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> | |
15 | #include <linux/mempool.h> | |
16 | #include <linux/slab.h> | |
17 | #include <linux/init.h> | |
18 | #include <linux/pci.h> | |
19 | #include <linux/delay.h> | |
faead26d | 20 | #include <linux/hardirq.h> |
c6132da1 | 21 | #include <linux/scatterlist.h> |
1da177e4 LT |
22 | |
23 | #include <scsi/scsi.h> | |
beb40487 | 24 | #include <scsi/scsi_cmnd.h> |
1da177e4 LT |
25 | #include <scsi/scsi_dbg.h> |
26 | #include <scsi/scsi_device.h> | |
27 | #include <scsi/scsi_driver.h> | |
28 | #include <scsi/scsi_eh.h> | |
29 | #include <scsi/scsi_host.h> | |
1da177e4 LT |
30 | |
31 | #include "scsi_priv.h" | |
32 | #include "scsi_logging.h" | |
33 | ||
34 | ||
6391a113 | 35 | #define SG_MEMPOOL_NR ARRAY_SIZE(scsi_sg_pools) |
5972511b | 36 | #define SG_MEMPOOL_SIZE 2 |
1da177e4 LT |
37 | |
38 | struct scsi_host_sg_pool { | |
39 | size_t size; | |
a8474ce2 | 40 | char *name; |
e18b890b | 41 | struct kmem_cache *slab; |
1da177e4 LT |
42 | mempool_t *pool; |
43 | }; | |
44 | ||
d3f46f39 JB |
45 | #define SP(x) { x, "sgpool-" __stringify(x) } |
46 | #if (SCSI_MAX_SG_SEGMENTS < 32) | |
47 | #error SCSI_MAX_SG_SEGMENTS is too small (must be 32 or greater) | |
48 | #endif | |
52c1da39 | 49 | static struct scsi_host_sg_pool scsi_sg_pools[] = { |
1da177e4 LT |
50 | SP(8), |
51 | SP(16), | |
fd820f40 | 52 | #if (SCSI_MAX_SG_SEGMENTS > 32) |
d3f46f39 | 53 | SP(32), |
fd820f40 | 54 | #if (SCSI_MAX_SG_SEGMENTS > 64) |
d3f46f39 JB |
55 | SP(64), |
56 | #if (SCSI_MAX_SG_SEGMENTS > 128) | |
1da177e4 | 57 | SP(128), |
d3f46f39 JB |
58 | #if (SCSI_MAX_SG_SEGMENTS > 256) |
59 | #error SCSI_MAX_SG_SEGMENTS is too large (256 MAX) | |
fd820f40 FT |
60 | #endif |
61 | #endif | |
62 | #endif | |
d3f46f39 JB |
63 | #endif |
64 | SP(SCSI_MAX_SG_SEGMENTS) | |
a8474ce2 | 65 | }; |
1da177e4 LT |
66 | #undef SP |
67 | ||
7027ad72 | 68 | struct kmem_cache *scsi_sdb_cache; |
6f9a35e2 | 69 | |
a1bf9d1d | 70 | static void scsi_run_queue(struct request_queue *q); |
e91442b6 JB |
71 | |
72 | /* | |
73 | * Function: scsi_unprep_request() | |
74 | * | |
75 | * Purpose: Remove all preparation done for a request, including its | |
76 | * associated scsi_cmnd, so that it can be requeued. | |
77 | * | |
78 | * Arguments: req - request to unprepare | |
79 | * | |
80 | * Lock status: Assumed that no locks are held upon entry. | |
81 | * | |
82 | * Returns: Nothing. | |
83 | */ | |
84 | static void scsi_unprep_request(struct request *req) | |
85 | { | |
86 | struct scsi_cmnd *cmd = req->special; | |
87 | ||
4aff5e23 | 88 | req->cmd_flags &= ~REQ_DONTPREP; |
beb40487 | 89 | req->special = NULL; |
e91442b6 | 90 | |
e91442b6 JB |
91 | scsi_put_command(cmd); |
92 | } | |
a1bf9d1d | 93 | |
4f5299ac JB |
94 | /** |
95 | * __scsi_queue_insert - private queue insertion | |
96 | * @cmd: The SCSI command being requeued | |
97 | * @reason: The reason for the requeue | |
98 | * @unbusy: Whether the queue should be unbusied | |
1da177e4 | 99 | * |
4f5299ac JB |
100 | * This is a private queue insertion. The public interface |
101 | * scsi_queue_insert() always assumes the queue should be unbusied | |
102 | * because it's always called before the completion. This function is | |
103 | * for a requeue after completion, which should only occur in this | |
104 | * file. | |
1da177e4 | 105 | */ |
4f5299ac | 106 | static int __scsi_queue_insert(struct scsi_cmnd *cmd, int reason, int unbusy) |
1da177e4 LT |
107 | { |
108 | struct Scsi_Host *host = cmd->device->host; | |
109 | struct scsi_device *device = cmd->device; | |
f0c0a376 | 110 | struct scsi_target *starget = scsi_target(device); |
a1bf9d1d TH |
111 | struct request_queue *q = device->request_queue; |
112 | unsigned long flags; | |
1da177e4 LT |
113 | |
114 | SCSI_LOG_MLQUEUE(1, | |
115 | printk("Inserting command %p into mlqueue\n", cmd)); | |
116 | ||
117 | /* | |
d8c37e7b | 118 | * Set the appropriate busy bit for the device/host. |
1da177e4 LT |
119 | * |
120 | * If the host/device isn't busy, assume that something actually | |
121 | * completed, and that we should be able to queue a command now. | |
122 | * | |
123 | * Note that the prior mid-layer assumption that any host could | |
124 | * always queue at least one command is now broken. The mid-layer | |
125 | * will implement a user specifiable stall (see | |
126 | * scsi_host.max_host_blocked and scsi_device.max_device_blocked) | |
127 | * if a command is requeued with no other commands outstanding | |
128 | * either for the device or for the host. | |
129 | */ | |
f0c0a376 MC |
130 | switch (reason) { |
131 | case SCSI_MLQUEUE_HOST_BUSY: | |
1da177e4 | 132 | host->host_blocked = host->max_host_blocked; |
f0c0a376 MC |
133 | break; |
134 | case SCSI_MLQUEUE_DEVICE_BUSY: | |
1da177e4 | 135 | device->device_blocked = device->max_device_blocked; |
f0c0a376 MC |
136 | break; |
137 | case SCSI_MLQUEUE_TARGET_BUSY: | |
138 | starget->target_blocked = starget->max_target_blocked; | |
139 | break; | |
140 | } | |
1da177e4 | 141 | |
1da177e4 LT |
142 | /* |
143 | * Decrement the counters, since these commands are no longer | |
144 | * active on the host/device. | |
145 | */ | |
4f5299ac JB |
146 | if (unbusy) |
147 | scsi_device_unbusy(device); | |
1da177e4 LT |
148 | |
149 | /* | |
a1bf9d1d TH |
150 | * Requeue this command. It will go before all other commands |
151 | * that are already in the queue. | |
1da177e4 LT |
152 | * |
153 | * NOTE: there is magic here about the way the queue is plugged if | |
154 | * we have no outstanding commands. | |
155 | * | |
a1bf9d1d | 156 | * Although we *don't* plug the queue, we call the request |
1da177e4 LT |
157 | * function. The SCSI request function detects the blocked condition |
158 | * and plugs the queue appropriately. | |
a1bf9d1d TH |
159 | */ |
160 | spin_lock_irqsave(q->queue_lock, flags); | |
59897dad | 161 | blk_requeue_request(q, cmd->request); |
a1bf9d1d TH |
162 | spin_unlock_irqrestore(q->queue_lock, flags); |
163 | ||
164 | scsi_run_queue(q); | |
165 | ||
1da177e4 LT |
166 | return 0; |
167 | } | |
168 | ||
4f5299ac JB |
169 | /* |
170 | * Function: scsi_queue_insert() | |
171 | * | |
172 | * Purpose: Insert a command in the midlevel queue. | |
173 | * | |
174 | * Arguments: cmd - command that we are adding to queue. | |
175 | * reason - why we are inserting command to queue. | |
176 | * | |
177 | * Lock status: Assumed that lock is not held upon entry. | |
178 | * | |
179 | * Returns: Nothing. | |
180 | * | |
181 | * Notes: We do this for one of two cases. Either the host is busy | |
182 | * and it cannot accept any more commands for the time being, | |
183 | * or the device returned QUEUE_FULL and can accept no more | |
184 | * commands. | |
185 | * Notes: This could be called either from an interrupt context or a | |
186 | * normal process context. | |
187 | */ | |
188 | int scsi_queue_insert(struct scsi_cmnd *cmd, int reason) | |
189 | { | |
190 | return __scsi_queue_insert(cmd, reason, 1); | |
191 | } | |
39216033 | 192 | /** |
33aa687d | 193 | * scsi_execute - insert request and wait for the result |
39216033 JB |
194 | * @sdev: scsi device |
195 | * @cmd: scsi command | |
196 | * @data_direction: data direction | |
197 | * @buffer: data buffer | |
198 | * @bufflen: len of buffer | |
199 | * @sense: optional sense buffer | |
200 | * @timeout: request timeout in seconds | |
201 | * @retries: number of times to retry request | |
33aa687d | 202 | * @flags: or into request flags; |
f4f4e47e | 203 | * @resid: optional residual length |
39216033 | 204 | * |
59c51591 | 205 | * returns the req->errors value which is the scsi_cmnd result |
ea73a9f2 | 206 | * field. |
eb44820c | 207 | */ |
33aa687d JB |
208 | int scsi_execute(struct scsi_device *sdev, const unsigned char *cmd, |
209 | int data_direction, void *buffer, unsigned bufflen, | |
f4f4e47e FT |
210 | unsigned char *sense, int timeout, int retries, int flags, |
211 | int *resid) | |
39216033 JB |
212 | { |
213 | struct request *req; | |
214 | int write = (data_direction == DMA_TO_DEVICE); | |
215 | int ret = DRIVER_ERROR << 24; | |
216 | ||
217 | req = blk_get_request(sdev->request_queue, write, __GFP_WAIT); | |
218 | ||
219 | if (bufflen && blk_rq_map_kern(sdev->request_queue, req, | |
220 | buffer, bufflen, __GFP_WAIT)) | |
221 | goto out; | |
222 | ||
223 | req->cmd_len = COMMAND_SIZE(cmd[0]); | |
224 | memcpy(req->cmd, cmd, req->cmd_len); | |
225 | req->sense = sense; | |
226 | req->sense_len = 0; | |
17e01f21 | 227 | req->retries = retries; |
39216033 | 228 | req->timeout = timeout; |
4aff5e23 JA |
229 | req->cmd_type = REQ_TYPE_BLOCK_PC; |
230 | req->cmd_flags |= flags | REQ_QUIET | REQ_PREEMPT; | |
39216033 JB |
231 | |
232 | /* | |
233 | * head injection *required* here otherwise quiesce won't work | |
234 | */ | |
235 | blk_execute_rq(req->q, NULL, req, 1); | |
236 | ||
bdb2b8ca AS |
237 | /* |
238 | * Some devices (USB mass-storage in particular) may transfer | |
239 | * garbage data together with a residue indicating that the data | |
240 | * is invalid. Prevent the garbage from being misinterpreted | |
241 | * and prevent security leaks by zeroing out the excess data. | |
242 | */ | |
c3a4d78c TH |
243 | if (unlikely(req->resid_len > 0 && req->resid_len <= bufflen)) |
244 | memset(buffer + (bufflen - req->resid_len), 0, req->resid_len); | |
bdb2b8ca | 245 | |
f4f4e47e | 246 | if (resid) |
c3a4d78c | 247 | *resid = req->resid_len; |
39216033 JB |
248 | ret = req->errors; |
249 | out: | |
250 | blk_put_request(req); | |
251 | ||
252 | return ret; | |
253 | } | |
33aa687d | 254 | EXPORT_SYMBOL(scsi_execute); |
39216033 | 255 | |
ea73a9f2 JB |
256 | |
257 | int scsi_execute_req(struct scsi_device *sdev, const unsigned char *cmd, | |
258 | int data_direction, void *buffer, unsigned bufflen, | |
f4f4e47e FT |
259 | struct scsi_sense_hdr *sshdr, int timeout, int retries, |
260 | int *resid) | |
ea73a9f2 JB |
261 | { |
262 | char *sense = NULL; | |
1ccb48bb | 263 | int result; |
264 | ||
ea73a9f2 | 265 | if (sshdr) { |
24669f75 | 266 | sense = kzalloc(SCSI_SENSE_BUFFERSIZE, GFP_NOIO); |
ea73a9f2 JB |
267 | if (!sense) |
268 | return DRIVER_ERROR << 24; | |
ea73a9f2 | 269 | } |
1ccb48bb | 270 | result = scsi_execute(sdev, cmd, data_direction, buffer, bufflen, |
f4f4e47e | 271 | sense, timeout, retries, 0, resid); |
ea73a9f2 | 272 | if (sshdr) |
e514385b | 273 | scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE, sshdr); |
ea73a9f2 JB |
274 | |
275 | kfree(sense); | |
276 | return result; | |
277 | } | |
278 | EXPORT_SYMBOL(scsi_execute_req); | |
279 | ||
1da177e4 LT |
280 | /* |
281 | * Function: scsi_init_cmd_errh() | |
282 | * | |
283 | * Purpose: Initialize cmd fields related to error handling. | |
284 | * | |
285 | * Arguments: cmd - command that is ready to be queued. | |
286 | * | |
1da177e4 LT |
287 | * Notes: This function has the job of initializing a number of |
288 | * fields related to error handling. Typically this will | |
289 | * be called once for each command, as required. | |
290 | */ | |
631c228c | 291 | static void scsi_init_cmd_errh(struct scsi_cmnd *cmd) |
1da177e4 | 292 | { |
1da177e4 | 293 | cmd->serial_number = 0; |
30b0c37b | 294 | scsi_set_resid(cmd, 0); |
b80ca4f7 | 295 | memset(cmd->sense_buffer, 0, SCSI_SENSE_BUFFERSIZE); |
1da177e4 | 296 | if (cmd->cmd_len == 0) |
db4742dd | 297 | cmd->cmd_len = scsi_command_size(cmd->cmnd); |
1da177e4 LT |
298 | } |
299 | ||
300 | void scsi_device_unbusy(struct scsi_device *sdev) | |
301 | { | |
302 | struct Scsi_Host *shost = sdev->host; | |
f0c0a376 | 303 | struct scsi_target *starget = scsi_target(sdev); |
1da177e4 LT |
304 | unsigned long flags; |
305 | ||
306 | spin_lock_irqsave(shost->host_lock, flags); | |
307 | shost->host_busy--; | |
f0c0a376 | 308 | starget->target_busy--; |
939647ee | 309 | if (unlikely(scsi_host_in_recovery(shost) && |
ee7863bc | 310 | (shost->host_failed || shost->host_eh_scheduled))) |
1da177e4 LT |
311 | scsi_eh_wakeup(shost); |
312 | spin_unlock(shost->host_lock); | |
152587de | 313 | spin_lock(sdev->request_queue->queue_lock); |
1da177e4 | 314 | sdev->device_busy--; |
152587de | 315 | spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags); |
1da177e4 LT |
316 | } |
317 | ||
318 | /* | |
319 | * Called for single_lun devices on IO completion. Clear starget_sdev_user, | |
320 | * and call blk_run_queue for all the scsi_devices on the target - | |
321 | * including current_sdev first. | |
322 | * | |
323 | * Called with *no* scsi locks held. | |
324 | */ | |
325 | static void scsi_single_lun_run(struct scsi_device *current_sdev) | |
326 | { | |
327 | struct Scsi_Host *shost = current_sdev->host; | |
328 | struct scsi_device *sdev, *tmp; | |
329 | struct scsi_target *starget = scsi_target(current_sdev); | |
330 | unsigned long flags; | |
331 | ||
332 | spin_lock_irqsave(shost->host_lock, flags); | |
333 | starget->starget_sdev_user = NULL; | |
334 | spin_unlock_irqrestore(shost->host_lock, flags); | |
335 | ||
336 | /* | |
337 | * Call blk_run_queue for all LUNs on the target, starting with | |
338 | * current_sdev. We race with others (to set starget_sdev_user), | |
339 | * but in most cases, we will be first. Ideally, each LU on the | |
340 | * target would get some limited time or requests on the target. | |
341 | */ | |
342 | blk_run_queue(current_sdev->request_queue); | |
343 | ||
344 | spin_lock_irqsave(shost->host_lock, flags); | |
345 | if (starget->starget_sdev_user) | |
346 | goto out; | |
347 | list_for_each_entry_safe(sdev, tmp, &starget->devices, | |
348 | same_target_siblings) { | |
349 | if (sdev == current_sdev) | |
350 | continue; | |
351 | if (scsi_device_get(sdev)) | |
352 | continue; | |
353 | ||
354 | spin_unlock_irqrestore(shost->host_lock, flags); | |
355 | blk_run_queue(sdev->request_queue); | |
356 | spin_lock_irqsave(shost->host_lock, flags); | |
357 | ||
358 | scsi_device_put(sdev); | |
359 | } | |
360 | out: | |
361 | spin_unlock_irqrestore(shost->host_lock, flags); | |
362 | } | |
363 | ||
9d112517 KU |
364 | static inline int scsi_device_is_busy(struct scsi_device *sdev) |
365 | { | |
366 | if (sdev->device_busy >= sdev->queue_depth || sdev->device_blocked) | |
367 | return 1; | |
368 | ||
369 | return 0; | |
370 | } | |
371 | ||
f0c0a376 MC |
372 | static inline int scsi_target_is_busy(struct scsi_target *starget) |
373 | { | |
374 | return ((starget->can_queue > 0 && | |
375 | starget->target_busy >= starget->can_queue) || | |
376 | starget->target_blocked); | |
377 | } | |
378 | ||
9d112517 KU |
379 | static inline int scsi_host_is_busy(struct Scsi_Host *shost) |
380 | { | |
381 | if ((shost->can_queue > 0 && shost->host_busy >= shost->can_queue) || | |
382 | shost->host_blocked || shost->host_self_blocked) | |
383 | return 1; | |
384 | ||
385 | return 0; | |
386 | } | |
387 | ||
1da177e4 LT |
388 | /* |
389 | * Function: scsi_run_queue() | |
390 | * | |
391 | * Purpose: Select a proper request queue to serve next | |
392 | * | |
393 | * Arguments: q - last request's queue | |
394 | * | |
395 | * Returns: Nothing | |
396 | * | |
397 | * Notes: The previous command was completely finished, start | |
398 | * a new one if possible. | |
399 | */ | |
400 | static void scsi_run_queue(struct request_queue *q) | |
401 | { | |
2a3a59e5 | 402 | struct scsi_device *sdev = q->queuedata; |
1da177e4 | 403 | struct Scsi_Host *shost = sdev->host; |
2a3a59e5 | 404 | LIST_HEAD(starved_list); |
1da177e4 LT |
405 | unsigned long flags; |
406 | ||
25d7c363 | 407 | if (scsi_target(sdev)->single_lun) |
1da177e4 LT |
408 | scsi_single_lun_run(sdev); |
409 | ||
410 | spin_lock_irqsave(shost->host_lock, flags); | |
2a3a59e5 MC |
411 | list_splice_init(&shost->starved_list, &starved_list); |
412 | ||
413 | while (!list_empty(&starved_list)) { | |
75ad23bc NP |
414 | int flagset; |
415 | ||
1da177e4 LT |
416 | /* |
417 | * As long as shost is accepting commands and we have | |
418 | * starved queues, call blk_run_queue. scsi_request_fn | |
419 | * drops the queue_lock and can add us back to the | |
420 | * starved_list. | |
421 | * | |
422 | * host_lock protects the starved_list and starved_entry. | |
423 | * scsi_request_fn must get the host_lock before checking | |
424 | * or modifying starved_list or starved_entry. | |
425 | */ | |
2a3a59e5 | 426 | if (scsi_host_is_busy(shost)) |
f0c0a376 | 427 | break; |
f0c0a376 | 428 | |
2a3a59e5 MC |
429 | sdev = list_entry(starved_list.next, |
430 | struct scsi_device, starved_entry); | |
431 | list_del_init(&sdev->starved_entry); | |
f0c0a376 MC |
432 | if (scsi_target_is_busy(scsi_target(sdev))) { |
433 | list_move_tail(&sdev->starved_entry, | |
434 | &shost->starved_list); | |
435 | continue; | |
436 | } | |
437 | ||
75ad23bc NP |
438 | spin_unlock(shost->host_lock); |
439 | ||
440 | spin_lock(sdev->request_queue->queue_lock); | |
441 | flagset = test_bit(QUEUE_FLAG_REENTER, &q->queue_flags) && | |
442 | !test_bit(QUEUE_FLAG_REENTER, | |
443 | &sdev->request_queue->queue_flags); | |
444 | if (flagset) | |
445 | queue_flag_set(QUEUE_FLAG_REENTER, sdev->request_queue); | |
446 | __blk_run_queue(sdev->request_queue); | |
447 | if (flagset) | |
448 | queue_flag_clear(QUEUE_FLAG_REENTER, sdev->request_queue); | |
449 | spin_unlock(sdev->request_queue->queue_lock); | |
04846f25 | 450 | |
75ad23bc | 451 | spin_lock(shost->host_lock); |
1da177e4 | 452 | } |
2a3a59e5 MC |
453 | /* put any unprocessed entries back */ |
454 | list_splice(&starved_list, &shost->starved_list); | |
1da177e4 LT |
455 | spin_unlock_irqrestore(shost->host_lock, flags); |
456 | ||
457 | blk_run_queue(q); | |
458 | } | |
459 | ||
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 | { | |
e91442b6 | 480 | struct request *req = cmd->request; |
283369cc TH |
481 | unsigned long flags; |
482 | ||
283369cc | 483 | spin_lock_irqsave(q->queue_lock, flags); |
02bd3499 | 484 | scsi_unprep_request(req); |
e91442b6 | 485 | blk_requeue_request(q, req); |
283369cc | 486 | spin_unlock_irqrestore(q->queue_lock, flags); |
1da177e4 LT |
487 | |
488 | scsi_run_queue(q); | |
489 | } | |
490 | ||
491 | void scsi_next_command(struct scsi_cmnd *cmd) | |
492 | { | |
49d7bc64 LT |
493 | struct scsi_device *sdev = cmd->device; |
494 | struct request_queue *q = sdev->request_queue; | |
495 | ||
496 | /* need to hold a reference on the device before we let go of the cmd */ | |
497 | get_device(&sdev->sdev_gendev); | |
1da177e4 LT |
498 | |
499 | scsi_put_command(cmd); | |
500 | scsi_run_queue(q); | |
49d7bc64 LT |
501 | |
502 | /* ok to remove device now */ | |
503 | put_device(&sdev->sdev_gendev); | |
1da177e4 LT |
504 | } |
505 | ||
506 | void scsi_run_host_queues(struct Scsi_Host *shost) | |
507 | { | |
508 | struct scsi_device *sdev; | |
509 | ||
510 | shost_for_each_device(sdev, shost) | |
511 | scsi_run_queue(sdev->request_queue); | |
512 | } | |
513 | ||
79ed2429 JB |
514 | static void __scsi_release_buffers(struct scsi_cmnd *, int); |
515 | ||
1da177e4 LT |
516 | /* |
517 | * Function: scsi_end_request() | |
518 | * | |
519 | * Purpose: Post-processing of completed commands (usually invoked at end | |
520 | * of upper level post-processing and scsi_io_completion). | |
521 | * | |
522 | * Arguments: cmd - command that is complete. | |
610d8b0c | 523 | * error - 0 if I/O indicates success, < 0 for I/O error. |
1da177e4 LT |
524 | * bytes - number of bytes of completed I/O |
525 | * requeue - indicates whether we should requeue leftovers. | |
526 | * | |
527 | * Lock status: Assumed that lock is not held upon entry. | |
528 | * | |
e91442b6 | 529 | * Returns: cmd if requeue required, NULL otherwise. |
1da177e4 LT |
530 | * |
531 | * Notes: This is called for block device requests in order to | |
532 | * mark some number of sectors as complete. | |
533 | * | |
534 | * We are guaranteeing that the request queue will be goosed | |
535 | * at some point during this call. | |
e91442b6 | 536 | * Notes: If cmd was requeued, upon return it will be a stale pointer. |
1da177e4 | 537 | */ |
610d8b0c | 538 | static struct scsi_cmnd *scsi_end_request(struct scsi_cmnd *cmd, int error, |
1da177e4 LT |
539 | int bytes, int requeue) |
540 | { | |
165125e1 | 541 | struct request_queue *q = cmd->device->request_queue; |
1da177e4 | 542 | struct request *req = cmd->request; |
1da177e4 LT |
543 | |
544 | /* | |
545 | * If there are blocks left over at the end, set up the command | |
546 | * to queue the remainder of them. | |
547 | */ | |
610d8b0c | 548 | if (blk_end_request(req, error, bytes)) { |
1da177e4 | 549 | /* kill remainder if no retrys */ |
4a27446f | 550 | if (error && scsi_noretry_cmd(cmd)) |
e458824f | 551 | blk_end_request_all(req, error); |
1da177e4 | 552 | else { |
e91442b6 | 553 | if (requeue) { |
1da177e4 LT |
554 | /* |
555 | * Bleah. Leftovers again. Stick the | |
556 | * leftovers in the front of the | |
557 | * queue, and goose the queue again. | |
558 | */ | |
79ed2429 | 559 | scsi_release_buffers(cmd); |
1da177e4 | 560 | scsi_requeue_command(q, cmd); |
e91442b6 JB |
561 | cmd = NULL; |
562 | } | |
1da177e4 LT |
563 | return cmd; |
564 | } | |
565 | } | |
566 | ||
1da177e4 LT |
567 | /* |
568 | * This will goose the queue request function at the end, so we don't | |
569 | * need to worry about launching another command. | |
570 | */ | |
79ed2429 | 571 | __scsi_release_buffers(cmd, 0); |
1da177e4 LT |
572 | scsi_next_command(cmd); |
573 | return NULL; | |
574 | } | |
575 | ||
a8474ce2 JA |
576 | static inline unsigned int scsi_sgtable_index(unsigned short nents) |
577 | { | |
578 | unsigned int index; | |
579 | ||
d3f46f39 JB |
580 | BUG_ON(nents > SCSI_MAX_SG_SEGMENTS); |
581 | ||
582 | if (nents <= 8) | |
a8474ce2 | 583 | index = 0; |
d3f46f39 JB |
584 | else |
585 | index = get_count_order(nents) - 3; | |
1da177e4 | 586 | |
a8474ce2 JA |
587 | return index; |
588 | } | |
589 | ||
5ed7959e | 590 | static void scsi_sg_free(struct scatterlist *sgl, unsigned int nents) |
a8474ce2 JA |
591 | { |
592 | struct scsi_host_sg_pool *sgp; | |
a8474ce2 | 593 | |
5ed7959e JA |
594 | sgp = scsi_sg_pools + scsi_sgtable_index(nents); |
595 | mempool_free(sgl, sgp->pool); | |
596 | } | |
a8474ce2 | 597 | |
5ed7959e JA |
598 | static struct scatterlist *scsi_sg_alloc(unsigned int nents, gfp_t gfp_mask) |
599 | { | |
600 | struct scsi_host_sg_pool *sgp; | |
a8474ce2 | 601 | |
5ed7959e JA |
602 | sgp = scsi_sg_pools + scsi_sgtable_index(nents); |
603 | return mempool_alloc(sgp->pool, gfp_mask); | |
604 | } | |
a3bec5c5 | 605 | |
30b0c37b BH |
606 | static int scsi_alloc_sgtable(struct scsi_data_buffer *sdb, int nents, |
607 | gfp_t gfp_mask) | |
5ed7959e JA |
608 | { |
609 | int ret; | |
a8474ce2 | 610 | |
30b0c37b | 611 | BUG_ON(!nents); |
a8474ce2 | 612 | |
30b0c37b BH |
613 | ret = __sg_alloc_table(&sdb->table, nents, SCSI_MAX_SG_SEGMENTS, |
614 | gfp_mask, scsi_sg_alloc); | |
5ed7959e | 615 | if (unlikely(ret)) |
30b0c37b | 616 | __sg_free_table(&sdb->table, SCSI_MAX_SG_SEGMENTS, |
7cedb1f1 | 617 | scsi_sg_free); |
45711f1a | 618 | |
a8474ce2 | 619 | return ret; |
1da177e4 LT |
620 | } |
621 | ||
30b0c37b | 622 | static void scsi_free_sgtable(struct scsi_data_buffer *sdb) |
1da177e4 | 623 | { |
30b0c37b | 624 | __sg_free_table(&sdb->table, SCSI_MAX_SG_SEGMENTS, scsi_sg_free); |
1da177e4 LT |
625 | } |
626 | ||
79ed2429 JB |
627 | static void __scsi_release_buffers(struct scsi_cmnd *cmd, int do_bidi_check) |
628 | { | |
629 | ||
630 | if (cmd->sdb.table.nents) | |
631 | scsi_free_sgtable(&cmd->sdb); | |
632 | ||
633 | memset(&cmd->sdb, 0, sizeof(cmd->sdb)); | |
634 | ||
635 | if (do_bidi_check && scsi_bidi_cmnd(cmd)) { | |
636 | struct scsi_data_buffer *bidi_sdb = | |
637 | cmd->request->next_rq->special; | |
638 | scsi_free_sgtable(bidi_sdb); | |
639 | kmem_cache_free(scsi_sdb_cache, bidi_sdb); | |
640 | cmd->request->next_rq->special = NULL; | |
641 | } | |
642 | ||
643 | if (scsi_prot_sg_count(cmd)) | |
644 | scsi_free_sgtable(cmd->prot_sdb); | |
645 | } | |
646 | ||
1da177e4 LT |
647 | /* |
648 | * Function: scsi_release_buffers() | |
649 | * | |
650 | * Purpose: Completion processing for block device I/O requests. | |
651 | * | |
652 | * Arguments: cmd - command that we are bailing. | |
653 | * | |
654 | * Lock status: Assumed that no lock is held upon entry. | |
655 | * | |
656 | * Returns: Nothing | |
657 | * | |
658 | * Notes: In the event that an upper level driver rejects a | |
659 | * command, we must release resources allocated during | |
660 | * the __init_io() function. Primarily this would involve | |
661 | * the scatter-gather table, and potentially any bounce | |
662 | * buffers. | |
663 | */ | |
bb52d82f | 664 | void scsi_release_buffers(struct scsi_cmnd *cmd) |
1da177e4 | 665 | { |
79ed2429 | 666 | __scsi_release_buffers(cmd, 1); |
1da177e4 | 667 | } |
bb52d82f | 668 | EXPORT_SYMBOL(scsi_release_buffers); |
1da177e4 LT |
669 | |
670 | /* | |
671 | * Function: scsi_io_completion() | |
672 | * | |
673 | * Purpose: Completion processing for block device I/O requests. | |
674 | * | |
675 | * Arguments: cmd - command that is finished. | |
676 | * | |
677 | * Lock status: Assumed that no lock is held upon entry. | |
678 | * | |
679 | * Returns: Nothing | |
680 | * | |
681 | * Notes: This function is matched in terms of capabilities to | |
682 | * the function that created the scatter-gather list. | |
683 | * In other words, if there are no bounce buffers | |
684 | * (the normal case for most drivers), we don't need | |
685 | * the logic to deal with cleaning up afterwards. | |
686 | * | |
b60af5b0 AS |
687 | * We must call scsi_end_request(). This will finish off |
688 | * the specified number of sectors. If we are done, the | |
689 | * command block will be released and the queue function | |
690 | * will be goosed. If we are not done then we have to | |
691 | * figure out what to do next: | |
1da177e4 | 692 | * |
b60af5b0 AS |
693 | * a) We can call scsi_requeue_command(). The request |
694 | * will be unprepared and put back on the queue. Then | |
695 | * a new command will be created for it. This should | |
696 | * be used if we made forward progress, or if we want | |
697 | * to switch from READ(10) to READ(6) for example. | |
1da177e4 | 698 | * |
b60af5b0 AS |
699 | * b) We can call scsi_queue_insert(). The request will |
700 | * be put back on the queue and retried using the same | |
701 | * command as before, possibly after a delay. | |
702 | * | |
703 | * c) We can call blk_end_request() with -EIO to fail | |
704 | * the remainder of the request. | |
1da177e4 | 705 | */ |
03aba2f7 | 706 | void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes) |
1da177e4 LT |
707 | { |
708 | int result = cmd->result; | |
165125e1 | 709 | struct request_queue *q = cmd->device->request_queue; |
1da177e4 | 710 | struct request *req = cmd->request; |
fa8e36c3 | 711 | int error = 0; |
1da177e4 LT |
712 | struct scsi_sense_hdr sshdr; |
713 | int sense_valid = 0; | |
714 | int sense_deferred = 0; | |
b60af5b0 AS |
715 | enum {ACTION_FAIL, ACTION_REPREP, ACTION_RETRY, |
716 | ACTION_DELAYED_RETRY} action; | |
717 | char *description = NULL; | |
1da177e4 | 718 | |
1da177e4 LT |
719 | if (result) { |
720 | sense_valid = scsi_command_normalize_sense(cmd, &sshdr); | |
721 | if (sense_valid) | |
722 | sense_deferred = scsi_sense_is_deferred(&sshdr); | |
723 | } | |
631c228c | 724 | |
1da177e4 LT |
725 | if (blk_pc_request(req)) { /* SG_IO ioctl from block level */ |
726 | req->errors = result; | |
727 | if (result) { | |
1da177e4 LT |
728 | if (sense_valid && req->sense) { |
729 | /* | |
730 | * SG_IO wants current and deferred errors | |
731 | */ | |
732 | int len = 8 + cmd->sense_buffer[7]; | |
733 | ||
734 | if (len > SCSI_SENSE_BUFFERSIZE) | |
735 | len = SCSI_SENSE_BUFFERSIZE; | |
736 | memcpy(req->sense, cmd->sense_buffer, len); | |
737 | req->sense_len = len; | |
738 | } | |
fa8e36c3 JB |
739 | if (!sense_deferred) |
740 | error = -EIO; | |
b22f687d | 741 | } |
e6bb7a96 FT |
742 | |
743 | req->resid_len = scsi_get_resid(cmd); | |
744 | ||
6f9a35e2 | 745 | if (scsi_bidi_cmnd(cmd)) { |
e6bb7a96 FT |
746 | /* |
747 | * Bidi commands Must be complete as a whole, | |
748 | * both sides at once. | |
749 | */ | |
750 | req->next_rq->resid_len = scsi_in(cmd)->resid; | |
751 | ||
752 | blk_end_request_all(req, 0); | |
753 | ||
754 | scsi_release_buffers(cmd); | |
755 | scsi_next_command(cmd); | |
6f9a35e2 BH |
756 | return; |
757 | } | |
1da177e4 LT |
758 | } |
759 | ||
6f9a35e2 | 760 | BUG_ON(blk_bidi_rq(req)); /* bidi not support for !blk_pc_request yet */ |
30b0c37b | 761 | |
1da177e4 LT |
762 | /* |
763 | * Next deal with any sectors which we were able to correctly | |
764 | * handle. | |
765 | */ | |
83096ebf | 766 | SCSI_LOG_HLCOMPLETE(1, printk("%u sectors total, " |
d6b0c537 | 767 | "%d bytes done.\n", |
83096ebf | 768 | blk_rq_sectors(req), good_bytes)); |
d6b0c537 | 769 | |
a9bddd74 JB |
770 | /* |
771 | * Recovered errors need reporting, but they're always treated | |
772 | * as success, so fiddle the result code here. For BLOCK_PC | |
773 | * we already took a copy of the original into rq->errors which | |
774 | * is what gets returned to the user | |
775 | */ | |
776 | if (sense_valid && sshdr.sense_key == RECOVERED_ERROR) { | |
777 | if (!(req->cmd_flags & REQ_QUIET)) | |
778 | scsi_print_sense("", cmd); | |
779 | result = 0; | |
780 | /* BLOCK_PC may have set error */ | |
781 | error = 0; | |
782 | } | |
783 | ||
784 | /* | |
785 | * A number of bytes were successfully read. If there | |
d6b0c537 JB |
786 | * are leftovers and there is some kind of error |
787 | * (result != 0), retry the rest. | |
788 | */ | |
fa8e36c3 | 789 | if (scsi_end_request(cmd, error, good_bytes, result == 0) == NULL) |
d6b0c537 | 790 | return; |
03aba2f7 | 791 | |
3e695f89 MP |
792 | error = -EIO; |
793 | ||
b60af5b0 AS |
794 | if (host_byte(result) == DID_RESET) { |
795 | /* Third party bus reset or reset for error recovery | |
796 | * reasons. Just retry the command and see what | |
797 | * happens. | |
798 | */ | |
799 | action = ACTION_RETRY; | |
800 | } else if (sense_valid && !sense_deferred) { | |
1da177e4 LT |
801 | switch (sshdr.sense_key) { |
802 | case UNIT_ATTENTION: | |
803 | if (cmd->device->removable) { | |
03aba2f7 | 804 | /* Detected disc change. Set a bit |
1da177e4 LT |
805 | * and quietly refuse further access. |
806 | */ | |
807 | cmd->device->changed = 1; | |
b60af5b0 AS |
808 | description = "Media Changed"; |
809 | action = ACTION_FAIL; | |
1da177e4 | 810 | } else { |
03aba2f7 LT |
811 | /* Must have been a power glitch, or a |
812 | * bus reset. Could not have been a | |
813 | * media change, so we just retry the | |
b60af5b0 | 814 | * command and see what happens. |
03aba2f7 | 815 | */ |
b60af5b0 | 816 | action = ACTION_RETRY; |
1da177e4 LT |
817 | } |
818 | break; | |
819 | case ILLEGAL_REQUEST: | |
03aba2f7 LT |
820 | /* If we had an ILLEGAL REQUEST returned, then |
821 | * we may have performed an unsupported | |
822 | * command. The only thing this should be | |
823 | * would be a ten byte read where only a six | |
824 | * byte read was supported. Also, on a system | |
825 | * where READ CAPACITY failed, we may have | |
826 | * read past the end of the disk. | |
827 | */ | |
26a68019 JA |
828 | if ((cmd->device->use_10_for_rw && |
829 | sshdr.asc == 0x20 && sshdr.ascq == 0x00) && | |
1da177e4 LT |
830 | (cmd->cmnd[0] == READ_10 || |
831 | cmd->cmnd[0] == WRITE_10)) { | |
b60af5b0 | 832 | /* This will issue a new 6-byte command. */ |
1da177e4 | 833 | cmd->device->use_10_for_rw = 0; |
b60af5b0 | 834 | action = ACTION_REPREP; |
3e695f89 MP |
835 | } else if (sshdr.asc == 0x10) /* DIX */ { |
836 | description = "Host Data Integrity Failure"; | |
837 | action = ACTION_FAIL; | |
838 | error = -EILSEQ; | |
b60af5b0 AS |
839 | } else |
840 | action = ACTION_FAIL; | |
841 | break; | |
511e44f4 | 842 | case ABORTED_COMMAND: |
126c0982 | 843 | action = ACTION_FAIL; |
511e44f4 | 844 | if (sshdr.asc == 0x10) { /* DIF */ |
3e695f89 | 845 | description = "Target Data Integrity Failure"; |
3e695f89 | 846 | error = -EILSEQ; |
126c0982 | 847 | } |
1da177e4 LT |
848 | break; |
849 | case NOT_READY: | |
03aba2f7 | 850 | /* If the device is in the process of becoming |
f3e93f73 | 851 | * ready, or has a temporary blockage, retry. |
1da177e4 | 852 | */ |
f3e93f73 JB |
853 | if (sshdr.asc == 0x04) { |
854 | switch (sshdr.ascq) { | |
855 | case 0x01: /* becoming ready */ | |
856 | case 0x04: /* format in progress */ | |
857 | case 0x05: /* rebuild in progress */ | |
858 | case 0x06: /* recalculation in progress */ | |
859 | case 0x07: /* operation in progress */ | |
860 | case 0x08: /* Long write in progress */ | |
861 | case 0x09: /* self test in progress */ | |
b60af5b0 | 862 | action = ACTION_DELAYED_RETRY; |
f3e93f73 | 863 | break; |
3dbf6a54 AS |
864 | default: |
865 | description = "Device not ready"; | |
866 | action = ACTION_FAIL; | |
867 | break; | |
f3e93f73 | 868 | } |
b60af5b0 AS |
869 | } else { |
870 | description = "Device not ready"; | |
871 | action = ACTION_FAIL; | |
1da177e4 | 872 | } |
b60af5b0 | 873 | break; |
1da177e4 | 874 | case VOLUME_OVERFLOW: |
03aba2f7 | 875 | /* See SSC3rXX or current. */ |
b60af5b0 AS |
876 | action = ACTION_FAIL; |
877 | break; | |
1da177e4 | 878 | default: |
b60af5b0 AS |
879 | description = "Unhandled sense code"; |
880 | action = ACTION_FAIL; | |
1da177e4 LT |
881 | break; |
882 | } | |
b60af5b0 AS |
883 | } else { |
884 | description = "Unhandled error code"; | |
885 | action = ACTION_FAIL; | |
03aba2f7 | 886 | } |
b60af5b0 AS |
887 | |
888 | switch (action) { | |
889 | case ACTION_FAIL: | |
890 | /* Give up and fail the remainder of the request */ | |
79ed2429 | 891 | scsi_release_buffers(cmd); |
4aff5e23 | 892 | if (!(req->cmd_flags & REQ_QUIET)) { |
b60af5b0 | 893 | if (description) |
3dbf6a54 | 894 | scmd_printk(KERN_INFO, cmd, "%s\n", |
b60af5b0 | 895 | description); |
a4d04a4c | 896 | scsi_print_result(cmd); |
3173d8c3 JB |
897 | if (driver_byte(result) & DRIVER_SENSE) |
898 | scsi_print_sense("", cmd); | |
002b1eb2 | 899 | scsi_print_command(cmd); |
3173d8c3 | 900 | } |
ad630826 | 901 | if (blk_end_request_err(req, error)) |
da6c5c72 TH |
902 | scsi_requeue_command(q, cmd); |
903 | else | |
904 | scsi_next_command(cmd); | |
b60af5b0 AS |
905 | break; |
906 | case ACTION_REPREP: | |
907 | /* Unprep the request and put it back at the head of the queue. | |
908 | * A new command will be prepared and issued. | |
909 | */ | |
79ed2429 | 910 | scsi_release_buffers(cmd); |
b60af5b0 AS |
911 | scsi_requeue_command(q, cmd); |
912 | break; | |
913 | case ACTION_RETRY: | |
914 | /* Retry the same command immediately */ | |
4f5299ac | 915 | __scsi_queue_insert(cmd, SCSI_MLQUEUE_EH_RETRY, 0); |
b60af5b0 AS |
916 | break; |
917 | case ACTION_DELAYED_RETRY: | |
918 | /* Retry the same command after a delay */ | |
4f5299ac | 919 | __scsi_queue_insert(cmd, SCSI_MLQUEUE_DEVICE_BUSY, 0); |
b60af5b0 | 920 | break; |
1da177e4 LT |
921 | } |
922 | } | |
1da177e4 | 923 | |
6f9a35e2 BH |
924 | static int scsi_init_sgtable(struct request *req, struct scsi_data_buffer *sdb, |
925 | gfp_t gfp_mask) | |
1da177e4 | 926 | { |
6f9a35e2 | 927 | int count; |
1da177e4 LT |
928 | |
929 | /* | |
3b003157 | 930 | * If sg table allocation fails, requeue request later. |
1da177e4 | 931 | */ |
30b0c37b BH |
932 | if (unlikely(scsi_alloc_sgtable(sdb, req->nr_phys_segments, |
933 | gfp_mask))) { | |
1da177e4 | 934 | return BLKPREP_DEFER; |
7c72ce81 | 935 | } |
1da177e4 | 936 | |
3b003157 | 937 | req->buffer = NULL; |
1da177e4 LT |
938 | |
939 | /* | |
940 | * Next, walk the list, and fill in the addresses and sizes of | |
941 | * each segment. | |
942 | */ | |
30b0c37b BH |
943 | count = blk_rq_map_sg(req->q, req, sdb->table.sgl); |
944 | BUG_ON(count > sdb->table.nents); | |
945 | sdb->table.nents = count; | |
1011c1b9 | 946 | sdb->length = blk_rq_bytes(req); |
4a03d90e | 947 | return BLKPREP_OK; |
1da177e4 | 948 | } |
6f9a35e2 BH |
949 | |
950 | /* | |
951 | * Function: scsi_init_io() | |
952 | * | |
953 | * Purpose: SCSI I/O initialize function. | |
954 | * | |
955 | * Arguments: cmd - Command descriptor we wish to initialize | |
956 | * | |
957 | * Returns: 0 on success | |
958 | * BLKPREP_DEFER if the failure is retryable | |
959 | * BLKPREP_KILL if the failure is fatal | |
960 | */ | |
961 | int scsi_init_io(struct scsi_cmnd *cmd, gfp_t gfp_mask) | |
962 | { | |
963 | int error = scsi_init_sgtable(cmd->request, &cmd->sdb, gfp_mask); | |
964 | if (error) | |
965 | goto err_exit; | |
966 | ||
967 | if (blk_bidi_rq(cmd->request)) { | |
968 | struct scsi_data_buffer *bidi_sdb = kmem_cache_zalloc( | |
6362abd3 | 969 | scsi_sdb_cache, GFP_ATOMIC); |
6f9a35e2 BH |
970 | if (!bidi_sdb) { |
971 | error = BLKPREP_DEFER; | |
972 | goto err_exit; | |
973 | } | |
974 | ||
975 | cmd->request->next_rq->special = bidi_sdb; | |
976 | error = scsi_init_sgtable(cmd->request->next_rq, bidi_sdb, | |
977 | GFP_ATOMIC); | |
978 | if (error) | |
979 | goto err_exit; | |
980 | } | |
981 | ||
7027ad72 MP |
982 | if (blk_integrity_rq(cmd->request)) { |
983 | struct scsi_data_buffer *prot_sdb = cmd->prot_sdb; | |
984 | int ivecs, count; | |
985 | ||
986 | BUG_ON(prot_sdb == NULL); | |
987 | ivecs = blk_rq_count_integrity_sg(cmd->request); | |
988 | ||
989 | if (scsi_alloc_sgtable(prot_sdb, ivecs, gfp_mask)) { | |
990 | error = BLKPREP_DEFER; | |
991 | goto err_exit; | |
992 | } | |
993 | ||
994 | count = blk_rq_map_integrity_sg(cmd->request, | |
995 | prot_sdb->table.sgl); | |
996 | BUG_ON(unlikely(count > ivecs)); | |
997 | ||
998 | cmd->prot_sdb = prot_sdb; | |
999 | cmd->prot_sdb->table.nents = count; | |
1000 | } | |
1001 | ||
6f9a35e2 BH |
1002 | return BLKPREP_OK ; |
1003 | ||
1004 | err_exit: | |
1005 | scsi_release_buffers(cmd); | |
1006 | if (error == BLKPREP_KILL) | |
1007 | scsi_put_command(cmd); | |
1008 | else /* BLKPREP_DEFER */ | |
1009 | scsi_unprep_request(cmd->request); | |
1010 | ||
1011 | return error; | |
1012 | } | |
bb52d82f | 1013 | EXPORT_SYMBOL(scsi_init_io); |
1da177e4 | 1014 | |
3b003157 CH |
1015 | static struct scsi_cmnd *scsi_get_cmd_from_req(struct scsi_device *sdev, |
1016 | struct request *req) | |
1017 | { | |
1018 | struct scsi_cmnd *cmd; | |
1019 | ||
1020 | if (!req->special) { | |
1021 | cmd = scsi_get_command(sdev, GFP_ATOMIC); | |
1022 | if (unlikely(!cmd)) | |
1023 | return NULL; | |
1024 | req->special = cmd; | |
1025 | } else { | |
1026 | cmd = req->special; | |
1027 | } | |
1028 | ||
1029 | /* pull a tag out of the request if we have one */ | |
1030 | cmd->tag = req->tag; | |
1031 | cmd->request = req; | |
1032 | ||
64a87b24 BH |
1033 | cmd->cmnd = req->cmd; |
1034 | ||
3b003157 CH |
1035 | return cmd; |
1036 | } | |
1037 | ||
7f9a6bc4 | 1038 | int scsi_setup_blk_pc_cmnd(struct scsi_device *sdev, struct request *req) |
7b16318d | 1039 | { |
3b003157 | 1040 | struct scsi_cmnd *cmd; |
7f9a6bc4 JB |
1041 | int ret = scsi_prep_state_check(sdev, req); |
1042 | ||
1043 | if (ret != BLKPREP_OK) | |
1044 | return ret; | |
3b003157 CH |
1045 | |
1046 | cmd = scsi_get_cmd_from_req(sdev, req); | |
1047 | if (unlikely(!cmd)) | |
1048 | return BLKPREP_DEFER; | |
1049 | ||
1050 | /* | |
1051 | * BLOCK_PC requests may transfer data, in which case they must | |
1052 | * a bio attached to them. Or they might contain a SCSI command | |
1053 | * that does not transfer data, in which case they may optionally | |
1054 | * submit a request without an attached bio. | |
1055 | */ | |
1056 | if (req->bio) { | |
1057 | int ret; | |
1058 | ||
1059 | BUG_ON(!req->nr_phys_segments); | |
1060 | ||
bb52d82f | 1061 | ret = scsi_init_io(cmd, GFP_ATOMIC); |
3b003157 CH |
1062 | if (unlikely(ret)) |
1063 | return ret; | |
1064 | } else { | |
b0790410 | 1065 | BUG_ON(blk_rq_bytes(req)); |
3b003157 | 1066 | |
30b0c37b | 1067 | memset(&cmd->sdb, 0, sizeof(cmd->sdb)); |
3b003157 CH |
1068 | req->buffer = NULL; |
1069 | } | |
7b16318d | 1070 | |
7b16318d | 1071 | cmd->cmd_len = req->cmd_len; |
b0790410 | 1072 | if (!blk_rq_bytes(req)) |
7b16318d JB |
1073 | cmd->sc_data_direction = DMA_NONE; |
1074 | else if (rq_data_dir(req) == WRITE) | |
1075 | cmd->sc_data_direction = DMA_TO_DEVICE; | |
1076 | else | |
1077 | cmd->sc_data_direction = DMA_FROM_DEVICE; | |
1078 | ||
b0790410 | 1079 | cmd->transfersize = blk_rq_bytes(req); |
7b16318d | 1080 | cmd->allowed = req->retries; |
3b003157 | 1081 | return BLKPREP_OK; |
7b16318d | 1082 | } |
7f9a6bc4 | 1083 | EXPORT_SYMBOL(scsi_setup_blk_pc_cmnd); |
7b16318d | 1084 | |
3b003157 CH |
1085 | /* |
1086 | * Setup a REQ_TYPE_FS command. These are simple read/write request | |
1087 | * from filesystems that still need to be translated to SCSI CDBs from | |
1088 | * the ULD. | |
1089 | */ | |
7f9a6bc4 | 1090 | int scsi_setup_fs_cmnd(struct scsi_device *sdev, struct request *req) |
1da177e4 | 1091 | { |
1da177e4 | 1092 | struct scsi_cmnd *cmd; |
7f9a6bc4 | 1093 | int ret = scsi_prep_state_check(sdev, req); |
1da177e4 | 1094 | |
7f9a6bc4 JB |
1095 | if (ret != BLKPREP_OK) |
1096 | return ret; | |
a6a8d9f8 CS |
1097 | |
1098 | if (unlikely(sdev->scsi_dh_data && sdev->scsi_dh_data->scsi_dh | |
1099 | && sdev->scsi_dh_data->scsi_dh->prep_fn)) { | |
1100 | ret = sdev->scsi_dh_data->scsi_dh->prep_fn(sdev, req); | |
1101 | if (ret != BLKPREP_OK) | |
1102 | return ret; | |
1103 | } | |
1104 | ||
1da177e4 | 1105 | /* |
3b003157 | 1106 | * Filesystem requests must transfer data. |
1da177e4 | 1107 | */ |
3b003157 CH |
1108 | BUG_ON(!req->nr_phys_segments); |
1109 | ||
1110 | cmd = scsi_get_cmd_from_req(sdev, req); | |
1111 | if (unlikely(!cmd)) | |
1112 | return BLKPREP_DEFER; | |
1113 | ||
64a87b24 | 1114 | memset(cmd->cmnd, 0, BLK_MAX_CDB); |
bb52d82f | 1115 | return scsi_init_io(cmd, GFP_ATOMIC); |
3b003157 | 1116 | } |
7f9a6bc4 | 1117 | EXPORT_SYMBOL(scsi_setup_fs_cmnd); |
3b003157 | 1118 | |
7f9a6bc4 | 1119 | int scsi_prep_state_check(struct scsi_device *sdev, struct request *req) |
3b003157 | 1120 | { |
3b003157 CH |
1121 | int ret = BLKPREP_OK; |
1122 | ||
1da177e4 | 1123 | /* |
3b003157 CH |
1124 | * If the device is not in running state we will reject some |
1125 | * or all commands. | |
1da177e4 | 1126 | */ |
3b003157 CH |
1127 | if (unlikely(sdev->sdev_state != SDEV_RUNNING)) { |
1128 | switch (sdev->sdev_state) { | |
1129 | case SDEV_OFFLINE: | |
1130 | /* | |
1131 | * If the device is offline we refuse to process any | |
1132 | * commands. The device must be brought online | |
1133 | * before trying any recovery commands. | |
1134 | */ | |
1135 | sdev_printk(KERN_ERR, sdev, | |
1136 | "rejecting I/O to offline device\n"); | |
1137 | ret = BLKPREP_KILL; | |
1138 | break; | |
1139 | case SDEV_DEL: | |
1140 | /* | |
1141 | * If the device is fully deleted, we refuse to | |
1142 | * process any commands as well. | |
1143 | */ | |
9ccfc756 | 1144 | sdev_printk(KERN_ERR, sdev, |
3b003157 CH |
1145 | "rejecting I/O to dead device\n"); |
1146 | ret = BLKPREP_KILL; | |
1147 | break; | |
1148 | case SDEV_QUIESCE: | |
1149 | case SDEV_BLOCK: | |
6f4267e3 | 1150 | case SDEV_CREATED_BLOCK: |
3b003157 CH |
1151 | /* |
1152 | * If the devices is blocked we defer normal commands. | |
1153 | */ | |
1154 | if (!(req->cmd_flags & REQ_PREEMPT)) | |
1155 | ret = BLKPREP_DEFER; | |
1156 | break; | |
1157 | default: | |
1158 | /* | |
1159 | * For any other not fully online state we only allow | |
1160 | * special commands. In particular any user initiated | |
1161 | * command is not allowed. | |
1162 | */ | |
1163 | if (!(req->cmd_flags & REQ_PREEMPT)) | |
1164 | ret = BLKPREP_KILL; | |
1165 | break; | |
1da177e4 | 1166 | } |
1da177e4 | 1167 | } |
7f9a6bc4 JB |
1168 | return ret; |
1169 | } | |
1170 | EXPORT_SYMBOL(scsi_prep_state_check); | |
1da177e4 | 1171 | |
7f9a6bc4 JB |
1172 | int scsi_prep_return(struct request_queue *q, struct request *req, int ret) |
1173 | { | |
1174 | struct scsi_device *sdev = q->queuedata; | |
1da177e4 | 1175 | |
3b003157 CH |
1176 | switch (ret) { |
1177 | case BLKPREP_KILL: | |
1178 | req->errors = DID_NO_CONNECT << 16; | |
7f9a6bc4 JB |
1179 | /* release the command and kill it */ |
1180 | if (req->special) { | |
1181 | struct scsi_cmnd *cmd = req->special; | |
1182 | scsi_release_buffers(cmd); | |
1183 | scsi_put_command(cmd); | |
1184 | req->special = NULL; | |
1185 | } | |
3b003157 CH |
1186 | break; |
1187 | case BLKPREP_DEFER: | |
1da177e4 | 1188 | /* |
9934c8c0 | 1189 | * If we defer, the blk_peek_request() returns NULL, but the |
3b003157 CH |
1190 | * queue must be restarted, so we plug here if no returning |
1191 | * command will automatically do that. | |
1da177e4 | 1192 | */ |
3b003157 CH |
1193 | if (sdev->device_busy == 0) |
1194 | blk_plug_device(q); | |
1195 | break; | |
1196 | default: | |
1197 | req->cmd_flags |= REQ_DONTPREP; | |
1da177e4 LT |
1198 | } |
1199 | ||
3b003157 | 1200 | return ret; |
1da177e4 | 1201 | } |
7f9a6bc4 JB |
1202 | EXPORT_SYMBOL(scsi_prep_return); |
1203 | ||
751bf4d7 | 1204 | int scsi_prep_fn(struct request_queue *q, struct request *req) |
7f9a6bc4 JB |
1205 | { |
1206 | struct scsi_device *sdev = q->queuedata; | |
1207 | int ret = BLKPREP_KILL; | |
1208 | ||
1209 | if (req->cmd_type == REQ_TYPE_BLOCK_PC) | |
1210 | ret = scsi_setup_blk_pc_cmnd(sdev, req); | |
1211 | return scsi_prep_return(q, req, ret); | |
1212 | } | |
b391277a | 1213 | EXPORT_SYMBOL(scsi_prep_fn); |
1da177e4 LT |
1214 | |
1215 | /* | |
1216 | * scsi_dev_queue_ready: if we can send requests to sdev, return 1 else | |
1217 | * return 0. | |
1218 | * | |
1219 | * Called with the queue_lock held. | |
1220 | */ | |
1221 | static inline int scsi_dev_queue_ready(struct request_queue *q, | |
1222 | struct scsi_device *sdev) | |
1223 | { | |
1da177e4 LT |
1224 | if (sdev->device_busy == 0 && sdev->device_blocked) { |
1225 | /* | |
1226 | * unblock after device_blocked iterates to zero | |
1227 | */ | |
1228 | if (--sdev->device_blocked == 0) { | |
1229 | SCSI_LOG_MLQUEUE(3, | |
9ccfc756 JB |
1230 | sdev_printk(KERN_INFO, sdev, |
1231 | "unblocking device at zero depth\n")); | |
1da177e4 LT |
1232 | } else { |
1233 | blk_plug_device(q); | |
1234 | return 0; | |
1235 | } | |
1236 | } | |
9d112517 | 1237 | if (scsi_device_is_busy(sdev)) |
1da177e4 LT |
1238 | return 0; |
1239 | ||
1240 | return 1; | |
1241 | } | |
1242 | ||
f0c0a376 MC |
1243 | |
1244 | /* | |
1245 | * scsi_target_queue_ready: checks if there we can send commands to target | |
1246 | * @sdev: scsi device on starget to check. | |
1247 | * | |
1248 | * Called with the host lock held. | |
1249 | */ | |
1250 | static inline int scsi_target_queue_ready(struct Scsi_Host *shost, | |
1251 | struct scsi_device *sdev) | |
1252 | { | |
1253 | struct scsi_target *starget = scsi_target(sdev); | |
1254 | ||
1255 | if (starget->single_lun) { | |
1256 | if (starget->starget_sdev_user && | |
1257 | starget->starget_sdev_user != sdev) | |
1258 | return 0; | |
1259 | starget->starget_sdev_user = sdev; | |
1260 | } | |
1261 | ||
1262 | if (starget->target_busy == 0 && starget->target_blocked) { | |
1263 | /* | |
1264 | * unblock after target_blocked iterates to zero | |
1265 | */ | |
1266 | if (--starget->target_blocked == 0) { | |
1267 | SCSI_LOG_MLQUEUE(3, starget_printk(KERN_INFO, starget, | |
1268 | "unblocking target at zero depth\n")); | |
b4efdd58 | 1269 | } else |
f0c0a376 | 1270 | return 0; |
f0c0a376 MC |
1271 | } |
1272 | ||
1273 | if (scsi_target_is_busy(starget)) { | |
1274 | if (list_empty(&sdev->starved_entry)) { | |
1275 | list_add_tail(&sdev->starved_entry, | |
1276 | &shost->starved_list); | |
1277 | return 0; | |
1278 | } | |
1279 | } | |
1280 | ||
1281 | /* We're OK to process the command, so we can't be starved */ | |
1282 | if (!list_empty(&sdev->starved_entry)) | |
1283 | list_del_init(&sdev->starved_entry); | |
1284 | return 1; | |
1285 | } | |
1286 | ||
1da177e4 LT |
1287 | /* |
1288 | * scsi_host_queue_ready: if we can send requests to shost, return 1 else | |
1289 | * return 0. We must end up running the queue again whenever 0 is | |
1290 | * returned, else IO can hang. | |
1291 | * | |
1292 | * Called with host_lock held. | |
1293 | */ | |
1294 | static inline int scsi_host_queue_ready(struct request_queue *q, | |
1295 | struct Scsi_Host *shost, | |
1296 | struct scsi_device *sdev) | |
1297 | { | |
939647ee | 1298 | if (scsi_host_in_recovery(shost)) |
1da177e4 LT |
1299 | return 0; |
1300 | if (shost->host_busy == 0 && shost->host_blocked) { | |
1301 | /* | |
1302 | * unblock after host_blocked iterates to zero | |
1303 | */ | |
1304 | if (--shost->host_blocked == 0) { | |
1305 | SCSI_LOG_MLQUEUE(3, | |
1306 | printk("scsi%d unblocking host at zero depth\n", | |
1307 | shost->host_no)); | |
1308 | } else { | |
1da177e4 LT |
1309 | return 0; |
1310 | } | |
1311 | } | |
9d112517 | 1312 | if (scsi_host_is_busy(shost)) { |
1da177e4 LT |
1313 | if (list_empty(&sdev->starved_entry)) |
1314 | list_add_tail(&sdev->starved_entry, &shost->starved_list); | |
1315 | return 0; | |
1316 | } | |
1317 | ||
1318 | /* We're OK to process the command, so we can't be starved */ | |
1319 | if (!list_empty(&sdev->starved_entry)) | |
1320 | list_del_init(&sdev->starved_entry); | |
1321 | ||
1322 | return 1; | |
1323 | } | |
1324 | ||
6c5121b7 KU |
1325 | /* |
1326 | * Busy state exporting function for request stacking drivers. | |
1327 | * | |
1328 | * For efficiency, no lock is taken to check the busy state of | |
1329 | * shost/starget/sdev, since the returned value is not guaranteed and | |
1330 | * may be changed after request stacking drivers call the function, | |
1331 | * regardless of taking lock or not. | |
1332 | * | |
1333 | * When scsi can't dispatch I/Os anymore and needs to kill I/Os | |
1334 | * (e.g. !sdev), scsi needs to return 'not busy'. | |
1335 | * Otherwise, request stacking drivers may hold requests forever. | |
1336 | */ | |
1337 | static int scsi_lld_busy(struct request_queue *q) | |
1338 | { | |
1339 | struct scsi_device *sdev = q->queuedata; | |
1340 | struct Scsi_Host *shost; | |
1341 | struct scsi_target *starget; | |
1342 | ||
1343 | if (!sdev) | |
1344 | return 0; | |
1345 | ||
1346 | shost = sdev->host; | |
1347 | starget = scsi_target(sdev); | |
1348 | ||
1349 | if (scsi_host_in_recovery(shost) || scsi_host_is_busy(shost) || | |
1350 | scsi_target_is_busy(starget) || scsi_device_is_busy(sdev)) | |
1351 | return 1; | |
1352 | ||
1353 | return 0; | |
1354 | } | |
1355 | ||
1da177e4 | 1356 | /* |
e91442b6 | 1357 | * Kill a request for a dead device |
1da177e4 | 1358 | */ |
165125e1 | 1359 | static void scsi_kill_request(struct request *req, struct request_queue *q) |
1da177e4 | 1360 | { |
e91442b6 | 1361 | struct scsi_cmnd *cmd = req->special; |
03b14708 JS |
1362 | struct scsi_device *sdev; |
1363 | struct scsi_target *starget; | |
1364 | struct Scsi_Host *shost; | |
1da177e4 | 1365 | |
9934c8c0 | 1366 | blk_start_request(req); |
788ce43a | 1367 | |
e91442b6 JB |
1368 | if (unlikely(cmd == NULL)) { |
1369 | printk(KERN_CRIT "impossible request in %s.\n", | |
cadbd4a5 | 1370 | __func__); |
e91442b6 | 1371 | BUG(); |
1da177e4 | 1372 | } |
e91442b6 | 1373 | |
03b14708 JS |
1374 | sdev = cmd->device; |
1375 | starget = scsi_target(sdev); | |
1376 | shost = sdev->host; | |
e91442b6 JB |
1377 | scsi_init_cmd_errh(cmd); |
1378 | cmd->result = DID_NO_CONNECT << 16; | |
1379 | atomic_inc(&cmd->device->iorequest_cnt); | |
e36e0c80 TH |
1380 | |
1381 | /* | |
1382 | * SCSI request completion path will do scsi_device_unbusy(), | |
1383 | * bump busy counts. To bump the counters, we need to dance | |
1384 | * with the locks as normal issue path does. | |
1385 | */ | |
1386 | sdev->device_busy++; | |
1387 | spin_unlock(sdev->request_queue->queue_lock); | |
1388 | spin_lock(shost->host_lock); | |
1389 | shost->host_busy++; | |
f0c0a376 | 1390 | starget->target_busy++; |
e36e0c80 TH |
1391 | spin_unlock(shost->host_lock); |
1392 | spin_lock(sdev->request_queue->queue_lock); | |
1393 | ||
242f9dcb | 1394 | blk_complete_request(req); |
1da177e4 LT |
1395 | } |
1396 | ||
1aea6434 JA |
1397 | static void scsi_softirq_done(struct request *rq) |
1398 | { | |
242f9dcb JA |
1399 | struct scsi_cmnd *cmd = rq->special; |
1400 | unsigned long wait_for = (cmd->allowed + 1) * rq->timeout; | |
1aea6434 JA |
1401 | int disposition; |
1402 | ||
1403 | INIT_LIST_HEAD(&cmd->eh_entry); | |
1404 | ||
242f9dcb JA |
1405 | /* |
1406 | * Set the serial numbers back to zero | |
1407 | */ | |
1408 | cmd->serial_number = 0; | |
1409 | ||
1410 | atomic_inc(&cmd->device->iodone_cnt); | |
1411 | if (cmd->result) | |
1412 | atomic_inc(&cmd->device->ioerr_cnt); | |
1413 | ||
1aea6434 JA |
1414 | disposition = scsi_decide_disposition(cmd); |
1415 | if (disposition != SUCCESS && | |
1416 | time_before(cmd->jiffies_at_alloc + wait_for, jiffies)) { | |
1417 | sdev_printk(KERN_ERR, cmd->device, | |
1418 | "timing out command, waited %lus\n", | |
1419 | wait_for/HZ); | |
1420 | disposition = SUCCESS; | |
1421 | } | |
1422 | ||
1423 | scsi_log_completion(cmd, disposition); | |
1424 | ||
1425 | switch (disposition) { | |
1426 | case SUCCESS: | |
1427 | scsi_finish_command(cmd); | |
1428 | break; | |
1429 | case NEEDS_RETRY: | |
596f482a | 1430 | scsi_queue_insert(cmd, SCSI_MLQUEUE_EH_RETRY); |
1aea6434 JA |
1431 | break; |
1432 | case ADD_TO_MLQUEUE: | |
1433 | scsi_queue_insert(cmd, SCSI_MLQUEUE_DEVICE_BUSY); | |
1434 | break; | |
1435 | default: | |
1436 | if (!scsi_eh_scmd_add(cmd, 0)) | |
1437 | scsi_finish_command(cmd); | |
1438 | } | |
1439 | } | |
1440 | ||
1da177e4 LT |
1441 | /* |
1442 | * Function: scsi_request_fn() | |
1443 | * | |
1444 | * Purpose: Main strategy routine for SCSI. | |
1445 | * | |
1446 | * Arguments: q - Pointer to actual queue. | |
1447 | * | |
1448 | * Returns: Nothing | |
1449 | * | |
1450 | * Lock status: IO request lock assumed to be held when called. | |
1451 | */ | |
1452 | static void scsi_request_fn(struct request_queue *q) | |
1453 | { | |
1454 | struct scsi_device *sdev = q->queuedata; | |
1455 | struct Scsi_Host *shost; | |
1456 | struct scsi_cmnd *cmd; | |
1457 | struct request *req; | |
1458 | ||
1459 | if (!sdev) { | |
1460 | printk("scsi: killing requests for dead queue\n"); | |
9934c8c0 | 1461 | while ((req = blk_peek_request(q)) != NULL) |
e91442b6 | 1462 | scsi_kill_request(req, q); |
1da177e4 LT |
1463 | return; |
1464 | } | |
1465 | ||
1466 | if(!get_device(&sdev->sdev_gendev)) | |
1467 | /* We must be tearing the block queue down already */ | |
1468 | return; | |
1469 | ||
1470 | /* | |
1471 | * To start with, we keep looping until the queue is empty, or until | |
1472 | * the host is no longer able to accept any more requests. | |
1473 | */ | |
1474 | shost = sdev->host; | |
1475 | while (!blk_queue_plugged(q)) { | |
1476 | int rtn; | |
1477 | /* | |
1478 | * get next queueable request. We do this early to make sure | |
1479 | * that the request is fully prepared even if we cannot | |
1480 | * accept it. | |
1481 | */ | |
9934c8c0 | 1482 | req = blk_peek_request(q); |
1da177e4 LT |
1483 | if (!req || !scsi_dev_queue_ready(q, sdev)) |
1484 | break; | |
1485 | ||
1486 | if (unlikely(!scsi_device_online(sdev))) { | |
9ccfc756 JB |
1487 | sdev_printk(KERN_ERR, sdev, |
1488 | "rejecting I/O to offline device\n"); | |
e91442b6 | 1489 | scsi_kill_request(req, q); |
1da177e4 LT |
1490 | continue; |
1491 | } | |
1492 | ||
1493 | ||
1494 | /* | |
1495 | * Remove the request from the request list. | |
1496 | */ | |
1497 | if (!(blk_queue_tagged(q) && !blk_queue_start_tag(q, req))) | |
9934c8c0 | 1498 | blk_start_request(req); |
1da177e4 LT |
1499 | sdev->device_busy++; |
1500 | ||
1501 | spin_unlock(q->queue_lock); | |
e91442b6 JB |
1502 | cmd = req->special; |
1503 | if (unlikely(cmd == NULL)) { | |
1504 | printk(KERN_CRIT "impossible request in %s.\n" | |
1505 | "please mail a stack trace to " | |
4aff5e23 | 1506 | "linux-scsi@vger.kernel.org\n", |
cadbd4a5 | 1507 | __func__); |
4aff5e23 | 1508 | blk_dump_rq_flags(req, "foo"); |
e91442b6 JB |
1509 | BUG(); |
1510 | } | |
1da177e4 LT |
1511 | spin_lock(shost->host_lock); |
1512 | ||
ecefe8a9 MC |
1513 | /* |
1514 | * We hit this when the driver is using a host wide | |
1515 | * tag map. For device level tag maps the queue_depth check | |
1516 | * in the device ready fn would prevent us from trying | |
1517 | * to allocate a tag. Since the map is a shared host resource | |
1518 | * we add the dev to the starved list so it eventually gets | |
1519 | * a run when a tag is freed. | |
1520 | */ | |
6bd522f6 | 1521 | if (blk_queue_tagged(q) && !blk_rq_tagged(req)) { |
ecefe8a9 MC |
1522 | if (list_empty(&sdev->starved_entry)) |
1523 | list_add_tail(&sdev->starved_entry, | |
1524 | &shost->starved_list); | |
1525 | goto not_ready; | |
1526 | } | |
1527 | ||
f0c0a376 MC |
1528 | if (!scsi_target_queue_ready(shost, sdev)) |
1529 | goto not_ready; | |
1530 | ||
1da177e4 LT |
1531 | if (!scsi_host_queue_ready(q, shost, sdev)) |
1532 | goto not_ready; | |
f0c0a376 MC |
1533 | |
1534 | scsi_target(sdev)->target_busy++; | |
1da177e4 LT |
1535 | shost->host_busy++; |
1536 | ||
1537 | /* | |
1538 | * XXX(hch): This is rather suboptimal, scsi_dispatch_cmd will | |
1539 | * take the lock again. | |
1540 | */ | |
1541 | spin_unlock_irq(shost->host_lock); | |
1542 | ||
1da177e4 LT |
1543 | /* |
1544 | * Finally, initialize any error handling parameters, and set up | |
1545 | * the timers for timeouts. | |
1546 | */ | |
1547 | scsi_init_cmd_errh(cmd); | |
1548 | ||
1549 | /* | |
1550 | * Dispatch the command to the low-level driver. | |
1551 | */ | |
1552 | rtn = scsi_dispatch_cmd(cmd); | |
1553 | spin_lock_irq(q->queue_lock); | |
1554 | if(rtn) { | |
1555 | /* we're refusing the command; because of | |
1556 | * the way locks get dropped, we need to | |
1557 | * check here if plugging is required */ | |
1558 | if(sdev->device_busy == 0) | |
1559 | blk_plug_device(q); | |
1560 | ||
1561 | break; | |
1562 | } | |
1563 | } | |
1564 | ||
1565 | goto out; | |
1566 | ||
1567 | not_ready: | |
1568 | spin_unlock_irq(shost->host_lock); | |
1569 | ||
1570 | /* | |
1571 | * lock q, handle tag, requeue req, and decrement device_busy. We | |
1572 | * must return with queue_lock held. | |
1573 | * | |
1574 | * Decrementing device_busy without checking it is OK, as all such | |
1575 | * cases (host limits or settings) should run the queue at some | |
1576 | * later time. | |
1577 | */ | |
1578 | spin_lock_irq(q->queue_lock); | |
1579 | blk_requeue_request(q, req); | |
1580 | sdev->device_busy--; | |
1581 | if(sdev->device_busy == 0) | |
1582 | blk_plug_device(q); | |
1583 | out: | |
1584 | /* must be careful here...if we trigger the ->remove() function | |
1585 | * we cannot be holding the q lock */ | |
1586 | spin_unlock_irq(q->queue_lock); | |
1587 | put_device(&sdev->sdev_gendev); | |
1588 | spin_lock_irq(q->queue_lock); | |
1589 | } | |
1590 | ||
1591 | u64 scsi_calculate_bounce_limit(struct Scsi_Host *shost) | |
1592 | { | |
1593 | struct device *host_dev; | |
1594 | u64 bounce_limit = 0xffffffff; | |
1595 | ||
1596 | if (shost->unchecked_isa_dma) | |
1597 | return BLK_BOUNCE_ISA; | |
1598 | /* | |
1599 | * Platforms with virtual-DMA translation | |
1600 | * hardware have no practical limit. | |
1601 | */ | |
1602 | if (!PCI_DMA_BUS_IS_PHYS) | |
1603 | return BLK_BOUNCE_ANY; | |
1604 | ||
1605 | host_dev = scsi_get_device(shost); | |
1606 | if (host_dev && host_dev->dma_mask) | |
1607 | bounce_limit = *host_dev->dma_mask; | |
1608 | ||
1609 | return bounce_limit; | |
1610 | } | |
1611 | EXPORT_SYMBOL(scsi_calculate_bounce_limit); | |
1612 | ||
b58d9154 FT |
1613 | struct request_queue *__scsi_alloc_queue(struct Scsi_Host *shost, |
1614 | request_fn_proc *request_fn) | |
1da177e4 | 1615 | { |
1da177e4 | 1616 | struct request_queue *q; |
860ac568 | 1617 | struct device *dev = shost->shost_gendev.parent; |
1da177e4 | 1618 | |
b58d9154 | 1619 | q = blk_init_queue(request_fn, NULL); |
1da177e4 LT |
1620 | if (!q) |
1621 | return NULL; | |
1622 | ||
a8474ce2 JA |
1623 | /* |
1624 | * this limit is imposed by hardware restrictions | |
1625 | */ | |
1da177e4 | 1626 | blk_queue_max_hw_segments(q, shost->sg_tablesize); |
d3f46f39 | 1627 | blk_queue_max_phys_segments(q, SCSI_MAX_SG_CHAIN_SEGMENTS); |
a8474ce2 | 1628 | |
1da177e4 LT |
1629 | blk_queue_max_sectors(q, shost->max_sectors); |
1630 | blk_queue_bounce_limit(q, scsi_calculate_bounce_limit(shost)); | |
1631 | blk_queue_segment_boundary(q, shost->dma_boundary); | |
99c84dbd | 1632 | dma_set_seg_boundary(dev, shost->dma_boundary); |
1da177e4 | 1633 | |
860ac568 FT |
1634 | blk_queue_max_segment_size(q, dma_get_max_seg_size(dev)); |
1635 | ||
75ad23bc | 1636 | /* New queue, no concurrency on queue_flags */ |
1da177e4 | 1637 | if (!shost->use_clustering) |
75ad23bc | 1638 | queue_flag_clear_unlocked(QUEUE_FLAG_CLUSTER, q); |
465ff318 JB |
1639 | |
1640 | /* | |
1641 | * set a reasonable default alignment on word boundaries: the | |
1642 | * host and device may alter it using | |
1643 | * blk_queue_update_dma_alignment() later. | |
1644 | */ | |
1645 | blk_queue_dma_alignment(q, 0x03); | |
1646 | ||
1da177e4 LT |
1647 | return q; |
1648 | } | |
b58d9154 FT |
1649 | EXPORT_SYMBOL(__scsi_alloc_queue); |
1650 | ||
1651 | struct request_queue *scsi_alloc_queue(struct scsi_device *sdev) | |
1652 | { | |
1653 | struct request_queue *q; | |
1654 | ||
1655 | q = __scsi_alloc_queue(sdev->host, scsi_request_fn); | |
1656 | if (!q) | |
1657 | return NULL; | |
1658 | ||
1659 | blk_queue_prep_rq(q, scsi_prep_fn); | |
b58d9154 | 1660 | blk_queue_softirq_done(q, scsi_softirq_done); |
242f9dcb | 1661 | blk_queue_rq_timed_out(q, scsi_times_out); |
6c5121b7 | 1662 | blk_queue_lld_busy(q, scsi_lld_busy); |
b58d9154 FT |
1663 | return q; |
1664 | } | |
1da177e4 LT |
1665 | |
1666 | void scsi_free_queue(struct request_queue *q) | |
1667 | { | |
1668 | blk_cleanup_queue(q); | |
1669 | } | |
1670 | ||
1671 | /* | |
1672 | * Function: scsi_block_requests() | |
1673 | * | |
1674 | * Purpose: Utility function used by low-level drivers to prevent further | |
1675 | * commands from being queued to the device. | |
1676 | * | |
1677 | * Arguments: shost - Host in question | |
1678 | * | |
1679 | * Returns: Nothing | |
1680 | * | |
1681 | * Lock status: No locks are assumed held. | |
1682 | * | |
1683 | * Notes: There is no timer nor any other means by which the requests | |
1684 | * get unblocked other than the low-level driver calling | |
1685 | * scsi_unblock_requests(). | |
1686 | */ | |
1687 | void scsi_block_requests(struct Scsi_Host *shost) | |
1688 | { | |
1689 | shost->host_self_blocked = 1; | |
1690 | } | |
1691 | EXPORT_SYMBOL(scsi_block_requests); | |
1692 | ||
1693 | /* | |
1694 | * Function: scsi_unblock_requests() | |
1695 | * | |
1696 | * Purpose: Utility function used by low-level drivers to allow further | |
1697 | * commands from being queued to the device. | |
1698 | * | |
1699 | * Arguments: shost - Host in question | |
1700 | * | |
1701 | * Returns: Nothing | |
1702 | * | |
1703 | * Lock status: No locks are assumed held. | |
1704 | * | |
1705 | * Notes: There is no timer nor any other means by which the requests | |
1706 | * get unblocked other than the low-level driver calling | |
1707 | * scsi_unblock_requests(). | |
1708 | * | |
1709 | * This is done as an API function so that changes to the | |
1710 | * internals of the scsi mid-layer won't require wholesale | |
1711 | * changes to drivers that use this feature. | |
1712 | */ | |
1713 | void scsi_unblock_requests(struct Scsi_Host *shost) | |
1714 | { | |
1715 | shost->host_self_blocked = 0; | |
1716 | scsi_run_host_queues(shost); | |
1717 | } | |
1718 | EXPORT_SYMBOL(scsi_unblock_requests); | |
1719 | ||
1720 | int __init scsi_init_queue(void) | |
1721 | { | |
1722 | int i; | |
1723 | ||
6362abd3 MP |
1724 | scsi_sdb_cache = kmem_cache_create("scsi_data_buffer", |
1725 | sizeof(struct scsi_data_buffer), | |
1726 | 0, 0, NULL); | |
1727 | if (!scsi_sdb_cache) { | |
1728 | printk(KERN_ERR "SCSI: can't init scsi sdb cache\n"); | |
f078727b | 1729 | return -ENOMEM; |
6f9a35e2 BH |
1730 | } |
1731 | ||
1da177e4 LT |
1732 | for (i = 0; i < SG_MEMPOOL_NR; i++) { |
1733 | struct scsi_host_sg_pool *sgp = scsi_sg_pools + i; | |
1734 | int size = sgp->size * sizeof(struct scatterlist); | |
1735 | ||
1736 | sgp->slab = kmem_cache_create(sgp->name, size, 0, | |
20c2df83 | 1737 | SLAB_HWCACHE_ALIGN, NULL); |
1da177e4 LT |
1738 | if (!sgp->slab) { |
1739 | printk(KERN_ERR "SCSI: can't init sg slab %s\n", | |
1740 | sgp->name); | |
6362abd3 | 1741 | goto cleanup_sdb; |
1da177e4 LT |
1742 | } |
1743 | ||
93d2341c MD |
1744 | sgp->pool = mempool_create_slab_pool(SG_MEMPOOL_SIZE, |
1745 | sgp->slab); | |
1da177e4 LT |
1746 | if (!sgp->pool) { |
1747 | printk(KERN_ERR "SCSI: can't init sg mempool %s\n", | |
1748 | sgp->name); | |
6362abd3 | 1749 | goto cleanup_sdb; |
1da177e4 LT |
1750 | } |
1751 | } | |
1752 | ||
1753 | return 0; | |
3d9dd6ee | 1754 | |
6362abd3 | 1755 | cleanup_sdb: |
3d9dd6ee FT |
1756 | for (i = 0; i < SG_MEMPOOL_NR; i++) { |
1757 | struct scsi_host_sg_pool *sgp = scsi_sg_pools + i; | |
1758 | if (sgp->pool) | |
1759 | mempool_destroy(sgp->pool); | |
1760 | if (sgp->slab) | |
1761 | kmem_cache_destroy(sgp->slab); | |
1762 | } | |
6362abd3 | 1763 | kmem_cache_destroy(scsi_sdb_cache); |
3d9dd6ee FT |
1764 | |
1765 | return -ENOMEM; | |
1da177e4 LT |
1766 | } |
1767 | ||
1768 | void scsi_exit_queue(void) | |
1769 | { | |
1770 | int i; | |
1771 | ||
6362abd3 | 1772 | kmem_cache_destroy(scsi_sdb_cache); |
aa7b5cd7 | 1773 | |
1da177e4 LT |
1774 | for (i = 0; i < SG_MEMPOOL_NR; i++) { |
1775 | struct scsi_host_sg_pool *sgp = scsi_sg_pools + i; | |
1776 | mempool_destroy(sgp->pool); | |
1777 | kmem_cache_destroy(sgp->slab); | |
1778 | } | |
1779 | } | |
5baba830 JB |
1780 | |
1781 | /** | |
1782 | * scsi_mode_select - issue a mode select | |
1783 | * @sdev: SCSI device to be queried | |
1784 | * @pf: Page format bit (1 == standard, 0 == vendor specific) | |
1785 | * @sp: Save page bit (0 == don't save, 1 == save) | |
1786 | * @modepage: mode page being requested | |
1787 | * @buffer: request buffer (may not be smaller than eight bytes) | |
1788 | * @len: length of request buffer. | |
1789 | * @timeout: command timeout | |
1790 | * @retries: number of retries before failing | |
1791 | * @data: returns a structure abstracting the mode header data | |
eb44820c | 1792 | * @sshdr: place to put sense data (or NULL if no sense to be collected). |
5baba830 JB |
1793 | * must be SCSI_SENSE_BUFFERSIZE big. |
1794 | * | |
1795 | * Returns zero if successful; negative error number or scsi | |
1796 | * status on error | |
1797 | * | |
1798 | */ | |
1799 | int | |
1800 | scsi_mode_select(struct scsi_device *sdev, int pf, int sp, int modepage, | |
1801 | unsigned char *buffer, int len, int timeout, int retries, | |
1802 | struct scsi_mode_data *data, struct scsi_sense_hdr *sshdr) | |
1803 | { | |
1804 | unsigned char cmd[10]; | |
1805 | unsigned char *real_buffer; | |
1806 | int ret; | |
1807 | ||
1808 | memset(cmd, 0, sizeof(cmd)); | |
1809 | cmd[1] = (pf ? 0x10 : 0) | (sp ? 0x01 : 0); | |
1810 | ||
1811 | if (sdev->use_10_for_ms) { | |
1812 | if (len > 65535) | |
1813 | return -EINVAL; | |
1814 | real_buffer = kmalloc(8 + len, GFP_KERNEL); | |
1815 | if (!real_buffer) | |
1816 | return -ENOMEM; | |
1817 | memcpy(real_buffer + 8, buffer, len); | |
1818 | len += 8; | |
1819 | real_buffer[0] = 0; | |
1820 | real_buffer[1] = 0; | |
1821 | real_buffer[2] = data->medium_type; | |
1822 | real_buffer[3] = data->device_specific; | |
1823 | real_buffer[4] = data->longlba ? 0x01 : 0; | |
1824 | real_buffer[5] = 0; | |
1825 | real_buffer[6] = data->block_descriptor_length >> 8; | |
1826 | real_buffer[7] = data->block_descriptor_length; | |
1827 | ||
1828 | cmd[0] = MODE_SELECT_10; | |
1829 | cmd[7] = len >> 8; | |
1830 | cmd[8] = len; | |
1831 | } else { | |
1832 | if (len > 255 || data->block_descriptor_length > 255 || | |
1833 | data->longlba) | |
1834 | return -EINVAL; | |
1835 | ||
1836 | real_buffer = kmalloc(4 + len, GFP_KERNEL); | |
1837 | if (!real_buffer) | |
1838 | return -ENOMEM; | |
1839 | memcpy(real_buffer + 4, buffer, len); | |
1840 | len += 4; | |
1841 | real_buffer[0] = 0; | |
1842 | real_buffer[1] = data->medium_type; | |
1843 | real_buffer[2] = data->device_specific; | |
1844 | real_buffer[3] = data->block_descriptor_length; | |
1845 | ||
1846 | ||
1847 | cmd[0] = MODE_SELECT; | |
1848 | cmd[4] = len; | |
1849 | } | |
1850 | ||
1851 | ret = scsi_execute_req(sdev, cmd, DMA_TO_DEVICE, real_buffer, len, | |
f4f4e47e | 1852 | sshdr, timeout, retries, NULL); |
5baba830 JB |
1853 | kfree(real_buffer); |
1854 | return ret; | |
1855 | } | |
1856 | EXPORT_SYMBOL_GPL(scsi_mode_select); | |
1857 | ||
1da177e4 | 1858 | /** |
eb44820c | 1859 | * scsi_mode_sense - issue a mode sense, falling back from 10 to six bytes if necessary. |
1cf72699 | 1860 | * @sdev: SCSI device to be queried |
1da177e4 LT |
1861 | * @dbd: set if mode sense will allow block descriptors to be returned |
1862 | * @modepage: mode page being requested | |
1863 | * @buffer: request buffer (may not be smaller than eight bytes) | |
1864 | * @len: length of request buffer. | |
1865 | * @timeout: command timeout | |
1866 | * @retries: number of retries before failing | |
1867 | * @data: returns a structure abstracting the mode header data | |
eb44820c | 1868 | * @sshdr: place to put sense data (or NULL if no sense to be collected). |
1cf72699 | 1869 | * must be SCSI_SENSE_BUFFERSIZE big. |
1da177e4 LT |
1870 | * |
1871 | * Returns zero if unsuccessful, or the header offset (either 4 | |
1872 | * or 8 depending on whether a six or ten byte command was | |
1873 | * issued) if successful. | |
eb44820c | 1874 | */ |
1da177e4 | 1875 | int |
1cf72699 | 1876 | scsi_mode_sense(struct scsi_device *sdev, int dbd, int modepage, |
1da177e4 | 1877 | unsigned char *buffer, int len, int timeout, int retries, |
5baba830 JB |
1878 | struct scsi_mode_data *data, struct scsi_sense_hdr *sshdr) |
1879 | { | |
1da177e4 LT |
1880 | unsigned char cmd[12]; |
1881 | int use_10_for_ms; | |
1882 | int header_length; | |
1cf72699 | 1883 | int result; |
ea73a9f2 | 1884 | struct scsi_sense_hdr my_sshdr; |
1da177e4 LT |
1885 | |
1886 | memset(data, 0, sizeof(*data)); | |
1887 | memset(&cmd[0], 0, 12); | |
1888 | cmd[1] = dbd & 0x18; /* allows DBD and LLBA bits */ | |
1889 | cmd[2] = modepage; | |
1890 | ||
ea73a9f2 JB |
1891 | /* caller might not be interested in sense, but we need it */ |
1892 | if (!sshdr) | |
1893 | sshdr = &my_sshdr; | |
1894 | ||
1da177e4 | 1895 | retry: |
1cf72699 | 1896 | use_10_for_ms = sdev->use_10_for_ms; |
1da177e4 LT |
1897 | |
1898 | if (use_10_for_ms) { | |
1899 | if (len < 8) | |
1900 | len = 8; | |
1901 | ||
1902 | cmd[0] = MODE_SENSE_10; | |
1903 | cmd[8] = len; | |
1904 | header_length = 8; | |
1905 | } else { | |
1906 | if (len < 4) | |
1907 | len = 4; | |
1908 | ||
1909 | cmd[0] = MODE_SENSE; | |
1910 | cmd[4] = len; | |
1911 | header_length = 4; | |
1912 | } | |
1913 | ||
1da177e4 LT |
1914 | memset(buffer, 0, len); |
1915 | ||
1cf72699 | 1916 | result = scsi_execute_req(sdev, cmd, DMA_FROM_DEVICE, buffer, len, |
f4f4e47e | 1917 | sshdr, timeout, retries, NULL); |
1da177e4 LT |
1918 | |
1919 | /* This code looks awful: what it's doing is making sure an | |
1920 | * ILLEGAL REQUEST sense return identifies the actual command | |
1921 | * byte as the problem. MODE_SENSE commands can return | |
1922 | * ILLEGAL REQUEST if the code page isn't supported */ | |
1923 | ||
1cf72699 JB |
1924 | if (use_10_for_ms && !scsi_status_is_good(result) && |
1925 | (driver_byte(result) & DRIVER_SENSE)) { | |
ea73a9f2 JB |
1926 | if (scsi_sense_valid(sshdr)) { |
1927 | if ((sshdr->sense_key == ILLEGAL_REQUEST) && | |
1928 | (sshdr->asc == 0x20) && (sshdr->ascq == 0)) { | |
1da177e4 LT |
1929 | /* |
1930 | * Invalid command operation code | |
1931 | */ | |
1cf72699 | 1932 | sdev->use_10_for_ms = 0; |
1da177e4 LT |
1933 | goto retry; |
1934 | } | |
1935 | } | |
1936 | } | |
1937 | ||
1cf72699 | 1938 | if(scsi_status_is_good(result)) { |
6d73c851 AV |
1939 | if (unlikely(buffer[0] == 0x86 && buffer[1] == 0x0b && |
1940 | (modepage == 6 || modepage == 8))) { | |
1941 | /* Initio breakage? */ | |
1942 | header_length = 0; | |
1943 | data->length = 13; | |
1944 | data->medium_type = 0; | |
1945 | data->device_specific = 0; | |
1946 | data->longlba = 0; | |
1947 | data->block_descriptor_length = 0; | |
1948 | } else if(use_10_for_ms) { | |
1da177e4 LT |
1949 | data->length = buffer[0]*256 + buffer[1] + 2; |
1950 | data->medium_type = buffer[2]; | |
1951 | data->device_specific = buffer[3]; | |
1952 | data->longlba = buffer[4] & 0x01; | |
1953 | data->block_descriptor_length = buffer[6]*256 | |
1954 | + buffer[7]; | |
1955 | } else { | |
1956 | data->length = buffer[0] + 1; | |
1957 | data->medium_type = buffer[1]; | |
1958 | data->device_specific = buffer[2]; | |
1959 | data->block_descriptor_length = buffer[3]; | |
1960 | } | |
6d73c851 | 1961 | data->header_length = header_length; |
1da177e4 LT |
1962 | } |
1963 | ||
1cf72699 | 1964 | return result; |
1da177e4 LT |
1965 | } |
1966 | EXPORT_SYMBOL(scsi_mode_sense); | |
1967 | ||
001aac25 JB |
1968 | /** |
1969 | * scsi_test_unit_ready - test if unit is ready | |
1970 | * @sdev: scsi device to change the state of. | |
1971 | * @timeout: command timeout | |
1972 | * @retries: number of retries before failing | |
1973 | * @sshdr_external: Optional pointer to struct scsi_sense_hdr for | |
1974 | * returning sense. Make sure that this is cleared before passing | |
1975 | * in. | |
1976 | * | |
1977 | * Returns zero if unsuccessful or an error if TUR failed. For | |
1978 | * removable media, a return of NOT_READY or UNIT_ATTENTION is | |
1979 | * translated to success, with the ->changed flag updated. | |
1980 | **/ | |
1da177e4 | 1981 | int |
001aac25 JB |
1982 | scsi_test_unit_ready(struct scsi_device *sdev, int timeout, int retries, |
1983 | struct scsi_sense_hdr *sshdr_external) | |
1da177e4 | 1984 | { |
1da177e4 LT |
1985 | char cmd[] = { |
1986 | TEST_UNIT_READY, 0, 0, 0, 0, 0, | |
1987 | }; | |
001aac25 | 1988 | struct scsi_sense_hdr *sshdr; |
1da177e4 | 1989 | int result; |
001aac25 JB |
1990 | |
1991 | if (!sshdr_external) | |
1992 | sshdr = kzalloc(sizeof(*sshdr), GFP_KERNEL); | |
1993 | else | |
1994 | sshdr = sshdr_external; | |
1995 | ||
1996 | /* try to eat the UNIT_ATTENTION if there are enough retries */ | |
1997 | do { | |
1998 | result = scsi_execute_req(sdev, cmd, DMA_NONE, NULL, 0, sshdr, | |
f4f4e47e | 1999 | timeout, retries, NULL); |
32c356d7 JB |
2000 | if (sdev->removable && scsi_sense_valid(sshdr) && |
2001 | sshdr->sense_key == UNIT_ATTENTION) | |
2002 | sdev->changed = 1; | |
2003 | } while (scsi_sense_valid(sshdr) && | |
2004 | sshdr->sense_key == UNIT_ATTENTION && --retries); | |
001aac25 JB |
2005 | |
2006 | if (!sshdr) | |
2007 | /* could not allocate sense buffer, so can't process it */ | |
2008 | return result; | |
1da177e4 | 2009 | |
32c356d7 JB |
2010 | if (sdev->removable && scsi_sense_valid(sshdr) && |
2011 | (sshdr->sense_key == UNIT_ATTENTION || | |
2012 | sshdr->sense_key == NOT_READY)) { | |
2013 | sdev->changed = 1; | |
2014 | result = 0; | |
1da177e4 | 2015 | } |
001aac25 JB |
2016 | if (!sshdr_external) |
2017 | kfree(sshdr); | |
1da177e4 LT |
2018 | return result; |
2019 | } | |
2020 | EXPORT_SYMBOL(scsi_test_unit_ready); | |
2021 | ||
2022 | /** | |
eb44820c | 2023 | * scsi_device_set_state - Take the given device through the device state model. |
1da177e4 LT |
2024 | * @sdev: scsi device to change the state of. |
2025 | * @state: state to change to. | |
2026 | * | |
2027 | * Returns zero if unsuccessful or an error if the requested | |
2028 | * transition is illegal. | |
eb44820c | 2029 | */ |
1da177e4 LT |
2030 | int |
2031 | scsi_device_set_state(struct scsi_device *sdev, enum scsi_device_state state) | |
2032 | { | |
2033 | enum scsi_device_state oldstate = sdev->sdev_state; | |
2034 | ||
2035 | if (state == oldstate) | |
2036 | return 0; | |
2037 | ||
2038 | switch (state) { | |
2039 | case SDEV_CREATED: | |
6f4267e3 JB |
2040 | switch (oldstate) { |
2041 | case SDEV_CREATED_BLOCK: | |
2042 | break; | |
2043 | default: | |
2044 | goto illegal; | |
2045 | } | |
2046 | break; | |
1da177e4 LT |
2047 | |
2048 | case SDEV_RUNNING: | |
2049 | switch (oldstate) { | |
2050 | case SDEV_CREATED: | |
2051 | case SDEV_OFFLINE: | |
2052 | case SDEV_QUIESCE: | |
2053 | case SDEV_BLOCK: | |
2054 | break; | |
2055 | default: | |
2056 | goto illegal; | |
2057 | } | |
2058 | break; | |
2059 | ||
2060 | case SDEV_QUIESCE: | |
2061 | switch (oldstate) { | |
2062 | case SDEV_RUNNING: | |
2063 | case SDEV_OFFLINE: | |
2064 | break; | |
2065 | default: | |
2066 | goto illegal; | |
2067 | } | |
2068 | break; | |
2069 | ||
2070 | case SDEV_OFFLINE: | |
2071 | switch (oldstate) { | |
2072 | case SDEV_CREATED: | |
2073 | case SDEV_RUNNING: | |
2074 | case SDEV_QUIESCE: | |
2075 | case SDEV_BLOCK: | |
2076 | break; | |
2077 | default: | |
2078 | goto illegal; | |
2079 | } | |
2080 | break; | |
2081 | ||
2082 | case SDEV_BLOCK: | |
2083 | switch (oldstate) { | |
1da177e4 | 2084 | case SDEV_RUNNING: |
6f4267e3 JB |
2085 | case SDEV_CREATED_BLOCK: |
2086 | break; | |
2087 | default: | |
2088 | goto illegal; | |
2089 | } | |
2090 | break; | |
2091 | ||
2092 | case SDEV_CREATED_BLOCK: | |
2093 | switch (oldstate) { | |
2094 | case SDEV_CREATED: | |
1da177e4 LT |
2095 | break; |
2096 | default: | |
2097 | goto illegal; | |
2098 | } | |
2099 | break; | |
2100 | ||
2101 | case SDEV_CANCEL: | |
2102 | switch (oldstate) { | |
2103 | case SDEV_CREATED: | |
2104 | case SDEV_RUNNING: | |
9ea72909 | 2105 | case SDEV_QUIESCE: |
1da177e4 LT |
2106 | case SDEV_OFFLINE: |
2107 | case SDEV_BLOCK: | |
2108 | break; | |
2109 | default: | |
2110 | goto illegal; | |
2111 | } | |
2112 | break; | |
2113 | ||
2114 | case SDEV_DEL: | |
2115 | switch (oldstate) { | |
309bd271 BK |
2116 | case SDEV_CREATED: |
2117 | case SDEV_RUNNING: | |
2118 | case SDEV_OFFLINE: | |
1da177e4 LT |
2119 | case SDEV_CANCEL: |
2120 | break; | |
2121 | default: | |
2122 | goto illegal; | |
2123 | } | |
2124 | break; | |
2125 | ||
2126 | } | |
2127 | sdev->sdev_state = state; | |
2128 | return 0; | |
2129 | ||
2130 | illegal: | |
2131 | SCSI_LOG_ERROR_RECOVERY(1, | |
9ccfc756 JB |
2132 | sdev_printk(KERN_ERR, sdev, |
2133 | "Illegal state transition %s->%s\n", | |
2134 | scsi_device_state_name(oldstate), | |
2135 | scsi_device_state_name(state)) | |
1da177e4 LT |
2136 | ); |
2137 | return -EINVAL; | |
2138 | } | |
2139 | EXPORT_SYMBOL(scsi_device_set_state); | |
2140 | ||
a341cd0f JG |
2141 | /** |
2142 | * sdev_evt_emit - emit a single SCSI device uevent | |
2143 | * @sdev: associated SCSI device | |
2144 | * @evt: event to emit | |
2145 | * | |
2146 | * Send a single uevent (scsi_event) to the associated scsi_device. | |
2147 | */ | |
2148 | static void scsi_evt_emit(struct scsi_device *sdev, struct scsi_event *evt) | |
2149 | { | |
2150 | int idx = 0; | |
2151 | char *envp[3]; | |
2152 | ||
2153 | switch (evt->evt_type) { | |
2154 | case SDEV_EVT_MEDIA_CHANGE: | |
2155 | envp[idx++] = "SDEV_MEDIA_CHANGE=1"; | |
2156 | break; | |
2157 | ||
2158 | default: | |
2159 | /* do nothing */ | |
2160 | break; | |
2161 | } | |
2162 | ||
2163 | envp[idx++] = NULL; | |
2164 | ||
2165 | kobject_uevent_env(&sdev->sdev_gendev.kobj, KOBJ_CHANGE, envp); | |
2166 | } | |
2167 | ||
2168 | /** | |
2169 | * sdev_evt_thread - send a uevent for each scsi event | |
2170 | * @work: work struct for scsi_device | |
2171 | * | |
2172 | * Dispatch queued events to their associated scsi_device kobjects | |
2173 | * as uevents. | |
2174 | */ | |
2175 | void scsi_evt_thread(struct work_struct *work) | |
2176 | { | |
2177 | struct scsi_device *sdev; | |
2178 | LIST_HEAD(event_list); | |
2179 | ||
2180 | sdev = container_of(work, struct scsi_device, event_work); | |
2181 | ||
2182 | while (1) { | |
2183 | struct scsi_event *evt; | |
2184 | struct list_head *this, *tmp; | |
2185 | unsigned long flags; | |
2186 | ||
2187 | spin_lock_irqsave(&sdev->list_lock, flags); | |
2188 | list_splice_init(&sdev->event_list, &event_list); | |
2189 | spin_unlock_irqrestore(&sdev->list_lock, flags); | |
2190 | ||
2191 | if (list_empty(&event_list)) | |
2192 | break; | |
2193 | ||
2194 | list_for_each_safe(this, tmp, &event_list) { | |
2195 | evt = list_entry(this, struct scsi_event, node); | |
2196 | list_del(&evt->node); | |
2197 | scsi_evt_emit(sdev, evt); | |
2198 | kfree(evt); | |
2199 | } | |
2200 | } | |
2201 | } | |
2202 | ||
2203 | /** | |
2204 | * sdev_evt_send - send asserted event to uevent thread | |
2205 | * @sdev: scsi_device event occurred on | |
2206 | * @evt: event to send | |
2207 | * | |
2208 | * Assert scsi device event asynchronously. | |
2209 | */ | |
2210 | void sdev_evt_send(struct scsi_device *sdev, struct scsi_event *evt) | |
2211 | { | |
2212 | unsigned long flags; | |
2213 | ||
4d1566ed KS |
2214 | #if 0 |
2215 | /* FIXME: currently this check eliminates all media change events | |
2216 | * for polled devices. Need to update to discriminate between AN | |
2217 | * and polled events */ | |
a341cd0f JG |
2218 | if (!test_bit(evt->evt_type, sdev->supported_events)) { |
2219 | kfree(evt); | |
2220 | return; | |
2221 | } | |
4d1566ed | 2222 | #endif |
a341cd0f JG |
2223 | |
2224 | spin_lock_irqsave(&sdev->list_lock, flags); | |
2225 | list_add_tail(&evt->node, &sdev->event_list); | |
2226 | schedule_work(&sdev->event_work); | |
2227 | spin_unlock_irqrestore(&sdev->list_lock, flags); | |
2228 | } | |
2229 | EXPORT_SYMBOL_GPL(sdev_evt_send); | |
2230 | ||
2231 | /** | |
2232 | * sdev_evt_alloc - allocate a new scsi event | |
2233 | * @evt_type: type of event to allocate | |
2234 | * @gfpflags: GFP flags for allocation | |
2235 | * | |
2236 | * Allocates and returns a new scsi_event. | |
2237 | */ | |
2238 | struct scsi_event *sdev_evt_alloc(enum scsi_device_event evt_type, | |
2239 | gfp_t gfpflags) | |
2240 | { | |
2241 | struct scsi_event *evt = kzalloc(sizeof(struct scsi_event), gfpflags); | |
2242 | if (!evt) | |
2243 | return NULL; | |
2244 | ||
2245 | evt->evt_type = evt_type; | |
2246 | INIT_LIST_HEAD(&evt->node); | |
2247 | ||
2248 | /* evt_type-specific initialization, if any */ | |
2249 | switch (evt_type) { | |
2250 | case SDEV_EVT_MEDIA_CHANGE: | |
2251 | default: | |
2252 | /* do nothing */ | |
2253 | break; | |
2254 | } | |
2255 | ||
2256 | return evt; | |
2257 | } | |
2258 | EXPORT_SYMBOL_GPL(sdev_evt_alloc); | |
2259 | ||
2260 | /** | |
2261 | * sdev_evt_send_simple - send asserted event to uevent thread | |
2262 | * @sdev: scsi_device event occurred on | |
2263 | * @evt_type: type of event to send | |
2264 | * @gfpflags: GFP flags for allocation | |
2265 | * | |
2266 | * Assert scsi device event asynchronously, given an event type. | |
2267 | */ | |
2268 | void sdev_evt_send_simple(struct scsi_device *sdev, | |
2269 | enum scsi_device_event evt_type, gfp_t gfpflags) | |
2270 | { | |
2271 | struct scsi_event *evt = sdev_evt_alloc(evt_type, gfpflags); | |
2272 | if (!evt) { | |
2273 | sdev_printk(KERN_ERR, sdev, "event %d eaten due to OOM\n", | |
2274 | evt_type); | |
2275 | return; | |
2276 | } | |
2277 | ||
2278 | sdev_evt_send(sdev, evt); | |
2279 | } | |
2280 | EXPORT_SYMBOL_GPL(sdev_evt_send_simple); | |
2281 | ||
1da177e4 LT |
2282 | /** |
2283 | * scsi_device_quiesce - Block user issued commands. | |
2284 | * @sdev: scsi device to quiesce. | |
2285 | * | |
2286 | * This works by trying to transition to the SDEV_QUIESCE state | |
2287 | * (which must be a legal transition). When the device is in this | |
2288 | * state, only special requests will be accepted, all others will | |
2289 | * be deferred. Since special requests may also be requeued requests, | |
2290 | * a successful return doesn't guarantee the device will be | |
2291 | * totally quiescent. | |
2292 | * | |
2293 | * Must be called with user context, may sleep. | |
2294 | * | |
2295 | * Returns zero if unsuccessful or an error if not. | |
eb44820c | 2296 | */ |
1da177e4 LT |
2297 | int |
2298 | scsi_device_quiesce(struct scsi_device *sdev) | |
2299 | { | |
2300 | int err = scsi_device_set_state(sdev, SDEV_QUIESCE); | |
2301 | if (err) | |
2302 | return err; | |
2303 | ||
2304 | scsi_run_queue(sdev->request_queue); | |
2305 | while (sdev->device_busy) { | |
2306 | msleep_interruptible(200); | |
2307 | scsi_run_queue(sdev->request_queue); | |
2308 | } | |
2309 | return 0; | |
2310 | } | |
2311 | EXPORT_SYMBOL(scsi_device_quiesce); | |
2312 | ||
2313 | /** | |
2314 | * scsi_device_resume - Restart user issued commands to a quiesced device. | |
2315 | * @sdev: scsi device to resume. | |
2316 | * | |
2317 | * Moves the device from quiesced back to running and restarts the | |
2318 | * queues. | |
2319 | * | |
2320 | * Must be called with user context, may sleep. | |
eb44820c | 2321 | */ |
1da177e4 LT |
2322 | void |
2323 | scsi_device_resume(struct scsi_device *sdev) | |
2324 | { | |
2325 | if(scsi_device_set_state(sdev, SDEV_RUNNING)) | |
2326 | return; | |
2327 | scsi_run_queue(sdev->request_queue); | |
2328 | } | |
2329 | EXPORT_SYMBOL(scsi_device_resume); | |
2330 | ||
2331 | static void | |
2332 | device_quiesce_fn(struct scsi_device *sdev, void *data) | |
2333 | { | |
2334 | scsi_device_quiesce(sdev); | |
2335 | } | |
2336 | ||
2337 | void | |
2338 | scsi_target_quiesce(struct scsi_target *starget) | |
2339 | { | |
2340 | starget_for_each_device(starget, NULL, device_quiesce_fn); | |
2341 | } | |
2342 | EXPORT_SYMBOL(scsi_target_quiesce); | |
2343 | ||
2344 | static void | |
2345 | device_resume_fn(struct scsi_device *sdev, void *data) | |
2346 | { | |
2347 | scsi_device_resume(sdev); | |
2348 | } | |
2349 | ||
2350 | void | |
2351 | scsi_target_resume(struct scsi_target *starget) | |
2352 | { | |
2353 | starget_for_each_device(starget, NULL, device_resume_fn); | |
2354 | } | |
2355 | EXPORT_SYMBOL(scsi_target_resume); | |
2356 | ||
2357 | /** | |
eb44820c | 2358 | * scsi_internal_device_block - internal function to put a device temporarily into the SDEV_BLOCK state |
1da177e4 LT |
2359 | * @sdev: device to block |
2360 | * | |
2361 | * Block request made by scsi lld's to temporarily stop all | |
2362 | * scsi commands on the specified device. Called from interrupt | |
2363 | * or normal process context. | |
2364 | * | |
2365 | * Returns zero if successful or error if not | |
2366 | * | |
2367 | * Notes: | |
2368 | * This routine transitions the device to the SDEV_BLOCK state | |
2369 | * (which must be a legal transition). When the device is in this | |
2370 | * state, all commands are deferred until the scsi lld reenables | |
2371 | * the device with scsi_device_unblock or device_block_tmo fires. | |
2372 | * This routine assumes the host_lock is held on entry. | |
eb44820c | 2373 | */ |
1da177e4 LT |
2374 | int |
2375 | scsi_internal_device_block(struct scsi_device *sdev) | |
2376 | { | |
165125e1 | 2377 | struct request_queue *q = sdev->request_queue; |
1da177e4 LT |
2378 | unsigned long flags; |
2379 | int err = 0; | |
2380 | ||
2381 | err = scsi_device_set_state(sdev, SDEV_BLOCK); | |
6f4267e3 JB |
2382 | if (err) { |
2383 | err = scsi_device_set_state(sdev, SDEV_CREATED_BLOCK); | |
2384 | ||
2385 | if (err) | |
2386 | return err; | |
2387 | } | |
1da177e4 LT |
2388 | |
2389 | /* | |
2390 | * The device has transitioned to SDEV_BLOCK. Stop the | |
2391 | * block layer from calling the midlayer with this device's | |
2392 | * request queue. | |
2393 | */ | |
2394 | spin_lock_irqsave(q->queue_lock, flags); | |
2395 | blk_stop_queue(q); | |
2396 | spin_unlock_irqrestore(q->queue_lock, flags); | |
2397 | ||
2398 | return 0; | |
2399 | } | |
2400 | EXPORT_SYMBOL_GPL(scsi_internal_device_block); | |
2401 | ||
2402 | /** | |
2403 | * scsi_internal_device_unblock - resume a device after a block request | |
2404 | * @sdev: device to resume | |
2405 | * | |
2406 | * Called by scsi lld's or the midlayer to restart the device queue | |
2407 | * for the previously suspended scsi device. Called from interrupt or | |
2408 | * normal process context. | |
2409 | * | |
2410 | * Returns zero if successful or error if not. | |
2411 | * | |
2412 | * Notes: | |
2413 | * This routine transitions the device to the SDEV_RUNNING state | |
2414 | * (which must be a legal transition) allowing the midlayer to | |
2415 | * goose the queue for this device. This routine assumes the | |
2416 | * host_lock is held upon entry. | |
eb44820c | 2417 | */ |
1da177e4 LT |
2418 | int |
2419 | scsi_internal_device_unblock(struct scsi_device *sdev) | |
2420 | { | |
165125e1 | 2421 | struct request_queue *q = sdev->request_queue; |
1da177e4 LT |
2422 | unsigned long flags; |
2423 | ||
2424 | /* | |
2425 | * Try to transition the scsi device to SDEV_RUNNING | |
2426 | * and goose the device queue if successful. | |
2427 | */ | |
5c10e63c TY |
2428 | if (sdev->sdev_state == SDEV_BLOCK) |
2429 | sdev->sdev_state = SDEV_RUNNING; | |
2430 | else if (sdev->sdev_state == SDEV_CREATED_BLOCK) | |
2431 | sdev->sdev_state = SDEV_CREATED; | |
2432 | else | |
2433 | return -EINVAL; | |
1da177e4 LT |
2434 | |
2435 | spin_lock_irqsave(q->queue_lock, flags); | |
2436 | blk_start_queue(q); | |
2437 | spin_unlock_irqrestore(q->queue_lock, flags); | |
2438 | ||
2439 | return 0; | |
2440 | } | |
2441 | EXPORT_SYMBOL_GPL(scsi_internal_device_unblock); | |
2442 | ||
2443 | static void | |
2444 | device_block(struct scsi_device *sdev, void *data) | |
2445 | { | |
2446 | scsi_internal_device_block(sdev); | |
2447 | } | |
2448 | ||
2449 | static int | |
2450 | target_block(struct device *dev, void *data) | |
2451 | { | |
2452 | if (scsi_is_target_device(dev)) | |
2453 | starget_for_each_device(to_scsi_target(dev), NULL, | |
2454 | device_block); | |
2455 | return 0; | |
2456 | } | |
2457 | ||
2458 | void | |
2459 | scsi_target_block(struct device *dev) | |
2460 | { | |
2461 | if (scsi_is_target_device(dev)) | |
2462 | starget_for_each_device(to_scsi_target(dev), NULL, | |
2463 | device_block); | |
2464 | else | |
2465 | device_for_each_child(dev, NULL, target_block); | |
2466 | } | |
2467 | EXPORT_SYMBOL_GPL(scsi_target_block); | |
2468 | ||
2469 | static void | |
2470 | device_unblock(struct scsi_device *sdev, void *data) | |
2471 | { | |
2472 | scsi_internal_device_unblock(sdev); | |
2473 | } | |
2474 | ||
2475 | static int | |
2476 | target_unblock(struct device *dev, void *data) | |
2477 | { | |
2478 | if (scsi_is_target_device(dev)) | |
2479 | starget_for_each_device(to_scsi_target(dev), NULL, | |
2480 | device_unblock); | |
2481 | return 0; | |
2482 | } | |
2483 | ||
2484 | void | |
2485 | scsi_target_unblock(struct device *dev) | |
2486 | { | |
2487 | if (scsi_is_target_device(dev)) | |
2488 | starget_for_each_device(to_scsi_target(dev), NULL, | |
2489 | device_unblock); | |
2490 | else | |
2491 | device_for_each_child(dev, NULL, target_unblock); | |
2492 | } | |
2493 | EXPORT_SYMBOL_GPL(scsi_target_unblock); | |
cdb8c2a6 GL |
2494 | |
2495 | /** | |
2496 | * scsi_kmap_atomic_sg - find and atomically map an sg-elemnt | |
eb44820c | 2497 | * @sgl: scatter-gather list |
cdb8c2a6 GL |
2498 | * @sg_count: number of segments in sg |
2499 | * @offset: offset in bytes into sg, on return offset into the mapped area | |
2500 | * @len: bytes to map, on return number of bytes mapped | |
2501 | * | |
2502 | * Returns virtual address of the start of the mapped page | |
2503 | */ | |
c6132da1 | 2504 | void *scsi_kmap_atomic_sg(struct scatterlist *sgl, int sg_count, |
cdb8c2a6 GL |
2505 | size_t *offset, size_t *len) |
2506 | { | |
2507 | int i; | |
2508 | size_t sg_len = 0, len_complete = 0; | |
c6132da1 | 2509 | struct scatterlist *sg; |
cdb8c2a6 GL |
2510 | struct page *page; |
2511 | ||
22cfefb5 AM |
2512 | WARN_ON(!irqs_disabled()); |
2513 | ||
c6132da1 | 2514 | for_each_sg(sgl, sg, sg_count, i) { |
cdb8c2a6 | 2515 | len_complete = sg_len; /* Complete sg-entries */ |
c6132da1 | 2516 | sg_len += sg->length; |
cdb8c2a6 GL |
2517 | if (sg_len > *offset) |
2518 | break; | |
2519 | } | |
2520 | ||
2521 | if (unlikely(i == sg_count)) { | |
169e1a2a AM |
2522 | printk(KERN_ERR "%s: Bytes in sg: %zu, requested offset %zu, " |
2523 | "elements %d\n", | |
cadbd4a5 | 2524 | __func__, sg_len, *offset, sg_count); |
cdb8c2a6 GL |
2525 | WARN_ON(1); |
2526 | return NULL; | |
2527 | } | |
2528 | ||
2529 | /* Offset starting from the beginning of first page in this sg-entry */ | |
c6132da1 | 2530 | *offset = *offset - len_complete + sg->offset; |
cdb8c2a6 GL |
2531 | |
2532 | /* Assumption: contiguous pages can be accessed as "page + i" */ | |
45711f1a | 2533 | page = nth_page(sg_page(sg), (*offset >> PAGE_SHIFT)); |
cdb8c2a6 GL |
2534 | *offset &= ~PAGE_MASK; |
2535 | ||
2536 | /* Bytes in this sg-entry from *offset to the end of the page */ | |
2537 | sg_len = PAGE_SIZE - *offset; | |
2538 | if (*len > sg_len) | |
2539 | *len = sg_len; | |
2540 | ||
2541 | return kmap_atomic(page, KM_BIO_SRC_IRQ); | |
2542 | } | |
2543 | EXPORT_SYMBOL(scsi_kmap_atomic_sg); | |
2544 | ||
2545 | /** | |
eb44820c | 2546 | * scsi_kunmap_atomic_sg - atomically unmap a virtual address, previously mapped with scsi_kmap_atomic_sg |
cdb8c2a6 GL |
2547 | * @virt: virtual address to be unmapped |
2548 | */ | |
2549 | void scsi_kunmap_atomic_sg(void *virt) | |
2550 | { | |
2551 | kunmap_atomic(virt, KM_BIO_SRC_IRQ); | |
2552 | } | |
2553 | EXPORT_SYMBOL(scsi_kunmap_atomic_sg); |