Commit | Line | Data |
---|---|---|
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" | |
e79c82cc | 32 | #define ALUA_DH_VER "2.0" |
057ea7c9 | 33 | |
057ea7c9 HR |
34 | #define TPGS_SUPPORT_NONE 0x00 |
35 | #define TPGS_SUPPORT_OPTIMIZED 0x01 | |
36 | #define TPGS_SUPPORT_NONOPTIMIZED 0x02 | |
37 | #define TPGS_SUPPORT_STANDBY 0x04 | |
38 | #define TPGS_SUPPORT_UNAVAILABLE 0x08 | |
69723d17 | 39 | #define TPGS_SUPPORT_LBA_DEPENDENT 0x10 |
057ea7c9 HR |
40 | #define TPGS_SUPPORT_OFFLINE 0x40 |
41 | #define TPGS_SUPPORT_TRANSITION 0x80 | |
42 | ||
3588c5a2 RE |
43 | #define RTPG_FMT_MASK 0x70 |
44 | #define RTPG_FMT_EXT_HDR 0x10 | |
45 | ||
057ea7c9 HR |
46 | #define TPGS_MODE_UNINITIALIZED -1 |
47 | #define TPGS_MODE_NONE 0x0 | |
48 | #define TPGS_MODE_IMPLICIT 0x1 | |
49 | #define TPGS_MODE_EXPLICIT 0x2 | |
50 | ||
c49c8345 | 51 | #define ALUA_RTPG_SIZE 128 |
3588c5a2 | 52 | #define ALUA_FAILOVER_TIMEOUT 60 |
057ea7c9 | 53 | #define ALUA_FAILOVER_RETRIES 5 |
03197b61 | 54 | #define ALUA_RTPG_DELAY_MSECS 5 |
057ea7c9 | 55 | |
6c4fc044 | 56 | /* device handler flags */ |
03197b61 HR |
57 | #define ALUA_OPTIMIZE_STPG 0x01 |
58 | #define ALUA_RTPG_EXT_HDR_UNSUPP 0x02 | |
00642a1b | 59 | #define ALUA_SYNC_STPG 0x04 |
03197b61 HR |
60 | /* State machine flags */ |
61 | #define ALUA_PG_RUN_RTPG 0x10 | |
62 | #define ALUA_PG_RUN_STPG 0x20 | |
63 | #define ALUA_PG_RUNNING 0x40 | |
4335d092 | 64 | |
aa90f490 HR |
65 | static uint optimize_stpg; |
66 | module_param(optimize_stpg, uint, S_IRUGO|S_IWUSR); | |
67 | 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."); | |
68 | ||
43394c67 HR |
69 | static LIST_HEAD(port_group_list); |
70 | static DEFINE_SPINLOCK(port_group_lock); | |
03197b61 | 71 | static struct workqueue_struct *kaluad_wq; |
00642a1b | 72 | static struct workqueue_struct *kaluad_sync_wq; |
43394c67 HR |
73 | |
74 | struct alua_port_group { | |
75 | struct kref kref; | |
03197b61 | 76 | struct rcu_head rcu; |
43394c67 | 77 | struct list_head node; |
0047220c HR |
78 | unsigned char device_id_str[256]; |
79 | int device_id_len; | |
057ea7c9 | 80 | int group_id; |
057ea7c9 HR |
81 | int tpgs; |
82 | int state; | |
dcd3a754 | 83 | int pref; |
4335d092 | 84 | unsigned flags; /* used for optimizing STPG */ |
3588c5a2 | 85 | unsigned char transition_tmo; |
03197b61 HR |
86 | unsigned long expiry; |
87 | unsigned long interval; | |
88 | struct delayed_work rtpg_work; | |
89 | spinlock_t lock; | |
90 | struct list_head rtpg_list; | |
91 | struct scsi_device *rtpg_sdev; | |
43394c67 HR |
92 | }; |
93 | ||
94 | struct alua_dh_data { | |
95 | struct alua_port_group *pg; | |
96 | int group_id; | |
03197b61 | 97 | spinlock_t pg_lock; |
96e65865 | 98 | struct scsi_device *sdev; |
03197b61 HR |
99 | int init_error; |
100 | struct mutex init_mutex; | |
101 | }; | |
102 | ||
103 | struct alua_queue_data { | |
104 | struct list_head entry; | |
96e65865 CS |
105 | activate_complete callback_fn; |
106 | void *callback_data; | |
057ea7c9 HR |
107 | }; |
108 | ||
109 | #define ALUA_POLICY_SWITCH_CURRENT 0 | |
110 | #define ALUA_POLICY_SWITCH_ALL 1 | |
111 | ||
03197b61 HR |
112 | static void alua_rtpg_work(struct work_struct *work); |
113 | static void alua_rtpg_queue(struct alua_port_group *pg, | |
114 | struct scsi_device *sdev, | |
2b35865e HR |
115 | struct alua_queue_data *qdata, bool force); |
116 | static void alua_check(struct scsi_device *sdev, bool force); | |
96e65865 | 117 | |
43394c67 HR |
118 | static void release_port_group(struct kref *kref) |
119 | { | |
120 | struct alua_port_group *pg; | |
121 | ||
122 | pg = container_of(kref, struct alua_port_group, kref); | |
03197b61 HR |
123 | if (pg->rtpg_sdev) |
124 | flush_delayed_work(&pg->rtpg_work); | |
43394c67 HR |
125 | spin_lock(&port_group_lock); |
126 | list_del(&pg->node); | |
127 | spin_unlock(&port_group_lock); | |
03197b61 | 128 | kfree_rcu(pg, rcu); |
43394c67 HR |
129 | } |
130 | ||
057ea7c9 HR |
131 | /* |
132 | * submit_rtpg - Issue a REPORT TARGET GROUP STATES command | |
133 | * @sdev: sdev the command should be sent to | |
134 | */ | |
40bb61a7 HR |
135 | static int submit_rtpg(struct scsi_device *sdev, unsigned char *buff, |
136 | int bufflen, struct scsi_sense_hdr *sshdr, int flags) | |
057ea7c9 | 137 | { |
40bb61a7 HR |
138 | u8 cdb[COMMAND_SIZE(MAINTENANCE_IN)]; |
139 | int req_flags = REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT | | |
140 | REQ_FAILFAST_DRIVER; | |
057ea7c9 HR |
141 | |
142 | /* Prepare the command. */ | |
40bb61a7 HR |
143 | memset(cdb, 0x0, COMMAND_SIZE(MAINTENANCE_IN)); |
144 | cdb[0] = MAINTENANCE_IN; | |
d42ae5f3 | 145 | if (!(flags & ALUA_RTPG_EXT_HDR_UNSUPP)) |
40bb61a7 | 146 | cdb[1] = MI_REPORT_TARGET_PGS | MI_EXT_HDR_PARAM_FMT; |
8e67ce60 | 147 | else |
40bb61a7 HR |
148 | cdb[1] = MI_REPORT_TARGET_PGS; |
149 | put_unaligned_be32(bufflen, &cdb[6]); | |
150 | ||
151 | return scsi_execute_req_flags(sdev, cdb, DMA_FROM_DEVICE, | |
152 | buff, bufflen, sshdr, | |
153 | ALUA_FAILOVER_TIMEOUT * HZ, | |
154 | ALUA_FAILOVER_RETRIES, NULL, req_flags); | |
057ea7c9 HR |
155 | } |
156 | ||
96e65865 | 157 | /* |
b2460756 | 158 | * submit_stpg - Issue a SET TARGET PORT GROUP command |
057ea7c9 HR |
159 | * |
160 | * Currently we're only setting the current target port group state | |
161 | * to 'active/optimized' and let the array firmware figure out | |
162 | * the states of the remaining groups. | |
163 | */ | |
40bb61a7 HR |
164 | static int submit_stpg(struct scsi_device *sdev, int group_id, |
165 | struct scsi_sense_hdr *sshdr) | |
057ea7c9 | 166 | { |
40bb61a7 | 167 | u8 cdb[COMMAND_SIZE(MAINTENANCE_OUT)]; |
b2460756 | 168 | unsigned char stpg_data[8]; |
057ea7c9 | 169 | int stpg_len = 8; |
40bb61a7 HR |
170 | int req_flags = REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT | |
171 | REQ_FAILFAST_DRIVER; | |
057ea7c9 HR |
172 | |
173 | /* Prepare the data buffer */ | |
b2460756 | 174 | memset(stpg_data, 0, stpg_len); |
5115fc7e | 175 | stpg_data[4] = SCSI_ACCESS_STATE_OPTIMAL; |
b2460756 | 176 | put_unaligned_be16(group_id, &stpg_data[6]); |
057ea7c9 | 177 | |
057ea7c9 | 178 | /* Prepare the command. */ |
40bb61a7 HR |
179 | memset(cdb, 0x0, COMMAND_SIZE(MAINTENANCE_OUT)); |
180 | cdb[0] = MAINTENANCE_OUT; | |
181 | cdb[1] = MO_SET_TARGET_PGS; | |
182 | put_unaligned_be32(stpg_len, &cdb[6]); | |
183 | ||
184 | return scsi_execute_req_flags(sdev, cdb, DMA_TO_DEVICE, | |
185 | stpg_data, stpg_len, | |
186 | sshdr, ALUA_FAILOVER_TIMEOUT * HZ, | |
187 | ALUA_FAILOVER_RETRIES, NULL, req_flags); | |
057ea7c9 HR |
188 | } |
189 | ||
0047220c HR |
190 | struct alua_port_group *alua_find_get_pg(char *id_str, size_t id_size, |
191 | int group_id) | |
192 | { | |
193 | struct alua_port_group *pg; | |
194 | ||
195 | list_for_each_entry(pg, &port_group_list, node) { | |
196 | if (pg->group_id != group_id) | |
197 | continue; | |
198 | if (pg->device_id_len != id_size) | |
199 | continue; | |
200 | if (strncmp(pg->device_id_str, id_str, id_size)) | |
201 | continue; | |
202 | if (!kref_get_unless_zero(&pg->kref)) | |
203 | continue; | |
204 | return pg; | |
205 | } | |
206 | ||
207 | return NULL; | |
208 | } | |
209 | ||
43394c67 HR |
210 | /* |
211 | * alua_alloc_pg - Allocate a new port_group structure | |
212 | * @sdev: scsi device | |
213 | * @h: alua device_handler data | |
214 | * @group_id: port group id | |
215 | * | |
216 | * Allocate a new port_group structure for a given | |
217 | * device. | |
218 | */ | |
219 | struct alua_port_group *alua_alloc_pg(struct scsi_device *sdev, | |
220 | int group_id, int tpgs) | |
221 | { | |
0047220c | 222 | struct alua_port_group *pg, *tmp_pg; |
43394c67 HR |
223 | |
224 | pg = kzalloc(sizeof(struct alua_port_group), GFP_KERNEL); | |
225 | if (!pg) | |
0047220c | 226 | return ERR_PTR(-ENOMEM); |
43394c67 | 227 | |
0047220c HR |
228 | pg->device_id_len = scsi_vpd_lun_id(sdev, pg->device_id_str, |
229 | sizeof(pg->device_id_str)); | |
230 | if (pg->device_id_len <= 0) { | |
231 | /* | |
232 | * Internal error: TPGS supported but no device | |
233 | * identifcation found. Disable ALUA support. | |
234 | */ | |
235 | kfree(pg); | |
236 | sdev_printk(KERN_INFO, sdev, | |
237 | "%s: No device descriptors found\n", | |
238 | ALUA_DH_NAME); | |
239 | return ERR_PTR(-ENXIO); | |
240 | } | |
43394c67 HR |
241 | pg->group_id = group_id; |
242 | pg->tpgs = tpgs; | |
5115fc7e | 243 | pg->state = SCSI_ACCESS_STATE_OPTIMAL; |
aa90f490 HR |
244 | if (optimize_stpg) |
245 | pg->flags |= ALUA_OPTIMIZE_STPG; | |
43394c67 | 246 | kref_init(&pg->kref); |
03197b61 HR |
247 | INIT_DELAYED_WORK(&pg->rtpg_work, alua_rtpg_work); |
248 | INIT_LIST_HEAD(&pg->rtpg_list); | |
249 | INIT_LIST_HEAD(&pg->node); | |
250 | spin_lock_init(&pg->lock); | |
0047220c | 251 | |
43394c67 | 252 | spin_lock(&port_group_lock); |
0047220c HR |
253 | tmp_pg = alua_find_get_pg(pg->device_id_str, pg->device_id_len, |
254 | group_id); | |
255 | if (tmp_pg) { | |
256 | spin_unlock(&port_group_lock); | |
257 | kfree(pg); | |
258 | return tmp_pg; | |
259 | } | |
260 | ||
43394c67 HR |
261 | list_add(&pg->node, &port_group_list); |
262 | spin_unlock(&port_group_lock); | |
263 | ||
264 | return pg; | |
265 | } | |
266 | ||
057ea7c9 | 267 | /* |
d7c48feb | 268 | * alua_check_tpgs - Evaluate TPGS setting |
057ea7c9 HR |
269 | * @sdev: device to be checked |
270 | * | |
d7c48feb | 271 | * Examine the TPGS setting of the sdev to find out if ALUA |
057ea7c9 HR |
272 | * is supported. |
273 | */ | |
ad0ea64c | 274 | static int alua_check_tpgs(struct scsi_device *sdev) |
057ea7c9 | 275 | { |
ad0ea64c | 276 | int tpgs = TPGS_MODE_NONE; |
057ea7c9 | 277 | |
db5a6a60 HR |
278 | /* |
279 | * ALUA support for non-disk devices is fraught with | |
280 | * difficulties, so disable it for now. | |
281 | */ | |
282 | if (sdev->type != TYPE_DISK) { | |
db5a6a60 HR |
283 | sdev_printk(KERN_INFO, sdev, |
284 | "%s: disable for non-disk devices\n", | |
285 | ALUA_DH_NAME); | |
ad0ea64c | 286 | return tpgs; |
db5a6a60 HR |
287 | } |
288 | ||
ad0ea64c HR |
289 | tpgs = scsi_device_tpgs(sdev); |
290 | switch (tpgs) { | |
057ea7c9 HR |
291 | case TPGS_MODE_EXPLICIT|TPGS_MODE_IMPLICIT: |
292 | sdev_printk(KERN_INFO, sdev, | |
293 | "%s: supports implicit and explicit TPGS\n", | |
294 | ALUA_DH_NAME); | |
295 | break; | |
296 | case TPGS_MODE_EXPLICIT: | |
297 | sdev_printk(KERN_INFO, sdev, "%s: supports explicit TPGS\n", | |
298 | ALUA_DH_NAME); | |
299 | break; | |
300 | case TPGS_MODE_IMPLICIT: | |
301 | sdev_printk(KERN_INFO, sdev, "%s: supports implicit TPGS\n", | |
302 | ALUA_DH_NAME); | |
303 | break; | |
6cc05d45 | 304 | case TPGS_MODE_NONE: |
057ea7c9 HR |
305 | sdev_printk(KERN_INFO, sdev, "%s: not supported\n", |
306 | ALUA_DH_NAME); | |
057ea7c9 | 307 | break; |
6cc05d45 HR |
308 | default: |
309 | sdev_printk(KERN_INFO, sdev, | |
310 | "%s: unsupported TPGS setting %d\n", | |
ad0ea64c HR |
311 | ALUA_DH_NAME, tpgs); |
312 | tpgs = TPGS_MODE_NONE; | |
6cc05d45 | 313 | break; |
057ea7c9 HR |
314 | } |
315 | ||
ad0ea64c | 316 | return tpgs; |
057ea7c9 HR |
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 | */ | |
a4253fde HR |
326 | static int alua_check_vpd(struct scsi_device *sdev, struct alua_dh_data *h, |
327 | int tpgs) | |
057ea7c9 | 328 | { |
83ea0e5e | 329 | int rel_port = -1, group_id; |
03197b61 | 330 | struct alua_port_group *pg, *old_pg = NULL; |
057ea7c9 | 331 | |
83ea0e5e HR |
332 | group_id = scsi_vpd_tpg_id(sdev, &rel_port); |
333 | if (group_id < 0) { | |
057ea7c9 HR |
334 | /* |
335 | * Internal error; TPGS supported but required | |
336 | * VPD identification descriptors not present. | |
337 | * Disable ALUA support | |
338 | */ | |
339 | sdev_printk(KERN_INFO, sdev, | |
340 | "%s: No target port descriptors found\n", | |
341 | ALUA_DH_NAME); | |
9b80dcec | 342 | return SCSI_DH_DEV_UNSUPP; |
057ea7c9 | 343 | } |
a4253fde | 344 | |
03197b61 HR |
345 | pg = alua_alloc_pg(sdev, group_id, tpgs); |
346 | if (IS_ERR(pg)) { | |
347 | if (PTR_ERR(pg) == -ENOMEM) | |
a4253fde HR |
348 | return SCSI_DH_NOMEM; |
349 | return SCSI_DH_DEV_UNSUPP; | |
350 | } | |
9b80dcec | 351 | sdev_printk(KERN_INFO, sdev, |
a4253fde | 352 | "%s: device %s port group %x rel port %x\n", |
03197b61 HR |
353 | ALUA_DH_NAME, pg->device_id_str, group_id, rel_port); |
354 | ||
355 | /* Check for existing port group references */ | |
356 | spin_lock(&h->pg_lock); | |
357 | old_pg = h->pg; | |
358 | if (old_pg != pg) { | |
359 | /* port group has changed. Update to new port group */ | |
360 | rcu_assign_pointer(h->pg, pg); | |
361 | } | |
851cde99 HR |
362 | if (sdev->synchronous_alua) |
363 | pg->flags |= ALUA_SYNC_STPG; | |
2b35865e | 364 | alua_rtpg_queue(h->pg, sdev, NULL, true); |
03197b61 HR |
365 | spin_unlock(&h->pg_lock); |
366 | ||
367 | if (old_pg) | |
368 | kref_put(&old_pg->kref, release_port_group); | |
057ea7c9 | 369 | |
03197b61 | 370 | return SCSI_DH_OK; |
057ea7c9 HR |
371 | } |
372 | ||
5115fc7e | 373 | static char print_alua_state(unsigned char state) |
057ea7c9 HR |
374 | { |
375 | switch (state) { | |
5115fc7e | 376 | case SCSI_ACCESS_STATE_OPTIMAL: |
057ea7c9 | 377 | return 'A'; |
5115fc7e | 378 | case SCSI_ACCESS_STATE_ACTIVE: |
057ea7c9 | 379 | return 'N'; |
5115fc7e | 380 | case SCSI_ACCESS_STATE_STANDBY: |
057ea7c9 | 381 | return 'S'; |
5115fc7e | 382 | case SCSI_ACCESS_STATE_UNAVAILABLE: |
057ea7c9 | 383 | return 'U'; |
5115fc7e | 384 | case SCSI_ACCESS_STATE_LBA: |
69723d17 | 385 | return 'L'; |
5115fc7e | 386 | case SCSI_ACCESS_STATE_OFFLINE: |
057ea7c9 | 387 | return 'O'; |
5115fc7e | 388 | case SCSI_ACCESS_STATE_TRANSITIONING: |
057ea7c9 HR |
389 | return 'T'; |
390 | default: | |
391 | return 'X'; | |
392 | } | |
393 | } | |
394 | ||
395 | static int alua_check_sense(struct scsi_device *sdev, | |
396 | struct scsi_sense_hdr *sense_hdr) | |
397 | { | |
398 | switch (sense_hdr->sense_key) { | |
399 | case NOT_READY: | |
2b35865e | 400 | if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x0a) { |
057ea7c9 HR |
401 | /* |
402 | * LUN Not Accessible - ALUA state transition | |
403 | */ | |
2b35865e HR |
404 | alua_check(sdev, false); |
405 | return NEEDS_RETRY; | |
406 | } | |
057ea7c9 HR |
407 | break; |
408 | case UNIT_ATTENTION: | |
2b35865e | 409 | if (sense_hdr->asc == 0x29 && sense_hdr->ascq == 0x00) { |
057ea7c9 | 410 | /* |
2b35865e HR |
411 | * Power On, Reset, or Bus Device Reset. |
412 | * Might have obscured a state transition, | |
413 | * so schedule a recheck. | |
057ea7c9 | 414 | */ |
2b35865e | 415 | alua_check(sdev, true); |
c7dbb627 | 416 | return ADD_TO_MLQUEUE; |
2b35865e | 417 | } |
c20ee7b5 SS |
418 | if (sense_hdr->asc == 0x29 && sense_hdr->ascq == 0x04) |
419 | /* | |
420 | * Device internal reset | |
421 | */ | |
422 | return ADD_TO_MLQUEUE; | |
410f02d8 MB |
423 | if (sense_hdr->asc == 0x2a && sense_hdr->ascq == 0x01) |
424 | /* | |
425 | * Mode Parameters Changed | |
426 | */ | |
427 | return ADD_TO_MLQUEUE; | |
2b35865e | 428 | if (sense_hdr->asc == 0x2a && sense_hdr->ascq == 0x06) { |
057ea7c9 HR |
429 | /* |
430 | * ALUA state changed | |
431 | */ | |
2b35865e | 432 | alua_check(sdev, true); |
c7dbb627 | 433 | return ADD_TO_MLQUEUE; |
2b35865e HR |
434 | } |
435 | if (sense_hdr->asc == 0x2a && sense_hdr->ascq == 0x07) { | |
057ea7c9 HR |
436 | /* |
437 | * Implicit ALUA state transition failed | |
438 | */ | |
2b35865e | 439 | alua_check(sdev, true); |
c7dbb627 | 440 | return ADD_TO_MLQUEUE; |
2b35865e | 441 | } |
bf81973a MB |
442 | if (sense_hdr->asc == 0x3f && sense_hdr->ascq == 0x03) |
443 | /* | |
444 | * Inquiry data has changed | |
445 | */ | |
446 | return ADD_TO_MLQUEUE; | |
447 | if (sense_hdr->asc == 0x3f && sense_hdr->ascq == 0x0e) | |
4d086f6b IH |
448 | /* |
449 | * REPORTED_LUNS_DATA_HAS_CHANGED is reported | |
450 | * when switching controllers on targets like | |
451 | * Intel Multi-Flex. We can just retry. | |
452 | */ | |
453 | return ADD_TO_MLQUEUE; | |
057ea7c9 HR |
454 | break; |
455 | } | |
456 | ||
457 | return SCSI_RETURN_NOT_HANDLED; | |
458 | } | |
459 | ||
9d2c3039 HR |
460 | /* |
461 | * alua_tur - Send a TEST UNIT READY | |
462 | * @sdev: device to which the TEST UNIT READY command should be send | |
463 | * | |
464 | * Send a TEST UNIT READY to @sdev to figure out the device state | |
465 | * Returns SCSI_DH_RETRY if the sense code is NOT READY/ALUA TRANSITIONING, | |
466 | * SCSI_DH_OK if no error occurred, and SCSI_DH_IO otherwise. | |
467 | */ | |
468 | static int alua_tur(struct scsi_device *sdev) | |
469 | { | |
470 | struct scsi_sense_hdr sense_hdr; | |
471 | int retval; | |
472 | ||
473 | retval = scsi_test_unit_ready(sdev, ALUA_FAILOVER_TIMEOUT * HZ, | |
474 | ALUA_FAILOVER_RETRIES, &sense_hdr); | |
475 | if (sense_hdr.sense_key == NOT_READY && | |
476 | sense_hdr.asc == 0x04 && sense_hdr.ascq == 0x0a) | |
477 | return SCSI_DH_RETRY; | |
478 | else if (retval) | |
479 | return SCSI_DH_IO; | |
480 | else | |
481 | return SCSI_DH_OK; | |
482 | } | |
483 | ||
057ea7c9 HR |
484 | /* |
485 | * alua_rtpg - Evaluate REPORT TARGET GROUP STATES | |
486 | * @sdev: the device to be evaluated. | |
487 | * | |
488 | * Evaluate the Target Port Group State. | |
489 | * Returns SCSI_DH_DEV_OFFLINED if the path is | |
25985edc | 490 | * found to be unusable. |
057ea7c9 | 491 | */ |
28261402 | 492 | static int alua_rtpg(struct scsi_device *sdev, struct alua_port_group *pg) |
057ea7c9 HR |
493 | { |
494 | struct scsi_sense_hdr sense_hdr; | |
c57168a1 | 495 | struct alua_port_group *tmp_pg; |
c49c8345 | 496 | int len, k, off, valid_states = 0, bufflen = ALUA_RTPG_SIZE; |
c57168a1 | 497 | unsigned char *desc, *buff; |
5597cafc | 498 | unsigned err, retval; |
3588c5a2 RE |
499 | unsigned int tpg_desc_tbl_off; |
500 | unsigned char orig_transition_tmo; | |
c57168a1 | 501 | unsigned long flags; |
3588c5a2 | 502 | |
03197b61 HR |
503 | if (!pg->expiry) { |
504 | unsigned long transition_tmo = ALUA_FAILOVER_TIMEOUT * HZ; | |
505 | ||
506 | if (pg->transition_tmo) | |
507 | transition_tmo = pg->transition_tmo * HZ; | |
508 | ||
509 | pg->expiry = round_jiffies_up(jiffies + transition_tmo); | |
510 | } | |
057ea7c9 | 511 | |
c49c8345 HR |
512 | buff = kzalloc(bufflen, GFP_KERNEL); |
513 | if (!buff) | |
514 | return SCSI_DH_DEV_TEMP_BUSY; | |
515 | ||
057ea7c9 | 516 | retry: |
43394c67 | 517 | retval = submit_rtpg(sdev, buff, bufflen, &sense_hdr, pg->flags); |
40bb61a7 | 518 | |
5597cafc | 519 | if (retval) { |
40bb61a7 | 520 | if (!scsi_sense_valid(&sense_hdr)) { |
5597cafc HR |
521 | sdev_printk(KERN_INFO, sdev, |
522 | "%s: rtpg failed, result %d\n", | |
523 | ALUA_DH_NAME, retval); | |
c49c8345 | 524 | kfree(buff); |
40bb61a7 | 525 | if (driver_byte(retval) == DRIVER_ERROR) |
5597cafc | 526 | return SCSI_DH_DEV_TEMP_BUSY; |
057ea7c9 | 527 | return SCSI_DH_IO; |
5597cafc | 528 | } |
057ea7c9 | 529 | |
8e67ce60 RE |
530 | /* |
531 | * submit_rtpg() has failed on existing arrays | |
532 | * when requesting extended header info, and | |
533 | * the array doesn't support extended headers, | |
534 | * even though it shouldn't according to T10. | |
535 | * The retry without rtpg_ext_hdr_req set | |
536 | * handles this. | |
537 | */ | |
43394c67 | 538 | if (!(pg->flags & ALUA_RTPG_EXT_HDR_UNSUPP) && |
8e67ce60 RE |
539 | sense_hdr.sense_key == ILLEGAL_REQUEST && |
540 | sense_hdr.asc == 0x24 && sense_hdr.ascq == 0) { | |
43394c67 | 541 | pg->flags |= ALUA_RTPG_EXT_HDR_UNSUPP; |
8e67ce60 RE |
542 | goto retry; |
543 | } | |
e2d817db HR |
544 | /* |
545 | * Retry on ALUA state transition or if any | |
546 | * UNIT ATTENTION occurred. | |
547 | */ | |
548 | if (sense_hdr.sense_key == NOT_READY && | |
549 | sense_hdr.asc == 0x04 && sense_hdr.ascq == 0x0a) | |
550 | err = SCSI_DH_RETRY; | |
551 | else if (sense_hdr.sense_key == UNIT_ATTENTION) | |
552 | err = SCSI_DH_RETRY; | |
03197b61 HR |
553 | if (err == SCSI_DH_RETRY && |
554 | pg->expiry != 0 && time_before(jiffies, pg->expiry)) { | |
80bd68d6 HR |
555 | sdev_printk(KERN_ERR, sdev, "%s: rtpg retry\n", |
556 | ALUA_DH_NAME); | |
557 | scsi_print_sense_hdr(sdev, ALUA_DH_NAME, &sense_hdr); | |
03197b61 | 558 | return err; |
80bd68d6 HR |
559 | } |
560 | sdev_printk(KERN_ERR, sdev, "%s: rtpg failed\n", | |
561 | ALUA_DH_NAME); | |
562 | scsi_print_sense_hdr(sdev, ALUA_DH_NAME, &sense_hdr); | |
c49c8345 | 563 | kfree(buff); |
03197b61 | 564 | pg->expiry = 0; |
80bd68d6 | 565 | return SCSI_DH_IO; |
057ea7c9 | 566 | } |
057ea7c9 | 567 | |
c49c8345 | 568 | len = get_unaligned_be32(&buff[0]) + 4; |
057ea7c9 | 569 | |
c49c8345 | 570 | if (len > bufflen) { |
057ea7c9 | 571 | /* Resubmit with the correct length */ |
c49c8345 HR |
572 | kfree(buff); |
573 | bufflen = len; | |
574 | buff = kmalloc(bufflen, GFP_KERNEL); | |
575 | if (!buff) { | |
057ea7c9 | 576 | sdev_printk(KERN_WARNING, sdev, |
cadbd4a5 | 577 | "%s: kmalloc buffer failed\n",__func__); |
057ea7c9 | 578 | /* Temporary failure, bypass */ |
03197b61 | 579 | pg->expiry = 0; |
057ea7c9 HR |
580 | return SCSI_DH_DEV_TEMP_BUSY; |
581 | } | |
582 | goto retry; | |
583 | } | |
584 | ||
43394c67 | 585 | orig_transition_tmo = pg->transition_tmo; |
c49c8345 | 586 | if ((buff[4] & RTPG_FMT_MASK) == RTPG_FMT_EXT_HDR && buff[5] != 0) |
43394c67 | 587 | pg->transition_tmo = buff[5]; |
3588c5a2 | 588 | else |
43394c67 | 589 | pg->transition_tmo = ALUA_FAILOVER_TIMEOUT; |
3588c5a2 | 590 | |
28261402 | 591 | if (orig_transition_tmo != pg->transition_tmo) { |
3588c5a2 RE |
592 | sdev_printk(KERN_INFO, sdev, |
593 | "%s: transition timeout set to %d seconds\n", | |
43394c67 | 594 | ALUA_DH_NAME, pg->transition_tmo); |
03197b61 | 595 | pg->expiry = jiffies + pg->transition_tmo * HZ; |
3588c5a2 RE |
596 | } |
597 | ||
c49c8345 | 598 | if ((buff[4] & RTPG_FMT_MASK) == RTPG_FMT_EXT_HDR) |
3588c5a2 RE |
599 | tpg_desc_tbl_off = 8; |
600 | else | |
601 | tpg_desc_tbl_off = 4; | |
602 | ||
c57168a1 | 603 | for (k = tpg_desc_tbl_off, desc = buff + tpg_desc_tbl_off; |
3588c5a2 | 604 | k < len; |
c57168a1 HR |
605 | k += off, desc += off) { |
606 | u16 group_id = get_unaligned_be16(&desc[2]); | |
607 | ||
608 | spin_lock_irqsave(&port_group_lock, flags); | |
609 | tmp_pg = alua_find_get_pg(pg->device_id_str, pg->device_id_len, | |
610 | group_id); | |
611 | spin_unlock_irqrestore(&port_group_lock, flags); | |
612 | if (tmp_pg) { | |
613 | if (spin_trylock_irqsave(&tmp_pg->lock, flags)) { | |
614 | if ((tmp_pg == pg) || | |
615 | !(tmp_pg->flags & ALUA_PG_RUNNING)) { | |
616 | tmp_pg->state = desc[0] & 0x0f; | |
617 | tmp_pg->pref = desc[0] >> 7; | |
618 | } | |
619 | if (tmp_pg == pg) | |
620 | valid_states = desc[1]; | |
621 | spin_unlock_irqrestore(&tmp_pg->lock, flags); | |
622 | } | |
623 | kref_put(&tmp_pg->kref, release_port_group); | |
057ea7c9 | 624 | } |
c57168a1 | 625 | off = 8 + (desc[7] * 4); |
057ea7c9 HR |
626 | } |
627 | ||
c57168a1 | 628 | spin_lock_irqsave(&pg->lock, flags); |
057ea7c9 | 629 | sdev_printk(KERN_INFO, sdev, |
dcd3a754 | 630 | "%s: port group %02x state %c %s supports %c%c%c%c%c%c%c\n", |
43394c67 HR |
631 | ALUA_DH_NAME, pg->group_id, print_alua_state(pg->state), |
632 | pg->pref ? "preferred" : "non-preferred", | |
057ea7c9 HR |
633 | valid_states&TPGS_SUPPORT_TRANSITION?'T':'t', |
634 | valid_states&TPGS_SUPPORT_OFFLINE?'O':'o', | |
69723d17 | 635 | valid_states&TPGS_SUPPORT_LBA_DEPENDENT?'L':'l', |
057ea7c9 HR |
636 | valid_states&TPGS_SUPPORT_UNAVAILABLE?'U':'u', |
637 | valid_states&TPGS_SUPPORT_STANDBY?'S':'s', | |
638 | valid_states&TPGS_SUPPORT_NONOPTIMIZED?'N':'n', | |
639 | valid_states&TPGS_SUPPORT_OPTIMIZED?'A':'a'); | |
640 | ||
43394c67 | 641 | switch (pg->state) { |
5115fc7e | 642 | case SCSI_ACCESS_STATE_TRANSITIONING: |
03197b61 | 643 | if (time_before(jiffies, pg->expiry)) { |
28261402 | 644 | /* State transition, retry */ |
03197b61 HR |
645 | pg->interval = 2; |
646 | err = SCSI_DH_RETRY; | |
647 | } else { | |
648 | /* Transitioning time exceeded, set port to standby */ | |
649 | err = SCSI_DH_IO; | |
5115fc7e | 650 | pg->state = SCSI_ACCESS_STATE_STANDBY; |
03197b61 | 651 | pg->expiry = 0; |
057ea7c9 | 652 | } |
69723d17 | 653 | break; |
5115fc7e | 654 | case SCSI_ACCESS_STATE_OFFLINE: |
e47f8976 | 655 | /* Path unusable */ |
69723d17 | 656 | err = SCSI_DH_DEV_OFFLINED; |
03197b61 | 657 | pg->expiry = 0; |
69723d17 HR |
658 | break; |
659 | default: | |
660 | /* Useable path if active */ | |
661 | err = SCSI_DH_OK; | |
03197b61 | 662 | pg->expiry = 0; |
69723d17 | 663 | break; |
057ea7c9 | 664 | } |
c57168a1 | 665 | spin_unlock_irqrestore(&pg->lock, flags); |
c49c8345 | 666 | kfree(buff); |
057ea7c9 HR |
667 | return err; |
668 | } | |
669 | ||
f2ecf13a HR |
670 | /* |
671 | * alua_stpg - Issue a SET TARGET PORT GROUP command | |
672 | * | |
673 | * Issue a SET TARGET PORT GROUP command and evaluate the | |
b2460756 HR |
674 | * response. Returns SCSI_DH_RETRY per default to trigger |
675 | * a re-evaluation of the target group state or SCSI_DH_OK | |
676 | * if no further action needs to be taken. | |
f2ecf13a | 677 | */ |
43394c67 | 678 | static unsigned alua_stpg(struct scsi_device *sdev, struct alua_port_group *pg) |
f2ecf13a | 679 | { |
b2460756 HR |
680 | int retval; |
681 | struct scsi_sense_hdr sense_hdr; | |
f2ecf13a | 682 | |
43394c67 | 683 | if (!(pg->tpgs & TPGS_MODE_EXPLICIT)) { |
b2460756 HR |
684 | /* Only implicit ALUA supported, retry */ |
685 | return SCSI_DH_RETRY; | |
686 | } | |
43394c67 | 687 | switch (pg->state) { |
5115fc7e | 688 | case SCSI_ACCESS_STATE_OPTIMAL: |
b2460756 | 689 | return SCSI_DH_OK; |
5115fc7e | 690 | case SCSI_ACCESS_STATE_ACTIVE: |
43394c67 HR |
691 | if ((pg->flags & ALUA_OPTIMIZE_STPG) && |
692 | !pg->pref && | |
693 | (pg->tpgs & TPGS_MODE_IMPLICIT)) | |
b2460756 | 694 | return SCSI_DH_OK; |
f2ecf13a | 695 | break; |
5115fc7e HR |
696 | case SCSI_ACCESS_STATE_STANDBY: |
697 | case SCSI_ACCESS_STATE_UNAVAILABLE: | |
f2ecf13a | 698 | break; |
5115fc7e | 699 | case SCSI_ACCESS_STATE_OFFLINE: |
b2460756 | 700 | return SCSI_DH_IO; |
5115fc7e | 701 | case SCSI_ACCESS_STATE_TRANSITIONING: |
f2ecf13a HR |
702 | break; |
703 | default: | |
b2460756 HR |
704 | sdev_printk(KERN_INFO, sdev, |
705 | "%s: stpg failed, unhandled TPGS state %d", | |
43394c67 | 706 | ALUA_DH_NAME, pg->state); |
b2460756 | 707 | return SCSI_DH_NOSYS; |
f2ecf13a | 708 | } |
43394c67 | 709 | retval = submit_stpg(sdev, pg->group_id, &sense_hdr); |
f2ecf13a | 710 | |
b2460756 | 711 | if (retval) { |
40bb61a7 | 712 | if (!scsi_sense_valid(&sense_hdr)) { |
b2460756 HR |
713 | sdev_printk(KERN_INFO, sdev, |
714 | "%s: stpg failed, result %d", | |
715 | ALUA_DH_NAME, retval); | |
40bb61a7 | 716 | if (driver_byte(retval) == DRIVER_ERROR) |
b2460756 HR |
717 | return SCSI_DH_DEV_TEMP_BUSY; |
718 | } else { | |
43394c67 | 719 | sdev_printk(KERN_INFO, sdev, "%s: stpg failed\n", |
b2460756 HR |
720 | ALUA_DH_NAME); |
721 | scsi_print_sense_hdr(sdev, ALUA_DH_NAME, &sense_hdr); | |
722 | } | |
f2ecf13a | 723 | } |
b2460756 HR |
724 | /* Retry RTPG */ |
725 | return SCSI_DH_RETRY; | |
f2ecf13a HR |
726 | } |
727 | ||
03197b61 HR |
728 | static void alua_rtpg_work(struct work_struct *work) |
729 | { | |
730 | struct alua_port_group *pg = | |
731 | container_of(work, struct alua_port_group, rtpg_work.work); | |
732 | struct scsi_device *sdev; | |
733 | LIST_HEAD(qdata_list); | |
734 | int err = SCSI_DH_OK; | |
735 | struct alua_queue_data *qdata, *tmp; | |
736 | unsigned long flags; | |
00642a1b | 737 | struct workqueue_struct *alua_wq = kaluad_wq; |
03197b61 HR |
738 | |
739 | spin_lock_irqsave(&pg->lock, flags); | |
740 | sdev = pg->rtpg_sdev; | |
741 | if (!sdev) { | |
742 | WARN_ON(pg->flags & ALUA_PG_RUN_RTPG); | |
743 | WARN_ON(pg->flags & ALUA_PG_RUN_STPG); | |
744 | spin_unlock_irqrestore(&pg->lock, flags); | |
745 | return; | |
746 | } | |
00642a1b HR |
747 | if (pg->flags & ALUA_SYNC_STPG) |
748 | alua_wq = kaluad_sync_wq; | |
03197b61 HR |
749 | pg->flags |= ALUA_PG_RUNNING; |
750 | if (pg->flags & ALUA_PG_RUN_RTPG) { | |
9d2c3039 HR |
751 | int state = pg->state; |
752 | ||
03197b61 HR |
753 | pg->flags &= ~ALUA_PG_RUN_RTPG; |
754 | spin_unlock_irqrestore(&pg->lock, flags); | |
5115fc7e | 755 | if (state == SCSI_ACCESS_STATE_TRANSITIONING) { |
9d2c3039 HR |
756 | if (alua_tur(sdev) == SCSI_DH_RETRY) { |
757 | spin_lock_irqsave(&pg->lock, flags); | |
758 | pg->flags &= ~ALUA_PG_RUNNING; | |
759 | pg->flags |= ALUA_PG_RUN_RTPG; | |
760 | spin_unlock_irqrestore(&pg->lock, flags); | |
761 | queue_delayed_work(alua_wq, &pg->rtpg_work, | |
762 | pg->interval * HZ); | |
763 | return; | |
764 | } | |
765 | /* Send RTPG on failure or if TUR indicates SUCCESS */ | |
766 | } | |
03197b61 HR |
767 | err = alua_rtpg(sdev, pg); |
768 | spin_lock_irqsave(&pg->lock, flags); | |
2b35865e | 769 | if (err == SCSI_DH_RETRY || pg->flags & ALUA_PG_RUN_RTPG) { |
03197b61 HR |
770 | pg->flags &= ~ALUA_PG_RUNNING; |
771 | pg->flags |= ALUA_PG_RUN_RTPG; | |
772 | spin_unlock_irqrestore(&pg->lock, flags); | |
00642a1b | 773 | queue_delayed_work(alua_wq, &pg->rtpg_work, |
03197b61 HR |
774 | pg->interval * HZ); |
775 | return; | |
776 | } | |
777 | if (err != SCSI_DH_OK) | |
778 | pg->flags &= ~ALUA_PG_RUN_STPG; | |
779 | } | |
780 | if (pg->flags & ALUA_PG_RUN_STPG) { | |
781 | pg->flags &= ~ALUA_PG_RUN_STPG; | |
782 | spin_unlock_irqrestore(&pg->lock, flags); | |
783 | err = alua_stpg(sdev, pg); | |
784 | spin_lock_irqsave(&pg->lock, flags); | |
2b35865e | 785 | if (err == SCSI_DH_RETRY || pg->flags & ALUA_PG_RUN_RTPG) { |
03197b61 HR |
786 | pg->flags |= ALUA_PG_RUN_RTPG; |
787 | pg->interval = 0; | |
788 | pg->flags &= ~ALUA_PG_RUNNING; | |
789 | spin_unlock_irqrestore(&pg->lock, flags); | |
00642a1b | 790 | queue_delayed_work(alua_wq, &pg->rtpg_work, |
03197b61 HR |
791 | pg->interval * HZ); |
792 | return; | |
793 | } | |
794 | } | |
795 | ||
796 | list_splice_init(&pg->rtpg_list, &qdata_list); | |
797 | pg->rtpg_sdev = NULL; | |
798 | spin_unlock_irqrestore(&pg->lock, flags); | |
799 | ||
800 | list_for_each_entry_safe(qdata, tmp, &qdata_list, entry) { | |
801 | list_del(&qdata->entry); | |
802 | if (qdata->callback_fn) | |
803 | qdata->callback_fn(qdata->callback_data, err); | |
804 | kfree(qdata); | |
805 | } | |
806 | spin_lock_irqsave(&pg->lock, flags); | |
807 | pg->flags &= ~ALUA_PG_RUNNING; | |
808 | spin_unlock_irqrestore(&pg->lock, flags); | |
809 | scsi_device_put(sdev); | |
810 | kref_put(&pg->kref, release_port_group); | |
811 | } | |
812 | ||
813 | static void alua_rtpg_queue(struct alua_port_group *pg, | |
814 | struct scsi_device *sdev, | |
2b35865e | 815 | struct alua_queue_data *qdata, bool force) |
03197b61 HR |
816 | { |
817 | int start_queue = 0; | |
818 | unsigned long flags; | |
00642a1b | 819 | struct workqueue_struct *alua_wq = kaluad_wq; |
03197b61 HR |
820 | |
821 | if (!pg) | |
822 | return; | |
823 | ||
824 | spin_lock_irqsave(&pg->lock, flags); | |
825 | if (qdata) { | |
826 | list_add_tail(&qdata->entry, &pg->rtpg_list); | |
827 | pg->flags |= ALUA_PG_RUN_STPG; | |
2b35865e | 828 | force = true; |
03197b61 HR |
829 | } |
830 | if (pg->rtpg_sdev == NULL) { | |
831 | pg->interval = 0; | |
832 | pg->flags |= ALUA_PG_RUN_RTPG; | |
833 | kref_get(&pg->kref); | |
834 | pg->rtpg_sdev = sdev; | |
835 | scsi_device_get(sdev); | |
836 | start_queue = 1; | |
2b35865e HR |
837 | } else if (!(pg->flags & ALUA_PG_RUN_RTPG) && force) { |
838 | pg->flags |= ALUA_PG_RUN_RTPG; | |
839 | /* Do not queue if the worker is already running */ | |
840 | if (!(pg->flags & ALUA_PG_RUNNING)) { | |
841 | kref_get(&pg->kref); | |
842 | start_queue = 1; | |
843 | } | |
03197b61 | 844 | } |
2b35865e | 845 | |
00642a1b HR |
846 | if (pg->flags & ALUA_SYNC_STPG) |
847 | alua_wq = kaluad_sync_wq; | |
03197b61 HR |
848 | spin_unlock_irqrestore(&pg->lock, flags); |
849 | ||
850 | if (start_queue && | |
00642a1b | 851 | !queue_delayed_work(alua_wq, &pg->rtpg_work, |
03197b61 HR |
852 | msecs_to_jiffies(ALUA_RTPG_DELAY_MSECS))) { |
853 | scsi_device_put(sdev); | |
854 | kref_put(&pg->kref, release_port_group); | |
855 | } | |
856 | } | |
857 | ||
057ea7c9 HR |
858 | /* |
859 | * alua_initialize - Initialize ALUA state | |
860 | * @sdev: the device to be initialized | |
861 | * | |
862 | * For the prep_fn to work correctly we have | |
863 | * to initialize the ALUA state for the device. | |
864 | */ | |
865 | static int alua_initialize(struct scsi_device *sdev, struct alua_dh_data *h) | |
866 | { | |
43394c67 | 867 | int err = SCSI_DH_DEV_UNSUPP, tpgs; |
057ea7c9 | 868 | |
03197b61 | 869 | mutex_lock(&h->init_mutex); |
43394c67 | 870 | tpgs = alua_check_tpgs(sdev); |
a4253fde HR |
871 | if (tpgs != TPGS_MODE_NONE) |
872 | err = alua_check_vpd(sdev, h, tpgs); | |
03197b61 HR |
873 | h->init_error = err; |
874 | mutex_unlock(&h->init_mutex); | |
057ea7c9 HR |
875 | return err; |
876 | } | |
4335d092 MB |
877 | /* |
878 | * alua_set_params - set/unset the optimize flag | |
879 | * @sdev: device on the path to be activated | |
880 | * params - parameters in the following format | |
881 | * "no_of_params\0param1\0param2\0param3\0...\0" | |
882 | * For example, to set the flag pass the following parameters | |
883 | * from multipath.conf | |
884 | * hardware_handler "2 alua 1" | |
885 | */ | |
886 | static int alua_set_params(struct scsi_device *sdev, const char *params) | |
887 | { | |
ee14c674 | 888 | struct alua_dh_data *h = sdev->handler_data; |
03197b61 | 889 | struct alua_port_group __rcu *pg = NULL; |
4335d092 MB |
890 | unsigned int optimize = 0, argc; |
891 | const char *p = params; | |
892 | int result = SCSI_DH_OK; | |
03197b61 | 893 | unsigned long flags; |
4335d092 MB |
894 | |
895 | if ((sscanf(params, "%u", &argc) != 1) || (argc != 1)) | |
896 | return -EINVAL; | |
897 | ||
898 | while (*p++) | |
899 | ; | |
900 | if ((sscanf(p, "%u", &optimize) != 1) || (optimize > 1)) | |
901 | return -EINVAL; | |
902 | ||
03197b61 HR |
903 | rcu_read_lock(); |
904 | pg = rcu_dereference(h->pg); | |
905 | if (!pg) { | |
906 | rcu_read_unlock(); | |
43394c67 | 907 | return -ENXIO; |
03197b61 HR |
908 | } |
909 | spin_lock_irqsave(&pg->lock, flags); | |
4335d092 | 910 | if (optimize) |
43394c67 | 911 | pg->flags |= ALUA_OPTIMIZE_STPG; |
4335d092 | 912 | else |
43394c67 | 913 | pg->flags &= ~ALUA_OPTIMIZE_STPG; |
03197b61 HR |
914 | spin_unlock_irqrestore(&pg->lock, flags); |
915 | rcu_read_unlock(); | |
4335d092 MB |
916 | |
917 | return result; | |
918 | } | |
057ea7c9 HR |
919 | |
920 | /* | |
921 | * alua_activate - activate a path | |
922 | * @sdev: device on the path to be activated | |
923 | * | |
924 | * We're currently switching the port group to be activated only and | |
925 | * let the array figure out the rest. | |
926 | * There may be other arrays which require us to switch all port groups | |
927 | * based on a certain policy. But until we actually encounter them it | |
928 | * should be okay. | |
929 | */ | |
3ae31f6a CS |
930 | static int alua_activate(struct scsi_device *sdev, |
931 | activate_complete fn, void *data) | |
057ea7c9 | 932 | { |
ee14c674 | 933 | struct alua_dh_data *h = sdev->handler_data; |
057ea7c9 | 934 | int err = SCSI_DH_OK; |
03197b61 HR |
935 | struct alua_queue_data *qdata; |
936 | struct alua_port_group __rcu *pg; | |
057ea7c9 | 937 | |
03197b61 HR |
938 | qdata = kzalloc(sizeof(*qdata), GFP_KERNEL); |
939 | if (!qdata) { | |
940 | err = SCSI_DH_RES_TEMP_UNAVAIL; | |
46ccf6b5 | 941 | goto out; |
03197b61 HR |
942 | } |
943 | qdata->callback_fn = fn; | |
944 | qdata->callback_data = data; | |
945 | ||
946 | mutex_lock(&h->init_mutex); | |
947 | rcu_read_lock(); | |
948 | pg = rcu_dereference(h->pg); | |
949 | if (!pg || !kref_get_unless_zero(&pg->kref)) { | |
950 | rcu_read_unlock(); | |
951 | kfree(qdata); | |
952 | err = h->init_error; | |
953 | mutex_unlock(&h->init_mutex); | |
43394c67 HR |
954 | goto out; |
955 | } | |
03197b61 HR |
956 | fn = NULL; |
957 | rcu_read_unlock(); | |
958 | mutex_unlock(&h->init_mutex); | |
959 | ||
2b35865e | 960 | alua_rtpg_queue(pg, sdev, qdata, true); |
03197b61 | 961 | kref_put(&pg->kref, release_port_group); |
057ea7c9 | 962 | out: |
b2460756 | 963 | if (fn) |
3ae31f6a CS |
964 | fn(data, err); |
965 | return 0; | |
057ea7c9 HR |
966 | } |
967 | ||
2b35865e HR |
968 | /* |
969 | * alua_check - check path status | |
970 | * @sdev: device on the path to be checked | |
971 | * | |
972 | * Check the device status | |
973 | */ | |
974 | static void alua_check(struct scsi_device *sdev, bool force) | |
975 | { | |
976 | struct alua_dh_data *h = sdev->handler_data; | |
977 | struct alua_port_group *pg; | |
978 | ||
979 | rcu_read_lock(); | |
980 | pg = rcu_dereference(h->pg); | |
981 | if (!pg || !kref_get_unless_zero(&pg->kref)) { | |
982 | rcu_read_unlock(); | |
983 | return; | |
984 | } | |
985 | rcu_read_unlock(); | |
986 | ||
987 | alua_rtpg_queue(pg, sdev, NULL, force); | |
988 | kref_put(&pg->kref, release_port_group); | |
989 | } | |
990 | ||
057ea7c9 HR |
991 | /* |
992 | * alua_prep_fn - request callback | |
993 | * | |
994 | * Fail I/O to all paths not in state | |
995 | * active/optimized or active/non-optimized. | |
996 | */ | |
997 | static int alua_prep_fn(struct scsi_device *sdev, struct request *req) | |
998 | { | |
ee14c674 | 999 | struct alua_dh_data *h = sdev->handler_data; |
03197b61 | 1000 | struct alua_port_group __rcu *pg; |
5115fc7e | 1001 | unsigned char state = SCSI_ACCESS_STATE_OPTIMAL; |
057ea7c9 HR |
1002 | int ret = BLKPREP_OK; |
1003 | ||
03197b61 HR |
1004 | rcu_read_lock(); |
1005 | pg = rcu_dereference(h->pg); | |
1006 | if (pg) | |
1007 | state = pg->state; | |
1008 | rcu_read_unlock(); | |
5115fc7e | 1009 | if (state == SCSI_ACCESS_STATE_TRANSITIONING) |
69723d17 | 1010 | ret = BLKPREP_DEFER; |
5115fc7e HR |
1011 | else if (state != SCSI_ACCESS_STATE_OPTIMAL && |
1012 | state != SCSI_ACCESS_STATE_ACTIVE && | |
1013 | state != SCSI_ACCESS_STATE_LBA) { | |
057ea7c9 HR |
1014 | ret = BLKPREP_KILL; |
1015 | req->cmd_flags |= REQ_QUIET; | |
1016 | } | |
1017 | return ret; | |
1018 | ||
1019 | } | |
1020 | ||
d3d32891 HR |
1021 | static void alua_rescan(struct scsi_device *sdev) |
1022 | { | |
1023 | struct alua_dh_data *h = sdev->handler_data; | |
1024 | ||
1025 | alua_initialize(sdev, h); | |
1026 | } | |
1027 | ||
057ea7c9 HR |
1028 | /* |
1029 | * alua_bus_attach - Attach device handler | |
1030 | * @sdev: device to be attached to | |
1031 | */ | |
ee14c674 | 1032 | static int alua_bus_attach(struct scsi_device *sdev) |
057ea7c9 | 1033 | { |
057ea7c9 | 1034 | struct alua_dh_data *h; |
43394c67 | 1035 | int err, ret = -EINVAL; |
057ea7c9 | 1036 | |
cd37743f | 1037 | h = kzalloc(sizeof(*h) , GFP_KERNEL); |
1d520328 | 1038 | if (!h) |
ee14c674 | 1039 | return -ENOMEM; |
03197b61 HR |
1040 | spin_lock_init(&h->pg_lock); |
1041 | rcu_assign_pointer(h->pg, NULL); | |
1042 | h->init_error = SCSI_DH_OK; | |
96e65865 | 1043 | h->sdev = sdev; |
057ea7c9 | 1044 | |
03197b61 | 1045 | mutex_init(&h->init_mutex); |
057ea7c9 | 1046 | err = alua_initialize(sdev, h); |
43394c67 HR |
1047 | if (err == SCSI_DH_NOMEM) |
1048 | ret = -ENOMEM; | |
1d520328 | 1049 | if (err != SCSI_DH_OK && err != SCSI_DH_DEV_OFFLINED) |
057ea7c9 HR |
1050 | goto failed; |
1051 | ||
ee14c674 CH |
1052 | sdev->handler_data = h; |
1053 | return 0; | |
057ea7c9 | 1054 | failed: |
cd37743f | 1055 | kfree(h); |
43394c67 | 1056 | return ret; |
057ea7c9 HR |
1057 | } |
1058 | ||
1059 | /* | |
1060 | * alua_bus_detach - Detach device handler | |
1061 | * @sdev: device to be detached from | |
1062 | */ | |
1063 | static void alua_bus_detach(struct scsi_device *sdev) | |
1064 | { | |
ee14c674 | 1065 | struct alua_dh_data *h = sdev->handler_data; |
03197b61 HR |
1066 | struct alua_port_group *pg; |
1067 | ||
1068 | spin_lock(&h->pg_lock); | |
1069 | pg = h->pg; | |
1070 | rcu_assign_pointer(h->pg, NULL); | |
1071 | h->sdev = NULL; | |
1072 | spin_unlock(&h->pg_lock); | |
1073 | if (pg) | |
1074 | kref_put(&pg->kref, release_port_group); | |
057ea7c9 | 1075 | |
ee14c674 | 1076 | sdev->handler_data = NULL; |
cd37743f | 1077 | kfree(h); |
057ea7c9 HR |
1078 | } |
1079 | ||
1d520328 CH |
1080 | static struct scsi_device_handler alua_dh = { |
1081 | .name = ALUA_DH_NAME, | |
1082 | .module = THIS_MODULE, | |
1083 | .attach = alua_bus_attach, | |
1084 | .detach = alua_bus_detach, | |
1085 | .prep_fn = alua_prep_fn, | |
1086 | .check_sense = alua_check_sense, | |
1087 | .activate = alua_activate, | |
d3d32891 | 1088 | .rescan = alua_rescan, |
1d520328 | 1089 | .set_params = alua_set_params, |
1d520328 CH |
1090 | }; |
1091 | ||
057ea7c9 HR |
1092 | static int __init alua_init(void) |
1093 | { | |
1094 | int r; | |
1095 | ||
03197b61 HR |
1096 | kaluad_wq = alloc_workqueue("kaluad", WQ_MEM_RECLAIM, 0); |
1097 | if (!kaluad_wq) { | |
1098 | /* Temporary failure, bypass */ | |
1099 | return SCSI_DH_DEV_TEMP_BUSY; | |
1100 | } | |
00642a1b HR |
1101 | kaluad_sync_wq = create_workqueue("kaluad_sync"); |
1102 | if (!kaluad_sync_wq) { | |
1103 | destroy_workqueue(kaluad_wq); | |
1104 | return SCSI_DH_DEV_TEMP_BUSY; | |
1105 | } | |
057ea7c9 | 1106 | r = scsi_register_device_handler(&alua_dh); |
03197b61 | 1107 | if (r != 0) { |
057ea7c9 HR |
1108 | printk(KERN_ERR "%s: Failed to register scsi device handler", |
1109 | ALUA_DH_NAME); | |
00642a1b | 1110 | destroy_workqueue(kaluad_sync_wq); |
03197b61 HR |
1111 | destroy_workqueue(kaluad_wq); |
1112 | } | |
057ea7c9 HR |
1113 | return r; |
1114 | } | |
1115 | ||
1116 | static void __exit alua_exit(void) | |
1117 | { | |
1118 | scsi_unregister_device_handler(&alua_dh); | |
00642a1b | 1119 | destroy_workqueue(kaluad_sync_wq); |
03197b61 | 1120 | destroy_workqueue(kaluad_wq); |
057ea7c9 HR |
1121 | } |
1122 | ||
1123 | module_init(alua_init); | |
1124 | module_exit(alua_exit); | |
1125 | ||
1126 | MODULE_DESCRIPTION("DM Multipath ALUA support"); | |
1127 | MODULE_AUTHOR("Hannes Reinecke <hare@suse.de>"); | |
1128 | MODULE_LICENSE("GPL"); | |
1129 | MODULE_VERSION(ALUA_DH_VER); |