Commit | Line | Data |
---|---|---|
1da177e4 | 1 | /* |
d285203c CH |
2 | * Copyright (C) 1999 Eric Youngdale |
3 | * Copyright (C) 2014 Christoph Hellwig | |
1da177e4 LT |
4 | * |
5 | * SCSI queueing library. | |
6 | * Initial versions: Eric Youngdale (eric@andante.org). | |
7 | * Based upon conversations with large numbers | |
8 | * of people at Linux Expo. | |
9 | */ | |
10 | ||
11 | #include <linux/bio.h> | |
d3f46f39 | 12 | #include <linux/bitops.h> |
1da177e4 LT |
13 | #include <linux/blkdev.h> |
14 | #include <linux/completion.h> | |
15 | #include <linux/kernel.h> | |
09703660 | 16 | #include <linux/export.h> |
1da177e4 LT |
17 | #include <linux/init.h> |
18 | #include <linux/pci.h> | |
19 | #include <linux/delay.h> | |
faead26d | 20 | #include <linux/hardirq.h> |
c6132da1 | 21 | #include <linux/scatterlist.h> |
d285203c | 22 | #include <linux/blk-mq.h> |
f1569ff1 | 23 | #include <linux/ratelimit.h> |
a8aa3978 | 24 | #include <asm/unaligned.h> |
1da177e4 LT |
25 | |
26 | #include <scsi/scsi.h> | |
beb40487 | 27 | #include <scsi/scsi_cmnd.h> |
1da177e4 LT |
28 | #include <scsi/scsi_dbg.h> |
29 | #include <scsi/scsi_device.h> | |
30 | #include <scsi/scsi_driver.h> | |
31 | #include <scsi/scsi_eh.h> | |
32 | #include <scsi/scsi_host.h> | |
7aa686d3 | 33 | #include <scsi/scsi_transport.h> /* __scsi_init_queue() */ |
ee14c674 | 34 | #include <scsi/scsi_dh.h> |
1da177e4 | 35 | |
3b5382c4 CH |
36 | #include <trace/events/scsi.h> |
37 | ||
0eebd005 | 38 | #include "scsi_debugfs.h" |
1da177e4 LT |
39 | #include "scsi_priv.h" |
40 | #include "scsi_logging.h" | |
41 | ||
e9c787e6 | 42 | static struct kmem_cache *scsi_sdb_cache; |
0a6ac4ee CH |
43 | static struct kmem_cache *scsi_sense_cache; |
44 | static struct kmem_cache *scsi_sense_isadma_cache; | |
45 | static DEFINE_MUTEX(scsi_sense_cache_mutex); | |
1da177e4 | 46 | |
a45a1f36 BVA |
47 | static void scsi_mq_uninit_cmd(struct scsi_cmnd *cmd); |
48 | ||
0a6ac4ee | 49 | static inline struct kmem_cache * |
8e688254 | 50 | scsi_select_sense_cache(bool unchecked_isa_dma) |
0a6ac4ee | 51 | { |
8e688254 | 52 | return unchecked_isa_dma ? scsi_sense_isadma_cache : scsi_sense_cache; |
0a6ac4ee CH |
53 | } |
54 | ||
8e688254 BVA |
55 | static void scsi_free_sense_buffer(bool unchecked_isa_dma, |
56 | unsigned char *sense_buffer) | |
0a6ac4ee | 57 | { |
8e688254 BVA |
58 | kmem_cache_free(scsi_select_sense_cache(unchecked_isa_dma), |
59 | sense_buffer); | |
0a6ac4ee CH |
60 | } |
61 | ||
8e688254 | 62 | static unsigned char *scsi_alloc_sense_buffer(bool unchecked_isa_dma, |
e9c787e6 | 63 | gfp_t gfp_mask, int numa_node) |
0a6ac4ee | 64 | { |
8e688254 BVA |
65 | return kmem_cache_alloc_node(scsi_select_sense_cache(unchecked_isa_dma), |
66 | gfp_mask, numa_node); | |
0a6ac4ee CH |
67 | } |
68 | ||
69 | int scsi_init_sense_cache(struct Scsi_Host *shost) | |
70 | { | |
71 | struct kmem_cache *cache; | |
72 | int ret = 0; | |
73 | ||
8e688254 | 74 | cache = scsi_select_sense_cache(shost->unchecked_isa_dma); |
0a6ac4ee CH |
75 | if (cache) |
76 | return 0; | |
77 | ||
78 | mutex_lock(&scsi_sense_cache_mutex); | |
79 | if (shost->unchecked_isa_dma) { | |
80 | scsi_sense_isadma_cache = | |
81 | kmem_cache_create("scsi_sense_cache(DMA)", | |
0afe76e8 DW |
82 | SCSI_SENSE_BUFFERSIZE, 0, |
83 | SLAB_HWCACHE_ALIGN | SLAB_CACHE_DMA, NULL); | |
0a6ac4ee CH |
84 | if (!scsi_sense_isadma_cache) |
85 | ret = -ENOMEM; | |
86 | } else { | |
87 | scsi_sense_cache = | |
0afe76e8 DW |
88 | kmem_cache_create_usercopy("scsi_sense_cache", |
89 | SCSI_SENSE_BUFFERSIZE, 0, SLAB_HWCACHE_ALIGN, | |
90 | 0, SCSI_SENSE_BUFFERSIZE, NULL); | |
0a6ac4ee CH |
91 | if (!scsi_sense_cache) |
92 | ret = -ENOMEM; | |
93 | } | |
94 | ||
95 | mutex_unlock(&scsi_sense_cache_mutex); | |
96 | return ret; | |
97 | } | |
6f9a35e2 | 98 | |
a488e749 JA |
99 | /* |
100 | * When to reinvoke queueing after a resource shortage. It's 3 msecs to | |
101 | * not change behaviour from the previous unplug mechanism, experimentation | |
102 | * may prove this needs changing. | |
103 | */ | |
104 | #define SCSI_QUEUE_DELAY 3 | |
105 | ||
de3e8bf3 CH |
106 | static void |
107 | scsi_set_blocked(struct scsi_cmnd *cmd, int reason) | |
1da177e4 LT |
108 | { |
109 | struct Scsi_Host *host = cmd->device->host; | |
110 | struct scsi_device *device = cmd->device; | |
f0c0a376 | 111 | struct scsi_target *starget = scsi_target(device); |
1da177e4 LT |
112 | |
113 | /* | |
d8c37e7b | 114 | * Set the appropriate busy bit for the device/host. |
1da177e4 LT |
115 | * |
116 | * If the host/device isn't busy, assume that something actually | |
117 | * completed, and that we should be able to queue a command now. | |
118 | * | |
119 | * Note that the prior mid-layer assumption that any host could | |
120 | * always queue at least one command is now broken. The mid-layer | |
121 | * will implement a user specifiable stall (see | |
122 | * scsi_host.max_host_blocked and scsi_device.max_device_blocked) | |
123 | * if a command is requeued with no other commands outstanding | |
124 | * either for the device or for the host. | |
125 | */ | |
f0c0a376 MC |
126 | switch (reason) { |
127 | case SCSI_MLQUEUE_HOST_BUSY: | |
cd9070c9 | 128 | atomic_set(&host->host_blocked, host->max_host_blocked); |
f0c0a376 MC |
129 | break; |
130 | case SCSI_MLQUEUE_DEVICE_BUSY: | |
573e5913 | 131 | case SCSI_MLQUEUE_EH_RETRY: |
cd9070c9 CH |
132 | atomic_set(&device->device_blocked, |
133 | device->max_device_blocked); | |
f0c0a376 MC |
134 | break; |
135 | case SCSI_MLQUEUE_TARGET_BUSY: | |
cd9070c9 CH |
136 | atomic_set(&starget->target_blocked, |
137 | starget->max_target_blocked); | |
f0c0a376 MC |
138 | break; |
139 | } | |
de3e8bf3 CH |
140 | } |
141 | ||
d285203c CH |
142 | static void scsi_mq_requeue_cmd(struct scsi_cmnd *cmd) |
143 | { | |
144 | struct scsi_device *sdev = cmd->device; | |
d285203c | 145 | |
a45a1f36 BVA |
146 | if (cmd->request->rq_flags & RQF_DONTPREP) { |
147 | cmd->request->rq_flags &= ~RQF_DONTPREP; | |
148 | scsi_mq_uninit_cmd(cmd); | |
149 | } else { | |
150 | WARN_ON_ONCE(true); | |
151 | } | |
2b053aca | 152 | blk_mq_requeue_request(cmd->request, true); |
d285203c CH |
153 | put_device(&sdev->sdev_gendev); |
154 | } | |
155 | ||
de3e8bf3 CH |
156 | /** |
157 | * __scsi_queue_insert - private queue insertion | |
158 | * @cmd: The SCSI command being requeued | |
159 | * @reason: The reason for the requeue | |
160 | * @unbusy: Whether the queue should be unbusied | |
161 | * | |
162 | * This is a private queue insertion. The public interface | |
163 | * scsi_queue_insert() always assumes the queue should be unbusied | |
164 | * because it's always called before the completion. This function is | |
165 | * for a requeue after completion, which should only occur in this | |
166 | * file. | |
167 | */ | |
08640e81 | 168 | static void __scsi_queue_insert(struct scsi_cmnd *cmd, int reason, bool unbusy) |
de3e8bf3 CH |
169 | { |
170 | struct scsi_device *device = cmd->device; | |
de3e8bf3 CH |
171 | |
172 | SCSI_LOG_MLQUEUE(1, scmd_printk(KERN_INFO, cmd, | |
173 | "Inserting command %p into mlqueue\n", cmd)); | |
174 | ||
175 | scsi_set_blocked(cmd, reason); | |
1da177e4 | 176 | |
1da177e4 LT |
177 | /* |
178 | * Decrement the counters, since these commands are no longer | |
179 | * active on the host/device. | |
180 | */ | |
4f5299ac JB |
181 | if (unbusy) |
182 | scsi_device_unbusy(device); | |
1da177e4 LT |
183 | |
184 | /* | |
a1bf9d1d | 185 | * Requeue this command. It will go before all other commands |
b485462a BVA |
186 | * that are already in the queue. Schedule requeue work under |
187 | * lock such that the kblockd_schedule_work() call happens | |
188 | * before blk_cleanup_queue() finishes. | |
a488e749 | 189 | */ |
644373a4 | 190 | cmd->result = 0; |
f664a3cc JA |
191 | |
192 | /* | |
193 | * Before a SCSI command is dispatched, | |
194 | * get_device(&sdev->sdev_gendev) is called and the host, | |
195 | * target and device busy counters are increased. Since | |
196 | * requeuing a request causes these actions to be repeated and | |
197 | * since scsi_device_unbusy() has already been called, | |
198 | * put_device(&device->sdev_gendev) must still be called. Call | |
199 | * put_device() after blk_mq_requeue_request() to avoid that | |
200 | * removal of the SCSI device can start before requeueing has | |
201 | * happened. | |
202 | */ | |
203 | blk_mq_requeue_request(cmd->request, true); | |
204 | put_device(&device->sdev_gendev); | |
1da177e4 LT |
205 | } |
206 | ||
4f5299ac JB |
207 | /* |
208 | * Function: scsi_queue_insert() | |
209 | * | |
210 | * Purpose: Insert a command in the midlevel queue. | |
211 | * | |
212 | * Arguments: cmd - command that we are adding to queue. | |
213 | * reason - why we are inserting command to queue. | |
214 | * | |
215 | * Lock status: Assumed that lock is not held upon entry. | |
216 | * | |
217 | * Returns: Nothing. | |
218 | * | |
219 | * Notes: We do this for one of two cases. Either the host is busy | |
220 | * and it cannot accept any more commands for the time being, | |
221 | * or the device returned QUEUE_FULL and can accept no more | |
222 | * commands. | |
223 | * Notes: This could be called either from an interrupt context or a | |
224 | * normal process context. | |
225 | */ | |
84feb166 | 226 | void scsi_queue_insert(struct scsi_cmnd *cmd, int reason) |
4f5299ac | 227 | { |
08640e81 | 228 | __scsi_queue_insert(cmd, reason, true); |
4f5299ac | 229 | } |
e8064021 | 230 | |
76aaf87b CH |
231 | |
232 | /** | |
704f8392 | 233 | * __scsi_execute - insert request and wait for the result |
76aaf87b CH |
234 | * @sdev: scsi device |
235 | * @cmd: scsi command | |
236 | * @data_direction: data direction | |
237 | * @buffer: data buffer | |
238 | * @bufflen: len of buffer | |
239 | * @sense: optional sense buffer | |
240 | * @sshdr: optional decoded sense header | |
241 | * @timeout: request timeout in seconds | |
242 | * @retries: number of times to retry request | |
243 | * @flags: flags for ->cmd_flags | |
244 | * @rq_flags: flags for ->rq_flags | |
245 | * @resid: optional residual length | |
246 | * | |
17d5363b CH |
247 | * Returns the scsi_cmnd result field if a command was executed, or a negative |
248 | * Linux error code if we didn't get that far. | |
76aaf87b | 249 | */ |
704f8392 | 250 | int __scsi_execute(struct scsi_device *sdev, const unsigned char *cmd, |
33aa687d | 251 | int data_direction, void *buffer, unsigned bufflen, |
3949e2f0 CH |
252 | unsigned char *sense, struct scsi_sense_hdr *sshdr, |
253 | int timeout, int retries, u64 flags, req_flags_t rq_flags, | |
254 | int *resid) | |
39216033 JB |
255 | { |
256 | struct request *req; | |
82ed4db4 | 257 | struct scsi_request *rq; |
39216033 JB |
258 | int ret = DRIVER_ERROR << 24; |
259 | ||
ff005a06 | 260 | req = blk_get_request(sdev->request_queue, |
aebf526b | 261 | data_direction == DMA_TO_DEVICE ? |
039c635f | 262 | REQ_OP_SCSI_OUT : REQ_OP_SCSI_IN, BLK_MQ_REQ_PREEMPT); |
a492f075 | 263 | if (IS_ERR(req)) |
bfe159a5 | 264 | return ret; |
82ed4db4 | 265 | rq = scsi_req(req); |
39216033 JB |
266 | |
267 | if (bufflen && blk_rq_map_kern(sdev->request_queue, req, | |
0eb0b63c | 268 | buffer, bufflen, GFP_NOIO)) |
39216033 JB |
269 | goto out; |
270 | ||
82ed4db4 CH |
271 | rq->cmd_len = COMMAND_SIZE(cmd[0]); |
272 | memcpy(rq->cmd, cmd, rq->cmd_len); | |
64c7f1d1 | 273 | rq->retries = retries; |
39216033 | 274 | req->timeout = timeout; |
e8064021 | 275 | req->cmd_flags |= flags; |
039c635f | 276 | req->rq_flags |= rq_flags | RQF_QUIET; |
39216033 JB |
277 | |
278 | /* | |
279 | * head injection *required* here otherwise quiesce won't work | |
280 | */ | |
281 | blk_execute_rq(req->q, NULL, req, 1); | |
282 | ||
bdb2b8ca AS |
283 | /* |
284 | * Some devices (USB mass-storage in particular) may transfer | |
285 | * garbage data together with a residue indicating that the data | |
286 | * is invalid. Prevent the garbage from being misinterpreted | |
287 | * and prevent security leaks by zeroing out the excess data. | |
288 | */ | |
82ed4db4 CH |
289 | if (unlikely(rq->resid_len > 0 && rq->resid_len <= bufflen)) |
290 | memset(buffer + (bufflen - rq->resid_len), 0, rq->resid_len); | |
bdb2b8ca | 291 | |
f4f4e47e | 292 | if (resid) |
82ed4db4 CH |
293 | *resid = rq->resid_len; |
294 | if (sense && rq->sense_len) | |
295 | memcpy(sense, rq->sense, SCSI_SENSE_BUFFERSIZE); | |
3949e2f0 CH |
296 | if (sshdr) |
297 | scsi_normalize_sense(rq->sense, rq->sense_len, sshdr); | |
17d5363b | 298 | ret = rq->result; |
39216033 JB |
299 | out: |
300 | blk_put_request(req); | |
301 | ||
302 | return ret; | |
303 | } | |
704f8392 | 304 | EXPORT_SYMBOL(__scsi_execute); |
39216033 | 305 | |
1da177e4 LT |
306 | /* |
307 | * Function: scsi_init_cmd_errh() | |
308 | * | |
309 | * Purpose: Initialize cmd fields related to error handling. | |
310 | * | |
311 | * Arguments: cmd - command that is ready to be queued. | |
312 | * | |
1da177e4 LT |
313 | * Notes: This function has the job of initializing a number of |
314 | * fields related to error handling. Typically this will | |
315 | * be called once for each command, as required. | |
316 | */ | |
631c228c | 317 | static void scsi_init_cmd_errh(struct scsi_cmnd *cmd) |
1da177e4 | 318 | { |
30b0c37b | 319 | scsi_set_resid(cmd, 0); |
b80ca4f7 | 320 | memset(cmd->sense_buffer, 0, SCSI_SENSE_BUFFERSIZE); |
1da177e4 | 321 | if (cmd->cmd_len == 0) |
db4742dd | 322 | cmd->cmd_len = scsi_command_size(cmd->cmnd); |
1da177e4 LT |
323 | } |
324 | ||
3bd6f43f BVA |
325 | /* |
326 | * Decrement the host_busy counter and wake up the error handler if necessary. | |
327 | * Avoid as follows that the error handler is not woken up if shost->host_busy | |
328 | * == shost->host_failed: use call_rcu() in scsi_eh_scmd_add() in combination | |
329 | * with an RCU read lock in this function to ensure that this function in its | |
330 | * entirety either finishes before scsi_eh_scmd_add() increases the | |
331 | * host_failed counter or that it notices the shost state change made by | |
332 | * scsi_eh_scmd_add(). | |
333 | */ | |
334 | static void scsi_dec_host_busy(struct Scsi_Host *shost) | |
1da177e4 | 335 | { |
1da177e4 LT |
336 | unsigned long flags; |
337 | ||
3bd6f43f | 338 | rcu_read_lock(); |
d772a65d | 339 | atomic_dec(&shost->host_busy); |
3bd6f43f | 340 | if (unlikely(scsi_host_in_recovery(shost))) { |
74665016 | 341 | spin_lock_irqsave(shost->host_lock, flags); |
3bd6f43f BVA |
342 | if (shost->host_failed || shost->host_eh_scheduled) |
343 | scsi_eh_wakeup(shost); | |
74665016 CH |
344 | spin_unlock_irqrestore(shost->host_lock, flags); |
345 | } | |
3bd6f43f BVA |
346 | rcu_read_unlock(); |
347 | } | |
348 | ||
349 | void scsi_device_unbusy(struct scsi_device *sdev) | |
350 | { | |
351 | struct Scsi_Host *shost = sdev->host; | |
352 | struct scsi_target *starget = scsi_target(sdev); | |
353 | ||
354 | scsi_dec_host_busy(shost); | |
355 | ||
356 | if (starget->can_queue > 0) | |
357 | atomic_dec(&starget->target_busy); | |
74665016 | 358 | |
71e75c97 | 359 | atomic_dec(&sdev->device_busy); |
1da177e4 LT |
360 | } |
361 | ||
d285203c CH |
362 | static void scsi_kick_queue(struct request_queue *q) |
363 | { | |
f664a3cc | 364 | blk_mq_run_hw_queues(q, false); |
d285203c CH |
365 | } |
366 | ||
1da177e4 LT |
367 | /* |
368 | * Called for single_lun devices on IO completion. Clear starget_sdev_user, | |
369 | * and call blk_run_queue for all the scsi_devices on the target - | |
370 | * including current_sdev first. | |
371 | * | |
372 | * Called with *no* scsi locks held. | |
373 | */ | |
374 | static void scsi_single_lun_run(struct scsi_device *current_sdev) | |
375 | { | |
376 | struct Scsi_Host *shost = current_sdev->host; | |
377 | struct scsi_device *sdev, *tmp; | |
378 | struct scsi_target *starget = scsi_target(current_sdev); | |
379 | unsigned long flags; | |
380 | ||
381 | spin_lock_irqsave(shost->host_lock, flags); | |
382 | starget->starget_sdev_user = NULL; | |
383 | spin_unlock_irqrestore(shost->host_lock, flags); | |
384 | ||
385 | /* | |
386 | * Call blk_run_queue for all LUNs on the target, starting with | |
387 | * current_sdev. We race with others (to set starget_sdev_user), | |
388 | * but in most cases, we will be first. Ideally, each LU on the | |
389 | * target would get some limited time or requests on the target. | |
390 | */ | |
d285203c | 391 | scsi_kick_queue(current_sdev->request_queue); |
1da177e4 LT |
392 | |
393 | spin_lock_irqsave(shost->host_lock, flags); | |
394 | if (starget->starget_sdev_user) | |
395 | goto out; | |
396 | list_for_each_entry_safe(sdev, tmp, &starget->devices, | |
397 | same_target_siblings) { | |
398 | if (sdev == current_sdev) | |
399 | continue; | |
400 | if (scsi_device_get(sdev)) | |
401 | continue; | |
402 | ||
403 | spin_unlock_irqrestore(shost->host_lock, flags); | |
d285203c | 404 | scsi_kick_queue(sdev->request_queue); |
1da177e4 LT |
405 | spin_lock_irqsave(shost->host_lock, flags); |
406 | ||
407 | scsi_device_put(sdev); | |
408 | } | |
409 | out: | |
410 | spin_unlock_irqrestore(shost->host_lock, flags); | |
411 | } | |
412 | ||
cd9070c9 | 413 | static inline bool scsi_device_is_busy(struct scsi_device *sdev) |
9d112517 | 414 | { |
cd9070c9 CH |
415 | if (atomic_read(&sdev->device_busy) >= sdev->queue_depth) |
416 | return true; | |
417 | if (atomic_read(&sdev->device_blocked) > 0) | |
418 | return true; | |
419 | return false; | |
9d112517 KU |
420 | } |
421 | ||
cd9070c9 | 422 | static inline bool scsi_target_is_busy(struct scsi_target *starget) |
f0c0a376 | 423 | { |
2ccbb008 CH |
424 | if (starget->can_queue > 0) { |
425 | if (atomic_read(&starget->target_busy) >= starget->can_queue) | |
426 | return true; | |
427 | if (atomic_read(&starget->target_blocked) > 0) | |
428 | return true; | |
429 | } | |
cd9070c9 | 430 | return false; |
f0c0a376 MC |
431 | } |
432 | ||
cd9070c9 | 433 | static inline bool scsi_host_is_busy(struct Scsi_Host *shost) |
9d112517 | 434 | { |
d772a65d | 435 | if (shost->can_queue > 0 && |
cd9070c9 CH |
436 | atomic_read(&shost->host_busy) >= shost->can_queue) |
437 | return true; | |
438 | if (atomic_read(&shost->host_blocked) > 0) | |
439 | return true; | |
440 | if (shost->host_self_blocked) | |
441 | return true; | |
442 | return false; | |
9d112517 KU |
443 | } |
444 | ||
21a05df5 | 445 | static void scsi_starved_list_run(struct Scsi_Host *shost) |
1da177e4 | 446 | { |
2a3a59e5 | 447 | LIST_HEAD(starved_list); |
21a05df5 | 448 | struct scsi_device *sdev; |
1da177e4 LT |
449 | unsigned long flags; |
450 | ||
1da177e4 | 451 | spin_lock_irqsave(shost->host_lock, flags); |
2a3a59e5 MC |
452 | list_splice_init(&shost->starved_list, &starved_list); |
453 | ||
454 | while (!list_empty(&starved_list)) { | |
e2eb7244 JB |
455 | struct request_queue *slq; |
456 | ||
1da177e4 LT |
457 | /* |
458 | * As long as shost is accepting commands and we have | |
459 | * starved queues, call blk_run_queue. scsi_request_fn | |
460 | * drops the queue_lock and can add us back to the | |
461 | * starved_list. | |
462 | * | |
463 | * host_lock protects the starved_list and starved_entry. | |
464 | * scsi_request_fn must get the host_lock before checking | |
465 | * or modifying starved_list or starved_entry. | |
466 | */ | |
2a3a59e5 | 467 | if (scsi_host_is_busy(shost)) |
f0c0a376 | 468 | break; |
f0c0a376 | 469 | |
2a3a59e5 MC |
470 | sdev = list_entry(starved_list.next, |
471 | struct scsi_device, starved_entry); | |
472 | list_del_init(&sdev->starved_entry); | |
f0c0a376 MC |
473 | if (scsi_target_is_busy(scsi_target(sdev))) { |
474 | list_move_tail(&sdev->starved_entry, | |
475 | &shost->starved_list); | |
476 | continue; | |
477 | } | |
478 | ||
e2eb7244 JB |
479 | /* |
480 | * Once we drop the host lock, a racing scsi_remove_device() | |
481 | * call may remove the sdev from the starved list and destroy | |
482 | * it and the queue. Mitigate by taking a reference to the | |
483 | * queue and never touching the sdev again after we drop the | |
484 | * host lock. Note: if __scsi_remove_device() invokes | |
485 | * blk_cleanup_queue() before the queue is run from this | |
486 | * function then blk_run_queue() will return immediately since | |
487 | * blk_cleanup_queue() marks the queue with QUEUE_FLAG_DYING. | |
488 | */ | |
489 | slq = sdev->request_queue; | |
490 | if (!blk_get_queue(slq)) | |
491 | continue; | |
492 | spin_unlock_irqrestore(shost->host_lock, flags); | |
493 | ||
d285203c | 494 | scsi_kick_queue(slq); |
e2eb7244 JB |
495 | blk_put_queue(slq); |
496 | ||
497 | spin_lock_irqsave(shost->host_lock, flags); | |
1da177e4 | 498 | } |
2a3a59e5 MC |
499 | /* put any unprocessed entries back */ |
500 | list_splice(&starved_list, &shost->starved_list); | |
1da177e4 | 501 | spin_unlock_irqrestore(shost->host_lock, flags); |
21a05df5 CH |
502 | } |
503 | ||
504 | /* | |
505 | * Function: scsi_run_queue() | |
506 | * | |
507 | * Purpose: Select a proper request queue to serve next | |
508 | * | |
509 | * Arguments: q - last request's queue | |
510 | * | |
511 | * Returns: Nothing | |
512 | * | |
513 | * Notes: The previous command was completely finished, start | |
514 | * a new one if possible. | |
515 | */ | |
516 | static void scsi_run_queue(struct request_queue *q) | |
517 | { | |
518 | struct scsi_device *sdev = q->queuedata; | |
519 | ||
520 | if (scsi_target(sdev)->single_lun) | |
521 | scsi_single_lun_run(sdev); | |
522 | if (!list_empty(&sdev->host->starved_list)) | |
523 | scsi_starved_list_run(sdev->host); | |
1da177e4 | 524 | |
f664a3cc | 525 | blk_mq_run_hw_queues(q, false); |
1da177e4 LT |
526 | } |
527 | ||
9937a5e2 JA |
528 | void scsi_requeue_run_queue(struct work_struct *work) |
529 | { | |
530 | struct scsi_device *sdev; | |
531 | struct request_queue *q; | |
532 | ||
533 | sdev = container_of(work, struct scsi_device, requeue_work); | |
534 | q = sdev->request_queue; | |
535 | scsi_run_queue(q); | |
536 | } | |
537 | ||
1da177e4 LT |
538 | void scsi_run_host_queues(struct Scsi_Host *shost) |
539 | { | |
540 | struct scsi_device *sdev; | |
541 | ||
542 | shost_for_each_device(sdev, shost) | |
543 | scsi_run_queue(sdev->request_queue); | |
544 | } | |
545 | ||
d285203c CH |
546 | static void scsi_uninit_cmd(struct scsi_cmnd *cmd) |
547 | { | |
57292b58 | 548 | if (!blk_rq_is_passthrough(cmd->request)) { |
d285203c CH |
549 | struct scsi_driver *drv = scsi_cmd_to_driver(cmd); |
550 | ||
551 | if (drv->uninit_command) | |
552 | drv->uninit_command(cmd); | |
553 | } | |
554 | } | |
555 | ||
556 | static void scsi_mq_free_sgtables(struct scsi_cmnd *cmd) | |
557 | { | |
558 | if (cmd->sdb.table.nents) | |
001d63be | 559 | sg_free_table_chained(&cmd->sdb.table, true); |
d285203c | 560 | if (scsi_prot_sg_count(cmd)) |
001d63be | 561 | sg_free_table_chained(&cmd->prot_sdb->table, true); |
d285203c CH |
562 | } |
563 | ||
564 | static void scsi_mq_uninit_cmd(struct scsi_cmnd *cmd) | |
565 | { | |
d285203c CH |
566 | scsi_mq_free_sgtables(cmd); |
567 | scsi_uninit_cmd(cmd); | |
2dd6fb59 | 568 | scsi_del_cmd_from_list(cmd); |
d285203c CH |
569 | } |
570 | ||
7e63b5a4 | 571 | /* Returns false when no more bytes to process, true if there are more */ |
2a842aca | 572 | static bool scsi_end_request(struct request *req, blk_status_t error, |
ae3d56d8 | 573 | unsigned int bytes) |
f6d47e74 | 574 | { |
bed2213d | 575 | struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req); |
f6d47e74 CH |
576 | struct scsi_device *sdev = cmd->device; |
577 | struct request_queue *q = sdev->request_queue; | |
f6d47e74 CH |
578 | |
579 | if (blk_update_request(req, error, bytes)) | |
580 | return true; | |
581 | ||
f6d47e74 CH |
582 | if (blk_queue_add_random(q)) |
583 | add_disk_randomness(req->rq_disk); | |
584 | ||
64104f70 BVA |
585 | if (!blk_rq_is_scsi(req)) { |
586 | WARN_ON_ONCE(!(cmd->flags & SCMD_INITIALIZED)); | |
587 | cmd->flags &= ~SCMD_INITIALIZED; | |
3be8828f | 588 | destroy_rcu_head(&cmd->rcu); |
64104f70 BVA |
589 | } |
590 | ||
f664a3cc JA |
591 | /* |
592 | * In the MQ case the command gets freed by __blk_mq_end_request, | |
593 | * so we have to do all cleanup that depends on it earlier. | |
594 | * | |
595 | * We also can't kick the queues from irq context, so we | |
596 | * will have to defer it to a workqueue. | |
597 | */ | |
598 | scsi_mq_uninit_cmd(cmd); | |
f81426a8 | 599 | |
a78b03bc JA |
600 | /* |
601 | * queue is still alive, so grab the ref for preventing it | |
602 | * from being cleaned up during running queue. | |
603 | */ | |
604 | percpu_ref_get(&q->q_usage_counter); | |
f81426a8 | 605 | |
f664a3cc | 606 | __blk_mq_end_request(req, error); |
d285203c | 607 | |
f664a3cc JA |
608 | if (scsi_target(sdev)->single_lun || |
609 | !list_empty(&sdev->host->starved_list)) | |
610 | kblockd_schedule_work(&sdev->requeue_work); | |
611 | else | |
612 | blk_mq_run_hw_queues(q, true); | |
f6d47e74 | 613 | |
a78b03bc | 614 | percpu_ref_put(&q->q_usage_counter); |
bb3ec62a | 615 | put_device(&sdev->sdev_gendev); |
f6d47e74 CH |
616 | return false; |
617 | } | |
618 | ||
0f7f6234 | 619 | /** |
a77b32d8 BVA |
620 | * scsi_result_to_blk_status - translate a SCSI result code into blk_status_t |
621 | * @cmd: SCSI command | |
0f7f6234 HR |
622 | * @result: scsi error code |
623 | * | |
a77b32d8 BVA |
624 | * Translate a SCSI result code into a blk_status_t value. May reset the host |
625 | * byte of @cmd->result. | |
0f7f6234 | 626 | */ |
a77b32d8 | 627 | static blk_status_t scsi_result_to_blk_status(struct scsi_cmnd *cmd, int result) |
63583cca | 628 | { |
2a842aca | 629 | switch (host_byte(result)) { |
f4abab3f BVA |
630 | case DID_OK: |
631 | /* | |
632 | * Also check the other bytes than the status byte in result | |
633 | * to handle the case when a SCSI LLD sets result to | |
634 | * DRIVER_SENSE << 24 without setting SAM_STAT_CHECK_CONDITION. | |
635 | */ | |
636 | if (scsi_status_is_good(result) && (result & ~0xff) == 0) | |
637 | return BLK_STS_OK; | |
638 | return BLK_STS_IOERR; | |
63583cca | 639 | case DID_TRANSPORT_FAILFAST: |
2a842aca | 640 | return BLK_STS_TRANSPORT; |
63583cca | 641 | case DID_TARGET_FAILURE: |
2082ebc4 | 642 | set_host_byte(cmd, DID_OK); |
2a842aca | 643 | return BLK_STS_TARGET; |
63583cca | 644 | case DID_NEXUS_FAILURE: |
4a067cf8 | 645 | set_host_byte(cmd, DID_OK); |
2a842aca | 646 | return BLK_STS_NEXUS; |
a9d6ceb8 HR |
647 | case DID_ALLOC_FAILURE: |
648 | set_host_byte(cmd, DID_OK); | |
2a842aca | 649 | return BLK_STS_NOSPC; |
7e782af5 HR |
650 | case DID_MEDIUM_ERROR: |
651 | set_host_byte(cmd, DID_OK); | |
2a842aca | 652 | return BLK_STS_MEDIUM; |
63583cca | 653 | default: |
2a842aca | 654 | return BLK_STS_IOERR; |
63583cca | 655 | } |
63583cca HR |
656 | } |
657 | ||
4ae61c68 DG |
658 | /* Helper for scsi_io_completion() when "reprep" action required. */ |
659 | static void scsi_io_completion_reprep(struct scsi_cmnd *cmd, | |
660 | struct request_queue *q) | |
661 | { | |
662 | /* A new command will be prepared and issued. */ | |
f664a3cc | 663 | scsi_mq_requeue_cmd(cmd); |
4ae61c68 DG |
664 | } |
665 | ||
da32baea DG |
666 | /* Helper for scsi_io_completion() when special action required. */ |
667 | static void scsi_io_completion_action(struct scsi_cmnd *cmd, int result) | |
1da177e4 | 668 | { |
165125e1 | 669 | struct request_queue *q = cmd->device->request_queue; |
1da177e4 | 670 | struct request *req = cmd->request; |
da32baea | 671 | int level = 0; |
b60af5b0 AS |
672 | enum {ACTION_FAIL, ACTION_REPREP, ACTION_RETRY, |
673 | ACTION_DELAYED_RETRY} action; | |
ee60b2c5 | 674 | unsigned long wait_for = (cmd->allowed + 1) * req->timeout; |
da32baea DG |
675 | struct scsi_sense_hdr sshdr; |
676 | bool sense_valid; | |
677 | bool sense_current = true; /* false implies "deferred sense" */ | |
678 | blk_status_t blk_stat; | |
1da177e4 | 679 | |
da32baea DG |
680 | sense_valid = scsi_command_normalize_sense(cmd, &sshdr); |
681 | if (sense_valid) | |
682 | sense_current = !scsi_sense_is_deferred(&sshdr); | |
03aba2f7 | 683 | |
da32baea | 684 | blk_stat = scsi_result_to_blk_status(cmd, result); |
3e695f89 | 685 | |
b60af5b0 AS |
686 | if (host_byte(result) == DID_RESET) { |
687 | /* Third party bus reset or reset for error recovery | |
688 | * reasons. Just retry the command and see what | |
689 | * happens. | |
690 | */ | |
691 | action = ACTION_RETRY; | |
da32baea | 692 | } else if (sense_valid && sense_current) { |
1da177e4 LT |
693 | switch (sshdr.sense_key) { |
694 | case UNIT_ATTENTION: | |
695 | if (cmd->device->removable) { | |
03aba2f7 | 696 | /* Detected disc change. Set a bit |
1da177e4 LT |
697 | * and quietly refuse further access. |
698 | */ | |
699 | cmd->device->changed = 1; | |
b60af5b0 | 700 | action = ACTION_FAIL; |
1da177e4 | 701 | } else { |
03aba2f7 LT |
702 | /* Must have been a power glitch, or a |
703 | * bus reset. Could not have been a | |
704 | * media change, so we just retry the | |
b60af5b0 | 705 | * command and see what happens. |
03aba2f7 | 706 | */ |
b60af5b0 | 707 | action = ACTION_RETRY; |
1da177e4 LT |
708 | } |
709 | break; | |
710 | case ILLEGAL_REQUEST: | |
03aba2f7 LT |
711 | /* If we had an ILLEGAL REQUEST returned, then |
712 | * we may have performed an unsupported | |
713 | * command. The only thing this should be | |
714 | * would be a ten byte read where only a six | |
715 | * byte read was supported. Also, on a system | |
716 | * where READ CAPACITY failed, we may have | |
717 | * read past the end of the disk. | |
718 | */ | |
26a68019 JA |
719 | if ((cmd->device->use_10_for_rw && |
720 | sshdr.asc == 0x20 && sshdr.ascq == 0x00) && | |
1da177e4 LT |
721 | (cmd->cmnd[0] == READ_10 || |
722 | cmd->cmnd[0] == WRITE_10)) { | |
b60af5b0 | 723 | /* This will issue a new 6-byte command. */ |
1da177e4 | 724 | cmd->device->use_10_for_rw = 0; |
b60af5b0 | 725 | action = ACTION_REPREP; |
3e695f89 | 726 | } else if (sshdr.asc == 0x10) /* DIX */ { |
3e695f89 | 727 | action = ACTION_FAIL; |
da32baea | 728 | blk_stat = BLK_STS_PROTECTION; |
c98a0eb0 | 729 | /* INVALID COMMAND OPCODE or INVALID FIELD IN CDB */ |
5db44863 | 730 | } else if (sshdr.asc == 0x20 || sshdr.asc == 0x24) { |
c98a0eb0 | 731 | action = ACTION_FAIL; |
da32baea | 732 | blk_stat = BLK_STS_TARGET; |
b60af5b0 AS |
733 | } else |
734 | action = ACTION_FAIL; | |
735 | break; | |
511e44f4 | 736 | case ABORTED_COMMAND: |
126c0982 | 737 | action = ACTION_FAIL; |
e6c11dbb | 738 | if (sshdr.asc == 0x10) /* DIF */ |
da32baea | 739 | blk_stat = BLK_STS_PROTECTION; |
1da177e4 LT |
740 | break; |
741 | case NOT_READY: | |
03aba2f7 | 742 | /* If the device is in the process of becoming |
f3e93f73 | 743 | * ready, or has a temporary blockage, retry. |
1da177e4 | 744 | */ |
f3e93f73 JB |
745 | if (sshdr.asc == 0x04) { |
746 | switch (sshdr.ascq) { | |
747 | case 0x01: /* becoming ready */ | |
748 | case 0x04: /* format in progress */ | |
749 | case 0x05: /* rebuild in progress */ | |
750 | case 0x06: /* recalculation in progress */ | |
751 | case 0x07: /* operation in progress */ | |
752 | case 0x08: /* Long write in progress */ | |
753 | case 0x09: /* self test in progress */ | |
d8705f11 | 754 | case 0x14: /* space allocation in progress */ |
e37c7d9a DG |
755 | case 0x1a: /* start stop unit in progress */ |
756 | case 0x1b: /* sanitize in progress */ | |
757 | case 0x1d: /* configuration in progress */ | |
758 | case 0x24: /* depopulation in progress */ | |
b60af5b0 | 759 | action = ACTION_DELAYED_RETRY; |
f3e93f73 | 760 | break; |
3dbf6a54 | 761 | default: |
3dbf6a54 AS |
762 | action = ACTION_FAIL; |
763 | break; | |
f3e93f73 | 764 | } |
e6c11dbb | 765 | } else |
b60af5b0 | 766 | action = ACTION_FAIL; |
b60af5b0 | 767 | break; |
1da177e4 | 768 | case VOLUME_OVERFLOW: |
03aba2f7 | 769 | /* See SSC3rXX or current. */ |
b60af5b0 AS |
770 | action = ACTION_FAIL; |
771 | break; | |
1da177e4 | 772 | default: |
b60af5b0 | 773 | action = ACTION_FAIL; |
1da177e4 LT |
774 | break; |
775 | } | |
e6c11dbb | 776 | } else |
b60af5b0 | 777 | action = ACTION_FAIL; |
b60af5b0 | 778 | |
ee60b2c5 | 779 | if (action != ACTION_FAIL && |
e6c11dbb | 780 | time_before(cmd->jiffies_at_alloc + wait_for, jiffies)) |
ee60b2c5 | 781 | action = ACTION_FAIL; |
ee60b2c5 | 782 | |
b60af5b0 AS |
783 | switch (action) { |
784 | case ACTION_FAIL: | |
785 | /* Give up and fail the remainder of the request */ | |
e8064021 | 786 | if (!(req->rq_flags & RQF_QUIET)) { |
f1569ff1 HR |
787 | static DEFINE_RATELIMIT_STATE(_rs, |
788 | DEFAULT_RATELIMIT_INTERVAL, | |
789 | DEFAULT_RATELIMIT_BURST); | |
790 | ||
791 | if (unlikely(scsi_logging_level)) | |
da32baea DG |
792 | level = |
793 | SCSI_LOG_LEVEL(SCSI_LOG_MLCOMPLETE_SHIFT, | |
794 | SCSI_LOG_MLCOMPLETE_BITS); | |
f1569ff1 HR |
795 | |
796 | /* | |
797 | * if logging is enabled the failure will be printed | |
798 | * in scsi_log_completion(), so avoid duplicate messages | |
799 | */ | |
800 | if (!level && __ratelimit(&_rs)) { | |
801 | scsi_print_result(cmd, NULL, FAILED); | |
c65be1a6 | 802 | if (driver_byte(result) == DRIVER_SENSE) |
f1569ff1 HR |
803 | scsi_print_sense(cmd); |
804 | scsi_print_command(cmd); | |
805 | } | |
3173d8c3 | 806 | } |
ae3d56d8 | 807 | if (!scsi_end_request(req, blk_stat, blk_rq_err_bytes(req))) |
f6d47e74 | 808 | return; |
bc85dc50 | 809 | /*FALLTHRU*/ |
b60af5b0 | 810 | case ACTION_REPREP: |
4ae61c68 | 811 | scsi_io_completion_reprep(cmd, q); |
b60af5b0 AS |
812 | break; |
813 | case ACTION_RETRY: | |
814 | /* Retry the same command immediately */ | |
08640e81 | 815 | __scsi_queue_insert(cmd, SCSI_MLQUEUE_EH_RETRY, false); |
b60af5b0 AS |
816 | break; |
817 | case ACTION_DELAYED_RETRY: | |
818 | /* Retry the same command after a delay */ | |
08640e81 | 819 | __scsi_queue_insert(cmd, SCSI_MLQUEUE_DEVICE_BUSY, false); |
b60af5b0 | 820 | break; |
1da177e4 LT |
821 | } |
822 | } | |
1da177e4 | 823 | |
ab831084 DG |
824 | /* |
825 | * Helper for scsi_io_completion() when cmd->result is non-zero. Returns a | |
826 | * new result that may suppress further error checking. Also modifies | |
827 | * *blk_statp in some cases. | |
828 | */ | |
829 | static int scsi_io_completion_nz_result(struct scsi_cmnd *cmd, int result, | |
830 | blk_status_t *blk_statp) | |
831 | { | |
832 | bool sense_valid; | |
833 | bool sense_current = true; /* false implies "deferred sense" */ | |
834 | struct request *req = cmd->request; | |
835 | struct scsi_sense_hdr sshdr; | |
836 | ||
837 | sense_valid = scsi_command_normalize_sense(cmd, &sshdr); | |
838 | if (sense_valid) | |
839 | sense_current = !scsi_sense_is_deferred(&sshdr); | |
840 | ||
841 | if (blk_rq_is_passthrough(req)) { | |
842 | if (sense_valid) { | |
843 | /* | |
844 | * SG_IO wants current and deferred errors | |
845 | */ | |
846 | scsi_req(req)->sense_len = | |
847 | min(8 + cmd->sense_buffer[7], | |
848 | SCSI_SENSE_BUFFERSIZE); | |
849 | } | |
850 | if (sense_current) | |
851 | *blk_statp = scsi_result_to_blk_status(cmd, result); | |
852 | } else if (blk_rq_bytes(req) == 0 && sense_current) { | |
853 | /* | |
854 | * Flush commands do not transfers any data, and thus cannot use | |
855 | * good_bytes != blk_rq_bytes(req) as the signal for an error. | |
856 | * This sets *blk_statp explicitly for the problem case. | |
857 | */ | |
858 | *blk_statp = scsi_result_to_blk_status(cmd, result); | |
859 | } | |
860 | /* | |
861 | * Recovered errors need reporting, but they're always treated as | |
862 | * success, so fiddle the result code here. For passthrough requests | |
863 | * we already took a copy of the original into sreq->result which | |
864 | * is what gets returned to the user | |
865 | */ | |
866 | if (sense_valid && (sshdr.sense_key == RECOVERED_ERROR)) { | |
867 | bool do_print = true; | |
868 | /* | |
869 | * if ATA PASS-THROUGH INFORMATION AVAILABLE [0x0, 0x1d] | |
870 | * skip print since caller wants ATA registers. Only occurs | |
871 | * on SCSI ATA PASS_THROUGH commands when CK_COND=1 | |
872 | */ | |
873 | if ((sshdr.asc == 0x0) && (sshdr.ascq == 0x1d)) | |
874 | do_print = false; | |
875 | else if (req->rq_flags & RQF_QUIET) | |
876 | do_print = false; | |
877 | if (do_print) | |
878 | scsi_print_sense(cmd); | |
879 | result = 0; | |
880 | /* for passthrough, *blk_statp may be set */ | |
881 | *blk_statp = BLK_STS_OK; | |
882 | } | |
883 | /* | |
884 | * Another corner case: the SCSI status byte is non-zero but 'good'. | |
885 | * Example: PRE-FETCH command returns SAM_STAT_CONDITION_MET when | |
886 | * it is able to fit nominated LBs in its cache (and SAM_STAT_GOOD | |
887 | * if it can't fit). Treat SAM_STAT_CONDITION_MET and the related | |
888 | * intermediate statuses (both obsolete in SAM-4) as good. | |
889 | */ | |
890 | if (status_byte(result) && scsi_status_is_good(result)) { | |
891 | result = 0; | |
892 | *blk_statp = BLK_STS_OK; | |
893 | } | |
894 | return result; | |
895 | } | |
896 | ||
1da177e4 LT |
897 | /* |
898 | * Function: scsi_io_completion() | |
899 | * | |
900 | * Purpose: Completion processing for block device I/O requests. | |
901 | * | |
902 | * Arguments: cmd - command that is finished. | |
903 | * | |
904 | * Lock status: Assumed that no lock is held upon entry. | |
905 | * | |
906 | * Returns: Nothing | |
907 | * | |
bc85dc50 CH |
908 | * Notes: We will finish off the specified number of sectors. If we |
909 | * are done, the command block will be released and the queue | |
910 | * function will be goosed. If we are not done then we have to | |
b60af5b0 | 911 | * figure out what to do next: |
1da177e4 | 912 | * |
b60af5b0 AS |
913 | * a) We can call scsi_requeue_command(). The request |
914 | * will be unprepared and put back on the queue. Then | |
915 | * a new command will be created for it. This should | |
916 | * be used if we made forward progress, or if we want | |
917 | * to switch from READ(10) to READ(6) for example. | |
1da177e4 | 918 | * |
bc85dc50 | 919 | * b) We can call __scsi_queue_insert(). The request will |
b60af5b0 AS |
920 | * be put back on the queue and retried using the same |
921 | * command as before, possibly after a delay. | |
922 | * | |
1f7cbb8e DG |
923 | * c) We can call scsi_end_request() with blk_stat other than |
924 | * BLK_STS_OK, to fail the remainder of the request. | |
1da177e4 | 925 | */ |
03aba2f7 | 926 | void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes) |
1da177e4 LT |
927 | { |
928 | int result = cmd->result; | |
165125e1 | 929 | struct request_queue *q = cmd->device->request_queue; |
1da177e4 | 930 | struct request *req = cmd->request; |
1f7cbb8e | 931 | blk_status_t blk_stat = BLK_STS_OK; |
1da177e4 | 932 | |
0d437906 | 933 | if (unlikely(result)) /* a nz result may or may not be an error */ |
ab831084 | 934 | result = scsi_io_completion_nz_result(cmd, result, &blk_stat); |
631c228c | 935 | |
0d437906 | 936 | if (unlikely(blk_rq_is_passthrough(req))) { |
27c41973 | 937 | /* |
a77b32d8 | 938 | * scsi_result_to_blk_status may have reset the host_byte |
27c41973 | 939 | */ |
17d5363b | 940 | scsi_req(req)->result = cmd->result; |
8e1695a0 | 941 | } |
30b0c37b | 942 | |
1da177e4 LT |
943 | /* |
944 | * Next deal with any sectors which we were able to correctly | |
945 | * handle. | |
946 | */ | |
91921e01 HR |
947 | SCSI_LOG_HLCOMPLETE(1, scmd_printk(KERN_INFO, cmd, |
948 | "%u sectors total, %d bytes done.\n", | |
949 | blk_rq_sectors(req), good_bytes)); | |
d6b0c537 | 950 | |
a9bddd74 | 951 | /* |
1f7cbb8e DG |
952 | * Next deal with any sectors which we were able to correctly |
953 | * handle. Failed, zero length commands always need to drop down | |
954 | * to retry code. Fast path should return in this block. | |
d6b0c537 | 955 | */ |
0d437906 | 956 | if (likely(blk_rq_bytes(req) > 0 || blk_stat == BLK_STS_OK)) { |
ae3d56d8 | 957 | if (likely(!scsi_end_request(req, blk_stat, good_bytes))) |
1f7cbb8e DG |
958 | return; /* no bytes remaining */ |
959 | } | |
bc85dc50 | 960 | |
0d437906 DG |
961 | /* Kill remainder if no retries. */ |
962 | if (unlikely(blk_stat && scsi_noretry_cmd(cmd))) { | |
ae3d56d8 | 963 | if (scsi_end_request(req, blk_stat, blk_rq_bytes(req))) |
8e1695a0 DG |
964 | WARN_ONCE(true, |
965 | "Bytes remaining after failed, no-retry command"); | |
f6d47e74 | 966 | return; |
bc85dc50 CH |
967 | } |
968 | ||
969 | /* | |
970 | * If there had been no error, but we have leftover bytes in the | |
971 | * requeues just queue the command up again. | |
d6b0c537 | 972 | */ |
0d437906 | 973 | if (likely(result == 0)) |
4ae61c68 DG |
974 | scsi_io_completion_reprep(cmd, q); |
975 | else | |
da32baea | 976 | scsi_io_completion_action(cmd, result); |
1da177e4 | 977 | } |
1da177e4 | 978 | |
159b2cbf CH |
979 | static blk_status_t scsi_init_sgtable(struct request *req, |
980 | struct scsi_data_buffer *sdb) | |
1da177e4 | 981 | { |
6f9a35e2 | 982 | int count; |
1da177e4 LT |
983 | |
984 | /* | |
3b003157 | 985 | * If sg table allocation fails, requeue request later. |
1da177e4 | 986 | */ |
f9d03f96 CH |
987 | if (unlikely(sg_alloc_table_chained(&sdb->table, |
988 | blk_rq_nr_phys_segments(req), sdb->table.sgl))) | |
159b2cbf | 989 | return BLK_STS_RESOURCE; |
1da177e4 | 990 | |
1da177e4 LT |
991 | /* |
992 | * Next, walk the list, and fill in the addresses and sizes of | |
993 | * each segment. | |
994 | */ | |
30b0c37b BH |
995 | count = blk_rq_map_sg(req->q, req, sdb->table.sgl); |
996 | BUG_ON(count > sdb->table.nents); | |
997 | sdb->table.nents = count; | |
fd102b12 | 998 | sdb->length = blk_rq_payload_bytes(req); |
159b2cbf | 999 | return BLK_STS_OK; |
1da177e4 | 1000 | } |
6f9a35e2 BH |
1001 | |
1002 | /* | |
1003 | * Function: scsi_init_io() | |
1004 | * | |
1005 | * Purpose: SCSI I/O initialize function. | |
1006 | * | |
1007 | * Arguments: cmd - Command descriptor we wish to initialize | |
1008 | * | |
159b2cbf CH |
1009 | * Returns: BLK_STS_OK on success |
1010 | * BLK_STS_RESOURCE if the failure is retryable | |
1011 | * BLK_STS_IOERR if the failure is fatal | |
6f9a35e2 | 1012 | */ |
159b2cbf | 1013 | blk_status_t scsi_init_io(struct scsi_cmnd *cmd) |
6f9a35e2 | 1014 | { |
13f05c8d | 1015 | struct request *rq = cmd->request; |
159b2cbf | 1016 | blk_status_t ret; |
13f05c8d | 1017 | |
fd3fc0b4 | 1018 | if (WARN_ON_ONCE(!blk_rq_nr_phys_segments(rq))) |
159b2cbf | 1019 | return BLK_STS_IOERR; |
635d98b1 | 1020 | |
159b2cbf CH |
1021 | ret = scsi_init_sgtable(rq, &cmd->sdb); |
1022 | if (ret) | |
1023 | return ret; | |
6f9a35e2 | 1024 | |
13f05c8d | 1025 | if (blk_integrity_rq(rq)) { |
7027ad72 MP |
1026 | struct scsi_data_buffer *prot_sdb = cmd->prot_sdb; |
1027 | int ivecs, count; | |
1028 | ||
14784565 | 1029 | if (WARN_ON_ONCE(!prot_sdb)) { |
91724c20 EM |
1030 | /* |
1031 | * This can happen if someone (e.g. multipath) | |
1032 | * queues a command to a device on an adapter | |
1033 | * that does not support DIX. | |
1034 | */ | |
159b2cbf | 1035 | ret = BLK_STS_IOERR; |
14784565 | 1036 | goto out_free_sgtables; |
91724c20 EM |
1037 | } |
1038 | ||
13f05c8d | 1039 | ivecs = blk_rq_count_integrity_sg(rq->q, rq->bio); |
7027ad72 | 1040 | |
001d63be | 1041 | if (sg_alloc_table_chained(&prot_sdb->table, ivecs, |
22cc3d4c | 1042 | prot_sdb->table.sgl)) { |
159b2cbf | 1043 | ret = BLK_STS_RESOURCE; |
14784565 | 1044 | goto out_free_sgtables; |
7027ad72 MP |
1045 | } |
1046 | ||
13f05c8d | 1047 | count = blk_rq_map_integrity_sg(rq->q, rq->bio, |
7027ad72 | 1048 | prot_sdb->table.sgl); |
6f1d8a53 IS |
1049 | BUG_ON(count > ivecs); |
1050 | BUG_ON(count > queue_max_integrity_segments(rq->q)); | |
7027ad72 MP |
1051 | |
1052 | cmd->prot_sdb = prot_sdb; | |
1053 | cmd->prot_sdb->table.nents = count; | |
1054 | } | |
1055 | ||
159b2cbf | 1056 | return BLK_STS_OK; |
14784565 | 1057 | out_free_sgtables: |
f664a3cc | 1058 | scsi_mq_free_sgtables(cmd); |
159b2cbf | 1059 | return ret; |
6f9a35e2 | 1060 | } |
bb52d82f | 1061 | EXPORT_SYMBOL(scsi_init_io); |
1da177e4 | 1062 | |
ca18d6f7 | 1063 | /** |
832889f5 | 1064 | * scsi_initialize_rq - initialize struct scsi_cmnd partially |
35c0506f | 1065 | * @rq: Request associated with the SCSI command to be initialized. |
ca18d6f7 | 1066 | * |
832889f5 BVA |
1067 | * This function initializes the members of struct scsi_cmnd that must be |
1068 | * initialized before request processing starts and that won't be | |
1069 | * reinitialized if a SCSI command is requeued. | |
1070 | * | |
64104f70 BVA |
1071 | * Called from inside blk_get_request() for pass-through requests and from |
1072 | * inside scsi_init_command() for filesystem requests. | |
ca18d6f7 | 1073 | */ |
e4c9470b | 1074 | static void scsi_initialize_rq(struct request *rq) |
ca18d6f7 | 1075 | { |
c8d9cf22 BVA |
1076 | struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq); |
1077 | ||
1078 | scsi_req_init(&cmd->req); | |
3be8828f | 1079 | init_rcu_head(&cmd->rcu); |
832889f5 BVA |
1080 | cmd->jiffies_at_alloc = jiffies; |
1081 | cmd->retries = 0; | |
ca18d6f7 | 1082 | } |
ca18d6f7 | 1083 | |
2dd6fb59 BVA |
1084 | /* Add a command to the list used by the aacraid and dpt_i2o drivers */ |
1085 | void scsi_add_cmd_to_list(struct scsi_cmnd *cmd) | |
1086 | { | |
1087 | struct scsi_device *sdev = cmd->device; | |
1088 | struct Scsi_Host *shost = sdev->host; | |
1089 | unsigned long flags; | |
1090 | ||
1091 | if (shost->use_cmd_list) { | |
1092 | spin_lock_irqsave(&sdev->list_lock, flags); | |
1093 | list_add_tail(&cmd->list, &sdev->cmd_list); | |
1094 | spin_unlock_irqrestore(&sdev->list_lock, flags); | |
1095 | } | |
1096 | } | |
1097 | ||
1098 | /* Remove a command from the list used by the aacraid and dpt_i2o drivers */ | |
1099 | void scsi_del_cmd_from_list(struct scsi_cmnd *cmd) | |
1100 | { | |
1101 | struct scsi_device *sdev = cmd->device; | |
1102 | struct Scsi_Host *shost = sdev->host; | |
1103 | unsigned long flags; | |
1104 | ||
1105 | if (shost->use_cmd_list) { | |
1106 | spin_lock_irqsave(&sdev->list_lock, flags); | |
1107 | BUG_ON(list_empty(&cmd->list)); | |
1108 | list_del_init(&cmd->list); | |
1109 | spin_unlock_irqrestore(&sdev->list_lock, flags); | |
1110 | } | |
1111 | } | |
1112 | ||
ca18d6f7 | 1113 | /* Called after a request has been started. */ |
e9c787e6 | 1114 | void scsi_init_command(struct scsi_device *dev, struct scsi_cmnd *cmd) |
3b003157 | 1115 | { |
e9c787e6 CH |
1116 | void *buf = cmd->sense_buffer; |
1117 | void *prot = cmd->prot_sdb; | |
64104f70 BVA |
1118 | struct request *rq = blk_mq_rq_from_pdu(cmd); |
1119 | unsigned int flags = cmd->flags & SCMD_PRESERVED_FLAGS; | |
832889f5 BVA |
1120 | unsigned long jiffies_at_alloc; |
1121 | int retries; | |
64104f70 BVA |
1122 | |
1123 | if (!blk_rq_is_scsi(rq) && !(flags & SCMD_INITIALIZED)) { | |
1124 | flags |= SCMD_INITIALIZED; | |
1125 | scsi_initialize_rq(rq); | |
1126 | } | |
3b003157 | 1127 | |
832889f5 BVA |
1128 | jiffies_at_alloc = cmd->jiffies_at_alloc; |
1129 | retries = cmd->retries; | |
82ed4db4 CH |
1130 | /* zero out the cmd, except for the embedded scsi_request */ |
1131 | memset((char *)cmd + sizeof(cmd->req), 0, | |
ee524236 | 1132 | sizeof(*cmd) - sizeof(cmd->req) + dev->host->hostt->cmd_size); |
3b003157 | 1133 | |
e9c787e6 CH |
1134 | cmd->device = dev; |
1135 | cmd->sense_buffer = buf; | |
1136 | cmd->prot_sdb = prot; | |
64104f70 | 1137 | cmd->flags = flags; |
e9c787e6 | 1138 | INIT_DELAYED_WORK(&cmd->abort_work, scmd_eh_abort_handler); |
832889f5 BVA |
1139 | cmd->jiffies_at_alloc = jiffies_at_alloc; |
1140 | cmd->retries = retries; | |
64a87b24 | 1141 | |
2dd6fb59 | 1142 | scsi_add_cmd_to_list(cmd); |
3b003157 CH |
1143 | } |
1144 | ||
785ba83b CH |
1145 | static blk_status_t scsi_setup_scsi_cmnd(struct scsi_device *sdev, |
1146 | struct request *req) | |
7b16318d | 1147 | { |
bed2213d | 1148 | struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req); |
3b003157 CH |
1149 | |
1150 | /* | |
aebf526b | 1151 | * Passthrough requests may transfer data, in which case they must |
3b003157 CH |
1152 | * a bio attached to them. Or they might contain a SCSI command |
1153 | * that does not transfer data, in which case they may optionally | |
1154 | * submit a request without an attached bio. | |
1155 | */ | |
1156 | if (req->bio) { | |
159b2cbf CH |
1157 | blk_status_t ret = scsi_init_io(cmd); |
1158 | if (unlikely(ret != BLK_STS_OK)) | |
1159 | return ret; | |
3b003157 | 1160 | } else { |
b0790410 | 1161 | BUG_ON(blk_rq_bytes(req)); |
3b003157 | 1162 | |
30b0c37b | 1163 | memset(&cmd->sdb, 0, sizeof(cmd->sdb)); |
3b003157 | 1164 | } |
7b16318d | 1165 | |
82ed4db4 CH |
1166 | cmd->cmd_len = scsi_req(req)->cmd_len; |
1167 | cmd->cmnd = scsi_req(req)->cmd; | |
b0790410 | 1168 | cmd->transfersize = blk_rq_bytes(req); |
64c7f1d1 | 1169 | cmd->allowed = scsi_req(req)->retries; |
785ba83b | 1170 | return BLK_STS_OK; |
7b16318d | 1171 | } |
7b16318d | 1172 | |
3b003157 | 1173 | /* |
aebf526b | 1174 | * Setup a normal block command. These are simple request from filesystems |
3868cf8e | 1175 | * that still need to be translated to SCSI CDBs from the ULD. |
3b003157 | 1176 | */ |
785ba83b CH |
1177 | static blk_status_t scsi_setup_fs_cmnd(struct scsi_device *sdev, |
1178 | struct request *req) | |
1da177e4 | 1179 | { |
bed2213d | 1180 | struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req); |
a6a8d9f8 | 1181 | |
ee14c674 | 1182 | if (unlikely(sdev->handler && sdev->handler->prep_fn)) { |
4c1cb67c CH |
1183 | blk_status_t ret = sdev->handler->prep_fn(sdev, req); |
1184 | if (ret != BLK_STS_OK) | |
1185 | return ret; | |
a6a8d9f8 CS |
1186 | } |
1187 | ||
82ed4db4 | 1188 | cmd->cmnd = scsi_req(req)->cmd = scsi_req(req)->__cmd; |
64a87b24 | 1189 | memset(cmd->cmnd, 0, BLK_MAX_CDB); |
159b2cbf | 1190 | return scsi_cmd_to_driver(cmd)->init_command(cmd); |
3b003157 CH |
1191 | } |
1192 | ||
785ba83b CH |
1193 | static blk_status_t scsi_setup_cmnd(struct scsi_device *sdev, |
1194 | struct request *req) | |
6af7a4ff | 1195 | { |
bed2213d | 1196 | struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req); |
6af7a4ff CH |
1197 | |
1198 | if (!blk_rq_bytes(req)) | |
1199 | cmd->sc_data_direction = DMA_NONE; | |
1200 | else if (rq_data_dir(req) == WRITE) | |
1201 | cmd->sc_data_direction = DMA_TO_DEVICE; | |
1202 | else | |
1203 | cmd->sc_data_direction = DMA_FROM_DEVICE; | |
1204 | ||
aebf526b CH |
1205 | if (blk_rq_is_scsi(req)) |
1206 | return scsi_setup_scsi_cmnd(sdev, req); | |
1207 | else | |
6af7a4ff | 1208 | return scsi_setup_fs_cmnd(sdev, req); |
6af7a4ff CH |
1209 | } |
1210 | ||
c092d4ec | 1211 | static blk_status_t |
a1b73fc1 | 1212 | scsi_prep_state_check(struct scsi_device *sdev, struct request *req) |
3b003157 | 1213 | { |
c092d4ec CH |
1214 | switch (sdev->sdev_state) { |
1215 | case SDEV_OFFLINE: | |
1216 | case SDEV_TRANSPORT_OFFLINE: | |
1217 | /* | |
1218 | * If the device is offline we refuse to process any | |
1219 | * commands. The device must be brought online | |
1220 | * before trying any recovery commands. | |
1221 | */ | |
1222 | sdev_printk(KERN_ERR, sdev, | |
1223 | "rejecting I/O to offline device\n"); | |
1224 | return BLK_STS_IOERR; | |
1225 | case SDEV_DEL: | |
1226 | /* | |
1227 | * If the device is fully deleted, we refuse to | |
1228 | * process any commands as well. | |
1229 | */ | |
1230 | sdev_printk(KERN_ERR, sdev, | |
1231 | "rejecting I/O to dead device\n"); | |
1232 | return BLK_STS_IOERR; | |
1233 | case SDEV_BLOCK: | |
1234 | case SDEV_CREATED_BLOCK: | |
1235 | return BLK_STS_RESOURCE; | |
1236 | case SDEV_QUIESCE: | |
1237 | /* | |
1238 | * If the devices is blocked we defer normal commands. | |
1239 | */ | |
1240 | if (req && !(req->rq_flags & RQF_PREEMPT)) | |
1241 | return BLK_STS_RESOURCE; | |
1242 | return BLK_STS_OK; | |
1243 | default: | |
1244 | /* | |
1245 | * For any other not fully online state we only allow | |
1246 | * special commands. In particular any user initiated | |
1247 | * command is not allowed. | |
1248 | */ | |
1249 | if (req && !(req->rq_flags & RQF_PREEMPT)) | |
1250 | return BLK_STS_IOERR; | |
1251 | return BLK_STS_OK; | |
1da177e4 | 1252 | } |
7f9a6bc4 | 1253 | } |
1da177e4 | 1254 | |
1da177e4 LT |
1255 | /* |
1256 | * scsi_dev_queue_ready: if we can send requests to sdev, return 1 else | |
1257 | * return 0. | |
1258 | * | |
1259 | * Called with the queue_lock held. | |
1260 | */ | |
1261 | static inline int scsi_dev_queue_ready(struct request_queue *q, | |
1262 | struct scsi_device *sdev) | |
1263 | { | |
71e75c97 CH |
1264 | unsigned int busy; |
1265 | ||
1266 | busy = atomic_inc_return(&sdev->device_busy) - 1; | |
cd9070c9 | 1267 | if (atomic_read(&sdev->device_blocked)) { |
71e75c97 CH |
1268 | if (busy) |
1269 | goto out_dec; | |
1270 | ||
1da177e4 LT |
1271 | /* |
1272 | * unblock after device_blocked iterates to zero | |
1273 | */ | |
f664a3cc | 1274 | if (atomic_dec_return(&sdev->device_blocked) > 0) |
71e75c97 | 1275 | goto out_dec; |
71e75c97 CH |
1276 | SCSI_LOG_MLQUEUE(3, sdev_printk(KERN_INFO, sdev, |
1277 | "unblocking device at zero depth\n")); | |
1da177e4 | 1278 | } |
71e75c97 CH |
1279 | |
1280 | if (busy >= sdev->queue_depth) | |
1281 | goto out_dec; | |
1da177e4 LT |
1282 | |
1283 | return 1; | |
71e75c97 CH |
1284 | out_dec: |
1285 | atomic_dec(&sdev->device_busy); | |
1286 | return 0; | |
1da177e4 LT |
1287 | } |
1288 | ||
f0c0a376 MC |
1289 | /* |
1290 | * scsi_target_queue_ready: checks if there we can send commands to target | |
1291 | * @sdev: scsi device on starget to check. | |
f0c0a376 MC |
1292 | */ |
1293 | static inline int scsi_target_queue_ready(struct Scsi_Host *shost, | |
1294 | struct scsi_device *sdev) | |
1295 | { | |
1296 | struct scsi_target *starget = scsi_target(sdev); | |
7ae65c0f | 1297 | unsigned int busy; |
f0c0a376 MC |
1298 | |
1299 | if (starget->single_lun) { | |
7ae65c0f | 1300 | spin_lock_irq(shost->host_lock); |
f0c0a376 | 1301 | if (starget->starget_sdev_user && |
7ae65c0f CH |
1302 | starget->starget_sdev_user != sdev) { |
1303 | spin_unlock_irq(shost->host_lock); | |
1304 | return 0; | |
1305 | } | |
f0c0a376 | 1306 | starget->starget_sdev_user = sdev; |
7ae65c0f | 1307 | spin_unlock_irq(shost->host_lock); |
f0c0a376 MC |
1308 | } |
1309 | ||
2ccbb008 CH |
1310 | if (starget->can_queue <= 0) |
1311 | return 1; | |
1312 | ||
7ae65c0f | 1313 | busy = atomic_inc_return(&starget->target_busy) - 1; |
cd9070c9 | 1314 | if (atomic_read(&starget->target_blocked) > 0) { |
7ae65c0f CH |
1315 | if (busy) |
1316 | goto starved; | |
1317 | ||
f0c0a376 MC |
1318 | /* |
1319 | * unblock after target_blocked iterates to zero | |
1320 | */ | |
cd9070c9 | 1321 | if (atomic_dec_return(&starget->target_blocked) > 0) |
7ae65c0f | 1322 | goto out_dec; |
cf68d334 CH |
1323 | |
1324 | SCSI_LOG_MLQUEUE(3, starget_printk(KERN_INFO, starget, | |
1325 | "unblocking target at zero depth\n")); | |
f0c0a376 MC |
1326 | } |
1327 | ||
2ccbb008 | 1328 | if (busy >= starget->can_queue) |
7ae65c0f | 1329 | goto starved; |
f0c0a376 | 1330 | |
7ae65c0f CH |
1331 | return 1; |
1332 | ||
1333 | starved: | |
1334 | spin_lock_irq(shost->host_lock); | |
1335 | list_move_tail(&sdev->starved_entry, &shost->starved_list); | |
cf68d334 | 1336 | spin_unlock_irq(shost->host_lock); |
7ae65c0f | 1337 | out_dec: |
2ccbb008 CH |
1338 | if (starget->can_queue > 0) |
1339 | atomic_dec(&starget->target_busy); | |
7ae65c0f | 1340 | return 0; |
f0c0a376 MC |
1341 | } |
1342 | ||
1da177e4 LT |
1343 | /* |
1344 | * scsi_host_queue_ready: if we can send requests to shost, return 1 else | |
1345 | * return 0. We must end up running the queue again whenever 0 is | |
1346 | * returned, else IO can hang. | |
1da177e4 LT |
1347 | */ |
1348 | static inline int scsi_host_queue_ready(struct request_queue *q, | |
1349 | struct Scsi_Host *shost, | |
1350 | struct scsi_device *sdev) | |
1351 | { | |
74665016 | 1352 | unsigned int busy; |
cf68d334 | 1353 | |
939647ee | 1354 | if (scsi_host_in_recovery(shost)) |
74665016 CH |
1355 | return 0; |
1356 | ||
d772a65d | 1357 | busy = atomic_inc_return(&shost->host_busy) - 1; |
cd9070c9 | 1358 | if (atomic_read(&shost->host_blocked) > 0) { |
d772a65d | 1359 | if (busy) |
74665016 CH |
1360 | goto starved; |
1361 | ||
1da177e4 LT |
1362 | /* |
1363 | * unblock after host_blocked iterates to zero | |
1364 | */ | |
cd9070c9 | 1365 | if (atomic_dec_return(&shost->host_blocked) > 0) |
74665016 | 1366 | goto out_dec; |
cf68d334 CH |
1367 | |
1368 | SCSI_LOG_MLQUEUE(3, | |
1369 | shost_printk(KERN_INFO, shost, | |
1370 | "unblocking host at zero depth\n")); | |
1da177e4 | 1371 | } |
74665016 | 1372 | |
d772a65d | 1373 | if (shost->can_queue > 0 && busy >= shost->can_queue) |
74665016 CH |
1374 | goto starved; |
1375 | if (shost->host_self_blocked) | |
1376 | goto starved; | |
1da177e4 LT |
1377 | |
1378 | /* We're OK to process the command, so we can't be starved */ | |
74665016 CH |
1379 | if (!list_empty(&sdev->starved_entry)) { |
1380 | spin_lock_irq(shost->host_lock); | |
1381 | if (!list_empty(&sdev->starved_entry)) | |
1382 | list_del_init(&sdev->starved_entry); | |
1383 | spin_unlock_irq(shost->host_lock); | |
1384 | } | |
1da177e4 | 1385 | |
74665016 CH |
1386 | return 1; |
1387 | ||
1388 | starved: | |
1389 | spin_lock_irq(shost->host_lock); | |
1390 | if (list_empty(&sdev->starved_entry)) | |
1391 | list_add_tail(&sdev->starved_entry, &shost->starved_list); | |
cf68d334 | 1392 | spin_unlock_irq(shost->host_lock); |
74665016 | 1393 | out_dec: |
3bd6f43f | 1394 | scsi_dec_host_busy(shost); |
74665016 | 1395 | return 0; |
1da177e4 LT |
1396 | } |
1397 | ||
6c5121b7 KU |
1398 | /* |
1399 | * Busy state exporting function for request stacking drivers. | |
1400 | * | |
1401 | * For efficiency, no lock is taken to check the busy state of | |
1402 | * shost/starget/sdev, since the returned value is not guaranteed and | |
1403 | * may be changed after request stacking drivers call the function, | |
1404 | * regardless of taking lock or not. | |
1405 | * | |
67bd9413 BVA |
1406 | * When scsi can't dispatch I/Os anymore and needs to kill I/Os scsi |
1407 | * needs to return 'not busy'. Otherwise, request stacking drivers | |
1408 | * may hold requests forever. | |
6c5121b7 | 1409 | */ |
f664a3cc | 1410 | static bool scsi_mq_lld_busy(struct request_queue *q) |
6c5121b7 KU |
1411 | { |
1412 | struct scsi_device *sdev = q->queuedata; | |
1413 | struct Scsi_Host *shost; | |
6c5121b7 | 1414 | |
3f3299d5 | 1415 | if (blk_queue_dying(q)) |
f664a3cc | 1416 | return false; |
6c5121b7 KU |
1417 | |
1418 | shost = sdev->host; | |
6c5121b7 | 1419 | |
b7e94a16 JN |
1420 | /* |
1421 | * Ignore host/starget busy state. | |
1422 | * Since block layer does not have a concept of fairness across | |
1423 | * multiple queues, congestion of host/starget needs to be handled | |
1424 | * in SCSI layer. | |
1425 | */ | |
1426 | if (scsi_host_in_recovery(shost) || scsi_device_is_busy(sdev)) | |
f664a3cc | 1427 | return true; |
e36e0c80 | 1428 | |
f664a3cc | 1429 | return false; |
1da177e4 LT |
1430 | } |
1431 | ||
1aea6434 JA |
1432 | static void scsi_softirq_done(struct request *rq) |
1433 | { | |
bed2213d | 1434 | struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq); |
242f9dcb | 1435 | unsigned long wait_for = (cmd->allowed + 1) * rq->timeout; |
1aea6434 JA |
1436 | int disposition; |
1437 | ||
1438 | INIT_LIST_HEAD(&cmd->eh_entry); | |
1439 | ||
242f9dcb JA |
1440 | atomic_inc(&cmd->device->iodone_cnt); |
1441 | if (cmd->result) | |
1442 | atomic_inc(&cmd->device->ioerr_cnt); | |
1443 | ||
1aea6434 JA |
1444 | disposition = scsi_decide_disposition(cmd); |
1445 | if (disposition != SUCCESS && | |
1446 | time_before(cmd->jiffies_at_alloc + wait_for, jiffies)) { | |
1447 | sdev_printk(KERN_ERR, cmd->device, | |
1448 | "timing out command, waited %lus\n", | |
1449 | wait_for/HZ); | |
1450 | disposition = SUCCESS; | |
1451 | } | |
91921e01 | 1452 | |
1aea6434 JA |
1453 | scsi_log_completion(cmd, disposition); |
1454 | ||
1455 | switch (disposition) { | |
1456 | case SUCCESS: | |
1457 | scsi_finish_command(cmd); | |
1458 | break; | |
1459 | case NEEDS_RETRY: | |
596f482a | 1460 | scsi_queue_insert(cmd, SCSI_MLQUEUE_EH_RETRY); |
1aea6434 JA |
1461 | break; |
1462 | case ADD_TO_MLQUEUE: | |
1463 | scsi_queue_insert(cmd, SCSI_MLQUEUE_DEVICE_BUSY); | |
1464 | break; | |
1465 | default: | |
a0658632 | 1466 | scsi_eh_scmd_add(cmd); |
2171b6d0 | 1467 | break; |
1aea6434 JA |
1468 | } |
1469 | } | |
1470 | ||
82042a2c CH |
1471 | /** |
1472 | * scsi_dispatch_command - Dispatch a command to the low-level driver. | |
1473 | * @cmd: command block we are dispatching. | |
1474 | * | |
1475 | * Return: nonzero return request was rejected and device's queue needs to be | |
1476 | * plugged. | |
1477 | */ | |
1478 | static int scsi_dispatch_cmd(struct scsi_cmnd *cmd) | |
1479 | { | |
1480 | struct Scsi_Host *host = cmd->device->host; | |
1481 | int rtn = 0; | |
1482 | ||
1483 | atomic_inc(&cmd->device->iorequest_cnt); | |
1484 | ||
1485 | /* check if the device is still usable */ | |
1486 | if (unlikely(cmd->device->sdev_state == SDEV_DEL)) { | |
1487 | /* in SDEV_DEL we error all commands. DID_NO_CONNECT | |
1488 | * returns an immediate error upwards, and signals | |
1489 | * that the device is no longer present */ | |
1490 | cmd->result = DID_NO_CONNECT << 16; | |
1491 | goto done; | |
1492 | } | |
1493 | ||
1494 | /* Check to see if the scsi lld made this device blocked. */ | |
1495 | if (unlikely(scsi_device_blocked(cmd->device))) { | |
1496 | /* | |
1497 | * in blocked state, the command is just put back on | |
1498 | * the device queue. The suspend state has already | |
1499 | * blocked the queue so future requests should not | |
1500 | * occur until the device transitions out of the | |
1501 | * suspend state. | |
1502 | */ | |
1503 | SCSI_LOG_MLQUEUE(3, scmd_printk(KERN_INFO, cmd, | |
1504 | "queuecommand : device blocked\n")); | |
1505 | return SCSI_MLQUEUE_DEVICE_BUSY; | |
1506 | } | |
1507 | ||
1508 | /* Store the LUN value in cmnd, if needed. */ | |
1509 | if (cmd->device->lun_in_cdb) | |
1510 | cmd->cmnd[1] = (cmd->cmnd[1] & 0x1f) | | |
1511 | (cmd->device->lun << 5 & 0xe0); | |
1512 | ||
1513 | scsi_log_send(cmd); | |
1514 | ||
1515 | /* | |
1516 | * Before we queue this command, check if the command | |
1517 | * length exceeds what the host adapter can handle. | |
1518 | */ | |
1519 | if (cmd->cmd_len > cmd->device->host->max_cmd_len) { | |
1520 | SCSI_LOG_MLQUEUE(3, scmd_printk(KERN_INFO, cmd, | |
1521 | "queuecommand : command too long. " | |
1522 | "cdb_size=%d host->max_cmd_len=%d\n", | |
1523 | cmd->cmd_len, cmd->device->host->max_cmd_len)); | |
1524 | cmd->result = (DID_ABORT << 16); | |
1525 | goto done; | |
1526 | } | |
1527 | ||
1528 | if (unlikely(host->shost_state == SHOST_DEL)) { | |
1529 | cmd->result = (DID_NO_CONNECT << 16); | |
1530 | goto done; | |
1531 | ||
1532 | } | |
1533 | ||
1534 | trace_scsi_dispatch_cmd_start(cmd); | |
1535 | rtn = host->hostt->queuecommand(host, cmd); | |
1536 | if (rtn) { | |
1537 | trace_scsi_dispatch_cmd_error(cmd, rtn); | |
1538 | if (rtn != SCSI_MLQUEUE_DEVICE_BUSY && | |
1539 | rtn != SCSI_MLQUEUE_TARGET_BUSY) | |
1540 | rtn = SCSI_MLQUEUE_HOST_BUSY; | |
1541 | ||
1542 | SCSI_LOG_MLQUEUE(3, scmd_printk(KERN_INFO, cmd, | |
1543 | "queuecommand : request rejected\n")); | |
1544 | } | |
1545 | ||
1546 | return rtn; | |
1547 | done: | |
1548 | cmd->scsi_done(cmd); | |
1549 | return 0; | |
1550 | } | |
1551 | ||
be4c186c BVA |
1552 | /* Size in bytes of the sg-list stored in the scsi-mq command-private data. */ |
1553 | static unsigned int scsi_mq_sgl_size(struct Scsi_Host *shost) | |
1554 | { | |
1555 | return min_t(unsigned int, shost->sg_tablesize, SG_CHUNK_SIZE) * | |
1556 | sizeof(struct scatterlist); | |
1557 | } | |
1558 | ||
785ba83b | 1559 | static blk_status_t scsi_mq_prep_fn(struct request *req) |
d285203c CH |
1560 | { |
1561 | struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req); | |
1562 | struct scsi_device *sdev = req->q->queuedata; | |
1563 | struct Scsi_Host *shost = sdev->host; | |
d285203c CH |
1564 | struct scatterlist *sg; |
1565 | ||
08f78436 | 1566 | scsi_init_command(sdev, cmd); |
d285203c | 1567 | |
d285203c | 1568 | cmd->request = req; |
d285203c | 1569 | cmd->tag = req->tag; |
d285203c CH |
1570 | cmd->prot_op = SCSI_PROT_NORMAL; |
1571 | ||
d285203c CH |
1572 | sg = (void *)cmd + sizeof(struct scsi_cmnd) + shost->hostt->cmd_size; |
1573 | cmd->sdb.table.sgl = sg; | |
1574 | ||
1575 | if (scsi_host_get_prot(shost)) { | |
d285203c CH |
1576 | memset(cmd->prot_sdb, 0, sizeof(struct scsi_data_buffer)); |
1577 | ||
1578 | cmd->prot_sdb->table.sgl = | |
1579 | (struct scatterlist *)(cmd->prot_sdb + 1); | |
1580 | } | |
1581 | ||
fe052529 CH |
1582 | blk_mq_start_request(req); |
1583 | ||
8fe8ffb1 | 1584 | return scsi_setup_cmnd(sdev, req); |
d285203c CH |
1585 | } |
1586 | ||
1587 | static void scsi_mq_done(struct scsi_cmnd *cmd) | |
1588 | { | |
f1342709 KB |
1589 | if (unlikely(test_and_set_bit(SCMD_STATE_COMPLETE, &cmd->state))) |
1590 | return; | |
d285203c | 1591 | trace_scsi_dispatch_cmd_done(cmd); |
f1342709 KB |
1592 | |
1593 | /* | |
1594 | * If the block layer didn't complete the request due to a timeout | |
1595 | * injection, scsi must clear its internal completed state so that the | |
1596 | * timeout handler will see it needs to escalate its own error | |
1597 | * recovery. | |
1598 | */ | |
1599 | if (unlikely(!blk_mq_complete_request(cmd->request))) | |
1600 | clear_bit(SCMD_STATE_COMPLETE, &cmd->state); | |
d285203c CH |
1601 | } |
1602 | ||
0df21c86 | 1603 | static void scsi_mq_put_budget(struct blk_mq_hw_ctx *hctx) |
d285203c | 1604 | { |
0df21c86 ML |
1605 | struct request_queue *q = hctx->queue; |
1606 | struct scsi_device *sdev = q->queuedata; | |
0df21c86 | 1607 | |
0df21c86 ML |
1608 | atomic_dec(&sdev->device_busy); |
1609 | put_device(&sdev->sdev_gendev); | |
1610 | } | |
1611 | ||
88022d72 | 1612 | static bool scsi_mq_get_budget(struct blk_mq_hw_ctx *hctx) |
0df21c86 ML |
1613 | { |
1614 | struct request_queue *q = hctx->queue; | |
d285203c | 1615 | struct scsi_device *sdev = q->queuedata; |
d285203c | 1616 | |
d285203c CH |
1617 | if (!get_device(&sdev->sdev_gendev)) |
1618 | goto out; | |
d285203c CH |
1619 | if (!scsi_dev_queue_ready(q, sdev)) |
1620 | goto out_put_device; | |
d285203c | 1621 | |
88022d72 | 1622 | return true; |
0df21c86 | 1623 | |
0df21c86 ML |
1624 | out_put_device: |
1625 | put_device(&sdev->sdev_gendev); | |
1626 | out: | |
7e70aa78 ML |
1627 | if (atomic_read(&sdev->device_busy) == 0 && !scsi_device_blocked(sdev)) |
1628 | blk_mq_delay_run_hw_queue(hctx, SCSI_QUEUE_DELAY); | |
88022d72 | 1629 | return false; |
0df21c86 ML |
1630 | } |
1631 | ||
fc17b653 | 1632 | static blk_status_t scsi_queue_rq(struct blk_mq_hw_ctx *hctx, |
74c45052 | 1633 | const struct blk_mq_queue_data *bd) |
d285203c | 1634 | { |
74c45052 | 1635 | struct request *req = bd->rq; |
d285203c CH |
1636 | struct request_queue *q = req->q; |
1637 | struct scsi_device *sdev = q->queuedata; | |
1638 | struct Scsi_Host *shost = sdev->host; | |
1639 | struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req); | |
fc17b653 | 1640 | blk_status_t ret; |
d285203c CH |
1641 | int reason; |
1642 | ||
c092d4ec CH |
1643 | /* |
1644 | * If the device is not in running state we will reject some or all | |
1645 | * commands. | |
1646 | */ | |
1647 | if (unlikely(sdev->sdev_state != SDEV_RUNNING)) { | |
1648 | ret = scsi_prep_state_check(sdev, req); | |
1649 | if (ret != BLK_STS_OK) | |
1650 | goto out_put_budget; | |
1651 | } | |
d285203c | 1652 | |
fc17b653 | 1653 | ret = BLK_STS_RESOURCE; |
d285203c | 1654 | if (!scsi_target_queue_ready(shost, sdev)) |
826a70a0 | 1655 | goto out_put_budget; |
d285203c CH |
1656 | if (!scsi_host_queue_ready(q, shost, sdev)) |
1657 | goto out_dec_target_busy; | |
1658 | ||
e8064021 | 1659 | if (!(req->rq_flags & RQF_DONTPREP)) { |
785ba83b | 1660 | ret = scsi_mq_prep_fn(req); |
fc17b653 | 1661 | if (ret != BLK_STS_OK) |
d285203c | 1662 | goto out_dec_host_busy; |
e8064021 | 1663 | req->rq_flags |= RQF_DONTPREP; |
fe052529 | 1664 | } else { |
cd464d83 | 1665 | clear_bit(SCMD_STATE_COMPLETE, &cmd->state); |
fe052529 | 1666 | blk_mq_start_request(req); |
d285203c CH |
1667 | } |
1668 | ||
125c99bc CH |
1669 | if (sdev->simple_tags) |
1670 | cmd->flags |= SCMD_TAGGED; | |
b1dd2aac | 1671 | else |
125c99bc | 1672 | cmd->flags &= ~SCMD_TAGGED; |
b1dd2aac | 1673 | |
d285203c CH |
1674 | scsi_init_cmd_errh(cmd); |
1675 | cmd->scsi_done = scsi_mq_done; | |
1676 | ||
1677 | reason = scsi_dispatch_cmd(cmd); | |
1678 | if (reason) { | |
1679 | scsi_set_blocked(cmd, reason); | |
fc17b653 | 1680 | ret = BLK_STS_RESOURCE; |
d285203c CH |
1681 | goto out_dec_host_busy; |
1682 | } | |
1683 | ||
fc17b653 | 1684 | return BLK_STS_OK; |
d285203c CH |
1685 | |
1686 | out_dec_host_busy: | |
3bd6f43f | 1687 | scsi_dec_host_busy(shost); |
d285203c CH |
1688 | out_dec_target_busy: |
1689 | if (scsi_target(sdev)->can_queue > 0) | |
1690 | atomic_dec(&scsi_target(sdev)->target_busy); | |
0df21c86 ML |
1691 | out_put_budget: |
1692 | scsi_mq_put_budget(hctx); | |
d285203c | 1693 | switch (ret) { |
fc17b653 CH |
1694 | case BLK_STS_OK: |
1695 | break; | |
1696 | case BLK_STS_RESOURCE: | |
86ff7c2a ML |
1697 | if (atomic_read(&sdev->device_busy) || |
1698 | scsi_device_blocked(sdev)) | |
1699 | ret = BLK_STS_DEV_RESOURCE; | |
d285203c | 1700 | break; |
fc17b653 | 1701 | default: |
d285203c CH |
1702 | /* |
1703 | * Make sure to release all allocated ressources when | |
1704 | * we hit an error, as we will never see this command | |
1705 | * again. | |
1706 | */ | |
e8064021 | 1707 | if (req->rq_flags & RQF_DONTPREP) |
d285203c CH |
1708 | scsi_mq_uninit_cmd(cmd); |
1709 | break; | |
d285203c CH |
1710 | } |
1711 | return ret; | |
1712 | } | |
1713 | ||
0152fb6b CH |
1714 | static enum blk_eh_timer_return scsi_timeout(struct request *req, |
1715 | bool reserved) | |
1716 | { | |
1717 | if (reserved) | |
1718 | return BLK_EH_RESET_TIMER; | |
1719 | return scsi_times_out(req); | |
1720 | } | |
1721 | ||
e7008ff5 BVA |
1722 | static int scsi_mq_init_request(struct blk_mq_tag_set *set, struct request *rq, |
1723 | unsigned int hctx_idx, unsigned int numa_node) | |
d285203c | 1724 | { |
d6296d39 | 1725 | struct Scsi_Host *shost = set->driver_data; |
8e688254 | 1726 | const bool unchecked_isa_dma = shost->unchecked_isa_dma; |
d285203c | 1727 | struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq); |
08f78436 | 1728 | struct scatterlist *sg; |
d285203c | 1729 | |
8e688254 BVA |
1730 | if (unchecked_isa_dma) |
1731 | cmd->flags |= SCMD_UNCHECKED_ISA_DMA; | |
1732 | cmd->sense_buffer = scsi_alloc_sense_buffer(unchecked_isa_dma, | |
1733 | GFP_KERNEL, numa_node); | |
d285203c CH |
1734 | if (!cmd->sense_buffer) |
1735 | return -ENOMEM; | |
82ed4db4 | 1736 | cmd->req.sense = cmd->sense_buffer; |
08f78436 BVA |
1737 | |
1738 | if (scsi_host_get_prot(shost)) { | |
1739 | sg = (void *)cmd + sizeof(struct scsi_cmnd) + | |
1740 | shost->hostt->cmd_size; | |
1741 | cmd->prot_sdb = (void *)sg + scsi_mq_sgl_size(shost); | |
1742 | } | |
1743 | ||
d285203c CH |
1744 | return 0; |
1745 | } | |
1746 | ||
e7008ff5 BVA |
1747 | static void scsi_mq_exit_request(struct blk_mq_tag_set *set, struct request *rq, |
1748 | unsigned int hctx_idx) | |
d285203c CH |
1749 | { |
1750 | struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq); | |
1751 | ||
8e688254 BVA |
1752 | scsi_free_sense_buffer(cmd->flags & SCMD_UNCHECKED_ISA_DMA, |
1753 | cmd->sense_buffer); | |
d285203c CH |
1754 | } |
1755 | ||
2d9c5c20 CH |
1756 | static int scsi_map_queues(struct blk_mq_tag_set *set) |
1757 | { | |
1758 | struct Scsi_Host *shost = container_of(set, struct Scsi_Host, tag_set); | |
1759 | ||
1760 | if (shost->hostt->map_queues) | |
1761 | return shost->hostt->map_queues(shost); | |
ed76e329 | 1762 | return blk_mq_map_queues(&set->map[0]); |
2d9c5c20 CH |
1763 | } |
1764 | ||
d48777a6 | 1765 | void __scsi_init_queue(struct Scsi_Host *shost, struct request_queue *q) |
1da177e4 | 1766 | { |
6f381fa3 | 1767 | struct device *dev = shost->dma_dev; |
1da177e4 | 1768 | |
a8474ce2 JA |
1769 | /* |
1770 | * this limit is imposed by hardware restrictions | |
1771 | */ | |
8a78362c | 1772 | blk_queue_max_segments(q, min_t(unsigned short, shost->sg_tablesize, |
65e8617f | 1773 | SG_MAX_SEGMENTS)); |
a8474ce2 | 1774 | |
13f05c8d MP |
1775 | if (scsi_host_prot_dma(shost)) { |
1776 | shost->sg_prot_tablesize = | |
1777 | min_not_zero(shost->sg_prot_tablesize, | |
1778 | (unsigned short)SCSI_MAX_PROT_SG_SEGMENTS); | |
1779 | BUG_ON(shost->sg_prot_tablesize < shost->sg_tablesize); | |
1780 | blk_queue_max_integrity_segments(q, shost->sg_prot_tablesize); | |
1781 | } | |
1782 | ||
086fa5ff | 1783 | blk_queue_max_hw_sectors(q, shost->max_sectors); |
21e07dba CH |
1784 | if (shost->unchecked_isa_dma) |
1785 | blk_queue_bounce_limit(q, BLK_BOUNCE_ISA); | |
1da177e4 | 1786 | blk_queue_segment_boundary(q, shost->dma_boundary); |
99c84dbd | 1787 | dma_set_seg_boundary(dev, shost->dma_boundary); |
1da177e4 | 1788 | |
a8cf59a6 CH |
1789 | blk_queue_max_segment_size(q, shost->max_segment_size); |
1790 | dma_set_max_seg_size(dev, shost->max_segment_size); | |
465ff318 JB |
1791 | |
1792 | /* | |
90addc6b HC |
1793 | * Set a reasonable default alignment: The larger of 32-byte (dword), |
1794 | * which is a common minimum for HBAs, and the minimum DMA alignment, | |
1795 | * which is set by the platform. | |
1796 | * | |
1797 | * Devices that require a bigger alignment can increase it later. | |
465ff318 | 1798 | */ |
90addc6b | 1799 | blk_queue_dma_alignment(q, max(4, dma_get_cache_alignment()) - 1); |
d285203c | 1800 | } |
d48777a6 | 1801 | EXPORT_SYMBOL_GPL(__scsi_init_queue); |
465ff318 | 1802 | |
f363b089 | 1803 | static const struct blk_mq_ops scsi_mq_ops = { |
0df21c86 ML |
1804 | .get_budget = scsi_mq_get_budget, |
1805 | .put_budget = scsi_mq_put_budget, | |
d285203c CH |
1806 | .queue_rq = scsi_queue_rq, |
1807 | .complete = scsi_softirq_done, | |
0152fb6b | 1808 | .timeout = scsi_timeout, |
0eebd005 BVA |
1809 | #ifdef CONFIG_BLK_DEBUG_FS |
1810 | .show_rq = scsi_show_rq, | |
1811 | #endif | |
e7008ff5 BVA |
1812 | .init_request = scsi_mq_init_request, |
1813 | .exit_request = scsi_mq_exit_request, | |
ca18d6f7 | 1814 | .initialize_rq_fn = scsi_initialize_rq, |
3a7ea2c4 | 1815 | .busy = scsi_mq_lld_busy, |
2d9c5c20 | 1816 | .map_queues = scsi_map_queues, |
d285203c CH |
1817 | }; |
1818 | ||
1819 | struct request_queue *scsi_mq_alloc_queue(struct scsi_device *sdev) | |
1820 | { | |
1821 | sdev->request_queue = blk_mq_init_queue(&sdev->host->tag_set); | |
1822 | if (IS_ERR(sdev->request_queue)) | |
1823 | return NULL; | |
1824 | ||
1825 | sdev->request_queue->queuedata = sdev; | |
1826 | __scsi_init_queue(sdev->host, sdev->request_queue); | |
17cb960f | 1827 | blk_queue_flag_set(QUEUE_FLAG_SCSI_PASSTHROUGH, sdev->request_queue); |
d285203c CH |
1828 | return sdev->request_queue; |
1829 | } | |
1830 | ||
1831 | int scsi_mq_setup_tags(struct Scsi_Host *shost) | |
1832 | { | |
be4c186c | 1833 | unsigned int cmd_size, sgl_size; |
d285203c | 1834 | |
be4c186c | 1835 | sgl_size = scsi_mq_sgl_size(shost); |
d285203c CH |
1836 | cmd_size = sizeof(struct scsi_cmnd) + shost->hostt->cmd_size + sgl_size; |
1837 | if (scsi_host_get_prot(shost)) | |
1838 | cmd_size += sizeof(struct scsi_data_buffer) + sgl_size; | |
1839 | ||
1840 | memset(&shost->tag_set, 0, sizeof(shost->tag_set)); | |
1841 | shost->tag_set.ops = &scsi_mq_ops; | |
efec4b90 | 1842 | shost->tag_set.nr_hw_queues = shost->nr_hw_queues ? : 1; |
d285203c CH |
1843 | shost->tag_set.queue_depth = shost->can_queue; |
1844 | shost->tag_set.cmd_size = cmd_size; | |
1845 | shost->tag_set.numa_node = NUMA_NO_NODE; | |
56d18f62 | 1846 | shost->tag_set.flags = BLK_MQ_F_SHOULD_MERGE; |
24391c0d SL |
1847 | shost->tag_set.flags |= |
1848 | BLK_ALLOC_POLICY_TO_MQ_FLAG(shost->hostt->tag_alloc_policy); | |
d285203c CH |
1849 | shost->tag_set.driver_data = shost; |
1850 | ||
1851 | return blk_mq_alloc_tag_set(&shost->tag_set); | |
1852 | } | |
1853 | ||
1854 | void scsi_mq_destroy_tags(struct Scsi_Host *shost) | |
1855 | { | |
1856 | blk_mq_free_tag_set(&shost->tag_set); | |
1857 | } | |
1858 | ||
857de6e0 HR |
1859 | /** |
1860 | * scsi_device_from_queue - return sdev associated with a request_queue | |
1861 | * @q: The request queue to return the sdev from | |
1862 | * | |
1863 | * Return the sdev associated with a request queue or NULL if the | |
1864 | * request_queue does not reference a SCSI device. | |
1865 | */ | |
1866 | struct scsi_device *scsi_device_from_queue(struct request_queue *q) | |
1867 | { | |
1868 | struct scsi_device *sdev = NULL; | |
1869 | ||
f664a3cc | 1870 | if (q->mq_ops == &scsi_mq_ops) |
857de6e0 HR |
1871 | sdev = q->queuedata; |
1872 | if (!sdev || !get_device(&sdev->sdev_gendev)) | |
1873 | sdev = NULL; | |
1874 | ||
1875 | return sdev; | |
1876 | } | |
1877 | EXPORT_SYMBOL_GPL(scsi_device_from_queue); | |
1878 | ||
1da177e4 LT |
1879 | /* |
1880 | * Function: scsi_block_requests() | |
1881 | * | |
1882 | * Purpose: Utility function used by low-level drivers to prevent further | |
1883 | * commands from being queued to the device. | |
1884 | * | |
1885 | * Arguments: shost - Host in question | |
1886 | * | |
1887 | * Returns: Nothing | |
1888 | * | |
1889 | * Lock status: No locks are assumed held. | |
1890 | * | |
1891 | * Notes: There is no timer nor any other means by which the requests | |
1892 | * get unblocked other than the low-level driver calling | |
1893 | * scsi_unblock_requests(). | |
1894 | */ | |
1895 | void scsi_block_requests(struct Scsi_Host *shost) | |
1896 | { | |
1897 | shost->host_self_blocked = 1; | |
1898 | } | |
1899 | EXPORT_SYMBOL(scsi_block_requests); | |
1900 | ||
1901 | /* | |
1902 | * Function: scsi_unblock_requests() | |
1903 | * | |
1904 | * Purpose: Utility function used by low-level drivers to allow further | |
1905 | * commands from being queued to the device. | |
1906 | * | |
1907 | * Arguments: shost - Host in question | |
1908 | * | |
1909 | * Returns: Nothing | |
1910 | * | |
1911 | * Lock status: No locks are assumed held. | |
1912 | * | |
1913 | * Notes: There is no timer nor any other means by which the requests | |
1914 | * get unblocked other than the low-level driver calling | |
1915 | * scsi_unblock_requests(). | |
1916 | * | |
1917 | * This is done as an API function so that changes to the | |
1918 | * internals of the scsi mid-layer won't require wholesale | |
1919 | * changes to drivers that use this feature. | |
1920 | */ | |
1921 | void scsi_unblock_requests(struct Scsi_Host *shost) | |
1922 | { | |
1923 | shost->host_self_blocked = 0; | |
1924 | scsi_run_host_queues(shost); | |
1925 | } | |
1926 | EXPORT_SYMBOL(scsi_unblock_requests); | |
1927 | ||
1928 | int __init scsi_init_queue(void) | |
1929 | { | |
6362abd3 MP |
1930 | scsi_sdb_cache = kmem_cache_create("scsi_data_buffer", |
1931 | sizeof(struct scsi_data_buffer), | |
1932 | 0, 0, NULL); | |
1933 | if (!scsi_sdb_cache) { | |
1934 | printk(KERN_ERR "SCSI: can't init scsi sdb cache\n"); | |
f078727b | 1935 | return -ENOMEM; |
6f9a35e2 BH |
1936 | } |
1937 | ||
1da177e4 LT |
1938 | return 0; |
1939 | } | |
1940 | ||
1941 | void scsi_exit_queue(void) | |
1942 | { | |
0a6ac4ee CH |
1943 | kmem_cache_destroy(scsi_sense_cache); |
1944 | kmem_cache_destroy(scsi_sense_isadma_cache); | |
6362abd3 | 1945 | kmem_cache_destroy(scsi_sdb_cache); |
1da177e4 | 1946 | } |
5baba830 JB |
1947 | |
1948 | /** | |
1949 | * scsi_mode_select - issue a mode select | |
1950 | * @sdev: SCSI device to be queried | |
1951 | * @pf: Page format bit (1 == standard, 0 == vendor specific) | |
1952 | * @sp: Save page bit (0 == don't save, 1 == save) | |
1953 | * @modepage: mode page being requested | |
1954 | * @buffer: request buffer (may not be smaller than eight bytes) | |
1955 | * @len: length of request buffer. | |
1956 | * @timeout: command timeout | |
1957 | * @retries: number of retries before failing | |
1958 | * @data: returns a structure abstracting the mode header data | |
eb44820c | 1959 | * @sshdr: place to put sense data (or NULL if no sense to be collected). |
5baba830 JB |
1960 | * must be SCSI_SENSE_BUFFERSIZE big. |
1961 | * | |
1962 | * Returns zero if successful; negative error number or scsi | |
1963 | * status on error | |
1964 | * | |
1965 | */ | |
1966 | int | |
1967 | scsi_mode_select(struct scsi_device *sdev, int pf, int sp, int modepage, | |
1968 | unsigned char *buffer, int len, int timeout, int retries, | |
1969 | struct scsi_mode_data *data, struct scsi_sense_hdr *sshdr) | |
1970 | { | |
1971 | unsigned char cmd[10]; | |
1972 | unsigned char *real_buffer; | |
1973 | int ret; | |
1974 | ||
1975 | memset(cmd, 0, sizeof(cmd)); | |
1976 | cmd[1] = (pf ? 0x10 : 0) | (sp ? 0x01 : 0); | |
1977 | ||
1978 | if (sdev->use_10_for_ms) { | |
1979 | if (len > 65535) | |
1980 | return -EINVAL; | |
1981 | real_buffer = kmalloc(8 + len, GFP_KERNEL); | |
1982 | if (!real_buffer) | |
1983 | return -ENOMEM; | |
1984 | memcpy(real_buffer + 8, buffer, len); | |
1985 | len += 8; | |
1986 | real_buffer[0] = 0; | |
1987 | real_buffer[1] = 0; | |
1988 | real_buffer[2] = data->medium_type; | |
1989 | real_buffer[3] = data->device_specific; | |
1990 | real_buffer[4] = data->longlba ? 0x01 : 0; | |
1991 | real_buffer[5] = 0; | |
1992 | real_buffer[6] = data->block_descriptor_length >> 8; | |
1993 | real_buffer[7] = data->block_descriptor_length; | |
1994 | ||
1995 | cmd[0] = MODE_SELECT_10; | |
1996 | cmd[7] = len >> 8; | |
1997 | cmd[8] = len; | |
1998 | } else { | |
1999 | if (len > 255 || data->block_descriptor_length > 255 || | |
2000 | data->longlba) | |
2001 | return -EINVAL; | |
2002 | ||
2003 | real_buffer = kmalloc(4 + len, GFP_KERNEL); | |
2004 | if (!real_buffer) | |
2005 | return -ENOMEM; | |
2006 | memcpy(real_buffer + 4, buffer, len); | |
2007 | len += 4; | |
2008 | real_buffer[0] = 0; | |
2009 | real_buffer[1] = data->medium_type; | |
2010 | real_buffer[2] = data->device_specific; | |
2011 | real_buffer[3] = data->block_descriptor_length; | |
2012 | ||
2013 | ||
2014 | cmd[0] = MODE_SELECT; | |
2015 | cmd[4] = len; | |
2016 | } | |
2017 | ||
2018 | ret = scsi_execute_req(sdev, cmd, DMA_TO_DEVICE, real_buffer, len, | |
f4f4e47e | 2019 | sshdr, timeout, retries, NULL); |
5baba830 JB |
2020 | kfree(real_buffer); |
2021 | return ret; | |
2022 | } | |
2023 | EXPORT_SYMBOL_GPL(scsi_mode_select); | |
2024 | ||
1da177e4 | 2025 | /** |
eb44820c | 2026 | * scsi_mode_sense - issue a mode sense, falling back from 10 to six bytes if necessary. |
1cf72699 | 2027 | * @sdev: SCSI device to be queried |
1da177e4 LT |
2028 | * @dbd: set if mode sense will allow block descriptors to be returned |
2029 | * @modepage: mode page being requested | |
2030 | * @buffer: request buffer (may not be smaller than eight bytes) | |
2031 | * @len: length of request buffer. | |
2032 | * @timeout: command timeout | |
2033 | * @retries: number of retries before failing | |
2034 | * @data: returns a structure abstracting the mode header data | |
eb44820c | 2035 | * @sshdr: place to put sense data (or NULL if no sense to be collected). |
1cf72699 | 2036 | * must be SCSI_SENSE_BUFFERSIZE big. |
1da177e4 LT |
2037 | * |
2038 | * Returns zero if unsuccessful, or the header offset (either 4 | |
2039 | * or 8 depending on whether a six or ten byte command was | |
2040 | * issued) if successful. | |
eb44820c | 2041 | */ |
1da177e4 | 2042 | int |
1cf72699 | 2043 | scsi_mode_sense(struct scsi_device *sdev, int dbd, int modepage, |
1da177e4 | 2044 | unsigned char *buffer, int len, int timeout, int retries, |
5baba830 JB |
2045 | struct scsi_mode_data *data, struct scsi_sense_hdr *sshdr) |
2046 | { | |
1da177e4 LT |
2047 | unsigned char cmd[12]; |
2048 | int use_10_for_ms; | |
2049 | int header_length; | |
0ae80ba9 | 2050 | int result, retry_count = retries; |
ea73a9f2 | 2051 | struct scsi_sense_hdr my_sshdr; |
1da177e4 LT |
2052 | |
2053 | memset(data, 0, sizeof(*data)); | |
2054 | memset(&cmd[0], 0, 12); | |
2055 | cmd[1] = dbd & 0x18; /* allows DBD and LLBA bits */ | |
2056 | cmd[2] = modepage; | |
2057 | ||
ea73a9f2 JB |
2058 | /* caller might not be interested in sense, but we need it */ |
2059 | if (!sshdr) | |
2060 | sshdr = &my_sshdr; | |
2061 | ||
1da177e4 | 2062 | retry: |
1cf72699 | 2063 | use_10_for_ms = sdev->use_10_for_ms; |
1da177e4 LT |
2064 | |
2065 | if (use_10_for_ms) { | |
2066 | if (len < 8) | |
2067 | len = 8; | |
2068 | ||
2069 | cmd[0] = MODE_SENSE_10; | |
2070 | cmd[8] = len; | |
2071 | header_length = 8; | |
2072 | } else { | |
2073 | if (len < 4) | |
2074 | len = 4; | |
2075 | ||
2076 | cmd[0] = MODE_SENSE; | |
2077 | cmd[4] = len; | |
2078 | header_length = 4; | |
2079 | } | |
2080 | ||
1da177e4 LT |
2081 | memset(buffer, 0, len); |
2082 | ||
1cf72699 | 2083 | result = scsi_execute_req(sdev, cmd, DMA_FROM_DEVICE, buffer, len, |
f4f4e47e | 2084 | sshdr, timeout, retries, NULL); |
1da177e4 LT |
2085 | |
2086 | /* This code looks awful: what it's doing is making sure an | |
2087 | * ILLEGAL REQUEST sense return identifies the actual command | |
2088 | * byte as the problem. MODE_SENSE commands can return | |
2089 | * ILLEGAL REQUEST if the code page isn't supported */ | |
2090 | ||
1cf72699 | 2091 | if (use_10_for_ms && !scsi_status_is_good(result) && |
c65be1a6 | 2092 | driver_byte(result) == DRIVER_SENSE) { |
ea73a9f2 JB |
2093 | if (scsi_sense_valid(sshdr)) { |
2094 | if ((sshdr->sense_key == ILLEGAL_REQUEST) && | |
2095 | (sshdr->asc == 0x20) && (sshdr->ascq == 0)) { | |
1da177e4 LT |
2096 | /* |
2097 | * Invalid command operation code | |
2098 | */ | |
1cf72699 | 2099 | sdev->use_10_for_ms = 0; |
1da177e4 LT |
2100 | goto retry; |
2101 | } | |
2102 | } | |
2103 | } | |
2104 | ||
1cf72699 | 2105 | if(scsi_status_is_good(result)) { |
6d73c851 AV |
2106 | if (unlikely(buffer[0] == 0x86 && buffer[1] == 0x0b && |
2107 | (modepage == 6 || modepage == 8))) { | |
2108 | /* Initio breakage? */ | |
2109 | header_length = 0; | |
2110 | data->length = 13; | |
2111 | data->medium_type = 0; | |
2112 | data->device_specific = 0; | |
2113 | data->longlba = 0; | |
2114 | data->block_descriptor_length = 0; | |
2115 | } else if(use_10_for_ms) { | |
1da177e4 LT |
2116 | data->length = buffer[0]*256 + buffer[1] + 2; |
2117 | data->medium_type = buffer[2]; | |
2118 | data->device_specific = buffer[3]; | |
2119 | data->longlba = buffer[4] & 0x01; | |
2120 | data->block_descriptor_length = buffer[6]*256 | |
2121 | + buffer[7]; | |
2122 | } else { | |
2123 | data->length = buffer[0] + 1; | |
2124 | data->medium_type = buffer[1]; | |
2125 | data->device_specific = buffer[2]; | |
2126 | data->block_descriptor_length = buffer[3]; | |
2127 | } | |
6d73c851 | 2128 | data->header_length = header_length; |
0ae80ba9 HR |
2129 | } else if ((status_byte(result) == CHECK_CONDITION) && |
2130 | scsi_sense_valid(sshdr) && | |
2131 | sshdr->sense_key == UNIT_ATTENTION && retry_count) { | |
2132 | retry_count--; | |
2133 | goto retry; | |
1da177e4 LT |
2134 | } |
2135 | ||
1cf72699 | 2136 | return result; |
1da177e4 LT |
2137 | } |
2138 | EXPORT_SYMBOL(scsi_mode_sense); | |
2139 | ||
001aac25 JB |
2140 | /** |
2141 | * scsi_test_unit_ready - test if unit is ready | |
2142 | * @sdev: scsi device to change the state of. | |
2143 | * @timeout: command timeout | |
2144 | * @retries: number of retries before failing | |
74a78ebd | 2145 | * @sshdr: outpout pointer for decoded sense information. |
001aac25 JB |
2146 | * |
2147 | * Returns zero if unsuccessful or an error if TUR failed. For | |
9f8a2c23 | 2148 | * removable media, UNIT_ATTENTION sets ->changed flag. |
001aac25 | 2149 | **/ |
1da177e4 | 2150 | int |
001aac25 | 2151 | scsi_test_unit_ready(struct scsi_device *sdev, int timeout, int retries, |
74a78ebd | 2152 | struct scsi_sense_hdr *sshdr) |
1da177e4 | 2153 | { |
1da177e4 LT |
2154 | char cmd[] = { |
2155 | TEST_UNIT_READY, 0, 0, 0, 0, 0, | |
2156 | }; | |
2157 | int result; | |
001aac25 | 2158 | |
001aac25 JB |
2159 | /* try to eat the UNIT_ATTENTION if there are enough retries */ |
2160 | do { | |
2161 | result = scsi_execute_req(sdev, cmd, DMA_NONE, NULL, 0, sshdr, | |
9b91fd34 | 2162 | timeout, 1, NULL); |
32c356d7 JB |
2163 | if (sdev->removable && scsi_sense_valid(sshdr) && |
2164 | sshdr->sense_key == UNIT_ATTENTION) | |
2165 | sdev->changed = 1; | |
2166 | } while (scsi_sense_valid(sshdr) && | |
2167 | sshdr->sense_key == UNIT_ATTENTION && --retries); | |
001aac25 | 2168 | |
1da177e4 LT |
2169 | return result; |
2170 | } | |
2171 | EXPORT_SYMBOL(scsi_test_unit_ready); | |
2172 | ||
2173 | /** | |
eb44820c | 2174 | * scsi_device_set_state - Take the given device through the device state model. |
1da177e4 LT |
2175 | * @sdev: scsi device to change the state of. |
2176 | * @state: state to change to. | |
2177 | * | |
23cb27fd | 2178 | * Returns zero if successful or an error if the requested |
1da177e4 | 2179 | * transition is illegal. |
eb44820c | 2180 | */ |
1da177e4 LT |
2181 | int |
2182 | scsi_device_set_state(struct scsi_device *sdev, enum scsi_device_state state) | |
2183 | { | |
2184 | enum scsi_device_state oldstate = sdev->sdev_state; | |
2185 | ||
2186 | if (state == oldstate) | |
2187 | return 0; | |
2188 | ||
2189 | switch (state) { | |
2190 | case SDEV_CREATED: | |
6f4267e3 JB |
2191 | switch (oldstate) { |
2192 | case SDEV_CREATED_BLOCK: | |
2193 | break; | |
2194 | default: | |
2195 | goto illegal; | |
2196 | } | |
2197 | break; | |
1da177e4 LT |
2198 | |
2199 | case SDEV_RUNNING: | |
2200 | switch (oldstate) { | |
2201 | case SDEV_CREATED: | |
2202 | case SDEV_OFFLINE: | |
1b8d2620 | 2203 | case SDEV_TRANSPORT_OFFLINE: |
1da177e4 LT |
2204 | case SDEV_QUIESCE: |
2205 | case SDEV_BLOCK: | |
2206 | break; | |
2207 | default: | |
2208 | goto illegal; | |
2209 | } | |
2210 | break; | |
2211 | ||
2212 | case SDEV_QUIESCE: | |
2213 | switch (oldstate) { | |
2214 | case SDEV_RUNNING: | |
2215 | case SDEV_OFFLINE: | |
1b8d2620 | 2216 | case SDEV_TRANSPORT_OFFLINE: |
1da177e4 LT |
2217 | break; |
2218 | default: | |
2219 | goto illegal; | |
2220 | } | |
2221 | break; | |
2222 | ||
2223 | case SDEV_OFFLINE: | |
1b8d2620 | 2224 | case SDEV_TRANSPORT_OFFLINE: |
1da177e4 LT |
2225 | switch (oldstate) { |
2226 | case SDEV_CREATED: | |
2227 | case SDEV_RUNNING: | |
2228 | case SDEV_QUIESCE: | |
2229 | case SDEV_BLOCK: | |
2230 | break; | |
2231 | default: | |
2232 | goto illegal; | |
2233 | } | |
2234 | break; | |
2235 | ||
2236 | case SDEV_BLOCK: | |
2237 | switch (oldstate) { | |
1da177e4 | 2238 | case SDEV_RUNNING: |
6f4267e3 | 2239 | case SDEV_CREATED_BLOCK: |
a33e5bfb | 2240 | case SDEV_OFFLINE: |
6f4267e3 JB |
2241 | break; |
2242 | default: | |
2243 | goto illegal; | |
2244 | } | |
2245 | break; | |
2246 | ||
2247 | case SDEV_CREATED_BLOCK: | |
2248 | switch (oldstate) { | |
2249 | case SDEV_CREATED: | |
1da177e4 LT |
2250 | break; |
2251 | default: | |
2252 | goto illegal; | |
2253 | } | |
2254 | break; | |
2255 | ||
2256 | case SDEV_CANCEL: | |
2257 | switch (oldstate) { | |
2258 | case SDEV_CREATED: | |
2259 | case SDEV_RUNNING: | |
9ea72909 | 2260 | case SDEV_QUIESCE: |
1da177e4 | 2261 | case SDEV_OFFLINE: |
1b8d2620 | 2262 | case SDEV_TRANSPORT_OFFLINE: |
1da177e4 LT |
2263 | break; |
2264 | default: | |
2265 | goto illegal; | |
2266 | } | |
2267 | break; | |
2268 | ||
2269 | case SDEV_DEL: | |
2270 | switch (oldstate) { | |
309bd271 BK |
2271 | case SDEV_CREATED: |
2272 | case SDEV_RUNNING: | |
2273 | case SDEV_OFFLINE: | |
1b8d2620 | 2274 | case SDEV_TRANSPORT_OFFLINE: |
1da177e4 | 2275 | case SDEV_CANCEL: |
255ee932 | 2276 | case SDEV_BLOCK: |
0516c08d | 2277 | case SDEV_CREATED_BLOCK: |
1da177e4 LT |
2278 | break; |
2279 | default: | |
2280 | goto illegal; | |
2281 | } | |
2282 | break; | |
2283 | ||
2284 | } | |
2285 | sdev->sdev_state = state; | |
2286 | return 0; | |
2287 | ||
2288 | illegal: | |
91921e01 | 2289 | SCSI_LOG_ERROR_RECOVERY(1, |
9ccfc756 | 2290 | sdev_printk(KERN_ERR, sdev, |
91921e01 | 2291 | "Illegal state transition %s->%s", |
9ccfc756 JB |
2292 | scsi_device_state_name(oldstate), |
2293 | scsi_device_state_name(state)) | |
1da177e4 LT |
2294 | ); |
2295 | return -EINVAL; | |
2296 | } | |
2297 | EXPORT_SYMBOL(scsi_device_set_state); | |
2298 | ||
a341cd0f JG |
2299 | /** |
2300 | * sdev_evt_emit - emit a single SCSI device uevent | |
2301 | * @sdev: associated SCSI device | |
2302 | * @evt: event to emit | |
2303 | * | |
2304 | * Send a single uevent (scsi_event) to the associated scsi_device. | |
2305 | */ | |
2306 | static void scsi_evt_emit(struct scsi_device *sdev, struct scsi_event *evt) | |
2307 | { | |
2308 | int idx = 0; | |
2309 | char *envp[3]; | |
2310 | ||
2311 | switch (evt->evt_type) { | |
2312 | case SDEV_EVT_MEDIA_CHANGE: | |
2313 | envp[idx++] = "SDEV_MEDIA_CHANGE=1"; | |
2314 | break; | |
279afdfe | 2315 | case SDEV_EVT_INQUIRY_CHANGE_REPORTED: |
d3d32891 | 2316 | scsi_rescan_device(&sdev->sdev_gendev); |
279afdfe EM |
2317 | envp[idx++] = "SDEV_UA=INQUIRY_DATA_HAS_CHANGED"; |
2318 | break; | |
2319 | case SDEV_EVT_CAPACITY_CHANGE_REPORTED: | |
2320 | envp[idx++] = "SDEV_UA=CAPACITY_DATA_HAS_CHANGED"; | |
2321 | break; | |
2322 | case SDEV_EVT_SOFT_THRESHOLD_REACHED_REPORTED: | |
2323 | envp[idx++] = "SDEV_UA=THIN_PROVISIONING_SOFT_THRESHOLD_REACHED"; | |
2324 | break; | |
2325 | case SDEV_EVT_MODE_PARAMETER_CHANGE_REPORTED: | |
2326 | envp[idx++] = "SDEV_UA=MODE_PARAMETERS_CHANGED"; | |
2327 | break; | |
2328 | case SDEV_EVT_LUN_CHANGE_REPORTED: | |
2329 | envp[idx++] = "SDEV_UA=REPORTED_LUNS_DATA_HAS_CHANGED"; | |
2330 | break; | |
14c3e677 HR |
2331 | case SDEV_EVT_ALUA_STATE_CHANGE_REPORTED: |
2332 | envp[idx++] = "SDEV_UA=ASYMMETRIC_ACCESS_STATE_CHANGED"; | |
2333 | break; | |
cf3431bb HR |
2334 | case SDEV_EVT_POWER_ON_RESET_OCCURRED: |
2335 | envp[idx++] = "SDEV_UA=POWER_ON_RESET_OCCURRED"; | |
2336 | break; | |
a341cd0f JG |
2337 | default: |
2338 | /* do nothing */ | |
2339 | break; | |
2340 | } | |
2341 | ||
2342 | envp[idx++] = NULL; | |
2343 | ||
2344 | kobject_uevent_env(&sdev->sdev_gendev.kobj, KOBJ_CHANGE, envp); | |
2345 | } | |
2346 | ||
2347 | /** | |
2348 | * sdev_evt_thread - send a uevent for each scsi event | |
2349 | * @work: work struct for scsi_device | |
2350 | * | |
2351 | * Dispatch queued events to their associated scsi_device kobjects | |
2352 | * as uevents. | |
2353 | */ | |
2354 | void scsi_evt_thread(struct work_struct *work) | |
2355 | { | |
2356 | struct scsi_device *sdev; | |
279afdfe | 2357 | enum scsi_device_event evt_type; |
a341cd0f JG |
2358 | LIST_HEAD(event_list); |
2359 | ||
2360 | sdev = container_of(work, struct scsi_device, event_work); | |
2361 | ||
279afdfe EM |
2362 | for (evt_type = SDEV_EVT_FIRST; evt_type <= SDEV_EVT_LAST; evt_type++) |
2363 | if (test_and_clear_bit(evt_type, sdev->pending_events)) | |
2364 | sdev_evt_send_simple(sdev, evt_type, GFP_KERNEL); | |
2365 | ||
a341cd0f JG |
2366 | while (1) { |
2367 | struct scsi_event *evt; | |
2368 | struct list_head *this, *tmp; | |
2369 | unsigned long flags; | |
2370 | ||
2371 | spin_lock_irqsave(&sdev->list_lock, flags); | |
2372 | list_splice_init(&sdev->event_list, &event_list); | |
2373 | spin_unlock_irqrestore(&sdev->list_lock, flags); | |
2374 | ||
2375 | if (list_empty(&event_list)) | |
2376 | break; | |
2377 | ||
2378 | list_for_each_safe(this, tmp, &event_list) { | |
2379 | evt = list_entry(this, struct scsi_event, node); | |
2380 | list_del(&evt->node); | |
2381 | scsi_evt_emit(sdev, evt); | |
2382 | kfree(evt); | |
2383 | } | |
2384 | } | |
2385 | } | |
2386 | ||
2387 | /** | |
2388 | * sdev_evt_send - send asserted event to uevent thread | |
2389 | * @sdev: scsi_device event occurred on | |
2390 | * @evt: event to send | |
2391 | * | |
2392 | * Assert scsi device event asynchronously. | |
2393 | */ | |
2394 | void sdev_evt_send(struct scsi_device *sdev, struct scsi_event *evt) | |
2395 | { | |
2396 | unsigned long flags; | |
2397 | ||
4d1566ed KS |
2398 | #if 0 |
2399 | /* FIXME: currently this check eliminates all media change events | |
2400 | * for polled devices. Need to update to discriminate between AN | |
2401 | * and polled events */ | |
a341cd0f JG |
2402 | if (!test_bit(evt->evt_type, sdev->supported_events)) { |
2403 | kfree(evt); | |
2404 | return; | |
2405 | } | |
4d1566ed | 2406 | #endif |
a341cd0f JG |
2407 | |
2408 | spin_lock_irqsave(&sdev->list_lock, flags); | |
2409 | list_add_tail(&evt->node, &sdev->event_list); | |
2410 | schedule_work(&sdev->event_work); | |
2411 | spin_unlock_irqrestore(&sdev->list_lock, flags); | |
2412 | } | |
2413 | EXPORT_SYMBOL_GPL(sdev_evt_send); | |
2414 | ||
2415 | /** | |
2416 | * sdev_evt_alloc - allocate a new scsi event | |
2417 | * @evt_type: type of event to allocate | |
2418 | * @gfpflags: GFP flags for allocation | |
2419 | * | |
2420 | * Allocates and returns a new scsi_event. | |
2421 | */ | |
2422 | struct scsi_event *sdev_evt_alloc(enum scsi_device_event evt_type, | |
2423 | gfp_t gfpflags) | |
2424 | { | |
2425 | struct scsi_event *evt = kzalloc(sizeof(struct scsi_event), gfpflags); | |
2426 | if (!evt) | |
2427 | return NULL; | |
2428 | ||
2429 | evt->evt_type = evt_type; | |
2430 | INIT_LIST_HEAD(&evt->node); | |
2431 | ||
2432 | /* evt_type-specific initialization, if any */ | |
2433 | switch (evt_type) { | |
2434 | case SDEV_EVT_MEDIA_CHANGE: | |
279afdfe EM |
2435 | case SDEV_EVT_INQUIRY_CHANGE_REPORTED: |
2436 | case SDEV_EVT_CAPACITY_CHANGE_REPORTED: | |
2437 | case SDEV_EVT_SOFT_THRESHOLD_REACHED_REPORTED: | |
2438 | case SDEV_EVT_MODE_PARAMETER_CHANGE_REPORTED: | |
2439 | case SDEV_EVT_LUN_CHANGE_REPORTED: | |
14c3e677 | 2440 | case SDEV_EVT_ALUA_STATE_CHANGE_REPORTED: |
cf3431bb | 2441 | case SDEV_EVT_POWER_ON_RESET_OCCURRED: |
a341cd0f JG |
2442 | default: |
2443 | /* do nothing */ | |
2444 | break; | |
2445 | } | |
2446 | ||
2447 | return evt; | |
2448 | } | |
2449 | EXPORT_SYMBOL_GPL(sdev_evt_alloc); | |
2450 | ||
2451 | /** | |
2452 | * sdev_evt_send_simple - send asserted event to uevent thread | |
2453 | * @sdev: scsi_device event occurred on | |
2454 | * @evt_type: type of event to send | |
2455 | * @gfpflags: GFP flags for allocation | |
2456 | * | |
2457 | * Assert scsi device event asynchronously, given an event type. | |
2458 | */ | |
2459 | void sdev_evt_send_simple(struct scsi_device *sdev, | |
2460 | enum scsi_device_event evt_type, gfp_t gfpflags) | |
2461 | { | |
2462 | struct scsi_event *evt = sdev_evt_alloc(evt_type, gfpflags); | |
2463 | if (!evt) { | |
2464 | sdev_printk(KERN_ERR, sdev, "event %d eaten due to OOM\n", | |
2465 | evt_type); | |
2466 | return; | |
2467 | } | |
2468 | ||
2469 | sdev_evt_send(sdev, evt); | |
2470 | } | |
2471 | EXPORT_SYMBOL_GPL(sdev_evt_send_simple); | |
2472 | ||
1da177e4 LT |
2473 | /** |
2474 | * scsi_device_quiesce - Block user issued commands. | |
2475 | * @sdev: scsi device to quiesce. | |
2476 | * | |
2477 | * This works by trying to transition to the SDEV_QUIESCE state | |
2478 | * (which must be a legal transition). When the device is in this | |
2479 | * state, only special requests will be accepted, all others will | |
2480 | * be deferred. Since special requests may also be requeued requests, | |
2481 | * a successful return doesn't guarantee the device will be | |
2482 | * totally quiescent. | |
2483 | * | |
2484 | * Must be called with user context, may sleep. | |
2485 | * | |
2486 | * Returns zero if unsuccessful or an error if not. | |
eb44820c | 2487 | */ |
1da177e4 LT |
2488 | int |
2489 | scsi_device_quiesce(struct scsi_device *sdev) | |
2490 | { | |
3a0a5299 | 2491 | struct request_queue *q = sdev->request_queue; |
0db6ca8a BVA |
2492 | int err; |
2493 | ||
3a0a5299 BVA |
2494 | /* |
2495 | * It is allowed to call scsi_device_quiesce() multiple times from | |
2496 | * the same context but concurrent scsi_device_quiesce() calls are | |
2497 | * not allowed. | |
2498 | */ | |
2499 | WARN_ON_ONCE(sdev->quiesced_by && sdev->quiesced_by != current); | |
2500 | ||
cd84a62e BVA |
2501 | if (sdev->quiesced_by == current) |
2502 | return 0; | |
2503 | ||
2504 | blk_set_pm_only(q); | |
3a0a5299 BVA |
2505 | |
2506 | blk_mq_freeze_queue(q); | |
2507 | /* | |
cd84a62e | 2508 | * Ensure that the effect of blk_set_pm_only() will be visible |
3a0a5299 BVA |
2509 | * for percpu_ref_tryget() callers that occur after the queue |
2510 | * unfreeze even if the queue was already frozen before this function | |
2511 | * was called. See also https://lwn.net/Articles/573497/. | |
2512 | */ | |
2513 | synchronize_rcu(); | |
2514 | blk_mq_unfreeze_queue(q); | |
2515 | ||
0db6ca8a BVA |
2516 | mutex_lock(&sdev->state_mutex); |
2517 | err = scsi_device_set_state(sdev, SDEV_QUIESCE); | |
3a0a5299 BVA |
2518 | if (err == 0) |
2519 | sdev->quiesced_by = current; | |
2520 | else | |
cd84a62e | 2521 | blk_clear_pm_only(q); |
0db6ca8a BVA |
2522 | mutex_unlock(&sdev->state_mutex); |
2523 | ||
3a0a5299 | 2524 | return err; |
1da177e4 LT |
2525 | } |
2526 | EXPORT_SYMBOL(scsi_device_quiesce); | |
2527 | ||
2528 | /** | |
2529 | * scsi_device_resume - Restart user issued commands to a quiesced device. | |
2530 | * @sdev: scsi device to resume. | |
2531 | * | |
2532 | * Moves the device from quiesced back to running and restarts the | |
2533 | * queues. | |
2534 | * | |
2535 | * Must be called with user context, may sleep. | |
eb44820c | 2536 | */ |
a7a20d10 | 2537 | void scsi_device_resume(struct scsi_device *sdev) |
1da177e4 | 2538 | { |
a7a20d10 DW |
2539 | /* check if the device state was mutated prior to resume, and if |
2540 | * so assume the state is being managed elsewhere (for example | |
2541 | * device deleted during suspend) | |
2542 | */ | |
0db6ca8a | 2543 | mutex_lock(&sdev->state_mutex); |
3a0a5299 | 2544 | sdev->quiesced_by = NULL; |
cd84a62e | 2545 | blk_clear_pm_only(sdev->request_queue); |
3a0a5299 BVA |
2546 | if (sdev->sdev_state == SDEV_QUIESCE) |
2547 | scsi_device_set_state(sdev, SDEV_RUNNING); | |
0db6ca8a | 2548 | mutex_unlock(&sdev->state_mutex); |
1da177e4 LT |
2549 | } |
2550 | EXPORT_SYMBOL(scsi_device_resume); | |
2551 | ||
2552 | static void | |
2553 | device_quiesce_fn(struct scsi_device *sdev, void *data) | |
2554 | { | |
2555 | scsi_device_quiesce(sdev); | |
2556 | } | |
2557 | ||
2558 | void | |
2559 | scsi_target_quiesce(struct scsi_target *starget) | |
2560 | { | |
2561 | starget_for_each_device(starget, NULL, device_quiesce_fn); | |
2562 | } | |
2563 | EXPORT_SYMBOL(scsi_target_quiesce); | |
2564 | ||
2565 | static void | |
2566 | device_resume_fn(struct scsi_device *sdev, void *data) | |
2567 | { | |
2568 | scsi_device_resume(sdev); | |
2569 | } | |
2570 | ||
2571 | void | |
2572 | scsi_target_resume(struct scsi_target *starget) | |
2573 | { | |
2574 | starget_for_each_device(starget, NULL, device_resume_fn); | |
2575 | } | |
2576 | EXPORT_SYMBOL(scsi_target_resume); | |
2577 | ||
2578 | /** | |
551eb598 BVA |
2579 | * scsi_internal_device_block_nowait - try to transition to the SDEV_BLOCK state |
2580 | * @sdev: device to block | |
1da177e4 | 2581 | * |
551eb598 | 2582 | * Pause SCSI command processing on the specified device. Does not sleep. |
1da177e4 | 2583 | * |
551eb598 | 2584 | * Returns zero if successful or a negative error code upon failure. |
669f0441 | 2585 | * |
551eb598 BVA |
2586 | * Notes: |
2587 | * This routine transitions the device to the SDEV_BLOCK state (which must be | |
2588 | * a legal transition). When the device is in this state, command processing | |
2589 | * is paused until the device leaves the SDEV_BLOCK state. See also | |
2590 | * scsi_internal_device_unblock_nowait(). | |
eb44820c | 2591 | */ |
551eb598 | 2592 | int scsi_internal_device_block_nowait(struct scsi_device *sdev) |
1da177e4 | 2593 | { |
165125e1 | 2594 | struct request_queue *q = sdev->request_queue; |
1da177e4 LT |
2595 | int err = 0; |
2596 | ||
2597 | err = scsi_device_set_state(sdev, SDEV_BLOCK); | |
6f4267e3 JB |
2598 | if (err) { |
2599 | err = scsi_device_set_state(sdev, SDEV_CREATED_BLOCK); | |
2600 | ||
2601 | if (err) | |
2602 | return err; | |
2603 | } | |
1da177e4 LT |
2604 | |
2605 | /* | |
2606 | * The device has transitioned to SDEV_BLOCK. Stop the | |
2607 | * block layer from calling the midlayer with this device's | |
2608 | * request queue. | |
2609 | */ | |
f664a3cc | 2610 | blk_mq_quiesce_queue_nowait(q); |
1da177e4 LT |
2611 | return 0; |
2612 | } | |
551eb598 BVA |
2613 | EXPORT_SYMBOL_GPL(scsi_internal_device_block_nowait); |
2614 | ||
1da177e4 | 2615 | /** |
551eb598 BVA |
2616 | * scsi_internal_device_block - try to transition to the SDEV_BLOCK state |
2617 | * @sdev: device to block | |
2618 | * | |
2619 | * Pause SCSI command processing on the specified device and wait until all | |
2620 | * ongoing scsi_request_fn() / scsi_queue_rq() calls have finished. May sleep. | |
1da177e4 | 2621 | * |
551eb598 | 2622 | * Returns zero if successful or a negative error code upon failure. |
1da177e4 | 2623 | * |
551eb598 BVA |
2624 | * Note: |
2625 | * This routine transitions the device to the SDEV_BLOCK state (which must be | |
2626 | * a legal transition). When the device is in this state, command processing | |
2627 | * is paused until the device leaves the SDEV_BLOCK state. See also | |
2628 | * scsi_internal_device_unblock(). | |
1da177e4 | 2629 | * |
551eb598 BVA |
2630 | * To do: avoid that scsi_send_eh_cmnd() calls queuecommand() after |
2631 | * scsi_internal_device_block() has blocked a SCSI device and also | |
2632 | * remove the rport mutex lock and unlock calls from srp_queuecommand(). | |
eb44820c | 2633 | */ |
551eb598 | 2634 | static int scsi_internal_device_block(struct scsi_device *sdev) |
1da177e4 | 2635 | { |
551eb598 BVA |
2636 | struct request_queue *q = sdev->request_queue; |
2637 | int err; | |
2638 | ||
0db6ca8a | 2639 | mutex_lock(&sdev->state_mutex); |
551eb598 | 2640 | err = scsi_internal_device_block_nowait(sdev); |
f664a3cc JA |
2641 | if (err == 0) |
2642 | blk_mq_quiesce_queue(q); | |
0db6ca8a BVA |
2643 | mutex_unlock(&sdev->state_mutex); |
2644 | ||
551eb598 BVA |
2645 | return err; |
2646 | } | |
1da177e4 | 2647 | |
66483a4a BVA |
2648 | void scsi_start_queue(struct scsi_device *sdev) |
2649 | { | |
2650 | struct request_queue *q = sdev->request_queue; | |
5d9fb5cc | 2651 | |
f664a3cc | 2652 | blk_mq_unquiesce_queue(q); |
66483a4a BVA |
2653 | } |
2654 | ||
1da177e4 | 2655 | /** |
43f7571b | 2656 | * scsi_internal_device_unblock_nowait - resume a device after a block request |
1da177e4 | 2657 | * @sdev: device to resume |
43f7571b | 2658 | * @new_state: state to set the device to after unblocking |
1da177e4 | 2659 | * |
43f7571b BVA |
2660 | * Restart the device queue for a previously suspended SCSI device. Does not |
2661 | * sleep. | |
1da177e4 | 2662 | * |
43f7571b | 2663 | * Returns zero if successful or a negative error code upon failure. |
1da177e4 | 2664 | * |
43f7571b BVA |
2665 | * Notes: |
2666 | * This routine transitions the device to the SDEV_RUNNING state or to one of | |
2667 | * the offline states (which must be a legal transition) allowing the midlayer | |
2668 | * to goose the queue for this device. | |
eb44820c | 2669 | */ |
43f7571b BVA |
2670 | int scsi_internal_device_unblock_nowait(struct scsi_device *sdev, |
2671 | enum scsi_device_state new_state) | |
1da177e4 | 2672 | { |
5d9fb5cc MC |
2673 | /* |
2674 | * Try to transition the scsi device to SDEV_RUNNING or one of the | |
2675 | * offlined states and goose the device queue if successful. | |
1da177e4 | 2676 | */ |
8cd1ec78 HR |
2677 | switch (sdev->sdev_state) { |
2678 | case SDEV_BLOCK: | |
2679 | case SDEV_TRANSPORT_OFFLINE: | |
5d9fb5cc | 2680 | sdev->sdev_state = new_state; |
8cd1ec78 HR |
2681 | break; |
2682 | case SDEV_CREATED_BLOCK: | |
5d9fb5cc MC |
2683 | if (new_state == SDEV_TRANSPORT_OFFLINE || |
2684 | new_state == SDEV_OFFLINE) | |
2685 | sdev->sdev_state = new_state; | |
2686 | else | |
2687 | sdev->sdev_state = SDEV_CREATED; | |
8cd1ec78 HR |
2688 | break; |
2689 | case SDEV_CANCEL: | |
2690 | case SDEV_OFFLINE: | |
2691 | break; | |
2692 | default: | |
5c10e63c | 2693 | return -EINVAL; |
8cd1ec78 | 2694 | } |
66483a4a | 2695 | scsi_start_queue(sdev); |
1da177e4 LT |
2696 | |
2697 | return 0; | |
2698 | } | |
43f7571b BVA |
2699 | EXPORT_SYMBOL_GPL(scsi_internal_device_unblock_nowait); |
2700 | ||
2701 | /** | |
2702 | * scsi_internal_device_unblock - resume a device after a block request | |
2703 | * @sdev: device to resume | |
2704 | * @new_state: state to set the device to after unblocking | |
2705 | * | |
2706 | * Restart the device queue for a previously suspended SCSI device. May sleep. | |
2707 | * | |
2708 | * Returns zero if successful or a negative error code upon failure. | |
2709 | * | |
2710 | * Notes: | |
2711 | * This routine transitions the device to the SDEV_RUNNING state or to one of | |
2712 | * the offline states (which must be a legal transition) allowing the midlayer | |
2713 | * to goose the queue for this device. | |
2714 | */ | |
2715 | static int scsi_internal_device_unblock(struct scsi_device *sdev, | |
2716 | enum scsi_device_state new_state) | |
2717 | { | |
0db6ca8a BVA |
2718 | int ret; |
2719 | ||
2720 | mutex_lock(&sdev->state_mutex); | |
2721 | ret = scsi_internal_device_unblock_nowait(sdev, new_state); | |
2722 | mutex_unlock(&sdev->state_mutex); | |
2723 | ||
2724 | return ret; | |
43f7571b | 2725 | } |
1da177e4 LT |
2726 | |
2727 | static void | |
2728 | device_block(struct scsi_device *sdev, void *data) | |
2729 | { | |
551eb598 | 2730 | scsi_internal_device_block(sdev); |
1da177e4 LT |
2731 | } |
2732 | ||
2733 | static int | |
2734 | target_block(struct device *dev, void *data) | |
2735 | { | |
2736 | if (scsi_is_target_device(dev)) | |
2737 | starget_for_each_device(to_scsi_target(dev), NULL, | |
2738 | device_block); | |
2739 | return 0; | |
2740 | } | |
2741 | ||
2742 | void | |
2743 | scsi_target_block(struct device *dev) | |
2744 | { | |
2745 | if (scsi_is_target_device(dev)) | |
2746 | starget_for_each_device(to_scsi_target(dev), NULL, | |
2747 | device_block); | |
2748 | else | |
2749 | device_for_each_child(dev, NULL, target_block); | |
2750 | } | |
2751 | EXPORT_SYMBOL_GPL(scsi_target_block); | |
2752 | ||
2753 | static void | |
2754 | device_unblock(struct scsi_device *sdev, void *data) | |
2755 | { | |
5d9fb5cc | 2756 | scsi_internal_device_unblock(sdev, *(enum scsi_device_state *)data); |
1da177e4 LT |
2757 | } |
2758 | ||
2759 | static int | |
2760 | target_unblock(struct device *dev, void *data) | |
2761 | { | |
2762 | if (scsi_is_target_device(dev)) | |
5d9fb5cc | 2763 | starget_for_each_device(to_scsi_target(dev), data, |
1da177e4 LT |
2764 | device_unblock); |
2765 | return 0; | |
2766 | } | |
2767 | ||
2768 | void | |
5d9fb5cc | 2769 | scsi_target_unblock(struct device *dev, enum scsi_device_state new_state) |
1da177e4 LT |
2770 | { |
2771 | if (scsi_is_target_device(dev)) | |
5d9fb5cc | 2772 | starget_for_each_device(to_scsi_target(dev), &new_state, |
1da177e4 LT |
2773 | device_unblock); |
2774 | else | |
5d9fb5cc | 2775 | device_for_each_child(dev, &new_state, target_unblock); |
1da177e4 LT |
2776 | } |
2777 | EXPORT_SYMBOL_GPL(scsi_target_unblock); | |
cdb8c2a6 GL |
2778 | |
2779 | /** | |
2780 | * scsi_kmap_atomic_sg - find and atomically map an sg-elemnt | |
eb44820c | 2781 | * @sgl: scatter-gather list |
cdb8c2a6 GL |
2782 | * @sg_count: number of segments in sg |
2783 | * @offset: offset in bytes into sg, on return offset into the mapped area | |
2784 | * @len: bytes to map, on return number of bytes mapped | |
2785 | * | |
2786 | * Returns virtual address of the start of the mapped page | |
2787 | */ | |
c6132da1 | 2788 | void *scsi_kmap_atomic_sg(struct scatterlist *sgl, int sg_count, |
cdb8c2a6 GL |
2789 | size_t *offset, size_t *len) |
2790 | { | |
2791 | int i; | |
2792 | size_t sg_len = 0, len_complete = 0; | |
c6132da1 | 2793 | struct scatterlist *sg; |
cdb8c2a6 GL |
2794 | struct page *page; |
2795 | ||
22cfefb5 AM |
2796 | WARN_ON(!irqs_disabled()); |
2797 | ||
c6132da1 | 2798 | for_each_sg(sgl, sg, sg_count, i) { |
cdb8c2a6 | 2799 | len_complete = sg_len; /* Complete sg-entries */ |
c6132da1 | 2800 | sg_len += sg->length; |
cdb8c2a6 GL |
2801 | if (sg_len > *offset) |
2802 | break; | |
2803 | } | |
2804 | ||
2805 | if (unlikely(i == sg_count)) { | |
169e1a2a AM |
2806 | printk(KERN_ERR "%s: Bytes in sg: %zu, requested offset %zu, " |
2807 | "elements %d\n", | |
cadbd4a5 | 2808 | __func__, sg_len, *offset, sg_count); |
cdb8c2a6 GL |
2809 | WARN_ON(1); |
2810 | return NULL; | |
2811 | } | |
2812 | ||
2813 | /* Offset starting from the beginning of first page in this sg-entry */ | |
c6132da1 | 2814 | *offset = *offset - len_complete + sg->offset; |
cdb8c2a6 GL |
2815 | |
2816 | /* Assumption: contiguous pages can be accessed as "page + i" */ | |
45711f1a | 2817 | page = nth_page(sg_page(sg), (*offset >> PAGE_SHIFT)); |
cdb8c2a6 GL |
2818 | *offset &= ~PAGE_MASK; |
2819 | ||
2820 | /* Bytes in this sg-entry from *offset to the end of the page */ | |
2821 | sg_len = PAGE_SIZE - *offset; | |
2822 | if (*len > sg_len) | |
2823 | *len = sg_len; | |
2824 | ||
77dfce07 | 2825 | return kmap_atomic(page); |
cdb8c2a6 GL |
2826 | } |
2827 | EXPORT_SYMBOL(scsi_kmap_atomic_sg); | |
2828 | ||
2829 | /** | |
eb44820c | 2830 | * scsi_kunmap_atomic_sg - atomically unmap a virtual address, previously mapped with scsi_kmap_atomic_sg |
cdb8c2a6 GL |
2831 | * @virt: virtual address to be unmapped |
2832 | */ | |
2833 | void scsi_kunmap_atomic_sg(void *virt) | |
2834 | { | |
77dfce07 | 2835 | kunmap_atomic(virt); |
cdb8c2a6 GL |
2836 | } |
2837 | EXPORT_SYMBOL(scsi_kunmap_atomic_sg); | |
6f4c827e AL |
2838 | |
2839 | void sdev_disable_disk_events(struct scsi_device *sdev) | |
2840 | { | |
2841 | atomic_inc(&sdev->disk_events_disable_depth); | |
2842 | } | |
2843 | EXPORT_SYMBOL(sdev_disable_disk_events); | |
2844 | ||
2845 | void sdev_enable_disk_events(struct scsi_device *sdev) | |
2846 | { | |
2847 | if (WARN_ON_ONCE(atomic_read(&sdev->disk_events_disable_depth) <= 0)) | |
2848 | return; | |
2849 | atomic_dec(&sdev->disk_events_disable_depth); | |
2850 | } | |
2851 | EXPORT_SYMBOL(sdev_enable_disk_events); | |
9983bed3 HR |
2852 | |
2853 | /** | |
2854 | * scsi_vpd_lun_id - return a unique device identification | |
2855 | * @sdev: SCSI device | |
2856 | * @id: buffer for the identification | |
2857 | * @id_len: length of the buffer | |
2858 | * | |
2859 | * Copies a unique device identification into @id based | |
2860 | * on the information in the VPD page 0x83 of the device. | |
2861 | * The string will be formatted as a SCSI name string. | |
2862 | * | |
2863 | * Returns the length of the identification or error on failure. | |
2864 | * If the identifier is longer than the supplied buffer the actual | |
2865 | * identifier length is returned and the buffer is not zero-padded. | |
2866 | */ | |
2867 | int scsi_vpd_lun_id(struct scsi_device *sdev, char *id, size_t id_len) | |
2868 | { | |
2869 | u8 cur_id_type = 0xff; | |
2870 | u8 cur_id_size = 0; | |
ccf1e004 BVA |
2871 | const unsigned char *d, *cur_id_str; |
2872 | const struct scsi_vpd *vpd_pg83; | |
9983bed3 HR |
2873 | int id_size = -EINVAL; |
2874 | ||
2875 | rcu_read_lock(); | |
2876 | vpd_pg83 = rcu_dereference(sdev->vpd_pg83); | |
2877 | if (!vpd_pg83) { | |
2878 | rcu_read_unlock(); | |
2879 | return -ENXIO; | |
2880 | } | |
2881 | ||
2882 | /* | |
2883 | * Look for the correct descriptor. | |
2884 | * Order of preference for lun descriptor: | |
2885 | * - SCSI name string | |
2886 | * - NAA IEEE Registered Extended | |
2887 | * - EUI-64 based 16-byte | |
2888 | * - EUI-64 based 12-byte | |
2889 | * - NAA IEEE Registered | |
2890 | * - NAA IEEE Extended | |
d230823a | 2891 | * - T10 Vendor ID |
9983bed3 HR |
2892 | * as longer descriptors reduce the likelyhood |
2893 | * of identification clashes. | |
2894 | */ | |
2895 | ||
2896 | /* The id string must be at least 20 bytes + terminating NULL byte */ | |
2897 | if (id_len < 21) { | |
2898 | rcu_read_unlock(); | |
2899 | return -EINVAL; | |
2900 | } | |
2901 | ||
2902 | memset(id, 0, id_len); | |
ccf1e004 BVA |
2903 | d = vpd_pg83->data + 4; |
2904 | while (d < vpd_pg83->data + vpd_pg83->len) { | |
9983bed3 HR |
2905 | /* Skip designators not referring to the LUN */ |
2906 | if ((d[1] & 0x30) != 0x00) | |
2907 | goto next_desig; | |
2908 | ||
2909 | switch (d[1] & 0xf) { | |
d230823a HR |
2910 | case 0x1: |
2911 | /* T10 Vendor ID */ | |
2912 | if (cur_id_size > d[3]) | |
2913 | break; | |
2914 | /* Prefer anything */ | |
2915 | if (cur_id_type > 0x01 && cur_id_type != 0xff) | |
2916 | break; | |
2917 | cur_id_size = d[3]; | |
2918 | if (cur_id_size + 4 > id_len) | |
2919 | cur_id_size = id_len - 4; | |
2920 | cur_id_str = d + 4; | |
2921 | cur_id_type = d[1] & 0xf; | |
2922 | id_size = snprintf(id, id_len, "t10.%*pE", | |
2923 | cur_id_size, cur_id_str); | |
2924 | break; | |
9983bed3 HR |
2925 | case 0x2: |
2926 | /* EUI-64 */ | |
2927 | if (cur_id_size > d[3]) | |
2928 | break; | |
2929 | /* Prefer NAA IEEE Registered Extended */ | |
2930 | if (cur_id_type == 0x3 && | |
2931 | cur_id_size == d[3]) | |
2932 | break; | |
2933 | cur_id_size = d[3]; | |
2934 | cur_id_str = d + 4; | |
2935 | cur_id_type = d[1] & 0xf; | |
2936 | switch (cur_id_size) { | |
2937 | case 8: | |
2938 | id_size = snprintf(id, id_len, | |
2939 | "eui.%8phN", | |
2940 | cur_id_str); | |
2941 | break; | |
2942 | case 12: | |
2943 | id_size = snprintf(id, id_len, | |
2944 | "eui.%12phN", | |
2945 | cur_id_str); | |
2946 | break; | |
2947 | case 16: | |
2948 | id_size = snprintf(id, id_len, | |
2949 | "eui.%16phN", | |
2950 | cur_id_str); | |
2951 | break; | |
2952 | default: | |
2953 | cur_id_size = 0; | |
2954 | break; | |
2955 | } | |
2956 | break; | |
2957 | case 0x3: | |
2958 | /* NAA */ | |
2959 | if (cur_id_size > d[3]) | |
2960 | break; | |
2961 | cur_id_size = d[3]; | |
2962 | cur_id_str = d + 4; | |
2963 | cur_id_type = d[1] & 0xf; | |
2964 | switch (cur_id_size) { | |
2965 | case 8: | |
2966 | id_size = snprintf(id, id_len, | |
2967 | "naa.%8phN", | |
2968 | cur_id_str); | |
2969 | break; | |
2970 | case 16: | |
2971 | id_size = snprintf(id, id_len, | |
2972 | "naa.%16phN", | |
2973 | cur_id_str); | |
2974 | break; | |
2975 | default: | |
2976 | cur_id_size = 0; | |
2977 | break; | |
2978 | } | |
2979 | break; | |
2980 | case 0x8: | |
2981 | /* SCSI name string */ | |
2982 | if (cur_id_size + 4 > d[3]) | |
2983 | break; | |
2984 | /* Prefer others for truncated descriptor */ | |
2985 | if (cur_id_size && d[3] > id_len) | |
2986 | break; | |
2987 | cur_id_size = id_size = d[3]; | |
2988 | cur_id_str = d + 4; | |
2989 | cur_id_type = d[1] & 0xf; | |
2990 | if (cur_id_size >= id_len) | |
2991 | cur_id_size = id_len - 1; | |
2992 | memcpy(id, cur_id_str, cur_id_size); | |
2993 | /* Decrease priority for truncated descriptor */ | |
2994 | if (cur_id_size != id_size) | |
2995 | cur_id_size = 6; | |
2996 | break; | |
2997 | default: | |
2998 | break; | |
2999 | } | |
3000 | next_desig: | |
3001 | d += d[3] + 4; | |
3002 | } | |
3003 | rcu_read_unlock(); | |
3004 | ||
3005 | return id_size; | |
3006 | } | |
3007 | EXPORT_SYMBOL(scsi_vpd_lun_id); | |
a8aa3978 HR |
3008 | |
3009 | /* | |
3010 | * scsi_vpd_tpg_id - return a target port group identifier | |
3011 | * @sdev: SCSI device | |
3012 | * | |
3013 | * Returns the Target Port Group identifier from the information | |
3014 | * froom VPD page 0x83 of the device. | |
3015 | * | |
3016 | * Returns the identifier or error on failure. | |
3017 | */ | |
3018 | int scsi_vpd_tpg_id(struct scsi_device *sdev, int *rel_id) | |
3019 | { | |
ccf1e004 BVA |
3020 | const unsigned char *d; |
3021 | const struct scsi_vpd *vpd_pg83; | |
a8aa3978 HR |
3022 | int group_id = -EAGAIN, rel_port = -1; |
3023 | ||
3024 | rcu_read_lock(); | |
3025 | vpd_pg83 = rcu_dereference(sdev->vpd_pg83); | |
3026 | if (!vpd_pg83) { | |
3027 | rcu_read_unlock(); | |
3028 | return -ENXIO; | |
3029 | } | |
3030 | ||
ccf1e004 BVA |
3031 | d = vpd_pg83->data + 4; |
3032 | while (d < vpd_pg83->data + vpd_pg83->len) { | |
a8aa3978 HR |
3033 | switch (d[1] & 0xf) { |
3034 | case 0x4: | |
3035 | /* Relative target port */ | |
3036 | rel_port = get_unaligned_be16(&d[6]); | |
3037 | break; | |
3038 | case 0x5: | |
3039 | /* Target port group */ | |
3040 | group_id = get_unaligned_be16(&d[6]); | |
3041 | break; | |
3042 | default: | |
3043 | break; | |
3044 | } | |
3045 | d += d[3] + 4; | |
3046 | } | |
3047 | rcu_read_unlock(); | |
3048 | ||
3049 | if (group_id >= 0 && rel_id && rel_port != -1) | |
3050 | *rel_id = rel_port; | |
3051 | ||
3052 | return group_id; | |
3053 | } | |
3054 | EXPORT_SYMBOL(scsi_vpd_tpg_id); |