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 | |
43394c67 HR |
67 | static LIST_HEAD(port_group_list); |
68 | static DEFINE_SPINLOCK(port_group_lock); | |
69 | ||
70 | struct alua_port_group { | |
71 | struct kref kref; | |
72 | struct list_head node; | |
0047220c HR |
73 | unsigned char device_id_str[256]; |
74 | int device_id_len; | |
057ea7c9 | 75 | int group_id; |
057ea7c9 HR |
76 | int tpgs; |
77 | int state; | |
dcd3a754 | 78 | int pref; |
4335d092 | 79 | unsigned flags; /* used for optimizing STPG */ |
3588c5a2 | 80 | unsigned char transition_tmo; |
43394c67 HR |
81 | }; |
82 | ||
83 | struct alua_dh_data { | |
84 | struct alua_port_group *pg; | |
85 | int group_id; | |
86 | int rel_port; | |
96e65865 CS |
87 | struct scsi_device *sdev; |
88 | activate_complete callback_fn; | |
89 | void *callback_data; | |
057ea7c9 HR |
90 | }; |
91 | ||
92 | #define ALUA_POLICY_SWITCH_CURRENT 0 | |
93 | #define ALUA_POLICY_SWITCH_ALL 1 | |
94 | ||
96e65865 | 95 | static char print_alua_state(int); |
96e65865 | 96 | |
43394c67 HR |
97 | static void release_port_group(struct kref *kref) |
98 | { | |
99 | struct alua_port_group *pg; | |
100 | ||
101 | pg = container_of(kref, struct alua_port_group, kref); | |
102 | spin_lock(&port_group_lock); | |
103 | list_del(&pg->node); | |
104 | spin_unlock(&port_group_lock); | |
105 | kfree(pg); | |
106 | } | |
107 | ||
057ea7c9 HR |
108 | /* |
109 | * submit_rtpg - Issue a REPORT TARGET GROUP STATES command | |
110 | * @sdev: sdev the command should be sent to | |
111 | */ | |
40bb61a7 HR |
112 | static int submit_rtpg(struct scsi_device *sdev, unsigned char *buff, |
113 | int bufflen, struct scsi_sense_hdr *sshdr, int flags) | |
057ea7c9 | 114 | { |
40bb61a7 HR |
115 | u8 cdb[COMMAND_SIZE(MAINTENANCE_IN)]; |
116 | int req_flags = REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT | | |
117 | REQ_FAILFAST_DRIVER; | |
057ea7c9 HR |
118 | |
119 | /* Prepare the command. */ | |
40bb61a7 HR |
120 | memset(cdb, 0x0, COMMAND_SIZE(MAINTENANCE_IN)); |
121 | cdb[0] = MAINTENANCE_IN; | |
d42ae5f3 | 122 | if (!(flags & ALUA_RTPG_EXT_HDR_UNSUPP)) |
40bb61a7 | 123 | cdb[1] = MI_REPORT_TARGET_PGS | MI_EXT_HDR_PARAM_FMT; |
8e67ce60 | 124 | else |
40bb61a7 HR |
125 | cdb[1] = MI_REPORT_TARGET_PGS; |
126 | put_unaligned_be32(bufflen, &cdb[6]); | |
127 | ||
128 | return scsi_execute_req_flags(sdev, cdb, DMA_FROM_DEVICE, | |
129 | buff, bufflen, sshdr, | |
130 | ALUA_FAILOVER_TIMEOUT * HZ, | |
131 | ALUA_FAILOVER_RETRIES, NULL, req_flags); | |
057ea7c9 HR |
132 | } |
133 | ||
96e65865 | 134 | /* |
b2460756 | 135 | * submit_stpg - Issue a SET TARGET PORT GROUP command |
057ea7c9 HR |
136 | * |
137 | * Currently we're only setting the current target port group state | |
138 | * to 'active/optimized' and let the array firmware figure out | |
139 | * the states of the remaining groups. | |
140 | */ | |
40bb61a7 HR |
141 | static int submit_stpg(struct scsi_device *sdev, int group_id, |
142 | struct scsi_sense_hdr *sshdr) | |
057ea7c9 | 143 | { |
40bb61a7 | 144 | u8 cdb[COMMAND_SIZE(MAINTENANCE_OUT)]; |
b2460756 | 145 | unsigned char stpg_data[8]; |
057ea7c9 | 146 | int stpg_len = 8; |
40bb61a7 HR |
147 | int req_flags = REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT | |
148 | REQ_FAILFAST_DRIVER; | |
057ea7c9 HR |
149 | |
150 | /* Prepare the data buffer */ | |
b2460756 HR |
151 | memset(stpg_data, 0, stpg_len); |
152 | stpg_data[4] = TPGS_STATE_OPTIMIZED & 0x0f; | |
153 | put_unaligned_be16(group_id, &stpg_data[6]); | |
057ea7c9 | 154 | |
057ea7c9 | 155 | /* Prepare the command. */ |
40bb61a7 HR |
156 | memset(cdb, 0x0, COMMAND_SIZE(MAINTENANCE_OUT)); |
157 | cdb[0] = MAINTENANCE_OUT; | |
158 | cdb[1] = MO_SET_TARGET_PGS; | |
159 | put_unaligned_be32(stpg_len, &cdb[6]); | |
160 | ||
161 | return scsi_execute_req_flags(sdev, cdb, DMA_TO_DEVICE, | |
162 | stpg_data, stpg_len, | |
163 | sshdr, ALUA_FAILOVER_TIMEOUT * HZ, | |
164 | ALUA_FAILOVER_RETRIES, NULL, req_flags); | |
057ea7c9 HR |
165 | } |
166 | ||
0047220c HR |
167 | struct alua_port_group *alua_find_get_pg(char *id_str, size_t id_size, |
168 | int group_id) | |
169 | { | |
170 | struct alua_port_group *pg; | |
171 | ||
172 | list_for_each_entry(pg, &port_group_list, node) { | |
173 | if (pg->group_id != group_id) | |
174 | continue; | |
175 | if (pg->device_id_len != id_size) | |
176 | continue; | |
177 | if (strncmp(pg->device_id_str, id_str, id_size)) | |
178 | continue; | |
179 | if (!kref_get_unless_zero(&pg->kref)) | |
180 | continue; | |
181 | return pg; | |
182 | } | |
183 | ||
184 | return NULL; | |
185 | } | |
186 | ||
43394c67 HR |
187 | /* |
188 | * alua_alloc_pg - Allocate a new port_group structure | |
189 | * @sdev: scsi device | |
190 | * @h: alua device_handler data | |
191 | * @group_id: port group id | |
192 | * | |
193 | * Allocate a new port_group structure for a given | |
194 | * device. | |
195 | */ | |
196 | struct alua_port_group *alua_alloc_pg(struct scsi_device *sdev, | |
197 | int group_id, int tpgs) | |
198 | { | |
0047220c | 199 | struct alua_port_group *pg, *tmp_pg; |
43394c67 HR |
200 | |
201 | pg = kzalloc(sizeof(struct alua_port_group), GFP_KERNEL); | |
202 | if (!pg) | |
0047220c | 203 | return ERR_PTR(-ENOMEM); |
43394c67 | 204 | |
0047220c HR |
205 | pg->device_id_len = scsi_vpd_lun_id(sdev, pg->device_id_str, |
206 | sizeof(pg->device_id_str)); | |
207 | if (pg->device_id_len <= 0) { | |
208 | /* | |
209 | * Internal error: TPGS supported but no device | |
210 | * identifcation found. Disable ALUA support. | |
211 | */ | |
212 | kfree(pg); | |
213 | sdev_printk(KERN_INFO, sdev, | |
214 | "%s: No device descriptors found\n", | |
215 | ALUA_DH_NAME); | |
216 | return ERR_PTR(-ENXIO); | |
217 | } | |
43394c67 HR |
218 | pg->group_id = group_id; |
219 | pg->tpgs = tpgs; | |
220 | pg->state = TPGS_STATE_OPTIMIZED; | |
221 | kref_init(&pg->kref); | |
0047220c | 222 | |
43394c67 | 223 | spin_lock(&port_group_lock); |
0047220c HR |
224 | tmp_pg = alua_find_get_pg(pg->device_id_str, pg->device_id_len, |
225 | group_id); | |
226 | if (tmp_pg) { | |
227 | spin_unlock(&port_group_lock); | |
228 | kfree(pg); | |
229 | return tmp_pg; | |
230 | } | |
231 | ||
43394c67 HR |
232 | list_add(&pg->node, &port_group_list); |
233 | spin_unlock(&port_group_lock); | |
234 | ||
235 | return pg; | |
236 | } | |
237 | ||
057ea7c9 | 238 | /* |
d7c48feb | 239 | * alua_check_tpgs - Evaluate TPGS setting |
057ea7c9 HR |
240 | * @sdev: device to be checked |
241 | * | |
d7c48feb | 242 | * Examine the TPGS setting of the sdev to find out if ALUA |
057ea7c9 HR |
243 | * is supported. |
244 | */ | |
ad0ea64c | 245 | static int alua_check_tpgs(struct scsi_device *sdev) |
057ea7c9 | 246 | { |
ad0ea64c | 247 | int tpgs = TPGS_MODE_NONE; |
057ea7c9 | 248 | |
db5a6a60 HR |
249 | /* |
250 | * ALUA support for non-disk devices is fraught with | |
251 | * difficulties, so disable it for now. | |
252 | */ | |
253 | if (sdev->type != TYPE_DISK) { | |
db5a6a60 HR |
254 | sdev_printk(KERN_INFO, sdev, |
255 | "%s: disable for non-disk devices\n", | |
256 | ALUA_DH_NAME); | |
ad0ea64c | 257 | return tpgs; |
db5a6a60 HR |
258 | } |
259 | ||
ad0ea64c HR |
260 | tpgs = scsi_device_tpgs(sdev); |
261 | switch (tpgs) { | |
057ea7c9 HR |
262 | case TPGS_MODE_EXPLICIT|TPGS_MODE_IMPLICIT: |
263 | sdev_printk(KERN_INFO, sdev, | |
264 | "%s: supports implicit and explicit TPGS\n", | |
265 | ALUA_DH_NAME); | |
266 | break; | |
267 | case TPGS_MODE_EXPLICIT: | |
268 | sdev_printk(KERN_INFO, sdev, "%s: supports explicit TPGS\n", | |
269 | ALUA_DH_NAME); | |
270 | break; | |
271 | case TPGS_MODE_IMPLICIT: | |
272 | sdev_printk(KERN_INFO, sdev, "%s: supports implicit TPGS\n", | |
273 | ALUA_DH_NAME); | |
274 | break; | |
6cc05d45 | 275 | case TPGS_MODE_NONE: |
057ea7c9 HR |
276 | sdev_printk(KERN_INFO, sdev, "%s: not supported\n", |
277 | ALUA_DH_NAME); | |
057ea7c9 | 278 | break; |
6cc05d45 HR |
279 | default: |
280 | sdev_printk(KERN_INFO, sdev, | |
281 | "%s: unsupported TPGS setting %d\n", | |
ad0ea64c HR |
282 | ALUA_DH_NAME, tpgs); |
283 | tpgs = TPGS_MODE_NONE; | |
6cc05d45 | 284 | break; |
057ea7c9 HR |
285 | } |
286 | ||
ad0ea64c | 287 | return tpgs; |
057ea7c9 HR |
288 | } |
289 | ||
290 | /* | |
9b80dcec | 291 | * alua_check_vpd - Evaluate INQUIRY vpd page 0x83 |
057ea7c9 HR |
292 | * @sdev: device to be checked |
293 | * | |
294 | * Extract the relative target port and the target port group | |
295 | * descriptor from the list of identificators. | |
296 | */ | |
9b80dcec | 297 | static int alua_check_vpd(struct scsi_device *sdev, struct alua_dh_data *h) |
057ea7c9 | 298 | { |
83ea0e5e | 299 | int rel_port = -1, group_id; |
057ea7c9 | 300 | |
83ea0e5e HR |
301 | group_id = scsi_vpd_tpg_id(sdev, &rel_port); |
302 | if (group_id < 0) { | |
057ea7c9 HR |
303 | /* |
304 | * Internal error; TPGS supported but required | |
305 | * VPD identification descriptors not present. | |
306 | * Disable ALUA support | |
307 | */ | |
308 | sdev_printk(KERN_INFO, sdev, | |
309 | "%s: No target port descriptors found\n", | |
310 | ALUA_DH_NAME); | |
9b80dcec | 311 | return SCSI_DH_DEV_UNSUPP; |
057ea7c9 | 312 | } |
83ea0e5e HR |
313 | h->group_id = group_id; |
314 | ||
9b80dcec | 315 | sdev_printk(KERN_INFO, sdev, |
0047220c | 316 | "%s: port group %x rel port %x\n", |
9b80dcec | 317 | ALUA_DH_NAME, h->group_id, h->rel_port); |
057ea7c9 | 318 | |
9b80dcec | 319 | return 0; |
057ea7c9 HR |
320 | } |
321 | ||
322 | static char print_alua_state(int state) | |
323 | { | |
324 | switch (state) { | |
325 | case TPGS_STATE_OPTIMIZED: | |
326 | return 'A'; | |
327 | case TPGS_STATE_NONOPTIMIZED: | |
328 | return 'N'; | |
329 | case TPGS_STATE_STANDBY: | |
330 | return 'S'; | |
331 | case TPGS_STATE_UNAVAILABLE: | |
332 | return 'U'; | |
69723d17 HR |
333 | case TPGS_STATE_LBA_DEPENDENT: |
334 | return 'L'; | |
057ea7c9 HR |
335 | case TPGS_STATE_OFFLINE: |
336 | return 'O'; | |
337 | case TPGS_STATE_TRANSITIONING: | |
338 | return 'T'; | |
339 | default: | |
340 | return 'X'; | |
341 | } | |
342 | } | |
343 | ||
344 | static int alua_check_sense(struct scsi_device *sdev, | |
345 | struct scsi_sense_hdr *sense_hdr) | |
346 | { | |
347 | switch (sense_hdr->sense_key) { | |
348 | case NOT_READY: | |
349 | if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x0a) | |
350 | /* | |
351 | * LUN Not Accessible - ALUA state transition | |
352 | */ | |
c7dbb627 | 353 | return ADD_TO_MLQUEUE; |
057ea7c9 HR |
354 | break; |
355 | case UNIT_ATTENTION: | |
356 | if (sense_hdr->asc == 0x29 && sense_hdr->ascq == 0x00) | |
357 | /* | |
358 | * Power On, Reset, or Bus Device Reset, just retry. | |
359 | */ | |
c7dbb627 | 360 | return ADD_TO_MLQUEUE; |
c20ee7b5 SS |
361 | if (sense_hdr->asc == 0x29 && sense_hdr->ascq == 0x04) |
362 | /* | |
363 | * Device internal reset | |
364 | */ | |
365 | return ADD_TO_MLQUEUE; | |
410f02d8 MB |
366 | if (sense_hdr->asc == 0x2a && sense_hdr->ascq == 0x01) |
367 | /* | |
368 | * Mode Parameters Changed | |
369 | */ | |
370 | return ADD_TO_MLQUEUE; | |
bf81973a | 371 | if (sense_hdr->asc == 0x2a && sense_hdr->ascq == 0x06) |
057ea7c9 HR |
372 | /* |
373 | * ALUA state changed | |
374 | */ | |
c7dbb627 | 375 | return ADD_TO_MLQUEUE; |
bf81973a | 376 | if (sense_hdr->asc == 0x2a && sense_hdr->ascq == 0x07) |
057ea7c9 HR |
377 | /* |
378 | * Implicit ALUA state transition failed | |
379 | */ | |
c7dbb627 | 380 | return ADD_TO_MLQUEUE; |
bf81973a MB |
381 | if (sense_hdr->asc == 0x3f && sense_hdr->ascq == 0x03) |
382 | /* | |
383 | * Inquiry data has changed | |
384 | */ | |
385 | return ADD_TO_MLQUEUE; | |
386 | if (sense_hdr->asc == 0x3f && sense_hdr->ascq == 0x0e) | |
4d086f6b IH |
387 | /* |
388 | * REPORTED_LUNS_DATA_HAS_CHANGED is reported | |
389 | * when switching controllers on targets like | |
390 | * Intel Multi-Flex. We can just retry. | |
391 | */ | |
392 | return ADD_TO_MLQUEUE; | |
057ea7c9 HR |
393 | break; |
394 | } | |
395 | ||
396 | return SCSI_RETURN_NOT_HANDLED; | |
397 | } | |
398 | ||
057ea7c9 HR |
399 | /* |
400 | * alua_rtpg - Evaluate REPORT TARGET GROUP STATES | |
401 | * @sdev: the device to be evaluated. | |
a8e5a2d5 | 402 | * @wait_for_transition: if nonzero, wait ALUA_FAILOVER_TIMEOUT seconds for device to exit transitioning state |
057ea7c9 HR |
403 | * |
404 | * Evaluate the Target Port Group State. | |
405 | * Returns SCSI_DH_DEV_OFFLINED if the path is | |
25985edc | 406 | * found to be unusable. |
057ea7c9 | 407 | */ |
43394c67 | 408 | static int alua_rtpg(struct scsi_device *sdev, struct alua_port_group *pg, int wait_for_transition) |
057ea7c9 HR |
409 | { |
410 | struct scsi_sense_hdr sense_hdr; | |
c49c8345 HR |
411 | int len, k, off, valid_states = 0, bufflen = ALUA_RTPG_SIZE; |
412 | unsigned char *ucp, *buff; | |
5597cafc | 413 | unsigned err, retval; |
bc97f4bb | 414 | unsigned long expiry, interval = 0; |
3588c5a2 RE |
415 | unsigned int tpg_desc_tbl_off; |
416 | unsigned char orig_transition_tmo; | |
417 | ||
43394c67 | 418 | if (!pg->transition_tmo) |
3588c5a2 RE |
419 | expiry = round_jiffies_up(jiffies + ALUA_FAILOVER_TIMEOUT * HZ); |
420 | else | |
43394c67 | 421 | expiry = round_jiffies_up(jiffies + pg->transition_tmo * HZ); |
057ea7c9 | 422 | |
c49c8345 HR |
423 | buff = kzalloc(bufflen, GFP_KERNEL); |
424 | if (!buff) | |
425 | return SCSI_DH_DEV_TEMP_BUSY; | |
426 | ||
057ea7c9 | 427 | retry: |
43394c67 | 428 | retval = submit_rtpg(sdev, buff, bufflen, &sense_hdr, pg->flags); |
40bb61a7 | 429 | |
5597cafc | 430 | if (retval) { |
40bb61a7 | 431 | if (!scsi_sense_valid(&sense_hdr)) { |
5597cafc HR |
432 | sdev_printk(KERN_INFO, sdev, |
433 | "%s: rtpg failed, result %d\n", | |
434 | ALUA_DH_NAME, retval); | |
c49c8345 | 435 | kfree(buff); |
40bb61a7 | 436 | if (driver_byte(retval) == DRIVER_ERROR) |
5597cafc | 437 | return SCSI_DH_DEV_TEMP_BUSY; |
057ea7c9 | 438 | return SCSI_DH_IO; |
5597cafc | 439 | } |
057ea7c9 | 440 | |
8e67ce60 RE |
441 | /* |
442 | * submit_rtpg() has failed on existing arrays | |
443 | * when requesting extended header info, and | |
444 | * the array doesn't support extended headers, | |
445 | * even though it shouldn't according to T10. | |
446 | * The retry without rtpg_ext_hdr_req set | |
447 | * handles this. | |
448 | */ | |
43394c67 | 449 | if (!(pg->flags & ALUA_RTPG_EXT_HDR_UNSUPP) && |
8e67ce60 RE |
450 | sense_hdr.sense_key == ILLEGAL_REQUEST && |
451 | sense_hdr.asc == 0x24 && sense_hdr.ascq == 0) { | |
43394c67 | 452 | pg->flags |= ALUA_RTPG_EXT_HDR_UNSUPP; |
8e67ce60 RE |
453 | goto retry; |
454 | } | |
e2d817db HR |
455 | /* |
456 | * Retry on ALUA state transition or if any | |
457 | * UNIT ATTENTION occurred. | |
458 | */ | |
459 | if (sense_hdr.sense_key == NOT_READY && | |
460 | sense_hdr.asc == 0x04 && sense_hdr.ascq == 0x0a) | |
461 | err = SCSI_DH_RETRY; | |
462 | else if (sense_hdr.sense_key == UNIT_ATTENTION) | |
463 | err = SCSI_DH_RETRY; | |
464 | if (err == SCSI_DH_RETRY && time_before(jiffies, expiry)) { | |
80bd68d6 HR |
465 | sdev_printk(KERN_ERR, sdev, "%s: rtpg retry\n", |
466 | ALUA_DH_NAME); | |
467 | scsi_print_sense_hdr(sdev, ALUA_DH_NAME, &sense_hdr); | |
057ea7c9 | 468 | goto retry; |
80bd68d6 HR |
469 | } |
470 | sdev_printk(KERN_ERR, sdev, "%s: rtpg failed\n", | |
471 | ALUA_DH_NAME); | |
472 | scsi_print_sense_hdr(sdev, ALUA_DH_NAME, &sense_hdr); | |
c49c8345 | 473 | kfree(buff); |
80bd68d6 | 474 | return SCSI_DH_IO; |
057ea7c9 | 475 | } |
057ea7c9 | 476 | |
c49c8345 | 477 | len = get_unaligned_be32(&buff[0]) + 4; |
057ea7c9 | 478 | |
c49c8345 | 479 | if (len > bufflen) { |
057ea7c9 | 480 | /* Resubmit with the correct length */ |
c49c8345 HR |
481 | kfree(buff); |
482 | bufflen = len; | |
483 | buff = kmalloc(bufflen, GFP_KERNEL); | |
484 | if (!buff) { | |
057ea7c9 | 485 | sdev_printk(KERN_WARNING, sdev, |
cadbd4a5 | 486 | "%s: kmalloc buffer failed\n",__func__); |
057ea7c9 HR |
487 | /* Temporary failure, bypass */ |
488 | return SCSI_DH_DEV_TEMP_BUSY; | |
489 | } | |
490 | goto retry; | |
491 | } | |
492 | ||
43394c67 | 493 | orig_transition_tmo = pg->transition_tmo; |
c49c8345 | 494 | if ((buff[4] & RTPG_FMT_MASK) == RTPG_FMT_EXT_HDR && buff[5] != 0) |
43394c67 | 495 | pg->transition_tmo = buff[5]; |
3588c5a2 | 496 | else |
43394c67 | 497 | pg->transition_tmo = ALUA_FAILOVER_TIMEOUT; |
3588c5a2 | 498 | |
c49c8345 | 499 | if (wait_for_transition && |
43394c67 | 500 | (orig_transition_tmo != pg->transition_tmo)) { |
3588c5a2 RE |
501 | sdev_printk(KERN_INFO, sdev, |
502 | "%s: transition timeout set to %d seconds\n", | |
43394c67 HR |
503 | ALUA_DH_NAME, pg->transition_tmo); |
504 | expiry = jiffies + pg->transition_tmo * HZ; | |
3588c5a2 RE |
505 | } |
506 | ||
c49c8345 | 507 | if ((buff[4] & RTPG_FMT_MASK) == RTPG_FMT_EXT_HDR) |
3588c5a2 RE |
508 | tpg_desc_tbl_off = 8; |
509 | else | |
510 | tpg_desc_tbl_off = 4; | |
511 | ||
c49c8345 | 512 | for (k = tpg_desc_tbl_off, ucp = buff + tpg_desc_tbl_off; |
3588c5a2 RE |
513 | k < len; |
514 | k += off, ucp += off) { | |
515 | ||
43394c67 HR |
516 | if (pg->group_id == get_unaligned_be16(&ucp[2])) { |
517 | pg->state = ucp[0] & 0x0f; | |
518 | pg->pref = ucp[0] >> 7; | |
057ea7c9 HR |
519 | valid_states = ucp[1]; |
520 | } | |
521 | off = 8 + (ucp[7] * 4); | |
522 | } | |
523 | ||
524 | sdev_printk(KERN_INFO, sdev, | |
dcd3a754 | 525 | "%s: port group %02x state %c %s supports %c%c%c%c%c%c%c\n", |
43394c67 HR |
526 | ALUA_DH_NAME, pg->group_id, print_alua_state(pg->state), |
527 | pg->pref ? "preferred" : "non-preferred", | |
057ea7c9 HR |
528 | valid_states&TPGS_SUPPORT_TRANSITION?'T':'t', |
529 | valid_states&TPGS_SUPPORT_OFFLINE?'O':'o', | |
69723d17 | 530 | valid_states&TPGS_SUPPORT_LBA_DEPENDENT?'L':'l', |
057ea7c9 HR |
531 | valid_states&TPGS_SUPPORT_UNAVAILABLE?'U':'u', |
532 | valid_states&TPGS_SUPPORT_STANDBY?'S':'s', | |
533 | valid_states&TPGS_SUPPORT_NONOPTIMIZED?'N':'n', | |
534 | valid_states&TPGS_SUPPORT_OPTIMIZED?'A':'a'); | |
535 | ||
43394c67 | 536 | switch (pg->state) { |
69723d17 | 537 | case TPGS_STATE_TRANSITIONING: |
a8e5a2d5 SS |
538 | if (wait_for_transition) { |
539 | if (time_before(jiffies, expiry)) { | |
540 | /* State transition, retry */ | |
541 | interval += 2000; | |
542 | msleep(interval); | |
543 | goto retry; | |
544 | } | |
545 | err = SCSI_DH_RETRY; | |
546 | } else { | |
547 | err = SCSI_DH_OK; | |
057ea7c9 | 548 | } |
a8e5a2d5 | 549 | |
69723d17 | 550 | /* Transitioning time exceeded, set port to standby */ |
43394c67 | 551 | pg->state = TPGS_STATE_STANDBY; |
69723d17 HR |
552 | break; |
553 | case TPGS_STATE_OFFLINE: | |
e47f8976 | 554 | /* Path unusable */ |
69723d17 HR |
555 | err = SCSI_DH_DEV_OFFLINED; |
556 | break; | |
557 | default: | |
558 | /* Useable path if active */ | |
559 | err = SCSI_DH_OK; | |
560 | break; | |
057ea7c9 | 561 | } |
c49c8345 | 562 | kfree(buff); |
057ea7c9 HR |
563 | return err; |
564 | } | |
565 | ||
f2ecf13a HR |
566 | /* |
567 | * alua_stpg - Issue a SET TARGET PORT GROUP command | |
568 | * | |
569 | * Issue a SET TARGET PORT GROUP command and evaluate the | |
b2460756 HR |
570 | * response. Returns SCSI_DH_RETRY per default to trigger |
571 | * a re-evaluation of the target group state or SCSI_DH_OK | |
572 | * if no further action needs to be taken. | |
f2ecf13a | 573 | */ |
43394c67 | 574 | static unsigned alua_stpg(struct scsi_device *sdev, struct alua_port_group *pg) |
f2ecf13a | 575 | { |
b2460756 HR |
576 | int retval; |
577 | struct scsi_sense_hdr sense_hdr; | |
f2ecf13a | 578 | |
43394c67 | 579 | if (!(pg->tpgs & TPGS_MODE_EXPLICIT)) { |
b2460756 HR |
580 | /* Only implicit ALUA supported, retry */ |
581 | return SCSI_DH_RETRY; | |
582 | } | |
43394c67 | 583 | switch (pg->state) { |
b2460756 HR |
584 | case TPGS_STATE_OPTIMIZED: |
585 | return SCSI_DH_OK; | |
f2ecf13a | 586 | case TPGS_STATE_NONOPTIMIZED: |
43394c67 HR |
587 | if ((pg->flags & ALUA_OPTIMIZE_STPG) && |
588 | !pg->pref && | |
589 | (pg->tpgs & TPGS_MODE_IMPLICIT)) | |
b2460756 | 590 | return SCSI_DH_OK; |
f2ecf13a HR |
591 | break; |
592 | case TPGS_STATE_STANDBY: | |
593 | case TPGS_STATE_UNAVAILABLE: | |
f2ecf13a HR |
594 | break; |
595 | case TPGS_STATE_OFFLINE: | |
b2460756 | 596 | return SCSI_DH_IO; |
f2ecf13a | 597 | case TPGS_STATE_TRANSITIONING: |
f2ecf13a HR |
598 | break; |
599 | default: | |
b2460756 HR |
600 | sdev_printk(KERN_INFO, sdev, |
601 | "%s: stpg failed, unhandled TPGS state %d", | |
43394c67 | 602 | ALUA_DH_NAME, pg->state); |
b2460756 | 603 | return SCSI_DH_NOSYS; |
f2ecf13a | 604 | } |
43394c67 | 605 | retval = submit_stpg(sdev, pg->group_id, &sense_hdr); |
f2ecf13a | 606 | |
b2460756 | 607 | if (retval) { |
40bb61a7 | 608 | if (!scsi_sense_valid(&sense_hdr)) { |
b2460756 HR |
609 | sdev_printk(KERN_INFO, sdev, |
610 | "%s: stpg failed, result %d", | |
611 | ALUA_DH_NAME, retval); | |
40bb61a7 | 612 | if (driver_byte(retval) == DRIVER_ERROR) |
b2460756 HR |
613 | return SCSI_DH_DEV_TEMP_BUSY; |
614 | } else { | |
43394c67 | 615 | sdev_printk(KERN_INFO, sdev, "%s: stpg failed\n", |
b2460756 HR |
616 | ALUA_DH_NAME); |
617 | scsi_print_sense_hdr(sdev, ALUA_DH_NAME, &sense_hdr); | |
618 | } | |
f2ecf13a | 619 | } |
b2460756 HR |
620 | /* Retry RTPG */ |
621 | return SCSI_DH_RETRY; | |
f2ecf13a HR |
622 | } |
623 | ||
057ea7c9 HR |
624 | /* |
625 | * alua_initialize - Initialize ALUA state | |
626 | * @sdev: the device to be initialized | |
627 | * | |
628 | * For the prep_fn to work correctly we have | |
629 | * to initialize the ALUA state for the device. | |
630 | */ | |
631 | static int alua_initialize(struct scsi_device *sdev, struct alua_dh_data *h) | |
632 | { | |
43394c67 | 633 | int err = SCSI_DH_DEV_UNSUPP, tpgs; |
057ea7c9 | 634 | |
43394c67 HR |
635 | tpgs = alua_check_tpgs(sdev); |
636 | if (tpgs == TPGS_MODE_NONE) | |
057ea7c9 HR |
637 | goto out; |
638 | ||
9b80dcec | 639 | err = alua_check_vpd(sdev, h); |
057ea7c9 HR |
640 | if (err != SCSI_DH_OK) |
641 | goto out; | |
642 | ||
43394c67 | 643 | h->pg = alua_alloc_pg(sdev, h->group_id, tpgs); |
0047220c HR |
644 | if (IS_ERR(h->pg)) { |
645 | if (PTR_ERR(h->pg) == -ENOMEM) | |
646 | err = SCSI_DH_NOMEM; | |
057ea7c9 | 647 | goto out; |
43394c67 HR |
648 | } |
649 | kref_get(&h->pg->kref); | |
650 | err = alua_rtpg(sdev, h->pg, 0); | |
651 | kref_put(&h->pg->kref, release_port_group); | |
057ea7c9 HR |
652 | out: |
653 | return err; | |
654 | } | |
4335d092 MB |
655 | /* |
656 | * alua_set_params - set/unset the optimize flag | |
657 | * @sdev: device on the path to be activated | |
658 | * params - parameters in the following format | |
659 | * "no_of_params\0param1\0param2\0param3\0...\0" | |
660 | * For example, to set the flag pass the following parameters | |
661 | * from multipath.conf | |
662 | * hardware_handler "2 alua 1" | |
663 | */ | |
664 | static int alua_set_params(struct scsi_device *sdev, const char *params) | |
665 | { | |
ee14c674 | 666 | struct alua_dh_data *h = sdev->handler_data; |
43394c67 | 667 | struct alua_port_group *pg = NULL; |
4335d092 MB |
668 | unsigned int optimize = 0, argc; |
669 | const char *p = params; | |
670 | int result = SCSI_DH_OK; | |
671 | ||
672 | if ((sscanf(params, "%u", &argc) != 1) || (argc != 1)) | |
673 | return -EINVAL; | |
674 | ||
675 | while (*p++) | |
676 | ; | |
677 | if ((sscanf(p, "%u", &optimize) != 1) || (optimize > 1)) | |
678 | return -EINVAL; | |
679 | ||
43394c67 HR |
680 | pg = h->pg; |
681 | if (!pg) | |
682 | return -ENXIO; | |
683 | ||
4335d092 | 684 | if (optimize) |
43394c67 | 685 | pg->flags |= ALUA_OPTIMIZE_STPG; |
4335d092 | 686 | else |
43394c67 | 687 | pg->flags &= ~ALUA_OPTIMIZE_STPG; |
4335d092 MB |
688 | |
689 | return result; | |
690 | } | |
057ea7c9 | 691 | |
7a3ad392 SS |
692 | static uint optimize_stpg; |
693 | module_param(optimize_stpg, uint, S_IRUGO|S_IWUSR); | |
694 | 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."); | |
695 | ||
057ea7c9 HR |
696 | /* |
697 | * alua_activate - activate a path | |
698 | * @sdev: device on the path to be activated | |
699 | * | |
700 | * We're currently switching the port group to be activated only and | |
701 | * let the array figure out the rest. | |
702 | * There may be other arrays which require us to switch all port groups | |
703 | * based on a certain policy. But until we actually encounter them it | |
704 | * should be okay. | |
705 | */ | |
3ae31f6a CS |
706 | static int alua_activate(struct scsi_device *sdev, |
707 | activate_complete fn, void *data) | |
057ea7c9 | 708 | { |
ee14c674 | 709 | struct alua_dh_data *h = sdev->handler_data; |
057ea7c9 HR |
710 | int err = SCSI_DH_OK; |
711 | ||
43394c67 | 712 | if (!h->pg) |
46ccf6b5 | 713 | goto out; |
057ea7c9 | 714 | |
43394c67 HR |
715 | kref_get(&h->pg->kref); |
716 | ||
7a3ad392 | 717 | if (optimize_stpg) |
43394c67 | 718 | h->pg->flags |= ALUA_OPTIMIZE_STPG; |
7a3ad392 | 719 | |
43394c67 HR |
720 | err = alua_rtpg(sdev, h->pg, 1); |
721 | if (err != SCSI_DH_OK) { | |
722 | kref_put(&h->pg->kref, release_port_group); | |
723 | goto out; | |
724 | } | |
725 | err = alua_stpg(sdev, h->pg); | |
dd5cc408 | 726 | if (err == SCSI_DH_RETRY) |
43394c67 HR |
727 | err = alua_rtpg(sdev, h->pg, 1); |
728 | kref_put(&h->pg->kref, release_port_group); | |
057ea7c9 | 729 | out: |
b2460756 | 730 | if (fn) |
3ae31f6a CS |
731 | fn(data, err); |
732 | return 0; | |
057ea7c9 HR |
733 | } |
734 | ||
735 | /* | |
736 | * alua_prep_fn - request callback | |
737 | * | |
738 | * Fail I/O to all paths not in state | |
739 | * active/optimized or active/non-optimized. | |
740 | */ | |
741 | static int alua_prep_fn(struct scsi_device *sdev, struct request *req) | |
742 | { | |
ee14c674 | 743 | struct alua_dh_data *h = sdev->handler_data; |
43394c67 | 744 | int state; |
057ea7c9 HR |
745 | int ret = BLKPREP_OK; |
746 | ||
43394c67 HR |
747 | if (!h->pg) |
748 | return ret; | |
749 | kref_get(&h->pg->kref); | |
750 | state = h->pg->state; | |
751 | kref_put(&h->pg->kref, release_port_group); | |
752 | if (state == TPGS_STATE_TRANSITIONING) | |
69723d17 | 753 | ret = BLKPREP_DEFER; |
43394c67 HR |
754 | else if (state != TPGS_STATE_OPTIMIZED && |
755 | state != TPGS_STATE_NONOPTIMIZED && | |
756 | state != TPGS_STATE_LBA_DEPENDENT) { | |
057ea7c9 HR |
757 | ret = BLKPREP_KILL; |
758 | req->cmd_flags |= REQ_QUIET; | |
759 | } | |
760 | return ret; | |
761 | ||
762 | } | |
763 | ||
057ea7c9 HR |
764 | /* |
765 | * alua_bus_attach - Attach device handler | |
766 | * @sdev: device to be attached to | |
767 | */ | |
ee14c674 | 768 | static int alua_bus_attach(struct scsi_device *sdev) |
057ea7c9 | 769 | { |
057ea7c9 | 770 | struct alua_dh_data *h; |
43394c67 | 771 | int err, ret = -EINVAL; |
057ea7c9 | 772 | |
cd37743f | 773 | h = kzalloc(sizeof(*h) , GFP_KERNEL); |
1d520328 | 774 | if (!h) |
ee14c674 | 775 | return -ENOMEM; |
43394c67 | 776 | h->pg = NULL; |
057ea7c9 | 777 | h->rel_port = -1; |
96e65865 | 778 | h->sdev = sdev; |
057ea7c9 HR |
779 | |
780 | err = alua_initialize(sdev, h); | |
43394c67 HR |
781 | if (err == SCSI_DH_NOMEM) |
782 | ret = -ENOMEM; | |
1d520328 | 783 | if (err != SCSI_DH_OK && err != SCSI_DH_DEV_OFFLINED) |
057ea7c9 HR |
784 | goto failed; |
785 | ||
ee14c674 CH |
786 | sdev->handler_data = h; |
787 | return 0; | |
057ea7c9 | 788 | failed: |
cd37743f | 789 | kfree(h); |
43394c67 | 790 | return ret; |
057ea7c9 HR |
791 | } |
792 | ||
793 | /* | |
794 | * alua_bus_detach - Detach device handler | |
795 | * @sdev: device to be detached from | |
796 | */ | |
797 | static void alua_bus_detach(struct scsi_device *sdev) | |
798 | { | |
ee14c674 | 799 | struct alua_dh_data *h = sdev->handler_data; |
057ea7c9 | 800 | |
43394c67 HR |
801 | if (h->pg) { |
802 | kref_put(&h->pg->kref, release_port_group); | |
803 | h->pg = NULL; | |
804 | } | |
ee14c674 | 805 | sdev->handler_data = NULL; |
cd37743f | 806 | kfree(h); |
057ea7c9 HR |
807 | } |
808 | ||
1d520328 CH |
809 | static struct scsi_device_handler alua_dh = { |
810 | .name = ALUA_DH_NAME, | |
811 | .module = THIS_MODULE, | |
812 | .attach = alua_bus_attach, | |
813 | .detach = alua_bus_detach, | |
814 | .prep_fn = alua_prep_fn, | |
815 | .check_sense = alua_check_sense, | |
816 | .activate = alua_activate, | |
817 | .set_params = alua_set_params, | |
1d520328 CH |
818 | }; |
819 | ||
057ea7c9 HR |
820 | static int __init alua_init(void) |
821 | { | |
822 | int r; | |
823 | ||
824 | r = scsi_register_device_handler(&alua_dh); | |
825 | if (r != 0) | |
826 | printk(KERN_ERR "%s: Failed to register scsi device handler", | |
827 | ALUA_DH_NAME); | |
828 | return r; | |
829 | } | |
830 | ||
831 | static void __exit alua_exit(void) | |
832 | { | |
833 | scsi_unregister_device_handler(&alua_dh); | |
834 | } | |
835 | ||
836 | module_init(alua_init); | |
837 | module_exit(alua_exit); | |
838 | ||
839 | MODULE_DESCRIPTION("DM Multipath ALUA support"); | |
840 | MODULE_AUTHOR("Hannes Reinecke <hare@suse.de>"); | |
841 | MODULE_LICENSE("GPL"); | |
842 | MODULE_VERSION(ALUA_DH_VER); |