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Commit | Line | Data |
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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)", | |
82 | SCSI_SENSE_BUFFERSIZE, 0, | |
83 | SLAB_HWCACHE_ALIGN | SLAB_CACHE_DMA, NULL); | |
84 | if (!scsi_sense_isadma_cache) | |
85 | ret = -ENOMEM; | |
86 | } else { | |
87 | scsi_sense_cache = | |
88 | kmem_cache_create("scsi_sense_cache", | |
89 | SCSI_SENSE_BUFFERSIZE, 0, SLAB_HWCACHE_ALIGN, NULL); | |
90 | if (!scsi_sense_cache) | |
91 | ret = -ENOMEM; | |
92 | } | |
93 | ||
94 | mutex_unlock(&scsi_sense_cache_mutex); | |
95 | return ret; | |
96 | } | |
6f9a35e2 | 97 | |
a488e749 JA |
98 | /* |
99 | * When to reinvoke queueing after a resource shortage. It's 3 msecs to | |
100 | * not change behaviour from the previous unplug mechanism, experimentation | |
101 | * may prove this needs changing. | |
102 | */ | |
103 | #define SCSI_QUEUE_DELAY 3 | |
104 | ||
de3e8bf3 CH |
105 | static void |
106 | scsi_set_blocked(struct scsi_cmnd *cmd, int reason) | |
1da177e4 LT |
107 | { |
108 | struct Scsi_Host *host = cmd->device->host; | |
109 | struct scsi_device *device = cmd->device; | |
f0c0a376 | 110 | struct scsi_target *starget = scsi_target(device); |
1da177e4 LT |
111 | |
112 | /* | |
d8c37e7b | 113 | * Set the appropriate busy bit for the device/host. |
1da177e4 LT |
114 | * |
115 | * If the host/device isn't busy, assume that something actually | |
116 | * completed, and that we should be able to queue a command now. | |
117 | * | |
118 | * Note that the prior mid-layer assumption that any host could | |
119 | * always queue at least one command is now broken. The mid-layer | |
120 | * will implement a user specifiable stall (see | |
121 | * scsi_host.max_host_blocked and scsi_device.max_device_blocked) | |
122 | * if a command is requeued with no other commands outstanding | |
123 | * either for the device or for the host. | |
124 | */ | |
f0c0a376 MC |
125 | switch (reason) { |
126 | case SCSI_MLQUEUE_HOST_BUSY: | |
cd9070c9 | 127 | atomic_set(&host->host_blocked, host->max_host_blocked); |
f0c0a376 MC |
128 | break; |
129 | case SCSI_MLQUEUE_DEVICE_BUSY: | |
573e5913 | 130 | case SCSI_MLQUEUE_EH_RETRY: |
cd9070c9 CH |
131 | atomic_set(&device->device_blocked, |
132 | device->max_device_blocked); | |
f0c0a376 MC |
133 | break; |
134 | case SCSI_MLQUEUE_TARGET_BUSY: | |
cd9070c9 CH |
135 | atomic_set(&starget->target_blocked, |
136 | starget->max_target_blocked); | |
f0c0a376 MC |
137 | break; |
138 | } | |
de3e8bf3 CH |
139 | } |
140 | ||
d285203c CH |
141 | static void scsi_mq_requeue_cmd(struct scsi_cmnd *cmd) |
142 | { | |
143 | struct scsi_device *sdev = cmd->device; | |
d285203c | 144 | |
a45a1f36 BVA |
145 | if (cmd->request->rq_flags & RQF_DONTPREP) { |
146 | cmd->request->rq_flags &= ~RQF_DONTPREP; | |
147 | scsi_mq_uninit_cmd(cmd); | |
148 | } else { | |
149 | WARN_ON_ONCE(true); | |
150 | } | |
2b053aca | 151 | blk_mq_requeue_request(cmd->request, true); |
d285203c CH |
152 | put_device(&sdev->sdev_gendev); |
153 | } | |
154 | ||
de3e8bf3 CH |
155 | /** |
156 | * __scsi_queue_insert - private queue insertion | |
157 | * @cmd: The SCSI command being requeued | |
158 | * @reason: The reason for the requeue | |
159 | * @unbusy: Whether the queue should be unbusied | |
160 | * | |
161 | * This is a private queue insertion. The public interface | |
162 | * scsi_queue_insert() always assumes the queue should be unbusied | |
163 | * because it's always called before the completion. This function is | |
164 | * for a requeue after completion, which should only occur in this | |
165 | * file. | |
166 | */ | |
167 | static void __scsi_queue_insert(struct scsi_cmnd *cmd, int reason, int unbusy) | |
168 | { | |
169 | struct scsi_device *device = cmd->device; | |
170 | struct request_queue *q = device->request_queue; | |
171 | unsigned long flags; | |
172 | ||
173 | SCSI_LOG_MLQUEUE(1, scmd_printk(KERN_INFO, cmd, | |
174 | "Inserting command %p into mlqueue\n", cmd)); | |
175 | ||
176 | scsi_set_blocked(cmd, reason); | |
1da177e4 | 177 | |
1da177e4 LT |
178 | /* |
179 | * Decrement the counters, since these commands are no longer | |
180 | * active on the host/device. | |
181 | */ | |
4f5299ac JB |
182 | if (unbusy) |
183 | scsi_device_unbusy(device); | |
1da177e4 LT |
184 | |
185 | /* | |
a1bf9d1d | 186 | * Requeue this command. It will go before all other commands |
b485462a BVA |
187 | * that are already in the queue. Schedule requeue work under |
188 | * lock such that the kblockd_schedule_work() call happens | |
189 | * before blk_cleanup_queue() finishes. | |
a488e749 | 190 | */ |
644373a4 | 191 | cmd->result = 0; |
d285203c CH |
192 | if (q->mq_ops) { |
193 | scsi_mq_requeue_cmd(cmd); | |
194 | return; | |
195 | } | |
a1bf9d1d | 196 | spin_lock_irqsave(q->queue_lock, flags); |
59897dad | 197 | blk_requeue_request(q, cmd->request); |
59c3d45e | 198 | kblockd_schedule_work(&device->requeue_work); |
b485462a | 199 | spin_unlock_irqrestore(q->queue_lock, flags); |
1da177e4 LT |
200 | } |
201 | ||
4f5299ac JB |
202 | /* |
203 | * Function: scsi_queue_insert() | |
204 | * | |
205 | * Purpose: Insert a command in the midlevel queue. | |
206 | * | |
207 | * Arguments: cmd - command that we are adding to queue. | |
208 | * reason - why we are inserting command to queue. | |
209 | * | |
210 | * Lock status: Assumed that lock is not held upon entry. | |
211 | * | |
212 | * Returns: Nothing. | |
213 | * | |
214 | * Notes: We do this for one of two cases. Either the host is busy | |
215 | * and it cannot accept any more commands for the time being, | |
216 | * or the device returned QUEUE_FULL and can accept no more | |
217 | * commands. | |
218 | * Notes: This could be called either from an interrupt context or a | |
219 | * normal process context. | |
220 | */ | |
84feb166 | 221 | void scsi_queue_insert(struct scsi_cmnd *cmd, int reason) |
4f5299ac | 222 | { |
84feb166 | 223 | __scsi_queue_insert(cmd, reason, 1); |
4f5299ac | 224 | } |
e8064021 | 225 | |
76aaf87b CH |
226 | |
227 | /** | |
228 | * scsi_execute - insert request and wait for the result | |
229 | * @sdev: scsi device | |
230 | * @cmd: scsi command | |
231 | * @data_direction: data direction | |
232 | * @buffer: data buffer | |
233 | * @bufflen: len of buffer | |
234 | * @sense: optional sense buffer | |
235 | * @sshdr: optional decoded sense header | |
236 | * @timeout: request timeout in seconds | |
237 | * @retries: number of times to retry request | |
238 | * @flags: flags for ->cmd_flags | |
239 | * @rq_flags: flags for ->rq_flags | |
240 | * @resid: optional residual length | |
241 | * | |
17d5363b CH |
242 | * Returns the scsi_cmnd result field if a command was executed, or a negative |
243 | * Linux error code if we didn't get that far. | |
76aaf87b CH |
244 | */ |
245 | int scsi_execute(struct scsi_device *sdev, const unsigned char *cmd, | |
33aa687d | 246 | int data_direction, void *buffer, unsigned bufflen, |
3949e2f0 CH |
247 | unsigned char *sense, struct scsi_sense_hdr *sshdr, |
248 | int timeout, int retries, u64 flags, req_flags_t rq_flags, | |
249 | int *resid) | |
39216033 JB |
250 | { |
251 | struct request *req; | |
82ed4db4 | 252 | struct scsi_request *rq; |
39216033 JB |
253 | int ret = DRIVER_ERROR << 24; |
254 | ||
039c635f | 255 | req = blk_get_request_flags(sdev->request_queue, |
aebf526b | 256 | data_direction == DMA_TO_DEVICE ? |
039c635f | 257 | REQ_OP_SCSI_OUT : REQ_OP_SCSI_IN, BLK_MQ_REQ_PREEMPT); |
a492f075 | 258 | if (IS_ERR(req)) |
bfe159a5 | 259 | return ret; |
82ed4db4 | 260 | rq = scsi_req(req); |
39216033 JB |
261 | |
262 | if (bufflen && blk_rq_map_kern(sdev->request_queue, req, | |
71baba4b | 263 | buffer, bufflen, __GFP_RECLAIM)) |
39216033 JB |
264 | goto out; |
265 | ||
82ed4db4 CH |
266 | rq->cmd_len = COMMAND_SIZE(cmd[0]); |
267 | memcpy(rq->cmd, cmd, rq->cmd_len); | |
64c7f1d1 | 268 | rq->retries = retries; |
39216033 | 269 | req->timeout = timeout; |
e8064021 | 270 | req->cmd_flags |= flags; |
039c635f | 271 | req->rq_flags |= rq_flags | RQF_QUIET; |
39216033 JB |
272 | |
273 | /* | |
274 | * head injection *required* here otherwise quiesce won't work | |
275 | */ | |
276 | blk_execute_rq(req->q, NULL, req, 1); | |
277 | ||
bdb2b8ca AS |
278 | /* |
279 | * Some devices (USB mass-storage in particular) may transfer | |
280 | * garbage data together with a residue indicating that the data | |
281 | * is invalid. Prevent the garbage from being misinterpreted | |
282 | * and prevent security leaks by zeroing out the excess data. | |
283 | */ | |
82ed4db4 CH |
284 | if (unlikely(rq->resid_len > 0 && rq->resid_len <= bufflen)) |
285 | memset(buffer + (bufflen - rq->resid_len), 0, rq->resid_len); | |
bdb2b8ca | 286 | |
f4f4e47e | 287 | if (resid) |
82ed4db4 CH |
288 | *resid = rq->resid_len; |
289 | if (sense && rq->sense_len) | |
290 | memcpy(sense, rq->sense, SCSI_SENSE_BUFFERSIZE); | |
3949e2f0 CH |
291 | if (sshdr) |
292 | scsi_normalize_sense(rq->sense, rq->sense_len, sshdr); | |
17d5363b | 293 | ret = rq->result; |
39216033 JB |
294 | out: |
295 | blk_put_request(req); | |
296 | ||
297 | return ret; | |
298 | } | |
33aa687d | 299 | EXPORT_SYMBOL(scsi_execute); |
39216033 | 300 | |
1da177e4 LT |
301 | /* |
302 | * Function: scsi_init_cmd_errh() | |
303 | * | |
304 | * Purpose: Initialize cmd fields related to error handling. | |
305 | * | |
306 | * Arguments: cmd - command that is ready to be queued. | |
307 | * | |
1da177e4 LT |
308 | * Notes: This function has the job of initializing a number of |
309 | * fields related to error handling. Typically this will | |
310 | * be called once for each command, as required. | |
311 | */ | |
631c228c | 312 | static void scsi_init_cmd_errh(struct scsi_cmnd *cmd) |
1da177e4 | 313 | { |
1da177e4 | 314 | cmd->serial_number = 0; |
30b0c37b | 315 | scsi_set_resid(cmd, 0); |
b80ca4f7 | 316 | memset(cmd->sense_buffer, 0, SCSI_SENSE_BUFFERSIZE); |
1da177e4 | 317 | if (cmd->cmd_len == 0) |
db4742dd | 318 | cmd->cmd_len = scsi_command_size(cmd->cmnd); |
1da177e4 LT |
319 | } |
320 | ||
af2f8f5f BVA |
321 | /* |
322 | * Decrement the host_busy counter and wake up the error handler if necessary. | |
323 | * Avoid as follows that the error handler is not woken up if shost->host_busy | |
324 | * == shost->host_failed: use call_rcu() in scsi_eh_scmd_add() in combination | |
325 | * with an RCU read lock in this function to ensure that this function in its | |
326 | * entirety either finishes before scsi_eh_scmd_add() increases the | |
327 | * host_failed counter or that it notices the shost state change made by | |
328 | * scsi_eh_scmd_add(). | |
329 | */ | |
330 | static void scsi_dec_host_busy(struct Scsi_Host *shost) | |
1da177e4 | 331 | { |
1da177e4 LT |
332 | unsigned long flags; |
333 | ||
af2f8f5f | 334 | rcu_read_lock(); |
74665016 | 335 | atomic_dec(&shost->host_busy); |
af2f8f5f | 336 | if (unlikely(scsi_host_in_recovery(shost))) { |
74665016 | 337 | spin_lock_irqsave(shost->host_lock, flags); |
af2f8f5f BVA |
338 | if (shost->host_failed || shost->host_eh_scheduled) |
339 | scsi_eh_wakeup(shost); | |
74665016 CH |
340 | spin_unlock_irqrestore(shost->host_lock, flags); |
341 | } | |
af2f8f5f BVA |
342 | rcu_read_unlock(); |
343 | } | |
344 | ||
345 | void scsi_device_unbusy(struct scsi_device *sdev) | |
346 | { | |
347 | struct Scsi_Host *shost = sdev->host; | |
348 | struct scsi_target *starget = scsi_target(sdev); | |
349 | ||
350 | scsi_dec_host_busy(shost); | |
351 | ||
352 | if (starget->can_queue > 0) | |
353 | atomic_dec(&starget->target_busy); | |
74665016 | 354 | |
71e75c97 | 355 | atomic_dec(&sdev->device_busy); |
1da177e4 LT |
356 | } |
357 | ||
d285203c CH |
358 | static void scsi_kick_queue(struct request_queue *q) |
359 | { | |
360 | if (q->mq_ops) | |
361 | blk_mq_start_hw_queues(q); | |
362 | else | |
363 | blk_run_queue(q); | |
364 | } | |
365 | ||
1da177e4 LT |
366 | /* |
367 | * Called for single_lun devices on IO completion. Clear starget_sdev_user, | |
368 | * and call blk_run_queue for all the scsi_devices on the target - | |
369 | * including current_sdev first. | |
370 | * | |
371 | * Called with *no* scsi locks held. | |
372 | */ | |
373 | static void scsi_single_lun_run(struct scsi_device *current_sdev) | |
374 | { | |
375 | struct Scsi_Host *shost = current_sdev->host; | |
376 | struct scsi_device *sdev, *tmp; | |
377 | struct scsi_target *starget = scsi_target(current_sdev); | |
378 | unsigned long flags; | |
379 | ||
380 | spin_lock_irqsave(shost->host_lock, flags); | |
381 | starget->starget_sdev_user = NULL; | |
382 | spin_unlock_irqrestore(shost->host_lock, flags); | |
383 | ||
384 | /* | |
385 | * Call blk_run_queue for all LUNs on the target, starting with | |
386 | * current_sdev. We race with others (to set starget_sdev_user), | |
387 | * but in most cases, we will be first. Ideally, each LU on the | |
388 | * target would get some limited time or requests on the target. | |
389 | */ | |
d285203c | 390 | scsi_kick_queue(current_sdev->request_queue); |
1da177e4 LT |
391 | |
392 | spin_lock_irqsave(shost->host_lock, flags); | |
393 | if (starget->starget_sdev_user) | |
394 | goto out; | |
395 | list_for_each_entry_safe(sdev, tmp, &starget->devices, | |
396 | same_target_siblings) { | |
397 | if (sdev == current_sdev) | |
398 | continue; | |
399 | if (scsi_device_get(sdev)) | |
400 | continue; | |
401 | ||
402 | spin_unlock_irqrestore(shost->host_lock, flags); | |
d285203c | 403 | scsi_kick_queue(sdev->request_queue); |
1da177e4 LT |
404 | spin_lock_irqsave(shost->host_lock, flags); |
405 | ||
406 | scsi_device_put(sdev); | |
407 | } | |
408 | out: | |
409 | spin_unlock_irqrestore(shost->host_lock, flags); | |
410 | } | |
411 | ||
cd9070c9 | 412 | static inline bool scsi_device_is_busy(struct scsi_device *sdev) |
9d112517 | 413 | { |
cd9070c9 CH |
414 | if (atomic_read(&sdev->device_busy) >= sdev->queue_depth) |
415 | return true; | |
416 | if (atomic_read(&sdev->device_blocked) > 0) | |
417 | return true; | |
418 | return false; | |
9d112517 KU |
419 | } |
420 | ||
cd9070c9 | 421 | static inline bool scsi_target_is_busy(struct scsi_target *starget) |
f0c0a376 | 422 | { |
2ccbb008 CH |
423 | if (starget->can_queue > 0) { |
424 | if (atomic_read(&starget->target_busy) >= starget->can_queue) | |
425 | return true; | |
426 | if (atomic_read(&starget->target_blocked) > 0) | |
427 | return true; | |
428 | } | |
cd9070c9 | 429 | return false; |
f0c0a376 MC |
430 | } |
431 | ||
cd9070c9 | 432 | static inline bool scsi_host_is_busy(struct Scsi_Host *shost) |
9d112517 | 433 | { |
cd9070c9 CH |
434 | if (shost->can_queue > 0 && |
435 | atomic_read(&shost->host_busy) >= shost->can_queue) | |
436 | return true; | |
437 | if (atomic_read(&shost->host_blocked) > 0) | |
438 | return true; | |
439 | if (shost->host_self_blocked) | |
440 | return true; | |
441 | return false; | |
9d112517 KU |
442 | } |
443 | ||
21a05df5 | 444 | static void scsi_starved_list_run(struct Scsi_Host *shost) |
1da177e4 | 445 | { |
2a3a59e5 | 446 | LIST_HEAD(starved_list); |
21a05df5 | 447 | struct scsi_device *sdev; |
1da177e4 LT |
448 | unsigned long flags; |
449 | ||
1da177e4 | 450 | spin_lock_irqsave(shost->host_lock, flags); |
2a3a59e5 MC |
451 | list_splice_init(&shost->starved_list, &starved_list); |
452 | ||
453 | while (!list_empty(&starved_list)) { | |
e2eb7244 JB |
454 | struct request_queue *slq; |
455 | ||
1da177e4 LT |
456 | /* |
457 | * As long as shost is accepting commands and we have | |
458 | * starved queues, call blk_run_queue. scsi_request_fn | |
459 | * drops the queue_lock and can add us back to the | |
460 | * starved_list. | |
461 | * | |
462 | * host_lock protects the starved_list and starved_entry. | |
463 | * scsi_request_fn must get the host_lock before checking | |
464 | * or modifying starved_list or starved_entry. | |
465 | */ | |
2a3a59e5 | 466 | if (scsi_host_is_busy(shost)) |
f0c0a376 | 467 | break; |
f0c0a376 | 468 | |
2a3a59e5 MC |
469 | sdev = list_entry(starved_list.next, |
470 | struct scsi_device, starved_entry); | |
471 | list_del_init(&sdev->starved_entry); | |
f0c0a376 MC |
472 | if (scsi_target_is_busy(scsi_target(sdev))) { |
473 | list_move_tail(&sdev->starved_entry, | |
474 | &shost->starved_list); | |
475 | continue; | |
476 | } | |
477 | ||
e2eb7244 JB |
478 | /* |
479 | * Once we drop the host lock, a racing scsi_remove_device() | |
480 | * call may remove the sdev from the starved list and destroy | |
481 | * it and the queue. Mitigate by taking a reference to the | |
482 | * queue and never touching the sdev again after we drop the | |
483 | * host lock. Note: if __scsi_remove_device() invokes | |
484 | * blk_cleanup_queue() before the queue is run from this | |
485 | * function then blk_run_queue() will return immediately since | |
486 | * blk_cleanup_queue() marks the queue with QUEUE_FLAG_DYING. | |
487 | */ | |
488 | slq = sdev->request_queue; | |
489 | if (!blk_get_queue(slq)) | |
490 | continue; | |
491 | spin_unlock_irqrestore(shost->host_lock, flags); | |
492 | ||
d285203c | 493 | scsi_kick_queue(slq); |
e2eb7244 JB |
494 | blk_put_queue(slq); |
495 | ||
496 | spin_lock_irqsave(shost->host_lock, flags); | |
1da177e4 | 497 | } |
2a3a59e5 MC |
498 | /* put any unprocessed entries back */ |
499 | list_splice(&starved_list, &shost->starved_list); | |
1da177e4 | 500 | spin_unlock_irqrestore(shost->host_lock, flags); |
21a05df5 CH |
501 | } |
502 | ||
503 | /* | |
504 | * Function: scsi_run_queue() | |
505 | * | |
506 | * Purpose: Select a proper request queue to serve next | |
507 | * | |
508 | * Arguments: q - last request's queue | |
509 | * | |
510 | * Returns: Nothing | |
511 | * | |
512 | * Notes: The previous command was completely finished, start | |
513 | * a new one if possible. | |
514 | */ | |
515 | static void scsi_run_queue(struct request_queue *q) | |
516 | { | |
517 | struct scsi_device *sdev = q->queuedata; | |
518 | ||
519 | if (scsi_target(sdev)->single_lun) | |
520 | scsi_single_lun_run(sdev); | |
521 | if (!list_empty(&sdev->host->starved_list)) | |
522 | scsi_starved_list_run(sdev->host); | |
1da177e4 | 523 | |
d285203c | 524 | if (q->mq_ops) |
36e3cf27 | 525 | blk_mq_run_hw_queues(q, false); |
d285203c CH |
526 | else |
527 | blk_run_queue(q); | |
1da177e4 LT |
528 | } |
529 | ||
9937a5e2 JA |
530 | void scsi_requeue_run_queue(struct work_struct *work) |
531 | { | |
532 | struct scsi_device *sdev; | |
533 | struct request_queue *q; | |
534 | ||
535 | sdev = container_of(work, struct scsi_device, requeue_work); | |
536 | q = sdev->request_queue; | |
537 | scsi_run_queue(q); | |
538 | } | |
539 | ||
1da177e4 LT |
540 | /* |
541 | * Function: scsi_requeue_command() | |
542 | * | |
543 | * Purpose: Handle post-processing of completed commands. | |
544 | * | |
545 | * Arguments: q - queue to operate on | |
546 | * cmd - command that may need to be requeued. | |
547 | * | |
548 | * Returns: Nothing | |
549 | * | |
550 | * Notes: After command completion, there may be blocks left | |
551 | * over which weren't finished by the previous command | |
552 | * this can be for a number of reasons - the main one is | |
553 | * I/O errors in the middle of the request, in which case | |
554 | * we need to request the blocks that come after the bad | |
555 | * sector. | |
e91442b6 | 556 | * Notes: Upon return, cmd is a stale pointer. |
1da177e4 LT |
557 | */ |
558 | static void scsi_requeue_command(struct request_queue *q, struct scsi_cmnd *cmd) | |
559 | { | |
940f5d47 | 560 | struct scsi_device *sdev = cmd->device; |
e91442b6 | 561 | struct request *req = cmd->request; |
283369cc TH |
562 | unsigned long flags; |
563 | ||
283369cc | 564 | spin_lock_irqsave(q->queue_lock, flags); |
134997a0 CH |
565 | blk_unprep_request(req); |
566 | req->special = NULL; | |
567 | scsi_put_command(cmd); | |
e91442b6 | 568 | blk_requeue_request(q, req); |
283369cc | 569 | spin_unlock_irqrestore(q->queue_lock, flags); |
1da177e4 LT |
570 | |
571 | scsi_run_queue(q); | |
940f5d47 BVA |
572 | |
573 | put_device(&sdev->sdev_gendev); | |
1da177e4 LT |
574 | } |
575 | ||
1da177e4 LT |
576 | void scsi_run_host_queues(struct Scsi_Host *shost) |
577 | { | |
578 | struct scsi_device *sdev; | |
579 | ||
580 | shost_for_each_device(sdev, shost) | |
581 | scsi_run_queue(sdev->request_queue); | |
582 | } | |
583 | ||
d285203c CH |
584 | static void scsi_uninit_cmd(struct scsi_cmnd *cmd) |
585 | { | |
57292b58 | 586 | if (!blk_rq_is_passthrough(cmd->request)) { |
d285203c CH |
587 | struct scsi_driver *drv = scsi_cmd_to_driver(cmd); |
588 | ||
589 | if (drv->uninit_command) | |
590 | drv->uninit_command(cmd); | |
591 | } | |
592 | } | |
593 | ||
594 | static void scsi_mq_free_sgtables(struct scsi_cmnd *cmd) | |
595 | { | |
91dbc08d ML |
596 | struct scsi_data_buffer *sdb; |
597 | ||
d285203c | 598 | if (cmd->sdb.table.nents) |
001d63be | 599 | sg_free_table_chained(&cmd->sdb.table, true); |
91dbc08d ML |
600 | if (cmd->request->next_rq) { |
601 | sdb = cmd->request->next_rq->special; | |
602 | if (sdb) | |
001d63be | 603 | sg_free_table_chained(&sdb->table, true); |
91dbc08d | 604 | } |
d285203c | 605 | if (scsi_prot_sg_count(cmd)) |
001d63be | 606 | sg_free_table_chained(&cmd->prot_sdb->table, true); |
d285203c CH |
607 | } |
608 | ||
609 | static void scsi_mq_uninit_cmd(struct scsi_cmnd *cmd) | |
610 | { | |
d285203c CH |
611 | scsi_mq_free_sgtables(cmd); |
612 | scsi_uninit_cmd(cmd); | |
2dd6fb59 | 613 | scsi_del_cmd_from_list(cmd); |
d285203c CH |
614 | } |
615 | ||
1da177e4 LT |
616 | /* |
617 | * Function: scsi_release_buffers() | |
618 | * | |
c682adf3 | 619 | * Purpose: Free resources allocate for a scsi_command. |
1da177e4 LT |
620 | * |
621 | * Arguments: cmd - command that we are bailing. | |
622 | * | |
623 | * Lock status: Assumed that no lock is held upon entry. | |
624 | * | |
625 | * Returns: Nothing | |
626 | * | |
627 | * Notes: In the event that an upper level driver rejects a | |
628 | * command, we must release resources allocated during | |
629 | * the __init_io() function. Primarily this would involve | |
c682adf3 | 630 | * the scatter-gather table. |
1da177e4 | 631 | */ |
f1bea55d | 632 | static void scsi_release_buffers(struct scsi_cmnd *cmd) |
1da177e4 | 633 | { |
c682adf3 | 634 | if (cmd->sdb.table.nents) |
001d63be | 635 | sg_free_table_chained(&cmd->sdb.table, false); |
c682adf3 CH |
636 | |
637 | memset(&cmd->sdb, 0, sizeof(cmd->sdb)); | |
638 | ||
639 | if (scsi_prot_sg_count(cmd)) | |
001d63be | 640 | sg_free_table_chained(&cmd->prot_sdb->table, false); |
1da177e4 LT |
641 | } |
642 | ||
c682adf3 CH |
643 | static void scsi_release_bidi_buffers(struct scsi_cmnd *cmd) |
644 | { | |
645 | struct scsi_data_buffer *bidi_sdb = cmd->request->next_rq->special; | |
646 | ||
001d63be | 647 | sg_free_table_chained(&bidi_sdb->table, false); |
c682adf3 CH |
648 | kmem_cache_free(scsi_sdb_cache, bidi_sdb); |
649 | cmd->request->next_rq->special = NULL; | |
650 | } | |
651 | ||
2a842aca | 652 | static bool scsi_end_request(struct request *req, blk_status_t error, |
f6d47e74 CH |
653 | unsigned int bytes, unsigned int bidi_bytes) |
654 | { | |
bed2213d | 655 | struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req); |
f6d47e74 CH |
656 | struct scsi_device *sdev = cmd->device; |
657 | struct request_queue *q = sdev->request_queue; | |
f6d47e74 CH |
658 | |
659 | if (blk_update_request(req, error, bytes)) | |
660 | return true; | |
661 | ||
662 | /* Bidi request must be completed as a whole */ | |
663 | if (unlikely(bidi_bytes) && | |
664 | blk_update_request(req->next_rq, error, bidi_bytes)) | |
665 | return true; | |
666 | ||
667 | if (blk_queue_add_random(q)) | |
668 | add_disk_randomness(req->rq_disk); | |
669 | ||
64104f70 BVA |
670 | if (!blk_rq_is_scsi(req)) { |
671 | WARN_ON_ONCE(!(cmd->flags & SCMD_INITIALIZED)); | |
672 | cmd->flags &= ~SCMD_INITIALIZED; | |
dbe55f8b | 673 | destroy_rcu_head(&cmd->rcu); |
64104f70 BVA |
674 | } |
675 | ||
d285203c CH |
676 | if (req->mq_ctx) { |
677 | /* | |
c8a446ad | 678 | * In the MQ case the command gets freed by __blk_mq_end_request, |
d285203c CH |
679 | * so we have to do all cleanup that depends on it earlier. |
680 | * | |
681 | * We also can't kick the queues from irq context, so we | |
682 | * will have to defer it to a workqueue. | |
683 | */ | |
684 | scsi_mq_uninit_cmd(cmd); | |
685 | ||
c8a446ad | 686 | __blk_mq_end_request(req, error); |
d285203c CH |
687 | |
688 | if (scsi_target(sdev)->single_lun || | |
689 | !list_empty(&sdev->host->starved_list)) | |
690 | kblockd_schedule_work(&sdev->requeue_work); | |
691 | else | |
36e3cf27 | 692 | blk_mq_run_hw_queues(q, true); |
d285203c CH |
693 | } else { |
694 | unsigned long flags; | |
695 | ||
f81426a8 DG |
696 | if (bidi_bytes) |
697 | scsi_release_bidi_buffers(cmd); | |
e9c787e6 CH |
698 | scsi_release_buffers(cmd); |
699 | scsi_put_command(cmd); | |
f81426a8 | 700 | |
d285203c CH |
701 | spin_lock_irqsave(q->queue_lock, flags); |
702 | blk_finish_request(req, error); | |
703 | spin_unlock_irqrestore(q->queue_lock, flags); | |
704 | ||
bb3ec62a | 705 | scsi_run_queue(q); |
d285203c | 706 | } |
f6d47e74 | 707 | |
bb3ec62a | 708 | put_device(&sdev->sdev_gendev); |
f6d47e74 CH |
709 | return false; |
710 | } | |
711 | ||
0f7f6234 HR |
712 | /** |
713 | * __scsi_error_from_host_byte - translate SCSI error code into errno | |
714 | * @cmd: SCSI command (unused) | |
715 | * @result: scsi error code | |
716 | * | |
2a842aca | 717 | * Translate SCSI error code into block errors. |
0f7f6234 | 718 | */ |
2a842aca CH |
719 | static blk_status_t __scsi_error_from_host_byte(struct scsi_cmnd *cmd, |
720 | int result) | |
63583cca | 721 | { |
2a842aca | 722 | switch (host_byte(result)) { |
63583cca | 723 | case DID_TRANSPORT_FAILFAST: |
2a842aca | 724 | return BLK_STS_TRANSPORT; |
63583cca | 725 | case DID_TARGET_FAILURE: |
2082ebc4 | 726 | set_host_byte(cmd, DID_OK); |
2a842aca | 727 | return BLK_STS_TARGET; |
63583cca | 728 | case DID_NEXUS_FAILURE: |
2a842aca | 729 | return BLK_STS_NEXUS; |
a9d6ceb8 HR |
730 | case DID_ALLOC_FAILURE: |
731 | set_host_byte(cmd, DID_OK); | |
2a842aca | 732 | return BLK_STS_NOSPC; |
7e782af5 HR |
733 | case DID_MEDIUM_ERROR: |
734 | set_host_byte(cmd, DID_OK); | |
2a842aca | 735 | return BLK_STS_MEDIUM; |
63583cca | 736 | default: |
2a842aca | 737 | return BLK_STS_IOERR; |
63583cca | 738 | } |
63583cca HR |
739 | } |
740 | ||
1da177e4 LT |
741 | /* |
742 | * Function: scsi_io_completion() | |
743 | * | |
744 | * Purpose: Completion processing for block device I/O requests. | |
745 | * | |
746 | * Arguments: cmd - command that is finished. | |
747 | * | |
748 | * Lock status: Assumed that no lock is held upon entry. | |
749 | * | |
750 | * Returns: Nothing | |
751 | * | |
bc85dc50 CH |
752 | * Notes: We will finish off the specified number of sectors. If we |
753 | * are done, the command block will be released and the queue | |
754 | * function will be goosed. If we are not done then we have to | |
b60af5b0 | 755 | * figure out what to do next: |
1da177e4 | 756 | * |
b60af5b0 AS |
757 | * a) We can call scsi_requeue_command(). The request |
758 | * will be unprepared and put back on the queue. Then | |
759 | * a new command will be created for it. This should | |
760 | * be used if we made forward progress, or if we want | |
761 | * to switch from READ(10) to READ(6) for example. | |
1da177e4 | 762 | * |
bc85dc50 | 763 | * b) We can call __scsi_queue_insert(). The request will |
b60af5b0 AS |
764 | * be put back on the queue and retried using the same |
765 | * command as before, possibly after a delay. | |
766 | * | |
f6d47e74 | 767 | * c) We can call scsi_end_request() with -EIO to fail |
b60af5b0 | 768 | * the remainder of the request. |
1da177e4 | 769 | */ |
03aba2f7 | 770 | void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes) |
1da177e4 LT |
771 | { |
772 | int result = cmd->result; | |
165125e1 | 773 | struct request_queue *q = cmd->device->request_queue; |
1da177e4 | 774 | struct request *req = cmd->request; |
2a842aca | 775 | blk_status_t error = BLK_STS_OK; |
1da177e4 | 776 | struct scsi_sense_hdr sshdr; |
4753cbc0 | 777 | bool sense_valid = false; |
c11c004b | 778 | int sense_deferred = 0, level = 0; |
b60af5b0 AS |
779 | enum {ACTION_FAIL, ACTION_REPREP, ACTION_RETRY, |
780 | ACTION_DELAYED_RETRY} action; | |
ee60b2c5 | 781 | unsigned long wait_for = (cmd->allowed + 1) * req->timeout; |
1da177e4 | 782 | |
1da177e4 LT |
783 | if (result) { |
784 | sense_valid = scsi_command_normalize_sense(cmd, &sshdr); | |
785 | if (sense_valid) | |
786 | sense_deferred = scsi_sense_is_deferred(&sshdr); | |
787 | } | |
631c228c | 788 | |
57292b58 | 789 | if (blk_rq_is_passthrough(req)) { |
1da177e4 | 790 | if (result) { |
82ed4db4 | 791 | if (sense_valid) { |
1da177e4 LT |
792 | /* |
793 | * SG_IO wants current and deferred errors | |
794 | */ | |
82ed4db4 CH |
795 | scsi_req(req)->sense_len = |
796 | min(8 + cmd->sense_buffer[7], | |
797 | SCSI_SENSE_BUFFERSIZE); | |
1da177e4 | 798 | } |
fa8e36c3 | 799 | if (!sense_deferred) |
63583cca | 800 | error = __scsi_error_from_host_byte(cmd, result); |
b22f687d | 801 | } |
27c41973 MS |
802 | /* |
803 | * __scsi_error_from_host_byte may have reset the host_byte | |
804 | */ | |
17d5363b | 805 | scsi_req(req)->result = cmd->result; |
82ed4db4 | 806 | scsi_req(req)->resid_len = scsi_get_resid(cmd); |
e6bb7a96 | 807 | |
6f9a35e2 | 808 | if (scsi_bidi_cmnd(cmd)) { |
e6bb7a96 FT |
809 | /* |
810 | * Bidi commands Must be complete as a whole, | |
811 | * both sides at once. | |
812 | */ | |
82ed4db4 | 813 | scsi_req(req->next_rq)->resid_len = scsi_in(cmd)->resid; |
2a842aca | 814 | if (scsi_end_request(req, BLK_STS_OK, blk_rq_bytes(req), |
f6d47e74 CH |
815 | blk_rq_bytes(req->next_rq))) |
816 | BUG(); | |
6f9a35e2 BH |
817 | return; |
818 | } | |
89fb4cd1 JB |
819 | } else if (blk_rq_bytes(req) == 0 && result && !sense_deferred) { |
820 | /* | |
aebf526b | 821 | * Flush commands do not transfers any data, and thus cannot use |
89fb4cd1 JB |
822 | * good_bytes != blk_rq_bytes(req) as the signal for an error. |
823 | * This sets the error explicitly for the problem case. | |
824 | */ | |
825 | error = __scsi_error_from_host_byte(cmd, result); | |
1da177e4 LT |
826 | } |
827 | ||
57292b58 | 828 | /* no bidi support for !blk_rq_is_passthrough yet */ |
33659ebb | 829 | BUG_ON(blk_bidi_rq(req)); |
30b0c37b | 830 | |
1da177e4 LT |
831 | /* |
832 | * Next deal with any sectors which we were able to correctly | |
833 | * handle. | |
834 | */ | |
91921e01 HR |
835 | SCSI_LOG_HLCOMPLETE(1, scmd_printk(KERN_INFO, cmd, |
836 | "%u sectors total, %d bytes done.\n", | |
837 | blk_rq_sectors(req), good_bytes)); | |
d6b0c537 | 838 | |
a9bddd74 | 839 | /* |
aebf526b CH |
840 | * Recovered errors need reporting, but they're always treated as |
841 | * success, so fiddle the result code here. For passthrough requests | |
17d5363b | 842 | * we already took a copy of the original into sreq->result which |
a9bddd74 JB |
843 | * is what gets returned to the user |
844 | */ | |
e7efe593 DG |
845 | if (sense_valid && (sshdr.sense_key == RECOVERED_ERROR)) { |
846 | /* if ATA PASS-THROUGH INFORMATION AVAILABLE skip | |
847 | * print since caller wants ATA registers. Only occurs on | |
848 | * SCSI ATA PASS_THROUGH commands when CK_COND=1 | |
849 | */ | |
850 | if ((sshdr.asc == 0x0) && (sshdr.ascq == 0x1d)) | |
851 | ; | |
e8064021 | 852 | else if (!(req->rq_flags & RQF_QUIET)) |
d811b848 | 853 | scsi_print_sense(cmd); |
a9bddd74 | 854 | result = 0; |
aebf526b | 855 | /* for passthrough error may be set */ |
2a842aca | 856 | error = BLK_STS_OK; |
a9bddd74 | 857 | } |
315de539 DG |
858 | /* |
859 | * Another corner case: the SCSI status byte is non-zero but 'good'. | |
860 | * Example: PRE-FETCH command returns SAM_STAT_CONDITION_MET when | |
861 | * it is able to fit nominated LBs in its cache (and SAM_STAT_GOOD | |
862 | * if it can't fit). Treat SAM_STAT_CONDITION_MET and the related | |
863 | * intermediate statuses (both obsolete in SAM-4) as good. | |
864 | */ | |
865 | if (status_byte(result) && scsi_status_is_good(result)) { | |
866 | result = 0; | |
867 | error = BLK_STS_OK; | |
868 | } | |
a9bddd74 JB |
869 | |
870 | /* | |
a621bac3 JB |
871 | * special case: failed zero length commands always need to |
872 | * drop down into the retry code. Otherwise, if we finished | |
873 | * all bytes in the request we are done now. | |
d6b0c537 | 874 | */ |
a621bac3 JB |
875 | if (!(blk_rq_bytes(req) == 0 && error) && |
876 | !scsi_end_request(req, error, good_bytes, 0)) | |
f6d47e74 | 877 | return; |
bc85dc50 CH |
878 | |
879 | /* | |
880 | * Kill remainder if no retrys. | |
881 | */ | |
882 | if (error && scsi_noretry_cmd(cmd)) { | |
f6d47e74 CH |
883 | if (scsi_end_request(req, error, blk_rq_bytes(req), 0)) |
884 | BUG(); | |
885 | return; | |
bc85dc50 CH |
886 | } |
887 | ||
888 | /* | |
889 | * If there had been no error, but we have leftover bytes in the | |
890 | * requeues just queue the command up again. | |
d6b0c537 | 891 | */ |
bc85dc50 CH |
892 | if (result == 0) |
893 | goto requeue; | |
03aba2f7 | 894 | |
63583cca | 895 | error = __scsi_error_from_host_byte(cmd, result); |
3e695f89 | 896 | |
b60af5b0 AS |
897 | if (host_byte(result) == DID_RESET) { |
898 | /* Third party bus reset or reset for error recovery | |
899 | * reasons. Just retry the command and see what | |
900 | * happens. | |
901 | */ | |
902 | action = ACTION_RETRY; | |
903 | } else if (sense_valid && !sense_deferred) { | |
1da177e4 LT |
904 | switch (sshdr.sense_key) { |
905 | case UNIT_ATTENTION: | |
906 | if (cmd->device->removable) { | |
03aba2f7 | 907 | /* Detected disc change. Set a bit |
1da177e4 LT |
908 | * and quietly refuse further access. |
909 | */ | |
910 | cmd->device->changed = 1; | |
b60af5b0 | 911 | action = ACTION_FAIL; |
1da177e4 | 912 | } else { |
03aba2f7 LT |
913 | /* Must have been a power glitch, or a |
914 | * bus reset. Could not have been a | |
915 | * media change, so we just retry the | |
b60af5b0 | 916 | * command and see what happens. |
03aba2f7 | 917 | */ |
b60af5b0 | 918 | action = ACTION_RETRY; |
1da177e4 LT |
919 | } |
920 | break; | |
921 | case ILLEGAL_REQUEST: | |
03aba2f7 LT |
922 | /* If we had an ILLEGAL REQUEST returned, then |
923 | * we may have performed an unsupported | |
924 | * command. The only thing this should be | |
925 | * would be a ten byte read where only a six | |
926 | * byte read was supported. Also, on a system | |
927 | * where READ CAPACITY failed, we may have | |
928 | * read past the end of the disk. | |
929 | */ | |
26a68019 JA |
930 | if ((cmd->device->use_10_for_rw && |
931 | sshdr.asc == 0x20 && sshdr.ascq == 0x00) && | |
1da177e4 LT |
932 | (cmd->cmnd[0] == READ_10 || |
933 | cmd->cmnd[0] == WRITE_10)) { | |
b60af5b0 | 934 | /* This will issue a new 6-byte command. */ |
1da177e4 | 935 | cmd->device->use_10_for_rw = 0; |
b60af5b0 | 936 | action = ACTION_REPREP; |
3e695f89 | 937 | } else if (sshdr.asc == 0x10) /* DIX */ { |
3e695f89 | 938 | action = ACTION_FAIL; |
2a842aca | 939 | error = BLK_STS_PROTECTION; |
c98a0eb0 | 940 | /* INVALID COMMAND OPCODE or INVALID FIELD IN CDB */ |
5db44863 | 941 | } else if (sshdr.asc == 0x20 || sshdr.asc == 0x24) { |
c98a0eb0 | 942 | action = ACTION_FAIL; |
2a842aca | 943 | error = BLK_STS_TARGET; |
b60af5b0 AS |
944 | } else |
945 | action = ACTION_FAIL; | |
946 | break; | |
511e44f4 | 947 | case ABORTED_COMMAND: |
126c0982 | 948 | action = ACTION_FAIL; |
e6c11dbb | 949 | if (sshdr.asc == 0x10) /* DIF */ |
2a842aca | 950 | error = BLK_STS_PROTECTION; |
1da177e4 LT |
951 | break; |
952 | case NOT_READY: | |
03aba2f7 | 953 | /* If the device is in the process of becoming |
f3e93f73 | 954 | * ready, or has a temporary blockage, retry. |
1da177e4 | 955 | */ |
f3e93f73 JB |
956 | if (sshdr.asc == 0x04) { |
957 | switch (sshdr.ascq) { | |
958 | case 0x01: /* becoming ready */ | |
959 | case 0x04: /* format in progress */ | |
960 | case 0x05: /* rebuild in progress */ | |
961 | case 0x06: /* recalculation in progress */ | |
962 | case 0x07: /* operation in progress */ | |
963 | case 0x08: /* Long write in progress */ | |
964 | case 0x09: /* self test in progress */ | |
d8705f11 | 965 | case 0x14: /* space allocation in progress */ |
b60af5b0 | 966 | action = ACTION_DELAYED_RETRY; |
f3e93f73 | 967 | break; |
3dbf6a54 | 968 | default: |
3dbf6a54 AS |
969 | action = ACTION_FAIL; |
970 | break; | |
f3e93f73 | 971 | } |
e6c11dbb | 972 | } else |
b60af5b0 | 973 | action = ACTION_FAIL; |
b60af5b0 | 974 | break; |
1da177e4 | 975 | case VOLUME_OVERFLOW: |
03aba2f7 | 976 | /* See SSC3rXX or current. */ |
b60af5b0 AS |
977 | action = ACTION_FAIL; |
978 | break; | |
1da177e4 | 979 | default: |
b60af5b0 | 980 | action = ACTION_FAIL; |
1da177e4 LT |
981 | break; |
982 | } | |
e6c11dbb | 983 | } else |
b60af5b0 | 984 | action = ACTION_FAIL; |
b60af5b0 | 985 | |
ee60b2c5 | 986 | if (action != ACTION_FAIL && |
e6c11dbb | 987 | time_before(cmd->jiffies_at_alloc + wait_for, jiffies)) |
ee60b2c5 | 988 | action = ACTION_FAIL; |
ee60b2c5 | 989 | |
b60af5b0 AS |
990 | switch (action) { |
991 | case ACTION_FAIL: | |
992 | /* Give up and fail the remainder of the request */ | |
e8064021 | 993 | if (!(req->rq_flags & RQF_QUIET)) { |
f1569ff1 HR |
994 | static DEFINE_RATELIMIT_STATE(_rs, |
995 | DEFAULT_RATELIMIT_INTERVAL, | |
996 | DEFAULT_RATELIMIT_BURST); | |
997 | ||
998 | if (unlikely(scsi_logging_level)) | |
999 | level = SCSI_LOG_LEVEL(SCSI_LOG_MLCOMPLETE_SHIFT, | |
1000 | SCSI_LOG_MLCOMPLETE_BITS); | |
1001 | ||
1002 | /* | |
1003 | * if logging is enabled the failure will be printed | |
1004 | * in scsi_log_completion(), so avoid duplicate messages | |
1005 | */ | |
1006 | if (!level && __ratelimit(&_rs)) { | |
1007 | scsi_print_result(cmd, NULL, FAILED); | |
1008 | if (driver_byte(result) & DRIVER_SENSE) | |
1009 | scsi_print_sense(cmd); | |
1010 | scsi_print_command(cmd); | |
1011 | } | |
3173d8c3 | 1012 | } |
f6d47e74 CH |
1013 | if (!scsi_end_request(req, error, blk_rq_err_bytes(req), 0)) |
1014 | return; | |
bc85dc50 | 1015 | /*FALLTHRU*/ |
b60af5b0 | 1016 | case ACTION_REPREP: |
bc85dc50 | 1017 | requeue: |
b60af5b0 AS |
1018 | /* Unprep the request and put it back at the head of the queue. |
1019 | * A new command will be prepared and issued. | |
1020 | */ | |
d285203c | 1021 | if (q->mq_ops) { |
d285203c CH |
1022 | scsi_mq_requeue_cmd(cmd); |
1023 | } else { | |
1024 | scsi_release_buffers(cmd); | |
1025 | scsi_requeue_command(q, cmd); | |
1026 | } | |
b60af5b0 AS |
1027 | break; |
1028 | case ACTION_RETRY: | |
1029 | /* Retry the same command immediately */ | |
4f5299ac | 1030 | __scsi_queue_insert(cmd, SCSI_MLQUEUE_EH_RETRY, 0); |
b60af5b0 AS |
1031 | break; |
1032 | case ACTION_DELAYED_RETRY: | |
1033 | /* Retry the same command after a delay */ | |
4f5299ac | 1034 | __scsi_queue_insert(cmd, SCSI_MLQUEUE_DEVICE_BUSY, 0); |
b60af5b0 | 1035 | break; |
1da177e4 LT |
1036 | } |
1037 | } | |
1da177e4 | 1038 | |
3c356bde | 1039 | static int scsi_init_sgtable(struct request *req, struct scsi_data_buffer *sdb) |
1da177e4 | 1040 | { |
6f9a35e2 | 1041 | int count; |
1da177e4 LT |
1042 | |
1043 | /* | |
3b003157 | 1044 | * If sg table allocation fails, requeue request later. |
1da177e4 | 1045 | */ |
f9d03f96 CH |
1046 | if (unlikely(sg_alloc_table_chained(&sdb->table, |
1047 | blk_rq_nr_phys_segments(req), sdb->table.sgl))) | |
1da177e4 | 1048 | return BLKPREP_DEFER; |
1da177e4 | 1049 | |
1da177e4 LT |
1050 | /* |
1051 | * Next, walk the list, and fill in the addresses and sizes of | |
1052 | * each segment. | |
1053 | */ | |
30b0c37b BH |
1054 | count = blk_rq_map_sg(req->q, req, sdb->table.sgl); |
1055 | BUG_ON(count > sdb->table.nents); | |
1056 | sdb->table.nents = count; | |
fd102b12 | 1057 | sdb->length = blk_rq_payload_bytes(req); |
4a03d90e | 1058 | return BLKPREP_OK; |
1da177e4 | 1059 | } |
6f9a35e2 BH |
1060 | |
1061 | /* | |
1062 | * Function: scsi_init_io() | |
1063 | * | |
1064 | * Purpose: SCSI I/O initialize function. | |
1065 | * | |
1066 | * Arguments: cmd - Command descriptor we wish to initialize | |
1067 | * | |
1068 | * Returns: 0 on success | |
1069 | * BLKPREP_DEFER if the failure is retryable | |
1070 | * BLKPREP_KILL if the failure is fatal | |
1071 | */ | |
3c356bde | 1072 | int scsi_init_io(struct scsi_cmnd *cmd) |
6f9a35e2 | 1073 | { |
5e012aad | 1074 | struct scsi_device *sdev = cmd->device; |
13f05c8d | 1075 | struct request *rq = cmd->request; |
d285203c | 1076 | bool is_mq = (rq->mq_ctx != NULL); |
e7661a8e | 1077 | int error = BLKPREP_KILL; |
13f05c8d | 1078 | |
fd3fc0b4 | 1079 | if (WARN_ON_ONCE(!blk_rq_nr_phys_segments(rq))) |
e7661a8e | 1080 | goto err_exit; |
635d98b1 | 1081 | |
3c356bde | 1082 | error = scsi_init_sgtable(rq, &cmd->sdb); |
6f9a35e2 BH |
1083 | if (error) |
1084 | goto err_exit; | |
1085 | ||
13f05c8d | 1086 | if (blk_bidi_rq(rq)) { |
d285203c CH |
1087 | if (!rq->q->mq_ops) { |
1088 | struct scsi_data_buffer *bidi_sdb = | |
1089 | kmem_cache_zalloc(scsi_sdb_cache, GFP_ATOMIC); | |
1090 | if (!bidi_sdb) { | |
1091 | error = BLKPREP_DEFER; | |
1092 | goto err_exit; | |
1093 | } | |
1094 | ||
1095 | rq->next_rq->special = bidi_sdb; | |
6f9a35e2 BH |
1096 | } |
1097 | ||
3c356bde | 1098 | error = scsi_init_sgtable(rq->next_rq, rq->next_rq->special); |
6f9a35e2 BH |
1099 | if (error) |
1100 | goto err_exit; | |
1101 | } | |
1102 | ||
13f05c8d | 1103 | if (blk_integrity_rq(rq)) { |
7027ad72 MP |
1104 | struct scsi_data_buffer *prot_sdb = cmd->prot_sdb; |
1105 | int ivecs, count; | |
1106 | ||
91724c20 EM |
1107 | if (prot_sdb == NULL) { |
1108 | /* | |
1109 | * This can happen if someone (e.g. multipath) | |
1110 | * queues a command to a device on an adapter | |
1111 | * that does not support DIX. | |
1112 | */ | |
1113 | WARN_ON_ONCE(1); | |
1114 | error = BLKPREP_KILL; | |
1115 | goto err_exit; | |
1116 | } | |
1117 | ||
13f05c8d | 1118 | ivecs = blk_rq_count_integrity_sg(rq->q, rq->bio); |
7027ad72 | 1119 | |
001d63be | 1120 | if (sg_alloc_table_chained(&prot_sdb->table, ivecs, |
22cc3d4c | 1121 | prot_sdb->table.sgl)) { |
7027ad72 MP |
1122 | error = BLKPREP_DEFER; |
1123 | goto err_exit; | |
1124 | } | |
1125 | ||
13f05c8d | 1126 | count = blk_rq_map_integrity_sg(rq->q, rq->bio, |
7027ad72 MP |
1127 | prot_sdb->table.sgl); |
1128 | BUG_ON(unlikely(count > ivecs)); | |
13f05c8d | 1129 | BUG_ON(unlikely(count > queue_max_integrity_segments(rq->q))); |
7027ad72 MP |
1130 | |
1131 | cmd->prot_sdb = prot_sdb; | |
1132 | cmd->prot_sdb->table.nents = count; | |
1133 | } | |
1134 | ||
d285203c | 1135 | return BLKPREP_OK; |
6f9a35e2 | 1136 | err_exit: |
d285203c CH |
1137 | if (is_mq) { |
1138 | scsi_mq_free_sgtables(cmd); | |
1139 | } else { | |
1140 | scsi_release_buffers(cmd); | |
1141 | cmd->request->special = NULL; | |
1142 | scsi_put_command(cmd); | |
1143 | put_device(&sdev->sdev_gendev); | |
1144 | } | |
6f9a35e2 BH |
1145 | return error; |
1146 | } | |
bb52d82f | 1147 | EXPORT_SYMBOL(scsi_init_io); |
1da177e4 | 1148 | |
ca18d6f7 | 1149 | /** |
832889f5 | 1150 | * scsi_initialize_rq - initialize struct scsi_cmnd partially |
35c0506f | 1151 | * @rq: Request associated with the SCSI command to be initialized. |
ca18d6f7 | 1152 | * |
832889f5 BVA |
1153 | * This function initializes the members of struct scsi_cmnd that must be |
1154 | * initialized before request processing starts and that won't be | |
1155 | * reinitialized if a SCSI command is requeued. | |
1156 | * | |
64104f70 BVA |
1157 | * Called from inside blk_get_request() for pass-through requests and from |
1158 | * inside scsi_init_command() for filesystem requests. | |
ca18d6f7 BVA |
1159 | */ |
1160 | void scsi_initialize_rq(struct request *rq) | |
1161 | { | |
c8d9cf22 BVA |
1162 | struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq); |
1163 | ||
1164 | scsi_req_init(&cmd->req); | |
dbe55f8b | 1165 | init_rcu_head(&cmd->rcu); |
832889f5 BVA |
1166 | cmd->jiffies_at_alloc = jiffies; |
1167 | cmd->retries = 0; | |
ca18d6f7 BVA |
1168 | } |
1169 | EXPORT_SYMBOL(scsi_initialize_rq); | |
1170 | ||
2dd6fb59 BVA |
1171 | /* Add a command to the list used by the aacraid and dpt_i2o drivers */ |
1172 | void scsi_add_cmd_to_list(struct scsi_cmnd *cmd) | |
1173 | { | |
1174 | struct scsi_device *sdev = cmd->device; | |
1175 | struct Scsi_Host *shost = sdev->host; | |
1176 | unsigned long flags; | |
1177 | ||
1178 | if (shost->use_cmd_list) { | |
1179 | spin_lock_irqsave(&sdev->list_lock, flags); | |
1180 | list_add_tail(&cmd->list, &sdev->cmd_list); | |
1181 | spin_unlock_irqrestore(&sdev->list_lock, flags); | |
1182 | } | |
1183 | } | |
1184 | ||
1185 | /* Remove a command from the list used by the aacraid and dpt_i2o drivers */ | |
1186 | void scsi_del_cmd_from_list(struct scsi_cmnd *cmd) | |
1187 | { | |
1188 | struct scsi_device *sdev = cmd->device; | |
1189 | struct Scsi_Host *shost = sdev->host; | |
1190 | unsigned long flags; | |
1191 | ||
1192 | if (shost->use_cmd_list) { | |
1193 | spin_lock_irqsave(&sdev->list_lock, flags); | |
1194 | BUG_ON(list_empty(&cmd->list)); | |
1195 | list_del_init(&cmd->list); | |
1196 | spin_unlock_irqrestore(&sdev->list_lock, flags); | |
1197 | } | |
1198 | } | |
1199 | ||
ca18d6f7 | 1200 | /* Called after a request has been started. */ |
e9c787e6 | 1201 | void scsi_init_command(struct scsi_device *dev, struct scsi_cmnd *cmd) |
3b003157 | 1202 | { |
e9c787e6 CH |
1203 | void *buf = cmd->sense_buffer; |
1204 | void *prot = cmd->prot_sdb; | |
64104f70 BVA |
1205 | struct request *rq = blk_mq_rq_from_pdu(cmd); |
1206 | unsigned int flags = cmd->flags & SCMD_PRESERVED_FLAGS; | |
832889f5 BVA |
1207 | unsigned long jiffies_at_alloc; |
1208 | int retries; | |
64104f70 BVA |
1209 | |
1210 | if (!blk_rq_is_scsi(rq) && !(flags & SCMD_INITIALIZED)) { | |
1211 | flags |= SCMD_INITIALIZED; | |
1212 | scsi_initialize_rq(rq); | |
1213 | } | |
3b003157 | 1214 | |
832889f5 BVA |
1215 | jiffies_at_alloc = cmd->jiffies_at_alloc; |
1216 | retries = cmd->retries; | |
82ed4db4 CH |
1217 | /* zero out the cmd, except for the embedded scsi_request */ |
1218 | memset((char *)cmd + sizeof(cmd->req), 0, | |
ee524236 | 1219 | sizeof(*cmd) - sizeof(cmd->req) + dev->host->hostt->cmd_size); |
3b003157 | 1220 | |
e9c787e6 CH |
1221 | cmd->device = dev; |
1222 | cmd->sense_buffer = buf; | |
1223 | cmd->prot_sdb = prot; | |
64104f70 | 1224 | cmd->flags = flags; |
e9c787e6 | 1225 | INIT_DELAYED_WORK(&cmd->abort_work, scmd_eh_abort_handler); |
832889f5 BVA |
1226 | cmd->jiffies_at_alloc = jiffies_at_alloc; |
1227 | cmd->retries = retries; | |
64a87b24 | 1228 | |
2dd6fb59 | 1229 | scsi_add_cmd_to_list(cmd); |
3b003157 CH |
1230 | } |
1231 | ||
aebf526b | 1232 | static int scsi_setup_scsi_cmnd(struct scsi_device *sdev, struct request *req) |
7b16318d | 1233 | { |
bed2213d | 1234 | struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req); |
3b003157 CH |
1235 | |
1236 | /* | |
aebf526b | 1237 | * Passthrough requests may transfer data, in which case they must |
3b003157 CH |
1238 | * a bio attached to them. Or they might contain a SCSI command |
1239 | * that does not transfer data, in which case they may optionally | |
1240 | * submit a request without an attached bio. | |
1241 | */ | |
1242 | if (req->bio) { | |
3c356bde | 1243 | int ret = scsi_init_io(cmd); |
3b003157 CH |
1244 | if (unlikely(ret)) |
1245 | return ret; | |
1246 | } else { | |
b0790410 | 1247 | BUG_ON(blk_rq_bytes(req)); |
3b003157 | 1248 | |
30b0c37b | 1249 | memset(&cmd->sdb, 0, sizeof(cmd->sdb)); |
3b003157 | 1250 | } |
7b16318d | 1251 | |
82ed4db4 CH |
1252 | cmd->cmd_len = scsi_req(req)->cmd_len; |
1253 | cmd->cmnd = scsi_req(req)->cmd; | |
b0790410 | 1254 | cmd->transfersize = blk_rq_bytes(req); |
64c7f1d1 | 1255 | cmd->allowed = scsi_req(req)->retries; |
3b003157 | 1256 | return BLKPREP_OK; |
7b16318d | 1257 | } |
7b16318d | 1258 | |
3b003157 | 1259 | /* |
aebf526b | 1260 | * Setup a normal block command. These are simple request from filesystems |
3868cf8e | 1261 | * that still need to be translated to SCSI CDBs from the ULD. |
3b003157 | 1262 | */ |
3868cf8e | 1263 | static int scsi_setup_fs_cmnd(struct scsi_device *sdev, struct request *req) |
1da177e4 | 1264 | { |
bed2213d | 1265 | struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req); |
a6a8d9f8 | 1266 | |
ee14c674 CH |
1267 | if (unlikely(sdev->handler && sdev->handler->prep_fn)) { |
1268 | int ret = sdev->handler->prep_fn(sdev, req); | |
a6a8d9f8 CS |
1269 | if (ret != BLKPREP_OK) |
1270 | return ret; | |
1271 | } | |
1272 | ||
82ed4db4 | 1273 | cmd->cmnd = scsi_req(req)->cmd = scsi_req(req)->__cmd; |
64a87b24 | 1274 | memset(cmd->cmnd, 0, BLK_MAX_CDB); |
3868cf8e | 1275 | return scsi_cmd_to_driver(cmd)->init_command(cmd); |
3b003157 CH |
1276 | } |
1277 | ||
6af7a4ff CH |
1278 | static int scsi_setup_cmnd(struct scsi_device *sdev, struct request *req) |
1279 | { | |
bed2213d | 1280 | struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req); |
6af7a4ff CH |
1281 | |
1282 | if (!blk_rq_bytes(req)) | |
1283 | cmd->sc_data_direction = DMA_NONE; | |
1284 | else if (rq_data_dir(req) == WRITE) | |
1285 | cmd->sc_data_direction = DMA_TO_DEVICE; | |
1286 | else | |
1287 | cmd->sc_data_direction = DMA_FROM_DEVICE; | |
1288 | ||
aebf526b CH |
1289 | if (blk_rq_is_scsi(req)) |
1290 | return scsi_setup_scsi_cmnd(sdev, req); | |
1291 | else | |
6af7a4ff | 1292 | return scsi_setup_fs_cmnd(sdev, req); |
6af7a4ff CH |
1293 | } |
1294 | ||
a1b73fc1 CH |
1295 | static int |
1296 | scsi_prep_state_check(struct scsi_device *sdev, struct request *req) | |
3b003157 | 1297 | { |
3b003157 CH |
1298 | int ret = BLKPREP_OK; |
1299 | ||
1da177e4 | 1300 | /* |
3b003157 CH |
1301 | * If the device is not in running state we will reject some |
1302 | * or all commands. | |
1da177e4 | 1303 | */ |
3b003157 CH |
1304 | if (unlikely(sdev->sdev_state != SDEV_RUNNING)) { |
1305 | switch (sdev->sdev_state) { | |
1306 | case SDEV_OFFLINE: | |
1b8d2620 | 1307 | case SDEV_TRANSPORT_OFFLINE: |
3b003157 CH |
1308 | /* |
1309 | * If the device is offline we refuse to process any | |
1310 | * commands. The device must be brought online | |
1311 | * before trying any recovery commands. | |
1312 | */ | |
1313 | sdev_printk(KERN_ERR, sdev, | |
1314 | "rejecting I/O to offline device\n"); | |
1315 | ret = BLKPREP_KILL; | |
1316 | break; | |
1317 | case SDEV_DEL: | |
1318 | /* | |
1319 | * If the device is fully deleted, we refuse to | |
1320 | * process any commands as well. | |
1321 | */ | |
9ccfc756 | 1322 | sdev_printk(KERN_ERR, sdev, |
3b003157 CH |
1323 | "rejecting I/O to dead device\n"); |
1324 | ret = BLKPREP_KILL; | |
1325 | break; | |
3b003157 | 1326 | case SDEV_BLOCK: |
6f4267e3 | 1327 | case SDEV_CREATED_BLOCK: |
bba0bdd7 BVA |
1328 | ret = BLKPREP_DEFER; |
1329 | break; | |
1330 | case SDEV_QUIESCE: | |
3b003157 CH |
1331 | /* |
1332 | * If the devices is blocked we defer normal commands. | |
1333 | */ | |
aeec7762 | 1334 | if (req && !(req->rq_flags & RQF_PREEMPT)) |
3b003157 CH |
1335 | ret = BLKPREP_DEFER; |
1336 | break; | |
1337 | default: | |
1338 | /* | |
1339 | * For any other not fully online state we only allow | |
1340 | * special commands. In particular any user initiated | |
1341 | * command is not allowed. | |
1342 | */ | |
aeec7762 | 1343 | if (req && !(req->rq_flags & RQF_PREEMPT)) |
3b003157 CH |
1344 | ret = BLKPREP_KILL; |
1345 | break; | |
1da177e4 | 1346 | } |
1da177e4 | 1347 | } |
7f9a6bc4 JB |
1348 | return ret; |
1349 | } | |
1da177e4 | 1350 | |
a1b73fc1 CH |
1351 | static int |
1352 | scsi_prep_return(struct request_queue *q, struct request *req, int ret) | |
7f9a6bc4 JB |
1353 | { |
1354 | struct scsi_device *sdev = q->queuedata; | |
1da177e4 | 1355 | |
3b003157 CH |
1356 | switch (ret) { |
1357 | case BLKPREP_KILL: | |
e1cd3911 | 1358 | case BLKPREP_INVALID: |
17d5363b | 1359 | scsi_req(req)->result = DID_NO_CONNECT << 16; |
7f9a6bc4 JB |
1360 | /* release the command and kill it */ |
1361 | if (req->special) { | |
1362 | struct scsi_cmnd *cmd = req->special; | |
1363 | scsi_release_buffers(cmd); | |
1364 | scsi_put_command(cmd); | |
68c03d91 | 1365 | put_device(&sdev->sdev_gendev); |
7f9a6bc4 JB |
1366 | req->special = NULL; |
1367 | } | |
3b003157 CH |
1368 | break; |
1369 | case BLKPREP_DEFER: | |
1da177e4 | 1370 | /* |
9934c8c0 | 1371 | * If we defer, the blk_peek_request() returns NULL, but the |
a488e749 JA |
1372 | * queue must be restarted, so we schedule a callback to happen |
1373 | * shortly. | |
1da177e4 | 1374 | */ |
71e75c97 | 1375 | if (atomic_read(&sdev->device_busy) == 0) |
a488e749 | 1376 | blk_delay_queue(q, SCSI_QUEUE_DELAY); |
3b003157 CH |
1377 | break; |
1378 | default: | |
e8064021 | 1379 | req->rq_flags |= RQF_DONTPREP; |
1da177e4 LT |
1380 | } |
1381 | ||
3b003157 | 1382 | return ret; |
1da177e4 | 1383 | } |
7f9a6bc4 | 1384 | |
a1b73fc1 | 1385 | static int scsi_prep_fn(struct request_queue *q, struct request *req) |
7f9a6bc4 JB |
1386 | { |
1387 | struct scsi_device *sdev = q->queuedata; | |
e9c787e6 | 1388 | struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req); |
a1b73fc1 CH |
1389 | int ret; |
1390 | ||
1391 | ret = scsi_prep_state_check(sdev, req); | |
1392 | if (ret != BLKPREP_OK) | |
1393 | goto out; | |
1394 | ||
e9c787e6 CH |
1395 | if (!req->special) { |
1396 | /* Bail if we can't get a reference to the device */ | |
1397 | if (unlikely(!get_device(&sdev->sdev_gendev))) { | |
1398 | ret = BLKPREP_DEFER; | |
1399 | goto out; | |
1400 | } | |
1401 | ||
1402 | scsi_init_command(sdev, cmd); | |
1403 | req->special = cmd; | |
a1b73fc1 | 1404 | } |
7f9a6bc4 | 1405 | |
e9c787e6 CH |
1406 | cmd->tag = req->tag; |
1407 | cmd->request = req; | |
e9c787e6 CH |
1408 | cmd->prot_op = SCSI_PROT_NORMAL; |
1409 | ||
6af7a4ff | 1410 | ret = scsi_setup_cmnd(sdev, req); |
a1b73fc1 | 1411 | out: |
7f9a6bc4 JB |
1412 | return scsi_prep_return(q, req, ret); |
1413 | } | |
a1b73fc1 CH |
1414 | |
1415 | static void scsi_unprep_fn(struct request_queue *q, struct request *req) | |
1416 | { | |
bed2213d | 1417 | scsi_uninit_cmd(blk_mq_rq_to_pdu(req)); |
a1b73fc1 | 1418 | } |
1da177e4 LT |
1419 | |
1420 | /* | |
1421 | * scsi_dev_queue_ready: if we can send requests to sdev, return 1 else | |
1422 | * return 0. | |
1423 | * | |
1424 | * Called with the queue_lock held. | |
1425 | */ | |
1426 | static inline int scsi_dev_queue_ready(struct request_queue *q, | |
1427 | struct scsi_device *sdev) | |
1428 | { | |
71e75c97 CH |
1429 | unsigned int busy; |
1430 | ||
1431 | busy = atomic_inc_return(&sdev->device_busy) - 1; | |
cd9070c9 | 1432 | if (atomic_read(&sdev->device_blocked)) { |
71e75c97 CH |
1433 | if (busy) |
1434 | goto out_dec; | |
1435 | ||
1da177e4 LT |
1436 | /* |
1437 | * unblock after device_blocked iterates to zero | |
1438 | */ | |
cd9070c9 | 1439 | if (atomic_dec_return(&sdev->device_blocked) > 0) { |
d285203c CH |
1440 | /* |
1441 | * For the MQ case we take care of this in the caller. | |
1442 | */ | |
1443 | if (!q->mq_ops) | |
1444 | blk_delay_queue(q, SCSI_QUEUE_DELAY); | |
71e75c97 | 1445 | goto out_dec; |
1da177e4 | 1446 | } |
71e75c97 CH |
1447 | SCSI_LOG_MLQUEUE(3, sdev_printk(KERN_INFO, sdev, |
1448 | "unblocking device at zero depth\n")); | |
1da177e4 | 1449 | } |
71e75c97 CH |
1450 | |
1451 | if (busy >= sdev->queue_depth) | |
1452 | goto out_dec; | |
1da177e4 LT |
1453 | |
1454 | return 1; | |
71e75c97 CH |
1455 | out_dec: |
1456 | atomic_dec(&sdev->device_busy); | |
1457 | return 0; | |
1da177e4 LT |
1458 | } |
1459 | ||
f0c0a376 MC |
1460 | /* |
1461 | * scsi_target_queue_ready: checks if there we can send commands to target | |
1462 | * @sdev: scsi device on starget to check. | |
f0c0a376 MC |
1463 | */ |
1464 | static inline int scsi_target_queue_ready(struct Scsi_Host *shost, | |
1465 | struct scsi_device *sdev) | |
1466 | { | |
1467 | struct scsi_target *starget = scsi_target(sdev); | |
7ae65c0f | 1468 | unsigned int busy; |
f0c0a376 MC |
1469 | |
1470 | if (starget->single_lun) { | |
7ae65c0f | 1471 | spin_lock_irq(shost->host_lock); |
f0c0a376 | 1472 | if (starget->starget_sdev_user && |
7ae65c0f CH |
1473 | starget->starget_sdev_user != sdev) { |
1474 | spin_unlock_irq(shost->host_lock); | |
1475 | return 0; | |
1476 | } | |
f0c0a376 | 1477 | starget->starget_sdev_user = sdev; |
7ae65c0f | 1478 | spin_unlock_irq(shost->host_lock); |
f0c0a376 MC |
1479 | } |
1480 | ||
2ccbb008 CH |
1481 | if (starget->can_queue <= 0) |
1482 | return 1; | |
1483 | ||
7ae65c0f | 1484 | busy = atomic_inc_return(&starget->target_busy) - 1; |
cd9070c9 | 1485 | if (atomic_read(&starget->target_blocked) > 0) { |
7ae65c0f CH |
1486 | if (busy) |
1487 | goto starved; | |
1488 | ||
f0c0a376 MC |
1489 | /* |
1490 | * unblock after target_blocked iterates to zero | |
1491 | */ | |
cd9070c9 | 1492 | if (atomic_dec_return(&starget->target_blocked) > 0) |
7ae65c0f | 1493 | goto out_dec; |
cf68d334 CH |
1494 | |
1495 | SCSI_LOG_MLQUEUE(3, starget_printk(KERN_INFO, starget, | |
1496 | "unblocking target at zero depth\n")); | |
f0c0a376 MC |
1497 | } |
1498 | ||
2ccbb008 | 1499 | if (busy >= starget->can_queue) |
7ae65c0f | 1500 | goto starved; |
f0c0a376 | 1501 | |
7ae65c0f CH |
1502 | return 1; |
1503 | ||
1504 | starved: | |
1505 | spin_lock_irq(shost->host_lock); | |
1506 | list_move_tail(&sdev->starved_entry, &shost->starved_list); | |
cf68d334 | 1507 | spin_unlock_irq(shost->host_lock); |
7ae65c0f | 1508 | out_dec: |
2ccbb008 CH |
1509 | if (starget->can_queue > 0) |
1510 | atomic_dec(&starget->target_busy); | |
7ae65c0f | 1511 | return 0; |
f0c0a376 MC |
1512 | } |
1513 | ||
1da177e4 LT |
1514 | /* |
1515 | * scsi_host_queue_ready: if we can send requests to shost, return 1 else | |
1516 | * return 0. We must end up running the queue again whenever 0 is | |
1517 | * returned, else IO can hang. | |
1da177e4 LT |
1518 | */ |
1519 | static inline int scsi_host_queue_ready(struct request_queue *q, | |
1520 | struct Scsi_Host *shost, | |
1521 | struct scsi_device *sdev) | |
1522 | { | |
74665016 | 1523 | unsigned int busy; |
cf68d334 | 1524 | |
939647ee | 1525 | if (scsi_host_in_recovery(shost)) |
74665016 CH |
1526 | return 0; |
1527 | ||
1528 | busy = atomic_inc_return(&shost->host_busy) - 1; | |
cd9070c9 | 1529 | if (atomic_read(&shost->host_blocked) > 0) { |
74665016 CH |
1530 | if (busy) |
1531 | goto starved; | |
1532 | ||
1da177e4 LT |
1533 | /* |
1534 | * unblock after host_blocked iterates to zero | |
1535 | */ | |
cd9070c9 | 1536 | if (atomic_dec_return(&shost->host_blocked) > 0) |
74665016 | 1537 | goto out_dec; |
cf68d334 CH |
1538 | |
1539 | SCSI_LOG_MLQUEUE(3, | |
1540 | shost_printk(KERN_INFO, shost, | |
1541 | "unblocking host at zero depth\n")); | |
1da177e4 | 1542 | } |
74665016 CH |
1543 | |
1544 | if (shost->can_queue > 0 && busy >= shost->can_queue) | |
1545 | goto starved; | |
1546 | if (shost->host_self_blocked) | |
1547 | goto starved; | |
1da177e4 LT |
1548 | |
1549 | /* We're OK to process the command, so we can't be starved */ | |
74665016 CH |
1550 | if (!list_empty(&sdev->starved_entry)) { |
1551 | spin_lock_irq(shost->host_lock); | |
1552 | if (!list_empty(&sdev->starved_entry)) | |
1553 | list_del_init(&sdev->starved_entry); | |
1554 | spin_unlock_irq(shost->host_lock); | |
1555 | } | |
1da177e4 | 1556 | |
74665016 CH |
1557 | return 1; |
1558 | ||
1559 | starved: | |
1560 | spin_lock_irq(shost->host_lock); | |
1561 | if (list_empty(&sdev->starved_entry)) | |
1562 | list_add_tail(&sdev->starved_entry, &shost->starved_list); | |
cf68d334 | 1563 | spin_unlock_irq(shost->host_lock); |
74665016 | 1564 | out_dec: |
af2f8f5f | 1565 | scsi_dec_host_busy(shost); |
74665016 | 1566 | return 0; |
1da177e4 LT |
1567 | } |
1568 | ||
6c5121b7 KU |
1569 | /* |
1570 | * Busy state exporting function for request stacking drivers. | |
1571 | * | |
1572 | * For efficiency, no lock is taken to check the busy state of | |
1573 | * shost/starget/sdev, since the returned value is not guaranteed and | |
1574 | * may be changed after request stacking drivers call the function, | |
1575 | * regardless of taking lock or not. | |
1576 | * | |
67bd9413 BVA |
1577 | * When scsi can't dispatch I/Os anymore and needs to kill I/Os scsi |
1578 | * needs to return 'not busy'. Otherwise, request stacking drivers | |
1579 | * may hold requests forever. | |
6c5121b7 KU |
1580 | */ |
1581 | static int scsi_lld_busy(struct request_queue *q) | |
1582 | { | |
1583 | struct scsi_device *sdev = q->queuedata; | |
1584 | struct Scsi_Host *shost; | |
6c5121b7 | 1585 | |
3f3299d5 | 1586 | if (blk_queue_dying(q)) |
6c5121b7 KU |
1587 | return 0; |
1588 | ||
1589 | shost = sdev->host; | |
6c5121b7 | 1590 | |
b7e94a16 JN |
1591 | /* |
1592 | * Ignore host/starget busy state. | |
1593 | * Since block layer does not have a concept of fairness across | |
1594 | * multiple queues, congestion of host/starget needs to be handled | |
1595 | * in SCSI layer. | |
1596 | */ | |
1597 | if (scsi_host_in_recovery(shost) || scsi_device_is_busy(sdev)) | |
6c5121b7 KU |
1598 | return 1; |
1599 | ||
1600 | return 0; | |
1601 | } | |
1602 | ||
1da177e4 | 1603 | /* |
e91442b6 | 1604 | * Kill a request for a dead device |
1da177e4 | 1605 | */ |
165125e1 | 1606 | static void scsi_kill_request(struct request *req, struct request_queue *q) |
1da177e4 | 1607 | { |
bed2213d | 1608 | struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req); |
03b14708 JS |
1609 | struct scsi_device *sdev; |
1610 | struct scsi_target *starget; | |
1611 | struct Scsi_Host *shost; | |
1da177e4 | 1612 | |
9934c8c0 | 1613 | blk_start_request(req); |
788ce43a | 1614 | |
74571813 HR |
1615 | scmd_printk(KERN_INFO, cmd, "killing request\n"); |
1616 | ||
03b14708 JS |
1617 | sdev = cmd->device; |
1618 | starget = scsi_target(sdev); | |
1619 | shost = sdev->host; | |
e91442b6 JB |
1620 | scsi_init_cmd_errh(cmd); |
1621 | cmd->result = DID_NO_CONNECT << 16; | |
1622 | atomic_inc(&cmd->device->iorequest_cnt); | |
e36e0c80 TH |
1623 | |
1624 | /* | |
1625 | * SCSI request completion path will do scsi_device_unbusy(), | |
1626 | * bump busy counts. To bump the counters, we need to dance | |
1627 | * with the locks as normal issue path does. | |
1628 | */ | |
71e75c97 | 1629 | atomic_inc(&sdev->device_busy); |
74665016 | 1630 | atomic_inc(&shost->host_busy); |
2ccbb008 CH |
1631 | if (starget->can_queue > 0) |
1632 | atomic_inc(&starget->target_busy); | |
e36e0c80 | 1633 | |
242f9dcb | 1634 | blk_complete_request(req); |
1da177e4 LT |
1635 | } |
1636 | ||
1aea6434 JA |
1637 | static void scsi_softirq_done(struct request *rq) |
1638 | { | |
bed2213d | 1639 | struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq); |
242f9dcb | 1640 | unsigned long wait_for = (cmd->allowed + 1) * rq->timeout; |
1aea6434 JA |
1641 | int disposition; |
1642 | ||
1643 | INIT_LIST_HEAD(&cmd->eh_entry); | |
1644 | ||
242f9dcb JA |
1645 | atomic_inc(&cmd->device->iodone_cnt); |
1646 | if (cmd->result) | |
1647 | atomic_inc(&cmd->device->ioerr_cnt); | |
1648 | ||
1aea6434 JA |
1649 | disposition = scsi_decide_disposition(cmd); |
1650 | if (disposition != SUCCESS && | |
1651 | time_before(cmd->jiffies_at_alloc + wait_for, jiffies)) { | |
1652 | sdev_printk(KERN_ERR, cmd->device, | |
1653 | "timing out command, waited %lus\n", | |
1654 | wait_for/HZ); | |
1655 | disposition = SUCCESS; | |
1656 | } | |
91921e01 | 1657 | |
1aea6434 JA |
1658 | scsi_log_completion(cmd, disposition); |
1659 | ||
1660 | switch (disposition) { | |
1661 | case SUCCESS: | |
1662 | scsi_finish_command(cmd); | |
1663 | break; | |
1664 | case NEEDS_RETRY: | |
596f482a | 1665 | scsi_queue_insert(cmd, SCSI_MLQUEUE_EH_RETRY); |
1aea6434 JA |
1666 | break; |
1667 | case ADD_TO_MLQUEUE: | |
1668 | scsi_queue_insert(cmd, SCSI_MLQUEUE_DEVICE_BUSY); | |
1669 | break; | |
1670 | default: | |
a0658632 | 1671 | scsi_eh_scmd_add(cmd); |
2171b6d0 | 1672 | break; |
1aea6434 JA |
1673 | } |
1674 | } | |
1675 | ||
82042a2c CH |
1676 | /** |
1677 | * scsi_dispatch_command - Dispatch a command to the low-level driver. | |
1678 | * @cmd: command block we are dispatching. | |
1679 | * | |
1680 | * Return: nonzero return request was rejected and device's queue needs to be | |
1681 | * plugged. | |
1682 | */ | |
1683 | static int scsi_dispatch_cmd(struct scsi_cmnd *cmd) | |
1684 | { | |
1685 | struct Scsi_Host *host = cmd->device->host; | |
1686 | int rtn = 0; | |
1687 | ||
1688 | atomic_inc(&cmd->device->iorequest_cnt); | |
1689 | ||
1690 | /* check if the device is still usable */ | |
1691 | if (unlikely(cmd->device->sdev_state == SDEV_DEL)) { | |
1692 | /* in SDEV_DEL we error all commands. DID_NO_CONNECT | |
1693 | * returns an immediate error upwards, and signals | |
1694 | * that the device is no longer present */ | |
1695 | cmd->result = DID_NO_CONNECT << 16; | |
1696 | goto done; | |
1697 | } | |
1698 | ||
1699 | /* Check to see if the scsi lld made this device blocked. */ | |
1700 | if (unlikely(scsi_device_blocked(cmd->device))) { | |
1701 | /* | |
1702 | * in blocked state, the command is just put back on | |
1703 | * the device queue. The suspend state has already | |
1704 | * blocked the queue so future requests should not | |
1705 | * occur until the device transitions out of the | |
1706 | * suspend state. | |
1707 | */ | |
1708 | SCSI_LOG_MLQUEUE(3, scmd_printk(KERN_INFO, cmd, | |
1709 | "queuecommand : device blocked\n")); | |
1710 | return SCSI_MLQUEUE_DEVICE_BUSY; | |
1711 | } | |
1712 | ||
1713 | /* Store the LUN value in cmnd, if needed. */ | |
1714 | if (cmd->device->lun_in_cdb) | |
1715 | cmd->cmnd[1] = (cmd->cmnd[1] & 0x1f) | | |
1716 | (cmd->device->lun << 5 & 0xe0); | |
1717 | ||
1718 | scsi_log_send(cmd); | |
1719 | ||
1720 | /* | |
1721 | * Before we queue this command, check if the command | |
1722 | * length exceeds what the host adapter can handle. | |
1723 | */ | |
1724 | if (cmd->cmd_len > cmd->device->host->max_cmd_len) { | |
1725 | SCSI_LOG_MLQUEUE(3, scmd_printk(KERN_INFO, cmd, | |
1726 | "queuecommand : command too long. " | |
1727 | "cdb_size=%d host->max_cmd_len=%d\n", | |
1728 | cmd->cmd_len, cmd->device->host->max_cmd_len)); | |
1729 | cmd->result = (DID_ABORT << 16); | |
1730 | goto done; | |
1731 | } | |
1732 | ||
1733 | if (unlikely(host->shost_state == SHOST_DEL)) { | |
1734 | cmd->result = (DID_NO_CONNECT << 16); | |
1735 | goto done; | |
1736 | ||
1737 | } | |
1738 | ||
1739 | trace_scsi_dispatch_cmd_start(cmd); | |
1740 | rtn = host->hostt->queuecommand(host, cmd); | |
1741 | if (rtn) { | |
1742 | trace_scsi_dispatch_cmd_error(cmd, rtn); | |
1743 | if (rtn != SCSI_MLQUEUE_DEVICE_BUSY && | |
1744 | rtn != SCSI_MLQUEUE_TARGET_BUSY) | |
1745 | rtn = SCSI_MLQUEUE_HOST_BUSY; | |
1746 | ||
1747 | SCSI_LOG_MLQUEUE(3, scmd_printk(KERN_INFO, cmd, | |
1748 | "queuecommand : request rejected\n")); | |
1749 | } | |
1750 | ||
1751 | return rtn; | |
1752 | done: | |
1753 | cmd->scsi_done(cmd); | |
1754 | return 0; | |
1755 | } | |
1756 | ||
3b5382c4 CH |
1757 | /** |
1758 | * scsi_done - Invoke completion on finished SCSI command. | |
1759 | * @cmd: The SCSI Command for which a low-level device driver (LLDD) gives | |
1760 | * ownership back to SCSI Core -- i.e. the LLDD has finished with it. | |
1761 | * | |
1762 | * Description: This function is the mid-level's (SCSI Core) interrupt routine, | |
1763 | * which regains ownership of the SCSI command (de facto) from a LLDD, and | |
1764 | * calls blk_complete_request() for further processing. | |
1765 | * | |
1766 | * This function is interrupt context safe. | |
1767 | */ | |
1768 | static void scsi_done(struct scsi_cmnd *cmd) | |
1769 | { | |
1770 | trace_scsi_dispatch_cmd_done(cmd); | |
1771 | blk_complete_request(cmd->request); | |
1772 | } | |
1773 | ||
1da177e4 LT |
1774 | /* |
1775 | * Function: scsi_request_fn() | |
1776 | * | |
1777 | * Purpose: Main strategy routine for SCSI. | |
1778 | * | |
1779 | * Arguments: q - Pointer to actual queue. | |
1780 | * | |
1781 | * Returns: Nothing | |
1782 | * | |
e98f42bc DLM |
1783 | * Lock status: request queue lock assumed to be held when called. |
1784 | * | |
1785 | * Note: See sd_zbc.c sd_zbc_write_lock_zone() for write order | |
1786 | * protection for ZBC disks. | |
1da177e4 LT |
1787 | */ |
1788 | static void scsi_request_fn(struct request_queue *q) | |
613be1f6 BVA |
1789 | __releases(q->queue_lock) |
1790 | __acquires(q->queue_lock) | |
1da177e4 LT |
1791 | { |
1792 | struct scsi_device *sdev = q->queuedata; | |
1793 | struct Scsi_Host *shost; | |
1794 | struct scsi_cmnd *cmd; | |
1795 | struct request *req; | |
1796 | ||
1da177e4 LT |
1797 | /* |
1798 | * To start with, we keep looping until the queue is empty, or until | |
1799 | * the host is no longer able to accept any more requests. | |
1800 | */ | |
1801 | shost = sdev->host; | |
a488e749 | 1802 | for (;;) { |
1da177e4 LT |
1803 | int rtn; |
1804 | /* | |
1805 | * get next queueable request. We do this early to make sure | |
91921e01 | 1806 | * that the request is fully prepared even if we cannot |
1da177e4 LT |
1807 | * accept it. |
1808 | */ | |
9934c8c0 | 1809 | req = blk_peek_request(q); |
71e75c97 | 1810 | if (!req) |
1da177e4 LT |
1811 | break; |
1812 | ||
1813 | if (unlikely(!scsi_device_online(sdev))) { | |
9ccfc756 JB |
1814 | sdev_printk(KERN_ERR, sdev, |
1815 | "rejecting I/O to offline device\n"); | |
e91442b6 | 1816 | scsi_kill_request(req, q); |
1da177e4 LT |
1817 | continue; |
1818 | } | |
1819 | ||
71e75c97 CH |
1820 | if (!scsi_dev_queue_ready(q, sdev)) |
1821 | break; | |
1da177e4 LT |
1822 | |
1823 | /* | |
1824 | * Remove the request from the request list. | |
1825 | */ | |
1826 | if (!(blk_queue_tagged(q) && !blk_queue_start_tag(q, req))) | |
9934c8c0 | 1827 | blk_start_request(req); |
1da177e4 | 1828 | |
cf68d334 | 1829 | spin_unlock_irq(q->queue_lock); |
bed2213d BVA |
1830 | cmd = blk_mq_rq_to_pdu(req); |
1831 | if (cmd != req->special) { | |
e91442b6 JB |
1832 | printk(KERN_CRIT "impossible request in %s.\n" |
1833 | "please mail a stack trace to " | |
4aff5e23 | 1834 | "linux-scsi@vger.kernel.org\n", |
cadbd4a5 | 1835 | __func__); |
4aff5e23 | 1836 | blk_dump_rq_flags(req, "foo"); |
e91442b6 JB |
1837 | BUG(); |
1838 | } | |
1da177e4 | 1839 | |
ecefe8a9 MC |
1840 | /* |
1841 | * We hit this when the driver is using a host wide | |
1842 | * tag map. For device level tag maps the queue_depth check | |
1843 | * in the device ready fn would prevent us from trying | |
1844 | * to allocate a tag. Since the map is a shared host resource | |
1845 | * we add the dev to the starved list so it eventually gets | |
1846 | * a run when a tag is freed. | |
1847 | */ | |
e8064021 | 1848 | if (blk_queue_tagged(q) && !(req->rq_flags & RQF_QUEUED)) { |
cf68d334 | 1849 | spin_lock_irq(shost->host_lock); |
ecefe8a9 MC |
1850 | if (list_empty(&sdev->starved_entry)) |
1851 | list_add_tail(&sdev->starved_entry, | |
1852 | &shost->starved_list); | |
cf68d334 | 1853 | spin_unlock_irq(shost->host_lock); |
ecefe8a9 MC |
1854 | goto not_ready; |
1855 | } | |
1856 | ||
f0c0a376 MC |
1857 | if (!scsi_target_queue_ready(shost, sdev)) |
1858 | goto not_ready; | |
1859 | ||
1da177e4 | 1860 | if (!scsi_host_queue_ready(q, shost, sdev)) |
cf68d334 | 1861 | goto host_not_ready; |
125c99bc CH |
1862 | |
1863 | if (sdev->simple_tags) | |
1864 | cmd->flags |= SCMD_TAGGED; | |
1865 | else | |
1866 | cmd->flags &= ~SCMD_TAGGED; | |
1da177e4 | 1867 | |
1da177e4 LT |
1868 | /* |
1869 | * Finally, initialize any error handling parameters, and set up | |
1870 | * the timers for timeouts. | |
1871 | */ | |
1872 | scsi_init_cmd_errh(cmd); | |
1873 | ||
1874 | /* | |
1875 | * Dispatch the command to the low-level driver. | |
1876 | */ | |
3b5382c4 | 1877 | cmd->scsi_done = scsi_done; |
1da177e4 | 1878 | rtn = scsi_dispatch_cmd(cmd); |
d0d3bbf9 CH |
1879 | if (rtn) { |
1880 | scsi_queue_insert(cmd, rtn); | |
1881 | spin_lock_irq(q->queue_lock); | |
a488e749 | 1882 | goto out_delay; |
d0d3bbf9 CH |
1883 | } |
1884 | spin_lock_irq(q->queue_lock); | |
1da177e4 LT |
1885 | } |
1886 | ||
613be1f6 | 1887 | return; |
1da177e4 | 1888 | |
cf68d334 | 1889 | host_not_ready: |
2ccbb008 CH |
1890 | if (scsi_target(sdev)->can_queue > 0) |
1891 | atomic_dec(&scsi_target(sdev)->target_busy); | |
cf68d334 | 1892 | not_ready: |
1da177e4 LT |
1893 | /* |
1894 | * lock q, handle tag, requeue req, and decrement device_busy. We | |
1895 | * must return with queue_lock held. | |
1896 | * | |
1897 | * Decrementing device_busy without checking it is OK, as all such | |
1898 | * cases (host limits or settings) should run the queue at some | |
1899 | * later time. | |
1900 | */ | |
1901 | spin_lock_irq(q->queue_lock); | |
1902 | blk_requeue_request(q, req); | |
71e75c97 | 1903 | atomic_dec(&sdev->device_busy); |
a488e749 | 1904 | out_delay: |
480cadc2 | 1905 | if (!atomic_read(&sdev->device_busy) && !scsi_device_blocked(sdev)) |
a488e749 | 1906 | blk_delay_queue(q, SCSI_QUEUE_DELAY); |
1da177e4 LT |
1907 | } |
1908 | ||
fc17b653 | 1909 | static inline blk_status_t prep_to_mq(int ret) |
d285203c CH |
1910 | { |
1911 | switch (ret) { | |
1912 | case BLKPREP_OK: | |
fc17b653 | 1913 | return BLK_STS_OK; |
d285203c | 1914 | case BLKPREP_DEFER: |
fc17b653 | 1915 | return BLK_STS_RESOURCE; |
d285203c | 1916 | default: |
fc17b653 | 1917 | return BLK_STS_IOERR; |
d285203c CH |
1918 | } |
1919 | } | |
1920 | ||
be4c186c BVA |
1921 | /* Size in bytes of the sg-list stored in the scsi-mq command-private data. */ |
1922 | static unsigned int scsi_mq_sgl_size(struct Scsi_Host *shost) | |
1923 | { | |
1924 | return min_t(unsigned int, shost->sg_tablesize, SG_CHUNK_SIZE) * | |
1925 | sizeof(struct scatterlist); | |
1926 | } | |
1927 | ||
d285203c CH |
1928 | static int scsi_mq_prep_fn(struct request *req) |
1929 | { | |
1930 | struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req); | |
1931 | struct scsi_device *sdev = req->q->queuedata; | |
1932 | struct Scsi_Host *shost = sdev->host; | |
d285203c CH |
1933 | struct scatterlist *sg; |
1934 | ||
08f78436 | 1935 | scsi_init_command(sdev, cmd); |
d285203c CH |
1936 | |
1937 | req->special = cmd; | |
1938 | ||
1939 | cmd->request = req; | |
d285203c CH |
1940 | |
1941 | cmd->tag = req->tag; | |
d285203c CH |
1942 | cmd->prot_op = SCSI_PROT_NORMAL; |
1943 | ||
d285203c CH |
1944 | sg = (void *)cmd + sizeof(struct scsi_cmnd) + shost->hostt->cmd_size; |
1945 | cmd->sdb.table.sgl = sg; | |
1946 | ||
1947 | if (scsi_host_get_prot(shost)) { | |
d285203c CH |
1948 | memset(cmd->prot_sdb, 0, sizeof(struct scsi_data_buffer)); |
1949 | ||
1950 | cmd->prot_sdb->table.sgl = | |
1951 | (struct scatterlist *)(cmd->prot_sdb + 1); | |
1952 | } | |
1953 | ||
1954 | if (blk_bidi_rq(req)) { | |
1955 | struct request *next_rq = req->next_rq; | |
1956 | struct scsi_data_buffer *bidi_sdb = blk_mq_rq_to_pdu(next_rq); | |
1957 | ||
1958 | memset(bidi_sdb, 0, sizeof(struct scsi_data_buffer)); | |
1959 | bidi_sdb->table.sgl = | |
1960 | (struct scatterlist *)(bidi_sdb + 1); | |
1961 | ||
1962 | next_rq->special = bidi_sdb; | |
1963 | } | |
1964 | ||
fe052529 CH |
1965 | blk_mq_start_request(req); |
1966 | ||
8fe8ffb1 | 1967 | return scsi_setup_cmnd(sdev, req); |
d285203c CH |
1968 | } |
1969 | ||
1970 | static void scsi_mq_done(struct scsi_cmnd *cmd) | |
1971 | { | |
1972 | trace_scsi_dispatch_cmd_done(cmd); | |
08e0029a | 1973 | blk_mq_complete_request(cmd->request); |
d285203c CH |
1974 | } |
1975 | ||
0df21c86 | 1976 | static void scsi_mq_put_budget(struct blk_mq_hw_ctx *hctx) |
d285203c | 1977 | { |
0df21c86 ML |
1978 | struct request_queue *q = hctx->queue; |
1979 | struct scsi_device *sdev = q->queuedata; | |
0df21c86 | 1980 | |
0df21c86 ML |
1981 | atomic_dec(&sdev->device_busy); |
1982 | put_device(&sdev->sdev_gendev); | |
1983 | } | |
1984 | ||
88022d72 | 1985 | static bool scsi_mq_get_budget(struct blk_mq_hw_ctx *hctx) |
0df21c86 ML |
1986 | { |
1987 | struct request_queue *q = hctx->queue; | |
d285203c | 1988 | struct scsi_device *sdev = q->queuedata; |
d285203c | 1989 | |
d285203c CH |
1990 | if (!get_device(&sdev->sdev_gendev)) |
1991 | goto out; | |
d285203c CH |
1992 | if (!scsi_dev_queue_ready(q, sdev)) |
1993 | goto out_put_device; | |
d285203c | 1994 | |
88022d72 | 1995 | return true; |
0df21c86 | 1996 | |
0df21c86 ML |
1997 | out_put_device: |
1998 | put_device(&sdev->sdev_gendev); | |
1999 | out: | |
7e70aa78 ML |
2000 | if (atomic_read(&sdev->device_busy) == 0 && !scsi_device_blocked(sdev)) |
2001 | blk_mq_delay_run_hw_queue(hctx, SCSI_QUEUE_DELAY); | |
88022d72 | 2002 | return false; |
0df21c86 ML |
2003 | } |
2004 | ||
fc17b653 | 2005 | static blk_status_t scsi_queue_rq(struct blk_mq_hw_ctx *hctx, |
74c45052 | 2006 | const struct blk_mq_queue_data *bd) |
d285203c | 2007 | { |
74c45052 | 2008 | struct request *req = bd->rq; |
d285203c CH |
2009 | struct request_queue *q = req->q; |
2010 | struct scsi_device *sdev = q->queuedata; | |
2011 | struct Scsi_Host *shost = sdev->host; | |
2012 | struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req); | |
fc17b653 | 2013 | blk_status_t ret; |
d285203c CH |
2014 | int reason; |
2015 | ||
2016 | ret = prep_to_mq(scsi_prep_state_check(sdev, req)); | |
fc17b653 | 2017 | if (ret != BLK_STS_OK) |
0df21c86 | 2018 | goto out_put_budget; |
d285203c | 2019 | |
fc17b653 | 2020 | ret = BLK_STS_RESOURCE; |
d285203c | 2021 | if (!scsi_target_queue_ready(shost, sdev)) |
826a70a0 | 2022 | goto out_put_budget; |
d285203c CH |
2023 | if (!scsi_host_queue_ready(q, shost, sdev)) |
2024 | goto out_dec_target_busy; | |
2025 | ||
e8064021 | 2026 | if (!(req->rq_flags & RQF_DONTPREP)) { |
d285203c | 2027 | ret = prep_to_mq(scsi_mq_prep_fn(req)); |
fc17b653 | 2028 | if (ret != BLK_STS_OK) |
d285203c | 2029 | goto out_dec_host_busy; |
e8064021 | 2030 | req->rq_flags |= RQF_DONTPREP; |
fe052529 CH |
2031 | } else { |
2032 | blk_mq_start_request(req); | |
d285203c CH |
2033 | } |
2034 | ||
125c99bc CH |
2035 | if (sdev->simple_tags) |
2036 | cmd->flags |= SCMD_TAGGED; | |
b1dd2aac | 2037 | else |
125c99bc | 2038 | cmd->flags &= ~SCMD_TAGGED; |
b1dd2aac | 2039 | |
d285203c CH |
2040 | scsi_init_cmd_errh(cmd); |
2041 | cmd->scsi_done = scsi_mq_done; | |
2042 | ||
2043 | reason = scsi_dispatch_cmd(cmd); | |
2044 | if (reason) { | |
2045 | scsi_set_blocked(cmd, reason); | |
fc17b653 | 2046 | ret = BLK_STS_RESOURCE; |
d285203c CH |
2047 | goto out_dec_host_busy; |
2048 | } | |
2049 | ||
fc17b653 | 2050 | return BLK_STS_OK; |
d285203c CH |
2051 | |
2052 | out_dec_host_busy: | |
af2f8f5f | 2053 | scsi_dec_host_busy(shost); |
d285203c CH |
2054 | out_dec_target_busy: |
2055 | if (scsi_target(sdev)->can_queue > 0) | |
2056 | atomic_dec(&scsi_target(sdev)->target_busy); | |
0df21c86 ML |
2057 | out_put_budget: |
2058 | scsi_mq_put_budget(hctx); | |
d285203c | 2059 | switch (ret) { |
fc17b653 CH |
2060 | case BLK_STS_OK: |
2061 | break; | |
2062 | case BLK_STS_RESOURCE: | |
d285203c CH |
2063 | if (atomic_read(&sdev->device_busy) == 0 && |
2064 | !scsi_device_blocked(sdev)) | |
36e3cf27 | 2065 | blk_mq_delay_run_hw_queue(hctx, SCSI_QUEUE_DELAY); |
d285203c | 2066 | break; |
fc17b653 | 2067 | default: |
d285203c CH |
2068 | /* |
2069 | * Make sure to release all allocated ressources when | |
2070 | * we hit an error, as we will never see this command | |
2071 | * again. | |
2072 | */ | |
e8064021 | 2073 | if (req->rq_flags & RQF_DONTPREP) |
d285203c CH |
2074 | scsi_mq_uninit_cmd(cmd); |
2075 | break; | |
d285203c CH |
2076 | } |
2077 | return ret; | |
2078 | } | |
2079 | ||
0152fb6b CH |
2080 | static enum blk_eh_timer_return scsi_timeout(struct request *req, |
2081 | bool reserved) | |
2082 | { | |
2083 | if (reserved) | |
2084 | return BLK_EH_RESET_TIMER; | |
2085 | return scsi_times_out(req); | |
2086 | } | |
2087 | ||
e7008ff5 BVA |
2088 | static int scsi_mq_init_request(struct blk_mq_tag_set *set, struct request *rq, |
2089 | unsigned int hctx_idx, unsigned int numa_node) | |
d285203c | 2090 | { |
d6296d39 | 2091 | struct Scsi_Host *shost = set->driver_data; |
8e688254 | 2092 | const bool unchecked_isa_dma = shost->unchecked_isa_dma; |
d285203c | 2093 | struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq); |
08f78436 | 2094 | struct scatterlist *sg; |
d285203c | 2095 | |
8e688254 BVA |
2096 | if (unchecked_isa_dma) |
2097 | cmd->flags |= SCMD_UNCHECKED_ISA_DMA; | |
2098 | cmd->sense_buffer = scsi_alloc_sense_buffer(unchecked_isa_dma, | |
2099 | GFP_KERNEL, numa_node); | |
d285203c CH |
2100 | if (!cmd->sense_buffer) |
2101 | return -ENOMEM; | |
82ed4db4 | 2102 | cmd->req.sense = cmd->sense_buffer; |
08f78436 BVA |
2103 | |
2104 | if (scsi_host_get_prot(shost)) { | |
2105 | sg = (void *)cmd + sizeof(struct scsi_cmnd) + | |
2106 | shost->hostt->cmd_size; | |
2107 | cmd->prot_sdb = (void *)sg + scsi_mq_sgl_size(shost); | |
2108 | } | |
2109 | ||
d285203c CH |
2110 | return 0; |
2111 | } | |
2112 | ||
e7008ff5 BVA |
2113 | static void scsi_mq_exit_request(struct blk_mq_tag_set *set, struct request *rq, |
2114 | unsigned int hctx_idx) | |
d285203c CH |
2115 | { |
2116 | struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq); | |
2117 | ||
8e688254 BVA |
2118 | scsi_free_sense_buffer(cmd->flags & SCMD_UNCHECKED_ISA_DMA, |
2119 | cmd->sense_buffer); | |
d285203c CH |
2120 | } |
2121 | ||
2d9c5c20 CH |
2122 | static int scsi_map_queues(struct blk_mq_tag_set *set) |
2123 | { | |
2124 | struct Scsi_Host *shost = container_of(set, struct Scsi_Host, tag_set); | |
2125 | ||
2126 | if (shost->hostt->map_queues) | |
2127 | return shost->hostt->map_queues(shost); | |
2128 | return blk_mq_map_queues(set); | |
2129 | } | |
2130 | ||
f1bea55d | 2131 | static u64 scsi_calculate_bounce_limit(struct Scsi_Host *shost) |
1da177e4 LT |
2132 | { |
2133 | struct device *host_dev; | |
2134 | u64 bounce_limit = 0xffffffff; | |
2135 | ||
2136 | if (shost->unchecked_isa_dma) | |
2137 | return BLK_BOUNCE_ISA; | |
2138 | /* | |
2139 | * Platforms with virtual-DMA translation | |
2140 | * hardware have no practical limit. | |
2141 | */ | |
2142 | if (!PCI_DMA_BUS_IS_PHYS) | |
2143 | return BLK_BOUNCE_ANY; | |
2144 | ||
2145 | host_dev = scsi_get_device(shost); | |
2146 | if (host_dev && host_dev->dma_mask) | |
e83b3664 | 2147 | bounce_limit = (u64)dma_max_pfn(host_dev) << PAGE_SHIFT; |
1da177e4 LT |
2148 | |
2149 | return bounce_limit; | |
2150 | } | |
1da177e4 | 2151 | |
d48777a6 | 2152 | void __scsi_init_queue(struct Scsi_Host *shost, struct request_queue *q) |
1da177e4 | 2153 | { |
6f381fa3 | 2154 | struct device *dev = shost->dma_dev; |
1da177e4 | 2155 | |
9efc160f BVA |
2156 | queue_flag_set_unlocked(QUEUE_FLAG_SCSI_PASSTHROUGH, q); |
2157 | ||
a8474ce2 JA |
2158 | /* |
2159 | * this limit is imposed by hardware restrictions | |
2160 | */ | |
8a78362c | 2161 | blk_queue_max_segments(q, min_t(unsigned short, shost->sg_tablesize, |
65e8617f | 2162 | SG_MAX_SEGMENTS)); |
a8474ce2 | 2163 | |
13f05c8d MP |
2164 | if (scsi_host_prot_dma(shost)) { |
2165 | shost->sg_prot_tablesize = | |
2166 | min_not_zero(shost->sg_prot_tablesize, | |
2167 | (unsigned short)SCSI_MAX_PROT_SG_SEGMENTS); | |
2168 | BUG_ON(shost->sg_prot_tablesize < shost->sg_tablesize); | |
2169 | blk_queue_max_integrity_segments(q, shost->sg_prot_tablesize); | |
2170 | } | |
2171 | ||
086fa5ff | 2172 | blk_queue_max_hw_sectors(q, shost->max_sectors); |
1da177e4 LT |
2173 | blk_queue_bounce_limit(q, scsi_calculate_bounce_limit(shost)); |
2174 | blk_queue_segment_boundary(q, shost->dma_boundary); | |
99c84dbd | 2175 | dma_set_seg_boundary(dev, shost->dma_boundary); |
1da177e4 | 2176 | |
860ac568 FT |
2177 | blk_queue_max_segment_size(q, dma_get_max_seg_size(dev)); |
2178 | ||
1da177e4 | 2179 | if (!shost->use_clustering) |
e692cb66 | 2180 | q->limits.cluster = 0; |
465ff318 JB |
2181 | |
2182 | /* | |
90addc6b HC |
2183 | * Set a reasonable default alignment: The larger of 32-byte (dword), |
2184 | * which is a common minimum for HBAs, and the minimum DMA alignment, | |
2185 | * which is set by the platform. | |
2186 | * | |
2187 | * Devices that require a bigger alignment can increase it later. | |
465ff318 | 2188 | */ |
90addc6b | 2189 | blk_queue_dma_alignment(q, max(4, dma_get_cache_alignment()) - 1); |
d285203c | 2190 | } |
d48777a6 | 2191 | EXPORT_SYMBOL_GPL(__scsi_init_queue); |
465ff318 | 2192 | |
e7008ff5 BVA |
2193 | static int scsi_old_init_rq(struct request_queue *q, struct request *rq, |
2194 | gfp_t gfp) | |
d285203c | 2195 | { |
e9c787e6 | 2196 | struct Scsi_Host *shost = q->rq_alloc_data; |
8e688254 | 2197 | const bool unchecked_isa_dma = shost->unchecked_isa_dma; |
e9c787e6 | 2198 | struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq); |
d285203c | 2199 | |
e9c787e6 CH |
2200 | memset(cmd, 0, sizeof(*cmd)); |
2201 | ||
8e688254 BVA |
2202 | if (unchecked_isa_dma) |
2203 | cmd->flags |= SCMD_UNCHECKED_ISA_DMA; | |
2204 | cmd->sense_buffer = scsi_alloc_sense_buffer(unchecked_isa_dma, gfp, | |
2205 | NUMA_NO_NODE); | |
e9c787e6 CH |
2206 | if (!cmd->sense_buffer) |
2207 | goto fail; | |
82ed4db4 | 2208 | cmd->req.sense = cmd->sense_buffer; |
e9c787e6 CH |
2209 | |
2210 | if (scsi_host_get_prot(shost) >= SHOST_DIX_TYPE0_PROTECTION) { | |
2211 | cmd->prot_sdb = kmem_cache_zalloc(scsi_sdb_cache, gfp); | |
2212 | if (!cmd->prot_sdb) | |
2213 | goto fail_free_sense; | |
2214 | } | |
2215 | ||
2216 | return 0; | |
2217 | ||
2218 | fail_free_sense: | |
8e688254 | 2219 | scsi_free_sense_buffer(unchecked_isa_dma, cmd->sense_buffer); |
e9c787e6 CH |
2220 | fail: |
2221 | return -ENOMEM; | |
2222 | } | |
2223 | ||
e7008ff5 | 2224 | static void scsi_old_exit_rq(struct request_queue *q, struct request *rq) |
e9c787e6 | 2225 | { |
e9c787e6 CH |
2226 | struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq); |
2227 | ||
2228 | if (cmd->prot_sdb) | |
2229 | kmem_cache_free(scsi_sdb_cache, cmd->prot_sdb); | |
8e688254 BVA |
2230 | scsi_free_sense_buffer(cmd->flags & SCMD_UNCHECKED_ISA_DMA, |
2231 | cmd->sense_buffer); | |
1da177e4 | 2232 | } |
b58d9154 | 2233 | |
e7008ff5 | 2234 | struct request_queue *scsi_old_alloc_queue(struct scsi_device *sdev) |
b58d9154 | 2235 | { |
e9c787e6 | 2236 | struct Scsi_Host *shost = sdev->host; |
b58d9154 FT |
2237 | struct request_queue *q; |
2238 | ||
e9c787e6 | 2239 | q = blk_alloc_queue_node(GFP_KERNEL, NUMA_NO_NODE); |
b58d9154 FT |
2240 | if (!q) |
2241 | return NULL; | |
e9c787e6 CH |
2242 | q->cmd_size = sizeof(struct scsi_cmnd) + shost->hostt->cmd_size; |
2243 | q->rq_alloc_data = shost; | |
2244 | q->request_fn = scsi_request_fn; | |
e7008ff5 BVA |
2245 | q->init_rq_fn = scsi_old_init_rq; |
2246 | q->exit_rq_fn = scsi_old_exit_rq; | |
ca18d6f7 | 2247 | q->initialize_rq_fn = scsi_initialize_rq; |
e9c787e6 CH |
2248 | |
2249 | if (blk_init_allocated_queue(q) < 0) { | |
2250 | blk_cleanup_queue(q); | |
2251 | return NULL; | |
2252 | } | |
b58d9154 | 2253 | |
e9c787e6 | 2254 | __scsi_init_queue(shost, q); |
b58d9154 | 2255 | blk_queue_prep_rq(q, scsi_prep_fn); |
a1b73fc1 | 2256 | blk_queue_unprep_rq(q, scsi_unprep_fn); |
b58d9154 | 2257 | blk_queue_softirq_done(q, scsi_softirq_done); |
242f9dcb | 2258 | blk_queue_rq_timed_out(q, scsi_times_out); |
6c5121b7 | 2259 | blk_queue_lld_busy(q, scsi_lld_busy); |
b58d9154 FT |
2260 | return q; |
2261 | } | |
1da177e4 | 2262 | |
f363b089 | 2263 | static const struct blk_mq_ops scsi_mq_ops = { |
0df21c86 ML |
2264 | .get_budget = scsi_mq_get_budget, |
2265 | .put_budget = scsi_mq_put_budget, | |
d285203c CH |
2266 | .queue_rq = scsi_queue_rq, |
2267 | .complete = scsi_softirq_done, | |
0152fb6b | 2268 | .timeout = scsi_timeout, |
0eebd005 BVA |
2269 | #ifdef CONFIG_BLK_DEBUG_FS |
2270 | .show_rq = scsi_show_rq, | |
2271 | #endif | |
e7008ff5 BVA |
2272 | .init_request = scsi_mq_init_request, |
2273 | .exit_request = scsi_mq_exit_request, | |
ca18d6f7 | 2274 | .initialize_rq_fn = scsi_initialize_rq, |
2d9c5c20 | 2275 | .map_queues = scsi_map_queues, |
d285203c CH |
2276 | }; |
2277 | ||
2278 | struct request_queue *scsi_mq_alloc_queue(struct scsi_device *sdev) | |
2279 | { | |
2280 | sdev->request_queue = blk_mq_init_queue(&sdev->host->tag_set); | |
2281 | if (IS_ERR(sdev->request_queue)) | |
2282 | return NULL; | |
2283 | ||
2284 | sdev->request_queue->queuedata = sdev; | |
2285 | __scsi_init_queue(sdev->host, sdev->request_queue); | |
2286 | return sdev->request_queue; | |
2287 | } | |
2288 | ||
2289 | int scsi_mq_setup_tags(struct Scsi_Host *shost) | |
2290 | { | |
be4c186c | 2291 | unsigned int cmd_size, sgl_size; |
d285203c | 2292 | |
be4c186c | 2293 | sgl_size = scsi_mq_sgl_size(shost); |
d285203c CH |
2294 | cmd_size = sizeof(struct scsi_cmnd) + shost->hostt->cmd_size + sgl_size; |
2295 | if (scsi_host_get_prot(shost)) | |
2296 | cmd_size += sizeof(struct scsi_data_buffer) + sgl_size; | |
2297 | ||
2298 | memset(&shost->tag_set, 0, sizeof(shost->tag_set)); | |
2299 | shost->tag_set.ops = &scsi_mq_ops; | |
efec4b90 | 2300 | shost->tag_set.nr_hw_queues = shost->nr_hw_queues ? : 1; |
d285203c CH |
2301 | shost->tag_set.queue_depth = shost->can_queue; |
2302 | shost->tag_set.cmd_size = cmd_size; | |
2303 | shost->tag_set.numa_node = NUMA_NO_NODE; | |
2304 | shost->tag_set.flags = BLK_MQ_F_SHOULD_MERGE | BLK_MQ_F_SG_MERGE; | |
24391c0d SL |
2305 | shost->tag_set.flags |= |
2306 | BLK_ALLOC_POLICY_TO_MQ_FLAG(shost->hostt->tag_alloc_policy); | |
d285203c CH |
2307 | shost->tag_set.driver_data = shost; |
2308 | ||
2309 | return blk_mq_alloc_tag_set(&shost->tag_set); | |
2310 | } | |
2311 | ||
2312 | void scsi_mq_destroy_tags(struct Scsi_Host *shost) | |
2313 | { | |
2314 | blk_mq_free_tag_set(&shost->tag_set); | |
2315 | } | |
2316 | ||
857de6e0 HR |
2317 | /** |
2318 | * scsi_device_from_queue - return sdev associated with a request_queue | |
2319 | * @q: The request queue to return the sdev from | |
2320 | * | |
2321 | * Return the sdev associated with a request queue or NULL if the | |
2322 | * request_queue does not reference a SCSI device. | |
2323 | */ | |
2324 | struct scsi_device *scsi_device_from_queue(struct request_queue *q) | |
2325 | { | |
2326 | struct scsi_device *sdev = NULL; | |
2327 | ||
2328 | if (q->mq_ops) { | |
2329 | if (q->mq_ops == &scsi_mq_ops) | |
2330 | sdev = q->queuedata; | |
2331 | } else if (q->request_fn == scsi_request_fn) | |
2332 | sdev = q->queuedata; | |
2333 | if (!sdev || !get_device(&sdev->sdev_gendev)) | |
2334 | sdev = NULL; | |
2335 | ||
2336 | return sdev; | |
2337 | } | |
2338 | EXPORT_SYMBOL_GPL(scsi_device_from_queue); | |
2339 | ||
1da177e4 LT |
2340 | /* |
2341 | * Function: scsi_block_requests() | |
2342 | * | |
2343 | * Purpose: Utility function used by low-level drivers to prevent further | |
2344 | * commands from being queued to the device. | |
2345 | * | |
2346 | * Arguments: shost - Host in question | |
2347 | * | |
2348 | * Returns: Nothing | |
2349 | * | |
2350 | * Lock status: No locks are assumed held. | |
2351 | * | |
2352 | * Notes: There is no timer nor any other means by which the requests | |
2353 | * get unblocked other than the low-level driver calling | |
2354 | * scsi_unblock_requests(). | |
2355 | */ | |
2356 | void scsi_block_requests(struct Scsi_Host *shost) | |
2357 | { | |
2358 | shost->host_self_blocked = 1; | |
2359 | } | |
2360 | EXPORT_SYMBOL(scsi_block_requests); | |
2361 | ||
2362 | /* | |
2363 | * Function: scsi_unblock_requests() | |
2364 | * | |
2365 | * Purpose: Utility function used by low-level drivers to allow further | |
2366 | * commands from being queued to the device. | |
2367 | * | |
2368 | * Arguments: shost - Host in question | |
2369 | * | |
2370 | * Returns: Nothing | |
2371 | * | |
2372 | * Lock status: No locks are assumed held. | |
2373 | * | |
2374 | * Notes: There is no timer nor any other means by which the requests | |
2375 | * get unblocked other than the low-level driver calling | |
2376 | * scsi_unblock_requests(). | |
2377 | * | |
2378 | * This is done as an API function so that changes to the | |
2379 | * internals of the scsi mid-layer won't require wholesale | |
2380 | * changes to drivers that use this feature. | |
2381 | */ | |
2382 | void scsi_unblock_requests(struct Scsi_Host *shost) | |
2383 | { | |
2384 | shost->host_self_blocked = 0; | |
2385 | scsi_run_host_queues(shost); | |
2386 | } | |
2387 | EXPORT_SYMBOL(scsi_unblock_requests); | |
2388 | ||
2389 | int __init scsi_init_queue(void) | |
2390 | { | |
6362abd3 MP |
2391 | scsi_sdb_cache = kmem_cache_create("scsi_data_buffer", |
2392 | sizeof(struct scsi_data_buffer), | |
2393 | 0, 0, NULL); | |
2394 | if (!scsi_sdb_cache) { | |
2395 | printk(KERN_ERR "SCSI: can't init scsi sdb cache\n"); | |
f078727b | 2396 | return -ENOMEM; |
6f9a35e2 BH |
2397 | } |
2398 | ||
1da177e4 LT |
2399 | return 0; |
2400 | } | |
2401 | ||
2402 | void scsi_exit_queue(void) | |
2403 | { | |
0a6ac4ee CH |
2404 | kmem_cache_destroy(scsi_sense_cache); |
2405 | kmem_cache_destroy(scsi_sense_isadma_cache); | |
6362abd3 | 2406 | kmem_cache_destroy(scsi_sdb_cache); |
1da177e4 | 2407 | } |
5baba830 JB |
2408 | |
2409 | /** | |
2410 | * scsi_mode_select - issue a mode select | |
2411 | * @sdev: SCSI device to be queried | |
2412 | * @pf: Page format bit (1 == standard, 0 == vendor specific) | |
2413 | * @sp: Save page bit (0 == don't save, 1 == save) | |
2414 | * @modepage: mode page being requested | |
2415 | * @buffer: request buffer (may not be smaller than eight bytes) | |
2416 | * @len: length of request buffer. | |
2417 | * @timeout: command timeout | |
2418 | * @retries: number of retries before failing | |
2419 | * @data: returns a structure abstracting the mode header data | |
eb44820c | 2420 | * @sshdr: place to put sense data (or NULL if no sense to be collected). |
5baba830 JB |
2421 | * must be SCSI_SENSE_BUFFERSIZE big. |
2422 | * | |
2423 | * Returns zero if successful; negative error number or scsi | |
2424 | * status on error | |
2425 | * | |
2426 | */ | |
2427 | int | |
2428 | scsi_mode_select(struct scsi_device *sdev, int pf, int sp, int modepage, | |
2429 | unsigned char *buffer, int len, int timeout, int retries, | |
2430 | struct scsi_mode_data *data, struct scsi_sense_hdr *sshdr) | |
2431 | { | |
2432 | unsigned char cmd[10]; | |
2433 | unsigned char *real_buffer; | |
2434 | int ret; | |
2435 | ||
2436 | memset(cmd, 0, sizeof(cmd)); | |
2437 | cmd[1] = (pf ? 0x10 : 0) | (sp ? 0x01 : 0); | |
2438 | ||
2439 | if (sdev->use_10_for_ms) { | |
2440 | if (len > 65535) | |
2441 | return -EINVAL; | |
2442 | real_buffer = kmalloc(8 + len, GFP_KERNEL); | |
2443 | if (!real_buffer) | |
2444 | return -ENOMEM; | |
2445 | memcpy(real_buffer + 8, buffer, len); | |
2446 | len += 8; | |
2447 | real_buffer[0] = 0; | |
2448 | real_buffer[1] = 0; | |
2449 | real_buffer[2] = data->medium_type; | |
2450 | real_buffer[3] = data->device_specific; | |
2451 | real_buffer[4] = data->longlba ? 0x01 : 0; | |
2452 | real_buffer[5] = 0; | |
2453 | real_buffer[6] = data->block_descriptor_length >> 8; | |
2454 | real_buffer[7] = data->block_descriptor_length; | |
2455 | ||
2456 | cmd[0] = MODE_SELECT_10; | |
2457 | cmd[7] = len >> 8; | |
2458 | cmd[8] = len; | |
2459 | } else { | |
2460 | if (len > 255 || data->block_descriptor_length > 255 || | |
2461 | data->longlba) | |
2462 | return -EINVAL; | |
2463 | ||
2464 | real_buffer = kmalloc(4 + len, GFP_KERNEL); | |
2465 | if (!real_buffer) | |
2466 | return -ENOMEM; | |
2467 | memcpy(real_buffer + 4, buffer, len); | |
2468 | len += 4; | |
2469 | real_buffer[0] = 0; | |
2470 | real_buffer[1] = data->medium_type; | |
2471 | real_buffer[2] = data->device_specific; | |
2472 | real_buffer[3] = data->block_descriptor_length; | |
2473 | ||
2474 | ||
2475 | cmd[0] = MODE_SELECT; | |
2476 | cmd[4] = len; | |
2477 | } | |
2478 | ||
2479 | ret = scsi_execute_req(sdev, cmd, DMA_TO_DEVICE, real_buffer, len, | |
f4f4e47e | 2480 | sshdr, timeout, retries, NULL); |
5baba830 JB |
2481 | kfree(real_buffer); |
2482 | return ret; | |
2483 | } | |
2484 | EXPORT_SYMBOL_GPL(scsi_mode_select); | |
2485 | ||
1da177e4 | 2486 | /** |
eb44820c | 2487 | * scsi_mode_sense - issue a mode sense, falling back from 10 to six bytes if necessary. |
1cf72699 | 2488 | * @sdev: SCSI device to be queried |
1da177e4 LT |
2489 | * @dbd: set if mode sense will allow block descriptors to be returned |
2490 | * @modepage: mode page being requested | |
2491 | * @buffer: request buffer (may not be smaller than eight bytes) | |
2492 | * @len: length of request buffer. | |
2493 | * @timeout: command timeout | |
2494 | * @retries: number of retries before failing | |
2495 | * @data: returns a structure abstracting the mode header data | |
eb44820c | 2496 | * @sshdr: place to put sense data (or NULL if no sense to be collected). |
1cf72699 | 2497 | * must be SCSI_SENSE_BUFFERSIZE big. |
1da177e4 LT |
2498 | * |
2499 | * Returns zero if unsuccessful, or the header offset (either 4 | |
2500 | * or 8 depending on whether a six or ten byte command was | |
2501 | * issued) if successful. | |
eb44820c | 2502 | */ |
1da177e4 | 2503 | int |
1cf72699 | 2504 | scsi_mode_sense(struct scsi_device *sdev, int dbd, int modepage, |
1da177e4 | 2505 | unsigned char *buffer, int len, int timeout, int retries, |
5baba830 JB |
2506 | struct scsi_mode_data *data, struct scsi_sense_hdr *sshdr) |
2507 | { | |
1da177e4 LT |
2508 | unsigned char cmd[12]; |
2509 | int use_10_for_ms; | |
2510 | int header_length; | |
0ae80ba9 | 2511 | int result, retry_count = retries; |
ea73a9f2 | 2512 | struct scsi_sense_hdr my_sshdr; |
1da177e4 LT |
2513 | |
2514 | memset(data, 0, sizeof(*data)); | |
2515 | memset(&cmd[0], 0, 12); | |
2516 | cmd[1] = dbd & 0x18; /* allows DBD and LLBA bits */ | |
2517 | cmd[2] = modepage; | |
2518 | ||
ea73a9f2 JB |
2519 | /* caller might not be interested in sense, but we need it */ |
2520 | if (!sshdr) | |
2521 | sshdr = &my_sshdr; | |
2522 | ||
1da177e4 | 2523 | retry: |
1cf72699 | 2524 | use_10_for_ms = sdev->use_10_for_ms; |
1da177e4 LT |
2525 | |
2526 | if (use_10_for_ms) { | |
2527 | if (len < 8) | |
2528 | len = 8; | |
2529 | ||
2530 | cmd[0] = MODE_SENSE_10; | |
2531 | cmd[8] = len; | |
2532 | header_length = 8; | |
2533 | } else { | |
2534 | if (len < 4) | |
2535 | len = 4; | |
2536 | ||
2537 | cmd[0] = MODE_SENSE; | |
2538 | cmd[4] = len; | |
2539 | header_length = 4; | |
2540 | } | |
2541 | ||
1da177e4 LT |
2542 | memset(buffer, 0, len); |
2543 | ||
1cf72699 | 2544 | result = scsi_execute_req(sdev, cmd, DMA_FROM_DEVICE, buffer, len, |
f4f4e47e | 2545 | sshdr, timeout, retries, NULL); |
1da177e4 LT |
2546 | |
2547 | /* This code looks awful: what it's doing is making sure an | |
2548 | * ILLEGAL REQUEST sense return identifies the actual command | |
2549 | * byte as the problem. MODE_SENSE commands can return | |
2550 | * ILLEGAL REQUEST if the code page isn't supported */ | |
2551 | ||
1cf72699 JB |
2552 | if (use_10_for_ms && !scsi_status_is_good(result) && |
2553 | (driver_byte(result) & DRIVER_SENSE)) { | |
ea73a9f2 JB |
2554 | if (scsi_sense_valid(sshdr)) { |
2555 | if ((sshdr->sense_key == ILLEGAL_REQUEST) && | |
2556 | (sshdr->asc == 0x20) && (sshdr->ascq == 0)) { | |
1da177e4 LT |
2557 | /* |
2558 | * Invalid command operation code | |
2559 | */ | |
1cf72699 | 2560 | sdev->use_10_for_ms = 0; |
1da177e4 LT |
2561 | goto retry; |
2562 | } | |
2563 | } | |
2564 | } | |
2565 | ||
1cf72699 | 2566 | if(scsi_status_is_good(result)) { |
6d73c851 AV |
2567 | if (unlikely(buffer[0] == 0x86 && buffer[1] == 0x0b && |
2568 | (modepage == 6 || modepage == 8))) { | |
2569 | /* Initio breakage? */ | |
2570 | header_length = 0; | |
2571 | data->length = 13; | |
2572 | data->medium_type = 0; | |
2573 | data->device_specific = 0; | |
2574 | data->longlba = 0; | |
2575 | data->block_descriptor_length = 0; | |
2576 | } else if(use_10_for_ms) { | |
1da177e4 LT |
2577 | data->length = buffer[0]*256 + buffer[1] + 2; |
2578 | data->medium_type = buffer[2]; | |
2579 | data->device_specific = buffer[3]; | |
2580 | data->longlba = buffer[4] & 0x01; | |
2581 | data->block_descriptor_length = buffer[6]*256 | |
2582 | + buffer[7]; | |
2583 | } else { | |
2584 | data->length = buffer[0] + 1; | |
2585 | data->medium_type = buffer[1]; | |
2586 | data->device_specific = buffer[2]; | |
2587 | data->block_descriptor_length = buffer[3]; | |
2588 | } | |
6d73c851 | 2589 | data->header_length = header_length; |
0ae80ba9 HR |
2590 | } else if ((status_byte(result) == CHECK_CONDITION) && |
2591 | scsi_sense_valid(sshdr) && | |
2592 | sshdr->sense_key == UNIT_ATTENTION && retry_count) { | |
2593 | retry_count--; | |
2594 | goto retry; | |
1da177e4 LT |
2595 | } |
2596 | ||
1cf72699 | 2597 | return result; |
1da177e4 LT |
2598 | } |
2599 | EXPORT_SYMBOL(scsi_mode_sense); | |
2600 | ||
001aac25 JB |
2601 | /** |
2602 | * scsi_test_unit_ready - test if unit is ready | |
2603 | * @sdev: scsi device to change the state of. | |
2604 | * @timeout: command timeout | |
2605 | * @retries: number of retries before failing | |
74a78ebd | 2606 | * @sshdr: outpout pointer for decoded sense information. |
001aac25 JB |
2607 | * |
2608 | * Returns zero if unsuccessful or an error if TUR failed. For | |
9f8a2c23 | 2609 | * removable media, UNIT_ATTENTION sets ->changed flag. |
001aac25 | 2610 | **/ |
1da177e4 | 2611 | int |
001aac25 | 2612 | scsi_test_unit_ready(struct scsi_device *sdev, int timeout, int retries, |
74a78ebd | 2613 | struct scsi_sense_hdr *sshdr) |
1da177e4 | 2614 | { |
1da177e4 LT |
2615 | char cmd[] = { |
2616 | TEST_UNIT_READY, 0, 0, 0, 0, 0, | |
2617 | }; | |
2618 | int result; | |
001aac25 | 2619 | |
001aac25 JB |
2620 | /* try to eat the UNIT_ATTENTION if there are enough retries */ |
2621 | do { | |
2622 | result = scsi_execute_req(sdev, cmd, DMA_NONE, NULL, 0, sshdr, | |
f4f4e47e | 2623 | timeout, retries, NULL); |
32c356d7 JB |
2624 | if (sdev->removable && scsi_sense_valid(sshdr) && |
2625 | sshdr->sense_key == UNIT_ATTENTION) | |
2626 | sdev->changed = 1; | |
2627 | } while (scsi_sense_valid(sshdr) && | |
2628 | sshdr->sense_key == UNIT_ATTENTION && --retries); | |
001aac25 | 2629 | |
1da177e4 LT |
2630 | return result; |
2631 | } | |
2632 | EXPORT_SYMBOL(scsi_test_unit_ready); | |
2633 | ||
2634 | /** | |
eb44820c | 2635 | * scsi_device_set_state - Take the given device through the device state model. |
1da177e4 LT |
2636 | * @sdev: scsi device to change the state of. |
2637 | * @state: state to change to. | |
2638 | * | |
23cb27fd | 2639 | * Returns zero if successful or an error if the requested |
1da177e4 | 2640 | * transition is illegal. |
eb44820c | 2641 | */ |
1da177e4 LT |
2642 | int |
2643 | scsi_device_set_state(struct scsi_device *sdev, enum scsi_device_state state) | |
2644 | { | |
2645 | enum scsi_device_state oldstate = sdev->sdev_state; | |
2646 | ||
2647 | if (state == oldstate) | |
2648 | return 0; | |
2649 | ||
2650 | switch (state) { | |
2651 | case SDEV_CREATED: | |
6f4267e3 JB |
2652 | switch (oldstate) { |
2653 | case SDEV_CREATED_BLOCK: | |
2654 | break; | |
2655 | default: | |
2656 | goto illegal; | |
2657 | } | |
2658 | break; | |
1da177e4 LT |
2659 | |
2660 | case SDEV_RUNNING: | |
2661 | switch (oldstate) { | |
2662 | case SDEV_CREATED: | |
2663 | case SDEV_OFFLINE: | |
1b8d2620 | 2664 | case SDEV_TRANSPORT_OFFLINE: |
1da177e4 LT |
2665 | case SDEV_QUIESCE: |
2666 | case SDEV_BLOCK: | |
2667 | break; | |
2668 | default: | |
2669 | goto illegal; | |
2670 | } | |
2671 | break; | |
2672 | ||
2673 | case SDEV_QUIESCE: | |
2674 | switch (oldstate) { | |
2675 | case SDEV_RUNNING: | |
2676 | case SDEV_OFFLINE: | |
1b8d2620 | 2677 | case SDEV_TRANSPORT_OFFLINE: |
1da177e4 LT |
2678 | break; |
2679 | default: | |
2680 | goto illegal; | |
2681 | } | |
2682 | break; | |
2683 | ||
2684 | case SDEV_OFFLINE: | |
1b8d2620 | 2685 | case SDEV_TRANSPORT_OFFLINE: |
1da177e4 LT |
2686 | switch (oldstate) { |
2687 | case SDEV_CREATED: | |
2688 | case SDEV_RUNNING: | |
2689 | case SDEV_QUIESCE: | |
2690 | case SDEV_BLOCK: | |
2691 | break; | |
2692 | default: | |
2693 | goto illegal; | |
2694 | } | |
2695 | break; | |
2696 | ||
2697 | case SDEV_BLOCK: | |
2698 | switch (oldstate) { | |
1da177e4 | 2699 | case SDEV_RUNNING: |
6f4267e3 JB |
2700 | case SDEV_CREATED_BLOCK: |
2701 | break; | |
2702 | default: | |
2703 | goto illegal; | |
2704 | } | |
2705 | break; | |
2706 | ||
2707 | case SDEV_CREATED_BLOCK: | |
2708 | switch (oldstate) { | |
2709 | case SDEV_CREATED: | |
1da177e4 LT |
2710 | break; |
2711 | default: | |
2712 | goto illegal; | |
2713 | } | |
2714 | break; | |
2715 | ||
2716 | case SDEV_CANCEL: | |
2717 | switch (oldstate) { | |
2718 | case SDEV_CREATED: | |
2719 | case SDEV_RUNNING: | |
9ea72909 | 2720 | case SDEV_QUIESCE: |
1da177e4 | 2721 | case SDEV_OFFLINE: |
1b8d2620 | 2722 | case SDEV_TRANSPORT_OFFLINE: |
1da177e4 LT |
2723 | break; |
2724 | default: | |
2725 | goto illegal; | |
2726 | } | |
2727 | break; | |
2728 | ||
2729 | case SDEV_DEL: | |
2730 | switch (oldstate) { | |
309bd271 BK |
2731 | case SDEV_CREATED: |
2732 | case SDEV_RUNNING: | |
2733 | case SDEV_OFFLINE: | |
1b8d2620 | 2734 | case SDEV_TRANSPORT_OFFLINE: |
1da177e4 | 2735 | case SDEV_CANCEL: |
255ee932 | 2736 | case SDEV_BLOCK: |
0516c08d | 2737 | case SDEV_CREATED_BLOCK: |
1da177e4 LT |
2738 | break; |
2739 | default: | |
2740 | goto illegal; | |
2741 | } | |
2742 | break; | |
2743 | ||
2744 | } | |
2745 | sdev->sdev_state = state; | |
2746 | return 0; | |
2747 | ||
2748 | illegal: | |
91921e01 | 2749 | SCSI_LOG_ERROR_RECOVERY(1, |
9ccfc756 | 2750 | sdev_printk(KERN_ERR, sdev, |
91921e01 | 2751 | "Illegal state transition %s->%s", |
9ccfc756 JB |
2752 | scsi_device_state_name(oldstate), |
2753 | scsi_device_state_name(state)) | |
1da177e4 LT |
2754 | ); |
2755 | return -EINVAL; | |
2756 | } | |
2757 | EXPORT_SYMBOL(scsi_device_set_state); | |
2758 | ||
a341cd0f JG |
2759 | /** |
2760 | * sdev_evt_emit - emit a single SCSI device uevent | |
2761 | * @sdev: associated SCSI device | |
2762 | * @evt: event to emit | |
2763 | * | |
2764 | * Send a single uevent (scsi_event) to the associated scsi_device. | |
2765 | */ | |
2766 | static void scsi_evt_emit(struct scsi_device *sdev, struct scsi_event *evt) | |
2767 | { | |
2768 | int idx = 0; | |
2769 | char *envp[3]; | |
2770 | ||
2771 | switch (evt->evt_type) { | |
2772 | case SDEV_EVT_MEDIA_CHANGE: | |
2773 | envp[idx++] = "SDEV_MEDIA_CHANGE=1"; | |
2774 | break; | |
279afdfe | 2775 | case SDEV_EVT_INQUIRY_CHANGE_REPORTED: |
d3d32891 | 2776 | scsi_rescan_device(&sdev->sdev_gendev); |
279afdfe EM |
2777 | envp[idx++] = "SDEV_UA=INQUIRY_DATA_HAS_CHANGED"; |
2778 | break; | |
2779 | case SDEV_EVT_CAPACITY_CHANGE_REPORTED: | |
2780 | envp[idx++] = "SDEV_UA=CAPACITY_DATA_HAS_CHANGED"; | |
2781 | break; | |
2782 | case SDEV_EVT_SOFT_THRESHOLD_REACHED_REPORTED: | |
2783 | envp[idx++] = "SDEV_UA=THIN_PROVISIONING_SOFT_THRESHOLD_REACHED"; | |
2784 | break; | |
2785 | case SDEV_EVT_MODE_PARAMETER_CHANGE_REPORTED: | |
2786 | envp[idx++] = "SDEV_UA=MODE_PARAMETERS_CHANGED"; | |
2787 | break; | |
2788 | case SDEV_EVT_LUN_CHANGE_REPORTED: | |
2789 | envp[idx++] = "SDEV_UA=REPORTED_LUNS_DATA_HAS_CHANGED"; | |
2790 | break; | |
14c3e677 HR |
2791 | case SDEV_EVT_ALUA_STATE_CHANGE_REPORTED: |
2792 | envp[idx++] = "SDEV_UA=ASYMMETRIC_ACCESS_STATE_CHANGED"; | |
2793 | break; | |
cf3431bb HR |
2794 | case SDEV_EVT_POWER_ON_RESET_OCCURRED: |
2795 | envp[idx++] = "SDEV_UA=POWER_ON_RESET_OCCURRED"; | |
2796 | break; | |
a341cd0f JG |
2797 | default: |
2798 | /* do nothing */ | |
2799 | break; | |
2800 | } | |
2801 | ||
2802 | envp[idx++] = NULL; | |
2803 | ||
2804 | kobject_uevent_env(&sdev->sdev_gendev.kobj, KOBJ_CHANGE, envp); | |
2805 | } | |
2806 | ||
2807 | /** | |
2808 | * sdev_evt_thread - send a uevent for each scsi event | |
2809 | * @work: work struct for scsi_device | |
2810 | * | |
2811 | * Dispatch queued events to their associated scsi_device kobjects | |
2812 | * as uevents. | |
2813 | */ | |
2814 | void scsi_evt_thread(struct work_struct *work) | |
2815 | { | |
2816 | struct scsi_device *sdev; | |
279afdfe | 2817 | enum scsi_device_event evt_type; |
a341cd0f JG |
2818 | LIST_HEAD(event_list); |
2819 | ||
2820 | sdev = container_of(work, struct scsi_device, event_work); | |
2821 | ||
279afdfe EM |
2822 | for (evt_type = SDEV_EVT_FIRST; evt_type <= SDEV_EVT_LAST; evt_type++) |
2823 | if (test_and_clear_bit(evt_type, sdev->pending_events)) | |
2824 | sdev_evt_send_simple(sdev, evt_type, GFP_KERNEL); | |
2825 | ||
a341cd0f JG |
2826 | while (1) { |
2827 | struct scsi_event *evt; | |
2828 | struct list_head *this, *tmp; | |
2829 | unsigned long flags; | |
2830 | ||
2831 | spin_lock_irqsave(&sdev->list_lock, flags); | |
2832 | list_splice_init(&sdev->event_list, &event_list); | |
2833 | spin_unlock_irqrestore(&sdev->list_lock, flags); | |
2834 | ||
2835 | if (list_empty(&event_list)) | |
2836 | break; | |
2837 | ||
2838 | list_for_each_safe(this, tmp, &event_list) { | |
2839 | evt = list_entry(this, struct scsi_event, node); | |
2840 | list_del(&evt->node); | |
2841 | scsi_evt_emit(sdev, evt); | |
2842 | kfree(evt); | |
2843 | } | |
2844 | } | |
2845 | } | |
2846 | ||
2847 | /** | |
2848 | * sdev_evt_send - send asserted event to uevent thread | |
2849 | * @sdev: scsi_device event occurred on | |
2850 | * @evt: event to send | |
2851 | * | |
2852 | * Assert scsi device event asynchronously. | |
2853 | */ | |
2854 | void sdev_evt_send(struct scsi_device *sdev, struct scsi_event *evt) | |
2855 | { | |
2856 | unsigned long flags; | |
2857 | ||
4d1566ed KS |
2858 | #if 0 |
2859 | /* FIXME: currently this check eliminates all media change events | |
2860 | * for polled devices. Need to update to discriminate between AN | |
2861 | * and polled events */ | |
a341cd0f JG |
2862 | if (!test_bit(evt->evt_type, sdev->supported_events)) { |
2863 | kfree(evt); | |
2864 | return; | |
2865 | } | |
4d1566ed | 2866 | #endif |
a341cd0f JG |
2867 | |
2868 | spin_lock_irqsave(&sdev->list_lock, flags); | |
2869 | list_add_tail(&evt->node, &sdev->event_list); | |
2870 | schedule_work(&sdev->event_work); | |
2871 | spin_unlock_irqrestore(&sdev->list_lock, flags); | |
2872 | } | |
2873 | EXPORT_SYMBOL_GPL(sdev_evt_send); | |
2874 | ||
2875 | /** | |
2876 | * sdev_evt_alloc - allocate a new scsi event | |
2877 | * @evt_type: type of event to allocate | |
2878 | * @gfpflags: GFP flags for allocation | |
2879 | * | |
2880 | * Allocates and returns a new scsi_event. | |
2881 | */ | |
2882 | struct scsi_event *sdev_evt_alloc(enum scsi_device_event evt_type, | |
2883 | gfp_t gfpflags) | |
2884 | { | |
2885 | struct scsi_event *evt = kzalloc(sizeof(struct scsi_event), gfpflags); | |
2886 | if (!evt) | |
2887 | return NULL; | |
2888 | ||
2889 | evt->evt_type = evt_type; | |
2890 | INIT_LIST_HEAD(&evt->node); | |
2891 | ||
2892 | /* evt_type-specific initialization, if any */ | |
2893 | switch (evt_type) { | |
2894 | case SDEV_EVT_MEDIA_CHANGE: | |
279afdfe EM |
2895 | case SDEV_EVT_INQUIRY_CHANGE_REPORTED: |
2896 | case SDEV_EVT_CAPACITY_CHANGE_REPORTED: | |
2897 | case SDEV_EVT_SOFT_THRESHOLD_REACHED_REPORTED: | |
2898 | case SDEV_EVT_MODE_PARAMETER_CHANGE_REPORTED: | |
2899 | case SDEV_EVT_LUN_CHANGE_REPORTED: | |
14c3e677 | 2900 | case SDEV_EVT_ALUA_STATE_CHANGE_REPORTED: |
cf3431bb | 2901 | case SDEV_EVT_POWER_ON_RESET_OCCURRED: |
a341cd0f JG |
2902 | default: |
2903 | /* do nothing */ | |
2904 | break; | |
2905 | } | |
2906 | ||
2907 | return evt; | |
2908 | } | |
2909 | EXPORT_SYMBOL_GPL(sdev_evt_alloc); | |
2910 | ||
2911 | /** | |
2912 | * sdev_evt_send_simple - send asserted event to uevent thread | |
2913 | * @sdev: scsi_device event occurred on | |
2914 | * @evt_type: type of event to send | |
2915 | * @gfpflags: GFP flags for allocation | |
2916 | * | |
2917 | * Assert scsi device event asynchronously, given an event type. | |
2918 | */ | |
2919 | void sdev_evt_send_simple(struct scsi_device *sdev, | |
2920 | enum scsi_device_event evt_type, gfp_t gfpflags) | |
2921 | { | |
2922 | struct scsi_event *evt = sdev_evt_alloc(evt_type, gfpflags); | |
2923 | if (!evt) { | |
2924 | sdev_printk(KERN_ERR, sdev, "event %d eaten due to OOM\n", | |
2925 | evt_type); | |
2926 | return; | |
2927 | } | |
2928 | ||
2929 | sdev_evt_send(sdev, evt); | |
2930 | } | |
2931 | EXPORT_SYMBOL_GPL(sdev_evt_send_simple); | |
2932 | ||
669f0441 BVA |
2933 | /** |
2934 | * scsi_request_fn_active() - number of kernel threads inside scsi_request_fn() | |
2935 | * @sdev: SCSI device to count the number of scsi_request_fn() callers for. | |
2936 | */ | |
2937 | static int scsi_request_fn_active(struct scsi_device *sdev) | |
2938 | { | |
2939 | struct request_queue *q = sdev->request_queue; | |
2940 | int request_fn_active; | |
2941 | ||
2942 | WARN_ON_ONCE(sdev->host->use_blk_mq); | |
2943 | ||
2944 | spin_lock_irq(q->queue_lock); | |
2945 | request_fn_active = q->request_fn_active; | |
2946 | spin_unlock_irq(q->queue_lock); | |
2947 | ||
2948 | return request_fn_active; | |
2949 | } | |
2950 | ||
2951 | /** | |
2952 | * scsi_wait_for_queuecommand() - wait for ongoing queuecommand() calls | |
2953 | * @sdev: SCSI device pointer. | |
2954 | * | |
2955 | * Wait until the ongoing shost->hostt->queuecommand() calls that are | |
2956 | * invoked from scsi_request_fn() have finished. | |
2957 | */ | |
2958 | static void scsi_wait_for_queuecommand(struct scsi_device *sdev) | |
2959 | { | |
2960 | WARN_ON_ONCE(sdev->host->use_blk_mq); | |
2961 | ||
2962 | while (scsi_request_fn_active(sdev)) | |
2963 | msleep(20); | |
2964 | } | |
2965 | ||
1da177e4 LT |
2966 | /** |
2967 | * scsi_device_quiesce - Block user issued commands. | |
2968 | * @sdev: scsi device to quiesce. | |
2969 | * | |
2970 | * This works by trying to transition to the SDEV_QUIESCE state | |
2971 | * (which must be a legal transition). When the device is in this | |
2972 | * state, only special requests will be accepted, all others will | |
2973 | * be deferred. Since special requests may also be requeued requests, | |
2974 | * a successful return doesn't guarantee the device will be | |
2975 | * totally quiescent. | |
2976 | * | |
2977 | * Must be called with user context, may sleep. | |
2978 | * | |
2979 | * Returns zero if unsuccessful or an error if not. | |
eb44820c | 2980 | */ |
1da177e4 LT |
2981 | int |
2982 | scsi_device_quiesce(struct scsi_device *sdev) | |
2983 | { | |
3a0a5299 | 2984 | struct request_queue *q = sdev->request_queue; |
0db6ca8a BVA |
2985 | int err; |
2986 | ||
3a0a5299 BVA |
2987 | /* |
2988 | * It is allowed to call scsi_device_quiesce() multiple times from | |
2989 | * the same context but concurrent scsi_device_quiesce() calls are | |
2990 | * not allowed. | |
2991 | */ | |
2992 | WARN_ON_ONCE(sdev->quiesced_by && sdev->quiesced_by != current); | |
2993 | ||
2994 | blk_set_preempt_only(q); | |
2995 | ||
2996 | blk_mq_freeze_queue(q); | |
2997 | /* | |
2998 | * Ensure that the effect of blk_set_preempt_only() will be visible | |
2999 | * for percpu_ref_tryget() callers that occur after the queue | |
3000 | * unfreeze even if the queue was already frozen before this function | |
3001 | * was called. See also https://lwn.net/Articles/573497/. | |
3002 | */ | |
3003 | synchronize_rcu(); | |
3004 | blk_mq_unfreeze_queue(q); | |
3005 | ||
0db6ca8a BVA |
3006 | mutex_lock(&sdev->state_mutex); |
3007 | err = scsi_device_set_state(sdev, SDEV_QUIESCE); | |
3a0a5299 BVA |
3008 | if (err == 0) |
3009 | sdev->quiesced_by = current; | |
3010 | else | |
3011 | blk_clear_preempt_only(q); | |
0db6ca8a BVA |
3012 | mutex_unlock(&sdev->state_mutex); |
3013 | ||
3a0a5299 | 3014 | return err; |
1da177e4 LT |
3015 | } |
3016 | EXPORT_SYMBOL(scsi_device_quiesce); | |
3017 | ||
3018 | /** | |
3019 | * scsi_device_resume - Restart user issued commands to a quiesced device. | |
3020 | * @sdev: scsi device to resume. | |
3021 | * | |
3022 | * Moves the device from quiesced back to running and restarts the | |
3023 | * queues. | |
3024 | * | |
3025 | * Must be called with user context, may sleep. | |
eb44820c | 3026 | */ |
a7a20d10 | 3027 | void scsi_device_resume(struct scsi_device *sdev) |
1da177e4 | 3028 | { |
a7a20d10 DW |
3029 | /* check if the device state was mutated prior to resume, and if |
3030 | * so assume the state is being managed elsewhere (for example | |
3031 | * device deleted during suspend) | |
3032 | */ | |
0db6ca8a | 3033 | mutex_lock(&sdev->state_mutex); |
3a0a5299 BVA |
3034 | WARN_ON_ONCE(!sdev->quiesced_by); |
3035 | sdev->quiesced_by = NULL; | |
3036 | blk_clear_preempt_only(sdev->request_queue); | |
3037 | if (sdev->sdev_state == SDEV_QUIESCE) | |
3038 | scsi_device_set_state(sdev, SDEV_RUNNING); | |
0db6ca8a | 3039 | mutex_unlock(&sdev->state_mutex); |
1da177e4 LT |
3040 | } |
3041 | EXPORT_SYMBOL(scsi_device_resume); | |
3042 | ||
3043 | static void | |
3044 | device_quiesce_fn(struct scsi_device *sdev, void *data) | |
3045 | { | |
3046 | scsi_device_quiesce(sdev); | |
3047 | } | |
3048 | ||
3049 | void | |
3050 | scsi_target_quiesce(struct scsi_target *starget) | |
3051 | { | |
3052 | starget_for_each_device(starget, NULL, device_quiesce_fn); | |
3053 | } | |
3054 | EXPORT_SYMBOL(scsi_target_quiesce); | |
3055 | ||
3056 | static void | |
3057 | device_resume_fn(struct scsi_device *sdev, void *data) | |
3058 | { | |
3059 | scsi_device_resume(sdev); | |
3060 | } | |
3061 | ||
3062 | void | |
3063 | scsi_target_resume(struct scsi_target *starget) | |
3064 | { | |
3065 | starget_for_each_device(starget, NULL, device_resume_fn); | |
3066 | } | |
3067 | EXPORT_SYMBOL(scsi_target_resume); | |
3068 | ||
3069 | /** | |
551eb598 BVA |
3070 | * scsi_internal_device_block_nowait - try to transition to the SDEV_BLOCK state |
3071 | * @sdev: device to block | |
1da177e4 | 3072 | * |
551eb598 | 3073 | * Pause SCSI command processing on the specified device. Does not sleep. |
1da177e4 | 3074 | * |
551eb598 | 3075 | * Returns zero if successful or a negative error code upon failure. |
669f0441 | 3076 | * |
551eb598 BVA |
3077 | * Notes: |
3078 | * This routine transitions the device to the SDEV_BLOCK state (which must be | |
3079 | * a legal transition). When the device is in this state, command processing | |
3080 | * is paused until the device leaves the SDEV_BLOCK state. See also | |
3081 | * scsi_internal_device_unblock_nowait(). | |
eb44820c | 3082 | */ |
551eb598 | 3083 | int scsi_internal_device_block_nowait(struct scsi_device *sdev) |
1da177e4 | 3084 | { |
165125e1 | 3085 | struct request_queue *q = sdev->request_queue; |
1da177e4 LT |
3086 | unsigned long flags; |
3087 | int err = 0; | |
3088 | ||
3089 | err = scsi_device_set_state(sdev, SDEV_BLOCK); | |
6f4267e3 JB |
3090 | if (err) { |
3091 | err = scsi_device_set_state(sdev, SDEV_CREATED_BLOCK); | |
3092 | ||
3093 | if (err) | |
3094 | return err; | |
3095 | } | |
1da177e4 LT |
3096 | |
3097 | /* | |
3098 | * The device has transitioned to SDEV_BLOCK. Stop the | |
3099 | * block layer from calling the midlayer with this device's | |
3100 | * request queue. | |
3101 | */ | |
d285203c | 3102 | if (q->mq_ops) { |
90311148 | 3103 | blk_mq_quiesce_queue_nowait(q); |
d285203c CH |
3104 | } else { |
3105 | spin_lock_irqsave(q->queue_lock, flags); | |
3106 | blk_stop_queue(q); | |
3107 | spin_unlock_irqrestore(q->queue_lock, flags); | |
3108 | } | |
1da177e4 LT |
3109 | |
3110 | return 0; | |
3111 | } | |
551eb598 BVA |
3112 | EXPORT_SYMBOL_GPL(scsi_internal_device_block_nowait); |
3113 | ||
1da177e4 | 3114 | /** |
551eb598 BVA |
3115 | * scsi_internal_device_block - try to transition to the SDEV_BLOCK state |
3116 | * @sdev: device to block | |
3117 | * | |
3118 | * Pause SCSI command processing on the specified device and wait until all | |
3119 | * ongoing scsi_request_fn() / scsi_queue_rq() calls have finished. May sleep. | |
1da177e4 | 3120 | * |
551eb598 | 3121 | * Returns zero if successful or a negative error code upon failure. |
1da177e4 | 3122 | * |
551eb598 BVA |
3123 | * Note: |
3124 | * This routine transitions the device to the SDEV_BLOCK state (which must be | |
3125 | * a legal transition). When the device is in this state, command processing | |
3126 | * is paused until the device leaves the SDEV_BLOCK state. See also | |
3127 | * scsi_internal_device_unblock(). | |
1da177e4 | 3128 | * |
551eb598 BVA |
3129 | * To do: avoid that scsi_send_eh_cmnd() calls queuecommand() after |
3130 | * scsi_internal_device_block() has blocked a SCSI device and also | |
3131 | * remove the rport mutex lock and unlock calls from srp_queuecommand(). | |
eb44820c | 3132 | */ |
551eb598 | 3133 | static int scsi_internal_device_block(struct scsi_device *sdev) |
1da177e4 | 3134 | { |
551eb598 BVA |
3135 | struct request_queue *q = sdev->request_queue; |
3136 | int err; | |
3137 | ||
0db6ca8a | 3138 | mutex_lock(&sdev->state_mutex); |
551eb598 BVA |
3139 | err = scsi_internal_device_block_nowait(sdev); |
3140 | if (err == 0) { | |
3141 | if (q->mq_ops) | |
3142 | blk_mq_quiesce_queue(q); | |
3143 | else | |
3144 | scsi_wait_for_queuecommand(sdev); | |
3145 | } | |
0db6ca8a BVA |
3146 | mutex_unlock(&sdev->state_mutex); |
3147 | ||
551eb598 BVA |
3148 | return err; |
3149 | } | |
1da177e4 | 3150 | |
66483a4a BVA |
3151 | void scsi_start_queue(struct scsi_device *sdev) |
3152 | { | |
3153 | struct request_queue *q = sdev->request_queue; | |
1da177e4 | 3154 | unsigned long flags; |
5d9fb5cc | 3155 | |
66483a4a | 3156 | if (q->mq_ops) { |
90311148 | 3157 | blk_mq_unquiesce_queue(q); |
66483a4a BVA |
3158 | } else { |
3159 | spin_lock_irqsave(q->queue_lock, flags); | |
3160 | blk_start_queue(q); | |
3161 | spin_unlock_irqrestore(q->queue_lock, flags); | |
3162 | } | |
3163 | } | |
3164 | ||
1da177e4 | 3165 | /** |
43f7571b | 3166 | * scsi_internal_device_unblock_nowait - resume a device after a block request |
1da177e4 | 3167 | * @sdev: device to resume |
43f7571b | 3168 | * @new_state: state to set the device to after unblocking |
1da177e4 | 3169 | * |
43f7571b BVA |
3170 | * Restart the device queue for a previously suspended SCSI device. Does not |
3171 | * sleep. | |
1da177e4 | 3172 | * |
43f7571b | 3173 | * Returns zero if successful or a negative error code upon failure. |
1da177e4 | 3174 | * |
43f7571b BVA |
3175 | * Notes: |
3176 | * This routine transitions the device to the SDEV_RUNNING state or to one of | |
3177 | * the offline states (which must be a legal transition) allowing the midlayer | |
3178 | * to goose the queue for this device. | |
eb44820c | 3179 | */ |
43f7571b BVA |
3180 | int scsi_internal_device_unblock_nowait(struct scsi_device *sdev, |
3181 | enum scsi_device_state new_state) | |
1da177e4 | 3182 | { |
5d9fb5cc MC |
3183 | /* |
3184 | * Try to transition the scsi device to SDEV_RUNNING or one of the | |
3185 | * offlined states and goose the device queue if successful. | |
1da177e4 | 3186 | */ |
8cd1ec78 HR |
3187 | switch (sdev->sdev_state) { |
3188 | case SDEV_BLOCK: | |
3189 | case SDEV_TRANSPORT_OFFLINE: | |
5d9fb5cc | 3190 | sdev->sdev_state = new_state; |
8cd1ec78 HR |
3191 | break; |
3192 | case SDEV_CREATED_BLOCK: | |
5d9fb5cc MC |
3193 | if (new_state == SDEV_TRANSPORT_OFFLINE || |
3194 | new_state == SDEV_OFFLINE) | |
3195 | sdev->sdev_state = new_state; | |
3196 | else | |
3197 | sdev->sdev_state = SDEV_CREATED; | |
8cd1ec78 HR |
3198 | break; |
3199 | case SDEV_CANCEL: | |
3200 | case SDEV_OFFLINE: | |
3201 | break; | |
3202 | default: | |
5c10e63c | 3203 | return -EINVAL; |
8cd1ec78 | 3204 | } |
66483a4a | 3205 | scsi_start_queue(sdev); |
1da177e4 LT |
3206 | |
3207 | return 0; | |
3208 | } | |
43f7571b BVA |
3209 | EXPORT_SYMBOL_GPL(scsi_internal_device_unblock_nowait); |
3210 | ||
3211 | /** | |
3212 | * scsi_internal_device_unblock - resume a device after a block request | |
3213 | * @sdev: device to resume | |
3214 | * @new_state: state to set the device to after unblocking | |
3215 | * | |
3216 | * Restart the device queue for a previously suspended SCSI device. May sleep. | |
3217 | * | |
3218 | * Returns zero if successful or a negative error code upon failure. | |
3219 | * | |
3220 | * Notes: | |
3221 | * This routine transitions the device to the SDEV_RUNNING state or to one of | |
3222 | * the offline states (which must be a legal transition) allowing the midlayer | |
3223 | * to goose the queue for this device. | |
3224 | */ | |
3225 | static int scsi_internal_device_unblock(struct scsi_device *sdev, | |
3226 | enum scsi_device_state new_state) | |
3227 | { | |
0db6ca8a BVA |
3228 | int ret; |
3229 | ||
3230 | mutex_lock(&sdev->state_mutex); | |
3231 | ret = scsi_internal_device_unblock_nowait(sdev, new_state); | |
3232 | mutex_unlock(&sdev->state_mutex); | |
3233 | ||
3234 | return ret; | |
43f7571b | 3235 | } |
1da177e4 LT |
3236 | |
3237 | static void | |
3238 | device_block(struct scsi_device *sdev, void *data) | |
3239 | { | |
551eb598 | 3240 | scsi_internal_device_block(sdev); |
1da177e4 LT |
3241 | } |
3242 | ||
3243 | static int | |
3244 | target_block(struct device *dev, void *data) | |
3245 | { | |
3246 | if (scsi_is_target_device(dev)) | |
3247 | starget_for_each_device(to_scsi_target(dev), NULL, | |
3248 | device_block); | |
3249 | return 0; | |
3250 | } | |
3251 | ||
3252 | void | |
3253 | scsi_target_block(struct device *dev) | |
3254 | { | |
3255 | if (scsi_is_target_device(dev)) | |
3256 | starget_for_each_device(to_scsi_target(dev), NULL, | |
3257 | device_block); | |
3258 | else | |
3259 | device_for_each_child(dev, NULL, target_block); | |
3260 | } | |
3261 | EXPORT_SYMBOL_GPL(scsi_target_block); | |
3262 | ||
3263 | static void | |
3264 | device_unblock(struct scsi_device *sdev, void *data) | |
3265 | { | |
5d9fb5cc | 3266 | scsi_internal_device_unblock(sdev, *(enum scsi_device_state *)data); |
1da177e4 LT |
3267 | } |
3268 | ||
3269 | static int | |
3270 | target_unblock(struct device *dev, void *data) | |
3271 | { | |
3272 | if (scsi_is_target_device(dev)) | |
5d9fb5cc | 3273 | starget_for_each_device(to_scsi_target(dev), data, |
1da177e4 LT |
3274 | device_unblock); |
3275 | return 0; | |
3276 | } | |
3277 | ||
3278 | void | |
5d9fb5cc | 3279 | scsi_target_unblock(struct device *dev, enum scsi_device_state new_state) |
1da177e4 LT |
3280 | { |
3281 | if (scsi_is_target_device(dev)) | |
5d9fb5cc | 3282 | starget_for_each_device(to_scsi_target(dev), &new_state, |
1da177e4 LT |
3283 | device_unblock); |
3284 | else | |
5d9fb5cc | 3285 | device_for_each_child(dev, &new_state, target_unblock); |
1da177e4 LT |
3286 | } |
3287 | EXPORT_SYMBOL_GPL(scsi_target_unblock); | |
cdb8c2a6 GL |
3288 | |
3289 | /** | |
3290 | * scsi_kmap_atomic_sg - find and atomically map an sg-elemnt | |
eb44820c | 3291 | * @sgl: scatter-gather list |
cdb8c2a6 GL |
3292 | * @sg_count: number of segments in sg |
3293 | * @offset: offset in bytes into sg, on return offset into the mapped area | |
3294 | * @len: bytes to map, on return number of bytes mapped | |
3295 | * | |
3296 | * Returns virtual address of the start of the mapped page | |
3297 | */ | |
c6132da1 | 3298 | void *scsi_kmap_atomic_sg(struct scatterlist *sgl, int sg_count, |
cdb8c2a6 GL |
3299 | size_t *offset, size_t *len) |
3300 | { | |
3301 | int i; | |
3302 | size_t sg_len = 0, len_complete = 0; | |
c6132da1 | 3303 | struct scatterlist *sg; |
cdb8c2a6 GL |
3304 | struct page *page; |
3305 | ||
22cfefb5 AM |
3306 | WARN_ON(!irqs_disabled()); |
3307 | ||
c6132da1 | 3308 | for_each_sg(sgl, sg, sg_count, i) { |
cdb8c2a6 | 3309 | len_complete = sg_len; /* Complete sg-entries */ |
c6132da1 | 3310 | sg_len += sg->length; |
cdb8c2a6 GL |
3311 | if (sg_len > *offset) |
3312 | break; | |
3313 | } | |
3314 | ||
3315 | if (unlikely(i == sg_count)) { | |
169e1a2a AM |
3316 | printk(KERN_ERR "%s: Bytes in sg: %zu, requested offset %zu, " |
3317 | "elements %d\n", | |
cadbd4a5 | 3318 | __func__, sg_len, *offset, sg_count); |
cdb8c2a6 GL |
3319 | WARN_ON(1); |
3320 | return NULL; | |
3321 | } | |
3322 | ||
3323 | /* Offset starting from the beginning of first page in this sg-entry */ | |
c6132da1 | 3324 | *offset = *offset - len_complete + sg->offset; |
cdb8c2a6 GL |
3325 | |
3326 | /* Assumption: contiguous pages can be accessed as "page + i" */ | |
45711f1a | 3327 | page = nth_page(sg_page(sg), (*offset >> PAGE_SHIFT)); |
cdb8c2a6 GL |
3328 | *offset &= ~PAGE_MASK; |
3329 | ||
3330 | /* Bytes in this sg-entry from *offset to the end of the page */ | |
3331 | sg_len = PAGE_SIZE - *offset; | |
3332 | if (*len > sg_len) | |
3333 | *len = sg_len; | |
3334 | ||
77dfce07 | 3335 | return kmap_atomic(page); |
cdb8c2a6 GL |
3336 | } |
3337 | EXPORT_SYMBOL(scsi_kmap_atomic_sg); | |
3338 | ||
3339 | /** | |
eb44820c | 3340 | * scsi_kunmap_atomic_sg - atomically unmap a virtual address, previously mapped with scsi_kmap_atomic_sg |
cdb8c2a6 GL |
3341 | * @virt: virtual address to be unmapped |
3342 | */ | |
3343 | void scsi_kunmap_atomic_sg(void *virt) | |
3344 | { | |
77dfce07 | 3345 | kunmap_atomic(virt); |
cdb8c2a6 GL |
3346 | } |
3347 | EXPORT_SYMBOL(scsi_kunmap_atomic_sg); | |
6f4c827e AL |
3348 | |
3349 | void sdev_disable_disk_events(struct scsi_device *sdev) | |
3350 | { | |
3351 | atomic_inc(&sdev->disk_events_disable_depth); | |
3352 | } | |
3353 | EXPORT_SYMBOL(sdev_disable_disk_events); | |
3354 | ||
3355 | void sdev_enable_disk_events(struct scsi_device *sdev) | |
3356 | { | |
3357 | if (WARN_ON_ONCE(atomic_read(&sdev->disk_events_disable_depth) <= 0)) | |
3358 | return; | |
3359 | atomic_dec(&sdev->disk_events_disable_depth); | |
3360 | } | |
3361 | EXPORT_SYMBOL(sdev_enable_disk_events); | |
9983bed3 HR |
3362 | |
3363 | /** | |
3364 | * scsi_vpd_lun_id - return a unique device identification | |
3365 | * @sdev: SCSI device | |
3366 | * @id: buffer for the identification | |
3367 | * @id_len: length of the buffer | |
3368 | * | |
3369 | * Copies a unique device identification into @id based | |
3370 | * on the information in the VPD page 0x83 of the device. | |
3371 | * The string will be formatted as a SCSI name string. | |
3372 | * | |
3373 | * Returns the length of the identification or error on failure. | |
3374 | * If the identifier is longer than the supplied buffer the actual | |
3375 | * identifier length is returned and the buffer is not zero-padded. | |
3376 | */ | |
3377 | int scsi_vpd_lun_id(struct scsi_device *sdev, char *id, size_t id_len) | |
3378 | { | |
3379 | u8 cur_id_type = 0xff; | |
3380 | u8 cur_id_size = 0; | |
ccf1e004 BVA |
3381 | const unsigned char *d, *cur_id_str; |
3382 | const struct scsi_vpd *vpd_pg83; | |
9983bed3 HR |
3383 | int id_size = -EINVAL; |
3384 | ||
3385 | rcu_read_lock(); | |
3386 | vpd_pg83 = rcu_dereference(sdev->vpd_pg83); | |
3387 | if (!vpd_pg83) { | |
3388 | rcu_read_unlock(); | |
3389 | return -ENXIO; | |
3390 | } | |
3391 | ||
3392 | /* | |
3393 | * Look for the correct descriptor. | |
3394 | * Order of preference for lun descriptor: | |
3395 | * - SCSI name string | |
3396 | * - NAA IEEE Registered Extended | |
3397 | * - EUI-64 based 16-byte | |
3398 | * - EUI-64 based 12-byte | |
3399 | * - NAA IEEE Registered | |
3400 | * - NAA IEEE Extended | |
d230823a | 3401 | * - T10 Vendor ID |
9983bed3 HR |
3402 | * as longer descriptors reduce the likelyhood |
3403 | * of identification clashes. | |
3404 | */ | |
3405 | ||
3406 | /* The id string must be at least 20 bytes + terminating NULL byte */ | |
3407 | if (id_len < 21) { | |
3408 | rcu_read_unlock(); | |
3409 | return -EINVAL; | |
3410 | } | |
3411 | ||
3412 | memset(id, 0, id_len); | |
ccf1e004 BVA |
3413 | d = vpd_pg83->data + 4; |
3414 | while (d < vpd_pg83->data + vpd_pg83->len) { | |
9983bed3 HR |
3415 | /* Skip designators not referring to the LUN */ |
3416 | if ((d[1] & 0x30) != 0x00) | |
3417 | goto next_desig; | |
3418 | ||
3419 | switch (d[1] & 0xf) { | |
d230823a HR |
3420 | case 0x1: |
3421 | /* T10 Vendor ID */ | |
3422 | if (cur_id_size > d[3]) | |
3423 | break; | |
3424 | /* Prefer anything */ | |
3425 | if (cur_id_type > 0x01 && cur_id_type != 0xff) | |
3426 | break; | |
3427 | cur_id_size = d[3]; | |
3428 | if (cur_id_size + 4 > id_len) | |
3429 | cur_id_size = id_len - 4; | |
3430 | cur_id_str = d + 4; | |
3431 | cur_id_type = d[1] & 0xf; | |
3432 | id_size = snprintf(id, id_len, "t10.%*pE", | |
3433 | cur_id_size, cur_id_str); | |
3434 | break; | |
9983bed3 HR |
3435 | case 0x2: |
3436 | /* EUI-64 */ | |
3437 | if (cur_id_size > d[3]) | |
3438 | break; | |
3439 | /* Prefer NAA IEEE Registered Extended */ | |
3440 | if (cur_id_type == 0x3 && | |
3441 | cur_id_size == d[3]) | |
3442 | break; | |
3443 | cur_id_size = d[3]; | |
3444 | cur_id_str = d + 4; | |
3445 | cur_id_type = d[1] & 0xf; | |
3446 | switch (cur_id_size) { | |
3447 | case 8: | |
3448 | id_size = snprintf(id, id_len, | |
3449 | "eui.%8phN", | |
3450 | cur_id_str); | |
3451 | break; | |
3452 | case 12: | |
3453 | id_size = snprintf(id, id_len, | |
3454 | "eui.%12phN", | |
3455 | cur_id_str); | |
3456 | break; | |
3457 | case 16: | |
3458 | id_size = snprintf(id, id_len, | |
3459 | "eui.%16phN", | |
3460 | cur_id_str); | |
3461 | break; | |
3462 | default: | |
3463 | cur_id_size = 0; | |
3464 | break; | |
3465 | } | |
3466 | break; | |
3467 | case 0x3: | |
3468 | /* NAA */ | |
3469 | if (cur_id_size > d[3]) | |
3470 | break; | |
3471 | cur_id_size = d[3]; | |
3472 | cur_id_str = d + 4; | |
3473 | cur_id_type = d[1] & 0xf; | |
3474 | switch (cur_id_size) { | |
3475 | case 8: | |
3476 | id_size = snprintf(id, id_len, | |
3477 | "naa.%8phN", | |
3478 | cur_id_str); | |
3479 | break; | |
3480 | case 16: | |
3481 | id_size = snprintf(id, id_len, | |
3482 | "naa.%16phN", | |
3483 | cur_id_str); | |
3484 | break; | |
3485 | default: | |
3486 | cur_id_size = 0; | |
3487 | break; | |
3488 | } | |
3489 | break; | |
3490 | case 0x8: | |
3491 | /* SCSI name string */ | |
3492 | if (cur_id_size + 4 > d[3]) | |
3493 | break; | |
3494 | /* Prefer others for truncated descriptor */ | |
3495 | if (cur_id_size && d[3] > id_len) | |
3496 | break; | |
3497 | cur_id_size = id_size = d[3]; | |
3498 | cur_id_str = d + 4; | |
3499 | cur_id_type = d[1] & 0xf; | |
3500 | if (cur_id_size >= id_len) | |
3501 | cur_id_size = id_len - 1; | |
3502 | memcpy(id, cur_id_str, cur_id_size); | |
3503 | /* Decrease priority for truncated descriptor */ | |
3504 | if (cur_id_size != id_size) | |
3505 | cur_id_size = 6; | |
3506 | break; | |
3507 | default: | |
3508 | break; | |
3509 | } | |
3510 | next_desig: | |
3511 | d += d[3] + 4; | |
3512 | } | |
3513 | rcu_read_unlock(); | |
3514 | ||
3515 | return id_size; | |
3516 | } | |
3517 | EXPORT_SYMBOL(scsi_vpd_lun_id); | |
a8aa3978 HR |
3518 | |
3519 | /* | |
3520 | * scsi_vpd_tpg_id - return a target port group identifier | |
3521 | * @sdev: SCSI device | |
3522 | * | |
3523 | * Returns the Target Port Group identifier from the information | |
3524 | * froom VPD page 0x83 of the device. | |
3525 | * | |
3526 | * Returns the identifier or error on failure. | |
3527 | */ | |
3528 | int scsi_vpd_tpg_id(struct scsi_device *sdev, int *rel_id) | |
3529 | { | |
ccf1e004 BVA |
3530 | const unsigned char *d; |
3531 | const struct scsi_vpd *vpd_pg83; | |
a8aa3978 HR |
3532 | int group_id = -EAGAIN, rel_port = -1; |
3533 | ||
3534 | rcu_read_lock(); | |
3535 | vpd_pg83 = rcu_dereference(sdev->vpd_pg83); | |
3536 | if (!vpd_pg83) { | |
3537 | rcu_read_unlock(); | |
3538 | return -ENXIO; | |
3539 | } | |
3540 | ||
ccf1e004 BVA |
3541 | d = vpd_pg83->data + 4; |
3542 | while (d < vpd_pg83->data + vpd_pg83->len) { | |
a8aa3978 HR |
3543 | switch (d[1] & 0xf) { |
3544 | case 0x4: | |
3545 | /* Relative target port */ | |
3546 | rel_port = get_unaligned_be16(&d[6]); | |
3547 | break; | |
3548 | case 0x5: | |
3549 | /* Target port group */ | |
3550 | group_id = get_unaligned_be16(&d[6]); | |
3551 | break; | |
3552 | default: | |
3553 | break; | |
3554 | } | |
3555 | d += d[3] + 4; | |
3556 | } | |
3557 | rcu_read_unlock(); | |
3558 | ||
3559 | if (group_id >= 0 && rel_id && rel_port != -1) | |
3560 | *rel_id = rel_port; | |
3561 | ||
3562 | return group_id; | |
3563 | } | |
3564 | EXPORT_SYMBOL(scsi_vpd_tpg_id); |