Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * scsi_lib.c Copyright (C) 1999 Eric Youngdale | |
3 | * | |
4 | * SCSI queueing library. | |
5 | * Initial versions: Eric Youngdale (eric@andante.org). | |
6 | * Based upon conversations with large numbers | |
7 | * of people at Linux Expo. | |
8 | */ | |
9 | ||
10 | #include <linux/bio.h> | |
d3f46f39 | 11 | #include <linux/bitops.h> |
1da177e4 LT |
12 | #include <linux/blkdev.h> |
13 | #include <linux/completion.h> | |
14 | #include <linux/kernel.h> | |
09703660 | 15 | #include <linux/export.h> |
1da177e4 LT |
16 | #include <linux/mempool.h> |
17 | #include <linux/slab.h> | |
18 | #include <linux/init.h> | |
19 | #include <linux/pci.h> | |
20 | #include <linux/delay.h> | |
faead26d | 21 | #include <linux/hardirq.h> |
c6132da1 | 22 | #include <linux/scatterlist.h> |
1da177e4 LT |
23 | |
24 | #include <scsi/scsi.h> | |
beb40487 | 25 | #include <scsi/scsi_cmnd.h> |
1da177e4 LT |
26 | #include <scsi/scsi_dbg.h> |
27 | #include <scsi/scsi_device.h> | |
28 | #include <scsi/scsi_driver.h> | |
29 | #include <scsi/scsi_eh.h> | |
30 | #include <scsi/scsi_host.h> | |
1da177e4 LT |
31 | |
32 | #include "scsi_priv.h" | |
33 | #include "scsi_logging.h" | |
34 | ||
35 | ||
6391a113 | 36 | #define SG_MEMPOOL_NR ARRAY_SIZE(scsi_sg_pools) |
5972511b | 37 | #define SG_MEMPOOL_SIZE 2 |
1da177e4 LT |
38 | |
39 | struct scsi_host_sg_pool { | |
40 | size_t size; | |
a8474ce2 | 41 | char *name; |
e18b890b | 42 | struct kmem_cache *slab; |
1da177e4 LT |
43 | mempool_t *pool; |
44 | }; | |
45 | ||
d3f46f39 JB |
46 | #define SP(x) { x, "sgpool-" __stringify(x) } |
47 | #if (SCSI_MAX_SG_SEGMENTS < 32) | |
48 | #error SCSI_MAX_SG_SEGMENTS is too small (must be 32 or greater) | |
49 | #endif | |
52c1da39 | 50 | static struct scsi_host_sg_pool scsi_sg_pools[] = { |
1da177e4 LT |
51 | SP(8), |
52 | SP(16), | |
fd820f40 | 53 | #if (SCSI_MAX_SG_SEGMENTS > 32) |
d3f46f39 | 54 | SP(32), |
fd820f40 | 55 | #if (SCSI_MAX_SG_SEGMENTS > 64) |
d3f46f39 JB |
56 | SP(64), |
57 | #if (SCSI_MAX_SG_SEGMENTS > 128) | |
1da177e4 | 58 | SP(128), |
d3f46f39 JB |
59 | #if (SCSI_MAX_SG_SEGMENTS > 256) |
60 | #error SCSI_MAX_SG_SEGMENTS is too large (256 MAX) | |
fd820f40 FT |
61 | #endif |
62 | #endif | |
63 | #endif | |
d3f46f39 JB |
64 | #endif |
65 | SP(SCSI_MAX_SG_SEGMENTS) | |
a8474ce2 | 66 | }; |
1da177e4 LT |
67 | #undef SP |
68 | ||
7027ad72 | 69 | struct kmem_cache *scsi_sdb_cache; |
6f9a35e2 | 70 | |
a488e749 JA |
71 | /* |
72 | * When to reinvoke queueing after a resource shortage. It's 3 msecs to | |
73 | * not change behaviour from the previous unplug mechanism, experimentation | |
74 | * may prove this needs changing. | |
75 | */ | |
76 | #define SCSI_QUEUE_DELAY 3 | |
77 | ||
4f5299ac JB |
78 | /** |
79 | * __scsi_queue_insert - private queue insertion | |
80 | * @cmd: The SCSI command being requeued | |
81 | * @reason: The reason for the requeue | |
82 | * @unbusy: Whether the queue should be unbusied | |
1da177e4 | 83 | * |
4f5299ac JB |
84 | * This is a private queue insertion. The public interface |
85 | * scsi_queue_insert() always assumes the queue should be unbusied | |
86 | * because it's always called before the completion. This function is | |
87 | * for a requeue after completion, which should only occur in this | |
88 | * file. | |
1da177e4 | 89 | */ |
84feb166 | 90 | static void __scsi_queue_insert(struct scsi_cmnd *cmd, int reason, int unbusy) |
1da177e4 LT |
91 | { |
92 | struct Scsi_Host *host = cmd->device->host; | |
93 | struct scsi_device *device = cmd->device; | |
f0c0a376 | 94 | struct scsi_target *starget = scsi_target(device); |
a1bf9d1d TH |
95 | struct request_queue *q = device->request_queue; |
96 | unsigned long flags; | |
1da177e4 LT |
97 | |
98 | SCSI_LOG_MLQUEUE(1, | |
99 | printk("Inserting command %p into mlqueue\n", cmd)); | |
100 | ||
101 | /* | |
d8c37e7b | 102 | * Set the appropriate busy bit for the device/host. |
1da177e4 LT |
103 | * |
104 | * If the host/device isn't busy, assume that something actually | |
105 | * completed, and that we should be able to queue a command now. | |
106 | * | |
107 | * Note that the prior mid-layer assumption that any host could | |
108 | * always queue at least one command is now broken. The mid-layer | |
109 | * will implement a user specifiable stall (see | |
110 | * scsi_host.max_host_blocked and scsi_device.max_device_blocked) | |
111 | * if a command is requeued with no other commands outstanding | |
112 | * either for the device or for the host. | |
113 | */ | |
f0c0a376 MC |
114 | switch (reason) { |
115 | case SCSI_MLQUEUE_HOST_BUSY: | |
1da177e4 | 116 | host->host_blocked = host->max_host_blocked; |
f0c0a376 MC |
117 | break; |
118 | case SCSI_MLQUEUE_DEVICE_BUSY: | |
573e5913 | 119 | case SCSI_MLQUEUE_EH_RETRY: |
1da177e4 | 120 | device->device_blocked = device->max_device_blocked; |
f0c0a376 MC |
121 | break; |
122 | case SCSI_MLQUEUE_TARGET_BUSY: | |
123 | starget->target_blocked = starget->max_target_blocked; | |
124 | break; | |
125 | } | |
1da177e4 | 126 | |
1da177e4 LT |
127 | /* |
128 | * Decrement the counters, since these commands are no longer | |
129 | * active on the host/device. | |
130 | */ | |
4f5299ac JB |
131 | if (unbusy) |
132 | scsi_device_unbusy(device); | |
1da177e4 LT |
133 | |
134 | /* | |
a1bf9d1d | 135 | * Requeue this command. It will go before all other commands |
b485462a BVA |
136 | * that are already in the queue. Schedule requeue work under |
137 | * lock such that the kblockd_schedule_work() call happens | |
138 | * before blk_cleanup_queue() finishes. | |
a488e749 | 139 | */ |
644373a4 | 140 | cmd->result = 0; |
a1bf9d1d | 141 | spin_lock_irqsave(q->queue_lock, flags); |
59897dad | 142 | blk_requeue_request(q, cmd->request); |
9937a5e2 | 143 | kblockd_schedule_work(q, &device->requeue_work); |
b485462a | 144 | spin_unlock_irqrestore(q->queue_lock, flags); |
1da177e4 LT |
145 | } |
146 | ||
4f5299ac JB |
147 | /* |
148 | * Function: scsi_queue_insert() | |
149 | * | |
150 | * Purpose: Insert a command in the midlevel queue. | |
151 | * | |
152 | * Arguments: cmd - command that we are adding to queue. | |
153 | * reason - why we are inserting command to queue. | |
154 | * | |
155 | * Lock status: Assumed that lock is not held upon entry. | |
156 | * | |
157 | * Returns: Nothing. | |
158 | * | |
159 | * Notes: We do this for one of two cases. Either the host is busy | |
160 | * and it cannot accept any more commands for the time being, | |
161 | * or the device returned QUEUE_FULL and can accept no more | |
162 | * commands. | |
163 | * Notes: This could be called either from an interrupt context or a | |
164 | * normal process context. | |
165 | */ | |
84feb166 | 166 | void scsi_queue_insert(struct scsi_cmnd *cmd, int reason) |
4f5299ac | 167 | { |
84feb166 | 168 | __scsi_queue_insert(cmd, reason, 1); |
4f5299ac | 169 | } |
39216033 | 170 | /** |
33aa687d | 171 | * scsi_execute - insert request and wait for the result |
39216033 JB |
172 | * @sdev: scsi device |
173 | * @cmd: scsi command | |
174 | * @data_direction: data direction | |
175 | * @buffer: data buffer | |
176 | * @bufflen: len of buffer | |
177 | * @sense: optional sense buffer | |
178 | * @timeout: request timeout in seconds | |
179 | * @retries: number of times to retry request | |
33aa687d | 180 | * @flags: or into request flags; |
f4f4e47e | 181 | * @resid: optional residual length |
39216033 | 182 | * |
59c51591 | 183 | * returns the req->errors value which is the scsi_cmnd result |
ea73a9f2 | 184 | * field. |
eb44820c | 185 | */ |
33aa687d JB |
186 | int scsi_execute(struct scsi_device *sdev, const unsigned char *cmd, |
187 | int data_direction, void *buffer, unsigned bufflen, | |
2bfad21e | 188 | unsigned char *sense, int timeout, int retries, u64 flags, |
f4f4e47e | 189 | int *resid) |
39216033 JB |
190 | { |
191 | struct request *req; | |
192 | int write = (data_direction == DMA_TO_DEVICE); | |
193 | int ret = DRIVER_ERROR << 24; | |
194 | ||
195 | req = blk_get_request(sdev->request_queue, write, __GFP_WAIT); | |
bfe159a5 JB |
196 | if (!req) |
197 | return ret; | |
39216033 JB |
198 | |
199 | if (bufflen && blk_rq_map_kern(sdev->request_queue, req, | |
200 | buffer, bufflen, __GFP_WAIT)) | |
201 | goto out; | |
202 | ||
203 | req->cmd_len = COMMAND_SIZE(cmd[0]); | |
204 | memcpy(req->cmd, cmd, req->cmd_len); | |
205 | req->sense = sense; | |
206 | req->sense_len = 0; | |
17e01f21 | 207 | req->retries = retries; |
39216033 | 208 | req->timeout = timeout; |
4aff5e23 JA |
209 | req->cmd_type = REQ_TYPE_BLOCK_PC; |
210 | req->cmd_flags |= flags | REQ_QUIET | REQ_PREEMPT; | |
39216033 JB |
211 | |
212 | /* | |
213 | * head injection *required* here otherwise quiesce won't work | |
214 | */ | |
215 | blk_execute_rq(req->q, NULL, req, 1); | |
216 | ||
bdb2b8ca AS |
217 | /* |
218 | * Some devices (USB mass-storage in particular) may transfer | |
219 | * garbage data together with a residue indicating that the data | |
220 | * is invalid. Prevent the garbage from being misinterpreted | |
221 | * and prevent security leaks by zeroing out the excess data. | |
222 | */ | |
c3a4d78c TH |
223 | if (unlikely(req->resid_len > 0 && req->resid_len <= bufflen)) |
224 | memset(buffer + (bufflen - req->resid_len), 0, req->resid_len); | |
bdb2b8ca | 225 | |
f4f4e47e | 226 | if (resid) |
c3a4d78c | 227 | *resid = req->resid_len; |
39216033 JB |
228 | ret = req->errors; |
229 | out: | |
230 | blk_put_request(req); | |
231 | ||
232 | return ret; | |
233 | } | |
33aa687d | 234 | EXPORT_SYMBOL(scsi_execute); |
39216033 | 235 | |
9b21493c | 236 | int scsi_execute_req_flags(struct scsi_device *sdev, const unsigned char *cmd, |
ea73a9f2 | 237 | int data_direction, void *buffer, unsigned bufflen, |
f4f4e47e | 238 | struct scsi_sense_hdr *sshdr, int timeout, int retries, |
2bfad21e | 239 | int *resid, u64 flags) |
ea73a9f2 JB |
240 | { |
241 | char *sense = NULL; | |
1ccb48bb | 242 | int result; |
243 | ||
ea73a9f2 | 244 | if (sshdr) { |
24669f75 | 245 | sense = kzalloc(SCSI_SENSE_BUFFERSIZE, GFP_NOIO); |
ea73a9f2 JB |
246 | if (!sense) |
247 | return DRIVER_ERROR << 24; | |
ea73a9f2 | 248 | } |
1ccb48bb | 249 | result = scsi_execute(sdev, cmd, data_direction, buffer, bufflen, |
9b21493c | 250 | sense, timeout, retries, flags, resid); |
ea73a9f2 | 251 | if (sshdr) |
e514385b | 252 | scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE, sshdr); |
ea73a9f2 JB |
253 | |
254 | kfree(sense); | |
255 | return result; | |
256 | } | |
9b21493c | 257 | EXPORT_SYMBOL(scsi_execute_req_flags); |
ea73a9f2 | 258 | |
1da177e4 LT |
259 | /* |
260 | * Function: scsi_init_cmd_errh() | |
261 | * | |
262 | * Purpose: Initialize cmd fields related to error handling. | |
263 | * | |
264 | * Arguments: cmd - command that is ready to be queued. | |
265 | * | |
1da177e4 LT |
266 | * Notes: This function has the job of initializing a number of |
267 | * fields related to error handling. Typically this will | |
268 | * be called once for each command, as required. | |
269 | */ | |
631c228c | 270 | static void scsi_init_cmd_errh(struct scsi_cmnd *cmd) |
1da177e4 | 271 | { |
1da177e4 | 272 | cmd->serial_number = 0; |
30b0c37b | 273 | scsi_set_resid(cmd, 0); |
b80ca4f7 | 274 | memset(cmd->sense_buffer, 0, SCSI_SENSE_BUFFERSIZE); |
1da177e4 | 275 | if (cmd->cmd_len == 0) |
db4742dd | 276 | cmd->cmd_len = scsi_command_size(cmd->cmnd); |
1da177e4 LT |
277 | } |
278 | ||
279 | void scsi_device_unbusy(struct scsi_device *sdev) | |
280 | { | |
281 | struct Scsi_Host *shost = sdev->host; | |
f0c0a376 | 282 | struct scsi_target *starget = scsi_target(sdev); |
1da177e4 LT |
283 | unsigned long flags; |
284 | ||
285 | spin_lock_irqsave(shost->host_lock, flags); | |
286 | shost->host_busy--; | |
f0c0a376 | 287 | starget->target_busy--; |
939647ee | 288 | if (unlikely(scsi_host_in_recovery(shost) && |
ee7863bc | 289 | (shost->host_failed || shost->host_eh_scheduled))) |
1da177e4 LT |
290 | scsi_eh_wakeup(shost); |
291 | spin_unlock(shost->host_lock); | |
152587de | 292 | spin_lock(sdev->request_queue->queue_lock); |
1da177e4 | 293 | sdev->device_busy--; |
152587de | 294 | spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags); |
1da177e4 LT |
295 | } |
296 | ||
297 | /* | |
298 | * Called for single_lun devices on IO completion. Clear starget_sdev_user, | |
299 | * and call blk_run_queue for all the scsi_devices on the target - | |
300 | * including current_sdev first. | |
301 | * | |
302 | * Called with *no* scsi locks held. | |
303 | */ | |
304 | static void scsi_single_lun_run(struct scsi_device *current_sdev) | |
305 | { | |
306 | struct Scsi_Host *shost = current_sdev->host; | |
307 | struct scsi_device *sdev, *tmp; | |
308 | struct scsi_target *starget = scsi_target(current_sdev); | |
309 | unsigned long flags; | |
310 | ||
311 | spin_lock_irqsave(shost->host_lock, flags); | |
312 | starget->starget_sdev_user = NULL; | |
313 | spin_unlock_irqrestore(shost->host_lock, flags); | |
314 | ||
315 | /* | |
316 | * Call blk_run_queue for all LUNs on the target, starting with | |
317 | * current_sdev. We race with others (to set starget_sdev_user), | |
318 | * but in most cases, we will be first. Ideally, each LU on the | |
319 | * target would get some limited time or requests on the target. | |
320 | */ | |
321 | blk_run_queue(current_sdev->request_queue); | |
322 | ||
323 | spin_lock_irqsave(shost->host_lock, flags); | |
324 | if (starget->starget_sdev_user) | |
325 | goto out; | |
326 | list_for_each_entry_safe(sdev, tmp, &starget->devices, | |
327 | same_target_siblings) { | |
328 | if (sdev == current_sdev) | |
329 | continue; | |
330 | if (scsi_device_get(sdev)) | |
331 | continue; | |
332 | ||
333 | spin_unlock_irqrestore(shost->host_lock, flags); | |
334 | blk_run_queue(sdev->request_queue); | |
335 | spin_lock_irqsave(shost->host_lock, flags); | |
336 | ||
337 | scsi_device_put(sdev); | |
338 | } | |
339 | out: | |
340 | spin_unlock_irqrestore(shost->host_lock, flags); | |
341 | } | |
342 | ||
9d112517 KU |
343 | static inline int scsi_device_is_busy(struct scsi_device *sdev) |
344 | { | |
345 | if (sdev->device_busy >= sdev->queue_depth || sdev->device_blocked) | |
346 | return 1; | |
347 | ||
348 | return 0; | |
349 | } | |
350 | ||
f0c0a376 MC |
351 | static inline int scsi_target_is_busy(struct scsi_target *starget) |
352 | { | |
353 | return ((starget->can_queue > 0 && | |
354 | starget->target_busy >= starget->can_queue) || | |
355 | starget->target_blocked); | |
356 | } | |
357 | ||
9d112517 KU |
358 | static inline int scsi_host_is_busy(struct Scsi_Host *shost) |
359 | { | |
360 | if ((shost->can_queue > 0 && shost->host_busy >= shost->can_queue) || | |
361 | shost->host_blocked || shost->host_self_blocked) | |
362 | return 1; | |
363 | ||
364 | return 0; | |
365 | } | |
366 | ||
21a05df5 | 367 | static void scsi_starved_list_run(struct Scsi_Host *shost) |
1da177e4 | 368 | { |
2a3a59e5 | 369 | LIST_HEAD(starved_list); |
21a05df5 | 370 | struct scsi_device *sdev; |
1da177e4 LT |
371 | unsigned long flags; |
372 | ||
1da177e4 | 373 | spin_lock_irqsave(shost->host_lock, flags); |
2a3a59e5 MC |
374 | list_splice_init(&shost->starved_list, &starved_list); |
375 | ||
376 | while (!list_empty(&starved_list)) { | |
e2eb7244 JB |
377 | struct request_queue *slq; |
378 | ||
1da177e4 LT |
379 | /* |
380 | * As long as shost is accepting commands and we have | |
381 | * starved queues, call blk_run_queue. scsi_request_fn | |
382 | * drops the queue_lock and can add us back to the | |
383 | * starved_list. | |
384 | * | |
385 | * host_lock protects the starved_list and starved_entry. | |
386 | * scsi_request_fn must get the host_lock before checking | |
387 | * or modifying starved_list or starved_entry. | |
388 | */ | |
2a3a59e5 | 389 | if (scsi_host_is_busy(shost)) |
f0c0a376 | 390 | break; |
f0c0a376 | 391 | |
2a3a59e5 MC |
392 | sdev = list_entry(starved_list.next, |
393 | struct scsi_device, starved_entry); | |
394 | list_del_init(&sdev->starved_entry); | |
f0c0a376 MC |
395 | if (scsi_target_is_busy(scsi_target(sdev))) { |
396 | list_move_tail(&sdev->starved_entry, | |
397 | &shost->starved_list); | |
398 | continue; | |
399 | } | |
400 | ||
e2eb7244 JB |
401 | /* |
402 | * Once we drop the host lock, a racing scsi_remove_device() | |
403 | * call may remove the sdev from the starved list and destroy | |
404 | * it and the queue. Mitigate by taking a reference to the | |
405 | * queue and never touching the sdev again after we drop the | |
406 | * host lock. Note: if __scsi_remove_device() invokes | |
407 | * blk_cleanup_queue() before the queue is run from this | |
408 | * function then blk_run_queue() will return immediately since | |
409 | * blk_cleanup_queue() marks the queue with QUEUE_FLAG_DYING. | |
410 | */ | |
411 | slq = sdev->request_queue; | |
412 | if (!blk_get_queue(slq)) | |
413 | continue; | |
414 | spin_unlock_irqrestore(shost->host_lock, flags); | |
415 | ||
416 | blk_run_queue(slq); | |
417 | blk_put_queue(slq); | |
418 | ||
419 | spin_lock_irqsave(shost->host_lock, flags); | |
1da177e4 | 420 | } |
2a3a59e5 MC |
421 | /* put any unprocessed entries back */ |
422 | list_splice(&starved_list, &shost->starved_list); | |
1da177e4 | 423 | spin_unlock_irqrestore(shost->host_lock, flags); |
21a05df5 CH |
424 | } |
425 | ||
426 | /* | |
427 | * Function: scsi_run_queue() | |
428 | * | |
429 | * Purpose: Select a proper request queue to serve next | |
430 | * | |
431 | * Arguments: q - last request's queue | |
432 | * | |
433 | * Returns: Nothing | |
434 | * | |
435 | * Notes: The previous command was completely finished, start | |
436 | * a new one if possible. | |
437 | */ | |
438 | static void scsi_run_queue(struct request_queue *q) | |
439 | { | |
440 | struct scsi_device *sdev = q->queuedata; | |
441 | ||
442 | if (scsi_target(sdev)->single_lun) | |
443 | scsi_single_lun_run(sdev); | |
444 | if (!list_empty(&sdev->host->starved_list)) | |
445 | scsi_starved_list_run(sdev->host); | |
1da177e4 LT |
446 | |
447 | blk_run_queue(q); | |
448 | } | |
449 | ||
9937a5e2 JA |
450 | void scsi_requeue_run_queue(struct work_struct *work) |
451 | { | |
452 | struct scsi_device *sdev; | |
453 | struct request_queue *q; | |
454 | ||
455 | sdev = container_of(work, struct scsi_device, requeue_work); | |
456 | q = sdev->request_queue; | |
457 | scsi_run_queue(q); | |
458 | } | |
459 | ||
1da177e4 LT |
460 | /* |
461 | * Function: scsi_requeue_command() | |
462 | * | |
463 | * Purpose: Handle post-processing of completed commands. | |
464 | * | |
465 | * Arguments: q - queue to operate on | |
466 | * cmd - command that may need to be requeued. | |
467 | * | |
468 | * Returns: Nothing | |
469 | * | |
470 | * Notes: After command completion, there may be blocks left | |
471 | * over which weren't finished by the previous command | |
472 | * this can be for a number of reasons - the main one is | |
473 | * I/O errors in the middle of the request, in which case | |
474 | * we need to request the blocks that come after the bad | |
475 | * sector. | |
e91442b6 | 476 | * Notes: Upon return, cmd is a stale pointer. |
1da177e4 LT |
477 | */ |
478 | static void scsi_requeue_command(struct request_queue *q, struct scsi_cmnd *cmd) | |
479 | { | |
940f5d47 | 480 | struct scsi_device *sdev = cmd->device; |
e91442b6 | 481 | struct request *req = cmd->request; |
283369cc TH |
482 | unsigned long flags; |
483 | ||
283369cc | 484 | spin_lock_irqsave(q->queue_lock, flags); |
134997a0 CH |
485 | blk_unprep_request(req); |
486 | req->special = NULL; | |
487 | scsi_put_command(cmd); | |
e91442b6 | 488 | blk_requeue_request(q, req); |
283369cc | 489 | spin_unlock_irqrestore(q->queue_lock, flags); |
1da177e4 LT |
490 | |
491 | scsi_run_queue(q); | |
940f5d47 BVA |
492 | |
493 | put_device(&sdev->sdev_gendev); | |
1da177e4 LT |
494 | } |
495 | ||
496 | void scsi_next_command(struct scsi_cmnd *cmd) | |
497 | { | |
49d7bc64 LT |
498 | struct scsi_device *sdev = cmd->device; |
499 | struct request_queue *q = sdev->request_queue; | |
500 | ||
1da177e4 LT |
501 | scsi_put_command(cmd); |
502 | scsi_run_queue(q); | |
49d7bc64 | 503 | |
49d7bc64 | 504 | put_device(&sdev->sdev_gendev); |
1da177e4 LT |
505 | } |
506 | ||
507 | void scsi_run_host_queues(struct Scsi_Host *shost) | |
508 | { | |
509 | struct scsi_device *sdev; | |
510 | ||
511 | shost_for_each_device(sdev, shost) | |
512 | scsi_run_queue(sdev->request_queue); | |
513 | } | |
514 | ||
79ed2429 JB |
515 | static void __scsi_release_buffers(struct scsi_cmnd *, int); |
516 | ||
1da177e4 LT |
517 | /* |
518 | * Function: scsi_end_request() | |
519 | * | |
520 | * Purpose: Post-processing of completed commands (usually invoked at end | |
521 | * of upper level post-processing and scsi_io_completion). | |
522 | * | |
523 | * Arguments: cmd - command that is complete. | |
610d8b0c | 524 | * error - 0 if I/O indicates success, < 0 for I/O error. |
1da177e4 LT |
525 | * bytes - number of bytes of completed I/O |
526 | * requeue - indicates whether we should requeue leftovers. | |
527 | * | |
528 | * Lock status: Assumed that lock is not held upon entry. | |
529 | * | |
e91442b6 | 530 | * Returns: cmd if requeue required, NULL otherwise. |
1da177e4 LT |
531 | * |
532 | * Notes: This is called for block device requests in order to | |
533 | * mark some number of sectors as complete. | |
534 | * | |
535 | * We are guaranteeing that the request queue will be goosed | |
536 | * at some point during this call. | |
e91442b6 | 537 | * Notes: If cmd was requeued, upon return it will be a stale pointer. |
1da177e4 | 538 | */ |
610d8b0c | 539 | static struct scsi_cmnd *scsi_end_request(struct scsi_cmnd *cmd, int error, |
1da177e4 LT |
540 | int bytes, int requeue) |
541 | { | |
165125e1 | 542 | struct request_queue *q = cmd->device->request_queue; |
1da177e4 | 543 | struct request *req = cmd->request; |
1da177e4 LT |
544 | |
545 | /* | |
546 | * If there are blocks left over at the end, set up the command | |
547 | * to queue the remainder of them. | |
548 | */ | |
610d8b0c | 549 | if (blk_end_request(req, error, bytes)) { |
1da177e4 | 550 | /* kill remainder if no retrys */ |
4a27446f | 551 | if (error && scsi_noretry_cmd(cmd)) |
e458824f | 552 | blk_end_request_all(req, error); |
1da177e4 | 553 | else { |
e91442b6 | 554 | if (requeue) { |
1da177e4 LT |
555 | /* |
556 | * Bleah. Leftovers again. Stick the | |
557 | * leftovers in the front of the | |
558 | * queue, and goose the queue again. | |
559 | */ | |
79ed2429 | 560 | scsi_release_buffers(cmd); |
1da177e4 | 561 | scsi_requeue_command(q, cmd); |
e91442b6 JB |
562 | cmd = NULL; |
563 | } | |
1da177e4 LT |
564 | return cmd; |
565 | } | |
566 | } | |
567 | ||
1da177e4 LT |
568 | /* |
569 | * This will goose the queue request function at the end, so we don't | |
570 | * need to worry about launching another command. | |
571 | */ | |
79ed2429 | 572 | __scsi_release_buffers(cmd, 0); |
1da177e4 LT |
573 | scsi_next_command(cmd); |
574 | return NULL; | |
575 | } | |
576 | ||
a8474ce2 JA |
577 | static inline unsigned int scsi_sgtable_index(unsigned short nents) |
578 | { | |
579 | unsigned int index; | |
580 | ||
d3f46f39 JB |
581 | BUG_ON(nents > SCSI_MAX_SG_SEGMENTS); |
582 | ||
583 | if (nents <= 8) | |
a8474ce2 | 584 | index = 0; |
d3f46f39 JB |
585 | else |
586 | index = get_count_order(nents) - 3; | |
1da177e4 | 587 | |
a8474ce2 JA |
588 | return index; |
589 | } | |
590 | ||
5ed7959e | 591 | static void scsi_sg_free(struct scatterlist *sgl, unsigned int nents) |
a8474ce2 JA |
592 | { |
593 | struct scsi_host_sg_pool *sgp; | |
a8474ce2 | 594 | |
5ed7959e JA |
595 | sgp = scsi_sg_pools + scsi_sgtable_index(nents); |
596 | mempool_free(sgl, sgp->pool); | |
597 | } | |
a8474ce2 | 598 | |
5ed7959e JA |
599 | static struct scatterlist *scsi_sg_alloc(unsigned int nents, gfp_t gfp_mask) |
600 | { | |
601 | struct scsi_host_sg_pool *sgp; | |
a8474ce2 | 602 | |
5ed7959e JA |
603 | sgp = scsi_sg_pools + scsi_sgtable_index(nents); |
604 | return mempool_alloc(sgp->pool, gfp_mask); | |
605 | } | |
a3bec5c5 | 606 | |
30b0c37b BH |
607 | static int scsi_alloc_sgtable(struct scsi_data_buffer *sdb, int nents, |
608 | gfp_t gfp_mask) | |
5ed7959e JA |
609 | { |
610 | int ret; | |
a8474ce2 | 611 | |
30b0c37b | 612 | BUG_ON(!nents); |
a8474ce2 | 613 | |
30b0c37b BH |
614 | ret = __sg_alloc_table(&sdb->table, nents, SCSI_MAX_SG_SEGMENTS, |
615 | gfp_mask, scsi_sg_alloc); | |
5ed7959e | 616 | if (unlikely(ret)) |
30b0c37b | 617 | __sg_free_table(&sdb->table, SCSI_MAX_SG_SEGMENTS, |
7cedb1f1 | 618 | scsi_sg_free); |
45711f1a | 619 | |
a8474ce2 | 620 | return ret; |
1da177e4 LT |
621 | } |
622 | ||
30b0c37b | 623 | static void scsi_free_sgtable(struct scsi_data_buffer *sdb) |
1da177e4 | 624 | { |
30b0c37b | 625 | __sg_free_table(&sdb->table, SCSI_MAX_SG_SEGMENTS, scsi_sg_free); |
1da177e4 LT |
626 | } |
627 | ||
79ed2429 JB |
628 | static void __scsi_release_buffers(struct scsi_cmnd *cmd, int do_bidi_check) |
629 | { | |
630 | ||
631 | if (cmd->sdb.table.nents) | |
632 | scsi_free_sgtable(&cmd->sdb); | |
633 | ||
634 | memset(&cmd->sdb, 0, sizeof(cmd->sdb)); | |
635 | ||
636 | if (do_bidi_check && scsi_bidi_cmnd(cmd)) { | |
637 | struct scsi_data_buffer *bidi_sdb = | |
638 | cmd->request->next_rq->special; | |
639 | scsi_free_sgtable(bidi_sdb); | |
640 | kmem_cache_free(scsi_sdb_cache, bidi_sdb); | |
641 | cmd->request->next_rq->special = NULL; | |
642 | } | |
643 | ||
644 | if (scsi_prot_sg_count(cmd)) | |
645 | scsi_free_sgtable(cmd->prot_sdb); | |
646 | } | |
647 | ||
1da177e4 LT |
648 | /* |
649 | * Function: scsi_release_buffers() | |
650 | * | |
651 | * Purpose: Completion processing for block device I/O requests. | |
652 | * | |
653 | * Arguments: cmd - command that we are bailing. | |
654 | * | |
655 | * Lock status: Assumed that no lock is held upon entry. | |
656 | * | |
657 | * Returns: Nothing | |
658 | * | |
659 | * Notes: In the event that an upper level driver rejects a | |
660 | * command, we must release resources allocated during | |
661 | * the __init_io() function. Primarily this would involve | |
662 | * the scatter-gather table, and potentially any bounce | |
663 | * buffers. | |
664 | */ | |
bb52d82f | 665 | void scsi_release_buffers(struct scsi_cmnd *cmd) |
1da177e4 | 666 | { |
79ed2429 | 667 | __scsi_release_buffers(cmd, 1); |
1da177e4 | 668 | } |
bb52d82f | 669 | EXPORT_SYMBOL(scsi_release_buffers); |
1da177e4 | 670 | |
0f7f6234 HR |
671 | /** |
672 | * __scsi_error_from_host_byte - translate SCSI error code into errno | |
673 | * @cmd: SCSI command (unused) | |
674 | * @result: scsi error code | |
675 | * | |
676 | * Translate SCSI error code into standard UNIX errno. | |
677 | * Return values: | |
678 | * -ENOLINK temporary transport failure | |
679 | * -EREMOTEIO permanent target failure, do not retry | |
680 | * -EBADE permanent nexus failure, retry on other path | |
a9d6ceb8 | 681 | * -ENOSPC No write space available |
7e782af5 | 682 | * -ENODATA Medium error |
0f7f6234 HR |
683 | * -EIO unspecified I/O error |
684 | */ | |
63583cca HR |
685 | static int __scsi_error_from_host_byte(struct scsi_cmnd *cmd, int result) |
686 | { | |
687 | int error = 0; | |
688 | ||
689 | switch(host_byte(result)) { | |
690 | case DID_TRANSPORT_FAILFAST: | |
691 | error = -ENOLINK; | |
692 | break; | |
693 | case DID_TARGET_FAILURE: | |
2082ebc4 | 694 | set_host_byte(cmd, DID_OK); |
63583cca HR |
695 | error = -EREMOTEIO; |
696 | break; | |
697 | case DID_NEXUS_FAILURE: | |
2082ebc4 | 698 | set_host_byte(cmd, DID_OK); |
63583cca HR |
699 | error = -EBADE; |
700 | break; | |
a9d6ceb8 HR |
701 | case DID_ALLOC_FAILURE: |
702 | set_host_byte(cmd, DID_OK); | |
703 | error = -ENOSPC; | |
704 | break; | |
7e782af5 HR |
705 | case DID_MEDIUM_ERROR: |
706 | set_host_byte(cmd, DID_OK); | |
707 | error = -ENODATA; | |
708 | break; | |
63583cca HR |
709 | default: |
710 | error = -EIO; | |
711 | break; | |
712 | } | |
713 | ||
714 | return error; | |
715 | } | |
716 | ||
1da177e4 LT |
717 | /* |
718 | * Function: scsi_io_completion() | |
719 | * | |
720 | * Purpose: Completion processing for block device I/O requests. | |
721 | * | |
722 | * Arguments: cmd - command that is finished. | |
723 | * | |
724 | * Lock status: Assumed that no lock is held upon entry. | |
725 | * | |
726 | * Returns: Nothing | |
727 | * | |
728 | * Notes: This function is matched in terms of capabilities to | |
729 | * the function that created the scatter-gather list. | |
730 | * In other words, if there are no bounce buffers | |
731 | * (the normal case for most drivers), we don't need | |
732 | * the logic to deal with cleaning up afterwards. | |
733 | * | |
b60af5b0 AS |
734 | * We must call scsi_end_request(). This will finish off |
735 | * the specified number of sectors. If we are done, the | |
736 | * command block will be released and the queue function | |
737 | * will be goosed. If we are not done then we have to | |
738 | * figure out what to do next: | |
1da177e4 | 739 | * |
b60af5b0 AS |
740 | * a) We can call scsi_requeue_command(). The request |
741 | * will be unprepared and put back on the queue. Then | |
742 | * a new command will be created for it. This should | |
743 | * be used if we made forward progress, or if we want | |
744 | * to switch from READ(10) to READ(6) for example. | |
1da177e4 | 745 | * |
b60af5b0 AS |
746 | * b) We can call scsi_queue_insert(). The request will |
747 | * be put back on the queue and retried using the same | |
748 | * command as before, possibly after a delay. | |
749 | * | |
750 | * c) We can call blk_end_request() with -EIO to fail | |
751 | * the remainder of the request. | |
1da177e4 | 752 | */ |
03aba2f7 | 753 | void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes) |
1da177e4 LT |
754 | { |
755 | int result = cmd->result; | |
165125e1 | 756 | struct request_queue *q = cmd->device->request_queue; |
1da177e4 | 757 | struct request *req = cmd->request; |
fa8e36c3 | 758 | int error = 0; |
1da177e4 LT |
759 | struct scsi_sense_hdr sshdr; |
760 | int sense_valid = 0; | |
761 | int sense_deferred = 0; | |
b60af5b0 AS |
762 | enum {ACTION_FAIL, ACTION_REPREP, ACTION_RETRY, |
763 | ACTION_DELAYED_RETRY} action; | |
764 | char *description = NULL; | |
ee60b2c5 | 765 | unsigned long wait_for = (cmd->allowed + 1) * req->timeout; |
1da177e4 | 766 | |
1da177e4 LT |
767 | if (result) { |
768 | sense_valid = scsi_command_normalize_sense(cmd, &sshdr); | |
769 | if (sense_valid) | |
770 | sense_deferred = scsi_sense_is_deferred(&sshdr); | |
771 | } | |
631c228c | 772 | |
33659ebb | 773 | if (req->cmd_type == REQ_TYPE_BLOCK_PC) { /* SG_IO ioctl from block level */ |
1da177e4 | 774 | if (result) { |
1da177e4 LT |
775 | if (sense_valid && req->sense) { |
776 | /* | |
777 | * SG_IO wants current and deferred errors | |
778 | */ | |
779 | int len = 8 + cmd->sense_buffer[7]; | |
780 | ||
781 | if (len > SCSI_SENSE_BUFFERSIZE) | |
782 | len = SCSI_SENSE_BUFFERSIZE; | |
783 | memcpy(req->sense, cmd->sense_buffer, len); | |
784 | req->sense_len = len; | |
785 | } | |
fa8e36c3 | 786 | if (!sense_deferred) |
63583cca | 787 | error = __scsi_error_from_host_byte(cmd, result); |
b22f687d | 788 | } |
27c41973 MS |
789 | /* |
790 | * __scsi_error_from_host_byte may have reset the host_byte | |
791 | */ | |
792 | req->errors = cmd->result; | |
e6bb7a96 FT |
793 | |
794 | req->resid_len = scsi_get_resid(cmd); | |
795 | ||
6f9a35e2 | 796 | if (scsi_bidi_cmnd(cmd)) { |
e6bb7a96 FT |
797 | /* |
798 | * Bidi commands Must be complete as a whole, | |
799 | * both sides at once. | |
800 | */ | |
801 | req->next_rq->resid_len = scsi_in(cmd)->resid; | |
802 | ||
63c43b0e | 803 | scsi_release_buffers(cmd); |
e6bb7a96 FT |
804 | blk_end_request_all(req, 0); |
805 | ||
e6bb7a96 | 806 | scsi_next_command(cmd); |
6f9a35e2 BH |
807 | return; |
808 | } | |
1da177e4 LT |
809 | } |
810 | ||
33659ebb CH |
811 | /* no bidi support for !REQ_TYPE_BLOCK_PC yet */ |
812 | BUG_ON(blk_bidi_rq(req)); | |
30b0c37b | 813 | |
1da177e4 LT |
814 | /* |
815 | * Next deal with any sectors which we were able to correctly | |
816 | * handle. | |
817 | */ | |
83096ebf | 818 | SCSI_LOG_HLCOMPLETE(1, printk("%u sectors total, " |
d6b0c537 | 819 | "%d bytes done.\n", |
83096ebf | 820 | blk_rq_sectors(req), good_bytes)); |
d6b0c537 | 821 | |
a9bddd74 JB |
822 | /* |
823 | * Recovered errors need reporting, but they're always treated | |
824 | * as success, so fiddle the result code here. For BLOCK_PC | |
825 | * we already took a copy of the original into rq->errors which | |
826 | * is what gets returned to the user | |
827 | */ | |
e7efe593 DG |
828 | if (sense_valid && (sshdr.sense_key == RECOVERED_ERROR)) { |
829 | /* if ATA PASS-THROUGH INFORMATION AVAILABLE skip | |
830 | * print since caller wants ATA registers. Only occurs on | |
831 | * SCSI ATA PASS_THROUGH commands when CK_COND=1 | |
832 | */ | |
833 | if ((sshdr.asc == 0x0) && (sshdr.ascq == 0x1d)) | |
834 | ; | |
835 | else if (!(req->cmd_flags & REQ_QUIET)) | |
a9bddd74 JB |
836 | scsi_print_sense("", cmd); |
837 | result = 0; | |
838 | /* BLOCK_PC may have set error */ | |
839 | error = 0; | |
840 | } | |
841 | ||
842 | /* | |
843 | * A number of bytes were successfully read. If there | |
d6b0c537 JB |
844 | * are leftovers and there is some kind of error |
845 | * (result != 0), retry the rest. | |
846 | */ | |
fa8e36c3 | 847 | if (scsi_end_request(cmd, error, good_bytes, result == 0) == NULL) |
d6b0c537 | 848 | return; |
03aba2f7 | 849 | |
63583cca | 850 | error = __scsi_error_from_host_byte(cmd, result); |
3e695f89 | 851 | |
b60af5b0 AS |
852 | if (host_byte(result) == DID_RESET) { |
853 | /* Third party bus reset or reset for error recovery | |
854 | * reasons. Just retry the command and see what | |
855 | * happens. | |
856 | */ | |
857 | action = ACTION_RETRY; | |
858 | } else if (sense_valid && !sense_deferred) { | |
1da177e4 LT |
859 | switch (sshdr.sense_key) { |
860 | case UNIT_ATTENTION: | |
861 | if (cmd->device->removable) { | |
03aba2f7 | 862 | /* Detected disc change. Set a bit |
1da177e4 LT |
863 | * and quietly refuse further access. |
864 | */ | |
865 | cmd->device->changed = 1; | |
b60af5b0 AS |
866 | description = "Media Changed"; |
867 | action = ACTION_FAIL; | |
1da177e4 | 868 | } else { |
03aba2f7 LT |
869 | /* Must have been a power glitch, or a |
870 | * bus reset. Could not have been a | |
871 | * media change, so we just retry the | |
b60af5b0 | 872 | * command and see what happens. |
03aba2f7 | 873 | */ |
b60af5b0 | 874 | action = ACTION_RETRY; |
1da177e4 LT |
875 | } |
876 | break; | |
877 | case ILLEGAL_REQUEST: | |
03aba2f7 LT |
878 | /* If we had an ILLEGAL REQUEST returned, then |
879 | * we may have performed an unsupported | |
880 | * command. The only thing this should be | |
881 | * would be a ten byte read where only a six | |
882 | * byte read was supported. Also, on a system | |
883 | * where READ CAPACITY failed, we may have | |
884 | * read past the end of the disk. | |
885 | */ | |
26a68019 JA |
886 | if ((cmd->device->use_10_for_rw && |
887 | sshdr.asc == 0x20 && sshdr.ascq == 0x00) && | |
1da177e4 LT |
888 | (cmd->cmnd[0] == READ_10 || |
889 | cmd->cmnd[0] == WRITE_10)) { | |
b60af5b0 | 890 | /* This will issue a new 6-byte command. */ |
1da177e4 | 891 | cmd->device->use_10_for_rw = 0; |
b60af5b0 | 892 | action = ACTION_REPREP; |
3e695f89 MP |
893 | } else if (sshdr.asc == 0x10) /* DIX */ { |
894 | description = "Host Data Integrity Failure"; | |
895 | action = ACTION_FAIL; | |
896 | error = -EILSEQ; | |
c98a0eb0 | 897 | /* INVALID COMMAND OPCODE or INVALID FIELD IN CDB */ |
5db44863 MP |
898 | } else if (sshdr.asc == 0x20 || sshdr.asc == 0x24) { |
899 | switch (cmd->cmnd[0]) { | |
900 | case UNMAP: | |
901 | description = "Discard failure"; | |
902 | break; | |
903 | case WRITE_SAME: | |
904 | case WRITE_SAME_16: | |
905 | if (cmd->cmnd[1] & 0x8) | |
906 | description = "Discard failure"; | |
907 | else | |
908 | description = | |
909 | "Write same failure"; | |
910 | break; | |
911 | default: | |
912 | description = "Invalid command failure"; | |
913 | break; | |
914 | } | |
c98a0eb0 | 915 | action = ACTION_FAIL; |
66a651aa | 916 | error = -EREMOTEIO; |
b60af5b0 AS |
917 | } else |
918 | action = ACTION_FAIL; | |
919 | break; | |
511e44f4 | 920 | case ABORTED_COMMAND: |
126c0982 | 921 | action = ACTION_FAIL; |
511e44f4 | 922 | if (sshdr.asc == 0x10) { /* DIF */ |
3e695f89 | 923 | description = "Target Data Integrity Failure"; |
3e695f89 | 924 | error = -EILSEQ; |
126c0982 | 925 | } |
1da177e4 LT |
926 | break; |
927 | case NOT_READY: | |
03aba2f7 | 928 | /* If the device is in the process of becoming |
f3e93f73 | 929 | * ready, or has a temporary blockage, retry. |
1da177e4 | 930 | */ |
f3e93f73 JB |
931 | if (sshdr.asc == 0x04) { |
932 | switch (sshdr.ascq) { | |
933 | case 0x01: /* becoming ready */ | |
934 | case 0x04: /* format in progress */ | |
935 | case 0x05: /* rebuild in progress */ | |
936 | case 0x06: /* recalculation in progress */ | |
937 | case 0x07: /* operation in progress */ | |
938 | case 0x08: /* Long write in progress */ | |
939 | case 0x09: /* self test in progress */ | |
d8705f11 | 940 | case 0x14: /* space allocation in progress */ |
b60af5b0 | 941 | action = ACTION_DELAYED_RETRY; |
f3e93f73 | 942 | break; |
3dbf6a54 AS |
943 | default: |
944 | description = "Device not ready"; | |
945 | action = ACTION_FAIL; | |
946 | break; | |
f3e93f73 | 947 | } |
b60af5b0 AS |
948 | } else { |
949 | description = "Device not ready"; | |
950 | action = ACTION_FAIL; | |
1da177e4 | 951 | } |
b60af5b0 | 952 | break; |
1da177e4 | 953 | case VOLUME_OVERFLOW: |
03aba2f7 | 954 | /* See SSC3rXX or current. */ |
b60af5b0 AS |
955 | action = ACTION_FAIL; |
956 | break; | |
1da177e4 | 957 | default: |
b60af5b0 AS |
958 | description = "Unhandled sense code"; |
959 | action = ACTION_FAIL; | |
1da177e4 LT |
960 | break; |
961 | } | |
b60af5b0 AS |
962 | } else { |
963 | description = "Unhandled error code"; | |
964 | action = ACTION_FAIL; | |
03aba2f7 | 965 | } |
b60af5b0 | 966 | |
ee60b2c5 ET |
967 | if (action != ACTION_FAIL && |
968 | time_before(cmd->jiffies_at_alloc + wait_for, jiffies)) { | |
969 | action = ACTION_FAIL; | |
970 | description = "Command timed out"; | |
971 | } | |
972 | ||
b60af5b0 AS |
973 | switch (action) { |
974 | case ACTION_FAIL: | |
975 | /* Give up and fail the remainder of the request */ | |
79ed2429 | 976 | scsi_release_buffers(cmd); |
4aff5e23 | 977 | if (!(req->cmd_flags & REQ_QUIET)) { |
b60af5b0 | 978 | if (description) |
3dbf6a54 | 979 | scmd_printk(KERN_INFO, cmd, "%s\n", |
b60af5b0 | 980 | description); |
a4d04a4c | 981 | scsi_print_result(cmd); |
3173d8c3 JB |
982 | if (driver_byte(result) & DRIVER_SENSE) |
983 | scsi_print_sense("", cmd); | |
002b1eb2 | 984 | scsi_print_command(cmd); |
3173d8c3 | 985 | } |
ad630826 | 986 | if (blk_end_request_err(req, error)) |
da6c5c72 TH |
987 | scsi_requeue_command(q, cmd); |
988 | else | |
989 | scsi_next_command(cmd); | |
b60af5b0 AS |
990 | break; |
991 | case ACTION_REPREP: | |
992 | /* Unprep the request and put it back at the head of the queue. | |
993 | * A new command will be prepared and issued. | |
994 | */ | |
79ed2429 | 995 | scsi_release_buffers(cmd); |
b60af5b0 AS |
996 | scsi_requeue_command(q, cmd); |
997 | break; | |
998 | case ACTION_RETRY: | |
999 | /* Retry the same command immediately */ | |
4f5299ac | 1000 | __scsi_queue_insert(cmd, SCSI_MLQUEUE_EH_RETRY, 0); |
b60af5b0 AS |
1001 | break; |
1002 | case ACTION_DELAYED_RETRY: | |
1003 | /* Retry the same command after a delay */ | |
4f5299ac | 1004 | __scsi_queue_insert(cmd, SCSI_MLQUEUE_DEVICE_BUSY, 0); |
b60af5b0 | 1005 | break; |
1da177e4 LT |
1006 | } |
1007 | } | |
1da177e4 | 1008 | |
6f9a35e2 BH |
1009 | static int scsi_init_sgtable(struct request *req, struct scsi_data_buffer *sdb, |
1010 | gfp_t gfp_mask) | |
1da177e4 | 1011 | { |
6f9a35e2 | 1012 | int count; |
1da177e4 LT |
1013 | |
1014 | /* | |
3b003157 | 1015 | * If sg table allocation fails, requeue request later. |
1da177e4 | 1016 | */ |
30b0c37b BH |
1017 | if (unlikely(scsi_alloc_sgtable(sdb, req->nr_phys_segments, |
1018 | gfp_mask))) { | |
1da177e4 | 1019 | return BLKPREP_DEFER; |
7c72ce81 | 1020 | } |
1da177e4 | 1021 | |
3b003157 | 1022 | req->buffer = NULL; |
1da177e4 LT |
1023 | |
1024 | /* | |
1025 | * Next, walk the list, and fill in the addresses and sizes of | |
1026 | * each segment. | |
1027 | */ | |
30b0c37b BH |
1028 | count = blk_rq_map_sg(req->q, req, sdb->table.sgl); |
1029 | BUG_ON(count > sdb->table.nents); | |
1030 | sdb->table.nents = count; | |
1011c1b9 | 1031 | sdb->length = blk_rq_bytes(req); |
4a03d90e | 1032 | return BLKPREP_OK; |
1da177e4 | 1033 | } |
6f9a35e2 BH |
1034 | |
1035 | /* | |
1036 | * Function: scsi_init_io() | |
1037 | * | |
1038 | * Purpose: SCSI I/O initialize function. | |
1039 | * | |
1040 | * Arguments: cmd - Command descriptor we wish to initialize | |
1041 | * | |
1042 | * Returns: 0 on success | |
1043 | * BLKPREP_DEFER if the failure is retryable | |
1044 | * BLKPREP_KILL if the failure is fatal | |
1045 | */ | |
1046 | int scsi_init_io(struct scsi_cmnd *cmd, gfp_t gfp_mask) | |
1047 | { | |
5e012aad | 1048 | struct scsi_device *sdev = cmd->device; |
13f05c8d MP |
1049 | struct request *rq = cmd->request; |
1050 | ||
1051 | int error = scsi_init_sgtable(rq, &cmd->sdb, gfp_mask); | |
6f9a35e2 BH |
1052 | if (error) |
1053 | goto err_exit; | |
1054 | ||
13f05c8d | 1055 | if (blk_bidi_rq(rq)) { |
6f9a35e2 | 1056 | struct scsi_data_buffer *bidi_sdb = kmem_cache_zalloc( |
6362abd3 | 1057 | scsi_sdb_cache, GFP_ATOMIC); |
6f9a35e2 BH |
1058 | if (!bidi_sdb) { |
1059 | error = BLKPREP_DEFER; | |
1060 | goto err_exit; | |
1061 | } | |
1062 | ||
13f05c8d MP |
1063 | rq->next_rq->special = bidi_sdb; |
1064 | error = scsi_init_sgtable(rq->next_rq, bidi_sdb, GFP_ATOMIC); | |
6f9a35e2 BH |
1065 | if (error) |
1066 | goto err_exit; | |
1067 | } | |
1068 | ||
13f05c8d | 1069 | if (blk_integrity_rq(rq)) { |
7027ad72 MP |
1070 | struct scsi_data_buffer *prot_sdb = cmd->prot_sdb; |
1071 | int ivecs, count; | |
1072 | ||
1073 | BUG_ON(prot_sdb == NULL); | |
13f05c8d | 1074 | ivecs = blk_rq_count_integrity_sg(rq->q, rq->bio); |
7027ad72 MP |
1075 | |
1076 | if (scsi_alloc_sgtable(prot_sdb, ivecs, gfp_mask)) { | |
1077 | error = BLKPREP_DEFER; | |
1078 | goto err_exit; | |
1079 | } | |
1080 | ||
13f05c8d | 1081 | count = blk_rq_map_integrity_sg(rq->q, rq->bio, |
7027ad72 MP |
1082 | prot_sdb->table.sgl); |
1083 | BUG_ON(unlikely(count > ivecs)); | |
13f05c8d | 1084 | BUG_ON(unlikely(count > queue_max_integrity_segments(rq->q))); |
7027ad72 MP |
1085 | |
1086 | cmd->prot_sdb = prot_sdb; | |
1087 | cmd->prot_sdb->table.nents = count; | |
1088 | } | |
1089 | ||
6f9a35e2 BH |
1090 | return BLKPREP_OK ; |
1091 | ||
1092 | err_exit: | |
1093 | scsi_release_buffers(cmd); | |
610a6349 | 1094 | cmd->request->special = NULL; |
3a5c19c2 | 1095 | scsi_put_command(cmd); |
5e012aad | 1096 | put_device(&sdev->sdev_gendev); |
6f9a35e2 BH |
1097 | return error; |
1098 | } | |
bb52d82f | 1099 | EXPORT_SYMBOL(scsi_init_io); |
1da177e4 | 1100 | |
3b003157 CH |
1101 | static struct scsi_cmnd *scsi_get_cmd_from_req(struct scsi_device *sdev, |
1102 | struct request *req) | |
1103 | { | |
1104 | struct scsi_cmnd *cmd; | |
1105 | ||
1106 | if (!req->special) { | |
04796336 CH |
1107 | /* Bail if we can't get a reference to the device */ |
1108 | if (!get_device(&sdev->sdev_gendev)) | |
1109 | return NULL; | |
1110 | ||
3b003157 | 1111 | cmd = scsi_get_command(sdev, GFP_ATOMIC); |
04796336 CH |
1112 | if (unlikely(!cmd)) { |
1113 | put_device(&sdev->sdev_gendev); | |
3b003157 | 1114 | return NULL; |
04796336 | 1115 | } |
3b003157 CH |
1116 | req->special = cmd; |
1117 | } else { | |
1118 | cmd = req->special; | |
1119 | } | |
1120 | ||
1121 | /* pull a tag out of the request if we have one */ | |
1122 | cmd->tag = req->tag; | |
1123 | cmd->request = req; | |
1124 | ||
64a87b24 | 1125 | cmd->cmnd = req->cmd; |
72f7d322 | 1126 | cmd->prot_op = SCSI_PROT_NORMAL; |
64a87b24 | 1127 | |
3b003157 CH |
1128 | return cmd; |
1129 | } | |
1130 | ||
7f9a6bc4 | 1131 | int scsi_setup_blk_pc_cmnd(struct scsi_device *sdev, struct request *req) |
7b16318d | 1132 | { |
3b003157 | 1133 | struct scsi_cmnd *cmd; |
7f9a6bc4 JB |
1134 | int ret = scsi_prep_state_check(sdev, req); |
1135 | ||
1136 | if (ret != BLKPREP_OK) | |
1137 | return ret; | |
3b003157 CH |
1138 | |
1139 | cmd = scsi_get_cmd_from_req(sdev, req); | |
1140 | if (unlikely(!cmd)) | |
1141 | return BLKPREP_DEFER; | |
1142 | ||
1143 | /* | |
1144 | * BLOCK_PC requests may transfer data, in which case they must | |
1145 | * a bio attached to them. Or they might contain a SCSI command | |
1146 | * that does not transfer data, in which case they may optionally | |
1147 | * submit a request without an attached bio. | |
1148 | */ | |
1149 | if (req->bio) { | |
1150 | int ret; | |
1151 | ||
1152 | BUG_ON(!req->nr_phys_segments); | |
1153 | ||
bb52d82f | 1154 | ret = scsi_init_io(cmd, GFP_ATOMIC); |
3b003157 CH |
1155 | if (unlikely(ret)) |
1156 | return ret; | |
1157 | } else { | |
b0790410 | 1158 | BUG_ON(blk_rq_bytes(req)); |
3b003157 | 1159 | |
30b0c37b | 1160 | memset(&cmd->sdb, 0, sizeof(cmd->sdb)); |
3b003157 CH |
1161 | req->buffer = NULL; |
1162 | } | |
7b16318d | 1163 | |
7b16318d | 1164 | cmd->cmd_len = req->cmd_len; |
b0790410 | 1165 | if (!blk_rq_bytes(req)) |
7b16318d JB |
1166 | cmd->sc_data_direction = DMA_NONE; |
1167 | else if (rq_data_dir(req) == WRITE) | |
1168 | cmd->sc_data_direction = DMA_TO_DEVICE; | |
1169 | else | |
1170 | cmd->sc_data_direction = DMA_FROM_DEVICE; | |
1171 | ||
b0790410 | 1172 | cmd->transfersize = blk_rq_bytes(req); |
7b16318d | 1173 | cmd->allowed = req->retries; |
3b003157 | 1174 | return BLKPREP_OK; |
7b16318d | 1175 | } |
7f9a6bc4 | 1176 | EXPORT_SYMBOL(scsi_setup_blk_pc_cmnd); |
7b16318d | 1177 | |
3b003157 CH |
1178 | /* |
1179 | * Setup a REQ_TYPE_FS command. These are simple read/write request | |
1180 | * from filesystems that still need to be translated to SCSI CDBs from | |
1181 | * the ULD. | |
1182 | */ | |
7f9a6bc4 | 1183 | int scsi_setup_fs_cmnd(struct scsi_device *sdev, struct request *req) |
1da177e4 | 1184 | { |
1da177e4 | 1185 | struct scsi_cmnd *cmd; |
7f9a6bc4 | 1186 | int ret = scsi_prep_state_check(sdev, req); |
1da177e4 | 1187 | |
7f9a6bc4 JB |
1188 | if (ret != BLKPREP_OK) |
1189 | return ret; | |
a6a8d9f8 CS |
1190 | |
1191 | if (unlikely(sdev->scsi_dh_data && sdev->scsi_dh_data->scsi_dh | |
1192 | && sdev->scsi_dh_data->scsi_dh->prep_fn)) { | |
1193 | ret = sdev->scsi_dh_data->scsi_dh->prep_fn(sdev, req); | |
1194 | if (ret != BLKPREP_OK) | |
1195 | return ret; | |
1196 | } | |
1197 | ||
1da177e4 | 1198 | /* |
3b003157 | 1199 | * Filesystem requests must transfer data. |
1da177e4 | 1200 | */ |
3b003157 CH |
1201 | BUG_ON(!req->nr_phys_segments); |
1202 | ||
1203 | cmd = scsi_get_cmd_from_req(sdev, req); | |
1204 | if (unlikely(!cmd)) | |
1205 | return BLKPREP_DEFER; | |
1206 | ||
64a87b24 | 1207 | memset(cmd->cmnd, 0, BLK_MAX_CDB); |
bb52d82f | 1208 | return scsi_init_io(cmd, GFP_ATOMIC); |
3b003157 | 1209 | } |
7f9a6bc4 | 1210 | EXPORT_SYMBOL(scsi_setup_fs_cmnd); |
3b003157 | 1211 | |
7f9a6bc4 | 1212 | int scsi_prep_state_check(struct scsi_device *sdev, struct request *req) |
3b003157 | 1213 | { |
3b003157 CH |
1214 | int ret = BLKPREP_OK; |
1215 | ||
1da177e4 | 1216 | /* |
3b003157 CH |
1217 | * If the device is not in running state we will reject some |
1218 | * or all commands. | |
1da177e4 | 1219 | */ |
3b003157 CH |
1220 | if (unlikely(sdev->sdev_state != SDEV_RUNNING)) { |
1221 | switch (sdev->sdev_state) { | |
1222 | case SDEV_OFFLINE: | |
1b8d2620 | 1223 | case SDEV_TRANSPORT_OFFLINE: |
3b003157 CH |
1224 | /* |
1225 | * If the device is offline we refuse to process any | |
1226 | * commands. The device must be brought online | |
1227 | * before trying any recovery commands. | |
1228 | */ | |
1229 | sdev_printk(KERN_ERR, sdev, | |
1230 | "rejecting I/O to offline device\n"); | |
1231 | ret = BLKPREP_KILL; | |
1232 | break; | |
1233 | case SDEV_DEL: | |
1234 | /* | |
1235 | * If the device is fully deleted, we refuse to | |
1236 | * process any commands as well. | |
1237 | */ | |
9ccfc756 | 1238 | sdev_printk(KERN_ERR, sdev, |
3b003157 CH |
1239 | "rejecting I/O to dead device\n"); |
1240 | ret = BLKPREP_KILL; | |
1241 | break; | |
1242 | case SDEV_QUIESCE: | |
1243 | case SDEV_BLOCK: | |
6f4267e3 | 1244 | case SDEV_CREATED_BLOCK: |
3b003157 CH |
1245 | /* |
1246 | * If the devices is blocked we defer normal commands. | |
1247 | */ | |
1248 | if (!(req->cmd_flags & REQ_PREEMPT)) | |
1249 | ret = BLKPREP_DEFER; | |
1250 | break; | |
1251 | default: | |
1252 | /* | |
1253 | * For any other not fully online state we only allow | |
1254 | * special commands. In particular any user initiated | |
1255 | * command is not allowed. | |
1256 | */ | |
1257 | if (!(req->cmd_flags & REQ_PREEMPT)) | |
1258 | ret = BLKPREP_KILL; | |
1259 | break; | |
1da177e4 | 1260 | } |
1da177e4 | 1261 | } |
7f9a6bc4 JB |
1262 | return ret; |
1263 | } | |
1264 | EXPORT_SYMBOL(scsi_prep_state_check); | |
1da177e4 | 1265 | |
7f9a6bc4 JB |
1266 | int scsi_prep_return(struct request_queue *q, struct request *req, int ret) |
1267 | { | |
1268 | struct scsi_device *sdev = q->queuedata; | |
1da177e4 | 1269 | |
3b003157 CH |
1270 | switch (ret) { |
1271 | case BLKPREP_KILL: | |
1272 | req->errors = DID_NO_CONNECT << 16; | |
7f9a6bc4 JB |
1273 | /* release the command and kill it */ |
1274 | if (req->special) { | |
1275 | struct scsi_cmnd *cmd = req->special; | |
1276 | scsi_release_buffers(cmd); | |
1277 | scsi_put_command(cmd); | |
68c03d91 | 1278 | put_device(&sdev->sdev_gendev); |
7f9a6bc4 JB |
1279 | req->special = NULL; |
1280 | } | |
3b003157 CH |
1281 | break; |
1282 | case BLKPREP_DEFER: | |
1da177e4 | 1283 | /* |
9934c8c0 | 1284 | * If we defer, the blk_peek_request() returns NULL, but the |
a488e749 JA |
1285 | * queue must be restarted, so we schedule a callback to happen |
1286 | * shortly. | |
1da177e4 | 1287 | */ |
3b003157 | 1288 | if (sdev->device_busy == 0) |
a488e749 | 1289 | blk_delay_queue(q, SCSI_QUEUE_DELAY); |
3b003157 CH |
1290 | break; |
1291 | default: | |
1292 | req->cmd_flags |= REQ_DONTPREP; | |
1da177e4 LT |
1293 | } |
1294 | ||
3b003157 | 1295 | return ret; |
1da177e4 | 1296 | } |
7f9a6bc4 JB |
1297 | EXPORT_SYMBOL(scsi_prep_return); |
1298 | ||
751bf4d7 | 1299 | int scsi_prep_fn(struct request_queue *q, struct request *req) |
7f9a6bc4 JB |
1300 | { |
1301 | struct scsi_device *sdev = q->queuedata; | |
1302 | int ret = BLKPREP_KILL; | |
1303 | ||
1304 | if (req->cmd_type == REQ_TYPE_BLOCK_PC) | |
1305 | ret = scsi_setup_blk_pc_cmnd(sdev, req); | |
1306 | return scsi_prep_return(q, req, ret); | |
1307 | } | |
b391277a | 1308 | EXPORT_SYMBOL(scsi_prep_fn); |
1da177e4 LT |
1309 | |
1310 | /* | |
1311 | * scsi_dev_queue_ready: if we can send requests to sdev, return 1 else | |
1312 | * return 0. | |
1313 | * | |
1314 | * Called with the queue_lock held. | |
1315 | */ | |
1316 | static inline int scsi_dev_queue_ready(struct request_queue *q, | |
1317 | struct scsi_device *sdev) | |
1318 | { | |
1da177e4 LT |
1319 | if (sdev->device_busy == 0 && sdev->device_blocked) { |
1320 | /* | |
1321 | * unblock after device_blocked iterates to zero | |
1322 | */ | |
1323 | if (--sdev->device_blocked == 0) { | |
1324 | SCSI_LOG_MLQUEUE(3, | |
9ccfc756 JB |
1325 | sdev_printk(KERN_INFO, sdev, |
1326 | "unblocking device at zero depth\n")); | |
1da177e4 | 1327 | } else { |
a488e749 | 1328 | blk_delay_queue(q, SCSI_QUEUE_DELAY); |
1da177e4 LT |
1329 | return 0; |
1330 | } | |
1331 | } | |
9d112517 | 1332 | if (scsi_device_is_busy(sdev)) |
1da177e4 LT |
1333 | return 0; |
1334 | ||
1335 | return 1; | |
1336 | } | |
1337 | ||
f0c0a376 MC |
1338 | |
1339 | /* | |
1340 | * scsi_target_queue_ready: checks if there we can send commands to target | |
1341 | * @sdev: scsi device on starget to check. | |
1342 | * | |
1343 | * Called with the host lock held. | |
1344 | */ | |
1345 | static inline int scsi_target_queue_ready(struct Scsi_Host *shost, | |
1346 | struct scsi_device *sdev) | |
1347 | { | |
1348 | struct scsi_target *starget = scsi_target(sdev); | |
1349 | ||
1350 | if (starget->single_lun) { | |
1351 | if (starget->starget_sdev_user && | |
1352 | starget->starget_sdev_user != sdev) | |
1353 | return 0; | |
1354 | starget->starget_sdev_user = sdev; | |
1355 | } | |
1356 | ||
1357 | if (starget->target_busy == 0 && starget->target_blocked) { | |
1358 | /* | |
1359 | * unblock after target_blocked iterates to zero | |
1360 | */ | |
1361 | if (--starget->target_blocked == 0) { | |
1362 | SCSI_LOG_MLQUEUE(3, starget_printk(KERN_INFO, starget, | |
1363 | "unblocking target at zero depth\n")); | |
b4efdd58 | 1364 | } else |
f0c0a376 | 1365 | return 0; |
f0c0a376 MC |
1366 | } |
1367 | ||
1368 | if (scsi_target_is_busy(starget)) { | |
466c08c7 | 1369 | list_move_tail(&sdev->starved_entry, &shost->starved_list); |
fd01a663 | 1370 | return 0; |
f0c0a376 MC |
1371 | } |
1372 | ||
f0c0a376 MC |
1373 | return 1; |
1374 | } | |
1375 | ||
1da177e4 LT |
1376 | /* |
1377 | * scsi_host_queue_ready: if we can send requests to shost, return 1 else | |
1378 | * return 0. We must end up running the queue again whenever 0 is | |
1379 | * returned, else IO can hang. | |
1380 | * | |
1381 | * Called with host_lock held. | |
1382 | */ | |
1383 | static inline int scsi_host_queue_ready(struct request_queue *q, | |
1384 | struct Scsi_Host *shost, | |
1385 | struct scsi_device *sdev) | |
1386 | { | |
939647ee | 1387 | if (scsi_host_in_recovery(shost)) |
1da177e4 LT |
1388 | return 0; |
1389 | if (shost->host_busy == 0 && shost->host_blocked) { | |
1390 | /* | |
1391 | * unblock after host_blocked iterates to zero | |
1392 | */ | |
1393 | if (--shost->host_blocked == 0) { | |
1394 | SCSI_LOG_MLQUEUE(3, | |
1395 | printk("scsi%d unblocking host at zero depth\n", | |
1396 | shost->host_no)); | |
1397 | } else { | |
1da177e4 LT |
1398 | return 0; |
1399 | } | |
1400 | } | |
9d112517 | 1401 | if (scsi_host_is_busy(shost)) { |
1da177e4 LT |
1402 | if (list_empty(&sdev->starved_entry)) |
1403 | list_add_tail(&sdev->starved_entry, &shost->starved_list); | |
1404 | return 0; | |
1405 | } | |
1406 | ||
1407 | /* We're OK to process the command, so we can't be starved */ | |
1408 | if (!list_empty(&sdev->starved_entry)) | |
1409 | list_del_init(&sdev->starved_entry); | |
1410 | ||
1411 | return 1; | |
1412 | } | |
1413 | ||
6c5121b7 KU |
1414 | /* |
1415 | * Busy state exporting function for request stacking drivers. | |
1416 | * | |
1417 | * For efficiency, no lock is taken to check the busy state of | |
1418 | * shost/starget/sdev, since the returned value is not guaranteed and | |
1419 | * may be changed after request stacking drivers call the function, | |
1420 | * regardless of taking lock or not. | |
1421 | * | |
67bd9413 BVA |
1422 | * When scsi can't dispatch I/Os anymore and needs to kill I/Os scsi |
1423 | * needs to return 'not busy'. Otherwise, request stacking drivers | |
1424 | * may hold requests forever. | |
6c5121b7 KU |
1425 | */ |
1426 | static int scsi_lld_busy(struct request_queue *q) | |
1427 | { | |
1428 | struct scsi_device *sdev = q->queuedata; | |
1429 | struct Scsi_Host *shost; | |
6c5121b7 | 1430 | |
3f3299d5 | 1431 | if (blk_queue_dying(q)) |
6c5121b7 KU |
1432 | return 0; |
1433 | ||
1434 | shost = sdev->host; | |
6c5121b7 | 1435 | |
b7e94a16 JN |
1436 | /* |
1437 | * Ignore host/starget busy state. | |
1438 | * Since block layer does not have a concept of fairness across | |
1439 | * multiple queues, congestion of host/starget needs to be handled | |
1440 | * in SCSI layer. | |
1441 | */ | |
1442 | if (scsi_host_in_recovery(shost) || scsi_device_is_busy(sdev)) | |
6c5121b7 KU |
1443 | return 1; |
1444 | ||
1445 | return 0; | |
1446 | } | |
1447 | ||
1da177e4 | 1448 | /* |
e91442b6 | 1449 | * Kill a request for a dead device |
1da177e4 | 1450 | */ |
165125e1 | 1451 | static void scsi_kill_request(struct request *req, struct request_queue *q) |
1da177e4 | 1452 | { |
e91442b6 | 1453 | struct scsi_cmnd *cmd = req->special; |
03b14708 JS |
1454 | struct scsi_device *sdev; |
1455 | struct scsi_target *starget; | |
1456 | struct Scsi_Host *shost; | |
1da177e4 | 1457 | |
9934c8c0 | 1458 | blk_start_request(req); |
788ce43a | 1459 | |
74571813 HR |
1460 | scmd_printk(KERN_INFO, cmd, "killing request\n"); |
1461 | ||
03b14708 JS |
1462 | sdev = cmd->device; |
1463 | starget = scsi_target(sdev); | |
1464 | shost = sdev->host; | |
e91442b6 JB |
1465 | scsi_init_cmd_errh(cmd); |
1466 | cmd->result = DID_NO_CONNECT << 16; | |
1467 | atomic_inc(&cmd->device->iorequest_cnt); | |
e36e0c80 TH |
1468 | |
1469 | /* | |
1470 | * SCSI request completion path will do scsi_device_unbusy(), | |
1471 | * bump busy counts. To bump the counters, we need to dance | |
1472 | * with the locks as normal issue path does. | |
1473 | */ | |
1474 | sdev->device_busy++; | |
1475 | spin_unlock(sdev->request_queue->queue_lock); | |
1476 | spin_lock(shost->host_lock); | |
1477 | shost->host_busy++; | |
f0c0a376 | 1478 | starget->target_busy++; |
e36e0c80 TH |
1479 | spin_unlock(shost->host_lock); |
1480 | spin_lock(sdev->request_queue->queue_lock); | |
1481 | ||
242f9dcb | 1482 | blk_complete_request(req); |
1da177e4 LT |
1483 | } |
1484 | ||
1aea6434 JA |
1485 | static void scsi_softirq_done(struct request *rq) |
1486 | { | |
242f9dcb JA |
1487 | struct scsi_cmnd *cmd = rq->special; |
1488 | unsigned long wait_for = (cmd->allowed + 1) * rq->timeout; | |
1aea6434 JA |
1489 | int disposition; |
1490 | ||
1491 | INIT_LIST_HEAD(&cmd->eh_entry); | |
1492 | ||
242f9dcb JA |
1493 | atomic_inc(&cmd->device->iodone_cnt); |
1494 | if (cmd->result) | |
1495 | atomic_inc(&cmd->device->ioerr_cnt); | |
1496 | ||
1aea6434 JA |
1497 | disposition = scsi_decide_disposition(cmd); |
1498 | if (disposition != SUCCESS && | |
1499 | time_before(cmd->jiffies_at_alloc + wait_for, jiffies)) { | |
1500 | sdev_printk(KERN_ERR, cmd->device, | |
1501 | "timing out command, waited %lus\n", | |
1502 | wait_for/HZ); | |
1503 | disposition = SUCCESS; | |
1504 | } | |
1505 | ||
1506 | scsi_log_completion(cmd, disposition); | |
1507 | ||
1508 | switch (disposition) { | |
1509 | case SUCCESS: | |
1510 | scsi_finish_command(cmd); | |
1511 | break; | |
1512 | case NEEDS_RETRY: | |
596f482a | 1513 | scsi_queue_insert(cmd, SCSI_MLQUEUE_EH_RETRY); |
1aea6434 JA |
1514 | break; |
1515 | case ADD_TO_MLQUEUE: | |
1516 | scsi_queue_insert(cmd, SCSI_MLQUEUE_DEVICE_BUSY); | |
1517 | break; | |
1518 | default: | |
1519 | if (!scsi_eh_scmd_add(cmd, 0)) | |
1520 | scsi_finish_command(cmd); | |
1521 | } | |
1522 | } | |
1523 | ||
1da177e4 LT |
1524 | /* |
1525 | * Function: scsi_request_fn() | |
1526 | * | |
1527 | * Purpose: Main strategy routine for SCSI. | |
1528 | * | |
1529 | * Arguments: q - Pointer to actual queue. | |
1530 | * | |
1531 | * Returns: Nothing | |
1532 | * | |
1533 | * Lock status: IO request lock assumed to be held when called. | |
1534 | */ | |
1535 | static void scsi_request_fn(struct request_queue *q) | |
613be1f6 BVA |
1536 | __releases(q->queue_lock) |
1537 | __acquires(q->queue_lock) | |
1da177e4 LT |
1538 | { |
1539 | struct scsi_device *sdev = q->queuedata; | |
1540 | struct Scsi_Host *shost; | |
1541 | struct scsi_cmnd *cmd; | |
1542 | struct request *req; | |
1543 | ||
1da177e4 LT |
1544 | /* |
1545 | * To start with, we keep looping until the queue is empty, or until | |
1546 | * the host is no longer able to accept any more requests. | |
1547 | */ | |
1548 | shost = sdev->host; | |
a488e749 | 1549 | for (;;) { |
1da177e4 LT |
1550 | int rtn; |
1551 | /* | |
1552 | * get next queueable request. We do this early to make sure | |
1553 | * that the request is fully prepared even if we cannot | |
1554 | * accept it. | |
1555 | */ | |
9934c8c0 | 1556 | req = blk_peek_request(q); |
1da177e4 LT |
1557 | if (!req || !scsi_dev_queue_ready(q, sdev)) |
1558 | break; | |
1559 | ||
1560 | if (unlikely(!scsi_device_online(sdev))) { | |
9ccfc756 JB |
1561 | sdev_printk(KERN_ERR, sdev, |
1562 | "rejecting I/O to offline device\n"); | |
e91442b6 | 1563 | scsi_kill_request(req, q); |
1da177e4 LT |
1564 | continue; |
1565 | } | |
1566 | ||
1567 | ||
1568 | /* | |
1569 | * Remove the request from the request list. | |
1570 | */ | |
1571 | if (!(blk_queue_tagged(q) && !blk_queue_start_tag(q, req))) | |
9934c8c0 | 1572 | blk_start_request(req); |
1da177e4 LT |
1573 | sdev->device_busy++; |
1574 | ||
1575 | spin_unlock(q->queue_lock); | |
e91442b6 JB |
1576 | cmd = req->special; |
1577 | if (unlikely(cmd == NULL)) { | |
1578 | printk(KERN_CRIT "impossible request in %s.\n" | |
1579 | "please mail a stack trace to " | |
4aff5e23 | 1580 | "linux-scsi@vger.kernel.org\n", |
cadbd4a5 | 1581 | __func__); |
4aff5e23 | 1582 | blk_dump_rq_flags(req, "foo"); |
e91442b6 JB |
1583 | BUG(); |
1584 | } | |
1da177e4 LT |
1585 | spin_lock(shost->host_lock); |
1586 | ||
ecefe8a9 MC |
1587 | /* |
1588 | * We hit this when the driver is using a host wide | |
1589 | * tag map. For device level tag maps the queue_depth check | |
1590 | * in the device ready fn would prevent us from trying | |
1591 | * to allocate a tag. Since the map is a shared host resource | |
1592 | * we add the dev to the starved list so it eventually gets | |
1593 | * a run when a tag is freed. | |
1594 | */ | |
6bd522f6 | 1595 | if (blk_queue_tagged(q) && !blk_rq_tagged(req)) { |
ecefe8a9 MC |
1596 | if (list_empty(&sdev->starved_entry)) |
1597 | list_add_tail(&sdev->starved_entry, | |
1598 | &shost->starved_list); | |
1599 | goto not_ready; | |
1600 | } | |
1601 | ||
f0c0a376 MC |
1602 | if (!scsi_target_queue_ready(shost, sdev)) |
1603 | goto not_ready; | |
1604 | ||
1da177e4 LT |
1605 | if (!scsi_host_queue_ready(q, shost, sdev)) |
1606 | goto not_ready; | |
f0c0a376 MC |
1607 | |
1608 | scsi_target(sdev)->target_busy++; | |
1da177e4 LT |
1609 | shost->host_busy++; |
1610 | ||
1611 | /* | |
1612 | * XXX(hch): This is rather suboptimal, scsi_dispatch_cmd will | |
1613 | * take the lock again. | |
1614 | */ | |
1615 | spin_unlock_irq(shost->host_lock); | |
1616 | ||
1da177e4 LT |
1617 | /* |
1618 | * Finally, initialize any error handling parameters, and set up | |
1619 | * the timers for timeouts. | |
1620 | */ | |
1621 | scsi_init_cmd_errh(cmd); | |
1622 | ||
1623 | /* | |
1624 | * Dispatch the command to the low-level driver. | |
1625 | */ | |
1626 | rtn = scsi_dispatch_cmd(cmd); | |
1627 | spin_lock_irq(q->queue_lock); | |
a488e749 JA |
1628 | if (rtn) |
1629 | goto out_delay; | |
1da177e4 LT |
1630 | } |
1631 | ||
613be1f6 | 1632 | return; |
1da177e4 LT |
1633 | |
1634 | not_ready: | |
1635 | spin_unlock_irq(shost->host_lock); | |
1636 | ||
1637 | /* | |
1638 | * lock q, handle tag, requeue req, and decrement device_busy. We | |
1639 | * must return with queue_lock held. | |
1640 | * | |
1641 | * Decrementing device_busy without checking it is OK, as all such | |
1642 | * cases (host limits or settings) should run the queue at some | |
1643 | * later time. | |
1644 | */ | |
1645 | spin_lock_irq(q->queue_lock); | |
1646 | blk_requeue_request(q, req); | |
1647 | sdev->device_busy--; | |
a488e749 JA |
1648 | out_delay: |
1649 | if (sdev->device_busy == 0) | |
1650 | blk_delay_queue(q, SCSI_QUEUE_DELAY); | |
1da177e4 LT |
1651 | } |
1652 | ||
1653 | u64 scsi_calculate_bounce_limit(struct Scsi_Host *shost) | |
1654 | { | |
1655 | struct device *host_dev; | |
1656 | u64 bounce_limit = 0xffffffff; | |
1657 | ||
1658 | if (shost->unchecked_isa_dma) | |
1659 | return BLK_BOUNCE_ISA; | |
1660 | /* | |
1661 | * Platforms with virtual-DMA translation | |
1662 | * hardware have no practical limit. | |
1663 | */ | |
1664 | if (!PCI_DMA_BUS_IS_PHYS) | |
1665 | return BLK_BOUNCE_ANY; | |
1666 | ||
1667 | host_dev = scsi_get_device(shost); | |
1668 | if (host_dev && host_dev->dma_mask) | |
e83b3664 | 1669 | bounce_limit = (u64)dma_max_pfn(host_dev) << PAGE_SHIFT; |
1da177e4 LT |
1670 | |
1671 | return bounce_limit; | |
1672 | } | |
1673 | EXPORT_SYMBOL(scsi_calculate_bounce_limit); | |
1674 | ||
b58d9154 FT |
1675 | struct request_queue *__scsi_alloc_queue(struct Scsi_Host *shost, |
1676 | request_fn_proc *request_fn) | |
1da177e4 | 1677 | { |
1da177e4 | 1678 | struct request_queue *q; |
6f381fa3 | 1679 | struct device *dev = shost->dma_dev; |
1da177e4 | 1680 | |
b58d9154 | 1681 | q = blk_init_queue(request_fn, NULL); |
1da177e4 LT |
1682 | if (!q) |
1683 | return NULL; | |
1684 | ||
a8474ce2 JA |
1685 | /* |
1686 | * this limit is imposed by hardware restrictions | |
1687 | */ | |
8a78362c MP |
1688 | blk_queue_max_segments(q, min_t(unsigned short, shost->sg_tablesize, |
1689 | SCSI_MAX_SG_CHAIN_SEGMENTS)); | |
a8474ce2 | 1690 | |
13f05c8d MP |
1691 | if (scsi_host_prot_dma(shost)) { |
1692 | shost->sg_prot_tablesize = | |
1693 | min_not_zero(shost->sg_prot_tablesize, | |
1694 | (unsigned short)SCSI_MAX_PROT_SG_SEGMENTS); | |
1695 | BUG_ON(shost->sg_prot_tablesize < shost->sg_tablesize); | |
1696 | blk_queue_max_integrity_segments(q, shost->sg_prot_tablesize); | |
1697 | } | |
1698 | ||
086fa5ff | 1699 | blk_queue_max_hw_sectors(q, shost->max_sectors); |
1da177e4 LT |
1700 | blk_queue_bounce_limit(q, scsi_calculate_bounce_limit(shost)); |
1701 | blk_queue_segment_boundary(q, shost->dma_boundary); | |
99c84dbd | 1702 | dma_set_seg_boundary(dev, shost->dma_boundary); |
1da177e4 | 1703 | |
860ac568 FT |
1704 | blk_queue_max_segment_size(q, dma_get_max_seg_size(dev)); |
1705 | ||
1da177e4 | 1706 | if (!shost->use_clustering) |
e692cb66 | 1707 | q->limits.cluster = 0; |
465ff318 JB |
1708 | |
1709 | /* | |
1710 | * set a reasonable default alignment on word boundaries: the | |
1711 | * host and device may alter it using | |
1712 | * blk_queue_update_dma_alignment() later. | |
1713 | */ | |
1714 | blk_queue_dma_alignment(q, 0x03); | |
1715 | ||
1da177e4 LT |
1716 | return q; |
1717 | } | |
b58d9154 FT |
1718 | EXPORT_SYMBOL(__scsi_alloc_queue); |
1719 | ||
1720 | struct request_queue *scsi_alloc_queue(struct scsi_device *sdev) | |
1721 | { | |
1722 | struct request_queue *q; | |
1723 | ||
1724 | q = __scsi_alloc_queue(sdev->host, scsi_request_fn); | |
1725 | if (!q) | |
1726 | return NULL; | |
1727 | ||
1728 | blk_queue_prep_rq(q, scsi_prep_fn); | |
b58d9154 | 1729 | blk_queue_softirq_done(q, scsi_softirq_done); |
242f9dcb | 1730 | blk_queue_rq_timed_out(q, scsi_times_out); |
6c5121b7 | 1731 | blk_queue_lld_busy(q, scsi_lld_busy); |
b58d9154 FT |
1732 | return q; |
1733 | } | |
1da177e4 | 1734 | |
1da177e4 LT |
1735 | /* |
1736 | * Function: scsi_block_requests() | |
1737 | * | |
1738 | * Purpose: Utility function used by low-level drivers to prevent further | |
1739 | * commands from being queued to the device. | |
1740 | * | |
1741 | * Arguments: shost - Host in question | |
1742 | * | |
1743 | * Returns: Nothing | |
1744 | * | |
1745 | * Lock status: No locks are assumed held. | |
1746 | * | |
1747 | * Notes: There is no timer nor any other means by which the requests | |
1748 | * get unblocked other than the low-level driver calling | |
1749 | * scsi_unblock_requests(). | |
1750 | */ | |
1751 | void scsi_block_requests(struct Scsi_Host *shost) | |
1752 | { | |
1753 | shost->host_self_blocked = 1; | |
1754 | } | |
1755 | EXPORT_SYMBOL(scsi_block_requests); | |
1756 | ||
1757 | /* | |
1758 | * Function: scsi_unblock_requests() | |
1759 | * | |
1760 | * Purpose: Utility function used by low-level drivers to allow further | |
1761 | * commands from being queued to the device. | |
1762 | * | |
1763 | * Arguments: shost - Host in question | |
1764 | * | |
1765 | * Returns: Nothing | |
1766 | * | |
1767 | * Lock status: No locks are assumed held. | |
1768 | * | |
1769 | * Notes: There is no timer nor any other means by which the requests | |
1770 | * get unblocked other than the low-level driver calling | |
1771 | * scsi_unblock_requests(). | |
1772 | * | |
1773 | * This is done as an API function so that changes to the | |
1774 | * internals of the scsi mid-layer won't require wholesale | |
1775 | * changes to drivers that use this feature. | |
1776 | */ | |
1777 | void scsi_unblock_requests(struct Scsi_Host *shost) | |
1778 | { | |
1779 | shost->host_self_blocked = 0; | |
1780 | scsi_run_host_queues(shost); | |
1781 | } | |
1782 | EXPORT_SYMBOL(scsi_unblock_requests); | |
1783 | ||
1784 | int __init scsi_init_queue(void) | |
1785 | { | |
1786 | int i; | |
1787 | ||
6362abd3 MP |
1788 | scsi_sdb_cache = kmem_cache_create("scsi_data_buffer", |
1789 | sizeof(struct scsi_data_buffer), | |
1790 | 0, 0, NULL); | |
1791 | if (!scsi_sdb_cache) { | |
1792 | printk(KERN_ERR "SCSI: can't init scsi sdb cache\n"); | |
f078727b | 1793 | return -ENOMEM; |
6f9a35e2 BH |
1794 | } |
1795 | ||
1da177e4 LT |
1796 | for (i = 0; i < SG_MEMPOOL_NR; i++) { |
1797 | struct scsi_host_sg_pool *sgp = scsi_sg_pools + i; | |
1798 | int size = sgp->size * sizeof(struct scatterlist); | |
1799 | ||
1800 | sgp->slab = kmem_cache_create(sgp->name, size, 0, | |
20c2df83 | 1801 | SLAB_HWCACHE_ALIGN, NULL); |
1da177e4 LT |
1802 | if (!sgp->slab) { |
1803 | printk(KERN_ERR "SCSI: can't init sg slab %s\n", | |
1804 | sgp->name); | |
6362abd3 | 1805 | goto cleanup_sdb; |
1da177e4 LT |
1806 | } |
1807 | ||
93d2341c MD |
1808 | sgp->pool = mempool_create_slab_pool(SG_MEMPOOL_SIZE, |
1809 | sgp->slab); | |
1da177e4 LT |
1810 | if (!sgp->pool) { |
1811 | printk(KERN_ERR "SCSI: can't init sg mempool %s\n", | |
1812 | sgp->name); | |
6362abd3 | 1813 | goto cleanup_sdb; |
1da177e4 LT |
1814 | } |
1815 | } | |
1816 | ||
1817 | return 0; | |
3d9dd6ee | 1818 | |
6362abd3 | 1819 | cleanup_sdb: |
3d9dd6ee FT |
1820 | for (i = 0; i < SG_MEMPOOL_NR; i++) { |
1821 | struct scsi_host_sg_pool *sgp = scsi_sg_pools + i; | |
1822 | if (sgp->pool) | |
1823 | mempool_destroy(sgp->pool); | |
1824 | if (sgp->slab) | |
1825 | kmem_cache_destroy(sgp->slab); | |
1826 | } | |
6362abd3 | 1827 | kmem_cache_destroy(scsi_sdb_cache); |
3d9dd6ee FT |
1828 | |
1829 | return -ENOMEM; | |
1da177e4 LT |
1830 | } |
1831 | ||
1832 | void scsi_exit_queue(void) | |
1833 | { | |
1834 | int i; | |
1835 | ||
6362abd3 | 1836 | kmem_cache_destroy(scsi_sdb_cache); |
aa7b5cd7 | 1837 | |
1da177e4 LT |
1838 | for (i = 0; i < SG_MEMPOOL_NR; i++) { |
1839 | struct scsi_host_sg_pool *sgp = scsi_sg_pools + i; | |
1840 | mempool_destroy(sgp->pool); | |
1841 | kmem_cache_destroy(sgp->slab); | |
1842 | } | |
1843 | } | |
5baba830 JB |
1844 | |
1845 | /** | |
1846 | * scsi_mode_select - issue a mode select | |
1847 | * @sdev: SCSI device to be queried | |
1848 | * @pf: Page format bit (1 == standard, 0 == vendor specific) | |
1849 | * @sp: Save page bit (0 == don't save, 1 == save) | |
1850 | * @modepage: mode page being requested | |
1851 | * @buffer: request buffer (may not be smaller than eight bytes) | |
1852 | * @len: length of request buffer. | |
1853 | * @timeout: command timeout | |
1854 | * @retries: number of retries before failing | |
1855 | * @data: returns a structure abstracting the mode header data | |
eb44820c | 1856 | * @sshdr: place to put sense data (or NULL if no sense to be collected). |
5baba830 JB |
1857 | * must be SCSI_SENSE_BUFFERSIZE big. |
1858 | * | |
1859 | * Returns zero if successful; negative error number or scsi | |
1860 | * status on error | |
1861 | * | |
1862 | */ | |
1863 | int | |
1864 | scsi_mode_select(struct scsi_device *sdev, int pf, int sp, int modepage, | |
1865 | unsigned char *buffer, int len, int timeout, int retries, | |
1866 | struct scsi_mode_data *data, struct scsi_sense_hdr *sshdr) | |
1867 | { | |
1868 | unsigned char cmd[10]; | |
1869 | unsigned char *real_buffer; | |
1870 | int ret; | |
1871 | ||
1872 | memset(cmd, 0, sizeof(cmd)); | |
1873 | cmd[1] = (pf ? 0x10 : 0) | (sp ? 0x01 : 0); | |
1874 | ||
1875 | if (sdev->use_10_for_ms) { | |
1876 | if (len > 65535) | |
1877 | return -EINVAL; | |
1878 | real_buffer = kmalloc(8 + len, GFP_KERNEL); | |
1879 | if (!real_buffer) | |
1880 | return -ENOMEM; | |
1881 | memcpy(real_buffer + 8, buffer, len); | |
1882 | len += 8; | |
1883 | real_buffer[0] = 0; | |
1884 | real_buffer[1] = 0; | |
1885 | real_buffer[2] = data->medium_type; | |
1886 | real_buffer[3] = data->device_specific; | |
1887 | real_buffer[4] = data->longlba ? 0x01 : 0; | |
1888 | real_buffer[5] = 0; | |
1889 | real_buffer[6] = data->block_descriptor_length >> 8; | |
1890 | real_buffer[7] = data->block_descriptor_length; | |
1891 | ||
1892 | cmd[0] = MODE_SELECT_10; | |
1893 | cmd[7] = len >> 8; | |
1894 | cmd[8] = len; | |
1895 | } else { | |
1896 | if (len > 255 || data->block_descriptor_length > 255 || | |
1897 | data->longlba) | |
1898 | return -EINVAL; | |
1899 | ||
1900 | real_buffer = kmalloc(4 + len, GFP_KERNEL); | |
1901 | if (!real_buffer) | |
1902 | return -ENOMEM; | |
1903 | memcpy(real_buffer + 4, buffer, len); | |
1904 | len += 4; | |
1905 | real_buffer[0] = 0; | |
1906 | real_buffer[1] = data->medium_type; | |
1907 | real_buffer[2] = data->device_specific; | |
1908 | real_buffer[3] = data->block_descriptor_length; | |
1909 | ||
1910 | ||
1911 | cmd[0] = MODE_SELECT; | |
1912 | cmd[4] = len; | |
1913 | } | |
1914 | ||
1915 | ret = scsi_execute_req(sdev, cmd, DMA_TO_DEVICE, real_buffer, len, | |
f4f4e47e | 1916 | sshdr, timeout, retries, NULL); |
5baba830 JB |
1917 | kfree(real_buffer); |
1918 | return ret; | |
1919 | } | |
1920 | EXPORT_SYMBOL_GPL(scsi_mode_select); | |
1921 | ||
1da177e4 | 1922 | /** |
eb44820c | 1923 | * scsi_mode_sense - issue a mode sense, falling back from 10 to six bytes if necessary. |
1cf72699 | 1924 | * @sdev: SCSI device to be queried |
1da177e4 LT |
1925 | * @dbd: set if mode sense will allow block descriptors to be returned |
1926 | * @modepage: mode page being requested | |
1927 | * @buffer: request buffer (may not be smaller than eight bytes) | |
1928 | * @len: length of request buffer. | |
1929 | * @timeout: command timeout | |
1930 | * @retries: number of retries before failing | |
1931 | * @data: returns a structure abstracting the mode header data | |
eb44820c | 1932 | * @sshdr: place to put sense data (or NULL if no sense to be collected). |
1cf72699 | 1933 | * must be SCSI_SENSE_BUFFERSIZE big. |
1da177e4 LT |
1934 | * |
1935 | * Returns zero if unsuccessful, or the header offset (either 4 | |
1936 | * or 8 depending on whether a six or ten byte command was | |
1937 | * issued) if successful. | |
eb44820c | 1938 | */ |
1da177e4 | 1939 | int |
1cf72699 | 1940 | scsi_mode_sense(struct scsi_device *sdev, int dbd, int modepage, |
1da177e4 | 1941 | unsigned char *buffer, int len, int timeout, int retries, |
5baba830 JB |
1942 | struct scsi_mode_data *data, struct scsi_sense_hdr *sshdr) |
1943 | { | |
1da177e4 LT |
1944 | unsigned char cmd[12]; |
1945 | int use_10_for_ms; | |
1946 | int header_length; | |
1cf72699 | 1947 | int result; |
ea73a9f2 | 1948 | struct scsi_sense_hdr my_sshdr; |
1da177e4 LT |
1949 | |
1950 | memset(data, 0, sizeof(*data)); | |
1951 | memset(&cmd[0], 0, 12); | |
1952 | cmd[1] = dbd & 0x18; /* allows DBD and LLBA bits */ | |
1953 | cmd[2] = modepage; | |
1954 | ||
ea73a9f2 JB |
1955 | /* caller might not be interested in sense, but we need it */ |
1956 | if (!sshdr) | |
1957 | sshdr = &my_sshdr; | |
1958 | ||
1da177e4 | 1959 | retry: |
1cf72699 | 1960 | use_10_for_ms = sdev->use_10_for_ms; |
1da177e4 LT |
1961 | |
1962 | if (use_10_for_ms) { | |
1963 | if (len < 8) | |
1964 | len = 8; | |
1965 | ||
1966 | cmd[0] = MODE_SENSE_10; | |
1967 | cmd[8] = len; | |
1968 | header_length = 8; | |
1969 | } else { | |
1970 | if (len < 4) | |
1971 | len = 4; | |
1972 | ||
1973 | cmd[0] = MODE_SENSE; | |
1974 | cmd[4] = len; | |
1975 | header_length = 4; | |
1976 | } | |
1977 | ||
1da177e4 LT |
1978 | memset(buffer, 0, len); |
1979 | ||
1cf72699 | 1980 | result = scsi_execute_req(sdev, cmd, DMA_FROM_DEVICE, buffer, len, |
f4f4e47e | 1981 | sshdr, timeout, retries, NULL); |
1da177e4 LT |
1982 | |
1983 | /* This code looks awful: what it's doing is making sure an | |
1984 | * ILLEGAL REQUEST sense return identifies the actual command | |
1985 | * byte as the problem. MODE_SENSE commands can return | |
1986 | * ILLEGAL REQUEST if the code page isn't supported */ | |
1987 | ||
1cf72699 JB |
1988 | if (use_10_for_ms && !scsi_status_is_good(result) && |
1989 | (driver_byte(result) & DRIVER_SENSE)) { | |
ea73a9f2 JB |
1990 | if (scsi_sense_valid(sshdr)) { |
1991 | if ((sshdr->sense_key == ILLEGAL_REQUEST) && | |
1992 | (sshdr->asc == 0x20) && (sshdr->ascq == 0)) { | |
1da177e4 LT |
1993 | /* |
1994 | * Invalid command operation code | |
1995 | */ | |
1cf72699 | 1996 | sdev->use_10_for_ms = 0; |
1da177e4 LT |
1997 | goto retry; |
1998 | } | |
1999 | } | |
2000 | } | |
2001 | ||
1cf72699 | 2002 | if(scsi_status_is_good(result)) { |
6d73c851 AV |
2003 | if (unlikely(buffer[0] == 0x86 && buffer[1] == 0x0b && |
2004 | (modepage == 6 || modepage == 8))) { | |
2005 | /* Initio breakage? */ | |
2006 | header_length = 0; | |
2007 | data->length = 13; | |
2008 | data->medium_type = 0; | |
2009 | data->device_specific = 0; | |
2010 | data->longlba = 0; | |
2011 | data->block_descriptor_length = 0; | |
2012 | } else if(use_10_for_ms) { | |
1da177e4 LT |
2013 | data->length = buffer[0]*256 + buffer[1] + 2; |
2014 | data->medium_type = buffer[2]; | |
2015 | data->device_specific = buffer[3]; | |
2016 | data->longlba = buffer[4] & 0x01; | |
2017 | data->block_descriptor_length = buffer[6]*256 | |
2018 | + buffer[7]; | |
2019 | } else { | |
2020 | data->length = buffer[0] + 1; | |
2021 | data->medium_type = buffer[1]; | |
2022 | data->device_specific = buffer[2]; | |
2023 | data->block_descriptor_length = buffer[3]; | |
2024 | } | |
6d73c851 | 2025 | data->header_length = header_length; |
1da177e4 LT |
2026 | } |
2027 | ||
1cf72699 | 2028 | return result; |
1da177e4 LT |
2029 | } |
2030 | EXPORT_SYMBOL(scsi_mode_sense); | |
2031 | ||
001aac25 JB |
2032 | /** |
2033 | * scsi_test_unit_ready - test if unit is ready | |
2034 | * @sdev: scsi device to change the state of. | |
2035 | * @timeout: command timeout | |
2036 | * @retries: number of retries before failing | |
2037 | * @sshdr_external: Optional pointer to struct scsi_sense_hdr for | |
2038 | * returning sense. Make sure that this is cleared before passing | |
2039 | * in. | |
2040 | * | |
2041 | * Returns zero if unsuccessful or an error if TUR failed. For | |
9f8a2c23 | 2042 | * removable media, UNIT_ATTENTION sets ->changed flag. |
001aac25 | 2043 | **/ |
1da177e4 | 2044 | int |
001aac25 JB |
2045 | scsi_test_unit_ready(struct scsi_device *sdev, int timeout, int retries, |
2046 | struct scsi_sense_hdr *sshdr_external) | |
1da177e4 | 2047 | { |
1da177e4 LT |
2048 | char cmd[] = { |
2049 | TEST_UNIT_READY, 0, 0, 0, 0, 0, | |
2050 | }; | |
001aac25 | 2051 | struct scsi_sense_hdr *sshdr; |
1da177e4 | 2052 | int result; |
001aac25 JB |
2053 | |
2054 | if (!sshdr_external) | |
2055 | sshdr = kzalloc(sizeof(*sshdr), GFP_KERNEL); | |
2056 | else | |
2057 | sshdr = sshdr_external; | |
2058 | ||
2059 | /* try to eat the UNIT_ATTENTION if there are enough retries */ | |
2060 | do { | |
2061 | result = scsi_execute_req(sdev, cmd, DMA_NONE, NULL, 0, sshdr, | |
f4f4e47e | 2062 | timeout, retries, NULL); |
32c356d7 JB |
2063 | if (sdev->removable && scsi_sense_valid(sshdr) && |
2064 | sshdr->sense_key == UNIT_ATTENTION) | |
2065 | sdev->changed = 1; | |
2066 | } while (scsi_sense_valid(sshdr) && | |
2067 | sshdr->sense_key == UNIT_ATTENTION && --retries); | |
001aac25 | 2068 | |
001aac25 JB |
2069 | if (!sshdr_external) |
2070 | kfree(sshdr); | |
1da177e4 LT |
2071 | return result; |
2072 | } | |
2073 | EXPORT_SYMBOL(scsi_test_unit_ready); | |
2074 | ||
2075 | /** | |
eb44820c | 2076 | * scsi_device_set_state - Take the given device through the device state model. |
1da177e4 LT |
2077 | * @sdev: scsi device to change the state of. |
2078 | * @state: state to change to. | |
2079 | * | |
2080 | * Returns zero if unsuccessful or an error if the requested | |
2081 | * transition is illegal. | |
eb44820c | 2082 | */ |
1da177e4 LT |
2083 | int |
2084 | scsi_device_set_state(struct scsi_device *sdev, enum scsi_device_state state) | |
2085 | { | |
2086 | enum scsi_device_state oldstate = sdev->sdev_state; | |
2087 | ||
2088 | if (state == oldstate) | |
2089 | return 0; | |
2090 | ||
2091 | switch (state) { | |
2092 | case SDEV_CREATED: | |
6f4267e3 JB |
2093 | switch (oldstate) { |
2094 | case SDEV_CREATED_BLOCK: | |
2095 | break; | |
2096 | default: | |
2097 | goto illegal; | |
2098 | } | |
2099 | break; | |
1da177e4 LT |
2100 | |
2101 | case SDEV_RUNNING: | |
2102 | switch (oldstate) { | |
2103 | case SDEV_CREATED: | |
2104 | case SDEV_OFFLINE: | |
1b8d2620 | 2105 | case SDEV_TRANSPORT_OFFLINE: |
1da177e4 LT |
2106 | case SDEV_QUIESCE: |
2107 | case SDEV_BLOCK: | |
2108 | break; | |
2109 | default: | |
2110 | goto illegal; | |
2111 | } | |
2112 | break; | |
2113 | ||
2114 | case SDEV_QUIESCE: | |
2115 | switch (oldstate) { | |
2116 | case SDEV_RUNNING: | |
2117 | case SDEV_OFFLINE: | |
1b8d2620 | 2118 | case SDEV_TRANSPORT_OFFLINE: |
1da177e4 LT |
2119 | break; |
2120 | default: | |
2121 | goto illegal; | |
2122 | } | |
2123 | break; | |
2124 | ||
2125 | case SDEV_OFFLINE: | |
1b8d2620 | 2126 | case SDEV_TRANSPORT_OFFLINE: |
1da177e4 LT |
2127 | switch (oldstate) { |
2128 | case SDEV_CREATED: | |
2129 | case SDEV_RUNNING: | |
2130 | case SDEV_QUIESCE: | |
2131 | case SDEV_BLOCK: | |
2132 | break; | |
2133 | default: | |
2134 | goto illegal; | |
2135 | } | |
2136 | break; | |
2137 | ||
2138 | case SDEV_BLOCK: | |
2139 | switch (oldstate) { | |
1da177e4 | 2140 | case SDEV_RUNNING: |
6f4267e3 JB |
2141 | case SDEV_CREATED_BLOCK: |
2142 | break; | |
2143 | default: | |
2144 | goto illegal; | |
2145 | } | |
2146 | break; | |
2147 | ||
2148 | case SDEV_CREATED_BLOCK: | |
2149 | switch (oldstate) { | |
2150 | case SDEV_CREATED: | |
1da177e4 LT |
2151 | break; |
2152 | default: | |
2153 | goto illegal; | |
2154 | } | |
2155 | break; | |
2156 | ||
2157 | case SDEV_CANCEL: | |
2158 | switch (oldstate) { | |
2159 | case SDEV_CREATED: | |
2160 | case SDEV_RUNNING: | |
9ea72909 | 2161 | case SDEV_QUIESCE: |
1da177e4 | 2162 | case SDEV_OFFLINE: |
1b8d2620 | 2163 | case SDEV_TRANSPORT_OFFLINE: |
1da177e4 LT |
2164 | case SDEV_BLOCK: |
2165 | break; | |
2166 | default: | |
2167 | goto illegal; | |
2168 | } | |
2169 | break; | |
2170 | ||
2171 | case SDEV_DEL: | |
2172 | switch (oldstate) { | |
309bd271 BK |
2173 | case SDEV_CREATED: |
2174 | case SDEV_RUNNING: | |
2175 | case SDEV_OFFLINE: | |
1b8d2620 | 2176 | case SDEV_TRANSPORT_OFFLINE: |
1da177e4 | 2177 | case SDEV_CANCEL: |
0516c08d | 2178 | case SDEV_CREATED_BLOCK: |
1da177e4 LT |
2179 | break; |
2180 | default: | |
2181 | goto illegal; | |
2182 | } | |
2183 | break; | |
2184 | ||
2185 | } | |
2186 | sdev->sdev_state = state; | |
2187 | return 0; | |
2188 | ||
2189 | illegal: | |
2190 | SCSI_LOG_ERROR_RECOVERY(1, | |
9ccfc756 JB |
2191 | sdev_printk(KERN_ERR, sdev, |
2192 | "Illegal state transition %s->%s\n", | |
2193 | scsi_device_state_name(oldstate), | |
2194 | scsi_device_state_name(state)) | |
1da177e4 LT |
2195 | ); |
2196 | return -EINVAL; | |
2197 | } | |
2198 | EXPORT_SYMBOL(scsi_device_set_state); | |
2199 | ||
a341cd0f JG |
2200 | /** |
2201 | * sdev_evt_emit - emit a single SCSI device uevent | |
2202 | * @sdev: associated SCSI device | |
2203 | * @evt: event to emit | |
2204 | * | |
2205 | * Send a single uevent (scsi_event) to the associated scsi_device. | |
2206 | */ | |
2207 | static void scsi_evt_emit(struct scsi_device *sdev, struct scsi_event *evt) | |
2208 | { | |
2209 | int idx = 0; | |
2210 | char *envp[3]; | |
2211 | ||
2212 | switch (evt->evt_type) { | |
2213 | case SDEV_EVT_MEDIA_CHANGE: | |
2214 | envp[idx++] = "SDEV_MEDIA_CHANGE=1"; | |
2215 | break; | |
279afdfe EM |
2216 | case SDEV_EVT_INQUIRY_CHANGE_REPORTED: |
2217 | envp[idx++] = "SDEV_UA=INQUIRY_DATA_HAS_CHANGED"; | |
2218 | break; | |
2219 | case SDEV_EVT_CAPACITY_CHANGE_REPORTED: | |
2220 | envp[idx++] = "SDEV_UA=CAPACITY_DATA_HAS_CHANGED"; | |
2221 | break; | |
2222 | case SDEV_EVT_SOFT_THRESHOLD_REACHED_REPORTED: | |
2223 | envp[idx++] = "SDEV_UA=THIN_PROVISIONING_SOFT_THRESHOLD_REACHED"; | |
2224 | break; | |
2225 | case SDEV_EVT_MODE_PARAMETER_CHANGE_REPORTED: | |
2226 | envp[idx++] = "SDEV_UA=MODE_PARAMETERS_CHANGED"; | |
2227 | break; | |
2228 | case SDEV_EVT_LUN_CHANGE_REPORTED: | |
2229 | envp[idx++] = "SDEV_UA=REPORTED_LUNS_DATA_HAS_CHANGED"; | |
2230 | break; | |
a341cd0f JG |
2231 | default: |
2232 | /* do nothing */ | |
2233 | break; | |
2234 | } | |
2235 | ||
2236 | envp[idx++] = NULL; | |
2237 | ||
2238 | kobject_uevent_env(&sdev->sdev_gendev.kobj, KOBJ_CHANGE, envp); | |
2239 | } | |
2240 | ||
2241 | /** | |
2242 | * sdev_evt_thread - send a uevent for each scsi event | |
2243 | * @work: work struct for scsi_device | |
2244 | * | |
2245 | * Dispatch queued events to their associated scsi_device kobjects | |
2246 | * as uevents. | |
2247 | */ | |
2248 | void scsi_evt_thread(struct work_struct *work) | |
2249 | { | |
2250 | struct scsi_device *sdev; | |
279afdfe | 2251 | enum scsi_device_event evt_type; |
a341cd0f JG |
2252 | LIST_HEAD(event_list); |
2253 | ||
2254 | sdev = container_of(work, struct scsi_device, event_work); | |
2255 | ||
279afdfe EM |
2256 | for (evt_type = SDEV_EVT_FIRST; evt_type <= SDEV_EVT_LAST; evt_type++) |
2257 | if (test_and_clear_bit(evt_type, sdev->pending_events)) | |
2258 | sdev_evt_send_simple(sdev, evt_type, GFP_KERNEL); | |
2259 | ||
a341cd0f JG |
2260 | while (1) { |
2261 | struct scsi_event *evt; | |
2262 | struct list_head *this, *tmp; | |
2263 | unsigned long flags; | |
2264 | ||
2265 | spin_lock_irqsave(&sdev->list_lock, flags); | |
2266 | list_splice_init(&sdev->event_list, &event_list); | |
2267 | spin_unlock_irqrestore(&sdev->list_lock, flags); | |
2268 | ||
2269 | if (list_empty(&event_list)) | |
2270 | break; | |
2271 | ||
2272 | list_for_each_safe(this, tmp, &event_list) { | |
2273 | evt = list_entry(this, struct scsi_event, node); | |
2274 | list_del(&evt->node); | |
2275 | scsi_evt_emit(sdev, evt); | |
2276 | kfree(evt); | |
2277 | } | |
2278 | } | |
2279 | } | |
2280 | ||
2281 | /** | |
2282 | * sdev_evt_send - send asserted event to uevent thread | |
2283 | * @sdev: scsi_device event occurred on | |
2284 | * @evt: event to send | |
2285 | * | |
2286 | * Assert scsi device event asynchronously. | |
2287 | */ | |
2288 | void sdev_evt_send(struct scsi_device *sdev, struct scsi_event *evt) | |
2289 | { | |
2290 | unsigned long flags; | |
2291 | ||
4d1566ed KS |
2292 | #if 0 |
2293 | /* FIXME: currently this check eliminates all media change events | |
2294 | * for polled devices. Need to update to discriminate between AN | |
2295 | * and polled events */ | |
a341cd0f JG |
2296 | if (!test_bit(evt->evt_type, sdev->supported_events)) { |
2297 | kfree(evt); | |
2298 | return; | |
2299 | } | |
4d1566ed | 2300 | #endif |
a341cd0f JG |
2301 | |
2302 | spin_lock_irqsave(&sdev->list_lock, flags); | |
2303 | list_add_tail(&evt->node, &sdev->event_list); | |
2304 | schedule_work(&sdev->event_work); | |
2305 | spin_unlock_irqrestore(&sdev->list_lock, flags); | |
2306 | } | |
2307 | EXPORT_SYMBOL_GPL(sdev_evt_send); | |
2308 | ||
2309 | /** | |
2310 | * sdev_evt_alloc - allocate a new scsi event | |
2311 | * @evt_type: type of event to allocate | |
2312 | * @gfpflags: GFP flags for allocation | |
2313 | * | |
2314 | * Allocates and returns a new scsi_event. | |
2315 | */ | |
2316 | struct scsi_event *sdev_evt_alloc(enum scsi_device_event evt_type, | |
2317 | gfp_t gfpflags) | |
2318 | { | |
2319 | struct scsi_event *evt = kzalloc(sizeof(struct scsi_event), gfpflags); | |
2320 | if (!evt) | |
2321 | return NULL; | |
2322 | ||
2323 | evt->evt_type = evt_type; | |
2324 | INIT_LIST_HEAD(&evt->node); | |
2325 | ||
2326 | /* evt_type-specific initialization, if any */ | |
2327 | switch (evt_type) { | |
2328 | case SDEV_EVT_MEDIA_CHANGE: | |
279afdfe EM |
2329 | case SDEV_EVT_INQUIRY_CHANGE_REPORTED: |
2330 | case SDEV_EVT_CAPACITY_CHANGE_REPORTED: | |
2331 | case SDEV_EVT_SOFT_THRESHOLD_REACHED_REPORTED: | |
2332 | case SDEV_EVT_MODE_PARAMETER_CHANGE_REPORTED: | |
2333 | case SDEV_EVT_LUN_CHANGE_REPORTED: | |
a341cd0f JG |
2334 | default: |
2335 | /* do nothing */ | |
2336 | break; | |
2337 | } | |
2338 | ||
2339 | return evt; | |
2340 | } | |
2341 | EXPORT_SYMBOL_GPL(sdev_evt_alloc); | |
2342 | ||
2343 | /** | |
2344 | * sdev_evt_send_simple - send asserted event to uevent thread | |
2345 | * @sdev: scsi_device event occurred on | |
2346 | * @evt_type: type of event to send | |
2347 | * @gfpflags: GFP flags for allocation | |
2348 | * | |
2349 | * Assert scsi device event asynchronously, given an event type. | |
2350 | */ | |
2351 | void sdev_evt_send_simple(struct scsi_device *sdev, | |
2352 | enum scsi_device_event evt_type, gfp_t gfpflags) | |
2353 | { | |
2354 | struct scsi_event *evt = sdev_evt_alloc(evt_type, gfpflags); | |
2355 | if (!evt) { | |
2356 | sdev_printk(KERN_ERR, sdev, "event %d eaten due to OOM\n", | |
2357 | evt_type); | |
2358 | return; | |
2359 | } | |
2360 | ||
2361 | sdev_evt_send(sdev, evt); | |
2362 | } | |
2363 | EXPORT_SYMBOL_GPL(sdev_evt_send_simple); | |
2364 | ||
1da177e4 LT |
2365 | /** |
2366 | * scsi_device_quiesce - Block user issued commands. | |
2367 | * @sdev: scsi device to quiesce. | |
2368 | * | |
2369 | * This works by trying to transition to the SDEV_QUIESCE state | |
2370 | * (which must be a legal transition). When the device is in this | |
2371 | * state, only special requests will be accepted, all others will | |
2372 | * be deferred. Since special requests may also be requeued requests, | |
2373 | * a successful return doesn't guarantee the device will be | |
2374 | * totally quiescent. | |
2375 | * | |
2376 | * Must be called with user context, may sleep. | |
2377 | * | |
2378 | * Returns zero if unsuccessful or an error if not. | |
eb44820c | 2379 | */ |
1da177e4 LT |
2380 | int |
2381 | scsi_device_quiesce(struct scsi_device *sdev) | |
2382 | { | |
2383 | int err = scsi_device_set_state(sdev, SDEV_QUIESCE); | |
2384 | if (err) | |
2385 | return err; | |
2386 | ||
2387 | scsi_run_queue(sdev->request_queue); | |
2388 | while (sdev->device_busy) { | |
2389 | msleep_interruptible(200); | |
2390 | scsi_run_queue(sdev->request_queue); | |
2391 | } | |
2392 | return 0; | |
2393 | } | |
2394 | EXPORT_SYMBOL(scsi_device_quiesce); | |
2395 | ||
2396 | /** | |
2397 | * scsi_device_resume - Restart user issued commands to a quiesced device. | |
2398 | * @sdev: scsi device to resume. | |
2399 | * | |
2400 | * Moves the device from quiesced back to running and restarts the | |
2401 | * queues. | |
2402 | * | |
2403 | * Must be called with user context, may sleep. | |
eb44820c | 2404 | */ |
a7a20d10 | 2405 | void scsi_device_resume(struct scsi_device *sdev) |
1da177e4 | 2406 | { |
a7a20d10 DW |
2407 | /* check if the device state was mutated prior to resume, and if |
2408 | * so assume the state is being managed elsewhere (for example | |
2409 | * device deleted during suspend) | |
2410 | */ | |
2411 | if (sdev->sdev_state != SDEV_QUIESCE || | |
2412 | scsi_device_set_state(sdev, SDEV_RUNNING)) | |
1da177e4 LT |
2413 | return; |
2414 | scsi_run_queue(sdev->request_queue); | |
2415 | } | |
2416 | EXPORT_SYMBOL(scsi_device_resume); | |
2417 | ||
2418 | static void | |
2419 | device_quiesce_fn(struct scsi_device *sdev, void *data) | |
2420 | { | |
2421 | scsi_device_quiesce(sdev); | |
2422 | } | |
2423 | ||
2424 | void | |
2425 | scsi_target_quiesce(struct scsi_target *starget) | |
2426 | { | |
2427 | starget_for_each_device(starget, NULL, device_quiesce_fn); | |
2428 | } | |
2429 | EXPORT_SYMBOL(scsi_target_quiesce); | |
2430 | ||
2431 | static void | |
2432 | device_resume_fn(struct scsi_device *sdev, void *data) | |
2433 | { | |
2434 | scsi_device_resume(sdev); | |
2435 | } | |
2436 | ||
2437 | void | |
2438 | scsi_target_resume(struct scsi_target *starget) | |
2439 | { | |
2440 | starget_for_each_device(starget, NULL, device_resume_fn); | |
2441 | } | |
2442 | EXPORT_SYMBOL(scsi_target_resume); | |
2443 | ||
2444 | /** | |
eb44820c | 2445 | * scsi_internal_device_block - internal function to put a device temporarily into the SDEV_BLOCK state |
1da177e4 LT |
2446 | * @sdev: device to block |
2447 | * | |
2448 | * Block request made by scsi lld's to temporarily stop all | |
2449 | * scsi commands on the specified device. Called from interrupt | |
2450 | * or normal process context. | |
2451 | * | |
2452 | * Returns zero if successful or error if not | |
2453 | * | |
2454 | * Notes: | |
2455 | * This routine transitions the device to the SDEV_BLOCK state | |
2456 | * (which must be a legal transition). When the device is in this | |
2457 | * state, all commands are deferred until the scsi lld reenables | |
2458 | * the device with scsi_device_unblock or device_block_tmo fires. | |
eb44820c | 2459 | */ |
1da177e4 LT |
2460 | int |
2461 | scsi_internal_device_block(struct scsi_device *sdev) | |
2462 | { | |
165125e1 | 2463 | struct request_queue *q = sdev->request_queue; |
1da177e4 LT |
2464 | unsigned long flags; |
2465 | int err = 0; | |
2466 | ||
2467 | err = scsi_device_set_state(sdev, SDEV_BLOCK); | |
6f4267e3 JB |
2468 | if (err) { |
2469 | err = scsi_device_set_state(sdev, SDEV_CREATED_BLOCK); | |
2470 | ||
2471 | if (err) | |
2472 | return err; | |
2473 | } | |
1da177e4 LT |
2474 | |
2475 | /* | |
2476 | * The device has transitioned to SDEV_BLOCK. Stop the | |
2477 | * block layer from calling the midlayer with this device's | |
2478 | * request queue. | |
2479 | */ | |
2480 | spin_lock_irqsave(q->queue_lock, flags); | |
2481 | blk_stop_queue(q); | |
2482 | spin_unlock_irqrestore(q->queue_lock, flags); | |
2483 | ||
2484 | return 0; | |
2485 | } | |
2486 | EXPORT_SYMBOL_GPL(scsi_internal_device_block); | |
2487 | ||
2488 | /** | |
2489 | * scsi_internal_device_unblock - resume a device after a block request | |
2490 | * @sdev: device to resume | |
5d9fb5cc | 2491 | * @new_state: state to set devices to after unblocking |
1da177e4 LT |
2492 | * |
2493 | * Called by scsi lld's or the midlayer to restart the device queue | |
2494 | * for the previously suspended scsi device. Called from interrupt or | |
2495 | * normal process context. | |
2496 | * | |
2497 | * Returns zero if successful or error if not. | |
2498 | * | |
2499 | * Notes: | |
2500 | * This routine transitions the device to the SDEV_RUNNING state | |
5d9fb5cc | 2501 | * or to one of the offline states (which must be a legal transition) |
d075498c | 2502 | * allowing the midlayer to goose the queue for this device. |
eb44820c | 2503 | */ |
1da177e4 | 2504 | int |
5d9fb5cc MC |
2505 | scsi_internal_device_unblock(struct scsi_device *sdev, |
2506 | enum scsi_device_state new_state) | |
1da177e4 | 2507 | { |
165125e1 | 2508 | struct request_queue *q = sdev->request_queue; |
1da177e4 | 2509 | unsigned long flags; |
5d9fb5cc MC |
2510 | |
2511 | /* | |
2512 | * Try to transition the scsi device to SDEV_RUNNING or one of the | |
2513 | * offlined states and goose the device queue if successful. | |
1da177e4 | 2514 | */ |
0e58076b VC |
2515 | if ((sdev->sdev_state == SDEV_BLOCK) || |
2516 | (sdev->sdev_state == SDEV_TRANSPORT_OFFLINE)) | |
5d9fb5cc MC |
2517 | sdev->sdev_state = new_state; |
2518 | else if (sdev->sdev_state == SDEV_CREATED_BLOCK) { | |
2519 | if (new_state == SDEV_TRANSPORT_OFFLINE || | |
2520 | new_state == SDEV_OFFLINE) | |
2521 | sdev->sdev_state = new_state; | |
2522 | else | |
2523 | sdev->sdev_state = SDEV_CREATED; | |
2524 | } else if (sdev->sdev_state != SDEV_CANCEL && | |
986fe6c7 | 2525 | sdev->sdev_state != SDEV_OFFLINE) |
5c10e63c | 2526 | return -EINVAL; |
1da177e4 LT |
2527 | |
2528 | spin_lock_irqsave(q->queue_lock, flags); | |
2529 | blk_start_queue(q); | |
2530 | spin_unlock_irqrestore(q->queue_lock, flags); | |
2531 | ||
2532 | return 0; | |
2533 | } | |
2534 | EXPORT_SYMBOL_GPL(scsi_internal_device_unblock); | |
2535 | ||
2536 | static void | |
2537 | device_block(struct scsi_device *sdev, void *data) | |
2538 | { | |
2539 | scsi_internal_device_block(sdev); | |
2540 | } | |
2541 | ||
2542 | static int | |
2543 | target_block(struct device *dev, void *data) | |
2544 | { | |
2545 | if (scsi_is_target_device(dev)) | |
2546 | starget_for_each_device(to_scsi_target(dev), NULL, | |
2547 | device_block); | |
2548 | return 0; | |
2549 | } | |
2550 | ||
2551 | void | |
2552 | scsi_target_block(struct device *dev) | |
2553 | { | |
2554 | if (scsi_is_target_device(dev)) | |
2555 | starget_for_each_device(to_scsi_target(dev), NULL, | |
2556 | device_block); | |
2557 | else | |
2558 | device_for_each_child(dev, NULL, target_block); | |
2559 | } | |
2560 | EXPORT_SYMBOL_GPL(scsi_target_block); | |
2561 | ||
2562 | static void | |
2563 | device_unblock(struct scsi_device *sdev, void *data) | |
2564 | { | |
5d9fb5cc | 2565 | scsi_internal_device_unblock(sdev, *(enum scsi_device_state *)data); |
1da177e4 LT |
2566 | } |
2567 | ||
2568 | static int | |
2569 | target_unblock(struct device *dev, void *data) | |
2570 | { | |
2571 | if (scsi_is_target_device(dev)) | |
5d9fb5cc | 2572 | starget_for_each_device(to_scsi_target(dev), data, |
1da177e4 LT |
2573 | device_unblock); |
2574 | return 0; | |
2575 | } | |
2576 | ||
2577 | void | |
5d9fb5cc | 2578 | scsi_target_unblock(struct device *dev, enum scsi_device_state new_state) |
1da177e4 LT |
2579 | { |
2580 | if (scsi_is_target_device(dev)) | |
5d9fb5cc | 2581 | starget_for_each_device(to_scsi_target(dev), &new_state, |
1da177e4 LT |
2582 | device_unblock); |
2583 | else | |
5d9fb5cc | 2584 | device_for_each_child(dev, &new_state, target_unblock); |
1da177e4 LT |
2585 | } |
2586 | EXPORT_SYMBOL_GPL(scsi_target_unblock); | |
cdb8c2a6 GL |
2587 | |
2588 | /** | |
2589 | * scsi_kmap_atomic_sg - find and atomically map an sg-elemnt | |
eb44820c | 2590 | * @sgl: scatter-gather list |
cdb8c2a6 GL |
2591 | * @sg_count: number of segments in sg |
2592 | * @offset: offset in bytes into sg, on return offset into the mapped area | |
2593 | * @len: bytes to map, on return number of bytes mapped | |
2594 | * | |
2595 | * Returns virtual address of the start of the mapped page | |
2596 | */ | |
c6132da1 | 2597 | void *scsi_kmap_atomic_sg(struct scatterlist *sgl, int sg_count, |
cdb8c2a6 GL |
2598 | size_t *offset, size_t *len) |
2599 | { | |
2600 | int i; | |
2601 | size_t sg_len = 0, len_complete = 0; | |
c6132da1 | 2602 | struct scatterlist *sg; |
cdb8c2a6 GL |
2603 | struct page *page; |
2604 | ||
22cfefb5 AM |
2605 | WARN_ON(!irqs_disabled()); |
2606 | ||
c6132da1 | 2607 | for_each_sg(sgl, sg, sg_count, i) { |
cdb8c2a6 | 2608 | len_complete = sg_len; /* Complete sg-entries */ |
c6132da1 | 2609 | sg_len += sg->length; |
cdb8c2a6 GL |
2610 | if (sg_len > *offset) |
2611 | break; | |
2612 | } | |
2613 | ||
2614 | if (unlikely(i == sg_count)) { | |
169e1a2a AM |
2615 | printk(KERN_ERR "%s: Bytes in sg: %zu, requested offset %zu, " |
2616 | "elements %d\n", | |
cadbd4a5 | 2617 | __func__, sg_len, *offset, sg_count); |
cdb8c2a6 GL |
2618 | WARN_ON(1); |
2619 | return NULL; | |
2620 | } | |
2621 | ||
2622 | /* Offset starting from the beginning of first page in this sg-entry */ | |
c6132da1 | 2623 | *offset = *offset - len_complete + sg->offset; |
cdb8c2a6 GL |
2624 | |
2625 | /* Assumption: contiguous pages can be accessed as "page + i" */ | |
45711f1a | 2626 | page = nth_page(sg_page(sg), (*offset >> PAGE_SHIFT)); |
cdb8c2a6 GL |
2627 | *offset &= ~PAGE_MASK; |
2628 | ||
2629 | /* Bytes in this sg-entry from *offset to the end of the page */ | |
2630 | sg_len = PAGE_SIZE - *offset; | |
2631 | if (*len > sg_len) | |
2632 | *len = sg_len; | |
2633 | ||
77dfce07 | 2634 | return kmap_atomic(page); |
cdb8c2a6 GL |
2635 | } |
2636 | EXPORT_SYMBOL(scsi_kmap_atomic_sg); | |
2637 | ||
2638 | /** | |
eb44820c | 2639 | * scsi_kunmap_atomic_sg - atomically unmap a virtual address, previously mapped with scsi_kmap_atomic_sg |
cdb8c2a6 GL |
2640 | * @virt: virtual address to be unmapped |
2641 | */ | |
2642 | void scsi_kunmap_atomic_sg(void *virt) | |
2643 | { | |
77dfce07 | 2644 | kunmap_atomic(virt); |
cdb8c2a6 GL |
2645 | } |
2646 | EXPORT_SYMBOL(scsi_kunmap_atomic_sg); | |
6f4c827e AL |
2647 | |
2648 | void sdev_disable_disk_events(struct scsi_device *sdev) | |
2649 | { | |
2650 | atomic_inc(&sdev->disk_events_disable_depth); | |
2651 | } | |
2652 | EXPORT_SYMBOL(sdev_disable_disk_events); | |
2653 | ||
2654 | void sdev_enable_disk_events(struct scsi_device *sdev) | |
2655 | { | |
2656 | if (WARN_ON_ONCE(atomic_read(&sdev->disk_events_disable_depth) <= 0)) | |
2657 | return; | |
2658 | atomic_dec(&sdev->disk_events_disable_depth); | |
2659 | } | |
2660 | EXPORT_SYMBOL(sdev_enable_disk_events); |