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> |
f1569ff1 | 25 | #include <linux/ratelimit.h> |
1da177e4 LT |
26 | |
27 | #include <scsi/scsi.h> | |
beb40487 | 28 | #include <scsi/scsi_cmnd.h> |
1da177e4 LT |
29 | #include <scsi/scsi_dbg.h> |
30 | #include <scsi/scsi_device.h> | |
31 | #include <scsi/scsi_driver.h> | |
32 | #include <scsi/scsi_eh.h> | |
33 | #include <scsi/scsi_host.h> | |
ee14c674 | 34 | #include <scsi/scsi_dh.h> |
1da177e4 | 35 | |
3b5382c4 CH |
36 | #include <trace/events/scsi.h> |
37 | ||
1da177e4 LT |
38 | #include "scsi_priv.h" |
39 | #include "scsi_logging.h" | |
40 | ||
41 | ||
6391a113 | 42 | #define SG_MEMPOOL_NR ARRAY_SIZE(scsi_sg_pools) |
5972511b | 43 | #define SG_MEMPOOL_SIZE 2 |
1da177e4 LT |
44 | |
45 | struct scsi_host_sg_pool { | |
46 | size_t size; | |
a8474ce2 | 47 | char *name; |
e18b890b | 48 | struct kmem_cache *slab; |
1da177e4 LT |
49 | mempool_t *pool; |
50 | }; | |
51 | ||
037e6d86 | 52 | #define SP(x) { .size = x, "sgpool-" __stringify(x) } |
d3f46f39 JB |
53 | #if (SCSI_MAX_SG_SEGMENTS < 32) |
54 | #error SCSI_MAX_SG_SEGMENTS is too small (must be 32 or greater) | |
55 | #endif | |
52c1da39 | 56 | static struct scsi_host_sg_pool scsi_sg_pools[] = { |
1da177e4 LT |
57 | SP(8), |
58 | SP(16), | |
fd820f40 | 59 | #if (SCSI_MAX_SG_SEGMENTS > 32) |
d3f46f39 | 60 | SP(32), |
fd820f40 | 61 | #if (SCSI_MAX_SG_SEGMENTS > 64) |
d3f46f39 JB |
62 | SP(64), |
63 | #if (SCSI_MAX_SG_SEGMENTS > 128) | |
1da177e4 | 64 | SP(128), |
d3f46f39 JB |
65 | #if (SCSI_MAX_SG_SEGMENTS > 256) |
66 | #error SCSI_MAX_SG_SEGMENTS is too large (256 MAX) | |
fd820f40 FT |
67 | #endif |
68 | #endif | |
69 | #endif | |
d3f46f39 JB |
70 | #endif |
71 | SP(SCSI_MAX_SG_SEGMENTS) | |
a8474ce2 | 72 | }; |
1da177e4 LT |
73 | #undef SP |
74 | ||
7027ad72 | 75 | struct kmem_cache *scsi_sdb_cache; |
6f9a35e2 | 76 | |
a488e749 JA |
77 | /* |
78 | * When to reinvoke queueing after a resource shortage. It's 3 msecs to | |
79 | * not change behaviour from the previous unplug mechanism, experimentation | |
80 | * may prove this needs changing. | |
81 | */ | |
82 | #define SCSI_QUEUE_DELAY 3 | |
83 | ||
de3e8bf3 CH |
84 | static void |
85 | scsi_set_blocked(struct scsi_cmnd *cmd, int reason) | |
1da177e4 LT |
86 | { |
87 | struct Scsi_Host *host = cmd->device->host; | |
88 | struct scsi_device *device = cmd->device; | |
f0c0a376 | 89 | struct scsi_target *starget = scsi_target(device); |
1da177e4 LT |
90 | |
91 | /* | |
d8c37e7b | 92 | * Set the appropriate busy bit for the device/host. |
1da177e4 LT |
93 | * |
94 | * If the host/device isn't busy, assume that something actually | |
95 | * completed, and that we should be able to queue a command now. | |
96 | * | |
97 | * Note that the prior mid-layer assumption that any host could | |
98 | * always queue at least one command is now broken. The mid-layer | |
99 | * will implement a user specifiable stall (see | |
100 | * scsi_host.max_host_blocked and scsi_device.max_device_blocked) | |
101 | * if a command is requeued with no other commands outstanding | |
102 | * either for the device or for the host. | |
103 | */ | |
f0c0a376 MC |
104 | switch (reason) { |
105 | case SCSI_MLQUEUE_HOST_BUSY: | |
cd9070c9 | 106 | atomic_set(&host->host_blocked, host->max_host_blocked); |
f0c0a376 MC |
107 | break; |
108 | case SCSI_MLQUEUE_DEVICE_BUSY: | |
573e5913 | 109 | case SCSI_MLQUEUE_EH_RETRY: |
cd9070c9 CH |
110 | atomic_set(&device->device_blocked, |
111 | device->max_device_blocked); | |
f0c0a376 MC |
112 | break; |
113 | case SCSI_MLQUEUE_TARGET_BUSY: | |
cd9070c9 CH |
114 | atomic_set(&starget->target_blocked, |
115 | starget->max_target_blocked); | |
f0c0a376 MC |
116 | break; |
117 | } | |
de3e8bf3 CH |
118 | } |
119 | ||
d285203c CH |
120 | static void scsi_mq_requeue_cmd(struct scsi_cmnd *cmd) |
121 | { | |
122 | struct scsi_device *sdev = cmd->device; | |
123 | struct request_queue *q = cmd->request->q; | |
124 | ||
125 | blk_mq_requeue_request(cmd->request); | |
126 | blk_mq_kick_requeue_list(q); | |
127 | put_device(&sdev->sdev_gendev); | |
128 | } | |
129 | ||
de3e8bf3 CH |
130 | /** |
131 | * __scsi_queue_insert - private queue insertion | |
132 | * @cmd: The SCSI command being requeued | |
133 | * @reason: The reason for the requeue | |
134 | * @unbusy: Whether the queue should be unbusied | |
135 | * | |
136 | * This is a private queue insertion. The public interface | |
137 | * scsi_queue_insert() always assumes the queue should be unbusied | |
138 | * because it's always called before the completion. This function is | |
139 | * for a requeue after completion, which should only occur in this | |
140 | * file. | |
141 | */ | |
142 | static void __scsi_queue_insert(struct scsi_cmnd *cmd, int reason, int unbusy) | |
143 | { | |
144 | struct scsi_device *device = cmd->device; | |
145 | struct request_queue *q = device->request_queue; | |
146 | unsigned long flags; | |
147 | ||
148 | SCSI_LOG_MLQUEUE(1, scmd_printk(KERN_INFO, cmd, | |
149 | "Inserting command %p into mlqueue\n", cmd)); | |
150 | ||
151 | scsi_set_blocked(cmd, reason); | |
1da177e4 | 152 | |
1da177e4 LT |
153 | /* |
154 | * Decrement the counters, since these commands are no longer | |
155 | * active on the host/device. | |
156 | */ | |
4f5299ac JB |
157 | if (unbusy) |
158 | scsi_device_unbusy(device); | |
1da177e4 LT |
159 | |
160 | /* | |
a1bf9d1d | 161 | * Requeue this command. It will go before all other commands |
b485462a BVA |
162 | * that are already in the queue. Schedule requeue work under |
163 | * lock such that the kblockd_schedule_work() call happens | |
164 | * before blk_cleanup_queue() finishes. | |
a488e749 | 165 | */ |
644373a4 | 166 | cmd->result = 0; |
d285203c CH |
167 | if (q->mq_ops) { |
168 | scsi_mq_requeue_cmd(cmd); | |
169 | return; | |
170 | } | |
a1bf9d1d | 171 | spin_lock_irqsave(q->queue_lock, flags); |
59897dad | 172 | blk_requeue_request(q, cmd->request); |
59c3d45e | 173 | kblockd_schedule_work(&device->requeue_work); |
b485462a | 174 | spin_unlock_irqrestore(q->queue_lock, flags); |
1da177e4 LT |
175 | } |
176 | ||
4f5299ac JB |
177 | /* |
178 | * Function: scsi_queue_insert() | |
179 | * | |
180 | * Purpose: Insert a command in the midlevel queue. | |
181 | * | |
182 | * Arguments: cmd - command that we are adding to queue. | |
183 | * reason - why we are inserting command to queue. | |
184 | * | |
185 | * Lock status: Assumed that lock is not held upon entry. | |
186 | * | |
187 | * Returns: Nothing. | |
188 | * | |
189 | * Notes: We do this for one of two cases. Either the host is busy | |
190 | * and it cannot accept any more commands for the time being, | |
191 | * or the device returned QUEUE_FULL and can accept no more | |
192 | * commands. | |
193 | * Notes: This could be called either from an interrupt context or a | |
194 | * normal process context. | |
195 | */ | |
84feb166 | 196 | void scsi_queue_insert(struct scsi_cmnd *cmd, int reason) |
4f5299ac | 197 | { |
84feb166 | 198 | __scsi_queue_insert(cmd, reason, 1); |
4f5299ac | 199 | } |
39216033 | 200 | /** |
33aa687d | 201 | * scsi_execute - insert request and wait for the result |
39216033 JB |
202 | * @sdev: scsi device |
203 | * @cmd: scsi command | |
204 | * @data_direction: data direction | |
205 | * @buffer: data buffer | |
206 | * @bufflen: len of buffer | |
207 | * @sense: optional sense buffer | |
208 | * @timeout: request timeout in seconds | |
209 | * @retries: number of times to retry request | |
33aa687d | 210 | * @flags: or into request flags; |
f4f4e47e | 211 | * @resid: optional residual length |
39216033 | 212 | * |
59c51591 | 213 | * returns the req->errors value which is the scsi_cmnd result |
ea73a9f2 | 214 | * field. |
eb44820c | 215 | */ |
33aa687d JB |
216 | int scsi_execute(struct scsi_device *sdev, const unsigned char *cmd, |
217 | int data_direction, void *buffer, unsigned bufflen, | |
2bfad21e | 218 | unsigned char *sense, int timeout, int retries, u64 flags, |
f4f4e47e | 219 | int *resid) |
39216033 JB |
220 | { |
221 | struct request *req; | |
222 | int write = (data_direction == DMA_TO_DEVICE); | |
223 | int ret = DRIVER_ERROR << 24; | |
224 | ||
71baba4b | 225 | req = blk_get_request(sdev->request_queue, write, __GFP_RECLAIM); |
a492f075 | 226 | if (IS_ERR(req)) |
bfe159a5 | 227 | return ret; |
f27b087b | 228 | blk_rq_set_block_pc(req); |
39216033 JB |
229 | |
230 | if (bufflen && blk_rq_map_kern(sdev->request_queue, req, | |
71baba4b | 231 | buffer, bufflen, __GFP_RECLAIM)) |
39216033 JB |
232 | goto out; |
233 | ||
234 | req->cmd_len = COMMAND_SIZE(cmd[0]); | |
235 | memcpy(req->cmd, cmd, req->cmd_len); | |
236 | req->sense = sense; | |
237 | req->sense_len = 0; | |
17e01f21 | 238 | req->retries = retries; |
39216033 | 239 | req->timeout = timeout; |
4aff5e23 | 240 | req->cmd_flags |= flags | REQ_QUIET | REQ_PREEMPT; |
39216033 JB |
241 | |
242 | /* | |
243 | * head injection *required* here otherwise quiesce won't work | |
244 | */ | |
245 | blk_execute_rq(req->q, NULL, req, 1); | |
246 | ||
bdb2b8ca AS |
247 | /* |
248 | * Some devices (USB mass-storage in particular) may transfer | |
249 | * garbage data together with a residue indicating that the data | |
250 | * is invalid. Prevent the garbage from being misinterpreted | |
251 | * and prevent security leaks by zeroing out the excess data. | |
252 | */ | |
c3a4d78c TH |
253 | if (unlikely(req->resid_len > 0 && req->resid_len <= bufflen)) |
254 | memset(buffer + (bufflen - req->resid_len), 0, req->resid_len); | |
bdb2b8ca | 255 | |
f4f4e47e | 256 | if (resid) |
c3a4d78c | 257 | *resid = req->resid_len; |
39216033 JB |
258 | ret = req->errors; |
259 | out: | |
260 | blk_put_request(req); | |
261 | ||
262 | return ret; | |
263 | } | |
33aa687d | 264 | EXPORT_SYMBOL(scsi_execute); |
39216033 | 265 | |
9b21493c | 266 | int scsi_execute_req_flags(struct scsi_device *sdev, const unsigned char *cmd, |
ea73a9f2 | 267 | int data_direction, void *buffer, unsigned bufflen, |
f4f4e47e | 268 | struct scsi_sense_hdr *sshdr, int timeout, int retries, |
2bfad21e | 269 | int *resid, u64 flags) |
ea73a9f2 JB |
270 | { |
271 | char *sense = NULL; | |
1ccb48bb | 272 | int result; |
273 | ||
ea73a9f2 | 274 | if (sshdr) { |
24669f75 | 275 | sense = kzalloc(SCSI_SENSE_BUFFERSIZE, GFP_NOIO); |
ea73a9f2 JB |
276 | if (!sense) |
277 | return DRIVER_ERROR << 24; | |
ea73a9f2 | 278 | } |
1ccb48bb | 279 | result = scsi_execute(sdev, cmd, data_direction, buffer, bufflen, |
9b21493c | 280 | sense, timeout, retries, flags, resid); |
ea73a9f2 | 281 | if (sshdr) |
e514385b | 282 | scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE, sshdr); |
ea73a9f2 JB |
283 | |
284 | kfree(sense); | |
285 | return result; | |
286 | } | |
9b21493c | 287 | EXPORT_SYMBOL(scsi_execute_req_flags); |
ea73a9f2 | 288 | |
1da177e4 LT |
289 | /* |
290 | * Function: scsi_init_cmd_errh() | |
291 | * | |
292 | * Purpose: Initialize cmd fields related to error handling. | |
293 | * | |
294 | * Arguments: cmd - command that is ready to be queued. | |
295 | * | |
1da177e4 LT |
296 | * Notes: This function has the job of initializing a number of |
297 | * fields related to error handling. Typically this will | |
298 | * be called once for each command, as required. | |
299 | */ | |
631c228c | 300 | static void scsi_init_cmd_errh(struct scsi_cmnd *cmd) |
1da177e4 | 301 | { |
1da177e4 | 302 | cmd->serial_number = 0; |
30b0c37b | 303 | scsi_set_resid(cmd, 0); |
b80ca4f7 | 304 | memset(cmd->sense_buffer, 0, SCSI_SENSE_BUFFERSIZE); |
1da177e4 | 305 | if (cmd->cmd_len == 0) |
db4742dd | 306 | cmd->cmd_len = scsi_command_size(cmd->cmnd); |
1da177e4 LT |
307 | } |
308 | ||
309 | void scsi_device_unbusy(struct scsi_device *sdev) | |
310 | { | |
311 | struct Scsi_Host *shost = sdev->host; | |
f0c0a376 | 312 | struct scsi_target *starget = scsi_target(sdev); |
1da177e4 LT |
313 | unsigned long flags; |
314 | ||
74665016 | 315 | atomic_dec(&shost->host_busy); |
2ccbb008 CH |
316 | if (starget->can_queue > 0) |
317 | atomic_dec(&starget->target_busy); | |
74665016 | 318 | |
939647ee | 319 | if (unlikely(scsi_host_in_recovery(shost) && |
74665016 CH |
320 | (shost->host_failed || shost->host_eh_scheduled))) { |
321 | spin_lock_irqsave(shost->host_lock, flags); | |
1da177e4 | 322 | scsi_eh_wakeup(shost); |
74665016 CH |
323 | spin_unlock_irqrestore(shost->host_lock, flags); |
324 | } | |
325 | ||
71e75c97 | 326 | atomic_dec(&sdev->device_busy); |
1da177e4 LT |
327 | } |
328 | ||
d285203c CH |
329 | static void scsi_kick_queue(struct request_queue *q) |
330 | { | |
331 | if (q->mq_ops) | |
332 | blk_mq_start_hw_queues(q); | |
333 | else | |
334 | blk_run_queue(q); | |
335 | } | |
336 | ||
1da177e4 LT |
337 | /* |
338 | * Called for single_lun devices on IO completion. Clear starget_sdev_user, | |
339 | * and call blk_run_queue for all the scsi_devices on the target - | |
340 | * including current_sdev first. | |
341 | * | |
342 | * Called with *no* scsi locks held. | |
343 | */ | |
344 | static void scsi_single_lun_run(struct scsi_device *current_sdev) | |
345 | { | |
346 | struct Scsi_Host *shost = current_sdev->host; | |
347 | struct scsi_device *sdev, *tmp; | |
348 | struct scsi_target *starget = scsi_target(current_sdev); | |
349 | unsigned long flags; | |
350 | ||
351 | spin_lock_irqsave(shost->host_lock, flags); | |
352 | starget->starget_sdev_user = NULL; | |
353 | spin_unlock_irqrestore(shost->host_lock, flags); | |
354 | ||
355 | /* | |
356 | * Call blk_run_queue for all LUNs on the target, starting with | |
357 | * current_sdev. We race with others (to set starget_sdev_user), | |
358 | * but in most cases, we will be first. Ideally, each LU on the | |
359 | * target would get some limited time or requests on the target. | |
360 | */ | |
d285203c | 361 | scsi_kick_queue(current_sdev->request_queue); |
1da177e4 LT |
362 | |
363 | spin_lock_irqsave(shost->host_lock, flags); | |
364 | if (starget->starget_sdev_user) | |
365 | goto out; | |
366 | list_for_each_entry_safe(sdev, tmp, &starget->devices, | |
367 | same_target_siblings) { | |
368 | if (sdev == current_sdev) | |
369 | continue; | |
370 | if (scsi_device_get(sdev)) | |
371 | continue; | |
372 | ||
373 | spin_unlock_irqrestore(shost->host_lock, flags); | |
d285203c | 374 | scsi_kick_queue(sdev->request_queue); |
1da177e4 LT |
375 | spin_lock_irqsave(shost->host_lock, flags); |
376 | ||
377 | scsi_device_put(sdev); | |
378 | } | |
379 | out: | |
380 | spin_unlock_irqrestore(shost->host_lock, flags); | |
381 | } | |
382 | ||
cd9070c9 | 383 | static inline bool scsi_device_is_busy(struct scsi_device *sdev) |
9d112517 | 384 | { |
cd9070c9 CH |
385 | if (atomic_read(&sdev->device_busy) >= sdev->queue_depth) |
386 | return true; | |
387 | if (atomic_read(&sdev->device_blocked) > 0) | |
388 | return true; | |
389 | return false; | |
9d112517 KU |
390 | } |
391 | ||
cd9070c9 | 392 | static inline bool scsi_target_is_busy(struct scsi_target *starget) |
f0c0a376 | 393 | { |
2ccbb008 CH |
394 | if (starget->can_queue > 0) { |
395 | if (atomic_read(&starget->target_busy) >= starget->can_queue) | |
396 | return true; | |
397 | if (atomic_read(&starget->target_blocked) > 0) | |
398 | return true; | |
399 | } | |
cd9070c9 | 400 | return false; |
f0c0a376 MC |
401 | } |
402 | ||
cd9070c9 | 403 | static inline bool scsi_host_is_busy(struct Scsi_Host *shost) |
9d112517 | 404 | { |
cd9070c9 CH |
405 | if (shost->can_queue > 0 && |
406 | atomic_read(&shost->host_busy) >= shost->can_queue) | |
407 | return true; | |
408 | if (atomic_read(&shost->host_blocked) > 0) | |
409 | return true; | |
410 | if (shost->host_self_blocked) | |
411 | return true; | |
412 | return false; | |
9d112517 KU |
413 | } |
414 | ||
21a05df5 | 415 | static void scsi_starved_list_run(struct Scsi_Host *shost) |
1da177e4 | 416 | { |
2a3a59e5 | 417 | LIST_HEAD(starved_list); |
21a05df5 | 418 | struct scsi_device *sdev; |
1da177e4 LT |
419 | unsigned long flags; |
420 | ||
1da177e4 | 421 | spin_lock_irqsave(shost->host_lock, flags); |
2a3a59e5 MC |
422 | list_splice_init(&shost->starved_list, &starved_list); |
423 | ||
424 | while (!list_empty(&starved_list)) { | |
e2eb7244 JB |
425 | struct request_queue *slq; |
426 | ||
1da177e4 LT |
427 | /* |
428 | * As long as shost is accepting commands and we have | |
429 | * starved queues, call blk_run_queue. scsi_request_fn | |
430 | * drops the queue_lock and can add us back to the | |
431 | * starved_list. | |
432 | * | |
433 | * host_lock protects the starved_list and starved_entry. | |
434 | * scsi_request_fn must get the host_lock before checking | |
435 | * or modifying starved_list or starved_entry. | |
436 | */ | |
2a3a59e5 | 437 | if (scsi_host_is_busy(shost)) |
f0c0a376 | 438 | break; |
f0c0a376 | 439 | |
2a3a59e5 MC |
440 | sdev = list_entry(starved_list.next, |
441 | struct scsi_device, starved_entry); | |
442 | list_del_init(&sdev->starved_entry); | |
f0c0a376 MC |
443 | if (scsi_target_is_busy(scsi_target(sdev))) { |
444 | list_move_tail(&sdev->starved_entry, | |
445 | &shost->starved_list); | |
446 | continue; | |
447 | } | |
448 | ||
e2eb7244 JB |
449 | /* |
450 | * Once we drop the host lock, a racing scsi_remove_device() | |
451 | * call may remove the sdev from the starved list and destroy | |
452 | * it and the queue. Mitigate by taking a reference to the | |
453 | * queue and never touching the sdev again after we drop the | |
454 | * host lock. Note: if __scsi_remove_device() invokes | |
455 | * blk_cleanup_queue() before the queue is run from this | |
456 | * function then blk_run_queue() will return immediately since | |
457 | * blk_cleanup_queue() marks the queue with QUEUE_FLAG_DYING. | |
458 | */ | |
459 | slq = sdev->request_queue; | |
460 | if (!blk_get_queue(slq)) | |
461 | continue; | |
462 | spin_unlock_irqrestore(shost->host_lock, flags); | |
463 | ||
d285203c | 464 | scsi_kick_queue(slq); |
e2eb7244 JB |
465 | blk_put_queue(slq); |
466 | ||
467 | spin_lock_irqsave(shost->host_lock, flags); | |
1da177e4 | 468 | } |
2a3a59e5 MC |
469 | /* put any unprocessed entries back */ |
470 | list_splice(&starved_list, &shost->starved_list); | |
1da177e4 | 471 | spin_unlock_irqrestore(shost->host_lock, flags); |
21a05df5 CH |
472 | } |
473 | ||
474 | /* | |
475 | * Function: scsi_run_queue() | |
476 | * | |
477 | * Purpose: Select a proper request queue to serve next | |
478 | * | |
479 | * Arguments: q - last request's queue | |
480 | * | |
481 | * Returns: Nothing | |
482 | * | |
483 | * Notes: The previous command was completely finished, start | |
484 | * a new one if possible. | |
485 | */ | |
486 | static void scsi_run_queue(struct request_queue *q) | |
487 | { | |
488 | struct scsi_device *sdev = q->queuedata; | |
489 | ||
490 | if (scsi_target(sdev)->single_lun) | |
491 | scsi_single_lun_run(sdev); | |
492 | if (!list_empty(&sdev->host->starved_list)) | |
493 | scsi_starved_list_run(sdev->host); | |
1da177e4 | 494 | |
d285203c CH |
495 | if (q->mq_ops) |
496 | blk_mq_start_stopped_hw_queues(q, false); | |
497 | else | |
498 | blk_run_queue(q); | |
1da177e4 LT |
499 | } |
500 | ||
9937a5e2 JA |
501 | void scsi_requeue_run_queue(struct work_struct *work) |
502 | { | |
503 | struct scsi_device *sdev; | |
504 | struct request_queue *q; | |
505 | ||
506 | sdev = container_of(work, struct scsi_device, requeue_work); | |
507 | q = sdev->request_queue; | |
508 | scsi_run_queue(q); | |
509 | } | |
510 | ||
1da177e4 LT |
511 | /* |
512 | * Function: scsi_requeue_command() | |
513 | * | |
514 | * Purpose: Handle post-processing of completed commands. | |
515 | * | |
516 | * Arguments: q - queue to operate on | |
517 | * cmd - command that may need to be requeued. | |
518 | * | |
519 | * Returns: Nothing | |
520 | * | |
521 | * Notes: After command completion, there may be blocks left | |
522 | * over which weren't finished by the previous command | |
523 | * this can be for a number of reasons - the main one is | |
524 | * I/O errors in the middle of the request, in which case | |
525 | * we need to request the blocks that come after the bad | |
526 | * sector. | |
e91442b6 | 527 | * Notes: Upon return, cmd is a stale pointer. |
1da177e4 LT |
528 | */ |
529 | static void scsi_requeue_command(struct request_queue *q, struct scsi_cmnd *cmd) | |
530 | { | |
940f5d47 | 531 | struct scsi_device *sdev = cmd->device; |
e91442b6 | 532 | struct request *req = cmd->request; |
283369cc TH |
533 | unsigned long flags; |
534 | ||
283369cc | 535 | spin_lock_irqsave(q->queue_lock, flags); |
134997a0 CH |
536 | blk_unprep_request(req); |
537 | req->special = NULL; | |
538 | scsi_put_command(cmd); | |
e91442b6 | 539 | blk_requeue_request(q, req); |
283369cc | 540 | spin_unlock_irqrestore(q->queue_lock, flags); |
1da177e4 LT |
541 | |
542 | scsi_run_queue(q); | |
940f5d47 BVA |
543 | |
544 | put_device(&sdev->sdev_gendev); | |
1da177e4 LT |
545 | } |
546 | ||
1da177e4 LT |
547 | void scsi_run_host_queues(struct Scsi_Host *shost) |
548 | { | |
549 | struct scsi_device *sdev; | |
550 | ||
551 | shost_for_each_device(sdev, shost) | |
552 | scsi_run_queue(sdev->request_queue); | |
553 | } | |
554 | ||
a8474ce2 JA |
555 | static inline unsigned int scsi_sgtable_index(unsigned short nents) |
556 | { | |
557 | unsigned int index; | |
558 | ||
d3f46f39 JB |
559 | BUG_ON(nents > SCSI_MAX_SG_SEGMENTS); |
560 | ||
561 | if (nents <= 8) | |
a8474ce2 | 562 | index = 0; |
d3f46f39 JB |
563 | else |
564 | index = get_count_order(nents) - 3; | |
1da177e4 | 565 | |
a8474ce2 JA |
566 | return index; |
567 | } | |
568 | ||
5ed7959e | 569 | static void scsi_sg_free(struct scatterlist *sgl, unsigned int nents) |
a8474ce2 JA |
570 | { |
571 | struct scsi_host_sg_pool *sgp; | |
a8474ce2 | 572 | |
5ed7959e JA |
573 | sgp = scsi_sg_pools + scsi_sgtable_index(nents); |
574 | mempool_free(sgl, sgp->pool); | |
575 | } | |
a8474ce2 | 576 | |
5ed7959e JA |
577 | static struct scatterlist *scsi_sg_alloc(unsigned int nents, gfp_t gfp_mask) |
578 | { | |
579 | struct scsi_host_sg_pool *sgp; | |
a8474ce2 | 580 | |
5ed7959e JA |
581 | sgp = scsi_sg_pools + scsi_sgtable_index(nents); |
582 | return mempool_alloc(sgp->pool, gfp_mask); | |
583 | } | |
a3bec5c5 | 584 | |
d285203c | 585 | static void scsi_free_sgtable(struct scsi_data_buffer *sdb, bool mq) |
c53c6d6a | 586 | { |
0c958ecc | 587 | if (mq && sdb->table.orig_nents <= SCSI_MAX_SG_SEGMENTS) |
d285203c CH |
588 | return; |
589 | __sg_free_table(&sdb->table, SCSI_MAX_SG_SEGMENTS, mq, scsi_sg_free); | |
c53c6d6a CH |
590 | } |
591 | ||
3c356bde | 592 | static int scsi_alloc_sgtable(struct scsi_data_buffer *sdb, int nents, bool mq) |
5ed7959e | 593 | { |
d285203c | 594 | struct scatterlist *first_chunk = NULL; |
5ed7959e | 595 | int ret; |
a8474ce2 | 596 | |
30b0c37b | 597 | BUG_ON(!nents); |
a8474ce2 | 598 | |
d285203c CH |
599 | if (mq) { |
600 | if (nents <= SCSI_MAX_SG_SEGMENTS) { | |
0c958ecc TB |
601 | sdb->table.nents = sdb->table.orig_nents = nents; |
602 | sg_init_table(sdb->table.sgl, nents); | |
d285203c CH |
603 | return 0; |
604 | } | |
605 | first_chunk = sdb->table.sgl; | |
606 | } | |
607 | ||
30b0c37b | 608 | ret = __sg_alloc_table(&sdb->table, nents, SCSI_MAX_SG_SEGMENTS, |
70a0f2c1 | 609 | first_chunk, GFP_ATOMIC, scsi_sg_alloc); |
5ed7959e | 610 | if (unlikely(ret)) |
d285203c | 611 | scsi_free_sgtable(sdb, mq); |
a8474ce2 | 612 | return ret; |
1da177e4 LT |
613 | } |
614 | ||
d285203c CH |
615 | static void scsi_uninit_cmd(struct scsi_cmnd *cmd) |
616 | { | |
617 | if (cmd->request->cmd_type == REQ_TYPE_FS) { | |
618 | struct scsi_driver *drv = scsi_cmd_to_driver(cmd); | |
619 | ||
620 | if (drv->uninit_command) | |
621 | drv->uninit_command(cmd); | |
622 | } | |
623 | } | |
624 | ||
625 | static void scsi_mq_free_sgtables(struct scsi_cmnd *cmd) | |
626 | { | |
627 | if (cmd->sdb.table.nents) | |
628 | scsi_free_sgtable(&cmd->sdb, true); | |
629 | if (cmd->request->next_rq && cmd->request->next_rq->special) | |
630 | scsi_free_sgtable(cmd->request->next_rq->special, true); | |
631 | if (scsi_prot_sg_count(cmd)) | |
632 | scsi_free_sgtable(cmd->prot_sdb, true); | |
633 | } | |
634 | ||
635 | static void scsi_mq_uninit_cmd(struct scsi_cmnd *cmd) | |
636 | { | |
637 | struct scsi_device *sdev = cmd->device; | |
64bdcbc4 | 638 | struct Scsi_Host *shost = sdev->host; |
d285203c CH |
639 | unsigned long flags; |
640 | ||
d285203c CH |
641 | scsi_mq_free_sgtables(cmd); |
642 | scsi_uninit_cmd(cmd); | |
643 | ||
64bdcbc4 KD |
644 | if (shost->use_cmd_list) { |
645 | BUG_ON(list_empty(&cmd->list)); | |
646 | spin_lock_irqsave(&sdev->list_lock, flags); | |
647 | list_del_init(&cmd->list); | |
648 | spin_unlock_irqrestore(&sdev->list_lock, flags); | |
649 | } | |
d285203c CH |
650 | } |
651 | ||
1da177e4 LT |
652 | /* |
653 | * Function: scsi_release_buffers() | |
654 | * | |
c682adf3 | 655 | * Purpose: Free resources allocate for a scsi_command. |
1da177e4 LT |
656 | * |
657 | * Arguments: cmd - command that we are bailing. | |
658 | * | |
659 | * Lock status: Assumed that no lock is held upon entry. | |
660 | * | |
661 | * Returns: Nothing | |
662 | * | |
663 | * Notes: In the event that an upper level driver rejects a | |
664 | * command, we must release resources allocated during | |
665 | * the __init_io() function. Primarily this would involve | |
c682adf3 | 666 | * the scatter-gather table. |
1da177e4 | 667 | */ |
f1bea55d | 668 | static void scsi_release_buffers(struct scsi_cmnd *cmd) |
1da177e4 | 669 | { |
c682adf3 | 670 | if (cmd->sdb.table.nents) |
d285203c | 671 | scsi_free_sgtable(&cmd->sdb, false); |
c682adf3 CH |
672 | |
673 | memset(&cmd->sdb, 0, sizeof(cmd->sdb)); | |
674 | ||
675 | if (scsi_prot_sg_count(cmd)) | |
d285203c | 676 | scsi_free_sgtable(cmd->prot_sdb, false); |
1da177e4 LT |
677 | } |
678 | ||
c682adf3 CH |
679 | static void scsi_release_bidi_buffers(struct scsi_cmnd *cmd) |
680 | { | |
681 | struct scsi_data_buffer *bidi_sdb = cmd->request->next_rq->special; | |
682 | ||
d285203c | 683 | scsi_free_sgtable(bidi_sdb, false); |
c682adf3 CH |
684 | kmem_cache_free(scsi_sdb_cache, bidi_sdb); |
685 | cmd->request->next_rq->special = NULL; | |
686 | } | |
687 | ||
f6d47e74 CH |
688 | static bool scsi_end_request(struct request *req, int error, |
689 | unsigned int bytes, unsigned int bidi_bytes) | |
690 | { | |
691 | struct scsi_cmnd *cmd = req->special; | |
692 | struct scsi_device *sdev = cmd->device; | |
693 | struct request_queue *q = sdev->request_queue; | |
f6d47e74 CH |
694 | |
695 | if (blk_update_request(req, error, bytes)) | |
696 | return true; | |
697 | ||
698 | /* Bidi request must be completed as a whole */ | |
699 | if (unlikely(bidi_bytes) && | |
700 | blk_update_request(req->next_rq, error, bidi_bytes)) | |
701 | return true; | |
702 | ||
703 | if (blk_queue_add_random(q)) | |
704 | add_disk_randomness(req->rq_disk); | |
705 | ||
d285203c CH |
706 | if (req->mq_ctx) { |
707 | /* | |
c8a446ad | 708 | * In the MQ case the command gets freed by __blk_mq_end_request, |
d285203c CH |
709 | * so we have to do all cleanup that depends on it earlier. |
710 | * | |
711 | * We also can't kick the queues from irq context, so we | |
712 | * will have to defer it to a workqueue. | |
713 | */ | |
714 | scsi_mq_uninit_cmd(cmd); | |
715 | ||
c8a446ad | 716 | __blk_mq_end_request(req, error); |
d285203c CH |
717 | |
718 | if (scsi_target(sdev)->single_lun || | |
719 | !list_empty(&sdev->host->starved_list)) | |
720 | kblockd_schedule_work(&sdev->requeue_work); | |
721 | else | |
722 | blk_mq_start_stopped_hw_queues(q, true); | |
d285203c CH |
723 | } else { |
724 | unsigned long flags; | |
725 | ||
f81426a8 DG |
726 | if (bidi_bytes) |
727 | scsi_release_bidi_buffers(cmd); | |
728 | ||
d285203c CH |
729 | spin_lock_irqsave(q->queue_lock, flags); |
730 | blk_finish_request(req, error); | |
731 | spin_unlock_irqrestore(q->queue_lock, flags); | |
732 | ||
d285203c | 733 | scsi_release_buffers(cmd); |
bb3ec62a CH |
734 | |
735 | scsi_put_command(cmd); | |
736 | scsi_run_queue(q); | |
d285203c | 737 | } |
f6d47e74 | 738 | |
bb3ec62a | 739 | put_device(&sdev->sdev_gendev); |
f6d47e74 CH |
740 | return false; |
741 | } | |
742 | ||
0f7f6234 HR |
743 | /** |
744 | * __scsi_error_from_host_byte - translate SCSI error code into errno | |
745 | * @cmd: SCSI command (unused) | |
746 | * @result: scsi error code | |
747 | * | |
748 | * Translate SCSI error code into standard UNIX errno. | |
749 | * Return values: | |
750 | * -ENOLINK temporary transport failure | |
751 | * -EREMOTEIO permanent target failure, do not retry | |
752 | * -EBADE permanent nexus failure, retry on other path | |
a9d6ceb8 | 753 | * -ENOSPC No write space available |
7e782af5 | 754 | * -ENODATA Medium error |
0f7f6234 HR |
755 | * -EIO unspecified I/O error |
756 | */ | |
63583cca HR |
757 | static int __scsi_error_from_host_byte(struct scsi_cmnd *cmd, int result) |
758 | { | |
759 | int error = 0; | |
760 | ||
761 | switch(host_byte(result)) { | |
762 | case DID_TRANSPORT_FAILFAST: | |
763 | error = -ENOLINK; | |
764 | break; | |
765 | case DID_TARGET_FAILURE: | |
2082ebc4 | 766 | set_host_byte(cmd, DID_OK); |
63583cca HR |
767 | error = -EREMOTEIO; |
768 | break; | |
769 | case DID_NEXUS_FAILURE: | |
2082ebc4 | 770 | set_host_byte(cmd, DID_OK); |
63583cca HR |
771 | error = -EBADE; |
772 | break; | |
a9d6ceb8 HR |
773 | case DID_ALLOC_FAILURE: |
774 | set_host_byte(cmd, DID_OK); | |
775 | error = -ENOSPC; | |
776 | break; | |
7e782af5 HR |
777 | case DID_MEDIUM_ERROR: |
778 | set_host_byte(cmd, DID_OK); | |
779 | error = -ENODATA; | |
780 | break; | |
63583cca HR |
781 | default: |
782 | error = -EIO; | |
783 | break; | |
784 | } | |
785 | ||
786 | return error; | |
787 | } | |
788 | ||
1da177e4 LT |
789 | /* |
790 | * Function: scsi_io_completion() | |
791 | * | |
792 | * Purpose: Completion processing for block device I/O requests. | |
793 | * | |
794 | * Arguments: cmd - command that is finished. | |
795 | * | |
796 | * Lock status: Assumed that no lock is held upon entry. | |
797 | * | |
798 | * Returns: Nothing | |
799 | * | |
bc85dc50 CH |
800 | * Notes: We will finish off the specified number of sectors. If we |
801 | * are done, the command block will be released and the queue | |
802 | * function will be goosed. If we are not done then we have to | |
b60af5b0 | 803 | * figure out what to do next: |
1da177e4 | 804 | * |
b60af5b0 AS |
805 | * a) We can call scsi_requeue_command(). The request |
806 | * will be unprepared and put back on the queue. Then | |
807 | * a new command will be created for it. This should | |
808 | * be used if we made forward progress, or if we want | |
809 | * to switch from READ(10) to READ(6) for example. | |
1da177e4 | 810 | * |
bc85dc50 | 811 | * b) We can call __scsi_queue_insert(). The request will |
b60af5b0 AS |
812 | * be put back on the queue and retried using the same |
813 | * command as before, possibly after a delay. | |
814 | * | |
f6d47e74 | 815 | * c) We can call scsi_end_request() with -EIO to fail |
b60af5b0 | 816 | * the remainder of the request. |
1da177e4 | 817 | */ |
03aba2f7 | 818 | void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes) |
1da177e4 LT |
819 | { |
820 | int result = cmd->result; | |
165125e1 | 821 | struct request_queue *q = cmd->device->request_queue; |
1da177e4 | 822 | struct request *req = cmd->request; |
fa8e36c3 | 823 | int error = 0; |
1da177e4 | 824 | struct scsi_sense_hdr sshdr; |
4753cbc0 | 825 | bool sense_valid = false; |
c11c004b | 826 | int sense_deferred = 0, level = 0; |
b60af5b0 AS |
827 | enum {ACTION_FAIL, ACTION_REPREP, ACTION_RETRY, |
828 | ACTION_DELAYED_RETRY} action; | |
ee60b2c5 | 829 | unsigned long wait_for = (cmd->allowed + 1) * req->timeout; |
1da177e4 | 830 | |
1da177e4 LT |
831 | if (result) { |
832 | sense_valid = scsi_command_normalize_sense(cmd, &sshdr); | |
833 | if (sense_valid) | |
834 | sense_deferred = scsi_sense_is_deferred(&sshdr); | |
835 | } | |
631c228c | 836 | |
33659ebb | 837 | if (req->cmd_type == REQ_TYPE_BLOCK_PC) { /* SG_IO ioctl from block level */ |
1da177e4 | 838 | if (result) { |
1da177e4 LT |
839 | if (sense_valid && req->sense) { |
840 | /* | |
841 | * SG_IO wants current and deferred errors | |
842 | */ | |
843 | int len = 8 + cmd->sense_buffer[7]; | |
844 | ||
845 | if (len > SCSI_SENSE_BUFFERSIZE) | |
846 | len = SCSI_SENSE_BUFFERSIZE; | |
847 | memcpy(req->sense, cmd->sense_buffer, len); | |
848 | req->sense_len = len; | |
849 | } | |
fa8e36c3 | 850 | if (!sense_deferred) |
63583cca | 851 | error = __scsi_error_from_host_byte(cmd, result); |
b22f687d | 852 | } |
27c41973 MS |
853 | /* |
854 | * __scsi_error_from_host_byte may have reset the host_byte | |
855 | */ | |
856 | req->errors = cmd->result; | |
e6bb7a96 FT |
857 | |
858 | req->resid_len = scsi_get_resid(cmd); | |
859 | ||
6f9a35e2 | 860 | if (scsi_bidi_cmnd(cmd)) { |
e6bb7a96 FT |
861 | /* |
862 | * Bidi commands Must be complete as a whole, | |
863 | * both sides at once. | |
864 | */ | |
865 | req->next_rq->resid_len = scsi_in(cmd)->resid; | |
f6d47e74 CH |
866 | if (scsi_end_request(req, 0, blk_rq_bytes(req), |
867 | blk_rq_bytes(req->next_rq))) | |
868 | BUG(); | |
6f9a35e2 BH |
869 | return; |
870 | } | |
89fb4cd1 JB |
871 | } else if (blk_rq_bytes(req) == 0 && result && !sense_deferred) { |
872 | /* | |
873 | * Certain non BLOCK_PC requests are commands that don't | |
874 | * actually transfer anything (FLUSH), so cannot use | |
875 | * good_bytes != blk_rq_bytes(req) as the signal for an error. | |
876 | * This sets the error explicitly for the problem case. | |
877 | */ | |
878 | error = __scsi_error_from_host_byte(cmd, result); | |
1da177e4 LT |
879 | } |
880 | ||
33659ebb CH |
881 | /* no bidi support for !REQ_TYPE_BLOCK_PC yet */ |
882 | BUG_ON(blk_bidi_rq(req)); | |
30b0c37b | 883 | |
1da177e4 LT |
884 | /* |
885 | * Next deal with any sectors which we were able to correctly | |
886 | * handle. | |
887 | */ | |
91921e01 HR |
888 | SCSI_LOG_HLCOMPLETE(1, scmd_printk(KERN_INFO, cmd, |
889 | "%u sectors total, %d bytes done.\n", | |
890 | blk_rq_sectors(req), good_bytes)); | |
d6b0c537 | 891 | |
a9bddd74 JB |
892 | /* |
893 | * Recovered errors need reporting, but they're always treated | |
894 | * as success, so fiddle the result code here. For BLOCK_PC | |
895 | * we already took a copy of the original into rq->errors which | |
896 | * is what gets returned to the user | |
897 | */ | |
e7efe593 DG |
898 | if (sense_valid && (sshdr.sense_key == RECOVERED_ERROR)) { |
899 | /* if ATA PASS-THROUGH INFORMATION AVAILABLE skip | |
900 | * print since caller wants ATA registers. Only occurs on | |
901 | * SCSI ATA PASS_THROUGH commands when CK_COND=1 | |
902 | */ | |
903 | if ((sshdr.asc == 0x0) && (sshdr.ascq == 0x1d)) | |
904 | ; | |
905 | else if (!(req->cmd_flags & REQ_QUIET)) | |
d811b848 | 906 | scsi_print_sense(cmd); |
a9bddd74 JB |
907 | result = 0; |
908 | /* BLOCK_PC may have set error */ | |
909 | error = 0; | |
910 | } | |
911 | ||
912 | /* | |
0dec8c0d JB |
913 | * special case: failed zero length commands always need to |
914 | * drop down into the retry code. Otherwise, if we finished | |
915 | * all bytes in the request we are done now. | |
d6b0c537 | 916 | */ |
0dec8c0d JB |
917 | if (!(blk_rq_bytes(req) == 0 && error) && |
918 | !scsi_end_request(req, error, good_bytes, 0)) | |
f6d47e74 | 919 | return; |
bc85dc50 CH |
920 | |
921 | /* | |
922 | * Kill remainder if no retrys. | |
923 | */ | |
924 | if (error && scsi_noretry_cmd(cmd)) { | |
f6d47e74 CH |
925 | if (scsi_end_request(req, error, blk_rq_bytes(req), 0)) |
926 | BUG(); | |
927 | return; | |
bc85dc50 CH |
928 | } |
929 | ||
930 | /* | |
931 | * If there had been no error, but we have leftover bytes in the | |
932 | * requeues just queue the command up again. | |
d6b0c537 | 933 | */ |
bc85dc50 CH |
934 | if (result == 0) |
935 | goto requeue; | |
03aba2f7 | 936 | |
63583cca | 937 | error = __scsi_error_from_host_byte(cmd, result); |
3e695f89 | 938 | |
b60af5b0 AS |
939 | if (host_byte(result) == DID_RESET) { |
940 | /* Third party bus reset or reset for error recovery | |
941 | * reasons. Just retry the command and see what | |
942 | * happens. | |
943 | */ | |
944 | action = ACTION_RETRY; | |
945 | } else if (sense_valid && !sense_deferred) { | |
1da177e4 LT |
946 | switch (sshdr.sense_key) { |
947 | case UNIT_ATTENTION: | |
948 | if (cmd->device->removable) { | |
03aba2f7 | 949 | /* Detected disc change. Set a bit |
1da177e4 LT |
950 | * and quietly refuse further access. |
951 | */ | |
952 | cmd->device->changed = 1; | |
b60af5b0 | 953 | action = ACTION_FAIL; |
1da177e4 | 954 | } else { |
03aba2f7 LT |
955 | /* Must have been a power glitch, or a |
956 | * bus reset. Could not have been a | |
957 | * media change, so we just retry the | |
b60af5b0 | 958 | * command and see what happens. |
03aba2f7 | 959 | */ |
b60af5b0 | 960 | action = ACTION_RETRY; |
1da177e4 LT |
961 | } |
962 | break; | |
963 | case ILLEGAL_REQUEST: | |
03aba2f7 LT |
964 | /* If we had an ILLEGAL REQUEST returned, then |
965 | * we may have performed an unsupported | |
966 | * command. The only thing this should be | |
967 | * would be a ten byte read where only a six | |
968 | * byte read was supported. Also, on a system | |
969 | * where READ CAPACITY failed, we may have | |
970 | * read past the end of the disk. | |
971 | */ | |
26a68019 JA |
972 | if ((cmd->device->use_10_for_rw && |
973 | sshdr.asc == 0x20 && sshdr.ascq == 0x00) && | |
1da177e4 LT |
974 | (cmd->cmnd[0] == READ_10 || |
975 | cmd->cmnd[0] == WRITE_10)) { | |
b60af5b0 | 976 | /* This will issue a new 6-byte command. */ |
1da177e4 | 977 | cmd->device->use_10_for_rw = 0; |
b60af5b0 | 978 | action = ACTION_REPREP; |
3e695f89 | 979 | } else if (sshdr.asc == 0x10) /* DIX */ { |
3e695f89 MP |
980 | action = ACTION_FAIL; |
981 | error = -EILSEQ; | |
c98a0eb0 | 982 | /* INVALID COMMAND OPCODE or INVALID FIELD IN CDB */ |
5db44863 | 983 | } else if (sshdr.asc == 0x20 || sshdr.asc == 0x24) { |
c98a0eb0 | 984 | action = ACTION_FAIL; |
66a651aa | 985 | error = -EREMOTEIO; |
b60af5b0 AS |
986 | } else |
987 | action = ACTION_FAIL; | |
988 | break; | |
511e44f4 | 989 | case ABORTED_COMMAND: |
126c0982 | 990 | action = ACTION_FAIL; |
e6c11dbb | 991 | if (sshdr.asc == 0x10) /* DIF */ |
3e695f89 | 992 | error = -EILSEQ; |
1da177e4 LT |
993 | break; |
994 | case NOT_READY: | |
03aba2f7 | 995 | /* If the device is in the process of becoming |
f3e93f73 | 996 | * ready, or has a temporary blockage, retry. |
1da177e4 | 997 | */ |
f3e93f73 JB |
998 | if (sshdr.asc == 0x04) { |
999 | switch (sshdr.ascq) { | |
1000 | case 0x01: /* becoming ready */ | |
1001 | case 0x04: /* format in progress */ | |
1002 | case 0x05: /* rebuild in progress */ | |
1003 | case 0x06: /* recalculation in progress */ | |
1004 | case 0x07: /* operation in progress */ | |
1005 | case 0x08: /* Long write in progress */ | |
1006 | case 0x09: /* self test in progress */ | |
d8705f11 | 1007 | case 0x14: /* space allocation in progress */ |
b60af5b0 | 1008 | action = ACTION_DELAYED_RETRY; |
f3e93f73 | 1009 | break; |
3dbf6a54 | 1010 | default: |
3dbf6a54 AS |
1011 | action = ACTION_FAIL; |
1012 | break; | |
f3e93f73 | 1013 | } |
e6c11dbb | 1014 | } else |
b60af5b0 | 1015 | action = ACTION_FAIL; |
b60af5b0 | 1016 | break; |
1da177e4 | 1017 | case VOLUME_OVERFLOW: |
03aba2f7 | 1018 | /* See SSC3rXX or current. */ |
b60af5b0 AS |
1019 | action = ACTION_FAIL; |
1020 | break; | |
1da177e4 | 1021 | default: |
b60af5b0 | 1022 | action = ACTION_FAIL; |
1da177e4 LT |
1023 | break; |
1024 | } | |
e6c11dbb | 1025 | } else |
b60af5b0 | 1026 | action = ACTION_FAIL; |
b60af5b0 | 1027 | |
ee60b2c5 | 1028 | if (action != ACTION_FAIL && |
e6c11dbb | 1029 | time_before(cmd->jiffies_at_alloc + wait_for, jiffies)) |
ee60b2c5 | 1030 | action = ACTION_FAIL; |
ee60b2c5 | 1031 | |
b60af5b0 AS |
1032 | switch (action) { |
1033 | case ACTION_FAIL: | |
1034 | /* Give up and fail the remainder of the request */ | |
f1569ff1 HR |
1035 | if (!(req->cmd_flags & REQ_QUIET)) { |
1036 | static DEFINE_RATELIMIT_STATE(_rs, | |
1037 | DEFAULT_RATELIMIT_INTERVAL, | |
1038 | DEFAULT_RATELIMIT_BURST); | |
1039 | ||
1040 | if (unlikely(scsi_logging_level)) | |
1041 | level = SCSI_LOG_LEVEL(SCSI_LOG_MLCOMPLETE_SHIFT, | |
1042 | SCSI_LOG_MLCOMPLETE_BITS); | |
1043 | ||
1044 | /* | |
1045 | * if logging is enabled the failure will be printed | |
1046 | * in scsi_log_completion(), so avoid duplicate messages | |
1047 | */ | |
1048 | if (!level && __ratelimit(&_rs)) { | |
1049 | scsi_print_result(cmd, NULL, FAILED); | |
1050 | if (driver_byte(result) & DRIVER_SENSE) | |
1051 | scsi_print_sense(cmd); | |
1052 | scsi_print_command(cmd); | |
1053 | } | |
3173d8c3 | 1054 | } |
f6d47e74 CH |
1055 | if (!scsi_end_request(req, error, blk_rq_err_bytes(req), 0)) |
1056 | return; | |
bc85dc50 | 1057 | /*FALLTHRU*/ |
b60af5b0 | 1058 | case ACTION_REPREP: |
bc85dc50 | 1059 | requeue: |
b60af5b0 AS |
1060 | /* Unprep the request and put it back at the head of the queue. |
1061 | * A new command will be prepared and issued. | |
1062 | */ | |
d285203c CH |
1063 | if (q->mq_ops) { |
1064 | cmd->request->cmd_flags &= ~REQ_DONTPREP; | |
1065 | scsi_mq_uninit_cmd(cmd); | |
1066 | scsi_mq_requeue_cmd(cmd); | |
1067 | } else { | |
1068 | scsi_release_buffers(cmd); | |
1069 | scsi_requeue_command(q, cmd); | |
1070 | } | |
b60af5b0 AS |
1071 | break; |
1072 | case ACTION_RETRY: | |
1073 | /* Retry the same command immediately */ | |
4f5299ac | 1074 | __scsi_queue_insert(cmd, SCSI_MLQUEUE_EH_RETRY, 0); |
b60af5b0 AS |
1075 | break; |
1076 | case ACTION_DELAYED_RETRY: | |
1077 | /* Retry the same command after a delay */ | |
4f5299ac | 1078 | __scsi_queue_insert(cmd, SCSI_MLQUEUE_DEVICE_BUSY, 0); |
b60af5b0 | 1079 | break; |
1da177e4 LT |
1080 | } |
1081 | } | |
1da177e4 | 1082 | |
3c356bde | 1083 | static int scsi_init_sgtable(struct request *req, struct scsi_data_buffer *sdb) |
1da177e4 | 1084 | { |
6f9a35e2 | 1085 | int count; |
1da177e4 LT |
1086 | |
1087 | /* | |
3b003157 | 1088 | * If sg table allocation fails, requeue request later. |
1da177e4 | 1089 | */ |
30b0c37b | 1090 | if (unlikely(scsi_alloc_sgtable(sdb, req->nr_phys_segments, |
3c356bde | 1091 | req->mq_ctx != NULL))) |
1da177e4 | 1092 | return BLKPREP_DEFER; |
1da177e4 | 1093 | |
1da177e4 LT |
1094 | /* |
1095 | * Next, walk the list, and fill in the addresses and sizes of | |
1096 | * each segment. | |
1097 | */ | |
30b0c37b BH |
1098 | count = blk_rq_map_sg(req->q, req, sdb->table.sgl); |
1099 | BUG_ON(count > sdb->table.nents); | |
1100 | sdb->table.nents = count; | |
1011c1b9 | 1101 | sdb->length = blk_rq_bytes(req); |
4a03d90e | 1102 | return BLKPREP_OK; |
1da177e4 | 1103 | } |
6f9a35e2 BH |
1104 | |
1105 | /* | |
1106 | * Function: scsi_init_io() | |
1107 | * | |
1108 | * Purpose: SCSI I/O initialize function. | |
1109 | * | |
1110 | * Arguments: cmd - Command descriptor we wish to initialize | |
1111 | * | |
1112 | * Returns: 0 on success | |
1113 | * BLKPREP_DEFER if the failure is retryable | |
1114 | * BLKPREP_KILL if the failure is fatal | |
1115 | */ | |
3c356bde | 1116 | int scsi_init_io(struct scsi_cmnd *cmd) |
6f9a35e2 | 1117 | { |
5e012aad | 1118 | struct scsi_device *sdev = cmd->device; |
13f05c8d | 1119 | struct request *rq = cmd->request; |
d285203c | 1120 | bool is_mq = (rq->mq_ctx != NULL); |
635d98b1 | 1121 | int error; |
13f05c8d | 1122 | |
8107096d JT |
1123 | if (WARN_ON_ONCE(!rq->nr_phys_segments)) |
1124 | return -EINVAL; | |
635d98b1 | 1125 | |
3c356bde | 1126 | error = scsi_init_sgtable(rq, &cmd->sdb); |
6f9a35e2 BH |
1127 | if (error) |
1128 | goto err_exit; | |
1129 | ||
13f05c8d | 1130 | if (blk_bidi_rq(rq)) { |
d285203c CH |
1131 | if (!rq->q->mq_ops) { |
1132 | struct scsi_data_buffer *bidi_sdb = | |
1133 | kmem_cache_zalloc(scsi_sdb_cache, GFP_ATOMIC); | |
1134 | if (!bidi_sdb) { | |
1135 | error = BLKPREP_DEFER; | |
1136 | goto err_exit; | |
1137 | } | |
1138 | ||
1139 | rq->next_rq->special = bidi_sdb; | |
6f9a35e2 BH |
1140 | } |
1141 | ||
3c356bde | 1142 | error = scsi_init_sgtable(rq->next_rq, rq->next_rq->special); |
6f9a35e2 BH |
1143 | if (error) |
1144 | goto err_exit; | |
1145 | } | |
1146 | ||
13f05c8d | 1147 | if (blk_integrity_rq(rq)) { |
7027ad72 MP |
1148 | struct scsi_data_buffer *prot_sdb = cmd->prot_sdb; |
1149 | int ivecs, count; | |
1150 | ||
91724c20 EM |
1151 | if (prot_sdb == NULL) { |
1152 | /* | |
1153 | * This can happen if someone (e.g. multipath) | |
1154 | * queues a command to a device on an adapter | |
1155 | * that does not support DIX. | |
1156 | */ | |
1157 | WARN_ON_ONCE(1); | |
1158 | error = BLKPREP_KILL; | |
1159 | goto err_exit; | |
1160 | } | |
1161 | ||
13f05c8d | 1162 | ivecs = blk_rq_count_integrity_sg(rq->q, rq->bio); |
7027ad72 | 1163 | |
3c356bde | 1164 | if (scsi_alloc_sgtable(prot_sdb, ivecs, is_mq)) { |
7027ad72 MP |
1165 | error = BLKPREP_DEFER; |
1166 | goto err_exit; | |
1167 | } | |
1168 | ||
13f05c8d | 1169 | count = blk_rq_map_integrity_sg(rq->q, rq->bio, |
7027ad72 MP |
1170 | prot_sdb->table.sgl); |
1171 | BUG_ON(unlikely(count > ivecs)); | |
13f05c8d | 1172 | BUG_ON(unlikely(count > queue_max_integrity_segments(rq->q))); |
7027ad72 MP |
1173 | |
1174 | cmd->prot_sdb = prot_sdb; | |
1175 | cmd->prot_sdb->table.nents = count; | |
1176 | } | |
1177 | ||
d285203c | 1178 | return BLKPREP_OK; |
6f9a35e2 | 1179 | err_exit: |
d285203c CH |
1180 | if (is_mq) { |
1181 | scsi_mq_free_sgtables(cmd); | |
1182 | } else { | |
1183 | scsi_release_buffers(cmd); | |
1184 | cmd->request->special = NULL; | |
1185 | scsi_put_command(cmd); | |
1186 | put_device(&sdev->sdev_gendev); | |
1187 | } | |
6f9a35e2 BH |
1188 | return error; |
1189 | } | |
bb52d82f | 1190 | EXPORT_SYMBOL(scsi_init_io); |
1da177e4 | 1191 | |
3b003157 CH |
1192 | static struct scsi_cmnd *scsi_get_cmd_from_req(struct scsi_device *sdev, |
1193 | struct request *req) | |
1194 | { | |
1195 | struct scsi_cmnd *cmd; | |
1196 | ||
1197 | if (!req->special) { | |
04796336 CH |
1198 | /* Bail if we can't get a reference to the device */ |
1199 | if (!get_device(&sdev->sdev_gendev)) | |
1200 | return NULL; | |
1201 | ||
3b003157 | 1202 | cmd = scsi_get_command(sdev, GFP_ATOMIC); |
04796336 CH |
1203 | if (unlikely(!cmd)) { |
1204 | put_device(&sdev->sdev_gendev); | |
3b003157 | 1205 | return NULL; |
04796336 | 1206 | } |
3b003157 CH |
1207 | req->special = cmd; |
1208 | } else { | |
1209 | cmd = req->special; | |
1210 | } | |
1211 | ||
1212 | /* pull a tag out of the request if we have one */ | |
1213 | cmd->tag = req->tag; | |
1214 | cmd->request = req; | |
1215 | ||
64a87b24 | 1216 | cmd->cmnd = req->cmd; |
72f7d322 | 1217 | cmd->prot_op = SCSI_PROT_NORMAL; |
64a87b24 | 1218 | |
3b003157 CH |
1219 | return cmd; |
1220 | } | |
1221 | ||
4f1e5765 | 1222 | static int scsi_setup_blk_pc_cmnd(struct scsi_device *sdev, struct request *req) |
7b16318d | 1223 | { |
a1b73fc1 | 1224 | struct scsi_cmnd *cmd = req->special; |
3b003157 CH |
1225 | |
1226 | /* | |
1227 | * BLOCK_PC requests may transfer data, in which case they must | |
1228 | * a bio attached to them. Or they might contain a SCSI command | |
1229 | * that does not transfer data, in which case they may optionally | |
1230 | * submit a request without an attached bio. | |
1231 | */ | |
1232 | if (req->bio) { | |
3c356bde | 1233 | int ret = scsi_init_io(cmd); |
3b003157 CH |
1234 | if (unlikely(ret)) |
1235 | return ret; | |
1236 | } else { | |
b0790410 | 1237 | BUG_ON(blk_rq_bytes(req)); |
3b003157 | 1238 | |
30b0c37b | 1239 | memset(&cmd->sdb, 0, sizeof(cmd->sdb)); |
3b003157 | 1240 | } |
7b16318d | 1241 | |
7b16318d | 1242 | cmd->cmd_len = req->cmd_len; |
b0790410 | 1243 | cmd->transfersize = blk_rq_bytes(req); |
7b16318d | 1244 | cmd->allowed = req->retries; |
3b003157 | 1245 | return BLKPREP_OK; |
7b16318d | 1246 | } |
7b16318d | 1247 | |
3b003157 | 1248 | /* |
3868cf8e CH |
1249 | * Setup a REQ_TYPE_FS command. These are simple request from filesystems |
1250 | * that still need to be translated to SCSI CDBs from the ULD. | |
3b003157 | 1251 | */ |
3868cf8e | 1252 | static int scsi_setup_fs_cmnd(struct scsi_device *sdev, struct request *req) |
1da177e4 | 1253 | { |
a1b73fc1 | 1254 | struct scsi_cmnd *cmd = req->special; |
a6a8d9f8 | 1255 | |
ee14c674 CH |
1256 | if (unlikely(sdev->handler && sdev->handler->prep_fn)) { |
1257 | int ret = sdev->handler->prep_fn(sdev, req); | |
a6a8d9f8 CS |
1258 | if (ret != BLKPREP_OK) |
1259 | return ret; | |
1260 | } | |
1261 | ||
64a87b24 | 1262 | memset(cmd->cmnd, 0, BLK_MAX_CDB); |
3868cf8e | 1263 | return scsi_cmd_to_driver(cmd)->init_command(cmd); |
3b003157 CH |
1264 | } |
1265 | ||
6af7a4ff CH |
1266 | static int scsi_setup_cmnd(struct scsi_device *sdev, struct request *req) |
1267 | { | |
1268 | struct scsi_cmnd *cmd = req->special; | |
1269 | ||
1270 | if (!blk_rq_bytes(req)) | |
1271 | cmd->sc_data_direction = DMA_NONE; | |
1272 | else if (rq_data_dir(req) == WRITE) | |
1273 | cmd->sc_data_direction = DMA_TO_DEVICE; | |
1274 | else | |
1275 | cmd->sc_data_direction = DMA_FROM_DEVICE; | |
1276 | ||
1277 | switch (req->cmd_type) { | |
1278 | case REQ_TYPE_FS: | |
1279 | return scsi_setup_fs_cmnd(sdev, req); | |
1280 | case REQ_TYPE_BLOCK_PC: | |
1281 | return scsi_setup_blk_pc_cmnd(sdev, req); | |
1282 | default: | |
1283 | return BLKPREP_KILL; | |
1284 | } | |
1285 | } | |
1286 | ||
a1b73fc1 CH |
1287 | static int |
1288 | scsi_prep_state_check(struct scsi_device *sdev, struct request *req) | |
3b003157 | 1289 | { |
3b003157 CH |
1290 | int ret = BLKPREP_OK; |
1291 | ||
1da177e4 | 1292 | /* |
3b003157 CH |
1293 | * If the device is not in running state we will reject some |
1294 | * or all commands. | |
1da177e4 | 1295 | */ |
3b003157 CH |
1296 | if (unlikely(sdev->sdev_state != SDEV_RUNNING)) { |
1297 | switch (sdev->sdev_state) { | |
1298 | case SDEV_OFFLINE: | |
1b8d2620 | 1299 | case SDEV_TRANSPORT_OFFLINE: |
3b003157 CH |
1300 | /* |
1301 | * If the device is offline we refuse to process any | |
1302 | * commands. The device must be brought online | |
1303 | * before trying any recovery commands. | |
1304 | */ | |
1305 | sdev_printk(KERN_ERR, sdev, | |
1306 | "rejecting I/O to offline device\n"); | |
1307 | ret = BLKPREP_KILL; | |
1308 | break; | |
1309 | case SDEV_DEL: | |
1310 | /* | |
1311 | * If the device is fully deleted, we refuse to | |
1312 | * process any commands as well. | |
1313 | */ | |
9ccfc756 | 1314 | sdev_printk(KERN_ERR, sdev, |
3b003157 CH |
1315 | "rejecting I/O to dead device\n"); |
1316 | ret = BLKPREP_KILL; | |
1317 | break; | |
3b003157 | 1318 | case SDEV_BLOCK: |
6f4267e3 | 1319 | case SDEV_CREATED_BLOCK: |
bba0bdd7 BVA |
1320 | ret = BLKPREP_DEFER; |
1321 | break; | |
1322 | case SDEV_QUIESCE: | |
3b003157 CH |
1323 | /* |
1324 | * If the devices is blocked we defer normal commands. | |
1325 | */ | |
1326 | if (!(req->cmd_flags & REQ_PREEMPT)) | |
1327 | ret = BLKPREP_DEFER; | |
1328 | break; | |
1329 | default: | |
1330 | /* | |
1331 | * For any other not fully online state we only allow | |
1332 | * special commands. In particular any user initiated | |
1333 | * command is not allowed. | |
1334 | */ | |
1335 | if (!(req->cmd_flags & REQ_PREEMPT)) | |
1336 | ret = BLKPREP_KILL; | |
1337 | break; | |
1da177e4 | 1338 | } |
1da177e4 | 1339 | } |
7f9a6bc4 JB |
1340 | return ret; |
1341 | } | |
1da177e4 | 1342 | |
a1b73fc1 CH |
1343 | static int |
1344 | scsi_prep_return(struct request_queue *q, struct request *req, int ret) | |
7f9a6bc4 JB |
1345 | { |
1346 | struct scsi_device *sdev = q->queuedata; | |
1da177e4 | 1347 | |
3b003157 CH |
1348 | switch (ret) { |
1349 | case BLKPREP_KILL: | |
1350 | req->errors = DID_NO_CONNECT << 16; | |
7f9a6bc4 JB |
1351 | /* release the command and kill it */ |
1352 | if (req->special) { | |
1353 | struct scsi_cmnd *cmd = req->special; | |
1354 | scsi_release_buffers(cmd); | |
1355 | scsi_put_command(cmd); | |
68c03d91 | 1356 | put_device(&sdev->sdev_gendev); |
7f9a6bc4 JB |
1357 | req->special = NULL; |
1358 | } | |
3b003157 CH |
1359 | break; |
1360 | case BLKPREP_DEFER: | |
1da177e4 | 1361 | /* |
9934c8c0 | 1362 | * If we defer, the blk_peek_request() returns NULL, but the |
a488e749 JA |
1363 | * queue must be restarted, so we schedule a callback to happen |
1364 | * shortly. | |
1da177e4 | 1365 | */ |
71e75c97 | 1366 | if (atomic_read(&sdev->device_busy) == 0) |
a488e749 | 1367 | blk_delay_queue(q, SCSI_QUEUE_DELAY); |
3b003157 CH |
1368 | break; |
1369 | default: | |
1370 | req->cmd_flags |= REQ_DONTPREP; | |
1da177e4 LT |
1371 | } |
1372 | ||
3b003157 | 1373 | return ret; |
1da177e4 | 1374 | } |
7f9a6bc4 | 1375 | |
a1b73fc1 | 1376 | static int scsi_prep_fn(struct request_queue *q, struct request *req) |
7f9a6bc4 JB |
1377 | { |
1378 | struct scsi_device *sdev = q->queuedata; | |
a1b73fc1 CH |
1379 | struct scsi_cmnd *cmd; |
1380 | int ret; | |
1381 | ||
1382 | ret = scsi_prep_state_check(sdev, req); | |
1383 | if (ret != BLKPREP_OK) | |
1384 | goto out; | |
1385 | ||
1386 | cmd = scsi_get_cmd_from_req(sdev, req); | |
1387 | if (unlikely(!cmd)) { | |
1388 | ret = BLKPREP_DEFER; | |
1389 | goto out; | |
1390 | } | |
7f9a6bc4 | 1391 | |
6af7a4ff | 1392 | ret = scsi_setup_cmnd(sdev, req); |
a1b73fc1 | 1393 | out: |
7f9a6bc4 JB |
1394 | return scsi_prep_return(q, req, ret); |
1395 | } | |
a1b73fc1 CH |
1396 | |
1397 | static void scsi_unprep_fn(struct request_queue *q, struct request *req) | |
1398 | { | |
d285203c | 1399 | scsi_uninit_cmd(req->special); |
a1b73fc1 | 1400 | } |
1da177e4 LT |
1401 | |
1402 | /* | |
1403 | * scsi_dev_queue_ready: if we can send requests to sdev, return 1 else | |
1404 | * return 0. | |
1405 | * | |
1406 | * Called with the queue_lock held. | |
1407 | */ | |
1408 | static inline int scsi_dev_queue_ready(struct request_queue *q, | |
1409 | struct scsi_device *sdev) | |
1410 | { | |
71e75c97 CH |
1411 | unsigned int busy; |
1412 | ||
1413 | busy = atomic_inc_return(&sdev->device_busy) - 1; | |
cd9070c9 | 1414 | if (atomic_read(&sdev->device_blocked)) { |
71e75c97 CH |
1415 | if (busy) |
1416 | goto out_dec; | |
1417 | ||
1da177e4 LT |
1418 | /* |
1419 | * unblock after device_blocked iterates to zero | |
1420 | */ | |
cd9070c9 | 1421 | if (atomic_dec_return(&sdev->device_blocked) > 0) { |
d285203c CH |
1422 | /* |
1423 | * For the MQ case we take care of this in the caller. | |
1424 | */ | |
1425 | if (!q->mq_ops) | |
1426 | blk_delay_queue(q, SCSI_QUEUE_DELAY); | |
71e75c97 | 1427 | goto out_dec; |
1da177e4 | 1428 | } |
71e75c97 CH |
1429 | SCSI_LOG_MLQUEUE(3, sdev_printk(KERN_INFO, sdev, |
1430 | "unblocking device at zero depth\n")); | |
1da177e4 | 1431 | } |
71e75c97 CH |
1432 | |
1433 | if (busy >= sdev->queue_depth) | |
1434 | goto out_dec; | |
1da177e4 LT |
1435 | |
1436 | return 1; | |
71e75c97 CH |
1437 | out_dec: |
1438 | atomic_dec(&sdev->device_busy); | |
1439 | return 0; | |
1da177e4 LT |
1440 | } |
1441 | ||
f0c0a376 MC |
1442 | /* |
1443 | * scsi_target_queue_ready: checks if there we can send commands to target | |
1444 | * @sdev: scsi device on starget to check. | |
f0c0a376 MC |
1445 | */ |
1446 | static inline int scsi_target_queue_ready(struct Scsi_Host *shost, | |
1447 | struct scsi_device *sdev) | |
1448 | { | |
1449 | struct scsi_target *starget = scsi_target(sdev); | |
7ae65c0f | 1450 | unsigned int busy; |
f0c0a376 MC |
1451 | |
1452 | if (starget->single_lun) { | |
7ae65c0f | 1453 | spin_lock_irq(shost->host_lock); |
f0c0a376 | 1454 | if (starget->starget_sdev_user && |
7ae65c0f CH |
1455 | starget->starget_sdev_user != sdev) { |
1456 | spin_unlock_irq(shost->host_lock); | |
1457 | return 0; | |
1458 | } | |
f0c0a376 | 1459 | starget->starget_sdev_user = sdev; |
7ae65c0f | 1460 | spin_unlock_irq(shost->host_lock); |
f0c0a376 MC |
1461 | } |
1462 | ||
2ccbb008 CH |
1463 | if (starget->can_queue <= 0) |
1464 | return 1; | |
1465 | ||
7ae65c0f | 1466 | busy = atomic_inc_return(&starget->target_busy) - 1; |
cd9070c9 | 1467 | if (atomic_read(&starget->target_blocked) > 0) { |
7ae65c0f CH |
1468 | if (busy) |
1469 | goto starved; | |
1470 | ||
f0c0a376 MC |
1471 | /* |
1472 | * unblock after target_blocked iterates to zero | |
1473 | */ | |
cd9070c9 | 1474 | if (atomic_dec_return(&starget->target_blocked) > 0) |
7ae65c0f | 1475 | goto out_dec; |
cf68d334 CH |
1476 | |
1477 | SCSI_LOG_MLQUEUE(3, starget_printk(KERN_INFO, starget, | |
1478 | "unblocking target at zero depth\n")); | |
f0c0a376 MC |
1479 | } |
1480 | ||
2ccbb008 | 1481 | if (busy >= starget->can_queue) |
7ae65c0f | 1482 | goto starved; |
f0c0a376 | 1483 | |
7ae65c0f CH |
1484 | return 1; |
1485 | ||
1486 | starved: | |
1487 | spin_lock_irq(shost->host_lock); | |
1488 | list_move_tail(&sdev->starved_entry, &shost->starved_list); | |
cf68d334 | 1489 | spin_unlock_irq(shost->host_lock); |
7ae65c0f | 1490 | out_dec: |
2ccbb008 CH |
1491 | if (starget->can_queue > 0) |
1492 | atomic_dec(&starget->target_busy); | |
7ae65c0f | 1493 | return 0; |
f0c0a376 MC |
1494 | } |
1495 | ||
1da177e4 LT |
1496 | /* |
1497 | * scsi_host_queue_ready: if we can send requests to shost, return 1 else | |
1498 | * return 0. We must end up running the queue again whenever 0 is | |
1499 | * returned, else IO can hang. | |
1da177e4 LT |
1500 | */ |
1501 | static inline int scsi_host_queue_ready(struct request_queue *q, | |
1502 | struct Scsi_Host *shost, | |
1503 | struct scsi_device *sdev) | |
1504 | { | |
74665016 | 1505 | unsigned int busy; |
cf68d334 | 1506 | |
939647ee | 1507 | if (scsi_host_in_recovery(shost)) |
74665016 CH |
1508 | return 0; |
1509 | ||
1510 | busy = atomic_inc_return(&shost->host_busy) - 1; | |
cd9070c9 | 1511 | if (atomic_read(&shost->host_blocked) > 0) { |
74665016 CH |
1512 | if (busy) |
1513 | goto starved; | |
1514 | ||
1da177e4 LT |
1515 | /* |
1516 | * unblock after host_blocked iterates to zero | |
1517 | */ | |
cd9070c9 | 1518 | if (atomic_dec_return(&shost->host_blocked) > 0) |
74665016 | 1519 | goto out_dec; |
cf68d334 CH |
1520 | |
1521 | SCSI_LOG_MLQUEUE(3, | |
1522 | shost_printk(KERN_INFO, shost, | |
1523 | "unblocking host at zero depth\n")); | |
1da177e4 | 1524 | } |
74665016 CH |
1525 | |
1526 | if (shost->can_queue > 0 && busy >= shost->can_queue) | |
1527 | goto starved; | |
1528 | if (shost->host_self_blocked) | |
1529 | goto starved; | |
1da177e4 LT |
1530 | |
1531 | /* We're OK to process the command, so we can't be starved */ | |
74665016 CH |
1532 | if (!list_empty(&sdev->starved_entry)) { |
1533 | spin_lock_irq(shost->host_lock); | |
1534 | if (!list_empty(&sdev->starved_entry)) | |
1535 | list_del_init(&sdev->starved_entry); | |
1536 | spin_unlock_irq(shost->host_lock); | |
1537 | } | |
1da177e4 | 1538 | |
74665016 CH |
1539 | return 1; |
1540 | ||
1541 | starved: | |
1542 | spin_lock_irq(shost->host_lock); | |
1543 | if (list_empty(&sdev->starved_entry)) | |
1544 | list_add_tail(&sdev->starved_entry, &shost->starved_list); | |
cf68d334 | 1545 | spin_unlock_irq(shost->host_lock); |
74665016 CH |
1546 | out_dec: |
1547 | atomic_dec(&shost->host_busy); | |
1548 | return 0; | |
1da177e4 LT |
1549 | } |
1550 | ||
6c5121b7 KU |
1551 | /* |
1552 | * Busy state exporting function for request stacking drivers. | |
1553 | * | |
1554 | * For efficiency, no lock is taken to check the busy state of | |
1555 | * shost/starget/sdev, since the returned value is not guaranteed and | |
1556 | * may be changed after request stacking drivers call the function, | |
1557 | * regardless of taking lock or not. | |
1558 | * | |
67bd9413 BVA |
1559 | * When scsi can't dispatch I/Os anymore and needs to kill I/Os scsi |
1560 | * needs to return 'not busy'. Otherwise, request stacking drivers | |
1561 | * may hold requests forever. | |
6c5121b7 KU |
1562 | */ |
1563 | static int scsi_lld_busy(struct request_queue *q) | |
1564 | { | |
1565 | struct scsi_device *sdev = q->queuedata; | |
1566 | struct Scsi_Host *shost; | |
6c5121b7 | 1567 | |
3f3299d5 | 1568 | if (blk_queue_dying(q)) |
6c5121b7 KU |
1569 | return 0; |
1570 | ||
1571 | shost = sdev->host; | |
6c5121b7 | 1572 | |
b7e94a16 JN |
1573 | /* |
1574 | * Ignore host/starget busy state. | |
1575 | * Since block layer does not have a concept of fairness across | |
1576 | * multiple queues, congestion of host/starget needs to be handled | |
1577 | * in SCSI layer. | |
1578 | */ | |
1579 | if (scsi_host_in_recovery(shost) || scsi_device_is_busy(sdev)) | |
6c5121b7 KU |
1580 | return 1; |
1581 | ||
1582 | return 0; | |
1583 | } | |
1584 | ||
1da177e4 | 1585 | /* |
e91442b6 | 1586 | * Kill a request for a dead device |
1da177e4 | 1587 | */ |
165125e1 | 1588 | static void scsi_kill_request(struct request *req, struct request_queue *q) |
1da177e4 | 1589 | { |
e91442b6 | 1590 | struct scsi_cmnd *cmd = req->special; |
03b14708 JS |
1591 | struct scsi_device *sdev; |
1592 | struct scsi_target *starget; | |
1593 | struct Scsi_Host *shost; | |
1da177e4 | 1594 | |
9934c8c0 | 1595 | blk_start_request(req); |
788ce43a | 1596 | |
74571813 HR |
1597 | scmd_printk(KERN_INFO, cmd, "killing request\n"); |
1598 | ||
03b14708 JS |
1599 | sdev = cmd->device; |
1600 | starget = scsi_target(sdev); | |
1601 | shost = sdev->host; | |
e91442b6 JB |
1602 | scsi_init_cmd_errh(cmd); |
1603 | cmd->result = DID_NO_CONNECT << 16; | |
1604 | atomic_inc(&cmd->device->iorequest_cnt); | |
e36e0c80 TH |
1605 | |
1606 | /* | |
1607 | * SCSI request completion path will do scsi_device_unbusy(), | |
1608 | * bump busy counts. To bump the counters, we need to dance | |
1609 | * with the locks as normal issue path does. | |
1610 | */ | |
71e75c97 | 1611 | atomic_inc(&sdev->device_busy); |
74665016 | 1612 | atomic_inc(&shost->host_busy); |
2ccbb008 CH |
1613 | if (starget->can_queue > 0) |
1614 | atomic_inc(&starget->target_busy); | |
e36e0c80 | 1615 | |
242f9dcb | 1616 | blk_complete_request(req); |
1da177e4 LT |
1617 | } |
1618 | ||
1cac41cb | 1619 | void scsi_softirq_done(struct request *rq) |
1aea6434 | 1620 | { |
242f9dcb JA |
1621 | struct scsi_cmnd *cmd = rq->special; |
1622 | unsigned long wait_for = (cmd->allowed + 1) * rq->timeout; | |
1aea6434 JA |
1623 | int disposition; |
1624 | ||
1625 | INIT_LIST_HEAD(&cmd->eh_entry); | |
1626 | ||
242f9dcb JA |
1627 | atomic_inc(&cmd->device->iodone_cnt); |
1628 | if (cmd->result) | |
1629 | atomic_inc(&cmd->device->ioerr_cnt); | |
1630 | ||
1aea6434 JA |
1631 | disposition = scsi_decide_disposition(cmd); |
1632 | if (disposition != SUCCESS && | |
1633 | time_before(cmd->jiffies_at_alloc + wait_for, jiffies)) { | |
1634 | sdev_printk(KERN_ERR, cmd->device, | |
1635 | "timing out command, waited %lus\n", | |
1636 | wait_for/HZ); | |
1637 | disposition = SUCCESS; | |
1638 | } | |
91921e01 | 1639 | |
1aea6434 JA |
1640 | scsi_log_completion(cmd, disposition); |
1641 | ||
1642 | switch (disposition) { | |
1643 | case SUCCESS: | |
1644 | scsi_finish_command(cmd); | |
1645 | break; | |
1646 | case NEEDS_RETRY: | |
596f482a | 1647 | scsi_queue_insert(cmd, SCSI_MLQUEUE_EH_RETRY); |
1aea6434 JA |
1648 | break; |
1649 | case ADD_TO_MLQUEUE: | |
1650 | scsi_queue_insert(cmd, SCSI_MLQUEUE_DEVICE_BUSY); | |
1651 | break; | |
1652 | default: | |
1653 | if (!scsi_eh_scmd_add(cmd, 0)) | |
1654 | scsi_finish_command(cmd); | |
1655 | } | |
1656 | } | |
1657 | ||
82042a2c CH |
1658 | /** |
1659 | * scsi_dispatch_command - Dispatch a command to the low-level driver. | |
1660 | * @cmd: command block we are dispatching. | |
1661 | * | |
1662 | * Return: nonzero return request was rejected and device's queue needs to be | |
1663 | * plugged. | |
1664 | */ | |
1665 | static int scsi_dispatch_cmd(struct scsi_cmnd *cmd) | |
1666 | { | |
1667 | struct Scsi_Host *host = cmd->device->host; | |
1668 | int rtn = 0; | |
1669 | ||
1670 | atomic_inc(&cmd->device->iorequest_cnt); | |
1671 | ||
1672 | /* check if the device is still usable */ | |
1673 | if (unlikely(cmd->device->sdev_state == SDEV_DEL)) { | |
1674 | /* in SDEV_DEL we error all commands. DID_NO_CONNECT | |
1675 | * returns an immediate error upwards, and signals | |
1676 | * that the device is no longer present */ | |
1677 | cmd->result = DID_NO_CONNECT << 16; | |
1678 | goto done; | |
1679 | } | |
1680 | ||
1681 | /* Check to see if the scsi lld made this device blocked. */ | |
1682 | if (unlikely(scsi_device_blocked(cmd->device))) { | |
1683 | /* | |
1684 | * in blocked state, the command is just put back on | |
1685 | * the device queue. The suspend state has already | |
1686 | * blocked the queue so future requests should not | |
1687 | * occur until the device transitions out of the | |
1688 | * suspend state. | |
1689 | */ | |
1690 | SCSI_LOG_MLQUEUE(3, scmd_printk(KERN_INFO, cmd, | |
1691 | "queuecommand : device blocked\n")); | |
1692 | return SCSI_MLQUEUE_DEVICE_BUSY; | |
1693 | } | |
1694 | ||
1695 | /* Store the LUN value in cmnd, if needed. */ | |
1696 | if (cmd->device->lun_in_cdb) | |
1697 | cmd->cmnd[1] = (cmd->cmnd[1] & 0x1f) | | |
1698 | (cmd->device->lun << 5 & 0xe0); | |
1699 | ||
1700 | scsi_log_send(cmd); | |
1701 | ||
1702 | /* | |
1703 | * Before we queue this command, check if the command | |
1704 | * length exceeds what the host adapter can handle. | |
1705 | */ | |
1706 | if (cmd->cmd_len > cmd->device->host->max_cmd_len) { | |
1707 | SCSI_LOG_MLQUEUE(3, scmd_printk(KERN_INFO, cmd, | |
1708 | "queuecommand : command too long. " | |
1709 | "cdb_size=%d host->max_cmd_len=%d\n", | |
1710 | cmd->cmd_len, cmd->device->host->max_cmd_len)); | |
1711 | cmd->result = (DID_ABORT << 16); | |
1712 | goto done; | |
1713 | } | |
1714 | ||
1715 | if (unlikely(host->shost_state == SHOST_DEL)) { | |
1716 | cmd->result = (DID_NO_CONNECT << 16); | |
1717 | goto done; | |
1718 | ||
1719 | } | |
1720 | ||
1721 | trace_scsi_dispatch_cmd_start(cmd); | |
1722 | rtn = host->hostt->queuecommand(host, cmd); | |
1723 | if (rtn) { | |
1724 | trace_scsi_dispatch_cmd_error(cmd, rtn); | |
1725 | if (rtn != SCSI_MLQUEUE_DEVICE_BUSY && | |
1726 | rtn != SCSI_MLQUEUE_TARGET_BUSY) | |
1727 | rtn = SCSI_MLQUEUE_HOST_BUSY; | |
1728 | ||
1729 | SCSI_LOG_MLQUEUE(3, scmd_printk(KERN_INFO, cmd, | |
1730 | "queuecommand : request rejected\n")); | |
1731 | } | |
1732 | ||
1733 | return rtn; | |
1734 | done: | |
1735 | cmd->scsi_done(cmd); | |
1736 | return 0; | |
1737 | } | |
1738 | ||
3b5382c4 CH |
1739 | /** |
1740 | * scsi_done - Invoke completion on finished SCSI command. | |
1741 | * @cmd: The SCSI Command for which a low-level device driver (LLDD) gives | |
1742 | * ownership back to SCSI Core -- i.e. the LLDD has finished with it. | |
1743 | * | |
1744 | * Description: This function is the mid-level's (SCSI Core) interrupt routine, | |
1745 | * which regains ownership of the SCSI command (de facto) from a LLDD, and | |
1746 | * calls blk_complete_request() for further processing. | |
1747 | * | |
1748 | * This function is interrupt context safe. | |
1749 | */ | |
1750 | static void scsi_done(struct scsi_cmnd *cmd) | |
1751 | { | |
1752 | trace_scsi_dispatch_cmd_done(cmd); | |
1753 | blk_complete_request(cmd->request); | |
1754 | } | |
1755 | ||
1da177e4 LT |
1756 | /* |
1757 | * Function: scsi_request_fn() | |
1758 | * | |
1759 | * Purpose: Main strategy routine for SCSI. | |
1760 | * | |
1761 | * Arguments: q - Pointer to actual queue. | |
1762 | * | |
1763 | * Returns: Nothing | |
1764 | * | |
1765 | * Lock status: IO request lock assumed to be held when called. | |
1766 | */ | |
1767 | static void scsi_request_fn(struct request_queue *q) | |
613be1f6 BVA |
1768 | __releases(q->queue_lock) |
1769 | __acquires(q->queue_lock) | |
1da177e4 LT |
1770 | { |
1771 | struct scsi_device *sdev = q->queuedata; | |
1772 | struct Scsi_Host *shost; | |
1773 | struct scsi_cmnd *cmd; | |
1774 | struct request *req; | |
1775 | ||
1da177e4 LT |
1776 | /* |
1777 | * To start with, we keep looping until the queue is empty, or until | |
1778 | * the host is no longer able to accept any more requests. | |
1779 | */ | |
1780 | shost = sdev->host; | |
a488e749 | 1781 | for (;;) { |
1da177e4 LT |
1782 | int rtn; |
1783 | /* | |
1784 | * get next queueable request. We do this early to make sure | |
91921e01 | 1785 | * that the request is fully prepared even if we cannot |
1da177e4 LT |
1786 | * accept it. |
1787 | */ | |
9934c8c0 | 1788 | req = blk_peek_request(q); |
71e75c97 | 1789 | if (!req) |
1da177e4 LT |
1790 | break; |
1791 | ||
1792 | if (unlikely(!scsi_device_online(sdev))) { | |
9ccfc756 JB |
1793 | sdev_printk(KERN_ERR, sdev, |
1794 | "rejecting I/O to offline device\n"); | |
e91442b6 | 1795 | scsi_kill_request(req, q); |
1da177e4 LT |
1796 | continue; |
1797 | } | |
1798 | ||
71e75c97 CH |
1799 | if (!scsi_dev_queue_ready(q, sdev)) |
1800 | break; | |
1da177e4 LT |
1801 | |
1802 | /* | |
1803 | * Remove the request from the request list. | |
1804 | */ | |
1805 | if (!(blk_queue_tagged(q) && !blk_queue_start_tag(q, req))) | |
9934c8c0 | 1806 | blk_start_request(req); |
1da177e4 | 1807 | |
1cac41cb | 1808 | preempt_disable(); |
cf68d334 | 1809 | spin_unlock_irq(q->queue_lock); |
e91442b6 JB |
1810 | cmd = req->special; |
1811 | if (unlikely(cmd == NULL)) { | |
1812 | printk(KERN_CRIT "impossible request in %s.\n" | |
1813 | "please mail a stack trace to " | |
4aff5e23 | 1814 | "linux-scsi@vger.kernel.org\n", |
cadbd4a5 | 1815 | __func__); |
4aff5e23 | 1816 | blk_dump_rq_flags(req, "foo"); |
e91442b6 JB |
1817 | BUG(); |
1818 | } | |
1da177e4 | 1819 | |
ecefe8a9 MC |
1820 | /* |
1821 | * We hit this when the driver is using a host wide | |
1822 | * tag map. For device level tag maps the queue_depth check | |
1823 | * in the device ready fn would prevent us from trying | |
1824 | * to allocate a tag. Since the map is a shared host resource | |
1825 | * we add the dev to the starved list so it eventually gets | |
1826 | * a run when a tag is freed. | |
1827 | */ | |
125c99bc | 1828 | if (blk_queue_tagged(q) && !(req->cmd_flags & REQ_QUEUED)) { |
cf68d334 | 1829 | spin_lock_irq(shost->host_lock); |
ecefe8a9 MC |
1830 | if (list_empty(&sdev->starved_entry)) |
1831 | list_add_tail(&sdev->starved_entry, | |
1832 | &shost->starved_list); | |
1cac41cb | 1833 | preempt_enable_no_resched(); |
cf68d334 | 1834 | spin_unlock_irq(shost->host_lock); |
ecefe8a9 MC |
1835 | goto not_ready; |
1836 | } | |
1837 | ||
1cac41cb MB |
1838 | if (!scsi_target_queue_ready(shost, sdev)) { |
1839 | preempt_enable_no_resched(); | |
f0c0a376 | 1840 | goto not_ready; |
1cac41cb | 1841 | } |
f0c0a376 | 1842 | |
1cac41cb MB |
1843 | if (!scsi_host_queue_ready(q, shost, sdev)) { |
1844 | preempt_enable_no_resched(); | |
cf68d334 | 1845 | goto host_not_ready; |
1cac41cb | 1846 | } |
125c99bc CH |
1847 | |
1848 | if (sdev->simple_tags) | |
1849 | cmd->flags |= SCMD_TAGGED; | |
1850 | else | |
1851 | cmd->flags &= ~SCMD_TAGGED; | |
1da177e4 | 1852 | |
1da177e4 LT |
1853 | /* |
1854 | * Finally, initialize any error handling parameters, and set up | |
1855 | * the timers for timeouts. | |
1856 | */ | |
1857 | scsi_init_cmd_errh(cmd); | |
1858 | ||
1859 | /* | |
1860 | * Dispatch the command to the low-level driver. | |
1861 | */ | |
3b5382c4 | 1862 | cmd->scsi_done = scsi_done; |
1da177e4 | 1863 | rtn = scsi_dispatch_cmd(cmd); |
1cac41cb | 1864 | preempt_enable_no_resched(); |
d0d3bbf9 CH |
1865 | if (rtn) { |
1866 | scsi_queue_insert(cmd, rtn); | |
1867 | spin_lock_irq(q->queue_lock); | |
a488e749 | 1868 | goto out_delay; |
d0d3bbf9 CH |
1869 | } |
1870 | spin_lock_irq(q->queue_lock); | |
1da177e4 LT |
1871 | } |
1872 | ||
613be1f6 | 1873 | return; |
1da177e4 | 1874 | |
cf68d334 | 1875 | host_not_ready: |
2ccbb008 CH |
1876 | if (scsi_target(sdev)->can_queue > 0) |
1877 | atomic_dec(&scsi_target(sdev)->target_busy); | |
cf68d334 | 1878 | not_ready: |
1da177e4 LT |
1879 | /* |
1880 | * lock q, handle tag, requeue req, and decrement device_busy. We | |
1881 | * must return with queue_lock held. | |
1882 | * | |
1883 | * Decrementing device_busy without checking it is OK, as all such | |
1884 | * cases (host limits or settings) should run the queue at some | |
1885 | * later time. | |
1886 | */ | |
1887 | spin_lock_irq(q->queue_lock); | |
1888 | blk_requeue_request(q, req); | |
71e75c97 | 1889 | atomic_dec(&sdev->device_busy); |
a488e749 | 1890 | out_delay: |
480cadc2 | 1891 | if (!atomic_read(&sdev->device_busy) && !scsi_device_blocked(sdev)) |
a488e749 | 1892 | blk_delay_queue(q, SCSI_QUEUE_DELAY); |
1da177e4 LT |
1893 | } |
1894 | ||
d285203c CH |
1895 | static inline int prep_to_mq(int ret) |
1896 | { | |
1897 | switch (ret) { | |
1898 | case BLKPREP_OK: | |
1899 | return 0; | |
1900 | case BLKPREP_DEFER: | |
1901 | return BLK_MQ_RQ_QUEUE_BUSY; | |
1902 | default: | |
1903 | return BLK_MQ_RQ_QUEUE_ERROR; | |
1904 | } | |
1905 | } | |
1906 | ||
1907 | static int scsi_mq_prep_fn(struct request *req) | |
1908 | { | |
1909 | struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req); | |
1910 | struct scsi_device *sdev = req->q->queuedata; | |
1911 | struct Scsi_Host *shost = sdev->host; | |
1912 | unsigned char *sense_buf = cmd->sense_buffer; | |
1913 | struct scatterlist *sg; | |
1914 | ||
1915 | memset(cmd, 0, sizeof(struct scsi_cmnd)); | |
1916 | ||
1917 | req->special = cmd; | |
1918 | ||
1919 | cmd->request = req; | |
1920 | cmd->device = sdev; | |
1921 | cmd->sense_buffer = sense_buf; | |
1922 | ||
1923 | cmd->tag = req->tag; | |
1924 | ||
d285203c CH |
1925 | cmd->cmnd = req->cmd; |
1926 | cmd->prot_op = SCSI_PROT_NORMAL; | |
1927 | ||
1928 | INIT_LIST_HEAD(&cmd->list); | |
1929 | INIT_DELAYED_WORK(&cmd->abort_work, scmd_eh_abort_handler); | |
1930 | cmd->jiffies_at_alloc = jiffies; | |
1931 | ||
64bdcbc4 KD |
1932 | if (shost->use_cmd_list) { |
1933 | spin_lock_irq(&sdev->list_lock); | |
1934 | list_add_tail(&cmd->list, &sdev->cmd_list); | |
1935 | spin_unlock_irq(&sdev->list_lock); | |
1936 | } | |
d285203c CH |
1937 | |
1938 | sg = (void *)cmd + sizeof(struct scsi_cmnd) + shost->hostt->cmd_size; | |
1939 | cmd->sdb.table.sgl = sg; | |
1940 | ||
1941 | if (scsi_host_get_prot(shost)) { | |
1942 | cmd->prot_sdb = (void *)sg + | |
120bb3e1 TB |
1943 | min_t(unsigned int, |
1944 | shost->sg_tablesize, SCSI_MAX_SG_SEGMENTS) * | |
1945 | sizeof(struct scatterlist); | |
d285203c CH |
1946 | memset(cmd->prot_sdb, 0, sizeof(struct scsi_data_buffer)); |
1947 | ||
1948 | cmd->prot_sdb->table.sgl = | |
1949 | (struct scatterlist *)(cmd->prot_sdb + 1); | |
1950 | } | |
1951 | ||
1952 | if (blk_bidi_rq(req)) { | |
1953 | struct request *next_rq = req->next_rq; | |
1954 | struct scsi_data_buffer *bidi_sdb = blk_mq_rq_to_pdu(next_rq); | |
1955 | ||
1956 | memset(bidi_sdb, 0, sizeof(struct scsi_data_buffer)); | |
1957 | bidi_sdb->table.sgl = | |
1958 | (struct scatterlist *)(bidi_sdb + 1); | |
1959 | ||
1960 | next_rq->special = bidi_sdb; | |
1961 | } | |
1962 | ||
fe052529 CH |
1963 | blk_mq_start_request(req); |
1964 | ||
d285203c CH |
1965 | return scsi_setup_cmnd(sdev, req); |
1966 | } | |
1967 | ||
1968 | static void scsi_mq_done(struct scsi_cmnd *cmd) | |
1969 | { | |
1970 | trace_scsi_dispatch_cmd_done(cmd); | |
f4829a9b | 1971 | blk_mq_complete_request(cmd->request, cmd->request->errors); |
d285203c CH |
1972 | } |
1973 | ||
74c45052 JA |
1974 | static int scsi_queue_rq(struct blk_mq_hw_ctx *hctx, |
1975 | const struct blk_mq_queue_data *bd) | |
d285203c | 1976 | { |
74c45052 | 1977 | struct request *req = bd->rq; |
d285203c CH |
1978 | struct request_queue *q = req->q; |
1979 | struct scsi_device *sdev = q->queuedata; | |
1980 | struct Scsi_Host *shost = sdev->host; | |
1981 | struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req); | |
1982 | int ret; | |
1983 | int reason; | |
1984 | ||
1985 | ret = prep_to_mq(scsi_prep_state_check(sdev, req)); | |
1986 | if (ret) | |
1987 | goto out; | |
1988 | ||
1989 | ret = BLK_MQ_RQ_QUEUE_BUSY; | |
1990 | if (!get_device(&sdev->sdev_gendev)) | |
1991 | goto out; | |
1992 | ||
1993 | if (!scsi_dev_queue_ready(q, sdev)) | |
1994 | goto out_put_device; | |
1995 | if (!scsi_target_queue_ready(shost, sdev)) | |
1996 | goto out_dec_device_busy; | |
1997 | if (!scsi_host_queue_ready(q, shost, sdev)) | |
1998 | goto out_dec_target_busy; | |
1999 | ||
fe052529 | 2000 | |
d285203c CH |
2001 | if (!(req->cmd_flags & REQ_DONTPREP)) { |
2002 | ret = prep_to_mq(scsi_mq_prep_fn(req)); | |
2003 | if (ret) | |
2004 | goto out_dec_host_busy; | |
2005 | req->cmd_flags |= REQ_DONTPREP; | |
fe052529 CH |
2006 | } else { |
2007 | blk_mq_start_request(req); | |
d285203c CH |
2008 | } |
2009 | ||
125c99bc CH |
2010 | if (sdev->simple_tags) |
2011 | cmd->flags |= SCMD_TAGGED; | |
b1dd2aac | 2012 | else |
125c99bc | 2013 | cmd->flags &= ~SCMD_TAGGED; |
b1dd2aac | 2014 | |
d285203c CH |
2015 | scsi_init_cmd_errh(cmd); |
2016 | cmd->scsi_done = scsi_mq_done; | |
2017 | ||
2018 | reason = scsi_dispatch_cmd(cmd); | |
2019 | if (reason) { | |
2020 | scsi_set_blocked(cmd, reason); | |
2021 | ret = BLK_MQ_RQ_QUEUE_BUSY; | |
2022 | goto out_dec_host_busy; | |
2023 | } | |
2024 | ||
2025 | return BLK_MQ_RQ_QUEUE_OK; | |
2026 | ||
2027 | out_dec_host_busy: | |
2028 | atomic_dec(&shost->host_busy); | |
2029 | out_dec_target_busy: | |
2030 | if (scsi_target(sdev)->can_queue > 0) | |
2031 | atomic_dec(&scsi_target(sdev)->target_busy); | |
2032 | out_dec_device_busy: | |
2033 | atomic_dec(&sdev->device_busy); | |
2034 | out_put_device: | |
2035 | put_device(&sdev->sdev_gendev); | |
2036 | out: | |
2037 | switch (ret) { | |
2038 | case BLK_MQ_RQ_QUEUE_BUSY: | |
2039 | blk_mq_stop_hw_queue(hctx); | |
2040 | if (atomic_read(&sdev->device_busy) == 0 && | |
2041 | !scsi_device_blocked(sdev)) | |
2042 | blk_mq_delay_queue(hctx, SCSI_QUEUE_DELAY); | |
2043 | break; | |
2044 | case BLK_MQ_RQ_QUEUE_ERROR: | |
2045 | /* | |
2046 | * Make sure to release all allocated ressources when | |
2047 | * we hit an error, as we will never see this command | |
2048 | * again. | |
2049 | */ | |
2050 | if (req->cmd_flags & REQ_DONTPREP) | |
2051 | scsi_mq_uninit_cmd(cmd); | |
2052 | break; | |
2053 | default: | |
2054 | break; | |
2055 | } | |
2056 | return ret; | |
2057 | } | |
2058 | ||
0152fb6b CH |
2059 | static enum blk_eh_timer_return scsi_timeout(struct request *req, |
2060 | bool reserved) | |
2061 | { | |
2062 | if (reserved) | |
2063 | return BLK_EH_RESET_TIMER; | |
2064 | return scsi_times_out(req); | |
2065 | } | |
2066 | ||
d285203c CH |
2067 | static int scsi_init_request(void *data, struct request *rq, |
2068 | unsigned int hctx_idx, unsigned int request_idx, | |
2069 | unsigned int numa_node) | |
2070 | { | |
2071 | struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq); | |
2072 | ||
2073 | cmd->sense_buffer = kzalloc_node(SCSI_SENSE_BUFFERSIZE, GFP_KERNEL, | |
2074 | numa_node); | |
2075 | if (!cmd->sense_buffer) | |
2076 | return -ENOMEM; | |
2077 | return 0; | |
2078 | } | |
2079 | ||
2080 | static void scsi_exit_request(void *data, struct request *rq, | |
2081 | unsigned int hctx_idx, unsigned int request_idx) | |
2082 | { | |
2083 | struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq); | |
2084 | ||
2085 | kfree(cmd->sense_buffer); | |
2086 | } | |
2087 | ||
f1bea55d | 2088 | static u64 scsi_calculate_bounce_limit(struct Scsi_Host *shost) |
1da177e4 LT |
2089 | { |
2090 | struct device *host_dev; | |
2091 | u64 bounce_limit = 0xffffffff; | |
2092 | ||
2093 | if (shost->unchecked_isa_dma) | |
2094 | return BLK_BOUNCE_ISA; | |
2095 | /* | |
2096 | * Platforms with virtual-DMA translation | |
2097 | * hardware have no practical limit. | |
2098 | */ | |
2099 | if (!PCI_DMA_BUS_IS_PHYS) | |
2100 | return BLK_BOUNCE_ANY; | |
2101 | ||
2102 | host_dev = scsi_get_device(shost); | |
2103 | if (host_dev && host_dev->dma_mask) | |
e83b3664 | 2104 | bounce_limit = (u64)dma_max_pfn(host_dev) << PAGE_SHIFT; |
1da177e4 LT |
2105 | |
2106 | return bounce_limit; | |
2107 | } | |
1da177e4 | 2108 | |
d285203c | 2109 | static void __scsi_init_queue(struct Scsi_Host *shost, struct request_queue *q) |
1da177e4 | 2110 | { |
6f381fa3 | 2111 | struct device *dev = shost->dma_dev; |
1da177e4 | 2112 | |
a8474ce2 JA |
2113 | /* |
2114 | * this limit is imposed by hardware restrictions | |
2115 | */ | |
8a78362c MP |
2116 | blk_queue_max_segments(q, min_t(unsigned short, shost->sg_tablesize, |
2117 | SCSI_MAX_SG_CHAIN_SEGMENTS)); | |
a8474ce2 | 2118 | |
13f05c8d MP |
2119 | if (scsi_host_prot_dma(shost)) { |
2120 | shost->sg_prot_tablesize = | |
2121 | min_not_zero(shost->sg_prot_tablesize, | |
2122 | (unsigned short)SCSI_MAX_PROT_SG_SEGMENTS); | |
2123 | BUG_ON(shost->sg_prot_tablesize < shost->sg_tablesize); | |
2124 | blk_queue_max_integrity_segments(q, shost->sg_prot_tablesize); | |
2125 | } | |
2126 | ||
086fa5ff | 2127 | blk_queue_max_hw_sectors(q, shost->max_sectors); |
1da177e4 LT |
2128 | blk_queue_bounce_limit(q, scsi_calculate_bounce_limit(shost)); |
2129 | blk_queue_segment_boundary(q, shost->dma_boundary); | |
99c84dbd | 2130 | dma_set_seg_boundary(dev, shost->dma_boundary); |
1da177e4 | 2131 | |
860ac568 FT |
2132 | blk_queue_max_segment_size(q, dma_get_max_seg_size(dev)); |
2133 | ||
1da177e4 | 2134 | if (!shost->use_clustering) |
e692cb66 | 2135 | q->limits.cluster = 0; |
465ff318 JB |
2136 | |
2137 | /* | |
2138 | * set a reasonable default alignment on word boundaries: the | |
2139 | * host and device may alter it using | |
2140 | * blk_queue_update_dma_alignment() later. | |
2141 | */ | |
2142 | blk_queue_dma_alignment(q, 0x03); | |
d285203c | 2143 | } |
465ff318 | 2144 | |
d285203c CH |
2145 | struct request_queue *__scsi_alloc_queue(struct Scsi_Host *shost, |
2146 | request_fn_proc *request_fn) | |
2147 | { | |
2148 | struct request_queue *q; | |
2149 | ||
2150 | q = blk_init_queue(request_fn, NULL); | |
2151 | if (!q) | |
2152 | return NULL; | |
2153 | __scsi_init_queue(shost, q); | |
1da177e4 LT |
2154 | return q; |
2155 | } | |
b58d9154 FT |
2156 | EXPORT_SYMBOL(__scsi_alloc_queue); |
2157 | ||
2158 | struct request_queue *scsi_alloc_queue(struct scsi_device *sdev) | |
2159 | { | |
2160 | struct request_queue *q; | |
2161 | ||
2162 | q = __scsi_alloc_queue(sdev->host, scsi_request_fn); | |
2163 | if (!q) | |
2164 | return NULL; | |
2165 | ||
2166 | blk_queue_prep_rq(q, scsi_prep_fn); | |
a1b73fc1 | 2167 | blk_queue_unprep_rq(q, scsi_unprep_fn); |
b58d9154 | 2168 | blk_queue_softirq_done(q, scsi_softirq_done); |
242f9dcb | 2169 | blk_queue_rq_timed_out(q, scsi_times_out); |
6c5121b7 | 2170 | blk_queue_lld_busy(q, scsi_lld_busy); |
b58d9154 FT |
2171 | return q; |
2172 | } | |
1da177e4 | 2173 | |
d285203c CH |
2174 | static struct blk_mq_ops scsi_mq_ops = { |
2175 | .map_queue = blk_mq_map_queue, | |
2176 | .queue_rq = scsi_queue_rq, | |
2177 | .complete = scsi_softirq_done, | |
0152fb6b | 2178 | .timeout = scsi_timeout, |
d285203c CH |
2179 | .init_request = scsi_init_request, |
2180 | .exit_request = scsi_exit_request, | |
2181 | }; | |
2182 | ||
2183 | struct request_queue *scsi_mq_alloc_queue(struct scsi_device *sdev) | |
2184 | { | |
2185 | sdev->request_queue = blk_mq_init_queue(&sdev->host->tag_set); | |
2186 | if (IS_ERR(sdev->request_queue)) | |
2187 | return NULL; | |
2188 | ||
2189 | sdev->request_queue->queuedata = sdev; | |
2190 | __scsi_init_queue(sdev->host, sdev->request_queue); | |
2191 | return sdev->request_queue; | |
2192 | } | |
2193 | ||
2194 | int scsi_mq_setup_tags(struct Scsi_Host *shost) | |
2195 | { | |
2196 | unsigned int cmd_size, sgl_size, tbl_size; | |
2197 | ||
2198 | tbl_size = shost->sg_tablesize; | |
2199 | if (tbl_size > SCSI_MAX_SG_SEGMENTS) | |
2200 | tbl_size = SCSI_MAX_SG_SEGMENTS; | |
2201 | sgl_size = tbl_size * sizeof(struct scatterlist); | |
2202 | cmd_size = sizeof(struct scsi_cmnd) + shost->hostt->cmd_size + sgl_size; | |
2203 | if (scsi_host_get_prot(shost)) | |
2204 | cmd_size += sizeof(struct scsi_data_buffer) + sgl_size; | |
2205 | ||
2206 | memset(&shost->tag_set, 0, sizeof(shost->tag_set)); | |
2207 | shost->tag_set.ops = &scsi_mq_ops; | |
efec4b90 | 2208 | shost->tag_set.nr_hw_queues = shost->nr_hw_queues ? : 1; |
d285203c CH |
2209 | shost->tag_set.queue_depth = shost->can_queue; |
2210 | shost->tag_set.cmd_size = cmd_size; | |
2211 | shost->tag_set.numa_node = NUMA_NO_NODE; | |
2212 | shost->tag_set.flags = BLK_MQ_F_SHOULD_MERGE | BLK_MQ_F_SG_MERGE; | |
24391c0d SL |
2213 | shost->tag_set.flags |= |
2214 | BLK_ALLOC_POLICY_TO_MQ_FLAG(shost->hostt->tag_alloc_policy); | |
d285203c CH |
2215 | shost->tag_set.driver_data = shost; |
2216 | ||
2217 | return blk_mq_alloc_tag_set(&shost->tag_set); | |
2218 | } | |
2219 | ||
2220 | void scsi_mq_destroy_tags(struct Scsi_Host *shost) | |
2221 | { | |
2222 | blk_mq_free_tag_set(&shost->tag_set); | |
2223 | } | |
2224 | ||
33950b56 HR |
2225 | /** |
2226 | * scsi_device_from_queue - return sdev associated with a request_queue | |
2227 | * @q: The request queue to return the sdev from | |
2228 | * | |
2229 | * Return the sdev associated with a request queue or NULL if the | |
2230 | * request_queue does not reference a SCSI device. | |
2231 | */ | |
2232 | struct scsi_device *scsi_device_from_queue(struct request_queue *q) | |
2233 | { | |
2234 | struct scsi_device *sdev = NULL; | |
2235 | ||
2236 | if (q->mq_ops) { | |
2237 | if (q->mq_ops == &scsi_mq_ops) | |
2238 | sdev = q->queuedata; | |
2239 | } else if (q->request_fn == scsi_request_fn) | |
2240 | sdev = q->queuedata; | |
2241 | if (!sdev || !get_device(&sdev->sdev_gendev)) | |
2242 | sdev = NULL; | |
2243 | ||
2244 | return sdev; | |
2245 | } | |
2246 | EXPORT_SYMBOL_GPL(scsi_device_from_queue); | |
2247 | ||
1da177e4 LT |
2248 | /* |
2249 | * Function: scsi_block_requests() | |
2250 | * | |
2251 | * Purpose: Utility function used by low-level drivers to prevent further | |
2252 | * commands from being queued to the device. | |
2253 | * | |
2254 | * Arguments: shost - Host in question | |
2255 | * | |
2256 | * Returns: Nothing | |
2257 | * | |
2258 | * Lock status: No locks are assumed held. | |
2259 | * | |
2260 | * Notes: There is no timer nor any other means by which the requests | |
2261 | * get unblocked other than the low-level driver calling | |
2262 | * scsi_unblock_requests(). | |
2263 | */ | |
2264 | void scsi_block_requests(struct Scsi_Host *shost) | |
2265 | { | |
2266 | shost->host_self_blocked = 1; | |
2267 | } | |
2268 | EXPORT_SYMBOL(scsi_block_requests); | |
2269 | ||
2270 | /* | |
2271 | * Function: scsi_unblock_requests() | |
2272 | * | |
2273 | * Purpose: Utility function used by low-level drivers to allow further | |
2274 | * commands from being queued to the device. | |
2275 | * | |
2276 | * Arguments: shost - Host in question | |
2277 | * | |
2278 | * Returns: Nothing | |
2279 | * | |
2280 | * Lock status: No locks are assumed held. | |
2281 | * | |
2282 | * Notes: There is no timer nor any other means by which the requests | |
2283 | * get unblocked other than the low-level driver calling | |
2284 | * scsi_unblock_requests(). | |
2285 | * | |
2286 | * This is done as an API function so that changes to the | |
2287 | * internals of the scsi mid-layer won't require wholesale | |
2288 | * changes to drivers that use this feature. | |
2289 | */ | |
2290 | void scsi_unblock_requests(struct Scsi_Host *shost) | |
2291 | { | |
2292 | shost->host_self_blocked = 0; | |
2293 | scsi_run_host_queues(shost); | |
2294 | } | |
2295 | EXPORT_SYMBOL(scsi_unblock_requests); | |
2296 | ||
2297 | int __init scsi_init_queue(void) | |
2298 | { | |
2299 | int i; | |
2300 | ||
6362abd3 MP |
2301 | scsi_sdb_cache = kmem_cache_create("scsi_data_buffer", |
2302 | sizeof(struct scsi_data_buffer), | |
2303 | 0, 0, NULL); | |
2304 | if (!scsi_sdb_cache) { | |
2305 | printk(KERN_ERR "SCSI: can't init scsi sdb cache\n"); | |
f078727b | 2306 | return -ENOMEM; |
6f9a35e2 BH |
2307 | } |
2308 | ||
1da177e4 LT |
2309 | for (i = 0; i < SG_MEMPOOL_NR; i++) { |
2310 | struct scsi_host_sg_pool *sgp = scsi_sg_pools + i; | |
2311 | int size = sgp->size * sizeof(struct scatterlist); | |
2312 | ||
2313 | sgp->slab = kmem_cache_create(sgp->name, size, 0, | |
20c2df83 | 2314 | SLAB_HWCACHE_ALIGN, NULL); |
1da177e4 LT |
2315 | if (!sgp->slab) { |
2316 | printk(KERN_ERR "SCSI: can't init sg slab %s\n", | |
2317 | sgp->name); | |
6362abd3 | 2318 | goto cleanup_sdb; |
1da177e4 LT |
2319 | } |
2320 | ||
93d2341c MD |
2321 | sgp->pool = mempool_create_slab_pool(SG_MEMPOOL_SIZE, |
2322 | sgp->slab); | |
1da177e4 LT |
2323 | if (!sgp->pool) { |
2324 | printk(KERN_ERR "SCSI: can't init sg mempool %s\n", | |
2325 | sgp->name); | |
6362abd3 | 2326 | goto cleanup_sdb; |
1da177e4 LT |
2327 | } |
2328 | } | |
2329 | ||
2330 | return 0; | |
3d9dd6ee | 2331 | |
6362abd3 | 2332 | cleanup_sdb: |
3d9dd6ee FT |
2333 | for (i = 0; i < SG_MEMPOOL_NR; i++) { |
2334 | struct scsi_host_sg_pool *sgp = scsi_sg_pools + i; | |
2335 | if (sgp->pool) | |
2336 | mempool_destroy(sgp->pool); | |
2337 | if (sgp->slab) | |
2338 | kmem_cache_destroy(sgp->slab); | |
2339 | } | |
6362abd3 | 2340 | kmem_cache_destroy(scsi_sdb_cache); |
3d9dd6ee FT |
2341 | |
2342 | return -ENOMEM; | |
1da177e4 LT |
2343 | } |
2344 | ||
2345 | void scsi_exit_queue(void) | |
2346 | { | |
2347 | int i; | |
2348 | ||
6362abd3 | 2349 | kmem_cache_destroy(scsi_sdb_cache); |
aa7b5cd7 | 2350 | |
1da177e4 LT |
2351 | for (i = 0; i < SG_MEMPOOL_NR; i++) { |
2352 | struct scsi_host_sg_pool *sgp = scsi_sg_pools + i; | |
2353 | mempool_destroy(sgp->pool); | |
2354 | kmem_cache_destroy(sgp->slab); | |
2355 | } | |
2356 | } | |
5baba830 JB |
2357 | |
2358 | /** | |
2359 | * scsi_mode_select - issue a mode select | |
2360 | * @sdev: SCSI device to be queried | |
2361 | * @pf: Page format bit (1 == standard, 0 == vendor specific) | |
2362 | * @sp: Save page bit (0 == don't save, 1 == save) | |
2363 | * @modepage: mode page being requested | |
2364 | * @buffer: request buffer (may not be smaller than eight bytes) | |
2365 | * @len: length of request buffer. | |
2366 | * @timeout: command timeout | |
2367 | * @retries: number of retries before failing | |
2368 | * @data: returns a structure abstracting the mode header data | |
eb44820c | 2369 | * @sshdr: place to put sense data (or NULL if no sense to be collected). |
5baba830 JB |
2370 | * must be SCSI_SENSE_BUFFERSIZE big. |
2371 | * | |
2372 | * Returns zero if successful; negative error number or scsi | |
2373 | * status on error | |
2374 | * | |
2375 | */ | |
2376 | int | |
2377 | scsi_mode_select(struct scsi_device *sdev, int pf, int sp, int modepage, | |
2378 | unsigned char *buffer, int len, int timeout, int retries, | |
2379 | struct scsi_mode_data *data, struct scsi_sense_hdr *sshdr) | |
2380 | { | |
2381 | unsigned char cmd[10]; | |
2382 | unsigned char *real_buffer; | |
2383 | int ret; | |
2384 | ||
2385 | memset(cmd, 0, sizeof(cmd)); | |
2386 | cmd[1] = (pf ? 0x10 : 0) | (sp ? 0x01 : 0); | |
2387 | ||
2388 | if (sdev->use_10_for_ms) { | |
2389 | if (len > 65535) | |
2390 | return -EINVAL; | |
2391 | real_buffer = kmalloc(8 + len, GFP_KERNEL); | |
2392 | if (!real_buffer) | |
2393 | return -ENOMEM; | |
2394 | memcpy(real_buffer + 8, buffer, len); | |
2395 | len += 8; | |
2396 | real_buffer[0] = 0; | |
2397 | real_buffer[1] = 0; | |
2398 | real_buffer[2] = data->medium_type; | |
2399 | real_buffer[3] = data->device_specific; | |
2400 | real_buffer[4] = data->longlba ? 0x01 : 0; | |
2401 | real_buffer[5] = 0; | |
2402 | real_buffer[6] = data->block_descriptor_length >> 8; | |
2403 | real_buffer[7] = data->block_descriptor_length; | |
2404 | ||
2405 | cmd[0] = MODE_SELECT_10; | |
2406 | cmd[7] = len >> 8; | |
2407 | cmd[8] = len; | |
2408 | } else { | |
2409 | if (len > 255 || data->block_descriptor_length > 255 || | |
2410 | data->longlba) | |
2411 | return -EINVAL; | |
2412 | ||
2413 | real_buffer = kmalloc(4 + len, GFP_KERNEL); | |
2414 | if (!real_buffer) | |
2415 | return -ENOMEM; | |
2416 | memcpy(real_buffer + 4, buffer, len); | |
2417 | len += 4; | |
2418 | real_buffer[0] = 0; | |
2419 | real_buffer[1] = data->medium_type; | |
2420 | real_buffer[2] = data->device_specific; | |
2421 | real_buffer[3] = data->block_descriptor_length; | |
2422 | ||
2423 | ||
2424 | cmd[0] = MODE_SELECT; | |
2425 | cmd[4] = len; | |
2426 | } | |
2427 | ||
2428 | ret = scsi_execute_req(sdev, cmd, DMA_TO_DEVICE, real_buffer, len, | |
f4f4e47e | 2429 | sshdr, timeout, retries, NULL); |
5baba830 JB |
2430 | kfree(real_buffer); |
2431 | return ret; | |
2432 | } | |
2433 | EXPORT_SYMBOL_GPL(scsi_mode_select); | |
2434 | ||
1da177e4 | 2435 | /** |
eb44820c | 2436 | * scsi_mode_sense - issue a mode sense, falling back from 10 to six bytes if necessary. |
1cf72699 | 2437 | * @sdev: SCSI device to be queried |
1da177e4 LT |
2438 | * @dbd: set if mode sense will allow block descriptors to be returned |
2439 | * @modepage: mode page being requested | |
2440 | * @buffer: request buffer (may not be smaller than eight bytes) | |
2441 | * @len: length of request buffer. | |
2442 | * @timeout: command timeout | |
2443 | * @retries: number of retries before failing | |
2444 | * @data: returns a structure abstracting the mode header data | |
eb44820c | 2445 | * @sshdr: place to put sense data (or NULL if no sense to be collected). |
1cf72699 | 2446 | * must be SCSI_SENSE_BUFFERSIZE big. |
1da177e4 LT |
2447 | * |
2448 | * Returns zero if unsuccessful, or the header offset (either 4 | |
2449 | * or 8 depending on whether a six or ten byte command was | |
2450 | * issued) if successful. | |
eb44820c | 2451 | */ |
1da177e4 | 2452 | int |
1cf72699 | 2453 | scsi_mode_sense(struct scsi_device *sdev, int dbd, int modepage, |
1da177e4 | 2454 | unsigned char *buffer, int len, int timeout, int retries, |
5baba830 JB |
2455 | struct scsi_mode_data *data, struct scsi_sense_hdr *sshdr) |
2456 | { | |
1da177e4 LT |
2457 | unsigned char cmd[12]; |
2458 | int use_10_for_ms; | |
2459 | int header_length; | |
0ae80ba9 | 2460 | int result, retry_count = retries; |
ea73a9f2 | 2461 | struct scsi_sense_hdr my_sshdr; |
1da177e4 LT |
2462 | |
2463 | memset(data, 0, sizeof(*data)); | |
2464 | memset(&cmd[0], 0, 12); | |
2465 | cmd[1] = dbd & 0x18; /* allows DBD and LLBA bits */ | |
2466 | cmd[2] = modepage; | |
2467 | ||
ea73a9f2 JB |
2468 | /* caller might not be interested in sense, but we need it */ |
2469 | if (!sshdr) | |
2470 | sshdr = &my_sshdr; | |
2471 | ||
1da177e4 | 2472 | retry: |
1cf72699 | 2473 | use_10_for_ms = sdev->use_10_for_ms; |
1da177e4 LT |
2474 | |
2475 | if (use_10_for_ms) { | |
2476 | if (len < 8) | |
2477 | len = 8; | |
2478 | ||
2479 | cmd[0] = MODE_SENSE_10; | |
2480 | cmd[8] = len; | |
2481 | header_length = 8; | |
2482 | } else { | |
2483 | if (len < 4) | |
2484 | len = 4; | |
2485 | ||
2486 | cmd[0] = MODE_SENSE; | |
2487 | cmd[4] = len; | |
2488 | header_length = 4; | |
2489 | } | |
2490 | ||
1da177e4 LT |
2491 | memset(buffer, 0, len); |
2492 | ||
1cf72699 | 2493 | result = scsi_execute_req(sdev, cmd, DMA_FROM_DEVICE, buffer, len, |
f4f4e47e | 2494 | sshdr, timeout, retries, NULL); |
1da177e4 LT |
2495 | |
2496 | /* This code looks awful: what it's doing is making sure an | |
2497 | * ILLEGAL REQUEST sense return identifies the actual command | |
2498 | * byte as the problem. MODE_SENSE commands can return | |
2499 | * ILLEGAL REQUEST if the code page isn't supported */ | |
2500 | ||
1cf72699 JB |
2501 | if (use_10_for_ms && !scsi_status_is_good(result) && |
2502 | (driver_byte(result) & DRIVER_SENSE)) { | |
ea73a9f2 JB |
2503 | if (scsi_sense_valid(sshdr)) { |
2504 | if ((sshdr->sense_key == ILLEGAL_REQUEST) && | |
2505 | (sshdr->asc == 0x20) && (sshdr->ascq == 0)) { | |
1da177e4 LT |
2506 | /* |
2507 | * Invalid command operation code | |
2508 | */ | |
1cf72699 | 2509 | sdev->use_10_for_ms = 0; |
1da177e4 LT |
2510 | goto retry; |
2511 | } | |
2512 | } | |
2513 | } | |
2514 | ||
1cf72699 | 2515 | if(scsi_status_is_good(result)) { |
6d73c851 AV |
2516 | if (unlikely(buffer[0] == 0x86 && buffer[1] == 0x0b && |
2517 | (modepage == 6 || modepage == 8))) { | |
2518 | /* Initio breakage? */ | |
2519 | header_length = 0; | |
2520 | data->length = 13; | |
2521 | data->medium_type = 0; | |
2522 | data->device_specific = 0; | |
2523 | data->longlba = 0; | |
2524 | data->block_descriptor_length = 0; | |
2525 | } else if(use_10_for_ms) { | |
1da177e4 LT |
2526 | data->length = buffer[0]*256 + buffer[1] + 2; |
2527 | data->medium_type = buffer[2]; | |
2528 | data->device_specific = buffer[3]; | |
2529 | data->longlba = buffer[4] & 0x01; | |
2530 | data->block_descriptor_length = buffer[6]*256 | |
2531 | + buffer[7]; | |
2532 | } else { | |
2533 | data->length = buffer[0] + 1; | |
2534 | data->medium_type = buffer[1]; | |
2535 | data->device_specific = buffer[2]; | |
2536 | data->block_descriptor_length = buffer[3]; | |
2537 | } | |
6d73c851 | 2538 | data->header_length = header_length; |
0ae80ba9 HR |
2539 | } else if ((status_byte(result) == CHECK_CONDITION) && |
2540 | scsi_sense_valid(sshdr) && | |
2541 | sshdr->sense_key == UNIT_ATTENTION && retry_count) { | |
2542 | retry_count--; | |
2543 | goto retry; | |
1da177e4 LT |
2544 | } |
2545 | ||
1cf72699 | 2546 | return result; |
1da177e4 LT |
2547 | } |
2548 | EXPORT_SYMBOL(scsi_mode_sense); | |
2549 | ||
001aac25 JB |
2550 | /** |
2551 | * scsi_test_unit_ready - test if unit is ready | |
2552 | * @sdev: scsi device to change the state of. | |
2553 | * @timeout: command timeout | |
2554 | * @retries: number of retries before failing | |
2555 | * @sshdr_external: Optional pointer to struct scsi_sense_hdr for | |
2556 | * returning sense. Make sure that this is cleared before passing | |
2557 | * in. | |
2558 | * | |
2559 | * Returns zero if unsuccessful or an error if TUR failed. For | |
9f8a2c23 | 2560 | * removable media, UNIT_ATTENTION sets ->changed flag. |
001aac25 | 2561 | **/ |
1da177e4 | 2562 | int |
001aac25 JB |
2563 | scsi_test_unit_ready(struct scsi_device *sdev, int timeout, int retries, |
2564 | struct scsi_sense_hdr *sshdr_external) | |
1da177e4 | 2565 | { |
1da177e4 LT |
2566 | char cmd[] = { |
2567 | TEST_UNIT_READY, 0, 0, 0, 0, 0, | |
2568 | }; | |
001aac25 | 2569 | struct scsi_sense_hdr *sshdr; |
1da177e4 | 2570 | int result; |
001aac25 JB |
2571 | |
2572 | if (!sshdr_external) | |
2573 | sshdr = kzalloc(sizeof(*sshdr), GFP_KERNEL); | |
2574 | else | |
2575 | sshdr = sshdr_external; | |
2576 | ||
2577 | /* try to eat the UNIT_ATTENTION if there are enough retries */ | |
2578 | do { | |
2579 | result = scsi_execute_req(sdev, cmd, DMA_NONE, NULL, 0, sshdr, | |
f4f4e47e | 2580 | timeout, retries, NULL); |
32c356d7 JB |
2581 | if (sdev->removable && scsi_sense_valid(sshdr) && |
2582 | sshdr->sense_key == UNIT_ATTENTION) | |
2583 | sdev->changed = 1; | |
2584 | } while (scsi_sense_valid(sshdr) && | |
2585 | sshdr->sense_key == UNIT_ATTENTION && --retries); | |
001aac25 | 2586 | |
001aac25 JB |
2587 | if (!sshdr_external) |
2588 | kfree(sshdr); | |
1da177e4 LT |
2589 | return result; |
2590 | } | |
2591 | EXPORT_SYMBOL(scsi_test_unit_ready); | |
2592 | ||
2593 | /** | |
eb44820c | 2594 | * scsi_device_set_state - Take the given device through the device state model. |
1da177e4 LT |
2595 | * @sdev: scsi device to change the state of. |
2596 | * @state: state to change to. | |
2597 | * | |
2598 | * Returns zero if unsuccessful or an error if the requested | |
2599 | * transition is illegal. | |
eb44820c | 2600 | */ |
1da177e4 LT |
2601 | int |
2602 | scsi_device_set_state(struct scsi_device *sdev, enum scsi_device_state state) | |
2603 | { | |
2604 | enum scsi_device_state oldstate = sdev->sdev_state; | |
2605 | ||
2606 | if (state == oldstate) | |
2607 | return 0; | |
2608 | ||
2609 | switch (state) { | |
2610 | case SDEV_CREATED: | |
6f4267e3 JB |
2611 | switch (oldstate) { |
2612 | case SDEV_CREATED_BLOCK: | |
2613 | break; | |
2614 | default: | |
2615 | goto illegal; | |
2616 | } | |
2617 | break; | |
1da177e4 LT |
2618 | |
2619 | case SDEV_RUNNING: | |
2620 | switch (oldstate) { | |
2621 | case SDEV_CREATED: | |
2622 | case SDEV_OFFLINE: | |
1b8d2620 | 2623 | case SDEV_TRANSPORT_OFFLINE: |
1da177e4 LT |
2624 | case SDEV_QUIESCE: |
2625 | case SDEV_BLOCK: | |
2626 | break; | |
2627 | default: | |
2628 | goto illegal; | |
2629 | } | |
2630 | break; | |
2631 | ||
2632 | case SDEV_QUIESCE: | |
2633 | switch (oldstate) { | |
2634 | case SDEV_RUNNING: | |
2635 | case SDEV_OFFLINE: | |
1b8d2620 | 2636 | case SDEV_TRANSPORT_OFFLINE: |
1da177e4 LT |
2637 | break; |
2638 | default: | |
2639 | goto illegal; | |
2640 | } | |
2641 | break; | |
2642 | ||
2643 | case SDEV_OFFLINE: | |
1b8d2620 | 2644 | case SDEV_TRANSPORT_OFFLINE: |
1da177e4 LT |
2645 | switch (oldstate) { |
2646 | case SDEV_CREATED: | |
2647 | case SDEV_RUNNING: | |
2648 | case SDEV_QUIESCE: | |
2649 | case SDEV_BLOCK: | |
2650 | break; | |
2651 | default: | |
2652 | goto illegal; | |
2653 | } | |
2654 | break; | |
2655 | ||
2656 | case SDEV_BLOCK: | |
2657 | switch (oldstate) { | |
1da177e4 | 2658 | case SDEV_RUNNING: |
6f4267e3 JB |
2659 | case SDEV_CREATED_BLOCK: |
2660 | break; | |
2661 | default: | |
2662 | goto illegal; | |
2663 | } | |
2664 | break; | |
2665 | ||
2666 | case SDEV_CREATED_BLOCK: | |
2667 | switch (oldstate) { | |
2668 | case SDEV_CREATED: | |
1da177e4 LT |
2669 | break; |
2670 | default: | |
2671 | goto illegal; | |
2672 | } | |
2673 | break; | |
2674 | ||
2675 | case SDEV_CANCEL: | |
2676 | switch (oldstate) { | |
2677 | case SDEV_CREATED: | |
2678 | case SDEV_RUNNING: | |
9ea72909 | 2679 | case SDEV_QUIESCE: |
1da177e4 | 2680 | case SDEV_OFFLINE: |
1b8d2620 | 2681 | case SDEV_TRANSPORT_OFFLINE: |
1da177e4 LT |
2682 | case SDEV_BLOCK: |
2683 | break; | |
2684 | default: | |
2685 | goto illegal; | |
2686 | } | |
2687 | break; | |
2688 | ||
2689 | case SDEV_DEL: | |
2690 | switch (oldstate) { | |
309bd271 BK |
2691 | case SDEV_CREATED: |
2692 | case SDEV_RUNNING: | |
2693 | case SDEV_OFFLINE: | |
1b8d2620 | 2694 | case SDEV_TRANSPORT_OFFLINE: |
1da177e4 | 2695 | case SDEV_CANCEL: |
0516c08d | 2696 | case SDEV_CREATED_BLOCK: |
1da177e4 LT |
2697 | break; |
2698 | default: | |
2699 | goto illegal; | |
2700 | } | |
2701 | break; | |
2702 | ||
2703 | } | |
2704 | sdev->sdev_state = state; | |
2705 | return 0; | |
2706 | ||
2707 | illegal: | |
91921e01 | 2708 | SCSI_LOG_ERROR_RECOVERY(1, |
9ccfc756 | 2709 | sdev_printk(KERN_ERR, sdev, |
91921e01 | 2710 | "Illegal state transition %s->%s", |
9ccfc756 JB |
2711 | scsi_device_state_name(oldstate), |
2712 | scsi_device_state_name(state)) | |
1da177e4 LT |
2713 | ); |
2714 | return -EINVAL; | |
2715 | } | |
2716 | EXPORT_SYMBOL(scsi_device_set_state); | |
2717 | ||
a341cd0f JG |
2718 | /** |
2719 | * sdev_evt_emit - emit a single SCSI device uevent | |
2720 | * @sdev: associated SCSI device | |
2721 | * @evt: event to emit | |
2722 | * | |
2723 | * Send a single uevent (scsi_event) to the associated scsi_device. | |
2724 | */ | |
2725 | static void scsi_evt_emit(struct scsi_device *sdev, struct scsi_event *evt) | |
2726 | { | |
2727 | int idx = 0; | |
2728 | char *envp[3]; | |
2729 | ||
2730 | switch (evt->evt_type) { | |
2731 | case SDEV_EVT_MEDIA_CHANGE: | |
2732 | envp[idx++] = "SDEV_MEDIA_CHANGE=1"; | |
2733 | break; | |
279afdfe EM |
2734 | case SDEV_EVT_INQUIRY_CHANGE_REPORTED: |
2735 | envp[idx++] = "SDEV_UA=INQUIRY_DATA_HAS_CHANGED"; | |
2736 | break; | |
2737 | case SDEV_EVT_CAPACITY_CHANGE_REPORTED: | |
2738 | envp[idx++] = "SDEV_UA=CAPACITY_DATA_HAS_CHANGED"; | |
2739 | break; | |
2740 | case SDEV_EVT_SOFT_THRESHOLD_REACHED_REPORTED: | |
2741 | envp[idx++] = "SDEV_UA=THIN_PROVISIONING_SOFT_THRESHOLD_REACHED"; | |
2742 | break; | |
2743 | case SDEV_EVT_MODE_PARAMETER_CHANGE_REPORTED: | |
2744 | envp[idx++] = "SDEV_UA=MODE_PARAMETERS_CHANGED"; | |
2745 | break; | |
2746 | case SDEV_EVT_LUN_CHANGE_REPORTED: | |
2747 | envp[idx++] = "SDEV_UA=REPORTED_LUNS_DATA_HAS_CHANGED"; | |
2748 | break; | |
14c3e677 HR |
2749 | case SDEV_EVT_ALUA_STATE_CHANGE_REPORTED: |
2750 | envp[idx++] = "SDEV_UA=ASYMMETRIC_ACCESS_STATE_CHANGED"; | |
2751 | break; | |
a341cd0f JG |
2752 | default: |
2753 | /* do nothing */ | |
2754 | break; | |
2755 | } | |
2756 | ||
2757 | envp[idx++] = NULL; | |
2758 | ||
2759 | kobject_uevent_env(&sdev->sdev_gendev.kobj, KOBJ_CHANGE, envp); | |
2760 | } | |
2761 | ||
2762 | /** | |
2763 | * sdev_evt_thread - send a uevent for each scsi event | |
2764 | * @work: work struct for scsi_device | |
2765 | * | |
2766 | * Dispatch queued events to their associated scsi_device kobjects | |
2767 | * as uevents. | |
2768 | */ | |
2769 | void scsi_evt_thread(struct work_struct *work) | |
2770 | { | |
2771 | struct scsi_device *sdev; | |
279afdfe | 2772 | enum scsi_device_event evt_type; |
a341cd0f JG |
2773 | LIST_HEAD(event_list); |
2774 | ||
2775 | sdev = container_of(work, struct scsi_device, event_work); | |
2776 | ||
279afdfe EM |
2777 | for (evt_type = SDEV_EVT_FIRST; evt_type <= SDEV_EVT_LAST; evt_type++) |
2778 | if (test_and_clear_bit(evt_type, sdev->pending_events)) | |
2779 | sdev_evt_send_simple(sdev, evt_type, GFP_KERNEL); | |
2780 | ||
a341cd0f JG |
2781 | while (1) { |
2782 | struct scsi_event *evt; | |
2783 | struct list_head *this, *tmp; | |
2784 | unsigned long flags; | |
2785 | ||
2786 | spin_lock_irqsave(&sdev->list_lock, flags); | |
2787 | list_splice_init(&sdev->event_list, &event_list); | |
2788 | spin_unlock_irqrestore(&sdev->list_lock, flags); | |
2789 | ||
2790 | if (list_empty(&event_list)) | |
2791 | break; | |
2792 | ||
2793 | list_for_each_safe(this, tmp, &event_list) { | |
2794 | evt = list_entry(this, struct scsi_event, node); | |
2795 | list_del(&evt->node); | |
2796 | scsi_evt_emit(sdev, evt); | |
2797 | kfree(evt); | |
2798 | } | |
2799 | } | |
2800 | } | |
2801 | ||
2802 | /** | |
2803 | * sdev_evt_send - send asserted event to uevent thread | |
2804 | * @sdev: scsi_device event occurred on | |
2805 | * @evt: event to send | |
2806 | * | |
2807 | * Assert scsi device event asynchronously. | |
2808 | */ | |
2809 | void sdev_evt_send(struct scsi_device *sdev, struct scsi_event *evt) | |
2810 | { | |
2811 | unsigned long flags; | |
2812 | ||
4d1566ed KS |
2813 | #if 0 |
2814 | /* FIXME: currently this check eliminates all media change events | |
2815 | * for polled devices. Need to update to discriminate between AN | |
2816 | * and polled events */ | |
a341cd0f JG |
2817 | if (!test_bit(evt->evt_type, sdev->supported_events)) { |
2818 | kfree(evt); | |
2819 | return; | |
2820 | } | |
4d1566ed | 2821 | #endif |
a341cd0f JG |
2822 | |
2823 | spin_lock_irqsave(&sdev->list_lock, flags); | |
2824 | list_add_tail(&evt->node, &sdev->event_list); | |
2825 | schedule_work(&sdev->event_work); | |
2826 | spin_unlock_irqrestore(&sdev->list_lock, flags); | |
2827 | } | |
2828 | EXPORT_SYMBOL_GPL(sdev_evt_send); | |
2829 | ||
2830 | /** | |
2831 | * sdev_evt_alloc - allocate a new scsi event | |
2832 | * @evt_type: type of event to allocate | |
2833 | * @gfpflags: GFP flags for allocation | |
2834 | * | |
2835 | * Allocates and returns a new scsi_event. | |
2836 | */ | |
2837 | struct scsi_event *sdev_evt_alloc(enum scsi_device_event evt_type, | |
2838 | gfp_t gfpflags) | |
2839 | { | |
2840 | struct scsi_event *evt = kzalloc(sizeof(struct scsi_event), gfpflags); | |
2841 | if (!evt) | |
2842 | return NULL; | |
2843 | ||
2844 | evt->evt_type = evt_type; | |
2845 | INIT_LIST_HEAD(&evt->node); | |
2846 | ||
2847 | /* evt_type-specific initialization, if any */ | |
2848 | switch (evt_type) { | |
2849 | case SDEV_EVT_MEDIA_CHANGE: | |
279afdfe EM |
2850 | case SDEV_EVT_INQUIRY_CHANGE_REPORTED: |
2851 | case SDEV_EVT_CAPACITY_CHANGE_REPORTED: | |
2852 | case SDEV_EVT_SOFT_THRESHOLD_REACHED_REPORTED: | |
2853 | case SDEV_EVT_MODE_PARAMETER_CHANGE_REPORTED: | |
2854 | case SDEV_EVT_LUN_CHANGE_REPORTED: | |
14c3e677 | 2855 | case SDEV_EVT_ALUA_STATE_CHANGE_REPORTED: |
a341cd0f JG |
2856 | default: |
2857 | /* do nothing */ | |
2858 | break; | |
2859 | } | |
2860 | ||
2861 | return evt; | |
2862 | } | |
2863 | EXPORT_SYMBOL_GPL(sdev_evt_alloc); | |
2864 | ||
2865 | /** | |
2866 | * sdev_evt_send_simple - send asserted event to uevent thread | |
2867 | * @sdev: scsi_device event occurred on | |
2868 | * @evt_type: type of event to send | |
2869 | * @gfpflags: GFP flags for allocation | |
2870 | * | |
2871 | * Assert scsi device event asynchronously, given an event type. | |
2872 | */ | |
2873 | void sdev_evt_send_simple(struct scsi_device *sdev, | |
2874 | enum scsi_device_event evt_type, gfp_t gfpflags) | |
2875 | { | |
2876 | struct scsi_event *evt = sdev_evt_alloc(evt_type, gfpflags); | |
2877 | if (!evt) { | |
2878 | sdev_printk(KERN_ERR, sdev, "event %d eaten due to OOM\n", | |
2879 | evt_type); | |
2880 | return; | |
2881 | } | |
2882 | ||
2883 | sdev_evt_send(sdev, evt); | |
2884 | } | |
2885 | EXPORT_SYMBOL_GPL(sdev_evt_send_simple); | |
2886 | ||
1da177e4 LT |
2887 | /** |
2888 | * scsi_device_quiesce - Block user issued commands. | |
2889 | * @sdev: scsi device to quiesce. | |
2890 | * | |
2891 | * This works by trying to transition to the SDEV_QUIESCE state | |
2892 | * (which must be a legal transition). When the device is in this | |
2893 | * state, only special requests will be accepted, all others will | |
2894 | * be deferred. Since special requests may also be requeued requests, | |
2895 | * a successful return doesn't guarantee the device will be | |
2896 | * totally quiescent. | |
2897 | * | |
2898 | * Must be called with user context, may sleep. | |
2899 | * | |
2900 | * Returns zero if unsuccessful or an error if not. | |
eb44820c | 2901 | */ |
1da177e4 LT |
2902 | int |
2903 | scsi_device_quiesce(struct scsi_device *sdev) | |
2904 | { | |
2905 | int err = scsi_device_set_state(sdev, SDEV_QUIESCE); | |
2906 | if (err) | |
2907 | return err; | |
2908 | ||
2909 | scsi_run_queue(sdev->request_queue); | |
71e75c97 | 2910 | while (atomic_read(&sdev->device_busy)) { |
1da177e4 LT |
2911 | msleep_interruptible(200); |
2912 | scsi_run_queue(sdev->request_queue); | |
2913 | } | |
2914 | return 0; | |
2915 | } | |
2916 | EXPORT_SYMBOL(scsi_device_quiesce); | |
2917 | ||
2918 | /** | |
2919 | * scsi_device_resume - Restart user issued commands to a quiesced device. | |
2920 | * @sdev: scsi device to resume. | |
2921 | * | |
2922 | * Moves the device from quiesced back to running and restarts the | |
2923 | * queues. | |
2924 | * | |
2925 | * Must be called with user context, may sleep. | |
eb44820c | 2926 | */ |
a7a20d10 | 2927 | void scsi_device_resume(struct scsi_device *sdev) |
1da177e4 | 2928 | { |
a7a20d10 DW |
2929 | /* check if the device state was mutated prior to resume, and if |
2930 | * so assume the state is being managed elsewhere (for example | |
2931 | * device deleted during suspend) | |
2932 | */ | |
2933 | if (sdev->sdev_state != SDEV_QUIESCE || | |
2934 | scsi_device_set_state(sdev, SDEV_RUNNING)) | |
1da177e4 LT |
2935 | return; |
2936 | scsi_run_queue(sdev->request_queue); | |
2937 | } | |
2938 | EXPORT_SYMBOL(scsi_device_resume); | |
2939 | ||
2940 | static void | |
2941 | device_quiesce_fn(struct scsi_device *sdev, void *data) | |
2942 | { | |
2943 | scsi_device_quiesce(sdev); | |
2944 | } | |
2945 | ||
2946 | void | |
2947 | scsi_target_quiesce(struct scsi_target *starget) | |
2948 | { | |
2949 | starget_for_each_device(starget, NULL, device_quiesce_fn); | |
2950 | } | |
2951 | EXPORT_SYMBOL(scsi_target_quiesce); | |
2952 | ||
2953 | static void | |
2954 | device_resume_fn(struct scsi_device *sdev, void *data) | |
2955 | { | |
2956 | scsi_device_resume(sdev); | |
2957 | } | |
2958 | ||
2959 | void | |
2960 | scsi_target_resume(struct scsi_target *starget) | |
2961 | { | |
2962 | starget_for_each_device(starget, NULL, device_resume_fn); | |
2963 | } | |
2964 | EXPORT_SYMBOL(scsi_target_resume); | |
2965 | ||
2966 | /** | |
eb44820c | 2967 | * scsi_internal_device_block - internal function to put a device temporarily into the SDEV_BLOCK state |
1da177e4 LT |
2968 | * @sdev: device to block |
2969 | * | |
2970 | * Block request made by scsi lld's to temporarily stop all | |
2971 | * scsi commands on the specified device. Called from interrupt | |
2972 | * or normal process context. | |
2973 | * | |
2974 | * Returns zero if successful or error if not | |
2975 | * | |
2976 | * Notes: | |
2977 | * This routine transitions the device to the SDEV_BLOCK state | |
2978 | * (which must be a legal transition). When the device is in this | |
2979 | * state, all commands are deferred until the scsi lld reenables | |
2980 | * the device with scsi_device_unblock or device_block_tmo fires. | |
eb44820c | 2981 | */ |
1da177e4 LT |
2982 | int |
2983 | scsi_internal_device_block(struct scsi_device *sdev) | |
2984 | { | |
165125e1 | 2985 | struct request_queue *q = sdev->request_queue; |
1da177e4 LT |
2986 | unsigned long flags; |
2987 | int err = 0; | |
2988 | ||
2989 | err = scsi_device_set_state(sdev, SDEV_BLOCK); | |
6f4267e3 JB |
2990 | if (err) { |
2991 | err = scsi_device_set_state(sdev, SDEV_CREATED_BLOCK); | |
2992 | ||
2993 | if (err) | |
2994 | return err; | |
2995 | } | |
1da177e4 LT |
2996 | |
2997 | /* | |
2998 | * The device has transitioned to SDEV_BLOCK. Stop the | |
2999 | * block layer from calling the midlayer with this device's | |
3000 | * request queue. | |
3001 | */ | |
d285203c CH |
3002 | if (q->mq_ops) { |
3003 | blk_mq_stop_hw_queues(q); | |
3004 | } else { | |
3005 | spin_lock_irqsave(q->queue_lock, flags); | |
3006 | blk_stop_queue(q); | |
3007 | spin_unlock_irqrestore(q->queue_lock, flags); | |
3008 | } | |
1da177e4 LT |
3009 | |
3010 | return 0; | |
3011 | } | |
3012 | EXPORT_SYMBOL_GPL(scsi_internal_device_block); | |
3013 | ||
3014 | /** | |
3015 | * scsi_internal_device_unblock - resume a device after a block request | |
3016 | * @sdev: device to resume | |
5d9fb5cc | 3017 | * @new_state: state to set devices to after unblocking |
1da177e4 LT |
3018 | * |
3019 | * Called by scsi lld's or the midlayer to restart the device queue | |
3020 | * for the previously suspended scsi device. Called from interrupt or | |
3021 | * normal process context. | |
3022 | * | |
3023 | * Returns zero if successful or error if not. | |
3024 | * | |
3025 | * Notes: | |
3026 | * This routine transitions the device to the SDEV_RUNNING state | |
5d9fb5cc | 3027 | * or to one of the offline states (which must be a legal transition) |
d075498c | 3028 | * allowing the midlayer to goose the queue for this device. |
eb44820c | 3029 | */ |
1da177e4 | 3030 | int |
5d9fb5cc MC |
3031 | scsi_internal_device_unblock(struct scsi_device *sdev, |
3032 | enum scsi_device_state new_state) | |
1da177e4 | 3033 | { |
165125e1 | 3034 | struct request_queue *q = sdev->request_queue; |
1da177e4 | 3035 | unsigned long flags; |
5d9fb5cc MC |
3036 | |
3037 | /* | |
3038 | * Try to transition the scsi device to SDEV_RUNNING or one of the | |
3039 | * offlined states and goose the device queue if successful. | |
1da177e4 | 3040 | */ |
0e58076b VC |
3041 | if ((sdev->sdev_state == SDEV_BLOCK) || |
3042 | (sdev->sdev_state == SDEV_TRANSPORT_OFFLINE)) | |
5d9fb5cc MC |
3043 | sdev->sdev_state = new_state; |
3044 | else if (sdev->sdev_state == SDEV_CREATED_BLOCK) { | |
3045 | if (new_state == SDEV_TRANSPORT_OFFLINE || | |
3046 | new_state == SDEV_OFFLINE) | |
3047 | sdev->sdev_state = new_state; | |
3048 | else | |
3049 | sdev->sdev_state = SDEV_CREATED; | |
3050 | } else if (sdev->sdev_state != SDEV_CANCEL && | |
986fe6c7 | 3051 | sdev->sdev_state != SDEV_OFFLINE) |
5c10e63c | 3052 | return -EINVAL; |
1da177e4 | 3053 | |
d285203c CH |
3054 | if (q->mq_ops) { |
3055 | blk_mq_start_stopped_hw_queues(q, false); | |
3056 | } else { | |
3057 | spin_lock_irqsave(q->queue_lock, flags); | |
3058 | blk_start_queue(q); | |
3059 | spin_unlock_irqrestore(q->queue_lock, flags); | |
3060 | } | |
1da177e4 LT |
3061 | |
3062 | return 0; | |
3063 | } | |
3064 | EXPORT_SYMBOL_GPL(scsi_internal_device_unblock); | |
3065 | ||
3066 | static void | |
3067 | device_block(struct scsi_device *sdev, void *data) | |
3068 | { | |
3069 | scsi_internal_device_block(sdev); | |
3070 | } | |
3071 | ||
3072 | static int | |
3073 | target_block(struct device *dev, void *data) | |
3074 | { | |
3075 | if (scsi_is_target_device(dev)) | |
3076 | starget_for_each_device(to_scsi_target(dev), NULL, | |
3077 | device_block); | |
3078 | return 0; | |
3079 | } | |
3080 | ||
3081 | void | |
3082 | scsi_target_block(struct device *dev) | |
3083 | { | |
3084 | if (scsi_is_target_device(dev)) | |
3085 | starget_for_each_device(to_scsi_target(dev), NULL, | |
3086 | device_block); | |
3087 | else | |
3088 | device_for_each_child(dev, NULL, target_block); | |
3089 | } | |
3090 | EXPORT_SYMBOL_GPL(scsi_target_block); | |
3091 | ||
3092 | static void | |
3093 | device_unblock(struct scsi_device *sdev, void *data) | |
3094 | { | |
5d9fb5cc | 3095 | scsi_internal_device_unblock(sdev, *(enum scsi_device_state *)data); |
1da177e4 LT |
3096 | } |
3097 | ||
3098 | static int | |
3099 | target_unblock(struct device *dev, void *data) | |
3100 | { | |
3101 | if (scsi_is_target_device(dev)) | |
5d9fb5cc | 3102 | starget_for_each_device(to_scsi_target(dev), data, |
1da177e4 LT |
3103 | device_unblock); |
3104 | return 0; | |
3105 | } | |
3106 | ||
3107 | void | |
5d9fb5cc | 3108 | scsi_target_unblock(struct device *dev, enum scsi_device_state new_state) |
1da177e4 LT |
3109 | { |
3110 | if (scsi_is_target_device(dev)) | |
5d9fb5cc | 3111 | starget_for_each_device(to_scsi_target(dev), &new_state, |
1da177e4 LT |
3112 | device_unblock); |
3113 | else | |
5d9fb5cc | 3114 | device_for_each_child(dev, &new_state, target_unblock); |
1da177e4 LT |
3115 | } |
3116 | EXPORT_SYMBOL_GPL(scsi_target_unblock); | |
cdb8c2a6 GL |
3117 | |
3118 | /** | |
3119 | * scsi_kmap_atomic_sg - find and atomically map an sg-elemnt | |
eb44820c | 3120 | * @sgl: scatter-gather list |
cdb8c2a6 GL |
3121 | * @sg_count: number of segments in sg |
3122 | * @offset: offset in bytes into sg, on return offset into the mapped area | |
3123 | * @len: bytes to map, on return number of bytes mapped | |
3124 | * | |
3125 | * Returns virtual address of the start of the mapped page | |
3126 | */ | |
c6132da1 | 3127 | void *scsi_kmap_atomic_sg(struct scatterlist *sgl, int sg_count, |
cdb8c2a6 GL |
3128 | size_t *offset, size_t *len) |
3129 | { | |
3130 | int i; | |
3131 | size_t sg_len = 0, len_complete = 0; | |
c6132da1 | 3132 | struct scatterlist *sg; |
cdb8c2a6 GL |
3133 | struct page *page; |
3134 | ||
22cfefb5 AM |
3135 | WARN_ON(!irqs_disabled()); |
3136 | ||
c6132da1 | 3137 | for_each_sg(sgl, sg, sg_count, i) { |
cdb8c2a6 | 3138 | len_complete = sg_len; /* Complete sg-entries */ |
c6132da1 | 3139 | sg_len += sg->length; |
cdb8c2a6 GL |
3140 | if (sg_len > *offset) |
3141 | break; | |
3142 | } | |
3143 | ||
3144 | if (unlikely(i == sg_count)) { | |
169e1a2a AM |
3145 | printk(KERN_ERR "%s: Bytes in sg: %zu, requested offset %zu, " |
3146 | "elements %d\n", | |
cadbd4a5 | 3147 | __func__, sg_len, *offset, sg_count); |
cdb8c2a6 GL |
3148 | WARN_ON(1); |
3149 | return NULL; | |
3150 | } | |
3151 | ||
3152 | /* Offset starting from the beginning of first page in this sg-entry */ | |
c6132da1 | 3153 | *offset = *offset - len_complete + sg->offset; |
cdb8c2a6 GL |
3154 | |
3155 | /* Assumption: contiguous pages can be accessed as "page + i" */ | |
45711f1a | 3156 | page = nth_page(sg_page(sg), (*offset >> PAGE_SHIFT)); |
cdb8c2a6 GL |
3157 | *offset &= ~PAGE_MASK; |
3158 | ||
3159 | /* Bytes in this sg-entry from *offset to the end of the page */ | |
3160 | sg_len = PAGE_SIZE - *offset; | |
3161 | if (*len > sg_len) | |
3162 | *len = sg_len; | |
3163 | ||
77dfce07 | 3164 | return kmap_atomic(page); |
cdb8c2a6 GL |
3165 | } |
3166 | EXPORT_SYMBOL(scsi_kmap_atomic_sg); | |
3167 | ||
3168 | /** | |
eb44820c | 3169 | * scsi_kunmap_atomic_sg - atomically unmap a virtual address, previously mapped with scsi_kmap_atomic_sg |
cdb8c2a6 GL |
3170 | * @virt: virtual address to be unmapped |
3171 | */ | |
3172 | void scsi_kunmap_atomic_sg(void *virt) | |
3173 | { | |
77dfce07 | 3174 | kunmap_atomic(virt); |
cdb8c2a6 GL |
3175 | } |
3176 | EXPORT_SYMBOL(scsi_kunmap_atomic_sg); | |
6f4c827e AL |
3177 | |
3178 | void sdev_disable_disk_events(struct scsi_device *sdev) | |
3179 | { | |
3180 | atomic_inc(&sdev->disk_events_disable_depth); | |
3181 | } | |
3182 | EXPORT_SYMBOL(sdev_disable_disk_events); | |
3183 | ||
3184 | void sdev_enable_disk_events(struct scsi_device *sdev) | |
3185 | { | |
3186 | if (WARN_ON_ONCE(atomic_read(&sdev->disk_events_disable_depth) <= 0)) | |
3187 | return; | |
3188 | atomic_dec(&sdev->disk_events_disable_depth); | |
3189 | } | |
3190 | EXPORT_SYMBOL(sdev_enable_disk_events); |