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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 | |
0a6ac4ee | 47 | static inline struct kmem_cache * |
8e688254 | 48 | scsi_select_sense_cache(bool unchecked_isa_dma) |
0a6ac4ee | 49 | { |
8e688254 | 50 | return unchecked_isa_dma ? scsi_sense_isadma_cache : scsi_sense_cache; |
0a6ac4ee CH |
51 | } |
52 | ||
8e688254 BVA |
53 | static void scsi_free_sense_buffer(bool unchecked_isa_dma, |
54 | unsigned char *sense_buffer) | |
0a6ac4ee | 55 | { |
8e688254 BVA |
56 | kmem_cache_free(scsi_select_sense_cache(unchecked_isa_dma), |
57 | sense_buffer); | |
0a6ac4ee CH |
58 | } |
59 | ||
8e688254 | 60 | static unsigned char *scsi_alloc_sense_buffer(bool unchecked_isa_dma, |
e9c787e6 | 61 | gfp_t gfp_mask, int numa_node) |
0a6ac4ee | 62 | { |
8e688254 BVA |
63 | return kmem_cache_alloc_node(scsi_select_sense_cache(unchecked_isa_dma), |
64 | gfp_mask, numa_node); | |
0a6ac4ee CH |
65 | } |
66 | ||
67 | int scsi_init_sense_cache(struct Scsi_Host *shost) | |
68 | { | |
69 | struct kmem_cache *cache; | |
70 | int ret = 0; | |
71 | ||
8e688254 | 72 | cache = scsi_select_sense_cache(shost->unchecked_isa_dma); |
0a6ac4ee CH |
73 | if (cache) |
74 | return 0; | |
75 | ||
76 | mutex_lock(&scsi_sense_cache_mutex); | |
77 | if (shost->unchecked_isa_dma) { | |
78 | scsi_sense_isadma_cache = | |
79 | kmem_cache_create("scsi_sense_cache(DMA)", | |
80 | SCSI_SENSE_BUFFERSIZE, 0, | |
81 | SLAB_HWCACHE_ALIGN | SLAB_CACHE_DMA, NULL); | |
82 | if (!scsi_sense_isadma_cache) | |
83 | ret = -ENOMEM; | |
84 | } else { | |
85 | scsi_sense_cache = | |
86 | kmem_cache_create("scsi_sense_cache", | |
87 | SCSI_SENSE_BUFFERSIZE, 0, SLAB_HWCACHE_ALIGN, NULL); | |
88 | if (!scsi_sense_cache) | |
89 | ret = -ENOMEM; | |
90 | } | |
91 | ||
92 | mutex_unlock(&scsi_sense_cache_mutex); | |
93 | return ret; | |
94 | } | |
6f9a35e2 | 95 | |
a488e749 JA |
96 | /* |
97 | * When to reinvoke queueing after a resource shortage. It's 3 msecs to | |
98 | * not change behaviour from the previous unplug mechanism, experimentation | |
99 | * may prove this needs changing. | |
100 | */ | |
101 | #define SCSI_QUEUE_DELAY 3 | |
102 | ||
de3e8bf3 CH |
103 | static void |
104 | scsi_set_blocked(struct scsi_cmnd *cmd, int reason) | |
1da177e4 LT |
105 | { |
106 | struct Scsi_Host *host = cmd->device->host; | |
107 | struct scsi_device *device = cmd->device; | |
f0c0a376 | 108 | struct scsi_target *starget = scsi_target(device); |
1da177e4 LT |
109 | |
110 | /* | |
d8c37e7b | 111 | * Set the appropriate busy bit for the device/host. |
1da177e4 LT |
112 | * |
113 | * If the host/device isn't busy, assume that something actually | |
114 | * completed, and that we should be able to queue a command now. | |
115 | * | |
116 | * Note that the prior mid-layer assumption that any host could | |
117 | * always queue at least one command is now broken. The mid-layer | |
118 | * will implement a user specifiable stall (see | |
119 | * scsi_host.max_host_blocked and scsi_device.max_device_blocked) | |
120 | * if a command is requeued with no other commands outstanding | |
121 | * either for the device or for the host. | |
122 | */ | |
f0c0a376 MC |
123 | switch (reason) { |
124 | case SCSI_MLQUEUE_HOST_BUSY: | |
cd9070c9 | 125 | atomic_set(&host->host_blocked, host->max_host_blocked); |
f0c0a376 MC |
126 | break; |
127 | case SCSI_MLQUEUE_DEVICE_BUSY: | |
573e5913 | 128 | case SCSI_MLQUEUE_EH_RETRY: |
cd9070c9 CH |
129 | atomic_set(&device->device_blocked, |
130 | device->max_device_blocked); | |
f0c0a376 MC |
131 | break; |
132 | case SCSI_MLQUEUE_TARGET_BUSY: | |
cd9070c9 CH |
133 | atomic_set(&starget->target_blocked, |
134 | starget->max_target_blocked); | |
f0c0a376 MC |
135 | break; |
136 | } | |
de3e8bf3 CH |
137 | } |
138 | ||
d285203c CH |
139 | static void scsi_mq_requeue_cmd(struct scsi_cmnd *cmd) |
140 | { | |
141 | struct scsi_device *sdev = cmd->device; | |
d285203c | 142 | |
2b053aca | 143 | blk_mq_requeue_request(cmd->request, true); |
d285203c CH |
144 | put_device(&sdev->sdev_gendev); |
145 | } | |
146 | ||
de3e8bf3 CH |
147 | /** |
148 | * __scsi_queue_insert - private queue insertion | |
149 | * @cmd: The SCSI command being requeued | |
150 | * @reason: The reason for the requeue | |
151 | * @unbusy: Whether the queue should be unbusied | |
152 | * | |
153 | * This is a private queue insertion. The public interface | |
154 | * scsi_queue_insert() always assumes the queue should be unbusied | |
155 | * because it's always called before the completion. This function is | |
156 | * for a requeue after completion, which should only occur in this | |
157 | * file. | |
158 | */ | |
159 | static void __scsi_queue_insert(struct scsi_cmnd *cmd, int reason, int unbusy) | |
160 | { | |
161 | struct scsi_device *device = cmd->device; | |
162 | struct request_queue *q = device->request_queue; | |
163 | unsigned long flags; | |
164 | ||
165 | SCSI_LOG_MLQUEUE(1, scmd_printk(KERN_INFO, cmd, | |
166 | "Inserting command %p into mlqueue\n", cmd)); | |
167 | ||
168 | scsi_set_blocked(cmd, reason); | |
1da177e4 | 169 | |
1da177e4 LT |
170 | /* |
171 | * Decrement the counters, since these commands are no longer | |
172 | * active on the host/device. | |
173 | */ | |
4f5299ac JB |
174 | if (unbusy) |
175 | scsi_device_unbusy(device); | |
1da177e4 LT |
176 | |
177 | /* | |
a1bf9d1d | 178 | * Requeue this command. It will go before all other commands |
b485462a BVA |
179 | * that are already in the queue. Schedule requeue work under |
180 | * lock such that the kblockd_schedule_work() call happens | |
181 | * before blk_cleanup_queue() finishes. | |
a488e749 | 182 | */ |
644373a4 | 183 | cmd->result = 0; |
d285203c CH |
184 | if (q->mq_ops) { |
185 | scsi_mq_requeue_cmd(cmd); | |
186 | return; | |
187 | } | |
a1bf9d1d | 188 | spin_lock_irqsave(q->queue_lock, flags); |
59897dad | 189 | blk_requeue_request(q, cmd->request); |
59c3d45e | 190 | kblockd_schedule_work(&device->requeue_work); |
b485462a | 191 | spin_unlock_irqrestore(q->queue_lock, flags); |
1da177e4 LT |
192 | } |
193 | ||
4f5299ac JB |
194 | /* |
195 | * Function: scsi_queue_insert() | |
196 | * | |
197 | * Purpose: Insert a command in the midlevel queue. | |
198 | * | |
199 | * Arguments: cmd - command that we are adding to queue. | |
200 | * reason - why we are inserting command to queue. | |
201 | * | |
202 | * Lock status: Assumed that lock is not held upon entry. | |
203 | * | |
204 | * Returns: Nothing. | |
205 | * | |
206 | * Notes: We do this for one of two cases. Either the host is busy | |
207 | * and it cannot accept any more commands for the time being, | |
208 | * or the device returned QUEUE_FULL and can accept no more | |
209 | * commands. | |
210 | * Notes: This could be called either from an interrupt context or a | |
211 | * normal process context. | |
212 | */ | |
84feb166 | 213 | void scsi_queue_insert(struct scsi_cmnd *cmd, int reason) |
4f5299ac | 214 | { |
84feb166 | 215 | __scsi_queue_insert(cmd, reason, 1); |
4f5299ac | 216 | } |
e8064021 | 217 | |
76aaf87b CH |
218 | |
219 | /** | |
220 | * scsi_execute - insert request and wait for the result | |
221 | * @sdev: scsi device | |
222 | * @cmd: scsi command | |
223 | * @data_direction: data direction | |
224 | * @buffer: data buffer | |
225 | * @bufflen: len of buffer | |
226 | * @sense: optional sense buffer | |
227 | * @sshdr: optional decoded sense header | |
228 | * @timeout: request timeout in seconds | |
229 | * @retries: number of times to retry request | |
230 | * @flags: flags for ->cmd_flags | |
231 | * @rq_flags: flags for ->rq_flags | |
232 | * @resid: optional residual length | |
233 | * | |
17d5363b CH |
234 | * Returns the scsi_cmnd result field if a command was executed, or a negative |
235 | * Linux error code if we didn't get that far. | |
76aaf87b CH |
236 | */ |
237 | int scsi_execute(struct scsi_device *sdev, const unsigned char *cmd, | |
33aa687d | 238 | int data_direction, void *buffer, unsigned bufflen, |
3949e2f0 CH |
239 | unsigned char *sense, struct scsi_sense_hdr *sshdr, |
240 | int timeout, int retries, u64 flags, req_flags_t rq_flags, | |
241 | int *resid) | |
39216033 JB |
242 | { |
243 | struct request *req; | |
82ed4db4 | 244 | struct scsi_request *rq; |
39216033 JB |
245 | int ret = DRIVER_ERROR << 24; |
246 | ||
aebf526b CH |
247 | req = blk_get_request(sdev->request_queue, |
248 | data_direction == DMA_TO_DEVICE ? | |
249 | REQ_OP_SCSI_OUT : REQ_OP_SCSI_IN, __GFP_RECLAIM); | |
a492f075 | 250 | if (IS_ERR(req)) |
bfe159a5 | 251 | return ret; |
82ed4db4 | 252 | rq = scsi_req(req); |
39216033 JB |
253 | |
254 | if (bufflen && blk_rq_map_kern(sdev->request_queue, req, | |
71baba4b | 255 | buffer, bufflen, __GFP_RECLAIM)) |
39216033 JB |
256 | goto out; |
257 | ||
82ed4db4 CH |
258 | rq->cmd_len = COMMAND_SIZE(cmd[0]); |
259 | memcpy(rq->cmd, cmd, rq->cmd_len); | |
64c7f1d1 | 260 | rq->retries = retries; |
39216033 | 261 | req->timeout = timeout; |
e8064021 CH |
262 | req->cmd_flags |= flags; |
263 | req->rq_flags |= rq_flags | RQF_QUIET | RQF_PREEMPT; | |
39216033 JB |
264 | |
265 | /* | |
266 | * head injection *required* here otherwise quiesce won't work | |
267 | */ | |
268 | blk_execute_rq(req->q, NULL, req, 1); | |
269 | ||
bdb2b8ca AS |
270 | /* |
271 | * Some devices (USB mass-storage in particular) may transfer | |
272 | * garbage data together with a residue indicating that the data | |
273 | * is invalid. Prevent the garbage from being misinterpreted | |
274 | * and prevent security leaks by zeroing out the excess data. | |
275 | */ | |
82ed4db4 CH |
276 | if (unlikely(rq->resid_len > 0 && rq->resid_len <= bufflen)) |
277 | memset(buffer + (bufflen - rq->resid_len), 0, rq->resid_len); | |
bdb2b8ca | 278 | |
f4f4e47e | 279 | if (resid) |
82ed4db4 CH |
280 | *resid = rq->resid_len; |
281 | if (sense && rq->sense_len) | |
282 | memcpy(sense, rq->sense, SCSI_SENSE_BUFFERSIZE); | |
3949e2f0 CH |
283 | if (sshdr) |
284 | scsi_normalize_sense(rq->sense, rq->sense_len, sshdr); | |
17d5363b | 285 | ret = rq->result; |
39216033 JB |
286 | out: |
287 | blk_put_request(req); | |
288 | ||
289 | return ret; | |
290 | } | |
33aa687d | 291 | EXPORT_SYMBOL(scsi_execute); |
39216033 | 292 | |
1da177e4 LT |
293 | /* |
294 | * Function: scsi_init_cmd_errh() | |
295 | * | |
296 | * Purpose: Initialize cmd fields related to error handling. | |
297 | * | |
298 | * Arguments: cmd - command that is ready to be queued. | |
299 | * | |
1da177e4 LT |
300 | * Notes: This function has the job of initializing a number of |
301 | * fields related to error handling. Typically this will | |
302 | * be called once for each command, as required. | |
303 | */ | |
631c228c | 304 | static void scsi_init_cmd_errh(struct scsi_cmnd *cmd) |
1da177e4 | 305 | { |
1da177e4 | 306 | cmd->serial_number = 0; |
30b0c37b | 307 | scsi_set_resid(cmd, 0); |
b80ca4f7 | 308 | memset(cmd->sense_buffer, 0, SCSI_SENSE_BUFFERSIZE); |
1da177e4 | 309 | if (cmd->cmd_len == 0) |
db4742dd | 310 | cmd->cmd_len = scsi_command_size(cmd->cmnd); |
1da177e4 LT |
311 | } |
312 | ||
313 | void scsi_device_unbusy(struct scsi_device *sdev) | |
314 | { | |
315 | struct Scsi_Host *shost = sdev->host; | |
f0c0a376 | 316 | struct scsi_target *starget = scsi_target(sdev); |
1da177e4 LT |
317 | unsigned long flags; |
318 | ||
74665016 | 319 | atomic_dec(&shost->host_busy); |
2ccbb008 CH |
320 | if (starget->can_queue > 0) |
321 | atomic_dec(&starget->target_busy); | |
74665016 | 322 | |
939647ee | 323 | if (unlikely(scsi_host_in_recovery(shost) && |
74665016 CH |
324 | (shost->host_failed || shost->host_eh_scheduled))) { |
325 | spin_lock_irqsave(shost->host_lock, flags); | |
1da177e4 | 326 | scsi_eh_wakeup(shost); |
74665016 CH |
327 | spin_unlock_irqrestore(shost->host_lock, flags); |
328 | } | |
329 | ||
71e75c97 | 330 | atomic_dec(&sdev->device_busy); |
1da177e4 LT |
331 | } |
332 | ||
d285203c CH |
333 | static void scsi_kick_queue(struct request_queue *q) |
334 | { | |
335 | if (q->mq_ops) | |
336 | blk_mq_start_hw_queues(q); | |
337 | else | |
338 | blk_run_queue(q); | |
339 | } | |
340 | ||
1da177e4 LT |
341 | /* |
342 | * Called for single_lun devices on IO completion. Clear starget_sdev_user, | |
343 | * and call blk_run_queue for all the scsi_devices on the target - | |
344 | * including current_sdev first. | |
345 | * | |
346 | * Called with *no* scsi locks held. | |
347 | */ | |
348 | static void scsi_single_lun_run(struct scsi_device *current_sdev) | |
349 | { | |
350 | struct Scsi_Host *shost = current_sdev->host; | |
351 | struct scsi_device *sdev, *tmp; | |
352 | struct scsi_target *starget = scsi_target(current_sdev); | |
353 | unsigned long flags; | |
354 | ||
355 | spin_lock_irqsave(shost->host_lock, flags); | |
356 | starget->starget_sdev_user = NULL; | |
357 | spin_unlock_irqrestore(shost->host_lock, flags); | |
358 | ||
359 | /* | |
360 | * Call blk_run_queue for all LUNs on the target, starting with | |
361 | * current_sdev. We race with others (to set starget_sdev_user), | |
362 | * but in most cases, we will be first. Ideally, each LU on the | |
363 | * target would get some limited time or requests on the target. | |
364 | */ | |
d285203c | 365 | scsi_kick_queue(current_sdev->request_queue); |
1da177e4 LT |
366 | |
367 | spin_lock_irqsave(shost->host_lock, flags); | |
368 | if (starget->starget_sdev_user) | |
369 | goto out; | |
370 | list_for_each_entry_safe(sdev, tmp, &starget->devices, | |
371 | same_target_siblings) { | |
372 | if (sdev == current_sdev) | |
373 | continue; | |
374 | if (scsi_device_get(sdev)) | |
375 | continue; | |
376 | ||
377 | spin_unlock_irqrestore(shost->host_lock, flags); | |
d285203c | 378 | scsi_kick_queue(sdev->request_queue); |
1da177e4 LT |
379 | spin_lock_irqsave(shost->host_lock, flags); |
380 | ||
381 | scsi_device_put(sdev); | |
382 | } | |
383 | out: | |
384 | spin_unlock_irqrestore(shost->host_lock, flags); | |
385 | } | |
386 | ||
cd9070c9 | 387 | static inline bool scsi_device_is_busy(struct scsi_device *sdev) |
9d112517 | 388 | { |
cd9070c9 CH |
389 | if (atomic_read(&sdev->device_busy) >= sdev->queue_depth) |
390 | return true; | |
391 | if (atomic_read(&sdev->device_blocked) > 0) | |
392 | return true; | |
393 | return false; | |
9d112517 KU |
394 | } |
395 | ||
cd9070c9 | 396 | static inline bool scsi_target_is_busy(struct scsi_target *starget) |
f0c0a376 | 397 | { |
2ccbb008 CH |
398 | if (starget->can_queue > 0) { |
399 | if (atomic_read(&starget->target_busy) >= starget->can_queue) | |
400 | return true; | |
401 | if (atomic_read(&starget->target_blocked) > 0) | |
402 | return true; | |
403 | } | |
cd9070c9 | 404 | return false; |
f0c0a376 MC |
405 | } |
406 | ||
cd9070c9 | 407 | static inline bool scsi_host_is_busy(struct Scsi_Host *shost) |
9d112517 | 408 | { |
cd9070c9 CH |
409 | if (shost->can_queue > 0 && |
410 | atomic_read(&shost->host_busy) >= shost->can_queue) | |
411 | return true; | |
412 | if (atomic_read(&shost->host_blocked) > 0) | |
413 | return true; | |
414 | if (shost->host_self_blocked) | |
415 | return true; | |
416 | return false; | |
9d112517 KU |
417 | } |
418 | ||
21a05df5 | 419 | static void scsi_starved_list_run(struct Scsi_Host *shost) |
1da177e4 | 420 | { |
2a3a59e5 | 421 | LIST_HEAD(starved_list); |
21a05df5 | 422 | struct scsi_device *sdev; |
1da177e4 LT |
423 | unsigned long flags; |
424 | ||
1da177e4 | 425 | spin_lock_irqsave(shost->host_lock, flags); |
2a3a59e5 MC |
426 | list_splice_init(&shost->starved_list, &starved_list); |
427 | ||
428 | while (!list_empty(&starved_list)) { | |
e2eb7244 JB |
429 | struct request_queue *slq; |
430 | ||
1da177e4 LT |
431 | /* |
432 | * As long as shost is accepting commands and we have | |
433 | * starved queues, call blk_run_queue. scsi_request_fn | |
434 | * drops the queue_lock and can add us back to the | |
435 | * starved_list. | |
436 | * | |
437 | * host_lock protects the starved_list and starved_entry. | |
438 | * scsi_request_fn must get the host_lock before checking | |
439 | * or modifying starved_list or starved_entry. | |
440 | */ | |
2a3a59e5 | 441 | if (scsi_host_is_busy(shost)) |
f0c0a376 | 442 | break; |
f0c0a376 | 443 | |
2a3a59e5 MC |
444 | sdev = list_entry(starved_list.next, |
445 | struct scsi_device, starved_entry); | |
446 | list_del_init(&sdev->starved_entry); | |
f0c0a376 MC |
447 | if (scsi_target_is_busy(scsi_target(sdev))) { |
448 | list_move_tail(&sdev->starved_entry, | |
449 | &shost->starved_list); | |
450 | continue; | |
451 | } | |
452 | ||
e2eb7244 JB |
453 | /* |
454 | * Once we drop the host lock, a racing scsi_remove_device() | |
455 | * call may remove the sdev from the starved list and destroy | |
456 | * it and the queue. Mitigate by taking a reference to the | |
457 | * queue and never touching the sdev again after we drop the | |
458 | * host lock. Note: if __scsi_remove_device() invokes | |
459 | * blk_cleanup_queue() before the queue is run from this | |
460 | * function then blk_run_queue() will return immediately since | |
461 | * blk_cleanup_queue() marks the queue with QUEUE_FLAG_DYING. | |
462 | */ | |
463 | slq = sdev->request_queue; | |
464 | if (!blk_get_queue(slq)) | |
465 | continue; | |
466 | spin_unlock_irqrestore(shost->host_lock, flags); | |
467 | ||
d285203c | 468 | scsi_kick_queue(slq); |
e2eb7244 JB |
469 | blk_put_queue(slq); |
470 | ||
471 | spin_lock_irqsave(shost->host_lock, flags); | |
1da177e4 | 472 | } |
2a3a59e5 MC |
473 | /* put any unprocessed entries back */ |
474 | list_splice(&starved_list, &shost->starved_list); | |
1da177e4 | 475 | spin_unlock_irqrestore(shost->host_lock, flags); |
21a05df5 CH |
476 | } |
477 | ||
478 | /* | |
479 | * Function: scsi_run_queue() | |
480 | * | |
481 | * Purpose: Select a proper request queue to serve next | |
482 | * | |
483 | * Arguments: q - last request's queue | |
484 | * | |
485 | * Returns: Nothing | |
486 | * | |
487 | * Notes: The previous command was completely finished, start | |
488 | * a new one if possible. | |
489 | */ | |
490 | static void scsi_run_queue(struct request_queue *q) | |
491 | { | |
492 | struct scsi_device *sdev = q->queuedata; | |
493 | ||
494 | if (scsi_target(sdev)->single_lun) | |
495 | scsi_single_lun_run(sdev); | |
496 | if (!list_empty(&sdev->host->starved_list)) | |
497 | scsi_starved_list_run(sdev->host); | |
1da177e4 | 498 | |
d285203c | 499 | if (q->mq_ops) |
36e3cf27 | 500 | blk_mq_run_hw_queues(q, false); |
d285203c CH |
501 | else |
502 | blk_run_queue(q); | |
1da177e4 LT |
503 | } |
504 | ||
9937a5e2 JA |
505 | void scsi_requeue_run_queue(struct work_struct *work) |
506 | { | |
507 | struct scsi_device *sdev; | |
508 | struct request_queue *q; | |
509 | ||
510 | sdev = container_of(work, struct scsi_device, requeue_work); | |
511 | q = sdev->request_queue; | |
512 | scsi_run_queue(q); | |
513 | } | |
514 | ||
1da177e4 LT |
515 | /* |
516 | * Function: scsi_requeue_command() | |
517 | * | |
518 | * Purpose: Handle post-processing of completed commands. | |
519 | * | |
520 | * Arguments: q - queue to operate on | |
521 | * cmd - command that may need to be requeued. | |
522 | * | |
523 | * Returns: Nothing | |
524 | * | |
525 | * Notes: After command completion, there may be blocks left | |
526 | * over which weren't finished by the previous command | |
527 | * this can be for a number of reasons - the main one is | |
528 | * I/O errors in the middle of the request, in which case | |
529 | * we need to request the blocks that come after the bad | |
530 | * sector. | |
e91442b6 | 531 | * Notes: Upon return, cmd is a stale pointer. |
1da177e4 LT |
532 | */ |
533 | static void scsi_requeue_command(struct request_queue *q, struct scsi_cmnd *cmd) | |
534 | { | |
940f5d47 | 535 | struct scsi_device *sdev = cmd->device; |
e91442b6 | 536 | struct request *req = cmd->request; |
283369cc TH |
537 | unsigned long flags; |
538 | ||
283369cc | 539 | spin_lock_irqsave(q->queue_lock, flags); |
134997a0 CH |
540 | blk_unprep_request(req); |
541 | req->special = NULL; | |
542 | scsi_put_command(cmd); | |
e91442b6 | 543 | blk_requeue_request(q, req); |
283369cc | 544 | spin_unlock_irqrestore(q->queue_lock, flags); |
1da177e4 LT |
545 | |
546 | scsi_run_queue(q); | |
940f5d47 BVA |
547 | |
548 | put_device(&sdev->sdev_gendev); | |
1da177e4 LT |
549 | } |
550 | ||
1da177e4 LT |
551 | void scsi_run_host_queues(struct Scsi_Host *shost) |
552 | { | |
553 | struct scsi_device *sdev; | |
554 | ||
555 | shost_for_each_device(sdev, shost) | |
556 | scsi_run_queue(sdev->request_queue); | |
557 | } | |
558 | ||
d285203c CH |
559 | static void scsi_uninit_cmd(struct scsi_cmnd *cmd) |
560 | { | |
57292b58 | 561 | if (!blk_rq_is_passthrough(cmd->request)) { |
d285203c CH |
562 | struct scsi_driver *drv = scsi_cmd_to_driver(cmd); |
563 | ||
564 | if (drv->uninit_command) | |
565 | drv->uninit_command(cmd); | |
566 | } | |
567 | } | |
568 | ||
569 | static void scsi_mq_free_sgtables(struct scsi_cmnd *cmd) | |
570 | { | |
91dbc08d ML |
571 | struct scsi_data_buffer *sdb; |
572 | ||
d285203c | 573 | if (cmd->sdb.table.nents) |
001d63be | 574 | sg_free_table_chained(&cmd->sdb.table, true); |
91dbc08d ML |
575 | if (cmd->request->next_rq) { |
576 | sdb = cmd->request->next_rq->special; | |
577 | if (sdb) | |
001d63be | 578 | sg_free_table_chained(&sdb->table, true); |
91dbc08d | 579 | } |
d285203c | 580 | if (scsi_prot_sg_count(cmd)) |
001d63be | 581 | sg_free_table_chained(&cmd->prot_sdb->table, true); |
d285203c CH |
582 | } |
583 | ||
584 | static void scsi_mq_uninit_cmd(struct scsi_cmnd *cmd) | |
585 | { | |
d285203c CH |
586 | scsi_mq_free_sgtables(cmd); |
587 | scsi_uninit_cmd(cmd); | |
2dd6fb59 | 588 | scsi_del_cmd_from_list(cmd); |
d285203c CH |
589 | } |
590 | ||
1da177e4 LT |
591 | /* |
592 | * Function: scsi_release_buffers() | |
593 | * | |
c682adf3 | 594 | * Purpose: Free resources allocate for a scsi_command. |
1da177e4 LT |
595 | * |
596 | * Arguments: cmd - command that we are bailing. | |
597 | * | |
598 | * Lock status: Assumed that no lock is held upon entry. | |
599 | * | |
600 | * Returns: Nothing | |
601 | * | |
602 | * Notes: In the event that an upper level driver rejects a | |
603 | * command, we must release resources allocated during | |
604 | * the __init_io() function. Primarily this would involve | |
c682adf3 | 605 | * the scatter-gather table. |
1da177e4 | 606 | */ |
f1bea55d | 607 | static void scsi_release_buffers(struct scsi_cmnd *cmd) |
1da177e4 | 608 | { |
c682adf3 | 609 | if (cmd->sdb.table.nents) |
001d63be | 610 | sg_free_table_chained(&cmd->sdb.table, false); |
c682adf3 CH |
611 | |
612 | memset(&cmd->sdb, 0, sizeof(cmd->sdb)); | |
613 | ||
614 | if (scsi_prot_sg_count(cmd)) | |
001d63be | 615 | sg_free_table_chained(&cmd->prot_sdb->table, false); |
1da177e4 LT |
616 | } |
617 | ||
c682adf3 CH |
618 | static void scsi_release_bidi_buffers(struct scsi_cmnd *cmd) |
619 | { | |
620 | struct scsi_data_buffer *bidi_sdb = cmd->request->next_rq->special; | |
621 | ||
001d63be | 622 | sg_free_table_chained(&bidi_sdb->table, false); |
c682adf3 CH |
623 | kmem_cache_free(scsi_sdb_cache, bidi_sdb); |
624 | cmd->request->next_rq->special = NULL; | |
625 | } | |
626 | ||
2a842aca | 627 | static bool scsi_end_request(struct request *req, blk_status_t error, |
f6d47e74 CH |
628 | unsigned int bytes, unsigned int bidi_bytes) |
629 | { | |
630 | struct scsi_cmnd *cmd = req->special; | |
631 | struct scsi_device *sdev = cmd->device; | |
632 | struct request_queue *q = sdev->request_queue; | |
f6d47e74 CH |
633 | |
634 | if (blk_update_request(req, error, bytes)) | |
635 | return true; | |
636 | ||
637 | /* Bidi request must be completed as a whole */ | |
638 | if (unlikely(bidi_bytes) && | |
639 | blk_update_request(req->next_rq, error, bidi_bytes)) | |
640 | return true; | |
641 | ||
642 | if (blk_queue_add_random(q)) | |
643 | add_disk_randomness(req->rq_disk); | |
644 | ||
d285203c CH |
645 | if (req->mq_ctx) { |
646 | /* | |
c8a446ad | 647 | * In the MQ case the command gets freed by __blk_mq_end_request, |
d285203c CH |
648 | * so we have to do all cleanup that depends on it earlier. |
649 | * | |
650 | * We also can't kick the queues from irq context, so we | |
651 | * will have to defer it to a workqueue. | |
652 | */ | |
653 | scsi_mq_uninit_cmd(cmd); | |
654 | ||
c8a446ad | 655 | __blk_mq_end_request(req, error); |
d285203c CH |
656 | |
657 | if (scsi_target(sdev)->single_lun || | |
658 | !list_empty(&sdev->host->starved_list)) | |
659 | kblockd_schedule_work(&sdev->requeue_work); | |
660 | else | |
36e3cf27 | 661 | blk_mq_run_hw_queues(q, true); |
d285203c CH |
662 | } else { |
663 | unsigned long flags; | |
664 | ||
f81426a8 DG |
665 | if (bidi_bytes) |
666 | scsi_release_bidi_buffers(cmd); | |
e9c787e6 CH |
667 | scsi_release_buffers(cmd); |
668 | scsi_put_command(cmd); | |
f81426a8 | 669 | |
d285203c CH |
670 | spin_lock_irqsave(q->queue_lock, flags); |
671 | blk_finish_request(req, error); | |
672 | spin_unlock_irqrestore(q->queue_lock, flags); | |
673 | ||
bb3ec62a | 674 | scsi_run_queue(q); |
d285203c | 675 | } |
f6d47e74 | 676 | |
bb3ec62a | 677 | put_device(&sdev->sdev_gendev); |
f6d47e74 CH |
678 | return false; |
679 | } | |
680 | ||
0f7f6234 HR |
681 | /** |
682 | * __scsi_error_from_host_byte - translate SCSI error code into errno | |
683 | * @cmd: SCSI command (unused) | |
684 | * @result: scsi error code | |
685 | * | |
2a842aca | 686 | * Translate SCSI error code into block errors. |
0f7f6234 | 687 | */ |
2a842aca CH |
688 | static blk_status_t __scsi_error_from_host_byte(struct scsi_cmnd *cmd, |
689 | int result) | |
63583cca | 690 | { |
2a842aca | 691 | switch (host_byte(result)) { |
63583cca | 692 | case DID_TRANSPORT_FAILFAST: |
2a842aca | 693 | return BLK_STS_TRANSPORT; |
63583cca | 694 | case DID_TARGET_FAILURE: |
2082ebc4 | 695 | set_host_byte(cmd, DID_OK); |
2a842aca | 696 | return BLK_STS_TARGET; |
63583cca | 697 | case DID_NEXUS_FAILURE: |
2a842aca | 698 | return BLK_STS_NEXUS; |
a9d6ceb8 HR |
699 | case DID_ALLOC_FAILURE: |
700 | set_host_byte(cmd, DID_OK); | |
2a842aca | 701 | return BLK_STS_NOSPC; |
7e782af5 HR |
702 | case DID_MEDIUM_ERROR: |
703 | set_host_byte(cmd, DID_OK); | |
2a842aca | 704 | return BLK_STS_MEDIUM; |
63583cca | 705 | default: |
2a842aca | 706 | return BLK_STS_IOERR; |
63583cca | 707 | } |
63583cca HR |
708 | } |
709 | ||
1da177e4 LT |
710 | /* |
711 | * Function: scsi_io_completion() | |
712 | * | |
713 | * Purpose: Completion processing for block device I/O requests. | |
714 | * | |
715 | * Arguments: cmd - command that is finished. | |
716 | * | |
717 | * Lock status: Assumed that no lock is held upon entry. | |
718 | * | |
719 | * Returns: Nothing | |
720 | * | |
bc85dc50 CH |
721 | * Notes: We will finish off the specified number of sectors. If we |
722 | * are done, the command block will be released and the queue | |
723 | * function will be goosed. If we are not done then we have to | |
b60af5b0 | 724 | * figure out what to do next: |
1da177e4 | 725 | * |
b60af5b0 AS |
726 | * a) We can call scsi_requeue_command(). The request |
727 | * will be unprepared and put back on the queue. Then | |
728 | * a new command will be created for it. This should | |
729 | * be used if we made forward progress, or if we want | |
730 | * to switch from READ(10) to READ(6) for example. | |
1da177e4 | 731 | * |
bc85dc50 | 732 | * b) We can call __scsi_queue_insert(). The request will |
b60af5b0 AS |
733 | * be put back on the queue and retried using the same |
734 | * command as before, possibly after a delay. | |
735 | * | |
f6d47e74 | 736 | * c) We can call scsi_end_request() with -EIO to fail |
b60af5b0 | 737 | * the remainder of the request. |
1da177e4 | 738 | */ |
03aba2f7 | 739 | void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes) |
1da177e4 LT |
740 | { |
741 | int result = cmd->result; | |
165125e1 | 742 | struct request_queue *q = cmd->device->request_queue; |
1da177e4 | 743 | struct request *req = cmd->request; |
2a842aca | 744 | blk_status_t error = BLK_STS_OK; |
1da177e4 | 745 | struct scsi_sense_hdr sshdr; |
4753cbc0 | 746 | bool sense_valid = false; |
c11c004b | 747 | int sense_deferred = 0, level = 0; |
b60af5b0 AS |
748 | enum {ACTION_FAIL, ACTION_REPREP, ACTION_RETRY, |
749 | ACTION_DELAYED_RETRY} action; | |
ee60b2c5 | 750 | unsigned long wait_for = (cmd->allowed + 1) * req->timeout; |
1da177e4 | 751 | |
1da177e4 LT |
752 | if (result) { |
753 | sense_valid = scsi_command_normalize_sense(cmd, &sshdr); | |
754 | if (sense_valid) | |
755 | sense_deferred = scsi_sense_is_deferred(&sshdr); | |
756 | } | |
631c228c | 757 | |
57292b58 | 758 | if (blk_rq_is_passthrough(req)) { |
1da177e4 | 759 | if (result) { |
82ed4db4 | 760 | if (sense_valid) { |
1da177e4 LT |
761 | /* |
762 | * SG_IO wants current and deferred errors | |
763 | */ | |
82ed4db4 CH |
764 | scsi_req(req)->sense_len = |
765 | min(8 + cmd->sense_buffer[7], | |
766 | SCSI_SENSE_BUFFERSIZE); | |
1da177e4 | 767 | } |
fa8e36c3 | 768 | if (!sense_deferred) |
63583cca | 769 | error = __scsi_error_from_host_byte(cmd, result); |
b22f687d | 770 | } |
27c41973 MS |
771 | /* |
772 | * __scsi_error_from_host_byte may have reset the host_byte | |
773 | */ | |
17d5363b | 774 | scsi_req(req)->result = cmd->result; |
82ed4db4 | 775 | scsi_req(req)->resid_len = scsi_get_resid(cmd); |
e6bb7a96 | 776 | |
6f9a35e2 | 777 | if (scsi_bidi_cmnd(cmd)) { |
e6bb7a96 FT |
778 | /* |
779 | * Bidi commands Must be complete as a whole, | |
780 | * both sides at once. | |
781 | */ | |
82ed4db4 | 782 | scsi_req(req->next_rq)->resid_len = scsi_in(cmd)->resid; |
2a842aca | 783 | if (scsi_end_request(req, BLK_STS_OK, blk_rq_bytes(req), |
f6d47e74 CH |
784 | blk_rq_bytes(req->next_rq))) |
785 | BUG(); | |
6f9a35e2 BH |
786 | return; |
787 | } | |
89fb4cd1 JB |
788 | } else if (blk_rq_bytes(req) == 0 && result && !sense_deferred) { |
789 | /* | |
aebf526b | 790 | * Flush commands do not transfers any data, and thus cannot use |
89fb4cd1 JB |
791 | * good_bytes != blk_rq_bytes(req) as the signal for an error. |
792 | * This sets the error explicitly for the problem case. | |
793 | */ | |
794 | error = __scsi_error_from_host_byte(cmd, result); | |
1da177e4 LT |
795 | } |
796 | ||
57292b58 | 797 | /* no bidi support for !blk_rq_is_passthrough yet */ |
33659ebb | 798 | BUG_ON(blk_bidi_rq(req)); |
30b0c37b | 799 | |
1da177e4 LT |
800 | /* |
801 | * Next deal with any sectors which we were able to correctly | |
802 | * handle. | |
803 | */ | |
91921e01 HR |
804 | SCSI_LOG_HLCOMPLETE(1, scmd_printk(KERN_INFO, cmd, |
805 | "%u sectors total, %d bytes done.\n", | |
806 | blk_rq_sectors(req), good_bytes)); | |
d6b0c537 | 807 | |
a9bddd74 | 808 | /* |
aebf526b CH |
809 | * Recovered errors need reporting, but they're always treated as |
810 | * success, so fiddle the result code here. For passthrough requests | |
17d5363b | 811 | * we already took a copy of the original into sreq->result which |
a9bddd74 JB |
812 | * is what gets returned to the user |
813 | */ | |
e7efe593 DG |
814 | if (sense_valid && (sshdr.sense_key == RECOVERED_ERROR)) { |
815 | /* if ATA PASS-THROUGH INFORMATION AVAILABLE skip | |
816 | * print since caller wants ATA registers. Only occurs on | |
817 | * SCSI ATA PASS_THROUGH commands when CK_COND=1 | |
818 | */ | |
819 | if ((sshdr.asc == 0x0) && (sshdr.ascq == 0x1d)) | |
820 | ; | |
e8064021 | 821 | else if (!(req->rq_flags & RQF_QUIET)) |
d811b848 | 822 | scsi_print_sense(cmd); |
a9bddd74 | 823 | result = 0; |
aebf526b | 824 | /* for passthrough error may be set */ |
2a842aca | 825 | error = BLK_STS_OK; |
a9bddd74 JB |
826 | } |
827 | ||
828 | /* | |
a621bac3 JB |
829 | * special case: failed zero length commands always need to |
830 | * drop down into the retry code. Otherwise, if we finished | |
831 | * all bytes in the request we are done now. | |
d6b0c537 | 832 | */ |
a621bac3 JB |
833 | if (!(blk_rq_bytes(req) == 0 && error) && |
834 | !scsi_end_request(req, error, good_bytes, 0)) | |
f6d47e74 | 835 | return; |
bc85dc50 CH |
836 | |
837 | /* | |
838 | * Kill remainder if no retrys. | |
839 | */ | |
840 | if (error && scsi_noretry_cmd(cmd)) { | |
f6d47e74 CH |
841 | if (scsi_end_request(req, error, blk_rq_bytes(req), 0)) |
842 | BUG(); | |
843 | return; | |
bc85dc50 CH |
844 | } |
845 | ||
846 | /* | |
847 | * If there had been no error, but we have leftover bytes in the | |
848 | * requeues just queue the command up again. | |
d6b0c537 | 849 | */ |
bc85dc50 CH |
850 | if (result == 0) |
851 | goto requeue; | |
03aba2f7 | 852 | |
63583cca | 853 | error = __scsi_error_from_host_byte(cmd, result); |
3e695f89 | 854 | |
b60af5b0 AS |
855 | if (host_byte(result) == DID_RESET) { |
856 | /* Third party bus reset or reset for error recovery | |
857 | * reasons. Just retry the command and see what | |
858 | * happens. | |
859 | */ | |
860 | action = ACTION_RETRY; | |
861 | } else if (sense_valid && !sense_deferred) { | |
1da177e4 LT |
862 | switch (sshdr.sense_key) { |
863 | case UNIT_ATTENTION: | |
864 | if (cmd->device->removable) { | |
03aba2f7 | 865 | /* Detected disc change. Set a bit |
1da177e4 LT |
866 | * and quietly refuse further access. |
867 | */ | |
868 | cmd->device->changed = 1; | |
b60af5b0 | 869 | action = ACTION_FAIL; |
1da177e4 | 870 | } else { |
03aba2f7 LT |
871 | /* Must have been a power glitch, or a |
872 | * bus reset. Could not have been a | |
873 | * media change, so we just retry the | |
b60af5b0 | 874 | * command and see what happens. |
03aba2f7 | 875 | */ |
b60af5b0 | 876 | action = ACTION_RETRY; |
1da177e4 LT |
877 | } |
878 | break; | |
879 | case ILLEGAL_REQUEST: | |
03aba2f7 LT |
880 | /* If we had an ILLEGAL REQUEST returned, then |
881 | * we may have performed an unsupported | |
882 | * command. The only thing this should be | |
883 | * would be a ten byte read where only a six | |
884 | * byte read was supported. Also, on a system | |
885 | * where READ CAPACITY failed, we may have | |
886 | * read past the end of the disk. | |
887 | */ | |
26a68019 JA |
888 | if ((cmd->device->use_10_for_rw && |
889 | sshdr.asc == 0x20 && sshdr.ascq == 0x00) && | |
1da177e4 LT |
890 | (cmd->cmnd[0] == READ_10 || |
891 | cmd->cmnd[0] == WRITE_10)) { | |
b60af5b0 | 892 | /* This will issue a new 6-byte command. */ |
1da177e4 | 893 | cmd->device->use_10_for_rw = 0; |
b60af5b0 | 894 | action = ACTION_REPREP; |
3e695f89 | 895 | } else if (sshdr.asc == 0x10) /* DIX */ { |
3e695f89 | 896 | action = ACTION_FAIL; |
2a842aca | 897 | error = BLK_STS_PROTECTION; |
c98a0eb0 | 898 | /* INVALID COMMAND OPCODE or INVALID FIELD IN CDB */ |
5db44863 | 899 | } else if (sshdr.asc == 0x20 || sshdr.asc == 0x24) { |
c98a0eb0 | 900 | action = ACTION_FAIL; |
2a842aca | 901 | error = BLK_STS_TARGET; |
b60af5b0 AS |
902 | } else |
903 | action = ACTION_FAIL; | |
904 | break; | |
511e44f4 | 905 | case ABORTED_COMMAND: |
126c0982 | 906 | action = ACTION_FAIL; |
e6c11dbb | 907 | if (sshdr.asc == 0x10) /* DIF */ |
2a842aca | 908 | error = BLK_STS_PROTECTION; |
1da177e4 LT |
909 | break; |
910 | case NOT_READY: | |
03aba2f7 | 911 | /* If the device is in the process of becoming |
f3e93f73 | 912 | * ready, or has a temporary blockage, retry. |
1da177e4 | 913 | */ |
f3e93f73 JB |
914 | if (sshdr.asc == 0x04) { |
915 | switch (sshdr.ascq) { | |
916 | case 0x01: /* becoming ready */ | |
917 | case 0x04: /* format in progress */ | |
918 | case 0x05: /* rebuild in progress */ | |
919 | case 0x06: /* recalculation in progress */ | |
920 | case 0x07: /* operation in progress */ | |
921 | case 0x08: /* Long write in progress */ | |
922 | case 0x09: /* self test in progress */ | |
d8705f11 | 923 | case 0x14: /* space allocation in progress */ |
b60af5b0 | 924 | action = ACTION_DELAYED_RETRY; |
f3e93f73 | 925 | break; |
3dbf6a54 | 926 | default: |
3dbf6a54 AS |
927 | action = ACTION_FAIL; |
928 | break; | |
f3e93f73 | 929 | } |
e6c11dbb | 930 | } else |
b60af5b0 | 931 | action = ACTION_FAIL; |
b60af5b0 | 932 | break; |
1da177e4 | 933 | case VOLUME_OVERFLOW: |
03aba2f7 | 934 | /* See SSC3rXX or current. */ |
b60af5b0 AS |
935 | action = ACTION_FAIL; |
936 | break; | |
1da177e4 | 937 | default: |
b60af5b0 | 938 | action = ACTION_FAIL; |
1da177e4 LT |
939 | break; |
940 | } | |
e6c11dbb | 941 | } else |
b60af5b0 | 942 | action = ACTION_FAIL; |
b60af5b0 | 943 | |
ee60b2c5 | 944 | if (action != ACTION_FAIL && |
e6c11dbb | 945 | time_before(cmd->jiffies_at_alloc + wait_for, jiffies)) |
ee60b2c5 | 946 | action = ACTION_FAIL; |
ee60b2c5 | 947 | |
b60af5b0 AS |
948 | switch (action) { |
949 | case ACTION_FAIL: | |
950 | /* Give up and fail the remainder of the request */ | |
e8064021 | 951 | if (!(req->rq_flags & RQF_QUIET)) { |
f1569ff1 HR |
952 | static DEFINE_RATELIMIT_STATE(_rs, |
953 | DEFAULT_RATELIMIT_INTERVAL, | |
954 | DEFAULT_RATELIMIT_BURST); | |
955 | ||
956 | if (unlikely(scsi_logging_level)) | |
957 | level = SCSI_LOG_LEVEL(SCSI_LOG_MLCOMPLETE_SHIFT, | |
958 | SCSI_LOG_MLCOMPLETE_BITS); | |
959 | ||
960 | /* | |
961 | * if logging is enabled the failure will be printed | |
962 | * in scsi_log_completion(), so avoid duplicate messages | |
963 | */ | |
964 | if (!level && __ratelimit(&_rs)) { | |
965 | scsi_print_result(cmd, NULL, FAILED); | |
966 | if (driver_byte(result) & DRIVER_SENSE) | |
967 | scsi_print_sense(cmd); | |
968 | scsi_print_command(cmd); | |
969 | } | |
3173d8c3 | 970 | } |
f6d47e74 CH |
971 | if (!scsi_end_request(req, error, blk_rq_err_bytes(req), 0)) |
972 | return; | |
bc85dc50 | 973 | /*FALLTHRU*/ |
b60af5b0 | 974 | case ACTION_REPREP: |
bc85dc50 | 975 | requeue: |
b60af5b0 AS |
976 | /* Unprep the request and put it back at the head of the queue. |
977 | * A new command will be prepared and issued. | |
978 | */ | |
d285203c | 979 | if (q->mq_ops) { |
e8064021 | 980 | cmd->request->rq_flags &= ~RQF_DONTPREP; |
d285203c CH |
981 | scsi_mq_uninit_cmd(cmd); |
982 | scsi_mq_requeue_cmd(cmd); | |
983 | } else { | |
984 | scsi_release_buffers(cmd); | |
985 | scsi_requeue_command(q, cmd); | |
986 | } | |
b60af5b0 AS |
987 | break; |
988 | case ACTION_RETRY: | |
989 | /* Retry the same command immediately */ | |
4f5299ac | 990 | __scsi_queue_insert(cmd, SCSI_MLQUEUE_EH_RETRY, 0); |
b60af5b0 AS |
991 | break; |
992 | case ACTION_DELAYED_RETRY: | |
993 | /* Retry the same command after a delay */ | |
4f5299ac | 994 | __scsi_queue_insert(cmd, SCSI_MLQUEUE_DEVICE_BUSY, 0); |
b60af5b0 | 995 | break; |
1da177e4 LT |
996 | } |
997 | } | |
1da177e4 | 998 | |
3c356bde | 999 | static int scsi_init_sgtable(struct request *req, struct scsi_data_buffer *sdb) |
1da177e4 | 1000 | { |
6f9a35e2 | 1001 | int count; |
1da177e4 LT |
1002 | |
1003 | /* | |
3b003157 | 1004 | * If sg table allocation fails, requeue request later. |
1da177e4 | 1005 | */ |
f9d03f96 CH |
1006 | if (unlikely(sg_alloc_table_chained(&sdb->table, |
1007 | blk_rq_nr_phys_segments(req), sdb->table.sgl))) | |
1da177e4 | 1008 | return BLKPREP_DEFER; |
1da177e4 | 1009 | |
1da177e4 LT |
1010 | /* |
1011 | * Next, walk the list, and fill in the addresses and sizes of | |
1012 | * each segment. | |
1013 | */ | |
30b0c37b BH |
1014 | count = blk_rq_map_sg(req->q, req, sdb->table.sgl); |
1015 | BUG_ON(count > sdb->table.nents); | |
1016 | sdb->table.nents = count; | |
fd102b12 | 1017 | sdb->length = blk_rq_payload_bytes(req); |
4a03d90e | 1018 | return BLKPREP_OK; |
1da177e4 | 1019 | } |
6f9a35e2 BH |
1020 | |
1021 | /* | |
1022 | * Function: scsi_init_io() | |
1023 | * | |
1024 | * Purpose: SCSI I/O initialize function. | |
1025 | * | |
1026 | * Arguments: cmd - Command descriptor we wish to initialize | |
1027 | * | |
1028 | * Returns: 0 on success | |
1029 | * BLKPREP_DEFER if the failure is retryable | |
1030 | * BLKPREP_KILL if the failure is fatal | |
1031 | */ | |
3c356bde | 1032 | int scsi_init_io(struct scsi_cmnd *cmd) |
6f9a35e2 | 1033 | { |
5e012aad | 1034 | struct scsi_device *sdev = cmd->device; |
13f05c8d | 1035 | struct request *rq = cmd->request; |
d285203c | 1036 | bool is_mq = (rq->mq_ctx != NULL); |
e7661a8e | 1037 | int error = BLKPREP_KILL; |
13f05c8d | 1038 | |
fd3fc0b4 | 1039 | if (WARN_ON_ONCE(!blk_rq_nr_phys_segments(rq))) |
e7661a8e | 1040 | goto err_exit; |
635d98b1 | 1041 | |
3c356bde | 1042 | error = scsi_init_sgtable(rq, &cmd->sdb); |
6f9a35e2 BH |
1043 | if (error) |
1044 | goto err_exit; | |
1045 | ||
13f05c8d | 1046 | if (blk_bidi_rq(rq)) { |
d285203c CH |
1047 | if (!rq->q->mq_ops) { |
1048 | struct scsi_data_buffer *bidi_sdb = | |
1049 | kmem_cache_zalloc(scsi_sdb_cache, GFP_ATOMIC); | |
1050 | if (!bidi_sdb) { | |
1051 | error = BLKPREP_DEFER; | |
1052 | goto err_exit; | |
1053 | } | |
1054 | ||
1055 | rq->next_rq->special = bidi_sdb; | |
6f9a35e2 BH |
1056 | } |
1057 | ||
3c356bde | 1058 | error = scsi_init_sgtable(rq->next_rq, rq->next_rq->special); |
6f9a35e2 BH |
1059 | if (error) |
1060 | goto err_exit; | |
1061 | } | |
1062 | ||
13f05c8d | 1063 | if (blk_integrity_rq(rq)) { |
7027ad72 MP |
1064 | struct scsi_data_buffer *prot_sdb = cmd->prot_sdb; |
1065 | int ivecs, count; | |
1066 | ||
91724c20 EM |
1067 | if (prot_sdb == NULL) { |
1068 | /* | |
1069 | * This can happen if someone (e.g. multipath) | |
1070 | * queues a command to a device on an adapter | |
1071 | * that does not support DIX. | |
1072 | */ | |
1073 | WARN_ON_ONCE(1); | |
1074 | error = BLKPREP_KILL; | |
1075 | goto err_exit; | |
1076 | } | |
1077 | ||
13f05c8d | 1078 | ivecs = blk_rq_count_integrity_sg(rq->q, rq->bio); |
7027ad72 | 1079 | |
001d63be | 1080 | if (sg_alloc_table_chained(&prot_sdb->table, ivecs, |
22cc3d4c | 1081 | prot_sdb->table.sgl)) { |
7027ad72 MP |
1082 | error = BLKPREP_DEFER; |
1083 | goto err_exit; | |
1084 | } | |
1085 | ||
13f05c8d | 1086 | count = blk_rq_map_integrity_sg(rq->q, rq->bio, |
7027ad72 MP |
1087 | prot_sdb->table.sgl); |
1088 | BUG_ON(unlikely(count > ivecs)); | |
13f05c8d | 1089 | BUG_ON(unlikely(count > queue_max_integrity_segments(rq->q))); |
7027ad72 MP |
1090 | |
1091 | cmd->prot_sdb = prot_sdb; | |
1092 | cmd->prot_sdb->table.nents = count; | |
1093 | } | |
1094 | ||
d285203c | 1095 | return BLKPREP_OK; |
6f9a35e2 | 1096 | err_exit: |
d285203c CH |
1097 | if (is_mq) { |
1098 | scsi_mq_free_sgtables(cmd); | |
1099 | } else { | |
1100 | scsi_release_buffers(cmd); | |
1101 | cmd->request->special = NULL; | |
1102 | scsi_put_command(cmd); | |
1103 | put_device(&sdev->sdev_gendev); | |
1104 | } | |
6f9a35e2 BH |
1105 | return error; |
1106 | } | |
bb52d82f | 1107 | EXPORT_SYMBOL(scsi_init_io); |
1da177e4 | 1108 | |
ca18d6f7 BVA |
1109 | /** |
1110 | * scsi_initialize_rq - initialize struct scsi_cmnd.req | |
1111 | * | |
1112 | * Called from inside blk_get_request(). | |
1113 | */ | |
1114 | void scsi_initialize_rq(struct request *rq) | |
1115 | { | |
c8d9cf22 BVA |
1116 | struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq); |
1117 | ||
1118 | scsi_req_init(&cmd->req); | |
ca18d6f7 BVA |
1119 | } |
1120 | EXPORT_SYMBOL(scsi_initialize_rq); | |
1121 | ||
2dd6fb59 BVA |
1122 | /* Add a command to the list used by the aacraid and dpt_i2o drivers */ |
1123 | void scsi_add_cmd_to_list(struct scsi_cmnd *cmd) | |
1124 | { | |
1125 | struct scsi_device *sdev = cmd->device; | |
1126 | struct Scsi_Host *shost = sdev->host; | |
1127 | unsigned long flags; | |
1128 | ||
1129 | if (shost->use_cmd_list) { | |
1130 | spin_lock_irqsave(&sdev->list_lock, flags); | |
1131 | list_add_tail(&cmd->list, &sdev->cmd_list); | |
1132 | spin_unlock_irqrestore(&sdev->list_lock, flags); | |
1133 | } | |
1134 | } | |
1135 | ||
1136 | /* Remove a command from the list used by the aacraid and dpt_i2o drivers */ | |
1137 | void scsi_del_cmd_from_list(struct scsi_cmnd *cmd) | |
1138 | { | |
1139 | struct scsi_device *sdev = cmd->device; | |
1140 | struct Scsi_Host *shost = sdev->host; | |
1141 | unsigned long flags; | |
1142 | ||
1143 | if (shost->use_cmd_list) { | |
1144 | spin_lock_irqsave(&sdev->list_lock, flags); | |
1145 | BUG_ON(list_empty(&cmd->list)); | |
1146 | list_del_init(&cmd->list); | |
1147 | spin_unlock_irqrestore(&sdev->list_lock, flags); | |
1148 | } | |
1149 | } | |
1150 | ||
ca18d6f7 | 1151 | /* Called after a request has been started. */ |
e9c787e6 | 1152 | void scsi_init_command(struct scsi_device *dev, struct scsi_cmnd *cmd) |
3b003157 | 1153 | { |
e9c787e6 CH |
1154 | void *buf = cmd->sense_buffer; |
1155 | void *prot = cmd->prot_sdb; | |
8e688254 | 1156 | unsigned int unchecked_isa_dma = cmd->flags & SCMD_UNCHECKED_ISA_DMA; |
3b003157 | 1157 | |
82ed4db4 CH |
1158 | /* zero out the cmd, except for the embedded scsi_request */ |
1159 | memset((char *)cmd + sizeof(cmd->req), 0, | |
ee524236 | 1160 | sizeof(*cmd) - sizeof(cmd->req) + dev->host->hostt->cmd_size); |
3b003157 | 1161 | |
e9c787e6 CH |
1162 | cmd->device = dev; |
1163 | cmd->sense_buffer = buf; | |
1164 | cmd->prot_sdb = prot; | |
8e688254 | 1165 | cmd->flags = unchecked_isa_dma; |
e9c787e6 CH |
1166 | INIT_DELAYED_WORK(&cmd->abort_work, scmd_eh_abort_handler); |
1167 | cmd->jiffies_at_alloc = jiffies; | |
64a87b24 | 1168 | |
2dd6fb59 | 1169 | scsi_add_cmd_to_list(cmd); |
3b003157 CH |
1170 | } |
1171 | ||
aebf526b | 1172 | static int scsi_setup_scsi_cmnd(struct scsi_device *sdev, struct request *req) |
7b16318d | 1173 | { |
a1b73fc1 | 1174 | struct scsi_cmnd *cmd = req->special; |
3b003157 CH |
1175 | |
1176 | /* | |
aebf526b | 1177 | * Passthrough requests may transfer data, in which case they must |
3b003157 CH |
1178 | * a bio attached to them. Or they might contain a SCSI command |
1179 | * that does not transfer data, in which case they may optionally | |
1180 | * submit a request without an attached bio. | |
1181 | */ | |
1182 | if (req->bio) { | |
3c356bde | 1183 | int ret = scsi_init_io(cmd); |
3b003157 CH |
1184 | if (unlikely(ret)) |
1185 | return ret; | |
1186 | } else { | |
b0790410 | 1187 | BUG_ON(blk_rq_bytes(req)); |
3b003157 | 1188 | |
30b0c37b | 1189 | memset(&cmd->sdb, 0, sizeof(cmd->sdb)); |
3b003157 | 1190 | } |
7b16318d | 1191 | |
82ed4db4 CH |
1192 | cmd->cmd_len = scsi_req(req)->cmd_len; |
1193 | cmd->cmnd = scsi_req(req)->cmd; | |
b0790410 | 1194 | cmd->transfersize = blk_rq_bytes(req); |
64c7f1d1 | 1195 | cmd->allowed = scsi_req(req)->retries; |
3b003157 | 1196 | return BLKPREP_OK; |
7b16318d | 1197 | } |
7b16318d | 1198 | |
3b003157 | 1199 | /* |
aebf526b | 1200 | * Setup a normal block command. These are simple request from filesystems |
3868cf8e | 1201 | * that still need to be translated to SCSI CDBs from the ULD. |
3b003157 | 1202 | */ |
3868cf8e | 1203 | static int scsi_setup_fs_cmnd(struct scsi_device *sdev, struct request *req) |
1da177e4 | 1204 | { |
a1b73fc1 | 1205 | struct scsi_cmnd *cmd = req->special; |
a6a8d9f8 | 1206 | |
ee14c674 CH |
1207 | if (unlikely(sdev->handler && sdev->handler->prep_fn)) { |
1208 | int ret = sdev->handler->prep_fn(sdev, req); | |
a6a8d9f8 CS |
1209 | if (ret != BLKPREP_OK) |
1210 | return ret; | |
1211 | } | |
1212 | ||
82ed4db4 | 1213 | cmd->cmnd = scsi_req(req)->cmd = scsi_req(req)->__cmd; |
64a87b24 | 1214 | memset(cmd->cmnd, 0, BLK_MAX_CDB); |
3868cf8e | 1215 | return scsi_cmd_to_driver(cmd)->init_command(cmd); |
3b003157 CH |
1216 | } |
1217 | ||
6af7a4ff CH |
1218 | static int scsi_setup_cmnd(struct scsi_device *sdev, struct request *req) |
1219 | { | |
1220 | struct scsi_cmnd *cmd = req->special; | |
1221 | ||
1222 | if (!blk_rq_bytes(req)) | |
1223 | cmd->sc_data_direction = DMA_NONE; | |
1224 | else if (rq_data_dir(req) == WRITE) | |
1225 | cmd->sc_data_direction = DMA_TO_DEVICE; | |
1226 | else | |
1227 | cmd->sc_data_direction = DMA_FROM_DEVICE; | |
1228 | ||
aebf526b CH |
1229 | if (blk_rq_is_scsi(req)) |
1230 | return scsi_setup_scsi_cmnd(sdev, req); | |
1231 | else | |
6af7a4ff | 1232 | return scsi_setup_fs_cmnd(sdev, req); |
6af7a4ff CH |
1233 | } |
1234 | ||
a1b73fc1 CH |
1235 | static int |
1236 | scsi_prep_state_check(struct scsi_device *sdev, struct request *req) | |
3b003157 | 1237 | { |
3b003157 CH |
1238 | int ret = BLKPREP_OK; |
1239 | ||
1da177e4 | 1240 | /* |
3b003157 CH |
1241 | * If the device is not in running state we will reject some |
1242 | * or all commands. | |
1da177e4 | 1243 | */ |
3b003157 CH |
1244 | if (unlikely(sdev->sdev_state != SDEV_RUNNING)) { |
1245 | switch (sdev->sdev_state) { | |
1246 | case SDEV_OFFLINE: | |
1b8d2620 | 1247 | case SDEV_TRANSPORT_OFFLINE: |
3b003157 CH |
1248 | /* |
1249 | * If the device is offline we refuse to process any | |
1250 | * commands. The device must be brought online | |
1251 | * before trying any recovery commands. | |
1252 | */ | |
1253 | sdev_printk(KERN_ERR, sdev, | |
1254 | "rejecting I/O to offline device\n"); | |
1255 | ret = BLKPREP_KILL; | |
1256 | break; | |
1257 | case SDEV_DEL: | |
1258 | /* | |
1259 | * If the device is fully deleted, we refuse to | |
1260 | * process any commands as well. | |
1261 | */ | |
9ccfc756 | 1262 | sdev_printk(KERN_ERR, sdev, |
3b003157 CH |
1263 | "rejecting I/O to dead device\n"); |
1264 | ret = BLKPREP_KILL; | |
1265 | break; | |
3b003157 | 1266 | case SDEV_BLOCK: |
6f4267e3 | 1267 | case SDEV_CREATED_BLOCK: |
bba0bdd7 BVA |
1268 | ret = BLKPREP_DEFER; |
1269 | break; | |
1270 | case SDEV_QUIESCE: | |
3b003157 CH |
1271 | /* |
1272 | * If the devices is blocked we defer normal commands. | |
1273 | */ | |
e8064021 | 1274 | if (!(req->rq_flags & RQF_PREEMPT)) |
3b003157 CH |
1275 | ret = BLKPREP_DEFER; |
1276 | break; | |
1277 | default: | |
1278 | /* | |
1279 | * For any other not fully online state we only allow | |
1280 | * special commands. In particular any user initiated | |
1281 | * command is not allowed. | |
1282 | */ | |
e8064021 | 1283 | if (!(req->rq_flags & RQF_PREEMPT)) |
3b003157 CH |
1284 | ret = BLKPREP_KILL; |
1285 | break; | |
1da177e4 | 1286 | } |
1da177e4 | 1287 | } |
7f9a6bc4 JB |
1288 | return ret; |
1289 | } | |
1da177e4 | 1290 | |
a1b73fc1 CH |
1291 | static int |
1292 | scsi_prep_return(struct request_queue *q, struct request *req, int ret) | |
7f9a6bc4 JB |
1293 | { |
1294 | struct scsi_device *sdev = q->queuedata; | |
1da177e4 | 1295 | |
3b003157 CH |
1296 | switch (ret) { |
1297 | case BLKPREP_KILL: | |
e1cd3911 | 1298 | case BLKPREP_INVALID: |
17d5363b | 1299 | scsi_req(req)->result = DID_NO_CONNECT << 16; |
7f9a6bc4 JB |
1300 | /* release the command and kill it */ |
1301 | if (req->special) { | |
1302 | struct scsi_cmnd *cmd = req->special; | |
1303 | scsi_release_buffers(cmd); | |
1304 | scsi_put_command(cmd); | |
68c03d91 | 1305 | put_device(&sdev->sdev_gendev); |
7f9a6bc4 JB |
1306 | req->special = NULL; |
1307 | } | |
3b003157 CH |
1308 | break; |
1309 | case BLKPREP_DEFER: | |
1da177e4 | 1310 | /* |
9934c8c0 | 1311 | * If we defer, the blk_peek_request() returns NULL, but the |
a488e749 JA |
1312 | * queue must be restarted, so we schedule a callback to happen |
1313 | * shortly. | |
1da177e4 | 1314 | */ |
71e75c97 | 1315 | if (atomic_read(&sdev->device_busy) == 0) |
a488e749 | 1316 | blk_delay_queue(q, SCSI_QUEUE_DELAY); |
3b003157 CH |
1317 | break; |
1318 | default: | |
e8064021 | 1319 | req->rq_flags |= RQF_DONTPREP; |
1da177e4 LT |
1320 | } |
1321 | ||
3b003157 | 1322 | return ret; |
1da177e4 | 1323 | } |
7f9a6bc4 | 1324 | |
a1b73fc1 | 1325 | static int scsi_prep_fn(struct request_queue *q, struct request *req) |
7f9a6bc4 JB |
1326 | { |
1327 | struct scsi_device *sdev = q->queuedata; | |
e9c787e6 | 1328 | struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req); |
a1b73fc1 CH |
1329 | int ret; |
1330 | ||
1331 | ret = scsi_prep_state_check(sdev, req); | |
1332 | if (ret != BLKPREP_OK) | |
1333 | goto out; | |
1334 | ||
e9c787e6 CH |
1335 | if (!req->special) { |
1336 | /* Bail if we can't get a reference to the device */ | |
1337 | if (unlikely(!get_device(&sdev->sdev_gendev))) { | |
1338 | ret = BLKPREP_DEFER; | |
1339 | goto out; | |
1340 | } | |
1341 | ||
1342 | scsi_init_command(sdev, cmd); | |
1343 | req->special = cmd; | |
a1b73fc1 | 1344 | } |
7f9a6bc4 | 1345 | |
e9c787e6 CH |
1346 | cmd->tag = req->tag; |
1347 | cmd->request = req; | |
e9c787e6 CH |
1348 | cmd->prot_op = SCSI_PROT_NORMAL; |
1349 | ||
6af7a4ff | 1350 | ret = scsi_setup_cmnd(sdev, req); |
a1b73fc1 | 1351 | out: |
7f9a6bc4 JB |
1352 | return scsi_prep_return(q, req, ret); |
1353 | } | |
a1b73fc1 CH |
1354 | |
1355 | static void scsi_unprep_fn(struct request_queue *q, struct request *req) | |
1356 | { | |
d285203c | 1357 | scsi_uninit_cmd(req->special); |
a1b73fc1 | 1358 | } |
1da177e4 LT |
1359 | |
1360 | /* | |
1361 | * scsi_dev_queue_ready: if we can send requests to sdev, return 1 else | |
1362 | * return 0. | |
1363 | * | |
1364 | * Called with the queue_lock held. | |
1365 | */ | |
1366 | static inline int scsi_dev_queue_ready(struct request_queue *q, | |
1367 | struct scsi_device *sdev) | |
1368 | { | |
71e75c97 CH |
1369 | unsigned int busy; |
1370 | ||
1371 | busy = atomic_inc_return(&sdev->device_busy) - 1; | |
cd9070c9 | 1372 | if (atomic_read(&sdev->device_blocked)) { |
71e75c97 CH |
1373 | if (busy) |
1374 | goto out_dec; | |
1375 | ||
1da177e4 LT |
1376 | /* |
1377 | * unblock after device_blocked iterates to zero | |
1378 | */ | |
cd9070c9 | 1379 | if (atomic_dec_return(&sdev->device_blocked) > 0) { |
d285203c CH |
1380 | /* |
1381 | * For the MQ case we take care of this in the caller. | |
1382 | */ | |
1383 | if (!q->mq_ops) | |
1384 | blk_delay_queue(q, SCSI_QUEUE_DELAY); | |
71e75c97 | 1385 | goto out_dec; |
1da177e4 | 1386 | } |
71e75c97 CH |
1387 | SCSI_LOG_MLQUEUE(3, sdev_printk(KERN_INFO, sdev, |
1388 | "unblocking device at zero depth\n")); | |
1da177e4 | 1389 | } |
71e75c97 CH |
1390 | |
1391 | if (busy >= sdev->queue_depth) | |
1392 | goto out_dec; | |
1da177e4 LT |
1393 | |
1394 | return 1; | |
71e75c97 CH |
1395 | out_dec: |
1396 | atomic_dec(&sdev->device_busy); | |
1397 | return 0; | |
1da177e4 LT |
1398 | } |
1399 | ||
f0c0a376 MC |
1400 | /* |
1401 | * scsi_target_queue_ready: checks if there we can send commands to target | |
1402 | * @sdev: scsi device on starget to check. | |
f0c0a376 MC |
1403 | */ |
1404 | static inline int scsi_target_queue_ready(struct Scsi_Host *shost, | |
1405 | struct scsi_device *sdev) | |
1406 | { | |
1407 | struct scsi_target *starget = scsi_target(sdev); | |
7ae65c0f | 1408 | unsigned int busy; |
f0c0a376 MC |
1409 | |
1410 | if (starget->single_lun) { | |
7ae65c0f | 1411 | spin_lock_irq(shost->host_lock); |
f0c0a376 | 1412 | if (starget->starget_sdev_user && |
7ae65c0f CH |
1413 | starget->starget_sdev_user != sdev) { |
1414 | spin_unlock_irq(shost->host_lock); | |
1415 | return 0; | |
1416 | } | |
f0c0a376 | 1417 | starget->starget_sdev_user = sdev; |
7ae65c0f | 1418 | spin_unlock_irq(shost->host_lock); |
f0c0a376 MC |
1419 | } |
1420 | ||
2ccbb008 CH |
1421 | if (starget->can_queue <= 0) |
1422 | return 1; | |
1423 | ||
7ae65c0f | 1424 | busy = atomic_inc_return(&starget->target_busy) - 1; |
cd9070c9 | 1425 | if (atomic_read(&starget->target_blocked) > 0) { |
7ae65c0f CH |
1426 | if (busy) |
1427 | goto starved; | |
1428 | ||
f0c0a376 MC |
1429 | /* |
1430 | * unblock after target_blocked iterates to zero | |
1431 | */ | |
cd9070c9 | 1432 | if (atomic_dec_return(&starget->target_blocked) > 0) |
7ae65c0f | 1433 | goto out_dec; |
cf68d334 CH |
1434 | |
1435 | SCSI_LOG_MLQUEUE(3, starget_printk(KERN_INFO, starget, | |
1436 | "unblocking target at zero depth\n")); | |
f0c0a376 MC |
1437 | } |
1438 | ||
2ccbb008 | 1439 | if (busy >= starget->can_queue) |
7ae65c0f | 1440 | goto starved; |
f0c0a376 | 1441 | |
7ae65c0f CH |
1442 | return 1; |
1443 | ||
1444 | starved: | |
1445 | spin_lock_irq(shost->host_lock); | |
1446 | list_move_tail(&sdev->starved_entry, &shost->starved_list); | |
cf68d334 | 1447 | spin_unlock_irq(shost->host_lock); |
7ae65c0f | 1448 | out_dec: |
2ccbb008 CH |
1449 | if (starget->can_queue > 0) |
1450 | atomic_dec(&starget->target_busy); | |
7ae65c0f | 1451 | return 0; |
f0c0a376 MC |
1452 | } |
1453 | ||
1da177e4 LT |
1454 | /* |
1455 | * scsi_host_queue_ready: if we can send requests to shost, return 1 else | |
1456 | * return 0. We must end up running the queue again whenever 0 is | |
1457 | * returned, else IO can hang. | |
1da177e4 LT |
1458 | */ |
1459 | static inline int scsi_host_queue_ready(struct request_queue *q, | |
1460 | struct Scsi_Host *shost, | |
1461 | struct scsi_device *sdev) | |
1462 | { | |
74665016 | 1463 | unsigned int busy; |
cf68d334 | 1464 | |
939647ee | 1465 | if (scsi_host_in_recovery(shost)) |
74665016 CH |
1466 | return 0; |
1467 | ||
1468 | busy = atomic_inc_return(&shost->host_busy) - 1; | |
cd9070c9 | 1469 | if (atomic_read(&shost->host_blocked) > 0) { |
74665016 CH |
1470 | if (busy) |
1471 | goto starved; | |
1472 | ||
1da177e4 LT |
1473 | /* |
1474 | * unblock after host_blocked iterates to zero | |
1475 | */ | |
cd9070c9 | 1476 | if (atomic_dec_return(&shost->host_blocked) > 0) |
74665016 | 1477 | goto out_dec; |
cf68d334 CH |
1478 | |
1479 | SCSI_LOG_MLQUEUE(3, | |
1480 | shost_printk(KERN_INFO, shost, | |
1481 | "unblocking host at zero depth\n")); | |
1da177e4 | 1482 | } |
74665016 CH |
1483 | |
1484 | if (shost->can_queue > 0 && busy >= shost->can_queue) | |
1485 | goto starved; | |
1486 | if (shost->host_self_blocked) | |
1487 | goto starved; | |
1da177e4 LT |
1488 | |
1489 | /* We're OK to process the command, so we can't be starved */ | |
74665016 CH |
1490 | if (!list_empty(&sdev->starved_entry)) { |
1491 | spin_lock_irq(shost->host_lock); | |
1492 | if (!list_empty(&sdev->starved_entry)) | |
1493 | list_del_init(&sdev->starved_entry); | |
1494 | spin_unlock_irq(shost->host_lock); | |
1495 | } | |
1da177e4 | 1496 | |
74665016 CH |
1497 | return 1; |
1498 | ||
1499 | starved: | |
1500 | spin_lock_irq(shost->host_lock); | |
1501 | if (list_empty(&sdev->starved_entry)) | |
1502 | list_add_tail(&sdev->starved_entry, &shost->starved_list); | |
cf68d334 | 1503 | spin_unlock_irq(shost->host_lock); |
74665016 CH |
1504 | out_dec: |
1505 | atomic_dec(&shost->host_busy); | |
1506 | return 0; | |
1da177e4 LT |
1507 | } |
1508 | ||
6c5121b7 KU |
1509 | /* |
1510 | * Busy state exporting function for request stacking drivers. | |
1511 | * | |
1512 | * For efficiency, no lock is taken to check the busy state of | |
1513 | * shost/starget/sdev, since the returned value is not guaranteed and | |
1514 | * may be changed after request stacking drivers call the function, | |
1515 | * regardless of taking lock or not. | |
1516 | * | |
67bd9413 BVA |
1517 | * When scsi can't dispatch I/Os anymore and needs to kill I/Os scsi |
1518 | * needs to return 'not busy'. Otherwise, request stacking drivers | |
1519 | * may hold requests forever. | |
6c5121b7 KU |
1520 | */ |
1521 | static int scsi_lld_busy(struct request_queue *q) | |
1522 | { | |
1523 | struct scsi_device *sdev = q->queuedata; | |
1524 | struct Scsi_Host *shost; | |
6c5121b7 | 1525 | |
3f3299d5 | 1526 | if (blk_queue_dying(q)) |
6c5121b7 KU |
1527 | return 0; |
1528 | ||
1529 | shost = sdev->host; | |
6c5121b7 | 1530 | |
b7e94a16 JN |
1531 | /* |
1532 | * Ignore host/starget busy state. | |
1533 | * Since block layer does not have a concept of fairness across | |
1534 | * multiple queues, congestion of host/starget needs to be handled | |
1535 | * in SCSI layer. | |
1536 | */ | |
1537 | if (scsi_host_in_recovery(shost) || scsi_device_is_busy(sdev)) | |
6c5121b7 KU |
1538 | return 1; |
1539 | ||
1540 | return 0; | |
1541 | } | |
1542 | ||
1da177e4 | 1543 | /* |
e91442b6 | 1544 | * Kill a request for a dead device |
1da177e4 | 1545 | */ |
165125e1 | 1546 | static void scsi_kill_request(struct request *req, struct request_queue *q) |
1da177e4 | 1547 | { |
e91442b6 | 1548 | struct scsi_cmnd *cmd = req->special; |
03b14708 JS |
1549 | struct scsi_device *sdev; |
1550 | struct scsi_target *starget; | |
1551 | struct Scsi_Host *shost; | |
1da177e4 | 1552 | |
9934c8c0 | 1553 | blk_start_request(req); |
788ce43a | 1554 | |
74571813 HR |
1555 | scmd_printk(KERN_INFO, cmd, "killing request\n"); |
1556 | ||
03b14708 JS |
1557 | sdev = cmd->device; |
1558 | starget = scsi_target(sdev); | |
1559 | shost = sdev->host; | |
e91442b6 JB |
1560 | scsi_init_cmd_errh(cmd); |
1561 | cmd->result = DID_NO_CONNECT << 16; | |
1562 | atomic_inc(&cmd->device->iorequest_cnt); | |
e36e0c80 TH |
1563 | |
1564 | /* | |
1565 | * SCSI request completion path will do scsi_device_unbusy(), | |
1566 | * bump busy counts. To bump the counters, we need to dance | |
1567 | * with the locks as normal issue path does. | |
1568 | */ | |
71e75c97 | 1569 | atomic_inc(&sdev->device_busy); |
74665016 | 1570 | atomic_inc(&shost->host_busy); |
2ccbb008 CH |
1571 | if (starget->can_queue > 0) |
1572 | atomic_inc(&starget->target_busy); | |
e36e0c80 | 1573 | |
242f9dcb | 1574 | blk_complete_request(req); |
1da177e4 LT |
1575 | } |
1576 | ||
1aea6434 JA |
1577 | static void scsi_softirq_done(struct request *rq) |
1578 | { | |
242f9dcb JA |
1579 | struct scsi_cmnd *cmd = rq->special; |
1580 | unsigned long wait_for = (cmd->allowed + 1) * rq->timeout; | |
1aea6434 JA |
1581 | int disposition; |
1582 | ||
1583 | INIT_LIST_HEAD(&cmd->eh_entry); | |
1584 | ||
242f9dcb JA |
1585 | atomic_inc(&cmd->device->iodone_cnt); |
1586 | if (cmd->result) | |
1587 | atomic_inc(&cmd->device->ioerr_cnt); | |
1588 | ||
1aea6434 JA |
1589 | disposition = scsi_decide_disposition(cmd); |
1590 | if (disposition != SUCCESS && | |
1591 | time_before(cmd->jiffies_at_alloc + wait_for, jiffies)) { | |
1592 | sdev_printk(KERN_ERR, cmd->device, | |
1593 | "timing out command, waited %lus\n", | |
1594 | wait_for/HZ); | |
1595 | disposition = SUCCESS; | |
1596 | } | |
91921e01 | 1597 | |
1aea6434 JA |
1598 | scsi_log_completion(cmd, disposition); |
1599 | ||
1600 | switch (disposition) { | |
1601 | case SUCCESS: | |
1602 | scsi_finish_command(cmd); | |
1603 | break; | |
1604 | case NEEDS_RETRY: | |
596f482a | 1605 | scsi_queue_insert(cmd, SCSI_MLQUEUE_EH_RETRY); |
1aea6434 JA |
1606 | break; |
1607 | case ADD_TO_MLQUEUE: | |
1608 | scsi_queue_insert(cmd, SCSI_MLQUEUE_DEVICE_BUSY); | |
1609 | break; | |
1610 | default: | |
a0658632 | 1611 | scsi_eh_scmd_add(cmd); |
2171b6d0 | 1612 | break; |
1aea6434 JA |
1613 | } |
1614 | } | |
1615 | ||
82042a2c CH |
1616 | /** |
1617 | * scsi_dispatch_command - Dispatch a command to the low-level driver. | |
1618 | * @cmd: command block we are dispatching. | |
1619 | * | |
1620 | * Return: nonzero return request was rejected and device's queue needs to be | |
1621 | * plugged. | |
1622 | */ | |
1623 | static int scsi_dispatch_cmd(struct scsi_cmnd *cmd) | |
1624 | { | |
1625 | struct Scsi_Host *host = cmd->device->host; | |
1626 | int rtn = 0; | |
1627 | ||
1628 | atomic_inc(&cmd->device->iorequest_cnt); | |
1629 | ||
1630 | /* check if the device is still usable */ | |
1631 | if (unlikely(cmd->device->sdev_state == SDEV_DEL)) { | |
1632 | /* in SDEV_DEL we error all commands. DID_NO_CONNECT | |
1633 | * returns an immediate error upwards, and signals | |
1634 | * that the device is no longer present */ | |
1635 | cmd->result = DID_NO_CONNECT << 16; | |
1636 | goto done; | |
1637 | } | |
1638 | ||
1639 | /* Check to see if the scsi lld made this device blocked. */ | |
1640 | if (unlikely(scsi_device_blocked(cmd->device))) { | |
1641 | /* | |
1642 | * in blocked state, the command is just put back on | |
1643 | * the device queue. The suspend state has already | |
1644 | * blocked the queue so future requests should not | |
1645 | * occur until the device transitions out of the | |
1646 | * suspend state. | |
1647 | */ | |
1648 | SCSI_LOG_MLQUEUE(3, scmd_printk(KERN_INFO, cmd, | |
1649 | "queuecommand : device blocked\n")); | |
1650 | return SCSI_MLQUEUE_DEVICE_BUSY; | |
1651 | } | |
1652 | ||
1653 | /* Store the LUN value in cmnd, if needed. */ | |
1654 | if (cmd->device->lun_in_cdb) | |
1655 | cmd->cmnd[1] = (cmd->cmnd[1] & 0x1f) | | |
1656 | (cmd->device->lun << 5 & 0xe0); | |
1657 | ||
1658 | scsi_log_send(cmd); | |
1659 | ||
1660 | /* | |
1661 | * Before we queue this command, check if the command | |
1662 | * length exceeds what the host adapter can handle. | |
1663 | */ | |
1664 | if (cmd->cmd_len > cmd->device->host->max_cmd_len) { | |
1665 | SCSI_LOG_MLQUEUE(3, scmd_printk(KERN_INFO, cmd, | |
1666 | "queuecommand : command too long. " | |
1667 | "cdb_size=%d host->max_cmd_len=%d\n", | |
1668 | cmd->cmd_len, cmd->device->host->max_cmd_len)); | |
1669 | cmd->result = (DID_ABORT << 16); | |
1670 | goto done; | |
1671 | } | |
1672 | ||
1673 | if (unlikely(host->shost_state == SHOST_DEL)) { | |
1674 | cmd->result = (DID_NO_CONNECT << 16); | |
1675 | goto done; | |
1676 | ||
1677 | } | |
1678 | ||
1679 | trace_scsi_dispatch_cmd_start(cmd); | |
1680 | rtn = host->hostt->queuecommand(host, cmd); | |
1681 | if (rtn) { | |
1682 | trace_scsi_dispatch_cmd_error(cmd, rtn); | |
1683 | if (rtn != SCSI_MLQUEUE_DEVICE_BUSY && | |
1684 | rtn != SCSI_MLQUEUE_TARGET_BUSY) | |
1685 | rtn = SCSI_MLQUEUE_HOST_BUSY; | |
1686 | ||
1687 | SCSI_LOG_MLQUEUE(3, scmd_printk(KERN_INFO, cmd, | |
1688 | "queuecommand : request rejected\n")); | |
1689 | } | |
1690 | ||
1691 | return rtn; | |
1692 | done: | |
1693 | cmd->scsi_done(cmd); | |
1694 | return 0; | |
1695 | } | |
1696 | ||
3b5382c4 CH |
1697 | /** |
1698 | * scsi_done - Invoke completion on finished SCSI command. | |
1699 | * @cmd: The SCSI Command for which a low-level device driver (LLDD) gives | |
1700 | * ownership back to SCSI Core -- i.e. the LLDD has finished with it. | |
1701 | * | |
1702 | * Description: This function is the mid-level's (SCSI Core) interrupt routine, | |
1703 | * which regains ownership of the SCSI command (de facto) from a LLDD, and | |
1704 | * calls blk_complete_request() for further processing. | |
1705 | * | |
1706 | * This function is interrupt context safe. | |
1707 | */ | |
1708 | static void scsi_done(struct scsi_cmnd *cmd) | |
1709 | { | |
1710 | trace_scsi_dispatch_cmd_done(cmd); | |
1711 | blk_complete_request(cmd->request); | |
1712 | } | |
1713 | ||
1da177e4 LT |
1714 | /* |
1715 | * Function: scsi_request_fn() | |
1716 | * | |
1717 | * Purpose: Main strategy routine for SCSI. | |
1718 | * | |
1719 | * Arguments: q - Pointer to actual queue. | |
1720 | * | |
1721 | * Returns: Nothing | |
1722 | * | |
1723 | * Lock status: IO request lock assumed to be held when called. | |
1724 | */ | |
1725 | static void scsi_request_fn(struct request_queue *q) | |
613be1f6 BVA |
1726 | __releases(q->queue_lock) |
1727 | __acquires(q->queue_lock) | |
1da177e4 LT |
1728 | { |
1729 | struct scsi_device *sdev = q->queuedata; | |
1730 | struct Scsi_Host *shost; | |
1731 | struct scsi_cmnd *cmd; | |
1732 | struct request *req; | |
1733 | ||
1da177e4 LT |
1734 | /* |
1735 | * To start with, we keep looping until the queue is empty, or until | |
1736 | * the host is no longer able to accept any more requests. | |
1737 | */ | |
1738 | shost = sdev->host; | |
a488e749 | 1739 | for (;;) { |
1da177e4 LT |
1740 | int rtn; |
1741 | /* | |
1742 | * get next queueable request. We do this early to make sure | |
91921e01 | 1743 | * that the request is fully prepared even if we cannot |
1da177e4 LT |
1744 | * accept it. |
1745 | */ | |
9934c8c0 | 1746 | req = blk_peek_request(q); |
71e75c97 | 1747 | if (!req) |
1da177e4 LT |
1748 | break; |
1749 | ||
1750 | if (unlikely(!scsi_device_online(sdev))) { | |
9ccfc756 JB |
1751 | sdev_printk(KERN_ERR, sdev, |
1752 | "rejecting I/O to offline device\n"); | |
e91442b6 | 1753 | scsi_kill_request(req, q); |
1da177e4 LT |
1754 | continue; |
1755 | } | |
1756 | ||
71e75c97 CH |
1757 | if (!scsi_dev_queue_ready(q, sdev)) |
1758 | break; | |
1da177e4 LT |
1759 | |
1760 | /* | |
1761 | * Remove the request from the request list. | |
1762 | */ | |
1763 | if (!(blk_queue_tagged(q) && !blk_queue_start_tag(q, req))) | |
9934c8c0 | 1764 | blk_start_request(req); |
1da177e4 | 1765 | |
cf68d334 | 1766 | spin_unlock_irq(q->queue_lock); |
e91442b6 JB |
1767 | cmd = req->special; |
1768 | if (unlikely(cmd == NULL)) { | |
1769 | printk(KERN_CRIT "impossible request in %s.\n" | |
1770 | "please mail a stack trace to " | |
4aff5e23 | 1771 | "linux-scsi@vger.kernel.org\n", |
cadbd4a5 | 1772 | __func__); |
4aff5e23 | 1773 | blk_dump_rq_flags(req, "foo"); |
e91442b6 JB |
1774 | BUG(); |
1775 | } | |
1da177e4 | 1776 | |
ecefe8a9 MC |
1777 | /* |
1778 | * We hit this when the driver is using a host wide | |
1779 | * tag map. For device level tag maps the queue_depth check | |
1780 | * in the device ready fn would prevent us from trying | |
1781 | * to allocate a tag. Since the map is a shared host resource | |
1782 | * we add the dev to the starved list so it eventually gets | |
1783 | * a run when a tag is freed. | |
1784 | */ | |
e8064021 | 1785 | if (blk_queue_tagged(q) && !(req->rq_flags & RQF_QUEUED)) { |
cf68d334 | 1786 | spin_lock_irq(shost->host_lock); |
ecefe8a9 MC |
1787 | if (list_empty(&sdev->starved_entry)) |
1788 | list_add_tail(&sdev->starved_entry, | |
1789 | &shost->starved_list); | |
cf68d334 | 1790 | spin_unlock_irq(shost->host_lock); |
ecefe8a9 MC |
1791 | goto not_ready; |
1792 | } | |
1793 | ||
f0c0a376 MC |
1794 | if (!scsi_target_queue_ready(shost, sdev)) |
1795 | goto not_ready; | |
1796 | ||
1da177e4 | 1797 | if (!scsi_host_queue_ready(q, shost, sdev)) |
cf68d334 | 1798 | goto host_not_ready; |
125c99bc CH |
1799 | |
1800 | if (sdev->simple_tags) | |
1801 | cmd->flags |= SCMD_TAGGED; | |
1802 | else | |
1803 | cmd->flags &= ~SCMD_TAGGED; | |
1da177e4 | 1804 | |
1da177e4 LT |
1805 | /* |
1806 | * Finally, initialize any error handling parameters, and set up | |
1807 | * the timers for timeouts. | |
1808 | */ | |
1809 | scsi_init_cmd_errh(cmd); | |
1810 | ||
1811 | /* | |
1812 | * Dispatch the command to the low-level driver. | |
1813 | */ | |
3b5382c4 | 1814 | cmd->scsi_done = scsi_done; |
1da177e4 | 1815 | rtn = scsi_dispatch_cmd(cmd); |
d0d3bbf9 CH |
1816 | if (rtn) { |
1817 | scsi_queue_insert(cmd, rtn); | |
1818 | spin_lock_irq(q->queue_lock); | |
a488e749 | 1819 | goto out_delay; |
d0d3bbf9 CH |
1820 | } |
1821 | spin_lock_irq(q->queue_lock); | |
1da177e4 LT |
1822 | } |
1823 | ||
613be1f6 | 1824 | return; |
1da177e4 | 1825 | |
cf68d334 | 1826 | host_not_ready: |
2ccbb008 CH |
1827 | if (scsi_target(sdev)->can_queue > 0) |
1828 | atomic_dec(&scsi_target(sdev)->target_busy); | |
cf68d334 | 1829 | not_ready: |
1da177e4 LT |
1830 | /* |
1831 | * lock q, handle tag, requeue req, and decrement device_busy. We | |
1832 | * must return with queue_lock held. | |
1833 | * | |
1834 | * Decrementing device_busy without checking it is OK, as all such | |
1835 | * cases (host limits or settings) should run the queue at some | |
1836 | * later time. | |
1837 | */ | |
1838 | spin_lock_irq(q->queue_lock); | |
1839 | blk_requeue_request(q, req); | |
71e75c97 | 1840 | atomic_dec(&sdev->device_busy); |
a488e749 | 1841 | out_delay: |
480cadc2 | 1842 | if (!atomic_read(&sdev->device_busy) && !scsi_device_blocked(sdev)) |
a488e749 | 1843 | blk_delay_queue(q, SCSI_QUEUE_DELAY); |
1da177e4 LT |
1844 | } |
1845 | ||
fc17b653 | 1846 | static inline blk_status_t prep_to_mq(int ret) |
d285203c CH |
1847 | { |
1848 | switch (ret) { | |
1849 | case BLKPREP_OK: | |
fc17b653 | 1850 | return BLK_STS_OK; |
d285203c | 1851 | case BLKPREP_DEFER: |
fc17b653 | 1852 | return BLK_STS_RESOURCE; |
d285203c | 1853 | default: |
fc17b653 | 1854 | return BLK_STS_IOERR; |
d285203c CH |
1855 | } |
1856 | } | |
1857 | ||
be4c186c BVA |
1858 | /* Size in bytes of the sg-list stored in the scsi-mq command-private data. */ |
1859 | static unsigned int scsi_mq_sgl_size(struct Scsi_Host *shost) | |
1860 | { | |
1861 | return min_t(unsigned int, shost->sg_tablesize, SG_CHUNK_SIZE) * | |
1862 | sizeof(struct scatterlist); | |
1863 | } | |
1864 | ||
d285203c CH |
1865 | static int scsi_mq_prep_fn(struct request *req) |
1866 | { | |
1867 | struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req); | |
1868 | struct scsi_device *sdev = req->q->queuedata; | |
1869 | struct Scsi_Host *shost = sdev->host; | |
d285203c CH |
1870 | struct scatterlist *sg; |
1871 | ||
08f78436 | 1872 | scsi_init_command(sdev, cmd); |
d285203c CH |
1873 | |
1874 | req->special = cmd; | |
1875 | ||
1876 | cmd->request = req; | |
d285203c CH |
1877 | |
1878 | cmd->tag = req->tag; | |
d285203c CH |
1879 | cmd->prot_op = SCSI_PROT_NORMAL; |
1880 | ||
d285203c CH |
1881 | sg = (void *)cmd + sizeof(struct scsi_cmnd) + shost->hostt->cmd_size; |
1882 | cmd->sdb.table.sgl = sg; | |
1883 | ||
1884 | if (scsi_host_get_prot(shost)) { | |
d285203c CH |
1885 | memset(cmd->prot_sdb, 0, sizeof(struct scsi_data_buffer)); |
1886 | ||
1887 | cmd->prot_sdb->table.sgl = | |
1888 | (struct scatterlist *)(cmd->prot_sdb + 1); | |
1889 | } | |
1890 | ||
1891 | if (blk_bidi_rq(req)) { | |
1892 | struct request *next_rq = req->next_rq; | |
1893 | struct scsi_data_buffer *bidi_sdb = blk_mq_rq_to_pdu(next_rq); | |
1894 | ||
1895 | memset(bidi_sdb, 0, sizeof(struct scsi_data_buffer)); | |
1896 | bidi_sdb->table.sgl = | |
1897 | (struct scatterlist *)(bidi_sdb + 1); | |
1898 | ||
1899 | next_rq->special = bidi_sdb; | |
1900 | } | |
1901 | ||
fe052529 CH |
1902 | blk_mq_start_request(req); |
1903 | ||
d285203c CH |
1904 | return scsi_setup_cmnd(sdev, req); |
1905 | } | |
1906 | ||
1907 | static void scsi_mq_done(struct scsi_cmnd *cmd) | |
1908 | { | |
1909 | trace_scsi_dispatch_cmd_done(cmd); | |
08e0029a | 1910 | blk_mq_complete_request(cmd->request); |
d285203c CH |
1911 | } |
1912 | ||
fc17b653 | 1913 | static blk_status_t scsi_queue_rq(struct blk_mq_hw_ctx *hctx, |
74c45052 | 1914 | const struct blk_mq_queue_data *bd) |
d285203c | 1915 | { |
74c45052 | 1916 | struct request *req = bd->rq; |
d285203c CH |
1917 | struct request_queue *q = req->q; |
1918 | struct scsi_device *sdev = q->queuedata; | |
1919 | struct Scsi_Host *shost = sdev->host; | |
1920 | struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req); | |
fc17b653 | 1921 | blk_status_t ret; |
d285203c CH |
1922 | int reason; |
1923 | ||
1924 | ret = prep_to_mq(scsi_prep_state_check(sdev, req)); | |
fc17b653 | 1925 | if (ret != BLK_STS_OK) |
d285203c CH |
1926 | goto out; |
1927 | ||
fc17b653 | 1928 | ret = BLK_STS_RESOURCE; |
d285203c CH |
1929 | if (!get_device(&sdev->sdev_gendev)) |
1930 | goto out; | |
1931 | ||
1932 | if (!scsi_dev_queue_ready(q, sdev)) | |
1933 | goto out_put_device; | |
1934 | if (!scsi_target_queue_ready(shost, sdev)) | |
1935 | goto out_dec_device_busy; | |
1936 | if (!scsi_host_queue_ready(q, shost, sdev)) | |
1937 | goto out_dec_target_busy; | |
1938 | ||
e8064021 | 1939 | if (!(req->rq_flags & RQF_DONTPREP)) { |
d285203c | 1940 | ret = prep_to_mq(scsi_mq_prep_fn(req)); |
fc17b653 | 1941 | if (ret != BLK_STS_OK) |
d285203c | 1942 | goto out_dec_host_busy; |
e8064021 | 1943 | req->rq_flags |= RQF_DONTPREP; |
fe052529 CH |
1944 | } else { |
1945 | blk_mq_start_request(req); | |
d285203c CH |
1946 | } |
1947 | ||
125c99bc CH |
1948 | if (sdev->simple_tags) |
1949 | cmd->flags |= SCMD_TAGGED; | |
b1dd2aac | 1950 | else |
125c99bc | 1951 | cmd->flags &= ~SCMD_TAGGED; |
b1dd2aac | 1952 | |
d285203c CH |
1953 | scsi_init_cmd_errh(cmd); |
1954 | cmd->scsi_done = scsi_mq_done; | |
1955 | ||
1956 | reason = scsi_dispatch_cmd(cmd); | |
1957 | if (reason) { | |
1958 | scsi_set_blocked(cmd, reason); | |
fc17b653 | 1959 | ret = BLK_STS_RESOURCE; |
d285203c CH |
1960 | goto out_dec_host_busy; |
1961 | } | |
1962 | ||
fc17b653 | 1963 | return BLK_STS_OK; |
d285203c CH |
1964 | |
1965 | out_dec_host_busy: | |
1966 | atomic_dec(&shost->host_busy); | |
1967 | out_dec_target_busy: | |
1968 | if (scsi_target(sdev)->can_queue > 0) | |
1969 | atomic_dec(&scsi_target(sdev)->target_busy); | |
1970 | out_dec_device_busy: | |
1971 | atomic_dec(&sdev->device_busy); | |
1972 | out_put_device: | |
1973 | put_device(&sdev->sdev_gendev); | |
1974 | out: | |
1975 | switch (ret) { | |
fc17b653 CH |
1976 | case BLK_STS_OK: |
1977 | break; | |
1978 | case BLK_STS_RESOURCE: | |
d285203c CH |
1979 | if (atomic_read(&sdev->device_busy) == 0 && |
1980 | !scsi_device_blocked(sdev)) | |
36e3cf27 | 1981 | blk_mq_delay_run_hw_queue(hctx, SCSI_QUEUE_DELAY); |
d285203c | 1982 | break; |
fc17b653 | 1983 | default: |
d285203c CH |
1984 | /* |
1985 | * Make sure to release all allocated ressources when | |
1986 | * we hit an error, as we will never see this command | |
1987 | * again. | |
1988 | */ | |
e8064021 | 1989 | if (req->rq_flags & RQF_DONTPREP) |
d285203c CH |
1990 | scsi_mq_uninit_cmd(cmd); |
1991 | break; | |
d285203c CH |
1992 | } |
1993 | return ret; | |
1994 | } | |
1995 | ||
0152fb6b CH |
1996 | static enum blk_eh_timer_return scsi_timeout(struct request *req, |
1997 | bool reserved) | |
1998 | { | |
1999 | if (reserved) | |
2000 | return BLK_EH_RESET_TIMER; | |
2001 | return scsi_times_out(req); | |
2002 | } | |
2003 | ||
e7008ff5 BVA |
2004 | static int scsi_mq_init_request(struct blk_mq_tag_set *set, struct request *rq, |
2005 | unsigned int hctx_idx, unsigned int numa_node) | |
d285203c | 2006 | { |
d6296d39 | 2007 | struct Scsi_Host *shost = set->driver_data; |
8e688254 | 2008 | const bool unchecked_isa_dma = shost->unchecked_isa_dma; |
d285203c | 2009 | struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq); |
08f78436 | 2010 | struct scatterlist *sg; |
d285203c | 2011 | |
8e688254 BVA |
2012 | if (unchecked_isa_dma) |
2013 | cmd->flags |= SCMD_UNCHECKED_ISA_DMA; | |
2014 | cmd->sense_buffer = scsi_alloc_sense_buffer(unchecked_isa_dma, | |
2015 | GFP_KERNEL, numa_node); | |
d285203c CH |
2016 | if (!cmd->sense_buffer) |
2017 | return -ENOMEM; | |
82ed4db4 | 2018 | cmd->req.sense = cmd->sense_buffer; |
08f78436 BVA |
2019 | |
2020 | if (scsi_host_get_prot(shost)) { | |
2021 | sg = (void *)cmd + sizeof(struct scsi_cmnd) + | |
2022 | shost->hostt->cmd_size; | |
2023 | cmd->prot_sdb = (void *)sg + scsi_mq_sgl_size(shost); | |
2024 | } | |
2025 | ||
d285203c CH |
2026 | return 0; |
2027 | } | |
2028 | ||
e7008ff5 BVA |
2029 | static void scsi_mq_exit_request(struct blk_mq_tag_set *set, struct request *rq, |
2030 | unsigned int hctx_idx) | |
d285203c CH |
2031 | { |
2032 | struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq); | |
2033 | ||
8e688254 BVA |
2034 | scsi_free_sense_buffer(cmd->flags & SCMD_UNCHECKED_ISA_DMA, |
2035 | cmd->sense_buffer); | |
d285203c CH |
2036 | } |
2037 | ||
2d9c5c20 CH |
2038 | static int scsi_map_queues(struct blk_mq_tag_set *set) |
2039 | { | |
2040 | struct Scsi_Host *shost = container_of(set, struct Scsi_Host, tag_set); | |
2041 | ||
2042 | if (shost->hostt->map_queues) | |
2043 | return shost->hostt->map_queues(shost); | |
2044 | return blk_mq_map_queues(set); | |
2045 | } | |
2046 | ||
f1bea55d | 2047 | static u64 scsi_calculate_bounce_limit(struct Scsi_Host *shost) |
1da177e4 LT |
2048 | { |
2049 | struct device *host_dev; | |
2050 | u64 bounce_limit = 0xffffffff; | |
2051 | ||
2052 | if (shost->unchecked_isa_dma) | |
2053 | return BLK_BOUNCE_ISA; | |
2054 | /* | |
2055 | * Platforms with virtual-DMA translation | |
2056 | * hardware have no practical limit. | |
2057 | */ | |
2058 | if (!PCI_DMA_BUS_IS_PHYS) | |
2059 | return BLK_BOUNCE_ANY; | |
2060 | ||
2061 | host_dev = scsi_get_device(shost); | |
2062 | if (host_dev && host_dev->dma_mask) | |
e83b3664 | 2063 | bounce_limit = (u64)dma_max_pfn(host_dev) << PAGE_SHIFT; |
1da177e4 LT |
2064 | |
2065 | return bounce_limit; | |
2066 | } | |
1da177e4 | 2067 | |
d48777a6 | 2068 | void __scsi_init_queue(struct Scsi_Host *shost, struct request_queue *q) |
1da177e4 | 2069 | { |
6f381fa3 | 2070 | struct device *dev = shost->dma_dev; |
1da177e4 | 2071 | |
9efc160f BVA |
2072 | queue_flag_set_unlocked(QUEUE_FLAG_SCSI_PASSTHROUGH, q); |
2073 | ||
a8474ce2 JA |
2074 | /* |
2075 | * this limit is imposed by hardware restrictions | |
2076 | */ | |
8a78362c | 2077 | blk_queue_max_segments(q, min_t(unsigned short, shost->sg_tablesize, |
65e8617f | 2078 | SG_MAX_SEGMENTS)); |
a8474ce2 | 2079 | |
13f05c8d MP |
2080 | if (scsi_host_prot_dma(shost)) { |
2081 | shost->sg_prot_tablesize = | |
2082 | min_not_zero(shost->sg_prot_tablesize, | |
2083 | (unsigned short)SCSI_MAX_PROT_SG_SEGMENTS); | |
2084 | BUG_ON(shost->sg_prot_tablesize < shost->sg_tablesize); | |
2085 | blk_queue_max_integrity_segments(q, shost->sg_prot_tablesize); | |
2086 | } | |
2087 | ||
086fa5ff | 2088 | blk_queue_max_hw_sectors(q, shost->max_sectors); |
1da177e4 LT |
2089 | blk_queue_bounce_limit(q, scsi_calculate_bounce_limit(shost)); |
2090 | blk_queue_segment_boundary(q, shost->dma_boundary); | |
99c84dbd | 2091 | dma_set_seg_boundary(dev, shost->dma_boundary); |
1da177e4 | 2092 | |
860ac568 FT |
2093 | blk_queue_max_segment_size(q, dma_get_max_seg_size(dev)); |
2094 | ||
1da177e4 | 2095 | if (!shost->use_clustering) |
e692cb66 | 2096 | q->limits.cluster = 0; |
465ff318 JB |
2097 | |
2098 | /* | |
2099 | * set a reasonable default alignment on word boundaries: the | |
2100 | * host and device may alter it using | |
2101 | * blk_queue_update_dma_alignment() later. | |
2102 | */ | |
2103 | blk_queue_dma_alignment(q, 0x03); | |
d285203c | 2104 | } |
d48777a6 | 2105 | EXPORT_SYMBOL_GPL(__scsi_init_queue); |
465ff318 | 2106 | |
e7008ff5 BVA |
2107 | static int scsi_old_init_rq(struct request_queue *q, struct request *rq, |
2108 | gfp_t gfp) | |
d285203c | 2109 | { |
e9c787e6 | 2110 | struct Scsi_Host *shost = q->rq_alloc_data; |
8e688254 | 2111 | const bool unchecked_isa_dma = shost->unchecked_isa_dma; |
e9c787e6 | 2112 | struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq); |
d285203c | 2113 | |
e9c787e6 CH |
2114 | memset(cmd, 0, sizeof(*cmd)); |
2115 | ||
8e688254 BVA |
2116 | if (unchecked_isa_dma) |
2117 | cmd->flags |= SCMD_UNCHECKED_ISA_DMA; | |
2118 | cmd->sense_buffer = scsi_alloc_sense_buffer(unchecked_isa_dma, gfp, | |
2119 | NUMA_NO_NODE); | |
e9c787e6 CH |
2120 | if (!cmd->sense_buffer) |
2121 | goto fail; | |
82ed4db4 | 2122 | cmd->req.sense = cmd->sense_buffer; |
e9c787e6 CH |
2123 | |
2124 | if (scsi_host_get_prot(shost) >= SHOST_DIX_TYPE0_PROTECTION) { | |
2125 | cmd->prot_sdb = kmem_cache_zalloc(scsi_sdb_cache, gfp); | |
2126 | if (!cmd->prot_sdb) | |
2127 | goto fail_free_sense; | |
2128 | } | |
2129 | ||
2130 | return 0; | |
2131 | ||
2132 | fail_free_sense: | |
8e688254 | 2133 | scsi_free_sense_buffer(unchecked_isa_dma, cmd->sense_buffer); |
e9c787e6 CH |
2134 | fail: |
2135 | return -ENOMEM; | |
2136 | } | |
2137 | ||
e7008ff5 | 2138 | static void scsi_old_exit_rq(struct request_queue *q, struct request *rq) |
e9c787e6 | 2139 | { |
e9c787e6 CH |
2140 | struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq); |
2141 | ||
2142 | if (cmd->prot_sdb) | |
2143 | kmem_cache_free(scsi_sdb_cache, cmd->prot_sdb); | |
8e688254 BVA |
2144 | scsi_free_sense_buffer(cmd->flags & SCMD_UNCHECKED_ISA_DMA, |
2145 | cmd->sense_buffer); | |
1da177e4 | 2146 | } |
b58d9154 | 2147 | |
e7008ff5 | 2148 | struct request_queue *scsi_old_alloc_queue(struct scsi_device *sdev) |
b58d9154 | 2149 | { |
e9c787e6 | 2150 | struct Scsi_Host *shost = sdev->host; |
b58d9154 FT |
2151 | struct request_queue *q; |
2152 | ||
e9c787e6 | 2153 | q = blk_alloc_queue_node(GFP_KERNEL, NUMA_NO_NODE); |
b58d9154 FT |
2154 | if (!q) |
2155 | return NULL; | |
e9c787e6 CH |
2156 | q->cmd_size = sizeof(struct scsi_cmnd) + shost->hostt->cmd_size; |
2157 | q->rq_alloc_data = shost; | |
2158 | q->request_fn = scsi_request_fn; | |
e7008ff5 BVA |
2159 | q->init_rq_fn = scsi_old_init_rq; |
2160 | q->exit_rq_fn = scsi_old_exit_rq; | |
ca18d6f7 | 2161 | q->initialize_rq_fn = scsi_initialize_rq; |
e9c787e6 CH |
2162 | |
2163 | if (blk_init_allocated_queue(q) < 0) { | |
2164 | blk_cleanup_queue(q); | |
2165 | return NULL; | |
2166 | } | |
b58d9154 | 2167 | |
e9c787e6 | 2168 | __scsi_init_queue(shost, q); |
b58d9154 | 2169 | blk_queue_prep_rq(q, scsi_prep_fn); |
a1b73fc1 | 2170 | blk_queue_unprep_rq(q, scsi_unprep_fn); |
b58d9154 | 2171 | blk_queue_softirq_done(q, scsi_softirq_done); |
242f9dcb | 2172 | blk_queue_rq_timed_out(q, scsi_times_out); |
6c5121b7 | 2173 | blk_queue_lld_busy(q, scsi_lld_busy); |
b58d9154 FT |
2174 | return q; |
2175 | } | |
1da177e4 | 2176 | |
f363b089 | 2177 | static const struct blk_mq_ops scsi_mq_ops = { |
d285203c CH |
2178 | .queue_rq = scsi_queue_rq, |
2179 | .complete = scsi_softirq_done, | |
0152fb6b | 2180 | .timeout = scsi_timeout, |
0eebd005 BVA |
2181 | #ifdef CONFIG_BLK_DEBUG_FS |
2182 | .show_rq = scsi_show_rq, | |
2183 | #endif | |
e7008ff5 BVA |
2184 | .init_request = scsi_mq_init_request, |
2185 | .exit_request = scsi_mq_exit_request, | |
ca18d6f7 | 2186 | .initialize_rq_fn = scsi_initialize_rq, |
2d9c5c20 | 2187 | .map_queues = scsi_map_queues, |
d285203c CH |
2188 | }; |
2189 | ||
2190 | struct request_queue *scsi_mq_alloc_queue(struct scsi_device *sdev) | |
2191 | { | |
2192 | sdev->request_queue = blk_mq_init_queue(&sdev->host->tag_set); | |
2193 | if (IS_ERR(sdev->request_queue)) | |
2194 | return NULL; | |
2195 | ||
2196 | sdev->request_queue->queuedata = sdev; | |
2197 | __scsi_init_queue(sdev->host, sdev->request_queue); | |
2198 | return sdev->request_queue; | |
2199 | } | |
2200 | ||
2201 | int scsi_mq_setup_tags(struct Scsi_Host *shost) | |
2202 | { | |
be4c186c | 2203 | unsigned int cmd_size, sgl_size; |
d285203c | 2204 | |
be4c186c | 2205 | sgl_size = scsi_mq_sgl_size(shost); |
d285203c CH |
2206 | cmd_size = sizeof(struct scsi_cmnd) + shost->hostt->cmd_size + sgl_size; |
2207 | if (scsi_host_get_prot(shost)) | |
2208 | cmd_size += sizeof(struct scsi_data_buffer) + sgl_size; | |
2209 | ||
2210 | memset(&shost->tag_set, 0, sizeof(shost->tag_set)); | |
2211 | shost->tag_set.ops = &scsi_mq_ops; | |
efec4b90 | 2212 | shost->tag_set.nr_hw_queues = shost->nr_hw_queues ? : 1; |
d285203c CH |
2213 | shost->tag_set.queue_depth = shost->can_queue; |
2214 | shost->tag_set.cmd_size = cmd_size; | |
2215 | shost->tag_set.numa_node = NUMA_NO_NODE; | |
2216 | shost->tag_set.flags = BLK_MQ_F_SHOULD_MERGE | BLK_MQ_F_SG_MERGE; | |
24391c0d SL |
2217 | shost->tag_set.flags |= |
2218 | BLK_ALLOC_POLICY_TO_MQ_FLAG(shost->hostt->tag_alloc_policy); | |
d285203c CH |
2219 | shost->tag_set.driver_data = shost; |
2220 | ||
2221 | return blk_mq_alloc_tag_set(&shost->tag_set); | |
2222 | } | |
2223 | ||
2224 | void scsi_mq_destroy_tags(struct Scsi_Host *shost) | |
2225 | { | |
2226 | blk_mq_free_tag_set(&shost->tag_set); | |
2227 | } | |
2228 | ||
857de6e0 HR |
2229 | /** |
2230 | * scsi_device_from_queue - return sdev associated with a request_queue | |
2231 | * @q: The request queue to return the sdev from | |
2232 | * | |
2233 | * Return the sdev associated with a request queue or NULL if the | |
2234 | * request_queue does not reference a SCSI device. | |
2235 | */ | |
2236 | struct scsi_device *scsi_device_from_queue(struct request_queue *q) | |
2237 | { | |
2238 | struct scsi_device *sdev = NULL; | |
2239 | ||
2240 | if (q->mq_ops) { | |
2241 | if (q->mq_ops == &scsi_mq_ops) | |
2242 | sdev = q->queuedata; | |
2243 | } else if (q->request_fn == scsi_request_fn) | |
2244 | sdev = q->queuedata; | |
2245 | if (!sdev || !get_device(&sdev->sdev_gendev)) | |
2246 | sdev = NULL; | |
2247 | ||
2248 | return sdev; | |
2249 | } | |
2250 | EXPORT_SYMBOL_GPL(scsi_device_from_queue); | |
2251 | ||
1da177e4 LT |
2252 | /* |
2253 | * Function: scsi_block_requests() | |
2254 | * | |
2255 | * Purpose: Utility function used by low-level drivers to prevent further | |
2256 | * commands from being queued to the device. | |
2257 | * | |
2258 | * Arguments: shost - Host in question | |
2259 | * | |
2260 | * Returns: Nothing | |
2261 | * | |
2262 | * Lock status: No locks are assumed held. | |
2263 | * | |
2264 | * Notes: There is no timer nor any other means by which the requests | |
2265 | * get unblocked other than the low-level driver calling | |
2266 | * scsi_unblock_requests(). | |
2267 | */ | |
2268 | void scsi_block_requests(struct Scsi_Host *shost) | |
2269 | { | |
2270 | shost->host_self_blocked = 1; | |
2271 | } | |
2272 | EXPORT_SYMBOL(scsi_block_requests); | |
2273 | ||
2274 | /* | |
2275 | * Function: scsi_unblock_requests() | |
2276 | * | |
2277 | * Purpose: Utility function used by low-level drivers to allow further | |
2278 | * commands from being queued to the device. | |
2279 | * | |
2280 | * Arguments: shost - Host in question | |
2281 | * | |
2282 | * Returns: Nothing | |
2283 | * | |
2284 | * Lock status: No locks are assumed held. | |
2285 | * | |
2286 | * Notes: There is no timer nor any other means by which the requests | |
2287 | * get unblocked other than the low-level driver calling | |
2288 | * scsi_unblock_requests(). | |
2289 | * | |
2290 | * This is done as an API function so that changes to the | |
2291 | * internals of the scsi mid-layer won't require wholesale | |
2292 | * changes to drivers that use this feature. | |
2293 | */ | |
2294 | void scsi_unblock_requests(struct Scsi_Host *shost) | |
2295 | { | |
2296 | shost->host_self_blocked = 0; | |
2297 | scsi_run_host_queues(shost); | |
2298 | } | |
2299 | EXPORT_SYMBOL(scsi_unblock_requests); | |
2300 | ||
2301 | int __init scsi_init_queue(void) | |
2302 | { | |
6362abd3 MP |
2303 | scsi_sdb_cache = kmem_cache_create("scsi_data_buffer", |
2304 | sizeof(struct scsi_data_buffer), | |
2305 | 0, 0, NULL); | |
2306 | if (!scsi_sdb_cache) { | |
2307 | printk(KERN_ERR "SCSI: can't init scsi sdb cache\n"); | |
f078727b | 2308 | return -ENOMEM; |
6f9a35e2 BH |
2309 | } |
2310 | ||
1da177e4 LT |
2311 | return 0; |
2312 | } | |
2313 | ||
2314 | void scsi_exit_queue(void) | |
2315 | { | |
0a6ac4ee CH |
2316 | kmem_cache_destroy(scsi_sense_cache); |
2317 | kmem_cache_destroy(scsi_sense_isadma_cache); | |
6362abd3 | 2318 | kmem_cache_destroy(scsi_sdb_cache); |
1da177e4 | 2319 | } |
5baba830 JB |
2320 | |
2321 | /** | |
2322 | * scsi_mode_select - issue a mode select | |
2323 | * @sdev: SCSI device to be queried | |
2324 | * @pf: Page format bit (1 == standard, 0 == vendor specific) | |
2325 | * @sp: Save page bit (0 == don't save, 1 == save) | |
2326 | * @modepage: mode page being requested | |
2327 | * @buffer: request buffer (may not be smaller than eight bytes) | |
2328 | * @len: length of request buffer. | |
2329 | * @timeout: command timeout | |
2330 | * @retries: number of retries before failing | |
2331 | * @data: returns a structure abstracting the mode header data | |
eb44820c | 2332 | * @sshdr: place to put sense data (or NULL if no sense to be collected). |
5baba830 JB |
2333 | * must be SCSI_SENSE_BUFFERSIZE big. |
2334 | * | |
2335 | * Returns zero if successful; negative error number or scsi | |
2336 | * status on error | |
2337 | * | |
2338 | */ | |
2339 | int | |
2340 | scsi_mode_select(struct scsi_device *sdev, int pf, int sp, int modepage, | |
2341 | unsigned char *buffer, int len, int timeout, int retries, | |
2342 | struct scsi_mode_data *data, struct scsi_sense_hdr *sshdr) | |
2343 | { | |
2344 | unsigned char cmd[10]; | |
2345 | unsigned char *real_buffer; | |
2346 | int ret; | |
2347 | ||
2348 | memset(cmd, 0, sizeof(cmd)); | |
2349 | cmd[1] = (pf ? 0x10 : 0) | (sp ? 0x01 : 0); | |
2350 | ||
2351 | if (sdev->use_10_for_ms) { | |
2352 | if (len > 65535) | |
2353 | return -EINVAL; | |
2354 | real_buffer = kmalloc(8 + len, GFP_KERNEL); | |
2355 | if (!real_buffer) | |
2356 | return -ENOMEM; | |
2357 | memcpy(real_buffer + 8, buffer, len); | |
2358 | len += 8; | |
2359 | real_buffer[0] = 0; | |
2360 | real_buffer[1] = 0; | |
2361 | real_buffer[2] = data->medium_type; | |
2362 | real_buffer[3] = data->device_specific; | |
2363 | real_buffer[4] = data->longlba ? 0x01 : 0; | |
2364 | real_buffer[5] = 0; | |
2365 | real_buffer[6] = data->block_descriptor_length >> 8; | |
2366 | real_buffer[7] = data->block_descriptor_length; | |
2367 | ||
2368 | cmd[0] = MODE_SELECT_10; | |
2369 | cmd[7] = len >> 8; | |
2370 | cmd[8] = len; | |
2371 | } else { | |
2372 | if (len > 255 || data->block_descriptor_length > 255 || | |
2373 | data->longlba) | |
2374 | return -EINVAL; | |
2375 | ||
2376 | real_buffer = kmalloc(4 + len, GFP_KERNEL); | |
2377 | if (!real_buffer) | |
2378 | return -ENOMEM; | |
2379 | memcpy(real_buffer + 4, buffer, len); | |
2380 | len += 4; | |
2381 | real_buffer[0] = 0; | |
2382 | real_buffer[1] = data->medium_type; | |
2383 | real_buffer[2] = data->device_specific; | |
2384 | real_buffer[3] = data->block_descriptor_length; | |
2385 | ||
2386 | ||
2387 | cmd[0] = MODE_SELECT; | |
2388 | cmd[4] = len; | |
2389 | } | |
2390 | ||
2391 | ret = scsi_execute_req(sdev, cmd, DMA_TO_DEVICE, real_buffer, len, | |
f4f4e47e | 2392 | sshdr, timeout, retries, NULL); |
5baba830 JB |
2393 | kfree(real_buffer); |
2394 | return ret; | |
2395 | } | |
2396 | EXPORT_SYMBOL_GPL(scsi_mode_select); | |
2397 | ||
1da177e4 | 2398 | /** |
eb44820c | 2399 | * scsi_mode_sense - issue a mode sense, falling back from 10 to six bytes if necessary. |
1cf72699 | 2400 | * @sdev: SCSI device to be queried |
1da177e4 LT |
2401 | * @dbd: set if mode sense will allow block descriptors to be returned |
2402 | * @modepage: mode page being requested | |
2403 | * @buffer: request buffer (may not be smaller than eight bytes) | |
2404 | * @len: length of request buffer. | |
2405 | * @timeout: command timeout | |
2406 | * @retries: number of retries before failing | |
2407 | * @data: returns a structure abstracting the mode header data | |
eb44820c | 2408 | * @sshdr: place to put sense data (or NULL if no sense to be collected). |
1cf72699 | 2409 | * must be SCSI_SENSE_BUFFERSIZE big. |
1da177e4 LT |
2410 | * |
2411 | * Returns zero if unsuccessful, or the header offset (either 4 | |
2412 | * or 8 depending on whether a six or ten byte command was | |
2413 | * issued) if successful. | |
eb44820c | 2414 | */ |
1da177e4 | 2415 | int |
1cf72699 | 2416 | scsi_mode_sense(struct scsi_device *sdev, int dbd, int modepage, |
1da177e4 | 2417 | unsigned char *buffer, int len, int timeout, int retries, |
5baba830 JB |
2418 | struct scsi_mode_data *data, struct scsi_sense_hdr *sshdr) |
2419 | { | |
1da177e4 LT |
2420 | unsigned char cmd[12]; |
2421 | int use_10_for_ms; | |
2422 | int header_length; | |
0ae80ba9 | 2423 | int result, retry_count = retries; |
ea73a9f2 | 2424 | struct scsi_sense_hdr my_sshdr; |
1da177e4 LT |
2425 | |
2426 | memset(data, 0, sizeof(*data)); | |
2427 | memset(&cmd[0], 0, 12); | |
2428 | cmd[1] = dbd & 0x18; /* allows DBD and LLBA bits */ | |
2429 | cmd[2] = modepage; | |
2430 | ||
ea73a9f2 JB |
2431 | /* caller might not be interested in sense, but we need it */ |
2432 | if (!sshdr) | |
2433 | sshdr = &my_sshdr; | |
2434 | ||
1da177e4 | 2435 | retry: |
1cf72699 | 2436 | use_10_for_ms = sdev->use_10_for_ms; |
1da177e4 LT |
2437 | |
2438 | if (use_10_for_ms) { | |
2439 | if (len < 8) | |
2440 | len = 8; | |
2441 | ||
2442 | cmd[0] = MODE_SENSE_10; | |
2443 | cmd[8] = len; | |
2444 | header_length = 8; | |
2445 | } else { | |
2446 | if (len < 4) | |
2447 | len = 4; | |
2448 | ||
2449 | cmd[0] = MODE_SENSE; | |
2450 | cmd[4] = len; | |
2451 | header_length = 4; | |
2452 | } | |
2453 | ||
1da177e4 LT |
2454 | memset(buffer, 0, len); |
2455 | ||
1cf72699 | 2456 | result = scsi_execute_req(sdev, cmd, DMA_FROM_DEVICE, buffer, len, |
f4f4e47e | 2457 | sshdr, timeout, retries, NULL); |
1da177e4 LT |
2458 | |
2459 | /* This code looks awful: what it's doing is making sure an | |
2460 | * ILLEGAL REQUEST sense return identifies the actual command | |
2461 | * byte as the problem. MODE_SENSE commands can return | |
2462 | * ILLEGAL REQUEST if the code page isn't supported */ | |
2463 | ||
1cf72699 JB |
2464 | if (use_10_for_ms && !scsi_status_is_good(result) && |
2465 | (driver_byte(result) & DRIVER_SENSE)) { | |
ea73a9f2 JB |
2466 | if (scsi_sense_valid(sshdr)) { |
2467 | if ((sshdr->sense_key == ILLEGAL_REQUEST) && | |
2468 | (sshdr->asc == 0x20) && (sshdr->ascq == 0)) { | |
1da177e4 LT |
2469 | /* |
2470 | * Invalid command operation code | |
2471 | */ | |
1cf72699 | 2472 | sdev->use_10_for_ms = 0; |
1da177e4 LT |
2473 | goto retry; |
2474 | } | |
2475 | } | |
2476 | } | |
2477 | ||
1cf72699 | 2478 | if(scsi_status_is_good(result)) { |
6d73c851 AV |
2479 | if (unlikely(buffer[0] == 0x86 && buffer[1] == 0x0b && |
2480 | (modepage == 6 || modepage == 8))) { | |
2481 | /* Initio breakage? */ | |
2482 | header_length = 0; | |
2483 | data->length = 13; | |
2484 | data->medium_type = 0; | |
2485 | data->device_specific = 0; | |
2486 | data->longlba = 0; | |
2487 | data->block_descriptor_length = 0; | |
2488 | } else if(use_10_for_ms) { | |
1da177e4 LT |
2489 | data->length = buffer[0]*256 + buffer[1] + 2; |
2490 | data->medium_type = buffer[2]; | |
2491 | data->device_specific = buffer[3]; | |
2492 | data->longlba = buffer[4] & 0x01; | |
2493 | data->block_descriptor_length = buffer[6]*256 | |
2494 | + buffer[7]; | |
2495 | } else { | |
2496 | data->length = buffer[0] + 1; | |
2497 | data->medium_type = buffer[1]; | |
2498 | data->device_specific = buffer[2]; | |
2499 | data->block_descriptor_length = buffer[3]; | |
2500 | } | |
6d73c851 | 2501 | data->header_length = header_length; |
0ae80ba9 HR |
2502 | } else if ((status_byte(result) == CHECK_CONDITION) && |
2503 | scsi_sense_valid(sshdr) && | |
2504 | sshdr->sense_key == UNIT_ATTENTION && retry_count) { | |
2505 | retry_count--; | |
2506 | goto retry; | |
1da177e4 LT |
2507 | } |
2508 | ||
1cf72699 | 2509 | return result; |
1da177e4 LT |
2510 | } |
2511 | EXPORT_SYMBOL(scsi_mode_sense); | |
2512 | ||
001aac25 JB |
2513 | /** |
2514 | * scsi_test_unit_ready - test if unit is ready | |
2515 | * @sdev: scsi device to change the state of. | |
2516 | * @timeout: command timeout | |
2517 | * @retries: number of retries before failing | |
74a78ebd | 2518 | * @sshdr: outpout pointer for decoded sense information. |
001aac25 JB |
2519 | * |
2520 | * Returns zero if unsuccessful or an error if TUR failed. For | |
9f8a2c23 | 2521 | * removable media, UNIT_ATTENTION sets ->changed flag. |
001aac25 | 2522 | **/ |
1da177e4 | 2523 | int |
001aac25 | 2524 | scsi_test_unit_ready(struct scsi_device *sdev, int timeout, int retries, |
74a78ebd | 2525 | struct scsi_sense_hdr *sshdr) |
1da177e4 | 2526 | { |
1da177e4 LT |
2527 | char cmd[] = { |
2528 | TEST_UNIT_READY, 0, 0, 0, 0, 0, | |
2529 | }; | |
2530 | int result; | |
001aac25 | 2531 | |
001aac25 JB |
2532 | /* try to eat the UNIT_ATTENTION if there are enough retries */ |
2533 | do { | |
2534 | result = scsi_execute_req(sdev, cmd, DMA_NONE, NULL, 0, sshdr, | |
f4f4e47e | 2535 | timeout, retries, NULL); |
32c356d7 JB |
2536 | if (sdev->removable && scsi_sense_valid(sshdr) && |
2537 | sshdr->sense_key == UNIT_ATTENTION) | |
2538 | sdev->changed = 1; | |
2539 | } while (scsi_sense_valid(sshdr) && | |
2540 | sshdr->sense_key == UNIT_ATTENTION && --retries); | |
001aac25 | 2541 | |
1da177e4 LT |
2542 | return result; |
2543 | } | |
2544 | EXPORT_SYMBOL(scsi_test_unit_ready); | |
2545 | ||
2546 | /** | |
eb44820c | 2547 | * scsi_device_set_state - Take the given device through the device state model. |
1da177e4 LT |
2548 | * @sdev: scsi device to change the state of. |
2549 | * @state: state to change to. | |
2550 | * | |
2551 | * Returns zero if unsuccessful or an error if the requested | |
2552 | * transition is illegal. | |
eb44820c | 2553 | */ |
1da177e4 LT |
2554 | int |
2555 | scsi_device_set_state(struct scsi_device *sdev, enum scsi_device_state state) | |
2556 | { | |
2557 | enum scsi_device_state oldstate = sdev->sdev_state; | |
2558 | ||
2559 | if (state == oldstate) | |
2560 | return 0; | |
2561 | ||
2562 | switch (state) { | |
2563 | case SDEV_CREATED: | |
6f4267e3 JB |
2564 | switch (oldstate) { |
2565 | case SDEV_CREATED_BLOCK: | |
2566 | break; | |
2567 | default: | |
2568 | goto illegal; | |
2569 | } | |
2570 | break; | |
1da177e4 LT |
2571 | |
2572 | case SDEV_RUNNING: | |
2573 | switch (oldstate) { | |
2574 | case SDEV_CREATED: | |
2575 | case SDEV_OFFLINE: | |
1b8d2620 | 2576 | case SDEV_TRANSPORT_OFFLINE: |
1da177e4 LT |
2577 | case SDEV_QUIESCE: |
2578 | case SDEV_BLOCK: | |
2579 | break; | |
2580 | default: | |
2581 | goto illegal; | |
2582 | } | |
2583 | break; | |
2584 | ||
2585 | case SDEV_QUIESCE: | |
2586 | switch (oldstate) { | |
2587 | case SDEV_RUNNING: | |
2588 | case SDEV_OFFLINE: | |
1b8d2620 | 2589 | case SDEV_TRANSPORT_OFFLINE: |
1da177e4 LT |
2590 | break; |
2591 | default: | |
2592 | goto illegal; | |
2593 | } | |
2594 | break; | |
2595 | ||
2596 | case SDEV_OFFLINE: | |
1b8d2620 | 2597 | case SDEV_TRANSPORT_OFFLINE: |
1da177e4 LT |
2598 | switch (oldstate) { |
2599 | case SDEV_CREATED: | |
2600 | case SDEV_RUNNING: | |
2601 | case SDEV_QUIESCE: | |
2602 | case SDEV_BLOCK: | |
2603 | break; | |
2604 | default: | |
2605 | goto illegal; | |
2606 | } | |
2607 | break; | |
2608 | ||
2609 | case SDEV_BLOCK: | |
2610 | switch (oldstate) { | |
1da177e4 | 2611 | case SDEV_RUNNING: |
6f4267e3 JB |
2612 | case SDEV_CREATED_BLOCK: |
2613 | break; | |
2614 | default: | |
2615 | goto illegal; | |
2616 | } | |
2617 | break; | |
2618 | ||
2619 | case SDEV_CREATED_BLOCK: | |
2620 | switch (oldstate) { | |
2621 | case SDEV_CREATED: | |
1da177e4 LT |
2622 | break; |
2623 | default: | |
2624 | goto illegal; | |
2625 | } | |
2626 | break; | |
2627 | ||
2628 | case SDEV_CANCEL: | |
2629 | switch (oldstate) { | |
2630 | case SDEV_CREATED: | |
2631 | case SDEV_RUNNING: | |
9ea72909 | 2632 | case SDEV_QUIESCE: |
1da177e4 | 2633 | case SDEV_OFFLINE: |
1b8d2620 | 2634 | case SDEV_TRANSPORT_OFFLINE: |
1da177e4 LT |
2635 | break; |
2636 | default: | |
2637 | goto illegal; | |
2638 | } | |
2639 | break; | |
2640 | ||
2641 | case SDEV_DEL: | |
2642 | switch (oldstate) { | |
309bd271 BK |
2643 | case SDEV_CREATED: |
2644 | case SDEV_RUNNING: | |
2645 | case SDEV_OFFLINE: | |
1b8d2620 | 2646 | case SDEV_TRANSPORT_OFFLINE: |
1da177e4 | 2647 | case SDEV_CANCEL: |
255ee932 | 2648 | case SDEV_BLOCK: |
0516c08d | 2649 | case SDEV_CREATED_BLOCK: |
1da177e4 LT |
2650 | break; |
2651 | default: | |
2652 | goto illegal; | |
2653 | } | |
2654 | break; | |
2655 | ||
2656 | } | |
2657 | sdev->sdev_state = state; | |
8a97712e | 2658 | sysfs_notify(&sdev->sdev_gendev.kobj, NULL, "state"); |
1da177e4 LT |
2659 | return 0; |
2660 | ||
2661 | illegal: | |
91921e01 | 2662 | SCSI_LOG_ERROR_RECOVERY(1, |
9ccfc756 | 2663 | sdev_printk(KERN_ERR, sdev, |
91921e01 | 2664 | "Illegal state transition %s->%s", |
9ccfc756 JB |
2665 | scsi_device_state_name(oldstate), |
2666 | scsi_device_state_name(state)) | |
1da177e4 LT |
2667 | ); |
2668 | return -EINVAL; | |
2669 | } | |
2670 | EXPORT_SYMBOL(scsi_device_set_state); | |
2671 | ||
a341cd0f JG |
2672 | /** |
2673 | * sdev_evt_emit - emit a single SCSI device uevent | |
2674 | * @sdev: associated SCSI device | |
2675 | * @evt: event to emit | |
2676 | * | |
2677 | * Send a single uevent (scsi_event) to the associated scsi_device. | |
2678 | */ | |
2679 | static void scsi_evt_emit(struct scsi_device *sdev, struct scsi_event *evt) | |
2680 | { | |
2681 | int idx = 0; | |
2682 | char *envp[3]; | |
2683 | ||
2684 | switch (evt->evt_type) { | |
2685 | case SDEV_EVT_MEDIA_CHANGE: | |
2686 | envp[idx++] = "SDEV_MEDIA_CHANGE=1"; | |
2687 | break; | |
279afdfe | 2688 | case SDEV_EVT_INQUIRY_CHANGE_REPORTED: |
d3d32891 | 2689 | scsi_rescan_device(&sdev->sdev_gendev); |
279afdfe EM |
2690 | envp[idx++] = "SDEV_UA=INQUIRY_DATA_HAS_CHANGED"; |
2691 | break; | |
2692 | case SDEV_EVT_CAPACITY_CHANGE_REPORTED: | |
2693 | envp[idx++] = "SDEV_UA=CAPACITY_DATA_HAS_CHANGED"; | |
2694 | break; | |
2695 | case SDEV_EVT_SOFT_THRESHOLD_REACHED_REPORTED: | |
2696 | envp[idx++] = "SDEV_UA=THIN_PROVISIONING_SOFT_THRESHOLD_REACHED"; | |
2697 | break; | |
2698 | case SDEV_EVT_MODE_PARAMETER_CHANGE_REPORTED: | |
2699 | envp[idx++] = "SDEV_UA=MODE_PARAMETERS_CHANGED"; | |
2700 | break; | |
2701 | case SDEV_EVT_LUN_CHANGE_REPORTED: | |
2702 | envp[idx++] = "SDEV_UA=REPORTED_LUNS_DATA_HAS_CHANGED"; | |
2703 | break; | |
14c3e677 HR |
2704 | case SDEV_EVT_ALUA_STATE_CHANGE_REPORTED: |
2705 | envp[idx++] = "SDEV_UA=ASYMMETRIC_ACCESS_STATE_CHANGED"; | |
2706 | break; | |
a341cd0f JG |
2707 | default: |
2708 | /* do nothing */ | |
2709 | break; | |
2710 | } | |
2711 | ||
2712 | envp[idx++] = NULL; | |
2713 | ||
2714 | kobject_uevent_env(&sdev->sdev_gendev.kobj, KOBJ_CHANGE, envp); | |
2715 | } | |
2716 | ||
2717 | /** | |
2718 | * sdev_evt_thread - send a uevent for each scsi event | |
2719 | * @work: work struct for scsi_device | |
2720 | * | |
2721 | * Dispatch queued events to their associated scsi_device kobjects | |
2722 | * as uevents. | |
2723 | */ | |
2724 | void scsi_evt_thread(struct work_struct *work) | |
2725 | { | |
2726 | struct scsi_device *sdev; | |
279afdfe | 2727 | enum scsi_device_event evt_type; |
a341cd0f JG |
2728 | LIST_HEAD(event_list); |
2729 | ||
2730 | sdev = container_of(work, struct scsi_device, event_work); | |
2731 | ||
279afdfe EM |
2732 | for (evt_type = SDEV_EVT_FIRST; evt_type <= SDEV_EVT_LAST; evt_type++) |
2733 | if (test_and_clear_bit(evt_type, sdev->pending_events)) | |
2734 | sdev_evt_send_simple(sdev, evt_type, GFP_KERNEL); | |
2735 | ||
a341cd0f JG |
2736 | while (1) { |
2737 | struct scsi_event *evt; | |
2738 | struct list_head *this, *tmp; | |
2739 | unsigned long flags; | |
2740 | ||
2741 | spin_lock_irqsave(&sdev->list_lock, flags); | |
2742 | list_splice_init(&sdev->event_list, &event_list); | |
2743 | spin_unlock_irqrestore(&sdev->list_lock, flags); | |
2744 | ||
2745 | if (list_empty(&event_list)) | |
2746 | break; | |
2747 | ||
2748 | list_for_each_safe(this, tmp, &event_list) { | |
2749 | evt = list_entry(this, struct scsi_event, node); | |
2750 | list_del(&evt->node); | |
2751 | scsi_evt_emit(sdev, evt); | |
2752 | kfree(evt); | |
2753 | } | |
2754 | } | |
2755 | } | |
2756 | ||
2757 | /** | |
2758 | * sdev_evt_send - send asserted event to uevent thread | |
2759 | * @sdev: scsi_device event occurred on | |
2760 | * @evt: event to send | |
2761 | * | |
2762 | * Assert scsi device event asynchronously. | |
2763 | */ | |
2764 | void sdev_evt_send(struct scsi_device *sdev, struct scsi_event *evt) | |
2765 | { | |
2766 | unsigned long flags; | |
2767 | ||
4d1566ed KS |
2768 | #if 0 |
2769 | /* FIXME: currently this check eliminates all media change events | |
2770 | * for polled devices. Need to update to discriminate between AN | |
2771 | * and polled events */ | |
a341cd0f JG |
2772 | if (!test_bit(evt->evt_type, sdev->supported_events)) { |
2773 | kfree(evt); | |
2774 | return; | |
2775 | } | |
4d1566ed | 2776 | #endif |
a341cd0f JG |
2777 | |
2778 | spin_lock_irqsave(&sdev->list_lock, flags); | |
2779 | list_add_tail(&evt->node, &sdev->event_list); | |
2780 | schedule_work(&sdev->event_work); | |
2781 | spin_unlock_irqrestore(&sdev->list_lock, flags); | |
2782 | } | |
2783 | EXPORT_SYMBOL_GPL(sdev_evt_send); | |
2784 | ||
2785 | /** | |
2786 | * sdev_evt_alloc - allocate a new scsi event | |
2787 | * @evt_type: type of event to allocate | |
2788 | * @gfpflags: GFP flags for allocation | |
2789 | * | |
2790 | * Allocates and returns a new scsi_event. | |
2791 | */ | |
2792 | struct scsi_event *sdev_evt_alloc(enum scsi_device_event evt_type, | |
2793 | gfp_t gfpflags) | |
2794 | { | |
2795 | struct scsi_event *evt = kzalloc(sizeof(struct scsi_event), gfpflags); | |
2796 | if (!evt) | |
2797 | return NULL; | |
2798 | ||
2799 | evt->evt_type = evt_type; | |
2800 | INIT_LIST_HEAD(&evt->node); | |
2801 | ||
2802 | /* evt_type-specific initialization, if any */ | |
2803 | switch (evt_type) { | |
2804 | case SDEV_EVT_MEDIA_CHANGE: | |
279afdfe EM |
2805 | case SDEV_EVT_INQUIRY_CHANGE_REPORTED: |
2806 | case SDEV_EVT_CAPACITY_CHANGE_REPORTED: | |
2807 | case SDEV_EVT_SOFT_THRESHOLD_REACHED_REPORTED: | |
2808 | case SDEV_EVT_MODE_PARAMETER_CHANGE_REPORTED: | |
2809 | case SDEV_EVT_LUN_CHANGE_REPORTED: | |
14c3e677 | 2810 | case SDEV_EVT_ALUA_STATE_CHANGE_REPORTED: |
a341cd0f JG |
2811 | default: |
2812 | /* do nothing */ | |
2813 | break; | |
2814 | } | |
2815 | ||
2816 | return evt; | |
2817 | } | |
2818 | EXPORT_SYMBOL_GPL(sdev_evt_alloc); | |
2819 | ||
2820 | /** | |
2821 | * sdev_evt_send_simple - send asserted event to uevent thread | |
2822 | * @sdev: scsi_device event occurred on | |
2823 | * @evt_type: type of event to send | |
2824 | * @gfpflags: GFP flags for allocation | |
2825 | * | |
2826 | * Assert scsi device event asynchronously, given an event type. | |
2827 | */ | |
2828 | void sdev_evt_send_simple(struct scsi_device *sdev, | |
2829 | enum scsi_device_event evt_type, gfp_t gfpflags) | |
2830 | { | |
2831 | struct scsi_event *evt = sdev_evt_alloc(evt_type, gfpflags); | |
2832 | if (!evt) { | |
2833 | sdev_printk(KERN_ERR, sdev, "event %d eaten due to OOM\n", | |
2834 | evt_type); | |
2835 | return; | |
2836 | } | |
2837 | ||
2838 | sdev_evt_send(sdev, evt); | |
2839 | } | |
2840 | EXPORT_SYMBOL_GPL(sdev_evt_send_simple); | |
2841 | ||
669f0441 BVA |
2842 | /** |
2843 | * scsi_request_fn_active() - number of kernel threads inside scsi_request_fn() | |
2844 | * @sdev: SCSI device to count the number of scsi_request_fn() callers for. | |
2845 | */ | |
2846 | static int scsi_request_fn_active(struct scsi_device *sdev) | |
2847 | { | |
2848 | struct request_queue *q = sdev->request_queue; | |
2849 | int request_fn_active; | |
2850 | ||
2851 | WARN_ON_ONCE(sdev->host->use_blk_mq); | |
2852 | ||
2853 | spin_lock_irq(q->queue_lock); | |
2854 | request_fn_active = q->request_fn_active; | |
2855 | spin_unlock_irq(q->queue_lock); | |
2856 | ||
2857 | return request_fn_active; | |
2858 | } | |
2859 | ||
2860 | /** | |
2861 | * scsi_wait_for_queuecommand() - wait for ongoing queuecommand() calls | |
2862 | * @sdev: SCSI device pointer. | |
2863 | * | |
2864 | * Wait until the ongoing shost->hostt->queuecommand() calls that are | |
2865 | * invoked from scsi_request_fn() have finished. | |
2866 | */ | |
2867 | static void scsi_wait_for_queuecommand(struct scsi_device *sdev) | |
2868 | { | |
2869 | WARN_ON_ONCE(sdev->host->use_blk_mq); | |
2870 | ||
2871 | while (scsi_request_fn_active(sdev)) | |
2872 | msleep(20); | |
2873 | } | |
2874 | ||
1da177e4 LT |
2875 | /** |
2876 | * scsi_device_quiesce - Block user issued commands. | |
2877 | * @sdev: scsi device to quiesce. | |
2878 | * | |
2879 | * This works by trying to transition to the SDEV_QUIESCE state | |
2880 | * (which must be a legal transition). When the device is in this | |
2881 | * state, only special requests will be accepted, all others will | |
2882 | * be deferred. Since special requests may also be requeued requests, | |
2883 | * a successful return doesn't guarantee the device will be | |
2884 | * totally quiescent. | |
2885 | * | |
2886 | * Must be called with user context, may sleep. | |
2887 | * | |
2888 | * Returns zero if unsuccessful or an error if not. | |
eb44820c | 2889 | */ |
1da177e4 LT |
2890 | int |
2891 | scsi_device_quiesce(struct scsi_device *sdev) | |
2892 | { | |
0db6ca8a BVA |
2893 | int err; |
2894 | ||
2895 | mutex_lock(&sdev->state_mutex); | |
2896 | err = scsi_device_set_state(sdev, SDEV_QUIESCE); | |
2897 | mutex_unlock(&sdev->state_mutex); | |
2898 | ||
1da177e4 LT |
2899 | if (err) |
2900 | return err; | |
2901 | ||
2902 | scsi_run_queue(sdev->request_queue); | |
71e75c97 | 2903 | while (atomic_read(&sdev->device_busy)) { |
1da177e4 LT |
2904 | msleep_interruptible(200); |
2905 | scsi_run_queue(sdev->request_queue); | |
2906 | } | |
2907 | return 0; | |
2908 | } | |
2909 | EXPORT_SYMBOL(scsi_device_quiesce); | |
2910 | ||
2911 | /** | |
2912 | * scsi_device_resume - Restart user issued commands to a quiesced device. | |
2913 | * @sdev: scsi device to resume. | |
2914 | * | |
2915 | * Moves the device from quiesced back to running and restarts the | |
2916 | * queues. | |
2917 | * | |
2918 | * Must be called with user context, may sleep. | |
eb44820c | 2919 | */ |
a7a20d10 | 2920 | void scsi_device_resume(struct scsi_device *sdev) |
1da177e4 | 2921 | { |
a7a20d10 DW |
2922 | /* check if the device state was mutated prior to resume, and if |
2923 | * so assume the state is being managed elsewhere (for example | |
2924 | * device deleted during suspend) | |
2925 | */ | |
0db6ca8a BVA |
2926 | mutex_lock(&sdev->state_mutex); |
2927 | if (sdev->sdev_state == SDEV_QUIESCE && | |
2928 | scsi_device_set_state(sdev, SDEV_RUNNING) == 0) | |
2929 | scsi_run_queue(sdev->request_queue); | |
2930 | mutex_unlock(&sdev->state_mutex); | |
1da177e4 LT |
2931 | } |
2932 | EXPORT_SYMBOL(scsi_device_resume); | |
2933 | ||
2934 | static void | |
2935 | device_quiesce_fn(struct scsi_device *sdev, void *data) | |
2936 | { | |
2937 | scsi_device_quiesce(sdev); | |
2938 | } | |
2939 | ||
2940 | void | |
2941 | scsi_target_quiesce(struct scsi_target *starget) | |
2942 | { | |
2943 | starget_for_each_device(starget, NULL, device_quiesce_fn); | |
2944 | } | |
2945 | EXPORT_SYMBOL(scsi_target_quiesce); | |
2946 | ||
2947 | static void | |
2948 | device_resume_fn(struct scsi_device *sdev, void *data) | |
2949 | { | |
2950 | scsi_device_resume(sdev); | |
2951 | } | |
2952 | ||
2953 | void | |
2954 | scsi_target_resume(struct scsi_target *starget) | |
2955 | { | |
2956 | starget_for_each_device(starget, NULL, device_resume_fn); | |
2957 | } | |
2958 | EXPORT_SYMBOL(scsi_target_resume); | |
2959 | ||
2960 | /** | |
551eb598 BVA |
2961 | * scsi_internal_device_block_nowait - try to transition to the SDEV_BLOCK state |
2962 | * @sdev: device to block | |
1da177e4 | 2963 | * |
551eb598 | 2964 | * Pause SCSI command processing on the specified device. Does not sleep. |
1da177e4 | 2965 | * |
551eb598 | 2966 | * Returns zero if successful or a negative error code upon failure. |
669f0441 | 2967 | * |
551eb598 BVA |
2968 | * Notes: |
2969 | * This routine transitions the device to the SDEV_BLOCK state (which must be | |
2970 | * a legal transition). When the device is in this state, command processing | |
2971 | * is paused until the device leaves the SDEV_BLOCK state. See also | |
2972 | * scsi_internal_device_unblock_nowait(). | |
eb44820c | 2973 | */ |
551eb598 | 2974 | int scsi_internal_device_block_nowait(struct scsi_device *sdev) |
1da177e4 | 2975 | { |
165125e1 | 2976 | struct request_queue *q = sdev->request_queue; |
1da177e4 LT |
2977 | unsigned long flags; |
2978 | int err = 0; | |
2979 | ||
2980 | err = scsi_device_set_state(sdev, SDEV_BLOCK); | |
6f4267e3 JB |
2981 | if (err) { |
2982 | err = scsi_device_set_state(sdev, SDEV_CREATED_BLOCK); | |
2983 | ||
2984 | if (err) | |
2985 | return err; | |
2986 | } | |
1da177e4 LT |
2987 | |
2988 | /* | |
2989 | * The device has transitioned to SDEV_BLOCK. Stop the | |
2990 | * block layer from calling the midlayer with this device's | |
2991 | * request queue. | |
2992 | */ | |
d285203c | 2993 | if (q->mq_ops) { |
90311148 | 2994 | blk_mq_quiesce_queue_nowait(q); |
d285203c CH |
2995 | } else { |
2996 | spin_lock_irqsave(q->queue_lock, flags); | |
2997 | blk_stop_queue(q); | |
2998 | spin_unlock_irqrestore(q->queue_lock, flags); | |
2999 | } | |
1da177e4 LT |
3000 | |
3001 | return 0; | |
3002 | } | |
551eb598 BVA |
3003 | EXPORT_SYMBOL_GPL(scsi_internal_device_block_nowait); |
3004 | ||
1da177e4 | 3005 | /** |
551eb598 BVA |
3006 | * scsi_internal_device_block - try to transition to the SDEV_BLOCK state |
3007 | * @sdev: device to block | |
3008 | * | |
3009 | * Pause SCSI command processing on the specified device and wait until all | |
3010 | * ongoing scsi_request_fn() / scsi_queue_rq() calls have finished. May sleep. | |
1da177e4 | 3011 | * |
551eb598 | 3012 | * Returns zero if successful or a negative error code upon failure. |
1da177e4 | 3013 | * |
551eb598 BVA |
3014 | * Note: |
3015 | * This routine transitions the device to the SDEV_BLOCK state (which must be | |
3016 | * a legal transition). When the device is in this state, command processing | |
3017 | * is paused until the device leaves the SDEV_BLOCK state. See also | |
3018 | * scsi_internal_device_unblock(). | |
1da177e4 | 3019 | * |
551eb598 BVA |
3020 | * To do: avoid that scsi_send_eh_cmnd() calls queuecommand() after |
3021 | * scsi_internal_device_block() has blocked a SCSI device and also | |
3022 | * remove the rport mutex lock and unlock calls from srp_queuecommand(). | |
eb44820c | 3023 | */ |
551eb598 | 3024 | static int scsi_internal_device_block(struct scsi_device *sdev) |
1da177e4 | 3025 | { |
551eb598 BVA |
3026 | struct request_queue *q = sdev->request_queue; |
3027 | int err; | |
3028 | ||
0db6ca8a | 3029 | mutex_lock(&sdev->state_mutex); |
551eb598 BVA |
3030 | err = scsi_internal_device_block_nowait(sdev); |
3031 | if (err == 0) { | |
3032 | if (q->mq_ops) | |
3033 | blk_mq_quiesce_queue(q); | |
3034 | else | |
3035 | scsi_wait_for_queuecommand(sdev); | |
3036 | } | |
0db6ca8a BVA |
3037 | mutex_unlock(&sdev->state_mutex); |
3038 | ||
551eb598 BVA |
3039 | return err; |
3040 | } | |
1da177e4 | 3041 | |
66483a4a BVA |
3042 | void scsi_start_queue(struct scsi_device *sdev) |
3043 | { | |
3044 | struct request_queue *q = sdev->request_queue; | |
1da177e4 | 3045 | unsigned long flags; |
5d9fb5cc | 3046 | |
66483a4a | 3047 | if (q->mq_ops) { |
90311148 | 3048 | blk_mq_unquiesce_queue(q); |
66483a4a BVA |
3049 | } else { |
3050 | spin_lock_irqsave(q->queue_lock, flags); | |
3051 | blk_start_queue(q); | |
3052 | spin_unlock_irqrestore(q->queue_lock, flags); | |
3053 | } | |
3054 | } | |
3055 | ||
1da177e4 | 3056 | /** |
43f7571b | 3057 | * scsi_internal_device_unblock_nowait - resume a device after a block request |
1da177e4 | 3058 | * @sdev: device to resume |
43f7571b | 3059 | * @new_state: state to set the device to after unblocking |
1da177e4 | 3060 | * |
43f7571b BVA |
3061 | * Restart the device queue for a previously suspended SCSI device. Does not |
3062 | * sleep. | |
1da177e4 | 3063 | * |
43f7571b | 3064 | * Returns zero if successful or a negative error code upon failure. |
1da177e4 | 3065 | * |
43f7571b BVA |
3066 | * Notes: |
3067 | * This routine transitions the device to the SDEV_RUNNING state or to one of | |
3068 | * the offline states (which must be a legal transition) allowing the midlayer | |
3069 | * to goose the queue for this device. | |
eb44820c | 3070 | */ |
43f7571b BVA |
3071 | int scsi_internal_device_unblock_nowait(struct scsi_device *sdev, |
3072 | enum scsi_device_state new_state) | |
1da177e4 | 3073 | { |
5d9fb5cc MC |
3074 | /* |
3075 | * Try to transition the scsi device to SDEV_RUNNING or one of the | |
3076 | * offlined states and goose the device queue if successful. | |
1da177e4 | 3077 | */ |
8cd1ec78 HR |
3078 | switch (sdev->sdev_state) { |
3079 | case SDEV_BLOCK: | |
3080 | case SDEV_TRANSPORT_OFFLINE: | |
5d9fb5cc | 3081 | sdev->sdev_state = new_state; |
8a97712e | 3082 | sysfs_notify(&sdev->sdev_gendev.kobj, NULL, "state"); |
8cd1ec78 HR |
3083 | break; |
3084 | case SDEV_CREATED_BLOCK: | |
5d9fb5cc MC |
3085 | if (new_state == SDEV_TRANSPORT_OFFLINE || |
3086 | new_state == SDEV_OFFLINE) | |
3087 | sdev->sdev_state = new_state; | |
3088 | else | |
3089 | sdev->sdev_state = SDEV_CREATED; | |
8a97712e | 3090 | sysfs_notify(&sdev->sdev_gendev.kobj, NULL, "state"); |
8cd1ec78 HR |
3091 | break; |
3092 | case SDEV_CANCEL: | |
3093 | case SDEV_OFFLINE: | |
3094 | break; | |
3095 | default: | |
5c10e63c | 3096 | return -EINVAL; |
8cd1ec78 | 3097 | } |
66483a4a | 3098 | scsi_start_queue(sdev); |
1da177e4 LT |
3099 | |
3100 | return 0; | |
3101 | } | |
43f7571b BVA |
3102 | EXPORT_SYMBOL_GPL(scsi_internal_device_unblock_nowait); |
3103 | ||
3104 | /** | |
3105 | * scsi_internal_device_unblock - resume a device after a block request | |
3106 | * @sdev: device to resume | |
3107 | * @new_state: state to set the device to after unblocking | |
3108 | * | |
3109 | * Restart the device queue for a previously suspended SCSI device. May sleep. | |
3110 | * | |
3111 | * Returns zero if successful or a negative error code upon failure. | |
3112 | * | |
3113 | * Notes: | |
3114 | * This routine transitions the device to the SDEV_RUNNING state or to one of | |
3115 | * the offline states (which must be a legal transition) allowing the midlayer | |
3116 | * to goose the queue for this device. | |
3117 | */ | |
3118 | static int scsi_internal_device_unblock(struct scsi_device *sdev, | |
3119 | enum scsi_device_state new_state) | |
3120 | { | |
0db6ca8a BVA |
3121 | int ret; |
3122 | ||
3123 | mutex_lock(&sdev->state_mutex); | |
3124 | ret = scsi_internal_device_unblock_nowait(sdev, new_state); | |
3125 | mutex_unlock(&sdev->state_mutex); | |
3126 | ||
3127 | return ret; | |
43f7571b | 3128 | } |
1da177e4 LT |
3129 | |
3130 | static void | |
3131 | device_block(struct scsi_device *sdev, void *data) | |
3132 | { | |
551eb598 | 3133 | scsi_internal_device_block(sdev); |
1da177e4 LT |
3134 | } |
3135 | ||
3136 | static int | |
3137 | target_block(struct device *dev, void *data) | |
3138 | { | |
3139 | if (scsi_is_target_device(dev)) | |
3140 | starget_for_each_device(to_scsi_target(dev), NULL, | |
3141 | device_block); | |
3142 | return 0; | |
3143 | } | |
3144 | ||
3145 | void | |
3146 | scsi_target_block(struct device *dev) | |
3147 | { | |
3148 | if (scsi_is_target_device(dev)) | |
3149 | starget_for_each_device(to_scsi_target(dev), NULL, | |
3150 | device_block); | |
3151 | else | |
3152 | device_for_each_child(dev, NULL, target_block); | |
3153 | } | |
3154 | EXPORT_SYMBOL_GPL(scsi_target_block); | |
3155 | ||
3156 | static void | |
3157 | device_unblock(struct scsi_device *sdev, void *data) | |
3158 | { | |
5d9fb5cc | 3159 | scsi_internal_device_unblock(sdev, *(enum scsi_device_state *)data); |
1da177e4 LT |
3160 | } |
3161 | ||
3162 | static int | |
3163 | target_unblock(struct device *dev, void *data) | |
3164 | { | |
3165 | if (scsi_is_target_device(dev)) | |
5d9fb5cc | 3166 | starget_for_each_device(to_scsi_target(dev), data, |
1da177e4 LT |
3167 | device_unblock); |
3168 | return 0; | |
3169 | } | |
3170 | ||
3171 | void | |
5d9fb5cc | 3172 | scsi_target_unblock(struct device *dev, enum scsi_device_state new_state) |
1da177e4 LT |
3173 | { |
3174 | if (scsi_is_target_device(dev)) | |
5d9fb5cc | 3175 | starget_for_each_device(to_scsi_target(dev), &new_state, |
1da177e4 LT |
3176 | device_unblock); |
3177 | else | |
5d9fb5cc | 3178 | device_for_each_child(dev, &new_state, target_unblock); |
1da177e4 LT |
3179 | } |
3180 | EXPORT_SYMBOL_GPL(scsi_target_unblock); | |
cdb8c2a6 GL |
3181 | |
3182 | /** | |
3183 | * scsi_kmap_atomic_sg - find and atomically map an sg-elemnt | |
eb44820c | 3184 | * @sgl: scatter-gather list |
cdb8c2a6 GL |
3185 | * @sg_count: number of segments in sg |
3186 | * @offset: offset in bytes into sg, on return offset into the mapped area | |
3187 | * @len: bytes to map, on return number of bytes mapped | |
3188 | * | |
3189 | * Returns virtual address of the start of the mapped page | |
3190 | */ | |
c6132da1 | 3191 | void *scsi_kmap_atomic_sg(struct scatterlist *sgl, int sg_count, |
cdb8c2a6 GL |
3192 | size_t *offset, size_t *len) |
3193 | { | |
3194 | int i; | |
3195 | size_t sg_len = 0, len_complete = 0; | |
c6132da1 | 3196 | struct scatterlist *sg; |
cdb8c2a6 GL |
3197 | struct page *page; |
3198 | ||
22cfefb5 AM |
3199 | WARN_ON(!irqs_disabled()); |
3200 | ||
c6132da1 | 3201 | for_each_sg(sgl, sg, sg_count, i) { |
cdb8c2a6 | 3202 | len_complete = sg_len; /* Complete sg-entries */ |
c6132da1 | 3203 | sg_len += sg->length; |
cdb8c2a6 GL |
3204 | if (sg_len > *offset) |
3205 | break; | |
3206 | } | |
3207 | ||
3208 | if (unlikely(i == sg_count)) { | |
169e1a2a AM |
3209 | printk(KERN_ERR "%s: Bytes in sg: %zu, requested offset %zu, " |
3210 | "elements %d\n", | |
cadbd4a5 | 3211 | __func__, sg_len, *offset, sg_count); |
cdb8c2a6 GL |
3212 | WARN_ON(1); |
3213 | return NULL; | |
3214 | } | |
3215 | ||
3216 | /* Offset starting from the beginning of first page in this sg-entry */ | |
c6132da1 | 3217 | *offset = *offset - len_complete + sg->offset; |
cdb8c2a6 GL |
3218 | |
3219 | /* Assumption: contiguous pages can be accessed as "page + i" */ | |
45711f1a | 3220 | page = nth_page(sg_page(sg), (*offset >> PAGE_SHIFT)); |
cdb8c2a6 GL |
3221 | *offset &= ~PAGE_MASK; |
3222 | ||
3223 | /* Bytes in this sg-entry from *offset to the end of the page */ | |
3224 | sg_len = PAGE_SIZE - *offset; | |
3225 | if (*len > sg_len) | |
3226 | *len = sg_len; | |
3227 | ||
77dfce07 | 3228 | return kmap_atomic(page); |
cdb8c2a6 GL |
3229 | } |
3230 | EXPORT_SYMBOL(scsi_kmap_atomic_sg); | |
3231 | ||
3232 | /** | |
eb44820c | 3233 | * scsi_kunmap_atomic_sg - atomically unmap a virtual address, previously mapped with scsi_kmap_atomic_sg |
cdb8c2a6 GL |
3234 | * @virt: virtual address to be unmapped |
3235 | */ | |
3236 | void scsi_kunmap_atomic_sg(void *virt) | |
3237 | { | |
77dfce07 | 3238 | kunmap_atomic(virt); |
cdb8c2a6 GL |
3239 | } |
3240 | EXPORT_SYMBOL(scsi_kunmap_atomic_sg); | |
6f4c827e AL |
3241 | |
3242 | void sdev_disable_disk_events(struct scsi_device *sdev) | |
3243 | { | |
3244 | atomic_inc(&sdev->disk_events_disable_depth); | |
3245 | } | |
3246 | EXPORT_SYMBOL(sdev_disable_disk_events); | |
3247 | ||
3248 | void sdev_enable_disk_events(struct scsi_device *sdev) | |
3249 | { | |
3250 | if (WARN_ON_ONCE(atomic_read(&sdev->disk_events_disable_depth) <= 0)) | |
3251 | return; | |
3252 | atomic_dec(&sdev->disk_events_disable_depth); | |
3253 | } | |
3254 | EXPORT_SYMBOL(sdev_enable_disk_events); | |
9983bed3 HR |
3255 | |
3256 | /** | |
3257 | * scsi_vpd_lun_id - return a unique device identification | |
3258 | * @sdev: SCSI device | |
3259 | * @id: buffer for the identification | |
3260 | * @id_len: length of the buffer | |
3261 | * | |
3262 | * Copies a unique device identification into @id based | |
3263 | * on the information in the VPD page 0x83 of the device. | |
3264 | * The string will be formatted as a SCSI name string. | |
3265 | * | |
3266 | * Returns the length of the identification or error on failure. | |
3267 | * If the identifier is longer than the supplied buffer the actual | |
3268 | * identifier length is returned and the buffer is not zero-padded. | |
3269 | */ | |
3270 | int scsi_vpd_lun_id(struct scsi_device *sdev, char *id, size_t id_len) | |
3271 | { | |
3272 | u8 cur_id_type = 0xff; | |
3273 | u8 cur_id_size = 0; | |
3274 | unsigned char *d, *cur_id_str; | |
3275 | unsigned char __rcu *vpd_pg83; | |
3276 | int id_size = -EINVAL; | |
3277 | ||
3278 | rcu_read_lock(); | |
3279 | vpd_pg83 = rcu_dereference(sdev->vpd_pg83); | |
3280 | if (!vpd_pg83) { | |
3281 | rcu_read_unlock(); | |
3282 | return -ENXIO; | |
3283 | } | |
3284 | ||
3285 | /* | |
3286 | * Look for the correct descriptor. | |
3287 | * Order of preference for lun descriptor: | |
3288 | * - SCSI name string | |
3289 | * - NAA IEEE Registered Extended | |
3290 | * - EUI-64 based 16-byte | |
3291 | * - EUI-64 based 12-byte | |
3292 | * - NAA IEEE Registered | |
3293 | * - NAA IEEE Extended | |
d230823a | 3294 | * - T10 Vendor ID |
9983bed3 HR |
3295 | * as longer descriptors reduce the likelyhood |
3296 | * of identification clashes. | |
3297 | */ | |
3298 | ||
3299 | /* The id string must be at least 20 bytes + terminating NULL byte */ | |
3300 | if (id_len < 21) { | |
3301 | rcu_read_unlock(); | |
3302 | return -EINVAL; | |
3303 | } | |
3304 | ||
3305 | memset(id, 0, id_len); | |
3306 | d = vpd_pg83 + 4; | |
3307 | while (d < vpd_pg83 + sdev->vpd_pg83_len) { | |
3308 | /* Skip designators not referring to the LUN */ | |
3309 | if ((d[1] & 0x30) != 0x00) | |
3310 | goto next_desig; | |
3311 | ||
3312 | switch (d[1] & 0xf) { | |
d230823a HR |
3313 | case 0x1: |
3314 | /* T10 Vendor ID */ | |
3315 | if (cur_id_size > d[3]) | |
3316 | break; | |
3317 | /* Prefer anything */ | |
3318 | if (cur_id_type > 0x01 && cur_id_type != 0xff) | |
3319 | break; | |
3320 | cur_id_size = d[3]; | |
3321 | if (cur_id_size + 4 > id_len) | |
3322 | cur_id_size = id_len - 4; | |
3323 | cur_id_str = d + 4; | |
3324 | cur_id_type = d[1] & 0xf; | |
3325 | id_size = snprintf(id, id_len, "t10.%*pE", | |
3326 | cur_id_size, cur_id_str); | |
3327 | break; | |
9983bed3 HR |
3328 | case 0x2: |
3329 | /* EUI-64 */ | |
3330 | if (cur_id_size > d[3]) | |
3331 | break; | |
3332 | /* Prefer NAA IEEE Registered Extended */ | |
3333 | if (cur_id_type == 0x3 && | |
3334 | cur_id_size == d[3]) | |
3335 | break; | |
3336 | cur_id_size = d[3]; | |
3337 | cur_id_str = d + 4; | |
3338 | cur_id_type = d[1] & 0xf; | |
3339 | switch (cur_id_size) { | |
3340 | case 8: | |
3341 | id_size = snprintf(id, id_len, | |
3342 | "eui.%8phN", | |
3343 | cur_id_str); | |
3344 | break; | |
3345 | case 12: | |
3346 | id_size = snprintf(id, id_len, | |
3347 | "eui.%12phN", | |
3348 | cur_id_str); | |
3349 | break; | |
3350 | case 16: | |
3351 | id_size = snprintf(id, id_len, | |
3352 | "eui.%16phN", | |
3353 | cur_id_str); | |
3354 | break; | |
3355 | default: | |
3356 | cur_id_size = 0; | |
3357 | break; | |
3358 | } | |
3359 | break; | |
3360 | case 0x3: | |
3361 | /* NAA */ | |
3362 | if (cur_id_size > d[3]) | |
3363 | break; | |
3364 | cur_id_size = d[3]; | |
3365 | cur_id_str = d + 4; | |
3366 | cur_id_type = d[1] & 0xf; | |
3367 | switch (cur_id_size) { | |
3368 | case 8: | |
3369 | id_size = snprintf(id, id_len, | |
3370 | "naa.%8phN", | |
3371 | cur_id_str); | |
3372 | break; | |
3373 | case 16: | |
3374 | id_size = snprintf(id, id_len, | |
3375 | "naa.%16phN", | |
3376 | cur_id_str); | |
3377 | break; | |
3378 | default: | |
3379 | cur_id_size = 0; | |
3380 | break; | |
3381 | } | |
3382 | break; | |
3383 | case 0x8: | |
3384 | /* SCSI name string */ | |
3385 | if (cur_id_size + 4 > d[3]) | |
3386 | break; | |
3387 | /* Prefer others for truncated descriptor */ | |
3388 | if (cur_id_size && d[3] > id_len) | |
3389 | break; | |
3390 | cur_id_size = id_size = d[3]; | |
3391 | cur_id_str = d + 4; | |
3392 | cur_id_type = d[1] & 0xf; | |
3393 | if (cur_id_size >= id_len) | |
3394 | cur_id_size = id_len - 1; | |
3395 | memcpy(id, cur_id_str, cur_id_size); | |
3396 | /* Decrease priority for truncated descriptor */ | |
3397 | if (cur_id_size != id_size) | |
3398 | cur_id_size = 6; | |
3399 | break; | |
3400 | default: | |
3401 | break; | |
3402 | } | |
3403 | next_desig: | |
3404 | d += d[3] + 4; | |
3405 | } | |
3406 | rcu_read_unlock(); | |
3407 | ||
3408 | return id_size; | |
3409 | } | |
3410 | EXPORT_SYMBOL(scsi_vpd_lun_id); | |
a8aa3978 HR |
3411 | |
3412 | /* | |
3413 | * scsi_vpd_tpg_id - return a target port group identifier | |
3414 | * @sdev: SCSI device | |
3415 | * | |
3416 | * Returns the Target Port Group identifier from the information | |
3417 | * froom VPD page 0x83 of the device. | |
3418 | * | |
3419 | * Returns the identifier or error on failure. | |
3420 | */ | |
3421 | int scsi_vpd_tpg_id(struct scsi_device *sdev, int *rel_id) | |
3422 | { | |
3423 | unsigned char *d; | |
3424 | unsigned char __rcu *vpd_pg83; | |
3425 | int group_id = -EAGAIN, rel_port = -1; | |
3426 | ||
3427 | rcu_read_lock(); | |
3428 | vpd_pg83 = rcu_dereference(sdev->vpd_pg83); | |
3429 | if (!vpd_pg83) { | |
3430 | rcu_read_unlock(); | |
3431 | return -ENXIO; | |
3432 | } | |
3433 | ||
3434 | d = sdev->vpd_pg83 + 4; | |
3435 | while (d < sdev->vpd_pg83 + sdev->vpd_pg83_len) { | |
3436 | switch (d[1] & 0xf) { | |
3437 | case 0x4: | |
3438 | /* Relative target port */ | |
3439 | rel_port = get_unaligned_be16(&d[6]); | |
3440 | break; | |
3441 | case 0x5: | |
3442 | /* Target port group */ | |
3443 | group_id = get_unaligned_be16(&d[6]); | |
3444 | break; | |
3445 | default: | |
3446 | break; | |
3447 | } | |
3448 | d += d[3] + 4; | |
3449 | } | |
3450 | rcu_read_unlock(); | |
3451 | ||
3452 | if (group_id >= 0 && rel_id && rel_port != -1) | |
3453 | *rel_id = rel_port; | |
3454 | ||
3455 | return group_id; | |
3456 | } | |
3457 | EXPORT_SYMBOL(scsi_vpd_tpg_id); |