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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> |
cb0a168c | 27 | #include <scsi/scsi_proto.h> |
80bd68d6 | 28 | #include <scsi/scsi_dbg.h> |
057ea7c9 HR |
29 | #include <scsi/scsi_eh.h> |
30 | #include <scsi/scsi_dh.h> | |
31 | ||
32 | #define ALUA_DH_NAME "alua" | |
e79c82cc | 33 | #define ALUA_DH_VER "2.0" |
057ea7c9 | 34 | |
057ea7c9 HR |
35 | #define TPGS_SUPPORT_NONE 0x00 |
36 | #define TPGS_SUPPORT_OPTIMIZED 0x01 | |
37 | #define TPGS_SUPPORT_NONOPTIMIZED 0x02 | |
38 | #define TPGS_SUPPORT_STANDBY 0x04 | |
39 | #define TPGS_SUPPORT_UNAVAILABLE 0x08 | |
69723d17 | 40 | #define TPGS_SUPPORT_LBA_DEPENDENT 0x10 |
057ea7c9 HR |
41 | #define TPGS_SUPPORT_OFFLINE 0x40 |
42 | #define TPGS_SUPPORT_TRANSITION 0x80 | |
80c716fa | 43 | #define TPGS_SUPPORT_ALL 0xdf |
057ea7c9 | 44 | |
3588c5a2 RE |
45 | #define RTPG_FMT_MASK 0x70 |
46 | #define RTPG_FMT_EXT_HDR 0x10 | |
47 | ||
057ea7c9 HR |
48 | #define TPGS_MODE_UNINITIALIZED -1 |
49 | #define TPGS_MODE_NONE 0x0 | |
50 | #define TPGS_MODE_IMPLICIT 0x1 | |
51 | #define TPGS_MODE_EXPLICIT 0x2 | |
52 | ||
c49c8345 | 53 | #define ALUA_RTPG_SIZE 128 |
3588c5a2 | 54 | #define ALUA_FAILOVER_TIMEOUT 60 |
057ea7c9 | 55 | #define ALUA_FAILOVER_RETRIES 5 |
03197b61 | 56 | #define ALUA_RTPG_DELAY_MSECS 5 |
057ea7c9 | 57 | |
6c4fc044 | 58 | /* device handler flags */ |
03197b61 HR |
59 | #define ALUA_OPTIMIZE_STPG 0x01 |
60 | #define ALUA_RTPG_EXT_HDR_UNSUPP 0x02 | |
61 | /* State machine flags */ | |
62 | #define ALUA_PG_RUN_RTPG 0x10 | |
63 | #define ALUA_PG_RUN_STPG 0x20 | |
64 | #define ALUA_PG_RUNNING 0x40 | |
4335d092 | 65 | |
aa90f490 HR |
66 | static uint optimize_stpg; |
67 | module_param(optimize_stpg, uint, S_IRUGO|S_IWUSR); | |
68 | 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."); | |
69 | ||
43394c67 HR |
70 | static LIST_HEAD(port_group_list); |
71 | static DEFINE_SPINLOCK(port_group_lock); | |
03197b61 | 72 | static struct workqueue_struct *kaluad_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; |
cb0a168c | 78 | struct list_head dh_list; |
0047220c HR |
79 | unsigned char device_id_str[256]; |
80 | int device_id_len; | |
057ea7c9 | 81 | int group_id; |
057ea7c9 HR |
82 | int tpgs; |
83 | int state; | |
dcd3a754 | 84 | int pref; |
80c716fa | 85 | int valid_states; |
4335d092 | 86 | unsigned flags; /* used for optimizing STPG */ |
3588c5a2 | 87 | unsigned char transition_tmo; |
03197b61 HR |
88 | unsigned long expiry; |
89 | unsigned long interval; | |
90 | struct delayed_work rtpg_work; | |
91 | spinlock_t lock; | |
92 | struct list_head rtpg_list; | |
93 | struct scsi_device *rtpg_sdev; | |
43394c67 HR |
94 | }; |
95 | ||
96 | struct alua_dh_data { | |
cb0a168c | 97 | struct list_head node; |
d29425b0 | 98 | struct alua_port_group __rcu *pg; |
43394c67 | 99 | int group_id; |
03197b61 | 100 | spinlock_t pg_lock; |
96e65865 | 101 | struct scsi_device *sdev; |
03197b61 HR |
102 | int init_error; |
103 | struct mutex init_mutex; | |
104 | }; | |
105 | ||
106 | struct alua_queue_data { | |
107 | struct list_head entry; | |
96e65865 CS |
108 | activate_complete callback_fn; |
109 | void *callback_data; | |
057ea7c9 HR |
110 | }; |
111 | ||
112 | #define ALUA_POLICY_SWITCH_CURRENT 0 | |
113 | #define ALUA_POLICY_SWITCH_ALL 1 | |
114 | ||
03197b61 | 115 | static void alua_rtpg_work(struct work_struct *work); |
7cb689fe | 116 | static bool alua_rtpg_queue(struct alua_port_group *pg, |
03197b61 | 117 | struct scsi_device *sdev, |
2b35865e HR |
118 | struct alua_queue_data *qdata, bool force); |
119 | static void alua_check(struct scsi_device *sdev, bool force); | |
96e65865 | 120 | |
43394c67 HR |
121 | static void release_port_group(struct kref *kref) |
122 | { | |
123 | struct alua_port_group *pg; | |
124 | ||
125 | pg = container_of(kref, struct alua_port_group, kref); | |
03197b61 HR |
126 | if (pg->rtpg_sdev) |
127 | flush_delayed_work(&pg->rtpg_work); | |
43394c67 HR |
128 | spin_lock(&port_group_lock); |
129 | list_del(&pg->node); | |
130 | spin_unlock(&port_group_lock); | |
03197b61 | 131 | kfree_rcu(pg, rcu); |
43394c67 HR |
132 | } |
133 | ||
057ea7c9 HR |
134 | /* |
135 | * submit_rtpg - Issue a REPORT TARGET GROUP STATES command | |
136 | * @sdev: sdev the command should be sent to | |
137 | */ | |
40bb61a7 HR |
138 | static int submit_rtpg(struct scsi_device *sdev, unsigned char *buff, |
139 | int bufflen, struct scsi_sense_hdr *sshdr, int flags) | |
057ea7c9 | 140 | { |
92eb5062 | 141 | u8 cdb[MAX_COMMAND_SIZE]; |
40bb61a7 HR |
142 | int req_flags = REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT | |
143 | REQ_FAILFAST_DRIVER; | |
057ea7c9 HR |
144 | |
145 | /* Prepare the command. */ | |
92eb5062 | 146 | memset(cdb, 0x0, MAX_COMMAND_SIZE); |
40bb61a7 | 147 | cdb[0] = MAINTENANCE_IN; |
d42ae5f3 | 148 | if (!(flags & ALUA_RTPG_EXT_HDR_UNSUPP)) |
40bb61a7 | 149 | cdb[1] = MI_REPORT_TARGET_PGS | MI_EXT_HDR_PARAM_FMT; |
8e67ce60 | 150 | else |
40bb61a7 HR |
151 | cdb[1] = MI_REPORT_TARGET_PGS; |
152 | put_unaligned_be32(bufflen, &cdb[6]); | |
153 | ||
fcbfffe2 CH |
154 | return scsi_execute(sdev, cdb, DMA_FROM_DEVICE, buff, bufflen, NULL, |
155 | sshdr, ALUA_FAILOVER_TIMEOUT * HZ, | |
156 | ALUA_FAILOVER_RETRIES, req_flags, 0, NULL); | |
057ea7c9 HR |
157 | } |
158 | ||
96e65865 | 159 | /* |
b2460756 | 160 | * submit_stpg - Issue a SET TARGET PORT GROUP command |
057ea7c9 HR |
161 | * |
162 | * Currently we're only setting the current target port group state | |
163 | * to 'active/optimized' and let the array firmware figure out | |
164 | * the states of the remaining groups. | |
165 | */ | |
40bb61a7 HR |
166 | static int submit_stpg(struct scsi_device *sdev, int group_id, |
167 | struct scsi_sense_hdr *sshdr) | |
057ea7c9 | 168 | { |
92eb5062 | 169 | u8 cdb[MAX_COMMAND_SIZE]; |
b2460756 | 170 | unsigned char stpg_data[8]; |
057ea7c9 | 171 | int stpg_len = 8; |
40bb61a7 HR |
172 | int req_flags = REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT | |
173 | REQ_FAILFAST_DRIVER; | |
057ea7c9 HR |
174 | |
175 | /* Prepare the data buffer */ | |
b2460756 | 176 | memset(stpg_data, 0, stpg_len); |
5115fc7e | 177 | stpg_data[4] = SCSI_ACCESS_STATE_OPTIMAL; |
b2460756 | 178 | put_unaligned_be16(group_id, &stpg_data[6]); |
057ea7c9 | 179 | |
057ea7c9 | 180 | /* Prepare the command. */ |
92eb5062 | 181 | memset(cdb, 0x0, MAX_COMMAND_SIZE); |
40bb61a7 HR |
182 | cdb[0] = MAINTENANCE_OUT; |
183 | cdb[1] = MO_SET_TARGET_PGS; | |
184 | put_unaligned_be32(stpg_len, &cdb[6]); | |
185 | ||
fcbfffe2 CH |
186 | return scsi_execute(sdev, cdb, DMA_TO_DEVICE, stpg_data, stpg_len, NULL, |
187 | sshdr, ALUA_FAILOVER_TIMEOUT * HZ, | |
188 | ALUA_FAILOVER_RETRIES, req_flags, 0, NULL); | |
057ea7c9 HR |
189 | } |
190 | ||
1f275f97 BVA |
191 | static struct alua_port_group *alua_find_get_pg(char *id_str, size_t id_size, |
192 | int group_id) | |
0047220c HR |
193 | { |
194 | struct alua_port_group *pg; | |
195 | ||
fe8b9534 HR |
196 | if (!id_str || !id_size || !strlen(id_str)) |
197 | return NULL; | |
198 | ||
0047220c HR |
199 | list_for_each_entry(pg, &port_group_list, node) { |
200 | if (pg->group_id != group_id) | |
201 | continue; | |
fe8b9534 | 202 | if (!pg->device_id_len || pg->device_id_len != id_size) |
0047220c HR |
203 | continue; |
204 | if (strncmp(pg->device_id_str, id_str, id_size)) | |
205 | continue; | |
206 | if (!kref_get_unless_zero(&pg->kref)) | |
207 | continue; | |
208 | return pg; | |
209 | } | |
210 | ||
211 | return NULL; | |
212 | } | |
213 | ||
43394c67 HR |
214 | /* |
215 | * alua_alloc_pg - Allocate a new port_group structure | |
216 | * @sdev: scsi device | |
43394c67 | 217 | * @group_id: port group id |
2e8c3002 | 218 | * @tpgs: target port group settings |
43394c67 HR |
219 | * |
220 | * Allocate a new port_group structure for a given | |
221 | * device. | |
222 | */ | |
1f275f97 BVA |
223 | static struct alua_port_group *alua_alloc_pg(struct scsi_device *sdev, |
224 | int group_id, int tpgs) | |
43394c67 | 225 | { |
0047220c | 226 | struct alua_port_group *pg, *tmp_pg; |
43394c67 HR |
227 | |
228 | pg = kzalloc(sizeof(struct alua_port_group), GFP_KERNEL); | |
229 | if (!pg) | |
0047220c | 230 | return ERR_PTR(-ENOMEM); |
43394c67 | 231 | |
0047220c HR |
232 | pg->device_id_len = scsi_vpd_lun_id(sdev, pg->device_id_str, |
233 | sizeof(pg->device_id_str)); | |
234 | if (pg->device_id_len <= 0) { | |
235 | /* | |
fe8b9534 HR |
236 | * TPGS supported but no device identification found. |
237 | * Generate private device identification. | |
0047220c | 238 | */ |
0047220c HR |
239 | sdev_printk(KERN_INFO, sdev, |
240 | "%s: No device descriptors found\n", | |
241 | ALUA_DH_NAME); | |
fe8b9534 HR |
242 | pg->device_id_str[0] = '\0'; |
243 | pg->device_id_len = 0; | |
0047220c | 244 | } |
43394c67 HR |
245 | pg->group_id = group_id; |
246 | pg->tpgs = tpgs; | |
5115fc7e | 247 | pg->state = SCSI_ACCESS_STATE_OPTIMAL; |
80c716fa | 248 | pg->valid_states = TPGS_SUPPORT_ALL; |
aa90f490 HR |
249 | if (optimize_stpg) |
250 | pg->flags |= ALUA_OPTIMIZE_STPG; | |
43394c67 | 251 | kref_init(&pg->kref); |
03197b61 HR |
252 | INIT_DELAYED_WORK(&pg->rtpg_work, alua_rtpg_work); |
253 | INIT_LIST_HEAD(&pg->rtpg_list); | |
254 | INIT_LIST_HEAD(&pg->node); | |
cb0a168c | 255 | INIT_LIST_HEAD(&pg->dh_list); |
03197b61 | 256 | spin_lock_init(&pg->lock); |
0047220c | 257 | |
43394c67 | 258 | spin_lock(&port_group_lock); |
0047220c HR |
259 | tmp_pg = alua_find_get_pg(pg->device_id_str, pg->device_id_len, |
260 | group_id); | |
261 | if (tmp_pg) { | |
262 | spin_unlock(&port_group_lock); | |
263 | kfree(pg); | |
264 | return tmp_pg; | |
265 | } | |
266 | ||
43394c67 HR |
267 | list_add(&pg->node, &port_group_list); |
268 | spin_unlock(&port_group_lock); | |
269 | ||
270 | return pg; | |
271 | } | |
272 | ||
057ea7c9 | 273 | /* |
d7c48feb | 274 | * alua_check_tpgs - Evaluate TPGS setting |
057ea7c9 HR |
275 | * @sdev: device to be checked |
276 | * | |
d7c48feb | 277 | * Examine the TPGS setting of the sdev to find out if ALUA |
057ea7c9 HR |
278 | * is supported. |
279 | */ | |
ad0ea64c | 280 | static int alua_check_tpgs(struct scsi_device *sdev) |
057ea7c9 | 281 | { |
ad0ea64c | 282 | int tpgs = TPGS_MODE_NONE; |
057ea7c9 | 283 | |
db5a6a60 HR |
284 | /* |
285 | * ALUA support for non-disk devices is fraught with | |
286 | * difficulties, so disable it for now. | |
287 | */ | |
288 | if (sdev->type != TYPE_DISK) { | |
db5a6a60 HR |
289 | sdev_printk(KERN_INFO, sdev, |
290 | "%s: disable for non-disk devices\n", | |
291 | ALUA_DH_NAME); | |
ad0ea64c | 292 | return tpgs; |
db5a6a60 HR |
293 | } |
294 | ||
ad0ea64c HR |
295 | tpgs = scsi_device_tpgs(sdev); |
296 | switch (tpgs) { | |
057ea7c9 HR |
297 | case TPGS_MODE_EXPLICIT|TPGS_MODE_IMPLICIT: |
298 | sdev_printk(KERN_INFO, sdev, | |
299 | "%s: supports implicit and explicit TPGS\n", | |
300 | ALUA_DH_NAME); | |
301 | break; | |
302 | case TPGS_MODE_EXPLICIT: | |
303 | sdev_printk(KERN_INFO, sdev, "%s: supports explicit TPGS\n", | |
304 | ALUA_DH_NAME); | |
305 | break; | |
306 | case TPGS_MODE_IMPLICIT: | |
307 | sdev_printk(KERN_INFO, sdev, "%s: supports implicit TPGS\n", | |
308 | ALUA_DH_NAME); | |
309 | break; | |
6cc05d45 | 310 | case TPGS_MODE_NONE: |
057ea7c9 HR |
311 | sdev_printk(KERN_INFO, sdev, "%s: not supported\n", |
312 | ALUA_DH_NAME); | |
057ea7c9 | 313 | break; |
6cc05d45 HR |
314 | default: |
315 | sdev_printk(KERN_INFO, sdev, | |
316 | "%s: unsupported TPGS setting %d\n", | |
ad0ea64c HR |
317 | ALUA_DH_NAME, tpgs); |
318 | tpgs = TPGS_MODE_NONE; | |
6cc05d45 | 319 | break; |
057ea7c9 HR |
320 | } |
321 | ||
ad0ea64c | 322 | return tpgs; |
057ea7c9 HR |
323 | } |
324 | ||
325 | /* | |
9b80dcec | 326 | * alua_check_vpd - Evaluate INQUIRY vpd page 0x83 |
057ea7c9 HR |
327 | * @sdev: device to be checked |
328 | * | |
329 | * Extract the relative target port and the target port group | |
330 | * descriptor from the list of identificators. | |
331 | */ | |
a4253fde HR |
332 | static int alua_check_vpd(struct scsi_device *sdev, struct alua_dh_data *h, |
333 | int tpgs) | |
057ea7c9 | 334 | { |
83ea0e5e | 335 | int rel_port = -1, group_id; |
03197b61 | 336 | struct alua_port_group *pg, *old_pg = NULL; |
100bcb85 | 337 | bool pg_updated = false; |
cb0a168c | 338 | unsigned long flags; |
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 | } | |
fe8b9534 HR |
359 | if (pg->device_id_len) |
360 | sdev_printk(KERN_INFO, sdev, | |
361 | "%s: device %s port group %x rel port %x\n", | |
362 | ALUA_DH_NAME, pg->device_id_str, | |
363 | group_id, rel_port); | |
364 | else | |
365 | sdev_printk(KERN_INFO, sdev, | |
366 | "%s: port group %x rel port %x\n", | |
367 | ALUA_DH_NAME, group_id, rel_port); | |
03197b61 HR |
368 | |
369 | /* Check for existing port group references */ | |
370 | spin_lock(&h->pg_lock); | |
d29425b0 | 371 | old_pg = rcu_dereference_protected(h->pg, lockdep_is_held(&h->pg_lock)); |
03197b61 HR |
372 | if (old_pg != pg) { |
373 | /* port group has changed. Update to new port group */ | |
cb0a168c HR |
374 | if (h->pg) { |
375 | spin_lock_irqsave(&old_pg->lock, flags); | |
376 | list_del_rcu(&h->node); | |
377 | spin_unlock_irqrestore(&old_pg->lock, flags); | |
378 | } | |
03197b61 | 379 | rcu_assign_pointer(h->pg, pg); |
cb0a168c | 380 | pg_updated = true; |
03197b61 | 381 | } |
cb0a168c HR |
382 | |
383 | spin_lock_irqsave(&pg->lock, flags); | |
cb0a168c HR |
384 | if (pg_updated) |
385 | list_add_rcu(&h->node, &pg->dh_list); | |
386 | spin_unlock_irqrestore(&pg->lock, flags); | |
387 | ||
d29425b0 BVA |
388 | alua_rtpg_queue(rcu_dereference_protected(h->pg, |
389 | lockdep_is_held(&h->pg_lock)), | |
390 | sdev, NULL, true); | |
03197b61 HR |
391 | spin_unlock(&h->pg_lock); |
392 | ||
393 | if (old_pg) | |
394 | kref_put(&old_pg->kref, release_port_group); | |
057ea7c9 | 395 | |
03197b61 | 396 | return SCSI_DH_OK; |
057ea7c9 HR |
397 | } |
398 | ||
5115fc7e | 399 | static char print_alua_state(unsigned char state) |
057ea7c9 HR |
400 | { |
401 | switch (state) { | |
5115fc7e | 402 | case SCSI_ACCESS_STATE_OPTIMAL: |
057ea7c9 | 403 | return 'A'; |
5115fc7e | 404 | case SCSI_ACCESS_STATE_ACTIVE: |
057ea7c9 | 405 | return 'N'; |
5115fc7e | 406 | case SCSI_ACCESS_STATE_STANDBY: |
057ea7c9 | 407 | return 'S'; |
5115fc7e | 408 | case SCSI_ACCESS_STATE_UNAVAILABLE: |
057ea7c9 | 409 | return 'U'; |
5115fc7e | 410 | case SCSI_ACCESS_STATE_LBA: |
69723d17 | 411 | return 'L'; |
5115fc7e | 412 | case SCSI_ACCESS_STATE_OFFLINE: |
057ea7c9 | 413 | return 'O'; |
5115fc7e | 414 | case SCSI_ACCESS_STATE_TRANSITIONING: |
057ea7c9 HR |
415 | return 'T'; |
416 | default: | |
417 | return 'X'; | |
418 | } | |
419 | } | |
420 | ||
421 | static int alua_check_sense(struct scsi_device *sdev, | |
422 | struct scsi_sense_hdr *sense_hdr) | |
423 | { | |
424 | switch (sense_hdr->sense_key) { | |
425 | case NOT_READY: | |
2b35865e | 426 | if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x0a) { |
057ea7c9 HR |
427 | /* |
428 | * LUN Not Accessible - ALUA state transition | |
429 | */ | |
2b35865e HR |
430 | alua_check(sdev, false); |
431 | return NEEDS_RETRY; | |
432 | } | |
057ea7c9 HR |
433 | break; |
434 | case UNIT_ATTENTION: | |
2b35865e | 435 | if (sense_hdr->asc == 0x29 && sense_hdr->ascq == 0x00) { |
057ea7c9 | 436 | /* |
2b35865e HR |
437 | * Power On, Reset, or Bus Device Reset. |
438 | * Might have obscured a state transition, | |
439 | * so schedule a recheck. | |
057ea7c9 | 440 | */ |
2b35865e | 441 | alua_check(sdev, true); |
c7dbb627 | 442 | return ADD_TO_MLQUEUE; |
2b35865e | 443 | } |
c20ee7b5 SS |
444 | if (sense_hdr->asc == 0x29 && sense_hdr->ascq == 0x04) |
445 | /* | |
446 | * Device internal reset | |
447 | */ | |
448 | return ADD_TO_MLQUEUE; | |
410f02d8 MB |
449 | if (sense_hdr->asc == 0x2a && sense_hdr->ascq == 0x01) |
450 | /* | |
451 | * Mode Parameters Changed | |
452 | */ | |
453 | return ADD_TO_MLQUEUE; | |
2b35865e | 454 | if (sense_hdr->asc == 0x2a && sense_hdr->ascq == 0x06) { |
057ea7c9 HR |
455 | /* |
456 | * ALUA state changed | |
457 | */ | |
2b35865e | 458 | alua_check(sdev, true); |
c7dbb627 | 459 | return ADD_TO_MLQUEUE; |
2b35865e HR |
460 | } |
461 | if (sense_hdr->asc == 0x2a && sense_hdr->ascq == 0x07) { | |
057ea7c9 HR |
462 | /* |
463 | * Implicit ALUA state transition failed | |
464 | */ | |
2b35865e | 465 | alua_check(sdev, true); |
c7dbb627 | 466 | return ADD_TO_MLQUEUE; |
2b35865e | 467 | } |
bf81973a MB |
468 | if (sense_hdr->asc == 0x3f && sense_hdr->ascq == 0x03) |
469 | /* | |
470 | * Inquiry data has changed | |
471 | */ | |
472 | return ADD_TO_MLQUEUE; | |
473 | if (sense_hdr->asc == 0x3f && sense_hdr->ascq == 0x0e) | |
4d086f6b IH |
474 | /* |
475 | * REPORTED_LUNS_DATA_HAS_CHANGED is reported | |
476 | * when switching controllers on targets like | |
477 | * Intel Multi-Flex. We can just retry. | |
478 | */ | |
479 | return ADD_TO_MLQUEUE; | |
057ea7c9 HR |
480 | break; |
481 | } | |
482 | ||
483 | return SCSI_RETURN_NOT_HANDLED; | |
484 | } | |
485 | ||
9d2c3039 HR |
486 | /* |
487 | * alua_tur - Send a TEST UNIT READY | |
488 | * @sdev: device to which the TEST UNIT READY command should be send | |
489 | * | |
490 | * Send a TEST UNIT READY to @sdev to figure out the device state | |
491 | * Returns SCSI_DH_RETRY if the sense code is NOT READY/ALUA TRANSITIONING, | |
492 | * SCSI_DH_OK if no error occurred, and SCSI_DH_IO otherwise. | |
493 | */ | |
494 | static int alua_tur(struct scsi_device *sdev) | |
495 | { | |
496 | struct scsi_sense_hdr sense_hdr; | |
497 | int retval; | |
498 | ||
499 | retval = scsi_test_unit_ready(sdev, ALUA_FAILOVER_TIMEOUT * HZ, | |
500 | ALUA_FAILOVER_RETRIES, &sense_hdr); | |
501 | if (sense_hdr.sense_key == NOT_READY && | |
502 | sense_hdr.asc == 0x04 && sense_hdr.ascq == 0x0a) | |
503 | return SCSI_DH_RETRY; | |
504 | else if (retval) | |
505 | return SCSI_DH_IO; | |
506 | else | |
507 | return SCSI_DH_OK; | |
508 | } | |
509 | ||
057ea7c9 HR |
510 | /* |
511 | * alua_rtpg - Evaluate REPORT TARGET GROUP STATES | |
512 | * @sdev: the device to be evaluated. | |
513 | * | |
514 | * Evaluate the Target Port Group State. | |
515 | * Returns SCSI_DH_DEV_OFFLINED if the path is | |
25985edc | 516 | * found to be unusable. |
057ea7c9 | 517 | */ |
28261402 | 518 | static int alua_rtpg(struct scsi_device *sdev, struct alua_port_group *pg) |
057ea7c9 HR |
519 | { |
520 | struct scsi_sense_hdr sense_hdr; | |
c57168a1 | 521 | struct alua_port_group *tmp_pg; |
80c716fa | 522 | int len, k, off, bufflen = ALUA_RTPG_SIZE; |
c57168a1 | 523 | unsigned char *desc, *buff; |
5597cafc | 524 | unsigned err, retval; |
3588c5a2 RE |
525 | unsigned int tpg_desc_tbl_off; |
526 | unsigned char orig_transition_tmo; | |
c57168a1 | 527 | unsigned long flags; |
3588c5a2 | 528 | |
03197b61 HR |
529 | if (!pg->expiry) { |
530 | unsigned long transition_tmo = ALUA_FAILOVER_TIMEOUT * HZ; | |
531 | ||
532 | if (pg->transition_tmo) | |
533 | transition_tmo = pg->transition_tmo * HZ; | |
534 | ||
535 | pg->expiry = round_jiffies_up(jiffies + transition_tmo); | |
536 | } | |
057ea7c9 | 537 | |
c49c8345 HR |
538 | buff = kzalloc(bufflen, GFP_KERNEL); |
539 | if (!buff) | |
540 | return SCSI_DH_DEV_TEMP_BUSY; | |
541 | ||
057ea7c9 | 542 | retry: |
a4bd8520 | 543 | err = 0; |
43394c67 | 544 | retval = submit_rtpg(sdev, buff, bufflen, &sense_hdr, pg->flags); |
40bb61a7 | 545 | |
5597cafc | 546 | if (retval) { |
80c716fa HR |
547 | /* |
548 | * Some (broken) implementations have a habit of returning | |
549 | * an error during things like firmware update etc. | |
550 | * But if the target only supports active/optimized there's | |
551 | * not much we can do; it's not that we can switch paths | |
552 | * or anything. | |
553 | * So ignore any errors to avoid spurious failures during | |
554 | * path failover. | |
555 | */ | |
556 | if ((pg->valid_states & ~TPGS_SUPPORT_OPTIMIZED) == 0) { | |
557 | sdev_printk(KERN_INFO, sdev, | |
558 | "%s: ignoring rtpg result %d\n", | |
559 | ALUA_DH_NAME, retval); | |
560 | kfree(buff); | |
561 | return SCSI_DH_OK; | |
562 | } | |
40bb61a7 | 563 | if (!scsi_sense_valid(&sense_hdr)) { |
5597cafc HR |
564 | sdev_printk(KERN_INFO, sdev, |
565 | "%s: rtpg failed, result %d\n", | |
566 | ALUA_DH_NAME, retval); | |
c49c8345 | 567 | kfree(buff); |
40bb61a7 | 568 | if (driver_byte(retval) == DRIVER_ERROR) |
5597cafc | 569 | return SCSI_DH_DEV_TEMP_BUSY; |
057ea7c9 | 570 | return SCSI_DH_IO; |
5597cafc | 571 | } |
057ea7c9 | 572 | |
8e67ce60 RE |
573 | /* |
574 | * submit_rtpg() has failed on existing arrays | |
575 | * when requesting extended header info, and | |
576 | * the array doesn't support extended headers, | |
577 | * even though it shouldn't according to T10. | |
578 | * The retry without rtpg_ext_hdr_req set | |
579 | * handles this. | |
580 | */ | |
43394c67 | 581 | if (!(pg->flags & ALUA_RTPG_EXT_HDR_UNSUPP) && |
8e67ce60 RE |
582 | sense_hdr.sense_key == ILLEGAL_REQUEST && |
583 | sense_hdr.asc == 0x24 && sense_hdr.ascq == 0) { | |
43394c67 | 584 | pg->flags |= ALUA_RTPG_EXT_HDR_UNSUPP; |
8e67ce60 RE |
585 | goto retry; |
586 | } | |
e2d817db HR |
587 | /* |
588 | * Retry on ALUA state transition or if any | |
589 | * UNIT ATTENTION occurred. | |
590 | */ | |
591 | if (sense_hdr.sense_key == NOT_READY && | |
592 | sense_hdr.asc == 0x04 && sense_hdr.ascq == 0x0a) | |
593 | err = SCSI_DH_RETRY; | |
594 | else if (sense_hdr.sense_key == UNIT_ATTENTION) | |
595 | err = SCSI_DH_RETRY; | |
03197b61 HR |
596 | if (err == SCSI_DH_RETRY && |
597 | pg->expiry != 0 && time_before(jiffies, pg->expiry)) { | |
80bd68d6 HR |
598 | sdev_printk(KERN_ERR, sdev, "%s: rtpg retry\n", |
599 | ALUA_DH_NAME); | |
600 | scsi_print_sense_hdr(sdev, ALUA_DH_NAME, &sense_hdr); | |
086acff2 | 601 | kfree(buff); |
03197b61 | 602 | return err; |
80bd68d6 HR |
603 | } |
604 | sdev_printk(KERN_ERR, sdev, "%s: rtpg failed\n", | |
605 | ALUA_DH_NAME); | |
606 | scsi_print_sense_hdr(sdev, ALUA_DH_NAME, &sense_hdr); | |
c49c8345 | 607 | kfree(buff); |
03197b61 | 608 | pg->expiry = 0; |
80bd68d6 | 609 | return SCSI_DH_IO; |
057ea7c9 | 610 | } |
057ea7c9 | 611 | |
c49c8345 | 612 | len = get_unaligned_be32(&buff[0]) + 4; |
057ea7c9 | 613 | |
c49c8345 | 614 | if (len > bufflen) { |
057ea7c9 | 615 | /* Resubmit with the correct length */ |
c49c8345 HR |
616 | kfree(buff); |
617 | bufflen = len; | |
618 | buff = kmalloc(bufflen, GFP_KERNEL); | |
619 | if (!buff) { | |
057ea7c9 | 620 | sdev_printk(KERN_WARNING, sdev, |
cadbd4a5 | 621 | "%s: kmalloc buffer failed\n",__func__); |
057ea7c9 | 622 | /* Temporary failure, bypass */ |
03197b61 | 623 | pg->expiry = 0; |
057ea7c9 HR |
624 | return SCSI_DH_DEV_TEMP_BUSY; |
625 | } | |
626 | goto retry; | |
627 | } | |
628 | ||
43394c67 | 629 | orig_transition_tmo = pg->transition_tmo; |
c49c8345 | 630 | if ((buff[4] & RTPG_FMT_MASK) == RTPG_FMT_EXT_HDR && buff[5] != 0) |
43394c67 | 631 | pg->transition_tmo = buff[5]; |
3588c5a2 | 632 | else |
43394c67 | 633 | pg->transition_tmo = ALUA_FAILOVER_TIMEOUT; |
3588c5a2 | 634 | |
28261402 | 635 | if (orig_transition_tmo != pg->transition_tmo) { |
3588c5a2 RE |
636 | sdev_printk(KERN_INFO, sdev, |
637 | "%s: transition timeout set to %d seconds\n", | |
43394c67 | 638 | ALUA_DH_NAME, pg->transition_tmo); |
03197b61 | 639 | pg->expiry = jiffies + pg->transition_tmo * HZ; |
3588c5a2 RE |
640 | } |
641 | ||
c49c8345 | 642 | if ((buff[4] & RTPG_FMT_MASK) == RTPG_FMT_EXT_HDR) |
3588c5a2 RE |
643 | tpg_desc_tbl_off = 8; |
644 | else | |
645 | tpg_desc_tbl_off = 4; | |
646 | ||
c57168a1 | 647 | for (k = tpg_desc_tbl_off, desc = buff + tpg_desc_tbl_off; |
3588c5a2 | 648 | k < len; |
c57168a1 HR |
649 | k += off, desc += off) { |
650 | u16 group_id = get_unaligned_be16(&desc[2]); | |
651 | ||
652 | spin_lock_irqsave(&port_group_lock, flags); | |
653 | tmp_pg = alua_find_get_pg(pg->device_id_str, pg->device_id_len, | |
654 | group_id); | |
655 | spin_unlock_irqrestore(&port_group_lock, flags); | |
656 | if (tmp_pg) { | |
657 | if (spin_trylock_irqsave(&tmp_pg->lock, flags)) { | |
658 | if ((tmp_pg == pg) || | |
659 | !(tmp_pg->flags & ALUA_PG_RUNNING)) { | |
cb0a168c HR |
660 | struct alua_dh_data *h; |
661 | ||
c57168a1 HR |
662 | tmp_pg->state = desc[0] & 0x0f; |
663 | tmp_pg->pref = desc[0] >> 7; | |
cb0a168c HR |
664 | rcu_read_lock(); |
665 | list_for_each_entry_rcu(h, | |
666 | &tmp_pg->dh_list, node) { | |
667 | /* h->sdev should always be valid */ | |
668 | BUG_ON(!h->sdev); | |
669 | h->sdev->access_state = desc[0]; | |
670 | } | |
671 | rcu_read_unlock(); | |
c57168a1 HR |
672 | } |
673 | if (tmp_pg == pg) | |
80c716fa | 674 | tmp_pg->valid_states = desc[1]; |
c57168a1 HR |
675 | spin_unlock_irqrestore(&tmp_pg->lock, flags); |
676 | } | |
677 | kref_put(&tmp_pg->kref, release_port_group); | |
057ea7c9 | 678 | } |
c57168a1 | 679 | off = 8 + (desc[7] * 4); |
057ea7c9 HR |
680 | } |
681 | ||
c57168a1 | 682 | spin_lock_irqsave(&pg->lock, flags); |
057ea7c9 | 683 | sdev_printk(KERN_INFO, sdev, |
dcd3a754 | 684 | "%s: port group %02x state %c %s supports %c%c%c%c%c%c%c\n", |
43394c67 HR |
685 | ALUA_DH_NAME, pg->group_id, print_alua_state(pg->state), |
686 | pg->pref ? "preferred" : "non-preferred", | |
80c716fa HR |
687 | pg->valid_states&TPGS_SUPPORT_TRANSITION?'T':'t', |
688 | pg->valid_states&TPGS_SUPPORT_OFFLINE?'O':'o', | |
689 | pg->valid_states&TPGS_SUPPORT_LBA_DEPENDENT?'L':'l', | |
690 | pg->valid_states&TPGS_SUPPORT_UNAVAILABLE?'U':'u', | |
691 | pg->valid_states&TPGS_SUPPORT_STANDBY?'S':'s', | |
692 | pg->valid_states&TPGS_SUPPORT_NONOPTIMIZED?'N':'n', | |
693 | pg->valid_states&TPGS_SUPPORT_OPTIMIZED?'A':'a'); | |
057ea7c9 | 694 | |
43394c67 | 695 | switch (pg->state) { |
5115fc7e | 696 | case SCSI_ACCESS_STATE_TRANSITIONING: |
03197b61 | 697 | if (time_before(jiffies, pg->expiry)) { |
28261402 | 698 | /* State transition, retry */ |
03197b61 HR |
699 | pg->interval = 2; |
700 | err = SCSI_DH_RETRY; | |
701 | } else { | |
cb0a168c HR |
702 | struct alua_dh_data *h; |
703 | ||
03197b61 HR |
704 | /* Transitioning time exceeded, set port to standby */ |
705 | err = SCSI_DH_IO; | |
5115fc7e | 706 | pg->state = SCSI_ACCESS_STATE_STANDBY; |
03197b61 | 707 | pg->expiry = 0; |
cb0a168c HR |
708 | rcu_read_lock(); |
709 | list_for_each_entry_rcu(h, &pg->dh_list, node) { | |
710 | BUG_ON(!h->sdev); | |
711 | h->sdev->access_state = | |
712 | (pg->state & SCSI_ACCESS_STATE_MASK); | |
713 | if (pg->pref) | |
714 | h->sdev->access_state |= | |
715 | SCSI_ACCESS_STATE_PREFERRED; | |
716 | } | |
717 | rcu_read_unlock(); | |
057ea7c9 | 718 | } |
69723d17 | 719 | break; |
5115fc7e | 720 | case SCSI_ACCESS_STATE_OFFLINE: |
e47f8976 | 721 | /* Path unusable */ |
69723d17 | 722 | err = SCSI_DH_DEV_OFFLINED; |
03197b61 | 723 | pg->expiry = 0; |
69723d17 HR |
724 | break; |
725 | default: | |
726 | /* Useable path if active */ | |
727 | err = SCSI_DH_OK; | |
03197b61 | 728 | pg->expiry = 0; |
69723d17 | 729 | break; |
057ea7c9 | 730 | } |
c57168a1 | 731 | spin_unlock_irqrestore(&pg->lock, flags); |
c49c8345 | 732 | kfree(buff); |
057ea7c9 HR |
733 | return err; |
734 | } | |
735 | ||
f2ecf13a HR |
736 | /* |
737 | * alua_stpg - Issue a SET TARGET PORT GROUP command | |
738 | * | |
739 | * Issue a SET TARGET PORT GROUP command and evaluate the | |
b2460756 HR |
740 | * response. Returns SCSI_DH_RETRY per default to trigger |
741 | * a re-evaluation of the target group state or SCSI_DH_OK | |
742 | * if no further action needs to be taken. | |
f2ecf13a | 743 | */ |
43394c67 | 744 | static unsigned alua_stpg(struct scsi_device *sdev, struct alua_port_group *pg) |
f2ecf13a | 745 | { |
b2460756 HR |
746 | int retval; |
747 | struct scsi_sense_hdr sense_hdr; | |
f2ecf13a | 748 | |
43394c67 | 749 | if (!(pg->tpgs & TPGS_MODE_EXPLICIT)) { |
b2460756 HR |
750 | /* Only implicit ALUA supported, retry */ |
751 | return SCSI_DH_RETRY; | |
752 | } | |
43394c67 | 753 | switch (pg->state) { |
5115fc7e | 754 | case SCSI_ACCESS_STATE_OPTIMAL: |
b2460756 | 755 | return SCSI_DH_OK; |
5115fc7e | 756 | case SCSI_ACCESS_STATE_ACTIVE: |
43394c67 HR |
757 | if ((pg->flags & ALUA_OPTIMIZE_STPG) && |
758 | !pg->pref && | |
759 | (pg->tpgs & TPGS_MODE_IMPLICIT)) | |
b2460756 | 760 | return SCSI_DH_OK; |
f2ecf13a | 761 | break; |
5115fc7e HR |
762 | case SCSI_ACCESS_STATE_STANDBY: |
763 | case SCSI_ACCESS_STATE_UNAVAILABLE: | |
f2ecf13a | 764 | break; |
5115fc7e | 765 | case SCSI_ACCESS_STATE_OFFLINE: |
b2460756 | 766 | return SCSI_DH_IO; |
5115fc7e | 767 | case SCSI_ACCESS_STATE_TRANSITIONING: |
f2ecf13a HR |
768 | break; |
769 | default: | |
b2460756 HR |
770 | sdev_printk(KERN_INFO, sdev, |
771 | "%s: stpg failed, unhandled TPGS state %d", | |
43394c67 | 772 | ALUA_DH_NAME, pg->state); |
b2460756 | 773 | return SCSI_DH_NOSYS; |
f2ecf13a | 774 | } |
43394c67 | 775 | retval = submit_stpg(sdev, pg->group_id, &sense_hdr); |
f2ecf13a | 776 | |
b2460756 | 777 | if (retval) { |
40bb61a7 | 778 | if (!scsi_sense_valid(&sense_hdr)) { |
b2460756 HR |
779 | sdev_printk(KERN_INFO, sdev, |
780 | "%s: stpg failed, result %d", | |
781 | ALUA_DH_NAME, retval); | |
40bb61a7 | 782 | if (driver_byte(retval) == DRIVER_ERROR) |
b2460756 HR |
783 | return SCSI_DH_DEV_TEMP_BUSY; |
784 | } else { | |
43394c67 | 785 | sdev_printk(KERN_INFO, sdev, "%s: stpg failed\n", |
b2460756 HR |
786 | ALUA_DH_NAME); |
787 | scsi_print_sense_hdr(sdev, ALUA_DH_NAME, &sense_hdr); | |
788 | } | |
f2ecf13a | 789 | } |
b2460756 HR |
790 | /* Retry RTPG */ |
791 | return SCSI_DH_RETRY; | |
f2ecf13a HR |
792 | } |
793 | ||
03197b61 HR |
794 | static void alua_rtpg_work(struct work_struct *work) |
795 | { | |
796 | struct alua_port_group *pg = | |
797 | container_of(work, struct alua_port_group, rtpg_work.work); | |
798 | struct scsi_device *sdev; | |
799 | LIST_HEAD(qdata_list); | |
800 | int err = SCSI_DH_OK; | |
801 | struct alua_queue_data *qdata, *tmp; | |
802 | unsigned long flags; | |
803 | ||
804 | spin_lock_irqsave(&pg->lock, flags); | |
805 | sdev = pg->rtpg_sdev; | |
806 | if (!sdev) { | |
807 | WARN_ON(pg->flags & ALUA_PG_RUN_RTPG); | |
808 | WARN_ON(pg->flags & ALUA_PG_RUN_STPG); | |
809 | spin_unlock_irqrestore(&pg->lock, flags); | |
1fdd1427 | 810 | kref_put(&pg->kref, release_port_group); |
03197b61 HR |
811 | return; |
812 | } | |
813 | pg->flags |= ALUA_PG_RUNNING; | |
814 | if (pg->flags & ALUA_PG_RUN_RTPG) { | |
9d2c3039 HR |
815 | int state = pg->state; |
816 | ||
03197b61 HR |
817 | pg->flags &= ~ALUA_PG_RUN_RTPG; |
818 | spin_unlock_irqrestore(&pg->lock, flags); | |
5115fc7e | 819 | if (state == SCSI_ACCESS_STATE_TRANSITIONING) { |
9d2c3039 HR |
820 | if (alua_tur(sdev) == SCSI_DH_RETRY) { |
821 | spin_lock_irqsave(&pg->lock, flags); | |
822 | pg->flags &= ~ALUA_PG_RUNNING; | |
823 | pg->flags |= ALUA_PG_RUN_RTPG; | |
824 | spin_unlock_irqrestore(&pg->lock, flags); | |
6934be4f | 825 | queue_delayed_work(kaluad_wq, &pg->rtpg_work, |
9d2c3039 HR |
826 | pg->interval * HZ); |
827 | return; | |
828 | } | |
829 | /* Send RTPG on failure or if TUR indicates SUCCESS */ | |
830 | } | |
03197b61 HR |
831 | err = alua_rtpg(sdev, pg); |
832 | spin_lock_irqsave(&pg->lock, flags); | |
2b35865e | 833 | if (err == SCSI_DH_RETRY || pg->flags & ALUA_PG_RUN_RTPG) { |
03197b61 HR |
834 | pg->flags &= ~ALUA_PG_RUNNING; |
835 | pg->flags |= ALUA_PG_RUN_RTPG; | |
836 | spin_unlock_irqrestore(&pg->lock, flags); | |
6934be4f | 837 | queue_delayed_work(kaluad_wq, &pg->rtpg_work, |
03197b61 HR |
838 | pg->interval * HZ); |
839 | return; | |
840 | } | |
841 | if (err != SCSI_DH_OK) | |
842 | pg->flags &= ~ALUA_PG_RUN_STPG; | |
843 | } | |
844 | if (pg->flags & ALUA_PG_RUN_STPG) { | |
845 | pg->flags &= ~ALUA_PG_RUN_STPG; | |
846 | spin_unlock_irqrestore(&pg->lock, flags); | |
847 | err = alua_stpg(sdev, pg); | |
848 | spin_lock_irqsave(&pg->lock, flags); | |
2b35865e | 849 | if (err == SCSI_DH_RETRY || pg->flags & ALUA_PG_RUN_RTPG) { |
03197b61 HR |
850 | pg->flags |= ALUA_PG_RUN_RTPG; |
851 | pg->interval = 0; | |
852 | pg->flags &= ~ALUA_PG_RUNNING; | |
853 | spin_unlock_irqrestore(&pg->lock, flags); | |
6934be4f | 854 | queue_delayed_work(kaluad_wq, &pg->rtpg_work, |
03197b61 HR |
855 | pg->interval * HZ); |
856 | return; | |
857 | } | |
858 | } | |
859 | ||
860 | list_splice_init(&pg->rtpg_list, &qdata_list); | |
861 | pg->rtpg_sdev = NULL; | |
862 | spin_unlock_irqrestore(&pg->lock, flags); | |
863 | ||
864 | list_for_each_entry_safe(qdata, tmp, &qdata_list, entry) { | |
865 | list_del(&qdata->entry); | |
866 | if (qdata->callback_fn) | |
867 | qdata->callback_fn(qdata->callback_data, err); | |
868 | kfree(qdata); | |
869 | } | |
870 | spin_lock_irqsave(&pg->lock, flags); | |
871 | pg->flags &= ~ALUA_PG_RUNNING; | |
872 | spin_unlock_irqrestore(&pg->lock, flags); | |
873 | scsi_device_put(sdev); | |
874 | kref_put(&pg->kref, release_port_group); | |
875 | } | |
876 | ||
7cb689fe BVA |
877 | /** |
878 | * alua_rtpg_queue() - cause RTPG to be submitted asynchronously | |
f5572475 BVA |
879 | * @pg: ALUA port group associated with @sdev. |
880 | * @sdev: SCSI device for which to submit an RTPG. | |
881 | * @qdata: Information about the callback to invoke after the RTPG. | |
882 | * @force: Whether or not to submit an RTPG if a work item that will submit an | |
883 | * RTPG already has been scheduled. | |
7cb689fe BVA |
884 | * |
885 | * Returns true if and only if alua_rtpg_work() will be called asynchronously. | |
886 | * That function is responsible for calling @qdata->fn(). | |
887 | */ | |
888 | static bool alua_rtpg_queue(struct alua_port_group *pg, | |
03197b61 | 889 | struct scsi_device *sdev, |
2b35865e | 890 | struct alua_queue_data *qdata, bool force) |
03197b61 HR |
891 | { |
892 | int start_queue = 0; | |
893 | unsigned long flags; | |
0aeccdfe | 894 | if (WARN_ON_ONCE(!pg) || scsi_device_get(sdev)) |
7cb689fe | 895 | return false; |
03197b61 HR |
896 | |
897 | spin_lock_irqsave(&pg->lock, flags); | |
898 | if (qdata) { | |
899 | list_add_tail(&qdata->entry, &pg->rtpg_list); | |
900 | pg->flags |= ALUA_PG_RUN_STPG; | |
2b35865e | 901 | force = true; |
03197b61 HR |
902 | } |
903 | if (pg->rtpg_sdev == NULL) { | |
904 | pg->interval = 0; | |
905 | pg->flags |= ALUA_PG_RUN_RTPG; | |
906 | kref_get(&pg->kref); | |
907 | pg->rtpg_sdev = sdev; | |
03197b61 | 908 | start_queue = 1; |
2b35865e HR |
909 | } else if (!(pg->flags & ALUA_PG_RUN_RTPG) && force) { |
910 | pg->flags |= ALUA_PG_RUN_RTPG; | |
911 | /* Do not queue if the worker is already running */ | |
912 | if (!(pg->flags & ALUA_PG_RUNNING)) { | |
913 | kref_get(&pg->kref); | |
914 | start_queue = 1; | |
915 | } | |
03197b61 | 916 | } |
2b35865e | 917 | |
03197b61 HR |
918 | spin_unlock_irqrestore(&pg->lock, flags); |
919 | ||
625fe857 | 920 | if (start_queue) { |
6934be4f | 921 | if (queue_delayed_work(kaluad_wq, &pg->rtpg_work, |
625fe857 BVA |
922 | msecs_to_jiffies(ALUA_RTPG_DELAY_MSECS))) |
923 | sdev = NULL; | |
924 | else | |
925 | kref_put(&pg->kref, release_port_group); | |
03197b61 | 926 | } |
625fe857 BVA |
927 | if (sdev) |
928 | scsi_device_put(sdev); | |
7cb689fe BVA |
929 | |
930 | return true; | |
03197b61 HR |
931 | } |
932 | ||
057ea7c9 HR |
933 | /* |
934 | * alua_initialize - Initialize ALUA state | |
935 | * @sdev: the device to be initialized | |
936 | * | |
937 | * For the prep_fn to work correctly we have | |
938 | * to initialize the ALUA state for the device. | |
939 | */ | |
940 | static int alua_initialize(struct scsi_device *sdev, struct alua_dh_data *h) | |
941 | { | |
43394c67 | 942 | int err = SCSI_DH_DEV_UNSUPP, tpgs; |
057ea7c9 | 943 | |
03197b61 | 944 | mutex_lock(&h->init_mutex); |
43394c67 | 945 | tpgs = alua_check_tpgs(sdev); |
a4253fde HR |
946 | if (tpgs != TPGS_MODE_NONE) |
947 | err = alua_check_vpd(sdev, h, tpgs); | |
03197b61 HR |
948 | h->init_error = err; |
949 | mutex_unlock(&h->init_mutex); | |
057ea7c9 HR |
950 | return err; |
951 | } | |
4335d092 MB |
952 | /* |
953 | * alua_set_params - set/unset the optimize flag | |
954 | * @sdev: device on the path to be activated | |
955 | * params - parameters in the following format | |
956 | * "no_of_params\0param1\0param2\0param3\0...\0" | |
957 | * For example, to set the flag pass the following parameters | |
958 | * from multipath.conf | |
959 | * hardware_handler "2 alua 1" | |
960 | */ | |
961 | static int alua_set_params(struct scsi_device *sdev, const char *params) | |
962 | { | |
ee14c674 | 963 | struct alua_dh_data *h = sdev->handler_data; |
d29425b0 | 964 | struct alua_port_group *pg = NULL; |
4335d092 MB |
965 | unsigned int optimize = 0, argc; |
966 | const char *p = params; | |
967 | int result = SCSI_DH_OK; | |
03197b61 | 968 | unsigned long flags; |
4335d092 MB |
969 | |
970 | if ((sscanf(params, "%u", &argc) != 1) || (argc != 1)) | |
971 | return -EINVAL; | |
972 | ||
973 | while (*p++) | |
974 | ; | |
975 | if ((sscanf(p, "%u", &optimize) != 1) || (optimize > 1)) | |
976 | return -EINVAL; | |
977 | ||
03197b61 HR |
978 | rcu_read_lock(); |
979 | pg = rcu_dereference(h->pg); | |
980 | if (!pg) { | |
981 | rcu_read_unlock(); | |
43394c67 | 982 | return -ENXIO; |
03197b61 HR |
983 | } |
984 | spin_lock_irqsave(&pg->lock, flags); | |
4335d092 | 985 | if (optimize) |
43394c67 | 986 | pg->flags |= ALUA_OPTIMIZE_STPG; |
4335d092 | 987 | else |
43394c67 | 988 | pg->flags &= ~ALUA_OPTIMIZE_STPG; |
03197b61 HR |
989 | spin_unlock_irqrestore(&pg->lock, flags); |
990 | rcu_read_unlock(); | |
4335d092 MB |
991 | |
992 | return result; | |
993 | } | |
057ea7c9 HR |
994 | |
995 | /* | |
996 | * alua_activate - activate a path | |
997 | * @sdev: device on the path to be activated | |
998 | * | |
999 | * We're currently switching the port group to be activated only and | |
1000 | * let the array figure out the rest. | |
1001 | * There may be other arrays which require us to switch all port groups | |
1002 | * based on a certain policy. But until we actually encounter them it | |
1003 | * should be okay. | |
1004 | */ | |
3ae31f6a CS |
1005 | static int alua_activate(struct scsi_device *sdev, |
1006 | activate_complete fn, void *data) | |
057ea7c9 | 1007 | { |
ee14c674 | 1008 | struct alua_dh_data *h = sdev->handler_data; |
057ea7c9 | 1009 | int err = SCSI_DH_OK; |
03197b61 | 1010 | struct alua_queue_data *qdata; |
d29425b0 | 1011 | struct alua_port_group *pg; |
057ea7c9 | 1012 | |
03197b61 HR |
1013 | qdata = kzalloc(sizeof(*qdata), GFP_KERNEL); |
1014 | if (!qdata) { | |
1015 | err = SCSI_DH_RES_TEMP_UNAVAIL; | |
46ccf6b5 | 1016 | goto out; |
03197b61 HR |
1017 | } |
1018 | qdata->callback_fn = fn; | |
1019 | qdata->callback_data = data; | |
1020 | ||
1021 | mutex_lock(&h->init_mutex); | |
1022 | rcu_read_lock(); | |
1023 | pg = rcu_dereference(h->pg); | |
1024 | if (!pg || !kref_get_unless_zero(&pg->kref)) { | |
1025 | rcu_read_unlock(); | |
1026 | kfree(qdata); | |
1027 | err = h->init_error; | |
1028 | mutex_unlock(&h->init_mutex); | |
43394c67 HR |
1029 | goto out; |
1030 | } | |
03197b61 HR |
1031 | rcu_read_unlock(); |
1032 | mutex_unlock(&h->init_mutex); | |
1033 | ||
7cb689fe BVA |
1034 | if (alua_rtpg_queue(pg, sdev, qdata, true)) |
1035 | fn = NULL; | |
1036 | else | |
1037 | err = SCSI_DH_DEV_OFFLINED; | |
03197b61 | 1038 | kref_put(&pg->kref, release_port_group); |
057ea7c9 | 1039 | out: |
b2460756 | 1040 | if (fn) |
3ae31f6a CS |
1041 | fn(data, err); |
1042 | return 0; | |
057ea7c9 HR |
1043 | } |
1044 | ||
2b35865e HR |
1045 | /* |
1046 | * alua_check - check path status | |
1047 | * @sdev: device on the path to be checked | |
1048 | * | |
1049 | * Check the device status | |
1050 | */ | |
1051 | static void alua_check(struct scsi_device *sdev, bool force) | |
1052 | { | |
1053 | struct alua_dh_data *h = sdev->handler_data; | |
1054 | struct alua_port_group *pg; | |
1055 | ||
1056 | rcu_read_lock(); | |
1057 | pg = rcu_dereference(h->pg); | |
1058 | if (!pg || !kref_get_unless_zero(&pg->kref)) { | |
1059 | rcu_read_unlock(); | |
1060 | return; | |
1061 | } | |
1062 | rcu_read_unlock(); | |
1063 | ||
1064 | alua_rtpg_queue(pg, sdev, NULL, force); | |
1065 | kref_put(&pg->kref, release_port_group); | |
1066 | } | |
1067 | ||
057ea7c9 HR |
1068 | /* |
1069 | * alua_prep_fn - request callback | |
1070 | * | |
1071 | * Fail I/O to all paths not in state | |
1072 | * active/optimized or active/non-optimized. | |
1073 | */ | |
4c1cb67c | 1074 | static blk_status_t alua_prep_fn(struct scsi_device *sdev, struct request *req) |
057ea7c9 | 1075 | { |
ee14c674 | 1076 | struct alua_dh_data *h = sdev->handler_data; |
d29425b0 | 1077 | struct alua_port_group *pg; |
5115fc7e | 1078 | unsigned char state = SCSI_ACCESS_STATE_OPTIMAL; |
057ea7c9 | 1079 | |
03197b61 HR |
1080 | rcu_read_lock(); |
1081 | pg = rcu_dereference(h->pg); | |
1082 | if (pg) | |
1083 | state = pg->state; | |
1084 | rcu_read_unlock(); | |
4c1cb67c CH |
1085 | |
1086 | switch (state) { | |
1087 | case SCSI_ACCESS_STATE_OPTIMAL: | |
1088 | case SCSI_ACCESS_STATE_ACTIVE: | |
1089 | case SCSI_ACCESS_STATE_LBA: | |
1090 | return BLK_STS_OK; | |
1091 | case SCSI_ACCESS_STATE_TRANSITIONING: | |
1092 | return BLK_STS_RESOURCE; | |
1093 | default: | |
e8064021 | 1094 | req->rq_flags |= RQF_QUIET; |
4c1cb67c | 1095 | return BLK_STS_IOERR; |
057ea7c9 | 1096 | } |
057ea7c9 HR |
1097 | } |
1098 | ||
d3d32891 HR |
1099 | static void alua_rescan(struct scsi_device *sdev) |
1100 | { | |
1101 | struct alua_dh_data *h = sdev->handler_data; | |
1102 | ||
1103 | alua_initialize(sdev, h); | |
1104 | } | |
1105 | ||
057ea7c9 HR |
1106 | /* |
1107 | * alua_bus_attach - Attach device handler | |
1108 | * @sdev: device to be attached to | |
1109 | */ | |
ee14c674 | 1110 | static int alua_bus_attach(struct scsi_device *sdev) |
057ea7c9 | 1111 | { |
057ea7c9 | 1112 | struct alua_dh_data *h; |
2a8f7a03 | 1113 | int err; |
057ea7c9 | 1114 | |
cd37743f | 1115 | h = kzalloc(sizeof(*h) , GFP_KERNEL); |
1d520328 | 1116 | if (!h) |
2a8f7a03 | 1117 | return SCSI_DH_NOMEM; |
03197b61 HR |
1118 | spin_lock_init(&h->pg_lock); |
1119 | rcu_assign_pointer(h->pg, NULL); | |
1120 | h->init_error = SCSI_DH_OK; | |
96e65865 | 1121 | h->sdev = sdev; |
cb0a168c | 1122 | INIT_LIST_HEAD(&h->node); |
057ea7c9 | 1123 | |
03197b61 | 1124 | mutex_init(&h->init_mutex); |
057ea7c9 | 1125 | err = alua_initialize(sdev, h); |
1d520328 | 1126 | if (err != SCSI_DH_OK && err != SCSI_DH_DEV_OFFLINED) |
057ea7c9 HR |
1127 | goto failed; |
1128 | ||
ee14c674 | 1129 | sdev->handler_data = h; |
2a8f7a03 | 1130 | return SCSI_DH_OK; |
057ea7c9 | 1131 | failed: |
cd37743f | 1132 | kfree(h); |
2a8f7a03 | 1133 | return err; |
057ea7c9 HR |
1134 | } |
1135 | ||
1136 | /* | |
1137 | * alua_bus_detach - Detach device handler | |
1138 | * @sdev: device to be detached from | |
1139 | */ | |
1140 | static void alua_bus_detach(struct scsi_device *sdev) | |
1141 | { | |
ee14c674 | 1142 | struct alua_dh_data *h = sdev->handler_data; |
03197b61 HR |
1143 | struct alua_port_group *pg; |
1144 | ||
1145 | spin_lock(&h->pg_lock); | |
d29425b0 | 1146 | pg = rcu_dereference_protected(h->pg, lockdep_is_held(&h->pg_lock)); |
03197b61 HR |
1147 | rcu_assign_pointer(h->pg, NULL); |
1148 | h->sdev = NULL; | |
1149 | spin_unlock(&h->pg_lock); | |
cb0a168c | 1150 | if (pg) { |
38c31599 | 1151 | spin_lock_irq(&pg->lock); |
cb0a168c | 1152 | list_del_rcu(&h->node); |
38c31599 | 1153 | spin_unlock_irq(&pg->lock); |
03197b61 | 1154 | kref_put(&pg->kref, release_port_group); |
cb0a168c | 1155 | } |
ee14c674 | 1156 | sdev->handler_data = NULL; |
cd37743f | 1157 | kfree(h); |
057ea7c9 HR |
1158 | } |
1159 | ||
1d520328 CH |
1160 | static struct scsi_device_handler alua_dh = { |
1161 | .name = ALUA_DH_NAME, | |
1162 | .module = THIS_MODULE, | |
1163 | .attach = alua_bus_attach, | |
1164 | .detach = alua_bus_detach, | |
1165 | .prep_fn = alua_prep_fn, | |
1166 | .check_sense = alua_check_sense, | |
1167 | .activate = alua_activate, | |
d3d32891 | 1168 | .rescan = alua_rescan, |
1d520328 | 1169 | .set_params = alua_set_params, |
1d520328 CH |
1170 | }; |
1171 | ||
057ea7c9 HR |
1172 | static int __init alua_init(void) |
1173 | { | |
1174 | int r; | |
1175 | ||
03197b61 HR |
1176 | kaluad_wq = alloc_workqueue("kaluad", WQ_MEM_RECLAIM, 0); |
1177 | if (!kaluad_wq) { | |
1178 | /* Temporary failure, bypass */ | |
1179 | return SCSI_DH_DEV_TEMP_BUSY; | |
1180 | } | |
6934be4f | 1181 | |
057ea7c9 | 1182 | r = scsi_register_device_handler(&alua_dh); |
03197b61 | 1183 | if (r != 0) { |
057ea7c9 HR |
1184 | printk(KERN_ERR "%s: Failed to register scsi device handler", |
1185 | ALUA_DH_NAME); | |
03197b61 HR |
1186 | destroy_workqueue(kaluad_wq); |
1187 | } | |
057ea7c9 HR |
1188 | return r; |
1189 | } | |
1190 | ||
1191 | static void __exit alua_exit(void) | |
1192 | { | |
1193 | scsi_unregister_device_handler(&alua_dh); | |
03197b61 | 1194 | destroy_workqueue(kaluad_wq); |
057ea7c9 HR |
1195 | } |
1196 | ||
1197 | module_init(alua_init); | |
1198 | module_exit(alua_exit); | |
1199 | ||
1200 | MODULE_DESCRIPTION("DM Multipath ALUA support"); | |
1201 | MODULE_AUTHOR("Hannes Reinecke <hare@suse.de>"); | |
1202 | MODULE_LICENSE("GPL"); | |
1203 | MODULE_VERSION(ALUA_DH_VER); |