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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> | |
ee14c674 | 33 | #include <scsi/scsi_dh.h> |
1da177e4 | 34 | |
3b5382c4 CH |
35 | #include <trace/events/scsi.h> |
36 | ||
1da177e4 LT |
37 | #include "scsi_priv.h" |
38 | #include "scsi_logging.h" | |
39 | ||
40 | ||
7027ad72 | 41 | struct kmem_cache *scsi_sdb_cache; |
6f9a35e2 | 42 | |
a488e749 JA |
43 | /* |
44 | * When to reinvoke queueing after a resource shortage. It's 3 msecs to | |
45 | * not change behaviour from the previous unplug mechanism, experimentation | |
46 | * may prove this needs changing. | |
47 | */ | |
48 | #define SCSI_QUEUE_DELAY 3 | |
49 | ||
de3e8bf3 CH |
50 | static void |
51 | scsi_set_blocked(struct scsi_cmnd *cmd, int reason) | |
1da177e4 LT |
52 | { |
53 | struct Scsi_Host *host = cmd->device->host; | |
54 | struct scsi_device *device = cmd->device; | |
f0c0a376 | 55 | struct scsi_target *starget = scsi_target(device); |
1da177e4 LT |
56 | |
57 | /* | |
d8c37e7b | 58 | * Set the appropriate busy bit for the device/host. |
1da177e4 LT |
59 | * |
60 | * If the host/device isn't busy, assume that something actually | |
61 | * completed, and that we should be able to queue a command now. | |
62 | * | |
63 | * Note that the prior mid-layer assumption that any host could | |
64 | * always queue at least one command is now broken. The mid-layer | |
65 | * will implement a user specifiable stall (see | |
66 | * scsi_host.max_host_blocked and scsi_device.max_device_blocked) | |
67 | * if a command is requeued with no other commands outstanding | |
68 | * either for the device or for the host. | |
69 | */ | |
f0c0a376 MC |
70 | switch (reason) { |
71 | case SCSI_MLQUEUE_HOST_BUSY: | |
cd9070c9 | 72 | atomic_set(&host->host_blocked, host->max_host_blocked); |
f0c0a376 MC |
73 | break; |
74 | case SCSI_MLQUEUE_DEVICE_BUSY: | |
573e5913 | 75 | case SCSI_MLQUEUE_EH_RETRY: |
cd9070c9 CH |
76 | atomic_set(&device->device_blocked, |
77 | device->max_device_blocked); | |
f0c0a376 MC |
78 | break; |
79 | case SCSI_MLQUEUE_TARGET_BUSY: | |
cd9070c9 CH |
80 | atomic_set(&starget->target_blocked, |
81 | starget->max_target_blocked); | |
f0c0a376 MC |
82 | break; |
83 | } | |
de3e8bf3 CH |
84 | } |
85 | ||
d285203c CH |
86 | static void scsi_mq_requeue_cmd(struct scsi_cmnd *cmd) |
87 | { | |
88 | struct scsi_device *sdev = cmd->device; | |
d285203c | 89 | |
2b053aca | 90 | blk_mq_requeue_request(cmd->request, true); |
d285203c CH |
91 | put_device(&sdev->sdev_gendev); |
92 | } | |
93 | ||
de3e8bf3 CH |
94 | /** |
95 | * __scsi_queue_insert - private queue insertion | |
96 | * @cmd: The SCSI command being requeued | |
97 | * @reason: The reason for the requeue | |
98 | * @unbusy: Whether the queue should be unbusied | |
99 | * | |
100 | * This is a private queue insertion. The public interface | |
101 | * scsi_queue_insert() always assumes the queue should be unbusied | |
102 | * because it's always called before the completion. This function is | |
103 | * for a requeue after completion, which should only occur in this | |
104 | * file. | |
105 | */ | |
106 | static void __scsi_queue_insert(struct scsi_cmnd *cmd, int reason, int unbusy) | |
107 | { | |
108 | struct scsi_device *device = cmd->device; | |
109 | struct request_queue *q = device->request_queue; | |
110 | unsigned long flags; | |
111 | ||
112 | SCSI_LOG_MLQUEUE(1, scmd_printk(KERN_INFO, cmd, | |
113 | "Inserting command %p into mlqueue\n", cmd)); | |
114 | ||
115 | scsi_set_blocked(cmd, reason); | |
1da177e4 | 116 | |
1da177e4 LT |
117 | /* |
118 | * Decrement the counters, since these commands are no longer | |
119 | * active on the host/device. | |
120 | */ | |
4f5299ac JB |
121 | if (unbusy) |
122 | scsi_device_unbusy(device); | |
1da177e4 LT |
123 | |
124 | /* | |
a1bf9d1d | 125 | * Requeue this command. It will go before all other commands |
b485462a BVA |
126 | * that are already in the queue. Schedule requeue work under |
127 | * lock such that the kblockd_schedule_work() call happens | |
128 | * before blk_cleanup_queue() finishes. | |
a488e749 | 129 | */ |
644373a4 | 130 | cmd->result = 0; |
d285203c CH |
131 | if (q->mq_ops) { |
132 | scsi_mq_requeue_cmd(cmd); | |
133 | return; | |
134 | } | |
a1bf9d1d | 135 | spin_lock_irqsave(q->queue_lock, flags); |
59897dad | 136 | blk_requeue_request(q, cmd->request); |
59c3d45e | 137 | kblockd_schedule_work(&device->requeue_work); |
b485462a | 138 | spin_unlock_irqrestore(q->queue_lock, flags); |
1da177e4 LT |
139 | } |
140 | ||
4f5299ac JB |
141 | /* |
142 | * Function: scsi_queue_insert() | |
143 | * | |
144 | * Purpose: Insert a command in the midlevel queue. | |
145 | * | |
146 | * Arguments: cmd - command that we are adding to queue. | |
147 | * reason - why we are inserting command to queue. | |
148 | * | |
149 | * Lock status: Assumed that lock is not held upon entry. | |
150 | * | |
151 | * Returns: Nothing. | |
152 | * | |
153 | * Notes: We do this for one of two cases. Either the host is busy | |
154 | * and it cannot accept any more commands for the time being, | |
155 | * or the device returned QUEUE_FULL and can accept no more | |
156 | * commands. | |
157 | * Notes: This could be called either from an interrupt context or a | |
158 | * normal process context. | |
159 | */ | |
84feb166 | 160 | void scsi_queue_insert(struct scsi_cmnd *cmd, int reason) |
4f5299ac | 161 | { |
84feb166 | 162 | __scsi_queue_insert(cmd, reason, 1); |
4f5299ac | 163 | } |
e8064021 CH |
164 | |
165 | static int __scsi_execute(struct scsi_device *sdev, const unsigned char *cmd, | |
33aa687d | 166 | int data_direction, void *buffer, unsigned bufflen, |
2bfad21e | 167 | unsigned char *sense, int timeout, int retries, u64 flags, |
e8064021 | 168 | req_flags_t rq_flags, int *resid) |
39216033 JB |
169 | { |
170 | struct request *req; | |
171 | int write = (data_direction == DMA_TO_DEVICE); | |
172 | int ret = DRIVER_ERROR << 24; | |
173 | ||
71baba4b | 174 | req = blk_get_request(sdev->request_queue, write, __GFP_RECLAIM); |
a492f075 | 175 | if (IS_ERR(req)) |
bfe159a5 | 176 | return ret; |
f27b087b | 177 | blk_rq_set_block_pc(req); |
39216033 JB |
178 | |
179 | if (bufflen && blk_rq_map_kern(sdev->request_queue, req, | |
71baba4b | 180 | buffer, bufflen, __GFP_RECLAIM)) |
39216033 JB |
181 | goto out; |
182 | ||
183 | req->cmd_len = COMMAND_SIZE(cmd[0]); | |
184 | memcpy(req->cmd, cmd, req->cmd_len); | |
185 | req->sense = sense; | |
186 | req->sense_len = 0; | |
17e01f21 | 187 | req->retries = retries; |
39216033 | 188 | req->timeout = timeout; |
e8064021 CH |
189 | req->cmd_flags |= flags; |
190 | req->rq_flags |= rq_flags | RQF_QUIET | RQF_PREEMPT; | |
39216033 JB |
191 | |
192 | /* | |
193 | * head injection *required* here otherwise quiesce won't work | |
194 | */ | |
195 | blk_execute_rq(req->q, NULL, req, 1); | |
196 | ||
bdb2b8ca AS |
197 | /* |
198 | * Some devices (USB mass-storage in particular) may transfer | |
199 | * garbage data together with a residue indicating that the data | |
200 | * is invalid. Prevent the garbage from being misinterpreted | |
201 | * and prevent security leaks by zeroing out the excess data. | |
202 | */ | |
c3a4d78c TH |
203 | if (unlikely(req->resid_len > 0 && req->resid_len <= bufflen)) |
204 | memset(buffer + (bufflen - req->resid_len), 0, req->resid_len); | |
bdb2b8ca | 205 | |
f4f4e47e | 206 | if (resid) |
c3a4d78c | 207 | *resid = req->resid_len; |
39216033 JB |
208 | ret = req->errors; |
209 | out: | |
210 | blk_put_request(req); | |
211 | ||
212 | return ret; | |
213 | } | |
e8064021 CH |
214 | |
215 | /** | |
216 | * scsi_execute - insert request and wait for the result | |
217 | * @sdev: scsi device | |
218 | * @cmd: scsi command | |
219 | * @data_direction: data direction | |
220 | * @buffer: data buffer | |
221 | * @bufflen: len of buffer | |
222 | * @sense: optional sense buffer | |
223 | * @timeout: request timeout in seconds | |
224 | * @retries: number of times to retry request | |
225 | * @flags: or into request flags; | |
226 | * @resid: optional residual length | |
227 | * | |
228 | * returns the req->errors value which is the scsi_cmnd result | |
229 | * field. | |
230 | */ | |
231 | int scsi_execute(struct scsi_device *sdev, const unsigned char *cmd, | |
232 | int data_direction, void *buffer, unsigned bufflen, | |
233 | unsigned char *sense, int timeout, int retries, u64 flags, | |
234 | int *resid) | |
235 | { | |
236 | return __scsi_execute(sdev, cmd, data_direction, buffer, bufflen, sense, | |
237 | timeout, retries, flags, 0, resid); | |
238 | } | |
33aa687d | 239 | EXPORT_SYMBOL(scsi_execute); |
39216033 | 240 | |
9b21493c | 241 | int scsi_execute_req_flags(struct scsi_device *sdev, const unsigned char *cmd, |
ea73a9f2 | 242 | int data_direction, void *buffer, unsigned bufflen, |
f4f4e47e | 243 | struct scsi_sense_hdr *sshdr, int timeout, int retries, |
e8064021 | 244 | int *resid, u64 flags, req_flags_t rq_flags) |
ea73a9f2 JB |
245 | { |
246 | char *sense = NULL; | |
1ccb48bb | 247 | int result; |
248 | ||
ea73a9f2 | 249 | if (sshdr) { |
24669f75 | 250 | sense = kzalloc(SCSI_SENSE_BUFFERSIZE, GFP_NOIO); |
ea73a9f2 JB |
251 | if (!sense) |
252 | return DRIVER_ERROR << 24; | |
ea73a9f2 | 253 | } |
e8064021 CH |
254 | result = __scsi_execute(sdev, cmd, data_direction, buffer, bufflen, |
255 | sense, timeout, retries, flags, rq_flags, resid); | |
ea73a9f2 | 256 | if (sshdr) |
e514385b | 257 | scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE, sshdr); |
ea73a9f2 JB |
258 | |
259 | kfree(sense); | |
260 | return result; | |
261 | } | |
9b21493c | 262 | EXPORT_SYMBOL(scsi_execute_req_flags); |
ea73a9f2 | 263 | |
1da177e4 LT |
264 | /* |
265 | * Function: scsi_init_cmd_errh() | |
266 | * | |
267 | * Purpose: Initialize cmd fields related to error handling. | |
268 | * | |
269 | * Arguments: cmd - command that is ready to be queued. | |
270 | * | |
1da177e4 LT |
271 | * Notes: This function has the job of initializing a number of |
272 | * fields related to error handling. Typically this will | |
273 | * be called once for each command, as required. | |
274 | */ | |
631c228c | 275 | static void scsi_init_cmd_errh(struct scsi_cmnd *cmd) |
1da177e4 | 276 | { |
1da177e4 | 277 | cmd->serial_number = 0; |
30b0c37b | 278 | scsi_set_resid(cmd, 0); |
b80ca4f7 | 279 | memset(cmd->sense_buffer, 0, SCSI_SENSE_BUFFERSIZE); |
1da177e4 | 280 | if (cmd->cmd_len == 0) |
db4742dd | 281 | cmd->cmd_len = scsi_command_size(cmd->cmnd); |
1da177e4 LT |
282 | } |
283 | ||
284 | void scsi_device_unbusy(struct scsi_device *sdev) | |
285 | { | |
286 | struct Scsi_Host *shost = sdev->host; | |
f0c0a376 | 287 | struct scsi_target *starget = scsi_target(sdev); |
1da177e4 LT |
288 | unsigned long flags; |
289 | ||
74665016 | 290 | atomic_dec(&shost->host_busy); |
2ccbb008 CH |
291 | if (starget->can_queue > 0) |
292 | atomic_dec(&starget->target_busy); | |
74665016 | 293 | |
939647ee | 294 | if (unlikely(scsi_host_in_recovery(shost) && |
74665016 CH |
295 | (shost->host_failed || shost->host_eh_scheduled))) { |
296 | spin_lock_irqsave(shost->host_lock, flags); | |
1da177e4 | 297 | scsi_eh_wakeup(shost); |
74665016 CH |
298 | spin_unlock_irqrestore(shost->host_lock, flags); |
299 | } | |
300 | ||
71e75c97 | 301 | atomic_dec(&sdev->device_busy); |
1da177e4 LT |
302 | } |
303 | ||
d285203c CH |
304 | static void scsi_kick_queue(struct request_queue *q) |
305 | { | |
306 | if (q->mq_ops) | |
307 | blk_mq_start_hw_queues(q); | |
308 | else | |
309 | blk_run_queue(q); | |
310 | } | |
311 | ||
1da177e4 LT |
312 | /* |
313 | * Called for single_lun devices on IO completion. Clear starget_sdev_user, | |
314 | * and call blk_run_queue for all the scsi_devices on the target - | |
315 | * including current_sdev first. | |
316 | * | |
317 | * Called with *no* scsi locks held. | |
318 | */ | |
319 | static void scsi_single_lun_run(struct scsi_device *current_sdev) | |
320 | { | |
321 | struct Scsi_Host *shost = current_sdev->host; | |
322 | struct scsi_device *sdev, *tmp; | |
323 | struct scsi_target *starget = scsi_target(current_sdev); | |
324 | unsigned long flags; | |
325 | ||
326 | spin_lock_irqsave(shost->host_lock, flags); | |
327 | starget->starget_sdev_user = NULL; | |
328 | spin_unlock_irqrestore(shost->host_lock, flags); | |
329 | ||
330 | /* | |
331 | * Call blk_run_queue for all LUNs on the target, starting with | |
332 | * current_sdev. We race with others (to set starget_sdev_user), | |
333 | * but in most cases, we will be first. Ideally, each LU on the | |
334 | * target would get some limited time or requests on the target. | |
335 | */ | |
d285203c | 336 | scsi_kick_queue(current_sdev->request_queue); |
1da177e4 LT |
337 | |
338 | spin_lock_irqsave(shost->host_lock, flags); | |
339 | if (starget->starget_sdev_user) | |
340 | goto out; | |
341 | list_for_each_entry_safe(sdev, tmp, &starget->devices, | |
342 | same_target_siblings) { | |
343 | if (sdev == current_sdev) | |
344 | continue; | |
345 | if (scsi_device_get(sdev)) | |
346 | continue; | |
347 | ||
348 | spin_unlock_irqrestore(shost->host_lock, flags); | |
d285203c | 349 | scsi_kick_queue(sdev->request_queue); |
1da177e4 LT |
350 | spin_lock_irqsave(shost->host_lock, flags); |
351 | ||
352 | scsi_device_put(sdev); | |
353 | } | |
354 | out: | |
355 | spin_unlock_irqrestore(shost->host_lock, flags); | |
356 | } | |
357 | ||
cd9070c9 | 358 | static inline bool scsi_device_is_busy(struct scsi_device *sdev) |
9d112517 | 359 | { |
cd9070c9 CH |
360 | if (atomic_read(&sdev->device_busy) >= sdev->queue_depth) |
361 | return true; | |
362 | if (atomic_read(&sdev->device_blocked) > 0) | |
363 | return true; | |
364 | return false; | |
9d112517 KU |
365 | } |
366 | ||
cd9070c9 | 367 | static inline bool scsi_target_is_busy(struct scsi_target *starget) |
f0c0a376 | 368 | { |
2ccbb008 CH |
369 | if (starget->can_queue > 0) { |
370 | if (atomic_read(&starget->target_busy) >= starget->can_queue) | |
371 | return true; | |
372 | if (atomic_read(&starget->target_blocked) > 0) | |
373 | return true; | |
374 | } | |
cd9070c9 | 375 | return false; |
f0c0a376 MC |
376 | } |
377 | ||
cd9070c9 | 378 | static inline bool scsi_host_is_busy(struct Scsi_Host *shost) |
9d112517 | 379 | { |
cd9070c9 CH |
380 | if (shost->can_queue > 0 && |
381 | atomic_read(&shost->host_busy) >= shost->can_queue) | |
382 | return true; | |
383 | if (atomic_read(&shost->host_blocked) > 0) | |
384 | return true; | |
385 | if (shost->host_self_blocked) | |
386 | return true; | |
387 | return false; | |
9d112517 KU |
388 | } |
389 | ||
21a05df5 | 390 | static void scsi_starved_list_run(struct Scsi_Host *shost) |
1da177e4 | 391 | { |
2a3a59e5 | 392 | LIST_HEAD(starved_list); |
21a05df5 | 393 | struct scsi_device *sdev; |
1da177e4 LT |
394 | unsigned long flags; |
395 | ||
1da177e4 | 396 | spin_lock_irqsave(shost->host_lock, flags); |
2a3a59e5 MC |
397 | list_splice_init(&shost->starved_list, &starved_list); |
398 | ||
399 | while (!list_empty(&starved_list)) { | |
e2eb7244 JB |
400 | struct request_queue *slq; |
401 | ||
1da177e4 LT |
402 | /* |
403 | * As long as shost is accepting commands and we have | |
404 | * starved queues, call blk_run_queue. scsi_request_fn | |
405 | * drops the queue_lock and can add us back to the | |
406 | * starved_list. | |
407 | * | |
408 | * host_lock protects the starved_list and starved_entry. | |
409 | * scsi_request_fn must get the host_lock before checking | |
410 | * or modifying starved_list or starved_entry. | |
411 | */ | |
2a3a59e5 | 412 | if (scsi_host_is_busy(shost)) |
f0c0a376 | 413 | break; |
f0c0a376 | 414 | |
2a3a59e5 MC |
415 | sdev = list_entry(starved_list.next, |
416 | struct scsi_device, starved_entry); | |
417 | list_del_init(&sdev->starved_entry); | |
f0c0a376 MC |
418 | if (scsi_target_is_busy(scsi_target(sdev))) { |
419 | list_move_tail(&sdev->starved_entry, | |
420 | &shost->starved_list); | |
421 | continue; | |
422 | } | |
423 | ||
e2eb7244 JB |
424 | /* |
425 | * Once we drop the host lock, a racing scsi_remove_device() | |
426 | * call may remove the sdev from the starved list and destroy | |
427 | * it and the queue. Mitigate by taking a reference to the | |
428 | * queue and never touching the sdev again after we drop the | |
429 | * host lock. Note: if __scsi_remove_device() invokes | |
430 | * blk_cleanup_queue() before the queue is run from this | |
431 | * function then blk_run_queue() will return immediately since | |
432 | * blk_cleanup_queue() marks the queue with QUEUE_FLAG_DYING. | |
433 | */ | |
434 | slq = sdev->request_queue; | |
435 | if (!blk_get_queue(slq)) | |
436 | continue; | |
437 | spin_unlock_irqrestore(shost->host_lock, flags); | |
438 | ||
d285203c | 439 | scsi_kick_queue(slq); |
e2eb7244 JB |
440 | blk_put_queue(slq); |
441 | ||
442 | spin_lock_irqsave(shost->host_lock, flags); | |
1da177e4 | 443 | } |
2a3a59e5 MC |
444 | /* put any unprocessed entries back */ |
445 | list_splice(&starved_list, &shost->starved_list); | |
1da177e4 | 446 | spin_unlock_irqrestore(shost->host_lock, flags); |
21a05df5 CH |
447 | } |
448 | ||
449 | /* | |
450 | * Function: scsi_run_queue() | |
451 | * | |
452 | * Purpose: Select a proper request queue to serve next | |
453 | * | |
454 | * Arguments: q - last request's queue | |
455 | * | |
456 | * Returns: Nothing | |
457 | * | |
458 | * Notes: The previous command was completely finished, start | |
459 | * a new one if possible. | |
460 | */ | |
461 | static void scsi_run_queue(struct request_queue *q) | |
462 | { | |
463 | struct scsi_device *sdev = q->queuedata; | |
464 | ||
465 | if (scsi_target(sdev)->single_lun) | |
466 | scsi_single_lun_run(sdev); | |
467 | if (!list_empty(&sdev->host->starved_list)) | |
468 | scsi_starved_list_run(sdev->host); | |
1da177e4 | 469 | |
d285203c CH |
470 | if (q->mq_ops) |
471 | blk_mq_start_stopped_hw_queues(q, false); | |
472 | else | |
473 | blk_run_queue(q); | |
1da177e4 LT |
474 | } |
475 | ||
9937a5e2 JA |
476 | void scsi_requeue_run_queue(struct work_struct *work) |
477 | { | |
478 | struct scsi_device *sdev; | |
479 | struct request_queue *q; | |
480 | ||
481 | sdev = container_of(work, struct scsi_device, requeue_work); | |
482 | q = sdev->request_queue; | |
483 | scsi_run_queue(q); | |
484 | } | |
485 | ||
1da177e4 LT |
486 | /* |
487 | * Function: scsi_requeue_command() | |
488 | * | |
489 | * Purpose: Handle post-processing of completed commands. | |
490 | * | |
491 | * Arguments: q - queue to operate on | |
492 | * cmd - command that may need to be requeued. | |
493 | * | |
494 | * Returns: Nothing | |
495 | * | |
496 | * Notes: After command completion, there may be blocks left | |
497 | * over which weren't finished by the previous command | |
498 | * this can be for a number of reasons - the main one is | |
499 | * I/O errors in the middle of the request, in which case | |
500 | * we need to request the blocks that come after the bad | |
501 | * sector. | |
e91442b6 | 502 | * Notes: Upon return, cmd is a stale pointer. |
1da177e4 LT |
503 | */ |
504 | static void scsi_requeue_command(struct request_queue *q, struct scsi_cmnd *cmd) | |
505 | { | |
940f5d47 | 506 | struct scsi_device *sdev = cmd->device; |
e91442b6 | 507 | struct request *req = cmd->request; |
283369cc TH |
508 | unsigned long flags; |
509 | ||
283369cc | 510 | spin_lock_irqsave(q->queue_lock, flags); |
134997a0 CH |
511 | blk_unprep_request(req); |
512 | req->special = NULL; | |
513 | scsi_put_command(cmd); | |
e91442b6 | 514 | blk_requeue_request(q, req); |
283369cc | 515 | spin_unlock_irqrestore(q->queue_lock, flags); |
1da177e4 LT |
516 | |
517 | scsi_run_queue(q); | |
940f5d47 BVA |
518 | |
519 | put_device(&sdev->sdev_gendev); | |
1da177e4 LT |
520 | } |
521 | ||
1da177e4 LT |
522 | void scsi_run_host_queues(struct Scsi_Host *shost) |
523 | { | |
524 | struct scsi_device *sdev; | |
525 | ||
526 | shost_for_each_device(sdev, shost) | |
527 | scsi_run_queue(sdev->request_queue); | |
528 | } | |
529 | ||
d285203c CH |
530 | static void scsi_uninit_cmd(struct scsi_cmnd *cmd) |
531 | { | |
532 | if (cmd->request->cmd_type == REQ_TYPE_FS) { | |
533 | struct scsi_driver *drv = scsi_cmd_to_driver(cmd); | |
534 | ||
535 | if (drv->uninit_command) | |
536 | drv->uninit_command(cmd); | |
537 | } | |
538 | } | |
539 | ||
540 | static void scsi_mq_free_sgtables(struct scsi_cmnd *cmd) | |
541 | { | |
91dbc08d ML |
542 | struct scsi_data_buffer *sdb; |
543 | ||
d285203c | 544 | if (cmd->sdb.table.nents) |
001d63be | 545 | sg_free_table_chained(&cmd->sdb.table, true); |
91dbc08d ML |
546 | if (cmd->request->next_rq) { |
547 | sdb = cmd->request->next_rq->special; | |
548 | if (sdb) | |
001d63be | 549 | sg_free_table_chained(&sdb->table, true); |
91dbc08d | 550 | } |
d285203c | 551 | if (scsi_prot_sg_count(cmd)) |
001d63be | 552 | sg_free_table_chained(&cmd->prot_sdb->table, true); |
d285203c CH |
553 | } |
554 | ||
555 | static void scsi_mq_uninit_cmd(struct scsi_cmnd *cmd) | |
556 | { | |
557 | struct scsi_device *sdev = cmd->device; | |
64bdcbc4 | 558 | struct Scsi_Host *shost = sdev->host; |
d285203c CH |
559 | unsigned long flags; |
560 | ||
d285203c CH |
561 | scsi_mq_free_sgtables(cmd); |
562 | scsi_uninit_cmd(cmd); | |
563 | ||
64bdcbc4 KD |
564 | if (shost->use_cmd_list) { |
565 | BUG_ON(list_empty(&cmd->list)); | |
566 | spin_lock_irqsave(&sdev->list_lock, flags); | |
567 | list_del_init(&cmd->list); | |
568 | spin_unlock_irqrestore(&sdev->list_lock, flags); | |
569 | } | |
d285203c CH |
570 | } |
571 | ||
1da177e4 LT |
572 | /* |
573 | * Function: scsi_release_buffers() | |
574 | * | |
c682adf3 | 575 | * Purpose: Free resources allocate for a scsi_command. |
1da177e4 LT |
576 | * |
577 | * Arguments: cmd - command that we are bailing. | |
578 | * | |
579 | * Lock status: Assumed that no lock is held upon entry. | |
580 | * | |
581 | * Returns: Nothing | |
582 | * | |
583 | * Notes: In the event that an upper level driver rejects a | |
584 | * command, we must release resources allocated during | |
585 | * the __init_io() function. Primarily this would involve | |
c682adf3 | 586 | * the scatter-gather table. |
1da177e4 | 587 | */ |
f1bea55d | 588 | static void scsi_release_buffers(struct scsi_cmnd *cmd) |
1da177e4 | 589 | { |
c682adf3 | 590 | if (cmd->sdb.table.nents) |
001d63be | 591 | sg_free_table_chained(&cmd->sdb.table, false); |
c682adf3 CH |
592 | |
593 | memset(&cmd->sdb, 0, sizeof(cmd->sdb)); | |
594 | ||
595 | if (scsi_prot_sg_count(cmd)) | |
001d63be | 596 | sg_free_table_chained(&cmd->prot_sdb->table, false); |
1da177e4 LT |
597 | } |
598 | ||
c682adf3 CH |
599 | static void scsi_release_bidi_buffers(struct scsi_cmnd *cmd) |
600 | { | |
601 | struct scsi_data_buffer *bidi_sdb = cmd->request->next_rq->special; | |
602 | ||
001d63be | 603 | sg_free_table_chained(&bidi_sdb->table, false); |
c682adf3 CH |
604 | kmem_cache_free(scsi_sdb_cache, bidi_sdb); |
605 | cmd->request->next_rq->special = NULL; | |
606 | } | |
607 | ||
f6d47e74 CH |
608 | static bool scsi_end_request(struct request *req, int error, |
609 | unsigned int bytes, unsigned int bidi_bytes) | |
610 | { | |
611 | struct scsi_cmnd *cmd = req->special; | |
612 | struct scsi_device *sdev = cmd->device; | |
613 | struct request_queue *q = sdev->request_queue; | |
f6d47e74 CH |
614 | |
615 | if (blk_update_request(req, error, bytes)) | |
616 | return true; | |
617 | ||
618 | /* Bidi request must be completed as a whole */ | |
619 | if (unlikely(bidi_bytes) && | |
620 | blk_update_request(req->next_rq, error, bidi_bytes)) | |
621 | return true; | |
622 | ||
623 | if (blk_queue_add_random(q)) | |
624 | add_disk_randomness(req->rq_disk); | |
625 | ||
d285203c CH |
626 | if (req->mq_ctx) { |
627 | /* | |
c8a446ad | 628 | * In the MQ case the command gets freed by __blk_mq_end_request, |
d285203c CH |
629 | * so we have to do all cleanup that depends on it earlier. |
630 | * | |
631 | * We also can't kick the queues from irq context, so we | |
632 | * will have to defer it to a workqueue. | |
633 | */ | |
634 | scsi_mq_uninit_cmd(cmd); | |
635 | ||
c8a446ad | 636 | __blk_mq_end_request(req, error); |
d285203c CH |
637 | |
638 | if (scsi_target(sdev)->single_lun || | |
639 | !list_empty(&sdev->host->starved_list)) | |
640 | kblockd_schedule_work(&sdev->requeue_work); | |
641 | else | |
642 | blk_mq_start_stopped_hw_queues(q, true); | |
d285203c CH |
643 | } else { |
644 | unsigned long flags; | |
645 | ||
f81426a8 DG |
646 | if (bidi_bytes) |
647 | scsi_release_bidi_buffers(cmd); | |
648 | ||
d285203c CH |
649 | spin_lock_irqsave(q->queue_lock, flags); |
650 | blk_finish_request(req, error); | |
651 | spin_unlock_irqrestore(q->queue_lock, flags); | |
652 | ||
d285203c | 653 | scsi_release_buffers(cmd); |
bb3ec62a CH |
654 | |
655 | scsi_put_command(cmd); | |
656 | scsi_run_queue(q); | |
d285203c | 657 | } |
f6d47e74 | 658 | |
bb3ec62a | 659 | put_device(&sdev->sdev_gendev); |
f6d47e74 CH |
660 | return false; |
661 | } | |
662 | ||
0f7f6234 HR |
663 | /** |
664 | * __scsi_error_from_host_byte - translate SCSI error code into errno | |
665 | * @cmd: SCSI command (unused) | |
666 | * @result: scsi error code | |
667 | * | |
668 | * Translate SCSI error code into standard UNIX errno. | |
669 | * Return values: | |
670 | * -ENOLINK temporary transport failure | |
671 | * -EREMOTEIO permanent target failure, do not retry | |
672 | * -EBADE permanent nexus failure, retry on other path | |
a9d6ceb8 | 673 | * -ENOSPC No write space available |
7e782af5 | 674 | * -ENODATA Medium error |
0f7f6234 HR |
675 | * -EIO unspecified I/O error |
676 | */ | |
63583cca HR |
677 | static int __scsi_error_from_host_byte(struct scsi_cmnd *cmd, int result) |
678 | { | |
679 | int error = 0; | |
680 | ||
681 | switch(host_byte(result)) { | |
682 | case DID_TRANSPORT_FAILFAST: | |
683 | error = -ENOLINK; | |
684 | break; | |
685 | case DID_TARGET_FAILURE: | |
2082ebc4 | 686 | set_host_byte(cmd, DID_OK); |
63583cca HR |
687 | error = -EREMOTEIO; |
688 | break; | |
689 | case DID_NEXUS_FAILURE: | |
2082ebc4 | 690 | set_host_byte(cmd, DID_OK); |
63583cca HR |
691 | error = -EBADE; |
692 | break; | |
a9d6ceb8 HR |
693 | case DID_ALLOC_FAILURE: |
694 | set_host_byte(cmd, DID_OK); | |
695 | error = -ENOSPC; | |
696 | break; | |
7e782af5 HR |
697 | case DID_MEDIUM_ERROR: |
698 | set_host_byte(cmd, DID_OK); | |
699 | error = -ENODATA; | |
700 | break; | |
63583cca HR |
701 | default: |
702 | error = -EIO; | |
703 | break; | |
704 | } | |
705 | ||
706 | return error; | |
707 | } | |
708 | ||
1da177e4 LT |
709 | /* |
710 | * Function: scsi_io_completion() | |
711 | * | |
712 | * Purpose: Completion processing for block device I/O requests. | |
713 | * | |
714 | * Arguments: cmd - command that is finished. | |
715 | * | |
716 | * Lock status: Assumed that no lock is held upon entry. | |
717 | * | |
718 | * Returns: Nothing | |
719 | * | |
bc85dc50 CH |
720 | * Notes: We will finish off the specified number of sectors. If we |
721 | * are done, the command block will be released and the queue | |
722 | * function will be goosed. If we are not done then we have to | |
b60af5b0 | 723 | * figure out what to do next: |
1da177e4 | 724 | * |
b60af5b0 AS |
725 | * a) We can call scsi_requeue_command(). The request |
726 | * will be unprepared and put back on the queue. Then | |
727 | * a new command will be created for it. This should | |
728 | * be used if we made forward progress, or if we want | |
729 | * to switch from READ(10) to READ(6) for example. | |
1da177e4 | 730 | * |
bc85dc50 | 731 | * b) We can call __scsi_queue_insert(). The request will |
b60af5b0 AS |
732 | * be put back on the queue and retried using the same |
733 | * command as before, possibly after a delay. | |
734 | * | |
f6d47e74 | 735 | * c) We can call scsi_end_request() with -EIO to fail |
b60af5b0 | 736 | * the remainder of the request. |
1da177e4 | 737 | */ |
03aba2f7 | 738 | void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes) |
1da177e4 LT |
739 | { |
740 | int result = cmd->result; | |
165125e1 | 741 | struct request_queue *q = cmd->device->request_queue; |
1da177e4 | 742 | struct request *req = cmd->request; |
fa8e36c3 | 743 | int error = 0; |
1da177e4 | 744 | struct scsi_sense_hdr sshdr; |
4753cbc0 | 745 | bool sense_valid = false; |
c11c004b | 746 | int sense_deferred = 0, level = 0; |
b60af5b0 AS |
747 | enum {ACTION_FAIL, ACTION_REPREP, ACTION_RETRY, |
748 | ACTION_DELAYED_RETRY} action; | |
ee60b2c5 | 749 | unsigned long wait_for = (cmd->allowed + 1) * req->timeout; |
1da177e4 | 750 | |
1da177e4 LT |
751 | if (result) { |
752 | sense_valid = scsi_command_normalize_sense(cmd, &sshdr); | |
753 | if (sense_valid) | |
754 | sense_deferred = scsi_sense_is_deferred(&sshdr); | |
755 | } | |
631c228c | 756 | |
33659ebb | 757 | if (req->cmd_type == REQ_TYPE_BLOCK_PC) { /* SG_IO ioctl from block level */ |
1da177e4 | 758 | if (result) { |
1da177e4 LT |
759 | if (sense_valid && req->sense) { |
760 | /* | |
761 | * SG_IO wants current and deferred errors | |
762 | */ | |
763 | int len = 8 + cmd->sense_buffer[7]; | |
764 | ||
765 | if (len > SCSI_SENSE_BUFFERSIZE) | |
766 | len = SCSI_SENSE_BUFFERSIZE; | |
767 | memcpy(req->sense, cmd->sense_buffer, len); | |
768 | req->sense_len = len; | |
769 | } | |
fa8e36c3 | 770 | if (!sense_deferred) |
63583cca | 771 | error = __scsi_error_from_host_byte(cmd, result); |
b22f687d | 772 | } |
27c41973 MS |
773 | /* |
774 | * __scsi_error_from_host_byte may have reset the host_byte | |
775 | */ | |
776 | req->errors = cmd->result; | |
e6bb7a96 FT |
777 | |
778 | req->resid_len = scsi_get_resid(cmd); | |
779 | ||
6f9a35e2 | 780 | if (scsi_bidi_cmnd(cmd)) { |
e6bb7a96 FT |
781 | /* |
782 | * Bidi commands Must be complete as a whole, | |
783 | * both sides at once. | |
784 | */ | |
785 | req->next_rq->resid_len = scsi_in(cmd)->resid; | |
f6d47e74 CH |
786 | if (scsi_end_request(req, 0, blk_rq_bytes(req), |
787 | blk_rq_bytes(req->next_rq))) | |
788 | BUG(); | |
6f9a35e2 BH |
789 | return; |
790 | } | |
89fb4cd1 JB |
791 | } else if (blk_rq_bytes(req) == 0 && result && !sense_deferred) { |
792 | /* | |
793 | * Certain non BLOCK_PC requests are commands that don't | |
794 | * actually transfer anything (FLUSH), so cannot use | |
795 | * good_bytes != blk_rq_bytes(req) as the signal for an error. | |
796 | * This sets the error explicitly for the problem case. | |
797 | */ | |
798 | error = __scsi_error_from_host_byte(cmd, result); | |
1da177e4 LT |
799 | } |
800 | ||
33659ebb CH |
801 | /* no bidi support for !REQ_TYPE_BLOCK_PC yet */ |
802 | BUG_ON(blk_bidi_rq(req)); | |
30b0c37b | 803 | |
1da177e4 LT |
804 | /* |
805 | * Next deal with any sectors which we were able to correctly | |
806 | * handle. | |
807 | */ | |
91921e01 HR |
808 | SCSI_LOG_HLCOMPLETE(1, scmd_printk(KERN_INFO, cmd, |
809 | "%u sectors total, %d bytes done.\n", | |
810 | blk_rq_sectors(req), good_bytes)); | |
d6b0c537 | 811 | |
a9bddd74 JB |
812 | /* |
813 | * Recovered errors need reporting, but they're always treated | |
814 | * as success, so fiddle the result code here. For BLOCK_PC | |
815 | * we already took a copy of the original into rq->errors which | |
816 | * is what gets returned to the user | |
817 | */ | |
e7efe593 DG |
818 | if (sense_valid && (sshdr.sense_key == RECOVERED_ERROR)) { |
819 | /* if ATA PASS-THROUGH INFORMATION AVAILABLE skip | |
820 | * print since caller wants ATA registers. Only occurs on | |
821 | * SCSI ATA PASS_THROUGH commands when CK_COND=1 | |
822 | */ | |
823 | if ((sshdr.asc == 0x0) && (sshdr.ascq == 0x1d)) | |
824 | ; | |
e8064021 | 825 | else if (!(req->rq_flags & RQF_QUIET)) |
d811b848 | 826 | scsi_print_sense(cmd); |
a9bddd74 JB |
827 | result = 0; |
828 | /* BLOCK_PC may have set error */ | |
829 | error = 0; | |
830 | } | |
831 | ||
832 | /* | |
a621bac3 JB |
833 | * special case: failed zero length commands always need to |
834 | * drop down into the retry code. Otherwise, if we finished | |
835 | * all bytes in the request we are done now. | |
d6b0c537 | 836 | */ |
a621bac3 JB |
837 | if (!(blk_rq_bytes(req) == 0 && error) && |
838 | !scsi_end_request(req, error, good_bytes, 0)) | |
f6d47e74 | 839 | return; |
bc85dc50 CH |
840 | |
841 | /* | |
842 | * Kill remainder if no retrys. | |
843 | */ | |
844 | if (error && scsi_noretry_cmd(cmd)) { | |
f6d47e74 CH |
845 | if (scsi_end_request(req, error, blk_rq_bytes(req), 0)) |
846 | BUG(); | |
847 | return; | |
bc85dc50 CH |
848 | } |
849 | ||
850 | /* | |
851 | * If there had been no error, but we have leftover bytes in the | |
852 | * requeues just queue the command up again. | |
d6b0c537 | 853 | */ |
bc85dc50 CH |
854 | if (result == 0) |
855 | goto requeue; | |
03aba2f7 | 856 | |
63583cca | 857 | error = __scsi_error_from_host_byte(cmd, result); |
3e695f89 | 858 | |
b60af5b0 AS |
859 | if (host_byte(result) == DID_RESET) { |
860 | /* Third party bus reset or reset for error recovery | |
861 | * reasons. Just retry the command and see what | |
862 | * happens. | |
863 | */ | |
864 | action = ACTION_RETRY; | |
865 | } else if (sense_valid && !sense_deferred) { | |
1da177e4 LT |
866 | switch (sshdr.sense_key) { |
867 | case UNIT_ATTENTION: | |
868 | if (cmd->device->removable) { | |
03aba2f7 | 869 | /* Detected disc change. Set a bit |
1da177e4 LT |
870 | * and quietly refuse further access. |
871 | */ | |
872 | cmd->device->changed = 1; | |
b60af5b0 | 873 | action = ACTION_FAIL; |
1da177e4 | 874 | } else { |
03aba2f7 LT |
875 | /* Must have been a power glitch, or a |
876 | * bus reset. Could not have been a | |
877 | * media change, so we just retry the | |
b60af5b0 | 878 | * command and see what happens. |
03aba2f7 | 879 | */ |
b60af5b0 | 880 | action = ACTION_RETRY; |
1da177e4 LT |
881 | } |
882 | break; | |
883 | case ILLEGAL_REQUEST: | |
03aba2f7 LT |
884 | /* If we had an ILLEGAL REQUEST returned, then |
885 | * we may have performed an unsupported | |
886 | * command. The only thing this should be | |
887 | * would be a ten byte read where only a six | |
888 | * byte read was supported. Also, on a system | |
889 | * where READ CAPACITY failed, we may have | |
890 | * read past the end of the disk. | |
891 | */ | |
26a68019 JA |
892 | if ((cmd->device->use_10_for_rw && |
893 | sshdr.asc == 0x20 && sshdr.ascq == 0x00) && | |
1da177e4 LT |
894 | (cmd->cmnd[0] == READ_10 || |
895 | cmd->cmnd[0] == WRITE_10)) { | |
b60af5b0 | 896 | /* This will issue a new 6-byte command. */ |
1da177e4 | 897 | cmd->device->use_10_for_rw = 0; |
b60af5b0 | 898 | action = ACTION_REPREP; |
3e695f89 | 899 | } else if (sshdr.asc == 0x10) /* DIX */ { |
3e695f89 MP |
900 | action = ACTION_FAIL; |
901 | error = -EILSEQ; | |
c98a0eb0 | 902 | /* INVALID COMMAND OPCODE or INVALID FIELD IN CDB */ |
5db44863 | 903 | } else if (sshdr.asc == 0x20 || sshdr.asc == 0x24) { |
c98a0eb0 | 904 | action = ACTION_FAIL; |
66a651aa | 905 | error = -EREMOTEIO; |
b60af5b0 AS |
906 | } else |
907 | action = ACTION_FAIL; | |
908 | break; | |
511e44f4 | 909 | case ABORTED_COMMAND: |
126c0982 | 910 | action = ACTION_FAIL; |
e6c11dbb | 911 | if (sshdr.asc == 0x10) /* DIF */ |
3e695f89 | 912 | error = -EILSEQ; |
1da177e4 LT |
913 | break; |
914 | case NOT_READY: | |
03aba2f7 | 915 | /* If the device is in the process of becoming |
f3e93f73 | 916 | * ready, or has a temporary blockage, retry. |
1da177e4 | 917 | */ |
f3e93f73 JB |
918 | if (sshdr.asc == 0x04) { |
919 | switch (sshdr.ascq) { | |
920 | case 0x01: /* becoming ready */ | |
921 | case 0x04: /* format in progress */ | |
922 | case 0x05: /* rebuild in progress */ | |
923 | case 0x06: /* recalculation in progress */ | |
924 | case 0x07: /* operation in progress */ | |
925 | case 0x08: /* Long write in progress */ | |
926 | case 0x09: /* self test in progress */ | |
d8705f11 | 927 | case 0x14: /* space allocation in progress */ |
b60af5b0 | 928 | action = ACTION_DELAYED_RETRY; |
f3e93f73 | 929 | break; |
3dbf6a54 | 930 | default: |
3dbf6a54 AS |
931 | action = ACTION_FAIL; |
932 | break; | |
f3e93f73 | 933 | } |
e6c11dbb | 934 | } else |
b60af5b0 | 935 | action = ACTION_FAIL; |
b60af5b0 | 936 | break; |
1da177e4 | 937 | case VOLUME_OVERFLOW: |
03aba2f7 | 938 | /* See SSC3rXX or current. */ |
b60af5b0 AS |
939 | action = ACTION_FAIL; |
940 | break; | |
1da177e4 | 941 | default: |
b60af5b0 | 942 | action = ACTION_FAIL; |
1da177e4 LT |
943 | break; |
944 | } | |
e6c11dbb | 945 | } else |
b60af5b0 | 946 | action = ACTION_FAIL; |
b60af5b0 | 947 | |
ee60b2c5 | 948 | if (action != ACTION_FAIL && |
e6c11dbb | 949 | time_before(cmd->jiffies_at_alloc + wait_for, jiffies)) |
ee60b2c5 | 950 | action = ACTION_FAIL; |
ee60b2c5 | 951 | |
b60af5b0 AS |
952 | switch (action) { |
953 | case ACTION_FAIL: | |
954 | /* Give up and fail the remainder of the request */ | |
e8064021 | 955 | if (!(req->rq_flags & RQF_QUIET)) { |
f1569ff1 HR |
956 | static DEFINE_RATELIMIT_STATE(_rs, |
957 | DEFAULT_RATELIMIT_INTERVAL, | |
958 | DEFAULT_RATELIMIT_BURST); | |
959 | ||
960 | if (unlikely(scsi_logging_level)) | |
961 | level = SCSI_LOG_LEVEL(SCSI_LOG_MLCOMPLETE_SHIFT, | |
962 | SCSI_LOG_MLCOMPLETE_BITS); | |
963 | ||
964 | /* | |
965 | * if logging is enabled the failure will be printed | |
966 | * in scsi_log_completion(), so avoid duplicate messages | |
967 | */ | |
968 | if (!level && __ratelimit(&_rs)) { | |
969 | scsi_print_result(cmd, NULL, FAILED); | |
970 | if (driver_byte(result) & DRIVER_SENSE) | |
971 | scsi_print_sense(cmd); | |
972 | scsi_print_command(cmd); | |
973 | } | |
3173d8c3 | 974 | } |
f6d47e74 CH |
975 | if (!scsi_end_request(req, error, blk_rq_err_bytes(req), 0)) |
976 | return; | |
bc85dc50 | 977 | /*FALLTHRU*/ |
b60af5b0 | 978 | case ACTION_REPREP: |
bc85dc50 | 979 | requeue: |
b60af5b0 AS |
980 | /* Unprep the request and put it back at the head of the queue. |
981 | * A new command will be prepared and issued. | |
982 | */ | |
d285203c | 983 | if (q->mq_ops) { |
e8064021 | 984 | cmd->request->rq_flags &= ~RQF_DONTPREP; |
d285203c CH |
985 | scsi_mq_uninit_cmd(cmd); |
986 | scsi_mq_requeue_cmd(cmd); | |
987 | } else { | |
988 | scsi_release_buffers(cmd); | |
989 | scsi_requeue_command(q, cmd); | |
990 | } | |
b60af5b0 AS |
991 | break; |
992 | case ACTION_RETRY: | |
993 | /* Retry the same command immediately */ | |
4f5299ac | 994 | __scsi_queue_insert(cmd, SCSI_MLQUEUE_EH_RETRY, 0); |
b60af5b0 AS |
995 | break; |
996 | case ACTION_DELAYED_RETRY: | |
997 | /* Retry the same command after a delay */ | |
4f5299ac | 998 | __scsi_queue_insert(cmd, SCSI_MLQUEUE_DEVICE_BUSY, 0); |
b60af5b0 | 999 | break; |
1da177e4 LT |
1000 | } |
1001 | } | |
1da177e4 | 1002 | |
3c356bde | 1003 | static int scsi_init_sgtable(struct request *req, struct scsi_data_buffer *sdb) |
1da177e4 | 1004 | { |
6f9a35e2 | 1005 | int count; |
1da177e4 LT |
1006 | |
1007 | /* | |
3b003157 | 1008 | * If sg table allocation fails, requeue request later. |
1da177e4 | 1009 | */ |
001d63be | 1010 | if (unlikely(sg_alloc_table_chained(&sdb->table, req->nr_phys_segments, |
22cc3d4c | 1011 | sdb->table.sgl))) |
1da177e4 | 1012 | return BLKPREP_DEFER; |
1da177e4 | 1013 | |
1da177e4 LT |
1014 | /* |
1015 | * Next, walk the list, and fill in the addresses and sizes of | |
1016 | * each segment. | |
1017 | */ | |
30b0c37b BH |
1018 | count = blk_rq_map_sg(req->q, req, sdb->table.sgl); |
1019 | BUG_ON(count > sdb->table.nents); | |
1020 | sdb->table.nents = count; | |
1011c1b9 | 1021 | sdb->length = blk_rq_bytes(req); |
4a03d90e | 1022 | return BLKPREP_OK; |
1da177e4 | 1023 | } |
6f9a35e2 BH |
1024 | |
1025 | /* | |
1026 | * Function: scsi_init_io() | |
1027 | * | |
1028 | * Purpose: SCSI I/O initialize function. | |
1029 | * | |
1030 | * Arguments: cmd - Command descriptor we wish to initialize | |
1031 | * | |
1032 | * Returns: 0 on success | |
1033 | * BLKPREP_DEFER if the failure is retryable | |
1034 | * BLKPREP_KILL if the failure is fatal | |
1035 | */ | |
3c356bde | 1036 | int scsi_init_io(struct scsi_cmnd *cmd) |
6f9a35e2 | 1037 | { |
5e012aad | 1038 | struct scsi_device *sdev = cmd->device; |
13f05c8d | 1039 | struct request *rq = cmd->request; |
d285203c | 1040 | bool is_mq = (rq->mq_ctx != NULL); |
635d98b1 | 1041 | int error; |
13f05c8d | 1042 | |
635d98b1 CH |
1043 | BUG_ON(!rq->nr_phys_segments); |
1044 | ||
3c356bde | 1045 | error = scsi_init_sgtable(rq, &cmd->sdb); |
6f9a35e2 BH |
1046 | if (error) |
1047 | goto err_exit; | |
1048 | ||
13f05c8d | 1049 | if (blk_bidi_rq(rq)) { |
d285203c CH |
1050 | if (!rq->q->mq_ops) { |
1051 | struct scsi_data_buffer *bidi_sdb = | |
1052 | kmem_cache_zalloc(scsi_sdb_cache, GFP_ATOMIC); | |
1053 | if (!bidi_sdb) { | |
1054 | error = BLKPREP_DEFER; | |
1055 | goto err_exit; | |
1056 | } | |
1057 | ||
1058 | rq->next_rq->special = bidi_sdb; | |
6f9a35e2 BH |
1059 | } |
1060 | ||
3c356bde | 1061 | error = scsi_init_sgtable(rq->next_rq, rq->next_rq->special); |
6f9a35e2 BH |
1062 | if (error) |
1063 | goto err_exit; | |
1064 | } | |
1065 | ||
13f05c8d | 1066 | if (blk_integrity_rq(rq)) { |
7027ad72 MP |
1067 | struct scsi_data_buffer *prot_sdb = cmd->prot_sdb; |
1068 | int ivecs, count; | |
1069 | ||
91724c20 EM |
1070 | if (prot_sdb == NULL) { |
1071 | /* | |
1072 | * This can happen if someone (e.g. multipath) | |
1073 | * queues a command to a device on an adapter | |
1074 | * that does not support DIX. | |
1075 | */ | |
1076 | WARN_ON_ONCE(1); | |
1077 | error = BLKPREP_KILL; | |
1078 | goto err_exit; | |
1079 | } | |
1080 | ||
13f05c8d | 1081 | ivecs = blk_rq_count_integrity_sg(rq->q, rq->bio); |
7027ad72 | 1082 | |
001d63be | 1083 | if (sg_alloc_table_chained(&prot_sdb->table, ivecs, |
22cc3d4c | 1084 | prot_sdb->table.sgl)) { |
7027ad72 MP |
1085 | error = BLKPREP_DEFER; |
1086 | goto err_exit; | |
1087 | } | |
1088 | ||
13f05c8d | 1089 | count = blk_rq_map_integrity_sg(rq->q, rq->bio, |
7027ad72 MP |
1090 | prot_sdb->table.sgl); |
1091 | BUG_ON(unlikely(count > ivecs)); | |
13f05c8d | 1092 | BUG_ON(unlikely(count > queue_max_integrity_segments(rq->q))); |
7027ad72 MP |
1093 | |
1094 | cmd->prot_sdb = prot_sdb; | |
1095 | cmd->prot_sdb->table.nents = count; | |
1096 | } | |
1097 | ||
d285203c | 1098 | return BLKPREP_OK; |
6f9a35e2 | 1099 | err_exit: |
d285203c CH |
1100 | if (is_mq) { |
1101 | scsi_mq_free_sgtables(cmd); | |
1102 | } else { | |
1103 | scsi_release_buffers(cmd); | |
1104 | cmd->request->special = NULL; | |
1105 | scsi_put_command(cmd); | |
1106 | put_device(&sdev->sdev_gendev); | |
1107 | } | |
6f9a35e2 BH |
1108 | return error; |
1109 | } | |
bb52d82f | 1110 | EXPORT_SYMBOL(scsi_init_io); |
1da177e4 | 1111 | |
3b003157 CH |
1112 | static struct scsi_cmnd *scsi_get_cmd_from_req(struct scsi_device *sdev, |
1113 | struct request *req) | |
1114 | { | |
1115 | struct scsi_cmnd *cmd; | |
1116 | ||
1117 | if (!req->special) { | |
04796336 CH |
1118 | /* Bail if we can't get a reference to the device */ |
1119 | if (!get_device(&sdev->sdev_gendev)) | |
1120 | return NULL; | |
1121 | ||
3b003157 | 1122 | cmd = scsi_get_command(sdev, GFP_ATOMIC); |
04796336 CH |
1123 | if (unlikely(!cmd)) { |
1124 | put_device(&sdev->sdev_gendev); | |
3b003157 | 1125 | return NULL; |
04796336 | 1126 | } |
3b003157 CH |
1127 | req->special = cmd; |
1128 | } else { | |
1129 | cmd = req->special; | |
1130 | } | |
1131 | ||
1132 | /* pull a tag out of the request if we have one */ | |
1133 | cmd->tag = req->tag; | |
1134 | cmd->request = req; | |
1135 | ||
64a87b24 | 1136 | cmd->cmnd = req->cmd; |
72f7d322 | 1137 | cmd->prot_op = SCSI_PROT_NORMAL; |
64a87b24 | 1138 | |
3b003157 CH |
1139 | return cmd; |
1140 | } | |
1141 | ||
4f1e5765 | 1142 | static int scsi_setup_blk_pc_cmnd(struct scsi_device *sdev, struct request *req) |
7b16318d | 1143 | { |
a1b73fc1 | 1144 | struct scsi_cmnd *cmd = req->special; |
3b003157 CH |
1145 | |
1146 | /* | |
1147 | * BLOCK_PC requests may transfer data, in which case they must | |
1148 | * a bio attached to them. Or they might contain a SCSI command | |
1149 | * that does not transfer data, in which case they may optionally | |
1150 | * submit a request without an attached bio. | |
1151 | */ | |
1152 | if (req->bio) { | |
3c356bde | 1153 | int ret = scsi_init_io(cmd); |
3b003157 CH |
1154 | if (unlikely(ret)) |
1155 | return ret; | |
1156 | } else { | |
b0790410 | 1157 | BUG_ON(blk_rq_bytes(req)); |
3b003157 | 1158 | |
30b0c37b | 1159 | memset(&cmd->sdb, 0, sizeof(cmd->sdb)); |
3b003157 | 1160 | } |
7b16318d | 1161 | |
7b16318d | 1162 | cmd->cmd_len = req->cmd_len; |
b0790410 | 1163 | cmd->transfersize = blk_rq_bytes(req); |
7b16318d | 1164 | cmd->allowed = req->retries; |
3b003157 | 1165 | return BLKPREP_OK; |
7b16318d | 1166 | } |
7b16318d | 1167 | |
3b003157 | 1168 | /* |
3868cf8e CH |
1169 | * Setup a REQ_TYPE_FS command. These are simple request from filesystems |
1170 | * that still need to be translated to SCSI CDBs from the ULD. | |
3b003157 | 1171 | */ |
3868cf8e | 1172 | static int scsi_setup_fs_cmnd(struct scsi_device *sdev, struct request *req) |
1da177e4 | 1173 | { |
a1b73fc1 | 1174 | struct scsi_cmnd *cmd = req->special; |
a6a8d9f8 | 1175 | |
ee14c674 CH |
1176 | if (unlikely(sdev->handler && sdev->handler->prep_fn)) { |
1177 | int ret = sdev->handler->prep_fn(sdev, req); | |
a6a8d9f8 CS |
1178 | if (ret != BLKPREP_OK) |
1179 | return ret; | |
1180 | } | |
1181 | ||
64a87b24 | 1182 | memset(cmd->cmnd, 0, BLK_MAX_CDB); |
3868cf8e | 1183 | return scsi_cmd_to_driver(cmd)->init_command(cmd); |
3b003157 CH |
1184 | } |
1185 | ||
6af7a4ff CH |
1186 | static int scsi_setup_cmnd(struct scsi_device *sdev, struct request *req) |
1187 | { | |
1188 | struct scsi_cmnd *cmd = req->special; | |
1189 | ||
1190 | if (!blk_rq_bytes(req)) | |
1191 | cmd->sc_data_direction = DMA_NONE; | |
1192 | else if (rq_data_dir(req) == WRITE) | |
1193 | cmd->sc_data_direction = DMA_TO_DEVICE; | |
1194 | else | |
1195 | cmd->sc_data_direction = DMA_FROM_DEVICE; | |
1196 | ||
1197 | switch (req->cmd_type) { | |
1198 | case REQ_TYPE_FS: | |
1199 | return scsi_setup_fs_cmnd(sdev, req); | |
1200 | case REQ_TYPE_BLOCK_PC: | |
1201 | return scsi_setup_blk_pc_cmnd(sdev, req); | |
1202 | default: | |
1203 | return BLKPREP_KILL; | |
1204 | } | |
1205 | } | |
1206 | ||
a1b73fc1 CH |
1207 | static int |
1208 | scsi_prep_state_check(struct scsi_device *sdev, struct request *req) | |
3b003157 | 1209 | { |
3b003157 CH |
1210 | int ret = BLKPREP_OK; |
1211 | ||
1da177e4 | 1212 | /* |
3b003157 CH |
1213 | * If the device is not in running state we will reject some |
1214 | * or all commands. | |
1da177e4 | 1215 | */ |
3b003157 CH |
1216 | if (unlikely(sdev->sdev_state != SDEV_RUNNING)) { |
1217 | switch (sdev->sdev_state) { | |
1218 | case SDEV_OFFLINE: | |
1b8d2620 | 1219 | case SDEV_TRANSPORT_OFFLINE: |
3b003157 CH |
1220 | /* |
1221 | * If the device is offline we refuse to process any | |
1222 | * commands. The device must be brought online | |
1223 | * before trying any recovery commands. | |
1224 | */ | |
1225 | sdev_printk(KERN_ERR, sdev, | |
1226 | "rejecting I/O to offline device\n"); | |
1227 | ret = BLKPREP_KILL; | |
1228 | break; | |
1229 | case SDEV_DEL: | |
1230 | /* | |
1231 | * If the device is fully deleted, we refuse to | |
1232 | * process any commands as well. | |
1233 | */ | |
9ccfc756 | 1234 | sdev_printk(KERN_ERR, sdev, |
3b003157 CH |
1235 | "rejecting I/O to dead device\n"); |
1236 | ret = BLKPREP_KILL; | |
1237 | break; | |
3b003157 | 1238 | case SDEV_BLOCK: |
6f4267e3 | 1239 | case SDEV_CREATED_BLOCK: |
bba0bdd7 BVA |
1240 | ret = BLKPREP_DEFER; |
1241 | break; | |
1242 | case SDEV_QUIESCE: | |
3b003157 CH |
1243 | /* |
1244 | * If the devices is blocked we defer normal commands. | |
1245 | */ | |
e8064021 | 1246 | if (!(req->rq_flags & RQF_PREEMPT)) |
3b003157 CH |
1247 | ret = BLKPREP_DEFER; |
1248 | break; | |
1249 | default: | |
1250 | /* | |
1251 | * For any other not fully online state we only allow | |
1252 | * special commands. In particular any user initiated | |
1253 | * command is not allowed. | |
1254 | */ | |
e8064021 | 1255 | if (!(req->rq_flags & RQF_PREEMPT)) |
3b003157 CH |
1256 | ret = BLKPREP_KILL; |
1257 | break; | |
1da177e4 | 1258 | } |
1da177e4 | 1259 | } |
7f9a6bc4 JB |
1260 | return ret; |
1261 | } | |
1da177e4 | 1262 | |
a1b73fc1 CH |
1263 | static int |
1264 | scsi_prep_return(struct request_queue *q, struct request *req, int ret) | |
7f9a6bc4 JB |
1265 | { |
1266 | struct scsi_device *sdev = q->queuedata; | |
1da177e4 | 1267 | |
3b003157 CH |
1268 | switch (ret) { |
1269 | case BLKPREP_KILL: | |
e1cd3911 | 1270 | case BLKPREP_INVALID: |
3b003157 | 1271 | req->errors = DID_NO_CONNECT << 16; |
7f9a6bc4 JB |
1272 | /* release the command and kill it */ |
1273 | if (req->special) { | |
1274 | struct scsi_cmnd *cmd = req->special; | |
1275 | scsi_release_buffers(cmd); | |
1276 | scsi_put_command(cmd); | |
68c03d91 | 1277 | put_device(&sdev->sdev_gendev); |
7f9a6bc4 JB |
1278 | req->special = NULL; |
1279 | } | |
3b003157 CH |
1280 | break; |
1281 | case BLKPREP_DEFER: | |
1da177e4 | 1282 | /* |
9934c8c0 | 1283 | * If we defer, the blk_peek_request() returns NULL, but the |
a488e749 JA |
1284 | * queue must be restarted, so we schedule a callback to happen |
1285 | * shortly. | |
1da177e4 | 1286 | */ |
71e75c97 | 1287 | if (atomic_read(&sdev->device_busy) == 0) |
a488e749 | 1288 | blk_delay_queue(q, SCSI_QUEUE_DELAY); |
3b003157 CH |
1289 | break; |
1290 | default: | |
e8064021 | 1291 | req->rq_flags |= RQF_DONTPREP; |
1da177e4 LT |
1292 | } |
1293 | ||
3b003157 | 1294 | return ret; |
1da177e4 | 1295 | } |
7f9a6bc4 | 1296 | |
a1b73fc1 | 1297 | static int scsi_prep_fn(struct request_queue *q, struct request *req) |
7f9a6bc4 JB |
1298 | { |
1299 | struct scsi_device *sdev = q->queuedata; | |
a1b73fc1 CH |
1300 | struct scsi_cmnd *cmd; |
1301 | int ret; | |
1302 | ||
1303 | ret = scsi_prep_state_check(sdev, req); | |
1304 | if (ret != BLKPREP_OK) | |
1305 | goto out; | |
1306 | ||
1307 | cmd = scsi_get_cmd_from_req(sdev, req); | |
1308 | if (unlikely(!cmd)) { | |
1309 | ret = BLKPREP_DEFER; | |
1310 | goto out; | |
1311 | } | |
7f9a6bc4 | 1312 | |
6af7a4ff | 1313 | ret = scsi_setup_cmnd(sdev, req); |
a1b73fc1 | 1314 | out: |
7f9a6bc4 JB |
1315 | return scsi_prep_return(q, req, ret); |
1316 | } | |
a1b73fc1 CH |
1317 | |
1318 | static void scsi_unprep_fn(struct request_queue *q, struct request *req) | |
1319 | { | |
d285203c | 1320 | scsi_uninit_cmd(req->special); |
a1b73fc1 | 1321 | } |
1da177e4 LT |
1322 | |
1323 | /* | |
1324 | * scsi_dev_queue_ready: if we can send requests to sdev, return 1 else | |
1325 | * return 0. | |
1326 | * | |
1327 | * Called with the queue_lock held. | |
1328 | */ | |
1329 | static inline int scsi_dev_queue_ready(struct request_queue *q, | |
1330 | struct scsi_device *sdev) | |
1331 | { | |
71e75c97 CH |
1332 | unsigned int busy; |
1333 | ||
1334 | busy = atomic_inc_return(&sdev->device_busy) - 1; | |
cd9070c9 | 1335 | if (atomic_read(&sdev->device_blocked)) { |
71e75c97 CH |
1336 | if (busy) |
1337 | goto out_dec; | |
1338 | ||
1da177e4 LT |
1339 | /* |
1340 | * unblock after device_blocked iterates to zero | |
1341 | */ | |
cd9070c9 | 1342 | if (atomic_dec_return(&sdev->device_blocked) > 0) { |
d285203c CH |
1343 | /* |
1344 | * For the MQ case we take care of this in the caller. | |
1345 | */ | |
1346 | if (!q->mq_ops) | |
1347 | blk_delay_queue(q, SCSI_QUEUE_DELAY); | |
71e75c97 | 1348 | goto out_dec; |
1da177e4 | 1349 | } |
71e75c97 CH |
1350 | SCSI_LOG_MLQUEUE(3, sdev_printk(KERN_INFO, sdev, |
1351 | "unblocking device at zero depth\n")); | |
1da177e4 | 1352 | } |
71e75c97 CH |
1353 | |
1354 | if (busy >= sdev->queue_depth) | |
1355 | goto out_dec; | |
1da177e4 LT |
1356 | |
1357 | return 1; | |
71e75c97 CH |
1358 | out_dec: |
1359 | atomic_dec(&sdev->device_busy); | |
1360 | return 0; | |
1da177e4 LT |
1361 | } |
1362 | ||
f0c0a376 MC |
1363 | /* |
1364 | * scsi_target_queue_ready: checks if there we can send commands to target | |
1365 | * @sdev: scsi device on starget to check. | |
f0c0a376 MC |
1366 | */ |
1367 | static inline int scsi_target_queue_ready(struct Scsi_Host *shost, | |
1368 | struct scsi_device *sdev) | |
1369 | { | |
1370 | struct scsi_target *starget = scsi_target(sdev); | |
7ae65c0f | 1371 | unsigned int busy; |
f0c0a376 MC |
1372 | |
1373 | if (starget->single_lun) { | |
7ae65c0f | 1374 | spin_lock_irq(shost->host_lock); |
f0c0a376 | 1375 | if (starget->starget_sdev_user && |
7ae65c0f CH |
1376 | starget->starget_sdev_user != sdev) { |
1377 | spin_unlock_irq(shost->host_lock); | |
1378 | return 0; | |
1379 | } | |
f0c0a376 | 1380 | starget->starget_sdev_user = sdev; |
7ae65c0f | 1381 | spin_unlock_irq(shost->host_lock); |
f0c0a376 MC |
1382 | } |
1383 | ||
2ccbb008 CH |
1384 | if (starget->can_queue <= 0) |
1385 | return 1; | |
1386 | ||
7ae65c0f | 1387 | busy = atomic_inc_return(&starget->target_busy) - 1; |
cd9070c9 | 1388 | if (atomic_read(&starget->target_blocked) > 0) { |
7ae65c0f CH |
1389 | if (busy) |
1390 | goto starved; | |
1391 | ||
f0c0a376 MC |
1392 | /* |
1393 | * unblock after target_blocked iterates to zero | |
1394 | */ | |
cd9070c9 | 1395 | if (atomic_dec_return(&starget->target_blocked) > 0) |
7ae65c0f | 1396 | goto out_dec; |
cf68d334 CH |
1397 | |
1398 | SCSI_LOG_MLQUEUE(3, starget_printk(KERN_INFO, starget, | |
1399 | "unblocking target at zero depth\n")); | |
f0c0a376 MC |
1400 | } |
1401 | ||
2ccbb008 | 1402 | if (busy >= starget->can_queue) |
7ae65c0f | 1403 | goto starved; |
f0c0a376 | 1404 | |
7ae65c0f CH |
1405 | return 1; |
1406 | ||
1407 | starved: | |
1408 | spin_lock_irq(shost->host_lock); | |
1409 | list_move_tail(&sdev->starved_entry, &shost->starved_list); | |
cf68d334 | 1410 | spin_unlock_irq(shost->host_lock); |
7ae65c0f | 1411 | out_dec: |
2ccbb008 CH |
1412 | if (starget->can_queue > 0) |
1413 | atomic_dec(&starget->target_busy); | |
7ae65c0f | 1414 | return 0; |
f0c0a376 MC |
1415 | } |
1416 | ||
1da177e4 LT |
1417 | /* |
1418 | * scsi_host_queue_ready: if we can send requests to shost, return 1 else | |
1419 | * return 0. We must end up running the queue again whenever 0 is | |
1420 | * returned, else IO can hang. | |
1da177e4 LT |
1421 | */ |
1422 | static inline int scsi_host_queue_ready(struct request_queue *q, | |
1423 | struct Scsi_Host *shost, | |
1424 | struct scsi_device *sdev) | |
1425 | { | |
74665016 | 1426 | unsigned int busy; |
cf68d334 | 1427 | |
939647ee | 1428 | if (scsi_host_in_recovery(shost)) |
74665016 CH |
1429 | return 0; |
1430 | ||
1431 | busy = atomic_inc_return(&shost->host_busy) - 1; | |
cd9070c9 | 1432 | if (atomic_read(&shost->host_blocked) > 0) { |
74665016 CH |
1433 | if (busy) |
1434 | goto starved; | |
1435 | ||
1da177e4 LT |
1436 | /* |
1437 | * unblock after host_blocked iterates to zero | |
1438 | */ | |
cd9070c9 | 1439 | if (atomic_dec_return(&shost->host_blocked) > 0) |
74665016 | 1440 | goto out_dec; |
cf68d334 CH |
1441 | |
1442 | SCSI_LOG_MLQUEUE(3, | |
1443 | shost_printk(KERN_INFO, shost, | |
1444 | "unblocking host at zero depth\n")); | |
1da177e4 | 1445 | } |
74665016 CH |
1446 | |
1447 | if (shost->can_queue > 0 && busy >= shost->can_queue) | |
1448 | goto starved; | |
1449 | if (shost->host_self_blocked) | |
1450 | goto starved; | |
1da177e4 LT |
1451 | |
1452 | /* We're OK to process the command, so we can't be starved */ | |
74665016 CH |
1453 | if (!list_empty(&sdev->starved_entry)) { |
1454 | spin_lock_irq(shost->host_lock); | |
1455 | if (!list_empty(&sdev->starved_entry)) | |
1456 | list_del_init(&sdev->starved_entry); | |
1457 | spin_unlock_irq(shost->host_lock); | |
1458 | } | |
1da177e4 | 1459 | |
74665016 CH |
1460 | return 1; |
1461 | ||
1462 | starved: | |
1463 | spin_lock_irq(shost->host_lock); | |
1464 | if (list_empty(&sdev->starved_entry)) | |
1465 | list_add_tail(&sdev->starved_entry, &shost->starved_list); | |
cf68d334 | 1466 | spin_unlock_irq(shost->host_lock); |
74665016 CH |
1467 | out_dec: |
1468 | atomic_dec(&shost->host_busy); | |
1469 | return 0; | |
1da177e4 LT |
1470 | } |
1471 | ||
6c5121b7 KU |
1472 | /* |
1473 | * Busy state exporting function for request stacking drivers. | |
1474 | * | |
1475 | * For efficiency, no lock is taken to check the busy state of | |
1476 | * shost/starget/sdev, since the returned value is not guaranteed and | |
1477 | * may be changed after request stacking drivers call the function, | |
1478 | * regardless of taking lock or not. | |
1479 | * | |
67bd9413 BVA |
1480 | * When scsi can't dispatch I/Os anymore and needs to kill I/Os scsi |
1481 | * needs to return 'not busy'. Otherwise, request stacking drivers | |
1482 | * may hold requests forever. | |
6c5121b7 KU |
1483 | */ |
1484 | static int scsi_lld_busy(struct request_queue *q) | |
1485 | { | |
1486 | struct scsi_device *sdev = q->queuedata; | |
1487 | struct Scsi_Host *shost; | |
6c5121b7 | 1488 | |
3f3299d5 | 1489 | if (blk_queue_dying(q)) |
6c5121b7 KU |
1490 | return 0; |
1491 | ||
1492 | shost = sdev->host; | |
6c5121b7 | 1493 | |
b7e94a16 JN |
1494 | /* |
1495 | * Ignore host/starget busy state. | |
1496 | * Since block layer does not have a concept of fairness across | |
1497 | * multiple queues, congestion of host/starget needs to be handled | |
1498 | * in SCSI layer. | |
1499 | */ | |
1500 | if (scsi_host_in_recovery(shost) || scsi_device_is_busy(sdev)) | |
6c5121b7 KU |
1501 | return 1; |
1502 | ||
1503 | return 0; | |
1504 | } | |
1505 | ||
1da177e4 | 1506 | /* |
e91442b6 | 1507 | * Kill a request for a dead device |
1da177e4 | 1508 | */ |
165125e1 | 1509 | static void scsi_kill_request(struct request *req, struct request_queue *q) |
1da177e4 | 1510 | { |
e91442b6 | 1511 | struct scsi_cmnd *cmd = req->special; |
03b14708 JS |
1512 | struct scsi_device *sdev; |
1513 | struct scsi_target *starget; | |
1514 | struct Scsi_Host *shost; | |
1da177e4 | 1515 | |
9934c8c0 | 1516 | blk_start_request(req); |
788ce43a | 1517 | |
74571813 HR |
1518 | scmd_printk(KERN_INFO, cmd, "killing request\n"); |
1519 | ||
03b14708 JS |
1520 | sdev = cmd->device; |
1521 | starget = scsi_target(sdev); | |
1522 | shost = sdev->host; | |
e91442b6 JB |
1523 | scsi_init_cmd_errh(cmd); |
1524 | cmd->result = DID_NO_CONNECT << 16; | |
1525 | atomic_inc(&cmd->device->iorequest_cnt); | |
e36e0c80 TH |
1526 | |
1527 | /* | |
1528 | * SCSI request completion path will do scsi_device_unbusy(), | |
1529 | * bump busy counts. To bump the counters, we need to dance | |
1530 | * with the locks as normal issue path does. | |
1531 | */ | |
71e75c97 | 1532 | atomic_inc(&sdev->device_busy); |
74665016 | 1533 | atomic_inc(&shost->host_busy); |
2ccbb008 CH |
1534 | if (starget->can_queue > 0) |
1535 | atomic_inc(&starget->target_busy); | |
e36e0c80 | 1536 | |
242f9dcb | 1537 | blk_complete_request(req); |
1da177e4 LT |
1538 | } |
1539 | ||
1aea6434 JA |
1540 | static void scsi_softirq_done(struct request *rq) |
1541 | { | |
242f9dcb JA |
1542 | struct scsi_cmnd *cmd = rq->special; |
1543 | unsigned long wait_for = (cmd->allowed + 1) * rq->timeout; | |
1aea6434 JA |
1544 | int disposition; |
1545 | ||
1546 | INIT_LIST_HEAD(&cmd->eh_entry); | |
1547 | ||
242f9dcb JA |
1548 | atomic_inc(&cmd->device->iodone_cnt); |
1549 | if (cmd->result) | |
1550 | atomic_inc(&cmd->device->ioerr_cnt); | |
1551 | ||
1aea6434 JA |
1552 | disposition = scsi_decide_disposition(cmd); |
1553 | if (disposition != SUCCESS && | |
1554 | time_before(cmd->jiffies_at_alloc + wait_for, jiffies)) { | |
1555 | sdev_printk(KERN_ERR, cmd->device, | |
1556 | "timing out command, waited %lus\n", | |
1557 | wait_for/HZ); | |
1558 | disposition = SUCCESS; | |
1559 | } | |
91921e01 | 1560 | |
1aea6434 JA |
1561 | scsi_log_completion(cmd, disposition); |
1562 | ||
1563 | switch (disposition) { | |
1564 | case SUCCESS: | |
1565 | scsi_finish_command(cmd); | |
1566 | break; | |
1567 | case NEEDS_RETRY: | |
596f482a | 1568 | scsi_queue_insert(cmd, SCSI_MLQUEUE_EH_RETRY); |
1aea6434 JA |
1569 | break; |
1570 | case ADD_TO_MLQUEUE: | |
1571 | scsi_queue_insert(cmd, SCSI_MLQUEUE_DEVICE_BUSY); | |
1572 | break; | |
1573 | default: | |
1574 | if (!scsi_eh_scmd_add(cmd, 0)) | |
1575 | scsi_finish_command(cmd); | |
1576 | } | |
1577 | } | |
1578 | ||
82042a2c CH |
1579 | /** |
1580 | * scsi_dispatch_command - Dispatch a command to the low-level driver. | |
1581 | * @cmd: command block we are dispatching. | |
1582 | * | |
1583 | * Return: nonzero return request was rejected and device's queue needs to be | |
1584 | * plugged. | |
1585 | */ | |
1586 | static int scsi_dispatch_cmd(struct scsi_cmnd *cmd) | |
1587 | { | |
1588 | struct Scsi_Host *host = cmd->device->host; | |
1589 | int rtn = 0; | |
1590 | ||
1591 | atomic_inc(&cmd->device->iorequest_cnt); | |
1592 | ||
1593 | /* check if the device is still usable */ | |
1594 | if (unlikely(cmd->device->sdev_state == SDEV_DEL)) { | |
1595 | /* in SDEV_DEL we error all commands. DID_NO_CONNECT | |
1596 | * returns an immediate error upwards, and signals | |
1597 | * that the device is no longer present */ | |
1598 | cmd->result = DID_NO_CONNECT << 16; | |
1599 | goto done; | |
1600 | } | |
1601 | ||
1602 | /* Check to see if the scsi lld made this device blocked. */ | |
1603 | if (unlikely(scsi_device_blocked(cmd->device))) { | |
1604 | /* | |
1605 | * in blocked state, the command is just put back on | |
1606 | * the device queue. The suspend state has already | |
1607 | * blocked the queue so future requests should not | |
1608 | * occur until the device transitions out of the | |
1609 | * suspend state. | |
1610 | */ | |
1611 | SCSI_LOG_MLQUEUE(3, scmd_printk(KERN_INFO, cmd, | |
1612 | "queuecommand : device blocked\n")); | |
1613 | return SCSI_MLQUEUE_DEVICE_BUSY; | |
1614 | } | |
1615 | ||
1616 | /* Store the LUN value in cmnd, if needed. */ | |
1617 | if (cmd->device->lun_in_cdb) | |
1618 | cmd->cmnd[1] = (cmd->cmnd[1] & 0x1f) | | |
1619 | (cmd->device->lun << 5 & 0xe0); | |
1620 | ||
1621 | scsi_log_send(cmd); | |
1622 | ||
1623 | /* | |
1624 | * Before we queue this command, check if the command | |
1625 | * length exceeds what the host adapter can handle. | |
1626 | */ | |
1627 | if (cmd->cmd_len > cmd->device->host->max_cmd_len) { | |
1628 | SCSI_LOG_MLQUEUE(3, scmd_printk(KERN_INFO, cmd, | |
1629 | "queuecommand : command too long. " | |
1630 | "cdb_size=%d host->max_cmd_len=%d\n", | |
1631 | cmd->cmd_len, cmd->device->host->max_cmd_len)); | |
1632 | cmd->result = (DID_ABORT << 16); | |
1633 | goto done; | |
1634 | } | |
1635 | ||
1636 | if (unlikely(host->shost_state == SHOST_DEL)) { | |
1637 | cmd->result = (DID_NO_CONNECT << 16); | |
1638 | goto done; | |
1639 | ||
1640 | } | |
1641 | ||
1642 | trace_scsi_dispatch_cmd_start(cmd); | |
1643 | rtn = host->hostt->queuecommand(host, cmd); | |
1644 | if (rtn) { | |
1645 | trace_scsi_dispatch_cmd_error(cmd, rtn); | |
1646 | if (rtn != SCSI_MLQUEUE_DEVICE_BUSY && | |
1647 | rtn != SCSI_MLQUEUE_TARGET_BUSY) | |
1648 | rtn = SCSI_MLQUEUE_HOST_BUSY; | |
1649 | ||
1650 | SCSI_LOG_MLQUEUE(3, scmd_printk(KERN_INFO, cmd, | |
1651 | "queuecommand : request rejected\n")); | |
1652 | } | |
1653 | ||
1654 | return rtn; | |
1655 | done: | |
1656 | cmd->scsi_done(cmd); | |
1657 | return 0; | |
1658 | } | |
1659 | ||
3b5382c4 CH |
1660 | /** |
1661 | * scsi_done - Invoke completion on finished SCSI command. | |
1662 | * @cmd: The SCSI Command for which a low-level device driver (LLDD) gives | |
1663 | * ownership back to SCSI Core -- i.e. the LLDD has finished with it. | |
1664 | * | |
1665 | * Description: This function is the mid-level's (SCSI Core) interrupt routine, | |
1666 | * which regains ownership of the SCSI command (de facto) from a LLDD, and | |
1667 | * calls blk_complete_request() for further processing. | |
1668 | * | |
1669 | * This function is interrupt context safe. | |
1670 | */ | |
1671 | static void scsi_done(struct scsi_cmnd *cmd) | |
1672 | { | |
1673 | trace_scsi_dispatch_cmd_done(cmd); | |
1674 | blk_complete_request(cmd->request); | |
1675 | } | |
1676 | ||
1da177e4 LT |
1677 | /* |
1678 | * Function: scsi_request_fn() | |
1679 | * | |
1680 | * Purpose: Main strategy routine for SCSI. | |
1681 | * | |
1682 | * Arguments: q - Pointer to actual queue. | |
1683 | * | |
1684 | * Returns: Nothing | |
1685 | * | |
1686 | * Lock status: IO request lock assumed to be held when called. | |
1687 | */ | |
1688 | static void scsi_request_fn(struct request_queue *q) | |
613be1f6 BVA |
1689 | __releases(q->queue_lock) |
1690 | __acquires(q->queue_lock) | |
1da177e4 LT |
1691 | { |
1692 | struct scsi_device *sdev = q->queuedata; | |
1693 | struct Scsi_Host *shost; | |
1694 | struct scsi_cmnd *cmd; | |
1695 | struct request *req; | |
1696 | ||
1da177e4 LT |
1697 | /* |
1698 | * To start with, we keep looping until the queue is empty, or until | |
1699 | * the host is no longer able to accept any more requests. | |
1700 | */ | |
1701 | shost = sdev->host; | |
a488e749 | 1702 | for (;;) { |
1da177e4 LT |
1703 | int rtn; |
1704 | /* | |
1705 | * get next queueable request. We do this early to make sure | |
91921e01 | 1706 | * that the request is fully prepared even if we cannot |
1da177e4 LT |
1707 | * accept it. |
1708 | */ | |
9934c8c0 | 1709 | req = blk_peek_request(q); |
71e75c97 | 1710 | if (!req) |
1da177e4 LT |
1711 | break; |
1712 | ||
1713 | if (unlikely(!scsi_device_online(sdev))) { | |
9ccfc756 JB |
1714 | sdev_printk(KERN_ERR, sdev, |
1715 | "rejecting I/O to offline device\n"); | |
e91442b6 | 1716 | scsi_kill_request(req, q); |
1da177e4 LT |
1717 | continue; |
1718 | } | |
1719 | ||
71e75c97 CH |
1720 | if (!scsi_dev_queue_ready(q, sdev)) |
1721 | break; | |
1da177e4 LT |
1722 | |
1723 | /* | |
1724 | * Remove the request from the request list. | |
1725 | */ | |
1726 | if (!(blk_queue_tagged(q) && !blk_queue_start_tag(q, req))) | |
9934c8c0 | 1727 | blk_start_request(req); |
1da177e4 | 1728 | |
cf68d334 | 1729 | spin_unlock_irq(q->queue_lock); |
e91442b6 JB |
1730 | cmd = req->special; |
1731 | if (unlikely(cmd == NULL)) { | |
1732 | printk(KERN_CRIT "impossible request in %s.\n" | |
1733 | "please mail a stack trace to " | |
4aff5e23 | 1734 | "linux-scsi@vger.kernel.org\n", |
cadbd4a5 | 1735 | __func__); |
4aff5e23 | 1736 | blk_dump_rq_flags(req, "foo"); |
e91442b6 JB |
1737 | BUG(); |
1738 | } | |
1da177e4 | 1739 | |
ecefe8a9 MC |
1740 | /* |
1741 | * We hit this when the driver is using a host wide | |
1742 | * tag map. For device level tag maps the queue_depth check | |
1743 | * in the device ready fn would prevent us from trying | |
1744 | * to allocate a tag. Since the map is a shared host resource | |
1745 | * we add the dev to the starved list so it eventually gets | |
1746 | * a run when a tag is freed. | |
1747 | */ | |
e8064021 | 1748 | if (blk_queue_tagged(q) && !(req->rq_flags & RQF_QUEUED)) { |
cf68d334 | 1749 | spin_lock_irq(shost->host_lock); |
ecefe8a9 MC |
1750 | if (list_empty(&sdev->starved_entry)) |
1751 | list_add_tail(&sdev->starved_entry, | |
1752 | &shost->starved_list); | |
cf68d334 | 1753 | spin_unlock_irq(shost->host_lock); |
ecefe8a9 MC |
1754 | goto not_ready; |
1755 | } | |
1756 | ||
f0c0a376 MC |
1757 | if (!scsi_target_queue_ready(shost, sdev)) |
1758 | goto not_ready; | |
1759 | ||
1da177e4 | 1760 | if (!scsi_host_queue_ready(q, shost, sdev)) |
cf68d334 | 1761 | goto host_not_ready; |
125c99bc CH |
1762 | |
1763 | if (sdev->simple_tags) | |
1764 | cmd->flags |= SCMD_TAGGED; | |
1765 | else | |
1766 | cmd->flags &= ~SCMD_TAGGED; | |
1da177e4 | 1767 | |
1da177e4 LT |
1768 | /* |
1769 | * Finally, initialize any error handling parameters, and set up | |
1770 | * the timers for timeouts. | |
1771 | */ | |
1772 | scsi_init_cmd_errh(cmd); | |
1773 | ||
1774 | /* | |
1775 | * Dispatch the command to the low-level driver. | |
1776 | */ | |
3b5382c4 | 1777 | cmd->scsi_done = scsi_done; |
1da177e4 | 1778 | rtn = scsi_dispatch_cmd(cmd); |
d0d3bbf9 CH |
1779 | if (rtn) { |
1780 | scsi_queue_insert(cmd, rtn); | |
1781 | spin_lock_irq(q->queue_lock); | |
a488e749 | 1782 | goto out_delay; |
d0d3bbf9 CH |
1783 | } |
1784 | spin_lock_irq(q->queue_lock); | |
1da177e4 LT |
1785 | } |
1786 | ||
613be1f6 | 1787 | return; |
1da177e4 | 1788 | |
cf68d334 | 1789 | host_not_ready: |
2ccbb008 CH |
1790 | if (scsi_target(sdev)->can_queue > 0) |
1791 | atomic_dec(&scsi_target(sdev)->target_busy); | |
cf68d334 | 1792 | not_ready: |
1da177e4 LT |
1793 | /* |
1794 | * lock q, handle tag, requeue req, and decrement device_busy. We | |
1795 | * must return with queue_lock held. | |
1796 | * | |
1797 | * Decrementing device_busy without checking it is OK, as all such | |
1798 | * cases (host limits or settings) should run the queue at some | |
1799 | * later time. | |
1800 | */ | |
1801 | spin_lock_irq(q->queue_lock); | |
1802 | blk_requeue_request(q, req); | |
71e75c97 | 1803 | atomic_dec(&sdev->device_busy); |
a488e749 | 1804 | out_delay: |
480cadc2 | 1805 | if (!atomic_read(&sdev->device_busy) && !scsi_device_blocked(sdev)) |
a488e749 | 1806 | blk_delay_queue(q, SCSI_QUEUE_DELAY); |
1da177e4 LT |
1807 | } |
1808 | ||
d285203c CH |
1809 | static inline int prep_to_mq(int ret) |
1810 | { | |
1811 | switch (ret) { | |
1812 | case BLKPREP_OK: | |
1813 | return 0; | |
1814 | case BLKPREP_DEFER: | |
1815 | return BLK_MQ_RQ_QUEUE_BUSY; | |
1816 | default: | |
1817 | return BLK_MQ_RQ_QUEUE_ERROR; | |
1818 | } | |
1819 | } | |
1820 | ||
1821 | static int scsi_mq_prep_fn(struct request *req) | |
1822 | { | |
1823 | struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req); | |
1824 | struct scsi_device *sdev = req->q->queuedata; | |
1825 | struct Scsi_Host *shost = sdev->host; | |
1826 | unsigned char *sense_buf = cmd->sense_buffer; | |
1827 | struct scatterlist *sg; | |
1828 | ||
1829 | memset(cmd, 0, sizeof(struct scsi_cmnd)); | |
1830 | ||
1831 | req->special = cmd; | |
1832 | ||
1833 | cmd->request = req; | |
1834 | cmd->device = sdev; | |
1835 | cmd->sense_buffer = sense_buf; | |
1836 | ||
1837 | cmd->tag = req->tag; | |
1838 | ||
d285203c CH |
1839 | cmd->cmnd = req->cmd; |
1840 | cmd->prot_op = SCSI_PROT_NORMAL; | |
1841 | ||
1842 | INIT_LIST_HEAD(&cmd->list); | |
1843 | INIT_DELAYED_WORK(&cmd->abort_work, scmd_eh_abort_handler); | |
1844 | cmd->jiffies_at_alloc = jiffies; | |
1845 | ||
64bdcbc4 KD |
1846 | if (shost->use_cmd_list) { |
1847 | spin_lock_irq(&sdev->list_lock); | |
1848 | list_add_tail(&cmd->list, &sdev->cmd_list); | |
1849 | spin_unlock_irq(&sdev->list_lock); | |
1850 | } | |
d285203c CH |
1851 | |
1852 | sg = (void *)cmd + sizeof(struct scsi_cmnd) + shost->hostt->cmd_size; | |
1853 | cmd->sdb.table.sgl = sg; | |
1854 | ||
1855 | if (scsi_host_get_prot(shost)) { | |
1856 | cmd->prot_sdb = (void *)sg + | |
120bb3e1 | 1857 | min_t(unsigned int, |
65e8617f | 1858 | shost->sg_tablesize, SG_CHUNK_SIZE) * |
120bb3e1 | 1859 | sizeof(struct scatterlist); |
d285203c CH |
1860 | memset(cmd->prot_sdb, 0, sizeof(struct scsi_data_buffer)); |
1861 | ||
1862 | cmd->prot_sdb->table.sgl = | |
1863 | (struct scatterlist *)(cmd->prot_sdb + 1); | |
1864 | } | |
1865 | ||
1866 | if (blk_bidi_rq(req)) { | |
1867 | struct request *next_rq = req->next_rq; | |
1868 | struct scsi_data_buffer *bidi_sdb = blk_mq_rq_to_pdu(next_rq); | |
1869 | ||
1870 | memset(bidi_sdb, 0, sizeof(struct scsi_data_buffer)); | |
1871 | bidi_sdb->table.sgl = | |
1872 | (struct scatterlist *)(bidi_sdb + 1); | |
1873 | ||
1874 | next_rq->special = bidi_sdb; | |
1875 | } | |
1876 | ||
fe052529 CH |
1877 | blk_mq_start_request(req); |
1878 | ||
d285203c CH |
1879 | return scsi_setup_cmnd(sdev, req); |
1880 | } | |
1881 | ||
1882 | static void scsi_mq_done(struct scsi_cmnd *cmd) | |
1883 | { | |
1884 | trace_scsi_dispatch_cmd_done(cmd); | |
f4829a9b | 1885 | blk_mq_complete_request(cmd->request, cmd->request->errors); |
d285203c CH |
1886 | } |
1887 | ||
74c45052 JA |
1888 | static int scsi_queue_rq(struct blk_mq_hw_ctx *hctx, |
1889 | const struct blk_mq_queue_data *bd) | |
d285203c | 1890 | { |
74c45052 | 1891 | struct request *req = bd->rq; |
d285203c CH |
1892 | struct request_queue *q = req->q; |
1893 | struct scsi_device *sdev = q->queuedata; | |
1894 | struct Scsi_Host *shost = sdev->host; | |
1895 | struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req); | |
1896 | int ret; | |
1897 | int reason; | |
1898 | ||
1899 | ret = prep_to_mq(scsi_prep_state_check(sdev, req)); | |
1900 | if (ret) | |
1901 | goto out; | |
1902 | ||
1903 | ret = BLK_MQ_RQ_QUEUE_BUSY; | |
1904 | if (!get_device(&sdev->sdev_gendev)) | |
1905 | goto out; | |
1906 | ||
1907 | if (!scsi_dev_queue_ready(q, sdev)) | |
1908 | goto out_put_device; | |
1909 | if (!scsi_target_queue_ready(shost, sdev)) | |
1910 | goto out_dec_device_busy; | |
1911 | if (!scsi_host_queue_ready(q, shost, sdev)) | |
1912 | goto out_dec_target_busy; | |
1913 | ||
fe052529 | 1914 | |
e8064021 | 1915 | if (!(req->rq_flags & RQF_DONTPREP)) { |
d285203c CH |
1916 | ret = prep_to_mq(scsi_mq_prep_fn(req)); |
1917 | if (ret) | |
1918 | goto out_dec_host_busy; | |
e8064021 | 1919 | req->rq_flags |= RQF_DONTPREP; |
fe052529 CH |
1920 | } else { |
1921 | blk_mq_start_request(req); | |
d285203c CH |
1922 | } |
1923 | ||
125c99bc CH |
1924 | if (sdev->simple_tags) |
1925 | cmd->flags |= SCMD_TAGGED; | |
b1dd2aac | 1926 | else |
125c99bc | 1927 | cmd->flags &= ~SCMD_TAGGED; |
b1dd2aac | 1928 | |
d285203c CH |
1929 | scsi_init_cmd_errh(cmd); |
1930 | cmd->scsi_done = scsi_mq_done; | |
1931 | ||
1932 | reason = scsi_dispatch_cmd(cmd); | |
1933 | if (reason) { | |
1934 | scsi_set_blocked(cmd, reason); | |
1935 | ret = BLK_MQ_RQ_QUEUE_BUSY; | |
1936 | goto out_dec_host_busy; | |
1937 | } | |
1938 | ||
1939 | return BLK_MQ_RQ_QUEUE_OK; | |
1940 | ||
1941 | out_dec_host_busy: | |
1942 | atomic_dec(&shost->host_busy); | |
1943 | out_dec_target_busy: | |
1944 | if (scsi_target(sdev)->can_queue > 0) | |
1945 | atomic_dec(&scsi_target(sdev)->target_busy); | |
1946 | out_dec_device_busy: | |
1947 | atomic_dec(&sdev->device_busy); | |
1948 | out_put_device: | |
1949 | put_device(&sdev->sdev_gendev); | |
1950 | out: | |
1951 | switch (ret) { | |
1952 | case BLK_MQ_RQ_QUEUE_BUSY: | |
d285203c CH |
1953 | if (atomic_read(&sdev->device_busy) == 0 && |
1954 | !scsi_device_blocked(sdev)) | |
1955 | blk_mq_delay_queue(hctx, SCSI_QUEUE_DELAY); | |
1956 | break; | |
1957 | case BLK_MQ_RQ_QUEUE_ERROR: | |
1958 | /* | |
1959 | * Make sure to release all allocated ressources when | |
1960 | * we hit an error, as we will never see this command | |
1961 | * again. | |
1962 | */ | |
e8064021 | 1963 | if (req->rq_flags & RQF_DONTPREP) |
d285203c CH |
1964 | scsi_mq_uninit_cmd(cmd); |
1965 | break; | |
1966 | default: | |
1967 | break; | |
1968 | } | |
1969 | return ret; | |
1970 | } | |
1971 | ||
0152fb6b CH |
1972 | static enum blk_eh_timer_return scsi_timeout(struct request *req, |
1973 | bool reserved) | |
1974 | { | |
1975 | if (reserved) | |
1976 | return BLK_EH_RESET_TIMER; | |
1977 | return scsi_times_out(req); | |
1978 | } | |
1979 | ||
d285203c CH |
1980 | static int scsi_init_request(void *data, struct request *rq, |
1981 | unsigned int hctx_idx, unsigned int request_idx, | |
1982 | unsigned int numa_node) | |
1983 | { | |
1984 | struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq); | |
1985 | ||
1986 | cmd->sense_buffer = kzalloc_node(SCSI_SENSE_BUFFERSIZE, GFP_KERNEL, | |
1987 | numa_node); | |
1988 | if (!cmd->sense_buffer) | |
1989 | return -ENOMEM; | |
1990 | return 0; | |
1991 | } | |
1992 | ||
1993 | static void scsi_exit_request(void *data, struct request *rq, | |
1994 | unsigned int hctx_idx, unsigned int request_idx) | |
1995 | { | |
1996 | struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq); | |
1997 | ||
1998 | kfree(cmd->sense_buffer); | |
1999 | } | |
2000 | ||
f1bea55d | 2001 | static u64 scsi_calculate_bounce_limit(struct Scsi_Host *shost) |
1da177e4 LT |
2002 | { |
2003 | struct device *host_dev; | |
2004 | u64 bounce_limit = 0xffffffff; | |
2005 | ||
2006 | if (shost->unchecked_isa_dma) | |
2007 | return BLK_BOUNCE_ISA; | |
2008 | /* | |
2009 | * Platforms with virtual-DMA translation | |
2010 | * hardware have no practical limit. | |
2011 | */ | |
2012 | if (!PCI_DMA_BUS_IS_PHYS) | |
2013 | return BLK_BOUNCE_ANY; | |
2014 | ||
2015 | host_dev = scsi_get_device(shost); | |
2016 | if (host_dev && host_dev->dma_mask) | |
e83b3664 | 2017 | bounce_limit = (u64)dma_max_pfn(host_dev) << PAGE_SHIFT; |
1da177e4 LT |
2018 | |
2019 | return bounce_limit; | |
2020 | } | |
1da177e4 | 2021 | |
d285203c | 2022 | static void __scsi_init_queue(struct Scsi_Host *shost, struct request_queue *q) |
1da177e4 | 2023 | { |
6f381fa3 | 2024 | struct device *dev = shost->dma_dev; |
1da177e4 | 2025 | |
a8474ce2 JA |
2026 | /* |
2027 | * this limit is imposed by hardware restrictions | |
2028 | */ | |
8a78362c | 2029 | blk_queue_max_segments(q, min_t(unsigned short, shost->sg_tablesize, |
65e8617f | 2030 | SG_MAX_SEGMENTS)); |
a8474ce2 | 2031 | |
13f05c8d MP |
2032 | if (scsi_host_prot_dma(shost)) { |
2033 | shost->sg_prot_tablesize = | |
2034 | min_not_zero(shost->sg_prot_tablesize, | |
2035 | (unsigned short)SCSI_MAX_PROT_SG_SEGMENTS); | |
2036 | BUG_ON(shost->sg_prot_tablesize < shost->sg_tablesize); | |
2037 | blk_queue_max_integrity_segments(q, shost->sg_prot_tablesize); | |
2038 | } | |
2039 | ||
086fa5ff | 2040 | blk_queue_max_hw_sectors(q, shost->max_sectors); |
1da177e4 LT |
2041 | blk_queue_bounce_limit(q, scsi_calculate_bounce_limit(shost)); |
2042 | blk_queue_segment_boundary(q, shost->dma_boundary); | |
99c84dbd | 2043 | dma_set_seg_boundary(dev, shost->dma_boundary); |
1da177e4 | 2044 | |
860ac568 FT |
2045 | blk_queue_max_segment_size(q, dma_get_max_seg_size(dev)); |
2046 | ||
1da177e4 | 2047 | if (!shost->use_clustering) |
e692cb66 | 2048 | q->limits.cluster = 0; |
465ff318 JB |
2049 | |
2050 | /* | |
2051 | * set a reasonable default alignment on word boundaries: the | |
2052 | * host and device may alter it using | |
2053 | * blk_queue_update_dma_alignment() later. | |
2054 | */ | |
2055 | blk_queue_dma_alignment(q, 0x03); | |
d285203c | 2056 | } |
465ff318 | 2057 | |
d285203c CH |
2058 | struct request_queue *__scsi_alloc_queue(struct Scsi_Host *shost, |
2059 | request_fn_proc *request_fn) | |
2060 | { | |
2061 | struct request_queue *q; | |
2062 | ||
2063 | q = blk_init_queue(request_fn, NULL); | |
2064 | if (!q) | |
2065 | return NULL; | |
2066 | __scsi_init_queue(shost, q); | |
1da177e4 LT |
2067 | return q; |
2068 | } | |
b58d9154 FT |
2069 | EXPORT_SYMBOL(__scsi_alloc_queue); |
2070 | ||
2071 | struct request_queue *scsi_alloc_queue(struct scsi_device *sdev) | |
2072 | { | |
2073 | struct request_queue *q; | |
2074 | ||
2075 | q = __scsi_alloc_queue(sdev->host, scsi_request_fn); | |
2076 | if (!q) | |
2077 | return NULL; | |
2078 | ||
2079 | blk_queue_prep_rq(q, scsi_prep_fn); | |
a1b73fc1 | 2080 | blk_queue_unprep_rq(q, scsi_unprep_fn); |
b58d9154 | 2081 | blk_queue_softirq_done(q, scsi_softirq_done); |
242f9dcb | 2082 | blk_queue_rq_timed_out(q, scsi_times_out); |
6c5121b7 | 2083 | blk_queue_lld_busy(q, scsi_lld_busy); |
b58d9154 FT |
2084 | return q; |
2085 | } | |
1da177e4 | 2086 | |
d285203c | 2087 | static struct blk_mq_ops scsi_mq_ops = { |
d285203c CH |
2088 | .queue_rq = scsi_queue_rq, |
2089 | .complete = scsi_softirq_done, | |
0152fb6b | 2090 | .timeout = scsi_timeout, |
d285203c CH |
2091 | .init_request = scsi_init_request, |
2092 | .exit_request = scsi_exit_request, | |
2093 | }; | |
2094 | ||
2095 | struct request_queue *scsi_mq_alloc_queue(struct scsi_device *sdev) | |
2096 | { | |
2097 | sdev->request_queue = blk_mq_init_queue(&sdev->host->tag_set); | |
2098 | if (IS_ERR(sdev->request_queue)) | |
2099 | return NULL; | |
2100 | ||
2101 | sdev->request_queue->queuedata = sdev; | |
2102 | __scsi_init_queue(sdev->host, sdev->request_queue); | |
2103 | return sdev->request_queue; | |
2104 | } | |
2105 | ||
2106 | int scsi_mq_setup_tags(struct Scsi_Host *shost) | |
2107 | { | |
2108 | unsigned int cmd_size, sgl_size, tbl_size; | |
2109 | ||
2110 | tbl_size = shost->sg_tablesize; | |
65e8617f ML |
2111 | if (tbl_size > SG_CHUNK_SIZE) |
2112 | tbl_size = SG_CHUNK_SIZE; | |
d285203c CH |
2113 | sgl_size = tbl_size * sizeof(struct scatterlist); |
2114 | cmd_size = sizeof(struct scsi_cmnd) + shost->hostt->cmd_size + sgl_size; | |
2115 | if (scsi_host_get_prot(shost)) | |
2116 | cmd_size += sizeof(struct scsi_data_buffer) + sgl_size; | |
2117 | ||
2118 | memset(&shost->tag_set, 0, sizeof(shost->tag_set)); | |
2119 | shost->tag_set.ops = &scsi_mq_ops; | |
efec4b90 | 2120 | shost->tag_set.nr_hw_queues = shost->nr_hw_queues ? : 1; |
d285203c CH |
2121 | shost->tag_set.queue_depth = shost->can_queue; |
2122 | shost->tag_set.cmd_size = cmd_size; | |
2123 | shost->tag_set.numa_node = NUMA_NO_NODE; | |
2124 | shost->tag_set.flags = BLK_MQ_F_SHOULD_MERGE | BLK_MQ_F_SG_MERGE; | |
24391c0d SL |
2125 | shost->tag_set.flags |= |
2126 | BLK_ALLOC_POLICY_TO_MQ_FLAG(shost->hostt->tag_alloc_policy); | |
d285203c CH |
2127 | shost->tag_set.driver_data = shost; |
2128 | ||
2129 | return blk_mq_alloc_tag_set(&shost->tag_set); | |
2130 | } | |
2131 | ||
2132 | void scsi_mq_destroy_tags(struct Scsi_Host *shost) | |
2133 | { | |
2134 | blk_mq_free_tag_set(&shost->tag_set); | |
2135 | } | |
2136 | ||
1da177e4 LT |
2137 | /* |
2138 | * Function: scsi_block_requests() | |
2139 | * | |
2140 | * Purpose: Utility function used by low-level drivers to prevent further | |
2141 | * commands from being queued to the device. | |
2142 | * | |
2143 | * Arguments: shost - Host in question | |
2144 | * | |
2145 | * Returns: Nothing | |
2146 | * | |
2147 | * Lock status: No locks are assumed held. | |
2148 | * | |
2149 | * Notes: There is no timer nor any other means by which the requests | |
2150 | * get unblocked other than the low-level driver calling | |
2151 | * scsi_unblock_requests(). | |
2152 | */ | |
2153 | void scsi_block_requests(struct Scsi_Host *shost) | |
2154 | { | |
2155 | shost->host_self_blocked = 1; | |
2156 | } | |
2157 | EXPORT_SYMBOL(scsi_block_requests); | |
2158 | ||
2159 | /* | |
2160 | * Function: scsi_unblock_requests() | |
2161 | * | |
2162 | * Purpose: Utility function used by low-level drivers to allow further | |
2163 | * commands from being queued to the device. | |
2164 | * | |
2165 | * Arguments: shost - Host in question | |
2166 | * | |
2167 | * Returns: Nothing | |
2168 | * | |
2169 | * Lock status: No locks are assumed held. | |
2170 | * | |
2171 | * Notes: There is no timer nor any other means by which the requests | |
2172 | * get unblocked other than the low-level driver calling | |
2173 | * scsi_unblock_requests(). | |
2174 | * | |
2175 | * This is done as an API function so that changes to the | |
2176 | * internals of the scsi mid-layer won't require wholesale | |
2177 | * changes to drivers that use this feature. | |
2178 | */ | |
2179 | void scsi_unblock_requests(struct Scsi_Host *shost) | |
2180 | { | |
2181 | shost->host_self_blocked = 0; | |
2182 | scsi_run_host_queues(shost); | |
2183 | } | |
2184 | EXPORT_SYMBOL(scsi_unblock_requests); | |
2185 | ||
2186 | int __init scsi_init_queue(void) | |
2187 | { | |
6362abd3 MP |
2188 | scsi_sdb_cache = kmem_cache_create("scsi_data_buffer", |
2189 | sizeof(struct scsi_data_buffer), | |
2190 | 0, 0, NULL); | |
2191 | if (!scsi_sdb_cache) { | |
2192 | printk(KERN_ERR "SCSI: can't init scsi sdb cache\n"); | |
f078727b | 2193 | return -ENOMEM; |
6f9a35e2 BH |
2194 | } |
2195 | ||
1da177e4 LT |
2196 | return 0; |
2197 | } | |
2198 | ||
2199 | void scsi_exit_queue(void) | |
2200 | { | |
6362abd3 | 2201 | kmem_cache_destroy(scsi_sdb_cache); |
1da177e4 | 2202 | } |
5baba830 JB |
2203 | |
2204 | /** | |
2205 | * scsi_mode_select - issue a mode select | |
2206 | * @sdev: SCSI device to be queried | |
2207 | * @pf: Page format bit (1 == standard, 0 == vendor specific) | |
2208 | * @sp: Save page bit (0 == don't save, 1 == save) | |
2209 | * @modepage: mode page being requested | |
2210 | * @buffer: request buffer (may not be smaller than eight bytes) | |
2211 | * @len: length of request buffer. | |
2212 | * @timeout: command timeout | |
2213 | * @retries: number of retries before failing | |
2214 | * @data: returns a structure abstracting the mode header data | |
eb44820c | 2215 | * @sshdr: place to put sense data (or NULL if no sense to be collected). |
5baba830 JB |
2216 | * must be SCSI_SENSE_BUFFERSIZE big. |
2217 | * | |
2218 | * Returns zero if successful; negative error number or scsi | |
2219 | * status on error | |
2220 | * | |
2221 | */ | |
2222 | int | |
2223 | scsi_mode_select(struct scsi_device *sdev, int pf, int sp, int modepage, | |
2224 | unsigned char *buffer, int len, int timeout, int retries, | |
2225 | struct scsi_mode_data *data, struct scsi_sense_hdr *sshdr) | |
2226 | { | |
2227 | unsigned char cmd[10]; | |
2228 | unsigned char *real_buffer; | |
2229 | int ret; | |
2230 | ||
2231 | memset(cmd, 0, sizeof(cmd)); | |
2232 | cmd[1] = (pf ? 0x10 : 0) | (sp ? 0x01 : 0); | |
2233 | ||
2234 | if (sdev->use_10_for_ms) { | |
2235 | if (len > 65535) | |
2236 | return -EINVAL; | |
2237 | real_buffer = kmalloc(8 + len, GFP_KERNEL); | |
2238 | if (!real_buffer) | |
2239 | return -ENOMEM; | |
2240 | memcpy(real_buffer + 8, buffer, len); | |
2241 | len += 8; | |
2242 | real_buffer[0] = 0; | |
2243 | real_buffer[1] = 0; | |
2244 | real_buffer[2] = data->medium_type; | |
2245 | real_buffer[3] = data->device_specific; | |
2246 | real_buffer[4] = data->longlba ? 0x01 : 0; | |
2247 | real_buffer[5] = 0; | |
2248 | real_buffer[6] = data->block_descriptor_length >> 8; | |
2249 | real_buffer[7] = data->block_descriptor_length; | |
2250 | ||
2251 | cmd[0] = MODE_SELECT_10; | |
2252 | cmd[7] = len >> 8; | |
2253 | cmd[8] = len; | |
2254 | } else { | |
2255 | if (len > 255 || data->block_descriptor_length > 255 || | |
2256 | data->longlba) | |
2257 | return -EINVAL; | |
2258 | ||
2259 | real_buffer = kmalloc(4 + len, GFP_KERNEL); | |
2260 | if (!real_buffer) | |
2261 | return -ENOMEM; | |
2262 | memcpy(real_buffer + 4, buffer, len); | |
2263 | len += 4; | |
2264 | real_buffer[0] = 0; | |
2265 | real_buffer[1] = data->medium_type; | |
2266 | real_buffer[2] = data->device_specific; | |
2267 | real_buffer[3] = data->block_descriptor_length; | |
2268 | ||
2269 | ||
2270 | cmd[0] = MODE_SELECT; | |
2271 | cmd[4] = len; | |
2272 | } | |
2273 | ||
2274 | ret = scsi_execute_req(sdev, cmd, DMA_TO_DEVICE, real_buffer, len, | |
f4f4e47e | 2275 | sshdr, timeout, retries, NULL); |
5baba830 JB |
2276 | kfree(real_buffer); |
2277 | return ret; | |
2278 | } | |
2279 | EXPORT_SYMBOL_GPL(scsi_mode_select); | |
2280 | ||
1da177e4 | 2281 | /** |
eb44820c | 2282 | * scsi_mode_sense - issue a mode sense, falling back from 10 to six bytes if necessary. |
1cf72699 | 2283 | * @sdev: SCSI device to be queried |
1da177e4 LT |
2284 | * @dbd: set if mode sense will allow block descriptors to be returned |
2285 | * @modepage: mode page being requested | |
2286 | * @buffer: request buffer (may not be smaller than eight bytes) | |
2287 | * @len: length of request buffer. | |
2288 | * @timeout: command timeout | |
2289 | * @retries: number of retries before failing | |
2290 | * @data: returns a structure abstracting the mode header data | |
eb44820c | 2291 | * @sshdr: place to put sense data (or NULL if no sense to be collected). |
1cf72699 | 2292 | * must be SCSI_SENSE_BUFFERSIZE big. |
1da177e4 LT |
2293 | * |
2294 | * Returns zero if unsuccessful, or the header offset (either 4 | |
2295 | * or 8 depending on whether a six or ten byte command was | |
2296 | * issued) if successful. | |
eb44820c | 2297 | */ |
1da177e4 | 2298 | int |
1cf72699 | 2299 | scsi_mode_sense(struct scsi_device *sdev, int dbd, int modepage, |
1da177e4 | 2300 | unsigned char *buffer, int len, int timeout, int retries, |
5baba830 JB |
2301 | struct scsi_mode_data *data, struct scsi_sense_hdr *sshdr) |
2302 | { | |
1da177e4 LT |
2303 | unsigned char cmd[12]; |
2304 | int use_10_for_ms; | |
2305 | int header_length; | |
0ae80ba9 | 2306 | int result, retry_count = retries; |
ea73a9f2 | 2307 | struct scsi_sense_hdr my_sshdr; |
1da177e4 LT |
2308 | |
2309 | memset(data, 0, sizeof(*data)); | |
2310 | memset(&cmd[0], 0, 12); | |
2311 | cmd[1] = dbd & 0x18; /* allows DBD and LLBA bits */ | |
2312 | cmd[2] = modepage; | |
2313 | ||
ea73a9f2 JB |
2314 | /* caller might not be interested in sense, but we need it */ |
2315 | if (!sshdr) | |
2316 | sshdr = &my_sshdr; | |
2317 | ||
1da177e4 | 2318 | retry: |
1cf72699 | 2319 | use_10_for_ms = sdev->use_10_for_ms; |
1da177e4 LT |
2320 | |
2321 | if (use_10_for_ms) { | |
2322 | if (len < 8) | |
2323 | len = 8; | |
2324 | ||
2325 | cmd[0] = MODE_SENSE_10; | |
2326 | cmd[8] = len; | |
2327 | header_length = 8; | |
2328 | } else { | |
2329 | if (len < 4) | |
2330 | len = 4; | |
2331 | ||
2332 | cmd[0] = MODE_SENSE; | |
2333 | cmd[4] = len; | |
2334 | header_length = 4; | |
2335 | } | |
2336 | ||
1da177e4 LT |
2337 | memset(buffer, 0, len); |
2338 | ||
1cf72699 | 2339 | result = scsi_execute_req(sdev, cmd, DMA_FROM_DEVICE, buffer, len, |
f4f4e47e | 2340 | sshdr, timeout, retries, NULL); |
1da177e4 LT |
2341 | |
2342 | /* This code looks awful: what it's doing is making sure an | |
2343 | * ILLEGAL REQUEST sense return identifies the actual command | |
2344 | * byte as the problem. MODE_SENSE commands can return | |
2345 | * ILLEGAL REQUEST if the code page isn't supported */ | |
2346 | ||
1cf72699 JB |
2347 | if (use_10_for_ms && !scsi_status_is_good(result) && |
2348 | (driver_byte(result) & DRIVER_SENSE)) { | |
ea73a9f2 JB |
2349 | if (scsi_sense_valid(sshdr)) { |
2350 | if ((sshdr->sense_key == ILLEGAL_REQUEST) && | |
2351 | (sshdr->asc == 0x20) && (sshdr->ascq == 0)) { | |
1da177e4 LT |
2352 | /* |
2353 | * Invalid command operation code | |
2354 | */ | |
1cf72699 | 2355 | sdev->use_10_for_ms = 0; |
1da177e4 LT |
2356 | goto retry; |
2357 | } | |
2358 | } | |
2359 | } | |
2360 | ||
1cf72699 | 2361 | if(scsi_status_is_good(result)) { |
6d73c851 AV |
2362 | if (unlikely(buffer[0] == 0x86 && buffer[1] == 0x0b && |
2363 | (modepage == 6 || modepage == 8))) { | |
2364 | /* Initio breakage? */ | |
2365 | header_length = 0; | |
2366 | data->length = 13; | |
2367 | data->medium_type = 0; | |
2368 | data->device_specific = 0; | |
2369 | data->longlba = 0; | |
2370 | data->block_descriptor_length = 0; | |
2371 | } else if(use_10_for_ms) { | |
1da177e4 LT |
2372 | data->length = buffer[0]*256 + buffer[1] + 2; |
2373 | data->medium_type = buffer[2]; | |
2374 | data->device_specific = buffer[3]; | |
2375 | data->longlba = buffer[4] & 0x01; | |
2376 | data->block_descriptor_length = buffer[6]*256 | |
2377 | + buffer[7]; | |
2378 | } else { | |
2379 | data->length = buffer[0] + 1; | |
2380 | data->medium_type = buffer[1]; | |
2381 | data->device_specific = buffer[2]; | |
2382 | data->block_descriptor_length = buffer[3]; | |
2383 | } | |
6d73c851 | 2384 | data->header_length = header_length; |
0ae80ba9 HR |
2385 | } else if ((status_byte(result) == CHECK_CONDITION) && |
2386 | scsi_sense_valid(sshdr) && | |
2387 | sshdr->sense_key == UNIT_ATTENTION && retry_count) { | |
2388 | retry_count--; | |
2389 | goto retry; | |
1da177e4 LT |
2390 | } |
2391 | ||
1cf72699 | 2392 | return result; |
1da177e4 LT |
2393 | } |
2394 | EXPORT_SYMBOL(scsi_mode_sense); | |
2395 | ||
001aac25 JB |
2396 | /** |
2397 | * scsi_test_unit_ready - test if unit is ready | |
2398 | * @sdev: scsi device to change the state of. | |
2399 | * @timeout: command timeout | |
2400 | * @retries: number of retries before failing | |
2401 | * @sshdr_external: Optional pointer to struct scsi_sense_hdr for | |
2402 | * returning sense. Make sure that this is cleared before passing | |
2403 | * in. | |
2404 | * | |
2405 | * Returns zero if unsuccessful or an error if TUR failed. For | |
9f8a2c23 | 2406 | * removable media, UNIT_ATTENTION sets ->changed flag. |
001aac25 | 2407 | **/ |
1da177e4 | 2408 | int |
001aac25 JB |
2409 | scsi_test_unit_ready(struct scsi_device *sdev, int timeout, int retries, |
2410 | struct scsi_sense_hdr *sshdr_external) | |
1da177e4 | 2411 | { |
1da177e4 LT |
2412 | char cmd[] = { |
2413 | TEST_UNIT_READY, 0, 0, 0, 0, 0, | |
2414 | }; | |
001aac25 | 2415 | struct scsi_sense_hdr *sshdr; |
1da177e4 | 2416 | int result; |
001aac25 JB |
2417 | |
2418 | if (!sshdr_external) | |
2419 | sshdr = kzalloc(sizeof(*sshdr), GFP_KERNEL); | |
2420 | else | |
2421 | sshdr = sshdr_external; | |
2422 | ||
2423 | /* try to eat the UNIT_ATTENTION if there are enough retries */ | |
2424 | do { | |
2425 | result = scsi_execute_req(sdev, cmd, DMA_NONE, NULL, 0, sshdr, | |
f4f4e47e | 2426 | timeout, retries, NULL); |
32c356d7 JB |
2427 | if (sdev->removable && scsi_sense_valid(sshdr) && |
2428 | sshdr->sense_key == UNIT_ATTENTION) | |
2429 | sdev->changed = 1; | |
2430 | } while (scsi_sense_valid(sshdr) && | |
2431 | sshdr->sense_key == UNIT_ATTENTION && --retries); | |
001aac25 | 2432 | |
001aac25 JB |
2433 | if (!sshdr_external) |
2434 | kfree(sshdr); | |
1da177e4 LT |
2435 | return result; |
2436 | } | |
2437 | EXPORT_SYMBOL(scsi_test_unit_ready); | |
2438 | ||
2439 | /** | |
eb44820c | 2440 | * scsi_device_set_state - Take the given device through the device state model. |
1da177e4 LT |
2441 | * @sdev: scsi device to change the state of. |
2442 | * @state: state to change to. | |
2443 | * | |
2444 | * Returns zero if unsuccessful or an error if the requested | |
2445 | * transition is illegal. | |
eb44820c | 2446 | */ |
1da177e4 LT |
2447 | int |
2448 | scsi_device_set_state(struct scsi_device *sdev, enum scsi_device_state state) | |
2449 | { | |
2450 | enum scsi_device_state oldstate = sdev->sdev_state; | |
2451 | ||
2452 | if (state == oldstate) | |
2453 | return 0; | |
2454 | ||
2455 | switch (state) { | |
2456 | case SDEV_CREATED: | |
6f4267e3 JB |
2457 | switch (oldstate) { |
2458 | case SDEV_CREATED_BLOCK: | |
2459 | break; | |
2460 | default: | |
2461 | goto illegal; | |
2462 | } | |
2463 | break; | |
1da177e4 LT |
2464 | |
2465 | case SDEV_RUNNING: | |
2466 | switch (oldstate) { | |
2467 | case SDEV_CREATED: | |
2468 | case SDEV_OFFLINE: | |
1b8d2620 | 2469 | case SDEV_TRANSPORT_OFFLINE: |
1da177e4 LT |
2470 | case SDEV_QUIESCE: |
2471 | case SDEV_BLOCK: | |
2472 | break; | |
2473 | default: | |
2474 | goto illegal; | |
2475 | } | |
2476 | break; | |
2477 | ||
2478 | case SDEV_QUIESCE: | |
2479 | switch (oldstate) { | |
2480 | case SDEV_RUNNING: | |
2481 | case SDEV_OFFLINE: | |
1b8d2620 | 2482 | case SDEV_TRANSPORT_OFFLINE: |
1da177e4 LT |
2483 | break; |
2484 | default: | |
2485 | goto illegal; | |
2486 | } | |
2487 | break; | |
2488 | ||
2489 | case SDEV_OFFLINE: | |
1b8d2620 | 2490 | case SDEV_TRANSPORT_OFFLINE: |
1da177e4 LT |
2491 | switch (oldstate) { |
2492 | case SDEV_CREATED: | |
2493 | case SDEV_RUNNING: | |
2494 | case SDEV_QUIESCE: | |
2495 | case SDEV_BLOCK: | |
2496 | break; | |
2497 | default: | |
2498 | goto illegal; | |
2499 | } | |
2500 | break; | |
2501 | ||
2502 | case SDEV_BLOCK: | |
2503 | switch (oldstate) { | |
1da177e4 | 2504 | case SDEV_RUNNING: |
6f4267e3 JB |
2505 | case SDEV_CREATED_BLOCK: |
2506 | break; | |
2507 | default: | |
2508 | goto illegal; | |
2509 | } | |
2510 | break; | |
2511 | ||
2512 | case SDEV_CREATED_BLOCK: | |
2513 | switch (oldstate) { | |
2514 | case SDEV_CREATED: | |
1da177e4 LT |
2515 | break; |
2516 | default: | |
2517 | goto illegal; | |
2518 | } | |
2519 | break; | |
2520 | ||
2521 | case SDEV_CANCEL: | |
2522 | switch (oldstate) { | |
2523 | case SDEV_CREATED: | |
2524 | case SDEV_RUNNING: | |
9ea72909 | 2525 | case SDEV_QUIESCE: |
1da177e4 | 2526 | case SDEV_OFFLINE: |
1b8d2620 | 2527 | case SDEV_TRANSPORT_OFFLINE: |
1da177e4 LT |
2528 | case SDEV_BLOCK: |
2529 | break; | |
2530 | default: | |
2531 | goto illegal; | |
2532 | } | |
2533 | break; | |
2534 | ||
2535 | case SDEV_DEL: | |
2536 | switch (oldstate) { | |
309bd271 BK |
2537 | case SDEV_CREATED: |
2538 | case SDEV_RUNNING: | |
2539 | case SDEV_OFFLINE: | |
1b8d2620 | 2540 | case SDEV_TRANSPORT_OFFLINE: |
1da177e4 | 2541 | case SDEV_CANCEL: |
0516c08d | 2542 | case SDEV_CREATED_BLOCK: |
1da177e4 LT |
2543 | break; |
2544 | default: | |
2545 | goto illegal; | |
2546 | } | |
2547 | break; | |
2548 | ||
2549 | } | |
2550 | sdev->sdev_state = state; | |
2551 | return 0; | |
2552 | ||
2553 | illegal: | |
91921e01 | 2554 | SCSI_LOG_ERROR_RECOVERY(1, |
9ccfc756 | 2555 | sdev_printk(KERN_ERR, sdev, |
91921e01 | 2556 | "Illegal state transition %s->%s", |
9ccfc756 JB |
2557 | scsi_device_state_name(oldstate), |
2558 | scsi_device_state_name(state)) | |
1da177e4 LT |
2559 | ); |
2560 | return -EINVAL; | |
2561 | } | |
2562 | EXPORT_SYMBOL(scsi_device_set_state); | |
2563 | ||
a341cd0f JG |
2564 | /** |
2565 | * sdev_evt_emit - emit a single SCSI device uevent | |
2566 | * @sdev: associated SCSI device | |
2567 | * @evt: event to emit | |
2568 | * | |
2569 | * Send a single uevent (scsi_event) to the associated scsi_device. | |
2570 | */ | |
2571 | static void scsi_evt_emit(struct scsi_device *sdev, struct scsi_event *evt) | |
2572 | { | |
2573 | int idx = 0; | |
2574 | char *envp[3]; | |
2575 | ||
2576 | switch (evt->evt_type) { | |
2577 | case SDEV_EVT_MEDIA_CHANGE: | |
2578 | envp[idx++] = "SDEV_MEDIA_CHANGE=1"; | |
2579 | break; | |
279afdfe | 2580 | case SDEV_EVT_INQUIRY_CHANGE_REPORTED: |
d3d32891 | 2581 | scsi_rescan_device(&sdev->sdev_gendev); |
279afdfe EM |
2582 | envp[idx++] = "SDEV_UA=INQUIRY_DATA_HAS_CHANGED"; |
2583 | break; | |
2584 | case SDEV_EVT_CAPACITY_CHANGE_REPORTED: | |
2585 | envp[idx++] = "SDEV_UA=CAPACITY_DATA_HAS_CHANGED"; | |
2586 | break; | |
2587 | case SDEV_EVT_SOFT_THRESHOLD_REACHED_REPORTED: | |
2588 | envp[idx++] = "SDEV_UA=THIN_PROVISIONING_SOFT_THRESHOLD_REACHED"; | |
2589 | break; | |
2590 | case SDEV_EVT_MODE_PARAMETER_CHANGE_REPORTED: | |
2591 | envp[idx++] = "SDEV_UA=MODE_PARAMETERS_CHANGED"; | |
2592 | break; | |
2593 | case SDEV_EVT_LUN_CHANGE_REPORTED: | |
2594 | envp[idx++] = "SDEV_UA=REPORTED_LUNS_DATA_HAS_CHANGED"; | |
2595 | break; | |
14c3e677 HR |
2596 | case SDEV_EVT_ALUA_STATE_CHANGE_REPORTED: |
2597 | envp[idx++] = "SDEV_UA=ASYMMETRIC_ACCESS_STATE_CHANGED"; | |
2598 | break; | |
a341cd0f JG |
2599 | default: |
2600 | /* do nothing */ | |
2601 | break; | |
2602 | } | |
2603 | ||
2604 | envp[idx++] = NULL; | |
2605 | ||
2606 | kobject_uevent_env(&sdev->sdev_gendev.kobj, KOBJ_CHANGE, envp); | |
2607 | } | |
2608 | ||
2609 | /** | |
2610 | * sdev_evt_thread - send a uevent for each scsi event | |
2611 | * @work: work struct for scsi_device | |
2612 | * | |
2613 | * Dispatch queued events to their associated scsi_device kobjects | |
2614 | * as uevents. | |
2615 | */ | |
2616 | void scsi_evt_thread(struct work_struct *work) | |
2617 | { | |
2618 | struct scsi_device *sdev; | |
279afdfe | 2619 | enum scsi_device_event evt_type; |
a341cd0f JG |
2620 | LIST_HEAD(event_list); |
2621 | ||
2622 | sdev = container_of(work, struct scsi_device, event_work); | |
2623 | ||
279afdfe EM |
2624 | for (evt_type = SDEV_EVT_FIRST; evt_type <= SDEV_EVT_LAST; evt_type++) |
2625 | if (test_and_clear_bit(evt_type, sdev->pending_events)) | |
2626 | sdev_evt_send_simple(sdev, evt_type, GFP_KERNEL); | |
2627 | ||
a341cd0f JG |
2628 | while (1) { |
2629 | struct scsi_event *evt; | |
2630 | struct list_head *this, *tmp; | |
2631 | unsigned long flags; | |
2632 | ||
2633 | spin_lock_irqsave(&sdev->list_lock, flags); | |
2634 | list_splice_init(&sdev->event_list, &event_list); | |
2635 | spin_unlock_irqrestore(&sdev->list_lock, flags); | |
2636 | ||
2637 | if (list_empty(&event_list)) | |
2638 | break; | |
2639 | ||
2640 | list_for_each_safe(this, tmp, &event_list) { | |
2641 | evt = list_entry(this, struct scsi_event, node); | |
2642 | list_del(&evt->node); | |
2643 | scsi_evt_emit(sdev, evt); | |
2644 | kfree(evt); | |
2645 | } | |
2646 | } | |
2647 | } | |
2648 | ||
2649 | /** | |
2650 | * sdev_evt_send - send asserted event to uevent thread | |
2651 | * @sdev: scsi_device event occurred on | |
2652 | * @evt: event to send | |
2653 | * | |
2654 | * Assert scsi device event asynchronously. | |
2655 | */ | |
2656 | void sdev_evt_send(struct scsi_device *sdev, struct scsi_event *evt) | |
2657 | { | |
2658 | unsigned long flags; | |
2659 | ||
4d1566ed KS |
2660 | #if 0 |
2661 | /* FIXME: currently this check eliminates all media change events | |
2662 | * for polled devices. Need to update to discriminate between AN | |
2663 | * and polled events */ | |
a341cd0f JG |
2664 | if (!test_bit(evt->evt_type, sdev->supported_events)) { |
2665 | kfree(evt); | |
2666 | return; | |
2667 | } | |
4d1566ed | 2668 | #endif |
a341cd0f JG |
2669 | |
2670 | spin_lock_irqsave(&sdev->list_lock, flags); | |
2671 | list_add_tail(&evt->node, &sdev->event_list); | |
2672 | schedule_work(&sdev->event_work); | |
2673 | spin_unlock_irqrestore(&sdev->list_lock, flags); | |
2674 | } | |
2675 | EXPORT_SYMBOL_GPL(sdev_evt_send); | |
2676 | ||
2677 | /** | |
2678 | * sdev_evt_alloc - allocate a new scsi event | |
2679 | * @evt_type: type of event to allocate | |
2680 | * @gfpflags: GFP flags for allocation | |
2681 | * | |
2682 | * Allocates and returns a new scsi_event. | |
2683 | */ | |
2684 | struct scsi_event *sdev_evt_alloc(enum scsi_device_event evt_type, | |
2685 | gfp_t gfpflags) | |
2686 | { | |
2687 | struct scsi_event *evt = kzalloc(sizeof(struct scsi_event), gfpflags); | |
2688 | if (!evt) | |
2689 | return NULL; | |
2690 | ||
2691 | evt->evt_type = evt_type; | |
2692 | INIT_LIST_HEAD(&evt->node); | |
2693 | ||
2694 | /* evt_type-specific initialization, if any */ | |
2695 | switch (evt_type) { | |
2696 | case SDEV_EVT_MEDIA_CHANGE: | |
279afdfe EM |
2697 | case SDEV_EVT_INQUIRY_CHANGE_REPORTED: |
2698 | case SDEV_EVT_CAPACITY_CHANGE_REPORTED: | |
2699 | case SDEV_EVT_SOFT_THRESHOLD_REACHED_REPORTED: | |
2700 | case SDEV_EVT_MODE_PARAMETER_CHANGE_REPORTED: | |
2701 | case SDEV_EVT_LUN_CHANGE_REPORTED: | |
14c3e677 | 2702 | case SDEV_EVT_ALUA_STATE_CHANGE_REPORTED: |
a341cd0f JG |
2703 | default: |
2704 | /* do nothing */ | |
2705 | break; | |
2706 | } | |
2707 | ||
2708 | return evt; | |
2709 | } | |
2710 | EXPORT_SYMBOL_GPL(sdev_evt_alloc); | |
2711 | ||
2712 | /** | |
2713 | * sdev_evt_send_simple - send asserted event to uevent thread | |
2714 | * @sdev: scsi_device event occurred on | |
2715 | * @evt_type: type of event to send | |
2716 | * @gfpflags: GFP flags for allocation | |
2717 | * | |
2718 | * Assert scsi device event asynchronously, given an event type. | |
2719 | */ | |
2720 | void sdev_evt_send_simple(struct scsi_device *sdev, | |
2721 | enum scsi_device_event evt_type, gfp_t gfpflags) | |
2722 | { | |
2723 | struct scsi_event *evt = sdev_evt_alloc(evt_type, gfpflags); | |
2724 | if (!evt) { | |
2725 | sdev_printk(KERN_ERR, sdev, "event %d eaten due to OOM\n", | |
2726 | evt_type); | |
2727 | return; | |
2728 | } | |
2729 | ||
2730 | sdev_evt_send(sdev, evt); | |
2731 | } | |
2732 | EXPORT_SYMBOL_GPL(sdev_evt_send_simple); | |
2733 | ||
1da177e4 LT |
2734 | /** |
2735 | * scsi_device_quiesce - Block user issued commands. | |
2736 | * @sdev: scsi device to quiesce. | |
2737 | * | |
2738 | * This works by trying to transition to the SDEV_QUIESCE state | |
2739 | * (which must be a legal transition). When the device is in this | |
2740 | * state, only special requests will be accepted, all others will | |
2741 | * be deferred. Since special requests may also be requeued requests, | |
2742 | * a successful return doesn't guarantee the device will be | |
2743 | * totally quiescent. | |
2744 | * | |
2745 | * Must be called with user context, may sleep. | |
2746 | * | |
2747 | * Returns zero if unsuccessful or an error if not. | |
eb44820c | 2748 | */ |
1da177e4 LT |
2749 | int |
2750 | scsi_device_quiesce(struct scsi_device *sdev) | |
2751 | { | |
2752 | int err = scsi_device_set_state(sdev, SDEV_QUIESCE); | |
2753 | if (err) | |
2754 | return err; | |
2755 | ||
2756 | scsi_run_queue(sdev->request_queue); | |
71e75c97 | 2757 | while (atomic_read(&sdev->device_busy)) { |
1da177e4 LT |
2758 | msleep_interruptible(200); |
2759 | scsi_run_queue(sdev->request_queue); | |
2760 | } | |
2761 | return 0; | |
2762 | } | |
2763 | EXPORT_SYMBOL(scsi_device_quiesce); | |
2764 | ||
2765 | /** | |
2766 | * scsi_device_resume - Restart user issued commands to a quiesced device. | |
2767 | * @sdev: scsi device to resume. | |
2768 | * | |
2769 | * Moves the device from quiesced back to running and restarts the | |
2770 | * queues. | |
2771 | * | |
2772 | * Must be called with user context, may sleep. | |
eb44820c | 2773 | */ |
a7a20d10 | 2774 | void scsi_device_resume(struct scsi_device *sdev) |
1da177e4 | 2775 | { |
a7a20d10 DW |
2776 | /* check if the device state was mutated prior to resume, and if |
2777 | * so assume the state is being managed elsewhere (for example | |
2778 | * device deleted during suspend) | |
2779 | */ | |
2780 | if (sdev->sdev_state != SDEV_QUIESCE || | |
2781 | scsi_device_set_state(sdev, SDEV_RUNNING)) | |
1da177e4 LT |
2782 | return; |
2783 | scsi_run_queue(sdev->request_queue); | |
2784 | } | |
2785 | EXPORT_SYMBOL(scsi_device_resume); | |
2786 | ||
2787 | static void | |
2788 | device_quiesce_fn(struct scsi_device *sdev, void *data) | |
2789 | { | |
2790 | scsi_device_quiesce(sdev); | |
2791 | } | |
2792 | ||
2793 | void | |
2794 | scsi_target_quiesce(struct scsi_target *starget) | |
2795 | { | |
2796 | starget_for_each_device(starget, NULL, device_quiesce_fn); | |
2797 | } | |
2798 | EXPORT_SYMBOL(scsi_target_quiesce); | |
2799 | ||
2800 | static void | |
2801 | device_resume_fn(struct scsi_device *sdev, void *data) | |
2802 | { | |
2803 | scsi_device_resume(sdev); | |
2804 | } | |
2805 | ||
2806 | void | |
2807 | scsi_target_resume(struct scsi_target *starget) | |
2808 | { | |
2809 | starget_for_each_device(starget, NULL, device_resume_fn); | |
2810 | } | |
2811 | EXPORT_SYMBOL(scsi_target_resume); | |
2812 | ||
2813 | /** | |
eb44820c | 2814 | * scsi_internal_device_block - internal function to put a device temporarily into the SDEV_BLOCK state |
1da177e4 LT |
2815 | * @sdev: device to block |
2816 | * | |
2817 | * Block request made by scsi lld's to temporarily stop all | |
2818 | * scsi commands on the specified device. Called from interrupt | |
2819 | * or normal process context. | |
2820 | * | |
2821 | * Returns zero if successful or error if not | |
2822 | * | |
2823 | * Notes: | |
2824 | * This routine transitions the device to the SDEV_BLOCK state | |
2825 | * (which must be a legal transition). When the device is in this | |
2826 | * state, all commands are deferred until the scsi lld reenables | |
2827 | * the device with scsi_device_unblock or device_block_tmo fires. | |
eb44820c | 2828 | */ |
1da177e4 LT |
2829 | int |
2830 | scsi_internal_device_block(struct scsi_device *sdev) | |
2831 | { | |
165125e1 | 2832 | struct request_queue *q = sdev->request_queue; |
1da177e4 LT |
2833 | unsigned long flags; |
2834 | int err = 0; | |
2835 | ||
2836 | err = scsi_device_set_state(sdev, SDEV_BLOCK); | |
6f4267e3 JB |
2837 | if (err) { |
2838 | err = scsi_device_set_state(sdev, SDEV_CREATED_BLOCK); | |
2839 | ||
2840 | if (err) | |
2841 | return err; | |
2842 | } | |
1da177e4 LT |
2843 | |
2844 | /* | |
2845 | * The device has transitioned to SDEV_BLOCK. Stop the | |
2846 | * block layer from calling the midlayer with this device's | |
2847 | * request queue. | |
2848 | */ | |
d285203c CH |
2849 | if (q->mq_ops) { |
2850 | blk_mq_stop_hw_queues(q); | |
2851 | } else { | |
2852 | spin_lock_irqsave(q->queue_lock, flags); | |
2853 | blk_stop_queue(q); | |
2854 | spin_unlock_irqrestore(q->queue_lock, flags); | |
2855 | } | |
1da177e4 LT |
2856 | |
2857 | return 0; | |
2858 | } | |
2859 | EXPORT_SYMBOL_GPL(scsi_internal_device_block); | |
2860 | ||
2861 | /** | |
2862 | * scsi_internal_device_unblock - resume a device after a block request | |
2863 | * @sdev: device to resume | |
5d9fb5cc | 2864 | * @new_state: state to set devices to after unblocking |
1da177e4 LT |
2865 | * |
2866 | * Called by scsi lld's or the midlayer to restart the device queue | |
2867 | * for the previously suspended scsi device. Called from interrupt or | |
2868 | * normal process context. | |
2869 | * | |
2870 | * Returns zero if successful or error if not. | |
2871 | * | |
2872 | * Notes: | |
2873 | * This routine transitions the device to the SDEV_RUNNING state | |
5d9fb5cc | 2874 | * or to one of the offline states (which must be a legal transition) |
d075498c | 2875 | * allowing the midlayer to goose the queue for this device. |
eb44820c | 2876 | */ |
1da177e4 | 2877 | int |
5d9fb5cc MC |
2878 | scsi_internal_device_unblock(struct scsi_device *sdev, |
2879 | enum scsi_device_state new_state) | |
1da177e4 | 2880 | { |
165125e1 | 2881 | struct request_queue *q = sdev->request_queue; |
1da177e4 | 2882 | unsigned long flags; |
5d9fb5cc MC |
2883 | |
2884 | /* | |
2885 | * Try to transition the scsi device to SDEV_RUNNING or one of the | |
2886 | * offlined states and goose the device queue if successful. | |
1da177e4 | 2887 | */ |
0e58076b VC |
2888 | if ((sdev->sdev_state == SDEV_BLOCK) || |
2889 | (sdev->sdev_state == SDEV_TRANSPORT_OFFLINE)) | |
5d9fb5cc MC |
2890 | sdev->sdev_state = new_state; |
2891 | else if (sdev->sdev_state == SDEV_CREATED_BLOCK) { | |
2892 | if (new_state == SDEV_TRANSPORT_OFFLINE || | |
2893 | new_state == SDEV_OFFLINE) | |
2894 | sdev->sdev_state = new_state; | |
2895 | else | |
2896 | sdev->sdev_state = SDEV_CREATED; | |
2897 | } else if (sdev->sdev_state != SDEV_CANCEL && | |
986fe6c7 | 2898 | sdev->sdev_state != SDEV_OFFLINE) |
5c10e63c | 2899 | return -EINVAL; |
1da177e4 | 2900 | |
d285203c CH |
2901 | if (q->mq_ops) { |
2902 | blk_mq_start_stopped_hw_queues(q, false); | |
2903 | } else { | |
2904 | spin_lock_irqsave(q->queue_lock, flags); | |
2905 | blk_start_queue(q); | |
2906 | spin_unlock_irqrestore(q->queue_lock, flags); | |
2907 | } | |
1da177e4 LT |
2908 | |
2909 | return 0; | |
2910 | } | |
2911 | EXPORT_SYMBOL_GPL(scsi_internal_device_unblock); | |
2912 | ||
2913 | static void | |
2914 | device_block(struct scsi_device *sdev, void *data) | |
2915 | { | |
2916 | scsi_internal_device_block(sdev); | |
2917 | } | |
2918 | ||
2919 | static int | |
2920 | target_block(struct device *dev, void *data) | |
2921 | { | |
2922 | if (scsi_is_target_device(dev)) | |
2923 | starget_for_each_device(to_scsi_target(dev), NULL, | |
2924 | device_block); | |
2925 | return 0; | |
2926 | } | |
2927 | ||
2928 | void | |
2929 | scsi_target_block(struct device *dev) | |
2930 | { | |
2931 | if (scsi_is_target_device(dev)) | |
2932 | starget_for_each_device(to_scsi_target(dev), NULL, | |
2933 | device_block); | |
2934 | else | |
2935 | device_for_each_child(dev, NULL, target_block); | |
2936 | } | |
2937 | EXPORT_SYMBOL_GPL(scsi_target_block); | |
2938 | ||
2939 | static void | |
2940 | device_unblock(struct scsi_device *sdev, void *data) | |
2941 | { | |
5d9fb5cc | 2942 | scsi_internal_device_unblock(sdev, *(enum scsi_device_state *)data); |
1da177e4 LT |
2943 | } |
2944 | ||
2945 | static int | |
2946 | target_unblock(struct device *dev, void *data) | |
2947 | { | |
2948 | if (scsi_is_target_device(dev)) | |
5d9fb5cc | 2949 | starget_for_each_device(to_scsi_target(dev), data, |
1da177e4 LT |
2950 | device_unblock); |
2951 | return 0; | |
2952 | } | |
2953 | ||
2954 | void | |
5d9fb5cc | 2955 | scsi_target_unblock(struct device *dev, enum scsi_device_state new_state) |
1da177e4 LT |
2956 | { |
2957 | if (scsi_is_target_device(dev)) | |
5d9fb5cc | 2958 | starget_for_each_device(to_scsi_target(dev), &new_state, |
1da177e4 LT |
2959 | device_unblock); |
2960 | else | |
5d9fb5cc | 2961 | device_for_each_child(dev, &new_state, target_unblock); |
1da177e4 LT |
2962 | } |
2963 | EXPORT_SYMBOL_GPL(scsi_target_unblock); | |
cdb8c2a6 GL |
2964 | |
2965 | /** | |
2966 | * scsi_kmap_atomic_sg - find and atomically map an sg-elemnt | |
eb44820c | 2967 | * @sgl: scatter-gather list |
cdb8c2a6 GL |
2968 | * @sg_count: number of segments in sg |
2969 | * @offset: offset in bytes into sg, on return offset into the mapped area | |
2970 | * @len: bytes to map, on return number of bytes mapped | |
2971 | * | |
2972 | * Returns virtual address of the start of the mapped page | |
2973 | */ | |
c6132da1 | 2974 | void *scsi_kmap_atomic_sg(struct scatterlist *sgl, int sg_count, |
cdb8c2a6 GL |
2975 | size_t *offset, size_t *len) |
2976 | { | |
2977 | int i; | |
2978 | size_t sg_len = 0, len_complete = 0; | |
c6132da1 | 2979 | struct scatterlist *sg; |
cdb8c2a6 GL |
2980 | struct page *page; |
2981 | ||
22cfefb5 AM |
2982 | WARN_ON(!irqs_disabled()); |
2983 | ||
c6132da1 | 2984 | for_each_sg(sgl, sg, sg_count, i) { |
cdb8c2a6 | 2985 | len_complete = sg_len; /* Complete sg-entries */ |
c6132da1 | 2986 | sg_len += sg->length; |
cdb8c2a6 GL |
2987 | if (sg_len > *offset) |
2988 | break; | |
2989 | } | |
2990 | ||
2991 | if (unlikely(i == sg_count)) { | |
169e1a2a AM |
2992 | printk(KERN_ERR "%s: Bytes in sg: %zu, requested offset %zu, " |
2993 | "elements %d\n", | |
cadbd4a5 | 2994 | __func__, sg_len, *offset, sg_count); |
cdb8c2a6 GL |
2995 | WARN_ON(1); |
2996 | return NULL; | |
2997 | } | |
2998 | ||
2999 | /* Offset starting from the beginning of first page in this sg-entry */ | |
c6132da1 | 3000 | *offset = *offset - len_complete + sg->offset; |
cdb8c2a6 GL |
3001 | |
3002 | /* Assumption: contiguous pages can be accessed as "page + i" */ | |
45711f1a | 3003 | page = nth_page(sg_page(sg), (*offset >> PAGE_SHIFT)); |
cdb8c2a6 GL |
3004 | *offset &= ~PAGE_MASK; |
3005 | ||
3006 | /* Bytes in this sg-entry from *offset to the end of the page */ | |
3007 | sg_len = PAGE_SIZE - *offset; | |
3008 | if (*len > sg_len) | |
3009 | *len = sg_len; | |
3010 | ||
77dfce07 | 3011 | return kmap_atomic(page); |
cdb8c2a6 GL |
3012 | } |
3013 | EXPORT_SYMBOL(scsi_kmap_atomic_sg); | |
3014 | ||
3015 | /** | |
eb44820c | 3016 | * scsi_kunmap_atomic_sg - atomically unmap a virtual address, previously mapped with scsi_kmap_atomic_sg |
cdb8c2a6 GL |
3017 | * @virt: virtual address to be unmapped |
3018 | */ | |
3019 | void scsi_kunmap_atomic_sg(void *virt) | |
3020 | { | |
77dfce07 | 3021 | kunmap_atomic(virt); |
cdb8c2a6 GL |
3022 | } |
3023 | EXPORT_SYMBOL(scsi_kunmap_atomic_sg); | |
6f4c827e AL |
3024 | |
3025 | void sdev_disable_disk_events(struct scsi_device *sdev) | |
3026 | { | |
3027 | atomic_inc(&sdev->disk_events_disable_depth); | |
3028 | } | |
3029 | EXPORT_SYMBOL(sdev_disable_disk_events); | |
3030 | ||
3031 | void sdev_enable_disk_events(struct scsi_device *sdev) | |
3032 | { | |
3033 | if (WARN_ON_ONCE(atomic_read(&sdev->disk_events_disable_depth) <= 0)) | |
3034 | return; | |
3035 | atomic_dec(&sdev->disk_events_disable_depth); | |
3036 | } | |
3037 | EXPORT_SYMBOL(sdev_enable_disk_events); | |
9983bed3 HR |
3038 | |
3039 | /** | |
3040 | * scsi_vpd_lun_id - return a unique device identification | |
3041 | * @sdev: SCSI device | |
3042 | * @id: buffer for the identification | |
3043 | * @id_len: length of the buffer | |
3044 | * | |
3045 | * Copies a unique device identification into @id based | |
3046 | * on the information in the VPD page 0x83 of the device. | |
3047 | * The string will be formatted as a SCSI name string. | |
3048 | * | |
3049 | * Returns the length of the identification or error on failure. | |
3050 | * If the identifier is longer than the supplied buffer the actual | |
3051 | * identifier length is returned and the buffer is not zero-padded. | |
3052 | */ | |
3053 | int scsi_vpd_lun_id(struct scsi_device *sdev, char *id, size_t id_len) | |
3054 | { | |
3055 | u8 cur_id_type = 0xff; | |
3056 | u8 cur_id_size = 0; | |
3057 | unsigned char *d, *cur_id_str; | |
3058 | unsigned char __rcu *vpd_pg83; | |
3059 | int id_size = -EINVAL; | |
3060 | ||
3061 | rcu_read_lock(); | |
3062 | vpd_pg83 = rcu_dereference(sdev->vpd_pg83); | |
3063 | if (!vpd_pg83) { | |
3064 | rcu_read_unlock(); | |
3065 | return -ENXIO; | |
3066 | } | |
3067 | ||
3068 | /* | |
3069 | * Look for the correct descriptor. | |
3070 | * Order of preference for lun descriptor: | |
3071 | * - SCSI name string | |
3072 | * - NAA IEEE Registered Extended | |
3073 | * - EUI-64 based 16-byte | |
3074 | * - EUI-64 based 12-byte | |
3075 | * - NAA IEEE Registered | |
3076 | * - NAA IEEE Extended | |
d230823a | 3077 | * - T10 Vendor ID |
9983bed3 HR |
3078 | * as longer descriptors reduce the likelyhood |
3079 | * of identification clashes. | |
3080 | */ | |
3081 | ||
3082 | /* The id string must be at least 20 bytes + terminating NULL byte */ | |
3083 | if (id_len < 21) { | |
3084 | rcu_read_unlock(); | |
3085 | return -EINVAL; | |
3086 | } | |
3087 | ||
3088 | memset(id, 0, id_len); | |
3089 | d = vpd_pg83 + 4; | |
3090 | while (d < vpd_pg83 + sdev->vpd_pg83_len) { | |
3091 | /* Skip designators not referring to the LUN */ | |
3092 | if ((d[1] & 0x30) != 0x00) | |
3093 | goto next_desig; | |
3094 | ||
3095 | switch (d[1] & 0xf) { | |
d230823a HR |
3096 | case 0x1: |
3097 | /* T10 Vendor ID */ | |
3098 | if (cur_id_size > d[3]) | |
3099 | break; | |
3100 | /* Prefer anything */ | |
3101 | if (cur_id_type > 0x01 && cur_id_type != 0xff) | |
3102 | break; | |
3103 | cur_id_size = d[3]; | |
3104 | if (cur_id_size + 4 > id_len) | |
3105 | cur_id_size = id_len - 4; | |
3106 | cur_id_str = d + 4; | |
3107 | cur_id_type = d[1] & 0xf; | |
3108 | id_size = snprintf(id, id_len, "t10.%*pE", | |
3109 | cur_id_size, cur_id_str); | |
3110 | break; | |
9983bed3 HR |
3111 | case 0x2: |
3112 | /* EUI-64 */ | |
3113 | if (cur_id_size > d[3]) | |
3114 | break; | |
3115 | /* Prefer NAA IEEE Registered Extended */ | |
3116 | if (cur_id_type == 0x3 && | |
3117 | cur_id_size == d[3]) | |
3118 | break; | |
3119 | cur_id_size = d[3]; | |
3120 | cur_id_str = d + 4; | |
3121 | cur_id_type = d[1] & 0xf; | |
3122 | switch (cur_id_size) { | |
3123 | case 8: | |
3124 | id_size = snprintf(id, id_len, | |
3125 | "eui.%8phN", | |
3126 | cur_id_str); | |
3127 | break; | |
3128 | case 12: | |
3129 | id_size = snprintf(id, id_len, | |
3130 | "eui.%12phN", | |
3131 | cur_id_str); | |
3132 | break; | |
3133 | case 16: | |
3134 | id_size = snprintf(id, id_len, | |
3135 | "eui.%16phN", | |
3136 | cur_id_str); | |
3137 | break; | |
3138 | default: | |
3139 | cur_id_size = 0; | |
3140 | break; | |
3141 | } | |
3142 | break; | |
3143 | case 0x3: | |
3144 | /* NAA */ | |
3145 | if (cur_id_size > d[3]) | |
3146 | break; | |
3147 | cur_id_size = d[3]; | |
3148 | cur_id_str = d + 4; | |
3149 | cur_id_type = d[1] & 0xf; | |
3150 | switch (cur_id_size) { | |
3151 | case 8: | |
3152 | id_size = snprintf(id, id_len, | |
3153 | "naa.%8phN", | |
3154 | cur_id_str); | |
3155 | break; | |
3156 | case 16: | |
3157 | id_size = snprintf(id, id_len, | |
3158 | "naa.%16phN", | |
3159 | cur_id_str); | |
3160 | break; | |
3161 | default: | |
3162 | cur_id_size = 0; | |
3163 | break; | |
3164 | } | |
3165 | break; | |
3166 | case 0x8: | |
3167 | /* SCSI name string */ | |
3168 | if (cur_id_size + 4 > d[3]) | |
3169 | break; | |
3170 | /* Prefer others for truncated descriptor */ | |
3171 | if (cur_id_size && d[3] > id_len) | |
3172 | break; | |
3173 | cur_id_size = id_size = d[3]; | |
3174 | cur_id_str = d + 4; | |
3175 | cur_id_type = d[1] & 0xf; | |
3176 | if (cur_id_size >= id_len) | |
3177 | cur_id_size = id_len - 1; | |
3178 | memcpy(id, cur_id_str, cur_id_size); | |
3179 | /* Decrease priority for truncated descriptor */ | |
3180 | if (cur_id_size != id_size) | |
3181 | cur_id_size = 6; | |
3182 | break; | |
3183 | default: | |
3184 | break; | |
3185 | } | |
3186 | next_desig: | |
3187 | d += d[3] + 4; | |
3188 | } | |
3189 | rcu_read_unlock(); | |
3190 | ||
3191 | return id_size; | |
3192 | } | |
3193 | EXPORT_SYMBOL(scsi_vpd_lun_id); | |
a8aa3978 HR |
3194 | |
3195 | /* | |
3196 | * scsi_vpd_tpg_id - return a target port group identifier | |
3197 | * @sdev: SCSI device | |
3198 | * | |
3199 | * Returns the Target Port Group identifier from the information | |
3200 | * froom VPD page 0x83 of the device. | |
3201 | * | |
3202 | * Returns the identifier or error on failure. | |
3203 | */ | |
3204 | int scsi_vpd_tpg_id(struct scsi_device *sdev, int *rel_id) | |
3205 | { | |
3206 | unsigned char *d; | |
3207 | unsigned char __rcu *vpd_pg83; | |
3208 | int group_id = -EAGAIN, rel_port = -1; | |
3209 | ||
3210 | rcu_read_lock(); | |
3211 | vpd_pg83 = rcu_dereference(sdev->vpd_pg83); | |
3212 | if (!vpd_pg83) { | |
3213 | rcu_read_unlock(); | |
3214 | return -ENXIO; | |
3215 | } | |
3216 | ||
3217 | d = sdev->vpd_pg83 + 4; | |
3218 | while (d < sdev->vpd_pg83 + sdev->vpd_pg83_len) { | |
3219 | switch (d[1] & 0xf) { | |
3220 | case 0x4: | |
3221 | /* Relative target port */ | |
3222 | rel_port = get_unaligned_be16(&d[6]); | |
3223 | break; | |
3224 | case 0x5: | |
3225 | /* Target port group */ | |
3226 | group_id = get_unaligned_be16(&d[6]); | |
3227 | break; | |
3228 | default: | |
3229 | break; | |
3230 | } | |
3231 | d += d[3] + 4; | |
3232 | } | |
3233 | rcu_read_unlock(); | |
3234 | ||
3235 | if (group_id >= 0 && rel_id && rel_port != -1) | |
3236 | *rel_id = rel_port; | |
3237 | ||
3238 | return group_id; | |
3239 | } | |
3240 | EXPORT_SYMBOL(scsi_vpd_tpg_id); |