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457c8996 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
1da177e4 | 2 | /* |
d285203c CH |
3 | * Copyright (C) 1999 Eric Youngdale |
4 | * Copyright (C) 2014 Christoph Hellwig | |
1da177e4 LT |
5 | * |
6 | * SCSI queueing library. | |
7 | * Initial versions: Eric Youngdale (eric@andante.org). | |
8 | * Based upon conversations with large numbers | |
9 | * of people at Linux Expo. | |
10 | */ | |
11 | ||
12 | #include <linux/bio.h> | |
d3f46f39 | 13 | #include <linux/bitops.h> |
1da177e4 LT |
14 | #include <linux/blkdev.h> |
15 | #include <linux/completion.h> | |
16 | #include <linux/kernel.h> | |
09703660 | 17 | #include <linux/export.h> |
1da177e4 LT |
18 | #include <linux/init.h> |
19 | #include <linux/pci.h> | |
20 | #include <linux/delay.h> | |
faead26d | 21 | #include <linux/hardirq.h> |
c6132da1 | 22 | #include <linux/scatterlist.h> |
d285203c | 23 | #include <linux/blk-mq.h> |
fe45e630 | 24 | #include <linux/blk-integrity.h> |
f1569ff1 | 25 | #include <linux/ratelimit.h> |
a8aa3978 | 26 | #include <asm/unaligned.h> |
1da177e4 LT |
27 | |
28 | #include <scsi/scsi.h> | |
beb40487 | 29 | #include <scsi/scsi_cmnd.h> |
1da177e4 LT |
30 | #include <scsi/scsi_dbg.h> |
31 | #include <scsi/scsi_device.h> | |
32 | #include <scsi/scsi_driver.h> | |
33 | #include <scsi/scsi_eh.h> | |
34 | #include <scsi/scsi_host.h> | |
7aa686d3 | 35 | #include <scsi/scsi_transport.h> /* __scsi_init_queue() */ |
ee14c674 | 36 | #include <scsi/scsi_dh.h> |
1da177e4 | 37 | |
3b5382c4 CH |
38 | #include <trace/events/scsi.h> |
39 | ||
0eebd005 | 40 | #include "scsi_debugfs.h" |
1da177e4 LT |
41 | #include "scsi_priv.h" |
42 | #include "scsi_logging.h" | |
43 | ||
92524fa1 ML |
44 | /* |
45 | * Size of integrity metadata is usually small, 1 inline sg should | |
46 | * cover normal cases. | |
47 | */ | |
3e99b3b1 ML |
48 | #ifdef CONFIG_ARCH_NO_SG_CHAIN |
49 | #define SCSI_INLINE_PROT_SG_CNT 0 | |
50 | #define SCSI_INLINE_SG_CNT 0 | |
51 | #else | |
92524fa1 | 52 | #define SCSI_INLINE_PROT_SG_CNT 1 |
3dccdf53 | 53 | #define SCSI_INLINE_SG_CNT 2 |
3e99b3b1 | 54 | #endif |
3dccdf53 | 55 | |
0a6ac4ee | 56 | static struct kmem_cache *scsi_sense_cache; |
0a6ac4ee | 57 | static DEFINE_MUTEX(scsi_sense_cache_mutex); |
1da177e4 | 58 | |
a45a1f36 BVA |
59 | static void scsi_mq_uninit_cmd(struct scsi_cmnd *cmd); |
60 | ||
0a6ac4ee CH |
61 | int scsi_init_sense_cache(struct Scsi_Host *shost) |
62 | { | |
0a6ac4ee CH |
63 | int ret = 0; |
64 | ||
f9b0530f | 65 | mutex_lock(&scsi_sense_cache_mutex); |
aaff5eba | 66 | if (!scsi_sense_cache) { |
0a6ac4ee | 67 | scsi_sense_cache = |
0afe76e8 DW |
68 | kmem_cache_create_usercopy("scsi_sense_cache", |
69 | SCSI_SENSE_BUFFERSIZE, 0, SLAB_HWCACHE_ALIGN, | |
70 | 0, SCSI_SENSE_BUFFERSIZE, NULL); | |
0a6ac4ee CH |
71 | if (!scsi_sense_cache) |
72 | ret = -ENOMEM; | |
73 | } | |
0a6ac4ee CH |
74 | mutex_unlock(&scsi_sense_cache_mutex); |
75 | return ret; | |
76 | } | |
6f9a35e2 | 77 | |
de3e8bf3 CH |
78 | static void |
79 | scsi_set_blocked(struct scsi_cmnd *cmd, int reason) | |
1da177e4 LT |
80 | { |
81 | struct Scsi_Host *host = cmd->device->host; | |
82 | struct scsi_device *device = cmd->device; | |
f0c0a376 | 83 | struct scsi_target *starget = scsi_target(device); |
1da177e4 LT |
84 | |
85 | /* | |
d8c37e7b | 86 | * Set the appropriate busy bit for the device/host. |
1da177e4 LT |
87 | * |
88 | * If the host/device isn't busy, assume that something actually | |
89 | * completed, and that we should be able to queue a command now. | |
90 | * | |
91 | * Note that the prior mid-layer assumption that any host could | |
92 | * always queue at least one command is now broken. The mid-layer | |
93 | * will implement a user specifiable stall (see | |
94 | * scsi_host.max_host_blocked and scsi_device.max_device_blocked) | |
95 | * if a command is requeued with no other commands outstanding | |
96 | * either for the device or for the host. | |
97 | */ | |
f0c0a376 MC |
98 | switch (reason) { |
99 | case SCSI_MLQUEUE_HOST_BUSY: | |
cd9070c9 | 100 | atomic_set(&host->host_blocked, host->max_host_blocked); |
f0c0a376 MC |
101 | break; |
102 | case SCSI_MLQUEUE_DEVICE_BUSY: | |
573e5913 | 103 | case SCSI_MLQUEUE_EH_RETRY: |
cd9070c9 CH |
104 | atomic_set(&device->device_blocked, |
105 | device->max_device_blocked); | |
f0c0a376 MC |
106 | break; |
107 | case SCSI_MLQUEUE_TARGET_BUSY: | |
cd9070c9 CH |
108 | atomic_set(&starget->target_blocked, |
109 | starget->max_target_blocked); | |
f0c0a376 MC |
110 | break; |
111 | } | |
de3e8bf3 CH |
112 | } |
113 | ||
54249306 | 114 | static void scsi_mq_requeue_cmd(struct scsi_cmnd *cmd, unsigned long msecs) |
d285203c | 115 | { |
aa8e25e5 BVA |
116 | struct request *rq = scsi_cmd_to_rq(cmd); |
117 | ||
118 | if (rq->rq_flags & RQF_DONTPREP) { | |
119 | rq->rq_flags &= ~RQF_DONTPREP; | |
a45a1f36 BVA |
120 | scsi_mq_uninit_cmd(cmd); |
121 | } else { | |
122 | WARN_ON_ONCE(true); | |
123 | } | |
54249306 BB |
124 | |
125 | if (msecs) { | |
126 | blk_mq_requeue_request(rq, false); | |
127 | blk_mq_delay_kick_requeue_list(rq->q, msecs); | |
128 | } else | |
129 | blk_mq_requeue_request(rq, true); | |
d285203c CH |
130 | } |
131 | ||
de3e8bf3 CH |
132 | /** |
133 | * __scsi_queue_insert - private queue insertion | |
134 | * @cmd: The SCSI command being requeued | |
135 | * @reason: The reason for the requeue | |
136 | * @unbusy: Whether the queue should be unbusied | |
137 | * | |
138 | * This is a private queue insertion. The public interface | |
139 | * scsi_queue_insert() always assumes the queue should be unbusied | |
140 | * because it's always called before the completion. This function is | |
141 | * for a requeue after completion, which should only occur in this | |
142 | * file. | |
143 | */ | |
08640e81 | 144 | static void __scsi_queue_insert(struct scsi_cmnd *cmd, int reason, bool unbusy) |
de3e8bf3 CH |
145 | { |
146 | struct scsi_device *device = cmd->device; | |
de3e8bf3 CH |
147 | |
148 | SCSI_LOG_MLQUEUE(1, scmd_printk(KERN_INFO, cmd, | |
149 | "Inserting command %p into mlqueue\n", cmd)); | |
150 | ||
151 | scsi_set_blocked(cmd, reason); | |
1da177e4 | 152 | |
1da177e4 LT |
153 | /* |
154 | * Decrement the counters, since these commands are no longer | |
155 | * active on the host/device. | |
156 | */ | |
4f5299ac | 157 | if (unbusy) |
6eb045e0 | 158 | scsi_device_unbusy(device, cmd); |
1da177e4 LT |
159 | |
160 | /* | |
a1bf9d1d | 161 | * Requeue this command. It will go before all other commands |
b485462a BVA |
162 | * that are already in the queue. Schedule requeue work under |
163 | * lock such that the kblockd_schedule_work() call happens | |
6f8191fd | 164 | * before blk_mq_destroy_queue() finishes. |
a488e749 | 165 | */ |
644373a4 | 166 | cmd->result = 0; |
f664a3cc | 167 | |
aa8e25e5 | 168 | blk_mq_requeue_request(scsi_cmd_to_rq(cmd), true); |
1da177e4 LT |
169 | } |
170 | ||
ea941016 AA |
171 | /** |
172 | * scsi_queue_insert - Reinsert a command in the queue. | |
173 | * @cmd: command that we are adding to queue. | |
174 | * @reason: why we are inserting command to queue. | |
4f5299ac | 175 | * |
ea941016 AA |
176 | * We do this for one of two cases. Either the host is busy and it cannot accept |
177 | * any more commands for the time being, or the device returned QUEUE_FULL and | |
178 | * can accept no more commands. | |
4f5299ac | 179 | * |
ea941016 AA |
180 | * Context: This could be called either from an interrupt context or a normal |
181 | * process context. | |
4f5299ac | 182 | */ |
84feb166 | 183 | void scsi_queue_insert(struct scsi_cmnd *cmd, int reason) |
4f5299ac | 184 | { |
08640e81 | 185 | __scsi_queue_insert(cmd, reason, true); |
4f5299ac | 186 | } |
e8064021 | 187 | |
76aaf87b CH |
188 | |
189 | /** | |
704f8392 | 190 | * __scsi_execute - insert request and wait for the result |
76aaf87b CH |
191 | * @sdev: scsi device |
192 | * @cmd: scsi command | |
193 | * @data_direction: data direction | |
194 | * @buffer: data buffer | |
195 | * @bufflen: len of buffer | |
196 | * @sense: optional sense buffer | |
197 | * @sshdr: optional decoded sense header | |
422969bb | 198 | * @timeout: request timeout in HZ |
76aaf87b CH |
199 | * @retries: number of times to retry request |
200 | * @flags: flags for ->cmd_flags | |
201 | * @rq_flags: flags for ->rq_flags | |
202 | * @resid: optional residual length | |
203 | * | |
17d5363b CH |
204 | * Returns the scsi_cmnd result field if a command was executed, or a negative |
205 | * Linux error code if we didn't get that far. | |
76aaf87b | 206 | */ |
704f8392 | 207 | int __scsi_execute(struct scsi_device *sdev, const unsigned char *cmd, |
33aa687d | 208 | int data_direction, void *buffer, unsigned bufflen, |
3949e2f0 | 209 | unsigned char *sense, struct scsi_sense_hdr *sshdr, |
2599cac5 BVA |
210 | int timeout, int retries, blk_opf_t flags, |
211 | req_flags_t rq_flags, int *resid) | |
39216033 JB |
212 | { |
213 | struct request *req; | |
ce70fd9a | 214 | struct scsi_cmnd *scmd; |
ced202f7 | 215 | int ret; |
39216033 | 216 | |
68ec3b81 | 217 | req = scsi_alloc_request(sdev->request_queue, |
aebf526b | 218 | data_direction == DMA_TO_DEVICE ? |
da6269da | 219 | REQ_OP_DRV_OUT : REQ_OP_DRV_IN, |
e6044f71 | 220 | rq_flags & RQF_PM ? BLK_MQ_REQ_PM : 0); |
a492f075 | 221 | if (IS_ERR(req)) |
ced202f7 | 222 | return PTR_ERR(req); |
39216033 | 223 | |
ced202f7 HR |
224 | if (bufflen) { |
225 | ret = blk_rq_map_kern(sdev->request_queue, req, | |
226 | buffer, bufflen, GFP_NOIO); | |
227 | if (ret) | |
228 | goto out; | |
229 | } | |
ce70fd9a CH |
230 | scmd = blk_mq_rq_to_pdu(req); |
231 | scmd->cmd_len = COMMAND_SIZE(cmd[0]); | |
232 | memcpy(scmd->cmnd, cmd, scmd->cmd_len); | |
6aded12b | 233 | scmd->allowed = retries; |
39216033 | 234 | req->timeout = timeout; |
e8064021 | 235 | req->cmd_flags |= flags; |
039c635f | 236 | req->rq_flags |= rq_flags | RQF_QUIET; |
39216033 JB |
237 | |
238 | /* | |
239 | * head injection *required* here otherwise quiesce won't work | |
240 | */ | |
b84ba30b | 241 | blk_execute_rq(req, true); |
39216033 | 242 | |
bdb2b8ca AS |
243 | /* |
244 | * Some devices (USB mass-storage in particular) may transfer | |
245 | * garbage data together with a residue indicating that the data | |
246 | * is invalid. Prevent the garbage from being misinterpreted | |
247 | * and prevent security leaks by zeroing out the excess data. | |
248 | */ | |
a9a4ea11 CH |
249 | if (unlikely(scmd->resid_len > 0 && scmd->resid_len <= bufflen)) |
250 | memset(buffer + bufflen - scmd->resid_len, 0, scmd->resid_len); | |
bdb2b8ca | 251 | |
f4f4e47e | 252 | if (resid) |
a9a4ea11 | 253 | *resid = scmd->resid_len; |
5b794f98 CH |
254 | if (sense && scmd->sense_len) |
255 | memcpy(sense, scmd->sense_buffer, SCSI_SENSE_BUFFERSIZE); | |
3949e2f0 | 256 | if (sshdr) |
5b794f98 CH |
257 | scsi_normalize_sense(scmd->sense_buffer, scmd->sense_len, |
258 | sshdr); | |
dbb4c84d | 259 | ret = scmd->result; |
39216033 | 260 | out: |
0bf6d96c | 261 | blk_mq_free_request(req); |
39216033 JB |
262 | |
263 | return ret; | |
264 | } | |
704f8392 | 265 | EXPORT_SYMBOL(__scsi_execute); |
39216033 | 266 | |
3bd6f43f | 267 | /* |
6eb045e0 ML |
268 | * Wake up the error handler if necessary. Avoid as follows that the error |
269 | * handler is not woken up if host in-flight requests number == | |
270 | * shost->host_failed: use call_rcu() in scsi_eh_scmd_add() in combination | |
271 | * with an RCU read lock in this function to ensure that this function in | |
272 | * its entirety either finishes before scsi_eh_scmd_add() increases the | |
3bd6f43f BVA |
273 | * host_failed counter or that it notices the shost state change made by |
274 | * scsi_eh_scmd_add(). | |
275 | */ | |
6eb045e0 | 276 | static void scsi_dec_host_busy(struct Scsi_Host *shost, struct scsi_cmnd *cmd) |
1da177e4 | 277 | { |
1da177e4 LT |
278 | unsigned long flags; |
279 | ||
3bd6f43f | 280 | rcu_read_lock(); |
6eb045e0 | 281 | __clear_bit(SCMD_STATE_INFLIGHT, &cmd->state); |
3bd6f43f | 282 | if (unlikely(scsi_host_in_recovery(shost))) { |
74665016 | 283 | spin_lock_irqsave(shost->host_lock, flags); |
3bd6f43f BVA |
284 | if (shost->host_failed || shost->host_eh_scheduled) |
285 | scsi_eh_wakeup(shost); | |
74665016 CH |
286 | spin_unlock_irqrestore(shost->host_lock, flags); |
287 | } | |
3bd6f43f BVA |
288 | rcu_read_unlock(); |
289 | } | |
290 | ||
6eb045e0 | 291 | void scsi_device_unbusy(struct scsi_device *sdev, struct scsi_cmnd *cmd) |
3bd6f43f BVA |
292 | { |
293 | struct Scsi_Host *shost = sdev->host; | |
294 | struct scsi_target *starget = scsi_target(sdev); | |
295 | ||
6eb045e0 | 296 | scsi_dec_host_busy(shost, cmd); |
3bd6f43f BVA |
297 | |
298 | if (starget->can_queue > 0) | |
299 | atomic_dec(&starget->target_busy); | |
74665016 | 300 | |
020b0f0a | 301 | sbitmap_put(&sdev->budget_map, cmd->budget_token); |
2a5a24aa | 302 | cmd->budget_token = -1; |
1da177e4 LT |
303 | } |
304 | ||
d285203c CH |
305 | static void scsi_kick_queue(struct request_queue *q) |
306 | { | |
f664a3cc | 307 | blk_mq_run_hw_queues(q, false); |
d285203c CH |
308 | } |
309 | ||
d460f624 BVA |
310 | /* |
311 | * Kick the queue of SCSI device @sdev if @sdev != current_sdev. Called with | |
312 | * interrupts disabled. | |
313 | */ | |
314 | static void scsi_kick_sdev_queue(struct scsi_device *sdev, void *data) | |
315 | { | |
316 | struct scsi_device *current_sdev = data; | |
317 | ||
318 | if (sdev != current_sdev) | |
319 | blk_mq_run_hw_queues(sdev->request_queue, true); | |
320 | } | |
321 | ||
1da177e4 LT |
322 | /* |
323 | * Called for single_lun devices on IO completion. Clear starget_sdev_user, | |
324 | * and call blk_run_queue for all the scsi_devices on the target - | |
325 | * including current_sdev first. | |
326 | * | |
327 | * Called with *no* scsi locks held. | |
328 | */ | |
329 | static void scsi_single_lun_run(struct scsi_device *current_sdev) | |
330 | { | |
331 | struct Scsi_Host *shost = current_sdev->host; | |
1da177e4 LT |
332 | struct scsi_target *starget = scsi_target(current_sdev); |
333 | unsigned long flags; | |
334 | ||
335 | spin_lock_irqsave(shost->host_lock, flags); | |
336 | starget->starget_sdev_user = NULL; | |
337 | spin_unlock_irqrestore(shost->host_lock, flags); | |
338 | ||
339 | /* | |
340 | * Call blk_run_queue for all LUNs on the target, starting with | |
341 | * current_sdev. We race with others (to set starget_sdev_user), | |
342 | * but in most cases, we will be first. Ideally, each LU on the | |
343 | * target would get some limited time or requests on the target. | |
344 | */ | |
d285203c | 345 | scsi_kick_queue(current_sdev->request_queue); |
1da177e4 LT |
346 | |
347 | spin_lock_irqsave(shost->host_lock, flags); | |
d460f624 BVA |
348 | if (!starget->starget_sdev_user) |
349 | __starget_for_each_device(starget, current_sdev, | |
350 | scsi_kick_sdev_queue); | |
1da177e4 LT |
351 | spin_unlock_irqrestore(shost->host_lock, flags); |
352 | } | |
353 | ||
cd9070c9 | 354 | static inline bool scsi_device_is_busy(struct scsi_device *sdev) |
9d112517 | 355 | { |
8278807a | 356 | if (scsi_device_busy(sdev) >= sdev->queue_depth) |
cd9070c9 CH |
357 | return true; |
358 | if (atomic_read(&sdev->device_blocked) > 0) | |
359 | return true; | |
360 | return false; | |
9d112517 KU |
361 | } |
362 | ||
cd9070c9 | 363 | static inline bool scsi_target_is_busy(struct scsi_target *starget) |
f0c0a376 | 364 | { |
2ccbb008 CH |
365 | if (starget->can_queue > 0) { |
366 | if (atomic_read(&starget->target_busy) >= starget->can_queue) | |
367 | return true; | |
368 | if (atomic_read(&starget->target_blocked) > 0) | |
369 | return true; | |
370 | } | |
cd9070c9 | 371 | return false; |
f0c0a376 MC |
372 | } |
373 | ||
cd9070c9 | 374 | static inline bool scsi_host_is_busy(struct Scsi_Host *shost) |
9d112517 | 375 | { |
cd9070c9 CH |
376 | if (atomic_read(&shost->host_blocked) > 0) |
377 | return true; | |
378 | if (shost->host_self_blocked) | |
379 | return true; | |
380 | return false; | |
9d112517 KU |
381 | } |
382 | ||
21a05df5 | 383 | static void scsi_starved_list_run(struct Scsi_Host *shost) |
1da177e4 | 384 | { |
2a3a59e5 | 385 | LIST_HEAD(starved_list); |
21a05df5 | 386 | struct scsi_device *sdev; |
1da177e4 LT |
387 | unsigned long flags; |
388 | ||
1da177e4 | 389 | spin_lock_irqsave(shost->host_lock, flags); |
2a3a59e5 MC |
390 | list_splice_init(&shost->starved_list, &starved_list); |
391 | ||
392 | while (!list_empty(&starved_list)) { | |
e2eb7244 JB |
393 | struct request_queue *slq; |
394 | ||
1da177e4 LT |
395 | /* |
396 | * As long as shost is accepting commands and we have | |
397 | * starved queues, call blk_run_queue. scsi_request_fn | |
398 | * drops the queue_lock and can add us back to the | |
399 | * starved_list. | |
400 | * | |
401 | * host_lock protects the starved_list and starved_entry. | |
402 | * scsi_request_fn must get the host_lock before checking | |
403 | * or modifying starved_list or starved_entry. | |
404 | */ | |
2a3a59e5 | 405 | if (scsi_host_is_busy(shost)) |
f0c0a376 | 406 | break; |
f0c0a376 | 407 | |
2a3a59e5 MC |
408 | sdev = list_entry(starved_list.next, |
409 | struct scsi_device, starved_entry); | |
410 | list_del_init(&sdev->starved_entry); | |
f0c0a376 MC |
411 | if (scsi_target_is_busy(scsi_target(sdev))) { |
412 | list_move_tail(&sdev->starved_entry, | |
413 | &shost->starved_list); | |
414 | continue; | |
415 | } | |
416 | ||
e2eb7244 JB |
417 | /* |
418 | * Once we drop the host lock, a racing scsi_remove_device() | |
419 | * call may remove the sdev from the starved list and destroy | |
420 | * it and the queue. Mitigate by taking a reference to the | |
421 | * queue and never touching the sdev again after we drop the | |
422 | * host lock. Note: if __scsi_remove_device() invokes | |
6f8191fd | 423 | * blk_mq_destroy_queue() before the queue is run from this |
e2eb7244 | 424 | * function then blk_run_queue() will return immediately since |
6f8191fd | 425 | * blk_mq_destroy_queue() marks the queue with QUEUE_FLAG_DYING. |
e2eb7244 JB |
426 | */ |
427 | slq = sdev->request_queue; | |
428 | if (!blk_get_queue(slq)) | |
429 | continue; | |
430 | spin_unlock_irqrestore(shost->host_lock, flags); | |
431 | ||
d285203c | 432 | scsi_kick_queue(slq); |
e2eb7244 JB |
433 | blk_put_queue(slq); |
434 | ||
435 | spin_lock_irqsave(shost->host_lock, flags); | |
1da177e4 | 436 | } |
2a3a59e5 MC |
437 | /* put any unprocessed entries back */ |
438 | list_splice(&starved_list, &shost->starved_list); | |
1da177e4 | 439 | spin_unlock_irqrestore(shost->host_lock, flags); |
21a05df5 CH |
440 | } |
441 | ||
ea941016 AA |
442 | /** |
443 | * scsi_run_queue - Select a proper request queue to serve next. | |
444 | * @q: last request's queue | |
21a05df5 | 445 | * |
ea941016 | 446 | * The previous command was completely finished, start a new one if possible. |
21a05df5 CH |
447 | */ |
448 | static void scsi_run_queue(struct request_queue *q) | |
449 | { | |
450 | struct scsi_device *sdev = q->queuedata; | |
451 | ||
452 | if (scsi_target(sdev)->single_lun) | |
453 | scsi_single_lun_run(sdev); | |
454 | if (!list_empty(&sdev->host->starved_list)) | |
455 | scsi_starved_list_run(sdev->host); | |
1da177e4 | 456 | |
f664a3cc | 457 | blk_mq_run_hw_queues(q, false); |
1da177e4 LT |
458 | } |
459 | ||
9937a5e2 JA |
460 | void scsi_requeue_run_queue(struct work_struct *work) |
461 | { | |
462 | struct scsi_device *sdev; | |
463 | struct request_queue *q; | |
464 | ||
465 | sdev = container_of(work, struct scsi_device, requeue_work); | |
466 | q = sdev->request_queue; | |
467 | scsi_run_queue(q); | |
468 | } | |
469 | ||
1da177e4 LT |
470 | void scsi_run_host_queues(struct Scsi_Host *shost) |
471 | { | |
472 | struct scsi_device *sdev; | |
473 | ||
474 | shost_for_each_device(sdev, shost) | |
475 | scsi_run_queue(sdev->request_queue); | |
476 | } | |
477 | ||
d285203c CH |
478 | static void scsi_uninit_cmd(struct scsi_cmnd *cmd) |
479 | { | |
aa8e25e5 | 480 | if (!blk_rq_is_passthrough(scsi_cmd_to_rq(cmd))) { |
d285203c CH |
481 | struct scsi_driver *drv = scsi_cmd_to_driver(cmd); |
482 | ||
483 | if (drv->uninit_command) | |
484 | drv->uninit_command(cmd); | |
485 | } | |
486 | } | |
487 | ||
7007e9dd | 488 | void scsi_free_sgtables(struct scsi_cmnd *cmd) |
d285203c CH |
489 | { |
490 | if (cmd->sdb.table.nents) | |
3dccdf53 ML |
491 | sg_free_table_chained(&cmd->sdb.table, |
492 | SCSI_INLINE_SG_CNT); | |
d285203c | 493 | if (scsi_prot_sg_count(cmd)) |
92524fa1 ML |
494 | sg_free_table_chained(&cmd->prot_sdb->table, |
495 | SCSI_INLINE_PROT_SG_CNT); | |
d285203c | 496 | } |
7007e9dd | 497 | EXPORT_SYMBOL_GPL(scsi_free_sgtables); |
d285203c CH |
498 | |
499 | static void scsi_mq_uninit_cmd(struct scsi_cmnd *cmd) | |
500 | { | |
20a66f2b | 501 | scsi_free_sgtables(cmd); |
d285203c | 502 | scsi_uninit_cmd(cmd); |
d285203c CH |
503 | } |
504 | ||
3f0dcfbc ML |
505 | static void scsi_run_queue_async(struct scsi_device *sdev) |
506 | { | |
507 | if (scsi_target(sdev)->single_lun || | |
ed5dd6a6 | 508 | !list_empty(&sdev->host->starved_list)) { |
3f0dcfbc | 509 | kblockd_schedule_work(&sdev->requeue_work); |
ed5dd6a6 ML |
510 | } else { |
511 | /* | |
512 | * smp_mb() present in sbitmap_queue_clear() or implied in | |
513 | * .end_io is for ordering writing .device_busy in | |
514 | * scsi_device_unbusy() and reading sdev->restarts. | |
515 | */ | |
516 | int old = atomic_read(&sdev->restarts); | |
517 | ||
518 | /* | |
519 | * ->restarts has to be kept as non-zero if new budget | |
520 | * contention occurs. | |
521 | * | |
522 | * No need to run queue when either another re-run | |
523 | * queue wins in updating ->restarts or a new budget | |
524 | * contention occurs. | |
525 | */ | |
526 | if (old && atomic_cmpxchg(&sdev->restarts, old, 0) == old) | |
527 | blk_mq_run_hw_queues(sdev->request_queue, true); | |
528 | } | |
3f0dcfbc ML |
529 | } |
530 | ||
7e63b5a4 | 531 | /* Returns false when no more bytes to process, true if there are more */ |
2a842aca | 532 | static bool scsi_end_request(struct request *req, blk_status_t error, |
ae3d56d8 | 533 | unsigned int bytes) |
f6d47e74 | 534 | { |
bed2213d | 535 | struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req); |
f6d47e74 CH |
536 | struct scsi_device *sdev = cmd->device; |
537 | struct request_queue *q = sdev->request_queue; | |
f6d47e74 CH |
538 | |
539 | if (blk_update_request(req, error, bytes)) | |
540 | return true; | |
541 | ||
f3fa33ac | 542 | // XXX: |
f6d47e74 | 543 | if (blk_queue_add_random(q)) |
f3fa33ac | 544 | add_disk_randomness(req->q->disk); |
f6d47e74 | 545 | |
da6269da | 546 | if (!blk_rq_is_passthrough(req)) { |
64104f70 BVA |
547 | WARN_ON_ONCE(!(cmd->flags & SCMD_INITIALIZED)); |
548 | cmd->flags &= ~SCMD_INITIALIZED; | |
549 | } | |
550 | ||
db983f6e BVA |
551 | /* |
552 | * Calling rcu_barrier() is not necessary here because the | |
553 | * SCSI error handler guarantees that the function called by | |
554 | * call_rcu() has been called before scsi_end_request() is | |
555 | * called. | |
556 | */ | |
557 | destroy_rcu_head(&cmd->rcu); | |
558 | ||
f664a3cc JA |
559 | /* |
560 | * In the MQ case the command gets freed by __blk_mq_end_request, | |
561 | * so we have to do all cleanup that depends on it earlier. | |
562 | * | |
563 | * We also can't kick the queues from irq context, so we | |
564 | * will have to defer it to a workqueue. | |
565 | */ | |
566 | scsi_mq_uninit_cmd(cmd); | |
f81426a8 | 567 | |
a78b03bc JA |
568 | /* |
569 | * queue is still alive, so grab the ref for preventing it | |
570 | * from being cleaned up during running queue. | |
571 | */ | |
572 | percpu_ref_get(&q->q_usage_counter); | |
f81426a8 | 573 | |
f664a3cc | 574 | __blk_mq_end_request(req, error); |
d285203c | 575 | |
3f0dcfbc | 576 | scsi_run_queue_async(sdev); |
f6d47e74 | 577 | |
a78b03bc | 578 | percpu_ref_put(&q->q_usage_counter); |
f6d47e74 CH |
579 | return false; |
580 | } | |
581 | ||
36ebf1e2 MC |
582 | static inline u8 get_scsi_ml_byte(int result) |
583 | { | |
584 | return (result >> 8) & 0xff; | |
585 | } | |
586 | ||
0f7f6234 | 587 | /** |
a77b32d8 | 588 | * scsi_result_to_blk_status - translate a SCSI result code into blk_status_t |
0f7f6234 HR |
589 | * @result: scsi error code |
590 | * | |
7dfaae6a | 591 | * Translate a SCSI result code into a blk_status_t value. |
0f7f6234 | 592 | */ |
7dfaae6a | 593 | static blk_status_t scsi_result_to_blk_status(int result) |
63583cca | 594 | { |
36ebf1e2 MC |
595 | /* |
596 | * Check the scsi-ml byte first in case we converted a host or status | |
597 | * byte. | |
598 | */ | |
599 | switch (get_scsi_ml_byte(result)) { | |
600 | case SCSIML_STAT_OK: | |
601 | break; | |
602 | case SCSIML_STAT_RESV_CONFLICT: | |
603 | return BLK_STS_NEXUS; | |
604 | case SCSIML_STAT_NOSPC: | |
605 | return BLK_STS_NOSPC; | |
606 | case SCSIML_STAT_MED_ERROR: | |
607 | return BLK_STS_MEDIUM; | |
608 | case SCSIML_STAT_TGT_FAILURE: | |
609 | return BLK_STS_TARGET; | |
610 | } | |
611 | ||
2a842aca | 612 | switch (host_byte(result)) { |
f4abab3f | 613 | case DID_OK: |
a7479a84 | 614 | if (scsi_status_is_good(result)) |
f4abab3f BVA |
615 | return BLK_STS_OK; |
616 | return BLK_STS_IOERR; | |
63583cca | 617 | case DID_TRANSPORT_FAILFAST: |
962c8dcd | 618 | case DID_TRANSPORT_MARGINAL: |
2a842aca | 619 | return BLK_STS_TRANSPORT; |
63583cca | 620 | default: |
2a842aca | 621 | return BLK_STS_IOERR; |
63583cca | 622 | } |
63583cca HR |
623 | } |
624 | ||
79478bf9 CH |
625 | /** |
626 | * scsi_rq_err_bytes - determine number of bytes till the next failure boundary | |
627 | * @rq: request to examine | |
628 | * | |
629 | * Description: | |
630 | * A request could be merge of IOs which require different failure | |
631 | * handling. This function determines the number of bytes which | |
632 | * can be failed from the beginning of the request without | |
633 | * crossing into area which need to be retried further. | |
634 | * | |
635 | * Return: | |
636 | * The number of bytes to fail. | |
637 | */ | |
638 | static unsigned int scsi_rq_err_bytes(const struct request *rq) | |
639 | { | |
2599cac5 | 640 | blk_opf_t ff = rq->cmd_flags & REQ_FAILFAST_MASK; |
79478bf9 CH |
641 | unsigned int bytes = 0; |
642 | struct bio *bio; | |
643 | ||
644 | if (!(rq->rq_flags & RQF_MIXED_MERGE)) | |
645 | return blk_rq_bytes(rq); | |
646 | ||
647 | /* | |
648 | * Currently the only 'mixing' which can happen is between | |
649 | * different fastfail types. We can safely fail portions | |
650 | * which have all the failfast bits that the first one has - | |
651 | * the ones which are at least as eager to fail as the first | |
652 | * one. | |
653 | */ | |
654 | for (bio = rq->bio; bio; bio = bio->bi_next) { | |
655 | if ((bio->bi_opf & ff) != ff) | |
656 | break; | |
657 | bytes += bio->bi_iter.bi_size; | |
658 | } | |
659 | ||
660 | /* this could lead to infinite loop */ | |
661 | BUG_ON(blk_rq_bytes(rq) && !bytes); | |
662 | return bytes; | |
663 | } | |
664 | ||
2a242d59 MC |
665 | static bool scsi_cmd_runtime_exceeced(struct scsi_cmnd *cmd) |
666 | { | |
aa8e25e5 | 667 | struct request *req = scsi_cmd_to_rq(cmd); |
2a242d59 MC |
668 | unsigned long wait_for; |
669 | ||
670 | if (cmd->allowed == SCSI_CMD_RETRIES_NO_LIMIT) | |
671 | return false; | |
672 | ||
673 | wait_for = (cmd->allowed + 1) * req->timeout; | |
674 | if (time_before(cmd->jiffies_at_alloc + wait_for, jiffies)) { | |
675 | scmd_printk(KERN_ERR, cmd, "timing out command, waited %lus\n", | |
676 | wait_for/HZ); | |
677 | return true; | |
678 | } | |
679 | return false; | |
680 | } | |
681 | ||
54249306 BB |
682 | /* |
683 | * When ALUA transition state is returned, reprep the cmd to | |
684 | * use the ALUA handler's transition timeout. Delay the reprep | |
685 | * 1 sec to avoid aggressive retries of the target in that | |
686 | * state. | |
687 | */ | |
688 | #define ALUA_TRANSITION_REPREP_DELAY 1000 | |
689 | ||
da32baea DG |
690 | /* Helper for scsi_io_completion() when special action required. */ |
691 | static void scsi_io_completion_action(struct scsi_cmnd *cmd, int result) | |
1da177e4 | 692 | { |
aa8e25e5 | 693 | struct request *req = scsi_cmd_to_rq(cmd); |
da32baea | 694 | int level = 0; |
54249306 BB |
695 | enum {ACTION_FAIL, ACTION_REPREP, ACTION_DELAYED_REPREP, |
696 | ACTION_RETRY, ACTION_DELAYED_RETRY} action; | |
da32baea DG |
697 | struct scsi_sense_hdr sshdr; |
698 | bool sense_valid; | |
699 | bool sense_current = true; /* false implies "deferred sense" */ | |
700 | blk_status_t blk_stat; | |
1da177e4 | 701 | |
da32baea DG |
702 | sense_valid = scsi_command_normalize_sense(cmd, &sshdr); |
703 | if (sense_valid) | |
704 | sense_current = !scsi_sense_is_deferred(&sshdr); | |
03aba2f7 | 705 | |
7dfaae6a | 706 | blk_stat = scsi_result_to_blk_status(result); |
3e695f89 | 707 | |
b60af5b0 AS |
708 | if (host_byte(result) == DID_RESET) { |
709 | /* Third party bus reset or reset for error recovery | |
710 | * reasons. Just retry the command and see what | |
711 | * happens. | |
712 | */ | |
713 | action = ACTION_RETRY; | |
da32baea | 714 | } else if (sense_valid && sense_current) { |
1da177e4 LT |
715 | switch (sshdr.sense_key) { |
716 | case UNIT_ATTENTION: | |
717 | if (cmd->device->removable) { | |
03aba2f7 | 718 | /* Detected disc change. Set a bit |
1da177e4 LT |
719 | * and quietly refuse further access. |
720 | */ | |
721 | cmd->device->changed = 1; | |
b60af5b0 | 722 | action = ACTION_FAIL; |
1da177e4 | 723 | } else { |
03aba2f7 LT |
724 | /* Must have been a power glitch, or a |
725 | * bus reset. Could not have been a | |
726 | * media change, so we just retry the | |
b60af5b0 | 727 | * command and see what happens. |
03aba2f7 | 728 | */ |
b60af5b0 | 729 | action = ACTION_RETRY; |
1da177e4 LT |
730 | } |
731 | break; | |
732 | case ILLEGAL_REQUEST: | |
03aba2f7 LT |
733 | /* If we had an ILLEGAL REQUEST returned, then |
734 | * we may have performed an unsupported | |
735 | * command. The only thing this should be | |
736 | * would be a ten byte read where only a six | |
737 | * byte read was supported. Also, on a system | |
738 | * where READ CAPACITY failed, we may have | |
739 | * read past the end of the disk. | |
740 | */ | |
26a68019 JA |
741 | if ((cmd->device->use_10_for_rw && |
742 | sshdr.asc == 0x20 && sshdr.ascq == 0x00) && | |
1da177e4 LT |
743 | (cmd->cmnd[0] == READ_10 || |
744 | cmd->cmnd[0] == WRITE_10)) { | |
b60af5b0 | 745 | /* This will issue a new 6-byte command. */ |
1da177e4 | 746 | cmd->device->use_10_for_rw = 0; |
b60af5b0 | 747 | action = ACTION_REPREP; |
3e695f89 | 748 | } else if (sshdr.asc == 0x10) /* DIX */ { |
3e695f89 | 749 | action = ACTION_FAIL; |
da32baea | 750 | blk_stat = BLK_STS_PROTECTION; |
c98a0eb0 | 751 | /* INVALID COMMAND OPCODE or INVALID FIELD IN CDB */ |
5db44863 | 752 | } else if (sshdr.asc == 0x20 || sshdr.asc == 0x24) { |
c98a0eb0 | 753 | action = ACTION_FAIL; |
da32baea | 754 | blk_stat = BLK_STS_TARGET; |
b60af5b0 AS |
755 | } else |
756 | action = ACTION_FAIL; | |
757 | break; | |
511e44f4 | 758 | case ABORTED_COMMAND: |
126c0982 | 759 | action = ACTION_FAIL; |
e6c11dbb | 760 | if (sshdr.asc == 0x10) /* DIF */ |
da32baea | 761 | blk_stat = BLK_STS_PROTECTION; |
1da177e4 LT |
762 | break; |
763 | case NOT_READY: | |
03aba2f7 | 764 | /* If the device is in the process of becoming |
f3e93f73 | 765 | * ready, or has a temporary blockage, retry. |
1da177e4 | 766 | */ |
f3e93f73 JB |
767 | if (sshdr.asc == 0x04) { |
768 | switch (sshdr.ascq) { | |
769 | case 0x01: /* becoming ready */ | |
770 | case 0x04: /* format in progress */ | |
771 | case 0x05: /* rebuild in progress */ | |
772 | case 0x06: /* recalculation in progress */ | |
773 | case 0x07: /* operation in progress */ | |
774 | case 0x08: /* Long write in progress */ | |
775 | case 0x09: /* self test in progress */ | |
104739ac | 776 | case 0x11: /* notify (enable spinup) required */ |
d8705f11 | 777 | case 0x14: /* space allocation in progress */ |
e37c7d9a DG |
778 | case 0x1a: /* start stop unit in progress */ |
779 | case 0x1b: /* sanitize in progress */ | |
780 | case 0x1d: /* configuration in progress */ | |
781 | case 0x24: /* depopulation in progress */ | |
b60af5b0 | 782 | action = ACTION_DELAYED_RETRY; |
f3e93f73 | 783 | break; |
0d882320 | 784 | case 0x0a: /* ALUA state transition */ |
54249306 BB |
785 | action = ACTION_DELAYED_REPREP; |
786 | break; | |
3dbf6a54 | 787 | default: |
3dbf6a54 AS |
788 | action = ACTION_FAIL; |
789 | break; | |
f3e93f73 | 790 | } |
e6c11dbb | 791 | } else |
b60af5b0 | 792 | action = ACTION_FAIL; |
b60af5b0 | 793 | break; |
1da177e4 | 794 | case VOLUME_OVERFLOW: |
03aba2f7 | 795 | /* See SSC3rXX or current. */ |
b60af5b0 AS |
796 | action = ACTION_FAIL; |
797 | break; | |
d8f53b0a DLM |
798 | case DATA_PROTECT: |
799 | action = ACTION_FAIL; | |
800 | if ((sshdr.asc == 0x0C && sshdr.ascq == 0x12) || | |
801 | (sshdr.asc == 0x55 && | |
802 | (sshdr.ascq == 0x0E || sshdr.ascq == 0x0F))) { | |
803 | /* Insufficient zone resources */ | |
804 | blk_stat = BLK_STS_ZONE_OPEN_RESOURCE; | |
805 | } | |
806 | break; | |
1da177e4 | 807 | default: |
b60af5b0 | 808 | action = ACTION_FAIL; |
1da177e4 LT |
809 | break; |
810 | } | |
e6c11dbb | 811 | } else |
b60af5b0 | 812 | action = ACTION_FAIL; |
b60af5b0 | 813 | |
2a242d59 | 814 | if (action != ACTION_FAIL && scsi_cmd_runtime_exceeced(cmd)) |
ee60b2c5 | 815 | action = ACTION_FAIL; |
ee60b2c5 | 816 | |
b60af5b0 AS |
817 | switch (action) { |
818 | case ACTION_FAIL: | |
819 | /* Give up and fail the remainder of the request */ | |
e8064021 | 820 | if (!(req->rq_flags & RQF_QUIET)) { |
f1569ff1 HR |
821 | static DEFINE_RATELIMIT_STATE(_rs, |
822 | DEFAULT_RATELIMIT_INTERVAL, | |
823 | DEFAULT_RATELIMIT_BURST); | |
824 | ||
825 | if (unlikely(scsi_logging_level)) | |
da32baea DG |
826 | level = |
827 | SCSI_LOG_LEVEL(SCSI_LOG_MLCOMPLETE_SHIFT, | |
828 | SCSI_LOG_MLCOMPLETE_BITS); | |
f1569ff1 HR |
829 | |
830 | /* | |
831 | * if logging is enabled the failure will be printed | |
832 | * in scsi_log_completion(), so avoid duplicate messages | |
833 | */ | |
834 | if (!level && __ratelimit(&_rs)) { | |
835 | scsi_print_result(cmd, NULL, FAILED); | |
464a00c9 | 836 | if (sense_valid) |
f1569ff1 HR |
837 | scsi_print_sense(cmd); |
838 | scsi_print_command(cmd); | |
839 | } | |
3173d8c3 | 840 | } |
79478bf9 | 841 | if (!scsi_end_request(req, blk_stat, scsi_rq_err_bytes(req))) |
f6d47e74 | 842 | return; |
df561f66 | 843 | fallthrough; |
b60af5b0 | 844 | case ACTION_REPREP: |
54249306 BB |
845 | scsi_mq_requeue_cmd(cmd, 0); |
846 | break; | |
847 | case ACTION_DELAYED_REPREP: | |
848 | scsi_mq_requeue_cmd(cmd, ALUA_TRANSITION_REPREP_DELAY); | |
b60af5b0 AS |
849 | break; |
850 | case ACTION_RETRY: | |
851 | /* Retry the same command immediately */ | |
08640e81 | 852 | __scsi_queue_insert(cmd, SCSI_MLQUEUE_EH_RETRY, false); |
b60af5b0 AS |
853 | break; |
854 | case ACTION_DELAYED_RETRY: | |
855 | /* Retry the same command after a delay */ | |
08640e81 | 856 | __scsi_queue_insert(cmd, SCSI_MLQUEUE_DEVICE_BUSY, false); |
b60af5b0 | 857 | break; |
1da177e4 LT |
858 | } |
859 | } | |
1da177e4 | 860 | |
ab831084 DG |
861 | /* |
862 | * Helper for scsi_io_completion() when cmd->result is non-zero. Returns a | |
863 | * new result that may suppress further error checking. Also modifies | |
864 | * *blk_statp in some cases. | |
865 | */ | |
866 | static int scsi_io_completion_nz_result(struct scsi_cmnd *cmd, int result, | |
867 | blk_status_t *blk_statp) | |
868 | { | |
869 | bool sense_valid; | |
870 | bool sense_current = true; /* false implies "deferred sense" */ | |
aa8e25e5 | 871 | struct request *req = scsi_cmd_to_rq(cmd); |
ab831084 DG |
872 | struct scsi_sense_hdr sshdr; |
873 | ||
874 | sense_valid = scsi_command_normalize_sense(cmd, &sshdr); | |
875 | if (sense_valid) | |
876 | sense_current = !scsi_sense_is_deferred(&sshdr); | |
877 | ||
878 | if (blk_rq_is_passthrough(req)) { | |
879 | if (sense_valid) { | |
880 | /* | |
881 | * SG_IO wants current and deferred errors | |
882 | */ | |
5b794f98 CH |
883 | cmd->sense_len = min(8 + cmd->sense_buffer[7], |
884 | SCSI_SENSE_BUFFERSIZE); | |
ab831084 DG |
885 | } |
886 | if (sense_current) | |
7dfaae6a | 887 | *blk_statp = scsi_result_to_blk_status(result); |
ab831084 DG |
888 | } else if (blk_rq_bytes(req) == 0 && sense_current) { |
889 | /* | |
890 | * Flush commands do not transfers any data, and thus cannot use | |
891 | * good_bytes != blk_rq_bytes(req) as the signal for an error. | |
892 | * This sets *blk_statp explicitly for the problem case. | |
893 | */ | |
7dfaae6a | 894 | *blk_statp = scsi_result_to_blk_status(result); |
ab831084 DG |
895 | } |
896 | /* | |
897 | * Recovered errors need reporting, but they're always treated as | |
898 | * success, so fiddle the result code here. For passthrough requests | |
899 | * we already took a copy of the original into sreq->result which | |
900 | * is what gets returned to the user | |
901 | */ | |
902 | if (sense_valid && (sshdr.sense_key == RECOVERED_ERROR)) { | |
903 | bool do_print = true; | |
904 | /* | |
905 | * if ATA PASS-THROUGH INFORMATION AVAILABLE [0x0, 0x1d] | |
906 | * skip print since caller wants ATA registers. Only occurs | |
907 | * on SCSI ATA PASS_THROUGH commands when CK_COND=1 | |
908 | */ | |
909 | if ((sshdr.asc == 0x0) && (sshdr.ascq == 0x1d)) | |
910 | do_print = false; | |
911 | else if (req->rq_flags & RQF_QUIET) | |
912 | do_print = false; | |
913 | if (do_print) | |
914 | scsi_print_sense(cmd); | |
915 | result = 0; | |
916 | /* for passthrough, *blk_statp may be set */ | |
917 | *blk_statp = BLK_STS_OK; | |
918 | } | |
919 | /* | |
920 | * Another corner case: the SCSI status byte is non-zero but 'good'. | |
921 | * Example: PRE-FETCH command returns SAM_STAT_CONDITION_MET when | |
922 | * it is able to fit nominated LBs in its cache (and SAM_STAT_GOOD | |
923 | * if it can't fit). Treat SAM_STAT_CONDITION_MET and the related | |
924 | * intermediate statuses (both obsolete in SAM-4) as good. | |
925 | */ | |
3d45cefc | 926 | if ((result & 0xff) && scsi_status_is_good(result)) { |
ab831084 DG |
927 | result = 0; |
928 | *blk_statp = BLK_STS_OK; | |
929 | } | |
930 | return result; | |
931 | } | |
932 | ||
ea941016 AA |
933 | /** |
934 | * scsi_io_completion - Completion processing for SCSI commands. | |
935 | * @cmd: command that is finished. | |
936 | * @good_bytes: number of processed bytes. | |
1da177e4 | 937 | * |
ea941016 AA |
938 | * We will finish off the specified number of sectors. If we are done, the |
939 | * command block will be released and the queue function will be goosed. If we | |
940 | * are not done then we have to figure out what to do next: | |
1da177e4 | 941 | * |
54249306 | 942 | * a) We can call scsi_mq_requeue_cmd(). The request will be |
ea941016 AA |
943 | * unprepared and put back on the queue. Then a new command will |
944 | * be created for it. This should be used if we made forward | |
945 | * progress, or if we want to switch from READ(10) to READ(6) for | |
946 | * example. | |
1da177e4 | 947 | * |
ea941016 AA |
948 | * b) We can call scsi_io_completion_action(). The request will be |
949 | * put back on the queue and retried using the same command as | |
950 | * before, possibly after a delay. | |
b60af5b0 | 951 | * |
ea941016 AA |
952 | * c) We can call scsi_end_request() with blk_stat other than |
953 | * BLK_STS_OK, to fail the remainder of the request. | |
1da177e4 | 954 | */ |
03aba2f7 | 955 | void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes) |
1da177e4 LT |
956 | { |
957 | int result = cmd->result; | |
aa8e25e5 | 958 | struct request *req = scsi_cmd_to_rq(cmd); |
1f7cbb8e | 959 | blk_status_t blk_stat = BLK_STS_OK; |
1da177e4 | 960 | |
0d437906 | 961 | if (unlikely(result)) /* a nz result may or may not be an error */ |
ab831084 | 962 | result = scsi_io_completion_nz_result(cmd, result, &blk_stat); |
631c228c | 963 | |
1da177e4 LT |
964 | /* |
965 | * Next deal with any sectors which we were able to correctly | |
966 | * handle. | |
967 | */ | |
91921e01 HR |
968 | SCSI_LOG_HLCOMPLETE(1, scmd_printk(KERN_INFO, cmd, |
969 | "%u sectors total, %d bytes done.\n", | |
970 | blk_rq_sectors(req), good_bytes)); | |
d6b0c537 | 971 | |
a9bddd74 | 972 | /* |
ea941016 | 973 | * Failed, zero length commands always need to drop down |
1f7cbb8e | 974 | * to retry code. Fast path should return in this block. |
d6b0c537 | 975 | */ |
0d437906 | 976 | if (likely(blk_rq_bytes(req) > 0 || blk_stat == BLK_STS_OK)) { |
ae3d56d8 | 977 | if (likely(!scsi_end_request(req, blk_stat, good_bytes))) |
1f7cbb8e DG |
978 | return; /* no bytes remaining */ |
979 | } | |
bc85dc50 | 980 | |
0d437906 DG |
981 | /* Kill remainder if no retries. */ |
982 | if (unlikely(blk_stat && scsi_noretry_cmd(cmd))) { | |
ae3d56d8 | 983 | if (scsi_end_request(req, blk_stat, blk_rq_bytes(req))) |
8e1695a0 DG |
984 | WARN_ONCE(true, |
985 | "Bytes remaining after failed, no-retry command"); | |
f6d47e74 | 986 | return; |
bc85dc50 CH |
987 | } |
988 | ||
989 | /* | |
990 | * If there had been no error, but we have leftover bytes in the | |
e9076e7f | 991 | * request just queue the command up again. |
d6b0c537 | 992 | */ |
0d437906 | 993 | if (likely(result == 0)) |
54249306 | 994 | scsi_mq_requeue_cmd(cmd, 0); |
4ae61c68 | 995 | else |
da32baea | 996 | scsi_io_completion_action(cmd, result); |
1da177e4 | 997 | } |
1da177e4 | 998 | |
cc97923a CH |
999 | static inline bool scsi_cmd_needs_dma_drain(struct scsi_device *sdev, |
1000 | struct request *rq) | |
1da177e4 | 1001 | { |
cc97923a CH |
1002 | return sdev->dma_drain_len && blk_rq_is_passthrough(rq) && |
1003 | !op_is_write(req_op(rq)) && | |
1004 | sdev->host->hostt->dma_need_drain(rq); | |
1da177e4 | 1005 | } |
6f9a35e2 | 1006 | |
ea941016 | 1007 | /** |
76fc0df9 BVA |
1008 | * scsi_alloc_sgtables - Allocate and initialize data and integrity scatterlists |
1009 | * @cmd: SCSI command data structure to initialize. | |
1010 | * | |
1011 | * Initializes @cmd->sdb and also @cmd->prot_sdb if data integrity is enabled | |
1012 | * for @cmd. | |
6f9a35e2 | 1013 | * |
ea941016 AA |
1014 | * Returns: |
1015 | * * BLK_STS_OK - on success | |
1016 | * * BLK_STS_RESOURCE - if the failure is retryable | |
1017 | * * BLK_STS_IOERR - if the failure is fatal | |
6f9a35e2 | 1018 | */ |
7007e9dd | 1019 | blk_status_t scsi_alloc_sgtables(struct scsi_cmnd *cmd) |
6f9a35e2 | 1020 | { |
cc97923a | 1021 | struct scsi_device *sdev = cmd->device; |
aa8e25e5 | 1022 | struct request *rq = scsi_cmd_to_rq(cmd); |
cc97923a CH |
1023 | unsigned short nr_segs = blk_rq_nr_phys_segments(rq); |
1024 | struct scatterlist *last_sg = NULL; | |
159b2cbf | 1025 | blk_status_t ret; |
cc97923a | 1026 | bool need_drain = scsi_cmd_needs_dma_drain(sdev, rq); |
0475bd6c | 1027 | int count; |
13f05c8d | 1028 | |
cc97923a | 1029 | if (WARN_ON_ONCE(!nr_segs)) |
159b2cbf | 1030 | return BLK_STS_IOERR; |
635d98b1 | 1031 | |
cc97923a CH |
1032 | /* |
1033 | * Make sure there is space for the drain. The driver must adjust | |
1034 | * max_hw_segments to be prepared for this. | |
1035 | */ | |
1036 | if (need_drain) | |
1037 | nr_segs++; | |
1038 | ||
0475bd6c CH |
1039 | /* |
1040 | * If sg table allocation fails, requeue request later. | |
1041 | */ | |
cc97923a CH |
1042 | if (unlikely(sg_alloc_table_chained(&cmd->sdb.table, nr_segs, |
1043 | cmd->sdb.table.sgl, SCSI_INLINE_SG_CNT))) | |
0475bd6c CH |
1044 | return BLK_STS_RESOURCE; |
1045 | ||
1046 | /* | |
1047 | * Next, walk the list, and fill in the addresses and sizes of | |
1048 | * each segment. | |
1049 | */ | |
cc97923a CH |
1050 | count = __blk_rq_map_sg(rq->q, rq, cmd->sdb.table.sgl, &last_sg); |
1051 | ||
bdf8710d CH |
1052 | if (blk_rq_bytes(rq) & rq->q->dma_pad_mask) { |
1053 | unsigned int pad_len = | |
1054 | (rq->q->dma_pad_mask & ~blk_rq_bytes(rq)) + 1; | |
1055 | ||
1056 | last_sg->length += pad_len; | |
1057 | cmd->extra_len += pad_len; | |
1058 | } | |
1059 | ||
cc97923a CH |
1060 | if (need_drain) { |
1061 | sg_unmark_end(last_sg); | |
1062 | last_sg = sg_next(last_sg); | |
1063 | sg_set_buf(last_sg, sdev->dma_drain_buf, sdev->dma_drain_len); | |
1064 | sg_mark_end(last_sg); | |
1065 | ||
bdf8710d | 1066 | cmd->extra_len += sdev->dma_drain_len; |
cc97923a CH |
1067 | count++; |
1068 | } | |
1069 | ||
0475bd6c CH |
1070 | BUG_ON(count > cmd->sdb.table.nents); |
1071 | cmd->sdb.table.nents = count; | |
1072 | cmd->sdb.length = blk_rq_payload_bytes(rq); | |
6f9a35e2 | 1073 | |
13f05c8d | 1074 | if (blk_integrity_rq(rq)) { |
7027ad72 | 1075 | struct scsi_data_buffer *prot_sdb = cmd->prot_sdb; |
0475bd6c | 1076 | int ivecs; |
7027ad72 | 1077 | |
14784565 | 1078 | if (WARN_ON_ONCE(!prot_sdb)) { |
91724c20 EM |
1079 | /* |
1080 | * This can happen if someone (e.g. multipath) | |
1081 | * queues a command to a device on an adapter | |
1082 | * that does not support DIX. | |
1083 | */ | |
159b2cbf | 1084 | ret = BLK_STS_IOERR; |
14784565 | 1085 | goto out_free_sgtables; |
91724c20 EM |
1086 | } |
1087 | ||
13f05c8d | 1088 | ivecs = blk_rq_count_integrity_sg(rq->q, rq->bio); |
7027ad72 | 1089 | |
001d63be | 1090 | if (sg_alloc_table_chained(&prot_sdb->table, ivecs, |
4635873c | 1091 | prot_sdb->table.sgl, |
92524fa1 | 1092 | SCSI_INLINE_PROT_SG_CNT)) { |
159b2cbf | 1093 | ret = BLK_STS_RESOURCE; |
14784565 | 1094 | goto out_free_sgtables; |
7027ad72 MP |
1095 | } |
1096 | ||
13f05c8d | 1097 | count = blk_rq_map_integrity_sg(rq->q, rq->bio, |
7027ad72 | 1098 | prot_sdb->table.sgl); |
6f1d8a53 IS |
1099 | BUG_ON(count > ivecs); |
1100 | BUG_ON(count > queue_max_integrity_segments(rq->q)); | |
7027ad72 MP |
1101 | |
1102 | cmd->prot_sdb = prot_sdb; | |
1103 | cmd->prot_sdb->table.nents = count; | |
1104 | } | |
1105 | ||
159b2cbf | 1106 | return BLK_STS_OK; |
14784565 | 1107 | out_free_sgtables: |
20a66f2b | 1108 | scsi_free_sgtables(cmd); |
159b2cbf | 1109 | return ret; |
6f9a35e2 | 1110 | } |
7007e9dd | 1111 | EXPORT_SYMBOL(scsi_alloc_sgtables); |
1da177e4 | 1112 | |
ca18d6f7 | 1113 | /** |
832889f5 | 1114 | * scsi_initialize_rq - initialize struct scsi_cmnd partially |
35c0506f | 1115 | * @rq: Request associated with the SCSI command to be initialized. |
ca18d6f7 | 1116 | * |
832889f5 BVA |
1117 | * This function initializes the members of struct scsi_cmnd that must be |
1118 | * initialized before request processing starts and that won't be | |
1119 | * reinitialized if a SCSI command is requeued. | |
ca18d6f7 | 1120 | */ |
e4c9470b | 1121 | static void scsi_initialize_rq(struct request *rq) |
ca18d6f7 | 1122 | { |
c8d9cf22 BVA |
1123 | struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq); |
1124 | ||
ce70fd9a CH |
1125 | memset(cmd->cmnd, 0, sizeof(cmd->cmnd)); |
1126 | cmd->cmd_len = MAX_COMMAND_SIZE; | |
5b794f98 | 1127 | cmd->sense_len = 0; |
3be8828f | 1128 | init_rcu_head(&cmd->rcu); |
832889f5 BVA |
1129 | cmd->jiffies_at_alloc = jiffies; |
1130 | cmd->retries = 0; | |
ca18d6f7 | 1131 | } |
ca18d6f7 | 1132 | |
ea957547 BVA |
1133 | struct request *scsi_alloc_request(struct request_queue *q, blk_opf_t opf, |
1134 | blk_mq_req_flags_t flags) | |
68ec3b81 CH |
1135 | { |
1136 | struct request *rq; | |
1137 | ||
ea957547 | 1138 | rq = blk_mq_alloc_request(q, opf, flags); |
68ec3b81 CH |
1139 | if (!IS_ERR(rq)) |
1140 | scsi_initialize_rq(rq); | |
1141 | return rq; | |
1142 | } | |
1143 | EXPORT_SYMBOL_GPL(scsi_alloc_request); | |
1144 | ||
b7e9e1fb ML |
1145 | /* |
1146 | * Only called when the request isn't completed by SCSI, and not freed by | |
1147 | * SCSI | |
1148 | */ | |
1149 | static void scsi_cleanup_rq(struct request *rq) | |
1150 | { | |
1151 | if (rq->rq_flags & RQF_DONTPREP) { | |
1152 | scsi_mq_uninit_cmd(blk_mq_rq_to_pdu(rq)); | |
1153 | rq->rq_flags &= ~RQF_DONTPREP; | |
1154 | } | |
1155 | } | |
1156 | ||
65ca846a | 1157 | /* Called before a request is prepared. See also scsi_mq_prep_fn(). */ |
e9c787e6 | 1158 | void scsi_init_command(struct scsi_device *dev, struct scsi_cmnd *cmd) |
3b003157 | 1159 | { |
aa8e25e5 | 1160 | struct request *rq = scsi_cmd_to_rq(cmd); |
71bada34 CH |
1161 | |
1162 | if (!blk_rq_is_passthrough(rq) && !(cmd->flags & SCMD_INITIALIZED)) { | |
1163 | cmd->flags |= SCMD_INITIALIZED; | |
64104f70 BVA |
1164 | scsi_initialize_rq(rq); |
1165 | } | |
3b003157 | 1166 | |
e9c787e6 | 1167 | cmd->device = dev; |
5ae17501 | 1168 | INIT_LIST_HEAD(&cmd->eh_entry); |
e9c787e6 | 1169 | INIT_DELAYED_WORK(&cmd->abort_work, scmd_eh_abort_handler); |
3b003157 CH |
1170 | } |
1171 | ||
785ba83b CH |
1172 | static blk_status_t scsi_setup_scsi_cmnd(struct scsi_device *sdev, |
1173 | struct request *req) | |
7b16318d | 1174 | { |
bed2213d | 1175 | struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req); |
3b003157 CH |
1176 | |
1177 | /* | |
aebf526b | 1178 | * Passthrough requests may transfer data, in which case they must |
3b003157 CH |
1179 | * a bio attached to them. Or they might contain a SCSI command |
1180 | * that does not transfer data, in which case they may optionally | |
1181 | * submit a request without an attached bio. | |
1182 | */ | |
1183 | if (req->bio) { | |
7007e9dd | 1184 | blk_status_t ret = scsi_alloc_sgtables(cmd); |
159b2cbf CH |
1185 | if (unlikely(ret != BLK_STS_OK)) |
1186 | return ret; | |
3b003157 | 1187 | } else { |
b0790410 | 1188 | BUG_ON(blk_rq_bytes(req)); |
3b003157 | 1189 | |
30b0c37b | 1190 | memset(&cmd->sdb, 0, sizeof(cmd->sdb)); |
3b003157 | 1191 | } |
7b16318d | 1192 | |
b0790410 | 1193 | cmd->transfersize = blk_rq_bytes(req); |
785ba83b | 1194 | return BLK_STS_OK; |
7b16318d | 1195 | } |
7b16318d | 1196 | |
c092d4ec | 1197 | static blk_status_t |
822bd2db | 1198 | scsi_device_state_check(struct scsi_device *sdev, struct request *req) |
3b003157 | 1199 | { |
c092d4ec | 1200 | switch (sdev->sdev_state) { |
e6044f71 BVA |
1201 | case SDEV_CREATED: |
1202 | return BLK_STS_OK; | |
c092d4ec CH |
1203 | case SDEV_OFFLINE: |
1204 | case SDEV_TRANSPORT_OFFLINE: | |
1205 | /* | |
1206 | * If the device is offline we refuse to process any | |
1207 | * commands. The device must be brought online | |
1208 | * before trying any recovery commands. | |
1209 | */ | |
b0962c53 EM |
1210 | if (!sdev->offline_already) { |
1211 | sdev->offline_already = true; | |
1212 | sdev_printk(KERN_ERR, sdev, | |
1213 | "rejecting I/O to offline device\n"); | |
1214 | } | |
c092d4ec CH |
1215 | return BLK_STS_IOERR; |
1216 | case SDEV_DEL: | |
1217 | /* | |
1218 | * If the device is fully deleted, we refuse to | |
1219 | * process any commands as well. | |
1220 | */ | |
1221 | sdev_printk(KERN_ERR, sdev, | |
1222 | "rejecting I/O to dead device\n"); | |
1223 | return BLK_STS_IOERR; | |
1224 | case SDEV_BLOCK: | |
1225 | case SDEV_CREATED_BLOCK: | |
1226 | return BLK_STS_RESOURCE; | |
1227 | case SDEV_QUIESCE: | |
1228 | /* | |
e6044f71 BVA |
1229 | * If the device is blocked we only accept power management |
1230 | * commands. | |
c092d4ec | 1231 | */ |
e6044f71 | 1232 | if (req && WARN_ON_ONCE(!(req->rq_flags & RQF_PM))) |
c092d4ec CH |
1233 | return BLK_STS_RESOURCE; |
1234 | return BLK_STS_OK; | |
1235 | default: | |
1236 | /* | |
1237 | * For any other not fully online state we only allow | |
e6044f71 | 1238 | * power management commands. |
c092d4ec | 1239 | */ |
e6044f71 | 1240 | if (req && !(req->rq_flags & RQF_PM)) |
9574d434 | 1241 | return BLK_STS_OFFLINE; |
c092d4ec | 1242 | return BLK_STS_OK; |
1da177e4 | 1243 | } |
7f9a6bc4 | 1244 | } |
1da177e4 | 1245 | |
1da177e4 | 1246 | /* |
020b0f0a ML |
1247 | * scsi_dev_queue_ready: if we can send requests to sdev, assign one token |
1248 | * and return the token else return -1. | |
1da177e4 LT |
1249 | */ |
1250 | static inline int scsi_dev_queue_ready(struct request_queue *q, | |
1251 | struct scsi_device *sdev) | |
1252 | { | |
020b0f0a | 1253 | int token; |
71e75c97 | 1254 | |
020b0f0a | 1255 | token = sbitmap_get(&sdev->budget_map); |
cd9070c9 | 1256 | if (atomic_read(&sdev->device_blocked)) { |
020b0f0a ML |
1257 | if (token < 0) |
1258 | goto out; | |
1259 | ||
1260 | if (scsi_device_busy(sdev) > 1) | |
71e75c97 CH |
1261 | goto out_dec; |
1262 | ||
1da177e4 LT |
1263 | /* |
1264 | * unblock after device_blocked iterates to zero | |
1265 | */ | |
f664a3cc | 1266 | if (atomic_dec_return(&sdev->device_blocked) > 0) |
71e75c97 | 1267 | goto out_dec; |
71e75c97 CH |
1268 | SCSI_LOG_MLQUEUE(3, sdev_printk(KERN_INFO, sdev, |
1269 | "unblocking device at zero depth\n")); | |
1da177e4 | 1270 | } |
71e75c97 | 1271 | |
020b0f0a | 1272 | return token; |
71e75c97 | 1273 | out_dec: |
020b0f0a ML |
1274 | if (token >= 0) |
1275 | sbitmap_put(&sdev->budget_map, token); | |
1276 | out: | |
1277 | return -1; | |
1da177e4 LT |
1278 | } |
1279 | ||
f0c0a376 MC |
1280 | /* |
1281 | * scsi_target_queue_ready: checks if there we can send commands to target | |
1282 | * @sdev: scsi device on starget to check. | |
f0c0a376 MC |
1283 | */ |
1284 | static inline int scsi_target_queue_ready(struct Scsi_Host *shost, | |
1285 | struct scsi_device *sdev) | |
1286 | { | |
1287 | struct scsi_target *starget = scsi_target(sdev); | |
7ae65c0f | 1288 | unsigned int busy; |
f0c0a376 MC |
1289 | |
1290 | if (starget->single_lun) { | |
7ae65c0f | 1291 | spin_lock_irq(shost->host_lock); |
f0c0a376 | 1292 | if (starget->starget_sdev_user && |
7ae65c0f CH |
1293 | starget->starget_sdev_user != sdev) { |
1294 | spin_unlock_irq(shost->host_lock); | |
1295 | return 0; | |
1296 | } | |
f0c0a376 | 1297 | starget->starget_sdev_user = sdev; |
7ae65c0f | 1298 | spin_unlock_irq(shost->host_lock); |
f0c0a376 MC |
1299 | } |
1300 | ||
2ccbb008 CH |
1301 | if (starget->can_queue <= 0) |
1302 | return 1; | |
1303 | ||
7ae65c0f | 1304 | busy = atomic_inc_return(&starget->target_busy) - 1; |
cd9070c9 | 1305 | if (atomic_read(&starget->target_blocked) > 0) { |
7ae65c0f CH |
1306 | if (busy) |
1307 | goto starved; | |
1308 | ||
f0c0a376 MC |
1309 | /* |
1310 | * unblock after target_blocked iterates to zero | |
1311 | */ | |
cd9070c9 | 1312 | if (atomic_dec_return(&starget->target_blocked) > 0) |
7ae65c0f | 1313 | goto out_dec; |
cf68d334 CH |
1314 | |
1315 | SCSI_LOG_MLQUEUE(3, starget_printk(KERN_INFO, starget, | |
1316 | "unblocking target at zero depth\n")); | |
f0c0a376 MC |
1317 | } |
1318 | ||
2ccbb008 | 1319 | if (busy >= starget->can_queue) |
7ae65c0f | 1320 | goto starved; |
f0c0a376 | 1321 | |
7ae65c0f CH |
1322 | return 1; |
1323 | ||
1324 | starved: | |
1325 | spin_lock_irq(shost->host_lock); | |
1326 | list_move_tail(&sdev->starved_entry, &shost->starved_list); | |
cf68d334 | 1327 | spin_unlock_irq(shost->host_lock); |
7ae65c0f | 1328 | out_dec: |
2ccbb008 CH |
1329 | if (starget->can_queue > 0) |
1330 | atomic_dec(&starget->target_busy); | |
7ae65c0f | 1331 | return 0; |
f0c0a376 MC |
1332 | } |
1333 | ||
1da177e4 LT |
1334 | /* |
1335 | * scsi_host_queue_ready: if we can send requests to shost, return 1 else | |
1336 | * return 0. We must end up running the queue again whenever 0 is | |
1337 | * returned, else IO can hang. | |
1da177e4 LT |
1338 | */ |
1339 | static inline int scsi_host_queue_ready(struct request_queue *q, | |
1340 | struct Scsi_Host *shost, | |
6eb045e0 ML |
1341 | struct scsi_device *sdev, |
1342 | struct scsi_cmnd *cmd) | |
1da177e4 | 1343 | { |
cd9070c9 | 1344 | if (atomic_read(&shost->host_blocked) > 0) { |
6eb045e0 | 1345 | if (scsi_host_busy(shost) > 0) |
74665016 CH |
1346 | goto starved; |
1347 | ||
1da177e4 LT |
1348 | /* |
1349 | * unblock after host_blocked iterates to zero | |
1350 | */ | |
cd9070c9 | 1351 | if (atomic_dec_return(&shost->host_blocked) > 0) |
74665016 | 1352 | goto out_dec; |
cf68d334 CH |
1353 | |
1354 | SCSI_LOG_MLQUEUE(3, | |
1355 | shost_printk(KERN_INFO, shost, | |
1356 | "unblocking host at zero depth\n")); | |
1da177e4 | 1357 | } |
74665016 | 1358 | |
74665016 CH |
1359 | if (shost->host_self_blocked) |
1360 | goto starved; | |
1da177e4 LT |
1361 | |
1362 | /* We're OK to process the command, so we can't be starved */ | |
74665016 CH |
1363 | if (!list_empty(&sdev->starved_entry)) { |
1364 | spin_lock_irq(shost->host_lock); | |
1365 | if (!list_empty(&sdev->starved_entry)) | |
1366 | list_del_init(&sdev->starved_entry); | |
1367 | spin_unlock_irq(shost->host_lock); | |
1368 | } | |
1da177e4 | 1369 | |
6eb045e0 ML |
1370 | __set_bit(SCMD_STATE_INFLIGHT, &cmd->state); |
1371 | ||
74665016 CH |
1372 | return 1; |
1373 | ||
1374 | starved: | |
1375 | spin_lock_irq(shost->host_lock); | |
1376 | if (list_empty(&sdev->starved_entry)) | |
1377 | list_add_tail(&sdev->starved_entry, &shost->starved_list); | |
cf68d334 | 1378 | spin_unlock_irq(shost->host_lock); |
74665016 | 1379 | out_dec: |
6eb045e0 | 1380 | scsi_dec_host_busy(shost, cmd); |
74665016 | 1381 | return 0; |
1da177e4 LT |
1382 | } |
1383 | ||
6c5121b7 KU |
1384 | /* |
1385 | * Busy state exporting function for request stacking drivers. | |
1386 | * | |
1387 | * For efficiency, no lock is taken to check the busy state of | |
1388 | * shost/starget/sdev, since the returned value is not guaranteed and | |
1389 | * may be changed after request stacking drivers call the function, | |
1390 | * regardless of taking lock or not. | |
1391 | * | |
67bd9413 BVA |
1392 | * When scsi can't dispatch I/Os anymore and needs to kill I/Os scsi |
1393 | * needs to return 'not busy'. Otherwise, request stacking drivers | |
1394 | * may hold requests forever. | |
6c5121b7 | 1395 | */ |
f664a3cc | 1396 | static bool scsi_mq_lld_busy(struct request_queue *q) |
6c5121b7 KU |
1397 | { |
1398 | struct scsi_device *sdev = q->queuedata; | |
1399 | struct Scsi_Host *shost; | |
6c5121b7 | 1400 | |
3f3299d5 | 1401 | if (blk_queue_dying(q)) |
f664a3cc | 1402 | return false; |
6c5121b7 KU |
1403 | |
1404 | shost = sdev->host; | |
6c5121b7 | 1405 | |
b7e94a16 JN |
1406 | /* |
1407 | * Ignore host/starget busy state. | |
1408 | * Since block layer does not have a concept of fairness across | |
1409 | * multiple queues, congestion of host/starget needs to be handled | |
1410 | * in SCSI layer. | |
1411 | */ | |
1412 | if (scsi_host_in_recovery(shost) || scsi_device_is_busy(sdev)) | |
f664a3cc | 1413 | return true; |
e36e0c80 | 1414 | |
f664a3cc | 1415 | return false; |
1da177e4 LT |
1416 | } |
1417 | ||
0d2810cd BVA |
1418 | /* |
1419 | * Block layer request completion callback. May be called from interrupt | |
1420 | * context. | |
1421 | */ | |
1422 | static void scsi_complete(struct request *rq) | |
1aea6434 | 1423 | { |
bed2213d | 1424 | struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq); |
b8e162f9 | 1425 | enum scsi_disposition disposition; |
1aea6434 JA |
1426 | |
1427 | INIT_LIST_HEAD(&cmd->eh_entry); | |
1428 | ||
242f9dcb JA |
1429 | atomic_inc(&cmd->device->iodone_cnt); |
1430 | if (cmd->result) | |
1431 | atomic_inc(&cmd->device->ioerr_cnt); | |
1432 | ||
1aea6434 | 1433 | disposition = scsi_decide_disposition(cmd); |
2a242d59 | 1434 | if (disposition != SUCCESS && scsi_cmd_runtime_exceeced(cmd)) |
1aea6434 | 1435 | disposition = SUCCESS; |
91921e01 | 1436 | |
1aea6434 JA |
1437 | scsi_log_completion(cmd, disposition); |
1438 | ||
1439 | switch (disposition) { | |
4c7b4d63 BH |
1440 | case SUCCESS: |
1441 | scsi_finish_command(cmd); | |
1442 | break; | |
1443 | case NEEDS_RETRY: | |
1444 | scsi_queue_insert(cmd, SCSI_MLQUEUE_EH_RETRY); | |
1445 | break; | |
1446 | case ADD_TO_MLQUEUE: | |
1447 | scsi_queue_insert(cmd, SCSI_MLQUEUE_DEVICE_BUSY); | |
1448 | break; | |
1449 | default: | |
1450 | scsi_eh_scmd_add(cmd); | |
1451 | break; | |
1aea6434 JA |
1452 | } |
1453 | } | |
1454 | ||
82042a2c | 1455 | /** |
ae6b4e69 | 1456 | * scsi_dispatch_cmd - Dispatch a command to the low-level driver. |
82042a2c CH |
1457 | * @cmd: command block we are dispatching. |
1458 | * | |
1459 | * Return: nonzero return request was rejected and device's queue needs to be | |
1460 | * plugged. | |
1461 | */ | |
1462 | static int scsi_dispatch_cmd(struct scsi_cmnd *cmd) | |
1463 | { | |
1464 | struct Scsi_Host *host = cmd->device->host; | |
1465 | int rtn = 0; | |
1466 | ||
82042a2c CH |
1467 | /* check if the device is still usable */ |
1468 | if (unlikely(cmd->device->sdev_state == SDEV_DEL)) { | |
1469 | /* in SDEV_DEL we error all commands. DID_NO_CONNECT | |
1470 | * returns an immediate error upwards, and signals | |
1471 | * that the device is no longer present */ | |
1472 | cmd->result = DID_NO_CONNECT << 16; | |
1473 | goto done; | |
1474 | } | |
1475 | ||
1476 | /* Check to see if the scsi lld made this device blocked. */ | |
1477 | if (unlikely(scsi_device_blocked(cmd->device))) { | |
1478 | /* | |
1479 | * in blocked state, the command is just put back on | |
1480 | * the device queue. The suspend state has already | |
1481 | * blocked the queue so future requests should not | |
1482 | * occur until the device transitions out of the | |
1483 | * suspend state. | |
1484 | */ | |
1485 | SCSI_LOG_MLQUEUE(3, scmd_printk(KERN_INFO, cmd, | |
1486 | "queuecommand : device blocked\n")); | |
1487 | return SCSI_MLQUEUE_DEVICE_BUSY; | |
1488 | } | |
1489 | ||
1490 | /* Store the LUN value in cmnd, if needed. */ | |
1491 | if (cmd->device->lun_in_cdb) | |
1492 | cmd->cmnd[1] = (cmd->cmnd[1] & 0x1f) | | |
1493 | (cmd->device->lun << 5 & 0xe0); | |
1494 | ||
1495 | scsi_log_send(cmd); | |
1496 | ||
1497 | /* | |
1498 | * Before we queue this command, check if the command | |
1499 | * length exceeds what the host adapter can handle. | |
1500 | */ | |
1501 | if (cmd->cmd_len > cmd->device->host->max_cmd_len) { | |
1502 | SCSI_LOG_MLQUEUE(3, scmd_printk(KERN_INFO, cmd, | |
1503 | "queuecommand : command too long. " | |
1504 | "cdb_size=%d host->max_cmd_len=%d\n", | |
1505 | cmd->cmd_len, cmd->device->host->max_cmd_len)); | |
1506 | cmd->result = (DID_ABORT << 16); | |
1507 | goto done; | |
1508 | } | |
1509 | ||
1510 | if (unlikely(host->shost_state == SHOST_DEL)) { | |
1511 | cmd->result = (DID_NO_CONNECT << 16); | |
1512 | goto done; | |
1513 | ||
1514 | } | |
1515 | ||
1516 | trace_scsi_dispatch_cmd_start(cmd); | |
1517 | rtn = host->hostt->queuecommand(host, cmd); | |
1518 | if (rtn) { | |
1519 | trace_scsi_dispatch_cmd_error(cmd, rtn); | |
1520 | if (rtn != SCSI_MLQUEUE_DEVICE_BUSY && | |
1521 | rtn != SCSI_MLQUEUE_TARGET_BUSY) | |
1522 | rtn = SCSI_MLQUEUE_HOST_BUSY; | |
1523 | ||
1524 | SCSI_LOG_MLQUEUE(3, scmd_printk(KERN_INFO, cmd, | |
1525 | "queuecommand : request rejected\n")); | |
1526 | } | |
1527 | ||
1528 | return rtn; | |
1529 | done: | |
11b68e36 | 1530 | scsi_done(cmd); |
82042a2c CH |
1531 | return 0; |
1532 | } | |
1533 | ||
be4c186c | 1534 | /* Size in bytes of the sg-list stored in the scsi-mq command-private data. */ |
3dccdf53 | 1535 | static unsigned int scsi_mq_inline_sgl_size(struct Scsi_Host *shost) |
be4c186c | 1536 | { |
3dccdf53 | 1537 | return min_t(unsigned int, shost->sg_tablesize, SCSI_INLINE_SG_CNT) * |
be4c186c BVA |
1538 | sizeof(struct scatterlist); |
1539 | } | |
1540 | ||
5843cc3d | 1541 | static blk_status_t scsi_prepare_cmd(struct request *req) |
d285203c CH |
1542 | { |
1543 | struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req); | |
1544 | struct scsi_device *sdev = req->q->queuedata; | |
1545 | struct Scsi_Host *shost = sdev->host; | |
71bada34 | 1546 | bool in_flight = test_bit(SCMD_STATE_INFLIGHT, &cmd->state); |
d285203c CH |
1547 | struct scatterlist *sg; |
1548 | ||
08f78436 | 1549 | scsi_init_command(sdev, cmd); |
d285203c | 1550 | |
71bada34 | 1551 | cmd->eh_eflags = 0; |
71bada34 CH |
1552 | cmd->prot_type = 0; |
1553 | cmd->prot_flags = 0; | |
1554 | cmd->submitter = 0; | |
71bada34 CH |
1555 | memset(&cmd->sdb, 0, sizeof(cmd->sdb)); |
1556 | cmd->underflow = 0; | |
1557 | cmd->transfersize = 0; | |
1558 | cmd->host_scribble = NULL; | |
1559 | cmd->result = 0; | |
1560 | cmd->extra_len = 0; | |
1561 | cmd->state = 0; | |
1562 | if (in_flight) | |
1563 | __set_bit(SCMD_STATE_INFLIGHT, &cmd->state); | |
1564 | ||
1565 | /* | |
1566 | * Only clear the driver-private command data if the LLD does not supply | |
1567 | * a function to initialize that data. | |
1568 | */ | |
1569 | if (!shost->hostt->init_cmd_priv) | |
1570 | memset(cmd + 1, 0, shost->hostt->cmd_size); | |
1571 | ||
d285203c | 1572 | cmd->prot_op = SCSI_PROT_NORMAL; |
b6ba9b0e CH |
1573 | if (blk_rq_bytes(req)) |
1574 | cmd->sc_data_direction = rq_dma_dir(req); | |
1575 | else | |
1576 | cmd->sc_data_direction = DMA_NONE; | |
d285203c | 1577 | |
d285203c CH |
1578 | sg = (void *)cmd + sizeof(struct scsi_cmnd) + shost->hostt->cmd_size; |
1579 | cmd->sdb.table.sgl = sg; | |
1580 | ||
1581 | if (scsi_host_get_prot(shost)) { | |
d285203c CH |
1582 | memset(cmd->prot_sdb, 0, sizeof(struct scsi_data_buffer)); |
1583 | ||
1584 | cmd->prot_sdb->table.sgl = | |
1585 | (struct scatterlist *)(cmd->prot_sdb + 1); | |
1586 | } | |
1587 | ||
74e5e6c1 CH |
1588 | /* |
1589 | * Special handling for passthrough commands, which don't go to the ULP | |
1590 | * at all: | |
1591 | */ | |
da6269da | 1592 | if (blk_rq_is_passthrough(req)) |
74e5e6c1 CH |
1593 | return scsi_setup_scsi_cmnd(sdev, req); |
1594 | ||
1595 | if (sdev->handler && sdev->handler->prep_fn) { | |
1596 | blk_status_t ret = sdev->handler->prep_fn(sdev, req); | |
fe052529 | 1597 | |
74e5e6c1 CH |
1598 | if (ret != BLK_STS_OK) |
1599 | return ret; | |
1600 | } | |
1601 | ||
fac8e558 MC |
1602 | /* Usually overridden by the ULP */ |
1603 | cmd->allowed = 0; | |
ce70fd9a | 1604 | memset(cmd->cmnd, 0, sizeof(cmd->cmnd)); |
74e5e6c1 | 1605 | return scsi_cmd_to_driver(cmd)->init_command(cmd); |
d285203c CH |
1606 | } |
1607 | ||
b84b6ec0 | 1608 | static void scsi_done_internal(struct scsi_cmnd *cmd, bool complete_directly) |
d285203c | 1609 | { |
b84b6ec0 SAS |
1610 | struct request *req = scsi_cmd_to_rq(cmd); |
1611 | ||
bf23e619 BVA |
1612 | switch (cmd->submitter) { |
1613 | case SUBMITTED_BY_BLOCK_LAYER: | |
1614 | break; | |
1615 | case SUBMITTED_BY_SCSI_ERROR_HANDLER: | |
1616 | return scsi_eh_done(cmd); | |
1617 | case SUBMITTED_BY_SCSI_RESET_IOCTL: | |
1618 | return; | |
1619 | } | |
1620 | ||
aa8e25e5 | 1621 | if (unlikely(blk_should_fake_timeout(scsi_cmd_to_rq(cmd)->q))) |
15f73f5b | 1622 | return; |
f1342709 KB |
1623 | if (unlikely(test_and_set_bit(SCMD_STATE_COMPLETE, &cmd->state))) |
1624 | return; | |
d285203c | 1625 | trace_scsi_dispatch_cmd_done(cmd); |
b84b6ec0 SAS |
1626 | |
1627 | if (complete_directly) | |
1628 | blk_mq_complete_request_direct(req, scsi_complete); | |
1629 | else | |
1630 | blk_mq_complete_request(req); | |
1631 | } | |
1632 | ||
1633 | void scsi_done(struct scsi_cmnd *cmd) | |
1634 | { | |
1635 | scsi_done_internal(cmd, false); | |
d285203c | 1636 | } |
a710eacb | 1637 | EXPORT_SYMBOL(scsi_done); |
d285203c | 1638 | |
b84b6ec0 SAS |
1639 | void scsi_done_direct(struct scsi_cmnd *cmd) |
1640 | { | |
1641 | scsi_done_internal(cmd, true); | |
1642 | } | |
1643 | EXPORT_SYMBOL(scsi_done_direct); | |
1644 | ||
2a5a24aa | 1645 | static void scsi_mq_put_budget(struct request_queue *q, int budget_token) |
d285203c | 1646 | { |
0df21c86 | 1647 | struct scsi_device *sdev = q->queuedata; |
0df21c86 | 1648 | |
020b0f0a | 1649 | sbitmap_put(&sdev->budget_map, budget_token); |
0df21c86 ML |
1650 | } |
1651 | ||
90552cd2 BVA |
1652 | /* |
1653 | * When to reinvoke queueing after a resource shortage. It's 3 msecs to | |
1654 | * not change behaviour from the previous unplug mechanism, experimentation | |
1655 | * may prove this needs changing. | |
1656 | */ | |
1657 | #define SCSI_QUEUE_DELAY 3 | |
1658 | ||
2a5a24aa | 1659 | static int scsi_mq_get_budget(struct request_queue *q) |
0df21c86 | 1660 | { |
d285203c | 1661 | struct scsi_device *sdev = q->queuedata; |
020b0f0a | 1662 | int token = scsi_dev_queue_ready(q, sdev); |
d285203c | 1663 | |
020b0f0a ML |
1664 | if (token >= 0) |
1665 | return token; | |
ed5dd6a6 ML |
1666 | |
1667 | atomic_inc(&sdev->restarts); | |
1668 | ||
1669 | /* | |
1670 | * Orders atomic_inc(&sdev->restarts) and atomic_read(&sdev->device_busy). | |
1671 | * .restarts must be incremented before .device_busy is read because the | |
1672 | * code in scsi_run_queue_async() depends on the order of these operations. | |
1673 | */ | |
1674 | smp_mb__after_atomic(); | |
1675 | ||
1676 | /* | |
1677 | * If all in-flight requests originated from this LUN are completed | |
1678 | * before reading .device_busy, sdev->device_busy will be observed as | |
1679 | * zero, then blk_mq_delay_run_hw_queues() will dispatch this request | |
1680 | * soon. Otherwise, completion of one of these requests will observe | |
1681 | * the .restarts flag, and the request queue will be run for handling | |
1682 | * this request, see scsi_end_request(). | |
1683 | */ | |
8278807a | 1684 | if (unlikely(scsi_device_busy(sdev) == 0 && |
ed5dd6a6 ML |
1685 | !scsi_device_blocked(sdev))) |
1686 | blk_mq_delay_run_hw_queues(sdev->request_queue, SCSI_QUEUE_DELAY); | |
2a5a24aa | 1687 | return -1; |
0df21c86 ML |
1688 | } |
1689 | ||
d022d18c ML |
1690 | static void scsi_mq_set_rq_budget_token(struct request *req, int token) |
1691 | { | |
1692 | struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req); | |
1693 | ||
1694 | cmd->budget_token = token; | |
1695 | } | |
1696 | ||
1697 | static int scsi_mq_get_rq_budget_token(struct request *req) | |
1698 | { | |
1699 | struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req); | |
1700 | ||
1701 | return cmd->budget_token; | |
0df21c86 ML |
1702 | } |
1703 | ||
fc17b653 | 1704 | static blk_status_t scsi_queue_rq(struct blk_mq_hw_ctx *hctx, |
74c45052 | 1705 | const struct blk_mq_queue_data *bd) |
d285203c | 1706 | { |
74c45052 | 1707 | struct request *req = bd->rq; |
d285203c CH |
1708 | struct request_queue *q = req->q; |
1709 | struct scsi_device *sdev = q->queuedata; | |
1710 | struct Scsi_Host *shost = sdev->host; | |
1711 | struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req); | |
fc17b653 | 1712 | blk_status_t ret; |
d285203c CH |
1713 | int reason; |
1714 | ||
2a5a24aa ML |
1715 | WARN_ON_ONCE(cmd->budget_token < 0); |
1716 | ||
c092d4ec CH |
1717 | /* |
1718 | * If the device is not in running state we will reject some or all | |
1719 | * commands. | |
1720 | */ | |
1721 | if (unlikely(sdev->sdev_state != SDEV_RUNNING)) { | |
822bd2db | 1722 | ret = scsi_device_state_check(sdev, req); |
c092d4ec CH |
1723 | if (ret != BLK_STS_OK) |
1724 | goto out_put_budget; | |
1725 | } | |
d285203c | 1726 | |
fc17b653 | 1727 | ret = BLK_STS_RESOURCE; |
d285203c | 1728 | if (!scsi_target_queue_ready(shost, sdev)) |
826a70a0 | 1729 | goto out_put_budget; |
310bcaef BVA |
1730 | if (unlikely(scsi_host_in_recovery(shost))) { |
1731 | if (cmd->flags & SCMD_FAIL_IF_RECOVERING) | |
1732 | ret = BLK_STS_OFFLINE; | |
1733 | goto out_dec_target_busy; | |
1734 | } | |
6eb045e0 | 1735 | if (!scsi_host_queue_ready(q, shost, sdev, cmd)) |
d285203c CH |
1736 | goto out_dec_target_busy; |
1737 | ||
e8064021 | 1738 | if (!(req->rq_flags & RQF_DONTPREP)) { |
5843cc3d | 1739 | ret = scsi_prepare_cmd(req); |
fc17b653 | 1740 | if (ret != BLK_STS_OK) |
d285203c | 1741 | goto out_dec_host_busy; |
e8064021 | 1742 | req->rq_flags |= RQF_DONTPREP; |
fe052529 | 1743 | } else { |
cd464d83 | 1744 | clear_bit(SCMD_STATE_COMPLETE, &cmd->state); |
d285203c CH |
1745 | } |
1746 | ||
8930a6c2 | 1747 | cmd->flags &= SCMD_PRESERVED_FLAGS; |
125c99bc CH |
1748 | if (sdev->simple_tags) |
1749 | cmd->flags |= SCMD_TAGGED; | |
8930a6c2 PB |
1750 | if (bd->last) |
1751 | cmd->flags |= SCMD_LAST; | |
b1dd2aac | 1752 | |
3a8dc5bb CH |
1753 | scsi_set_resid(cmd, 0); |
1754 | memset(cmd->sense_buffer, 0, SCSI_SENSE_BUFFERSIZE); | |
bf23e619 | 1755 | cmd->submitter = SUBMITTED_BY_BLOCK_LAYER; |
d285203c | 1756 | |
ed7fb2d0 | 1757 | blk_mq_start_request(req); |
d285203c CH |
1758 | reason = scsi_dispatch_cmd(cmd); |
1759 | if (reason) { | |
1760 | scsi_set_blocked(cmd, reason); | |
fc17b653 | 1761 | ret = BLK_STS_RESOURCE; |
d285203c CH |
1762 | goto out_dec_host_busy; |
1763 | } | |
1764 | ||
cfee29ff | 1765 | atomic_inc(&cmd->device->iorequest_cnt); |
fc17b653 | 1766 | return BLK_STS_OK; |
d285203c CH |
1767 | |
1768 | out_dec_host_busy: | |
6eb045e0 | 1769 | scsi_dec_host_busy(shost, cmd); |
d285203c CH |
1770 | out_dec_target_busy: |
1771 | if (scsi_target(sdev)->can_queue > 0) | |
1772 | atomic_dec(&scsi_target(sdev)->target_busy); | |
0df21c86 | 1773 | out_put_budget: |
2a5a24aa ML |
1774 | scsi_mq_put_budget(q, cmd->budget_token); |
1775 | cmd->budget_token = -1; | |
d285203c | 1776 | switch (ret) { |
fc17b653 CH |
1777 | case BLK_STS_OK: |
1778 | break; | |
1779 | case BLK_STS_RESOURCE: | |
0512a75b | 1780 | case BLK_STS_ZONE_RESOURCE: |
673235f9 | 1781 | if (scsi_device_blocked(sdev)) |
86ff7c2a | 1782 | ret = BLK_STS_DEV_RESOURCE; |
d285203c | 1783 | break; |
268940b8 | 1784 | case BLK_STS_AGAIN: |
dbb4c84d | 1785 | cmd->result = DID_BUS_BUSY << 16; |
268940b8 HR |
1786 | if (req->rq_flags & RQF_DONTPREP) |
1787 | scsi_mq_uninit_cmd(cmd); | |
1788 | break; | |
fc17b653 | 1789 | default: |
be549d49 | 1790 | if (unlikely(!scsi_device_online(sdev))) |
dbb4c84d | 1791 | cmd->result = DID_NO_CONNECT << 16; |
be549d49 | 1792 | else |
dbb4c84d | 1793 | cmd->result = DID_ERROR << 16; |
d285203c | 1794 | /* |
be549d49 | 1795 | * Make sure to release all allocated resources when |
d285203c CH |
1796 | * we hit an error, as we will never see this command |
1797 | * again. | |
1798 | */ | |
e8064021 | 1799 | if (req->rq_flags & RQF_DONTPREP) |
d285203c | 1800 | scsi_mq_uninit_cmd(cmd); |
3f0dcfbc | 1801 | scsi_run_queue_async(sdev); |
d285203c | 1802 | break; |
d285203c CH |
1803 | } |
1804 | return ret; | |
1805 | } | |
1806 | ||
e7008ff5 BVA |
1807 | static int scsi_mq_init_request(struct blk_mq_tag_set *set, struct request *rq, |
1808 | unsigned int hctx_idx, unsigned int numa_node) | |
d285203c | 1809 | { |
d6296d39 | 1810 | struct Scsi_Host *shost = set->driver_data; |
d285203c | 1811 | struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq); |
08f78436 | 1812 | struct scatterlist *sg; |
65ca846a | 1813 | int ret = 0; |
d285203c | 1814 | |
aaff5eba CH |
1815 | cmd->sense_buffer = |
1816 | kmem_cache_alloc_node(scsi_sense_cache, GFP_KERNEL, numa_node); | |
d285203c CH |
1817 | if (!cmd->sense_buffer) |
1818 | return -ENOMEM; | |
08f78436 BVA |
1819 | |
1820 | if (scsi_host_get_prot(shost)) { | |
1821 | sg = (void *)cmd + sizeof(struct scsi_cmnd) + | |
1822 | shost->hostt->cmd_size; | |
3dccdf53 | 1823 | cmd->prot_sdb = (void *)sg + scsi_mq_inline_sgl_size(shost); |
08f78436 BVA |
1824 | } |
1825 | ||
65ca846a BVA |
1826 | if (shost->hostt->init_cmd_priv) { |
1827 | ret = shost->hostt->init_cmd_priv(shost, cmd); | |
1828 | if (ret < 0) | |
aaff5eba | 1829 | kmem_cache_free(scsi_sense_cache, cmd->sense_buffer); |
65ca846a BVA |
1830 | } |
1831 | ||
1832 | return ret; | |
d285203c CH |
1833 | } |
1834 | ||
e7008ff5 BVA |
1835 | static void scsi_mq_exit_request(struct blk_mq_tag_set *set, struct request *rq, |
1836 | unsigned int hctx_idx) | |
d285203c | 1837 | { |
65ca846a | 1838 | struct Scsi_Host *shost = set->driver_data; |
d285203c CH |
1839 | struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq); |
1840 | ||
65ca846a BVA |
1841 | if (shost->hostt->exit_cmd_priv) |
1842 | shost->hostt->exit_cmd_priv(shost, cmd); | |
aaff5eba | 1843 | kmem_cache_free(scsi_sense_cache, cmd->sense_buffer); |
d285203c CH |
1844 | } |
1845 | ||
af183095 | 1846 | |
5a72e899 | 1847 | static int scsi_mq_poll(struct blk_mq_hw_ctx *hctx, struct io_comp_batch *iob) |
af183095 | 1848 | { |
4309ea74 | 1849 | struct Scsi_Host *shost = hctx->driver_data; |
af183095 KD |
1850 | |
1851 | if (shost->hostt->mq_poll) | |
1852 | return shost->hostt->mq_poll(shost, hctx->queue_num); | |
1853 | ||
1854 | return 0; | |
1855 | } | |
1856 | ||
4309ea74 KD |
1857 | static int scsi_init_hctx(struct blk_mq_hw_ctx *hctx, void *data, |
1858 | unsigned int hctx_idx) | |
1859 | { | |
1860 | struct Scsi_Host *shost = data; | |
1861 | ||
1862 | hctx->driver_data = shost; | |
1863 | return 0; | |
1864 | } | |
1865 | ||
a4e1d0b7 | 1866 | static void scsi_map_queues(struct blk_mq_tag_set *set) |
2d9c5c20 CH |
1867 | { |
1868 | struct Scsi_Host *shost = container_of(set, struct Scsi_Host, tag_set); | |
1869 | ||
1870 | if (shost->hostt->map_queues) | |
1871 | return shost->hostt->map_queues(shost); | |
a4e1d0b7 | 1872 | blk_mq_map_queues(&set->map[HCTX_TYPE_DEFAULT]); |
2d9c5c20 CH |
1873 | } |
1874 | ||
d48777a6 | 1875 | void __scsi_init_queue(struct Scsi_Host *shost, struct request_queue *q) |
1da177e4 | 1876 | { |
6f381fa3 | 1877 | struct device *dev = shost->dma_dev; |
1da177e4 | 1878 | |
a8474ce2 JA |
1879 | /* |
1880 | * this limit is imposed by hardware restrictions | |
1881 | */ | |
8a78362c | 1882 | blk_queue_max_segments(q, min_t(unsigned short, shost->sg_tablesize, |
65e8617f | 1883 | SG_MAX_SEGMENTS)); |
a8474ce2 | 1884 | |
13f05c8d MP |
1885 | if (scsi_host_prot_dma(shost)) { |
1886 | shost->sg_prot_tablesize = | |
1887 | min_not_zero(shost->sg_prot_tablesize, | |
1888 | (unsigned short)SCSI_MAX_PROT_SG_SEGMENTS); | |
1889 | BUG_ON(shost->sg_prot_tablesize < shost->sg_tablesize); | |
1890 | blk_queue_max_integrity_segments(q, shost->sg_prot_tablesize); | |
1891 | } | |
1892 | ||
086fa5ff | 1893 | blk_queue_max_hw_sectors(q, shost->max_sectors); |
1da177e4 | 1894 | blk_queue_segment_boundary(q, shost->dma_boundary); |
99c84dbd | 1895 | dma_set_seg_boundary(dev, shost->dma_boundary); |
1da177e4 | 1896 | |
a8cf59a6 | 1897 | blk_queue_max_segment_size(q, shost->max_segment_size); |
7ad388d8 CH |
1898 | blk_queue_virt_boundary(q, shost->virt_boundary_mask); |
1899 | dma_set_max_seg_size(dev, queue_max_segment_size(q)); | |
465ff318 JB |
1900 | |
1901 | /* | |
90addc6b HC |
1902 | * Set a reasonable default alignment: The larger of 32-byte (dword), |
1903 | * which is a common minimum for HBAs, and the minimum DMA alignment, | |
1904 | * which is set by the platform. | |
1905 | * | |
1906 | * Devices that require a bigger alignment can increase it later. | |
465ff318 | 1907 | */ |
90addc6b | 1908 | blk_queue_dma_alignment(q, max(4, dma_get_cache_alignment()) - 1); |
d285203c | 1909 | } |
d48777a6 | 1910 | EXPORT_SYMBOL_GPL(__scsi_init_queue); |
465ff318 | 1911 | |
8930a6c2 PB |
1912 | static const struct blk_mq_ops scsi_mq_ops_no_commit = { |
1913 | .get_budget = scsi_mq_get_budget, | |
1914 | .put_budget = scsi_mq_put_budget, | |
1915 | .queue_rq = scsi_queue_rq, | |
0d2810cd | 1916 | .complete = scsi_complete, |
8930a6c2 PB |
1917 | .timeout = scsi_timeout, |
1918 | #ifdef CONFIG_BLK_DEBUG_FS | |
1919 | .show_rq = scsi_show_rq, | |
1920 | #endif | |
1921 | .init_request = scsi_mq_init_request, | |
1922 | .exit_request = scsi_mq_exit_request, | |
82a9ac71 | 1923 | .cleanup_rq = scsi_cleanup_rq, |
8930a6c2 PB |
1924 | .busy = scsi_mq_lld_busy, |
1925 | .map_queues = scsi_map_queues, | |
4309ea74 | 1926 | .init_hctx = scsi_init_hctx, |
af183095 | 1927 | .poll = scsi_mq_poll, |
d022d18c ML |
1928 | .set_rq_budget_token = scsi_mq_set_rq_budget_token, |
1929 | .get_rq_budget_token = scsi_mq_get_rq_budget_token, | |
8930a6c2 PB |
1930 | }; |
1931 | ||
1932 | ||
1933 | static void scsi_commit_rqs(struct blk_mq_hw_ctx *hctx) | |
1934 | { | |
4309ea74 | 1935 | struct Scsi_Host *shost = hctx->driver_data; |
8930a6c2 PB |
1936 | |
1937 | shost->hostt->commit_rqs(shost, hctx->queue_num); | |
1938 | } | |
1939 | ||
f363b089 | 1940 | static const struct blk_mq_ops scsi_mq_ops = { |
0df21c86 ML |
1941 | .get_budget = scsi_mq_get_budget, |
1942 | .put_budget = scsi_mq_put_budget, | |
d285203c | 1943 | .queue_rq = scsi_queue_rq, |
8930a6c2 | 1944 | .commit_rqs = scsi_commit_rqs, |
0d2810cd | 1945 | .complete = scsi_complete, |
0152fb6b | 1946 | .timeout = scsi_timeout, |
0eebd005 BVA |
1947 | #ifdef CONFIG_BLK_DEBUG_FS |
1948 | .show_rq = scsi_show_rq, | |
1949 | #endif | |
e7008ff5 BVA |
1950 | .init_request = scsi_mq_init_request, |
1951 | .exit_request = scsi_mq_exit_request, | |
b7e9e1fb | 1952 | .cleanup_rq = scsi_cleanup_rq, |
3a7ea2c4 | 1953 | .busy = scsi_mq_lld_busy, |
2d9c5c20 | 1954 | .map_queues = scsi_map_queues, |
4309ea74 | 1955 | .init_hctx = scsi_init_hctx, |
af183095 | 1956 | .poll = scsi_mq_poll, |
d022d18c ML |
1957 | .set_rq_budget_token = scsi_mq_set_rq_budget_token, |
1958 | .get_rq_budget_token = scsi_mq_get_rq_budget_token, | |
d285203c CH |
1959 | }; |
1960 | ||
d285203c CH |
1961 | int scsi_mq_setup_tags(struct Scsi_Host *shost) |
1962 | { | |
be4c186c | 1963 | unsigned int cmd_size, sgl_size; |
840e1b55 | 1964 | struct blk_mq_tag_set *tag_set = &shost->tag_set; |
d285203c | 1965 | |
9393c8de MS |
1966 | sgl_size = max_t(unsigned int, sizeof(struct scatterlist), |
1967 | scsi_mq_inline_sgl_size(shost)); | |
d285203c CH |
1968 | cmd_size = sizeof(struct scsi_cmnd) + shost->hostt->cmd_size + sgl_size; |
1969 | if (scsi_host_get_prot(shost)) | |
92524fa1 ML |
1970 | cmd_size += sizeof(struct scsi_data_buffer) + |
1971 | sizeof(struct scatterlist) * SCSI_INLINE_PROT_SG_CNT; | |
d285203c | 1972 | |
840e1b55 | 1973 | memset(tag_set, 0, sizeof(*tag_set)); |
8930a6c2 | 1974 | if (shost->hostt->commit_rqs) |
840e1b55 | 1975 | tag_set->ops = &scsi_mq_ops; |
8930a6c2 | 1976 | else |
840e1b55 YB |
1977 | tag_set->ops = &scsi_mq_ops_no_commit; |
1978 | tag_set->nr_hw_queues = shost->nr_hw_queues ? : 1; | |
af183095 | 1979 | tag_set->nr_maps = shost->nr_maps ? : 1; |
840e1b55 YB |
1980 | tag_set->queue_depth = shost->can_queue; |
1981 | tag_set->cmd_size = cmd_size; | |
973dac8a | 1982 | tag_set->numa_node = dev_to_node(shost->dma_dev); |
840e1b55 YB |
1983 | tag_set->flags = BLK_MQ_F_SHOULD_MERGE; |
1984 | tag_set->flags |= | |
24391c0d | 1985 | BLK_ALLOC_POLICY_TO_MQ_FLAG(shost->hostt->tag_alloc_policy); |
840e1b55 | 1986 | tag_set->driver_data = shost; |
bdb01301 HR |
1987 | if (shost->host_tagset) |
1988 | tag_set->flags |= BLK_MQ_F_TAG_HCTX_SHARED; | |
d285203c | 1989 | |
840e1b55 | 1990 | return blk_mq_alloc_tag_set(tag_set); |
d285203c CH |
1991 | } |
1992 | ||
8fe4ce58 | 1993 | void scsi_mq_free_tags(struct kref *kref) |
d285203c | 1994 | { |
8fe4ce58 BVA |
1995 | struct Scsi_Host *shost = container_of(kref, typeof(*shost), |
1996 | tagset_refcnt); | |
1997 | ||
d285203c | 1998 | blk_mq_free_tag_set(&shost->tag_set); |
8fe4ce58 | 1999 | complete(&shost->tagset_freed); |
d285203c CH |
2000 | } |
2001 | ||
857de6e0 HR |
2002 | /** |
2003 | * scsi_device_from_queue - return sdev associated with a request_queue | |
2004 | * @q: The request queue to return the sdev from | |
2005 | * | |
2006 | * Return the sdev associated with a request queue or NULL if the | |
2007 | * request_queue does not reference a SCSI device. | |
2008 | */ | |
2009 | struct scsi_device *scsi_device_from_queue(struct request_queue *q) | |
2010 | { | |
2011 | struct scsi_device *sdev = NULL; | |
2012 | ||
6b6fa7a5 SM |
2013 | if (q->mq_ops == &scsi_mq_ops_no_commit || |
2014 | q->mq_ops == &scsi_mq_ops) | |
857de6e0 HR |
2015 | sdev = q->queuedata; |
2016 | if (!sdev || !get_device(&sdev->sdev_gendev)) | |
2017 | sdev = NULL; | |
2018 | ||
2019 | return sdev; | |
2020 | } | |
4845012e CH |
2021 | /* |
2022 | * pktcdvd should have been integrated into the SCSI layers, but for historical | |
2023 | * reasons like the old IDE driver it isn't. This export allows it to safely | |
2024 | * probe if a given device is a SCSI one and only attach to that. | |
2025 | */ | |
2026 | #ifdef CONFIG_CDROM_PKTCDVD_MODULE | |
2027 | EXPORT_SYMBOL_GPL(scsi_device_from_queue); | |
2028 | #endif | |
857de6e0 | 2029 | |
ea941016 AA |
2030 | /** |
2031 | * scsi_block_requests - Utility function used by low-level drivers to prevent | |
2032 | * further commands from being queued to the device. | |
2033 | * @shost: host in question | |
1da177e4 | 2034 | * |
ea941016 AA |
2035 | * There is no timer nor any other means by which the requests get unblocked |
2036 | * other than the low-level driver calling scsi_unblock_requests(). | |
1da177e4 LT |
2037 | */ |
2038 | void scsi_block_requests(struct Scsi_Host *shost) | |
2039 | { | |
2040 | shost->host_self_blocked = 1; | |
2041 | } | |
2042 | EXPORT_SYMBOL(scsi_block_requests); | |
2043 | ||
ea941016 AA |
2044 | /** |
2045 | * scsi_unblock_requests - Utility function used by low-level drivers to allow | |
2046 | * further commands to be queued to the device. | |
2047 | * @shost: host in question | |
1da177e4 | 2048 | * |
ea941016 AA |
2049 | * There is no timer nor any other means by which the requests get unblocked |
2050 | * other than the low-level driver calling scsi_unblock_requests(). This is done | |
2051 | * as an API function so that changes to the internals of the scsi mid-layer | |
2052 | * won't require wholesale changes to drivers that use this feature. | |
1da177e4 LT |
2053 | */ |
2054 | void scsi_unblock_requests(struct Scsi_Host *shost) | |
2055 | { | |
2056 | shost->host_self_blocked = 0; | |
2057 | scsi_run_host_queues(shost); | |
2058 | } | |
2059 | EXPORT_SYMBOL(scsi_unblock_requests); | |
2060 | ||
1da177e4 LT |
2061 | void scsi_exit_queue(void) |
2062 | { | |
0a6ac4ee | 2063 | kmem_cache_destroy(scsi_sense_cache); |
1da177e4 | 2064 | } |
5baba830 JB |
2065 | |
2066 | /** | |
2067 | * scsi_mode_select - issue a mode select | |
2068 | * @sdev: SCSI device to be queried | |
2069 | * @pf: Page format bit (1 == standard, 0 == vendor specific) | |
2070 | * @sp: Save page bit (0 == don't save, 1 == save) | |
5baba830 JB |
2071 | * @buffer: request buffer (may not be smaller than eight bytes) |
2072 | * @len: length of request buffer. | |
2073 | * @timeout: command timeout | |
2074 | * @retries: number of retries before failing | |
2075 | * @data: returns a structure abstracting the mode header data | |
eb44820c | 2076 | * @sshdr: place to put sense data (or NULL if no sense to be collected). |
5baba830 JB |
2077 | * must be SCSI_SENSE_BUFFERSIZE big. |
2078 | * | |
2079 | * Returns zero if successful; negative error number or scsi | |
2080 | * status on error | |
2081 | * | |
2082 | */ | |
81d3f500 DLM |
2083 | int scsi_mode_select(struct scsi_device *sdev, int pf, int sp, |
2084 | unsigned char *buffer, int len, int timeout, int retries, | |
2085 | struct scsi_mode_data *data, struct scsi_sense_hdr *sshdr) | |
5baba830 JB |
2086 | { |
2087 | unsigned char cmd[10]; | |
2088 | unsigned char *real_buffer; | |
2089 | int ret; | |
2090 | ||
2091 | memset(cmd, 0, sizeof(cmd)); | |
2092 | cmd[1] = (pf ? 0x10 : 0) | (sp ? 0x01 : 0); | |
2093 | ||
a7d6840b DLM |
2094 | /* |
2095 | * Use MODE SELECT(10) if the device asked for it or if the mode page | |
2096 | * and the mode select header cannot fit within the maximumm 255 bytes | |
2097 | * of the MODE SELECT(6) command. | |
2098 | */ | |
2099 | if (sdev->use_10_for_ms || | |
2100 | len + 4 > 255 || | |
2101 | data->block_descriptor_length > 255) { | |
2102 | if (len > 65535 - 8) | |
5baba830 JB |
2103 | return -EINVAL; |
2104 | real_buffer = kmalloc(8 + len, GFP_KERNEL); | |
2105 | if (!real_buffer) | |
2106 | return -ENOMEM; | |
2107 | memcpy(real_buffer + 8, buffer, len); | |
2108 | len += 8; | |
2109 | real_buffer[0] = 0; | |
2110 | real_buffer[1] = 0; | |
2111 | real_buffer[2] = data->medium_type; | |
2112 | real_buffer[3] = data->device_specific; | |
2113 | real_buffer[4] = data->longlba ? 0x01 : 0; | |
2114 | real_buffer[5] = 0; | |
a7d6840b DLM |
2115 | put_unaligned_be16(data->block_descriptor_length, |
2116 | &real_buffer[6]); | |
5baba830 JB |
2117 | |
2118 | cmd[0] = MODE_SELECT_10; | |
a7d6840b | 2119 | put_unaligned_be16(len, &cmd[7]); |
5baba830 | 2120 | } else { |
a7d6840b | 2121 | if (data->longlba) |
5baba830 JB |
2122 | return -EINVAL; |
2123 | ||
2124 | real_buffer = kmalloc(4 + len, GFP_KERNEL); | |
2125 | if (!real_buffer) | |
2126 | return -ENOMEM; | |
2127 | memcpy(real_buffer + 4, buffer, len); | |
2128 | len += 4; | |
2129 | real_buffer[0] = 0; | |
2130 | real_buffer[1] = data->medium_type; | |
2131 | real_buffer[2] = data->device_specific; | |
2132 | real_buffer[3] = data->block_descriptor_length; | |
5baba830 JB |
2133 | |
2134 | cmd[0] = MODE_SELECT; | |
2135 | cmd[4] = len; | |
2136 | } | |
2137 | ||
2138 | ret = scsi_execute_req(sdev, cmd, DMA_TO_DEVICE, real_buffer, len, | |
f4f4e47e | 2139 | sshdr, timeout, retries, NULL); |
5baba830 JB |
2140 | kfree(real_buffer); |
2141 | return ret; | |
2142 | } | |
2143 | EXPORT_SYMBOL_GPL(scsi_mode_select); | |
2144 | ||
1da177e4 | 2145 | /** |
eb44820c | 2146 | * scsi_mode_sense - issue a mode sense, falling back from 10 to six bytes if necessary. |
1cf72699 | 2147 | * @sdev: SCSI device to be queried |
17b49bcb | 2148 | * @dbd: set to prevent mode sense from returning block descriptors |
1da177e4 LT |
2149 | * @modepage: mode page being requested |
2150 | * @buffer: request buffer (may not be smaller than eight bytes) | |
2151 | * @len: length of request buffer. | |
2152 | * @timeout: command timeout | |
2153 | * @retries: number of retries before failing | |
2154 | * @data: returns a structure abstracting the mode header data | |
eb44820c | 2155 | * @sshdr: place to put sense data (or NULL if no sense to be collected). |
1cf72699 | 2156 | * must be SCSI_SENSE_BUFFERSIZE big. |
1da177e4 | 2157 | * |
8793613d | 2158 | * Returns zero if successful, or a negative error number on failure |
eb44820c | 2159 | */ |
1da177e4 | 2160 | int |
1cf72699 | 2161 | scsi_mode_sense(struct scsi_device *sdev, int dbd, int modepage, |
1da177e4 | 2162 | unsigned char *buffer, int len, int timeout, int retries, |
5baba830 JB |
2163 | struct scsi_mode_data *data, struct scsi_sense_hdr *sshdr) |
2164 | { | |
1da177e4 LT |
2165 | unsigned char cmd[12]; |
2166 | int use_10_for_ms; | |
2167 | int header_length; | |
0ae80ba9 | 2168 | int result, retry_count = retries; |
ea73a9f2 | 2169 | struct scsi_sense_hdr my_sshdr; |
1da177e4 LT |
2170 | |
2171 | memset(data, 0, sizeof(*data)); | |
2172 | memset(&cmd[0], 0, 12); | |
0ec96913 CG |
2173 | |
2174 | dbd = sdev->set_dbd_for_ms ? 8 : dbd; | |
1da177e4 LT |
2175 | cmd[1] = dbd & 0x18; /* allows DBD and LLBA bits */ |
2176 | cmd[2] = modepage; | |
2177 | ||
ea73a9f2 JB |
2178 | /* caller might not be interested in sense, but we need it */ |
2179 | if (!sshdr) | |
2180 | sshdr = &my_sshdr; | |
2181 | ||
1da177e4 | 2182 | retry: |
17b49bcb | 2183 | use_10_for_ms = sdev->use_10_for_ms || len > 255; |
1da177e4 LT |
2184 | |
2185 | if (use_10_for_ms) { | |
17b49bcb DLM |
2186 | if (len < 8 || len > 65535) |
2187 | return -EINVAL; | |
1da177e4 LT |
2188 | |
2189 | cmd[0] = MODE_SENSE_10; | |
17b49bcb | 2190 | put_unaligned_be16(len, &cmd[7]); |
1da177e4 LT |
2191 | header_length = 8; |
2192 | } else { | |
2193 | if (len < 4) | |
17b49bcb | 2194 | return -EINVAL; |
1da177e4 LT |
2195 | |
2196 | cmd[0] = MODE_SENSE; | |
2197 | cmd[4] = len; | |
2198 | header_length = 4; | |
2199 | } | |
2200 | ||
1da177e4 LT |
2201 | memset(buffer, 0, len); |
2202 | ||
1cf72699 | 2203 | result = scsi_execute_req(sdev, cmd, DMA_FROM_DEVICE, buffer, len, |
f4f4e47e | 2204 | sshdr, timeout, retries, NULL); |
8793613d HR |
2205 | if (result < 0) |
2206 | return result; | |
1da177e4 LT |
2207 | |
2208 | /* This code looks awful: what it's doing is making sure an | |
2209 | * ILLEGAL REQUEST sense return identifies the actual command | |
2210 | * byte as the problem. MODE_SENSE commands can return | |
2211 | * ILLEGAL REQUEST if the code page isn't supported */ | |
2212 | ||
64aaa3dd | 2213 | if (!scsi_status_is_good(result)) { |
464a00c9 | 2214 | if (scsi_sense_valid(sshdr)) { |
ea73a9f2 JB |
2215 | if ((sshdr->sense_key == ILLEGAL_REQUEST) && |
2216 | (sshdr->asc == 0x20) && (sshdr->ascq == 0)) { | |
4c7b4d63 | 2217 | /* |
17b49bcb DLM |
2218 | * Invalid command operation code: retry using |
2219 | * MODE SENSE(6) if this was a MODE SENSE(10) | |
2220 | * request, except if the request mode page is | |
2221 | * too large for MODE SENSE single byte | |
2222 | * allocation length field. | |
1da177e4 | 2223 | */ |
64aaa3dd | 2224 | if (use_10_for_ms) { |
17b49bcb DLM |
2225 | if (len > 255) |
2226 | return -EIO; | |
64aaa3dd HR |
2227 | sdev->use_10_for_ms = 0; |
2228 | goto retry; | |
2229 | } | |
2230 | } | |
d0672a03 | 2231 | if (scsi_status_is_check_condition(result) && |
64aaa3dd HR |
2232 | sshdr->sense_key == UNIT_ATTENTION && |
2233 | retry_count) { | |
2234 | retry_count--; | |
1da177e4 LT |
2235 | goto retry; |
2236 | } | |
2237 | } | |
64aaa3dd | 2238 | return -EIO; |
1da177e4 | 2239 | } |
64aaa3dd HR |
2240 | if (unlikely(buffer[0] == 0x86 && buffer[1] == 0x0b && |
2241 | (modepage == 6 || modepage == 8))) { | |
2242 | /* Initio breakage? */ | |
2243 | header_length = 0; | |
2244 | data->length = 13; | |
2245 | data->medium_type = 0; | |
2246 | data->device_specific = 0; | |
2247 | data->longlba = 0; | |
2248 | data->block_descriptor_length = 0; | |
2249 | } else if (use_10_for_ms) { | |
17b49bcb | 2250 | data->length = get_unaligned_be16(&buffer[0]) + 2; |
64aaa3dd HR |
2251 | data->medium_type = buffer[2]; |
2252 | data->device_specific = buffer[3]; | |
2253 | data->longlba = buffer[4] & 0x01; | |
17b49bcb | 2254 | data->block_descriptor_length = get_unaligned_be16(&buffer[6]); |
64aaa3dd HR |
2255 | } else { |
2256 | data->length = buffer[0] + 1; | |
2257 | data->medium_type = buffer[1]; | |
2258 | data->device_specific = buffer[2]; | |
2259 | data->block_descriptor_length = buffer[3]; | |
1da177e4 | 2260 | } |
64aaa3dd HR |
2261 | data->header_length = header_length; |
2262 | ||
2263 | return 0; | |
1da177e4 LT |
2264 | } |
2265 | EXPORT_SYMBOL(scsi_mode_sense); | |
2266 | ||
001aac25 JB |
2267 | /** |
2268 | * scsi_test_unit_ready - test if unit is ready | |
2269 | * @sdev: scsi device to change the state of. | |
2270 | * @timeout: command timeout | |
2271 | * @retries: number of retries before failing | |
74a78ebd | 2272 | * @sshdr: outpout pointer for decoded sense information. |
001aac25 JB |
2273 | * |
2274 | * Returns zero if unsuccessful or an error if TUR failed. For | |
9f8a2c23 | 2275 | * removable media, UNIT_ATTENTION sets ->changed flag. |
001aac25 | 2276 | **/ |
1da177e4 | 2277 | int |
001aac25 | 2278 | scsi_test_unit_ready(struct scsi_device *sdev, int timeout, int retries, |
74a78ebd | 2279 | struct scsi_sense_hdr *sshdr) |
1da177e4 | 2280 | { |
1da177e4 LT |
2281 | char cmd[] = { |
2282 | TEST_UNIT_READY, 0, 0, 0, 0, 0, | |
2283 | }; | |
2284 | int result; | |
001aac25 | 2285 | |
001aac25 JB |
2286 | /* try to eat the UNIT_ATTENTION if there are enough retries */ |
2287 | do { | |
2288 | result = scsi_execute_req(sdev, cmd, DMA_NONE, NULL, 0, sshdr, | |
9b91fd34 | 2289 | timeout, 1, NULL); |
32c356d7 JB |
2290 | if (sdev->removable && scsi_sense_valid(sshdr) && |
2291 | sshdr->sense_key == UNIT_ATTENTION) | |
2292 | sdev->changed = 1; | |
2293 | } while (scsi_sense_valid(sshdr) && | |
2294 | sshdr->sense_key == UNIT_ATTENTION && --retries); | |
001aac25 | 2295 | |
1da177e4 LT |
2296 | return result; |
2297 | } | |
2298 | EXPORT_SYMBOL(scsi_test_unit_ready); | |
2299 | ||
2300 | /** | |
eb44820c | 2301 | * scsi_device_set_state - Take the given device through the device state model. |
1da177e4 LT |
2302 | * @sdev: scsi device to change the state of. |
2303 | * @state: state to change to. | |
2304 | * | |
23cb27fd | 2305 | * Returns zero if successful or an error if the requested |
1da177e4 | 2306 | * transition is illegal. |
eb44820c | 2307 | */ |
1da177e4 LT |
2308 | int |
2309 | scsi_device_set_state(struct scsi_device *sdev, enum scsi_device_state state) | |
2310 | { | |
2311 | enum scsi_device_state oldstate = sdev->sdev_state; | |
2312 | ||
2313 | if (state == oldstate) | |
2314 | return 0; | |
2315 | ||
2316 | switch (state) { | |
2317 | case SDEV_CREATED: | |
6f4267e3 JB |
2318 | switch (oldstate) { |
2319 | case SDEV_CREATED_BLOCK: | |
2320 | break; | |
2321 | default: | |
2322 | goto illegal; | |
2323 | } | |
2324 | break; | |
4c7b4d63 | 2325 | |
1da177e4 LT |
2326 | case SDEV_RUNNING: |
2327 | switch (oldstate) { | |
2328 | case SDEV_CREATED: | |
2329 | case SDEV_OFFLINE: | |
1b8d2620 | 2330 | case SDEV_TRANSPORT_OFFLINE: |
1da177e4 LT |
2331 | case SDEV_QUIESCE: |
2332 | case SDEV_BLOCK: | |
2333 | break; | |
2334 | default: | |
2335 | goto illegal; | |
2336 | } | |
2337 | break; | |
2338 | ||
2339 | case SDEV_QUIESCE: | |
2340 | switch (oldstate) { | |
2341 | case SDEV_RUNNING: | |
2342 | case SDEV_OFFLINE: | |
1b8d2620 | 2343 | case SDEV_TRANSPORT_OFFLINE: |
1da177e4 LT |
2344 | break; |
2345 | default: | |
2346 | goto illegal; | |
2347 | } | |
2348 | break; | |
2349 | ||
2350 | case SDEV_OFFLINE: | |
1b8d2620 | 2351 | case SDEV_TRANSPORT_OFFLINE: |
1da177e4 LT |
2352 | switch (oldstate) { |
2353 | case SDEV_CREATED: | |
2354 | case SDEV_RUNNING: | |
2355 | case SDEV_QUIESCE: | |
2356 | case SDEV_BLOCK: | |
2357 | break; | |
2358 | default: | |
2359 | goto illegal; | |
2360 | } | |
2361 | break; | |
2362 | ||
2363 | case SDEV_BLOCK: | |
2364 | switch (oldstate) { | |
1da177e4 | 2365 | case SDEV_RUNNING: |
6f4267e3 | 2366 | case SDEV_CREATED_BLOCK: |
6cbb7aed | 2367 | case SDEV_QUIESCE: |
a33e5bfb | 2368 | case SDEV_OFFLINE: |
6f4267e3 JB |
2369 | break; |
2370 | default: | |
2371 | goto illegal; | |
2372 | } | |
2373 | break; | |
2374 | ||
2375 | case SDEV_CREATED_BLOCK: | |
2376 | switch (oldstate) { | |
2377 | case SDEV_CREATED: | |
1da177e4 LT |
2378 | break; |
2379 | default: | |
2380 | goto illegal; | |
2381 | } | |
2382 | break; | |
2383 | ||
2384 | case SDEV_CANCEL: | |
2385 | switch (oldstate) { | |
2386 | case SDEV_CREATED: | |
2387 | case SDEV_RUNNING: | |
9ea72909 | 2388 | case SDEV_QUIESCE: |
1da177e4 | 2389 | case SDEV_OFFLINE: |
1b8d2620 | 2390 | case SDEV_TRANSPORT_OFFLINE: |
1da177e4 LT |
2391 | break; |
2392 | default: | |
2393 | goto illegal; | |
2394 | } | |
2395 | break; | |
2396 | ||
2397 | case SDEV_DEL: | |
2398 | switch (oldstate) { | |
309bd271 BK |
2399 | case SDEV_CREATED: |
2400 | case SDEV_RUNNING: | |
2401 | case SDEV_OFFLINE: | |
1b8d2620 | 2402 | case SDEV_TRANSPORT_OFFLINE: |
1da177e4 | 2403 | case SDEV_CANCEL: |
255ee932 | 2404 | case SDEV_BLOCK: |
0516c08d | 2405 | case SDEV_CREATED_BLOCK: |
1da177e4 LT |
2406 | break; |
2407 | default: | |
2408 | goto illegal; | |
2409 | } | |
2410 | break; | |
2411 | ||
2412 | } | |
b0962c53 | 2413 | sdev->offline_already = false; |
1da177e4 LT |
2414 | sdev->sdev_state = state; |
2415 | return 0; | |
2416 | ||
2417 | illegal: | |
91921e01 | 2418 | SCSI_LOG_ERROR_RECOVERY(1, |
9ccfc756 | 2419 | sdev_printk(KERN_ERR, sdev, |
91921e01 | 2420 | "Illegal state transition %s->%s", |
9ccfc756 JB |
2421 | scsi_device_state_name(oldstate), |
2422 | scsi_device_state_name(state)) | |
1da177e4 LT |
2423 | ); |
2424 | return -EINVAL; | |
2425 | } | |
2426 | EXPORT_SYMBOL(scsi_device_set_state); | |
2427 | ||
a341cd0f | 2428 | /** |
ae6b4e69 | 2429 | * scsi_evt_emit - emit a single SCSI device uevent |
a341cd0f JG |
2430 | * @sdev: associated SCSI device |
2431 | * @evt: event to emit | |
2432 | * | |
2433 | * Send a single uevent (scsi_event) to the associated scsi_device. | |
2434 | */ | |
2435 | static void scsi_evt_emit(struct scsi_device *sdev, struct scsi_event *evt) | |
2436 | { | |
2437 | int idx = 0; | |
2438 | char *envp[3]; | |
2439 | ||
2440 | switch (evt->evt_type) { | |
2441 | case SDEV_EVT_MEDIA_CHANGE: | |
2442 | envp[idx++] = "SDEV_MEDIA_CHANGE=1"; | |
2443 | break; | |
279afdfe | 2444 | case SDEV_EVT_INQUIRY_CHANGE_REPORTED: |
d3d32891 | 2445 | scsi_rescan_device(&sdev->sdev_gendev); |
279afdfe EM |
2446 | envp[idx++] = "SDEV_UA=INQUIRY_DATA_HAS_CHANGED"; |
2447 | break; | |
2448 | case SDEV_EVT_CAPACITY_CHANGE_REPORTED: | |
2449 | envp[idx++] = "SDEV_UA=CAPACITY_DATA_HAS_CHANGED"; | |
2450 | break; | |
2451 | case SDEV_EVT_SOFT_THRESHOLD_REACHED_REPORTED: | |
2452 | envp[idx++] = "SDEV_UA=THIN_PROVISIONING_SOFT_THRESHOLD_REACHED"; | |
2453 | break; | |
2454 | case SDEV_EVT_MODE_PARAMETER_CHANGE_REPORTED: | |
2455 | envp[idx++] = "SDEV_UA=MODE_PARAMETERS_CHANGED"; | |
2456 | break; | |
2457 | case SDEV_EVT_LUN_CHANGE_REPORTED: | |
2458 | envp[idx++] = "SDEV_UA=REPORTED_LUNS_DATA_HAS_CHANGED"; | |
2459 | break; | |
14c3e677 HR |
2460 | case SDEV_EVT_ALUA_STATE_CHANGE_REPORTED: |
2461 | envp[idx++] = "SDEV_UA=ASYMMETRIC_ACCESS_STATE_CHANGED"; | |
2462 | break; | |
cf3431bb HR |
2463 | case SDEV_EVT_POWER_ON_RESET_OCCURRED: |
2464 | envp[idx++] = "SDEV_UA=POWER_ON_RESET_OCCURRED"; | |
2465 | break; | |
a341cd0f JG |
2466 | default: |
2467 | /* do nothing */ | |
2468 | break; | |
2469 | } | |
2470 | ||
2471 | envp[idx++] = NULL; | |
2472 | ||
2473 | kobject_uevent_env(&sdev->sdev_gendev.kobj, KOBJ_CHANGE, envp); | |
2474 | } | |
2475 | ||
2476 | /** | |
ae6b4e69 | 2477 | * scsi_evt_thread - send a uevent for each scsi event |
a341cd0f JG |
2478 | * @work: work struct for scsi_device |
2479 | * | |
2480 | * Dispatch queued events to their associated scsi_device kobjects | |
2481 | * as uevents. | |
2482 | */ | |
2483 | void scsi_evt_thread(struct work_struct *work) | |
2484 | { | |
2485 | struct scsi_device *sdev; | |
279afdfe | 2486 | enum scsi_device_event evt_type; |
a341cd0f JG |
2487 | LIST_HEAD(event_list); |
2488 | ||
2489 | sdev = container_of(work, struct scsi_device, event_work); | |
2490 | ||
279afdfe EM |
2491 | for (evt_type = SDEV_EVT_FIRST; evt_type <= SDEV_EVT_LAST; evt_type++) |
2492 | if (test_and_clear_bit(evt_type, sdev->pending_events)) | |
2493 | sdev_evt_send_simple(sdev, evt_type, GFP_KERNEL); | |
2494 | ||
a341cd0f JG |
2495 | while (1) { |
2496 | struct scsi_event *evt; | |
2497 | struct list_head *this, *tmp; | |
2498 | unsigned long flags; | |
2499 | ||
2500 | spin_lock_irqsave(&sdev->list_lock, flags); | |
2501 | list_splice_init(&sdev->event_list, &event_list); | |
2502 | spin_unlock_irqrestore(&sdev->list_lock, flags); | |
2503 | ||
2504 | if (list_empty(&event_list)) | |
2505 | break; | |
2506 | ||
2507 | list_for_each_safe(this, tmp, &event_list) { | |
2508 | evt = list_entry(this, struct scsi_event, node); | |
2509 | list_del(&evt->node); | |
2510 | scsi_evt_emit(sdev, evt); | |
2511 | kfree(evt); | |
2512 | } | |
2513 | } | |
2514 | } | |
2515 | ||
2516 | /** | |
2517 | * sdev_evt_send - send asserted event to uevent thread | |
2518 | * @sdev: scsi_device event occurred on | |
2519 | * @evt: event to send | |
2520 | * | |
2521 | * Assert scsi device event asynchronously. | |
2522 | */ | |
2523 | void sdev_evt_send(struct scsi_device *sdev, struct scsi_event *evt) | |
2524 | { | |
2525 | unsigned long flags; | |
2526 | ||
4d1566ed KS |
2527 | #if 0 |
2528 | /* FIXME: currently this check eliminates all media change events | |
2529 | * for polled devices. Need to update to discriminate between AN | |
2530 | * and polled events */ | |
a341cd0f JG |
2531 | if (!test_bit(evt->evt_type, sdev->supported_events)) { |
2532 | kfree(evt); | |
2533 | return; | |
2534 | } | |
4d1566ed | 2535 | #endif |
a341cd0f JG |
2536 | |
2537 | spin_lock_irqsave(&sdev->list_lock, flags); | |
2538 | list_add_tail(&evt->node, &sdev->event_list); | |
2539 | schedule_work(&sdev->event_work); | |
2540 | spin_unlock_irqrestore(&sdev->list_lock, flags); | |
2541 | } | |
2542 | EXPORT_SYMBOL_GPL(sdev_evt_send); | |
2543 | ||
2544 | /** | |
2545 | * sdev_evt_alloc - allocate a new scsi event | |
2546 | * @evt_type: type of event to allocate | |
2547 | * @gfpflags: GFP flags for allocation | |
2548 | * | |
2549 | * Allocates and returns a new scsi_event. | |
2550 | */ | |
2551 | struct scsi_event *sdev_evt_alloc(enum scsi_device_event evt_type, | |
2552 | gfp_t gfpflags) | |
2553 | { | |
2554 | struct scsi_event *evt = kzalloc(sizeof(struct scsi_event), gfpflags); | |
2555 | if (!evt) | |
2556 | return NULL; | |
2557 | ||
2558 | evt->evt_type = evt_type; | |
2559 | INIT_LIST_HEAD(&evt->node); | |
2560 | ||
2561 | /* evt_type-specific initialization, if any */ | |
2562 | switch (evt_type) { | |
2563 | case SDEV_EVT_MEDIA_CHANGE: | |
279afdfe EM |
2564 | case SDEV_EVT_INQUIRY_CHANGE_REPORTED: |
2565 | case SDEV_EVT_CAPACITY_CHANGE_REPORTED: | |
2566 | case SDEV_EVT_SOFT_THRESHOLD_REACHED_REPORTED: | |
2567 | case SDEV_EVT_MODE_PARAMETER_CHANGE_REPORTED: | |
2568 | case SDEV_EVT_LUN_CHANGE_REPORTED: | |
14c3e677 | 2569 | case SDEV_EVT_ALUA_STATE_CHANGE_REPORTED: |
cf3431bb | 2570 | case SDEV_EVT_POWER_ON_RESET_OCCURRED: |
a341cd0f JG |
2571 | default: |
2572 | /* do nothing */ | |
2573 | break; | |
2574 | } | |
2575 | ||
2576 | return evt; | |
2577 | } | |
2578 | EXPORT_SYMBOL_GPL(sdev_evt_alloc); | |
2579 | ||
2580 | /** | |
2581 | * sdev_evt_send_simple - send asserted event to uevent thread | |
2582 | * @sdev: scsi_device event occurred on | |
2583 | * @evt_type: type of event to send | |
2584 | * @gfpflags: GFP flags for allocation | |
2585 | * | |
2586 | * Assert scsi device event asynchronously, given an event type. | |
2587 | */ | |
2588 | void sdev_evt_send_simple(struct scsi_device *sdev, | |
2589 | enum scsi_device_event evt_type, gfp_t gfpflags) | |
2590 | { | |
2591 | struct scsi_event *evt = sdev_evt_alloc(evt_type, gfpflags); | |
2592 | if (!evt) { | |
2593 | sdev_printk(KERN_ERR, sdev, "event %d eaten due to OOM\n", | |
2594 | evt_type); | |
2595 | return; | |
2596 | } | |
2597 | ||
2598 | sdev_evt_send(sdev, evt); | |
2599 | } | |
2600 | EXPORT_SYMBOL_GPL(sdev_evt_send_simple); | |
2601 | ||
1da177e4 | 2602 | /** |
e6044f71 | 2603 | * scsi_device_quiesce - Block all commands except power management. |
1da177e4 LT |
2604 | * @sdev: scsi device to quiesce. |
2605 | * | |
2606 | * This works by trying to transition to the SDEV_QUIESCE state | |
2607 | * (which must be a legal transition). When the device is in this | |
e6044f71 BVA |
2608 | * state, only power management requests will be accepted, all others will |
2609 | * be deferred. | |
1da177e4 LT |
2610 | * |
2611 | * Must be called with user context, may sleep. | |
2612 | * | |
2613 | * Returns zero if unsuccessful or an error if not. | |
eb44820c | 2614 | */ |
1da177e4 LT |
2615 | int |
2616 | scsi_device_quiesce(struct scsi_device *sdev) | |
2617 | { | |
3a0a5299 | 2618 | struct request_queue *q = sdev->request_queue; |
0db6ca8a BVA |
2619 | int err; |
2620 | ||
3a0a5299 BVA |
2621 | /* |
2622 | * It is allowed to call scsi_device_quiesce() multiple times from | |
2623 | * the same context but concurrent scsi_device_quiesce() calls are | |
2624 | * not allowed. | |
2625 | */ | |
2626 | WARN_ON_ONCE(sdev->quiesced_by && sdev->quiesced_by != current); | |
2627 | ||
cd84a62e BVA |
2628 | if (sdev->quiesced_by == current) |
2629 | return 0; | |
2630 | ||
2631 | blk_set_pm_only(q); | |
3a0a5299 BVA |
2632 | |
2633 | blk_mq_freeze_queue(q); | |
2634 | /* | |
cd84a62e | 2635 | * Ensure that the effect of blk_set_pm_only() will be visible |
3a0a5299 BVA |
2636 | * for percpu_ref_tryget() callers that occur after the queue |
2637 | * unfreeze even if the queue was already frozen before this function | |
2638 | * was called. See also https://lwn.net/Articles/573497/. | |
2639 | */ | |
2640 | synchronize_rcu(); | |
2641 | blk_mq_unfreeze_queue(q); | |
2642 | ||
0db6ca8a BVA |
2643 | mutex_lock(&sdev->state_mutex); |
2644 | err = scsi_device_set_state(sdev, SDEV_QUIESCE); | |
3a0a5299 BVA |
2645 | if (err == 0) |
2646 | sdev->quiesced_by = current; | |
2647 | else | |
cd84a62e | 2648 | blk_clear_pm_only(q); |
0db6ca8a BVA |
2649 | mutex_unlock(&sdev->state_mutex); |
2650 | ||
3a0a5299 | 2651 | return err; |
1da177e4 LT |
2652 | } |
2653 | EXPORT_SYMBOL(scsi_device_quiesce); | |
2654 | ||
2655 | /** | |
2656 | * scsi_device_resume - Restart user issued commands to a quiesced device. | |
2657 | * @sdev: scsi device to resume. | |
2658 | * | |
2659 | * Moves the device from quiesced back to running and restarts the | |
2660 | * queues. | |
2661 | * | |
2662 | * Must be called with user context, may sleep. | |
eb44820c | 2663 | */ |
a7a20d10 | 2664 | void scsi_device_resume(struct scsi_device *sdev) |
1da177e4 | 2665 | { |
a7a20d10 DW |
2666 | /* check if the device state was mutated prior to resume, and if |
2667 | * so assume the state is being managed elsewhere (for example | |
2668 | * device deleted during suspend) | |
2669 | */ | |
0db6ca8a | 2670 | mutex_lock(&sdev->state_mutex); |
e6044f71 BVA |
2671 | if (sdev->sdev_state == SDEV_QUIESCE) |
2672 | scsi_device_set_state(sdev, SDEV_RUNNING); | |
17605afa BVA |
2673 | if (sdev->quiesced_by) { |
2674 | sdev->quiesced_by = NULL; | |
2675 | blk_clear_pm_only(sdev->request_queue); | |
2676 | } | |
0db6ca8a | 2677 | mutex_unlock(&sdev->state_mutex); |
1da177e4 LT |
2678 | } |
2679 | EXPORT_SYMBOL(scsi_device_resume); | |
2680 | ||
2681 | static void | |
2682 | device_quiesce_fn(struct scsi_device *sdev, void *data) | |
2683 | { | |
2684 | scsi_device_quiesce(sdev); | |
2685 | } | |
2686 | ||
2687 | void | |
2688 | scsi_target_quiesce(struct scsi_target *starget) | |
2689 | { | |
2690 | starget_for_each_device(starget, NULL, device_quiesce_fn); | |
2691 | } | |
2692 | EXPORT_SYMBOL(scsi_target_quiesce); | |
2693 | ||
2694 | static void | |
2695 | device_resume_fn(struct scsi_device *sdev, void *data) | |
2696 | { | |
2697 | scsi_device_resume(sdev); | |
2698 | } | |
2699 | ||
2700 | void | |
2701 | scsi_target_resume(struct scsi_target *starget) | |
2702 | { | |
2703 | starget_for_each_device(starget, NULL, device_resume_fn); | |
2704 | } | |
2705 | EXPORT_SYMBOL(scsi_target_resume); | |
2706 | ||
d2b9f12b ML |
2707 | static int __scsi_internal_device_block_nowait(struct scsi_device *sdev) |
2708 | { | |
2709 | if (scsi_device_set_state(sdev, SDEV_BLOCK)) | |
2710 | return scsi_device_set_state(sdev, SDEV_CREATED_BLOCK); | |
2711 | ||
2712 | return 0; | |
2713 | } | |
2714 | ||
93542fbf ML |
2715 | void scsi_start_queue(struct scsi_device *sdev) |
2716 | { | |
2717 | if (cmpxchg(&sdev->queue_stopped, 1, 0)) | |
2718 | blk_mq_unquiesce_queue(sdev->request_queue); | |
2719 | } | |
2720 | ||
2721 | static void scsi_stop_queue(struct scsi_device *sdev, bool nowait) | |
2722 | { | |
2723 | /* | |
2724 | * The atomic variable of ->queue_stopped covers that | |
2725 | * blk_mq_quiesce_queue* is balanced with blk_mq_unquiesce_queue. | |
2726 | * | |
2727 | * However, we still need to wait until quiesce is done | |
2728 | * in case that queue has been stopped. | |
2729 | */ | |
2730 | if (!cmpxchg(&sdev->queue_stopped, 0, 1)) { | |
2731 | if (nowait) | |
2732 | blk_mq_quiesce_queue_nowait(sdev->request_queue); | |
2733 | else | |
2734 | blk_mq_quiesce_queue(sdev->request_queue); | |
2735 | } else { | |
2736 | if (!nowait) | |
483239c7 | 2737 | blk_mq_wait_quiesce_done(sdev->request_queue->tag_set); |
93542fbf ML |
2738 | } |
2739 | } | |
2740 | ||
1da177e4 | 2741 | /** |
551eb598 BVA |
2742 | * scsi_internal_device_block_nowait - try to transition to the SDEV_BLOCK state |
2743 | * @sdev: device to block | |
1da177e4 | 2744 | * |
551eb598 | 2745 | * Pause SCSI command processing on the specified device. Does not sleep. |
1da177e4 | 2746 | * |
551eb598 | 2747 | * Returns zero if successful or a negative error code upon failure. |
669f0441 | 2748 | * |
551eb598 BVA |
2749 | * Notes: |
2750 | * This routine transitions the device to the SDEV_BLOCK state (which must be | |
2751 | * a legal transition). When the device is in this state, command processing | |
2752 | * is paused until the device leaves the SDEV_BLOCK state. See also | |
2753 | * scsi_internal_device_unblock_nowait(). | |
eb44820c | 2754 | */ |
551eb598 | 2755 | int scsi_internal_device_block_nowait(struct scsi_device *sdev) |
1da177e4 | 2756 | { |
d2b9f12b | 2757 | int ret = __scsi_internal_device_block_nowait(sdev); |
1da177e4 | 2758 | |
4c7b4d63 | 2759 | /* |
1da177e4 LT |
2760 | * The device has transitioned to SDEV_BLOCK. Stop the |
2761 | * block layer from calling the midlayer with this device's | |
4c7b4d63 | 2762 | * request queue. |
1da177e4 | 2763 | */ |
d2b9f12b | 2764 | if (!ret) |
93542fbf | 2765 | scsi_stop_queue(sdev, true); |
d2b9f12b | 2766 | return ret; |
1da177e4 | 2767 | } |
551eb598 BVA |
2768 | EXPORT_SYMBOL_GPL(scsi_internal_device_block_nowait); |
2769 | ||
1da177e4 | 2770 | /** |
551eb598 BVA |
2771 | * scsi_internal_device_block - try to transition to the SDEV_BLOCK state |
2772 | * @sdev: device to block | |
2773 | * | |
2774 | * Pause SCSI command processing on the specified device and wait until all | |
2775 | * ongoing scsi_request_fn() / scsi_queue_rq() calls have finished. May sleep. | |
1da177e4 | 2776 | * |
551eb598 | 2777 | * Returns zero if successful or a negative error code upon failure. |
1da177e4 | 2778 | * |
551eb598 BVA |
2779 | * Note: |
2780 | * This routine transitions the device to the SDEV_BLOCK state (which must be | |
2781 | * a legal transition). When the device is in this state, command processing | |
2782 | * is paused until the device leaves the SDEV_BLOCK state. See also | |
2783 | * scsi_internal_device_unblock(). | |
eb44820c | 2784 | */ |
551eb598 | 2785 | static int scsi_internal_device_block(struct scsi_device *sdev) |
1da177e4 | 2786 | { |
551eb598 BVA |
2787 | int err; |
2788 | ||
0db6ca8a | 2789 | mutex_lock(&sdev->state_mutex); |
d2b9f12b | 2790 | err = __scsi_internal_device_block_nowait(sdev); |
f664a3cc | 2791 | if (err == 0) |
93542fbf | 2792 | scsi_stop_queue(sdev, false); |
0db6ca8a BVA |
2793 | mutex_unlock(&sdev->state_mutex); |
2794 | ||
551eb598 BVA |
2795 | return err; |
2796 | } | |
4c7b4d63 | 2797 | |
1da177e4 | 2798 | /** |
43f7571b | 2799 | * scsi_internal_device_unblock_nowait - resume a device after a block request |
1da177e4 | 2800 | * @sdev: device to resume |
43f7571b | 2801 | * @new_state: state to set the device to after unblocking |
1da177e4 | 2802 | * |
43f7571b BVA |
2803 | * Restart the device queue for a previously suspended SCSI device. Does not |
2804 | * sleep. | |
1da177e4 | 2805 | * |
43f7571b | 2806 | * Returns zero if successful or a negative error code upon failure. |
1da177e4 | 2807 | * |
43f7571b BVA |
2808 | * Notes: |
2809 | * This routine transitions the device to the SDEV_RUNNING state or to one of | |
2810 | * the offline states (which must be a legal transition) allowing the midlayer | |
2811 | * to goose the queue for this device. | |
eb44820c | 2812 | */ |
43f7571b BVA |
2813 | int scsi_internal_device_unblock_nowait(struct scsi_device *sdev, |
2814 | enum scsi_device_state new_state) | |
1da177e4 | 2815 | { |
09addb1d BVA |
2816 | switch (new_state) { |
2817 | case SDEV_RUNNING: | |
2818 | case SDEV_TRANSPORT_OFFLINE: | |
2819 | break; | |
2820 | default: | |
2821 | return -EINVAL; | |
2822 | } | |
2823 | ||
5d9fb5cc MC |
2824 | /* |
2825 | * Try to transition the scsi device to SDEV_RUNNING or one of the | |
2826 | * offlined states and goose the device queue if successful. | |
1da177e4 | 2827 | */ |
8cd1ec78 HR |
2828 | switch (sdev->sdev_state) { |
2829 | case SDEV_BLOCK: | |
2830 | case SDEV_TRANSPORT_OFFLINE: | |
5d9fb5cc | 2831 | sdev->sdev_state = new_state; |
8cd1ec78 HR |
2832 | break; |
2833 | case SDEV_CREATED_BLOCK: | |
5d9fb5cc MC |
2834 | if (new_state == SDEV_TRANSPORT_OFFLINE || |
2835 | new_state == SDEV_OFFLINE) | |
2836 | sdev->sdev_state = new_state; | |
2837 | else | |
2838 | sdev->sdev_state = SDEV_CREATED; | |
8cd1ec78 HR |
2839 | break; |
2840 | case SDEV_CANCEL: | |
2841 | case SDEV_OFFLINE: | |
2842 | break; | |
2843 | default: | |
5c10e63c | 2844 | return -EINVAL; |
8cd1ec78 | 2845 | } |
66483a4a | 2846 | scsi_start_queue(sdev); |
1da177e4 LT |
2847 | |
2848 | return 0; | |
2849 | } | |
43f7571b BVA |
2850 | EXPORT_SYMBOL_GPL(scsi_internal_device_unblock_nowait); |
2851 | ||
2852 | /** | |
2853 | * scsi_internal_device_unblock - resume a device after a block request | |
2854 | * @sdev: device to resume | |
2855 | * @new_state: state to set the device to after unblocking | |
2856 | * | |
2857 | * Restart the device queue for a previously suspended SCSI device. May sleep. | |
2858 | * | |
2859 | * Returns zero if successful or a negative error code upon failure. | |
2860 | * | |
2861 | * Notes: | |
2862 | * This routine transitions the device to the SDEV_RUNNING state or to one of | |
2863 | * the offline states (which must be a legal transition) allowing the midlayer | |
2864 | * to goose the queue for this device. | |
2865 | */ | |
2866 | static int scsi_internal_device_unblock(struct scsi_device *sdev, | |
2867 | enum scsi_device_state new_state) | |
2868 | { | |
0db6ca8a BVA |
2869 | int ret; |
2870 | ||
2871 | mutex_lock(&sdev->state_mutex); | |
2872 | ret = scsi_internal_device_unblock_nowait(sdev, new_state); | |
2873 | mutex_unlock(&sdev->state_mutex); | |
2874 | ||
2875 | return ret; | |
43f7571b | 2876 | } |
1da177e4 LT |
2877 | |
2878 | static void | |
2879 | device_block(struct scsi_device *sdev, void *data) | |
2880 | { | |
94ef80a5 BVA |
2881 | int ret; |
2882 | ||
2883 | ret = scsi_internal_device_block(sdev); | |
2884 | ||
2885 | WARN_ONCE(ret, "scsi_internal_device_block(%s) failed: ret = %d\n", | |
2886 | dev_name(&sdev->sdev_gendev), ret); | |
1da177e4 LT |
2887 | } |
2888 | ||
2889 | static int | |
2890 | target_block(struct device *dev, void *data) | |
2891 | { | |
2892 | if (scsi_is_target_device(dev)) | |
2893 | starget_for_each_device(to_scsi_target(dev), NULL, | |
2894 | device_block); | |
2895 | return 0; | |
2896 | } | |
2897 | ||
2898 | void | |
2899 | scsi_target_block(struct device *dev) | |
2900 | { | |
2901 | if (scsi_is_target_device(dev)) | |
2902 | starget_for_each_device(to_scsi_target(dev), NULL, | |
2903 | device_block); | |
2904 | else | |
2905 | device_for_each_child(dev, NULL, target_block); | |
2906 | } | |
2907 | EXPORT_SYMBOL_GPL(scsi_target_block); | |
2908 | ||
2909 | static void | |
2910 | device_unblock(struct scsi_device *sdev, void *data) | |
2911 | { | |
5d9fb5cc | 2912 | scsi_internal_device_unblock(sdev, *(enum scsi_device_state *)data); |
1da177e4 LT |
2913 | } |
2914 | ||
2915 | static int | |
2916 | target_unblock(struct device *dev, void *data) | |
2917 | { | |
2918 | if (scsi_is_target_device(dev)) | |
5d9fb5cc | 2919 | starget_for_each_device(to_scsi_target(dev), data, |
1da177e4 LT |
2920 | device_unblock); |
2921 | return 0; | |
2922 | } | |
2923 | ||
2924 | void | |
5d9fb5cc | 2925 | scsi_target_unblock(struct device *dev, enum scsi_device_state new_state) |
1da177e4 LT |
2926 | { |
2927 | if (scsi_is_target_device(dev)) | |
5d9fb5cc | 2928 | starget_for_each_device(to_scsi_target(dev), &new_state, |
1da177e4 LT |
2929 | device_unblock); |
2930 | else | |
5d9fb5cc | 2931 | device_for_each_child(dev, &new_state, target_unblock); |
1da177e4 LT |
2932 | } |
2933 | EXPORT_SYMBOL_GPL(scsi_target_unblock); | |
cdb8c2a6 | 2934 | |
2bb95584 HR |
2935 | int |
2936 | scsi_host_block(struct Scsi_Host *shost) | |
2937 | { | |
2938 | struct scsi_device *sdev; | |
2939 | int ret = 0; | |
2940 | ||
f983622a ML |
2941 | /* |
2942 | * Call scsi_internal_device_block_nowait so we can avoid | |
2943 | * calling synchronize_rcu() for each LUN. | |
2944 | */ | |
2bb95584 | 2945 | shost_for_each_device(sdev, shost) { |
f983622a ML |
2946 | mutex_lock(&sdev->state_mutex); |
2947 | ret = scsi_internal_device_block_nowait(sdev); | |
2948 | mutex_unlock(&sdev->state_mutex); | |
f30785db YB |
2949 | if (ret) { |
2950 | scsi_device_put(sdev); | |
2bb95584 | 2951 | break; |
f30785db | 2952 | } |
2bb95584 | 2953 | } |
f983622a ML |
2954 | |
2955 | /* | |
2956 | * SCSI never enables blk-mq's BLK_MQ_F_BLOCKING flag so | |
2957 | * calling synchronize_rcu() once is enough. | |
2958 | */ | |
2959 | WARN_ON_ONCE(shost->tag_set.flags & BLK_MQ_F_BLOCKING); | |
2960 | ||
2961 | if (!ret) | |
2962 | synchronize_rcu(); | |
2963 | ||
2bb95584 HR |
2964 | return ret; |
2965 | } | |
2966 | EXPORT_SYMBOL_GPL(scsi_host_block); | |
2967 | ||
2968 | int | |
2969 | scsi_host_unblock(struct Scsi_Host *shost, int new_state) | |
2970 | { | |
2971 | struct scsi_device *sdev; | |
2972 | int ret = 0; | |
2973 | ||
2974 | shost_for_each_device(sdev, shost) { | |
2975 | ret = scsi_internal_device_unblock(sdev, new_state); | |
4dea170f YB |
2976 | if (ret) { |
2977 | scsi_device_put(sdev); | |
2bb95584 | 2978 | break; |
4dea170f | 2979 | } |
2bb95584 HR |
2980 | } |
2981 | return ret; | |
2982 | } | |
2983 | EXPORT_SYMBOL_GPL(scsi_host_unblock); | |
2984 | ||
cdb8c2a6 GL |
2985 | /** |
2986 | * scsi_kmap_atomic_sg - find and atomically map an sg-elemnt | |
eb44820c | 2987 | * @sgl: scatter-gather list |
cdb8c2a6 GL |
2988 | * @sg_count: number of segments in sg |
2989 | * @offset: offset in bytes into sg, on return offset into the mapped area | |
2990 | * @len: bytes to map, on return number of bytes mapped | |
2991 | * | |
2992 | * Returns virtual address of the start of the mapped page | |
2993 | */ | |
c6132da1 | 2994 | void *scsi_kmap_atomic_sg(struct scatterlist *sgl, int sg_count, |
cdb8c2a6 GL |
2995 | size_t *offset, size_t *len) |
2996 | { | |
2997 | int i; | |
2998 | size_t sg_len = 0, len_complete = 0; | |
c6132da1 | 2999 | struct scatterlist *sg; |
cdb8c2a6 GL |
3000 | struct page *page; |
3001 | ||
22cfefb5 AM |
3002 | WARN_ON(!irqs_disabled()); |
3003 | ||
c6132da1 | 3004 | for_each_sg(sgl, sg, sg_count, i) { |
cdb8c2a6 | 3005 | len_complete = sg_len; /* Complete sg-entries */ |
c6132da1 | 3006 | sg_len += sg->length; |
cdb8c2a6 GL |
3007 | if (sg_len > *offset) |
3008 | break; | |
3009 | } | |
3010 | ||
3011 | if (unlikely(i == sg_count)) { | |
169e1a2a AM |
3012 | printk(KERN_ERR "%s: Bytes in sg: %zu, requested offset %zu, " |
3013 | "elements %d\n", | |
cadbd4a5 | 3014 | __func__, sg_len, *offset, sg_count); |
cdb8c2a6 GL |
3015 | WARN_ON(1); |
3016 | return NULL; | |
3017 | } | |
3018 | ||
3019 | /* Offset starting from the beginning of first page in this sg-entry */ | |
c6132da1 | 3020 | *offset = *offset - len_complete + sg->offset; |
cdb8c2a6 GL |
3021 | |
3022 | /* Assumption: contiguous pages can be accessed as "page + i" */ | |
45711f1a | 3023 | page = nth_page(sg_page(sg), (*offset >> PAGE_SHIFT)); |
cdb8c2a6 GL |
3024 | *offset &= ~PAGE_MASK; |
3025 | ||
3026 | /* Bytes in this sg-entry from *offset to the end of the page */ | |
3027 | sg_len = PAGE_SIZE - *offset; | |
3028 | if (*len > sg_len) | |
3029 | *len = sg_len; | |
3030 | ||
77dfce07 | 3031 | return kmap_atomic(page); |
cdb8c2a6 GL |
3032 | } |
3033 | EXPORT_SYMBOL(scsi_kmap_atomic_sg); | |
3034 | ||
3035 | /** | |
eb44820c | 3036 | * scsi_kunmap_atomic_sg - atomically unmap a virtual address, previously mapped with scsi_kmap_atomic_sg |
cdb8c2a6 GL |
3037 | * @virt: virtual address to be unmapped |
3038 | */ | |
3039 | void scsi_kunmap_atomic_sg(void *virt) | |
3040 | { | |
77dfce07 | 3041 | kunmap_atomic(virt); |
cdb8c2a6 GL |
3042 | } |
3043 | EXPORT_SYMBOL(scsi_kunmap_atomic_sg); | |
6f4c827e AL |
3044 | |
3045 | void sdev_disable_disk_events(struct scsi_device *sdev) | |
3046 | { | |
3047 | atomic_inc(&sdev->disk_events_disable_depth); | |
3048 | } | |
3049 | EXPORT_SYMBOL(sdev_disable_disk_events); | |
3050 | ||
3051 | void sdev_enable_disk_events(struct scsi_device *sdev) | |
3052 | { | |
3053 | if (WARN_ON_ONCE(atomic_read(&sdev->disk_events_disable_depth) <= 0)) | |
3054 | return; | |
3055 | atomic_dec(&sdev->disk_events_disable_depth); | |
3056 | } | |
3057 | EXPORT_SYMBOL(sdev_enable_disk_events); | |
9983bed3 | 3058 | |
2e4209b3 MW |
3059 | static unsigned char designator_prio(const unsigned char *d) |
3060 | { | |
3061 | if (d[1] & 0x30) | |
3062 | /* not associated with LUN */ | |
3063 | return 0; | |
3064 | ||
3065 | if (d[3] == 0) | |
3066 | /* invalid length */ | |
3067 | return 0; | |
3068 | ||
3069 | /* | |
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 | |
3077 | * - EUI-64 based 8-byte | |
3078 | * - SCSI name string (truncated) | |
3079 | * - T10 Vendor ID | |
3080 | * as longer descriptors reduce the likelyhood | |
3081 | * of identification clashes. | |
3082 | */ | |
3083 | ||
3084 | switch (d[1] & 0xf) { | |
3085 | case 8: | |
3086 | /* SCSI name string, variable-length UTF-8 */ | |
3087 | return 9; | |
3088 | case 3: | |
3089 | switch (d[4] >> 4) { | |
3090 | case 6: | |
3091 | /* NAA registered extended */ | |
3092 | return 8; | |
3093 | case 5: | |
3094 | /* NAA registered */ | |
3095 | return 5; | |
3096 | case 4: | |
3097 | /* NAA extended */ | |
3098 | return 4; | |
3099 | case 3: | |
3100 | /* NAA locally assigned */ | |
3101 | return 1; | |
3102 | default: | |
3103 | break; | |
3104 | } | |
3105 | break; | |
3106 | case 2: | |
3107 | switch (d[3]) { | |
3108 | case 16: | |
3109 | /* EUI64-based, 16 byte */ | |
3110 | return 7; | |
3111 | case 12: | |
3112 | /* EUI64-based, 12 byte */ | |
3113 | return 6; | |
3114 | case 8: | |
3115 | /* EUI64-based, 8 byte */ | |
3116 | return 3; | |
3117 | default: | |
3118 | break; | |
3119 | } | |
3120 | break; | |
3121 | case 1: | |
3122 | /* T10 vendor ID */ | |
3123 | return 1; | |
3124 | default: | |
3125 | break; | |
3126 | } | |
3127 | ||
3128 | return 0; | |
3129 | } | |
3130 | ||
9983bed3 HR |
3131 | /** |
3132 | * scsi_vpd_lun_id - return a unique device identification | |
3133 | * @sdev: SCSI device | |
3134 | * @id: buffer for the identification | |
3135 | * @id_len: length of the buffer | |
3136 | * | |
3137 | * Copies a unique device identification into @id based | |
3138 | * on the information in the VPD page 0x83 of the device. | |
3139 | * The string will be formatted as a SCSI name string. | |
3140 | * | |
3141 | * Returns the length of the identification or error on failure. | |
3142 | * If the identifier is longer than the supplied buffer the actual | |
3143 | * identifier length is returned and the buffer is not zero-padded. | |
3144 | */ | |
3145 | int scsi_vpd_lun_id(struct scsi_device *sdev, char *id, size_t id_len) | |
3146 | { | |
2e4209b3 | 3147 | u8 cur_id_prio = 0; |
9983bed3 | 3148 | u8 cur_id_size = 0; |
ccf1e004 BVA |
3149 | const unsigned char *d, *cur_id_str; |
3150 | const struct scsi_vpd *vpd_pg83; | |
9983bed3 HR |
3151 | int id_size = -EINVAL; |
3152 | ||
3153 | rcu_read_lock(); | |
3154 | vpd_pg83 = rcu_dereference(sdev->vpd_pg83); | |
3155 | if (!vpd_pg83) { | |
3156 | rcu_read_unlock(); | |
3157 | return -ENXIO; | |
3158 | } | |
3159 | ||
9983bed3 HR |
3160 | /* The id string must be at least 20 bytes + terminating NULL byte */ |
3161 | if (id_len < 21) { | |
3162 | rcu_read_unlock(); | |
3163 | return -EINVAL; | |
3164 | } | |
3165 | ||
3166 | memset(id, 0, id_len); | |
16d6317e MW |
3167 | for (d = vpd_pg83->data + 4; |
3168 | d < vpd_pg83->data + vpd_pg83->len; | |
3169 | d += d[3] + 4) { | |
2e4209b3 MW |
3170 | u8 prio = designator_prio(d); |
3171 | ||
3172 | if (prio == 0 || cur_id_prio > prio) | |
16d6317e | 3173 | continue; |
9983bed3 HR |
3174 | |
3175 | switch (d[1] & 0xf) { | |
d230823a HR |
3176 | case 0x1: |
3177 | /* T10 Vendor ID */ | |
3178 | if (cur_id_size > d[3]) | |
3179 | break; | |
2e4209b3 | 3180 | cur_id_prio = prio; |
d230823a HR |
3181 | cur_id_size = d[3]; |
3182 | if (cur_id_size + 4 > id_len) | |
3183 | cur_id_size = id_len - 4; | |
3184 | cur_id_str = d + 4; | |
d230823a HR |
3185 | id_size = snprintf(id, id_len, "t10.%*pE", |
3186 | cur_id_size, cur_id_str); | |
3187 | break; | |
9983bed3 HR |
3188 | case 0x2: |
3189 | /* EUI-64 */ | |
2e4209b3 | 3190 | cur_id_prio = prio; |
9983bed3 HR |
3191 | cur_id_size = d[3]; |
3192 | cur_id_str = d + 4; | |
9983bed3 HR |
3193 | switch (cur_id_size) { |
3194 | case 8: | |
3195 | id_size = snprintf(id, id_len, | |
3196 | "eui.%8phN", | |
3197 | cur_id_str); | |
3198 | break; | |
3199 | case 12: | |
3200 | id_size = snprintf(id, id_len, | |
3201 | "eui.%12phN", | |
3202 | cur_id_str); | |
3203 | break; | |
3204 | case 16: | |
3205 | id_size = snprintf(id, id_len, | |
3206 | "eui.%16phN", | |
3207 | cur_id_str); | |
3208 | break; | |
3209 | default: | |
9983bed3 HR |
3210 | break; |
3211 | } | |
3212 | break; | |
3213 | case 0x3: | |
3214 | /* NAA */ | |
2e4209b3 | 3215 | cur_id_prio = prio; |
9983bed3 HR |
3216 | cur_id_size = d[3]; |
3217 | cur_id_str = d + 4; | |
9983bed3 HR |
3218 | switch (cur_id_size) { |
3219 | case 8: | |
3220 | id_size = snprintf(id, id_len, | |
3221 | "naa.%8phN", | |
3222 | cur_id_str); | |
3223 | break; | |
3224 | case 16: | |
3225 | id_size = snprintf(id, id_len, | |
3226 | "naa.%16phN", | |
3227 | cur_id_str); | |
3228 | break; | |
3229 | default: | |
9983bed3 HR |
3230 | break; |
3231 | } | |
3232 | break; | |
3233 | case 0x8: | |
3234 | /* SCSI name string */ | |
2e4209b3 | 3235 | if (cur_id_size > d[3]) |
9983bed3 HR |
3236 | break; |
3237 | /* Prefer others for truncated descriptor */ | |
2e4209b3 MW |
3238 | if (d[3] > id_len) { |
3239 | prio = 2; | |
3240 | if (cur_id_prio > prio) | |
3241 | break; | |
3242 | } | |
3243 | cur_id_prio = prio; | |
9983bed3 HR |
3244 | cur_id_size = id_size = d[3]; |
3245 | cur_id_str = d + 4; | |
9983bed3 HR |
3246 | if (cur_id_size >= id_len) |
3247 | cur_id_size = id_len - 1; | |
3248 | memcpy(id, cur_id_str, cur_id_size); | |
9983bed3 HR |
3249 | break; |
3250 | default: | |
3251 | break; | |
3252 | } | |
9983bed3 HR |
3253 | } |
3254 | rcu_read_unlock(); | |
3255 | ||
3256 | return id_size; | |
3257 | } | |
3258 | EXPORT_SYMBOL(scsi_vpd_lun_id); | |
a8aa3978 HR |
3259 | |
3260 | /* | |
3261 | * scsi_vpd_tpg_id - return a target port group identifier | |
3262 | * @sdev: SCSI device | |
3263 | * | |
3264 | * Returns the Target Port Group identifier from the information | |
3265 | * froom VPD page 0x83 of the device. | |
3266 | * | |
3267 | * Returns the identifier or error on failure. | |
3268 | */ | |
3269 | int scsi_vpd_tpg_id(struct scsi_device *sdev, int *rel_id) | |
3270 | { | |
ccf1e004 BVA |
3271 | const unsigned char *d; |
3272 | const struct scsi_vpd *vpd_pg83; | |
a8aa3978 HR |
3273 | int group_id = -EAGAIN, rel_port = -1; |
3274 | ||
3275 | rcu_read_lock(); | |
3276 | vpd_pg83 = rcu_dereference(sdev->vpd_pg83); | |
3277 | if (!vpd_pg83) { | |
3278 | rcu_read_unlock(); | |
3279 | return -ENXIO; | |
3280 | } | |
3281 | ||
ccf1e004 BVA |
3282 | d = vpd_pg83->data + 4; |
3283 | while (d < vpd_pg83->data + vpd_pg83->len) { | |
a8aa3978 HR |
3284 | switch (d[1] & 0xf) { |
3285 | case 0x4: | |
3286 | /* Relative target port */ | |
3287 | rel_port = get_unaligned_be16(&d[6]); | |
3288 | break; | |
3289 | case 0x5: | |
3290 | /* Target port group */ | |
3291 | group_id = get_unaligned_be16(&d[6]); | |
3292 | break; | |
3293 | default: | |
3294 | break; | |
3295 | } | |
3296 | d += d[3] + 4; | |
3297 | } | |
3298 | rcu_read_unlock(); | |
3299 | ||
3300 | if (group_id >= 0 && rel_id && rel_port != -1) | |
3301 | *rel_id = rel_port; | |
3302 | ||
3303 | return group_id; | |
3304 | } | |
3305 | EXPORT_SYMBOL(scsi_vpd_tpg_id); | |
f2b1e9c6 HR |
3306 | |
3307 | /** | |
3308 | * scsi_build_sense - build sense data for a command | |
3309 | * @scmd: scsi command for which the sense should be formatted | |
3310 | * @desc: Sense format (non-zero == descriptor format, | |
3311 | * 0 == fixed format) | |
3312 | * @key: Sense key | |
3313 | * @asc: Additional sense code | |
3314 | * @ascq: Additional sense code qualifier | |
3315 | * | |
3316 | **/ | |
3317 | void scsi_build_sense(struct scsi_cmnd *scmd, int desc, u8 key, u8 asc, u8 ascq) | |
3318 | { | |
3319 | scsi_build_sense_buffer(desc, scmd->sense_buffer, key, asc, ascq); | |
464a00c9 | 3320 | scmd->result = SAM_STAT_CHECK_CONDITION; |
f2b1e9c6 HR |
3321 | } |
3322 | EXPORT_SYMBOL_GPL(scsi_build_sense); |