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 | 61 | #define ALUA_FAILOVER_RETRIES 5 |
03197b61 | 62 | #define ALUA_RTPG_DELAY_MSECS 5 |
057ea7c9 | 63 | |
6c4fc044 | 64 | /* device handler flags */ |
03197b61 HR |
65 | #define ALUA_OPTIMIZE_STPG 0x01 |
66 | #define ALUA_RTPG_EXT_HDR_UNSUPP 0x02 | |
00642a1b | 67 | #define ALUA_SYNC_STPG 0x04 |
03197b61 HR |
68 | /* State machine flags */ |
69 | #define ALUA_PG_RUN_RTPG 0x10 | |
70 | #define ALUA_PG_RUN_STPG 0x20 | |
71 | #define ALUA_PG_RUNNING 0x40 | |
4335d092 | 72 | |
aa90f490 HR |
73 | static uint optimize_stpg; |
74 | module_param(optimize_stpg, uint, S_IRUGO|S_IWUSR); | |
75 | 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."); | |
76 | ||
43394c67 HR |
77 | static LIST_HEAD(port_group_list); |
78 | static DEFINE_SPINLOCK(port_group_lock); | |
03197b61 | 79 | static struct workqueue_struct *kaluad_wq; |
00642a1b | 80 | static struct workqueue_struct *kaluad_sync_wq; |
43394c67 HR |
81 | |
82 | struct alua_port_group { | |
83 | struct kref kref; | |
03197b61 | 84 | struct rcu_head rcu; |
43394c67 | 85 | struct list_head node; |
0047220c HR |
86 | unsigned char device_id_str[256]; |
87 | int device_id_len; | |
057ea7c9 | 88 | int group_id; |
057ea7c9 HR |
89 | int tpgs; |
90 | int state; | |
dcd3a754 | 91 | int pref; |
4335d092 | 92 | unsigned flags; /* used for optimizing STPG */ |
3588c5a2 | 93 | unsigned char transition_tmo; |
03197b61 HR |
94 | unsigned long expiry; |
95 | unsigned long interval; | |
96 | struct delayed_work rtpg_work; | |
97 | spinlock_t lock; | |
98 | struct list_head rtpg_list; | |
99 | struct scsi_device *rtpg_sdev; | |
43394c67 HR |
100 | }; |
101 | ||
102 | struct alua_dh_data { | |
103 | struct alua_port_group *pg; | |
104 | int group_id; | |
03197b61 | 105 | spinlock_t pg_lock; |
96e65865 | 106 | struct scsi_device *sdev; |
03197b61 HR |
107 | int init_error; |
108 | struct mutex init_mutex; | |
109 | }; | |
110 | ||
111 | struct alua_queue_data { | |
112 | struct list_head entry; | |
96e65865 CS |
113 | activate_complete callback_fn; |
114 | void *callback_data; | |
057ea7c9 HR |
115 | }; |
116 | ||
117 | #define ALUA_POLICY_SWITCH_CURRENT 0 | |
118 | #define ALUA_POLICY_SWITCH_ALL 1 | |
119 | ||
03197b61 HR |
120 | static void alua_rtpg_work(struct work_struct *work); |
121 | static void alua_rtpg_queue(struct alua_port_group *pg, | |
122 | struct scsi_device *sdev, | |
2b35865e HR |
123 | struct alua_queue_data *qdata, bool force); |
124 | static void alua_check(struct scsi_device *sdev, bool force); | |
96e65865 | 125 | |
43394c67 HR |
126 | static void release_port_group(struct kref *kref) |
127 | { | |
128 | struct alua_port_group *pg; | |
129 | ||
130 | pg = container_of(kref, struct alua_port_group, kref); | |
03197b61 HR |
131 | if (pg->rtpg_sdev) |
132 | flush_delayed_work(&pg->rtpg_work); | |
43394c67 HR |
133 | spin_lock(&port_group_lock); |
134 | list_del(&pg->node); | |
135 | spin_unlock(&port_group_lock); | |
03197b61 | 136 | kfree_rcu(pg, rcu); |
43394c67 HR |
137 | } |
138 | ||
057ea7c9 HR |
139 | /* |
140 | * submit_rtpg - Issue a REPORT TARGET GROUP STATES command | |
141 | * @sdev: sdev the command should be sent to | |
142 | */ | |
40bb61a7 HR |
143 | static int submit_rtpg(struct scsi_device *sdev, unsigned char *buff, |
144 | int bufflen, struct scsi_sense_hdr *sshdr, int flags) | |
057ea7c9 | 145 | { |
40bb61a7 HR |
146 | u8 cdb[COMMAND_SIZE(MAINTENANCE_IN)]; |
147 | int req_flags = REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT | | |
148 | REQ_FAILFAST_DRIVER; | |
057ea7c9 HR |
149 | |
150 | /* Prepare the command. */ | |
40bb61a7 HR |
151 | memset(cdb, 0x0, COMMAND_SIZE(MAINTENANCE_IN)); |
152 | cdb[0] = MAINTENANCE_IN; | |
d42ae5f3 | 153 | if (!(flags & ALUA_RTPG_EXT_HDR_UNSUPP)) |
40bb61a7 | 154 | cdb[1] = MI_REPORT_TARGET_PGS | MI_EXT_HDR_PARAM_FMT; |
8e67ce60 | 155 | else |
40bb61a7 HR |
156 | cdb[1] = MI_REPORT_TARGET_PGS; |
157 | put_unaligned_be32(bufflen, &cdb[6]); | |
158 | ||
159 | return scsi_execute_req_flags(sdev, cdb, DMA_FROM_DEVICE, | |
160 | buff, bufflen, sshdr, | |
161 | ALUA_FAILOVER_TIMEOUT * HZ, | |
162 | ALUA_FAILOVER_RETRIES, NULL, req_flags); | |
057ea7c9 HR |
163 | } |
164 | ||
96e65865 | 165 | /* |
b2460756 | 166 | * submit_stpg - Issue a SET TARGET PORT GROUP command |
057ea7c9 HR |
167 | * |
168 | * Currently we're only setting the current target port group state | |
169 | * to 'active/optimized' and let the array firmware figure out | |
170 | * the states of the remaining groups. | |
171 | */ | |
40bb61a7 HR |
172 | static int submit_stpg(struct scsi_device *sdev, int group_id, |
173 | struct scsi_sense_hdr *sshdr) | |
057ea7c9 | 174 | { |
40bb61a7 | 175 | u8 cdb[COMMAND_SIZE(MAINTENANCE_OUT)]; |
b2460756 | 176 | unsigned char stpg_data[8]; |
057ea7c9 | 177 | int stpg_len = 8; |
40bb61a7 HR |
178 | int req_flags = REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT | |
179 | REQ_FAILFAST_DRIVER; | |
057ea7c9 HR |
180 | |
181 | /* Prepare the data buffer */ | |
b2460756 HR |
182 | memset(stpg_data, 0, stpg_len); |
183 | stpg_data[4] = TPGS_STATE_OPTIMIZED & 0x0f; | |
184 | put_unaligned_be16(group_id, &stpg_data[6]); | |
057ea7c9 | 185 | |
057ea7c9 | 186 | /* Prepare the command. */ |
40bb61a7 HR |
187 | memset(cdb, 0x0, COMMAND_SIZE(MAINTENANCE_OUT)); |
188 | cdb[0] = MAINTENANCE_OUT; | |
189 | cdb[1] = MO_SET_TARGET_PGS; | |
190 | put_unaligned_be32(stpg_len, &cdb[6]); | |
191 | ||
192 | return scsi_execute_req_flags(sdev, cdb, DMA_TO_DEVICE, | |
193 | stpg_data, stpg_len, | |
194 | sshdr, ALUA_FAILOVER_TIMEOUT * HZ, | |
195 | ALUA_FAILOVER_RETRIES, NULL, req_flags); | |
057ea7c9 HR |
196 | } |
197 | ||
0047220c HR |
198 | struct alua_port_group *alua_find_get_pg(char *id_str, size_t id_size, |
199 | int group_id) | |
200 | { | |
201 | struct alua_port_group *pg; | |
202 | ||
203 | list_for_each_entry(pg, &port_group_list, node) { | |
204 | if (pg->group_id != group_id) | |
205 | continue; | |
206 | if (pg->device_id_len != id_size) | |
207 | continue; | |
208 | if (strncmp(pg->device_id_str, id_str, id_size)) | |
209 | continue; | |
210 | if (!kref_get_unless_zero(&pg->kref)) | |
211 | continue; | |
212 | return pg; | |
213 | } | |
214 | ||
215 | return NULL; | |
216 | } | |
217 | ||
43394c67 HR |
218 | /* |
219 | * alua_alloc_pg - Allocate a new port_group structure | |
220 | * @sdev: scsi device | |
221 | * @h: alua device_handler data | |
222 | * @group_id: port group id | |
223 | * | |
224 | * Allocate a new port_group structure for a given | |
225 | * device. | |
226 | */ | |
227 | struct alua_port_group *alua_alloc_pg(struct scsi_device *sdev, | |
228 | int group_id, int tpgs) | |
229 | { | |
0047220c | 230 | struct alua_port_group *pg, *tmp_pg; |
43394c67 HR |
231 | |
232 | pg = kzalloc(sizeof(struct alua_port_group), GFP_KERNEL); | |
233 | if (!pg) | |
0047220c | 234 | return ERR_PTR(-ENOMEM); |
43394c67 | 235 | |
0047220c HR |
236 | pg->device_id_len = scsi_vpd_lun_id(sdev, pg->device_id_str, |
237 | sizeof(pg->device_id_str)); | |
238 | if (pg->device_id_len <= 0) { | |
239 | /* | |
240 | * Internal error: TPGS supported but no device | |
241 | * identifcation found. Disable ALUA support. | |
242 | */ | |
243 | kfree(pg); | |
244 | sdev_printk(KERN_INFO, sdev, | |
245 | "%s: No device descriptors found\n", | |
246 | ALUA_DH_NAME); | |
247 | return ERR_PTR(-ENXIO); | |
248 | } | |
43394c67 HR |
249 | pg->group_id = group_id; |
250 | pg->tpgs = tpgs; | |
251 | pg->state = TPGS_STATE_OPTIMIZED; | |
aa90f490 HR |
252 | if (optimize_stpg) |
253 | pg->flags |= ALUA_OPTIMIZE_STPG; | |
43394c67 | 254 | kref_init(&pg->kref); |
03197b61 HR |
255 | INIT_DELAYED_WORK(&pg->rtpg_work, alua_rtpg_work); |
256 | INIT_LIST_HEAD(&pg->rtpg_list); | |
257 | INIT_LIST_HEAD(&pg->node); | |
258 | spin_lock_init(&pg->lock); | |
0047220c | 259 | |
43394c67 | 260 | spin_lock(&port_group_lock); |
0047220c HR |
261 | tmp_pg = alua_find_get_pg(pg->device_id_str, pg->device_id_len, |
262 | group_id); | |
263 | if (tmp_pg) { | |
264 | spin_unlock(&port_group_lock); | |
265 | kfree(pg); | |
266 | return tmp_pg; | |
267 | } | |
268 | ||
43394c67 HR |
269 | list_add(&pg->node, &port_group_list); |
270 | spin_unlock(&port_group_lock); | |
271 | ||
272 | return pg; | |
273 | } | |
274 | ||
057ea7c9 | 275 | /* |
d7c48feb | 276 | * alua_check_tpgs - Evaluate TPGS setting |
057ea7c9 HR |
277 | * @sdev: device to be checked |
278 | * | |
d7c48feb | 279 | * Examine the TPGS setting of the sdev to find out if ALUA |
057ea7c9 HR |
280 | * is supported. |
281 | */ | |
ad0ea64c | 282 | static int alua_check_tpgs(struct scsi_device *sdev) |
057ea7c9 | 283 | { |
ad0ea64c | 284 | int tpgs = TPGS_MODE_NONE; |
057ea7c9 | 285 | |
db5a6a60 HR |
286 | /* |
287 | * ALUA support for non-disk devices is fraught with | |
288 | * difficulties, so disable it for now. | |
289 | */ | |
290 | if (sdev->type != TYPE_DISK) { | |
db5a6a60 HR |
291 | sdev_printk(KERN_INFO, sdev, |
292 | "%s: disable for non-disk devices\n", | |
293 | ALUA_DH_NAME); | |
ad0ea64c | 294 | return tpgs; |
db5a6a60 HR |
295 | } |
296 | ||
ad0ea64c HR |
297 | tpgs = scsi_device_tpgs(sdev); |
298 | switch (tpgs) { | |
057ea7c9 HR |
299 | case TPGS_MODE_EXPLICIT|TPGS_MODE_IMPLICIT: |
300 | sdev_printk(KERN_INFO, sdev, | |
301 | "%s: supports implicit and explicit TPGS\n", | |
302 | ALUA_DH_NAME); | |
303 | break; | |
304 | case TPGS_MODE_EXPLICIT: | |
305 | sdev_printk(KERN_INFO, sdev, "%s: supports explicit TPGS\n", | |
306 | ALUA_DH_NAME); | |
307 | break; | |
308 | case TPGS_MODE_IMPLICIT: | |
309 | sdev_printk(KERN_INFO, sdev, "%s: supports implicit TPGS\n", | |
310 | ALUA_DH_NAME); | |
311 | break; | |
6cc05d45 | 312 | case TPGS_MODE_NONE: |
057ea7c9 HR |
313 | sdev_printk(KERN_INFO, sdev, "%s: not supported\n", |
314 | ALUA_DH_NAME); | |
057ea7c9 | 315 | break; |
6cc05d45 HR |
316 | default: |
317 | sdev_printk(KERN_INFO, sdev, | |
318 | "%s: unsupported TPGS setting %d\n", | |
ad0ea64c HR |
319 | ALUA_DH_NAME, tpgs); |
320 | tpgs = TPGS_MODE_NONE; | |
6cc05d45 | 321 | break; |
057ea7c9 HR |
322 | } |
323 | ||
ad0ea64c | 324 | return tpgs; |
057ea7c9 HR |
325 | } |
326 | ||
327 | /* | |
9b80dcec | 328 | * alua_check_vpd - Evaluate INQUIRY vpd page 0x83 |
057ea7c9 HR |
329 | * @sdev: device to be checked |
330 | * | |
331 | * Extract the relative target port and the target port group | |
332 | * descriptor from the list of identificators. | |
333 | */ | |
a4253fde HR |
334 | static int alua_check_vpd(struct scsi_device *sdev, struct alua_dh_data *h, |
335 | int tpgs) | |
057ea7c9 | 336 | { |
83ea0e5e | 337 | int rel_port = -1, group_id; |
03197b61 | 338 | struct alua_port_group *pg, *old_pg = NULL; |
057ea7c9 | 339 | |
83ea0e5e HR |
340 | group_id = scsi_vpd_tpg_id(sdev, &rel_port); |
341 | if (group_id < 0) { | |
057ea7c9 HR |
342 | /* |
343 | * Internal error; TPGS supported but required | |
344 | * VPD identification descriptors not present. | |
345 | * Disable ALUA support | |
346 | */ | |
347 | sdev_printk(KERN_INFO, sdev, | |
348 | "%s: No target port descriptors found\n", | |
349 | ALUA_DH_NAME); | |
9b80dcec | 350 | return SCSI_DH_DEV_UNSUPP; |
057ea7c9 | 351 | } |
a4253fde | 352 | |
03197b61 HR |
353 | pg = alua_alloc_pg(sdev, group_id, tpgs); |
354 | if (IS_ERR(pg)) { | |
355 | if (PTR_ERR(pg) == -ENOMEM) | |
a4253fde HR |
356 | return SCSI_DH_NOMEM; |
357 | return SCSI_DH_DEV_UNSUPP; | |
358 | } | |
9b80dcec | 359 | sdev_printk(KERN_INFO, sdev, |
a4253fde | 360 | "%s: device %s port group %x rel port %x\n", |
03197b61 HR |
361 | ALUA_DH_NAME, pg->device_id_str, group_id, rel_port); |
362 | ||
363 | /* Check for existing port group references */ | |
364 | spin_lock(&h->pg_lock); | |
365 | old_pg = h->pg; | |
366 | if (old_pg != pg) { | |
367 | /* port group has changed. Update to new port group */ | |
368 | rcu_assign_pointer(h->pg, pg); | |
369 | } | |
851cde99 HR |
370 | if (sdev->synchronous_alua) |
371 | pg->flags |= ALUA_SYNC_STPG; | |
2b35865e | 372 | alua_rtpg_queue(h->pg, sdev, NULL, true); |
03197b61 HR |
373 | spin_unlock(&h->pg_lock); |
374 | ||
375 | if (old_pg) | |
376 | kref_put(&old_pg->kref, release_port_group); | |
057ea7c9 | 377 | |
03197b61 | 378 | return SCSI_DH_OK; |
057ea7c9 HR |
379 | } |
380 | ||
381 | static char print_alua_state(int state) | |
382 | { | |
383 | switch (state) { | |
384 | case TPGS_STATE_OPTIMIZED: | |
385 | return 'A'; | |
386 | case TPGS_STATE_NONOPTIMIZED: | |
387 | return 'N'; | |
388 | case TPGS_STATE_STANDBY: | |
389 | return 'S'; | |
390 | case TPGS_STATE_UNAVAILABLE: | |
391 | return 'U'; | |
69723d17 HR |
392 | case TPGS_STATE_LBA_DEPENDENT: |
393 | return 'L'; | |
057ea7c9 HR |
394 | case TPGS_STATE_OFFLINE: |
395 | return 'O'; | |
396 | case TPGS_STATE_TRANSITIONING: | |
397 | return 'T'; | |
398 | default: | |
399 | return 'X'; | |
400 | } | |
401 | } | |
402 | ||
403 | static int alua_check_sense(struct scsi_device *sdev, | |
404 | struct scsi_sense_hdr *sense_hdr) | |
405 | { | |
406 | switch (sense_hdr->sense_key) { | |
407 | case NOT_READY: | |
2b35865e | 408 | if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x0a) { |
057ea7c9 HR |
409 | /* |
410 | * LUN Not Accessible - ALUA state transition | |
411 | */ | |
2b35865e HR |
412 | alua_check(sdev, false); |
413 | return NEEDS_RETRY; | |
414 | } | |
057ea7c9 HR |
415 | break; |
416 | case UNIT_ATTENTION: | |
2b35865e | 417 | if (sense_hdr->asc == 0x29 && sense_hdr->ascq == 0x00) { |
057ea7c9 | 418 | /* |
2b35865e HR |
419 | * Power On, Reset, or Bus Device Reset. |
420 | * Might have obscured a state transition, | |
421 | * so schedule a recheck. | |
057ea7c9 | 422 | */ |
2b35865e | 423 | alua_check(sdev, true); |
c7dbb627 | 424 | return ADD_TO_MLQUEUE; |
2b35865e | 425 | } |
c20ee7b5 SS |
426 | if (sense_hdr->asc == 0x29 && sense_hdr->ascq == 0x04) |
427 | /* | |
428 | * Device internal reset | |
429 | */ | |
430 | return ADD_TO_MLQUEUE; | |
410f02d8 MB |
431 | if (sense_hdr->asc == 0x2a && sense_hdr->ascq == 0x01) |
432 | /* | |
433 | * Mode Parameters Changed | |
434 | */ | |
435 | return ADD_TO_MLQUEUE; | |
2b35865e | 436 | if (sense_hdr->asc == 0x2a && sense_hdr->ascq == 0x06) { |
057ea7c9 HR |
437 | /* |
438 | * ALUA state changed | |
439 | */ | |
2b35865e | 440 | alua_check(sdev, true); |
c7dbb627 | 441 | return ADD_TO_MLQUEUE; |
2b35865e HR |
442 | } |
443 | if (sense_hdr->asc == 0x2a && sense_hdr->ascq == 0x07) { | |
057ea7c9 HR |
444 | /* |
445 | * Implicit ALUA state transition failed | |
446 | */ | |
2b35865e | 447 | alua_check(sdev, true); |
c7dbb627 | 448 | return ADD_TO_MLQUEUE; |
2b35865e | 449 | } |
bf81973a MB |
450 | if (sense_hdr->asc == 0x3f && sense_hdr->ascq == 0x03) |
451 | /* | |
452 | * Inquiry data has changed | |
453 | */ | |
454 | return ADD_TO_MLQUEUE; | |
455 | if (sense_hdr->asc == 0x3f && sense_hdr->ascq == 0x0e) | |
4d086f6b IH |
456 | /* |
457 | * REPORTED_LUNS_DATA_HAS_CHANGED is reported | |
458 | * when switching controllers on targets like | |
459 | * Intel Multi-Flex. We can just retry. | |
460 | */ | |
461 | return ADD_TO_MLQUEUE; | |
057ea7c9 HR |
462 | break; |
463 | } | |
464 | ||
465 | return SCSI_RETURN_NOT_HANDLED; | |
466 | } | |
467 | ||
057ea7c9 HR |
468 | /* |
469 | * alua_rtpg - Evaluate REPORT TARGET GROUP STATES | |
470 | * @sdev: the device to be evaluated. | |
471 | * | |
472 | * Evaluate the Target Port Group State. | |
473 | * Returns SCSI_DH_DEV_OFFLINED if the path is | |
25985edc | 474 | * found to be unusable. |
057ea7c9 | 475 | */ |
28261402 | 476 | static int alua_rtpg(struct scsi_device *sdev, struct alua_port_group *pg) |
057ea7c9 HR |
477 | { |
478 | struct scsi_sense_hdr sense_hdr; | |
c49c8345 HR |
479 | int len, k, off, valid_states = 0, bufflen = ALUA_RTPG_SIZE; |
480 | unsigned char *ucp, *buff; | |
5597cafc | 481 | unsigned err, retval; |
3588c5a2 RE |
482 | unsigned int tpg_desc_tbl_off; |
483 | unsigned char orig_transition_tmo; | |
484 | ||
03197b61 HR |
485 | if (!pg->expiry) { |
486 | unsigned long transition_tmo = ALUA_FAILOVER_TIMEOUT * HZ; | |
487 | ||
488 | if (pg->transition_tmo) | |
489 | transition_tmo = pg->transition_tmo * HZ; | |
490 | ||
491 | pg->expiry = round_jiffies_up(jiffies + transition_tmo); | |
492 | } | |
057ea7c9 | 493 | |
c49c8345 HR |
494 | buff = kzalloc(bufflen, GFP_KERNEL); |
495 | if (!buff) | |
496 | return SCSI_DH_DEV_TEMP_BUSY; | |
497 | ||
057ea7c9 | 498 | retry: |
43394c67 | 499 | retval = submit_rtpg(sdev, buff, bufflen, &sense_hdr, pg->flags); |
40bb61a7 | 500 | |
5597cafc | 501 | if (retval) { |
40bb61a7 | 502 | if (!scsi_sense_valid(&sense_hdr)) { |
5597cafc HR |
503 | sdev_printk(KERN_INFO, sdev, |
504 | "%s: rtpg failed, result %d\n", | |
505 | ALUA_DH_NAME, retval); | |
c49c8345 | 506 | kfree(buff); |
40bb61a7 | 507 | if (driver_byte(retval) == DRIVER_ERROR) |
5597cafc | 508 | return SCSI_DH_DEV_TEMP_BUSY; |
057ea7c9 | 509 | return SCSI_DH_IO; |
5597cafc | 510 | } |
057ea7c9 | 511 | |
8e67ce60 RE |
512 | /* |
513 | * submit_rtpg() has failed on existing arrays | |
514 | * when requesting extended header info, and | |
515 | * the array doesn't support extended headers, | |
516 | * even though it shouldn't according to T10. | |
517 | * The retry without rtpg_ext_hdr_req set | |
518 | * handles this. | |
519 | */ | |
43394c67 | 520 | if (!(pg->flags & ALUA_RTPG_EXT_HDR_UNSUPP) && |
8e67ce60 RE |
521 | sense_hdr.sense_key == ILLEGAL_REQUEST && |
522 | sense_hdr.asc == 0x24 && sense_hdr.ascq == 0) { | |
43394c67 | 523 | pg->flags |= ALUA_RTPG_EXT_HDR_UNSUPP; |
8e67ce60 RE |
524 | goto retry; |
525 | } | |
e2d817db HR |
526 | /* |
527 | * Retry on ALUA state transition or if any | |
528 | * UNIT ATTENTION occurred. | |
529 | */ | |
530 | if (sense_hdr.sense_key == NOT_READY && | |
531 | sense_hdr.asc == 0x04 && sense_hdr.ascq == 0x0a) | |
532 | err = SCSI_DH_RETRY; | |
533 | else if (sense_hdr.sense_key == UNIT_ATTENTION) | |
534 | err = SCSI_DH_RETRY; | |
03197b61 HR |
535 | if (err == SCSI_DH_RETRY && |
536 | pg->expiry != 0 && time_before(jiffies, pg->expiry)) { | |
80bd68d6 HR |
537 | sdev_printk(KERN_ERR, sdev, "%s: rtpg retry\n", |
538 | ALUA_DH_NAME); | |
539 | scsi_print_sense_hdr(sdev, ALUA_DH_NAME, &sense_hdr); | |
03197b61 | 540 | return err; |
80bd68d6 HR |
541 | } |
542 | sdev_printk(KERN_ERR, sdev, "%s: rtpg failed\n", | |
543 | ALUA_DH_NAME); | |
544 | scsi_print_sense_hdr(sdev, ALUA_DH_NAME, &sense_hdr); | |
c49c8345 | 545 | kfree(buff); |
03197b61 | 546 | pg->expiry = 0; |
80bd68d6 | 547 | return SCSI_DH_IO; |
057ea7c9 | 548 | } |
057ea7c9 | 549 | |
c49c8345 | 550 | len = get_unaligned_be32(&buff[0]) + 4; |
057ea7c9 | 551 | |
c49c8345 | 552 | if (len > bufflen) { |
057ea7c9 | 553 | /* Resubmit with the correct length */ |
c49c8345 HR |
554 | kfree(buff); |
555 | bufflen = len; | |
556 | buff = kmalloc(bufflen, GFP_KERNEL); | |
557 | if (!buff) { | |
057ea7c9 | 558 | sdev_printk(KERN_WARNING, sdev, |
cadbd4a5 | 559 | "%s: kmalloc buffer failed\n",__func__); |
057ea7c9 | 560 | /* Temporary failure, bypass */ |
03197b61 | 561 | pg->expiry = 0; |
057ea7c9 HR |
562 | return SCSI_DH_DEV_TEMP_BUSY; |
563 | } | |
564 | goto retry; | |
565 | } | |
566 | ||
43394c67 | 567 | orig_transition_tmo = pg->transition_tmo; |
c49c8345 | 568 | if ((buff[4] & RTPG_FMT_MASK) == RTPG_FMT_EXT_HDR && buff[5] != 0) |
43394c67 | 569 | pg->transition_tmo = buff[5]; |
3588c5a2 | 570 | else |
43394c67 | 571 | pg->transition_tmo = ALUA_FAILOVER_TIMEOUT; |
3588c5a2 | 572 | |
28261402 | 573 | if (orig_transition_tmo != pg->transition_tmo) { |
3588c5a2 RE |
574 | sdev_printk(KERN_INFO, sdev, |
575 | "%s: transition timeout set to %d seconds\n", | |
43394c67 | 576 | ALUA_DH_NAME, pg->transition_tmo); |
03197b61 | 577 | pg->expiry = jiffies + pg->transition_tmo * HZ; |
3588c5a2 RE |
578 | } |
579 | ||
c49c8345 | 580 | if ((buff[4] & RTPG_FMT_MASK) == RTPG_FMT_EXT_HDR) |
3588c5a2 RE |
581 | tpg_desc_tbl_off = 8; |
582 | else | |
583 | tpg_desc_tbl_off = 4; | |
584 | ||
c49c8345 | 585 | for (k = tpg_desc_tbl_off, ucp = buff + tpg_desc_tbl_off; |
3588c5a2 RE |
586 | k < len; |
587 | k += off, ucp += off) { | |
588 | ||
43394c67 HR |
589 | if (pg->group_id == get_unaligned_be16(&ucp[2])) { |
590 | pg->state = ucp[0] & 0x0f; | |
591 | pg->pref = ucp[0] >> 7; | |
057ea7c9 HR |
592 | valid_states = ucp[1]; |
593 | } | |
594 | off = 8 + (ucp[7] * 4); | |
595 | } | |
596 | ||
597 | sdev_printk(KERN_INFO, sdev, | |
dcd3a754 | 598 | "%s: port group %02x state %c %s supports %c%c%c%c%c%c%c\n", |
43394c67 HR |
599 | ALUA_DH_NAME, pg->group_id, print_alua_state(pg->state), |
600 | pg->pref ? "preferred" : "non-preferred", | |
057ea7c9 HR |
601 | valid_states&TPGS_SUPPORT_TRANSITION?'T':'t', |
602 | valid_states&TPGS_SUPPORT_OFFLINE?'O':'o', | |
69723d17 | 603 | valid_states&TPGS_SUPPORT_LBA_DEPENDENT?'L':'l', |
057ea7c9 HR |
604 | valid_states&TPGS_SUPPORT_UNAVAILABLE?'U':'u', |
605 | valid_states&TPGS_SUPPORT_STANDBY?'S':'s', | |
606 | valid_states&TPGS_SUPPORT_NONOPTIMIZED?'N':'n', | |
607 | valid_states&TPGS_SUPPORT_OPTIMIZED?'A':'a'); | |
608 | ||
43394c67 | 609 | switch (pg->state) { |
69723d17 | 610 | case TPGS_STATE_TRANSITIONING: |
03197b61 | 611 | if (time_before(jiffies, pg->expiry)) { |
28261402 | 612 | /* State transition, retry */ |
03197b61 HR |
613 | pg->interval = 2; |
614 | err = SCSI_DH_RETRY; | |
615 | } else { | |
616 | /* Transitioning time exceeded, set port to standby */ | |
617 | err = SCSI_DH_IO; | |
618 | pg->state = TPGS_STATE_STANDBY; | |
619 | pg->expiry = 0; | |
057ea7c9 | 620 | } |
69723d17 HR |
621 | break; |
622 | case TPGS_STATE_OFFLINE: | |
e47f8976 | 623 | /* Path unusable */ |
69723d17 | 624 | err = SCSI_DH_DEV_OFFLINED; |
03197b61 | 625 | pg->expiry = 0; |
69723d17 HR |
626 | break; |
627 | default: | |
628 | /* Useable path if active */ | |
629 | err = SCSI_DH_OK; | |
03197b61 | 630 | pg->expiry = 0; |
69723d17 | 631 | break; |
057ea7c9 | 632 | } |
c49c8345 | 633 | kfree(buff); |
057ea7c9 HR |
634 | return err; |
635 | } | |
636 | ||
f2ecf13a HR |
637 | /* |
638 | * alua_stpg - Issue a SET TARGET PORT GROUP command | |
639 | * | |
640 | * Issue a SET TARGET PORT GROUP command and evaluate the | |
b2460756 HR |
641 | * response. Returns SCSI_DH_RETRY per default to trigger |
642 | * a re-evaluation of the target group state or SCSI_DH_OK | |
643 | * if no further action needs to be taken. | |
f2ecf13a | 644 | */ |
43394c67 | 645 | static unsigned alua_stpg(struct scsi_device *sdev, struct alua_port_group *pg) |
f2ecf13a | 646 | { |
b2460756 HR |
647 | int retval; |
648 | struct scsi_sense_hdr sense_hdr; | |
f2ecf13a | 649 | |
43394c67 | 650 | if (!(pg->tpgs & TPGS_MODE_EXPLICIT)) { |
b2460756 HR |
651 | /* Only implicit ALUA supported, retry */ |
652 | return SCSI_DH_RETRY; | |
653 | } | |
43394c67 | 654 | switch (pg->state) { |
b2460756 HR |
655 | case TPGS_STATE_OPTIMIZED: |
656 | return SCSI_DH_OK; | |
f2ecf13a | 657 | case TPGS_STATE_NONOPTIMIZED: |
43394c67 HR |
658 | if ((pg->flags & ALUA_OPTIMIZE_STPG) && |
659 | !pg->pref && | |
660 | (pg->tpgs & TPGS_MODE_IMPLICIT)) | |
b2460756 | 661 | return SCSI_DH_OK; |
f2ecf13a HR |
662 | break; |
663 | case TPGS_STATE_STANDBY: | |
664 | case TPGS_STATE_UNAVAILABLE: | |
f2ecf13a HR |
665 | break; |
666 | case TPGS_STATE_OFFLINE: | |
b2460756 | 667 | return SCSI_DH_IO; |
f2ecf13a | 668 | case TPGS_STATE_TRANSITIONING: |
f2ecf13a HR |
669 | break; |
670 | default: | |
b2460756 HR |
671 | sdev_printk(KERN_INFO, sdev, |
672 | "%s: stpg failed, unhandled TPGS state %d", | |
43394c67 | 673 | ALUA_DH_NAME, pg->state); |
b2460756 | 674 | return SCSI_DH_NOSYS; |
f2ecf13a | 675 | } |
43394c67 | 676 | retval = submit_stpg(sdev, pg->group_id, &sense_hdr); |
f2ecf13a | 677 | |
b2460756 | 678 | if (retval) { |
40bb61a7 | 679 | if (!scsi_sense_valid(&sense_hdr)) { |
b2460756 HR |
680 | sdev_printk(KERN_INFO, sdev, |
681 | "%s: stpg failed, result %d", | |
682 | ALUA_DH_NAME, retval); | |
40bb61a7 | 683 | if (driver_byte(retval) == DRIVER_ERROR) |
b2460756 HR |
684 | return SCSI_DH_DEV_TEMP_BUSY; |
685 | } else { | |
43394c67 | 686 | sdev_printk(KERN_INFO, sdev, "%s: stpg failed\n", |
b2460756 HR |
687 | ALUA_DH_NAME); |
688 | scsi_print_sense_hdr(sdev, ALUA_DH_NAME, &sense_hdr); | |
689 | } | |
f2ecf13a | 690 | } |
b2460756 HR |
691 | /* Retry RTPG */ |
692 | return SCSI_DH_RETRY; | |
f2ecf13a HR |
693 | } |
694 | ||
03197b61 HR |
695 | static void alua_rtpg_work(struct work_struct *work) |
696 | { | |
697 | struct alua_port_group *pg = | |
698 | container_of(work, struct alua_port_group, rtpg_work.work); | |
699 | struct scsi_device *sdev; | |
700 | LIST_HEAD(qdata_list); | |
701 | int err = SCSI_DH_OK; | |
702 | struct alua_queue_data *qdata, *tmp; | |
703 | unsigned long flags; | |
00642a1b | 704 | struct workqueue_struct *alua_wq = kaluad_wq; |
03197b61 HR |
705 | |
706 | spin_lock_irqsave(&pg->lock, flags); | |
707 | sdev = pg->rtpg_sdev; | |
708 | if (!sdev) { | |
709 | WARN_ON(pg->flags & ALUA_PG_RUN_RTPG); | |
710 | WARN_ON(pg->flags & ALUA_PG_RUN_STPG); | |
711 | spin_unlock_irqrestore(&pg->lock, flags); | |
712 | return; | |
713 | } | |
00642a1b HR |
714 | if (pg->flags & ALUA_SYNC_STPG) |
715 | alua_wq = kaluad_sync_wq; | |
03197b61 HR |
716 | pg->flags |= ALUA_PG_RUNNING; |
717 | if (pg->flags & ALUA_PG_RUN_RTPG) { | |
718 | pg->flags &= ~ALUA_PG_RUN_RTPG; | |
719 | spin_unlock_irqrestore(&pg->lock, flags); | |
720 | err = alua_rtpg(sdev, pg); | |
721 | spin_lock_irqsave(&pg->lock, flags); | |
2b35865e | 722 | if (err == SCSI_DH_RETRY || pg->flags & ALUA_PG_RUN_RTPG) { |
03197b61 HR |
723 | pg->flags &= ~ALUA_PG_RUNNING; |
724 | pg->flags |= ALUA_PG_RUN_RTPG; | |
725 | spin_unlock_irqrestore(&pg->lock, flags); | |
00642a1b | 726 | queue_delayed_work(alua_wq, &pg->rtpg_work, |
03197b61 HR |
727 | pg->interval * HZ); |
728 | return; | |
729 | } | |
730 | if (err != SCSI_DH_OK) | |
731 | pg->flags &= ~ALUA_PG_RUN_STPG; | |
732 | } | |
733 | if (pg->flags & ALUA_PG_RUN_STPG) { | |
734 | pg->flags &= ~ALUA_PG_RUN_STPG; | |
735 | spin_unlock_irqrestore(&pg->lock, flags); | |
736 | err = alua_stpg(sdev, pg); | |
737 | spin_lock_irqsave(&pg->lock, flags); | |
2b35865e | 738 | if (err == SCSI_DH_RETRY || pg->flags & ALUA_PG_RUN_RTPG) { |
03197b61 HR |
739 | pg->flags |= ALUA_PG_RUN_RTPG; |
740 | pg->interval = 0; | |
741 | pg->flags &= ~ALUA_PG_RUNNING; | |
742 | spin_unlock_irqrestore(&pg->lock, flags); | |
00642a1b | 743 | queue_delayed_work(alua_wq, &pg->rtpg_work, |
03197b61 HR |
744 | pg->interval * HZ); |
745 | return; | |
746 | } | |
747 | } | |
748 | ||
749 | list_splice_init(&pg->rtpg_list, &qdata_list); | |
750 | pg->rtpg_sdev = NULL; | |
751 | spin_unlock_irqrestore(&pg->lock, flags); | |
752 | ||
753 | list_for_each_entry_safe(qdata, tmp, &qdata_list, entry) { | |
754 | list_del(&qdata->entry); | |
755 | if (qdata->callback_fn) | |
756 | qdata->callback_fn(qdata->callback_data, err); | |
757 | kfree(qdata); | |
758 | } | |
759 | spin_lock_irqsave(&pg->lock, flags); | |
760 | pg->flags &= ~ALUA_PG_RUNNING; | |
761 | spin_unlock_irqrestore(&pg->lock, flags); | |
762 | scsi_device_put(sdev); | |
763 | kref_put(&pg->kref, release_port_group); | |
764 | } | |
765 | ||
766 | static void alua_rtpg_queue(struct alua_port_group *pg, | |
767 | struct scsi_device *sdev, | |
2b35865e | 768 | struct alua_queue_data *qdata, bool force) |
03197b61 HR |
769 | { |
770 | int start_queue = 0; | |
771 | unsigned long flags; | |
00642a1b | 772 | struct workqueue_struct *alua_wq = kaluad_wq; |
03197b61 HR |
773 | |
774 | if (!pg) | |
775 | return; | |
776 | ||
777 | spin_lock_irqsave(&pg->lock, flags); | |
778 | if (qdata) { | |
779 | list_add_tail(&qdata->entry, &pg->rtpg_list); | |
780 | pg->flags |= ALUA_PG_RUN_STPG; | |
2b35865e | 781 | force = true; |
03197b61 HR |
782 | } |
783 | if (pg->rtpg_sdev == NULL) { | |
784 | pg->interval = 0; | |
785 | pg->flags |= ALUA_PG_RUN_RTPG; | |
786 | kref_get(&pg->kref); | |
787 | pg->rtpg_sdev = sdev; | |
788 | scsi_device_get(sdev); | |
789 | start_queue = 1; | |
2b35865e HR |
790 | } else if (!(pg->flags & ALUA_PG_RUN_RTPG) && force) { |
791 | pg->flags |= ALUA_PG_RUN_RTPG; | |
792 | /* Do not queue if the worker is already running */ | |
793 | if (!(pg->flags & ALUA_PG_RUNNING)) { | |
794 | kref_get(&pg->kref); | |
795 | start_queue = 1; | |
796 | } | |
03197b61 | 797 | } |
2b35865e | 798 | |
00642a1b HR |
799 | if (pg->flags & ALUA_SYNC_STPG) |
800 | alua_wq = kaluad_sync_wq; | |
03197b61 HR |
801 | spin_unlock_irqrestore(&pg->lock, flags); |
802 | ||
803 | if (start_queue && | |
00642a1b | 804 | !queue_delayed_work(alua_wq, &pg->rtpg_work, |
03197b61 HR |
805 | msecs_to_jiffies(ALUA_RTPG_DELAY_MSECS))) { |
806 | scsi_device_put(sdev); | |
807 | kref_put(&pg->kref, release_port_group); | |
808 | } | |
809 | } | |
810 | ||
057ea7c9 HR |
811 | /* |
812 | * alua_initialize - Initialize ALUA state | |
813 | * @sdev: the device to be initialized | |
814 | * | |
815 | * For the prep_fn to work correctly we have | |
816 | * to initialize the ALUA state for the device. | |
817 | */ | |
818 | static int alua_initialize(struct scsi_device *sdev, struct alua_dh_data *h) | |
819 | { | |
43394c67 | 820 | int err = SCSI_DH_DEV_UNSUPP, tpgs; |
057ea7c9 | 821 | |
03197b61 | 822 | mutex_lock(&h->init_mutex); |
43394c67 | 823 | tpgs = alua_check_tpgs(sdev); |
a4253fde HR |
824 | if (tpgs != TPGS_MODE_NONE) |
825 | err = alua_check_vpd(sdev, h, tpgs); | |
03197b61 HR |
826 | h->init_error = err; |
827 | mutex_unlock(&h->init_mutex); | |
057ea7c9 HR |
828 | return err; |
829 | } | |
4335d092 MB |
830 | /* |
831 | * alua_set_params - set/unset the optimize flag | |
832 | * @sdev: device on the path to be activated | |
833 | * params - parameters in the following format | |
834 | * "no_of_params\0param1\0param2\0param3\0...\0" | |
835 | * For example, to set the flag pass the following parameters | |
836 | * from multipath.conf | |
837 | * hardware_handler "2 alua 1" | |
838 | */ | |
839 | static int alua_set_params(struct scsi_device *sdev, const char *params) | |
840 | { | |
ee14c674 | 841 | struct alua_dh_data *h = sdev->handler_data; |
03197b61 | 842 | struct alua_port_group __rcu *pg = NULL; |
4335d092 MB |
843 | unsigned int optimize = 0, argc; |
844 | const char *p = params; | |
845 | int result = SCSI_DH_OK; | |
03197b61 | 846 | unsigned long flags; |
4335d092 MB |
847 | |
848 | if ((sscanf(params, "%u", &argc) != 1) || (argc != 1)) | |
849 | return -EINVAL; | |
850 | ||
851 | while (*p++) | |
852 | ; | |
853 | if ((sscanf(p, "%u", &optimize) != 1) || (optimize > 1)) | |
854 | return -EINVAL; | |
855 | ||
03197b61 HR |
856 | rcu_read_lock(); |
857 | pg = rcu_dereference(h->pg); | |
858 | if (!pg) { | |
859 | rcu_read_unlock(); | |
43394c67 | 860 | return -ENXIO; |
03197b61 HR |
861 | } |
862 | spin_lock_irqsave(&pg->lock, flags); | |
4335d092 | 863 | if (optimize) |
43394c67 | 864 | pg->flags |= ALUA_OPTIMIZE_STPG; |
4335d092 | 865 | else |
43394c67 | 866 | pg->flags &= ~ALUA_OPTIMIZE_STPG; |
03197b61 HR |
867 | spin_unlock_irqrestore(&pg->lock, flags); |
868 | rcu_read_unlock(); | |
4335d092 MB |
869 | |
870 | return result; | |
871 | } | |
057ea7c9 HR |
872 | |
873 | /* | |
874 | * alua_activate - activate a path | |
875 | * @sdev: device on the path to be activated | |
876 | * | |
877 | * We're currently switching the port group to be activated only and | |
878 | * let the array figure out the rest. | |
879 | * There may be other arrays which require us to switch all port groups | |
880 | * based on a certain policy. But until we actually encounter them it | |
881 | * should be okay. | |
882 | */ | |
3ae31f6a CS |
883 | static int alua_activate(struct scsi_device *sdev, |
884 | activate_complete fn, void *data) | |
057ea7c9 | 885 | { |
ee14c674 | 886 | struct alua_dh_data *h = sdev->handler_data; |
057ea7c9 | 887 | int err = SCSI_DH_OK; |
03197b61 HR |
888 | struct alua_queue_data *qdata; |
889 | struct alua_port_group __rcu *pg; | |
057ea7c9 | 890 | |
03197b61 HR |
891 | qdata = kzalloc(sizeof(*qdata), GFP_KERNEL); |
892 | if (!qdata) { | |
893 | err = SCSI_DH_RES_TEMP_UNAVAIL; | |
46ccf6b5 | 894 | goto out; |
03197b61 HR |
895 | } |
896 | qdata->callback_fn = fn; | |
897 | qdata->callback_data = data; | |
898 | ||
899 | mutex_lock(&h->init_mutex); | |
900 | rcu_read_lock(); | |
901 | pg = rcu_dereference(h->pg); | |
902 | if (!pg || !kref_get_unless_zero(&pg->kref)) { | |
903 | rcu_read_unlock(); | |
904 | kfree(qdata); | |
905 | err = h->init_error; | |
906 | mutex_unlock(&h->init_mutex); | |
43394c67 HR |
907 | goto out; |
908 | } | |
03197b61 HR |
909 | fn = NULL; |
910 | rcu_read_unlock(); | |
911 | mutex_unlock(&h->init_mutex); | |
912 | ||
2b35865e | 913 | alua_rtpg_queue(pg, sdev, qdata, true); |
03197b61 | 914 | kref_put(&pg->kref, release_port_group); |
057ea7c9 | 915 | out: |
b2460756 | 916 | if (fn) |
3ae31f6a CS |
917 | fn(data, err); |
918 | return 0; | |
057ea7c9 HR |
919 | } |
920 | ||
2b35865e HR |
921 | /* |
922 | * alua_check - check path status | |
923 | * @sdev: device on the path to be checked | |
924 | * | |
925 | * Check the device status | |
926 | */ | |
927 | static void alua_check(struct scsi_device *sdev, bool force) | |
928 | { | |
929 | struct alua_dh_data *h = sdev->handler_data; | |
930 | struct alua_port_group *pg; | |
931 | ||
932 | rcu_read_lock(); | |
933 | pg = rcu_dereference(h->pg); | |
934 | if (!pg || !kref_get_unless_zero(&pg->kref)) { | |
935 | rcu_read_unlock(); | |
936 | return; | |
937 | } | |
938 | rcu_read_unlock(); | |
939 | ||
940 | alua_rtpg_queue(pg, sdev, NULL, force); | |
941 | kref_put(&pg->kref, release_port_group); | |
942 | } | |
943 | ||
057ea7c9 HR |
944 | /* |
945 | * alua_prep_fn - request callback | |
946 | * | |
947 | * Fail I/O to all paths not in state | |
948 | * active/optimized or active/non-optimized. | |
949 | */ | |
950 | static int alua_prep_fn(struct scsi_device *sdev, struct request *req) | |
951 | { | |
ee14c674 | 952 | struct alua_dh_data *h = sdev->handler_data; |
03197b61 HR |
953 | struct alua_port_group __rcu *pg; |
954 | int state = TPGS_STATE_OPTIMIZED; | |
057ea7c9 HR |
955 | int ret = BLKPREP_OK; |
956 | ||
03197b61 HR |
957 | rcu_read_lock(); |
958 | pg = rcu_dereference(h->pg); | |
959 | if (pg) | |
960 | state = pg->state; | |
961 | rcu_read_unlock(); | |
43394c67 | 962 | if (state == TPGS_STATE_TRANSITIONING) |
69723d17 | 963 | ret = BLKPREP_DEFER; |
43394c67 HR |
964 | else if (state != TPGS_STATE_OPTIMIZED && |
965 | state != TPGS_STATE_NONOPTIMIZED && | |
966 | state != TPGS_STATE_LBA_DEPENDENT) { | |
057ea7c9 HR |
967 | ret = BLKPREP_KILL; |
968 | req->cmd_flags |= REQ_QUIET; | |
969 | } | |
970 | return ret; | |
971 | ||
972 | } | |
973 | ||
057ea7c9 HR |
974 | /* |
975 | * alua_bus_attach - Attach device handler | |
976 | * @sdev: device to be attached to | |
977 | */ | |
ee14c674 | 978 | static int alua_bus_attach(struct scsi_device *sdev) |
057ea7c9 | 979 | { |
057ea7c9 | 980 | struct alua_dh_data *h; |
43394c67 | 981 | int err, ret = -EINVAL; |
057ea7c9 | 982 | |
cd37743f | 983 | h = kzalloc(sizeof(*h) , GFP_KERNEL); |
1d520328 | 984 | if (!h) |
ee14c674 | 985 | return -ENOMEM; |
03197b61 HR |
986 | spin_lock_init(&h->pg_lock); |
987 | rcu_assign_pointer(h->pg, NULL); | |
988 | h->init_error = SCSI_DH_OK; | |
96e65865 | 989 | h->sdev = sdev; |
057ea7c9 | 990 | |
03197b61 | 991 | mutex_init(&h->init_mutex); |
057ea7c9 | 992 | err = alua_initialize(sdev, h); |
43394c67 HR |
993 | if (err == SCSI_DH_NOMEM) |
994 | ret = -ENOMEM; | |
1d520328 | 995 | if (err != SCSI_DH_OK && err != SCSI_DH_DEV_OFFLINED) |
057ea7c9 HR |
996 | goto failed; |
997 | ||
ee14c674 CH |
998 | sdev->handler_data = h; |
999 | return 0; | |
057ea7c9 | 1000 | failed: |
cd37743f | 1001 | kfree(h); |
43394c67 | 1002 | return ret; |
057ea7c9 HR |
1003 | } |
1004 | ||
1005 | /* | |
1006 | * alua_bus_detach - Detach device handler | |
1007 | * @sdev: device to be detached from | |
1008 | */ | |
1009 | static void alua_bus_detach(struct scsi_device *sdev) | |
1010 | { | |
ee14c674 | 1011 | struct alua_dh_data *h = sdev->handler_data; |
03197b61 HR |
1012 | struct alua_port_group *pg; |
1013 | ||
1014 | spin_lock(&h->pg_lock); | |
1015 | pg = h->pg; | |
1016 | rcu_assign_pointer(h->pg, NULL); | |
1017 | h->sdev = NULL; | |
1018 | spin_unlock(&h->pg_lock); | |
1019 | if (pg) | |
1020 | kref_put(&pg->kref, release_port_group); | |
057ea7c9 | 1021 | |
ee14c674 | 1022 | sdev->handler_data = NULL; |
cd37743f | 1023 | kfree(h); |
057ea7c9 HR |
1024 | } |
1025 | ||
1d520328 CH |
1026 | static struct scsi_device_handler alua_dh = { |
1027 | .name = ALUA_DH_NAME, | |
1028 | .module = THIS_MODULE, | |
1029 | .attach = alua_bus_attach, | |
1030 | .detach = alua_bus_detach, | |
1031 | .prep_fn = alua_prep_fn, | |
1032 | .check_sense = alua_check_sense, | |
1033 | .activate = alua_activate, | |
1034 | .set_params = alua_set_params, | |
1d520328 CH |
1035 | }; |
1036 | ||
057ea7c9 HR |
1037 | static int __init alua_init(void) |
1038 | { | |
1039 | int r; | |
1040 | ||
03197b61 HR |
1041 | kaluad_wq = alloc_workqueue("kaluad", WQ_MEM_RECLAIM, 0); |
1042 | if (!kaluad_wq) { | |
1043 | /* Temporary failure, bypass */ | |
1044 | return SCSI_DH_DEV_TEMP_BUSY; | |
1045 | } | |
00642a1b HR |
1046 | kaluad_sync_wq = create_workqueue("kaluad_sync"); |
1047 | if (!kaluad_sync_wq) { | |
1048 | destroy_workqueue(kaluad_wq); | |
1049 | return SCSI_DH_DEV_TEMP_BUSY; | |
1050 | } | |
057ea7c9 | 1051 | r = scsi_register_device_handler(&alua_dh); |
03197b61 | 1052 | if (r != 0) { |
057ea7c9 HR |
1053 | printk(KERN_ERR "%s: Failed to register scsi device handler", |
1054 | ALUA_DH_NAME); | |
00642a1b | 1055 | destroy_workqueue(kaluad_sync_wq); |
03197b61 HR |
1056 | destroy_workqueue(kaluad_wq); |
1057 | } | |
057ea7c9 HR |
1058 | return r; |
1059 | } | |
1060 | ||
1061 | static void __exit alua_exit(void) | |
1062 | { | |
1063 | scsi_unregister_device_handler(&alua_dh); | |
00642a1b | 1064 | destroy_workqueue(kaluad_sync_wq); |
03197b61 | 1065 | destroy_workqueue(kaluad_wq); |
057ea7c9 HR |
1066 | } |
1067 | ||
1068 | module_init(alua_init); | |
1069 | module_exit(alua_exit); | |
1070 | ||
1071 | MODULE_DESCRIPTION("DM Multipath ALUA support"); | |
1072 | MODULE_AUTHOR("Hannes Reinecke <hare@suse.de>"); | |
1073 | MODULE_LICENSE("GPL"); | |
1074 | MODULE_VERSION(ALUA_DH_VER); |