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1a59d1b8 | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
057ea7c9 HR |
2 | /* |
3 | * Generic SCSI-3 ALUA SCSI Device Handler | |
4 | * | |
69723d17 | 5 | * Copyright (C) 2007-2010 Hannes Reinecke, SUSE Linux Products GmbH. |
057ea7c9 | 6 | * All rights reserved. |
057ea7c9 | 7 | */ |
5a0e3ad6 | 8 | #include <linux/slab.h> |
69723d17 | 9 | #include <linux/delay.h> |
acf3368f | 10 | #include <linux/module.h> |
a7089770 | 11 | #include <asm/unaligned.h> |
057ea7c9 | 12 | #include <scsi/scsi.h> |
cb0a168c | 13 | #include <scsi/scsi_proto.h> |
80bd68d6 | 14 | #include <scsi/scsi_dbg.h> |
057ea7c9 HR |
15 | #include <scsi/scsi_eh.h> |
16 | #include <scsi/scsi_dh.h> | |
17 | ||
18 | #define ALUA_DH_NAME "alua" | |
e79c82cc | 19 | #define ALUA_DH_VER "2.0" |
057ea7c9 | 20 | |
057ea7c9 HR |
21 | #define TPGS_SUPPORT_NONE 0x00 |
22 | #define TPGS_SUPPORT_OPTIMIZED 0x01 | |
23 | #define TPGS_SUPPORT_NONOPTIMIZED 0x02 | |
24 | #define TPGS_SUPPORT_STANDBY 0x04 | |
25 | #define TPGS_SUPPORT_UNAVAILABLE 0x08 | |
69723d17 | 26 | #define TPGS_SUPPORT_LBA_DEPENDENT 0x10 |
057ea7c9 HR |
27 | #define TPGS_SUPPORT_OFFLINE 0x40 |
28 | #define TPGS_SUPPORT_TRANSITION 0x80 | |
80c716fa | 29 | #define TPGS_SUPPORT_ALL 0xdf |
057ea7c9 | 30 | |
3588c5a2 RE |
31 | #define RTPG_FMT_MASK 0x70 |
32 | #define RTPG_FMT_EXT_HDR 0x10 | |
33 | ||
057ea7c9 HR |
34 | #define TPGS_MODE_UNINITIALIZED -1 |
35 | #define TPGS_MODE_NONE 0x0 | |
36 | #define TPGS_MODE_IMPLICIT 0x1 | |
37 | #define TPGS_MODE_EXPLICIT 0x2 | |
38 | ||
c49c8345 | 39 | #define ALUA_RTPG_SIZE 128 |
3588c5a2 | 40 | #define ALUA_FAILOVER_TIMEOUT 60 |
057ea7c9 | 41 | #define ALUA_FAILOVER_RETRIES 5 |
03197b61 | 42 | #define ALUA_RTPG_DELAY_MSECS 5 |
20122994 | 43 | #define ALUA_RTPG_RETRY_DELAY 2 |
057ea7c9 | 44 | |
6c4fc044 | 45 | /* device handler flags */ |
03197b61 HR |
46 | #define ALUA_OPTIMIZE_STPG 0x01 |
47 | #define ALUA_RTPG_EXT_HDR_UNSUPP 0x02 | |
48 | /* State machine flags */ | |
49 | #define ALUA_PG_RUN_RTPG 0x10 | |
50 | #define ALUA_PG_RUN_STPG 0x20 | |
51 | #define ALUA_PG_RUNNING 0x40 | |
4335d092 | 52 | |
aa90f490 HR |
53 | static uint optimize_stpg; |
54 | module_param(optimize_stpg, uint, S_IRUGO|S_IWUSR); | |
55 | 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."); | |
56 | ||
43394c67 HR |
57 | static LIST_HEAD(port_group_list); |
58 | static DEFINE_SPINLOCK(port_group_lock); | |
03197b61 | 59 | static struct workqueue_struct *kaluad_wq; |
43394c67 HR |
60 | |
61 | struct alua_port_group { | |
62 | struct kref kref; | |
03197b61 | 63 | struct rcu_head rcu; |
43394c67 | 64 | struct list_head node; |
cb0a168c | 65 | struct list_head dh_list; |
0047220c HR |
66 | unsigned char device_id_str[256]; |
67 | int device_id_len; | |
057ea7c9 | 68 | int group_id; |
057ea7c9 HR |
69 | int tpgs; |
70 | int state; | |
dcd3a754 | 71 | int pref; |
80c716fa | 72 | int valid_states; |
4335d092 | 73 | unsigned flags; /* used for optimizing STPG */ |
3588c5a2 | 74 | unsigned char transition_tmo; |
03197b61 HR |
75 | unsigned long expiry; |
76 | unsigned long interval; | |
77 | struct delayed_work rtpg_work; | |
78 | spinlock_t lock; | |
79 | struct list_head rtpg_list; | |
80 | struct scsi_device *rtpg_sdev; | |
43394c67 HR |
81 | }; |
82 | ||
83 | struct alua_dh_data { | |
cb0a168c | 84 | struct list_head node; |
d29425b0 | 85 | struct alua_port_group __rcu *pg; |
43394c67 | 86 | int group_id; |
03197b61 | 87 | spinlock_t pg_lock; |
96e65865 | 88 | struct scsi_device *sdev; |
03197b61 HR |
89 | int init_error; |
90 | struct mutex init_mutex; | |
91 | }; | |
92 | ||
93 | struct alua_queue_data { | |
94 | struct list_head entry; | |
96e65865 CS |
95 | activate_complete callback_fn; |
96 | void *callback_data; | |
057ea7c9 HR |
97 | }; |
98 | ||
99 | #define ALUA_POLICY_SWITCH_CURRENT 0 | |
100 | #define ALUA_POLICY_SWITCH_ALL 1 | |
101 | ||
03197b61 | 102 | static void alua_rtpg_work(struct work_struct *work); |
7cb689fe | 103 | static bool alua_rtpg_queue(struct alua_port_group *pg, |
03197b61 | 104 | struct scsi_device *sdev, |
2b35865e HR |
105 | struct alua_queue_data *qdata, bool force); |
106 | static void alua_check(struct scsi_device *sdev, bool force); | |
96e65865 | 107 | |
43394c67 HR |
108 | static void release_port_group(struct kref *kref) |
109 | { | |
110 | struct alua_port_group *pg; | |
111 | ||
112 | pg = container_of(kref, struct alua_port_group, kref); | |
03197b61 HR |
113 | if (pg->rtpg_sdev) |
114 | flush_delayed_work(&pg->rtpg_work); | |
43394c67 HR |
115 | spin_lock(&port_group_lock); |
116 | list_del(&pg->node); | |
117 | spin_unlock(&port_group_lock); | |
03197b61 | 118 | kfree_rcu(pg, rcu); |
43394c67 HR |
119 | } |
120 | ||
057ea7c9 HR |
121 | /* |
122 | * submit_rtpg - Issue a REPORT TARGET GROUP STATES command | |
123 | * @sdev: sdev the command should be sent to | |
124 | */ | |
40bb61a7 HR |
125 | static int submit_rtpg(struct scsi_device *sdev, unsigned char *buff, |
126 | int bufflen, struct scsi_sense_hdr *sshdr, int flags) | |
057ea7c9 | 127 | { |
92eb5062 | 128 | u8 cdb[MAX_COMMAND_SIZE]; |
40bb61a7 HR |
129 | int req_flags = REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT | |
130 | REQ_FAILFAST_DRIVER; | |
057ea7c9 HR |
131 | |
132 | /* Prepare the command. */ | |
92eb5062 | 133 | memset(cdb, 0x0, MAX_COMMAND_SIZE); |
40bb61a7 | 134 | cdb[0] = MAINTENANCE_IN; |
d42ae5f3 | 135 | if (!(flags & ALUA_RTPG_EXT_HDR_UNSUPP)) |
40bb61a7 | 136 | cdb[1] = MI_REPORT_TARGET_PGS | MI_EXT_HDR_PARAM_FMT; |
8e67ce60 | 137 | else |
40bb61a7 HR |
138 | cdb[1] = MI_REPORT_TARGET_PGS; |
139 | put_unaligned_be32(bufflen, &cdb[6]); | |
140 | ||
fcbfffe2 CH |
141 | return scsi_execute(sdev, cdb, DMA_FROM_DEVICE, buff, bufflen, NULL, |
142 | sshdr, ALUA_FAILOVER_TIMEOUT * HZ, | |
143 | ALUA_FAILOVER_RETRIES, req_flags, 0, NULL); | |
057ea7c9 HR |
144 | } |
145 | ||
96e65865 | 146 | /* |
b2460756 | 147 | * submit_stpg - Issue a SET TARGET PORT GROUP command |
057ea7c9 HR |
148 | * |
149 | * Currently we're only setting the current target port group state | |
150 | * to 'active/optimized' and let the array firmware figure out | |
151 | * the states of the remaining groups. | |
152 | */ | |
40bb61a7 HR |
153 | static int submit_stpg(struct scsi_device *sdev, int group_id, |
154 | struct scsi_sense_hdr *sshdr) | |
057ea7c9 | 155 | { |
92eb5062 | 156 | u8 cdb[MAX_COMMAND_SIZE]; |
b2460756 | 157 | unsigned char stpg_data[8]; |
057ea7c9 | 158 | int stpg_len = 8; |
40bb61a7 HR |
159 | int req_flags = REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT | |
160 | REQ_FAILFAST_DRIVER; | |
057ea7c9 HR |
161 | |
162 | /* Prepare the data buffer */ | |
b2460756 | 163 | memset(stpg_data, 0, stpg_len); |
5115fc7e | 164 | stpg_data[4] = SCSI_ACCESS_STATE_OPTIMAL; |
b2460756 | 165 | put_unaligned_be16(group_id, &stpg_data[6]); |
057ea7c9 | 166 | |
057ea7c9 | 167 | /* Prepare the command. */ |
92eb5062 | 168 | memset(cdb, 0x0, MAX_COMMAND_SIZE); |
40bb61a7 HR |
169 | cdb[0] = MAINTENANCE_OUT; |
170 | cdb[1] = MO_SET_TARGET_PGS; | |
171 | put_unaligned_be32(stpg_len, &cdb[6]); | |
172 | ||
fcbfffe2 CH |
173 | return scsi_execute(sdev, cdb, DMA_TO_DEVICE, stpg_data, stpg_len, NULL, |
174 | sshdr, ALUA_FAILOVER_TIMEOUT * HZ, | |
175 | ALUA_FAILOVER_RETRIES, req_flags, 0, NULL); | |
057ea7c9 HR |
176 | } |
177 | ||
1f275f97 BVA |
178 | static struct alua_port_group *alua_find_get_pg(char *id_str, size_t id_size, |
179 | int group_id) | |
0047220c HR |
180 | { |
181 | struct alua_port_group *pg; | |
182 | ||
fe8b9534 HR |
183 | if (!id_str || !id_size || !strlen(id_str)) |
184 | return NULL; | |
185 | ||
0047220c HR |
186 | list_for_each_entry(pg, &port_group_list, node) { |
187 | if (pg->group_id != group_id) | |
188 | continue; | |
fe8b9534 | 189 | if (!pg->device_id_len || pg->device_id_len != id_size) |
0047220c HR |
190 | continue; |
191 | if (strncmp(pg->device_id_str, id_str, id_size)) | |
192 | continue; | |
193 | if (!kref_get_unless_zero(&pg->kref)) | |
194 | continue; | |
195 | return pg; | |
196 | } | |
197 | ||
198 | return NULL; | |
199 | } | |
200 | ||
43394c67 HR |
201 | /* |
202 | * alua_alloc_pg - Allocate a new port_group structure | |
203 | * @sdev: scsi device | |
43394c67 | 204 | * @group_id: port group id |
2e8c3002 | 205 | * @tpgs: target port group settings |
43394c67 HR |
206 | * |
207 | * Allocate a new port_group structure for a given | |
208 | * device. | |
209 | */ | |
1f275f97 BVA |
210 | static struct alua_port_group *alua_alloc_pg(struct scsi_device *sdev, |
211 | int group_id, int tpgs) | |
43394c67 | 212 | { |
0047220c | 213 | struct alua_port_group *pg, *tmp_pg; |
43394c67 HR |
214 | |
215 | pg = kzalloc(sizeof(struct alua_port_group), GFP_KERNEL); | |
216 | if (!pg) | |
0047220c | 217 | return ERR_PTR(-ENOMEM); |
43394c67 | 218 | |
0047220c HR |
219 | pg->device_id_len = scsi_vpd_lun_id(sdev, pg->device_id_str, |
220 | sizeof(pg->device_id_str)); | |
221 | if (pg->device_id_len <= 0) { | |
222 | /* | |
fe8b9534 HR |
223 | * TPGS supported but no device identification found. |
224 | * Generate private device identification. | |
0047220c | 225 | */ |
0047220c HR |
226 | sdev_printk(KERN_INFO, sdev, |
227 | "%s: No device descriptors found\n", | |
228 | ALUA_DH_NAME); | |
fe8b9534 HR |
229 | pg->device_id_str[0] = '\0'; |
230 | pg->device_id_len = 0; | |
0047220c | 231 | } |
43394c67 HR |
232 | pg->group_id = group_id; |
233 | pg->tpgs = tpgs; | |
5115fc7e | 234 | pg->state = SCSI_ACCESS_STATE_OPTIMAL; |
80c716fa | 235 | pg->valid_states = TPGS_SUPPORT_ALL; |
aa90f490 HR |
236 | if (optimize_stpg) |
237 | pg->flags |= ALUA_OPTIMIZE_STPG; | |
43394c67 | 238 | kref_init(&pg->kref); |
03197b61 HR |
239 | INIT_DELAYED_WORK(&pg->rtpg_work, alua_rtpg_work); |
240 | INIT_LIST_HEAD(&pg->rtpg_list); | |
241 | INIT_LIST_HEAD(&pg->node); | |
cb0a168c | 242 | INIT_LIST_HEAD(&pg->dh_list); |
03197b61 | 243 | spin_lock_init(&pg->lock); |
0047220c | 244 | |
43394c67 | 245 | spin_lock(&port_group_lock); |
0047220c HR |
246 | tmp_pg = alua_find_get_pg(pg->device_id_str, pg->device_id_len, |
247 | group_id); | |
248 | if (tmp_pg) { | |
249 | spin_unlock(&port_group_lock); | |
250 | kfree(pg); | |
251 | return tmp_pg; | |
252 | } | |
253 | ||
43394c67 HR |
254 | list_add(&pg->node, &port_group_list); |
255 | spin_unlock(&port_group_lock); | |
256 | ||
257 | return pg; | |
258 | } | |
259 | ||
057ea7c9 | 260 | /* |
d7c48feb | 261 | * alua_check_tpgs - Evaluate TPGS setting |
057ea7c9 HR |
262 | * @sdev: device to be checked |
263 | * | |
d7c48feb | 264 | * Examine the TPGS setting of the sdev to find out if ALUA |
057ea7c9 HR |
265 | * is supported. |
266 | */ | |
ad0ea64c | 267 | static int alua_check_tpgs(struct scsi_device *sdev) |
057ea7c9 | 268 | { |
ad0ea64c | 269 | int tpgs = TPGS_MODE_NONE; |
057ea7c9 | 270 | |
db5a6a60 HR |
271 | /* |
272 | * ALUA support for non-disk devices is fraught with | |
273 | * difficulties, so disable it for now. | |
274 | */ | |
275 | if (sdev->type != TYPE_DISK) { | |
db5a6a60 HR |
276 | sdev_printk(KERN_INFO, sdev, |
277 | "%s: disable for non-disk devices\n", | |
278 | ALUA_DH_NAME); | |
ad0ea64c | 279 | return tpgs; |
db5a6a60 HR |
280 | } |
281 | ||
ad0ea64c HR |
282 | tpgs = scsi_device_tpgs(sdev); |
283 | switch (tpgs) { | |
057ea7c9 HR |
284 | case TPGS_MODE_EXPLICIT|TPGS_MODE_IMPLICIT: |
285 | sdev_printk(KERN_INFO, sdev, | |
286 | "%s: supports implicit and explicit TPGS\n", | |
287 | ALUA_DH_NAME); | |
288 | break; | |
289 | case TPGS_MODE_EXPLICIT: | |
290 | sdev_printk(KERN_INFO, sdev, "%s: supports explicit TPGS\n", | |
291 | ALUA_DH_NAME); | |
292 | break; | |
293 | case TPGS_MODE_IMPLICIT: | |
294 | sdev_printk(KERN_INFO, sdev, "%s: supports implicit TPGS\n", | |
295 | ALUA_DH_NAME); | |
296 | break; | |
6cc05d45 | 297 | case TPGS_MODE_NONE: |
057ea7c9 HR |
298 | sdev_printk(KERN_INFO, sdev, "%s: not supported\n", |
299 | ALUA_DH_NAME); | |
057ea7c9 | 300 | break; |
6cc05d45 HR |
301 | default: |
302 | sdev_printk(KERN_INFO, sdev, | |
303 | "%s: unsupported TPGS setting %d\n", | |
ad0ea64c HR |
304 | ALUA_DH_NAME, tpgs); |
305 | tpgs = TPGS_MODE_NONE; | |
6cc05d45 | 306 | break; |
057ea7c9 HR |
307 | } |
308 | ||
ad0ea64c | 309 | return tpgs; |
057ea7c9 HR |
310 | } |
311 | ||
312 | /* | |
9b80dcec | 313 | * alua_check_vpd - Evaluate INQUIRY vpd page 0x83 |
057ea7c9 HR |
314 | * @sdev: device to be checked |
315 | * | |
316 | * Extract the relative target port and the target port group | |
317 | * descriptor from the list of identificators. | |
318 | */ | |
a4253fde HR |
319 | static int alua_check_vpd(struct scsi_device *sdev, struct alua_dh_data *h, |
320 | int tpgs) | |
057ea7c9 | 321 | { |
83ea0e5e | 322 | int rel_port = -1, group_id; |
03197b61 | 323 | struct alua_port_group *pg, *old_pg = NULL; |
100bcb85 | 324 | bool pg_updated = false; |
cb0a168c | 325 | unsigned long flags; |
057ea7c9 | 326 | |
83ea0e5e HR |
327 | group_id = scsi_vpd_tpg_id(sdev, &rel_port); |
328 | if (group_id < 0) { | |
057ea7c9 HR |
329 | /* |
330 | * Internal error; TPGS supported but required | |
331 | * VPD identification descriptors not present. | |
332 | * Disable ALUA support | |
333 | */ | |
334 | sdev_printk(KERN_INFO, sdev, | |
335 | "%s: No target port descriptors found\n", | |
336 | ALUA_DH_NAME); | |
9b80dcec | 337 | return SCSI_DH_DEV_UNSUPP; |
057ea7c9 | 338 | } |
a4253fde | 339 | |
03197b61 HR |
340 | pg = alua_alloc_pg(sdev, group_id, tpgs); |
341 | if (IS_ERR(pg)) { | |
342 | if (PTR_ERR(pg) == -ENOMEM) | |
a4253fde HR |
343 | return SCSI_DH_NOMEM; |
344 | return SCSI_DH_DEV_UNSUPP; | |
345 | } | |
fe8b9534 HR |
346 | if (pg->device_id_len) |
347 | sdev_printk(KERN_INFO, sdev, | |
348 | "%s: device %s port group %x rel port %x\n", | |
349 | ALUA_DH_NAME, pg->device_id_str, | |
350 | group_id, rel_port); | |
351 | else | |
352 | sdev_printk(KERN_INFO, sdev, | |
353 | "%s: port group %x rel port %x\n", | |
354 | ALUA_DH_NAME, group_id, rel_port); | |
03197b61 HR |
355 | |
356 | /* Check for existing port group references */ | |
357 | spin_lock(&h->pg_lock); | |
d29425b0 | 358 | old_pg = rcu_dereference_protected(h->pg, lockdep_is_held(&h->pg_lock)); |
03197b61 HR |
359 | if (old_pg != pg) { |
360 | /* port group has changed. Update to new port group */ | |
cb0a168c HR |
361 | if (h->pg) { |
362 | spin_lock_irqsave(&old_pg->lock, flags); | |
363 | list_del_rcu(&h->node); | |
364 | spin_unlock_irqrestore(&old_pg->lock, flags); | |
365 | } | |
03197b61 | 366 | rcu_assign_pointer(h->pg, pg); |
cb0a168c | 367 | pg_updated = true; |
03197b61 | 368 | } |
cb0a168c HR |
369 | |
370 | spin_lock_irqsave(&pg->lock, flags); | |
cb0a168c HR |
371 | if (pg_updated) |
372 | list_add_rcu(&h->node, &pg->dh_list); | |
373 | spin_unlock_irqrestore(&pg->lock, flags); | |
374 | ||
d29425b0 BVA |
375 | alua_rtpg_queue(rcu_dereference_protected(h->pg, |
376 | lockdep_is_held(&h->pg_lock)), | |
377 | sdev, NULL, true); | |
03197b61 HR |
378 | spin_unlock(&h->pg_lock); |
379 | ||
380 | if (old_pg) | |
381 | kref_put(&old_pg->kref, release_port_group); | |
057ea7c9 | 382 | |
03197b61 | 383 | return SCSI_DH_OK; |
057ea7c9 HR |
384 | } |
385 | ||
5115fc7e | 386 | static char print_alua_state(unsigned char state) |
057ea7c9 HR |
387 | { |
388 | switch (state) { | |
5115fc7e | 389 | case SCSI_ACCESS_STATE_OPTIMAL: |
057ea7c9 | 390 | return 'A'; |
5115fc7e | 391 | case SCSI_ACCESS_STATE_ACTIVE: |
057ea7c9 | 392 | return 'N'; |
5115fc7e | 393 | case SCSI_ACCESS_STATE_STANDBY: |
057ea7c9 | 394 | return 'S'; |
5115fc7e | 395 | case SCSI_ACCESS_STATE_UNAVAILABLE: |
057ea7c9 | 396 | return 'U'; |
5115fc7e | 397 | case SCSI_ACCESS_STATE_LBA: |
69723d17 | 398 | return 'L'; |
5115fc7e | 399 | case SCSI_ACCESS_STATE_OFFLINE: |
057ea7c9 | 400 | return 'O'; |
5115fc7e | 401 | case SCSI_ACCESS_STATE_TRANSITIONING: |
057ea7c9 HR |
402 | return 'T'; |
403 | default: | |
404 | return 'X'; | |
405 | } | |
406 | } | |
407 | ||
408 | static int alua_check_sense(struct scsi_device *sdev, | |
409 | struct scsi_sense_hdr *sense_hdr) | |
410 | { | |
411 | switch (sense_hdr->sense_key) { | |
412 | case NOT_READY: | |
2b35865e | 413 | if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x0a) { |
057ea7c9 HR |
414 | /* |
415 | * LUN Not Accessible - ALUA state transition | |
416 | */ | |
2b35865e HR |
417 | alua_check(sdev, false); |
418 | return NEEDS_RETRY; | |
419 | } | |
057ea7c9 HR |
420 | break; |
421 | case UNIT_ATTENTION: | |
2b35865e | 422 | if (sense_hdr->asc == 0x29 && sense_hdr->ascq == 0x00) { |
057ea7c9 | 423 | /* |
2b35865e HR |
424 | * Power On, Reset, or Bus Device Reset. |
425 | * Might have obscured a state transition, | |
426 | * so schedule a recheck. | |
057ea7c9 | 427 | */ |
2b35865e | 428 | alua_check(sdev, true); |
c7dbb627 | 429 | return ADD_TO_MLQUEUE; |
2b35865e | 430 | } |
c20ee7b5 SS |
431 | if (sense_hdr->asc == 0x29 && sense_hdr->ascq == 0x04) |
432 | /* | |
433 | * Device internal reset | |
434 | */ | |
435 | return ADD_TO_MLQUEUE; | |
410f02d8 MB |
436 | if (sense_hdr->asc == 0x2a && sense_hdr->ascq == 0x01) |
437 | /* | |
438 | * Mode Parameters Changed | |
439 | */ | |
440 | return ADD_TO_MLQUEUE; | |
2b35865e | 441 | if (sense_hdr->asc == 0x2a && sense_hdr->ascq == 0x06) { |
057ea7c9 HR |
442 | /* |
443 | * ALUA state changed | |
444 | */ | |
2b35865e | 445 | alua_check(sdev, true); |
c7dbb627 | 446 | return ADD_TO_MLQUEUE; |
2b35865e HR |
447 | } |
448 | if (sense_hdr->asc == 0x2a && sense_hdr->ascq == 0x07) { | |
057ea7c9 HR |
449 | /* |
450 | * Implicit ALUA state transition failed | |
451 | */ | |
2b35865e | 452 | alua_check(sdev, true); |
c7dbb627 | 453 | return ADD_TO_MLQUEUE; |
2b35865e | 454 | } |
bf81973a MB |
455 | if (sense_hdr->asc == 0x3f && sense_hdr->ascq == 0x03) |
456 | /* | |
457 | * Inquiry data has changed | |
458 | */ | |
459 | return ADD_TO_MLQUEUE; | |
460 | if (sense_hdr->asc == 0x3f && sense_hdr->ascq == 0x0e) | |
4d086f6b IH |
461 | /* |
462 | * REPORTED_LUNS_DATA_HAS_CHANGED is reported | |
463 | * when switching controllers on targets like | |
464 | * Intel Multi-Flex. We can just retry. | |
465 | */ | |
466 | return ADD_TO_MLQUEUE; | |
057ea7c9 HR |
467 | break; |
468 | } | |
469 | ||
470 | return SCSI_RETURN_NOT_HANDLED; | |
471 | } | |
472 | ||
9d2c3039 HR |
473 | /* |
474 | * alua_tur - Send a TEST UNIT READY | |
475 | * @sdev: device to which the TEST UNIT READY command should be send | |
476 | * | |
477 | * Send a TEST UNIT READY to @sdev to figure out the device state | |
478 | * Returns SCSI_DH_RETRY if the sense code is NOT READY/ALUA TRANSITIONING, | |
479 | * SCSI_DH_OK if no error occurred, and SCSI_DH_IO otherwise. | |
480 | */ | |
481 | static int alua_tur(struct scsi_device *sdev) | |
482 | { | |
483 | struct scsi_sense_hdr sense_hdr; | |
484 | int retval; | |
485 | ||
486 | retval = scsi_test_unit_ready(sdev, ALUA_FAILOVER_TIMEOUT * HZ, | |
487 | ALUA_FAILOVER_RETRIES, &sense_hdr); | |
488 | if (sense_hdr.sense_key == NOT_READY && | |
489 | sense_hdr.asc == 0x04 && sense_hdr.ascq == 0x0a) | |
490 | return SCSI_DH_RETRY; | |
491 | else if (retval) | |
492 | return SCSI_DH_IO; | |
493 | else | |
494 | return SCSI_DH_OK; | |
495 | } | |
496 | ||
057ea7c9 HR |
497 | /* |
498 | * alua_rtpg - Evaluate REPORT TARGET GROUP STATES | |
499 | * @sdev: the device to be evaluated. | |
500 | * | |
501 | * Evaluate the Target Port Group State. | |
502 | * Returns SCSI_DH_DEV_OFFLINED if the path is | |
25985edc | 503 | * found to be unusable. |
057ea7c9 | 504 | */ |
28261402 | 505 | static int alua_rtpg(struct scsi_device *sdev, struct alua_port_group *pg) |
057ea7c9 HR |
506 | { |
507 | struct scsi_sense_hdr sense_hdr; | |
c57168a1 | 508 | struct alua_port_group *tmp_pg; |
80c716fa | 509 | int len, k, off, bufflen = ALUA_RTPG_SIZE; |
c57168a1 | 510 | unsigned char *desc, *buff; |
5597cafc | 511 | unsigned err, retval; |
3588c5a2 RE |
512 | unsigned int tpg_desc_tbl_off; |
513 | unsigned char orig_transition_tmo; | |
c57168a1 | 514 | unsigned long flags; |
3588c5a2 | 515 | |
03197b61 HR |
516 | if (!pg->expiry) { |
517 | unsigned long transition_tmo = ALUA_FAILOVER_TIMEOUT * HZ; | |
518 | ||
519 | if (pg->transition_tmo) | |
520 | transition_tmo = pg->transition_tmo * HZ; | |
521 | ||
522 | pg->expiry = round_jiffies_up(jiffies + transition_tmo); | |
523 | } | |
057ea7c9 | 524 | |
c49c8345 HR |
525 | buff = kzalloc(bufflen, GFP_KERNEL); |
526 | if (!buff) | |
527 | return SCSI_DH_DEV_TEMP_BUSY; | |
528 | ||
057ea7c9 | 529 | retry: |
a4bd8520 | 530 | err = 0; |
43394c67 | 531 | retval = submit_rtpg(sdev, buff, bufflen, &sense_hdr, pg->flags); |
40bb61a7 | 532 | |
5597cafc | 533 | if (retval) { |
80c716fa HR |
534 | /* |
535 | * Some (broken) implementations have a habit of returning | |
536 | * an error during things like firmware update etc. | |
537 | * But if the target only supports active/optimized there's | |
538 | * not much we can do; it's not that we can switch paths | |
539 | * or anything. | |
540 | * So ignore any errors to avoid spurious failures during | |
541 | * path failover. | |
542 | */ | |
543 | if ((pg->valid_states & ~TPGS_SUPPORT_OPTIMIZED) == 0) { | |
544 | sdev_printk(KERN_INFO, sdev, | |
545 | "%s: ignoring rtpg result %d\n", | |
546 | ALUA_DH_NAME, retval); | |
547 | kfree(buff); | |
548 | return SCSI_DH_OK; | |
549 | } | |
40bb61a7 | 550 | if (!scsi_sense_valid(&sense_hdr)) { |
5597cafc HR |
551 | sdev_printk(KERN_INFO, sdev, |
552 | "%s: rtpg failed, result %d\n", | |
553 | ALUA_DH_NAME, retval); | |
c49c8345 | 554 | kfree(buff); |
40bb61a7 | 555 | if (driver_byte(retval) == DRIVER_ERROR) |
5597cafc | 556 | return SCSI_DH_DEV_TEMP_BUSY; |
057ea7c9 | 557 | return SCSI_DH_IO; |
5597cafc | 558 | } |
057ea7c9 | 559 | |
8e67ce60 RE |
560 | /* |
561 | * submit_rtpg() has failed on existing arrays | |
562 | * when requesting extended header info, and | |
563 | * the array doesn't support extended headers, | |
564 | * even though it shouldn't according to T10. | |
565 | * The retry without rtpg_ext_hdr_req set | |
566 | * handles this. | |
567 | */ | |
43394c67 | 568 | if (!(pg->flags & ALUA_RTPG_EXT_HDR_UNSUPP) && |
8e67ce60 RE |
569 | sense_hdr.sense_key == ILLEGAL_REQUEST && |
570 | sense_hdr.asc == 0x24 && sense_hdr.ascq == 0) { | |
43394c67 | 571 | pg->flags |= ALUA_RTPG_EXT_HDR_UNSUPP; |
8e67ce60 RE |
572 | goto retry; |
573 | } | |
e2d817db HR |
574 | /* |
575 | * Retry on ALUA state transition or if any | |
576 | * UNIT ATTENTION occurred. | |
577 | */ | |
578 | if (sense_hdr.sense_key == NOT_READY && | |
579 | sense_hdr.asc == 0x04 && sense_hdr.ascq == 0x0a) | |
580 | err = SCSI_DH_RETRY; | |
581 | else if (sense_hdr.sense_key == UNIT_ATTENTION) | |
582 | err = SCSI_DH_RETRY; | |
03197b61 HR |
583 | if (err == SCSI_DH_RETRY && |
584 | pg->expiry != 0 && time_before(jiffies, pg->expiry)) { | |
80bd68d6 HR |
585 | sdev_printk(KERN_ERR, sdev, "%s: rtpg retry\n", |
586 | ALUA_DH_NAME); | |
587 | scsi_print_sense_hdr(sdev, ALUA_DH_NAME, &sense_hdr); | |
086acff2 | 588 | kfree(buff); |
03197b61 | 589 | return err; |
80bd68d6 HR |
590 | } |
591 | sdev_printk(KERN_ERR, sdev, "%s: rtpg failed\n", | |
592 | ALUA_DH_NAME); | |
593 | scsi_print_sense_hdr(sdev, ALUA_DH_NAME, &sense_hdr); | |
c49c8345 | 594 | kfree(buff); |
03197b61 | 595 | pg->expiry = 0; |
80bd68d6 | 596 | return SCSI_DH_IO; |
057ea7c9 | 597 | } |
057ea7c9 | 598 | |
c49c8345 | 599 | len = get_unaligned_be32(&buff[0]) + 4; |
057ea7c9 | 600 | |
c49c8345 | 601 | if (len > bufflen) { |
057ea7c9 | 602 | /* Resubmit with the correct length */ |
c49c8345 HR |
603 | kfree(buff); |
604 | bufflen = len; | |
605 | buff = kmalloc(bufflen, GFP_KERNEL); | |
606 | if (!buff) { | |
057ea7c9 | 607 | sdev_printk(KERN_WARNING, sdev, |
cadbd4a5 | 608 | "%s: kmalloc buffer failed\n",__func__); |
057ea7c9 | 609 | /* Temporary failure, bypass */ |
03197b61 | 610 | pg->expiry = 0; |
057ea7c9 HR |
611 | return SCSI_DH_DEV_TEMP_BUSY; |
612 | } | |
613 | goto retry; | |
614 | } | |
615 | ||
43394c67 | 616 | orig_transition_tmo = pg->transition_tmo; |
c49c8345 | 617 | if ((buff[4] & RTPG_FMT_MASK) == RTPG_FMT_EXT_HDR && buff[5] != 0) |
43394c67 | 618 | pg->transition_tmo = buff[5]; |
3588c5a2 | 619 | else |
43394c67 | 620 | pg->transition_tmo = ALUA_FAILOVER_TIMEOUT; |
3588c5a2 | 621 | |
28261402 | 622 | if (orig_transition_tmo != pg->transition_tmo) { |
3588c5a2 RE |
623 | sdev_printk(KERN_INFO, sdev, |
624 | "%s: transition timeout set to %d seconds\n", | |
43394c67 | 625 | ALUA_DH_NAME, pg->transition_tmo); |
03197b61 | 626 | pg->expiry = jiffies + pg->transition_tmo * HZ; |
3588c5a2 RE |
627 | } |
628 | ||
c49c8345 | 629 | if ((buff[4] & RTPG_FMT_MASK) == RTPG_FMT_EXT_HDR) |
3588c5a2 RE |
630 | tpg_desc_tbl_off = 8; |
631 | else | |
632 | tpg_desc_tbl_off = 4; | |
633 | ||
c57168a1 | 634 | for (k = tpg_desc_tbl_off, desc = buff + tpg_desc_tbl_off; |
3588c5a2 | 635 | k < len; |
c57168a1 HR |
636 | k += off, desc += off) { |
637 | u16 group_id = get_unaligned_be16(&desc[2]); | |
638 | ||
639 | spin_lock_irqsave(&port_group_lock, flags); | |
640 | tmp_pg = alua_find_get_pg(pg->device_id_str, pg->device_id_len, | |
641 | group_id); | |
642 | spin_unlock_irqrestore(&port_group_lock, flags); | |
643 | if (tmp_pg) { | |
644 | if (spin_trylock_irqsave(&tmp_pg->lock, flags)) { | |
645 | if ((tmp_pg == pg) || | |
646 | !(tmp_pg->flags & ALUA_PG_RUNNING)) { | |
cb0a168c HR |
647 | struct alua_dh_data *h; |
648 | ||
c57168a1 HR |
649 | tmp_pg->state = desc[0] & 0x0f; |
650 | tmp_pg->pref = desc[0] >> 7; | |
cb0a168c HR |
651 | rcu_read_lock(); |
652 | list_for_each_entry_rcu(h, | |
653 | &tmp_pg->dh_list, node) { | |
654 | /* h->sdev should always be valid */ | |
655 | BUG_ON(!h->sdev); | |
656 | h->sdev->access_state = desc[0]; | |
657 | } | |
658 | rcu_read_unlock(); | |
c57168a1 HR |
659 | } |
660 | if (tmp_pg == pg) | |
80c716fa | 661 | tmp_pg->valid_states = desc[1]; |
c57168a1 HR |
662 | spin_unlock_irqrestore(&tmp_pg->lock, flags); |
663 | } | |
664 | kref_put(&tmp_pg->kref, release_port_group); | |
057ea7c9 | 665 | } |
c57168a1 | 666 | off = 8 + (desc[7] * 4); |
057ea7c9 HR |
667 | } |
668 | ||
c57168a1 | 669 | spin_lock_irqsave(&pg->lock, flags); |
057ea7c9 | 670 | sdev_printk(KERN_INFO, sdev, |
dcd3a754 | 671 | "%s: port group %02x state %c %s supports %c%c%c%c%c%c%c\n", |
43394c67 HR |
672 | ALUA_DH_NAME, pg->group_id, print_alua_state(pg->state), |
673 | pg->pref ? "preferred" : "non-preferred", | |
80c716fa HR |
674 | pg->valid_states&TPGS_SUPPORT_TRANSITION?'T':'t', |
675 | pg->valid_states&TPGS_SUPPORT_OFFLINE?'O':'o', | |
676 | pg->valid_states&TPGS_SUPPORT_LBA_DEPENDENT?'L':'l', | |
677 | pg->valid_states&TPGS_SUPPORT_UNAVAILABLE?'U':'u', | |
678 | pg->valid_states&TPGS_SUPPORT_STANDBY?'S':'s', | |
679 | pg->valid_states&TPGS_SUPPORT_NONOPTIMIZED?'N':'n', | |
680 | pg->valid_states&TPGS_SUPPORT_OPTIMIZED?'A':'a'); | |
057ea7c9 | 681 | |
43394c67 | 682 | switch (pg->state) { |
5115fc7e | 683 | case SCSI_ACCESS_STATE_TRANSITIONING: |
03197b61 | 684 | if (time_before(jiffies, pg->expiry)) { |
28261402 | 685 | /* State transition, retry */ |
20122994 | 686 | pg->interval = ALUA_RTPG_RETRY_DELAY; |
03197b61 HR |
687 | err = SCSI_DH_RETRY; |
688 | } else { | |
cb0a168c HR |
689 | struct alua_dh_data *h; |
690 | ||
03197b61 HR |
691 | /* Transitioning time exceeded, set port to standby */ |
692 | err = SCSI_DH_IO; | |
5115fc7e | 693 | pg->state = SCSI_ACCESS_STATE_STANDBY; |
03197b61 | 694 | pg->expiry = 0; |
cb0a168c HR |
695 | rcu_read_lock(); |
696 | list_for_each_entry_rcu(h, &pg->dh_list, node) { | |
697 | BUG_ON(!h->sdev); | |
698 | h->sdev->access_state = | |
699 | (pg->state & SCSI_ACCESS_STATE_MASK); | |
700 | if (pg->pref) | |
701 | h->sdev->access_state |= | |
702 | SCSI_ACCESS_STATE_PREFERRED; | |
703 | } | |
704 | rcu_read_unlock(); | |
057ea7c9 | 705 | } |
69723d17 | 706 | break; |
5115fc7e | 707 | case SCSI_ACCESS_STATE_OFFLINE: |
e47f8976 | 708 | /* Path unusable */ |
69723d17 | 709 | err = SCSI_DH_DEV_OFFLINED; |
03197b61 | 710 | pg->expiry = 0; |
69723d17 HR |
711 | break; |
712 | default: | |
713 | /* Useable path if active */ | |
714 | err = SCSI_DH_OK; | |
03197b61 | 715 | pg->expiry = 0; |
69723d17 | 716 | break; |
057ea7c9 | 717 | } |
c57168a1 | 718 | spin_unlock_irqrestore(&pg->lock, flags); |
c49c8345 | 719 | kfree(buff); |
057ea7c9 HR |
720 | return err; |
721 | } | |
722 | ||
f2ecf13a HR |
723 | /* |
724 | * alua_stpg - Issue a SET TARGET PORT GROUP command | |
725 | * | |
726 | * Issue a SET TARGET PORT GROUP command and evaluate the | |
b2460756 HR |
727 | * response. Returns SCSI_DH_RETRY per default to trigger |
728 | * a re-evaluation of the target group state or SCSI_DH_OK | |
729 | * if no further action needs to be taken. | |
f2ecf13a | 730 | */ |
43394c67 | 731 | static unsigned alua_stpg(struct scsi_device *sdev, struct alua_port_group *pg) |
f2ecf13a | 732 | { |
b2460756 HR |
733 | int retval; |
734 | struct scsi_sense_hdr sense_hdr; | |
f2ecf13a | 735 | |
43394c67 | 736 | if (!(pg->tpgs & TPGS_MODE_EXPLICIT)) { |
b2460756 HR |
737 | /* Only implicit ALUA supported, retry */ |
738 | return SCSI_DH_RETRY; | |
739 | } | |
43394c67 | 740 | switch (pg->state) { |
5115fc7e | 741 | case SCSI_ACCESS_STATE_OPTIMAL: |
b2460756 | 742 | return SCSI_DH_OK; |
5115fc7e | 743 | case SCSI_ACCESS_STATE_ACTIVE: |
43394c67 HR |
744 | if ((pg->flags & ALUA_OPTIMIZE_STPG) && |
745 | !pg->pref && | |
746 | (pg->tpgs & TPGS_MODE_IMPLICIT)) | |
b2460756 | 747 | return SCSI_DH_OK; |
f2ecf13a | 748 | break; |
5115fc7e HR |
749 | case SCSI_ACCESS_STATE_STANDBY: |
750 | case SCSI_ACCESS_STATE_UNAVAILABLE: | |
f2ecf13a | 751 | break; |
5115fc7e | 752 | case SCSI_ACCESS_STATE_OFFLINE: |
b2460756 | 753 | return SCSI_DH_IO; |
5115fc7e | 754 | case SCSI_ACCESS_STATE_TRANSITIONING: |
f2ecf13a HR |
755 | break; |
756 | default: | |
b2460756 HR |
757 | sdev_printk(KERN_INFO, sdev, |
758 | "%s: stpg failed, unhandled TPGS state %d", | |
43394c67 | 759 | ALUA_DH_NAME, pg->state); |
b2460756 | 760 | return SCSI_DH_NOSYS; |
f2ecf13a | 761 | } |
43394c67 | 762 | retval = submit_stpg(sdev, pg->group_id, &sense_hdr); |
f2ecf13a | 763 | |
b2460756 | 764 | if (retval) { |
40bb61a7 | 765 | if (!scsi_sense_valid(&sense_hdr)) { |
b2460756 HR |
766 | sdev_printk(KERN_INFO, sdev, |
767 | "%s: stpg failed, result %d", | |
768 | ALUA_DH_NAME, retval); | |
40bb61a7 | 769 | if (driver_byte(retval) == DRIVER_ERROR) |
b2460756 HR |
770 | return SCSI_DH_DEV_TEMP_BUSY; |
771 | } else { | |
43394c67 | 772 | sdev_printk(KERN_INFO, sdev, "%s: stpg failed\n", |
b2460756 HR |
773 | ALUA_DH_NAME); |
774 | scsi_print_sense_hdr(sdev, ALUA_DH_NAME, &sense_hdr); | |
775 | } | |
f2ecf13a | 776 | } |
b2460756 HR |
777 | /* Retry RTPG */ |
778 | return SCSI_DH_RETRY; | |
f2ecf13a HR |
779 | } |
780 | ||
03197b61 HR |
781 | static void alua_rtpg_work(struct work_struct *work) |
782 | { | |
783 | struct alua_port_group *pg = | |
784 | container_of(work, struct alua_port_group, rtpg_work.work); | |
785 | struct scsi_device *sdev; | |
786 | LIST_HEAD(qdata_list); | |
787 | int err = SCSI_DH_OK; | |
788 | struct alua_queue_data *qdata, *tmp; | |
789 | unsigned long flags; | |
790 | ||
791 | spin_lock_irqsave(&pg->lock, flags); | |
792 | sdev = pg->rtpg_sdev; | |
793 | if (!sdev) { | |
794 | WARN_ON(pg->flags & ALUA_PG_RUN_RTPG); | |
795 | WARN_ON(pg->flags & ALUA_PG_RUN_STPG); | |
796 | spin_unlock_irqrestore(&pg->lock, flags); | |
1fdd1427 | 797 | kref_put(&pg->kref, release_port_group); |
03197b61 HR |
798 | return; |
799 | } | |
800 | pg->flags |= ALUA_PG_RUNNING; | |
801 | if (pg->flags & ALUA_PG_RUN_RTPG) { | |
9d2c3039 HR |
802 | int state = pg->state; |
803 | ||
03197b61 HR |
804 | pg->flags &= ~ALUA_PG_RUN_RTPG; |
805 | spin_unlock_irqrestore(&pg->lock, flags); | |
5115fc7e | 806 | if (state == SCSI_ACCESS_STATE_TRANSITIONING) { |
9d2c3039 HR |
807 | if (alua_tur(sdev) == SCSI_DH_RETRY) { |
808 | spin_lock_irqsave(&pg->lock, flags); | |
809 | pg->flags &= ~ALUA_PG_RUNNING; | |
810 | pg->flags |= ALUA_PG_RUN_RTPG; | |
20122994 HR |
811 | if (!pg->interval) |
812 | pg->interval = ALUA_RTPG_RETRY_DELAY; | |
9d2c3039 | 813 | spin_unlock_irqrestore(&pg->lock, flags); |
6934be4f | 814 | queue_delayed_work(kaluad_wq, &pg->rtpg_work, |
9d2c3039 HR |
815 | pg->interval * HZ); |
816 | return; | |
817 | } | |
818 | /* Send RTPG on failure or if TUR indicates SUCCESS */ | |
819 | } | |
03197b61 HR |
820 | err = alua_rtpg(sdev, pg); |
821 | spin_lock_irqsave(&pg->lock, flags); | |
2b35865e | 822 | if (err == SCSI_DH_RETRY || pg->flags & ALUA_PG_RUN_RTPG) { |
03197b61 | 823 | pg->flags &= ~ALUA_PG_RUNNING; |
20122994 HR |
824 | if (!pg->interval && !(pg->flags & ALUA_PG_RUN_RTPG)) |
825 | pg->interval = ALUA_RTPG_RETRY_DELAY; | |
03197b61 HR |
826 | pg->flags |= ALUA_PG_RUN_RTPG; |
827 | spin_unlock_irqrestore(&pg->lock, flags); | |
6934be4f | 828 | queue_delayed_work(kaluad_wq, &pg->rtpg_work, |
03197b61 HR |
829 | pg->interval * HZ); |
830 | return; | |
831 | } | |
832 | if (err != SCSI_DH_OK) | |
833 | pg->flags &= ~ALUA_PG_RUN_STPG; | |
834 | } | |
835 | if (pg->flags & ALUA_PG_RUN_STPG) { | |
836 | pg->flags &= ~ALUA_PG_RUN_STPG; | |
837 | spin_unlock_irqrestore(&pg->lock, flags); | |
838 | err = alua_stpg(sdev, pg); | |
839 | spin_lock_irqsave(&pg->lock, flags); | |
2b35865e | 840 | if (err == SCSI_DH_RETRY || pg->flags & ALUA_PG_RUN_RTPG) { |
03197b61 HR |
841 | pg->flags |= ALUA_PG_RUN_RTPG; |
842 | pg->interval = 0; | |
843 | pg->flags &= ~ALUA_PG_RUNNING; | |
844 | spin_unlock_irqrestore(&pg->lock, flags); | |
6934be4f | 845 | queue_delayed_work(kaluad_wq, &pg->rtpg_work, |
03197b61 HR |
846 | pg->interval * HZ); |
847 | return; | |
848 | } | |
849 | } | |
850 | ||
851 | list_splice_init(&pg->rtpg_list, &qdata_list); | |
852 | pg->rtpg_sdev = NULL; | |
853 | spin_unlock_irqrestore(&pg->lock, flags); | |
854 | ||
855 | list_for_each_entry_safe(qdata, tmp, &qdata_list, entry) { | |
856 | list_del(&qdata->entry); | |
857 | if (qdata->callback_fn) | |
858 | qdata->callback_fn(qdata->callback_data, err); | |
859 | kfree(qdata); | |
860 | } | |
861 | spin_lock_irqsave(&pg->lock, flags); | |
862 | pg->flags &= ~ALUA_PG_RUNNING; | |
863 | spin_unlock_irqrestore(&pg->lock, flags); | |
864 | scsi_device_put(sdev); | |
865 | kref_put(&pg->kref, release_port_group); | |
866 | } | |
867 | ||
7cb689fe BVA |
868 | /** |
869 | * alua_rtpg_queue() - cause RTPG to be submitted asynchronously | |
f5572475 BVA |
870 | * @pg: ALUA port group associated with @sdev. |
871 | * @sdev: SCSI device for which to submit an RTPG. | |
872 | * @qdata: Information about the callback to invoke after the RTPG. | |
873 | * @force: Whether or not to submit an RTPG if a work item that will submit an | |
874 | * RTPG already has been scheduled. | |
7cb689fe BVA |
875 | * |
876 | * Returns true if and only if alua_rtpg_work() will be called asynchronously. | |
877 | * That function is responsible for calling @qdata->fn(). | |
878 | */ | |
879 | static bool alua_rtpg_queue(struct alua_port_group *pg, | |
03197b61 | 880 | struct scsi_device *sdev, |
2b35865e | 881 | struct alua_queue_data *qdata, bool force) |
03197b61 HR |
882 | { |
883 | int start_queue = 0; | |
884 | unsigned long flags; | |
0aeccdfe | 885 | if (WARN_ON_ONCE(!pg) || scsi_device_get(sdev)) |
7cb689fe | 886 | return false; |
03197b61 HR |
887 | |
888 | spin_lock_irqsave(&pg->lock, flags); | |
889 | if (qdata) { | |
890 | list_add_tail(&qdata->entry, &pg->rtpg_list); | |
891 | pg->flags |= ALUA_PG_RUN_STPG; | |
2b35865e | 892 | force = true; |
03197b61 HR |
893 | } |
894 | if (pg->rtpg_sdev == NULL) { | |
895 | pg->interval = 0; | |
896 | pg->flags |= ALUA_PG_RUN_RTPG; | |
897 | kref_get(&pg->kref); | |
898 | pg->rtpg_sdev = sdev; | |
03197b61 | 899 | start_queue = 1; |
2b35865e HR |
900 | } else if (!(pg->flags & ALUA_PG_RUN_RTPG) && force) { |
901 | pg->flags |= ALUA_PG_RUN_RTPG; | |
902 | /* Do not queue if the worker is already running */ | |
903 | if (!(pg->flags & ALUA_PG_RUNNING)) { | |
904 | kref_get(&pg->kref); | |
905 | start_queue = 1; | |
906 | } | |
03197b61 | 907 | } |
2b35865e | 908 | |
03197b61 HR |
909 | spin_unlock_irqrestore(&pg->lock, flags); |
910 | ||
625fe857 | 911 | if (start_queue) { |
6934be4f | 912 | if (queue_delayed_work(kaluad_wq, &pg->rtpg_work, |
625fe857 BVA |
913 | msecs_to_jiffies(ALUA_RTPG_DELAY_MSECS))) |
914 | sdev = NULL; | |
915 | else | |
916 | kref_put(&pg->kref, release_port_group); | |
03197b61 | 917 | } |
625fe857 BVA |
918 | if (sdev) |
919 | scsi_device_put(sdev); | |
7cb689fe BVA |
920 | |
921 | return true; | |
03197b61 HR |
922 | } |
923 | ||
057ea7c9 HR |
924 | /* |
925 | * alua_initialize - Initialize ALUA state | |
926 | * @sdev: the device to be initialized | |
927 | * | |
928 | * For the prep_fn to work correctly we have | |
929 | * to initialize the ALUA state for the device. | |
930 | */ | |
931 | static int alua_initialize(struct scsi_device *sdev, struct alua_dh_data *h) | |
932 | { | |
43394c67 | 933 | int err = SCSI_DH_DEV_UNSUPP, tpgs; |
057ea7c9 | 934 | |
03197b61 | 935 | mutex_lock(&h->init_mutex); |
43394c67 | 936 | tpgs = alua_check_tpgs(sdev); |
a4253fde HR |
937 | if (tpgs != TPGS_MODE_NONE) |
938 | err = alua_check_vpd(sdev, h, tpgs); | |
03197b61 HR |
939 | h->init_error = err; |
940 | mutex_unlock(&h->init_mutex); | |
057ea7c9 HR |
941 | return err; |
942 | } | |
4335d092 MB |
943 | /* |
944 | * alua_set_params - set/unset the optimize flag | |
945 | * @sdev: device on the path to be activated | |
946 | * params - parameters in the following format | |
947 | * "no_of_params\0param1\0param2\0param3\0...\0" | |
948 | * For example, to set the flag pass the following parameters | |
949 | * from multipath.conf | |
950 | * hardware_handler "2 alua 1" | |
951 | */ | |
952 | static int alua_set_params(struct scsi_device *sdev, const char *params) | |
953 | { | |
ee14c674 | 954 | struct alua_dh_data *h = sdev->handler_data; |
d29425b0 | 955 | struct alua_port_group *pg = NULL; |
4335d092 MB |
956 | unsigned int optimize = 0, argc; |
957 | const char *p = params; | |
958 | int result = SCSI_DH_OK; | |
03197b61 | 959 | unsigned long flags; |
4335d092 MB |
960 | |
961 | if ((sscanf(params, "%u", &argc) != 1) || (argc != 1)) | |
962 | return -EINVAL; | |
963 | ||
964 | while (*p++) | |
965 | ; | |
966 | if ((sscanf(p, "%u", &optimize) != 1) || (optimize > 1)) | |
967 | return -EINVAL; | |
968 | ||
03197b61 HR |
969 | rcu_read_lock(); |
970 | pg = rcu_dereference(h->pg); | |
971 | if (!pg) { | |
972 | rcu_read_unlock(); | |
43394c67 | 973 | return -ENXIO; |
03197b61 HR |
974 | } |
975 | spin_lock_irqsave(&pg->lock, flags); | |
4335d092 | 976 | if (optimize) |
43394c67 | 977 | pg->flags |= ALUA_OPTIMIZE_STPG; |
4335d092 | 978 | else |
43394c67 | 979 | pg->flags &= ~ALUA_OPTIMIZE_STPG; |
03197b61 HR |
980 | spin_unlock_irqrestore(&pg->lock, flags); |
981 | rcu_read_unlock(); | |
4335d092 MB |
982 | |
983 | return result; | |
984 | } | |
057ea7c9 HR |
985 | |
986 | /* | |
987 | * alua_activate - activate a path | |
988 | * @sdev: device on the path to be activated | |
989 | * | |
990 | * We're currently switching the port group to be activated only and | |
991 | * let the array figure out the rest. | |
992 | * There may be other arrays which require us to switch all port groups | |
993 | * based on a certain policy. But until we actually encounter them it | |
994 | * should be okay. | |
995 | */ | |
3ae31f6a CS |
996 | static int alua_activate(struct scsi_device *sdev, |
997 | activate_complete fn, void *data) | |
057ea7c9 | 998 | { |
ee14c674 | 999 | struct alua_dh_data *h = sdev->handler_data; |
057ea7c9 | 1000 | int err = SCSI_DH_OK; |
03197b61 | 1001 | struct alua_queue_data *qdata; |
d29425b0 | 1002 | struct alua_port_group *pg; |
057ea7c9 | 1003 | |
03197b61 HR |
1004 | qdata = kzalloc(sizeof(*qdata), GFP_KERNEL); |
1005 | if (!qdata) { | |
1006 | err = SCSI_DH_RES_TEMP_UNAVAIL; | |
46ccf6b5 | 1007 | goto out; |
03197b61 HR |
1008 | } |
1009 | qdata->callback_fn = fn; | |
1010 | qdata->callback_data = data; | |
1011 | ||
1012 | mutex_lock(&h->init_mutex); | |
1013 | rcu_read_lock(); | |
1014 | pg = rcu_dereference(h->pg); | |
1015 | if (!pg || !kref_get_unless_zero(&pg->kref)) { | |
1016 | rcu_read_unlock(); | |
1017 | kfree(qdata); | |
1018 | err = h->init_error; | |
1019 | mutex_unlock(&h->init_mutex); | |
43394c67 HR |
1020 | goto out; |
1021 | } | |
03197b61 HR |
1022 | rcu_read_unlock(); |
1023 | mutex_unlock(&h->init_mutex); | |
1024 | ||
7cb689fe BVA |
1025 | if (alua_rtpg_queue(pg, sdev, qdata, true)) |
1026 | fn = NULL; | |
1027 | else | |
1028 | err = SCSI_DH_DEV_OFFLINED; | |
03197b61 | 1029 | kref_put(&pg->kref, release_port_group); |
057ea7c9 | 1030 | out: |
b2460756 | 1031 | if (fn) |
3ae31f6a CS |
1032 | fn(data, err); |
1033 | return 0; | |
057ea7c9 HR |
1034 | } |
1035 | ||
2b35865e HR |
1036 | /* |
1037 | * alua_check - check path status | |
1038 | * @sdev: device on the path to be checked | |
1039 | * | |
1040 | * Check the device status | |
1041 | */ | |
1042 | static void alua_check(struct scsi_device *sdev, bool force) | |
1043 | { | |
1044 | struct alua_dh_data *h = sdev->handler_data; | |
1045 | struct alua_port_group *pg; | |
1046 | ||
1047 | rcu_read_lock(); | |
1048 | pg = rcu_dereference(h->pg); | |
1049 | if (!pg || !kref_get_unless_zero(&pg->kref)) { | |
1050 | rcu_read_unlock(); | |
1051 | return; | |
1052 | } | |
1053 | rcu_read_unlock(); | |
1054 | ||
1055 | alua_rtpg_queue(pg, sdev, NULL, force); | |
1056 | kref_put(&pg->kref, release_port_group); | |
1057 | } | |
1058 | ||
057ea7c9 HR |
1059 | /* |
1060 | * alua_prep_fn - request callback | |
1061 | * | |
1062 | * Fail I/O to all paths not in state | |
1063 | * active/optimized or active/non-optimized. | |
1064 | */ | |
4c1cb67c | 1065 | static blk_status_t alua_prep_fn(struct scsi_device *sdev, struct request *req) |
057ea7c9 | 1066 | { |
ee14c674 | 1067 | struct alua_dh_data *h = sdev->handler_data; |
d29425b0 | 1068 | struct alua_port_group *pg; |
5115fc7e | 1069 | unsigned char state = SCSI_ACCESS_STATE_OPTIMAL; |
057ea7c9 | 1070 | |
03197b61 HR |
1071 | rcu_read_lock(); |
1072 | pg = rcu_dereference(h->pg); | |
1073 | if (pg) | |
1074 | state = pg->state; | |
1075 | rcu_read_unlock(); | |
4c1cb67c CH |
1076 | |
1077 | switch (state) { | |
1078 | case SCSI_ACCESS_STATE_OPTIMAL: | |
1079 | case SCSI_ACCESS_STATE_ACTIVE: | |
1080 | case SCSI_ACCESS_STATE_LBA: | |
1081 | return BLK_STS_OK; | |
1082 | case SCSI_ACCESS_STATE_TRANSITIONING: | |
1083 | return BLK_STS_RESOURCE; | |
1084 | default: | |
e8064021 | 1085 | req->rq_flags |= RQF_QUIET; |
4c1cb67c | 1086 | return BLK_STS_IOERR; |
057ea7c9 | 1087 | } |
057ea7c9 HR |
1088 | } |
1089 | ||
d3d32891 HR |
1090 | static void alua_rescan(struct scsi_device *sdev) |
1091 | { | |
1092 | struct alua_dh_data *h = sdev->handler_data; | |
1093 | ||
1094 | alua_initialize(sdev, h); | |
1095 | } | |
1096 | ||
057ea7c9 HR |
1097 | /* |
1098 | * alua_bus_attach - Attach device handler | |
1099 | * @sdev: device to be attached to | |
1100 | */ | |
ee14c674 | 1101 | static int alua_bus_attach(struct scsi_device *sdev) |
057ea7c9 | 1102 | { |
057ea7c9 | 1103 | struct alua_dh_data *h; |
2a8f7a03 | 1104 | int err; |
057ea7c9 | 1105 | |
cd37743f | 1106 | h = kzalloc(sizeof(*h) , GFP_KERNEL); |
1d520328 | 1107 | if (!h) |
2a8f7a03 | 1108 | return SCSI_DH_NOMEM; |
03197b61 HR |
1109 | spin_lock_init(&h->pg_lock); |
1110 | rcu_assign_pointer(h->pg, NULL); | |
1111 | h->init_error = SCSI_DH_OK; | |
96e65865 | 1112 | h->sdev = sdev; |
cb0a168c | 1113 | INIT_LIST_HEAD(&h->node); |
057ea7c9 | 1114 | |
03197b61 | 1115 | mutex_init(&h->init_mutex); |
057ea7c9 | 1116 | err = alua_initialize(sdev, h); |
1d520328 | 1117 | if (err != SCSI_DH_OK && err != SCSI_DH_DEV_OFFLINED) |
057ea7c9 HR |
1118 | goto failed; |
1119 | ||
ee14c674 | 1120 | sdev->handler_data = h; |
2a8f7a03 | 1121 | return SCSI_DH_OK; |
057ea7c9 | 1122 | failed: |
cd37743f | 1123 | kfree(h); |
2a8f7a03 | 1124 | return err; |
057ea7c9 HR |
1125 | } |
1126 | ||
1127 | /* | |
1128 | * alua_bus_detach - Detach device handler | |
1129 | * @sdev: device to be detached from | |
1130 | */ | |
1131 | static void alua_bus_detach(struct scsi_device *sdev) | |
1132 | { | |
ee14c674 | 1133 | struct alua_dh_data *h = sdev->handler_data; |
03197b61 HR |
1134 | struct alua_port_group *pg; |
1135 | ||
1136 | spin_lock(&h->pg_lock); | |
d29425b0 | 1137 | pg = rcu_dereference_protected(h->pg, lockdep_is_held(&h->pg_lock)); |
03197b61 HR |
1138 | rcu_assign_pointer(h->pg, NULL); |
1139 | h->sdev = NULL; | |
1140 | spin_unlock(&h->pg_lock); | |
cb0a168c | 1141 | if (pg) { |
38c31599 | 1142 | spin_lock_irq(&pg->lock); |
cb0a168c | 1143 | list_del_rcu(&h->node); |
38c31599 | 1144 | spin_unlock_irq(&pg->lock); |
03197b61 | 1145 | kref_put(&pg->kref, release_port_group); |
cb0a168c | 1146 | } |
ee14c674 | 1147 | sdev->handler_data = NULL; |
cd37743f | 1148 | kfree(h); |
057ea7c9 HR |
1149 | } |
1150 | ||
1d520328 CH |
1151 | static struct scsi_device_handler alua_dh = { |
1152 | .name = ALUA_DH_NAME, | |
1153 | .module = THIS_MODULE, | |
1154 | .attach = alua_bus_attach, | |
1155 | .detach = alua_bus_detach, | |
1156 | .prep_fn = alua_prep_fn, | |
1157 | .check_sense = alua_check_sense, | |
1158 | .activate = alua_activate, | |
d3d32891 | 1159 | .rescan = alua_rescan, |
1d520328 | 1160 | .set_params = alua_set_params, |
1d520328 CH |
1161 | }; |
1162 | ||
057ea7c9 HR |
1163 | static int __init alua_init(void) |
1164 | { | |
1165 | int r; | |
1166 | ||
03197b61 | 1167 | kaluad_wq = alloc_workqueue("kaluad", WQ_MEM_RECLAIM, 0); |
12e750bc Y |
1168 | if (!kaluad_wq) |
1169 | return -ENOMEM; | |
6934be4f | 1170 | |
057ea7c9 | 1171 | r = scsi_register_device_handler(&alua_dh); |
03197b61 | 1172 | if (r != 0) { |
057ea7c9 HR |
1173 | printk(KERN_ERR "%s: Failed to register scsi device handler", |
1174 | ALUA_DH_NAME); | |
03197b61 HR |
1175 | destroy_workqueue(kaluad_wq); |
1176 | } | |
057ea7c9 HR |
1177 | return r; |
1178 | } | |
1179 | ||
1180 | static void __exit alua_exit(void) | |
1181 | { | |
1182 | scsi_unregister_device_handler(&alua_dh); | |
03197b61 | 1183 | destroy_workqueue(kaluad_wq); |
057ea7c9 HR |
1184 | } |
1185 | ||
1186 | module_init(alua_init); | |
1187 | module_exit(alua_exit); | |
1188 | ||
1189 | MODULE_DESCRIPTION("DM Multipath ALUA support"); | |
1190 | MODULE_AUTHOR("Hannes Reinecke <hare@suse.de>"); | |
1191 | MODULE_LICENSE("GPL"); | |
1192 | MODULE_VERSION(ALUA_DH_VER); |