UNAVAILABLE?'U':'u', |
439 | valid_states&TPGS_SUPPORT_STANDBY?'S':'s', | |
440 | valid_states&TPGS_SUPPORT_NONOPTIMIZED?'N':'n', | |
441 | valid_states&TPGS_SUPPORT_OPTIMIZED?'A':'a'); | |
442 | ||
69723d17 HR |
443 | switch (h->state) { |
444 | case TPGS_STATE_TRANSITIONING: | |
a8e5a2d5 SS |
445 | if (wait_for_transition) { |
446 | if (time_before(jiffies, expiry)) { | |
447 | /* State transition, retry */ | |
448 | interval += 2000; | |
449 | msleep(interval); | |
450 | goto retry; | |
451 | } | |
452 | err = SCSI_DH_RETRY; | |
453 | } else { | |
454 | err = SCSI_DH_OK; | |
057ea7c9 | 455 | } |
a8e5a2d5 | 456 | |
69723d17 | 457 | /* Transitioning time exceeded, set port to standby */ |
69723d17 HR |
458 | h->state = TPGS_STATE_STANDBY; |
459 | break; | |
460 | case TPGS_STATE_OFFLINE: | |
e47f8976 | 461 | /* Path unusable */ |
69723d17 HR |
462 | err = SCSI_DH_DEV_OFFLINED; |
463 | break; | |
464 | default: | |
465 | /* Useable path if active */ | |
466 | err = SCSI_DH_OK; | |
467 | break; | |
057ea7c9 | 468 | } |
c49c8345 | 469 | kfree(buff); |
057ea7c9 HR |
470 | return err; |
471 | } | |
472 | ||
f2ecf13a HR |
473 | /* |
474 | * alua_stpg - Issue a SET TARGET PORT GROUP command | |
475 | * | |
476 | * Issue a SET TARGET PORT GROUP command and evaluate the | |
b2460756 HR |
477 | * response. Returns SCSI_DH_RETRY per default to trigger |
478 | * a re-evaluation of the target group state or SCSI_DH_OK | |
479 | * if no further action needs to be taken. | |
f2ecf13a | 480 | */ |
b2460756 | 481 | static unsigned alua_stpg(struct scsi_device *sdev, struct alua_dh_data *h) |
f2ecf13a | 482 | { |
b2460756 HR |
483 | int retval; |
484 | struct scsi_sense_hdr sense_hdr; | |
f2ecf13a | 485 | |
b2460756 HR |
486 | if (!(h->tpgs & TPGS_MODE_EXPLICIT)) { |
487 | /* Only implicit ALUA supported, retry */ | |
488 | return SCSI_DH_RETRY; | |
489 | } | |
f2ecf13a | 490 | switch (h->state) { |
b2460756 HR |
491 | case TPGS_STATE_OPTIMIZED: |
492 | return SCSI_DH_OK; | |
f2ecf13a | 493 | case TPGS_STATE_NONOPTIMIZED: |
f2ecf13a HR |
494 | if ((h->flags & ALUA_OPTIMIZE_STPG) && |
495 | !h->pref && | |
496 | (h->tpgs & TPGS_MODE_IMPLICIT)) | |
b2460756 | 497 | return SCSI_DH_OK; |
f2ecf13a HR |
498 | break; |
499 | case TPGS_STATE_STANDBY: | |
500 | case TPGS_STATE_UNAVAILABLE: | |
f2ecf13a HR |
501 | break; |
502 | case TPGS_STATE_OFFLINE: | |
b2460756 | 503 | return SCSI_DH_IO; |
f2ecf13a | 504 | case TPGS_STATE_TRANSITIONING: |
f2ecf13a HR |
505 | break; |
506 | default: | |
b2460756 HR |
507 | sdev_printk(KERN_INFO, sdev, |
508 | "%s: stpg failed, unhandled TPGS state %d", | |
509 | ALUA_DH_NAME, h->state); | |
510 | return SCSI_DH_NOSYS; | |
f2ecf13a | 511 | } |
40bb61a7 | 512 | retval = submit_stpg(sdev, h->group_id, &sense_hdr); |
f2ecf13a | 513 | |
b2460756 | 514 | if (retval) { |
40bb61a7 | 515 | if (!scsi_sense_valid(&sense_hdr)) { |
b2460756 HR |
516 | sdev_printk(KERN_INFO, sdev, |
517 | "%s: stpg failed, result %d", | |
518 | ALUA_DH_NAME, retval); | |
40bb61a7 | 519 | if (driver_byte(retval) == DRIVER_ERROR) |
b2460756 HR |
520 | return SCSI_DH_DEV_TEMP_BUSY; |
521 | } else { | |
522 | sdev_printk(KERN_INFO, h->sdev, "%s: stpg failed\n", | |
523 | ALUA_DH_NAME); | |
524 | scsi_print_sense_hdr(sdev, ALUA_DH_NAME, &sense_hdr); | |
525 | } | |
f2ecf13a | 526 | } |
b2460756 HR |
527 | /* Retry RTPG */ |
528 | return SCSI_DH_RETRY; | |
f2ecf13a HR |
529 | } |
530 | ||
057ea7c9 HR |
531 | /* |
532 | * alua_initialize - Initialize ALUA state | |
533 | * @sdev: the device to be initialized | |
534 | * | |
535 | * For the prep_fn to work correctly we have | |
536 | * to initialize the ALUA state for the device. | |
537 | */ | |
538 | static int alua_initialize(struct scsi_device *sdev, struct alua_dh_data *h) | |
539 | { | |
ad0ea64c | 540 | int err = SCSI_DH_DEV_UNSUPP; |
057ea7c9 | 541 | |
ad0ea64c HR |
542 | h->tpgs = alua_check_tpgs(sdev); |
543 | if (h->tpgs == TPGS_MODE_NONE) | |
057ea7c9 HR |
544 | goto out; |
545 | ||
9b80dcec | 546 | err = alua_check_vpd(sdev, h); |
057ea7c9 HR |
547 | if (err != SCSI_DH_OK) |
548 | goto out; | |
549 | ||
a8e5a2d5 | 550 | err = alua_rtpg(sdev, h, 0); |
057ea7c9 HR |
551 | if (err != SCSI_DH_OK) |
552 | goto out; | |
553 | ||
554 | out: | |
555 | return err; | |
556 | } | |
4335d092 MB |
557 | /* |
558 | * alua_set_params - set/unset the optimize flag | |
559 | * @sdev: device on the path to be activated | |
560 | * params - parameters in the following format | |
561 | * "no_of_params\0param1\0param2\0param3\0...\0" | |
562 | * For example, to set the flag pass the following parameters | |
563 | * from multipath.conf | |
564 | * hardware_handler "2 alua 1" | |
565 | */ | |
566 | static int alua_set_params(struct scsi_device *sdev, const char *params) | |
567 | { | |
ee14c674 | 568 | struct alua_dh_data *h = sdev->handler_data; |
4335d092 MB |
569 | unsigned int optimize = 0, argc; |
570 | const char *p = params; | |
571 | int result = SCSI_DH_OK; | |
572 | ||
573 | if ((sscanf(params, "%u", &argc) != 1) || (argc != 1)) | |
574 | return -EINVAL; | |
575 | ||
576 | while (*p++) | |
577 | ; | |
578 | if ((sscanf(p, "%u", &optimize) != 1) || (optimize > 1)) | |
579 | return -EINVAL; | |
580 | ||
581 | if (optimize) | |
582 | h->flags |= ALUA_OPTIMIZE_STPG; | |
583 | else | |
584 | h->flags &= ~ALUA_OPTIMIZE_STPG; | |
585 | ||
586 | return result; | |
587 | } | |
057ea7c9 | 588 | |
7a3ad392 SS |
589 | static uint optimize_stpg; |
590 | module_param(optimize_stpg, uint, S_IRUGO|S_IWUSR); | |
591 | 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."); | |
592 | ||
057ea7c9 HR |
593 | /* |
594 | * alua_activate - activate a path | |
595 | * @sdev: device on the path to be activated | |
596 | * | |
597 | * We're currently switching the port group to be activated only and | |
598 | * let the array figure out the rest. | |
599 | * There may be other arrays which require us to switch all port groups | |
600 | * based on a certain policy. But until we actually encounter them it | |
601 | * should be okay. | |
602 | */ | |
3ae31f6a CS |
603 | static int alua_activate(struct scsi_device *sdev, |
604 | activate_complete fn, void *data) | |
057ea7c9 | 605 | { |
ee14c674 | 606 | struct alua_dh_data *h = sdev->handler_data; |
057ea7c9 HR |
607 | int err = SCSI_DH_OK; |
608 | ||
a8e5a2d5 | 609 | err = alua_rtpg(sdev, h, 1); |
46ccf6b5 HR |
610 | if (err != SCSI_DH_OK) |
611 | goto out; | |
057ea7c9 | 612 | |
7a3ad392 SS |
613 | if (optimize_stpg) |
614 | h->flags |= ALUA_OPTIMIZE_STPG; | |
615 | ||
b2460756 | 616 | err = alua_stpg(sdev, h); |
dd5cc408 HR |
617 | if (err == SCSI_DH_RETRY) |
618 | err = alua_rtpg(sdev, h, 1); | |
057ea7c9 | 619 | out: |
b2460756 | 620 | if (fn) |
3ae31f6a CS |
621 | fn(data, err); |
622 | return 0; | |
057ea7c9 HR |
623 | } |
624 | ||
625 | /* | |
626 | * alua_prep_fn - request callback | |
627 | * | |
628 | * Fail I/O to all paths not in state | |
629 | * active/optimized or active/non-optimized. | |
630 | */ | |
631 | static int alua_prep_fn(struct scsi_device *sdev, struct request *req) | |
632 | { | |
ee14c674 | 633 | struct alua_dh_data *h = sdev->handler_data; |
057ea7c9 HR |
634 | int ret = BLKPREP_OK; |
635 | ||
69723d17 HR |
636 | if (h->state == TPGS_STATE_TRANSITIONING) |
637 | ret = BLKPREP_DEFER; | |
638 | else if (h->state != TPGS_STATE_OPTIMIZED && | |
639 | h->state != TPGS_STATE_NONOPTIMIZED && | |
640 | h->state != TPGS_STATE_LBA_DEPENDENT) { | |
057ea7c9 HR |
641 | ret = BLKPREP_KILL; |
642 | req->cmd_flags |= REQ_QUIET; | |
643 | } | |
644 | return ret; | |
645 | ||
646 | } | |
647 | ||
057ea7c9 HR |
648 | /* |
649 | * alua_bus_attach - Attach device handler | |
650 | * @sdev: device to be attached to | |
651 | */ | |
ee14c674 | 652 | static int alua_bus_attach(struct scsi_device *sdev) |
057ea7c9 | 653 | { |
057ea7c9 | 654 | struct alua_dh_data *h; |
1d520328 | 655 | int err; |
057ea7c9 | 656 | |
cd37743f | 657 | h = kzalloc(sizeof(*h) , GFP_KERNEL); |
1d520328 | 658 | if (!h) |
ee14c674 | 659 | return -ENOMEM; |
057ea7c9 HR |
660 | h->tpgs = TPGS_MODE_UNINITIALIZED; |
661 | h->state = TPGS_STATE_OPTIMIZED; | |
662 | h->group_id = -1; | |
663 | h->rel_port = -1; | |
96e65865 | 664 | h->sdev = sdev; |
057ea7c9 HR |
665 | |
666 | err = alua_initialize(sdev, h); | |
1d520328 | 667 | if (err != SCSI_DH_OK && err != SCSI_DH_DEV_OFFLINED) |
057ea7c9 HR |
668 | goto failed; |
669 | ||
ee14c674 CH |
670 | sdev->handler_data = h; |
671 | return 0; | |
057ea7c9 | 672 | failed: |
cd37743f | 673 | kfree(h); |
ee14c674 | 674 | return -EINVAL; |
057ea7c9 HR |
675 | } |
676 | ||
677 | /* | |
678 | * alua_bus_detach - Detach device handler | |
679 | * @sdev: device to be detached from | |
680 | */ | |
681 | static void alua_bus_detach(struct scsi_device *sdev) | |
682 | { | |
ee14c674 | 683 | struct alua_dh_data *h = sdev->handler_data; |
057ea7c9 | 684 | |
ee14c674 | 685 | sdev->handler_data = NULL; |
cd37743f | 686 | kfree(h); |
057ea7c9 HR |
687 | } |
688 | ||
1d520328 CH |
689 | static struct scsi_device_handler alua_dh = { |
690 | .name = ALUA_DH_NAME, | |
691 | .module = THIS_MODULE, | |
692 | .attach = alua_bus_attach, | |
693 | .detach = alua_bus_detach, | |
694 | .prep_fn = alua_prep_fn, | |
695 | .check_sense = alua_check_sense, | |
696 | .activate = alua_activate, | |
697 | .set_params = alua_set_params, | |
1d520328 CH |
698 | }; |
699 | ||
057ea7c9 HR |
700 | static int __init alua_init(void) |
701 | { | |
702 | int r; | |
703 | ||
704 | r = scsi_register_device_handler(&alua_dh); | |
705 | if (r != 0) | |
706 | printk(KERN_ERR "%s: Failed to register scsi device handler", | |
707 | ALUA_DH_NAME); | |
708 | return r; | |
709 | } | |
710 | ||
711 | static void __exit alua_exit(void) | |
712 | { | |
713 | scsi_unregister_device_handler(&alua_dh); | |
714 | } | |
715 | ||
716 | module_init(alua_init); | |
717 | module_exit(alua_exit); | |
718 | ||
719 | MODULE_DESCRIPTION("DM Multipath ALUA support"); | |
720 | MODULE_AUTHOR("Hannes Reinecke <hare@suse.de>"); | |
721 | MODULE_LICENSE("GPL"); | |
722 | MODULE_VERSION(ALUA_DH_VER); |