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 | |
1da177e4 LT |
94 | /* |
95 | * Function: scsi_queue_insert() | |
96 | * | |
97 | * Purpose: Insert a command in the midlevel queue. | |
98 | * | |
99 | * Arguments: cmd - command that we are adding to queue. | |
100 | * reason - why we are inserting command to queue. | |
101 | * | |
102 | * Lock status: Assumed that lock is not held upon entry. | |
103 | * | |
104 | * Returns: Nothing. | |
105 | * | |
106 | * Notes: We do this for one of two cases. Either the host is busy | |
107 | * and it cannot accept any more commands for the time being, | |
108 | * or the device returned QUEUE_FULL and can accept no more | |
109 | * commands. | |
110 | * Notes: This could be called either from an interrupt context or a | |
111 | * normal process context. | |
112 | */ | |
113 | int scsi_queue_insert(struct scsi_cmnd *cmd, int reason) | |
114 | { | |
115 | struct Scsi_Host *host = cmd->device->host; | |
116 | struct scsi_device *device = cmd->device; | |
f0c0a376 | 117 | struct scsi_target *starget = scsi_target(device); |
a1bf9d1d TH |
118 | struct request_queue *q = device->request_queue; |
119 | unsigned long flags; | |
1da177e4 LT |
120 | |
121 | SCSI_LOG_MLQUEUE(1, | |
122 | printk("Inserting command %p into mlqueue\n", cmd)); | |
123 | ||
124 | /* | |
d8c37e7b | 125 | * Set the appropriate busy bit for the device/host. |
1da177e4 LT |
126 | * |
127 | * If the host/device isn't busy, assume that something actually | |
128 | * completed, and that we should be able to queue a command now. | |
129 | * | |
130 | * Note that the prior mid-layer assumption that any host could | |
131 | * always queue at least one command is now broken. The mid-layer | |
132 | * will implement a user specifiable stall (see | |
133 | * scsi_host.max_host_blocked and scsi_device.max_device_blocked) | |
134 | * if a command is requeued with no other commands outstanding | |
135 | * either for the device or for the host. | |
136 | */ | |
f0c0a376 MC |
137 | switch (reason) { |
138 | case SCSI_MLQUEUE_HOST_BUSY: | |
1da177e4 | 139 | host->host_blocked = host->max_host_blocked; |
f0c0a376 MC |
140 | break; |
141 | case SCSI_MLQUEUE_DEVICE_BUSY: | |
1da177e4 | 142 | device->device_blocked = device->max_device_blocked; |
f0c0a376 MC |
143 | break; |
144 | case SCSI_MLQUEUE_TARGET_BUSY: | |
145 | starget->target_blocked = starget->max_target_blocked; | |
146 | break; | |
147 | } | |
1da177e4 | 148 | |
1da177e4 LT |
149 | /* |
150 | * Decrement the counters, since these commands are no longer | |
151 | * active on the host/device. | |
152 | */ | |
153 | scsi_device_unbusy(device); | |
154 | ||
155 | /* | |
a1bf9d1d TH |
156 | * Requeue this command. It will go before all other commands |
157 | * that are already in the queue. | |
1da177e4 LT |
158 | * |
159 | * NOTE: there is magic here about the way the queue is plugged if | |
160 | * we have no outstanding commands. | |
161 | * | |
a1bf9d1d | 162 | * Although we *don't* plug the queue, we call the request |
1da177e4 LT |
163 | * function. The SCSI request function detects the blocked condition |
164 | * and plugs the queue appropriately. | |
a1bf9d1d TH |
165 | */ |
166 | spin_lock_irqsave(q->queue_lock, flags); | |
59897dad | 167 | blk_requeue_request(q, cmd->request); |
a1bf9d1d TH |
168 | spin_unlock_irqrestore(q->queue_lock, flags); |
169 | ||
170 | scsi_run_queue(q); | |
171 | ||
1da177e4 LT |
172 | return 0; |
173 | } | |
174 | ||
39216033 | 175 | /** |
33aa687d | 176 | * scsi_execute - insert request and wait for the result |
39216033 JB |
177 | * @sdev: scsi device |
178 | * @cmd: scsi command | |
179 | * @data_direction: data direction | |
180 | * @buffer: data buffer | |
181 | * @bufflen: len of buffer | |
182 | * @sense: optional sense buffer | |
183 | * @timeout: request timeout in seconds | |
184 | * @retries: number of times to retry request | |
33aa687d | 185 | * @flags: or into request flags; |
39216033 | 186 | * |
59c51591 | 187 | * returns the req->errors value which is the scsi_cmnd result |
ea73a9f2 | 188 | * field. |
eb44820c | 189 | */ |
33aa687d JB |
190 | int scsi_execute(struct scsi_device *sdev, const unsigned char *cmd, |
191 | int data_direction, void *buffer, unsigned bufflen, | |
192 | unsigned char *sense, int timeout, int retries, int flags) | |
39216033 JB |
193 | { |
194 | struct request *req; | |
195 | int write = (data_direction == DMA_TO_DEVICE); | |
196 | int ret = DRIVER_ERROR << 24; | |
197 | ||
198 | req = blk_get_request(sdev->request_queue, write, __GFP_WAIT); | |
199 | ||
200 | if (bufflen && blk_rq_map_kern(sdev->request_queue, req, | |
201 | buffer, bufflen, __GFP_WAIT)) | |
202 | goto out; | |
203 | ||
204 | req->cmd_len = COMMAND_SIZE(cmd[0]); | |
205 | memcpy(req->cmd, cmd, req->cmd_len); | |
206 | req->sense = sense; | |
207 | req->sense_len = 0; | |
17e01f21 | 208 | req->retries = retries; |
39216033 | 209 | req->timeout = timeout; |
4aff5e23 JA |
210 | req->cmd_type = REQ_TYPE_BLOCK_PC; |
211 | req->cmd_flags |= flags | REQ_QUIET | REQ_PREEMPT; | |
39216033 JB |
212 | |
213 | /* | |
214 | * head injection *required* here otherwise quiesce won't work | |
215 | */ | |
216 | blk_execute_rq(req->q, NULL, req, 1); | |
217 | ||
bdb2b8ca AS |
218 | /* |
219 | * Some devices (USB mass-storage in particular) may transfer | |
220 | * garbage data together with a residue indicating that the data | |
221 | * is invalid. Prevent the garbage from being misinterpreted | |
222 | * and prevent security leaks by zeroing out the excess data. | |
223 | */ | |
224 | if (unlikely(req->data_len > 0 && req->data_len <= bufflen)) | |
225 | memset(buffer + (bufflen - req->data_len), 0, req->data_len); | |
226 | ||
39216033 JB |
227 | ret = req->errors; |
228 | out: | |
229 | blk_put_request(req); | |
230 | ||
231 | return ret; | |
232 | } | |
33aa687d | 233 | EXPORT_SYMBOL(scsi_execute); |
39216033 | 234 | |
ea73a9f2 JB |
235 | |
236 | int scsi_execute_req(struct scsi_device *sdev, const unsigned char *cmd, | |
237 | int data_direction, void *buffer, unsigned bufflen, | |
238 | struct scsi_sense_hdr *sshdr, int timeout, int retries) | |
239 | { | |
240 | char *sense = NULL; | |
1ccb48bb | 241 | int result; |
242 | ||
ea73a9f2 | 243 | if (sshdr) { |
24669f75 | 244 | sense = kzalloc(SCSI_SENSE_BUFFERSIZE, GFP_NOIO); |
ea73a9f2 JB |
245 | if (!sense) |
246 | return DRIVER_ERROR << 24; | |
ea73a9f2 | 247 | } |
1ccb48bb | 248 | result = scsi_execute(sdev, cmd, data_direction, buffer, bufflen, |
24669f75 | 249 | sense, timeout, retries, 0); |
ea73a9f2 | 250 | if (sshdr) |
e514385b | 251 | scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE, sshdr); |
ea73a9f2 JB |
252 | |
253 | kfree(sense); | |
254 | return result; | |
255 | } | |
256 | EXPORT_SYMBOL(scsi_execute_req); | |
257 | ||
6e68af66 MC |
258 | struct scsi_io_context { |
259 | void *data; | |
260 | void (*done)(void *data, char *sense, int result, int resid); | |
261 | char sense[SCSI_SENSE_BUFFERSIZE]; | |
262 | }; | |
263 | ||
e18b890b | 264 | static struct kmem_cache *scsi_io_context_cache; |
aa7b5cd7 | 265 | |
e650c305 | 266 | static void scsi_end_async(struct request *req, int uptodate) |
6e68af66 MC |
267 | { |
268 | struct scsi_io_context *sioc = req->end_io_data; | |
269 | ||
270 | if (sioc->done) | |
271 | sioc->done(sioc->data, sioc->sense, req->errors, req->data_len); | |
272 | ||
aa7b5cd7 | 273 | kmem_cache_free(scsi_io_context_cache, sioc); |
6e68af66 MC |
274 | __blk_put_request(req->q, req); |
275 | } | |
276 | ||
277 | static int scsi_merge_bio(struct request *rq, struct bio *bio) | |
278 | { | |
279 | struct request_queue *q = rq->q; | |
280 | ||
281 | bio->bi_flags &= ~(1 << BIO_SEG_VALID); | |
282 | if (rq_data_dir(rq) == WRITE) | |
283 | bio->bi_rw |= (1 << BIO_RW); | |
284 | blk_queue_bounce(q, &bio); | |
285 | ||
3001ca77 | 286 | return blk_rq_append_bio(q, rq, bio); |
6e68af66 MC |
287 | } |
288 | ||
6712ecf8 | 289 | static void scsi_bi_endio(struct bio *bio, int error) |
6e68af66 | 290 | { |
6e68af66 | 291 | bio_put(bio); |
6e68af66 MC |
292 | } |
293 | ||
294 | /** | |
295 | * scsi_req_map_sg - map a scatterlist into a request | |
296 | * @rq: request to fill | |
eb44820c | 297 | * @sgl: scatterlist |
6e68af66 MC |
298 | * @nsegs: number of elements |
299 | * @bufflen: len of buffer | |
300 | * @gfp: memory allocation flags | |
301 | * | |
302 | * scsi_req_map_sg maps a scatterlist into a request so that the | |
303 | * request can be sent to the block layer. We do not trust the scatterlist | |
304 | * sent to use, as some ULDs use that struct to only organize the pages. | |
305 | */ | |
306 | static int scsi_req_map_sg(struct request *rq, struct scatterlist *sgl, | |
307 | int nsegs, unsigned bufflen, gfp_t gfp) | |
308 | { | |
309 | struct request_queue *q = rq->q; | |
f5235962 | 310 | int nr_pages = (bufflen + sgl[0].offset + PAGE_SIZE - 1) >> PAGE_SHIFT; |
bd441dea | 311 | unsigned int data_len = bufflen, len, bytes, off; |
c6132da1 | 312 | struct scatterlist *sg; |
6e68af66 MC |
313 | struct page *page; |
314 | struct bio *bio = NULL; | |
315 | int i, err, nr_vecs = 0; | |
316 | ||
c6132da1 | 317 | for_each_sg(sgl, sg, nsegs, i) { |
45711f1a | 318 | page = sg_page(sg); |
c6132da1 JA |
319 | off = sg->offset; |
320 | len = sg->length; | |
6e68af66 | 321 | |
bd441dea MC |
322 | while (len > 0 && data_len > 0) { |
323 | /* | |
324 | * sg sends a scatterlist that is larger than | |
325 | * the data_len it wants transferred for certain | |
326 | * IO sizes | |
327 | */ | |
6e68af66 | 328 | bytes = min_t(unsigned int, len, PAGE_SIZE - off); |
bd441dea | 329 | bytes = min(bytes, data_len); |
6e68af66 MC |
330 | |
331 | if (!bio) { | |
332 | nr_vecs = min_t(int, BIO_MAX_PAGES, nr_pages); | |
333 | nr_pages -= nr_vecs; | |
334 | ||
335 | bio = bio_alloc(gfp, nr_vecs); | |
336 | if (!bio) { | |
337 | err = -ENOMEM; | |
338 | goto free_bios; | |
339 | } | |
340 | bio->bi_end_io = scsi_bi_endio; | |
341 | } | |
342 | ||
343 | if (bio_add_pc_page(q, bio, page, bytes, off) != | |
344 | bytes) { | |
345 | bio_put(bio); | |
346 | err = -EINVAL; | |
347 | goto free_bios; | |
348 | } | |
349 | ||
350 | if (bio->bi_vcnt >= nr_vecs) { | |
351 | err = scsi_merge_bio(rq, bio); | |
352 | if (err) { | |
6712ecf8 | 353 | bio_endio(bio, 0); |
6e68af66 MC |
354 | goto free_bios; |
355 | } | |
356 | bio = NULL; | |
357 | } | |
358 | ||
359 | page++; | |
360 | len -= bytes; | |
bd441dea | 361 | data_len -=bytes; |
6e68af66 MC |
362 | off = 0; |
363 | } | |
364 | } | |
365 | ||
366 | rq->buffer = rq->data = NULL; | |
bd441dea | 367 | rq->data_len = bufflen; |
6e68af66 MC |
368 | return 0; |
369 | ||
370 | free_bios: | |
371 | while ((bio = rq->bio) != NULL) { | |
372 | rq->bio = bio->bi_next; | |
373 | /* | |
374 | * call endio instead of bio_put incase it was bounced | |
375 | */ | |
6712ecf8 | 376 | bio_endio(bio, 0); |
6e68af66 MC |
377 | } |
378 | ||
379 | return err; | |
380 | } | |
381 | ||
382 | /** | |
383 | * scsi_execute_async - insert request | |
384 | * @sdev: scsi device | |
385 | * @cmd: scsi command | |
bb1d1073 | 386 | * @cmd_len: length of scsi cdb |
eb44820c | 387 | * @data_direction: DMA_TO_DEVICE, DMA_FROM_DEVICE, or DMA_NONE |
6e68af66 MC |
388 | * @buffer: data buffer (this can be a kernel buffer or scatterlist) |
389 | * @bufflen: len of buffer | |
390 | * @use_sg: if buffer is a scatterlist this is the number of elements | |
391 | * @timeout: request timeout in seconds | |
392 | * @retries: number of times to retry request | |
eb44820c RL |
393 | * @privdata: data passed to done() |
394 | * @done: callback function when done | |
395 | * @gfp: memory allocation flags | |
396 | */ | |
6e68af66 | 397 | int scsi_execute_async(struct scsi_device *sdev, const unsigned char *cmd, |
bb1d1073 | 398 | int cmd_len, int data_direction, void *buffer, unsigned bufflen, |
6e68af66 MC |
399 | int use_sg, int timeout, int retries, void *privdata, |
400 | void (*done)(void *, char *, int, int), gfp_t gfp) | |
401 | { | |
402 | struct request *req; | |
403 | struct scsi_io_context *sioc; | |
404 | int err = 0; | |
405 | int write = (data_direction == DMA_TO_DEVICE); | |
406 | ||
c3762229 | 407 | sioc = kmem_cache_zalloc(scsi_io_context_cache, gfp); |
6e68af66 MC |
408 | if (!sioc) |
409 | return DRIVER_ERROR << 24; | |
410 | ||
411 | req = blk_get_request(sdev->request_queue, write, gfp); | |
412 | if (!req) | |
413 | goto free_sense; | |
4aff5e23 JA |
414 | req->cmd_type = REQ_TYPE_BLOCK_PC; |
415 | req->cmd_flags |= REQ_QUIET; | |
6e68af66 MC |
416 | |
417 | if (use_sg) | |
418 | err = scsi_req_map_sg(req, buffer, use_sg, bufflen, gfp); | |
419 | else if (bufflen) | |
420 | err = blk_rq_map_kern(req->q, req, buffer, bufflen, gfp); | |
421 | ||
422 | if (err) | |
423 | goto free_req; | |
424 | ||
bb1d1073 | 425 | req->cmd_len = cmd_len; |
097b8457 | 426 | memset(req->cmd, 0, BLK_MAX_CDB); /* ATAPI hates garbage after CDB */ |
6e68af66 MC |
427 | memcpy(req->cmd, cmd, req->cmd_len); |
428 | req->sense = sioc->sense; | |
429 | req->sense_len = 0; | |
430 | req->timeout = timeout; | |
17e01f21 | 431 | req->retries = retries; |
6e68af66 MC |
432 | req->end_io_data = sioc; |
433 | ||
434 | sioc->data = privdata; | |
435 | sioc->done = done; | |
436 | ||
437 | blk_execute_rq_nowait(req->q, NULL, req, 1, scsi_end_async); | |
438 | return 0; | |
439 | ||
440 | free_req: | |
441 | blk_put_request(req); | |
442 | free_sense: | |
6470f2ba | 443 | kmem_cache_free(scsi_io_context_cache, sioc); |
6e68af66 MC |
444 | return DRIVER_ERROR << 24; |
445 | } | |
446 | EXPORT_SYMBOL_GPL(scsi_execute_async); | |
447 | ||
1da177e4 LT |
448 | /* |
449 | * Function: scsi_init_cmd_errh() | |
450 | * | |
451 | * Purpose: Initialize cmd fields related to error handling. | |
452 | * | |
453 | * Arguments: cmd - command that is ready to be queued. | |
454 | * | |
1da177e4 LT |
455 | * Notes: This function has the job of initializing a number of |
456 | * fields related to error handling. Typically this will | |
457 | * be called once for each command, as required. | |
458 | */ | |
631c228c | 459 | static void scsi_init_cmd_errh(struct scsi_cmnd *cmd) |
1da177e4 | 460 | { |
1da177e4 | 461 | cmd->serial_number = 0; |
30b0c37b | 462 | scsi_set_resid(cmd, 0); |
b80ca4f7 | 463 | memset(cmd->sense_buffer, 0, SCSI_SENSE_BUFFERSIZE); |
1da177e4 | 464 | if (cmd->cmd_len == 0) |
db4742dd | 465 | cmd->cmd_len = scsi_command_size(cmd->cmnd); |
1da177e4 LT |
466 | } |
467 | ||
468 | void scsi_device_unbusy(struct scsi_device *sdev) | |
469 | { | |
470 | struct Scsi_Host *shost = sdev->host; | |
f0c0a376 | 471 | struct scsi_target *starget = scsi_target(sdev); |
1da177e4 LT |
472 | unsigned long flags; |
473 | ||
474 | spin_lock_irqsave(shost->host_lock, flags); | |
475 | shost->host_busy--; | |
f0c0a376 | 476 | starget->target_busy--; |
939647ee | 477 | if (unlikely(scsi_host_in_recovery(shost) && |
ee7863bc | 478 | (shost->host_failed || shost->host_eh_scheduled))) |
1da177e4 LT |
479 | scsi_eh_wakeup(shost); |
480 | spin_unlock(shost->host_lock); | |
152587de | 481 | spin_lock(sdev->request_queue->queue_lock); |
1da177e4 | 482 | sdev->device_busy--; |
152587de | 483 | spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags); |
1da177e4 LT |
484 | } |
485 | ||
486 | /* | |
487 | * Called for single_lun devices on IO completion. Clear starget_sdev_user, | |
488 | * and call blk_run_queue for all the scsi_devices on the target - | |
489 | * including current_sdev first. | |
490 | * | |
491 | * Called with *no* scsi locks held. | |
492 | */ | |
493 | static void scsi_single_lun_run(struct scsi_device *current_sdev) | |
494 | { | |
495 | struct Scsi_Host *shost = current_sdev->host; | |
496 | struct scsi_device *sdev, *tmp; | |
497 | struct scsi_target *starget = scsi_target(current_sdev); | |
498 | unsigned long flags; | |
499 | ||
500 | spin_lock_irqsave(shost->host_lock, flags); | |
501 | starget->starget_sdev_user = NULL; | |
502 | spin_unlock_irqrestore(shost->host_lock, flags); | |
503 | ||
504 | /* | |
505 | * Call blk_run_queue for all LUNs on the target, starting with | |
506 | * current_sdev. We race with others (to set starget_sdev_user), | |
507 | * but in most cases, we will be first. Ideally, each LU on the | |
508 | * target would get some limited time or requests on the target. | |
509 | */ | |
510 | blk_run_queue(current_sdev->request_queue); | |
511 | ||
512 | spin_lock_irqsave(shost->host_lock, flags); | |
513 | if (starget->starget_sdev_user) | |
514 | goto out; | |
515 | list_for_each_entry_safe(sdev, tmp, &starget->devices, | |
516 | same_target_siblings) { | |
517 | if (sdev == current_sdev) | |
518 | continue; | |
519 | if (scsi_device_get(sdev)) | |
520 | continue; | |
521 | ||
522 | spin_unlock_irqrestore(shost->host_lock, flags); | |
523 | blk_run_queue(sdev->request_queue); | |
524 | spin_lock_irqsave(shost->host_lock, flags); | |
525 | ||
526 | scsi_device_put(sdev); | |
527 | } | |
528 | out: | |
529 | spin_unlock_irqrestore(shost->host_lock, flags); | |
530 | } | |
531 | ||
9d112517 KU |
532 | static inline int scsi_device_is_busy(struct scsi_device *sdev) |
533 | { | |
534 | if (sdev->device_busy >= sdev->queue_depth || sdev->device_blocked) | |
535 | return 1; | |
536 | ||
537 | return 0; | |
538 | } | |
539 | ||
f0c0a376 MC |
540 | static inline int scsi_target_is_busy(struct scsi_target *starget) |
541 | { | |
542 | return ((starget->can_queue > 0 && | |
543 | starget->target_busy >= starget->can_queue) || | |
544 | starget->target_blocked); | |
545 | } | |
546 | ||
9d112517 KU |
547 | static inline int scsi_host_is_busy(struct Scsi_Host *shost) |
548 | { | |
549 | if ((shost->can_queue > 0 && shost->host_busy >= shost->can_queue) || | |
550 | shost->host_blocked || shost->host_self_blocked) | |
551 | return 1; | |
552 | ||
553 | return 0; | |
554 | } | |
555 | ||
1da177e4 LT |
556 | /* |
557 | * Function: scsi_run_queue() | |
558 | * | |
559 | * Purpose: Select a proper request queue to serve next | |
560 | * | |
561 | * Arguments: q - last request's queue | |
562 | * | |
563 | * Returns: Nothing | |
564 | * | |
565 | * Notes: The previous command was completely finished, start | |
566 | * a new one if possible. | |
567 | */ | |
568 | static void scsi_run_queue(struct request_queue *q) | |
569 | { | |
f0c0a376 | 570 | struct scsi_device *starved_head = NULL, *sdev = q->queuedata; |
1da177e4 LT |
571 | struct Scsi_Host *shost = sdev->host; |
572 | unsigned long flags; | |
573 | ||
25d7c363 | 574 | if (scsi_target(sdev)->single_lun) |
1da177e4 LT |
575 | scsi_single_lun_run(sdev); |
576 | ||
577 | spin_lock_irqsave(shost->host_lock, flags); | |
9d112517 | 578 | while (!list_empty(&shost->starved_list) && !scsi_host_is_busy(shost)) { |
75ad23bc NP |
579 | int flagset; |
580 | ||
1da177e4 LT |
581 | /* |
582 | * As long as shost is accepting commands and we have | |
583 | * starved queues, call blk_run_queue. scsi_request_fn | |
584 | * drops the queue_lock and can add us back to the | |
585 | * starved_list. | |
586 | * | |
587 | * host_lock protects the starved_list and starved_entry. | |
588 | * scsi_request_fn must get the host_lock before checking | |
589 | * or modifying starved_list or starved_entry. | |
590 | */ | |
591 | sdev = list_entry(shost->starved_list.next, | |
592 | struct scsi_device, starved_entry); | |
f0c0a376 MC |
593 | /* |
594 | * The *queue_ready functions can add a device back onto the | |
595 | * starved list's tail, so we must check for a infinite loop. | |
596 | */ | |
597 | if (sdev == starved_head) | |
598 | break; | |
599 | if (!starved_head) | |
600 | starved_head = sdev; | |
601 | ||
602 | if (scsi_target_is_busy(scsi_target(sdev))) { | |
603 | list_move_tail(&sdev->starved_entry, | |
604 | &shost->starved_list); | |
605 | continue; | |
606 | } | |
607 | ||
1da177e4 | 608 | list_del_init(&sdev->starved_entry); |
75ad23bc NP |
609 | spin_unlock(shost->host_lock); |
610 | ||
611 | spin_lock(sdev->request_queue->queue_lock); | |
612 | flagset = test_bit(QUEUE_FLAG_REENTER, &q->queue_flags) && | |
613 | !test_bit(QUEUE_FLAG_REENTER, | |
614 | &sdev->request_queue->queue_flags); | |
615 | if (flagset) | |
616 | queue_flag_set(QUEUE_FLAG_REENTER, sdev->request_queue); | |
617 | __blk_run_queue(sdev->request_queue); | |
618 | if (flagset) | |
619 | queue_flag_clear(QUEUE_FLAG_REENTER, sdev->request_queue); | |
620 | spin_unlock(sdev->request_queue->queue_lock); | |
04846f25 | 621 | |
75ad23bc | 622 | spin_lock(shost->host_lock); |
1da177e4 LT |
623 | } |
624 | spin_unlock_irqrestore(shost->host_lock, flags); | |
625 | ||
626 | blk_run_queue(q); | |
627 | } | |
628 | ||
629 | /* | |
630 | * Function: scsi_requeue_command() | |
631 | * | |
632 | * Purpose: Handle post-processing of completed commands. | |
633 | * | |
634 | * Arguments: q - queue to operate on | |
635 | * cmd - command that may need to be requeued. | |
636 | * | |
637 | * Returns: Nothing | |
638 | * | |
639 | * Notes: After command completion, there may be blocks left | |
640 | * over which weren't finished by the previous command | |
641 | * this can be for a number of reasons - the main one is | |
642 | * I/O errors in the middle of the request, in which case | |
643 | * we need to request the blocks that come after the bad | |
644 | * sector. | |
e91442b6 | 645 | * Notes: Upon return, cmd is a stale pointer. |
1da177e4 LT |
646 | */ |
647 | static void scsi_requeue_command(struct request_queue *q, struct scsi_cmnd *cmd) | |
648 | { | |
e91442b6 | 649 | struct request *req = cmd->request; |
283369cc TH |
650 | unsigned long flags; |
651 | ||
e91442b6 | 652 | scsi_unprep_request(req); |
283369cc | 653 | spin_lock_irqsave(q->queue_lock, flags); |
e91442b6 | 654 | blk_requeue_request(q, req); |
283369cc | 655 | spin_unlock_irqrestore(q->queue_lock, flags); |
1da177e4 LT |
656 | |
657 | scsi_run_queue(q); | |
658 | } | |
659 | ||
660 | void scsi_next_command(struct scsi_cmnd *cmd) | |
661 | { | |
49d7bc64 LT |
662 | struct scsi_device *sdev = cmd->device; |
663 | struct request_queue *q = sdev->request_queue; | |
664 | ||
665 | /* need to hold a reference on the device before we let go of the cmd */ | |
666 | get_device(&sdev->sdev_gendev); | |
1da177e4 LT |
667 | |
668 | scsi_put_command(cmd); | |
669 | scsi_run_queue(q); | |
49d7bc64 LT |
670 | |
671 | /* ok to remove device now */ | |
672 | put_device(&sdev->sdev_gendev); | |
1da177e4 LT |
673 | } |
674 | ||
675 | void scsi_run_host_queues(struct Scsi_Host *shost) | |
676 | { | |
677 | struct scsi_device *sdev; | |
678 | ||
679 | shost_for_each_device(sdev, shost) | |
680 | scsi_run_queue(sdev->request_queue); | |
681 | } | |
682 | ||
683 | /* | |
684 | * Function: scsi_end_request() | |
685 | * | |
686 | * Purpose: Post-processing of completed commands (usually invoked at end | |
687 | * of upper level post-processing and scsi_io_completion). | |
688 | * | |
689 | * Arguments: cmd - command that is complete. | |
610d8b0c | 690 | * error - 0 if I/O indicates success, < 0 for I/O error. |
1da177e4 LT |
691 | * bytes - number of bytes of completed I/O |
692 | * requeue - indicates whether we should requeue leftovers. | |
693 | * | |
694 | * Lock status: Assumed that lock is not held upon entry. | |
695 | * | |
e91442b6 | 696 | * Returns: cmd if requeue required, NULL otherwise. |
1da177e4 LT |
697 | * |
698 | * Notes: This is called for block device requests in order to | |
699 | * mark some number of sectors as complete. | |
700 | * | |
701 | * We are guaranteeing that the request queue will be goosed | |
702 | * at some point during this call. | |
e91442b6 | 703 | * Notes: If cmd was requeued, upon return it will be a stale pointer. |
1da177e4 | 704 | */ |
610d8b0c | 705 | static struct scsi_cmnd *scsi_end_request(struct scsi_cmnd *cmd, int error, |
1da177e4 LT |
706 | int bytes, int requeue) |
707 | { | |
165125e1 | 708 | struct request_queue *q = cmd->device->request_queue; |
1da177e4 | 709 | struct request *req = cmd->request; |
1da177e4 LT |
710 | |
711 | /* | |
712 | * If there are blocks left over at the end, set up the command | |
713 | * to queue the remainder of them. | |
714 | */ | |
610d8b0c | 715 | if (blk_end_request(req, error, bytes)) { |
1da177e4 LT |
716 | int leftover = (req->hard_nr_sectors << 9); |
717 | ||
718 | if (blk_pc_request(req)) | |
719 | leftover = req->data_len; | |
720 | ||
721 | /* kill remainder if no retrys */ | |
4a27446f | 722 | if (error && scsi_noretry_cmd(cmd)) |
610d8b0c | 723 | blk_end_request(req, error, leftover); |
1da177e4 | 724 | else { |
e91442b6 | 725 | if (requeue) { |
1da177e4 LT |
726 | /* |
727 | * Bleah. Leftovers again. Stick the | |
728 | * leftovers in the front of the | |
729 | * queue, and goose the queue again. | |
730 | */ | |
731 | scsi_requeue_command(q, cmd); | |
e91442b6 JB |
732 | cmd = NULL; |
733 | } | |
1da177e4 LT |
734 | return cmd; |
735 | } | |
736 | } | |
737 | ||
1da177e4 LT |
738 | /* |
739 | * This will goose the queue request function at the end, so we don't | |
740 | * need to worry about launching another command. | |
741 | */ | |
742 | scsi_next_command(cmd); | |
743 | return NULL; | |
744 | } | |
745 | ||
a8474ce2 JA |
746 | static inline unsigned int scsi_sgtable_index(unsigned short nents) |
747 | { | |
748 | unsigned int index; | |
749 | ||
d3f46f39 JB |
750 | BUG_ON(nents > SCSI_MAX_SG_SEGMENTS); |
751 | ||
752 | if (nents <= 8) | |
a8474ce2 | 753 | index = 0; |
d3f46f39 JB |
754 | else |
755 | index = get_count_order(nents) - 3; | |
1da177e4 | 756 | |
a8474ce2 JA |
757 | return index; |
758 | } | |
759 | ||
5ed7959e | 760 | static void scsi_sg_free(struct scatterlist *sgl, unsigned int nents) |
a8474ce2 JA |
761 | { |
762 | struct scsi_host_sg_pool *sgp; | |
a8474ce2 | 763 | |
5ed7959e JA |
764 | sgp = scsi_sg_pools + scsi_sgtable_index(nents); |
765 | mempool_free(sgl, sgp->pool); | |
766 | } | |
a8474ce2 | 767 | |
5ed7959e JA |
768 | static struct scatterlist *scsi_sg_alloc(unsigned int nents, gfp_t gfp_mask) |
769 | { | |
770 | struct scsi_host_sg_pool *sgp; | |
a8474ce2 | 771 | |
5ed7959e JA |
772 | sgp = scsi_sg_pools + scsi_sgtable_index(nents); |
773 | return mempool_alloc(sgp->pool, gfp_mask); | |
774 | } | |
a3bec5c5 | 775 | |
30b0c37b BH |
776 | static int scsi_alloc_sgtable(struct scsi_data_buffer *sdb, int nents, |
777 | gfp_t gfp_mask) | |
5ed7959e JA |
778 | { |
779 | int ret; | |
a8474ce2 | 780 | |
30b0c37b | 781 | BUG_ON(!nents); |
a8474ce2 | 782 | |
30b0c37b BH |
783 | ret = __sg_alloc_table(&sdb->table, nents, SCSI_MAX_SG_SEGMENTS, |
784 | gfp_mask, scsi_sg_alloc); | |
5ed7959e | 785 | if (unlikely(ret)) |
30b0c37b | 786 | __sg_free_table(&sdb->table, SCSI_MAX_SG_SEGMENTS, |
7cedb1f1 | 787 | scsi_sg_free); |
45711f1a | 788 | |
a8474ce2 | 789 | return ret; |
1da177e4 LT |
790 | } |
791 | ||
30b0c37b | 792 | static void scsi_free_sgtable(struct scsi_data_buffer *sdb) |
1da177e4 | 793 | { |
30b0c37b | 794 | __sg_free_table(&sdb->table, SCSI_MAX_SG_SEGMENTS, scsi_sg_free); |
1da177e4 LT |
795 | } |
796 | ||
797 | /* | |
798 | * Function: scsi_release_buffers() | |
799 | * | |
800 | * Purpose: Completion processing for block device I/O requests. | |
801 | * | |
802 | * Arguments: cmd - command that we are bailing. | |
803 | * | |
804 | * Lock status: Assumed that no lock is held upon entry. | |
805 | * | |
806 | * Returns: Nothing | |
807 | * | |
808 | * Notes: In the event that an upper level driver rejects a | |
809 | * command, we must release resources allocated during | |
810 | * the __init_io() function. Primarily this would involve | |
811 | * the scatter-gather table, and potentially any bounce | |
812 | * buffers. | |
813 | */ | |
bb52d82f | 814 | void scsi_release_buffers(struct scsi_cmnd *cmd) |
1da177e4 | 815 | { |
30b0c37b BH |
816 | if (cmd->sdb.table.nents) |
817 | scsi_free_sgtable(&cmd->sdb); | |
1da177e4 | 818 | |
30b0c37b | 819 | memset(&cmd->sdb, 0, sizeof(cmd->sdb)); |
6f9a35e2 BH |
820 | |
821 | if (scsi_bidi_cmnd(cmd)) { | |
822 | struct scsi_data_buffer *bidi_sdb = | |
823 | cmd->request->next_rq->special; | |
824 | scsi_free_sgtable(bidi_sdb); | |
6362abd3 | 825 | kmem_cache_free(scsi_sdb_cache, bidi_sdb); |
6f9a35e2 BH |
826 | cmd->request->next_rq->special = NULL; |
827 | } | |
7027ad72 MP |
828 | |
829 | if (scsi_prot_sg_count(cmd)) | |
830 | scsi_free_sgtable(cmd->prot_sdb); | |
1da177e4 | 831 | } |
bb52d82f | 832 | EXPORT_SYMBOL(scsi_release_buffers); |
1da177e4 | 833 | |
6f9a35e2 BH |
834 | /* |
835 | * Bidi commands Must be complete as a whole, both sides at once. | |
836 | * If part of the bytes were written and lld returned | |
837 | * scsi_in()->resid and/or scsi_out()->resid this information will be left | |
838 | * in req->data_len and req->next_rq->data_len. The upper-layer driver can | |
839 | * decide what to do with this information. | |
840 | */ | |
8c5e03d3 | 841 | static void scsi_end_bidi_request(struct scsi_cmnd *cmd) |
6f9a35e2 | 842 | { |
b8de1631 KU |
843 | struct request *req = cmd->request; |
844 | unsigned int dlen = req->data_len; | |
845 | unsigned int next_dlen = req->next_rq->data_len; | |
846 | ||
847 | req->data_len = scsi_out(cmd)->resid; | |
848 | req->next_rq->data_len = scsi_in(cmd)->resid; | |
849 | ||
850 | /* The req and req->next_rq have not been completed */ | |
851 | BUG_ON(blk_end_bidi_request(req, 0, dlen, next_dlen)); | |
852 | ||
6f9a35e2 BH |
853 | scsi_release_buffers(cmd); |
854 | ||
855 | /* | |
856 | * This will goose the queue request function at the end, so we don't | |
857 | * need to worry about launching another command. | |
858 | */ | |
859 | scsi_next_command(cmd); | |
860 | } | |
861 | ||
1da177e4 LT |
862 | /* |
863 | * Function: scsi_io_completion() | |
864 | * | |
865 | * Purpose: Completion processing for block device I/O requests. | |
866 | * | |
867 | * Arguments: cmd - command that is finished. | |
868 | * | |
869 | * Lock status: Assumed that no lock is held upon entry. | |
870 | * | |
871 | * Returns: Nothing | |
872 | * | |
873 | * Notes: This function is matched in terms of capabilities to | |
874 | * the function that created the scatter-gather list. | |
875 | * In other words, if there are no bounce buffers | |
876 | * (the normal case for most drivers), we don't need | |
877 | * the logic to deal with cleaning up afterwards. | |
878 | * | |
879 | * We must do one of several things here: | |
880 | * | |
881 | * a) Call scsi_end_request. This will finish off the | |
882 | * specified number of sectors. If we are done, the | |
883 | * command block will be released, and the queue | |
884 | * function will be goosed. If we are not done, then | |
885 | * scsi_end_request will directly goose the queue. | |
886 | * | |
887 | * b) We can just use scsi_requeue_command() here. This would | |
888 | * be used if we just wanted to retry, for example. | |
889 | */ | |
03aba2f7 | 890 | void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes) |
1da177e4 LT |
891 | { |
892 | int result = cmd->result; | |
44ea91c5 | 893 | int this_count; |
165125e1 | 894 | struct request_queue *q = cmd->device->request_queue; |
1da177e4 | 895 | struct request *req = cmd->request; |
fa8e36c3 | 896 | int error = 0; |
1da177e4 LT |
897 | struct scsi_sense_hdr sshdr; |
898 | int sense_valid = 0; | |
899 | int sense_deferred = 0; | |
900 | ||
1da177e4 LT |
901 | if (result) { |
902 | sense_valid = scsi_command_normalize_sense(cmd, &sshdr); | |
903 | if (sense_valid) | |
904 | sense_deferred = scsi_sense_is_deferred(&sshdr); | |
905 | } | |
631c228c | 906 | |
1da177e4 LT |
907 | if (blk_pc_request(req)) { /* SG_IO ioctl from block level */ |
908 | req->errors = result; | |
909 | if (result) { | |
1da177e4 LT |
910 | if (sense_valid && req->sense) { |
911 | /* | |
912 | * SG_IO wants current and deferred errors | |
913 | */ | |
914 | int len = 8 + cmd->sense_buffer[7]; | |
915 | ||
916 | if (len > SCSI_SENSE_BUFFERSIZE) | |
917 | len = SCSI_SENSE_BUFFERSIZE; | |
918 | memcpy(req->sense, cmd->sense_buffer, len); | |
919 | req->sense_len = len; | |
920 | } | |
fa8e36c3 JB |
921 | if (!sense_deferred) |
922 | error = -EIO; | |
b22f687d | 923 | } |
6f9a35e2 BH |
924 | if (scsi_bidi_cmnd(cmd)) { |
925 | /* will also release_buffers */ | |
926 | scsi_end_bidi_request(cmd); | |
927 | return; | |
928 | } | |
30b0c37b | 929 | req->data_len = scsi_get_resid(cmd); |
1da177e4 LT |
930 | } |
931 | ||
6f9a35e2 | 932 | BUG_ON(blk_bidi_rq(req)); /* bidi not support for !blk_pc_request yet */ |
30b0c37b BH |
933 | scsi_release_buffers(cmd); |
934 | ||
1da177e4 LT |
935 | /* |
936 | * Next deal with any sectors which we were able to correctly | |
937 | * handle. | |
938 | */ | |
d6b0c537 JB |
939 | SCSI_LOG_HLCOMPLETE(1, printk("%ld sectors total, " |
940 | "%d bytes done.\n", | |
941 | req->nr_sectors, good_bytes)); | |
d6b0c537 | 942 | |
d6b0c537 JB |
943 | /* A number of bytes were successfully read. If there |
944 | * are leftovers and there is some kind of error | |
945 | * (result != 0), retry the rest. | |
946 | */ | |
fa8e36c3 | 947 | if (scsi_end_request(cmd, error, good_bytes, result == 0) == NULL) |
d6b0c537 | 948 | return; |
44ea91c5 | 949 | this_count = blk_rq_bytes(req); |
03aba2f7 LT |
950 | |
951 | /* good_bytes = 0, or (inclusive) there were leftovers and | |
952 | * result = 0, so scsi_end_request couldn't retry. | |
1da177e4 LT |
953 | */ |
954 | if (sense_valid && !sense_deferred) { | |
955 | switch (sshdr.sense_key) { | |
956 | case UNIT_ATTENTION: | |
957 | if (cmd->device->removable) { | |
03aba2f7 | 958 | /* Detected disc change. Set a bit |
1da177e4 LT |
959 | * and quietly refuse further access. |
960 | */ | |
961 | cmd->device->changed = 1; | |
610d8b0c | 962 | scsi_end_request(cmd, -EIO, this_count, 1); |
1da177e4 LT |
963 | return; |
964 | } else { | |
03aba2f7 LT |
965 | /* Must have been a power glitch, or a |
966 | * bus reset. Could not have been a | |
967 | * media change, so we just retry the | |
968 | * request and see what happens. | |
969 | */ | |
1da177e4 LT |
970 | scsi_requeue_command(q, cmd); |
971 | return; | |
972 | } | |
973 | break; | |
974 | case ILLEGAL_REQUEST: | |
03aba2f7 LT |
975 | /* If we had an ILLEGAL REQUEST returned, then |
976 | * we may have performed an unsupported | |
977 | * command. The only thing this should be | |
978 | * would be a ten byte read where only a six | |
979 | * byte read was supported. Also, on a system | |
980 | * where READ CAPACITY failed, we may have | |
981 | * read past the end of the disk. | |
982 | */ | |
26a68019 JA |
983 | if ((cmd->device->use_10_for_rw && |
984 | sshdr.asc == 0x20 && sshdr.ascq == 0x00) && | |
1da177e4 LT |
985 | (cmd->cmnd[0] == READ_10 || |
986 | cmd->cmnd[0] == WRITE_10)) { | |
987 | cmd->device->use_10_for_rw = 0; | |
03aba2f7 LT |
988 | /* This will cause a retry with a |
989 | * 6-byte command. | |
1da177e4 LT |
990 | */ |
991 | scsi_requeue_command(q, cmd); | |
511e44f4 MP |
992 | } else if (sshdr.asc == 0x10) /* DIX */ |
993 | scsi_end_request(cmd, -EIO, this_count, 0); | |
994 | else | |
610d8b0c | 995 | scsi_end_request(cmd, -EIO, this_count, 1); |
511e44f4 MP |
996 | return; |
997 | case ABORTED_COMMAND: | |
998 | if (sshdr.asc == 0x10) { /* DIF */ | |
999 | scsi_end_request(cmd, -EIO, this_count, 0); | |
1da177e4 LT |
1000 | return; |
1001 | } | |
1002 | break; | |
1003 | case NOT_READY: | |
03aba2f7 | 1004 | /* If the device is in the process of becoming |
f3e93f73 | 1005 | * ready, or has a temporary blockage, retry. |
1da177e4 | 1006 | */ |
f3e93f73 JB |
1007 | if (sshdr.asc == 0x04) { |
1008 | switch (sshdr.ascq) { | |
1009 | case 0x01: /* becoming ready */ | |
1010 | case 0x04: /* format in progress */ | |
1011 | case 0x05: /* rebuild in progress */ | |
1012 | case 0x06: /* recalculation in progress */ | |
1013 | case 0x07: /* operation in progress */ | |
1014 | case 0x08: /* Long write in progress */ | |
1015 | case 0x09: /* self test in progress */ | |
1016 | scsi_requeue_command(q, cmd); | |
1017 | return; | |
1018 | default: | |
1019 | break; | |
1020 | } | |
1da177e4 | 1021 | } |
311b581e JB |
1022 | if (!(req->cmd_flags & REQ_QUIET)) |
1023 | scsi_cmd_print_sense_hdr(cmd, | |
1024 | "Device not ready", | |
1025 | &sshdr); | |
1026 | ||
610d8b0c | 1027 | scsi_end_request(cmd, -EIO, this_count, 1); |
1da177e4 LT |
1028 | return; |
1029 | case VOLUME_OVERFLOW: | |
4aff5e23 | 1030 | if (!(req->cmd_flags & REQ_QUIET)) { |
3bf743e7 | 1031 | scmd_printk(KERN_INFO, cmd, |
03aba2f7 | 1032 | "Volume overflow, CDB: "); |
631c228c | 1033 | __scsi_print_command(cmd->cmnd); |
3173d8c3 JB |
1034 | scsi_print_sense("", cmd); |
1035 | } | |
03aba2f7 | 1036 | /* See SSC3rXX or current. */ |
610d8b0c | 1037 | scsi_end_request(cmd, -EIO, this_count, 1); |
1da177e4 LT |
1038 | return; |
1039 | default: | |
1040 | break; | |
1041 | } | |
03aba2f7 | 1042 | } |
1da177e4 | 1043 | if (host_byte(result) == DID_RESET) { |
03aba2f7 LT |
1044 | /* Third party bus reset or reset for error recovery |
1045 | * reasons. Just retry the request and see what | |
1046 | * happens. | |
1da177e4 LT |
1047 | */ |
1048 | scsi_requeue_command(q, cmd); | |
1049 | return; | |
1050 | } | |
1051 | if (result) { | |
4aff5e23 | 1052 | if (!(req->cmd_flags & REQ_QUIET)) { |
a4d04a4c | 1053 | scsi_print_result(cmd); |
3173d8c3 JB |
1054 | if (driver_byte(result) & DRIVER_SENSE) |
1055 | scsi_print_sense("", cmd); | |
1056 | } | |
1da177e4 | 1057 | } |
610d8b0c | 1058 | scsi_end_request(cmd, -EIO, this_count, !result); |
1da177e4 | 1059 | } |
1da177e4 | 1060 | |
6f9a35e2 BH |
1061 | static int scsi_init_sgtable(struct request *req, struct scsi_data_buffer *sdb, |
1062 | gfp_t gfp_mask) | |
1da177e4 | 1063 | { |
6f9a35e2 | 1064 | int count; |
1da177e4 LT |
1065 | |
1066 | /* | |
3b003157 | 1067 | * If sg table allocation fails, requeue request later. |
1da177e4 | 1068 | */ |
30b0c37b BH |
1069 | if (unlikely(scsi_alloc_sgtable(sdb, req->nr_phys_segments, |
1070 | gfp_mask))) { | |
1da177e4 | 1071 | return BLKPREP_DEFER; |
7c72ce81 | 1072 | } |
1da177e4 | 1073 | |
3b003157 | 1074 | req->buffer = NULL; |
1da177e4 LT |
1075 | |
1076 | /* | |
1077 | * Next, walk the list, and fill in the addresses and sizes of | |
1078 | * each segment. | |
1079 | */ | |
30b0c37b BH |
1080 | count = blk_rq_map_sg(req->q, req, sdb->table.sgl); |
1081 | BUG_ON(count > sdb->table.nents); | |
1082 | sdb->table.nents = count; | |
6b00769f TH |
1083 | if (blk_pc_request(req)) |
1084 | sdb->length = req->data_len; | |
1085 | else | |
1086 | sdb->length = req->nr_sectors << 9; | |
4a03d90e | 1087 | return BLKPREP_OK; |
1da177e4 | 1088 | } |
6f9a35e2 BH |
1089 | |
1090 | /* | |
1091 | * Function: scsi_init_io() | |
1092 | * | |
1093 | * Purpose: SCSI I/O initialize function. | |
1094 | * | |
1095 | * Arguments: cmd - Command descriptor we wish to initialize | |
1096 | * | |
1097 | * Returns: 0 on success | |
1098 | * BLKPREP_DEFER if the failure is retryable | |
1099 | * BLKPREP_KILL if the failure is fatal | |
1100 | */ | |
1101 | int scsi_init_io(struct scsi_cmnd *cmd, gfp_t gfp_mask) | |
1102 | { | |
1103 | int error = scsi_init_sgtable(cmd->request, &cmd->sdb, gfp_mask); | |
1104 | if (error) | |
1105 | goto err_exit; | |
1106 | ||
1107 | if (blk_bidi_rq(cmd->request)) { | |
1108 | struct scsi_data_buffer *bidi_sdb = kmem_cache_zalloc( | |
6362abd3 | 1109 | scsi_sdb_cache, GFP_ATOMIC); |
6f9a35e2 BH |
1110 | if (!bidi_sdb) { |
1111 | error = BLKPREP_DEFER; | |
1112 | goto err_exit; | |
1113 | } | |
1114 | ||
1115 | cmd->request->next_rq->special = bidi_sdb; | |
1116 | error = scsi_init_sgtable(cmd->request->next_rq, bidi_sdb, | |
1117 | GFP_ATOMIC); | |
1118 | if (error) | |
1119 | goto err_exit; | |
1120 | } | |
1121 | ||
7027ad72 MP |
1122 | if (blk_integrity_rq(cmd->request)) { |
1123 | struct scsi_data_buffer *prot_sdb = cmd->prot_sdb; | |
1124 | int ivecs, count; | |
1125 | ||
1126 | BUG_ON(prot_sdb == NULL); | |
1127 | ivecs = blk_rq_count_integrity_sg(cmd->request); | |
1128 | ||
1129 | if (scsi_alloc_sgtable(prot_sdb, ivecs, gfp_mask)) { | |
1130 | error = BLKPREP_DEFER; | |
1131 | goto err_exit; | |
1132 | } | |
1133 | ||
1134 | count = blk_rq_map_integrity_sg(cmd->request, | |
1135 | prot_sdb->table.sgl); | |
1136 | BUG_ON(unlikely(count > ivecs)); | |
1137 | ||
1138 | cmd->prot_sdb = prot_sdb; | |
1139 | cmd->prot_sdb->table.nents = count; | |
1140 | } | |
1141 | ||
6f9a35e2 BH |
1142 | return BLKPREP_OK ; |
1143 | ||
1144 | err_exit: | |
1145 | scsi_release_buffers(cmd); | |
1146 | if (error == BLKPREP_KILL) | |
1147 | scsi_put_command(cmd); | |
1148 | else /* BLKPREP_DEFER */ | |
1149 | scsi_unprep_request(cmd->request); | |
1150 | ||
1151 | return error; | |
1152 | } | |
bb52d82f | 1153 | EXPORT_SYMBOL(scsi_init_io); |
1da177e4 | 1154 | |
3b003157 CH |
1155 | static struct scsi_cmnd *scsi_get_cmd_from_req(struct scsi_device *sdev, |
1156 | struct request *req) | |
1157 | { | |
1158 | struct scsi_cmnd *cmd; | |
1159 | ||
1160 | if (!req->special) { | |
1161 | cmd = scsi_get_command(sdev, GFP_ATOMIC); | |
1162 | if (unlikely(!cmd)) | |
1163 | return NULL; | |
1164 | req->special = cmd; | |
1165 | } else { | |
1166 | cmd = req->special; | |
1167 | } | |
1168 | ||
1169 | /* pull a tag out of the request if we have one */ | |
1170 | cmd->tag = req->tag; | |
1171 | cmd->request = req; | |
1172 | ||
64a87b24 BH |
1173 | cmd->cmnd = req->cmd; |
1174 | ||
3b003157 CH |
1175 | return cmd; |
1176 | } | |
1177 | ||
7f9a6bc4 | 1178 | int scsi_setup_blk_pc_cmnd(struct scsi_device *sdev, struct request *req) |
7b16318d | 1179 | { |
3b003157 | 1180 | struct scsi_cmnd *cmd; |
7f9a6bc4 JB |
1181 | int ret = scsi_prep_state_check(sdev, req); |
1182 | ||
1183 | if (ret != BLKPREP_OK) | |
1184 | return ret; | |
3b003157 CH |
1185 | |
1186 | cmd = scsi_get_cmd_from_req(sdev, req); | |
1187 | if (unlikely(!cmd)) | |
1188 | return BLKPREP_DEFER; | |
1189 | ||
1190 | /* | |
1191 | * BLOCK_PC requests may transfer data, in which case they must | |
1192 | * a bio attached to them. Or they might contain a SCSI command | |
1193 | * that does not transfer data, in which case they may optionally | |
1194 | * submit a request without an attached bio. | |
1195 | */ | |
1196 | if (req->bio) { | |
1197 | int ret; | |
1198 | ||
1199 | BUG_ON(!req->nr_phys_segments); | |
1200 | ||
bb52d82f | 1201 | ret = scsi_init_io(cmd, GFP_ATOMIC); |
3b003157 CH |
1202 | if (unlikely(ret)) |
1203 | return ret; | |
1204 | } else { | |
1205 | BUG_ON(req->data_len); | |
1206 | BUG_ON(req->data); | |
1207 | ||
30b0c37b | 1208 | memset(&cmd->sdb, 0, sizeof(cmd->sdb)); |
3b003157 CH |
1209 | req->buffer = NULL; |
1210 | } | |
7b16318d | 1211 | |
7b16318d JB |
1212 | cmd->cmd_len = req->cmd_len; |
1213 | if (!req->data_len) | |
1214 | cmd->sc_data_direction = DMA_NONE; | |
1215 | else if (rq_data_dir(req) == WRITE) | |
1216 | cmd->sc_data_direction = DMA_TO_DEVICE; | |
1217 | else | |
1218 | cmd->sc_data_direction = DMA_FROM_DEVICE; | |
1219 | ||
1220 | cmd->transfersize = req->data_len; | |
1221 | cmd->allowed = req->retries; | |
3b003157 | 1222 | return BLKPREP_OK; |
7b16318d | 1223 | } |
7f9a6bc4 | 1224 | EXPORT_SYMBOL(scsi_setup_blk_pc_cmnd); |
7b16318d | 1225 | |
3b003157 CH |
1226 | /* |
1227 | * Setup a REQ_TYPE_FS command. These are simple read/write request | |
1228 | * from filesystems that still need to be translated to SCSI CDBs from | |
1229 | * the ULD. | |
1230 | */ | |
7f9a6bc4 | 1231 | int scsi_setup_fs_cmnd(struct scsi_device *sdev, struct request *req) |
1da177e4 | 1232 | { |
1da177e4 | 1233 | struct scsi_cmnd *cmd; |
7f9a6bc4 | 1234 | int ret = scsi_prep_state_check(sdev, req); |
1da177e4 | 1235 | |
7f9a6bc4 JB |
1236 | if (ret != BLKPREP_OK) |
1237 | return ret; | |
a6a8d9f8 CS |
1238 | |
1239 | if (unlikely(sdev->scsi_dh_data && sdev->scsi_dh_data->scsi_dh | |
1240 | && sdev->scsi_dh_data->scsi_dh->prep_fn)) { | |
1241 | ret = sdev->scsi_dh_data->scsi_dh->prep_fn(sdev, req); | |
1242 | if (ret != BLKPREP_OK) | |
1243 | return ret; | |
1244 | } | |
1245 | ||
1da177e4 | 1246 | /* |
3b003157 | 1247 | * Filesystem requests must transfer data. |
1da177e4 | 1248 | */ |
3b003157 CH |
1249 | BUG_ON(!req->nr_phys_segments); |
1250 | ||
1251 | cmd = scsi_get_cmd_from_req(sdev, req); | |
1252 | if (unlikely(!cmd)) | |
1253 | return BLKPREP_DEFER; | |
1254 | ||
64a87b24 | 1255 | memset(cmd->cmnd, 0, BLK_MAX_CDB); |
bb52d82f | 1256 | return scsi_init_io(cmd, GFP_ATOMIC); |
3b003157 | 1257 | } |
7f9a6bc4 | 1258 | EXPORT_SYMBOL(scsi_setup_fs_cmnd); |
3b003157 | 1259 | |
7f9a6bc4 | 1260 | int scsi_prep_state_check(struct scsi_device *sdev, struct request *req) |
3b003157 | 1261 | { |
3b003157 CH |
1262 | int ret = BLKPREP_OK; |
1263 | ||
1da177e4 | 1264 | /* |
3b003157 CH |
1265 | * If the device is not in running state we will reject some |
1266 | * or all commands. | |
1da177e4 | 1267 | */ |
3b003157 CH |
1268 | if (unlikely(sdev->sdev_state != SDEV_RUNNING)) { |
1269 | switch (sdev->sdev_state) { | |
1270 | case SDEV_OFFLINE: | |
1271 | /* | |
1272 | * If the device is offline we refuse to process any | |
1273 | * commands. The device must be brought online | |
1274 | * before trying any recovery commands. | |
1275 | */ | |
1276 | sdev_printk(KERN_ERR, sdev, | |
1277 | "rejecting I/O to offline device\n"); | |
1278 | ret = BLKPREP_KILL; | |
1279 | break; | |
1280 | case SDEV_DEL: | |
1281 | /* | |
1282 | * If the device is fully deleted, we refuse to | |
1283 | * process any commands as well. | |
1284 | */ | |
9ccfc756 | 1285 | sdev_printk(KERN_ERR, sdev, |
3b003157 CH |
1286 | "rejecting I/O to dead device\n"); |
1287 | ret = BLKPREP_KILL; | |
1288 | break; | |
1289 | case SDEV_QUIESCE: | |
1290 | case SDEV_BLOCK: | |
6f4267e3 | 1291 | case SDEV_CREATED_BLOCK: |
3b003157 CH |
1292 | /* |
1293 | * If the devices is blocked we defer normal commands. | |
1294 | */ | |
1295 | if (!(req->cmd_flags & REQ_PREEMPT)) | |
1296 | ret = BLKPREP_DEFER; | |
1297 | break; | |
1298 | default: | |
1299 | /* | |
1300 | * For any other not fully online state we only allow | |
1301 | * special commands. In particular any user initiated | |
1302 | * command is not allowed. | |
1303 | */ | |
1304 | if (!(req->cmd_flags & REQ_PREEMPT)) | |
1305 | ret = BLKPREP_KILL; | |
1306 | break; | |
1da177e4 | 1307 | } |
1da177e4 | 1308 | } |
7f9a6bc4 JB |
1309 | return ret; |
1310 | } | |
1311 | EXPORT_SYMBOL(scsi_prep_state_check); | |
1da177e4 | 1312 | |
7f9a6bc4 JB |
1313 | int scsi_prep_return(struct request_queue *q, struct request *req, int ret) |
1314 | { | |
1315 | struct scsi_device *sdev = q->queuedata; | |
1da177e4 | 1316 | |
3b003157 CH |
1317 | switch (ret) { |
1318 | case BLKPREP_KILL: | |
1319 | req->errors = DID_NO_CONNECT << 16; | |
7f9a6bc4 JB |
1320 | /* release the command and kill it */ |
1321 | if (req->special) { | |
1322 | struct scsi_cmnd *cmd = req->special; | |
1323 | scsi_release_buffers(cmd); | |
1324 | scsi_put_command(cmd); | |
1325 | req->special = NULL; | |
1326 | } | |
3b003157 CH |
1327 | break; |
1328 | case BLKPREP_DEFER: | |
1da177e4 | 1329 | /* |
3b003157 CH |
1330 | * If we defer, the elv_next_request() returns NULL, but the |
1331 | * queue must be restarted, so we plug here if no returning | |
1332 | * command will automatically do that. | |
1da177e4 | 1333 | */ |
3b003157 CH |
1334 | if (sdev->device_busy == 0) |
1335 | blk_plug_device(q); | |
1336 | break; | |
1337 | default: | |
1338 | req->cmd_flags |= REQ_DONTPREP; | |
1da177e4 LT |
1339 | } |
1340 | ||
3b003157 | 1341 | return ret; |
1da177e4 | 1342 | } |
7f9a6bc4 JB |
1343 | EXPORT_SYMBOL(scsi_prep_return); |
1344 | ||
751bf4d7 | 1345 | int scsi_prep_fn(struct request_queue *q, struct request *req) |
7f9a6bc4 JB |
1346 | { |
1347 | struct scsi_device *sdev = q->queuedata; | |
1348 | int ret = BLKPREP_KILL; | |
1349 | ||
1350 | if (req->cmd_type == REQ_TYPE_BLOCK_PC) | |
1351 | ret = scsi_setup_blk_pc_cmnd(sdev, req); | |
1352 | return scsi_prep_return(q, req, ret); | |
1353 | } | |
1da177e4 LT |
1354 | |
1355 | /* | |
1356 | * scsi_dev_queue_ready: if we can send requests to sdev, return 1 else | |
1357 | * return 0. | |
1358 | * | |
1359 | * Called with the queue_lock held. | |
1360 | */ | |
1361 | static inline int scsi_dev_queue_ready(struct request_queue *q, | |
1362 | struct scsi_device *sdev) | |
1363 | { | |
1da177e4 LT |
1364 | if (sdev->device_busy == 0 && sdev->device_blocked) { |
1365 | /* | |
1366 | * unblock after device_blocked iterates to zero | |
1367 | */ | |
1368 | if (--sdev->device_blocked == 0) { | |
1369 | SCSI_LOG_MLQUEUE(3, | |
9ccfc756 JB |
1370 | sdev_printk(KERN_INFO, sdev, |
1371 | "unblocking device at zero depth\n")); | |
1da177e4 LT |
1372 | } else { |
1373 | blk_plug_device(q); | |
1374 | return 0; | |
1375 | } | |
1376 | } | |
9d112517 | 1377 | if (scsi_device_is_busy(sdev)) |
1da177e4 LT |
1378 | return 0; |
1379 | ||
1380 | return 1; | |
1381 | } | |
1382 | ||
f0c0a376 MC |
1383 | |
1384 | /* | |
1385 | * scsi_target_queue_ready: checks if there we can send commands to target | |
1386 | * @sdev: scsi device on starget to check. | |
1387 | * | |
1388 | * Called with the host lock held. | |
1389 | */ | |
1390 | static inline int scsi_target_queue_ready(struct Scsi_Host *shost, | |
1391 | struct scsi_device *sdev) | |
1392 | { | |
1393 | struct scsi_target *starget = scsi_target(sdev); | |
1394 | ||
1395 | if (starget->single_lun) { | |
1396 | if (starget->starget_sdev_user && | |
1397 | starget->starget_sdev_user != sdev) | |
1398 | return 0; | |
1399 | starget->starget_sdev_user = sdev; | |
1400 | } | |
1401 | ||
1402 | if (starget->target_busy == 0 && starget->target_blocked) { | |
1403 | /* | |
1404 | * unblock after target_blocked iterates to zero | |
1405 | */ | |
1406 | if (--starget->target_blocked == 0) { | |
1407 | SCSI_LOG_MLQUEUE(3, starget_printk(KERN_INFO, starget, | |
1408 | "unblocking target at zero depth\n")); | |
1409 | } else { | |
1410 | blk_plug_device(sdev->request_queue); | |
1411 | return 0; | |
1412 | } | |
1413 | } | |
1414 | ||
1415 | if (scsi_target_is_busy(starget)) { | |
1416 | if (list_empty(&sdev->starved_entry)) { | |
1417 | list_add_tail(&sdev->starved_entry, | |
1418 | &shost->starved_list); | |
1419 | return 0; | |
1420 | } | |
1421 | } | |
1422 | ||
1423 | /* We're OK to process the command, so we can't be starved */ | |
1424 | if (!list_empty(&sdev->starved_entry)) | |
1425 | list_del_init(&sdev->starved_entry); | |
1426 | return 1; | |
1427 | } | |
1428 | ||
1da177e4 LT |
1429 | /* |
1430 | * scsi_host_queue_ready: if we can send requests to shost, return 1 else | |
1431 | * return 0. We must end up running the queue again whenever 0 is | |
1432 | * returned, else IO can hang. | |
1433 | * | |
1434 | * Called with host_lock held. | |
1435 | */ | |
1436 | static inline int scsi_host_queue_ready(struct request_queue *q, | |
1437 | struct Scsi_Host *shost, | |
1438 | struct scsi_device *sdev) | |
1439 | { | |
939647ee | 1440 | if (scsi_host_in_recovery(shost)) |
1da177e4 LT |
1441 | return 0; |
1442 | if (shost->host_busy == 0 && shost->host_blocked) { | |
1443 | /* | |
1444 | * unblock after host_blocked iterates to zero | |
1445 | */ | |
1446 | if (--shost->host_blocked == 0) { | |
1447 | SCSI_LOG_MLQUEUE(3, | |
1448 | printk("scsi%d unblocking host at zero depth\n", | |
1449 | shost->host_no)); | |
1450 | } else { | |
1da177e4 LT |
1451 | return 0; |
1452 | } | |
1453 | } | |
9d112517 | 1454 | if (scsi_host_is_busy(shost)) { |
1da177e4 LT |
1455 | if (list_empty(&sdev->starved_entry)) |
1456 | list_add_tail(&sdev->starved_entry, &shost->starved_list); | |
1457 | return 0; | |
1458 | } | |
1459 | ||
1460 | /* We're OK to process the command, so we can't be starved */ | |
1461 | if (!list_empty(&sdev->starved_entry)) | |
1462 | list_del_init(&sdev->starved_entry); | |
1463 | ||
1464 | return 1; | |
1465 | } | |
1466 | ||
6c5121b7 KU |
1467 | /* |
1468 | * Busy state exporting function for request stacking drivers. | |
1469 | * | |
1470 | * For efficiency, no lock is taken to check the busy state of | |
1471 | * shost/starget/sdev, since the returned value is not guaranteed and | |
1472 | * may be changed after request stacking drivers call the function, | |
1473 | * regardless of taking lock or not. | |
1474 | * | |
1475 | * When scsi can't dispatch I/Os anymore and needs to kill I/Os | |
1476 | * (e.g. !sdev), scsi needs to return 'not busy'. | |
1477 | * Otherwise, request stacking drivers may hold requests forever. | |
1478 | */ | |
1479 | static int scsi_lld_busy(struct request_queue *q) | |
1480 | { | |
1481 | struct scsi_device *sdev = q->queuedata; | |
1482 | struct Scsi_Host *shost; | |
1483 | struct scsi_target *starget; | |
1484 | ||
1485 | if (!sdev) | |
1486 | return 0; | |
1487 | ||
1488 | shost = sdev->host; | |
1489 | starget = scsi_target(sdev); | |
1490 | ||
1491 | if (scsi_host_in_recovery(shost) || scsi_host_is_busy(shost) || | |
1492 | scsi_target_is_busy(starget) || scsi_device_is_busy(sdev)) | |
1493 | return 1; | |
1494 | ||
1495 | return 0; | |
1496 | } | |
1497 | ||
1da177e4 | 1498 | /* |
e91442b6 | 1499 | * Kill a request for a dead device |
1da177e4 | 1500 | */ |
165125e1 | 1501 | static void scsi_kill_request(struct request *req, struct request_queue *q) |
1da177e4 | 1502 | { |
e91442b6 | 1503 | struct scsi_cmnd *cmd = req->special; |
e36e0c80 | 1504 | struct scsi_device *sdev = cmd->device; |
f0c0a376 | 1505 | struct scsi_target *starget = scsi_target(sdev); |
e36e0c80 | 1506 | struct Scsi_Host *shost = sdev->host; |
1da177e4 | 1507 | |
788ce43a JB |
1508 | blkdev_dequeue_request(req); |
1509 | ||
e91442b6 JB |
1510 | if (unlikely(cmd == NULL)) { |
1511 | printk(KERN_CRIT "impossible request in %s.\n", | |
cadbd4a5 | 1512 | __func__); |
e91442b6 | 1513 | BUG(); |
1da177e4 | 1514 | } |
e91442b6 JB |
1515 | |
1516 | scsi_init_cmd_errh(cmd); | |
1517 | cmd->result = DID_NO_CONNECT << 16; | |
1518 | atomic_inc(&cmd->device->iorequest_cnt); | |
e36e0c80 TH |
1519 | |
1520 | /* | |
1521 | * SCSI request completion path will do scsi_device_unbusy(), | |
1522 | * bump busy counts. To bump the counters, we need to dance | |
1523 | * with the locks as normal issue path does. | |
1524 | */ | |
1525 | sdev->device_busy++; | |
1526 | spin_unlock(sdev->request_queue->queue_lock); | |
1527 | spin_lock(shost->host_lock); | |
1528 | shost->host_busy++; | |
f0c0a376 | 1529 | starget->target_busy++; |
e36e0c80 TH |
1530 | spin_unlock(shost->host_lock); |
1531 | spin_lock(sdev->request_queue->queue_lock); | |
1532 | ||
242f9dcb | 1533 | blk_complete_request(req); |
1da177e4 LT |
1534 | } |
1535 | ||
1aea6434 JA |
1536 | static void scsi_softirq_done(struct request *rq) |
1537 | { | |
242f9dcb JA |
1538 | struct scsi_cmnd *cmd = rq->special; |
1539 | unsigned long wait_for = (cmd->allowed + 1) * rq->timeout; | |
1aea6434 JA |
1540 | int disposition; |
1541 | ||
1542 | INIT_LIST_HEAD(&cmd->eh_entry); | |
1543 | ||
242f9dcb JA |
1544 | /* |
1545 | * Set the serial numbers back to zero | |
1546 | */ | |
1547 | cmd->serial_number = 0; | |
1548 | ||
1549 | atomic_inc(&cmd->device->iodone_cnt); | |
1550 | if (cmd->result) | |
1551 | atomic_inc(&cmd->device->ioerr_cnt); | |
1552 | ||
1aea6434 JA |
1553 | disposition = scsi_decide_disposition(cmd); |
1554 | if (disposition != SUCCESS && | |
1555 | time_before(cmd->jiffies_at_alloc + wait_for, jiffies)) { | |
1556 | sdev_printk(KERN_ERR, cmd->device, | |
1557 | "timing out command, waited %lus\n", | |
1558 | wait_for/HZ); | |
1559 | disposition = SUCCESS; | |
1560 | } | |
1561 | ||
1562 | scsi_log_completion(cmd, disposition); | |
1563 | ||
1564 | switch (disposition) { | |
1565 | case SUCCESS: | |
1566 | scsi_finish_command(cmd); | |
1567 | break; | |
1568 | case NEEDS_RETRY: | |
596f482a | 1569 | scsi_queue_insert(cmd, SCSI_MLQUEUE_EH_RETRY); |
1aea6434 JA |
1570 | break; |
1571 | case ADD_TO_MLQUEUE: | |
1572 | scsi_queue_insert(cmd, SCSI_MLQUEUE_DEVICE_BUSY); | |
1573 | break; | |
1574 | default: | |
1575 | if (!scsi_eh_scmd_add(cmd, 0)) | |
1576 | scsi_finish_command(cmd); | |
1577 | } | |
1578 | } | |
1579 | ||
1da177e4 LT |
1580 | /* |
1581 | * Function: scsi_request_fn() | |
1582 | * | |
1583 | * Purpose: Main strategy routine for SCSI. | |
1584 | * | |
1585 | * Arguments: q - Pointer to actual queue. | |
1586 | * | |
1587 | * Returns: Nothing | |
1588 | * | |
1589 | * Lock status: IO request lock assumed to be held when called. | |
1590 | */ | |
1591 | static void scsi_request_fn(struct request_queue *q) | |
1592 | { | |
1593 | struct scsi_device *sdev = q->queuedata; | |
1594 | struct Scsi_Host *shost; | |
1595 | struct scsi_cmnd *cmd; | |
1596 | struct request *req; | |
1597 | ||
1598 | if (!sdev) { | |
1599 | printk("scsi: killing requests for dead queue\n"); | |
e91442b6 JB |
1600 | while ((req = elv_next_request(q)) != NULL) |
1601 | scsi_kill_request(req, q); | |
1da177e4 LT |
1602 | return; |
1603 | } | |
1604 | ||
1605 | if(!get_device(&sdev->sdev_gendev)) | |
1606 | /* We must be tearing the block queue down already */ | |
1607 | return; | |
1608 | ||
1609 | /* | |
1610 | * To start with, we keep looping until the queue is empty, or until | |
1611 | * the host is no longer able to accept any more requests. | |
1612 | */ | |
1613 | shost = sdev->host; | |
1614 | while (!blk_queue_plugged(q)) { | |
1615 | int rtn; | |
1616 | /* | |
1617 | * get next queueable request. We do this early to make sure | |
1618 | * that the request is fully prepared even if we cannot | |
1619 | * accept it. | |
1620 | */ | |
1621 | req = elv_next_request(q); | |
1622 | if (!req || !scsi_dev_queue_ready(q, sdev)) | |
1623 | break; | |
1624 | ||
1625 | if (unlikely(!scsi_device_online(sdev))) { | |
9ccfc756 JB |
1626 | sdev_printk(KERN_ERR, sdev, |
1627 | "rejecting I/O to offline device\n"); | |
e91442b6 | 1628 | scsi_kill_request(req, q); |
1da177e4 LT |
1629 | continue; |
1630 | } | |
1631 | ||
1632 | ||
1633 | /* | |
1634 | * Remove the request from the request list. | |
1635 | */ | |
1636 | if (!(blk_queue_tagged(q) && !blk_queue_start_tag(q, req))) | |
1637 | blkdev_dequeue_request(req); | |
1638 | sdev->device_busy++; | |
1639 | ||
1640 | spin_unlock(q->queue_lock); | |
e91442b6 JB |
1641 | cmd = req->special; |
1642 | if (unlikely(cmd == NULL)) { | |
1643 | printk(KERN_CRIT "impossible request in %s.\n" | |
1644 | "please mail a stack trace to " | |
4aff5e23 | 1645 | "linux-scsi@vger.kernel.org\n", |
cadbd4a5 | 1646 | __func__); |
4aff5e23 | 1647 | blk_dump_rq_flags(req, "foo"); |
e91442b6 JB |
1648 | BUG(); |
1649 | } | |
1da177e4 LT |
1650 | spin_lock(shost->host_lock); |
1651 | ||
ecefe8a9 MC |
1652 | /* |
1653 | * We hit this when the driver is using a host wide | |
1654 | * tag map. For device level tag maps the queue_depth check | |
1655 | * in the device ready fn would prevent us from trying | |
1656 | * to allocate a tag. Since the map is a shared host resource | |
1657 | * we add the dev to the starved list so it eventually gets | |
1658 | * a run when a tag is freed. | |
1659 | */ | |
6bd522f6 | 1660 | if (blk_queue_tagged(q) && !blk_rq_tagged(req)) { |
ecefe8a9 MC |
1661 | if (list_empty(&sdev->starved_entry)) |
1662 | list_add_tail(&sdev->starved_entry, | |
1663 | &shost->starved_list); | |
1664 | goto not_ready; | |
1665 | } | |
1666 | ||
f0c0a376 MC |
1667 | if (!scsi_target_queue_ready(shost, sdev)) |
1668 | goto not_ready; | |
1669 | ||
1da177e4 LT |
1670 | if (!scsi_host_queue_ready(q, shost, sdev)) |
1671 | goto not_ready; | |
f0c0a376 MC |
1672 | |
1673 | scsi_target(sdev)->target_busy++; | |
1da177e4 LT |
1674 | shost->host_busy++; |
1675 | ||
1676 | /* | |
1677 | * XXX(hch): This is rather suboptimal, scsi_dispatch_cmd will | |
1678 | * take the lock again. | |
1679 | */ | |
1680 | spin_unlock_irq(shost->host_lock); | |
1681 | ||
1da177e4 LT |
1682 | /* |
1683 | * Finally, initialize any error handling parameters, and set up | |
1684 | * the timers for timeouts. | |
1685 | */ | |
1686 | scsi_init_cmd_errh(cmd); | |
1687 | ||
1688 | /* | |
1689 | * Dispatch the command to the low-level driver. | |
1690 | */ | |
1691 | rtn = scsi_dispatch_cmd(cmd); | |
1692 | spin_lock_irq(q->queue_lock); | |
1693 | if(rtn) { | |
1694 | /* we're refusing the command; because of | |
1695 | * the way locks get dropped, we need to | |
1696 | * check here if plugging is required */ | |
1697 | if(sdev->device_busy == 0) | |
1698 | blk_plug_device(q); | |
1699 | ||
1700 | break; | |
1701 | } | |
1702 | } | |
1703 | ||
1704 | goto out; | |
1705 | ||
1706 | not_ready: | |
1707 | spin_unlock_irq(shost->host_lock); | |
1708 | ||
1709 | /* | |
1710 | * lock q, handle tag, requeue req, and decrement device_busy. We | |
1711 | * must return with queue_lock held. | |
1712 | * | |
1713 | * Decrementing device_busy without checking it is OK, as all such | |
1714 | * cases (host limits or settings) should run the queue at some | |
1715 | * later time. | |
1716 | */ | |
1717 | spin_lock_irq(q->queue_lock); | |
1718 | blk_requeue_request(q, req); | |
1719 | sdev->device_busy--; | |
1720 | if(sdev->device_busy == 0) | |
1721 | blk_plug_device(q); | |
1722 | out: | |
1723 | /* must be careful here...if we trigger the ->remove() function | |
1724 | * we cannot be holding the q lock */ | |
1725 | spin_unlock_irq(q->queue_lock); | |
1726 | put_device(&sdev->sdev_gendev); | |
1727 | spin_lock_irq(q->queue_lock); | |
1728 | } | |
1729 | ||
1730 | u64 scsi_calculate_bounce_limit(struct Scsi_Host *shost) | |
1731 | { | |
1732 | struct device *host_dev; | |
1733 | u64 bounce_limit = 0xffffffff; | |
1734 | ||
1735 | if (shost->unchecked_isa_dma) | |
1736 | return BLK_BOUNCE_ISA; | |
1737 | /* | |
1738 | * Platforms with virtual-DMA translation | |
1739 | * hardware have no practical limit. | |
1740 | */ | |
1741 | if (!PCI_DMA_BUS_IS_PHYS) | |
1742 | return BLK_BOUNCE_ANY; | |
1743 | ||
1744 | host_dev = scsi_get_device(shost); | |
1745 | if (host_dev && host_dev->dma_mask) | |
1746 | bounce_limit = *host_dev->dma_mask; | |
1747 | ||
1748 | return bounce_limit; | |
1749 | } | |
1750 | EXPORT_SYMBOL(scsi_calculate_bounce_limit); | |
1751 | ||
b58d9154 FT |
1752 | struct request_queue *__scsi_alloc_queue(struct Scsi_Host *shost, |
1753 | request_fn_proc *request_fn) | |
1da177e4 | 1754 | { |
1da177e4 | 1755 | struct request_queue *q; |
860ac568 | 1756 | struct device *dev = shost->shost_gendev.parent; |
1da177e4 | 1757 | |
b58d9154 | 1758 | q = blk_init_queue(request_fn, NULL); |
1da177e4 LT |
1759 | if (!q) |
1760 | return NULL; | |
1761 | ||
a8474ce2 JA |
1762 | /* |
1763 | * this limit is imposed by hardware restrictions | |
1764 | */ | |
1da177e4 | 1765 | blk_queue_max_hw_segments(q, shost->sg_tablesize); |
d3f46f39 | 1766 | blk_queue_max_phys_segments(q, SCSI_MAX_SG_CHAIN_SEGMENTS); |
a8474ce2 | 1767 | |
1da177e4 LT |
1768 | blk_queue_max_sectors(q, shost->max_sectors); |
1769 | blk_queue_bounce_limit(q, scsi_calculate_bounce_limit(shost)); | |
1770 | blk_queue_segment_boundary(q, shost->dma_boundary); | |
99c84dbd | 1771 | dma_set_seg_boundary(dev, shost->dma_boundary); |
1da177e4 | 1772 | |
860ac568 FT |
1773 | blk_queue_max_segment_size(q, dma_get_max_seg_size(dev)); |
1774 | ||
75ad23bc | 1775 | /* New queue, no concurrency on queue_flags */ |
1da177e4 | 1776 | if (!shost->use_clustering) |
75ad23bc | 1777 | queue_flag_clear_unlocked(QUEUE_FLAG_CLUSTER, q); |
465ff318 JB |
1778 | |
1779 | /* | |
1780 | * set a reasonable default alignment on word boundaries: the | |
1781 | * host and device may alter it using | |
1782 | * blk_queue_update_dma_alignment() later. | |
1783 | */ | |
1784 | blk_queue_dma_alignment(q, 0x03); | |
1785 | ||
1da177e4 LT |
1786 | return q; |
1787 | } | |
b58d9154 FT |
1788 | EXPORT_SYMBOL(__scsi_alloc_queue); |
1789 | ||
1790 | struct request_queue *scsi_alloc_queue(struct scsi_device *sdev) | |
1791 | { | |
1792 | struct request_queue *q; | |
1793 | ||
1794 | q = __scsi_alloc_queue(sdev->host, scsi_request_fn); | |
1795 | if (!q) | |
1796 | return NULL; | |
1797 | ||
1798 | blk_queue_prep_rq(q, scsi_prep_fn); | |
b58d9154 | 1799 | blk_queue_softirq_done(q, scsi_softirq_done); |
242f9dcb | 1800 | blk_queue_rq_timed_out(q, scsi_times_out); |
6c5121b7 | 1801 | blk_queue_lld_busy(q, scsi_lld_busy); |
b58d9154 FT |
1802 | return q; |
1803 | } | |
1da177e4 LT |
1804 | |
1805 | void scsi_free_queue(struct request_queue *q) | |
1806 | { | |
1807 | blk_cleanup_queue(q); | |
1808 | } | |
1809 | ||
1810 | /* | |
1811 | * Function: scsi_block_requests() | |
1812 | * | |
1813 | * Purpose: Utility function used by low-level drivers to prevent further | |
1814 | * commands from being queued to the device. | |
1815 | * | |
1816 | * Arguments: shost - Host in question | |
1817 | * | |
1818 | * Returns: Nothing | |
1819 | * | |
1820 | * Lock status: No locks are assumed held. | |
1821 | * | |
1822 | * Notes: There is no timer nor any other means by which the requests | |
1823 | * get unblocked other than the low-level driver calling | |
1824 | * scsi_unblock_requests(). | |
1825 | */ | |
1826 | void scsi_block_requests(struct Scsi_Host *shost) | |
1827 | { | |
1828 | shost->host_self_blocked = 1; | |
1829 | } | |
1830 | EXPORT_SYMBOL(scsi_block_requests); | |
1831 | ||
1832 | /* | |
1833 | * Function: scsi_unblock_requests() | |
1834 | * | |
1835 | * Purpose: Utility function used by low-level drivers to allow further | |
1836 | * commands from being queued to the device. | |
1837 | * | |
1838 | * Arguments: shost - Host in question | |
1839 | * | |
1840 | * Returns: Nothing | |
1841 | * | |
1842 | * Lock status: No locks are assumed held. | |
1843 | * | |
1844 | * Notes: There is no timer nor any other means by which the requests | |
1845 | * get unblocked other than the low-level driver calling | |
1846 | * scsi_unblock_requests(). | |
1847 | * | |
1848 | * This is done as an API function so that changes to the | |
1849 | * internals of the scsi mid-layer won't require wholesale | |
1850 | * changes to drivers that use this feature. | |
1851 | */ | |
1852 | void scsi_unblock_requests(struct Scsi_Host *shost) | |
1853 | { | |
1854 | shost->host_self_blocked = 0; | |
1855 | scsi_run_host_queues(shost); | |
1856 | } | |
1857 | EXPORT_SYMBOL(scsi_unblock_requests); | |
1858 | ||
1859 | int __init scsi_init_queue(void) | |
1860 | { | |
1861 | int i; | |
1862 | ||
aa7b5cd7 MC |
1863 | scsi_io_context_cache = kmem_cache_create("scsi_io_context", |
1864 | sizeof(struct scsi_io_context), | |
20c2df83 | 1865 | 0, 0, NULL); |
aa7b5cd7 MC |
1866 | if (!scsi_io_context_cache) { |
1867 | printk(KERN_ERR "SCSI: can't init scsi io context cache\n"); | |
1868 | return -ENOMEM; | |
1869 | } | |
1870 | ||
6362abd3 MP |
1871 | scsi_sdb_cache = kmem_cache_create("scsi_data_buffer", |
1872 | sizeof(struct scsi_data_buffer), | |
1873 | 0, 0, NULL); | |
1874 | if (!scsi_sdb_cache) { | |
1875 | printk(KERN_ERR "SCSI: can't init scsi sdb cache\n"); | |
3d9dd6ee | 1876 | goto cleanup_io_context; |
6f9a35e2 BH |
1877 | } |
1878 | ||
1da177e4 LT |
1879 | for (i = 0; i < SG_MEMPOOL_NR; i++) { |
1880 | struct scsi_host_sg_pool *sgp = scsi_sg_pools + i; | |
1881 | int size = sgp->size * sizeof(struct scatterlist); | |
1882 | ||
1883 | sgp->slab = kmem_cache_create(sgp->name, size, 0, | |
20c2df83 | 1884 | SLAB_HWCACHE_ALIGN, NULL); |
1da177e4 LT |
1885 | if (!sgp->slab) { |
1886 | printk(KERN_ERR "SCSI: can't init sg slab %s\n", | |
1887 | sgp->name); | |
6362abd3 | 1888 | goto cleanup_sdb; |
1da177e4 LT |
1889 | } |
1890 | ||
93d2341c MD |
1891 | sgp->pool = mempool_create_slab_pool(SG_MEMPOOL_SIZE, |
1892 | sgp->slab); | |
1da177e4 LT |
1893 | if (!sgp->pool) { |
1894 | printk(KERN_ERR "SCSI: can't init sg mempool %s\n", | |
1895 | sgp->name); | |
6362abd3 | 1896 | goto cleanup_sdb; |
1da177e4 LT |
1897 | } |
1898 | } | |
1899 | ||
1900 | return 0; | |
3d9dd6ee | 1901 | |
6362abd3 | 1902 | cleanup_sdb: |
3d9dd6ee FT |
1903 | for (i = 0; i < SG_MEMPOOL_NR; i++) { |
1904 | struct scsi_host_sg_pool *sgp = scsi_sg_pools + i; | |
1905 | if (sgp->pool) | |
1906 | mempool_destroy(sgp->pool); | |
1907 | if (sgp->slab) | |
1908 | kmem_cache_destroy(sgp->slab); | |
1909 | } | |
6362abd3 | 1910 | kmem_cache_destroy(scsi_sdb_cache); |
3d9dd6ee FT |
1911 | cleanup_io_context: |
1912 | kmem_cache_destroy(scsi_io_context_cache); | |
1913 | ||
1914 | return -ENOMEM; | |
1da177e4 LT |
1915 | } |
1916 | ||
1917 | void scsi_exit_queue(void) | |
1918 | { | |
1919 | int i; | |
1920 | ||
aa7b5cd7 | 1921 | kmem_cache_destroy(scsi_io_context_cache); |
6362abd3 | 1922 | kmem_cache_destroy(scsi_sdb_cache); |
aa7b5cd7 | 1923 | |
1da177e4 LT |
1924 | for (i = 0; i < SG_MEMPOOL_NR; i++) { |
1925 | struct scsi_host_sg_pool *sgp = scsi_sg_pools + i; | |
1926 | mempool_destroy(sgp->pool); | |
1927 | kmem_cache_destroy(sgp->slab); | |
1928 | } | |
1929 | } | |
5baba830 JB |
1930 | |
1931 | /** | |
1932 | * scsi_mode_select - issue a mode select | |
1933 | * @sdev: SCSI device to be queried | |
1934 | * @pf: Page format bit (1 == standard, 0 == vendor specific) | |
1935 | * @sp: Save page bit (0 == don't save, 1 == save) | |
1936 | * @modepage: mode page being requested | |
1937 | * @buffer: request buffer (may not be smaller than eight bytes) | |
1938 | * @len: length of request buffer. | |
1939 | * @timeout: command timeout | |
1940 | * @retries: number of retries before failing | |
1941 | * @data: returns a structure abstracting the mode header data | |
eb44820c | 1942 | * @sshdr: place to put sense data (or NULL if no sense to be collected). |
5baba830 JB |
1943 | * must be SCSI_SENSE_BUFFERSIZE big. |
1944 | * | |
1945 | * Returns zero if successful; negative error number or scsi | |
1946 | * status on error | |
1947 | * | |
1948 | */ | |
1949 | int | |
1950 | scsi_mode_select(struct scsi_device *sdev, int pf, int sp, int modepage, | |
1951 | unsigned char *buffer, int len, int timeout, int retries, | |
1952 | struct scsi_mode_data *data, struct scsi_sense_hdr *sshdr) | |
1953 | { | |
1954 | unsigned char cmd[10]; | |
1955 | unsigned char *real_buffer; | |
1956 | int ret; | |
1957 | ||
1958 | memset(cmd, 0, sizeof(cmd)); | |
1959 | cmd[1] = (pf ? 0x10 : 0) | (sp ? 0x01 : 0); | |
1960 | ||
1961 | if (sdev->use_10_for_ms) { | |
1962 | if (len > 65535) | |
1963 | return -EINVAL; | |
1964 | real_buffer = kmalloc(8 + len, GFP_KERNEL); | |
1965 | if (!real_buffer) | |
1966 | return -ENOMEM; | |
1967 | memcpy(real_buffer + 8, buffer, len); | |
1968 | len += 8; | |
1969 | real_buffer[0] = 0; | |
1970 | real_buffer[1] = 0; | |
1971 | real_buffer[2] = data->medium_type; | |
1972 | real_buffer[3] = data->device_specific; | |
1973 | real_buffer[4] = data->longlba ? 0x01 : 0; | |
1974 | real_buffer[5] = 0; | |
1975 | real_buffer[6] = data->block_descriptor_length >> 8; | |
1976 | real_buffer[7] = data->block_descriptor_length; | |
1977 | ||
1978 | cmd[0] = MODE_SELECT_10; | |
1979 | cmd[7] = len >> 8; | |
1980 | cmd[8] = len; | |
1981 | } else { | |
1982 | if (len > 255 || data->block_descriptor_length > 255 || | |
1983 | data->longlba) | |
1984 | return -EINVAL; | |
1985 | ||
1986 | real_buffer = kmalloc(4 + len, GFP_KERNEL); | |
1987 | if (!real_buffer) | |
1988 | return -ENOMEM; | |
1989 | memcpy(real_buffer + 4, buffer, len); | |
1990 | len += 4; | |
1991 | real_buffer[0] = 0; | |
1992 | real_buffer[1] = data->medium_type; | |
1993 | real_buffer[2] = data->device_specific; | |
1994 | real_buffer[3] = data->block_descriptor_length; | |
1995 | ||
1996 | ||
1997 | cmd[0] = MODE_SELECT; | |
1998 | cmd[4] = len; | |
1999 | } | |
2000 | ||
2001 | ret = scsi_execute_req(sdev, cmd, DMA_TO_DEVICE, real_buffer, len, | |
2002 | sshdr, timeout, retries); | |
2003 | kfree(real_buffer); | |
2004 | return ret; | |
2005 | } | |
2006 | EXPORT_SYMBOL_GPL(scsi_mode_select); | |
2007 | ||
1da177e4 | 2008 | /** |
eb44820c | 2009 | * scsi_mode_sense - issue a mode sense, falling back from 10 to six bytes if necessary. |
1cf72699 | 2010 | * @sdev: SCSI device to be queried |
1da177e4 LT |
2011 | * @dbd: set if mode sense will allow block descriptors to be returned |
2012 | * @modepage: mode page being requested | |
2013 | * @buffer: request buffer (may not be smaller than eight bytes) | |
2014 | * @len: length of request buffer. | |
2015 | * @timeout: command timeout | |
2016 | * @retries: number of retries before failing | |
2017 | * @data: returns a structure abstracting the mode header data | |
eb44820c | 2018 | * @sshdr: place to put sense data (or NULL if no sense to be collected). |
1cf72699 | 2019 | * must be SCSI_SENSE_BUFFERSIZE big. |
1da177e4 LT |
2020 | * |
2021 | * Returns zero if unsuccessful, or the header offset (either 4 | |
2022 | * or 8 depending on whether a six or ten byte command was | |
2023 | * issued) if successful. | |
eb44820c | 2024 | */ |
1da177e4 | 2025 | int |
1cf72699 | 2026 | scsi_mode_sense(struct scsi_device *sdev, int dbd, int modepage, |
1da177e4 | 2027 | unsigned char *buffer, int len, int timeout, int retries, |
5baba830 JB |
2028 | struct scsi_mode_data *data, struct scsi_sense_hdr *sshdr) |
2029 | { | |
1da177e4 LT |
2030 | unsigned char cmd[12]; |
2031 | int use_10_for_ms; | |
2032 | int header_length; | |
1cf72699 | 2033 | int result; |
ea73a9f2 | 2034 | struct scsi_sense_hdr my_sshdr; |
1da177e4 LT |
2035 | |
2036 | memset(data, 0, sizeof(*data)); | |
2037 | memset(&cmd[0], 0, 12); | |
2038 | cmd[1] = dbd & 0x18; /* allows DBD and LLBA bits */ | |
2039 | cmd[2] = modepage; | |
2040 | ||
ea73a9f2 JB |
2041 | /* caller might not be interested in sense, but we need it */ |
2042 | if (!sshdr) | |
2043 | sshdr = &my_sshdr; | |
2044 | ||
1da177e4 | 2045 | retry: |
1cf72699 | 2046 | use_10_for_ms = sdev->use_10_for_ms; |
1da177e4 LT |
2047 | |
2048 | if (use_10_for_ms) { | |
2049 | if (len < 8) | |
2050 | len = 8; | |
2051 | ||
2052 | cmd[0] = MODE_SENSE_10; | |
2053 | cmd[8] = len; | |
2054 | header_length = 8; | |
2055 | } else { | |
2056 | if (len < 4) | |
2057 | len = 4; | |
2058 | ||
2059 | cmd[0] = MODE_SENSE; | |
2060 | cmd[4] = len; | |
2061 | header_length = 4; | |
2062 | } | |
2063 | ||
1da177e4 LT |
2064 | memset(buffer, 0, len); |
2065 | ||
1cf72699 | 2066 | result = scsi_execute_req(sdev, cmd, DMA_FROM_DEVICE, buffer, len, |
ea73a9f2 | 2067 | sshdr, timeout, retries); |
1da177e4 LT |
2068 | |
2069 | /* This code looks awful: what it's doing is making sure an | |
2070 | * ILLEGAL REQUEST sense return identifies the actual command | |
2071 | * byte as the problem. MODE_SENSE commands can return | |
2072 | * ILLEGAL REQUEST if the code page isn't supported */ | |
2073 | ||
1cf72699 JB |
2074 | if (use_10_for_ms && !scsi_status_is_good(result) && |
2075 | (driver_byte(result) & DRIVER_SENSE)) { | |
ea73a9f2 JB |
2076 | if (scsi_sense_valid(sshdr)) { |
2077 | if ((sshdr->sense_key == ILLEGAL_REQUEST) && | |
2078 | (sshdr->asc == 0x20) && (sshdr->ascq == 0)) { | |
1da177e4 LT |
2079 | /* |
2080 | * Invalid command operation code | |
2081 | */ | |
1cf72699 | 2082 | sdev->use_10_for_ms = 0; |
1da177e4 LT |
2083 | goto retry; |
2084 | } | |
2085 | } | |
2086 | } | |
2087 | ||
1cf72699 | 2088 | if(scsi_status_is_good(result)) { |
6d73c851 AV |
2089 | if (unlikely(buffer[0] == 0x86 && buffer[1] == 0x0b && |
2090 | (modepage == 6 || modepage == 8))) { | |
2091 | /* Initio breakage? */ | |
2092 | header_length = 0; | |
2093 | data->length = 13; | |
2094 | data->medium_type = 0; | |
2095 | data->device_specific = 0; | |
2096 | data->longlba = 0; | |
2097 | data->block_descriptor_length = 0; | |
2098 | } else if(use_10_for_ms) { | |
1da177e4 LT |
2099 | data->length = buffer[0]*256 + buffer[1] + 2; |
2100 | data->medium_type = buffer[2]; | |
2101 | data->device_specific = buffer[3]; | |
2102 | data->longlba = buffer[4] & 0x01; | |
2103 | data->block_descriptor_length = buffer[6]*256 | |
2104 | + buffer[7]; | |
2105 | } else { | |
2106 | data->length = buffer[0] + 1; | |
2107 | data->medium_type = buffer[1]; | |
2108 | data->device_specific = buffer[2]; | |
2109 | data->block_descriptor_length = buffer[3]; | |
2110 | } | |
6d73c851 | 2111 | data->header_length = header_length; |
1da177e4 LT |
2112 | } |
2113 | ||
1cf72699 | 2114 | return result; |
1da177e4 LT |
2115 | } |
2116 | EXPORT_SYMBOL(scsi_mode_sense); | |
2117 | ||
001aac25 JB |
2118 | /** |
2119 | * scsi_test_unit_ready - test if unit is ready | |
2120 | * @sdev: scsi device to change the state of. | |
2121 | * @timeout: command timeout | |
2122 | * @retries: number of retries before failing | |
2123 | * @sshdr_external: Optional pointer to struct scsi_sense_hdr for | |
2124 | * returning sense. Make sure that this is cleared before passing | |
2125 | * in. | |
2126 | * | |
2127 | * Returns zero if unsuccessful or an error if TUR failed. For | |
2128 | * removable media, a return of NOT_READY or UNIT_ATTENTION is | |
2129 | * translated to success, with the ->changed flag updated. | |
2130 | **/ | |
1da177e4 | 2131 | int |
001aac25 JB |
2132 | scsi_test_unit_ready(struct scsi_device *sdev, int timeout, int retries, |
2133 | struct scsi_sense_hdr *sshdr_external) | |
1da177e4 | 2134 | { |
1da177e4 LT |
2135 | char cmd[] = { |
2136 | TEST_UNIT_READY, 0, 0, 0, 0, 0, | |
2137 | }; | |
001aac25 | 2138 | struct scsi_sense_hdr *sshdr; |
1da177e4 | 2139 | int result; |
001aac25 JB |
2140 | |
2141 | if (!sshdr_external) | |
2142 | sshdr = kzalloc(sizeof(*sshdr), GFP_KERNEL); | |
2143 | else | |
2144 | sshdr = sshdr_external; | |
2145 | ||
2146 | /* try to eat the UNIT_ATTENTION if there are enough retries */ | |
2147 | do { | |
2148 | result = scsi_execute_req(sdev, cmd, DMA_NONE, NULL, 0, sshdr, | |
2149 | timeout, retries); | |
32c356d7 JB |
2150 | if (sdev->removable && scsi_sense_valid(sshdr) && |
2151 | sshdr->sense_key == UNIT_ATTENTION) | |
2152 | sdev->changed = 1; | |
2153 | } while (scsi_sense_valid(sshdr) && | |
2154 | sshdr->sense_key == UNIT_ATTENTION && --retries); | |
001aac25 JB |
2155 | |
2156 | if (!sshdr) | |
2157 | /* could not allocate sense buffer, so can't process it */ | |
2158 | return result; | |
1da177e4 | 2159 | |
32c356d7 JB |
2160 | if (sdev->removable && scsi_sense_valid(sshdr) && |
2161 | (sshdr->sense_key == UNIT_ATTENTION || | |
2162 | sshdr->sense_key == NOT_READY)) { | |
2163 | sdev->changed = 1; | |
2164 | result = 0; | |
1da177e4 | 2165 | } |
001aac25 JB |
2166 | if (!sshdr_external) |
2167 | kfree(sshdr); | |
1da177e4 LT |
2168 | return result; |
2169 | } | |
2170 | EXPORT_SYMBOL(scsi_test_unit_ready); | |
2171 | ||
2172 | /** | |
eb44820c | 2173 | * scsi_device_set_state - Take the given device through the device state model. |
1da177e4 LT |
2174 | * @sdev: scsi device to change the state of. |
2175 | * @state: state to change to. | |
2176 | * | |
2177 | * Returns zero if unsuccessful or an error if the requested | |
2178 | * transition is illegal. | |
eb44820c | 2179 | */ |
1da177e4 LT |
2180 | int |
2181 | scsi_device_set_state(struct scsi_device *sdev, enum scsi_device_state state) | |
2182 | { | |
2183 | enum scsi_device_state oldstate = sdev->sdev_state; | |
2184 | ||
2185 | if (state == oldstate) | |
2186 | return 0; | |
2187 | ||
2188 | switch (state) { | |
2189 | case SDEV_CREATED: | |
6f4267e3 JB |
2190 | switch (oldstate) { |
2191 | case SDEV_CREATED_BLOCK: | |
2192 | break; | |
2193 | default: | |
2194 | goto illegal; | |
2195 | } | |
2196 | break; | |
1da177e4 LT |
2197 | |
2198 | case SDEV_RUNNING: | |
2199 | switch (oldstate) { | |
2200 | case SDEV_CREATED: | |
2201 | case SDEV_OFFLINE: | |
2202 | case SDEV_QUIESCE: | |
2203 | case SDEV_BLOCK: | |
2204 | break; | |
2205 | default: | |
2206 | goto illegal; | |
2207 | } | |
2208 | break; | |
2209 | ||
2210 | case SDEV_QUIESCE: | |
2211 | switch (oldstate) { | |
2212 | case SDEV_RUNNING: | |
2213 | case SDEV_OFFLINE: | |
2214 | break; | |
2215 | default: | |
2216 | goto illegal; | |
2217 | } | |
2218 | break; | |
2219 | ||
2220 | case SDEV_OFFLINE: | |
2221 | switch (oldstate) { | |
2222 | case SDEV_CREATED: | |
2223 | case SDEV_RUNNING: | |
2224 | case SDEV_QUIESCE: | |
2225 | case SDEV_BLOCK: | |
2226 | break; | |
2227 | default: | |
2228 | goto illegal; | |
2229 | } | |
2230 | break; | |
2231 | ||
2232 | case SDEV_BLOCK: | |
2233 | switch (oldstate) { | |
1da177e4 | 2234 | case SDEV_RUNNING: |
6f4267e3 JB |
2235 | case SDEV_CREATED_BLOCK: |
2236 | break; | |
2237 | default: | |
2238 | goto illegal; | |
2239 | } | |
2240 | break; | |
2241 | ||
2242 | case SDEV_CREATED_BLOCK: | |
2243 | switch (oldstate) { | |
2244 | case SDEV_CREATED: | |
1da177e4 LT |
2245 | break; |
2246 | default: | |
2247 | goto illegal; | |
2248 | } | |
2249 | break; | |
2250 | ||
2251 | case SDEV_CANCEL: | |
2252 | switch (oldstate) { | |
2253 | case SDEV_CREATED: | |
2254 | case SDEV_RUNNING: | |
9ea72909 | 2255 | case SDEV_QUIESCE: |
1da177e4 LT |
2256 | case SDEV_OFFLINE: |
2257 | case SDEV_BLOCK: | |
2258 | break; | |
2259 | default: | |
2260 | goto illegal; | |
2261 | } | |
2262 | break; | |
2263 | ||
2264 | case SDEV_DEL: | |
2265 | switch (oldstate) { | |
309bd271 BK |
2266 | case SDEV_CREATED: |
2267 | case SDEV_RUNNING: | |
2268 | case SDEV_OFFLINE: | |
1da177e4 LT |
2269 | case SDEV_CANCEL: |
2270 | break; | |
2271 | default: | |
2272 | goto illegal; | |
2273 | } | |
2274 | break; | |
2275 | ||
2276 | } | |
2277 | sdev->sdev_state = state; | |
2278 | return 0; | |
2279 | ||
2280 | illegal: | |
2281 | SCSI_LOG_ERROR_RECOVERY(1, | |
9ccfc756 JB |
2282 | sdev_printk(KERN_ERR, sdev, |
2283 | "Illegal state transition %s->%s\n", | |
2284 | scsi_device_state_name(oldstate), | |
2285 | scsi_device_state_name(state)) | |
1da177e4 LT |
2286 | ); |
2287 | return -EINVAL; | |
2288 | } | |
2289 | EXPORT_SYMBOL(scsi_device_set_state); | |
2290 | ||
a341cd0f JG |
2291 | /** |
2292 | * sdev_evt_emit - emit a single SCSI device uevent | |
2293 | * @sdev: associated SCSI device | |
2294 | * @evt: event to emit | |
2295 | * | |
2296 | * Send a single uevent (scsi_event) to the associated scsi_device. | |
2297 | */ | |
2298 | static void scsi_evt_emit(struct scsi_device *sdev, struct scsi_event *evt) | |
2299 | { | |
2300 | int idx = 0; | |
2301 | char *envp[3]; | |
2302 | ||
2303 | switch (evt->evt_type) { | |
2304 | case SDEV_EVT_MEDIA_CHANGE: | |
2305 | envp[idx++] = "SDEV_MEDIA_CHANGE=1"; | |
2306 | break; | |
2307 | ||
2308 | default: | |
2309 | /* do nothing */ | |
2310 | break; | |
2311 | } | |
2312 | ||
2313 | envp[idx++] = NULL; | |
2314 | ||
2315 | kobject_uevent_env(&sdev->sdev_gendev.kobj, KOBJ_CHANGE, envp); | |
2316 | } | |
2317 | ||
2318 | /** | |
2319 | * sdev_evt_thread - send a uevent for each scsi event | |
2320 | * @work: work struct for scsi_device | |
2321 | * | |
2322 | * Dispatch queued events to their associated scsi_device kobjects | |
2323 | * as uevents. | |
2324 | */ | |
2325 | void scsi_evt_thread(struct work_struct *work) | |
2326 | { | |
2327 | struct scsi_device *sdev; | |
2328 | LIST_HEAD(event_list); | |
2329 | ||
2330 | sdev = container_of(work, struct scsi_device, event_work); | |
2331 | ||
2332 | while (1) { | |
2333 | struct scsi_event *evt; | |
2334 | struct list_head *this, *tmp; | |
2335 | unsigned long flags; | |
2336 | ||
2337 | spin_lock_irqsave(&sdev->list_lock, flags); | |
2338 | list_splice_init(&sdev->event_list, &event_list); | |
2339 | spin_unlock_irqrestore(&sdev->list_lock, flags); | |
2340 | ||
2341 | if (list_empty(&event_list)) | |
2342 | break; | |
2343 | ||
2344 | list_for_each_safe(this, tmp, &event_list) { | |
2345 | evt = list_entry(this, struct scsi_event, node); | |
2346 | list_del(&evt->node); | |
2347 | scsi_evt_emit(sdev, evt); | |
2348 | kfree(evt); | |
2349 | } | |
2350 | } | |
2351 | } | |
2352 | ||
2353 | /** | |
2354 | * sdev_evt_send - send asserted event to uevent thread | |
2355 | * @sdev: scsi_device event occurred on | |
2356 | * @evt: event to send | |
2357 | * | |
2358 | * Assert scsi device event asynchronously. | |
2359 | */ | |
2360 | void sdev_evt_send(struct scsi_device *sdev, struct scsi_event *evt) | |
2361 | { | |
2362 | unsigned long flags; | |
2363 | ||
4d1566ed KS |
2364 | #if 0 |
2365 | /* FIXME: currently this check eliminates all media change events | |
2366 | * for polled devices. Need to update to discriminate between AN | |
2367 | * and polled events */ | |
a341cd0f JG |
2368 | if (!test_bit(evt->evt_type, sdev->supported_events)) { |
2369 | kfree(evt); | |
2370 | return; | |
2371 | } | |
4d1566ed | 2372 | #endif |
a341cd0f JG |
2373 | |
2374 | spin_lock_irqsave(&sdev->list_lock, flags); | |
2375 | list_add_tail(&evt->node, &sdev->event_list); | |
2376 | schedule_work(&sdev->event_work); | |
2377 | spin_unlock_irqrestore(&sdev->list_lock, flags); | |
2378 | } | |
2379 | EXPORT_SYMBOL_GPL(sdev_evt_send); | |
2380 | ||
2381 | /** | |
2382 | * sdev_evt_alloc - allocate a new scsi event | |
2383 | * @evt_type: type of event to allocate | |
2384 | * @gfpflags: GFP flags for allocation | |
2385 | * | |
2386 | * Allocates and returns a new scsi_event. | |
2387 | */ | |
2388 | struct scsi_event *sdev_evt_alloc(enum scsi_device_event evt_type, | |
2389 | gfp_t gfpflags) | |
2390 | { | |
2391 | struct scsi_event *evt = kzalloc(sizeof(struct scsi_event), gfpflags); | |
2392 | if (!evt) | |
2393 | return NULL; | |
2394 | ||
2395 | evt->evt_type = evt_type; | |
2396 | INIT_LIST_HEAD(&evt->node); | |
2397 | ||
2398 | /* evt_type-specific initialization, if any */ | |
2399 | switch (evt_type) { | |
2400 | case SDEV_EVT_MEDIA_CHANGE: | |
2401 | default: | |
2402 | /* do nothing */ | |
2403 | break; | |
2404 | } | |
2405 | ||
2406 | return evt; | |
2407 | } | |
2408 | EXPORT_SYMBOL_GPL(sdev_evt_alloc); | |
2409 | ||
2410 | /** | |
2411 | * sdev_evt_send_simple - send asserted event to uevent thread | |
2412 | * @sdev: scsi_device event occurred on | |
2413 | * @evt_type: type of event to send | |
2414 | * @gfpflags: GFP flags for allocation | |
2415 | * | |
2416 | * Assert scsi device event asynchronously, given an event type. | |
2417 | */ | |
2418 | void sdev_evt_send_simple(struct scsi_device *sdev, | |
2419 | enum scsi_device_event evt_type, gfp_t gfpflags) | |
2420 | { | |
2421 | struct scsi_event *evt = sdev_evt_alloc(evt_type, gfpflags); | |
2422 | if (!evt) { | |
2423 | sdev_printk(KERN_ERR, sdev, "event %d eaten due to OOM\n", | |
2424 | evt_type); | |
2425 | return; | |
2426 | } | |
2427 | ||
2428 | sdev_evt_send(sdev, evt); | |
2429 | } | |
2430 | EXPORT_SYMBOL_GPL(sdev_evt_send_simple); | |
2431 | ||
1da177e4 LT |
2432 | /** |
2433 | * scsi_device_quiesce - Block user issued commands. | |
2434 | * @sdev: scsi device to quiesce. | |
2435 | * | |
2436 | * This works by trying to transition to the SDEV_QUIESCE state | |
2437 | * (which must be a legal transition). When the device is in this | |
2438 | * state, only special requests will be accepted, all others will | |
2439 | * be deferred. Since special requests may also be requeued requests, | |
2440 | * a successful return doesn't guarantee the device will be | |
2441 | * totally quiescent. | |
2442 | * | |
2443 | * Must be called with user context, may sleep. | |
2444 | * | |
2445 | * Returns zero if unsuccessful or an error if not. | |
eb44820c | 2446 | */ |
1da177e4 LT |
2447 | int |
2448 | scsi_device_quiesce(struct scsi_device *sdev) | |
2449 | { | |
2450 | int err = scsi_device_set_state(sdev, SDEV_QUIESCE); | |
2451 | if (err) | |
2452 | return err; | |
2453 | ||
2454 | scsi_run_queue(sdev->request_queue); | |
2455 | while (sdev->device_busy) { | |
2456 | msleep_interruptible(200); | |
2457 | scsi_run_queue(sdev->request_queue); | |
2458 | } | |
2459 | return 0; | |
2460 | } | |
2461 | EXPORT_SYMBOL(scsi_device_quiesce); | |
2462 | ||
2463 | /** | |
2464 | * scsi_device_resume - Restart user issued commands to a quiesced device. | |
2465 | * @sdev: scsi device to resume. | |
2466 | * | |
2467 | * Moves the device from quiesced back to running and restarts the | |
2468 | * queues. | |
2469 | * | |
2470 | * Must be called with user context, may sleep. | |
eb44820c | 2471 | */ |
1da177e4 LT |
2472 | void |
2473 | scsi_device_resume(struct scsi_device *sdev) | |
2474 | { | |
2475 | if(scsi_device_set_state(sdev, SDEV_RUNNING)) | |
2476 | return; | |
2477 | scsi_run_queue(sdev->request_queue); | |
2478 | } | |
2479 | EXPORT_SYMBOL(scsi_device_resume); | |
2480 | ||
2481 | static void | |
2482 | device_quiesce_fn(struct scsi_device *sdev, void *data) | |
2483 | { | |
2484 | scsi_device_quiesce(sdev); | |
2485 | } | |
2486 | ||
2487 | void | |
2488 | scsi_target_quiesce(struct scsi_target *starget) | |
2489 | { | |
2490 | starget_for_each_device(starget, NULL, device_quiesce_fn); | |
2491 | } | |
2492 | EXPORT_SYMBOL(scsi_target_quiesce); | |
2493 | ||
2494 | static void | |
2495 | device_resume_fn(struct scsi_device *sdev, void *data) | |
2496 | { | |
2497 | scsi_device_resume(sdev); | |
2498 | } | |
2499 | ||
2500 | void | |
2501 | scsi_target_resume(struct scsi_target *starget) | |
2502 | { | |
2503 | starget_for_each_device(starget, NULL, device_resume_fn); | |
2504 | } | |
2505 | EXPORT_SYMBOL(scsi_target_resume); | |
2506 | ||
2507 | /** | |
eb44820c | 2508 | * scsi_internal_device_block - internal function to put a device temporarily into the SDEV_BLOCK state |
1da177e4 LT |
2509 | * @sdev: device to block |
2510 | * | |
2511 | * Block request made by scsi lld's to temporarily stop all | |
2512 | * scsi commands on the specified device. Called from interrupt | |
2513 | * or normal process context. | |
2514 | * | |
2515 | * Returns zero if successful or error if not | |
2516 | * | |
2517 | * Notes: | |
2518 | * This routine transitions the device to the SDEV_BLOCK state | |
2519 | * (which must be a legal transition). When the device is in this | |
2520 | * state, all commands are deferred until the scsi lld reenables | |
2521 | * the device with scsi_device_unblock or device_block_tmo fires. | |
2522 | * This routine assumes the host_lock is held on entry. | |
eb44820c | 2523 | */ |
1da177e4 LT |
2524 | int |
2525 | scsi_internal_device_block(struct scsi_device *sdev) | |
2526 | { | |
165125e1 | 2527 | struct request_queue *q = sdev->request_queue; |
1da177e4 LT |
2528 | unsigned long flags; |
2529 | int err = 0; | |
2530 | ||
2531 | err = scsi_device_set_state(sdev, SDEV_BLOCK); | |
6f4267e3 JB |
2532 | if (err) { |
2533 | err = scsi_device_set_state(sdev, SDEV_CREATED_BLOCK); | |
2534 | ||
2535 | if (err) | |
2536 | return err; | |
2537 | } | |
1da177e4 LT |
2538 | |
2539 | /* | |
2540 | * The device has transitioned to SDEV_BLOCK. Stop the | |
2541 | * block layer from calling the midlayer with this device's | |
2542 | * request queue. | |
2543 | */ | |
2544 | spin_lock_irqsave(q->queue_lock, flags); | |
2545 | blk_stop_queue(q); | |
2546 | spin_unlock_irqrestore(q->queue_lock, flags); | |
2547 | ||
2548 | return 0; | |
2549 | } | |
2550 | EXPORT_SYMBOL_GPL(scsi_internal_device_block); | |
2551 | ||
2552 | /** | |
2553 | * scsi_internal_device_unblock - resume a device after a block request | |
2554 | * @sdev: device to resume | |
2555 | * | |
2556 | * Called by scsi lld's or the midlayer to restart the device queue | |
2557 | * for the previously suspended scsi device. Called from interrupt or | |
2558 | * normal process context. | |
2559 | * | |
2560 | * Returns zero if successful or error if not. | |
2561 | * | |
2562 | * Notes: | |
2563 | * This routine transitions the device to the SDEV_RUNNING state | |
2564 | * (which must be a legal transition) allowing the midlayer to | |
2565 | * goose the queue for this device. This routine assumes the | |
2566 | * host_lock is held upon entry. | |
eb44820c | 2567 | */ |
1da177e4 LT |
2568 | int |
2569 | scsi_internal_device_unblock(struct scsi_device *sdev) | |
2570 | { | |
165125e1 | 2571 | struct request_queue *q = sdev->request_queue; |
1da177e4 LT |
2572 | int err; |
2573 | unsigned long flags; | |
2574 | ||
2575 | /* | |
2576 | * Try to transition the scsi device to SDEV_RUNNING | |
2577 | * and goose the device queue if successful. | |
2578 | */ | |
2579 | err = scsi_device_set_state(sdev, SDEV_RUNNING); | |
6f4267e3 JB |
2580 | if (err) { |
2581 | err = scsi_device_set_state(sdev, SDEV_CREATED); | |
2582 | ||
2583 | if (err) | |
2584 | return err; | |
2585 | } | |
1da177e4 LT |
2586 | |
2587 | spin_lock_irqsave(q->queue_lock, flags); | |
2588 | blk_start_queue(q); | |
2589 | spin_unlock_irqrestore(q->queue_lock, flags); | |
2590 | ||
2591 | return 0; | |
2592 | } | |
2593 | EXPORT_SYMBOL_GPL(scsi_internal_device_unblock); | |
2594 | ||
2595 | static void | |
2596 | device_block(struct scsi_device *sdev, void *data) | |
2597 | { | |
2598 | scsi_internal_device_block(sdev); | |
2599 | } | |
2600 | ||
2601 | static int | |
2602 | target_block(struct device *dev, void *data) | |
2603 | { | |
2604 | if (scsi_is_target_device(dev)) | |
2605 | starget_for_each_device(to_scsi_target(dev), NULL, | |
2606 | device_block); | |
2607 | return 0; | |
2608 | } | |
2609 | ||
2610 | void | |
2611 | scsi_target_block(struct device *dev) | |
2612 | { | |
2613 | if (scsi_is_target_device(dev)) | |
2614 | starget_for_each_device(to_scsi_target(dev), NULL, | |
2615 | device_block); | |
2616 | else | |
2617 | device_for_each_child(dev, NULL, target_block); | |
2618 | } | |
2619 | EXPORT_SYMBOL_GPL(scsi_target_block); | |
2620 | ||
2621 | static void | |
2622 | device_unblock(struct scsi_device *sdev, void *data) | |
2623 | { | |
2624 | scsi_internal_device_unblock(sdev); | |
2625 | } | |
2626 | ||
2627 | static int | |
2628 | target_unblock(struct device *dev, void *data) | |
2629 | { | |
2630 | if (scsi_is_target_device(dev)) | |
2631 | starget_for_each_device(to_scsi_target(dev), NULL, | |
2632 | device_unblock); | |
2633 | return 0; | |
2634 | } | |
2635 | ||
2636 | void | |
2637 | scsi_target_unblock(struct device *dev) | |
2638 | { | |
2639 | if (scsi_is_target_device(dev)) | |
2640 | starget_for_each_device(to_scsi_target(dev), NULL, | |
2641 | device_unblock); | |
2642 | else | |
2643 | device_for_each_child(dev, NULL, target_unblock); | |
2644 | } | |
2645 | EXPORT_SYMBOL_GPL(scsi_target_unblock); | |
cdb8c2a6 GL |
2646 | |
2647 | /** | |
2648 | * scsi_kmap_atomic_sg - find and atomically map an sg-elemnt | |
eb44820c | 2649 | * @sgl: scatter-gather list |
cdb8c2a6 GL |
2650 | * @sg_count: number of segments in sg |
2651 | * @offset: offset in bytes into sg, on return offset into the mapped area | |
2652 | * @len: bytes to map, on return number of bytes mapped | |
2653 | * | |
2654 | * Returns virtual address of the start of the mapped page | |
2655 | */ | |
c6132da1 | 2656 | void *scsi_kmap_atomic_sg(struct scatterlist *sgl, int sg_count, |
cdb8c2a6 GL |
2657 | size_t *offset, size_t *len) |
2658 | { | |
2659 | int i; | |
2660 | size_t sg_len = 0, len_complete = 0; | |
c6132da1 | 2661 | struct scatterlist *sg; |
cdb8c2a6 GL |
2662 | struct page *page; |
2663 | ||
22cfefb5 AM |
2664 | WARN_ON(!irqs_disabled()); |
2665 | ||
c6132da1 | 2666 | for_each_sg(sgl, sg, sg_count, i) { |
cdb8c2a6 | 2667 | len_complete = sg_len; /* Complete sg-entries */ |
c6132da1 | 2668 | sg_len += sg->length; |
cdb8c2a6 GL |
2669 | if (sg_len > *offset) |
2670 | break; | |
2671 | } | |
2672 | ||
2673 | if (unlikely(i == sg_count)) { | |
169e1a2a AM |
2674 | printk(KERN_ERR "%s: Bytes in sg: %zu, requested offset %zu, " |
2675 | "elements %d\n", | |
cadbd4a5 | 2676 | __func__, sg_len, *offset, sg_count); |
cdb8c2a6 GL |
2677 | WARN_ON(1); |
2678 | return NULL; | |
2679 | } | |
2680 | ||
2681 | /* Offset starting from the beginning of first page in this sg-entry */ | |
c6132da1 | 2682 | *offset = *offset - len_complete + sg->offset; |
cdb8c2a6 GL |
2683 | |
2684 | /* Assumption: contiguous pages can be accessed as "page + i" */ | |
45711f1a | 2685 | page = nth_page(sg_page(sg), (*offset >> PAGE_SHIFT)); |
cdb8c2a6 GL |
2686 | *offset &= ~PAGE_MASK; |
2687 | ||
2688 | /* Bytes in this sg-entry from *offset to the end of the page */ | |
2689 | sg_len = PAGE_SIZE - *offset; | |
2690 | if (*len > sg_len) | |
2691 | *len = sg_len; | |
2692 | ||
2693 | return kmap_atomic(page, KM_BIO_SRC_IRQ); | |
2694 | } | |
2695 | EXPORT_SYMBOL(scsi_kmap_atomic_sg); | |
2696 | ||
2697 | /** | |
eb44820c | 2698 | * scsi_kunmap_atomic_sg - atomically unmap a virtual address, previously mapped with scsi_kmap_atomic_sg |
cdb8c2a6 GL |
2699 | * @virt: virtual address to be unmapped |
2700 | */ | |
2701 | void scsi_kunmap_atomic_sg(void *virt) | |
2702 | { | |
2703 | kunmap_atomic(virt, KM_BIO_SRC_IRQ); | |
2704 | } | |
2705 | EXPORT_SYMBOL(scsi_kunmap_atomic_sg); |