Commit | Line | Data |
---|---|---|
1da177e4 | 1 | /* |
d285203c CH |
2 | * Copyright (C) 1999 Eric Youngdale |
3 | * Copyright (C) 2014 Christoph Hellwig | |
1da177e4 LT |
4 | * |
5 | * SCSI queueing library. | |
6 | * Initial versions: Eric Youngdale (eric@andante.org). | |
7 | * Based upon conversations with large numbers | |
8 | * of people at Linux Expo. | |
9 | */ | |
10 | ||
11 | #include <linux/bio.h> | |
d3f46f39 | 12 | #include <linux/bitops.h> |
1da177e4 LT |
13 | #include <linux/blkdev.h> |
14 | #include <linux/completion.h> | |
15 | #include <linux/kernel.h> | |
09703660 | 16 | #include <linux/export.h> |
1da177e4 LT |
17 | #include <linux/mempool.h> |
18 | #include <linux/slab.h> | |
19 | #include <linux/init.h> | |
20 | #include <linux/pci.h> | |
21 | #include <linux/delay.h> | |
faead26d | 22 | #include <linux/hardirq.h> |
c6132da1 | 23 | #include <linux/scatterlist.h> |
d285203c | 24 | #include <linux/blk-mq.h> |
1da177e4 LT |
25 | |
26 | #include <scsi/scsi.h> | |
beb40487 | 27 | #include <scsi/scsi_cmnd.h> |
1da177e4 LT |
28 | #include <scsi/scsi_dbg.h> |
29 | #include <scsi/scsi_device.h> | |
30 | #include <scsi/scsi_driver.h> | |
31 | #include <scsi/scsi_eh.h> | |
32 | #include <scsi/scsi_host.h> | |
1da177e4 | 33 | |
3b5382c4 CH |
34 | #include <trace/events/scsi.h> |
35 | ||
1da177e4 LT |
36 | #include "scsi_priv.h" |
37 | #include "scsi_logging.h" | |
38 | ||
39 | ||
6391a113 | 40 | #define SG_MEMPOOL_NR ARRAY_SIZE(scsi_sg_pools) |
5972511b | 41 | #define SG_MEMPOOL_SIZE 2 |
1da177e4 LT |
42 | |
43 | struct scsi_host_sg_pool { | |
44 | size_t size; | |
a8474ce2 | 45 | char *name; |
e18b890b | 46 | struct kmem_cache *slab; |
1da177e4 LT |
47 | mempool_t *pool; |
48 | }; | |
49 | ||
d3f46f39 JB |
50 | #define SP(x) { x, "sgpool-" __stringify(x) } |
51 | #if (SCSI_MAX_SG_SEGMENTS < 32) | |
52 | #error SCSI_MAX_SG_SEGMENTS is too small (must be 32 or greater) | |
53 | #endif | |
52c1da39 | 54 | static struct scsi_host_sg_pool scsi_sg_pools[] = { |
1da177e4 LT |
55 | SP(8), |
56 | SP(16), | |
fd820f40 | 57 | #if (SCSI_MAX_SG_SEGMENTS > 32) |
d3f46f39 | 58 | SP(32), |
fd820f40 | 59 | #if (SCSI_MAX_SG_SEGMENTS > 64) |
d3f46f39 JB |
60 | SP(64), |
61 | #if (SCSI_MAX_SG_SEGMENTS > 128) | |
1da177e4 | 62 | SP(128), |
d3f46f39 JB |
63 | #if (SCSI_MAX_SG_SEGMENTS > 256) |
64 | #error SCSI_MAX_SG_SEGMENTS is too large (256 MAX) | |
fd820f40 FT |
65 | #endif |
66 | #endif | |
67 | #endif | |
d3f46f39 JB |
68 | #endif |
69 | SP(SCSI_MAX_SG_SEGMENTS) | |
a8474ce2 | 70 | }; |
1da177e4 LT |
71 | #undef SP |
72 | ||
7027ad72 | 73 | struct kmem_cache *scsi_sdb_cache; |
6f9a35e2 | 74 | |
a488e749 JA |
75 | /* |
76 | * When to reinvoke queueing after a resource shortage. It's 3 msecs to | |
77 | * not change behaviour from the previous unplug mechanism, experimentation | |
78 | * may prove this needs changing. | |
79 | */ | |
80 | #define SCSI_QUEUE_DELAY 3 | |
81 | ||
de3e8bf3 CH |
82 | static void |
83 | scsi_set_blocked(struct scsi_cmnd *cmd, int reason) | |
1da177e4 LT |
84 | { |
85 | struct Scsi_Host *host = cmd->device->host; | |
86 | struct scsi_device *device = cmd->device; | |
f0c0a376 | 87 | struct scsi_target *starget = scsi_target(device); |
1da177e4 LT |
88 | |
89 | /* | |
d8c37e7b | 90 | * Set the appropriate busy bit for the device/host. |
1da177e4 LT |
91 | * |
92 | * If the host/device isn't busy, assume that something actually | |
93 | * completed, and that we should be able to queue a command now. | |
94 | * | |
95 | * Note that the prior mid-layer assumption that any host could | |
96 | * always queue at least one command is now broken. The mid-layer | |
97 | * will implement a user specifiable stall (see | |
98 | * scsi_host.max_host_blocked and scsi_device.max_device_blocked) | |
99 | * if a command is requeued with no other commands outstanding | |
100 | * either for the device or for the host. | |
101 | */ | |
f0c0a376 MC |
102 | switch (reason) { |
103 | case SCSI_MLQUEUE_HOST_BUSY: | |
cd9070c9 | 104 | atomic_set(&host->host_blocked, host->max_host_blocked); |
f0c0a376 MC |
105 | break; |
106 | case SCSI_MLQUEUE_DEVICE_BUSY: | |
573e5913 | 107 | case SCSI_MLQUEUE_EH_RETRY: |
cd9070c9 CH |
108 | atomic_set(&device->device_blocked, |
109 | device->max_device_blocked); | |
f0c0a376 MC |
110 | break; |
111 | case SCSI_MLQUEUE_TARGET_BUSY: | |
cd9070c9 CH |
112 | atomic_set(&starget->target_blocked, |
113 | starget->max_target_blocked); | |
f0c0a376 MC |
114 | break; |
115 | } | |
de3e8bf3 CH |
116 | } |
117 | ||
d285203c CH |
118 | static void scsi_mq_requeue_cmd(struct scsi_cmnd *cmd) |
119 | { | |
120 | struct scsi_device *sdev = cmd->device; | |
121 | struct request_queue *q = cmd->request->q; | |
122 | ||
123 | blk_mq_requeue_request(cmd->request); | |
124 | blk_mq_kick_requeue_list(q); | |
125 | put_device(&sdev->sdev_gendev); | |
126 | } | |
127 | ||
de3e8bf3 CH |
128 | /** |
129 | * __scsi_queue_insert - private queue insertion | |
130 | * @cmd: The SCSI command being requeued | |
131 | * @reason: The reason for the requeue | |
132 | * @unbusy: Whether the queue should be unbusied | |
133 | * | |
134 | * This is a private queue insertion. The public interface | |
135 | * scsi_queue_insert() always assumes the queue should be unbusied | |
136 | * because it's always called before the completion. This function is | |
137 | * for a requeue after completion, which should only occur in this | |
138 | * file. | |
139 | */ | |
140 | static void __scsi_queue_insert(struct scsi_cmnd *cmd, int reason, int unbusy) | |
141 | { | |
142 | struct scsi_device *device = cmd->device; | |
143 | struct request_queue *q = device->request_queue; | |
144 | unsigned long flags; | |
145 | ||
146 | SCSI_LOG_MLQUEUE(1, scmd_printk(KERN_INFO, cmd, | |
147 | "Inserting command %p into mlqueue\n", cmd)); | |
148 | ||
149 | scsi_set_blocked(cmd, reason); | |
1da177e4 | 150 | |
1da177e4 LT |
151 | /* |
152 | * Decrement the counters, since these commands are no longer | |
153 | * active on the host/device. | |
154 | */ | |
4f5299ac JB |
155 | if (unbusy) |
156 | scsi_device_unbusy(device); | |
1da177e4 LT |
157 | |
158 | /* | |
a1bf9d1d | 159 | * Requeue this command. It will go before all other commands |
b485462a BVA |
160 | * that are already in the queue. Schedule requeue work under |
161 | * lock such that the kblockd_schedule_work() call happens | |
162 | * before blk_cleanup_queue() finishes. | |
a488e749 | 163 | */ |
644373a4 | 164 | cmd->result = 0; |
d285203c CH |
165 | if (q->mq_ops) { |
166 | scsi_mq_requeue_cmd(cmd); | |
167 | return; | |
168 | } | |
a1bf9d1d | 169 | spin_lock_irqsave(q->queue_lock, flags); |
59897dad | 170 | blk_requeue_request(q, cmd->request); |
59c3d45e | 171 | kblockd_schedule_work(&device->requeue_work); |
b485462a | 172 | spin_unlock_irqrestore(q->queue_lock, flags); |
1da177e4 LT |
173 | } |
174 | ||
4f5299ac JB |
175 | /* |
176 | * Function: scsi_queue_insert() | |
177 | * | |
178 | * Purpose: Insert a command in the midlevel queue. | |
179 | * | |
180 | * Arguments: cmd - command that we are adding to queue. | |
181 | * reason - why we are inserting command to queue. | |
182 | * | |
183 | * Lock status: Assumed that lock is not held upon entry. | |
184 | * | |
185 | * Returns: Nothing. | |
186 | * | |
187 | * Notes: We do this for one of two cases. Either the host is busy | |
188 | * and it cannot accept any more commands for the time being, | |
189 | * or the device returned QUEUE_FULL and can accept no more | |
190 | * commands. | |
191 | * Notes: This could be called either from an interrupt context or a | |
192 | * normal process context. | |
193 | */ | |
84feb166 | 194 | void scsi_queue_insert(struct scsi_cmnd *cmd, int reason) |
4f5299ac | 195 | { |
84feb166 | 196 | __scsi_queue_insert(cmd, reason, 1); |
4f5299ac | 197 | } |
39216033 | 198 | /** |
33aa687d | 199 | * scsi_execute - insert request and wait for the result |
39216033 JB |
200 | * @sdev: scsi device |
201 | * @cmd: scsi command | |
202 | * @data_direction: data direction | |
203 | * @buffer: data buffer | |
204 | * @bufflen: len of buffer | |
205 | * @sense: optional sense buffer | |
206 | * @timeout: request timeout in seconds | |
207 | * @retries: number of times to retry request | |
33aa687d | 208 | * @flags: or into request flags; |
f4f4e47e | 209 | * @resid: optional residual length |
39216033 | 210 | * |
59c51591 | 211 | * returns the req->errors value which is the scsi_cmnd result |
ea73a9f2 | 212 | * field. |
eb44820c | 213 | */ |
33aa687d JB |
214 | int scsi_execute(struct scsi_device *sdev, const unsigned char *cmd, |
215 | int data_direction, void *buffer, unsigned bufflen, | |
2bfad21e | 216 | unsigned char *sense, int timeout, int retries, u64 flags, |
f4f4e47e | 217 | int *resid) |
39216033 JB |
218 | { |
219 | struct request *req; | |
220 | int write = (data_direction == DMA_TO_DEVICE); | |
221 | int ret = DRIVER_ERROR << 24; | |
222 | ||
223 | req = blk_get_request(sdev->request_queue, write, __GFP_WAIT); | |
bfe159a5 JB |
224 | if (!req) |
225 | return ret; | |
f27b087b | 226 | blk_rq_set_block_pc(req); |
39216033 JB |
227 | |
228 | if (bufflen && blk_rq_map_kern(sdev->request_queue, req, | |
229 | buffer, bufflen, __GFP_WAIT)) | |
230 | goto out; | |
231 | ||
232 | req->cmd_len = COMMAND_SIZE(cmd[0]); | |
233 | memcpy(req->cmd, cmd, req->cmd_len); | |
234 | req->sense = sense; | |
235 | req->sense_len = 0; | |
17e01f21 | 236 | req->retries = retries; |
39216033 | 237 | req->timeout = timeout; |
4aff5e23 | 238 | req->cmd_flags |= flags | REQ_QUIET | REQ_PREEMPT; |
39216033 JB |
239 | |
240 | /* | |
241 | * head injection *required* here otherwise quiesce won't work | |
242 | */ | |
243 | blk_execute_rq(req->q, NULL, req, 1); | |
244 | ||
bdb2b8ca AS |
245 | /* |
246 | * Some devices (USB mass-storage in particular) may transfer | |
247 | * garbage data together with a residue indicating that the data | |
248 | * is invalid. Prevent the garbage from being misinterpreted | |
249 | * and prevent security leaks by zeroing out the excess data. | |
250 | */ | |
c3a4d78c TH |
251 | if (unlikely(req->resid_len > 0 && req->resid_len <= bufflen)) |
252 | memset(buffer + (bufflen - req->resid_len), 0, req->resid_len); | |
bdb2b8ca | 253 | |
f4f4e47e | 254 | if (resid) |
c3a4d78c | 255 | *resid = req->resid_len; |
39216033 JB |
256 | ret = req->errors; |
257 | out: | |
258 | blk_put_request(req); | |
259 | ||
260 | return ret; | |
261 | } | |
33aa687d | 262 | EXPORT_SYMBOL(scsi_execute); |
39216033 | 263 | |
9b21493c | 264 | int scsi_execute_req_flags(struct scsi_device *sdev, const unsigned char *cmd, |
ea73a9f2 | 265 | int data_direction, void *buffer, unsigned bufflen, |
f4f4e47e | 266 | struct scsi_sense_hdr *sshdr, int timeout, int retries, |
2bfad21e | 267 | int *resid, u64 flags) |
ea73a9f2 JB |
268 | { |
269 | char *sense = NULL; | |
1ccb48bb | 270 | int result; |
271 | ||
ea73a9f2 | 272 | if (sshdr) { |
24669f75 | 273 | sense = kzalloc(SCSI_SENSE_BUFFERSIZE, GFP_NOIO); |
ea73a9f2 JB |
274 | if (!sense) |
275 | return DRIVER_ERROR << 24; | |
ea73a9f2 | 276 | } |
1ccb48bb | 277 | result = scsi_execute(sdev, cmd, data_direction, buffer, bufflen, |
9b21493c | 278 | sense, timeout, retries, flags, resid); |
ea73a9f2 | 279 | if (sshdr) |
e514385b | 280 | scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE, sshdr); |
ea73a9f2 JB |
281 | |
282 | kfree(sense); | |
283 | return result; | |
284 | } | |
9b21493c | 285 | EXPORT_SYMBOL(scsi_execute_req_flags); |
ea73a9f2 | 286 | |
1da177e4 LT |
287 | /* |
288 | * Function: scsi_init_cmd_errh() | |
289 | * | |
290 | * Purpose: Initialize cmd fields related to error handling. | |
291 | * | |
292 | * Arguments: cmd - command that is ready to be queued. | |
293 | * | |
1da177e4 LT |
294 | * Notes: This function has the job of initializing a number of |
295 | * fields related to error handling. Typically this will | |
296 | * be called once for each command, as required. | |
297 | */ | |
631c228c | 298 | static void scsi_init_cmd_errh(struct scsi_cmnd *cmd) |
1da177e4 | 299 | { |
1da177e4 | 300 | cmd->serial_number = 0; |
30b0c37b | 301 | scsi_set_resid(cmd, 0); |
b80ca4f7 | 302 | memset(cmd->sense_buffer, 0, SCSI_SENSE_BUFFERSIZE); |
1da177e4 | 303 | if (cmd->cmd_len == 0) |
db4742dd | 304 | cmd->cmd_len = scsi_command_size(cmd->cmnd); |
1da177e4 LT |
305 | } |
306 | ||
307 | void scsi_device_unbusy(struct scsi_device *sdev) | |
308 | { | |
309 | struct Scsi_Host *shost = sdev->host; | |
f0c0a376 | 310 | struct scsi_target *starget = scsi_target(sdev); |
1da177e4 LT |
311 | unsigned long flags; |
312 | ||
74665016 | 313 | atomic_dec(&shost->host_busy); |
2ccbb008 CH |
314 | if (starget->can_queue > 0) |
315 | atomic_dec(&starget->target_busy); | |
74665016 | 316 | |
939647ee | 317 | if (unlikely(scsi_host_in_recovery(shost) && |
74665016 CH |
318 | (shost->host_failed || shost->host_eh_scheduled))) { |
319 | spin_lock_irqsave(shost->host_lock, flags); | |
1da177e4 | 320 | scsi_eh_wakeup(shost); |
74665016 CH |
321 | spin_unlock_irqrestore(shost->host_lock, flags); |
322 | } | |
323 | ||
71e75c97 | 324 | atomic_dec(&sdev->device_busy); |
1da177e4 LT |
325 | } |
326 | ||
d285203c CH |
327 | static void scsi_kick_queue(struct request_queue *q) |
328 | { | |
329 | if (q->mq_ops) | |
330 | blk_mq_start_hw_queues(q); | |
331 | else | |
332 | blk_run_queue(q); | |
333 | } | |
334 | ||
1da177e4 LT |
335 | /* |
336 | * Called for single_lun devices on IO completion. Clear starget_sdev_user, | |
337 | * and call blk_run_queue for all the scsi_devices on the target - | |
338 | * including current_sdev first. | |
339 | * | |
340 | * Called with *no* scsi locks held. | |
341 | */ | |
342 | static void scsi_single_lun_run(struct scsi_device *current_sdev) | |
343 | { | |
344 | struct Scsi_Host *shost = current_sdev->host; | |
345 | struct scsi_device *sdev, *tmp; | |
346 | struct scsi_target *starget = scsi_target(current_sdev); | |
347 | unsigned long flags; | |
348 | ||
349 | spin_lock_irqsave(shost->host_lock, flags); | |
350 | starget->starget_sdev_user = NULL; | |
351 | spin_unlock_irqrestore(shost->host_lock, flags); | |
352 | ||
353 | /* | |
354 | * Call blk_run_queue for all LUNs on the target, starting with | |
355 | * current_sdev. We race with others (to set starget_sdev_user), | |
356 | * but in most cases, we will be first. Ideally, each LU on the | |
357 | * target would get some limited time or requests on the target. | |
358 | */ | |
d285203c | 359 | scsi_kick_queue(current_sdev->request_queue); |
1da177e4 LT |
360 | |
361 | spin_lock_irqsave(shost->host_lock, flags); | |
362 | if (starget->starget_sdev_user) | |
363 | goto out; | |
364 | list_for_each_entry_safe(sdev, tmp, &starget->devices, | |
365 | same_target_siblings) { | |
366 | if (sdev == current_sdev) | |
367 | continue; | |
368 | if (scsi_device_get(sdev)) | |
369 | continue; | |
370 | ||
371 | spin_unlock_irqrestore(shost->host_lock, flags); | |
d285203c | 372 | scsi_kick_queue(sdev->request_queue); |
1da177e4 LT |
373 | spin_lock_irqsave(shost->host_lock, flags); |
374 | ||
375 | scsi_device_put(sdev); | |
376 | } | |
377 | out: | |
378 | spin_unlock_irqrestore(shost->host_lock, flags); | |
379 | } | |
380 | ||
cd9070c9 | 381 | static inline bool scsi_device_is_busy(struct scsi_device *sdev) |
9d112517 | 382 | { |
cd9070c9 CH |
383 | if (atomic_read(&sdev->device_busy) >= sdev->queue_depth) |
384 | return true; | |
385 | if (atomic_read(&sdev->device_blocked) > 0) | |
386 | return true; | |
387 | return false; | |
9d112517 KU |
388 | } |
389 | ||
cd9070c9 | 390 | static inline bool scsi_target_is_busy(struct scsi_target *starget) |
f0c0a376 | 391 | { |
2ccbb008 CH |
392 | if (starget->can_queue > 0) { |
393 | if (atomic_read(&starget->target_busy) >= starget->can_queue) | |
394 | return true; | |
395 | if (atomic_read(&starget->target_blocked) > 0) | |
396 | return true; | |
397 | } | |
cd9070c9 | 398 | return false; |
f0c0a376 MC |
399 | } |
400 | ||
cd9070c9 | 401 | static inline bool scsi_host_is_busy(struct Scsi_Host *shost) |
9d112517 | 402 | { |
cd9070c9 CH |
403 | if (shost->can_queue > 0 && |
404 | atomic_read(&shost->host_busy) >= shost->can_queue) | |
405 | return true; | |
406 | if (atomic_read(&shost->host_blocked) > 0) | |
407 | return true; | |
408 | if (shost->host_self_blocked) | |
409 | return true; | |
410 | return false; | |
9d112517 KU |
411 | } |
412 | ||
21a05df5 | 413 | static void scsi_starved_list_run(struct Scsi_Host *shost) |
1da177e4 | 414 | { |
2a3a59e5 | 415 | LIST_HEAD(starved_list); |
21a05df5 | 416 | struct scsi_device *sdev; |
1da177e4 LT |
417 | unsigned long flags; |
418 | ||
1da177e4 | 419 | spin_lock_irqsave(shost->host_lock, flags); |
2a3a59e5 MC |
420 | list_splice_init(&shost->starved_list, &starved_list); |
421 | ||
422 | while (!list_empty(&starved_list)) { | |
e2eb7244 JB |
423 | struct request_queue *slq; |
424 | ||
1da177e4 LT |
425 | /* |
426 | * As long as shost is accepting commands and we have | |
427 | * starved queues, call blk_run_queue. scsi_request_fn | |
428 | * drops the queue_lock and can add us back to the | |
429 | * starved_list. | |
430 | * | |
431 | * host_lock protects the starved_list and starved_entry. | |
432 | * scsi_request_fn must get the host_lock before checking | |
433 | * or modifying starved_list or starved_entry. | |
434 | */ | |
2a3a59e5 | 435 | if (scsi_host_is_busy(shost)) |
f0c0a376 | 436 | break; |
f0c0a376 | 437 | |
2a3a59e5 MC |
438 | sdev = list_entry(starved_list.next, |
439 | struct scsi_device, starved_entry); | |
440 | list_del_init(&sdev->starved_entry); | |
f0c0a376 MC |
441 | if (scsi_target_is_busy(scsi_target(sdev))) { |
442 | list_move_tail(&sdev->starved_entry, | |
443 | &shost->starved_list); | |
444 | continue; | |
445 | } | |
446 | ||
e2eb7244 JB |
447 | /* |
448 | * Once we drop the host lock, a racing scsi_remove_device() | |
449 | * call may remove the sdev from the starved list and destroy | |
450 | * it and the queue. Mitigate by taking a reference to the | |
451 | * queue and never touching the sdev again after we drop the | |
452 | * host lock. Note: if __scsi_remove_device() invokes | |
453 | * blk_cleanup_queue() before the queue is run from this | |
454 | * function then blk_run_queue() will return immediately since | |
455 | * blk_cleanup_queue() marks the queue with QUEUE_FLAG_DYING. | |
456 | */ | |
457 | slq = sdev->request_queue; | |
458 | if (!blk_get_queue(slq)) | |
459 | continue; | |
460 | spin_unlock_irqrestore(shost->host_lock, flags); | |
461 | ||
d285203c | 462 | scsi_kick_queue(slq); |
e2eb7244 JB |
463 | blk_put_queue(slq); |
464 | ||
465 | spin_lock_irqsave(shost->host_lock, flags); | |
1da177e4 | 466 | } |
2a3a59e5 MC |
467 | /* put any unprocessed entries back */ |
468 | list_splice(&starved_list, &shost->starved_list); | |
1da177e4 | 469 | spin_unlock_irqrestore(shost->host_lock, flags); |
21a05df5 CH |
470 | } |
471 | ||
472 | /* | |
473 | * Function: scsi_run_queue() | |
474 | * | |
475 | * Purpose: Select a proper request queue to serve next | |
476 | * | |
477 | * Arguments: q - last request's queue | |
478 | * | |
479 | * Returns: Nothing | |
480 | * | |
481 | * Notes: The previous command was completely finished, start | |
482 | * a new one if possible. | |
483 | */ | |
484 | static void scsi_run_queue(struct request_queue *q) | |
485 | { | |
486 | struct scsi_device *sdev = q->queuedata; | |
487 | ||
488 | if (scsi_target(sdev)->single_lun) | |
489 | scsi_single_lun_run(sdev); | |
490 | if (!list_empty(&sdev->host->starved_list)) | |
491 | scsi_starved_list_run(sdev->host); | |
1da177e4 | 492 | |
d285203c CH |
493 | if (q->mq_ops) |
494 | blk_mq_start_stopped_hw_queues(q, false); | |
495 | else | |
496 | blk_run_queue(q); | |
1da177e4 LT |
497 | } |
498 | ||
9937a5e2 JA |
499 | void scsi_requeue_run_queue(struct work_struct *work) |
500 | { | |
501 | struct scsi_device *sdev; | |
502 | struct request_queue *q; | |
503 | ||
504 | sdev = container_of(work, struct scsi_device, requeue_work); | |
505 | q = sdev->request_queue; | |
506 | scsi_run_queue(q); | |
507 | } | |
508 | ||
1da177e4 LT |
509 | /* |
510 | * Function: scsi_requeue_command() | |
511 | * | |
512 | * Purpose: Handle post-processing of completed commands. | |
513 | * | |
514 | * Arguments: q - queue to operate on | |
515 | * cmd - command that may need to be requeued. | |
516 | * | |
517 | * Returns: Nothing | |
518 | * | |
519 | * Notes: After command completion, there may be blocks left | |
520 | * over which weren't finished by the previous command | |
521 | * this can be for a number of reasons - the main one is | |
522 | * I/O errors in the middle of the request, in which case | |
523 | * we need to request the blocks that come after the bad | |
524 | * sector. | |
e91442b6 | 525 | * Notes: Upon return, cmd is a stale pointer. |
1da177e4 LT |
526 | */ |
527 | static void scsi_requeue_command(struct request_queue *q, struct scsi_cmnd *cmd) | |
528 | { | |
940f5d47 | 529 | struct scsi_device *sdev = cmd->device; |
e91442b6 | 530 | struct request *req = cmd->request; |
283369cc TH |
531 | unsigned long flags; |
532 | ||
283369cc | 533 | spin_lock_irqsave(q->queue_lock, flags); |
134997a0 CH |
534 | blk_unprep_request(req); |
535 | req->special = NULL; | |
536 | scsi_put_command(cmd); | |
e91442b6 | 537 | blk_requeue_request(q, req); |
283369cc | 538 | spin_unlock_irqrestore(q->queue_lock, flags); |
1da177e4 LT |
539 | |
540 | scsi_run_queue(q); | |
940f5d47 BVA |
541 | |
542 | put_device(&sdev->sdev_gendev); | |
1da177e4 LT |
543 | } |
544 | ||
545 | void scsi_next_command(struct scsi_cmnd *cmd) | |
546 | { | |
49d7bc64 LT |
547 | struct scsi_device *sdev = cmd->device; |
548 | struct request_queue *q = sdev->request_queue; | |
549 | ||
1da177e4 LT |
550 | scsi_put_command(cmd); |
551 | scsi_run_queue(q); | |
49d7bc64 | 552 | |
49d7bc64 | 553 | put_device(&sdev->sdev_gendev); |
1da177e4 LT |
554 | } |
555 | ||
556 | void scsi_run_host_queues(struct Scsi_Host *shost) | |
557 | { | |
558 | struct scsi_device *sdev; | |
559 | ||
560 | shost_for_each_device(sdev, shost) | |
561 | scsi_run_queue(sdev->request_queue); | |
562 | } | |
563 | ||
a8474ce2 JA |
564 | static inline unsigned int scsi_sgtable_index(unsigned short nents) |
565 | { | |
566 | unsigned int index; | |
567 | ||
d3f46f39 JB |
568 | BUG_ON(nents > SCSI_MAX_SG_SEGMENTS); |
569 | ||
570 | if (nents <= 8) | |
a8474ce2 | 571 | index = 0; |
d3f46f39 JB |
572 | else |
573 | index = get_count_order(nents) - 3; | |
1da177e4 | 574 | |
a8474ce2 JA |
575 | return index; |
576 | } | |
577 | ||
5ed7959e | 578 | static void scsi_sg_free(struct scatterlist *sgl, unsigned int nents) |
a8474ce2 JA |
579 | { |
580 | struct scsi_host_sg_pool *sgp; | |
a8474ce2 | 581 | |
5ed7959e JA |
582 | sgp = scsi_sg_pools + scsi_sgtable_index(nents); |
583 | mempool_free(sgl, sgp->pool); | |
584 | } | |
a8474ce2 | 585 | |
5ed7959e JA |
586 | static struct scatterlist *scsi_sg_alloc(unsigned int nents, gfp_t gfp_mask) |
587 | { | |
588 | struct scsi_host_sg_pool *sgp; | |
a8474ce2 | 589 | |
5ed7959e JA |
590 | sgp = scsi_sg_pools + scsi_sgtable_index(nents); |
591 | return mempool_alloc(sgp->pool, gfp_mask); | |
592 | } | |
a3bec5c5 | 593 | |
d285203c | 594 | static void scsi_free_sgtable(struct scsi_data_buffer *sdb, bool mq) |
c53c6d6a | 595 | { |
d285203c CH |
596 | if (mq && sdb->table.nents <= SCSI_MAX_SG_SEGMENTS) |
597 | return; | |
598 | __sg_free_table(&sdb->table, SCSI_MAX_SG_SEGMENTS, mq, scsi_sg_free); | |
c53c6d6a CH |
599 | } |
600 | ||
30b0c37b | 601 | static int scsi_alloc_sgtable(struct scsi_data_buffer *sdb, int nents, |
d285203c | 602 | gfp_t gfp_mask, bool mq) |
5ed7959e | 603 | { |
d285203c | 604 | struct scatterlist *first_chunk = NULL; |
5ed7959e | 605 | int ret; |
a8474ce2 | 606 | |
30b0c37b | 607 | BUG_ON(!nents); |
a8474ce2 | 608 | |
d285203c CH |
609 | if (mq) { |
610 | if (nents <= SCSI_MAX_SG_SEGMENTS) { | |
611 | sdb->table.nents = nents; | |
612 | sg_init_table(sdb->table.sgl, sdb->table.nents); | |
613 | return 0; | |
614 | } | |
615 | first_chunk = sdb->table.sgl; | |
616 | } | |
617 | ||
30b0c37b | 618 | ret = __sg_alloc_table(&sdb->table, nents, SCSI_MAX_SG_SEGMENTS, |
d285203c | 619 | first_chunk, gfp_mask, scsi_sg_alloc); |
5ed7959e | 620 | if (unlikely(ret)) |
d285203c | 621 | scsi_free_sgtable(sdb, mq); |
a8474ce2 | 622 | return ret; |
1da177e4 LT |
623 | } |
624 | ||
d285203c CH |
625 | static void scsi_uninit_cmd(struct scsi_cmnd *cmd) |
626 | { | |
627 | if (cmd->request->cmd_type == REQ_TYPE_FS) { | |
628 | struct scsi_driver *drv = scsi_cmd_to_driver(cmd); | |
629 | ||
630 | if (drv->uninit_command) | |
631 | drv->uninit_command(cmd); | |
632 | } | |
633 | } | |
634 | ||
635 | static void scsi_mq_free_sgtables(struct scsi_cmnd *cmd) | |
636 | { | |
637 | if (cmd->sdb.table.nents) | |
638 | scsi_free_sgtable(&cmd->sdb, true); | |
639 | if (cmd->request->next_rq && cmd->request->next_rq->special) | |
640 | scsi_free_sgtable(cmd->request->next_rq->special, true); | |
641 | if (scsi_prot_sg_count(cmd)) | |
642 | scsi_free_sgtable(cmd->prot_sdb, true); | |
643 | } | |
644 | ||
645 | static void scsi_mq_uninit_cmd(struct scsi_cmnd *cmd) | |
646 | { | |
647 | struct scsi_device *sdev = cmd->device; | |
648 | unsigned long flags; | |
649 | ||
650 | BUG_ON(list_empty(&cmd->list)); | |
651 | ||
652 | scsi_mq_free_sgtables(cmd); | |
653 | scsi_uninit_cmd(cmd); | |
654 | ||
655 | spin_lock_irqsave(&sdev->list_lock, flags); | |
656 | list_del_init(&cmd->list); | |
657 | spin_unlock_irqrestore(&sdev->list_lock, flags); | |
658 | } | |
659 | ||
1da177e4 LT |
660 | /* |
661 | * Function: scsi_release_buffers() | |
662 | * | |
c682adf3 | 663 | * Purpose: Free resources allocate for a scsi_command. |
1da177e4 LT |
664 | * |
665 | * Arguments: cmd - command that we are bailing. | |
666 | * | |
667 | * Lock status: Assumed that no lock is held upon entry. | |
668 | * | |
669 | * Returns: Nothing | |
670 | * | |
671 | * Notes: In the event that an upper level driver rejects a | |
672 | * command, we must release resources allocated during | |
673 | * the __init_io() function. Primarily this would involve | |
c682adf3 | 674 | * the scatter-gather table. |
1da177e4 | 675 | */ |
f1bea55d | 676 | static void scsi_release_buffers(struct scsi_cmnd *cmd) |
1da177e4 | 677 | { |
c682adf3 | 678 | if (cmd->sdb.table.nents) |
d285203c | 679 | scsi_free_sgtable(&cmd->sdb, false); |
c682adf3 CH |
680 | |
681 | memset(&cmd->sdb, 0, sizeof(cmd->sdb)); | |
682 | ||
683 | if (scsi_prot_sg_count(cmd)) | |
d285203c | 684 | scsi_free_sgtable(cmd->prot_sdb, false); |
1da177e4 LT |
685 | } |
686 | ||
c682adf3 CH |
687 | static void scsi_release_bidi_buffers(struct scsi_cmnd *cmd) |
688 | { | |
689 | struct scsi_data_buffer *bidi_sdb = cmd->request->next_rq->special; | |
690 | ||
d285203c | 691 | scsi_free_sgtable(bidi_sdb, false); |
c682adf3 CH |
692 | kmem_cache_free(scsi_sdb_cache, bidi_sdb); |
693 | cmd->request->next_rq->special = NULL; | |
694 | } | |
695 | ||
f6d47e74 CH |
696 | static bool scsi_end_request(struct request *req, int error, |
697 | unsigned int bytes, unsigned int bidi_bytes) | |
698 | { | |
699 | struct scsi_cmnd *cmd = req->special; | |
700 | struct scsi_device *sdev = cmd->device; | |
701 | struct request_queue *q = sdev->request_queue; | |
f6d47e74 CH |
702 | |
703 | if (blk_update_request(req, error, bytes)) | |
704 | return true; | |
705 | ||
706 | /* Bidi request must be completed as a whole */ | |
707 | if (unlikely(bidi_bytes) && | |
708 | blk_update_request(req->next_rq, error, bidi_bytes)) | |
709 | return true; | |
710 | ||
711 | if (blk_queue_add_random(q)) | |
712 | add_disk_randomness(req->rq_disk); | |
713 | ||
d285203c CH |
714 | if (req->mq_ctx) { |
715 | /* | |
716 | * In the MQ case the command gets freed by __blk_mq_end_io, | |
717 | * so we have to do all cleanup that depends on it earlier. | |
718 | * | |
719 | * We also can't kick the queues from irq context, so we | |
720 | * will have to defer it to a workqueue. | |
721 | */ | |
722 | scsi_mq_uninit_cmd(cmd); | |
723 | ||
724 | __blk_mq_end_io(req, error); | |
725 | ||
726 | if (scsi_target(sdev)->single_lun || | |
727 | !list_empty(&sdev->host->starved_list)) | |
728 | kblockd_schedule_work(&sdev->requeue_work); | |
729 | else | |
730 | blk_mq_start_stopped_hw_queues(q, true); | |
731 | ||
732 | put_device(&sdev->sdev_gendev); | |
733 | } else { | |
734 | unsigned long flags; | |
735 | ||
736 | spin_lock_irqsave(q->queue_lock, flags); | |
737 | blk_finish_request(req, error); | |
738 | spin_unlock_irqrestore(q->queue_lock, flags); | |
739 | ||
740 | if (bidi_bytes) | |
741 | scsi_release_bidi_buffers(cmd); | |
742 | scsi_release_buffers(cmd); | |
743 | scsi_next_command(cmd); | |
744 | } | |
f6d47e74 | 745 | |
f6d47e74 CH |
746 | return false; |
747 | } | |
748 | ||
0f7f6234 HR |
749 | /** |
750 | * __scsi_error_from_host_byte - translate SCSI error code into errno | |
751 | * @cmd: SCSI command (unused) | |
752 | * @result: scsi error code | |
753 | * | |
754 | * Translate SCSI error code into standard UNIX errno. | |
755 | * Return values: | |
756 | * -ENOLINK temporary transport failure | |
757 | * -EREMOTEIO permanent target failure, do not retry | |
758 | * -EBADE permanent nexus failure, retry on other path | |
a9d6ceb8 | 759 | * -ENOSPC No write space available |
7e782af5 | 760 | * -ENODATA Medium error |
0f7f6234 HR |
761 | * -EIO unspecified I/O error |
762 | */ | |
63583cca HR |
763 | static int __scsi_error_from_host_byte(struct scsi_cmnd *cmd, int result) |
764 | { | |
765 | int error = 0; | |
766 | ||
767 | switch(host_byte(result)) { | |
768 | case DID_TRANSPORT_FAILFAST: | |
769 | error = -ENOLINK; | |
770 | break; | |
771 | case DID_TARGET_FAILURE: | |
2082ebc4 | 772 | set_host_byte(cmd, DID_OK); |
63583cca HR |
773 | error = -EREMOTEIO; |
774 | break; | |
775 | case DID_NEXUS_FAILURE: | |
2082ebc4 | 776 | set_host_byte(cmd, DID_OK); |
63583cca HR |
777 | error = -EBADE; |
778 | break; | |
a9d6ceb8 HR |
779 | case DID_ALLOC_FAILURE: |
780 | set_host_byte(cmd, DID_OK); | |
781 | error = -ENOSPC; | |
782 | break; | |
7e782af5 HR |
783 | case DID_MEDIUM_ERROR: |
784 | set_host_byte(cmd, DID_OK); | |
785 | error = -ENODATA; | |
786 | break; | |
63583cca HR |
787 | default: |
788 | error = -EIO; | |
789 | break; | |
790 | } | |
791 | ||
792 | return error; | |
793 | } | |
794 | ||
1da177e4 LT |
795 | /* |
796 | * Function: scsi_io_completion() | |
797 | * | |
798 | * Purpose: Completion processing for block device I/O requests. | |
799 | * | |
800 | * Arguments: cmd - command that is finished. | |
801 | * | |
802 | * Lock status: Assumed that no lock is held upon entry. | |
803 | * | |
804 | * Returns: Nothing | |
805 | * | |
bc85dc50 CH |
806 | * Notes: We will finish off the specified number of sectors. If we |
807 | * are done, the command block will be released and the queue | |
808 | * function will be goosed. If we are not done then we have to | |
b60af5b0 | 809 | * figure out what to do next: |
1da177e4 | 810 | * |
b60af5b0 AS |
811 | * a) We can call scsi_requeue_command(). The request |
812 | * will be unprepared and put back on the queue. Then | |
813 | * a new command will be created for it. This should | |
814 | * be used if we made forward progress, or if we want | |
815 | * to switch from READ(10) to READ(6) for example. | |
1da177e4 | 816 | * |
bc85dc50 | 817 | * b) We can call __scsi_queue_insert(). The request will |
b60af5b0 AS |
818 | * be put back on the queue and retried using the same |
819 | * command as before, possibly after a delay. | |
820 | * | |
f6d47e74 | 821 | * c) We can call scsi_end_request() with -EIO to fail |
b60af5b0 | 822 | * the remainder of the request. |
1da177e4 | 823 | */ |
03aba2f7 | 824 | void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes) |
1da177e4 LT |
825 | { |
826 | int result = cmd->result; | |
165125e1 | 827 | struct request_queue *q = cmd->device->request_queue; |
1da177e4 | 828 | struct request *req = cmd->request; |
fa8e36c3 | 829 | int error = 0; |
1da177e4 LT |
830 | struct scsi_sense_hdr sshdr; |
831 | int sense_valid = 0; | |
832 | int sense_deferred = 0; | |
b60af5b0 AS |
833 | enum {ACTION_FAIL, ACTION_REPREP, ACTION_RETRY, |
834 | ACTION_DELAYED_RETRY} action; | |
ee60b2c5 | 835 | unsigned long wait_for = (cmd->allowed + 1) * req->timeout; |
1da177e4 | 836 | |
1da177e4 LT |
837 | if (result) { |
838 | sense_valid = scsi_command_normalize_sense(cmd, &sshdr); | |
839 | if (sense_valid) | |
840 | sense_deferred = scsi_sense_is_deferred(&sshdr); | |
841 | } | |
631c228c | 842 | |
33659ebb | 843 | if (req->cmd_type == REQ_TYPE_BLOCK_PC) { /* SG_IO ioctl from block level */ |
1da177e4 | 844 | if (result) { |
1da177e4 LT |
845 | if (sense_valid && req->sense) { |
846 | /* | |
847 | * SG_IO wants current and deferred errors | |
848 | */ | |
849 | int len = 8 + cmd->sense_buffer[7]; | |
850 | ||
851 | if (len > SCSI_SENSE_BUFFERSIZE) | |
852 | len = SCSI_SENSE_BUFFERSIZE; | |
853 | memcpy(req->sense, cmd->sense_buffer, len); | |
854 | req->sense_len = len; | |
855 | } | |
fa8e36c3 | 856 | if (!sense_deferred) |
63583cca | 857 | error = __scsi_error_from_host_byte(cmd, result); |
b22f687d | 858 | } |
27c41973 MS |
859 | /* |
860 | * __scsi_error_from_host_byte may have reset the host_byte | |
861 | */ | |
862 | req->errors = cmd->result; | |
e6bb7a96 FT |
863 | |
864 | req->resid_len = scsi_get_resid(cmd); | |
865 | ||
6f9a35e2 | 866 | if (scsi_bidi_cmnd(cmd)) { |
e6bb7a96 FT |
867 | /* |
868 | * Bidi commands Must be complete as a whole, | |
869 | * both sides at once. | |
870 | */ | |
871 | req->next_rq->resid_len = scsi_in(cmd)->resid; | |
f6d47e74 CH |
872 | if (scsi_end_request(req, 0, blk_rq_bytes(req), |
873 | blk_rq_bytes(req->next_rq))) | |
874 | BUG(); | |
6f9a35e2 BH |
875 | return; |
876 | } | |
89fb4cd1 JB |
877 | } else if (blk_rq_bytes(req) == 0 && result && !sense_deferred) { |
878 | /* | |
879 | * Certain non BLOCK_PC requests are commands that don't | |
880 | * actually transfer anything (FLUSH), so cannot use | |
881 | * good_bytes != blk_rq_bytes(req) as the signal for an error. | |
882 | * This sets the error explicitly for the problem case. | |
883 | */ | |
884 | error = __scsi_error_from_host_byte(cmd, result); | |
1da177e4 LT |
885 | } |
886 | ||
33659ebb CH |
887 | /* no bidi support for !REQ_TYPE_BLOCK_PC yet */ |
888 | BUG_ON(blk_bidi_rq(req)); | |
30b0c37b | 889 | |
1da177e4 LT |
890 | /* |
891 | * Next deal with any sectors which we were able to correctly | |
892 | * handle. | |
893 | */ | |
91921e01 HR |
894 | SCSI_LOG_HLCOMPLETE(1, scmd_printk(KERN_INFO, cmd, |
895 | "%u sectors total, %d bytes done.\n", | |
896 | blk_rq_sectors(req), good_bytes)); | |
d6b0c537 | 897 | |
a9bddd74 JB |
898 | /* |
899 | * Recovered errors need reporting, but they're always treated | |
900 | * as success, so fiddle the result code here. For BLOCK_PC | |
901 | * we already took a copy of the original into rq->errors which | |
902 | * is what gets returned to the user | |
903 | */ | |
e7efe593 DG |
904 | if (sense_valid && (sshdr.sense_key == RECOVERED_ERROR)) { |
905 | /* if ATA PASS-THROUGH INFORMATION AVAILABLE skip | |
906 | * print since caller wants ATA registers. Only occurs on | |
907 | * SCSI ATA PASS_THROUGH commands when CK_COND=1 | |
908 | */ | |
909 | if ((sshdr.asc == 0x0) && (sshdr.ascq == 0x1d)) | |
910 | ; | |
911 | else if (!(req->cmd_flags & REQ_QUIET)) | |
a9bddd74 JB |
912 | scsi_print_sense("", cmd); |
913 | result = 0; | |
914 | /* BLOCK_PC may have set error */ | |
915 | error = 0; | |
916 | } | |
917 | ||
918 | /* | |
bc85dc50 | 919 | * If we finished all bytes in the request we are done now. |
d6b0c537 | 920 | */ |
f6d47e74 CH |
921 | if (!scsi_end_request(req, error, good_bytes, 0)) |
922 | return; | |
bc85dc50 CH |
923 | |
924 | /* | |
925 | * Kill remainder if no retrys. | |
926 | */ | |
927 | if (error && scsi_noretry_cmd(cmd)) { | |
f6d47e74 CH |
928 | if (scsi_end_request(req, error, blk_rq_bytes(req), 0)) |
929 | BUG(); | |
930 | return; | |
bc85dc50 CH |
931 | } |
932 | ||
933 | /* | |
934 | * If there had been no error, but we have leftover bytes in the | |
935 | * requeues just queue the command up again. | |
d6b0c537 | 936 | */ |
bc85dc50 CH |
937 | if (result == 0) |
938 | goto requeue; | |
03aba2f7 | 939 | |
63583cca | 940 | error = __scsi_error_from_host_byte(cmd, result); |
3e695f89 | 941 | |
b60af5b0 AS |
942 | if (host_byte(result) == DID_RESET) { |
943 | /* Third party bus reset or reset for error recovery | |
944 | * reasons. Just retry the command and see what | |
945 | * happens. | |
946 | */ | |
947 | action = ACTION_RETRY; | |
948 | } else if (sense_valid && !sense_deferred) { | |
1da177e4 LT |
949 | switch (sshdr.sense_key) { |
950 | case UNIT_ATTENTION: | |
951 | if (cmd->device->removable) { | |
03aba2f7 | 952 | /* Detected disc change. Set a bit |
1da177e4 LT |
953 | * and quietly refuse further access. |
954 | */ | |
955 | cmd->device->changed = 1; | |
b60af5b0 | 956 | action = ACTION_FAIL; |
1da177e4 | 957 | } else { |
03aba2f7 LT |
958 | /* Must have been a power glitch, or a |
959 | * bus reset. Could not have been a | |
960 | * media change, so we just retry the | |
b60af5b0 | 961 | * command and see what happens. |
03aba2f7 | 962 | */ |
b60af5b0 | 963 | action = ACTION_RETRY; |
1da177e4 LT |
964 | } |
965 | break; | |
966 | case ILLEGAL_REQUEST: | |
03aba2f7 LT |
967 | /* If we had an ILLEGAL REQUEST returned, then |
968 | * we may have performed an unsupported | |
969 | * command. The only thing this should be | |
970 | * would be a ten byte read where only a six | |
971 | * byte read was supported. Also, on a system | |
972 | * where READ CAPACITY failed, we may have | |
973 | * read past the end of the disk. | |
974 | */ | |
26a68019 JA |
975 | if ((cmd->device->use_10_for_rw && |
976 | sshdr.asc == 0x20 && sshdr.ascq == 0x00) && | |
1da177e4 LT |
977 | (cmd->cmnd[0] == READ_10 || |
978 | cmd->cmnd[0] == WRITE_10)) { | |
b60af5b0 | 979 | /* This will issue a new 6-byte command. */ |
1da177e4 | 980 | cmd->device->use_10_for_rw = 0; |
b60af5b0 | 981 | action = ACTION_REPREP; |
3e695f89 | 982 | } else if (sshdr.asc == 0x10) /* DIX */ { |
3e695f89 MP |
983 | action = ACTION_FAIL; |
984 | error = -EILSEQ; | |
c98a0eb0 | 985 | /* INVALID COMMAND OPCODE or INVALID FIELD IN CDB */ |
5db44863 | 986 | } else if (sshdr.asc == 0x20 || sshdr.asc == 0x24) { |
c98a0eb0 | 987 | action = ACTION_FAIL; |
66a651aa | 988 | error = -EREMOTEIO; |
b60af5b0 AS |
989 | } else |
990 | action = ACTION_FAIL; | |
991 | break; | |
511e44f4 | 992 | case ABORTED_COMMAND: |
126c0982 | 993 | action = ACTION_FAIL; |
e6c11dbb | 994 | if (sshdr.asc == 0x10) /* DIF */ |
3e695f89 | 995 | error = -EILSEQ; |
1da177e4 LT |
996 | break; |
997 | case NOT_READY: | |
03aba2f7 | 998 | /* If the device is in the process of becoming |
f3e93f73 | 999 | * ready, or has a temporary blockage, retry. |
1da177e4 | 1000 | */ |
f3e93f73 JB |
1001 | if (sshdr.asc == 0x04) { |
1002 | switch (sshdr.ascq) { | |
1003 | case 0x01: /* becoming ready */ | |
1004 | case 0x04: /* format in progress */ | |
1005 | case 0x05: /* rebuild in progress */ | |
1006 | case 0x06: /* recalculation in progress */ | |
1007 | case 0x07: /* operation in progress */ | |
1008 | case 0x08: /* Long write in progress */ | |
1009 | case 0x09: /* self test in progress */ | |
d8705f11 | 1010 | case 0x14: /* space allocation in progress */ |
b60af5b0 | 1011 | action = ACTION_DELAYED_RETRY; |
f3e93f73 | 1012 | break; |
3dbf6a54 | 1013 | default: |
3dbf6a54 AS |
1014 | action = ACTION_FAIL; |
1015 | break; | |
f3e93f73 | 1016 | } |
e6c11dbb | 1017 | } else |
b60af5b0 | 1018 | action = ACTION_FAIL; |
b60af5b0 | 1019 | break; |
1da177e4 | 1020 | case VOLUME_OVERFLOW: |
03aba2f7 | 1021 | /* See SSC3rXX or current. */ |
b60af5b0 AS |
1022 | action = ACTION_FAIL; |
1023 | break; | |
1da177e4 | 1024 | default: |
b60af5b0 | 1025 | action = ACTION_FAIL; |
1da177e4 LT |
1026 | break; |
1027 | } | |
e6c11dbb | 1028 | } else |
b60af5b0 | 1029 | action = ACTION_FAIL; |
b60af5b0 | 1030 | |
ee60b2c5 | 1031 | if (action != ACTION_FAIL && |
e6c11dbb | 1032 | time_before(cmd->jiffies_at_alloc + wait_for, jiffies)) |
ee60b2c5 | 1033 | action = ACTION_FAIL; |
ee60b2c5 | 1034 | |
b60af5b0 AS |
1035 | switch (action) { |
1036 | case ACTION_FAIL: | |
1037 | /* Give up and fail the remainder of the request */ | |
4aff5e23 | 1038 | if (!(req->cmd_flags & REQ_QUIET)) { |
a4d04a4c | 1039 | scsi_print_result(cmd); |
3173d8c3 JB |
1040 | if (driver_byte(result) & DRIVER_SENSE) |
1041 | scsi_print_sense("", cmd); | |
002b1eb2 | 1042 | scsi_print_command(cmd); |
3173d8c3 | 1043 | } |
f6d47e74 CH |
1044 | if (!scsi_end_request(req, error, blk_rq_err_bytes(req), 0)) |
1045 | return; | |
bc85dc50 | 1046 | /*FALLTHRU*/ |
b60af5b0 | 1047 | case ACTION_REPREP: |
bc85dc50 | 1048 | requeue: |
b60af5b0 AS |
1049 | /* Unprep the request and put it back at the head of the queue. |
1050 | * A new command will be prepared and issued. | |
1051 | */ | |
d285203c CH |
1052 | if (q->mq_ops) { |
1053 | cmd->request->cmd_flags &= ~REQ_DONTPREP; | |
1054 | scsi_mq_uninit_cmd(cmd); | |
1055 | scsi_mq_requeue_cmd(cmd); | |
1056 | } else { | |
1057 | scsi_release_buffers(cmd); | |
1058 | scsi_requeue_command(q, cmd); | |
1059 | } | |
b60af5b0 AS |
1060 | break; |
1061 | case ACTION_RETRY: | |
1062 | /* Retry the same command immediately */ | |
4f5299ac | 1063 | __scsi_queue_insert(cmd, SCSI_MLQUEUE_EH_RETRY, 0); |
b60af5b0 AS |
1064 | break; |
1065 | case ACTION_DELAYED_RETRY: | |
1066 | /* Retry the same command after a delay */ | |
4f5299ac | 1067 | __scsi_queue_insert(cmd, SCSI_MLQUEUE_DEVICE_BUSY, 0); |
b60af5b0 | 1068 | break; |
1da177e4 LT |
1069 | } |
1070 | } | |
1da177e4 | 1071 | |
6f9a35e2 BH |
1072 | static int scsi_init_sgtable(struct request *req, struct scsi_data_buffer *sdb, |
1073 | gfp_t gfp_mask) | |
1da177e4 | 1074 | { |
6f9a35e2 | 1075 | int count; |
1da177e4 LT |
1076 | |
1077 | /* | |
3b003157 | 1078 | * If sg table allocation fails, requeue request later. |
1da177e4 | 1079 | */ |
30b0c37b | 1080 | if (unlikely(scsi_alloc_sgtable(sdb, req->nr_phys_segments, |
d285203c | 1081 | gfp_mask, req->mq_ctx != NULL))) |
1da177e4 | 1082 | return BLKPREP_DEFER; |
1da177e4 | 1083 | |
1da177e4 LT |
1084 | /* |
1085 | * Next, walk the list, and fill in the addresses and sizes of | |
1086 | * each segment. | |
1087 | */ | |
30b0c37b BH |
1088 | count = blk_rq_map_sg(req->q, req, sdb->table.sgl); |
1089 | BUG_ON(count > sdb->table.nents); | |
1090 | sdb->table.nents = count; | |
1011c1b9 | 1091 | sdb->length = blk_rq_bytes(req); |
4a03d90e | 1092 | return BLKPREP_OK; |
1da177e4 | 1093 | } |
6f9a35e2 BH |
1094 | |
1095 | /* | |
1096 | * Function: scsi_init_io() | |
1097 | * | |
1098 | * Purpose: SCSI I/O initialize function. | |
1099 | * | |
1100 | * Arguments: cmd - Command descriptor we wish to initialize | |
1101 | * | |
1102 | * Returns: 0 on success | |
1103 | * BLKPREP_DEFER if the failure is retryable | |
1104 | * BLKPREP_KILL if the failure is fatal | |
1105 | */ | |
1106 | int scsi_init_io(struct scsi_cmnd *cmd, gfp_t gfp_mask) | |
1107 | { | |
5e012aad | 1108 | struct scsi_device *sdev = cmd->device; |
13f05c8d | 1109 | struct request *rq = cmd->request; |
d285203c | 1110 | bool is_mq = (rq->mq_ctx != NULL); |
635d98b1 | 1111 | int error; |
13f05c8d | 1112 | |
635d98b1 CH |
1113 | BUG_ON(!rq->nr_phys_segments); |
1114 | ||
1115 | error = scsi_init_sgtable(rq, &cmd->sdb, gfp_mask); | |
6f9a35e2 BH |
1116 | if (error) |
1117 | goto err_exit; | |
1118 | ||
13f05c8d | 1119 | if (blk_bidi_rq(rq)) { |
d285203c CH |
1120 | if (!rq->q->mq_ops) { |
1121 | struct scsi_data_buffer *bidi_sdb = | |
1122 | kmem_cache_zalloc(scsi_sdb_cache, GFP_ATOMIC); | |
1123 | if (!bidi_sdb) { | |
1124 | error = BLKPREP_DEFER; | |
1125 | goto err_exit; | |
1126 | } | |
1127 | ||
1128 | rq->next_rq->special = bidi_sdb; | |
6f9a35e2 BH |
1129 | } |
1130 | ||
d285203c CH |
1131 | error = scsi_init_sgtable(rq->next_rq, rq->next_rq->special, |
1132 | GFP_ATOMIC); | |
6f9a35e2 BH |
1133 | if (error) |
1134 | goto err_exit; | |
1135 | } | |
1136 | ||
13f05c8d | 1137 | if (blk_integrity_rq(rq)) { |
7027ad72 MP |
1138 | struct scsi_data_buffer *prot_sdb = cmd->prot_sdb; |
1139 | int ivecs, count; | |
1140 | ||
1141 | BUG_ON(prot_sdb == NULL); | |
13f05c8d | 1142 | ivecs = blk_rq_count_integrity_sg(rq->q, rq->bio); |
7027ad72 | 1143 | |
d285203c | 1144 | if (scsi_alloc_sgtable(prot_sdb, ivecs, gfp_mask, is_mq)) { |
7027ad72 MP |
1145 | error = BLKPREP_DEFER; |
1146 | goto err_exit; | |
1147 | } | |
1148 | ||
13f05c8d | 1149 | count = blk_rq_map_integrity_sg(rq->q, rq->bio, |
7027ad72 MP |
1150 | prot_sdb->table.sgl); |
1151 | BUG_ON(unlikely(count > ivecs)); | |
13f05c8d | 1152 | BUG_ON(unlikely(count > queue_max_integrity_segments(rq->q))); |
7027ad72 MP |
1153 | |
1154 | cmd->prot_sdb = prot_sdb; | |
1155 | cmd->prot_sdb->table.nents = count; | |
1156 | } | |
1157 | ||
d285203c | 1158 | return BLKPREP_OK; |
6f9a35e2 | 1159 | err_exit: |
d285203c CH |
1160 | if (is_mq) { |
1161 | scsi_mq_free_sgtables(cmd); | |
1162 | } else { | |
1163 | scsi_release_buffers(cmd); | |
1164 | cmd->request->special = NULL; | |
1165 | scsi_put_command(cmd); | |
1166 | put_device(&sdev->sdev_gendev); | |
1167 | } | |
6f9a35e2 BH |
1168 | return error; |
1169 | } | |
bb52d82f | 1170 | EXPORT_SYMBOL(scsi_init_io); |
1da177e4 | 1171 | |
3b003157 CH |
1172 | static struct scsi_cmnd *scsi_get_cmd_from_req(struct scsi_device *sdev, |
1173 | struct request *req) | |
1174 | { | |
1175 | struct scsi_cmnd *cmd; | |
1176 | ||
1177 | if (!req->special) { | |
04796336 CH |
1178 | /* Bail if we can't get a reference to the device */ |
1179 | if (!get_device(&sdev->sdev_gendev)) | |
1180 | return NULL; | |
1181 | ||
3b003157 | 1182 | cmd = scsi_get_command(sdev, GFP_ATOMIC); |
04796336 CH |
1183 | if (unlikely(!cmd)) { |
1184 | put_device(&sdev->sdev_gendev); | |
3b003157 | 1185 | return NULL; |
04796336 | 1186 | } |
3b003157 CH |
1187 | req->special = cmd; |
1188 | } else { | |
1189 | cmd = req->special; | |
1190 | } | |
1191 | ||
1192 | /* pull a tag out of the request if we have one */ | |
1193 | cmd->tag = req->tag; | |
1194 | cmd->request = req; | |
1195 | ||
64a87b24 | 1196 | cmd->cmnd = req->cmd; |
72f7d322 | 1197 | cmd->prot_op = SCSI_PROT_NORMAL; |
64a87b24 | 1198 | |
3b003157 CH |
1199 | return cmd; |
1200 | } | |
1201 | ||
4f1e5765 | 1202 | static int scsi_setup_blk_pc_cmnd(struct scsi_device *sdev, struct request *req) |
7b16318d | 1203 | { |
a1b73fc1 | 1204 | struct scsi_cmnd *cmd = req->special; |
3b003157 CH |
1205 | |
1206 | /* | |
1207 | * BLOCK_PC requests may transfer data, in which case they must | |
1208 | * a bio attached to them. Or they might contain a SCSI command | |
1209 | * that does not transfer data, in which case they may optionally | |
1210 | * submit a request without an attached bio. | |
1211 | */ | |
1212 | if (req->bio) { | |
635d98b1 | 1213 | int ret = scsi_init_io(cmd, GFP_ATOMIC); |
3b003157 CH |
1214 | if (unlikely(ret)) |
1215 | return ret; | |
1216 | } else { | |
b0790410 | 1217 | BUG_ON(blk_rq_bytes(req)); |
3b003157 | 1218 | |
30b0c37b | 1219 | memset(&cmd->sdb, 0, sizeof(cmd->sdb)); |
3b003157 | 1220 | } |
7b16318d | 1221 | |
7b16318d | 1222 | cmd->cmd_len = req->cmd_len; |
b0790410 | 1223 | cmd->transfersize = blk_rq_bytes(req); |
7b16318d | 1224 | cmd->allowed = req->retries; |
3b003157 | 1225 | return BLKPREP_OK; |
7b16318d | 1226 | } |
7b16318d | 1227 | |
3b003157 | 1228 | /* |
3868cf8e CH |
1229 | * Setup a REQ_TYPE_FS command. These are simple request from filesystems |
1230 | * that still need to be translated to SCSI CDBs from the ULD. | |
3b003157 | 1231 | */ |
3868cf8e | 1232 | static int scsi_setup_fs_cmnd(struct scsi_device *sdev, struct request *req) |
1da177e4 | 1233 | { |
a1b73fc1 | 1234 | struct scsi_cmnd *cmd = req->special; |
a6a8d9f8 CS |
1235 | |
1236 | if (unlikely(sdev->scsi_dh_data && sdev->scsi_dh_data->scsi_dh | |
1237 | && sdev->scsi_dh_data->scsi_dh->prep_fn)) { | |
a1b73fc1 | 1238 | int ret = sdev->scsi_dh_data->scsi_dh->prep_fn(sdev, req); |
a6a8d9f8 CS |
1239 | if (ret != BLKPREP_OK) |
1240 | return ret; | |
1241 | } | |
1242 | ||
64a87b24 | 1243 | memset(cmd->cmnd, 0, BLK_MAX_CDB); |
3868cf8e | 1244 | return scsi_cmd_to_driver(cmd)->init_command(cmd); |
3b003157 CH |
1245 | } |
1246 | ||
6af7a4ff CH |
1247 | static int scsi_setup_cmnd(struct scsi_device *sdev, struct request *req) |
1248 | { | |
1249 | struct scsi_cmnd *cmd = req->special; | |
1250 | ||
1251 | if (!blk_rq_bytes(req)) | |
1252 | cmd->sc_data_direction = DMA_NONE; | |
1253 | else if (rq_data_dir(req) == WRITE) | |
1254 | cmd->sc_data_direction = DMA_TO_DEVICE; | |
1255 | else | |
1256 | cmd->sc_data_direction = DMA_FROM_DEVICE; | |
1257 | ||
1258 | switch (req->cmd_type) { | |
1259 | case REQ_TYPE_FS: | |
1260 | return scsi_setup_fs_cmnd(sdev, req); | |
1261 | case REQ_TYPE_BLOCK_PC: | |
1262 | return scsi_setup_blk_pc_cmnd(sdev, req); | |
1263 | default: | |
1264 | return BLKPREP_KILL; | |
1265 | } | |
1266 | } | |
1267 | ||
a1b73fc1 CH |
1268 | static int |
1269 | scsi_prep_state_check(struct scsi_device *sdev, struct request *req) | |
3b003157 | 1270 | { |
3b003157 CH |
1271 | int ret = BLKPREP_OK; |
1272 | ||
1da177e4 | 1273 | /* |
3b003157 CH |
1274 | * If the device is not in running state we will reject some |
1275 | * or all commands. | |
1da177e4 | 1276 | */ |
3b003157 CH |
1277 | if (unlikely(sdev->sdev_state != SDEV_RUNNING)) { |
1278 | switch (sdev->sdev_state) { | |
1279 | case SDEV_OFFLINE: | |
1b8d2620 | 1280 | case SDEV_TRANSPORT_OFFLINE: |
3b003157 CH |
1281 | /* |
1282 | * If the device is offline we refuse to process any | |
1283 | * commands. The device must be brought online | |
1284 | * before trying any recovery commands. | |
1285 | */ | |
1286 | sdev_printk(KERN_ERR, sdev, | |
1287 | "rejecting I/O to offline device\n"); | |
1288 | ret = BLKPREP_KILL; | |
1289 | break; | |
1290 | case SDEV_DEL: | |
1291 | /* | |
1292 | * If the device is fully deleted, we refuse to | |
1293 | * process any commands as well. | |
1294 | */ | |
9ccfc756 | 1295 | sdev_printk(KERN_ERR, sdev, |
3b003157 CH |
1296 | "rejecting I/O to dead device\n"); |
1297 | ret = BLKPREP_KILL; | |
1298 | break; | |
1299 | case SDEV_QUIESCE: | |
1300 | case SDEV_BLOCK: | |
6f4267e3 | 1301 | case SDEV_CREATED_BLOCK: |
3b003157 CH |
1302 | /* |
1303 | * If the devices is blocked we defer normal commands. | |
1304 | */ | |
1305 | if (!(req->cmd_flags & REQ_PREEMPT)) | |
1306 | ret = BLKPREP_DEFER; | |
1307 | break; | |
1308 | default: | |
1309 | /* | |
1310 | * For any other not fully online state we only allow | |
1311 | * special commands. In particular any user initiated | |
1312 | * command is not allowed. | |
1313 | */ | |
1314 | if (!(req->cmd_flags & REQ_PREEMPT)) | |
1315 | ret = BLKPREP_KILL; | |
1316 | break; | |
1da177e4 | 1317 | } |
1da177e4 | 1318 | } |
7f9a6bc4 JB |
1319 | return ret; |
1320 | } | |
1da177e4 | 1321 | |
a1b73fc1 CH |
1322 | static int |
1323 | scsi_prep_return(struct request_queue *q, struct request *req, int ret) | |
7f9a6bc4 JB |
1324 | { |
1325 | struct scsi_device *sdev = q->queuedata; | |
1da177e4 | 1326 | |
3b003157 CH |
1327 | switch (ret) { |
1328 | case BLKPREP_KILL: | |
1329 | req->errors = DID_NO_CONNECT << 16; | |
7f9a6bc4 JB |
1330 | /* release the command and kill it */ |
1331 | if (req->special) { | |
1332 | struct scsi_cmnd *cmd = req->special; | |
1333 | scsi_release_buffers(cmd); | |
1334 | scsi_put_command(cmd); | |
68c03d91 | 1335 | put_device(&sdev->sdev_gendev); |
7f9a6bc4 JB |
1336 | req->special = NULL; |
1337 | } | |
3b003157 CH |
1338 | break; |
1339 | case BLKPREP_DEFER: | |
1da177e4 | 1340 | /* |
9934c8c0 | 1341 | * If we defer, the blk_peek_request() returns NULL, but the |
a488e749 JA |
1342 | * queue must be restarted, so we schedule a callback to happen |
1343 | * shortly. | |
1da177e4 | 1344 | */ |
71e75c97 | 1345 | if (atomic_read(&sdev->device_busy) == 0) |
a488e749 | 1346 | blk_delay_queue(q, SCSI_QUEUE_DELAY); |
3b003157 CH |
1347 | break; |
1348 | default: | |
1349 | req->cmd_flags |= REQ_DONTPREP; | |
1da177e4 LT |
1350 | } |
1351 | ||
3b003157 | 1352 | return ret; |
1da177e4 | 1353 | } |
7f9a6bc4 | 1354 | |
a1b73fc1 | 1355 | static int scsi_prep_fn(struct request_queue *q, struct request *req) |
7f9a6bc4 JB |
1356 | { |
1357 | struct scsi_device *sdev = q->queuedata; | |
a1b73fc1 CH |
1358 | struct scsi_cmnd *cmd; |
1359 | int ret; | |
1360 | ||
1361 | ret = scsi_prep_state_check(sdev, req); | |
1362 | if (ret != BLKPREP_OK) | |
1363 | goto out; | |
1364 | ||
1365 | cmd = scsi_get_cmd_from_req(sdev, req); | |
1366 | if (unlikely(!cmd)) { | |
1367 | ret = BLKPREP_DEFER; | |
1368 | goto out; | |
1369 | } | |
7f9a6bc4 | 1370 | |
6af7a4ff | 1371 | ret = scsi_setup_cmnd(sdev, req); |
a1b73fc1 | 1372 | out: |
7f9a6bc4 JB |
1373 | return scsi_prep_return(q, req, ret); |
1374 | } | |
a1b73fc1 CH |
1375 | |
1376 | static void scsi_unprep_fn(struct request_queue *q, struct request *req) | |
1377 | { | |
d285203c | 1378 | scsi_uninit_cmd(req->special); |
a1b73fc1 | 1379 | } |
1da177e4 LT |
1380 | |
1381 | /* | |
1382 | * scsi_dev_queue_ready: if we can send requests to sdev, return 1 else | |
1383 | * return 0. | |
1384 | * | |
1385 | * Called with the queue_lock held. | |
1386 | */ | |
1387 | static inline int scsi_dev_queue_ready(struct request_queue *q, | |
1388 | struct scsi_device *sdev) | |
1389 | { | |
71e75c97 CH |
1390 | unsigned int busy; |
1391 | ||
1392 | busy = atomic_inc_return(&sdev->device_busy) - 1; | |
cd9070c9 | 1393 | if (atomic_read(&sdev->device_blocked)) { |
71e75c97 CH |
1394 | if (busy) |
1395 | goto out_dec; | |
1396 | ||
1da177e4 LT |
1397 | /* |
1398 | * unblock after device_blocked iterates to zero | |
1399 | */ | |
cd9070c9 | 1400 | if (atomic_dec_return(&sdev->device_blocked) > 0) { |
d285203c CH |
1401 | /* |
1402 | * For the MQ case we take care of this in the caller. | |
1403 | */ | |
1404 | if (!q->mq_ops) | |
1405 | blk_delay_queue(q, SCSI_QUEUE_DELAY); | |
71e75c97 | 1406 | goto out_dec; |
1da177e4 | 1407 | } |
71e75c97 CH |
1408 | SCSI_LOG_MLQUEUE(3, sdev_printk(KERN_INFO, sdev, |
1409 | "unblocking device at zero depth\n")); | |
1da177e4 | 1410 | } |
71e75c97 CH |
1411 | |
1412 | if (busy >= sdev->queue_depth) | |
1413 | goto out_dec; | |
1da177e4 LT |
1414 | |
1415 | return 1; | |
71e75c97 CH |
1416 | out_dec: |
1417 | atomic_dec(&sdev->device_busy); | |
1418 | return 0; | |
1da177e4 LT |
1419 | } |
1420 | ||
f0c0a376 MC |
1421 | /* |
1422 | * scsi_target_queue_ready: checks if there we can send commands to target | |
1423 | * @sdev: scsi device on starget to check. | |
f0c0a376 MC |
1424 | */ |
1425 | static inline int scsi_target_queue_ready(struct Scsi_Host *shost, | |
1426 | struct scsi_device *sdev) | |
1427 | { | |
1428 | struct scsi_target *starget = scsi_target(sdev); | |
7ae65c0f | 1429 | unsigned int busy; |
f0c0a376 MC |
1430 | |
1431 | if (starget->single_lun) { | |
7ae65c0f | 1432 | spin_lock_irq(shost->host_lock); |
f0c0a376 | 1433 | if (starget->starget_sdev_user && |
7ae65c0f CH |
1434 | starget->starget_sdev_user != sdev) { |
1435 | spin_unlock_irq(shost->host_lock); | |
1436 | return 0; | |
1437 | } | |
f0c0a376 | 1438 | starget->starget_sdev_user = sdev; |
7ae65c0f | 1439 | spin_unlock_irq(shost->host_lock); |
f0c0a376 MC |
1440 | } |
1441 | ||
2ccbb008 CH |
1442 | if (starget->can_queue <= 0) |
1443 | return 1; | |
1444 | ||
7ae65c0f | 1445 | busy = atomic_inc_return(&starget->target_busy) - 1; |
cd9070c9 | 1446 | if (atomic_read(&starget->target_blocked) > 0) { |
7ae65c0f CH |
1447 | if (busy) |
1448 | goto starved; | |
1449 | ||
f0c0a376 MC |
1450 | /* |
1451 | * unblock after target_blocked iterates to zero | |
1452 | */ | |
cd9070c9 | 1453 | if (atomic_dec_return(&starget->target_blocked) > 0) |
7ae65c0f | 1454 | goto out_dec; |
cf68d334 CH |
1455 | |
1456 | SCSI_LOG_MLQUEUE(3, starget_printk(KERN_INFO, starget, | |
1457 | "unblocking target at zero depth\n")); | |
f0c0a376 MC |
1458 | } |
1459 | ||
2ccbb008 | 1460 | if (busy >= starget->can_queue) |
7ae65c0f | 1461 | goto starved; |
f0c0a376 | 1462 | |
7ae65c0f CH |
1463 | return 1; |
1464 | ||
1465 | starved: | |
1466 | spin_lock_irq(shost->host_lock); | |
1467 | list_move_tail(&sdev->starved_entry, &shost->starved_list); | |
cf68d334 | 1468 | spin_unlock_irq(shost->host_lock); |
7ae65c0f | 1469 | out_dec: |
2ccbb008 CH |
1470 | if (starget->can_queue > 0) |
1471 | atomic_dec(&starget->target_busy); | |
7ae65c0f | 1472 | return 0; |
f0c0a376 MC |
1473 | } |
1474 | ||
1da177e4 LT |
1475 | /* |
1476 | * scsi_host_queue_ready: if we can send requests to shost, return 1 else | |
1477 | * return 0. We must end up running the queue again whenever 0 is | |
1478 | * returned, else IO can hang. | |
1da177e4 LT |
1479 | */ |
1480 | static inline int scsi_host_queue_ready(struct request_queue *q, | |
1481 | struct Scsi_Host *shost, | |
1482 | struct scsi_device *sdev) | |
1483 | { | |
74665016 | 1484 | unsigned int busy; |
cf68d334 | 1485 | |
939647ee | 1486 | if (scsi_host_in_recovery(shost)) |
74665016 CH |
1487 | return 0; |
1488 | ||
1489 | busy = atomic_inc_return(&shost->host_busy) - 1; | |
cd9070c9 | 1490 | if (atomic_read(&shost->host_blocked) > 0) { |
74665016 CH |
1491 | if (busy) |
1492 | goto starved; | |
1493 | ||
1da177e4 LT |
1494 | /* |
1495 | * unblock after host_blocked iterates to zero | |
1496 | */ | |
cd9070c9 | 1497 | if (atomic_dec_return(&shost->host_blocked) > 0) |
74665016 | 1498 | goto out_dec; |
cf68d334 CH |
1499 | |
1500 | SCSI_LOG_MLQUEUE(3, | |
1501 | shost_printk(KERN_INFO, shost, | |
1502 | "unblocking host at zero depth\n")); | |
1da177e4 | 1503 | } |
74665016 CH |
1504 | |
1505 | if (shost->can_queue > 0 && busy >= shost->can_queue) | |
1506 | goto starved; | |
1507 | if (shost->host_self_blocked) | |
1508 | goto starved; | |
1da177e4 LT |
1509 | |
1510 | /* We're OK to process the command, so we can't be starved */ | |
74665016 CH |
1511 | if (!list_empty(&sdev->starved_entry)) { |
1512 | spin_lock_irq(shost->host_lock); | |
1513 | if (!list_empty(&sdev->starved_entry)) | |
1514 | list_del_init(&sdev->starved_entry); | |
1515 | spin_unlock_irq(shost->host_lock); | |
1516 | } | |
1da177e4 | 1517 | |
74665016 CH |
1518 | return 1; |
1519 | ||
1520 | starved: | |
1521 | spin_lock_irq(shost->host_lock); | |
1522 | if (list_empty(&sdev->starved_entry)) | |
1523 | list_add_tail(&sdev->starved_entry, &shost->starved_list); | |
cf68d334 | 1524 | spin_unlock_irq(shost->host_lock); |
74665016 CH |
1525 | out_dec: |
1526 | atomic_dec(&shost->host_busy); | |
1527 | return 0; | |
1da177e4 LT |
1528 | } |
1529 | ||
6c5121b7 KU |
1530 | /* |
1531 | * Busy state exporting function for request stacking drivers. | |
1532 | * | |
1533 | * For efficiency, no lock is taken to check the busy state of | |
1534 | * shost/starget/sdev, since the returned value is not guaranteed and | |
1535 | * may be changed after request stacking drivers call the function, | |
1536 | * regardless of taking lock or not. | |
1537 | * | |
67bd9413 BVA |
1538 | * When scsi can't dispatch I/Os anymore and needs to kill I/Os scsi |
1539 | * needs to return 'not busy'. Otherwise, request stacking drivers | |
1540 | * may hold requests forever. | |
6c5121b7 KU |
1541 | */ |
1542 | static int scsi_lld_busy(struct request_queue *q) | |
1543 | { | |
1544 | struct scsi_device *sdev = q->queuedata; | |
1545 | struct Scsi_Host *shost; | |
6c5121b7 | 1546 | |
3f3299d5 | 1547 | if (blk_queue_dying(q)) |
6c5121b7 KU |
1548 | return 0; |
1549 | ||
1550 | shost = sdev->host; | |
6c5121b7 | 1551 | |
b7e94a16 JN |
1552 | /* |
1553 | * Ignore host/starget busy state. | |
1554 | * Since block layer does not have a concept of fairness across | |
1555 | * multiple queues, congestion of host/starget needs to be handled | |
1556 | * in SCSI layer. | |
1557 | */ | |
1558 | if (scsi_host_in_recovery(shost) || scsi_device_is_busy(sdev)) | |
6c5121b7 KU |
1559 | return 1; |
1560 | ||
1561 | return 0; | |
1562 | } | |
1563 | ||
1da177e4 | 1564 | /* |
e91442b6 | 1565 | * Kill a request for a dead device |
1da177e4 | 1566 | */ |
165125e1 | 1567 | static void scsi_kill_request(struct request *req, struct request_queue *q) |
1da177e4 | 1568 | { |
e91442b6 | 1569 | struct scsi_cmnd *cmd = req->special; |
03b14708 JS |
1570 | struct scsi_device *sdev; |
1571 | struct scsi_target *starget; | |
1572 | struct Scsi_Host *shost; | |
1da177e4 | 1573 | |
9934c8c0 | 1574 | blk_start_request(req); |
788ce43a | 1575 | |
74571813 HR |
1576 | scmd_printk(KERN_INFO, cmd, "killing request\n"); |
1577 | ||
03b14708 JS |
1578 | sdev = cmd->device; |
1579 | starget = scsi_target(sdev); | |
1580 | shost = sdev->host; | |
e91442b6 JB |
1581 | scsi_init_cmd_errh(cmd); |
1582 | cmd->result = DID_NO_CONNECT << 16; | |
1583 | atomic_inc(&cmd->device->iorequest_cnt); | |
e36e0c80 TH |
1584 | |
1585 | /* | |
1586 | * SCSI request completion path will do scsi_device_unbusy(), | |
1587 | * bump busy counts. To bump the counters, we need to dance | |
1588 | * with the locks as normal issue path does. | |
1589 | */ | |
71e75c97 | 1590 | atomic_inc(&sdev->device_busy); |
74665016 | 1591 | atomic_inc(&shost->host_busy); |
2ccbb008 CH |
1592 | if (starget->can_queue > 0) |
1593 | atomic_inc(&starget->target_busy); | |
e36e0c80 | 1594 | |
242f9dcb | 1595 | blk_complete_request(req); |
1da177e4 LT |
1596 | } |
1597 | ||
1aea6434 JA |
1598 | static void scsi_softirq_done(struct request *rq) |
1599 | { | |
242f9dcb JA |
1600 | struct scsi_cmnd *cmd = rq->special; |
1601 | unsigned long wait_for = (cmd->allowed + 1) * rq->timeout; | |
1aea6434 JA |
1602 | int disposition; |
1603 | ||
1604 | INIT_LIST_HEAD(&cmd->eh_entry); | |
1605 | ||
242f9dcb JA |
1606 | atomic_inc(&cmd->device->iodone_cnt); |
1607 | if (cmd->result) | |
1608 | atomic_inc(&cmd->device->ioerr_cnt); | |
1609 | ||
1aea6434 JA |
1610 | disposition = scsi_decide_disposition(cmd); |
1611 | if (disposition != SUCCESS && | |
1612 | time_before(cmd->jiffies_at_alloc + wait_for, jiffies)) { | |
1613 | sdev_printk(KERN_ERR, cmd->device, | |
1614 | "timing out command, waited %lus\n", | |
1615 | wait_for/HZ); | |
1616 | disposition = SUCCESS; | |
1617 | } | |
91921e01 | 1618 | |
1aea6434 JA |
1619 | scsi_log_completion(cmd, disposition); |
1620 | ||
1621 | switch (disposition) { | |
1622 | case SUCCESS: | |
1623 | scsi_finish_command(cmd); | |
1624 | break; | |
1625 | case NEEDS_RETRY: | |
596f482a | 1626 | scsi_queue_insert(cmd, SCSI_MLQUEUE_EH_RETRY); |
1aea6434 JA |
1627 | break; |
1628 | case ADD_TO_MLQUEUE: | |
1629 | scsi_queue_insert(cmd, SCSI_MLQUEUE_DEVICE_BUSY); | |
1630 | break; | |
1631 | default: | |
1632 | if (!scsi_eh_scmd_add(cmd, 0)) | |
1633 | scsi_finish_command(cmd); | |
1634 | } | |
1635 | } | |
1636 | ||
3b5382c4 CH |
1637 | /** |
1638 | * scsi_done - Invoke completion on finished SCSI command. | |
1639 | * @cmd: The SCSI Command for which a low-level device driver (LLDD) gives | |
1640 | * ownership back to SCSI Core -- i.e. the LLDD has finished with it. | |
1641 | * | |
1642 | * Description: This function is the mid-level's (SCSI Core) interrupt routine, | |
1643 | * which regains ownership of the SCSI command (de facto) from a LLDD, and | |
1644 | * calls blk_complete_request() for further processing. | |
1645 | * | |
1646 | * This function is interrupt context safe. | |
1647 | */ | |
1648 | static void scsi_done(struct scsi_cmnd *cmd) | |
1649 | { | |
1650 | trace_scsi_dispatch_cmd_done(cmd); | |
1651 | blk_complete_request(cmd->request); | |
1652 | } | |
1653 | ||
1da177e4 LT |
1654 | /* |
1655 | * Function: scsi_request_fn() | |
1656 | * | |
1657 | * Purpose: Main strategy routine for SCSI. | |
1658 | * | |
1659 | * Arguments: q - Pointer to actual queue. | |
1660 | * | |
1661 | * Returns: Nothing | |
1662 | * | |
1663 | * Lock status: IO request lock assumed to be held when called. | |
1664 | */ | |
1665 | static void scsi_request_fn(struct request_queue *q) | |
613be1f6 BVA |
1666 | __releases(q->queue_lock) |
1667 | __acquires(q->queue_lock) | |
1da177e4 LT |
1668 | { |
1669 | struct scsi_device *sdev = q->queuedata; | |
1670 | struct Scsi_Host *shost; | |
1671 | struct scsi_cmnd *cmd; | |
1672 | struct request *req; | |
1673 | ||
1da177e4 LT |
1674 | /* |
1675 | * To start with, we keep looping until the queue is empty, or until | |
1676 | * the host is no longer able to accept any more requests. | |
1677 | */ | |
1678 | shost = sdev->host; | |
a488e749 | 1679 | for (;;) { |
1da177e4 LT |
1680 | int rtn; |
1681 | /* | |
1682 | * get next queueable request. We do this early to make sure | |
91921e01 | 1683 | * that the request is fully prepared even if we cannot |
1da177e4 LT |
1684 | * accept it. |
1685 | */ | |
9934c8c0 | 1686 | req = blk_peek_request(q); |
71e75c97 | 1687 | if (!req) |
1da177e4 LT |
1688 | break; |
1689 | ||
1690 | if (unlikely(!scsi_device_online(sdev))) { | |
9ccfc756 JB |
1691 | sdev_printk(KERN_ERR, sdev, |
1692 | "rejecting I/O to offline device\n"); | |
e91442b6 | 1693 | scsi_kill_request(req, q); |
1da177e4 LT |
1694 | continue; |
1695 | } | |
1696 | ||
71e75c97 CH |
1697 | if (!scsi_dev_queue_ready(q, sdev)) |
1698 | break; | |
1da177e4 LT |
1699 | |
1700 | /* | |
1701 | * Remove the request from the request list. | |
1702 | */ | |
1703 | if (!(blk_queue_tagged(q) && !blk_queue_start_tag(q, req))) | |
9934c8c0 | 1704 | blk_start_request(req); |
1da177e4 | 1705 | |
cf68d334 | 1706 | spin_unlock_irq(q->queue_lock); |
e91442b6 JB |
1707 | cmd = req->special; |
1708 | if (unlikely(cmd == NULL)) { | |
1709 | printk(KERN_CRIT "impossible request in %s.\n" | |
1710 | "please mail a stack trace to " | |
4aff5e23 | 1711 | "linux-scsi@vger.kernel.org\n", |
cadbd4a5 | 1712 | __func__); |
4aff5e23 | 1713 | blk_dump_rq_flags(req, "foo"); |
e91442b6 JB |
1714 | BUG(); |
1715 | } | |
1da177e4 | 1716 | |
ecefe8a9 MC |
1717 | /* |
1718 | * We hit this when the driver is using a host wide | |
1719 | * tag map. For device level tag maps the queue_depth check | |
1720 | * in the device ready fn would prevent us from trying | |
1721 | * to allocate a tag. Since the map is a shared host resource | |
1722 | * we add the dev to the starved list so it eventually gets | |
1723 | * a run when a tag is freed. | |
1724 | */ | |
6bd522f6 | 1725 | if (blk_queue_tagged(q) && !blk_rq_tagged(req)) { |
cf68d334 | 1726 | spin_lock_irq(shost->host_lock); |
ecefe8a9 MC |
1727 | if (list_empty(&sdev->starved_entry)) |
1728 | list_add_tail(&sdev->starved_entry, | |
1729 | &shost->starved_list); | |
cf68d334 | 1730 | spin_unlock_irq(shost->host_lock); |
ecefe8a9 MC |
1731 | goto not_ready; |
1732 | } | |
1733 | ||
f0c0a376 MC |
1734 | if (!scsi_target_queue_ready(shost, sdev)) |
1735 | goto not_ready; | |
1736 | ||
1da177e4 | 1737 | if (!scsi_host_queue_ready(q, shost, sdev)) |
cf68d334 | 1738 | goto host_not_ready; |
1da177e4 | 1739 | |
1da177e4 LT |
1740 | /* |
1741 | * Finally, initialize any error handling parameters, and set up | |
1742 | * the timers for timeouts. | |
1743 | */ | |
1744 | scsi_init_cmd_errh(cmd); | |
1745 | ||
1746 | /* | |
1747 | * Dispatch the command to the low-level driver. | |
1748 | */ | |
3b5382c4 | 1749 | cmd->scsi_done = scsi_done; |
1da177e4 | 1750 | rtn = scsi_dispatch_cmd(cmd); |
d0d3bbf9 CH |
1751 | if (rtn) { |
1752 | scsi_queue_insert(cmd, rtn); | |
1753 | spin_lock_irq(q->queue_lock); | |
a488e749 | 1754 | goto out_delay; |
d0d3bbf9 CH |
1755 | } |
1756 | spin_lock_irq(q->queue_lock); | |
1da177e4 LT |
1757 | } |
1758 | ||
613be1f6 | 1759 | return; |
1da177e4 | 1760 | |
cf68d334 | 1761 | host_not_ready: |
2ccbb008 CH |
1762 | if (scsi_target(sdev)->can_queue > 0) |
1763 | atomic_dec(&scsi_target(sdev)->target_busy); | |
cf68d334 | 1764 | not_ready: |
1da177e4 LT |
1765 | /* |
1766 | * lock q, handle tag, requeue req, and decrement device_busy. We | |
1767 | * must return with queue_lock held. | |
1768 | * | |
1769 | * Decrementing device_busy without checking it is OK, as all such | |
1770 | * cases (host limits or settings) should run the queue at some | |
1771 | * later time. | |
1772 | */ | |
1773 | spin_lock_irq(q->queue_lock); | |
1774 | blk_requeue_request(q, req); | |
71e75c97 | 1775 | atomic_dec(&sdev->device_busy); |
a488e749 | 1776 | out_delay: |
480cadc2 | 1777 | if (!atomic_read(&sdev->device_busy) && !scsi_device_blocked(sdev)) |
a488e749 | 1778 | blk_delay_queue(q, SCSI_QUEUE_DELAY); |
1da177e4 LT |
1779 | } |
1780 | ||
d285203c CH |
1781 | static inline int prep_to_mq(int ret) |
1782 | { | |
1783 | switch (ret) { | |
1784 | case BLKPREP_OK: | |
1785 | return 0; | |
1786 | case BLKPREP_DEFER: | |
1787 | return BLK_MQ_RQ_QUEUE_BUSY; | |
1788 | default: | |
1789 | return BLK_MQ_RQ_QUEUE_ERROR; | |
1790 | } | |
1791 | } | |
1792 | ||
1793 | static int scsi_mq_prep_fn(struct request *req) | |
1794 | { | |
1795 | struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req); | |
1796 | struct scsi_device *sdev = req->q->queuedata; | |
1797 | struct Scsi_Host *shost = sdev->host; | |
1798 | unsigned char *sense_buf = cmd->sense_buffer; | |
1799 | struct scatterlist *sg; | |
1800 | ||
1801 | memset(cmd, 0, sizeof(struct scsi_cmnd)); | |
1802 | ||
1803 | req->special = cmd; | |
1804 | ||
1805 | cmd->request = req; | |
1806 | cmd->device = sdev; | |
1807 | cmd->sense_buffer = sense_buf; | |
1808 | ||
1809 | cmd->tag = req->tag; | |
1810 | ||
d285203c CH |
1811 | cmd->cmnd = req->cmd; |
1812 | cmd->prot_op = SCSI_PROT_NORMAL; | |
1813 | ||
1814 | INIT_LIST_HEAD(&cmd->list); | |
1815 | INIT_DELAYED_WORK(&cmd->abort_work, scmd_eh_abort_handler); | |
1816 | cmd->jiffies_at_alloc = jiffies; | |
1817 | ||
1818 | /* | |
1819 | * XXX: cmd_list lookups are only used by two drivers, try to get | |
1820 | * rid of this list in common code. | |
1821 | */ | |
1822 | spin_lock_irq(&sdev->list_lock); | |
1823 | list_add_tail(&cmd->list, &sdev->cmd_list); | |
1824 | spin_unlock_irq(&sdev->list_lock); | |
1825 | ||
1826 | sg = (void *)cmd + sizeof(struct scsi_cmnd) + shost->hostt->cmd_size; | |
1827 | cmd->sdb.table.sgl = sg; | |
1828 | ||
1829 | if (scsi_host_get_prot(shost)) { | |
1830 | cmd->prot_sdb = (void *)sg + | |
1831 | shost->sg_tablesize * sizeof(struct scatterlist); | |
1832 | memset(cmd->prot_sdb, 0, sizeof(struct scsi_data_buffer)); | |
1833 | ||
1834 | cmd->prot_sdb->table.sgl = | |
1835 | (struct scatterlist *)(cmd->prot_sdb + 1); | |
1836 | } | |
1837 | ||
1838 | if (blk_bidi_rq(req)) { | |
1839 | struct request *next_rq = req->next_rq; | |
1840 | struct scsi_data_buffer *bidi_sdb = blk_mq_rq_to_pdu(next_rq); | |
1841 | ||
1842 | memset(bidi_sdb, 0, sizeof(struct scsi_data_buffer)); | |
1843 | bidi_sdb->table.sgl = | |
1844 | (struct scatterlist *)(bidi_sdb + 1); | |
1845 | ||
1846 | next_rq->special = bidi_sdb; | |
1847 | } | |
1848 | ||
1849 | return scsi_setup_cmnd(sdev, req); | |
1850 | } | |
1851 | ||
1852 | static void scsi_mq_done(struct scsi_cmnd *cmd) | |
1853 | { | |
1854 | trace_scsi_dispatch_cmd_done(cmd); | |
1855 | blk_mq_complete_request(cmd->request); | |
1856 | } | |
1857 | ||
1858 | static int scsi_queue_rq(struct blk_mq_hw_ctx *hctx, struct request *req) | |
1859 | { | |
1860 | struct request_queue *q = req->q; | |
1861 | struct scsi_device *sdev = q->queuedata; | |
1862 | struct Scsi_Host *shost = sdev->host; | |
1863 | struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req); | |
1864 | int ret; | |
1865 | int reason; | |
1866 | ||
1867 | ret = prep_to_mq(scsi_prep_state_check(sdev, req)); | |
1868 | if (ret) | |
1869 | goto out; | |
1870 | ||
1871 | ret = BLK_MQ_RQ_QUEUE_BUSY; | |
1872 | if (!get_device(&sdev->sdev_gendev)) | |
1873 | goto out; | |
1874 | ||
1875 | if (!scsi_dev_queue_ready(q, sdev)) | |
1876 | goto out_put_device; | |
1877 | if (!scsi_target_queue_ready(shost, sdev)) | |
1878 | goto out_dec_device_busy; | |
1879 | if (!scsi_host_queue_ready(q, shost, sdev)) | |
1880 | goto out_dec_target_busy; | |
1881 | ||
1882 | if (!(req->cmd_flags & REQ_DONTPREP)) { | |
1883 | ret = prep_to_mq(scsi_mq_prep_fn(req)); | |
1884 | if (ret) | |
1885 | goto out_dec_host_busy; | |
1886 | req->cmd_flags |= REQ_DONTPREP; | |
1887 | } | |
1888 | ||
1889 | scsi_init_cmd_errh(cmd); | |
1890 | cmd->scsi_done = scsi_mq_done; | |
1891 | ||
1892 | reason = scsi_dispatch_cmd(cmd); | |
1893 | if (reason) { | |
1894 | scsi_set_blocked(cmd, reason); | |
1895 | ret = BLK_MQ_RQ_QUEUE_BUSY; | |
1896 | goto out_dec_host_busy; | |
1897 | } | |
1898 | ||
1899 | return BLK_MQ_RQ_QUEUE_OK; | |
1900 | ||
1901 | out_dec_host_busy: | |
1902 | atomic_dec(&shost->host_busy); | |
1903 | out_dec_target_busy: | |
1904 | if (scsi_target(sdev)->can_queue > 0) | |
1905 | atomic_dec(&scsi_target(sdev)->target_busy); | |
1906 | out_dec_device_busy: | |
1907 | atomic_dec(&sdev->device_busy); | |
1908 | out_put_device: | |
1909 | put_device(&sdev->sdev_gendev); | |
1910 | out: | |
1911 | switch (ret) { | |
1912 | case BLK_MQ_RQ_QUEUE_BUSY: | |
1913 | blk_mq_stop_hw_queue(hctx); | |
1914 | if (atomic_read(&sdev->device_busy) == 0 && | |
1915 | !scsi_device_blocked(sdev)) | |
1916 | blk_mq_delay_queue(hctx, SCSI_QUEUE_DELAY); | |
1917 | break; | |
1918 | case BLK_MQ_RQ_QUEUE_ERROR: | |
1919 | /* | |
1920 | * Make sure to release all allocated ressources when | |
1921 | * we hit an error, as we will never see this command | |
1922 | * again. | |
1923 | */ | |
1924 | if (req->cmd_flags & REQ_DONTPREP) | |
1925 | scsi_mq_uninit_cmd(cmd); | |
1926 | break; | |
1927 | default: | |
1928 | break; | |
1929 | } | |
1930 | return ret; | |
1931 | } | |
1932 | ||
1933 | static int scsi_init_request(void *data, struct request *rq, | |
1934 | unsigned int hctx_idx, unsigned int request_idx, | |
1935 | unsigned int numa_node) | |
1936 | { | |
1937 | struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq); | |
1938 | ||
1939 | cmd->sense_buffer = kzalloc_node(SCSI_SENSE_BUFFERSIZE, GFP_KERNEL, | |
1940 | numa_node); | |
1941 | if (!cmd->sense_buffer) | |
1942 | return -ENOMEM; | |
1943 | return 0; | |
1944 | } | |
1945 | ||
1946 | static void scsi_exit_request(void *data, struct request *rq, | |
1947 | unsigned int hctx_idx, unsigned int request_idx) | |
1948 | { | |
1949 | struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq); | |
1950 | ||
1951 | kfree(cmd->sense_buffer); | |
1952 | } | |
1953 | ||
f1bea55d | 1954 | static u64 scsi_calculate_bounce_limit(struct Scsi_Host *shost) |
1da177e4 LT |
1955 | { |
1956 | struct device *host_dev; | |
1957 | u64 bounce_limit = 0xffffffff; | |
1958 | ||
1959 | if (shost->unchecked_isa_dma) | |
1960 | return BLK_BOUNCE_ISA; | |
1961 | /* | |
1962 | * Platforms with virtual-DMA translation | |
1963 | * hardware have no practical limit. | |
1964 | */ | |
1965 | if (!PCI_DMA_BUS_IS_PHYS) | |
1966 | return BLK_BOUNCE_ANY; | |
1967 | ||
1968 | host_dev = scsi_get_device(shost); | |
1969 | if (host_dev && host_dev->dma_mask) | |
e83b3664 | 1970 | bounce_limit = (u64)dma_max_pfn(host_dev) << PAGE_SHIFT; |
1da177e4 LT |
1971 | |
1972 | return bounce_limit; | |
1973 | } | |
1da177e4 | 1974 | |
d285203c | 1975 | static void __scsi_init_queue(struct Scsi_Host *shost, struct request_queue *q) |
1da177e4 | 1976 | { |
6f381fa3 | 1977 | struct device *dev = shost->dma_dev; |
1da177e4 | 1978 | |
a8474ce2 JA |
1979 | /* |
1980 | * this limit is imposed by hardware restrictions | |
1981 | */ | |
8a78362c MP |
1982 | blk_queue_max_segments(q, min_t(unsigned short, shost->sg_tablesize, |
1983 | SCSI_MAX_SG_CHAIN_SEGMENTS)); | |
a8474ce2 | 1984 | |
13f05c8d MP |
1985 | if (scsi_host_prot_dma(shost)) { |
1986 | shost->sg_prot_tablesize = | |
1987 | min_not_zero(shost->sg_prot_tablesize, | |
1988 | (unsigned short)SCSI_MAX_PROT_SG_SEGMENTS); | |
1989 | BUG_ON(shost->sg_prot_tablesize < shost->sg_tablesize); | |
1990 | blk_queue_max_integrity_segments(q, shost->sg_prot_tablesize); | |
1991 | } | |
1992 | ||
086fa5ff | 1993 | blk_queue_max_hw_sectors(q, shost->max_sectors); |
1da177e4 LT |
1994 | blk_queue_bounce_limit(q, scsi_calculate_bounce_limit(shost)); |
1995 | blk_queue_segment_boundary(q, shost->dma_boundary); | |
99c84dbd | 1996 | dma_set_seg_boundary(dev, shost->dma_boundary); |
1da177e4 | 1997 | |
860ac568 FT |
1998 | blk_queue_max_segment_size(q, dma_get_max_seg_size(dev)); |
1999 | ||
1da177e4 | 2000 | if (!shost->use_clustering) |
e692cb66 | 2001 | q->limits.cluster = 0; |
465ff318 JB |
2002 | |
2003 | /* | |
2004 | * set a reasonable default alignment on word boundaries: the | |
2005 | * host and device may alter it using | |
2006 | * blk_queue_update_dma_alignment() later. | |
2007 | */ | |
2008 | blk_queue_dma_alignment(q, 0x03); | |
d285203c | 2009 | } |
465ff318 | 2010 | |
d285203c CH |
2011 | struct request_queue *__scsi_alloc_queue(struct Scsi_Host *shost, |
2012 | request_fn_proc *request_fn) | |
2013 | { | |
2014 | struct request_queue *q; | |
2015 | ||
2016 | q = blk_init_queue(request_fn, NULL); | |
2017 | if (!q) | |
2018 | return NULL; | |
2019 | __scsi_init_queue(shost, q); | |
1da177e4 LT |
2020 | return q; |
2021 | } | |
b58d9154 FT |
2022 | EXPORT_SYMBOL(__scsi_alloc_queue); |
2023 | ||
2024 | struct request_queue *scsi_alloc_queue(struct scsi_device *sdev) | |
2025 | { | |
2026 | struct request_queue *q; | |
2027 | ||
2028 | q = __scsi_alloc_queue(sdev->host, scsi_request_fn); | |
2029 | if (!q) | |
2030 | return NULL; | |
2031 | ||
2032 | blk_queue_prep_rq(q, scsi_prep_fn); | |
a1b73fc1 | 2033 | blk_queue_unprep_rq(q, scsi_unprep_fn); |
b58d9154 | 2034 | blk_queue_softirq_done(q, scsi_softirq_done); |
242f9dcb | 2035 | blk_queue_rq_timed_out(q, scsi_times_out); |
6c5121b7 | 2036 | blk_queue_lld_busy(q, scsi_lld_busy); |
b58d9154 FT |
2037 | return q; |
2038 | } | |
1da177e4 | 2039 | |
d285203c CH |
2040 | static struct blk_mq_ops scsi_mq_ops = { |
2041 | .map_queue = blk_mq_map_queue, | |
2042 | .queue_rq = scsi_queue_rq, | |
2043 | .complete = scsi_softirq_done, | |
2044 | .timeout = scsi_times_out, | |
2045 | .init_request = scsi_init_request, | |
2046 | .exit_request = scsi_exit_request, | |
2047 | }; | |
2048 | ||
2049 | struct request_queue *scsi_mq_alloc_queue(struct scsi_device *sdev) | |
2050 | { | |
2051 | sdev->request_queue = blk_mq_init_queue(&sdev->host->tag_set); | |
2052 | if (IS_ERR(sdev->request_queue)) | |
2053 | return NULL; | |
2054 | ||
2055 | sdev->request_queue->queuedata = sdev; | |
2056 | __scsi_init_queue(sdev->host, sdev->request_queue); | |
2057 | return sdev->request_queue; | |
2058 | } | |
2059 | ||
2060 | int scsi_mq_setup_tags(struct Scsi_Host *shost) | |
2061 | { | |
2062 | unsigned int cmd_size, sgl_size, tbl_size; | |
2063 | ||
2064 | tbl_size = shost->sg_tablesize; | |
2065 | if (tbl_size > SCSI_MAX_SG_SEGMENTS) | |
2066 | tbl_size = SCSI_MAX_SG_SEGMENTS; | |
2067 | sgl_size = tbl_size * sizeof(struct scatterlist); | |
2068 | cmd_size = sizeof(struct scsi_cmnd) + shost->hostt->cmd_size + sgl_size; | |
2069 | if (scsi_host_get_prot(shost)) | |
2070 | cmd_size += sizeof(struct scsi_data_buffer) + sgl_size; | |
2071 | ||
2072 | memset(&shost->tag_set, 0, sizeof(shost->tag_set)); | |
2073 | shost->tag_set.ops = &scsi_mq_ops; | |
2074 | shost->tag_set.nr_hw_queues = 1; | |
2075 | shost->tag_set.queue_depth = shost->can_queue; | |
2076 | shost->tag_set.cmd_size = cmd_size; | |
2077 | shost->tag_set.numa_node = NUMA_NO_NODE; | |
2078 | shost->tag_set.flags = BLK_MQ_F_SHOULD_MERGE | BLK_MQ_F_SG_MERGE; | |
2079 | shost->tag_set.driver_data = shost; | |
2080 | ||
2081 | return blk_mq_alloc_tag_set(&shost->tag_set); | |
2082 | } | |
2083 | ||
2084 | void scsi_mq_destroy_tags(struct Scsi_Host *shost) | |
2085 | { | |
2086 | blk_mq_free_tag_set(&shost->tag_set); | |
2087 | } | |
2088 | ||
1da177e4 LT |
2089 | /* |
2090 | * Function: scsi_block_requests() | |
2091 | * | |
2092 | * Purpose: Utility function used by low-level drivers to prevent further | |
2093 | * commands from being queued to the device. | |
2094 | * | |
2095 | * Arguments: shost - Host in question | |
2096 | * | |
2097 | * Returns: Nothing | |
2098 | * | |
2099 | * Lock status: No locks are assumed held. | |
2100 | * | |
2101 | * Notes: There is no timer nor any other means by which the requests | |
2102 | * get unblocked other than the low-level driver calling | |
2103 | * scsi_unblock_requests(). | |
2104 | */ | |
2105 | void scsi_block_requests(struct Scsi_Host *shost) | |
2106 | { | |
2107 | shost->host_self_blocked = 1; | |
2108 | } | |
2109 | EXPORT_SYMBOL(scsi_block_requests); | |
2110 | ||
2111 | /* | |
2112 | * Function: scsi_unblock_requests() | |
2113 | * | |
2114 | * Purpose: Utility function used by low-level drivers to allow further | |
2115 | * commands from being queued to the device. | |
2116 | * | |
2117 | * Arguments: shost - Host in question | |
2118 | * | |
2119 | * Returns: Nothing | |
2120 | * | |
2121 | * Lock status: No locks are assumed held. | |
2122 | * | |
2123 | * Notes: There is no timer nor any other means by which the requests | |
2124 | * get unblocked other than the low-level driver calling | |
2125 | * scsi_unblock_requests(). | |
2126 | * | |
2127 | * This is done as an API function so that changes to the | |
2128 | * internals of the scsi mid-layer won't require wholesale | |
2129 | * changes to drivers that use this feature. | |
2130 | */ | |
2131 | void scsi_unblock_requests(struct Scsi_Host *shost) | |
2132 | { | |
2133 | shost->host_self_blocked = 0; | |
2134 | scsi_run_host_queues(shost); | |
2135 | } | |
2136 | EXPORT_SYMBOL(scsi_unblock_requests); | |
2137 | ||
2138 | int __init scsi_init_queue(void) | |
2139 | { | |
2140 | int i; | |
2141 | ||
6362abd3 MP |
2142 | scsi_sdb_cache = kmem_cache_create("scsi_data_buffer", |
2143 | sizeof(struct scsi_data_buffer), | |
2144 | 0, 0, NULL); | |
2145 | if (!scsi_sdb_cache) { | |
2146 | printk(KERN_ERR "SCSI: can't init scsi sdb cache\n"); | |
f078727b | 2147 | return -ENOMEM; |
6f9a35e2 BH |
2148 | } |
2149 | ||
1da177e4 LT |
2150 | for (i = 0; i < SG_MEMPOOL_NR; i++) { |
2151 | struct scsi_host_sg_pool *sgp = scsi_sg_pools + i; | |
2152 | int size = sgp->size * sizeof(struct scatterlist); | |
2153 | ||
2154 | sgp->slab = kmem_cache_create(sgp->name, size, 0, | |
20c2df83 | 2155 | SLAB_HWCACHE_ALIGN, NULL); |
1da177e4 LT |
2156 | if (!sgp->slab) { |
2157 | printk(KERN_ERR "SCSI: can't init sg slab %s\n", | |
2158 | sgp->name); | |
6362abd3 | 2159 | goto cleanup_sdb; |
1da177e4 LT |
2160 | } |
2161 | ||
93d2341c MD |
2162 | sgp->pool = mempool_create_slab_pool(SG_MEMPOOL_SIZE, |
2163 | sgp->slab); | |
1da177e4 LT |
2164 | if (!sgp->pool) { |
2165 | printk(KERN_ERR "SCSI: can't init sg mempool %s\n", | |
2166 | sgp->name); | |
6362abd3 | 2167 | goto cleanup_sdb; |
1da177e4 LT |
2168 | } |
2169 | } | |
2170 | ||
2171 | return 0; | |
3d9dd6ee | 2172 | |
6362abd3 | 2173 | cleanup_sdb: |
3d9dd6ee FT |
2174 | for (i = 0; i < SG_MEMPOOL_NR; i++) { |
2175 | struct scsi_host_sg_pool *sgp = scsi_sg_pools + i; | |
2176 | if (sgp->pool) | |
2177 | mempool_destroy(sgp->pool); | |
2178 | if (sgp->slab) | |
2179 | kmem_cache_destroy(sgp->slab); | |
2180 | } | |
6362abd3 | 2181 | kmem_cache_destroy(scsi_sdb_cache); |
3d9dd6ee FT |
2182 | |
2183 | return -ENOMEM; | |
1da177e4 LT |
2184 | } |
2185 | ||
2186 | void scsi_exit_queue(void) | |
2187 | { | |
2188 | int i; | |
2189 | ||
6362abd3 | 2190 | kmem_cache_destroy(scsi_sdb_cache); |
aa7b5cd7 | 2191 | |
1da177e4 LT |
2192 | for (i = 0; i < SG_MEMPOOL_NR; i++) { |
2193 | struct scsi_host_sg_pool *sgp = scsi_sg_pools + i; | |
2194 | mempool_destroy(sgp->pool); | |
2195 | kmem_cache_destroy(sgp->slab); | |
2196 | } | |
2197 | } | |
5baba830 JB |
2198 | |
2199 | /** | |
2200 | * scsi_mode_select - issue a mode select | |
2201 | * @sdev: SCSI device to be queried | |
2202 | * @pf: Page format bit (1 == standard, 0 == vendor specific) | |
2203 | * @sp: Save page bit (0 == don't save, 1 == save) | |
2204 | * @modepage: mode page being requested | |
2205 | * @buffer: request buffer (may not be smaller than eight bytes) | |
2206 | * @len: length of request buffer. | |
2207 | * @timeout: command timeout | |
2208 | * @retries: number of retries before failing | |
2209 | * @data: returns a structure abstracting the mode header data | |
eb44820c | 2210 | * @sshdr: place to put sense data (or NULL if no sense to be collected). |
5baba830 JB |
2211 | * must be SCSI_SENSE_BUFFERSIZE big. |
2212 | * | |
2213 | * Returns zero if successful; negative error number or scsi | |
2214 | * status on error | |
2215 | * | |
2216 | */ | |
2217 | int | |
2218 | scsi_mode_select(struct scsi_device *sdev, int pf, int sp, int modepage, | |
2219 | unsigned char *buffer, int len, int timeout, int retries, | |
2220 | struct scsi_mode_data *data, struct scsi_sense_hdr *sshdr) | |
2221 | { | |
2222 | unsigned char cmd[10]; | |
2223 | unsigned char *real_buffer; | |
2224 | int ret; | |
2225 | ||
2226 | memset(cmd, 0, sizeof(cmd)); | |
2227 | cmd[1] = (pf ? 0x10 : 0) | (sp ? 0x01 : 0); | |
2228 | ||
2229 | if (sdev->use_10_for_ms) { | |
2230 | if (len > 65535) | |
2231 | return -EINVAL; | |
2232 | real_buffer = kmalloc(8 + len, GFP_KERNEL); | |
2233 | if (!real_buffer) | |
2234 | return -ENOMEM; | |
2235 | memcpy(real_buffer + 8, buffer, len); | |
2236 | len += 8; | |
2237 | real_buffer[0] = 0; | |
2238 | real_buffer[1] = 0; | |
2239 | real_buffer[2] = data->medium_type; | |
2240 | real_buffer[3] = data->device_specific; | |
2241 | real_buffer[4] = data->longlba ? 0x01 : 0; | |
2242 | real_buffer[5] = 0; | |
2243 | real_buffer[6] = data->block_descriptor_length >> 8; | |
2244 | real_buffer[7] = data->block_descriptor_length; | |
2245 | ||
2246 | cmd[0] = MODE_SELECT_10; | |
2247 | cmd[7] = len >> 8; | |
2248 | cmd[8] = len; | |
2249 | } else { | |
2250 | if (len > 255 || data->block_descriptor_length > 255 || | |
2251 | data->longlba) | |
2252 | return -EINVAL; | |
2253 | ||
2254 | real_buffer = kmalloc(4 + len, GFP_KERNEL); | |
2255 | if (!real_buffer) | |
2256 | return -ENOMEM; | |
2257 | memcpy(real_buffer + 4, buffer, len); | |
2258 | len += 4; | |
2259 | real_buffer[0] = 0; | |
2260 | real_buffer[1] = data->medium_type; | |
2261 | real_buffer[2] = data->device_specific; | |
2262 | real_buffer[3] = data->block_descriptor_length; | |
2263 | ||
2264 | ||
2265 | cmd[0] = MODE_SELECT; | |
2266 | cmd[4] = len; | |
2267 | } | |
2268 | ||
2269 | ret = scsi_execute_req(sdev, cmd, DMA_TO_DEVICE, real_buffer, len, | |
f4f4e47e | 2270 | sshdr, timeout, retries, NULL); |
5baba830 JB |
2271 | kfree(real_buffer); |
2272 | return ret; | |
2273 | } | |
2274 | EXPORT_SYMBOL_GPL(scsi_mode_select); | |
2275 | ||
1da177e4 | 2276 | /** |
eb44820c | 2277 | * scsi_mode_sense - issue a mode sense, falling back from 10 to six bytes if necessary. |
1cf72699 | 2278 | * @sdev: SCSI device to be queried |
1da177e4 LT |
2279 | * @dbd: set if mode sense will allow block descriptors to be returned |
2280 | * @modepage: mode page being requested | |
2281 | * @buffer: request buffer (may not be smaller than eight bytes) | |
2282 | * @len: length of request buffer. | |
2283 | * @timeout: command timeout | |
2284 | * @retries: number of retries before failing | |
2285 | * @data: returns a structure abstracting the mode header data | |
eb44820c | 2286 | * @sshdr: place to put sense data (or NULL if no sense to be collected). |
1cf72699 | 2287 | * must be SCSI_SENSE_BUFFERSIZE big. |
1da177e4 LT |
2288 | * |
2289 | * Returns zero if unsuccessful, or the header offset (either 4 | |
2290 | * or 8 depending on whether a six or ten byte command was | |
2291 | * issued) if successful. | |
eb44820c | 2292 | */ |
1da177e4 | 2293 | int |
1cf72699 | 2294 | scsi_mode_sense(struct scsi_device *sdev, int dbd, int modepage, |
1da177e4 | 2295 | unsigned char *buffer, int len, int timeout, int retries, |
5baba830 JB |
2296 | struct scsi_mode_data *data, struct scsi_sense_hdr *sshdr) |
2297 | { | |
1da177e4 LT |
2298 | unsigned char cmd[12]; |
2299 | int use_10_for_ms; | |
2300 | int header_length; | |
1cf72699 | 2301 | int result; |
ea73a9f2 | 2302 | struct scsi_sense_hdr my_sshdr; |
1da177e4 LT |
2303 | |
2304 | memset(data, 0, sizeof(*data)); | |
2305 | memset(&cmd[0], 0, 12); | |
2306 | cmd[1] = dbd & 0x18; /* allows DBD and LLBA bits */ | |
2307 | cmd[2] = modepage; | |
2308 | ||
ea73a9f2 JB |
2309 | /* caller might not be interested in sense, but we need it */ |
2310 | if (!sshdr) | |
2311 | sshdr = &my_sshdr; | |
2312 | ||
1da177e4 | 2313 | retry: |
1cf72699 | 2314 | use_10_for_ms = sdev->use_10_for_ms; |
1da177e4 LT |
2315 | |
2316 | if (use_10_for_ms) { | |
2317 | if (len < 8) | |
2318 | len = 8; | |
2319 | ||
2320 | cmd[0] = MODE_SENSE_10; | |
2321 | cmd[8] = len; | |
2322 | header_length = 8; | |
2323 | } else { | |
2324 | if (len < 4) | |
2325 | len = 4; | |
2326 | ||
2327 | cmd[0] = MODE_SENSE; | |
2328 | cmd[4] = len; | |
2329 | header_length = 4; | |
2330 | } | |
2331 | ||
1da177e4 LT |
2332 | memset(buffer, 0, len); |
2333 | ||
1cf72699 | 2334 | result = scsi_execute_req(sdev, cmd, DMA_FROM_DEVICE, buffer, len, |
f4f4e47e | 2335 | sshdr, timeout, retries, NULL); |
1da177e4 LT |
2336 | |
2337 | /* This code looks awful: what it's doing is making sure an | |
2338 | * ILLEGAL REQUEST sense return identifies the actual command | |
2339 | * byte as the problem. MODE_SENSE commands can return | |
2340 | * ILLEGAL REQUEST if the code page isn't supported */ | |
2341 | ||
1cf72699 JB |
2342 | if (use_10_for_ms && !scsi_status_is_good(result) && |
2343 | (driver_byte(result) & DRIVER_SENSE)) { | |
ea73a9f2 JB |
2344 | if (scsi_sense_valid(sshdr)) { |
2345 | if ((sshdr->sense_key == ILLEGAL_REQUEST) && | |
2346 | (sshdr->asc == 0x20) && (sshdr->ascq == 0)) { | |
1da177e4 LT |
2347 | /* |
2348 | * Invalid command operation code | |
2349 | */ | |
1cf72699 | 2350 | sdev->use_10_for_ms = 0; |
1da177e4 LT |
2351 | goto retry; |
2352 | } | |
2353 | } | |
2354 | } | |
2355 | ||
1cf72699 | 2356 | if(scsi_status_is_good(result)) { |
6d73c851 AV |
2357 | if (unlikely(buffer[0] == 0x86 && buffer[1] == 0x0b && |
2358 | (modepage == 6 || modepage == 8))) { | |
2359 | /* Initio breakage? */ | |
2360 | header_length = 0; | |
2361 | data->length = 13; | |
2362 | data->medium_type = 0; | |
2363 | data->device_specific = 0; | |
2364 | data->longlba = 0; | |
2365 | data->block_descriptor_length = 0; | |
2366 | } else if(use_10_for_ms) { | |
1da177e4 LT |
2367 | data->length = buffer[0]*256 + buffer[1] + 2; |
2368 | data->medium_type = buffer[2]; | |
2369 | data->device_specific = buffer[3]; | |
2370 | data->longlba = buffer[4] & 0x01; | |
2371 | data->block_descriptor_length = buffer[6]*256 | |
2372 | + buffer[7]; | |
2373 | } else { | |
2374 | data->length = buffer[0] + 1; | |
2375 | data->medium_type = buffer[1]; | |
2376 | data->device_specific = buffer[2]; | |
2377 | data->block_descriptor_length = buffer[3]; | |
2378 | } | |
6d73c851 | 2379 | data->header_length = header_length; |
1da177e4 LT |
2380 | } |
2381 | ||
1cf72699 | 2382 | return result; |
1da177e4 LT |
2383 | } |
2384 | EXPORT_SYMBOL(scsi_mode_sense); | |
2385 | ||
001aac25 JB |
2386 | /** |
2387 | * scsi_test_unit_ready - test if unit is ready | |
2388 | * @sdev: scsi device to change the state of. | |
2389 | * @timeout: command timeout | |
2390 | * @retries: number of retries before failing | |
2391 | * @sshdr_external: Optional pointer to struct scsi_sense_hdr for | |
2392 | * returning sense. Make sure that this is cleared before passing | |
2393 | * in. | |
2394 | * | |
2395 | * Returns zero if unsuccessful or an error if TUR failed. For | |
9f8a2c23 | 2396 | * removable media, UNIT_ATTENTION sets ->changed flag. |
001aac25 | 2397 | **/ |
1da177e4 | 2398 | int |
001aac25 JB |
2399 | scsi_test_unit_ready(struct scsi_device *sdev, int timeout, int retries, |
2400 | struct scsi_sense_hdr *sshdr_external) | |
1da177e4 | 2401 | { |
1da177e4 LT |
2402 | char cmd[] = { |
2403 | TEST_UNIT_READY, 0, 0, 0, 0, 0, | |
2404 | }; | |
001aac25 | 2405 | struct scsi_sense_hdr *sshdr; |
1da177e4 | 2406 | int result; |
001aac25 JB |
2407 | |
2408 | if (!sshdr_external) | |
2409 | sshdr = kzalloc(sizeof(*sshdr), GFP_KERNEL); | |
2410 | else | |
2411 | sshdr = sshdr_external; | |
2412 | ||
2413 | /* try to eat the UNIT_ATTENTION if there are enough retries */ | |
2414 | do { | |
2415 | result = scsi_execute_req(sdev, cmd, DMA_NONE, NULL, 0, sshdr, | |
f4f4e47e | 2416 | timeout, retries, NULL); |
32c356d7 JB |
2417 | if (sdev->removable && scsi_sense_valid(sshdr) && |
2418 | sshdr->sense_key == UNIT_ATTENTION) | |
2419 | sdev->changed = 1; | |
2420 | } while (scsi_sense_valid(sshdr) && | |
2421 | sshdr->sense_key == UNIT_ATTENTION && --retries); | |
001aac25 | 2422 | |
001aac25 JB |
2423 | if (!sshdr_external) |
2424 | kfree(sshdr); | |
1da177e4 LT |
2425 | return result; |
2426 | } | |
2427 | EXPORT_SYMBOL(scsi_test_unit_ready); | |
2428 | ||
2429 | /** | |
eb44820c | 2430 | * scsi_device_set_state - Take the given device through the device state model. |
1da177e4 LT |
2431 | * @sdev: scsi device to change the state of. |
2432 | * @state: state to change to. | |
2433 | * | |
2434 | * Returns zero if unsuccessful or an error if the requested | |
2435 | * transition is illegal. | |
eb44820c | 2436 | */ |
1da177e4 LT |
2437 | int |
2438 | scsi_device_set_state(struct scsi_device *sdev, enum scsi_device_state state) | |
2439 | { | |
2440 | enum scsi_device_state oldstate = sdev->sdev_state; | |
2441 | ||
2442 | if (state == oldstate) | |
2443 | return 0; | |
2444 | ||
2445 | switch (state) { | |
2446 | case SDEV_CREATED: | |
6f4267e3 JB |
2447 | switch (oldstate) { |
2448 | case SDEV_CREATED_BLOCK: | |
2449 | break; | |
2450 | default: | |
2451 | goto illegal; | |
2452 | } | |
2453 | break; | |
1da177e4 LT |
2454 | |
2455 | case SDEV_RUNNING: | |
2456 | switch (oldstate) { | |
2457 | case SDEV_CREATED: | |
2458 | case SDEV_OFFLINE: | |
1b8d2620 | 2459 | case SDEV_TRANSPORT_OFFLINE: |
1da177e4 LT |
2460 | case SDEV_QUIESCE: |
2461 | case SDEV_BLOCK: | |
2462 | break; | |
2463 | default: | |
2464 | goto illegal; | |
2465 | } | |
2466 | break; | |
2467 | ||
2468 | case SDEV_QUIESCE: | |
2469 | switch (oldstate) { | |
2470 | case SDEV_RUNNING: | |
2471 | case SDEV_OFFLINE: | |
1b8d2620 | 2472 | case SDEV_TRANSPORT_OFFLINE: |
1da177e4 LT |
2473 | break; |
2474 | default: | |
2475 | goto illegal; | |
2476 | } | |
2477 | break; | |
2478 | ||
2479 | case SDEV_OFFLINE: | |
1b8d2620 | 2480 | case SDEV_TRANSPORT_OFFLINE: |
1da177e4 LT |
2481 | switch (oldstate) { |
2482 | case SDEV_CREATED: | |
2483 | case SDEV_RUNNING: | |
2484 | case SDEV_QUIESCE: | |
2485 | case SDEV_BLOCK: | |
2486 | break; | |
2487 | default: | |
2488 | goto illegal; | |
2489 | } | |
2490 | break; | |
2491 | ||
2492 | case SDEV_BLOCK: | |
2493 | switch (oldstate) { | |
1da177e4 | 2494 | case SDEV_RUNNING: |
6f4267e3 JB |
2495 | case SDEV_CREATED_BLOCK: |
2496 | break; | |
2497 | default: | |
2498 | goto illegal; | |
2499 | } | |
2500 | break; | |
2501 | ||
2502 | case SDEV_CREATED_BLOCK: | |
2503 | switch (oldstate) { | |
2504 | case SDEV_CREATED: | |
1da177e4 LT |
2505 | break; |
2506 | default: | |
2507 | goto illegal; | |
2508 | } | |
2509 | break; | |
2510 | ||
2511 | case SDEV_CANCEL: | |
2512 | switch (oldstate) { | |
2513 | case SDEV_CREATED: | |
2514 | case SDEV_RUNNING: | |
9ea72909 | 2515 | case SDEV_QUIESCE: |
1da177e4 | 2516 | case SDEV_OFFLINE: |
1b8d2620 | 2517 | case SDEV_TRANSPORT_OFFLINE: |
1da177e4 LT |
2518 | case SDEV_BLOCK: |
2519 | break; | |
2520 | default: | |
2521 | goto illegal; | |
2522 | } | |
2523 | break; | |
2524 | ||
2525 | case SDEV_DEL: | |
2526 | switch (oldstate) { | |
309bd271 BK |
2527 | case SDEV_CREATED: |
2528 | case SDEV_RUNNING: | |
2529 | case SDEV_OFFLINE: | |
1b8d2620 | 2530 | case SDEV_TRANSPORT_OFFLINE: |
1da177e4 | 2531 | case SDEV_CANCEL: |
0516c08d | 2532 | case SDEV_CREATED_BLOCK: |
1da177e4 LT |
2533 | break; |
2534 | default: | |
2535 | goto illegal; | |
2536 | } | |
2537 | break; | |
2538 | ||
2539 | } | |
2540 | sdev->sdev_state = state; | |
2541 | return 0; | |
2542 | ||
2543 | illegal: | |
91921e01 | 2544 | SCSI_LOG_ERROR_RECOVERY(1, |
9ccfc756 | 2545 | sdev_printk(KERN_ERR, sdev, |
91921e01 | 2546 | "Illegal state transition %s->%s", |
9ccfc756 JB |
2547 | scsi_device_state_name(oldstate), |
2548 | scsi_device_state_name(state)) | |
1da177e4 LT |
2549 | ); |
2550 | return -EINVAL; | |
2551 | } | |
2552 | EXPORT_SYMBOL(scsi_device_set_state); | |
2553 | ||
a341cd0f JG |
2554 | /** |
2555 | * sdev_evt_emit - emit a single SCSI device uevent | |
2556 | * @sdev: associated SCSI device | |
2557 | * @evt: event to emit | |
2558 | * | |
2559 | * Send a single uevent (scsi_event) to the associated scsi_device. | |
2560 | */ | |
2561 | static void scsi_evt_emit(struct scsi_device *sdev, struct scsi_event *evt) | |
2562 | { | |
2563 | int idx = 0; | |
2564 | char *envp[3]; | |
2565 | ||
2566 | switch (evt->evt_type) { | |
2567 | case SDEV_EVT_MEDIA_CHANGE: | |
2568 | envp[idx++] = "SDEV_MEDIA_CHANGE=1"; | |
2569 | break; | |
279afdfe EM |
2570 | case SDEV_EVT_INQUIRY_CHANGE_REPORTED: |
2571 | envp[idx++] = "SDEV_UA=INQUIRY_DATA_HAS_CHANGED"; | |
2572 | break; | |
2573 | case SDEV_EVT_CAPACITY_CHANGE_REPORTED: | |
2574 | envp[idx++] = "SDEV_UA=CAPACITY_DATA_HAS_CHANGED"; | |
2575 | break; | |
2576 | case SDEV_EVT_SOFT_THRESHOLD_REACHED_REPORTED: | |
2577 | envp[idx++] = "SDEV_UA=THIN_PROVISIONING_SOFT_THRESHOLD_REACHED"; | |
2578 | break; | |
2579 | case SDEV_EVT_MODE_PARAMETER_CHANGE_REPORTED: | |
2580 | envp[idx++] = "SDEV_UA=MODE_PARAMETERS_CHANGED"; | |
2581 | break; | |
2582 | case SDEV_EVT_LUN_CHANGE_REPORTED: | |
2583 | envp[idx++] = "SDEV_UA=REPORTED_LUNS_DATA_HAS_CHANGED"; | |
2584 | break; | |
a341cd0f JG |
2585 | default: |
2586 | /* do nothing */ | |
2587 | break; | |
2588 | } | |
2589 | ||
2590 | envp[idx++] = NULL; | |
2591 | ||
2592 | kobject_uevent_env(&sdev->sdev_gendev.kobj, KOBJ_CHANGE, envp); | |
2593 | } | |
2594 | ||
2595 | /** | |
2596 | * sdev_evt_thread - send a uevent for each scsi event | |
2597 | * @work: work struct for scsi_device | |
2598 | * | |
2599 | * Dispatch queued events to their associated scsi_device kobjects | |
2600 | * as uevents. | |
2601 | */ | |
2602 | void scsi_evt_thread(struct work_struct *work) | |
2603 | { | |
2604 | struct scsi_device *sdev; | |
279afdfe | 2605 | enum scsi_device_event evt_type; |
a341cd0f JG |
2606 | LIST_HEAD(event_list); |
2607 | ||
2608 | sdev = container_of(work, struct scsi_device, event_work); | |
2609 | ||
279afdfe EM |
2610 | for (evt_type = SDEV_EVT_FIRST; evt_type <= SDEV_EVT_LAST; evt_type++) |
2611 | if (test_and_clear_bit(evt_type, sdev->pending_events)) | |
2612 | sdev_evt_send_simple(sdev, evt_type, GFP_KERNEL); | |
2613 | ||
a341cd0f JG |
2614 | while (1) { |
2615 | struct scsi_event *evt; | |
2616 | struct list_head *this, *tmp; | |
2617 | unsigned long flags; | |
2618 | ||
2619 | spin_lock_irqsave(&sdev->list_lock, flags); | |
2620 | list_splice_init(&sdev->event_list, &event_list); | |
2621 | spin_unlock_irqrestore(&sdev->list_lock, flags); | |
2622 | ||
2623 | if (list_empty(&event_list)) | |
2624 | break; | |
2625 | ||
2626 | list_for_each_safe(this, tmp, &event_list) { | |
2627 | evt = list_entry(this, struct scsi_event, node); | |
2628 | list_del(&evt->node); | |
2629 | scsi_evt_emit(sdev, evt); | |
2630 | kfree(evt); | |
2631 | } | |
2632 | } | |
2633 | } | |
2634 | ||
2635 | /** | |
2636 | * sdev_evt_send - send asserted event to uevent thread | |
2637 | * @sdev: scsi_device event occurred on | |
2638 | * @evt: event to send | |
2639 | * | |
2640 | * Assert scsi device event asynchronously. | |
2641 | */ | |
2642 | void sdev_evt_send(struct scsi_device *sdev, struct scsi_event *evt) | |
2643 | { | |
2644 | unsigned long flags; | |
2645 | ||
4d1566ed KS |
2646 | #if 0 |
2647 | /* FIXME: currently this check eliminates all media change events | |
2648 | * for polled devices. Need to update to discriminate between AN | |
2649 | * and polled events */ | |
a341cd0f JG |
2650 | if (!test_bit(evt->evt_type, sdev->supported_events)) { |
2651 | kfree(evt); | |
2652 | return; | |
2653 | } | |
4d1566ed | 2654 | #endif |
a341cd0f JG |
2655 | |
2656 | spin_lock_irqsave(&sdev->list_lock, flags); | |
2657 | list_add_tail(&evt->node, &sdev->event_list); | |
2658 | schedule_work(&sdev->event_work); | |
2659 | spin_unlock_irqrestore(&sdev->list_lock, flags); | |
2660 | } | |
2661 | EXPORT_SYMBOL_GPL(sdev_evt_send); | |
2662 | ||
2663 | /** | |
2664 | * sdev_evt_alloc - allocate a new scsi event | |
2665 | * @evt_type: type of event to allocate | |
2666 | * @gfpflags: GFP flags for allocation | |
2667 | * | |
2668 | * Allocates and returns a new scsi_event. | |
2669 | */ | |
2670 | struct scsi_event *sdev_evt_alloc(enum scsi_device_event evt_type, | |
2671 | gfp_t gfpflags) | |
2672 | { | |
2673 | struct scsi_event *evt = kzalloc(sizeof(struct scsi_event), gfpflags); | |
2674 | if (!evt) | |
2675 | return NULL; | |
2676 | ||
2677 | evt->evt_type = evt_type; | |
2678 | INIT_LIST_HEAD(&evt->node); | |
2679 | ||
2680 | /* evt_type-specific initialization, if any */ | |
2681 | switch (evt_type) { | |
2682 | case SDEV_EVT_MEDIA_CHANGE: | |
279afdfe EM |
2683 | case SDEV_EVT_INQUIRY_CHANGE_REPORTED: |
2684 | case SDEV_EVT_CAPACITY_CHANGE_REPORTED: | |
2685 | case SDEV_EVT_SOFT_THRESHOLD_REACHED_REPORTED: | |
2686 | case SDEV_EVT_MODE_PARAMETER_CHANGE_REPORTED: | |
2687 | case SDEV_EVT_LUN_CHANGE_REPORTED: | |
a341cd0f JG |
2688 | default: |
2689 | /* do nothing */ | |
2690 | break; | |
2691 | } | |
2692 | ||
2693 | return evt; | |
2694 | } | |
2695 | EXPORT_SYMBOL_GPL(sdev_evt_alloc); | |
2696 | ||
2697 | /** | |
2698 | * sdev_evt_send_simple - send asserted event to uevent thread | |
2699 | * @sdev: scsi_device event occurred on | |
2700 | * @evt_type: type of event to send | |
2701 | * @gfpflags: GFP flags for allocation | |
2702 | * | |
2703 | * Assert scsi device event asynchronously, given an event type. | |
2704 | */ | |
2705 | void sdev_evt_send_simple(struct scsi_device *sdev, | |
2706 | enum scsi_device_event evt_type, gfp_t gfpflags) | |
2707 | { | |
2708 | struct scsi_event *evt = sdev_evt_alloc(evt_type, gfpflags); | |
2709 | if (!evt) { | |
2710 | sdev_printk(KERN_ERR, sdev, "event %d eaten due to OOM\n", | |
2711 | evt_type); | |
2712 | return; | |
2713 | } | |
2714 | ||
2715 | sdev_evt_send(sdev, evt); | |
2716 | } | |
2717 | EXPORT_SYMBOL_GPL(sdev_evt_send_simple); | |
2718 | ||
1da177e4 LT |
2719 | /** |
2720 | * scsi_device_quiesce - Block user issued commands. | |
2721 | * @sdev: scsi device to quiesce. | |
2722 | * | |
2723 | * This works by trying to transition to the SDEV_QUIESCE state | |
2724 | * (which must be a legal transition). When the device is in this | |
2725 | * state, only special requests will be accepted, all others will | |
2726 | * be deferred. Since special requests may also be requeued requests, | |
2727 | * a successful return doesn't guarantee the device will be | |
2728 | * totally quiescent. | |
2729 | * | |
2730 | * Must be called with user context, may sleep. | |
2731 | * | |
2732 | * Returns zero if unsuccessful or an error if not. | |
eb44820c | 2733 | */ |
1da177e4 LT |
2734 | int |
2735 | scsi_device_quiesce(struct scsi_device *sdev) | |
2736 | { | |
2737 | int err = scsi_device_set_state(sdev, SDEV_QUIESCE); | |
2738 | if (err) | |
2739 | return err; | |
2740 | ||
2741 | scsi_run_queue(sdev->request_queue); | |
71e75c97 | 2742 | while (atomic_read(&sdev->device_busy)) { |
1da177e4 LT |
2743 | msleep_interruptible(200); |
2744 | scsi_run_queue(sdev->request_queue); | |
2745 | } | |
2746 | return 0; | |
2747 | } | |
2748 | EXPORT_SYMBOL(scsi_device_quiesce); | |
2749 | ||
2750 | /** | |
2751 | * scsi_device_resume - Restart user issued commands to a quiesced device. | |
2752 | * @sdev: scsi device to resume. | |
2753 | * | |
2754 | * Moves the device from quiesced back to running and restarts the | |
2755 | * queues. | |
2756 | * | |
2757 | * Must be called with user context, may sleep. | |
eb44820c | 2758 | */ |
a7a20d10 | 2759 | void scsi_device_resume(struct scsi_device *sdev) |
1da177e4 | 2760 | { |
a7a20d10 DW |
2761 | /* check if the device state was mutated prior to resume, and if |
2762 | * so assume the state is being managed elsewhere (for example | |
2763 | * device deleted during suspend) | |
2764 | */ | |
2765 | if (sdev->sdev_state != SDEV_QUIESCE || | |
2766 | scsi_device_set_state(sdev, SDEV_RUNNING)) | |
1da177e4 LT |
2767 | return; |
2768 | scsi_run_queue(sdev->request_queue); | |
2769 | } | |
2770 | EXPORT_SYMBOL(scsi_device_resume); | |
2771 | ||
2772 | static void | |
2773 | device_quiesce_fn(struct scsi_device *sdev, void *data) | |
2774 | { | |
2775 | scsi_device_quiesce(sdev); | |
2776 | } | |
2777 | ||
2778 | void | |
2779 | scsi_target_quiesce(struct scsi_target *starget) | |
2780 | { | |
2781 | starget_for_each_device(starget, NULL, device_quiesce_fn); | |
2782 | } | |
2783 | EXPORT_SYMBOL(scsi_target_quiesce); | |
2784 | ||
2785 | static void | |
2786 | device_resume_fn(struct scsi_device *sdev, void *data) | |
2787 | { | |
2788 | scsi_device_resume(sdev); | |
2789 | } | |
2790 | ||
2791 | void | |
2792 | scsi_target_resume(struct scsi_target *starget) | |
2793 | { | |
2794 | starget_for_each_device(starget, NULL, device_resume_fn); | |
2795 | } | |
2796 | EXPORT_SYMBOL(scsi_target_resume); | |
2797 | ||
2798 | /** | |
eb44820c | 2799 | * scsi_internal_device_block - internal function to put a device temporarily into the SDEV_BLOCK state |
1da177e4 LT |
2800 | * @sdev: device to block |
2801 | * | |
2802 | * Block request made by scsi lld's to temporarily stop all | |
2803 | * scsi commands on the specified device. Called from interrupt | |
2804 | * or normal process context. | |
2805 | * | |
2806 | * Returns zero if successful or error if not | |
2807 | * | |
2808 | * Notes: | |
2809 | * This routine transitions the device to the SDEV_BLOCK state | |
2810 | * (which must be a legal transition). When the device is in this | |
2811 | * state, all commands are deferred until the scsi lld reenables | |
2812 | * the device with scsi_device_unblock or device_block_tmo fires. | |
eb44820c | 2813 | */ |
1da177e4 LT |
2814 | int |
2815 | scsi_internal_device_block(struct scsi_device *sdev) | |
2816 | { | |
165125e1 | 2817 | struct request_queue *q = sdev->request_queue; |
1da177e4 LT |
2818 | unsigned long flags; |
2819 | int err = 0; | |
2820 | ||
2821 | err = scsi_device_set_state(sdev, SDEV_BLOCK); | |
6f4267e3 JB |
2822 | if (err) { |
2823 | err = scsi_device_set_state(sdev, SDEV_CREATED_BLOCK); | |
2824 | ||
2825 | if (err) | |
2826 | return err; | |
2827 | } | |
1da177e4 LT |
2828 | |
2829 | /* | |
2830 | * The device has transitioned to SDEV_BLOCK. Stop the | |
2831 | * block layer from calling the midlayer with this device's | |
2832 | * request queue. | |
2833 | */ | |
d285203c CH |
2834 | if (q->mq_ops) { |
2835 | blk_mq_stop_hw_queues(q); | |
2836 | } else { | |
2837 | spin_lock_irqsave(q->queue_lock, flags); | |
2838 | blk_stop_queue(q); | |
2839 | spin_unlock_irqrestore(q->queue_lock, flags); | |
2840 | } | |
1da177e4 LT |
2841 | |
2842 | return 0; | |
2843 | } | |
2844 | EXPORT_SYMBOL_GPL(scsi_internal_device_block); | |
2845 | ||
2846 | /** | |
2847 | * scsi_internal_device_unblock - resume a device after a block request | |
2848 | * @sdev: device to resume | |
5d9fb5cc | 2849 | * @new_state: state to set devices to after unblocking |
1da177e4 LT |
2850 | * |
2851 | * Called by scsi lld's or the midlayer to restart the device queue | |
2852 | * for the previously suspended scsi device. Called from interrupt or | |
2853 | * normal process context. | |
2854 | * | |
2855 | * Returns zero if successful or error if not. | |
2856 | * | |
2857 | * Notes: | |
2858 | * This routine transitions the device to the SDEV_RUNNING state | |
5d9fb5cc | 2859 | * or to one of the offline states (which must be a legal transition) |
d075498c | 2860 | * allowing the midlayer to goose the queue for this device. |
eb44820c | 2861 | */ |
1da177e4 | 2862 | int |
5d9fb5cc MC |
2863 | scsi_internal_device_unblock(struct scsi_device *sdev, |
2864 | enum scsi_device_state new_state) | |
1da177e4 | 2865 | { |
165125e1 | 2866 | struct request_queue *q = sdev->request_queue; |
1da177e4 | 2867 | unsigned long flags; |
5d9fb5cc MC |
2868 | |
2869 | /* | |
2870 | * Try to transition the scsi device to SDEV_RUNNING or one of the | |
2871 | * offlined states and goose the device queue if successful. | |
1da177e4 | 2872 | */ |
0e58076b VC |
2873 | if ((sdev->sdev_state == SDEV_BLOCK) || |
2874 | (sdev->sdev_state == SDEV_TRANSPORT_OFFLINE)) | |
5d9fb5cc MC |
2875 | sdev->sdev_state = new_state; |
2876 | else if (sdev->sdev_state == SDEV_CREATED_BLOCK) { | |
2877 | if (new_state == SDEV_TRANSPORT_OFFLINE || | |
2878 | new_state == SDEV_OFFLINE) | |
2879 | sdev->sdev_state = new_state; | |
2880 | else | |
2881 | sdev->sdev_state = SDEV_CREATED; | |
2882 | } else if (sdev->sdev_state != SDEV_CANCEL && | |
986fe6c7 | 2883 | sdev->sdev_state != SDEV_OFFLINE) |
5c10e63c | 2884 | return -EINVAL; |
1da177e4 | 2885 | |
d285203c CH |
2886 | if (q->mq_ops) { |
2887 | blk_mq_start_stopped_hw_queues(q, false); | |
2888 | } else { | |
2889 | spin_lock_irqsave(q->queue_lock, flags); | |
2890 | blk_start_queue(q); | |
2891 | spin_unlock_irqrestore(q->queue_lock, flags); | |
2892 | } | |
1da177e4 LT |
2893 | |
2894 | return 0; | |
2895 | } | |
2896 | EXPORT_SYMBOL_GPL(scsi_internal_device_unblock); | |
2897 | ||
2898 | static void | |
2899 | device_block(struct scsi_device *sdev, void *data) | |
2900 | { | |
2901 | scsi_internal_device_block(sdev); | |
2902 | } | |
2903 | ||
2904 | static int | |
2905 | target_block(struct device *dev, void *data) | |
2906 | { | |
2907 | if (scsi_is_target_device(dev)) | |
2908 | starget_for_each_device(to_scsi_target(dev), NULL, | |
2909 | device_block); | |
2910 | return 0; | |
2911 | } | |
2912 | ||
2913 | void | |
2914 | scsi_target_block(struct device *dev) | |
2915 | { | |
2916 | if (scsi_is_target_device(dev)) | |
2917 | starget_for_each_device(to_scsi_target(dev), NULL, | |
2918 | device_block); | |
2919 | else | |
2920 | device_for_each_child(dev, NULL, target_block); | |
2921 | } | |
2922 | EXPORT_SYMBOL_GPL(scsi_target_block); | |
2923 | ||
2924 | static void | |
2925 | device_unblock(struct scsi_device *sdev, void *data) | |
2926 | { | |
5d9fb5cc | 2927 | scsi_internal_device_unblock(sdev, *(enum scsi_device_state *)data); |
1da177e4 LT |
2928 | } |
2929 | ||
2930 | static int | |
2931 | target_unblock(struct device *dev, void *data) | |
2932 | { | |
2933 | if (scsi_is_target_device(dev)) | |
5d9fb5cc | 2934 | starget_for_each_device(to_scsi_target(dev), data, |
1da177e4 LT |
2935 | device_unblock); |
2936 | return 0; | |
2937 | } | |
2938 | ||
2939 | void | |
5d9fb5cc | 2940 | scsi_target_unblock(struct device *dev, enum scsi_device_state new_state) |
1da177e4 LT |
2941 | { |
2942 | if (scsi_is_target_device(dev)) | |
5d9fb5cc | 2943 | starget_for_each_device(to_scsi_target(dev), &new_state, |
1da177e4 LT |
2944 | device_unblock); |
2945 | else | |
5d9fb5cc | 2946 | device_for_each_child(dev, &new_state, target_unblock); |
1da177e4 LT |
2947 | } |
2948 | EXPORT_SYMBOL_GPL(scsi_target_unblock); | |
cdb8c2a6 GL |
2949 | |
2950 | /** | |
2951 | * scsi_kmap_atomic_sg - find and atomically map an sg-elemnt | |
eb44820c | 2952 | * @sgl: scatter-gather list |
cdb8c2a6 GL |
2953 | * @sg_count: number of segments in sg |
2954 | * @offset: offset in bytes into sg, on return offset into the mapped area | |
2955 | * @len: bytes to map, on return number of bytes mapped | |
2956 | * | |
2957 | * Returns virtual address of the start of the mapped page | |
2958 | */ | |
c6132da1 | 2959 | void *scsi_kmap_atomic_sg(struct scatterlist *sgl, int sg_count, |
cdb8c2a6 GL |
2960 | size_t *offset, size_t *len) |
2961 | { | |
2962 | int i; | |
2963 | size_t sg_len = 0, len_complete = 0; | |
c6132da1 | 2964 | struct scatterlist *sg; |
cdb8c2a6 GL |
2965 | struct page *page; |
2966 | ||
22cfefb5 AM |
2967 | WARN_ON(!irqs_disabled()); |
2968 | ||
c6132da1 | 2969 | for_each_sg(sgl, sg, sg_count, i) { |
cdb8c2a6 | 2970 | len_complete = sg_len; /* Complete sg-entries */ |
c6132da1 | 2971 | sg_len += sg->length; |
cdb8c2a6 GL |
2972 | if (sg_len > *offset) |
2973 | break; | |
2974 | } | |
2975 | ||
2976 | if (unlikely(i == sg_count)) { | |
169e1a2a AM |
2977 | printk(KERN_ERR "%s: Bytes in sg: %zu, requested offset %zu, " |
2978 | "elements %d\n", | |
cadbd4a5 | 2979 | __func__, sg_len, *offset, sg_count); |
cdb8c2a6 GL |
2980 | WARN_ON(1); |
2981 | return NULL; | |
2982 | } | |
2983 | ||
2984 | /* Offset starting from the beginning of first page in this sg-entry */ | |
c6132da1 | 2985 | *offset = *offset - len_complete + sg->offset; |
cdb8c2a6 GL |
2986 | |
2987 | /* Assumption: contiguous pages can be accessed as "page + i" */ | |
45711f1a | 2988 | page = nth_page(sg_page(sg), (*offset >> PAGE_SHIFT)); |
cdb8c2a6 GL |
2989 | *offset &= ~PAGE_MASK; |
2990 | ||
2991 | /* Bytes in this sg-entry from *offset to the end of the page */ | |
2992 | sg_len = PAGE_SIZE - *offset; | |
2993 | if (*len > sg_len) | |
2994 | *len = sg_len; | |
2995 | ||
77dfce07 | 2996 | return kmap_atomic(page); |
cdb8c2a6 GL |
2997 | } |
2998 | EXPORT_SYMBOL(scsi_kmap_atomic_sg); | |
2999 | ||
3000 | /** | |
eb44820c | 3001 | * scsi_kunmap_atomic_sg - atomically unmap a virtual address, previously mapped with scsi_kmap_atomic_sg |
cdb8c2a6 GL |
3002 | * @virt: virtual address to be unmapped |
3003 | */ | |
3004 | void scsi_kunmap_atomic_sg(void *virt) | |
3005 | { | |
77dfce07 | 3006 | kunmap_atomic(virt); |
cdb8c2a6 GL |
3007 | } |
3008 | EXPORT_SYMBOL(scsi_kunmap_atomic_sg); | |
6f4c827e AL |
3009 | |
3010 | void sdev_disable_disk_events(struct scsi_device *sdev) | |
3011 | { | |
3012 | atomic_inc(&sdev->disk_events_disable_depth); | |
3013 | } | |
3014 | EXPORT_SYMBOL(sdev_disable_disk_events); | |
3015 | ||
3016 | void sdev_enable_disk_events(struct scsi_device *sdev) | |
3017 | { | |
3018 | if (WARN_ON_ONCE(atomic_read(&sdev->disk_events_disable_depth) <= 0)) | |
3019 | return; | |
3020 | atomic_dec(&sdev->disk_events_disable_depth); | |
3021 | } | |
3022 | EXPORT_SYMBOL(sdev_enable_disk_events); |