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1da177e4 LT |
1 | /* |
2 | * scsi_lib.c Copyright (C) 1999 Eric Youngdale | |
3 | * | |
4 | * SCSI queueing library. | |
5 | * Initial versions: Eric Youngdale (eric@andante.org). | |
6 | * Based upon conversations with large numbers | |
7 | * of people at Linux Expo. | |
8 | */ | |
9 | ||
10 | #include <linux/bio.h> | |
d3f46f39 | 11 | #include <linux/bitops.h> |
1da177e4 LT |
12 | #include <linux/blkdev.h> |
13 | #include <linux/completion.h> | |
14 | #include <linux/kernel.h> | |
15 | #include <linux/mempool.h> | |
16 | #include <linux/slab.h> | |
17 | #include <linux/init.h> | |
18 | #include <linux/pci.h> | |
19 | #include <linux/delay.h> | |
faead26d | 20 | #include <linux/hardirq.h> |
c6132da1 | 21 | #include <linux/scatterlist.h> |
1da177e4 LT |
22 | |
23 | #include <scsi/scsi.h> | |
beb40487 | 24 | #include <scsi/scsi_cmnd.h> |
1da177e4 LT |
25 | #include <scsi/scsi_dbg.h> |
26 | #include <scsi/scsi_device.h> | |
27 | #include <scsi/scsi_driver.h> | |
28 | #include <scsi/scsi_eh.h> | |
29 | #include <scsi/scsi_host.h> | |
1da177e4 LT |
30 | |
31 | #include "scsi_priv.h" | |
32 | #include "scsi_logging.h" | |
33 | ||
34 | ||
6391a113 | 35 | #define SG_MEMPOOL_NR ARRAY_SIZE(scsi_sg_pools) |
5972511b | 36 | #define SG_MEMPOOL_SIZE 2 |
1da177e4 LT |
37 | |
38 | struct scsi_host_sg_pool { | |
39 | size_t size; | |
a8474ce2 | 40 | char *name; |
e18b890b | 41 | struct kmem_cache *slab; |
1da177e4 LT |
42 | mempool_t *pool; |
43 | }; | |
44 | ||
d3f46f39 JB |
45 | #define SP(x) { x, "sgpool-" __stringify(x) } |
46 | #if (SCSI_MAX_SG_SEGMENTS < 32) | |
47 | #error SCSI_MAX_SG_SEGMENTS is too small (must be 32 or greater) | |
48 | #endif | |
52c1da39 | 49 | static struct scsi_host_sg_pool scsi_sg_pools[] = { |
1da177e4 LT |
50 | SP(8), |
51 | SP(16), | |
fd820f40 | 52 | #if (SCSI_MAX_SG_SEGMENTS > 32) |
d3f46f39 | 53 | SP(32), |
fd820f40 | 54 | #if (SCSI_MAX_SG_SEGMENTS > 64) |
d3f46f39 JB |
55 | SP(64), |
56 | #if (SCSI_MAX_SG_SEGMENTS > 128) | |
1da177e4 | 57 | SP(128), |
d3f46f39 JB |
58 | #if (SCSI_MAX_SG_SEGMENTS > 256) |
59 | #error SCSI_MAX_SG_SEGMENTS is too large (256 MAX) | |
fd820f40 FT |
60 | #endif |
61 | #endif | |
62 | #endif | |
d3f46f39 JB |
63 | #endif |
64 | SP(SCSI_MAX_SG_SEGMENTS) | |
a8474ce2 | 65 | }; |
1da177e4 LT |
66 | #undef SP |
67 | ||
7027ad72 | 68 | struct kmem_cache *scsi_sdb_cache; |
6f9a35e2 | 69 | |
a1bf9d1d | 70 | static void scsi_run_queue(struct request_queue *q); |
e91442b6 JB |
71 | |
72 | /* | |
73 | * Function: scsi_unprep_request() | |
74 | * | |
75 | * Purpose: Remove all preparation done for a request, including its | |
76 | * associated scsi_cmnd, so that it can be requeued. | |
77 | * | |
78 | * Arguments: req - request to unprepare | |
79 | * | |
80 | * Lock status: Assumed that no locks are held upon entry. | |
81 | * | |
82 | * Returns: Nothing. | |
83 | */ | |
84 | static void scsi_unprep_request(struct request *req) | |
85 | { | |
86 | struct scsi_cmnd *cmd = req->special; | |
87 | ||
4aff5e23 | 88 | req->cmd_flags &= ~REQ_DONTPREP; |
beb40487 | 89 | req->special = NULL; |
e91442b6 | 90 | |
e91442b6 JB |
91 | scsi_put_command(cmd); |
92 | } | |
a1bf9d1d | 93 | |
4f5299ac JB |
94 | /** |
95 | * __scsi_queue_insert - private queue insertion | |
96 | * @cmd: The SCSI command being requeued | |
97 | * @reason: The reason for the requeue | |
98 | * @unbusy: Whether the queue should be unbusied | |
1da177e4 | 99 | * |
4f5299ac JB |
100 | * This is a private queue insertion. The public interface |
101 | * scsi_queue_insert() always assumes the queue should be unbusied | |
102 | * because it's always called before the completion. This function is | |
103 | * for a requeue after completion, which should only occur in this | |
104 | * file. | |
1da177e4 | 105 | */ |
4f5299ac | 106 | static int __scsi_queue_insert(struct scsi_cmnd *cmd, int reason, int unbusy) |
1da177e4 LT |
107 | { |
108 | struct Scsi_Host *host = cmd->device->host; | |
109 | struct scsi_device *device = cmd->device; | |
f0c0a376 | 110 | struct scsi_target *starget = scsi_target(device); |
a1bf9d1d TH |
111 | struct request_queue *q = device->request_queue; |
112 | unsigned long flags; | |
1da177e4 LT |
113 | |
114 | SCSI_LOG_MLQUEUE(1, | |
115 | printk("Inserting command %p into mlqueue\n", cmd)); | |
116 | ||
117 | /* | |
d8c37e7b | 118 | * Set the appropriate busy bit for the device/host. |
1da177e4 LT |
119 | * |
120 | * If the host/device isn't busy, assume that something actually | |
121 | * completed, and that we should be able to queue a command now. | |
122 | * | |
123 | * Note that the prior mid-layer assumption that any host could | |
124 | * always queue at least one command is now broken. The mid-layer | |
125 | * will implement a user specifiable stall (see | |
126 | * scsi_host.max_host_blocked and scsi_device.max_device_blocked) | |
127 | * if a command is requeued with no other commands outstanding | |
128 | * either for the device or for the host. | |
129 | */ | |
f0c0a376 MC |
130 | switch (reason) { |
131 | case SCSI_MLQUEUE_HOST_BUSY: | |
1da177e4 | 132 | host->host_blocked = host->max_host_blocked; |
f0c0a376 MC |
133 | break; |
134 | case SCSI_MLQUEUE_DEVICE_BUSY: | |
1da177e4 | 135 | device->device_blocked = device->max_device_blocked; |
f0c0a376 MC |
136 | break; |
137 | case SCSI_MLQUEUE_TARGET_BUSY: | |
138 | starget->target_blocked = starget->max_target_blocked; | |
139 | break; | |
140 | } | |
1da177e4 | 141 | |
1da177e4 LT |
142 | /* |
143 | * Decrement the counters, since these commands are no longer | |
144 | * active on the host/device. | |
145 | */ | |
4f5299ac JB |
146 | if (unbusy) |
147 | scsi_device_unbusy(device); | |
1da177e4 LT |
148 | |
149 | /* | |
a1bf9d1d TH |
150 | * Requeue this command. It will go before all other commands |
151 | * that are already in the queue. | |
1da177e4 LT |
152 | * |
153 | * NOTE: there is magic here about the way the queue is plugged if | |
154 | * we have no outstanding commands. | |
155 | * | |
a1bf9d1d | 156 | * Although we *don't* plug the queue, we call the request |
1da177e4 LT |
157 | * function. The SCSI request function detects the blocked condition |
158 | * and plugs the queue appropriately. | |
a1bf9d1d TH |
159 | */ |
160 | spin_lock_irqsave(q->queue_lock, flags); | |
59897dad | 161 | blk_requeue_request(q, cmd->request); |
a1bf9d1d TH |
162 | spin_unlock_irqrestore(q->queue_lock, flags); |
163 | ||
164 | scsi_run_queue(q); | |
165 | ||
1da177e4 LT |
166 | return 0; |
167 | } | |
168 | ||
4f5299ac JB |
169 | /* |
170 | * Function: scsi_queue_insert() | |
171 | * | |
172 | * Purpose: Insert a command in the midlevel queue. | |
173 | * | |
174 | * Arguments: cmd - command that we are adding to queue. | |
175 | * reason - why we are inserting command to queue. | |
176 | * | |
177 | * Lock status: Assumed that lock is not held upon entry. | |
178 | * | |
179 | * Returns: Nothing. | |
180 | * | |
181 | * Notes: We do this for one of two cases. Either the host is busy | |
182 | * and it cannot accept any more commands for the time being, | |
183 | * or the device returned QUEUE_FULL and can accept no more | |
184 | * commands. | |
185 | * Notes: This could be called either from an interrupt context or a | |
186 | * normal process context. | |
187 | */ | |
188 | int scsi_queue_insert(struct scsi_cmnd *cmd, int reason) | |
189 | { | |
190 | return __scsi_queue_insert(cmd, reason, 1); | |
191 | } | |
39216033 | 192 | /** |
33aa687d | 193 | * scsi_execute - insert request and wait for the result |
39216033 JB |
194 | * @sdev: scsi device |
195 | * @cmd: scsi command | |
196 | * @data_direction: data direction | |
197 | * @buffer: data buffer | |
198 | * @bufflen: len of buffer | |
199 | * @sense: optional sense buffer | |
200 | * @timeout: request timeout in seconds | |
201 | * @retries: number of times to retry request | |
33aa687d | 202 | * @flags: or into request flags; |
f4f4e47e | 203 | * @resid: optional residual length |
39216033 | 204 | * |
59c51591 | 205 | * returns the req->errors value which is the scsi_cmnd result |
ea73a9f2 | 206 | * field. |
eb44820c | 207 | */ |
33aa687d JB |
208 | int scsi_execute(struct scsi_device *sdev, const unsigned char *cmd, |
209 | int data_direction, void *buffer, unsigned bufflen, | |
f4f4e47e FT |
210 | unsigned char *sense, int timeout, int retries, int flags, |
211 | int *resid) | |
39216033 JB |
212 | { |
213 | struct request *req; | |
214 | int write = (data_direction == DMA_TO_DEVICE); | |
215 | int ret = DRIVER_ERROR << 24; | |
216 | ||
217 | req = blk_get_request(sdev->request_queue, write, __GFP_WAIT); | |
218 | ||
219 | if (bufflen && blk_rq_map_kern(sdev->request_queue, req, | |
220 | buffer, bufflen, __GFP_WAIT)) | |
221 | goto out; | |
222 | ||
223 | req->cmd_len = COMMAND_SIZE(cmd[0]); | |
224 | memcpy(req->cmd, cmd, req->cmd_len); | |
225 | req->sense = sense; | |
226 | req->sense_len = 0; | |
17e01f21 | 227 | req->retries = retries; |
39216033 | 228 | req->timeout = timeout; |
4aff5e23 JA |
229 | req->cmd_type = REQ_TYPE_BLOCK_PC; |
230 | req->cmd_flags |= flags | REQ_QUIET | REQ_PREEMPT; | |
39216033 JB |
231 | |
232 | /* | |
233 | * head injection *required* here otherwise quiesce won't work | |
234 | */ | |
235 | blk_execute_rq(req->q, NULL, req, 1); | |
236 | ||
bdb2b8ca AS |
237 | /* |
238 | * Some devices (USB mass-storage in particular) may transfer | |
239 | * garbage data together with a residue indicating that the data | |
240 | * is invalid. Prevent the garbage from being misinterpreted | |
241 | * and prevent security leaks by zeroing out the excess data. | |
242 | */ | |
243 | if (unlikely(req->data_len > 0 && req->data_len <= bufflen)) | |
244 | memset(buffer + (bufflen - req->data_len), 0, req->data_len); | |
245 | ||
f4f4e47e FT |
246 | if (resid) |
247 | *resid = req->data_len; | |
39216033 JB |
248 | ret = req->errors; |
249 | out: | |
250 | blk_put_request(req); | |
251 | ||
252 | return ret; | |
253 | } | |
33aa687d | 254 | EXPORT_SYMBOL(scsi_execute); |
39216033 | 255 | |
ea73a9f2 JB |
256 | |
257 | int scsi_execute_req(struct scsi_device *sdev, const unsigned char *cmd, | |
258 | int data_direction, void *buffer, unsigned bufflen, | |
f4f4e47e FT |
259 | struct scsi_sense_hdr *sshdr, int timeout, int retries, |
260 | int *resid) | |
ea73a9f2 JB |
261 | { |
262 | char *sense = NULL; | |
1ccb48bb | 263 | int result; |
264 | ||
ea73a9f2 | 265 | if (sshdr) { |
24669f75 | 266 | sense = kzalloc(SCSI_SENSE_BUFFERSIZE, GFP_NOIO); |
ea73a9f2 JB |
267 | if (!sense) |
268 | return DRIVER_ERROR << 24; | |
ea73a9f2 | 269 | } |
1ccb48bb | 270 | result = scsi_execute(sdev, cmd, data_direction, buffer, bufflen, |
f4f4e47e | 271 | sense, timeout, retries, 0, resid); |
ea73a9f2 | 272 | if (sshdr) |
e514385b | 273 | scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE, sshdr); |
ea73a9f2 JB |
274 | |
275 | kfree(sense); | |
276 | return result; | |
277 | } | |
278 | EXPORT_SYMBOL(scsi_execute_req); | |
279 | ||
6e68af66 MC |
280 | struct scsi_io_context { |
281 | void *data; | |
282 | void (*done)(void *data, char *sense, int result, int resid); | |
283 | char sense[SCSI_SENSE_BUFFERSIZE]; | |
284 | }; | |
285 | ||
e18b890b | 286 | static struct kmem_cache *scsi_io_context_cache; |
aa7b5cd7 | 287 | |
e650c305 | 288 | static void scsi_end_async(struct request *req, int uptodate) |
6e68af66 MC |
289 | { |
290 | struct scsi_io_context *sioc = req->end_io_data; | |
291 | ||
292 | if (sioc->done) | |
293 | sioc->done(sioc->data, sioc->sense, req->errors, req->data_len); | |
294 | ||
aa7b5cd7 | 295 | kmem_cache_free(scsi_io_context_cache, sioc); |
6e68af66 MC |
296 | __blk_put_request(req->q, req); |
297 | } | |
298 | ||
299 | static int scsi_merge_bio(struct request *rq, struct bio *bio) | |
300 | { | |
301 | struct request_queue *q = rq->q; | |
302 | ||
303 | bio->bi_flags &= ~(1 << BIO_SEG_VALID); | |
304 | if (rq_data_dir(rq) == WRITE) | |
305 | bio->bi_rw |= (1 << BIO_RW); | |
306 | blk_queue_bounce(q, &bio); | |
307 | ||
3001ca77 | 308 | return blk_rq_append_bio(q, rq, bio); |
6e68af66 MC |
309 | } |
310 | ||
6712ecf8 | 311 | static void scsi_bi_endio(struct bio *bio, int error) |
6e68af66 | 312 | { |
6e68af66 | 313 | bio_put(bio); |
6e68af66 MC |
314 | } |
315 | ||
316 | /** | |
317 | * scsi_req_map_sg - map a scatterlist into a request | |
318 | * @rq: request to fill | |
eb44820c | 319 | * @sgl: scatterlist |
6e68af66 MC |
320 | * @nsegs: number of elements |
321 | * @bufflen: len of buffer | |
322 | * @gfp: memory allocation flags | |
323 | * | |
324 | * scsi_req_map_sg maps a scatterlist into a request so that the | |
325 | * request can be sent to the block layer. We do not trust the scatterlist | |
326 | * sent to use, as some ULDs use that struct to only organize the pages. | |
327 | */ | |
328 | static int scsi_req_map_sg(struct request *rq, struct scatterlist *sgl, | |
329 | int nsegs, unsigned bufflen, gfp_t gfp) | |
330 | { | |
331 | struct request_queue *q = rq->q; | |
f5235962 | 332 | int nr_pages = (bufflen + sgl[0].offset + PAGE_SIZE - 1) >> PAGE_SHIFT; |
bd441dea | 333 | unsigned int data_len = bufflen, len, bytes, off; |
c6132da1 | 334 | struct scatterlist *sg; |
6e68af66 MC |
335 | struct page *page; |
336 | struct bio *bio = NULL; | |
337 | int i, err, nr_vecs = 0; | |
338 | ||
c6132da1 | 339 | for_each_sg(sgl, sg, nsegs, i) { |
45711f1a | 340 | page = sg_page(sg); |
c6132da1 JA |
341 | off = sg->offset; |
342 | len = sg->length; | |
6e68af66 | 343 | |
bd441dea MC |
344 | while (len > 0 && data_len > 0) { |
345 | /* | |
346 | * sg sends a scatterlist that is larger than | |
347 | * the data_len it wants transferred for certain | |
348 | * IO sizes | |
349 | */ | |
6e68af66 | 350 | bytes = min_t(unsigned int, len, PAGE_SIZE - off); |
bd441dea | 351 | bytes = min(bytes, data_len); |
6e68af66 MC |
352 | |
353 | if (!bio) { | |
354 | nr_vecs = min_t(int, BIO_MAX_PAGES, nr_pages); | |
355 | nr_pages -= nr_vecs; | |
356 | ||
357 | bio = bio_alloc(gfp, nr_vecs); | |
358 | if (!bio) { | |
359 | err = -ENOMEM; | |
360 | goto free_bios; | |
361 | } | |
362 | bio->bi_end_io = scsi_bi_endio; | |
363 | } | |
364 | ||
365 | if (bio_add_pc_page(q, bio, page, bytes, off) != | |
366 | bytes) { | |
367 | bio_put(bio); | |
368 | err = -EINVAL; | |
369 | goto free_bios; | |
370 | } | |
371 | ||
372 | if (bio->bi_vcnt >= nr_vecs) { | |
373 | err = scsi_merge_bio(rq, bio); | |
374 | if (err) { | |
6712ecf8 | 375 | bio_endio(bio, 0); |
6e68af66 MC |
376 | goto free_bios; |
377 | } | |
378 | bio = NULL; | |
379 | } | |
380 | ||
381 | page++; | |
382 | len -= bytes; | |
bd441dea | 383 | data_len -=bytes; |
6e68af66 MC |
384 | off = 0; |
385 | } | |
386 | } | |
387 | ||
388 | rq->buffer = rq->data = NULL; | |
bd441dea | 389 | rq->data_len = bufflen; |
6e68af66 MC |
390 | return 0; |
391 | ||
392 | free_bios: | |
393 | while ((bio = rq->bio) != NULL) { | |
394 | rq->bio = bio->bi_next; | |
395 | /* | |
396 | * call endio instead of bio_put incase it was bounced | |
397 | */ | |
6712ecf8 | 398 | bio_endio(bio, 0); |
6e68af66 MC |
399 | } |
400 | ||
401 | return err; | |
402 | } | |
403 | ||
404 | /** | |
405 | * scsi_execute_async - insert request | |
406 | * @sdev: scsi device | |
407 | * @cmd: scsi command | |
bb1d1073 | 408 | * @cmd_len: length of scsi cdb |
eb44820c | 409 | * @data_direction: DMA_TO_DEVICE, DMA_FROM_DEVICE, or DMA_NONE |
6e68af66 MC |
410 | * @buffer: data buffer (this can be a kernel buffer or scatterlist) |
411 | * @bufflen: len of buffer | |
412 | * @use_sg: if buffer is a scatterlist this is the number of elements | |
413 | * @timeout: request timeout in seconds | |
414 | * @retries: number of times to retry request | |
eb44820c RL |
415 | * @privdata: data passed to done() |
416 | * @done: callback function when done | |
417 | * @gfp: memory allocation flags | |
418 | */ | |
6e68af66 | 419 | int scsi_execute_async(struct scsi_device *sdev, const unsigned char *cmd, |
bb1d1073 | 420 | int cmd_len, int data_direction, void *buffer, unsigned bufflen, |
6e68af66 MC |
421 | int use_sg, int timeout, int retries, void *privdata, |
422 | void (*done)(void *, char *, int, int), gfp_t gfp) | |
423 | { | |
424 | struct request *req; | |
425 | struct scsi_io_context *sioc; | |
426 | int err = 0; | |
427 | int write = (data_direction == DMA_TO_DEVICE); | |
428 | ||
c3762229 | 429 | sioc = kmem_cache_zalloc(scsi_io_context_cache, gfp); |
6e68af66 MC |
430 | if (!sioc) |
431 | return DRIVER_ERROR << 24; | |
432 | ||
433 | req = blk_get_request(sdev->request_queue, write, gfp); | |
434 | if (!req) | |
435 | goto free_sense; | |
4aff5e23 JA |
436 | req->cmd_type = REQ_TYPE_BLOCK_PC; |
437 | req->cmd_flags |= REQ_QUIET; | |
6e68af66 MC |
438 | |
439 | if (use_sg) | |
440 | err = scsi_req_map_sg(req, buffer, use_sg, bufflen, gfp); | |
441 | else if (bufflen) | |
442 | err = blk_rq_map_kern(req->q, req, buffer, bufflen, gfp); | |
443 | ||
444 | if (err) | |
445 | goto free_req; | |
446 | ||
bb1d1073 | 447 | req->cmd_len = cmd_len; |
097b8457 | 448 | memset(req->cmd, 0, BLK_MAX_CDB); /* ATAPI hates garbage after CDB */ |
6e68af66 MC |
449 | memcpy(req->cmd, cmd, req->cmd_len); |
450 | req->sense = sioc->sense; | |
451 | req->sense_len = 0; | |
452 | req->timeout = timeout; | |
17e01f21 | 453 | req->retries = retries; |
6e68af66 MC |
454 | req->end_io_data = sioc; |
455 | ||
456 | sioc->data = privdata; | |
457 | sioc->done = done; | |
458 | ||
459 | blk_execute_rq_nowait(req->q, NULL, req, 1, scsi_end_async); | |
460 | return 0; | |
461 | ||
462 | free_req: | |
463 | blk_put_request(req); | |
464 | free_sense: | |
6470f2ba | 465 | kmem_cache_free(scsi_io_context_cache, sioc); |
6e68af66 MC |
466 | return DRIVER_ERROR << 24; |
467 | } | |
468 | EXPORT_SYMBOL_GPL(scsi_execute_async); | |
469 | ||
1da177e4 LT |
470 | /* |
471 | * Function: scsi_init_cmd_errh() | |
472 | * | |
473 | * Purpose: Initialize cmd fields related to error handling. | |
474 | * | |
475 | * Arguments: cmd - command that is ready to be queued. | |
476 | * | |
1da177e4 LT |
477 | * Notes: This function has the job of initializing a number of |
478 | * fields related to error handling. Typically this will | |
479 | * be called once for each command, as required. | |
480 | */ | |
631c228c | 481 | static void scsi_init_cmd_errh(struct scsi_cmnd *cmd) |
1da177e4 | 482 | { |
1da177e4 | 483 | cmd->serial_number = 0; |
30b0c37b | 484 | scsi_set_resid(cmd, 0); |
b80ca4f7 | 485 | memset(cmd->sense_buffer, 0, SCSI_SENSE_BUFFERSIZE); |
1da177e4 | 486 | if (cmd->cmd_len == 0) |
db4742dd | 487 | cmd->cmd_len = scsi_command_size(cmd->cmnd); |
1da177e4 LT |
488 | } |
489 | ||
490 | void scsi_device_unbusy(struct scsi_device *sdev) | |
491 | { | |
492 | struct Scsi_Host *shost = sdev->host; | |
f0c0a376 | 493 | struct scsi_target *starget = scsi_target(sdev); |
1da177e4 LT |
494 | unsigned long flags; |
495 | ||
496 | spin_lock_irqsave(shost->host_lock, flags); | |
497 | shost->host_busy--; | |
f0c0a376 | 498 | starget->target_busy--; |
939647ee | 499 | if (unlikely(scsi_host_in_recovery(shost) && |
ee7863bc | 500 | (shost->host_failed || shost->host_eh_scheduled))) |
1da177e4 LT |
501 | scsi_eh_wakeup(shost); |
502 | spin_unlock(shost->host_lock); | |
152587de | 503 | spin_lock(sdev->request_queue->queue_lock); |
1da177e4 | 504 | sdev->device_busy--; |
152587de | 505 | spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags); |
1da177e4 LT |
506 | } |
507 | ||
508 | /* | |
509 | * Called for single_lun devices on IO completion. Clear starget_sdev_user, | |
510 | * and call blk_run_queue for all the scsi_devices on the target - | |
511 | * including current_sdev first. | |
512 | * | |
513 | * Called with *no* scsi locks held. | |
514 | */ | |
515 | static void scsi_single_lun_run(struct scsi_device *current_sdev) | |
516 | { | |
517 | struct Scsi_Host *shost = current_sdev->host; | |
518 | struct scsi_device *sdev, *tmp; | |
519 | struct scsi_target *starget = scsi_target(current_sdev); | |
520 | unsigned long flags; | |
521 | ||
522 | spin_lock_irqsave(shost->host_lock, flags); | |
523 | starget->starget_sdev_user = NULL; | |
524 | spin_unlock_irqrestore(shost->host_lock, flags); | |
525 | ||
526 | /* | |
527 | * Call blk_run_queue for all LUNs on the target, starting with | |
528 | * current_sdev. We race with others (to set starget_sdev_user), | |
529 | * but in most cases, we will be first. Ideally, each LU on the | |
530 | * target would get some limited time or requests on the target. | |
531 | */ | |
532 | blk_run_queue(current_sdev->request_queue); | |
533 | ||
534 | spin_lock_irqsave(shost->host_lock, flags); | |
535 | if (starget->starget_sdev_user) | |
536 | goto out; | |
537 | list_for_each_entry_safe(sdev, tmp, &starget->devices, | |
538 | same_target_siblings) { | |
539 | if (sdev == current_sdev) | |
540 | continue; | |
541 | if (scsi_device_get(sdev)) | |
542 | continue; | |
543 | ||
544 | spin_unlock_irqrestore(shost->host_lock, flags); | |
545 | blk_run_queue(sdev->request_queue); | |
546 | spin_lock_irqsave(shost->host_lock, flags); | |
547 | ||
548 | scsi_device_put(sdev); | |
549 | } | |
550 | out: | |
551 | spin_unlock_irqrestore(shost->host_lock, flags); | |
552 | } | |
553 | ||
9d112517 KU |
554 | static inline int scsi_device_is_busy(struct scsi_device *sdev) |
555 | { | |
556 | if (sdev->device_busy >= sdev->queue_depth || sdev->device_blocked) | |
557 | return 1; | |
558 | ||
559 | return 0; | |
560 | } | |
561 | ||
f0c0a376 MC |
562 | static inline int scsi_target_is_busy(struct scsi_target *starget) |
563 | { | |
564 | return ((starget->can_queue > 0 && | |
565 | starget->target_busy >= starget->can_queue) || | |
566 | starget->target_blocked); | |
567 | } | |
568 | ||
9d112517 KU |
569 | static inline int scsi_host_is_busy(struct Scsi_Host *shost) |
570 | { | |
571 | if ((shost->can_queue > 0 && shost->host_busy >= shost->can_queue) || | |
572 | shost->host_blocked || shost->host_self_blocked) | |
573 | return 1; | |
574 | ||
575 | return 0; | |
576 | } | |
577 | ||
1da177e4 LT |
578 | /* |
579 | * Function: scsi_run_queue() | |
580 | * | |
581 | * Purpose: Select a proper request queue to serve next | |
582 | * | |
583 | * Arguments: q - last request's queue | |
584 | * | |
585 | * Returns: Nothing | |
586 | * | |
587 | * Notes: The previous command was completely finished, start | |
588 | * a new one if possible. | |
589 | */ | |
590 | static void scsi_run_queue(struct request_queue *q) | |
591 | { | |
2a3a59e5 | 592 | struct scsi_device *sdev = q->queuedata; |
1da177e4 | 593 | struct Scsi_Host *shost = sdev->host; |
2a3a59e5 | 594 | LIST_HEAD(starved_list); |
1da177e4 LT |
595 | unsigned long flags; |
596 | ||
25d7c363 | 597 | if (scsi_target(sdev)->single_lun) |
1da177e4 LT |
598 | scsi_single_lun_run(sdev); |
599 | ||
600 | spin_lock_irqsave(shost->host_lock, flags); | |
2a3a59e5 MC |
601 | list_splice_init(&shost->starved_list, &starved_list); |
602 | ||
603 | while (!list_empty(&starved_list)) { | |
75ad23bc NP |
604 | int flagset; |
605 | ||
1da177e4 LT |
606 | /* |
607 | * As long as shost is accepting commands and we have | |
608 | * starved queues, call blk_run_queue. scsi_request_fn | |
609 | * drops the queue_lock and can add us back to the | |
610 | * starved_list. | |
611 | * | |
612 | * host_lock protects the starved_list and starved_entry. | |
613 | * scsi_request_fn must get the host_lock before checking | |
614 | * or modifying starved_list or starved_entry. | |
615 | */ | |
2a3a59e5 | 616 | if (scsi_host_is_busy(shost)) |
f0c0a376 | 617 | break; |
f0c0a376 | 618 | |
2a3a59e5 MC |
619 | sdev = list_entry(starved_list.next, |
620 | struct scsi_device, starved_entry); | |
621 | list_del_init(&sdev->starved_entry); | |
f0c0a376 MC |
622 | if (scsi_target_is_busy(scsi_target(sdev))) { |
623 | list_move_tail(&sdev->starved_entry, | |
624 | &shost->starved_list); | |
625 | continue; | |
626 | } | |
627 | ||
75ad23bc NP |
628 | spin_unlock(shost->host_lock); |
629 | ||
630 | spin_lock(sdev->request_queue->queue_lock); | |
631 | flagset = test_bit(QUEUE_FLAG_REENTER, &q->queue_flags) && | |
632 | !test_bit(QUEUE_FLAG_REENTER, | |
633 | &sdev->request_queue->queue_flags); | |
634 | if (flagset) | |
635 | queue_flag_set(QUEUE_FLAG_REENTER, sdev->request_queue); | |
636 | __blk_run_queue(sdev->request_queue); | |
637 | if (flagset) | |
638 | queue_flag_clear(QUEUE_FLAG_REENTER, sdev->request_queue); | |
639 | spin_unlock(sdev->request_queue->queue_lock); | |
04846f25 | 640 | |
75ad23bc | 641 | spin_lock(shost->host_lock); |
1da177e4 | 642 | } |
2a3a59e5 MC |
643 | /* put any unprocessed entries back */ |
644 | list_splice(&starved_list, &shost->starved_list); | |
1da177e4 LT |
645 | spin_unlock_irqrestore(shost->host_lock, flags); |
646 | ||
647 | blk_run_queue(q); | |
648 | } | |
649 | ||
650 | /* | |
651 | * Function: scsi_requeue_command() | |
652 | * | |
653 | * Purpose: Handle post-processing of completed commands. | |
654 | * | |
655 | * Arguments: q - queue to operate on | |
656 | * cmd - command that may need to be requeued. | |
657 | * | |
658 | * Returns: Nothing | |
659 | * | |
660 | * Notes: After command completion, there may be blocks left | |
661 | * over which weren't finished by the previous command | |
662 | * this can be for a number of reasons - the main one is | |
663 | * I/O errors in the middle of the request, in which case | |
664 | * we need to request the blocks that come after the bad | |
665 | * sector. | |
e91442b6 | 666 | * Notes: Upon return, cmd is a stale pointer. |
1da177e4 LT |
667 | */ |
668 | static void scsi_requeue_command(struct request_queue *q, struct scsi_cmnd *cmd) | |
669 | { | |
e91442b6 | 670 | struct request *req = cmd->request; |
283369cc TH |
671 | unsigned long flags; |
672 | ||
283369cc | 673 | spin_lock_irqsave(q->queue_lock, flags); |
02bd3499 | 674 | scsi_unprep_request(req); |
e91442b6 | 675 | blk_requeue_request(q, req); |
283369cc | 676 | spin_unlock_irqrestore(q->queue_lock, flags); |
1da177e4 LT |
677 | |
678 | scsi_run_queue(q); | |
679 | } | |
680 | ||
681 | void scsi_next_command(struct scsi_cmnd *cmd) | |
682 | { | |
49d7bc64 LT |
683 | struct scsi_device *sdev = cmd->device; |
684 | struct request_queue *q = sdev->request_queue; | |
685 | ||
686 | /* need to hold a reference on the device before we let go of the cmd */ | |
687 | get_device(&sdev->sdev_gendev); | |
1da177e4 LT |
688 | |
689 | scsi_put_command(cmd); | |
690 | scsi_run_queue(q); | |
49d7bc64 LT |
691 | |
692 | /* ok to remove device now */ | |
693 | put_device(&sdev->sdev_gendev); | |
1da177e4 LT |
694 | } |
695 | ||
696 | void scsi_run_host_queues(struct Scsi_Host *shost) | |
697 | { | |
698 | struct scsi_device *sdev; | |
699 | ||
700 | shost_for_each_device(sdev, shost) | |
701 | scsi_run_queue(sdev->request_queue); | |
702 | } | |
703 | ||
704 | /* | |
705 | * Function: scsi_end_request() | |
706 | * | |
707 | * Purpose: Post-processing of completed commands (usually invoked at end | |
708 | * of upper level post-processing and scsi_io_completion). | |
709 | * | |
710 | * Arguments: cmd - command that is complete. | |
610d8b0c | 711 | * error - 0 if I/O indicates success, < 0 for I/O error. |
1da177e4 LT |
712 | * bytes - number of bytes of completed I/O |
713 | * requeue - indicates whether we should requeue leftovers. | |
714 | * | |
715 | * Lock status: Assumed that lock is not held upon entry. | |
716 | * | |
e91442b6 | 717 | * Returns: cmd if requeue required, NULL otherwise. |
1da177e4 LT |
718 | * |
719 | * Notes: This is called for block device requests in order to | |
720 | * mark some number of sectors as complete. | |
721 | * | |
722 | * We are guaranteeing that the request queue will be goosed | |
723 | * at some point during this call. | |
e91442b6 | 724 | * Notes: If cmd was requeued, upon return it will be a stale pointer. |
1da177e4 | 725 | */ |
610d8b0c | 726 | static struct scsi_cmnd *scsi_end_request(struct scsi_cmnd *cmd, int error, |
1da177e4 LT |
727 | int bytes, int requeue) |
728 | { | |
165125e1 | 729 | struct request_queue *q = cmd->device->request_queue; |
1da177e4 | 730 | struct request *req = cmd->request; |
1da177e4 LT |
731 | |
732 | /* | |
733 | * If there are blocks left over at the end, set up the command | |
734 | * to queue the remainder of them. | |
735 | */ | |
610d8b0c | 736 | if (blk_end_request(req, error, bytes)) { |
1da177e4 LT |
737 | int leftover = (req->hard_nr_sectors << 9); |
738 | ||
739 | if (blk_pc_request(req)) | |
740 | leftover = req->data_len; | |
741 | ||
742 | /* kill remainder if no retrys */ | |
4a27446f | 743 | if (error && scsi_noretry_cmd(cmd)) |
610d8b0c | 744 | blk_end_request(req, error, leftover); |
1da177e4 | 745 | else { |
e91442b6 | 746 | if (requeue) { |
1da177e4 LT |
747 | /* |
748 | * Bleah. Leftovers again. Stick the | |
749 | * leftovers in the front of the | |
750 | * queue, and goose the queue again. | |
751 | */ | |
752 | scsi_requeue_command(q, cmd); | |
e91442b6 JB |
753 | cmd = NULL; |
754 | } | |
1da177e4 LT |
755 | return cmd; |
756 | } | |
757 | } | |
758 | ||
1da177e4 LT |
759 | /* |
760 | * This will goose the queue request function at the end, so we don't | |
761 | * need to worry about launching another command. | |
762 | */ | |
763 | scsi_next_command(cmd); | |
764 | return NULL; | |
765 | } | |
766 | ||
a8474ce2 JA |
767 | static inline unsigned int scsi_sgtable_index(unsigned short nents) |
768 | { | |
769 | unsigned int index; | |
770 | ||
d3f46f39 JB |
771 | BUG_ON(nents > SCSI_MAX_SG_SEGMENTS); |
772 | ||
773 | if (nents <= 8) | |
a8474ce2 | 774 | index = 0; |
d3f46f39 JB |
775 | else |
776 | index = get_count_order(nents) - 3; | |
1da177e4 | 777 | |
a8474ce2 JA |
778 | return index; |
779 | } | |
780 | ||
5ed7959e | 781 | static void scsi_sg_free(struct scatterlist *sgl, unsigned int nents) |
a8474ce2 JA |
782 | { |
783 | struct scsi_host_sg_pool *sgp; | |
a8474ce2 | 784 | |
5ed7959e JA |
785 | sgp = scsi_sg_pools + scsi_sgtable_index(nents); |
786 | mempool_free(sgl, sgp->pool); | |
787 | } | |
a8474ce2 | 788 | |
5ed7959e JA |
789 | static struct scatterlist *scsi_sg_alloc(unsigned int nents, gfp_t gfp_mask) |
790 | { | |
791 | struct scsi_host_sg_pool *sgp; | |
a8474ce2 | 792 | |
5ed7959e JA |
793 | sgp = scsi_sg_pools + scsi_sgtable_index(nents); |
794 | return mempool_alloc(sgp->pool, gfp_mask); | |
795 | } | |
a3bec5c5 | 796 | |
30b0c37b BH |
797 | static int scsi_alloc_sgtable(struct scsi_data_buffer *sdb, int nents, |
798 | gfp_t gfp_mask) | |
5ed7959e JA |
799 | { |
800 | int ret; | |
a8474ce2 | 801 | |
30b0c37b | 802 | BUG_ON(!nents); |
a8474ce2 | 803 | |
30b0c37b BH |
804 | ret = __sg_alloc_table(&sdb->table, nents, SCSI_MAX_SG_SEGMENTS, |
805 | gfp_mask, scsi_sg_alloc); | |
5ed7959e | 806 | if (unlikely(ret)) |
30b0c37b | 807 | __sg_free_table(&sdb->table, SCSI_MAX_SG_SEGMENTS, |
7cedb1f1 | 808 | scsi_sg_free); |
45711f1a | 809 | |
a8474ce2 | 810 | return ret; |
1da177e4 LT |
811 | } |
812 | ||
30b0c37b | 813 | static void scsi_free_sgtable(struct scsi_data_buffer *sdb) |
1da177e4 | 814 | { |
30b0c37b | 815 | __sg_free_table(&sdb->table, SCSI_MAX_SG_SEGMENTS, scsi_sg_free); |
1da177e4 LT |
816 | } |
817 | ||
818 | /* | |
819 | * Function: scsi_release_buffers() | |
820 | * | |
821 | * Purpose: Completion processing for block device I/O requests. | |
822 | * | |
823 | * Arguments: cmd - command that we are bailing. | |
824 | * | |
825 | * Lock status: Assumed that no lock is held upon entry. | |
826 | * | |
827 | * Returns: Nothing | |
828 | * | |
829 | * Notes: In the event that an upper level driver rejects a | |
830 | * command, we must release resources allocated during | |
831 | * the __init_io() function. Primarily this would involve | |
832 | * the scatter-gather table, and potentially any bounce | |
833 | * buffers. | |
834 | */ | |
bb52d82f | 835 | void scsi_release_buffers(struct scsi_cmnd *cmd) |
1da177e4 | 836 | { |
30b0c37b BH |
837 | if (cmd->sdb.table.nents) |
838 | scsi_free_sgtable(&cmd->sdb); | |
1da177e4 | 839 | |
30b0c37b | 840 | memset(&cmd->sdb, 0, sizeof(cmd->sdb)); |
6f9a35e2 BH |
841 | |
842 | if (scsi_bidi_cmnd(cmd)) { | |
843 | struct scsi_data_buffer *bidi_sdb = | |
844 | cmd->request->next_rq->special; | |
845 | scsi_free_sgtable(bidi_sdb); | |
6362abd3 | 846 | kmem_cache_free(scsi_sdb_cache, bidi_sdb); |
6f9a35e2 BH |
847 | cmd->request->next_rq->special = NULL; |
848 | } | |
7027ad72 MP |
849 | |
850 | if (scsi_prot_sg_count(cmd)) | |
851 | scsi_free_sgtable(cmd->prot_sdb); | |
1da177e4 | 852 | } |
bb52d82f | 853 | EXPORT_SYMBOL(scsi_release_buffers); |
1da177e4 | 854 | |
6f9a35e2 BH |
855 | /* |
856 | * Bidi commands Must be complete as a whole, both sides at once. | |
857 | * If part of the bytes were written and lld returned | |
858 | * scsi_in()->resid and/or scsi_out()->resid this information will be left | |
859 | * in req->data_len and req->next_rq->data_len. The upper-layer driver can | |
860 | * decide what to do with this information. | |
861 | */ | |
8c5e03d3 | 862 | static void scsi_end_bidi_request(struct scsi_cmnd *cmd) |
6f9a35e2 | 863 | { |
b8de1631 KU |
864 | struct request *req = cmd->request; |
865 | unsigned int dlen = req->data_len; | |
866 | unsigned int next_dlen = req->next_rq->data_len; | |
867 | ||
868 | req->data_len = scsi_out(cmd)->resid; | |
869 | req->next_rq->data_len = scsi_in(cmd)->resid; | |
870 | ||
871 | /* The req and req->next_rq have not been completed */ | |
872 | BUG_ON(blk_end_bidi_request(req, 0, dlen, next_dlen)); | |
873 | ||
6f9a35e2 BH |
874 | scsi_release_buffers(cmd); |
875 | ||
876 | /* | |
877 | * This will goose the queue request function at the end, so we don't | |
878 | * need to worry about launching another command. | |
879 | */ | |
880 | scsi_next_command(cmd); | |
881 | } | |
882 | ||
1da177e4 LT |
883 | /* |
884 | * Function: scsi_io_completion() | |
885 | * | |
886 | * Purpose: Completion processing for block device I/O requests. | |
887 | * | |
888 | * Arguments: cmd - command that is finished. | |
889 | * | |
890 | * Lock status: Assumed that no lock is held upon entry. | |
891 | * | |
892 | * Returns: Nothing | |
893 | * | |
894 | * Notes: This function is matched in terms of capabilities to | |
895 | * the function that created the scatter-gather list. | |
896 | * In other words, if there are no bounce buffers | |
897 | * (the normal case for most drivers), we don't need | |
898 | * the logic to deal with cleaning up afterwards. | |
899 | * | |
b60af5b0 AS |
900 | * We must call scsi_end_request(). This will finish off |
901 | * the specified number of sectors. If we are done, the | |
902 | * command block will be released and the queue function | |
903 | * will be goosed. If we are not done then we have to | |
904 | * figure out what to do next: | |
1da177e4 | 905 | * |
b60af5b0 AS |
906 | * a) We can call scsi_requeue_command(). The request |
907 | * will be unprepared and put back on the queue. Then | |
908 | * a new command will be created for it. This should | |
909 | * be used if we made forward progress, or if we want | |
910 | * to switch from READ(10) to READ(6) for example. | |
1da177e4 | 911 | * |
b60af5b0 AS |
912 | * b) We can call scsi_queue_insert(). The request will |
913 | * be put back on the queue and retried using the same | |
914 | * command as before, possibly after a delay. | |
915 | * | |
916 | * c) We can call blk_end_request() with -EIO to fail | |
917 | * the remainder of the request. | |
1da177e4 | 918 | */ |
03aba2f7 | 919 | void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes) |
1da177e4 LT |
920 | { |
921 | int result = cmd->result; | |
44ea91c5 | 922 | int this_count; |
165125e1 | 923 | struct request_queue *q = cmd->device->request_queue; |
1da177e4 | 924 | struct request *req = cmd->request; |
fa8e36c3 | 925 | int error = 0; |
1da177e4 LT |
926 | struct scsi_sense_hdr sshdr; |
927 | int sense_valid = 0; | |
928 | int sense_deferred = 0; | |
b60af5b0 AS |
929 | enum {ACTION_FAIL, ACTION_REPREP, ACTION_RETRY, |
930 | ACTION_DELAYED_RETRY} action; | |
931 | char *description = NULL; | |
1da177e4 | 932 | |
1da177e4 LT |
933 | if (result) { |
934 | sense_valid = scsi_command_normalize_sense(cmd, &sshdr); | |
935 | if (sense_valid) | |
936 | sense_deferred = scsi_sense_is_deferred(&sshdr); | |
937 | } | |
631c228c | 938 | |
1da177e4 LT |
939 | if (blk_pc_request(req)) { /* SG_IO ioctl from block level */ |
940 | req->errors = result; | |
941 | if (result) { | |
1da177e4 LT |
942 | if (sense_valid && req->sense) { |
943 | /* | |
944 | * SG_IO wants current and deferred errors | |
945 | */ | |
946 | int len = 8 + cmd->sense_buffer[7]; | |
947 | ||
948 | if (len > SCSI_SENSE_BUFFERSIZE) | |
949 | len = SCSI_SENSE_BUFFERSIZE; | |
950 | memcpy(req->sense, cmd->sense_buffer, len); | |
951 | req->sense_len = len; | |
952 | } | |
fa8e36c3 JB |
953 | if (!sense_deferred) |
954 | error = -EIO; | |
b22f687d | 955 | } |
6f9a35e2 BH |
956 | if (scsi_bidi_cmnd(cmd)) { |
957 | /* will also release_buffers */ | |
958 | scsi_end_bidi_request(cmd); | |
959 | return; | |
960 | } | |
30b0c37b | 961 | req->data_len = scsi_get_resid(cmd); |
1da177e4 LT |
962 | } |
963 | ||
6f9a35e2 | 964 | BUG_ON(blk_bidi_rq(req)); /* bidi not support for !blk_pc_request yet */ |
30b0c37b BH |
965 | scsi_release_buffers(cmd); |
966 | ||
1da177e4 LT |
967 | /* |
968 | * Next deal with any sectors which we were able to correctly | |
969 | * handle. | |
970 | */ | |
d6b0c537 JB |
971 | SCSI_LOG_HLCOMPLETE(1, printk("%ld sectors total, " |
972 | "%d bytes done.\n", | |
973 | req->nr_sectors, good_bytes)); | |
d6b0c537 | 974 | |
d6b0c537 JB |
975 | /* A number of bytes were successfully read. If there |
976 | * are leftovers and there is some kind of error | |
977 | * (result != 0), retry the rest. | |
978 | */ | |
fa8e36c3 | 979 | if (scsi_end_request(cmd, error, good_bytes, result == 0) == NULL) |
d6b0c537 | 980 | return; |
44ea91c5 | 981 | this_count = blk_rq_bytes(req); |
03aba2f7 | 982 | |
b60af5b0 AS |
983 | if (host_byte(result) == DID_RESET) { |
984 | /* Third party bus reset or reset for error recovery | |
985 | * reasons. Just retry the command and see what | |
986 | * happens. | |
987 | */ | |
988 | action = ACTION_RETRY; | |
989 | } else if (sense_valid && !sense_deferred) { | |
1da177e4 LT |
990 | switch (sshdr.sense_key) { |
991 | case UNIT_ATTENTION: | |
992 | if (cmd->device->removable) { | |
03aba2f7 | 993 | /* Detected disc change. Set a bit |
1da177e4 LT |
994 | * and quietly refuse further access. |
995 | */ | |
996 | cmd->device->changed = 1; | |
b60af5b0 AS |
997 | description = "Media Changed"; |
998 | action = ACTION_FAIL; | |
1da177e4 | 999 | } else { |
03aba2f7 LT |
1000 | /* Must have been a power glitch, or a |
1001 | * bus reset. Could not have been a | |
1002 | * media change, so we just retry the | |
b60af5b0 | 1003 | * command and see what happens. |
03aba2f7 | 1004 | */ |
b60af5b0 | 1005 | action = ACTION_RETRY; |
1da177e4 LT |
1006 | } |
1007 | break; | |
1008 | case ILLEGAL_REQUEST: | |
03aba2f7 LT |
1009 | /* If we had an ILLEGAL REQUEST returned, then |
1010 | * we may have performed an unsupported | |
1011 | * command. The only thing this should be | |
1012 | * would be a ten byte read where only a six | |
1013 | * byte read was supported. Also, on a system | |
1014 | * where READ CAPACITY failed, we may have | |
1015 | * read past the end of the disk. | |
1016 | */ | |
26a68019 JA |
1017 | if ((cmd->device->use_10_for_rw && |
1018 | sshdr.asc == 0x20 && sshdr.ascq == 0x00) && | |
1da177e4 LT |
1019 | (cmd->cmnd[0] == READ_10 || |
1020 | cmd->cmnd[0] == WRITE_10)) { | |
b60af5b0 | 1021 | /* This will issue a new 6-byte command. */ |
1da177e4 | 1022 | cmd->device->use_10_for_rw = 0; |
b60af5b0 AS |
1023 | action = ACTION_REPREP; |
1024 | } else | |
1025 | action = ACTION_FAIL; | |
1026 | break; | |
511e44f4 MP |
1027 | case ABORTED_COMMAND: |
1028 | if (sshdr.asc == 0x10) { /* DIF */ | |
b60af5b0 AS |
1029 | action = ACTION_FAIL; |
1030 | description = "Data Integrity Failure"; | |
1031 | } else | |
1032 | action = ACTION_RETRY; | |
1da177e4 LT |
1033 | break; |
1034 | case NOT_READY: | |
03aba2f7 | 1035 | /* If the device is in the process of becoming |
f3e93f73 | 1036 | * ready, or has a temporary blockage, retry. |
1da177e4 | 1037 | */ |
f3e93f73 JB |
1038 | if (sshdr.asc == 0x04) { |
1039 | switch (sshdr.ascq) { | |
1040 | case 0x01: /* becoming ready */ | |
1041 | case 0x04: /* format in progress */ | |
1042 | case 0x05: /* rebuild in progress */ | |
1043 | case 0x06: /* recalculation in progress */ | |
1044 | case 0x07: /* operation in progress */ | |
1045 | case 0x08: /* Long write in progress */ | |
1046 | case 0x09: /* self test in progress */ | |
b60af5b0 | 1047 | action = ACTION_DELAYED_RETRY; |
f3e93f73 | 1048 | break; |
3dbf6a54 AS |
1049 | default: |
1050 | description = "Device not ready"; | |
1051 | action = ACTION_FAIL; | |
1052 | break; | |
f3e93f73 | 1053 | } |
b60af5b0 AS |
1054 | } else { |
1055 | description = "Device not ready"; | |
1056 | action = ACTION_FAIL; | |
1da177e4 | 1057 | } |
b60af5b0 | 1058 | break; |
1da177e4 | 1059 | case VOLUME_OVERFLOW: |
03aba2f7 | 1060 | /* See SSC3rXX or current. */ |
b60af5b0 AS |
1061 | action = ACTION_FAIL; |
1062 | break; | |
1da177e4 | 1063 | default: |
b60af5b0 AS |
1064 | description = "Unhandled sense code"; |
1065 | action = ACTION_FAIL; | |
1da177e4 LT |
1066 | break; |
1067 | } | |
b60af5b0 AS |
1068 | } else { |
1069 | description = "Unhandled error code"; | |
1070 | action = ACTION_FAIL; | |
03aba2f7 | 1071 | } |
b60af5b0 AS |
1072 | |
1073 | switch (action) { | |
1074 | case ACTION_FAIL: | |
1075 | /* Give up and fail the remainder of the request */ | |
4aff5e23 | 1076 | if (!(req->cmd_flags & REQ_QUIET)) { |
b60af5b0 | 1077 | if (description) |
3dbf6a54 | 1078 | scmd_printk(KERN_INFO, cmd, "%s\n", |
b60af5b0 | 1079 | description); |
a4d04a4c | 1080 | scsi_print_result(cmd); |
3173d8c3 JB |
1081 | if (driver_byte(result) & DRIVER_SENSE) |
1082 | scsi_print_sense("", cmd); | |
1083 | } | |
b60af5b0 AS |
1084 | blk_end_request(req, -EIO, blk_rq_bytes(req)); |
1085 | scsi_next_command(cmd); | |
1086 | break; | |
1087 | case ACTION_REPREP: | |
1088 | /* Unprep the request and put it back at the head of the queue. | |
1089 | * A new command will be prepared and issued. | |
1090 | */ | |
1091 | scsi_requeue_command(q, cmd); | |
1092 | break; | |
1093 | case ACTION_RETRY: | |
1094 | /* Retry the same command immediately */ | |
4f5299ac | 1095 | __scsi_queue_insert(cmd, SCSI_MLQUEUE_EH_RETRY, 0); |
b60af5b0 AS |
1096 | break; |
1097 | case ACTION_DELAYED_RETRY: | |
1098 | /* Retry the same command after a delay */ | |
4f5299ac | 1099 | __scsi_queue_insert(cmd, SCSI_MLQUEUE_DEVICE_BUSY, 0); |
b60af5b0 | 1100 | break; |
1da177e4 LT |
1101 | } |
1102 | } | |
1da177e4 | 1103 | |
6f9a35e2 BH |
1104 | static int scsi_init_sgtable(struct request *req, struct scsi_data_buffer *sdb, |
1105 | gfp_t gfp_mask) | |
1da177e4 | 1106 | { |
6f9a35e2 | 1107 | int count; |
1da177e4 LT |
1108 | |
1109 | /* | |
3b003157 | 1110 | * If sg table allocation fails, requeue request later. |
1da177e4 | 1111 | */ |
30b0c37b BH |
1112 | if (unlikely(scsi_alloc_sgtable(sdb, req->nr_phys_segments, |
1113 | gfp_mask))) { | |
1da177e4 | 1114 | return BLKPREP_DEFER; |
7c72ce81 | 1115 | } |
1da177e4 | 1116 | |
3b003157 | 1117 | req->buffer = NULL; |
1da177e4 LT |
1118 | |
1119 | /* | |
1120 | * Next, walk the list, and fill in the addresses and sizes of | |
1121 | * each segment. | |
1122 | */ | |
30b0c37b BH |
1123 | count = blk_rq_map_sg(req->q, req, sdb->table.sgl); |
1124 | BUG_ON(count > sdb->table.nents); | |
1125 | sdb->table.nents = count; | |
6b00769f TH |
1126 | if (blk_pc_request(req)) |
1127 | sdb->length = req->data_len; | |
1128 | else | |
1129 | sdb->length = req->nr_sectors << 9; | |
4a03d90e | 1130 | return BLKPREP_OK; |
1da177e4 | 1131 | } |
6f9a35e2 BH |
1132 | |
1133 | /* | |
1134 | * Function: scsi_init_io() | |
1135 | * | |
1136 | * Purpose: SCSI I/O initialize function. | |
1137 | * | |
1138 | * Arguments: cmd - Command descriptor we wish to initialize | |
1139 | * | |
1140 | * Returns: 0 on success | |
1141 | * BLKPREP_DEFER if the failure is retryable | |
1142 | * BLKPREP_KILL if the failure is fatal | |
1143 | */ | |
1144 | int scsi_init_io(struct scsi_cmnd *cmd, gfp_t gfp_mask) | |
1145 | { | |
1146 | int error = scsi_init_sgtable(cmd->request, &cmd->sdb, gfp_mask); | |
1147 | if (error) | |
1148 | goto err_exit; | |
1149 | ||
1150 | if (blk_bidi_rq(cmd->request)) { | |
1151 | struct scsi_data_buffer *bidi_sdb = kmem_cache_zalloc( | |
6362abd3 | 1152 | scsi_sdb_cache, GFP_ATOMIC); |
6f9a35e2 BH |
1153 | if (!bidi_sdb) { |
1154 | error = BLKPREP_DEFER; | |
1155 | goto err_exit; | |
1156 | } | |
1157 | ||
1158 | cmd->request->next_rq->special = bidi_sdb; | |
1159 | error = scsi_init_sgtable(cmd->request->next_rq, bidi_sdb, | |
1160 | GFP_ATOMIC); | |
1161 | if (error) | |
1162 | goto err_exit; | |
1163 | } | |
1164 | ||
7027ad72 MP |
1165 | if (blk_integrity_rq(cmd->request)) { |
1166 | struct scsi_data_buffer *prot_sdb = cmd->prot_sdb; | |
1167 | int ivecs, count; | |
1168 | ||
1169 | BUG_ON(prot_sdb == NULL); | |
1170 | ivecs = blk_rq_count_integrity_sg(cmd->request); | |
1171 | ||
1172 | if (scsi_alloc_sgtable(prot_sdb, ivecs, gfp_mask)) { | |
1173 | error = BLKPREP_DEFER; | |
1174 | goto err_exit; | |
1175 | } | |
1176 | ||
1177 | count = blk_rq_map_integrity_sg(cmd->request, | |
1178 | prot_sdb->table.sgl); | |
1179 | BUG_ON(unlikely(count > ivecs)); | |
1180 | ||
1181 | cmd->prot_sdb = prot_sdb; | |
1182 | cmd->prot_sdb->table.nents = count; | |
1183 | } | |
1184 | ||
6f9a35e2 BH |
1185 | return BLKPREP_OK ; |
1186 | ||
1187 | err_exit: | |
1188 | scsi_release_buffers(cmd); | |
1189 | if (error == BLKPREP_KILL) | |
1190 | scsi_put_command(cmd); | |
1191 | else /* BLKPREP_DEFER */ | |
1192 | scsi_unprep_request(cmd->request); | |
1193 | ||
1194 | return error; | |
1195 | } | |
bb52d82f | 1196 | EXPORT_SYMBOL(scsi_init_io); |
1da177e4 | 1197 | |
3b003157 CH |
1198 | static struct scsi_cmnd *scsi_get_cmd_from_req(struct scsi_device *sdev, |
1199 | struct request *req) | |
1200 | { | |
1201 | struct scsi_cmnd *cmd; | |
1202 | ||
1203 | if (!req->special) { | |
1204 | cmd = scsi_get_command(sdev, GFP_ATOMIC); | |
1205 | if (unlikely(!cmd)) | |
1206 | return NULL; | |
1207 | req->special = cmd; | |
1208 | } else { | |
1209 | cmd = req->special; | |
1210 | } | |
1211 | ||
1212 | /* pull a tag out of the request if we have one */ | |
1213 | cmd->tag = req->tag; | |
1214 | cmd->request = req; | |
1215 | ||
64a87b24 BH |
1216 | cmd->cmnd = req->cmd; |
1217 | ||
3b003157 CH |
1218 | return cmd; |
1219 | } | |
1220 | ||
7f9a6bc4 | 1221 | int scsi_setup_blk_pc_cmnd(struct scsi_device *sdev, struct request *req) |
7b16318d | 1222 | { |
3b003157 | 1223 | struct scsi_cmnd *cmd; |
7f9a6bc4 JB |
1224 | int ret = scsi_prep_state_check(sdev, req); |
1225 | ||
1226 | if (ret != BLKPREP_OK) | |
1227 | return ret; | |
3b003157 CH |
1228 | |
1229 | cmd = scsi_get_cmd_from_req(sdev, req); | |
1230 | if (unlikely(!cmd)) | |
1231 | return BLKPREP_DEFER; | |
1232 | ||
1233 | /* | |
1234 | * BLOCK_PC requests may transfer data, in which case they must | |
1235 | * a bio attached to them. Or they might contain a SCSI command | |
1236 | * that does not transfer data, in which case they may optionally | |
1237 | * submit a request without an attached bio. | |
1238 | */ | |
1239 | if (req->bio) { | |
1240 | int ret; | |
1241 | ||
1242 | BUG_ON(!req->nr_phys_segments); | |
1243 | ||
bb52d82f | 1244 | ret = scsi_init_io(cmd, GFP_ATOMIC); |
3b003157 CH |
1245 | if (unlikely(ret)) |
1246 | return ret; | |
1247 | } else { | |
1248 | BUG_ON(req->data_len); | |
1249 | BUG_ON(req->data); | |
1250 | ||
30b0c37b | 1251 | memset(&cmd->sdb, 0, sizeof(cmd->sdb)); |
3b003157 CH |
1252 | req->buffer = NULL; |
1253 | } | |
7b16318d | 1254 | |
7b16318d JB |
1255 | cmd->cmd_len = req->cmd_len; |
1256 | if (!req->data_len) | |
1257 | cmd->sc_data_direction = DMA_NONE; | |
1258 | else if (rq_data_dir(req) == WRITE) | |
1259 | cmd->sc_data_direction = DMA_TO_DEVICE; | |
1260 | else | |
1261 | cmd->sc_data_direction = DMA_FROM_DEVICE; | |
1262 | ||
1263 | cmd->transfersize = req->data_len; | |
1264 | cmd->allowed = req->retries; | |
3b003157 | 1265 | return BLKPREP_OK; |
7b16318d | 1266 | } |
7f9a6bc4 | 1267 | EXPORT_SYMBOL(scsi_setup_blk_pc_cmnd); |
7b16318d | 1268 | |
3b003157 CH |
1269 | /* |
1270 | * Setup a REQ_TYPE_FS command. These are simple read/write request | |
1271 | * from filesystems that still need to be translated to SCSI CDBs from | |
1272 | * the ULD. | |
1273 | */ | |
7f9a6bc4 | 1274 | int scsi_setup_fs_cmnd(struct scsi_device *sdev, struct request *req) |
1da177e4 | 1275 | { |
1da177e4 | 1276 | struct scsi_cmnd *cmd; |
7f9a6bc4 | 1277 | int ret = scsi_prep_state_check(sdev, req); |
1da177e4 | 1278 | |
7f9a6bc4 JB |
1279 | if (ret != BLKPREP_OK) |
1280 | return ret; | |
a6a8d9f8 CS |
1281 | |
1282 | if (unlikely(sdev->scsi_dh_data && sdev->scsi_dh_data->scsi_dh | |
1283 | && sdev->scsi_dh_data->scsi_dh->prep_fn)) { | |
1284 | ret = sdev->scsi_dh_data->scsi_dh->prep_fn(sdev, req); | |
1285 | if (ret != BLKPREP_OK) | |
1286 | return ret; | |
1287 | } | |
1288 | ||
1da177e4 | 1289 | /* |
3b003157 | 1290 | * Filesystem requests must transfer data. |
1da177e4 | 1291 | */ |
3b003157 CH |
1292 | BUG_ON(!req->nr_phys_segments); |
1293 | ||
1294 | cmd = scsi_get_cmd_from_req(sdev, req); | |
1295 | if (unlikely(!cmd)) | |
1296 | return BLKPREP_DEFER; | |
1297 | ||
64a87b24 | 1298 | memset(cmd->cmnd, 0, BLK_MAX_CDB); |
bb52d82f | 1299 | return scsi_init_io(cmd, GFP_ATOMIC); |
3b003157 | 1300 | } |
7f9a6bc4 | 1301 | EXPORT_SYMBOL(scsi_setup_fs_cmnd); |
3b003157 | 1302 | |
7f9a6bc4 | 1303 | int scsi_prep_state_check(struct scsi_device *sdev, struct request *req) |
3b003157 | 1304 | { |
3b003157 CH |
1305 | int ret = BLKPREP_OK; |
1306 | ||
1da177e4 | 1307 | /* |
3b003157 CH |
1308 | * If the device is not in running state we will reject some |
1309 | * or all commands. | |
1da177e4 | 1310 | */ |
3b003157 CH |
1311 | if (unlikely(sdev->sdev_state != SDEV_RUNNING)) { |
1312 | switch (sdev->sdev_state) { | |
1313 | case SDEV_OFFLINE: | |
1314 | /* | |
1315 | * If the device is offline we refuse to process any | |
1316 | * commands. The device must be brought online | |
1317 | * before trying any recovery commands. | |
1318 | */ | |
1319 | sdev_printk(KERN_ERR, sdev, | |
1320 | "rejecting I/O to offline device\n"); | |
1321 | ret = BLKPREP_KILL; | |
1322 | break; | |
1323 | case SDEV_DEL: | |
1324 | /* | |
1325 | * If the device is fully deleted, we refuse to | |
1326 | * process any commands as well. | |
1327 | */ | |
9ccfc756 | 1328 | sdev_printk(KERN_ERR, sdev, |
3b003157 CH |
1329 | "rejecting I/O to dead device\n"); |
1330 | ret = BLKPREP_KILL; | |
1331 | break; | |
1332 | case SDEV_QUIESCE: | |
1333 | case SDEV_BLOCK: | |
6f4267e3 | 1334 | case SDEV_CREATED_BLOCK: |
3b003157 CH |
1335 | /* |
1336 | * If the devices is blocked we defer normal commands. | |
1337 | */ | |
1338 | if (!(req->cmd_flags & REQ_PREEMPT)) | |
1339 | ret = BLKPREP_DEFER; | |
1340 | break; | |
1341 | default: | |
1342 | /* | |
1343 | * For any other not fully online state we only allow | |
1344 | * special commands. In particular any user initiated | |
1345 | * command is not allowed. | |
1346 | */ | |
1347 | if (!(req->cmd_flags & REQ_PREEMPT)) | |
1348 | ret = BLKPREP_KILL; | |
1349 | break; | |
1da177e4 | 1350 | } |
1da177e4 | 1351 | } |
7f9a6bc4 JB |
1352 | return ret; |
1353 | } | |
1354 | EXPORT_SYMBOL(scsi_prep_state_check); | |
1da177e4 | 1355 | |
7f9a6bc4 JB |
1356 | int scsi_prep_return(struct request_queue *q, struct request *req, int ret) |
1357 | { | |
1358 | struct scsi_device *sdev = q->queuedata; | |
1da177e4 | 1359 | |
3b003157 CH |
1360 | switch (ret) { |
1361 | case BLKPREP_KILL: | |
1362 | req->errors = DID_NO_CONNECT << 16; | |
7f9a6bc4 JB |
1363 | /* release the command and kill it */ |
1364 | if (req->special) { | |
1365 | struct scsi_cmnd *cmd = req->special; | |
1366 | scsi_release_buffers(cmd); | |
1367 | scsi_put_command(cmd); | |
1368 | req->special = NULL; | |
1369 | } | |
3b003157 CH |
1370 | break; |
1371 | case BLKPREP_DEFER: | |
1da177e4 | 1372 | /* |
3b003157 CH |
1373 | * If we defer, the elv_next_request() returns NULL, but the |
1374 | * queue must be restarted, so we plug here if no returning | |
1375 | * command will automatically do that. | |
1da177e4 | 1376 | */ |
3b003157 CH |
1377 | if (sdev->device_busy == 0) |
1378 | blk_plug_device(q); | |
1379 | break; | |
1380 | default: | |
1381 | req->cmd_flags |= REQ_DONTPREP; | |
1da177e4 LT |
1382 | } |
1383 | ||
3b003157 | 1384 | return ret; |
1da177e4 | 1385 | } |
7f9a6bc4 JB |
1386 | EXPORT_SYMBOL(scsi_prep_return); |
1387 | ||
751bf4d7 | 1388 | int scsi_prep_fn(struct request_queue *q, struct request *req) |
7f9a6bc4 JB |
1389 | { |
1390 | struct scsi_device *sdev = q->queuedata; | |
1391 | int ret = BLKPREP_KILL; | |
1392 | ||
1393 | if (req->cmd_type == REQ_TYPE_BLOCK_PC) | |
1394 | ret = scsi_setup_blk_pc_cmnd(sdev, req); | |
1395 | return scsi_prep_return(q, req, ret); | |
1396 | } | |
1da177e4 LT |
1397 | |
1398 | /* | |
1399 | * scsi_dev_queue_ready: if we can send requests to sdev, return 1 else | |
1400 | * return 0. | |
1401 | * | |
1402 | * Called with the queue_lock held. | |
1403 | */ | |
1404 | static inline int scsi_dev_queue_ready(struct request_queue *q, | |
1405 | struct scsi_device *sdev) | |
1406 | { | |
1da177e4 LT |
1407 | if (sdev->device_busy == 0 && sdev->device_blocked) { |
1408 | /* | |
1409 | * unblock after device_blocked iterates to zero | |
1410 | */ | |
1411 | if (--sdev->device_blocked == 0) { | |
1412 | SCSI_LOG_MLQUEUE(3, | |
9ccfc756 JB |
1413 | sdev_printk(KERN_INFO, sdev, |
1414 | "unblocking device at zero depth\n")); | |
1da177e4 LT |
1415 | } else { |
1416 | blk_plug_device(q); | |
1417 | return 0; | |
1418 | } | |
1419 | } | |
9d112517 | 1420 | if (scsi_device_is_busy(sdev)) |
1da177e4 LT |
1421 | return 0; |
1422 | ||
1423 | return 1; | |
1424 | } | |
1425 | ||
f0c0a376 MC |
1426 | |
1427 | /* | |
1428 | * scsi_target_queue_ready: checks if there we can send commands to target | |
1429 | * @sdev: scsi device on starget to check. | |
1430 | * | |
1431 | * Called with the host lock held. | |
1432 | */ | |
1433 | static inline int scsi_target_queue_ready(struct Scsi_Host *shost, | |
1434 | struct scsi_device *sdev) | |
1435 | { | |
1436 | struct scsi_target *starget = scsi_target(sdev); | |
1437 | ||
1438 | if (starget->single_lun) { | |
1439 | if (starget->starget_sdev_user && | |
1440 | starget->starget_sdev_user != sdev) | |
1441 | return 0; | |
1442 | starget->starget_sdev_user = sdev; | |
1443 | } | |
1444 | ||
1445 | if (starget->target_busy == 0 && starget->target_blocked) { | |
1446 | /* | |
1447 | * unblock after target_blocked iterates to zero | |
1448 | */ | |
1449 | if (--starget->target_blocked == 0) { | |
1450 | SCSI_LOG_MLQUEUE(3, starget_printk(KERN_INFO, starget, | |
1451 | "unblocking target at zero depth\n")); | |
1452 | } else { | |
1453 | blk_plug_device(sdev->request_queue); | |
1454 | return 0; | |
1455 | } | |
1456 | } | |
1457 | ||
1458 | if (scsi_target_is_busy(starget)) { | |
1459 | if (list_empty(&sdev->starved_entry)) { | |
1460 | list_add_tail(&sdev->starved_entry, | |
1461 | &shost->starved_list); | |
1462 | return 0; | |
1463 | } | |
1464 | } | |
1465 | ||
1466 | /* We're OK to process the command, so we can't be starved */ | |
1467 | if (!list_empty(&sdev->starved_entry)) | |
1468 | list_del_init(&sdev->starved_entry); | |
1469 | return 1; | |
1470 | } | |
1471 | ||
1da177e4 LT |
1472 | /* |
1473 | * scsi_host_queue_ready: if we can send requests to shost, return 1 else | |
1474 | * return 0. We must end up running the queue again whenever 0 is | |
1475 | * returned, else IO can hang. | |
1476 | * | |
1477 | * Called with host_lock held. | |
1478 | */ | |
1479 | static inline int scsi_host_queue_ready(struct request_queue *q, | |
1480 | struct Scsi_Host *shost, | |
1481 | struct scsi_device *sdev) | |
1482 | { | |
939647ee | 1483 | if (scsi_host_in_recovery(shost)) |
1da177e4 LT |
1484 | return 0; |
1485 | if (shost->host_busy == 0 && shost->host_blocked) { | |
1486 | /* | |
1487 | * unblock after host_blocked iterates to zero | |
1488 | */ | |
1489 | if (--shost->host_blocked == 0) { | |
1490 | SCSI_LOG_MLQUEUE(3, | |
1491 | printk("scsi%d unblocking host at zero depth\n", | |
1492 | shost->host_no)); | |
1493 | } else { | |
1da177e4 LT |
1494 | return 0; |
1495 | } | |
1496 | } | |
9d112517 | 1497 | if (scsi_host_is_busy(shost)) { |
1da177e4 LT |
1498 | if (list_empty(&sdev->starved_entry)) |
1499 | list_add_tail(&sdev->starved_entry, &shost->starved_list); | |
1500 | return 0; | |
1501 | } | |
1502 | ||
1503 | /* We're OK to process the command, so we can't be starved */ | |
1504 | if (!list_empty(&sdev->starved_entry)) | |
1505 | list_del_init(&sdev->starved_entry); | |
1506 | ||
1507 | return 1; | |
1508 | } | |
1509 | ||
6c5121b7 KU |
1510 | /* |
1511 | * Busy state exporting function for request stacking drivers. | |
1512 | * | |
1513 | * For efficiency, no lock is taken to check the busy state of | |
1514 | * shost/starget/sdev, since the returned value is not guaranteed and | |
1515 | * may be changed after request stacking drivers call the function, | |
1516 | * regardless of taking lock or not. | |
1517 | * | |
1518 | * When scsi can't dispatch I/Os anymore and needs to kill I/Os | |
1519 | * (e.g. !sdev), scsi needs to return 'not busy'. | |
1520 | * Otherwise, request stacking drivers may hold requests forever. | |
1521 | */ | |
1522 | static int scsi_lld_busy(struct request_queue *q) | |
1523 | { | |
1524 | struct scsi_device *sdev = q->queuedata; | |
1525 | struct Scsi_Host *shost; | |
1526 | struct scsi_target *starget; | |
1527 | ||
1528 | if (!sdev) | |
1529 | return 0; | |
1530 | ||
1531 | shost = sdev->host; | |
1532 | starget = scsi_target(sdev); | |
1533 | ||
1534 | if (scsi_host_in_recovery(shost) || scsi_host_is_busy(shost) || | |
1535 | scsi_target_is_busy(starget) || scsi_device_is_busy(sdev)) | |
1536 | return 1; | |
1537 | ||
1538 | return 0; | |
1539 | } | |
1540 | ||
1da177e4 | 1541 | /* |
e91442b6 | 1542 | * Kill a request for a dead device |
1da177e4 | 1543 | */ |
165125e1 | 1544 | static void scsi_kill_request(struct request *req, struct request_queue *q) |
1da177e4 | 1545 | { |
e91442b6 | 1546 | struct scsi_cmnd *cmd = req->special; |
e36e0c80 | 1547 | struct scsi_device *sdev = cmd->device; |
f0c0a376 | 1548 | struct scsi_target *starget = scsi_target(sdev); |
e36e0c80 | 1549 | struct Scsi_Host *shost = sdev->host; |
1da177e4 | 1550 | |
788ce43a JB |
1551 | blkdev_dequeue_request(req); |
1552 | ||
e91442b6 JB |
1553 | if (unlikely(cmd == NULL)) { |
1554 | printk(KERN_CRIT "impossible request in %s.\n", | |
cadbd4a5 | 1555 | __func__); |
e91442b6 | 1556 | BUG(); |
1da177e4 | 1557 | } |
e91442b6 JB |
1558 | |
1559 | scsi_init_cmd_errh(cmd); | |
1560 | cmd->result = DID_NO_CONNECT << 16; | |
1561 | atomic_inc(&cmd->device->iorequest_cnt); | |
e36e0c80 TH |
1562 | |
1563 | /* | |
1564 | * SCSI request completion path will do scsi_device_unbusy(), | |
1565 | * bump busy counts. To bump the counters, we need to dance | |
1566 | * with the locks as normal issue path does. | |
1567 | */ | |
1568 | sdev->device_busy++; | |
1569 | spin_unlock(sdev->request_queue->queue_lock); | |
1570 | spin_lock(shost->host_lock); | |
1571 | shost->host_busy++; | |
f0c0a376 | 1572 | starget->target_busy++; |
e36e0c80 TH |
1573 | spin_unlock(shost->host_lock); |
1574 | spin_lock(sdev->request_queue->queue_lock); | |
1575 | ||
242f9dcb | 1576 | blk_complete_request(req); |
1da177e4 LT |
1577 | } |
1578 | ||
1aea6434 JA |
1579 | static void scsi_softirq_done(struct request *rq) |
1580 | { | |
242f9dcb JA |
1581 | struct scsi_cmnd *cmd = rq->special; |
1582 | unsigned long wait_for = (cmd->allowed + 1) * rq->timeout; | |
1aea6434 JA |
1583 | int disposition; |
1584 | ||
1585 | INIT_LIST_HEAD(&cmd->eh_entry); | |
1586 | ||
242f9dcb JA |
1587 | /* |
1588 | * Set the serial numbers back to zero | |
1589 | */ | |
1590 | cmd->serial_number = 0; | |
1591 | ||
1592 | atomic_inc(&cmd->device->iodone_cnt); | |
1593 | if (cmd->result) | |
1594 | atomic_inc(&cmd->device->ioerr_cnt); | |
1595 | ||
1aea6434 JA |
1596 | disposition = scsi_decide_disposition(cmd); |
1597 | if (disposition != SUCCESS && | |
1598 | time_before(cmd->jiffies_at_alloc + wait_for, jiffies)) { | |
1599 | sdev_printk(KERN_ERR, cmd->device, | |
1600 | "timing out command, waited %lus\n", | |
1601 | wait_for/HZ); | |
1602 | disposition = SUCCESS; | |
1603 | } | |
1604 | ||
1605 | scsi_log_completion(cmd, disposition); | |
1606 | ||
1607 | switch (disposition) { | |
1608 | case SUCCESS: | |
1609 | scsi_finish_command(cmd); | |
1610 | break; | |
1611 | case NEEDS_RETRY: | |
596f482a | 1612 | scsi_queue_insert(cmd, SCSI_MLQUEUE_EH_RETRY); |
1aea6434 JA |
1613 | break; |
1614 | case ADD_TO_MLQUEUE: | |
1615 | scsi_queue_insert(cmd, SCSI_MLQUEUE_DEVICE_BUSY); | |
1616 | break; | |
1617 | default: | |
1618 | if (!scsi_eh_scmd_add(cmd, 0)) | |
1619 | scsi_finish_command(cmd); | |
1620 | } | |
1621 | } | |
1622 | ||
1da177e4 LT |
1623 | /* |
1624 | * Function: scsi_request_fn() | |
1625 | * | |
1626 | * Purpose: Main strategy routine for SCSI. | |
1627 | * | |
1628 | * Arguments: q - Pointer to actual queue. | |
1629 | * | |
1630 | * Returns: Nothing | |
1631 | * | |
1632 | * Lock status: IO request lock assumed to be held when called. | |
1633 | */ | |
1634 | static void scsi_request_fn(struct request_queue *q) | |
1635 | { | |
1636 | struct scsi_device *sdev = q->queuedata; | |
1637 | struct Scsi_Host *shost; | |
1638 | struct scsi_cmnd *cmd; | |
1639 | struct request *req; | |
1640 | ||
1641 | if (!sdev) { | |
1642 | printk("scsi: killing requests for dead queue\n"); | |
e91442b6 JB |
1643 | while ((req = elv_next_request(q)) != NULL) |
1644 | scsi_kill_request(req, q); | |
1da177e4 LT |
1645 | return; |
1646 | } | |
1647 | ||
1648 | if(!get_device(&sdev->sdev_gendev)) | |
1649 | /* We must be tearing the block queue down already */ | |
1650 | return; | |
1651 | ||
1652 | /* | |
1653 | * To start with, we keep looping until the queue is empty, or until | |
1654 | * the host is no longer able to accept any more requests. | |
1655 | */ | |
1656 | shost = sdev->host; | |
1657 | while (!blk_queue_plugged(q)) { | |
1658 | int rtn; | |
1659 | /* | |
1660 | * get next queueable request. We do this early to make sure | |
1661 | * that the request is fully prepared even if we cannot | |
1662 | * accept it. | |
1663 | */ | |
1664 | req = elv_next_request(q); | |
1665 | if (!req || !scsi_dev_queue_ready(q, sdev)) | |
1666 | break; | |
1667 | ||
1668 | if (unlikely(!scsi_device_online(sdev))) { | |
9ccfc756 JB |
1669 | sdev_printk(KERN_ERR, sdev, |
1670 | "rejecting I/O to offline device\n"); | |
e91442b6 | 1671 | scsi_kill_request(req, q); |
1da177e4 LT |
1672 | continue; |
1673 | } | |
1674 | ||
1675 | ||
1676 | /* | |
1677 | * Remove the request from the request list. | |
1678 | */ | |
1679 | if (!(blk_queue_tagged(q) && !blk_queue_start_tag(q, req))) | |
1680 | blkdev_dequeue_request(req); | |
1681 | sdev->device_busy++; | |
1682 | ||
1683 | spin_unlock(q->queue_lock); | |
e91442b6 JB |
1684 | cmd = req->special; |
1685 | if (unlikely(cmd == NULL)) { | |
1686 | printk(KERN_CRIT "impossible request in %s.\n" | |
1687 | "please mail a stack trace to " | |
4aff5e23 | 1688 | "linux-scsi@vger.kernel.org\n", |
cadbd4a5 | 1689 | __func__); |
4aff5e23 | 1690 | blk_dump_rq_flags(req, "foo"); |
e91442b6 JB |
1691 | BUG(); |
1692 | } | |
1da177e4 LT |
1693 | spin_lock(shost->host_lock); |
1694 | ||
ecefe8a9 MC |
1695 | /* |
1696 | * We hit this when the driver is using a host wide | |
1697 | * tag map. For device level tag maps the queue_depth check | |
1698 | * in the device ready fn would prevent us from trying | |
1699 | * to allocate a tag. Since the map is a shared host resource | |
1700 | * we add the dev to the starved list so it eventually gets | |
1701 | * a run when a tag is freed. | |
1702 | */ | |
6bd522f6 | 1703 | if (blk_queue_tagged(q) && !blk_rq_tagged(req)) { |
ecefe8a9 MC |
1704 | if (list_empty(&sdev->starved_entry)) |
1705 | list_add_tail(&sdev->starved_entry, | |
1706 | &shost->starved_list); | |
1707 | goto not_ready; | |
1708 | } | |
1709 | ||
f0c0a376 MC |
1710 | if (!scsi_target_queue_ready(shost, sdev)) |
1711 | goto not_ready; | |
1712 | ||
1da177e4 LT |
1713 | if (!scsi_host_queue_ready(q, shost, sdev)) |
1714 | goto not_ready; | |
f0c0a376 MC |
1715 | |
1716 | scsi_target(sdev)->target_busy++; | |
1da177e4 LT |
1717 | shost->host_busy++; |
1718 | ||
1719 | /* | |
1720 | * XXX(hch): This is rather suboptimal, scsi_dispatch_cmd will | |
1721 | * take the lock again. | |
1722 | */ | |
1723 | spin_unlock_irq(shost->host_lock); | |
1724 | ||
1da177e4 LT |
1725 | /* |
1726 | * Finally, initialize any error handling parameters, and set up | |
1727 | * the timers for timeouts. | |
1728 | */ | |
1729 | scsi_init_cmd_errh(cmd); | |
1730 | ||
1731 | /* | |
1732 | * Dispatch the command to the low-level driver. | |
1733 | */ | |
1734 | rtn = scsi_dispatch_cmd(cmd); | |
1735 | spin_lock_irq(q->queue_lock); | |
1736 | if(rtn) { | |
1737 | /* we're refusing the command; because of | |
1738 | * the way locks get dropped, we need to | |
1739 | * check here if plugging is required */ | |
1740 | if(sdev->device_busy == 0) | |
1741 | blk_plug_device(q); | |
1742 | ||
1743 | break; | |
1744 | } | |
1745 | } | |
1746 | ||
1747 | goto out; | |
1748 | ||
1749 | not_ready: | |
1750 | spin_unlock_irq(shost->host_lock); | |
1751 | ||
1752 | /* | |
1753 | * lock q, handle tag, requeue req, and decrement device_busy. We | |
1754 | * must return with queue_lock held. | |
1755 | * | |
1756 | * Decrementing device_busy without checking it is OK, as all such | |
1757 | * cases (host limits or settings) should run the queue at some | |
1758 | * later time. | |
1759 | */ | |
1760 | spin_lock_irq(q->queue_lock); | |
1761 | blk_requeue_request(q, req); | |
1762 | sdev->device_busy--; | |
1763 | if(sdev->device_busy == 0) | |
1764 | blk_plug_device(q); | |
1765 | out: | |
1766 | /* must be careful here...if we trigger the ->remove() function | |
1767 | * we cannot be holding the q lock */ | |
1768 | spin_unlock_irq(q->queue_lock); | |
1769 | put_device(&sdev->sdev_gendev); | |
1770 | spin_lock_irq(q->queue_lock); | |
1771 | } | |
1772 | ||
1773 | u64 scsi_calculate_bounce_limit(struct Scsi_Host *shost) | |
1774 | { | |
1775 | struct device *host_dev; | |
1776 | u64 bounce_limit = 0xffffffff; | |
1777 | ||
1778 | if (shost->unchecked_isa_dma) | |
1779 | return BLK_BOUNCE_ISA; | |
1780 | /* | |
1781 | * Platforms with virtual-DMA translation | |
1782 | * hardware have no practical limit. | |
1783 | */ | |
1784 | if (!PCI_DMA_BUS_IS_PHYS) | |
1785 | return BLK_BOUNCE_ANY; | |
1786 | ||
1787 | host_dev = scsi_get_device(shost); | |
1788 | if (host_dev && host_dev->dma_mask) | |
1789 | bounce_limit = *host_dev->dma_mask; | |
1790 | ||
1791 | return bounce_limit; | |
1792 | } | |
1793 | EXPORT_SYMBOL(scsi_calculate_bounce_limit); | |
1794 | ||
b58d9154 FT |
1795 | struct request_queue *__scsi_alloc_queue(struct Scsi_Host *shost, |
1796 | request_fn_proc *request_fn) | |
1da177e4 | 1797 | { |
1da177e4 | 1798 | struct request_queue *q; |
860ac568 | 1799 | struct device *dev = shost->shost_gendev.parent; |
1da177e4 | 1800 | |
b58d9154 | 1801 | q = blk_init_queue(request_fn, NULL); |
1da177e4 LT |
1802 | if (!q) |
1803 | return NULL; | |
1804 | ||
a8474ce2 JA |
1805 | /* |
1806 | * this limit is imposed by hardware restrictions | |
1807 | */ | |
1da177e4 | 1808 | blk_queue_max_hw_segments(q, shost->sg_tablesize); |
d3f46f39 | 1809 | blk_queue_max_phys_segments(q, SCSI_MAX_SG_CHAIN_SEGMENTS); |
a8474ce2 | 1810 | |
1da177e4 LT |
1811 | blk_queue_max_sectors(q, shost->max_sectors); |
1812 | blk_queue_bounce_limit(q, scsi_calculate_bounce_limit(shost)); | |
1813 | blk_queue_segment_boundary(q, shost->dma_boundary); | |
99c84dbd | 1814 | dma_set_seg_boundary(dev, shost->dma_boundary); |
1da177e4 | 1815 | |
860ac568 FT |
1816 | blk_queue_max_segment_size(q, dma_get_max_seg_size(dev)); |
1817 | ||
75ad23bc | 1818 | /* New queue, no concurrency on queue_flags */ |
1da177e4 | 1819 | if (!shost->use_clustering) |
75ad23bc | 1820 | queue_flag_clear_unlocked(QUEUE_FLAG_CLUSTER, q); |
465ff318 JB |
1821 | |
1822 | /* | |
1823 | * set a reasonable default alignment on word boundaries: the | |
1824 | * host and device may alter it using | |
1825 | * blk_queue_update_dma_alignment() later. | |
1826 | */ | |
1827 | blk_queue_dma_alignment(q, 0x03); | |
1828 | ||
1da177e4 LT |
1829 | return q; |
1830 | } | |
b58d9154 FT |
1831 | EXPORT_SYMBOL(__scsi_alloc_queue); |
1832 | ||
1833 | struct request_queue *scsi_alloc_queue(struct scsi_device *sdev) | |
1834 | { | |
1835 | struct request_queue *q; | |
1836 | ||
1837 | q = __scsi_alloc_queue(sdev->host, scsi_request_fn); | |
1838 | if (!q) | |
1839 | return NULL; | |
1840 | ||
1841 | blk_queue_prep_rq(q, scsi_prep_fn); | |
b58d9154 | 1842 | blk_queue_softirq_done(q, scsi_softirq_done); |
242f9dcb | 1843 | blk_queue_rq_timed_out(q, scsi_times_out); |
6c5121b7 | 1844 | blk_queue_lld_busy(q, scsi_lld_busy); |
b58d9154 FT |
1845 | return q; |
1846 | } | |
1da177e4 LT |
1847 | |
1848 | void scsi_free_queue(struct request_queue *q) | |
1849 | { | |
1850 | blk_cleanup_queue(q); | |
1851 | } | |
1852 | ||
1853 | /* | |
1854 | * Function: scsi_block_requests() | |
1855 | * | |
1856 | * Purpose: Utility function used by low-level drivers to prevent further | |
1857 | * commands from being queued to the device. | |
1858 | * | |
1859 | * Arguments: shost - Host in question | |
1860 | * | |
1861 | * Returns: Nothing | |
1862 | * | |
1863 | * Lock status: No locks are assumed held. | |
1864 | * | |
1865 | * Notes: There is no timer nor any other means by which the requests | |
1866 | * get unblocked other than the low-level driver calling | |
1867 | * scsi_unblock_requests(). | |
1868 | */ | |
1869 | void scsi_block_requests(struct Scsi_Host *shost) | |
1870 | { | |
1871 | shost->host_self_blocked = 1; | |
1872 | } | |
1873 | EXPORT_SYMBOL(scsi_block_requests); | |
1874 | ||
1875 | /* | |
1876 | * Function: scsi_unblock_requests() | |
1877 | * | |
1878 | * Purpose: Utility function used by low-level drivers to allow further | |
1879 | * commands from being queued to the device. | |
1880 | * | |
1881 | * Arguments: shost - Host in question | |
1882 | * | |
1883 | * Returns: Nothing | |
1884 | * | |
1885 | * Lock status: No locks are assumed held. | |
1886 | * | |
1887 | * Notes: There is no timer nor any other means by which the requests | |
1888 | * get unblocked other than the low-level driver calling | |
1889 | * scsi_unblock_requests(). | |
1890 | * | |
1891 | * This is done as an API function so that changes to the | |
1892 | * internals of the scsi mid-layer won't require wholesale | |
1893 | * changes to drivers that use this feature. | |
1894 | */ | |
1895 | void scsi_unblock_requests(struct Scsi_Host *shost) | |
1896 | { | |
1897 | shost->host_self_blocked = 0; | |
1898 | scsi_run_host_queues(shost); | |
1899 | } | |
1900 | EXPORT_SYMBOL(scsi_unblock_requests); | |
1901 | ||
1902 | int __init scsi_init_queue(void) | |
1903 | { | |
1904 | int i; | |
1905 | ||
aa7b5cd7 MC |
1906 | scsi_io_context_cache = kmem_cache_create("scsi_io_context", |
1907 | sizeof(struct scsi_io_context), | |
20c2df83 | 1908 | 0, 0, NULL); |
aa7b5cd7 MC |
1909 | if (!scsi_io_context_cache) { |
1910 | printk(KERN_ERR "SCSI: can't init scsi io context cache\n"); | |
1911 | return -ENOMEM; | |
1912 | } | |
1913 | ||
6362abd3 MP |
1914 | scsi_sdb_cache = kmem_cache_create("scsi_data_buffer", |
1915 | sizeof(struct scsi_data_buffer), | |
1916 | 0, 0, NULL); | |
1917 | if (!scsi_sdb_cache) { | |
1918 | printk(KERN_ERR "SCSI: can't init scsi sdb cache\n"); | |
3d9dd6ee | 1919 | goto cleanup_io_context; |
6f9a35e2 BH |
1920 | } |
1921 | ||
1da177e4 LT |
1922 | for (i = 0; i < SG_MEMPOOL_NR; i++) { |
1923 | struct scsi_host_sg_pool *sgp = scsi_sg_pools + i; | |
1924 | int size = sgp->size * sizeof(struct scatterlist); | |
1925 | ||
1926 | sgp->slab = kmem_cache_create(sgp->name, size, 0, | |
20c2df83 | 1927 | SLAB_HWCACHE_ALIGN, NULL); |
1da177e4 LT |
1928 | if (!sgp->slab) { |
1929 | printk(KERN_ERR "SCSI: can't init sg slab %s\n", | |
1930 | sgp->name); | |
6362abd3 | 1931 | goto cleanup_sdb; |
1da177e4 LT |
1932 | } |
1933 | ||
93d2341c MD |
1934 | sgp->pool = mempool_create_slab_pool(SG_MEMPOOL_SIZE, |
1935 | sgp->slab); | |
1da177e4 LT |
1936 | if (!sgp->pool) { |
1937 | printk(KERN_ERR "SCSI: can't init sg mempool %s\n", | |
1938 | sgp->name); | |
6362abd3 | 1939 | goto cleanup_sdb; |
1da177e4 LT |
1940 | } |
1941 | } | |
1942 | ||
1943 | return 0; | |
3d9dd6ee | 1944 | |
6362abd3 | 1945 | cleanup_sdb: |
3d9dd6ee FT |
1946 | for (i = 0; i < SG_MEMPOOL_NR; i++) { |
1947 | struct scsi_host_sg_pool *sgp = scsi_sg_pools + i; | |
1948 | if (sgp->pool) | |
1949 | mempool_destroy(sgp->pool); | |
1950 | if (sgp->slab) | |
1951 | kmem_cache_destroy(sgp->slab); | |
1952 | } | |
6362abd3 | 1953 | kmem_cache_destroy(scsi_sdb_cache); |
3d9dd6ee FT |
1954 | cleanup_io_context: |
1955 | kmem_cache_destroy(scsi_io_context_cache); | |
1956 | ||
1957 | return -ENOMEM; | |
1da177e4 LT |
1958 | } |
1959 | ||
1960 | void scsi_exit_queue(void) | |
1961 | { | |
1962 | int i; | |
1963 | ||
aa7b5cd7 | 1964 | kmem_cache_destroy(scsi_io_context_cache); |
6362abd3 | 1965 | kmem_cache_destroy(scsi_sdb_cache); |
aa7b5cd7 | 1966 | |
1da177e4 LT |
1967 | for (i = 0; i < SG_MEMPOOL_NR; i++) { |
1968 | struct scsi_host_sg_pool *sgp = scsi_sg_pools + i; | |
1969 | mempool_destroy(sgp->pool); | |
1970 | kmem_cache_destroy(sgp->slab); | |
1971 | } | |
1972 | } | |
5baba830 JB |
1973 | |
1974 | /** | |
1975 | * scsi_mode_select - issue a mode select | |
1976 | * @sdev: SCSI device to be queried | |
1977 | * @pf: Page format bit (1 == standard, 0 == vendor specific) | |
1978 | * @sp: Save page bit (0 == don't save, 1 == save) | |
1979 | * @modepage: mode page being requested | |
1980 | * @buffer: request buffer (may not be smaller than eight bytes) | |
1981 | * @len: length of request buffer. | |
1982 | * @timeout: command timeout | |
1983 | * @retries: number of retries before failing | |
1984 | * @data: returns a structure abstracting the mode header data | |
eb44820c | 1985 | * @sshdr: place to put sense data (or NULL if no sense to be collected). |
5baba830 JB |
1986 | * must be SCSI_SENSE_BUFFERSIZE big. |
1987 | * | |
1988 | * Returns zero if successful; negative error number or scsi | |
1989 | * status on error | |
1990 | * | |
1991 | */ | |
1992 | int | |
1993 | scsi_mode_select(struct scsi_device *sdev, int pf, int sp, int modepage, | |
1994 | unsigned char *buffer, int len, int timeout, int retries, | |
1995 | struct scsi_mode_data *data, struct scsi_sense_hdr *sshdr) | |
1996 | { | |
1997 | unsigned char cmd[10]; | |
1998 | unsigned char *real_buffer; | |
1999 | int ret; | |
2000 | ||
2001 | memset(cmd, 0, sizeof(cmd)); | |
2002 | cmd[1] = (pf ? 0x10 : 0) | (sp ? 0x01 : 0); | |
2003 | ||
2004 | if (sdev->use_10_for_ms) { | |
2005 | if (len > 65535) | |
2006 | return -EINVAL; | |
2007 | real_buffer = kmalloc(8 + len, GFP_KERNEL); | |
2008 | if (!real_buffer) | |
2009 | return -ENOMEM; | |
2010 | memcpy(real_buffer + 8, buffer, len); | |
2011 | len += 8; | |
2012 | real_buffer[0] = 0; | |
2013 | real_buffer[1] = 0; | |
2014 | real_buffer[2] = data->medium_type; | |
2015 | real_buffer[3] = data->device_specific; | |
2016 | real_buffer[4] = data->longlba ? 0x01 : 0; | |
2017 | real_buffer[5] = 0; | |
2018 | real_buffer[6] = data->block_descriptor_length >> 8; | |
2019 | real_buffer[7] = data->block_descriptor_length; | |
2020 | ||
2021 | cmd[0] = MODE_SELECT_10; | |
2022 | cmd[7] = len >> 8; | |
2023 | cmd[8] = len; | |
2024 | } else { | |
2025 | if (len > 255 || data->block_descriptor_length > 255 || | |
2026 | data->longlba) | |
2027 | return -EINVAL; | |
2028 | ||
2029 | real_buffer = kmalloc(4 + len, GFP_KERNEL); | |
2030 | if (!real_buffer) | |
2031 | return -ENOMEM; | |
2032 | memcpy(real_buffer + 4, buffer, len); | |
2033 | len += 4; | |
2034 | real_buffer[0] = 0; | |
2035 | real_buffer[1] = data->medium_type; | |
2036 | real_buffer[2] = data->device_specific; | |
2037 | real_buffer[3] = data->block_descriptor_length; | |
2038 | ||
2039 | ||
2040 | cmd[0] = MODE_SELECT; | |
2041 | cmd[4] = len; | |
2042 | } | |
2043 | ||
2044 | ret = scsi_execute_req(sdev, cmd, DMA_TO_DEVICE, real_buffer, len, | |
f4f4e47e | 2045 | sshdr, timeout, retries, NULL); |
5baba830 JB |
2046 | kfree(real_buffer); |
2047 | return ret; | |
2048 | } | |
2049 | EXPORT_SYMBOL_GPL(scsi_mode_select); | |
2050 | ||
1da177e4 | 2051 | /** |
eb44820c | 2052 | * scsi_mode_sense - issue a mode sense, falling back from 10 to six bytes if necessary. |
1cf72699 | 2053 | * @sdev: SCSI device to be queried |
1da177e4 LT |
2054 | * @dbd: set if mode sense will allow block descriptors to be returned |
2055 | * @modepage: mode page being requested | |
2056 | * @buffer: request buffer (may not be smaller than eight bytes) | |
2057 | * @len: length of request buffer. | |
2058 | * @timeout: command timeout | |
2059 | * @retries: number of retries before failing | |
2060 | * @data: returns a structure abstracting the mode header data | |
eb44820c | 2061 | * @sshdr: place to put sense data (or NULL if no sense to be collected). |
1cf72699 | 2062 | * must be SCSI_SENSE_BUFFERSIZE big. |
1da177e4 LT |
2063 | * |
2064 | * Returns zero if unsuccessful, or the header offset (either 4 | |
2065 | * or 8 depending on whether a six or ten byte command was | |
2066 | * issued) if successful. | |
eb44820c | 2067 | */ |
1da177e4 | 2068 | int |
1cf72699 | 2069 | scsi_mode_sense(struct scsi_device *sdev, int dbd, int modepage, |
1da177e4 | 2070 | unsigned char *buffer, int len, int timeout, int retries, |
5baba830 JB |
2071 | struct scsi_mode_data *data, struct scsi_sense_hdr *sshdr) |
2072 | { | |
1da177e4 LT |
2073 | unsigned char cmd[12]; |
2074 | int use_10_for_ms; | |
2075 | int header_length; | |
1cf72699 | 2076 | int result; |
ea73a9f2 | 2077 | struct scsi_sense_hdr my_sshdr; |
1da177e4 LT |
2078 | |
2079 | memset(data, 0, sizeof(*data)); | |
2080 | memset(&cmd[0], 0, 12); | |
2081 | cmd[1] = dbd & 0x18; /* allows DBD and LLBA bits */ | |
2082 | cmd[2] = modepage; | |
2083 | ||
ea73a9f2 JB |
2084 | /* caller might not be interested in sense, but we need it */ |
2085 | if (!sshdr) | |
2086 | sshdr = &my_sshdr; | |
2087 | ||
1da177e4 | 2088 | retry: |
1cf72699 | 2089 | use_10_for_ms = sdev->use_10_for_ms; |
1da177e4 LT |
2090 | |
2091 | if (use_10_for_ms) { | |
2092 | if (len < 8) | |
2093 | len = 8; | |
2094 | ||
2095 | cmd[0] = MODE_SENSE_10; | |
2096 | cmd[8] = len; | |
2097 | header_length = 8; | |
2098 | } else { | |
2099 | if (len < 4) | |
2100 | len = 4; | |
2101 | ||
2102 | cmd[0] = MODE_SENSE; | |
2103 | cmd[4] = len; | |
2104 | header_length = 4; | |
2105 | } | |
2106 | ||
1da177e4 LT |
2107 | memset(buffer, 0, len); |
2108 | ||
1cf72699 | 2109 | result = scsi_execute_req(sdev, cmd, DMA_FROM_DEVICE, buffer, len, |
f4f4e47e | 2110 | sshdr, timeout, retries, NULL); |
1da177e4 LT |
2111 | |
2112 | /* This code looks awful: what it's doing is making sure an | |
2113 | * ILLEGAL REQUEST sense return identifies the actual command | |
2114 | * byte as the problem. MODE_SENSE commands can return | |
2115 | * ILLEGAL REQUEST if the code page isn't supported */ | |
2116 | ||
1cf72699 JB |
2117 | if (use_10_for_ms && !scsi_status_is_good(result) && |
2118 | (driver_byte(result) & DRIVER_SENSE)) { | |
ea73a9f2 JB |
2119 | if (scsi_sense_valid(sshdr)) { |
2120 | if ((sshdr->sense_key == ILLEGAL_REQUEST) && | |
2121 | (sshdr->asc == 0x20) && (sshdr->ascq == 0)) { | |
1da177e4 LT |
2122 | /* |
2123 | * Invalid command operation code | |
2124 | */ | |
1cf72699 | 2125 | sdev->use_10_for_ms = 0; |
1da177e4 LT |
2126 | goto retry; |
2127 | } | |
2128 | } | |
2129 | } | |
2130 | ||
1cf72699 | 2131 | if(scsi_status_is_good(result)) { |
6d73c851 AV |
2132 | if (unlikely(buffer[0] == 0x86 && buffer[1] == 0x0b && |
2133 | (modepage == 6 || modepage == 8))) { | |
2134 | /* Initio breakage? */ | |
2135 | header_length = 0; | |
2136 | data->length = 13; | |
2137 | data->medium_type = 0; | |
2138 | data->device_specific = 0; | |
2139 | data->longlba = 0; | |
2140 | data->block_descriptor_length = 0; | |
2141 | } else if(use_10_for_ms) { | |
1da177e4 LT |
2142 | data->length = buffer[0]*256 + buffer[1] + 2; |
2143 | data->medium_type = buffer[2]; | |
2144 | data->device_specific = buffer[3]; | |
2145 | data->longlba = buffer[4] & 0x01; | |
2146 | data->block_descriptor_length = buffer[6]*256 | |
2147 | + buffer[7]; | |
2148 | } else { | |
2149 | data->length = buffer[0] + 1; | |
2150 | data->medium_type = buffer[1]; | |
2151 | data->device_specific = buffer[2]; | |
2152 | data->block_descriptor_length = buffer[3]; | |
2153 | } | |
6d73c851 | 2154 | data->header_length = header_length; |
1da177e4 LT |
2155 | } |
2156 | ||
1cf72699 | 2157 | return result; |
1da177e4 LT |
2158 | } |
2159 | EXPORT_SYMBOL(scsi_mode_sense); | |
2160 | ||
001aac25 JB |
2161 | /** |
2162 | * scsi_test_unit_ready - test if unit is ready | |
2163 | * @sdev: scsi device to change the state of. | |
2164 | * @timeout: command timeout | |
2165 | * @retries: number of retries before failing | |
2166 | * @sshdr_external: Optional pointer to struct scsi_sense_hdr for | |
2167 | * returning sense. Make sure that this is cleared before passing | |
2168 | * in. | |
2169 | * | |
2170 | * Returns zero if unsuccessful or an error if TUR failed. For | |
2171 | * removable media, a return of NOT_READY or UNIT_ATTENTION is | |
2172 | * translated to success, with the ->changed flag updated. | |
2173 | **/ | |
1da177e4 | 2174 | int |
001aac25 JB |
2175 | scsi_test_unit_ready(struct scsi_device *sdev, int timeout, int retries, |
2176 | struct scsi_sense_hdr *sshdr_external) | |
1da177e4 | 2177 | { |
1da177e4 LT |
2178 | char cmd[] = { |
2179 | TEST_UNIT_READY, 0, 0, 0, 0, 0, | |
2180 | }; | |
001aac25 | 2181 | struct scsi_sense_hdr *sshdr; |
1da177e4 | 2182 | int result; |
001aac25 JB |
2183 | |
2184 | if (!sshdr_external) | |
2185 | sshdr = kzalloc(sizeof(*sshdr), GFP_KERNEL); | |
2186 | else | |
2187 | sshdr = sshdr_external; | |
2188 | ||
2189 | /* try to eat the UNIT_ATTENTION if there are enough retries */ | |
2190 | do { | |
2191 | result = scsi_execute_req(sdev, cmd, DMA_NONE, NULL, 0, sshdr, | |
f4f4e47e | 2192 | timeout, retries, NULL); |
32c356d7 JB |
2193 | if (sdev->removable && scsi_sense_valid(sshdr) && |
2194 | sshdr->sense_key == UNIT_ATTENTION) | |
2195 | sdev->changed = 1; | |
2196 | } while (scsi_sense_valid(sshdr) && | |
2197 | sshdr->sense_key == UNIT_ATTENTION && --retries); | |
001aac25 JB |
2198 | |
2199 | if (!sshdr) | |
2200 | /* could not allocate sense buffer, so can't process it */ | |
2201 | return result; | |
1da177e4 | 2202 | |
32c356d7 JB |
2203 | if (sdev->removable && scsi_sense_valid(sshdr) && |
2204 | (sshdr->sense_key == UNIT_ATTENTION || | |
2205 | sshdr->sense_key == NOT_READY)) { | |
2206 | sdev->changed = 1; | |
2207 | result = 0; | |
1da177e4 | 2208 | } |
001aac25 JB |
2209 | if (!sshdr_external) |
2210 | kfree(sshdr); | |
1da177e4 LT |
2211 | return result; |
2212 | } | |
2213 | EXPORT_SYMBOL(scsi_test_unit_ready); | |
2214 | ||
2215 | /** | |
eb44820c | 2216 | * scsi_device_set_state - Take the given device through the device state model. |
1da177e4 LT |
2217 | * @sdev: scsi device to change the state of. |
2218 | * @state: state to change to. | |
2219 | * | |
2220 | * Returns zero if unsuccessful or an error if the requested | |
2221 | * transition is illegal. | |
eb44820c | 2222 | */ |
1da177e4 LT |
2223 | int |
2224 | scsi_device_set_state(struct scsi_device *sdev, enum scsi_device_state state) | |
2225 | { | |
2226 | enum scsi_device_state oldstate = sdev->sdev_state; | |
2227 | ||
2228 | if (state == oldstate) | |
2229 | return 0; | |
2230 | ||
2231 | switch (state) { | |
2232 | case SDEV_CREATED: | |
6f4267e3 JB |
2233 | switch (oldstate) { |
2234 | case SDEV_CREATED_BLOCK: | |
2235 | break; | |
2236 | default: | |
2237 | goto illegal; | |
2238 | } | |
2239 | break; | |
1da177e4 LT |
2240 | |
2241 | case SDEV_RUNNING: | |
2242 | switch (oldstate) { | |
2243 | case SDEV_CREATED: | |
2244 | case SDEV_OFFLINE: | |
2245 | case SDEV_QUIESCE: | |
2246 | case SDEV_BLOCK: | |
2247 | break; | |
2248 | default: | |
2249 | goto illegal; | |
2250 | } | |
2251 | break; | |
2252 | ||
2253 | case SDEV_QUIESCE: | |
2254 | switch (oldstate) { | |
2255 | case SDEV_RUNNING: | |
2256 | case SDEV_OFFLINE: | |
2257 | break; | |
2258 | default: | |
2259 | goto illegal; | |
2260 | } | |
2261 | break; | |
2262 | ||
2263 | case SDEV_OFFLINE: | |
2264 | switch (oldstate) { | |
2265 | case SDEV_CREATED: | |
2266 | case SDEV_RUNNING: | |
2267 | case SDEV_QUIESCE: | |
2268 | case SDEV_BLOCK: | |
2269 | break; | |
2270 | default: | |
2271 | goto illegal; | |
2272 | } | |
2273 | break; | |
2274 | ||
2275 | case SDEV_BLOCK: | |
2276 | switch (oldstate) { | |
1da177e4 | 2277 | case SDEV_RUNNING: |
6f4267e3 JB |
2278 | case SDEV_CREATED_BLOCK: |
2279 | break; | |
2280 | default: | |
2281 | goto illegal; | |
2282 | } | |
2283 | break; | |
2284 | ||
2285 | case SDEV_CREATED_BLOCK: | |
2286 | switch (oldstate) { | |
2287 | case SDEV_CREATED: | |
1da177e4 LT |
2288 | break; |
2289 | default: | |
2290 | goto illegal; | |
2291 | } | |
2292 | break; | |
2293 | ||
2294 | case SDEV_CANCEL: | |
2295 | switch (oldstate) { | |
2296 | case SDEV_CREATED: | |
2297 | case SDEV_RUNNING: | |
9ea72909 | 2298 | case SDEV_QUIESCE: |
1da177e4 LT |
2299 | case SDEV_OFFLINE: |
2300 | case SDEV_BLOCK: | |
2301 | break; | |
2302 | default: | |
2303 | goto illegal; | |
2304 | } | |
2305 | break; | |
2306 | ||
2307 | case SDEV_DEL: | |
2308 | switch (oldstate) { | |
309bd271 BK |
2309 | case SDEV_CREATED: |
2310 | case SDEV_RUNNING: | |
2311 | case SDEV_OFFLINE: | |
1da177e4 LT |
2312 | case SDEV_CANCEL: |
2313 | break; | |
2314 | default: | |
2315 | goto illegal; | |
2316 | } | |
2317 | break; | |
2318 | ||
2319 | } | |
2320 | sdev->sdev_state = state; | |
2321 | return 0; | |
2322 | ||
2323 | illegal: | |
2324 | SCSI_LOG_ERROR_RECOVERY(1, | |
9ccfc756 JB |
2325 | sdev_printk(KERN_ERR, sdev, |
2326 | "Illegal state transition %s->%s\n", | |
2327 | scsi_device_state_name(oldstate), | |
2328 | scsi_device_state_name(state)) | |
1da177e4 LT |
2329 | ); |
2330 | return -EINVAL; | |
2331 | } | |
2332 | EXPORT_SYMBOL(scsi_device_set_state); | |
2333 | ||
a341cd0f JG |
2334 | /** |
2335 | * sdev_evt_emit - emit a single SCSI device uevent | |
2336 | * @sdev: associated SCSI device | |
2337 | * @evt: event to emit | |
2338 | * | |
2339 | * Send a single uevent (scsi_event) to the associated scsi_device. | |
2340 | */ | |
2341 | static void scsi_evt_emit(struct scsi_device *sdev, struct scsi_event *evt) | |
2342 | { | |
2343 | int idx = 0; | |
2344 | char *envp[3]; | |
2345 | ||
2346 | switch (evt->evt_type) { | |
2347 | case SDEV_EVT_MEDIA_CHANGE: | |
2348 | envp[idx++] = "SDEV_MEDIA_CHANGE=1"; | |
2349 | break; | |
2350 | ||
2351 | default: | |
2352 | /* do nothing */ | |
2353 | break; | |
2354 | } | |
2355 | ||
2356 | envp[idx++] = NULL; | |
2357 | ||
2358 | kobject_uevent_env(&sdev->sdev_gendev.kobj, KOBJ_CHANGE, envp); | |
2359 | } | |
2360 | ||
2361 | /** | |
2362 | * sdev_evt_thread - send a uevent for each scsi event | |
2363 | * @work: work struct for scsi_device | |
2364 | * | |
2365 | * Dispatch queued events to their associated scsi_device kobjects | |
2366 | * as uevents. | |
2367 | */ | |
2368 | void scsi_evt_thread(struct work_struct *work) | |
2369 | { | |
2370 | struct scsi_device *sdev; | |
2371 | LIST_HEAD(event_list); | |
2372 | ||
2373 | sdev = container_of(work, struct scsi_device, event_work); | |
2374 | ||
2375 | while (1) { | |
2376 | struct scsi_event *evt; | |
2377 | struct list_head *this, *tmp; | |
2378 | unsigned long flags; | |
2379 | ||
2380 | spin_lock_irqsave(&sdev->list_lock, flags); | |
2381 | list_splice_init(&sdev->event_list, &event_list); | |
2382 | spin_unlock_irqrestore(&sdev->list_lock, flags); | |
2383 | ||
2384 | if (list_empty(&event_list)) | |
2385 | break; | |
2386 | ||
2387 | list_for_each_safe(this, tmp, &event_list) { | |
2388 | evt = list_entry(this, struct scsi_event, node); | |
2389 | list_del(&evt->node); | |
2390 | scsi_evt_emit(sdev, evt); | |
2391 | kfree(evt); | |
2392 | } | |
2393 | } | |
2394 | } | |
2395 | ||
2396 | /** | |
2397 | * sdev_evt_send - send asserted event to uevent thread | |
2398 | * @sdev: scsi_device event occurred on | |
2399 | * @evt: event to send | |
2400 | * | |
2401 | * Assert scsi device event asynchronously. | |
2402 | */ | |
2403 | void sdev_evt_send(struct scsi_device *sdev, struct scsi_event *evt) | |
2404 | { | |
2405 | unsigned long flags; | |
2406 | ||
4d1566ed KS |
2407 | #if 0 |
2408 | /* FIXME: currently this check eliminates all media change events | |
2409 | * for polled devices. Need to update to discriminate between AN | |
2410 | * and polled events */ | |
a341cd0f JG |
2411 | if (!test_bit(evt->evt_type, sdev->supported_events)) { |
2412 | kfree(evt); | |
2413 | return; | |
2414 | } | |
4d1566ed | 2415 | #endif |
a341cd0f JG |
2416 | |
2417 | spin_lock_irqsave(&sdev->list_lock, flags); | |
2418 | list_add_tail(&evt->node, &sdev->event_list); | |
2419 | schedule_work(&sdev->event_work); | |
2420 | spin_unlock_irqrestore(&sdev->list_lock, flags); | |
2421 | } | |
2422 | EXPORT_SYMBOL_GPL(sdev_evt_send); | |
2423 | ||
2424 | /** | |
2425 | * sdev_evt_alloc - allocate a new scsi event | |
2426 | * @evt_type: type of event to allocate | |
2427 | * @gfpflags: GFP flags for allocation | |
2428 | * | |
2429 | * Allocates and returns a new scsi_event. | |
2430 | */ | |
2431 | struct scsi_event *sdev_evt_alloc(enum scsi_device_event evt_type, | |
2432 | gfp_t gfpflags) | |
2433 | { | |
2434 | struct scsi_event *evt = kzalloc(sizeof(struct scsi_event), gfpflags); | |
2435 | if (!evt) | |
2436 | return NULL; | |
2437 | ||
2438 | evt->evt_type = evt_type; | |
2439 | INIT_LIST_HEAD(&evt->node); | |
2440 | ||
2441 | /* evt_type-specific initialization, if any */ | |
2442 | switch (evt_type) { | |
2443 | case SDEV_EVT_MEDIA_CHANGE: | |
2444 | default: | |
2445 | /* do nothing */ | |
2446 | break; | |
2447 | } | |
2448 | ||
2449 | return evt; | |
2450 | } | |
2451 | EXPORT_SYMBOL_GPL(sdev_evt_alloc); | |
2452 | ||
2453 | /** | |
2454 | * sdev_evt_send_simple - send asserted event to uevent thread | |
2455 | * @sdev: scsi_device event occurred on | |
2456 | * @evt_type: type of event to send | |
2457 | * @gfpflags: GFP flags for allocation | |
2458 | * | |
2459 | * Assert scsi device event asynchronously, given an event type. | |
2460 | */ | |
2461 | void sdev_evt_send_simple(struct scsi_device *sdev, | |
2462 | enum scsi_device_event evt_type, gfp_t gfpflags) | |
2463 | { | |
2464 | struct scsi_event *evt = sdev_evt_alloc(evt_type, gfpflags); | |
2465 | if (!evt) { | |
2466 | sdev_printk(KERN_ERR, sdev, "event %d eaten due to OOM\n", | |
2467 | evt_type); | |
2468 | return; | |
2469 | } | |
2470 | ||
2471 | sdev_evt_send(sdev, evt); | |
2472 | } | |
2473 | EXPORT_SYMBOL_GPL(sdev_evt_send_simple); | |
2474 | ||
1da177e4 LT |
2475 | /** |
2476 | * scsi_device_quiesce - Block user issued commands. | |
2477 | * @sdev: scsi device to quiesce. | |
2478 | * | |
2479 | * This works by trying to transition to the SDEV_QUIESCE state | |
2480 | * (which must be a legal transition). When the device is in this | |
2481 | * state, only special requests will be accepted, all others will | |
2482 | * be deferred. Since special requests may also be requeued requests, | |
2483 | * a successful return doesn't guarantee the device will be | |
2484 | * totally quiescent. | |
2485 | * | |
2486 | * Must be called with user context, may sleep. | |
2487 | * | |
2488 | * Returns zero if unsuccessful or an error if not. | |
eb44820c | 2489 | */ |
1da177e4 LT |
2490 | int |
2491 | scsi_device_quiesce(struct scsi_device *sdev) | |
2492 | { | |
2493 | int err = scsi_device_set_state(sdev, SDEV_QUIESCE); | |
2494 | if (err) | |
2495 | return err; | |
2496 | ||
2497 | scsi_run_queue(sdev->request_queue); | |
2498 | while (sdev->device_busy) { | |
2499 | msleep_interruptible(200); | |
2500 | scsi_run_queue(sdev->request_queue); | |
2501 | } | |
2502 | return 0; | |
2503 | } | |
2504 | EXPORT_SYMBOL(scsi_device_quiesce); | |
2505 | ||
2506 | /** | |
2507 | * scsi_device_resume - Restart user issued commands to a quiesced device. | |
2508 | * @sdev: scsi device to resume. | |
2509 | * | |
2510 | * Moves the device from quiesced back to running and restarts the | |
2511 | * queues. | |
2512 | * | |
2513 | * Must be called with user context, may sleep. | |
eb44820c | 2514 | */ |
1da177e4 LT |
2515 | void |
2516 | scsi_device_resume(struct scsi_device *sdev) | |
2517 | { | |
2518 | if(scsi_device_set_state(sdev, SDEV_RUNNING)) | |
2519 | return; | |
2520 | scsi_run_queue(sdev->request_queue); | |
2521 | } | |
2522 | EXPORT_SYMBOL(scsi_device_resume); | |
2523 | ||
2524 | static void | |
2525 | device_quiesce_fn(struct scsi_device *sdev, void *data) | |
2526 | { | |
2527 | scsi_device_quiesce(sdev); | |
2528 | } | |
2529 | ||
2530 | void | |
2531 | scsi_target_quiesce(struct scsi_target *starget) | |
2532 | { | |
2533 | starget_for_each_device(starget, NULL, device_quiesce_fn); | |
2534 | } | |
2535 | EXPORT_SYMBOL(scsi_target_quiesce); | |
2536 | ||
2537 | static void | |
2538 | device_resume_fn(struct scsi_device *sdev, void *data) | |
2539 | { | |
2540 | scsi_device_resume(sdev); | |
2541 | } | |
2542 | ||
2543 | void | |
2544 | scsi_target_resume(struct scsi_target *starget) | |
2545 | { | |
2546 | starget_for_each_device(starget, NULL, device_resume_fn); | |
2547 | } | |
2548 | EXPORT_SYMBOL(scsi_target_resume); | |
2549 | ||
2550 | /** | |
eb44820c | 2551 | * scsi_internal_device_block - internal function to put a device temporarily into the SDEV_BLOCK state |
1da177e4 LT |
2552 | * @sdev: device to block |
2553 | * | |
2554 | * Block request made by scsi lld's to temporarily stop all | |
2555 | * scsi commands on the specified device. Called from interrupt | |
2556 | * or normal process context. | |
2557 | * | |
2558 | * Returns zero if successful or error if not | |
2559 | * | |
2560 | * Notes: | |
2561 | * This routine transitions the device to the SDEV_BLOCK state | |
2562 | * (which must be a legal transition). When the device is in this | |
2563 | * state, all commands are deferred until the scsi lld reenables | |
2564 | * the device with scsi_device_unblock or device_block_tmo fires. | |
2565 | * This routine assumes the host_lock is held on entry. | |
eb44820c | 2566 | */ |
1da177e4 LT |
2567 | int |
2568 | scsi_internal_device_block(struct scsi_device *sdev) | |
2569 | { | |
165125e1 | 2570 | struct request_queue *q = sdev->request_queue; |
1da177e4 LT |
2571 | unsigned long flags; |
2572 | int err = 0; | |
2573 | ||
2574 | err = scsi_device_set_state(sdev, SDEV_BLOCK); | |
6f4267e3 JB |
2575 | if (err) { |
2576 | err = scsi_device_set_state(sdev, SDEV_CREATED_BLOCK); | |
2577 | ||
2578 | if (err) | |
2579 | return err; | |
2580 | } | |
1da177e4 LT |
2581 | |
2582 | /* | |
2583 | * The device has transitioned to SDEV_BLOCK. Stop the | |
2584 | * block layer from calling the midlayer with this device's | |
2585 | * request queue. | |
2586 | */ | |
2587 | spin_lock_irqsave(q->queue_lock, flags); | |
2588 | blk_stop_queue(q); | |
2589 | spin_unlock_irqrestore(q->queue_lock, flags); | |
2590 | ||
2591 | return 0; | |
2592 | } | |
2593 | EXPORT_SYMBOL_GPL(scsi_internal_device_block); | |
2594 | ||
2595 | /** | |
2596 | * scsi_internal_device_unblock - resume a device after a block request | |
2597 | * @sdev: device to resume | |
2598 | * | |
2599 | * Called by scsi lld's or the midlayer to restart the device queue | |
2600 | * for the previously suspended scsi device. Called from interrupt or | |
2601 | * normal process context. | |
2602 | * | |
2603 | * Returns zero if successful or error if not. | |
2604 | * | |
2605 | * Notes: | |
2606 | * This routine transitions the device to the SDEV_RUNNING state | |
2607 | * (which must be a legal transition) allowing the midlayer to | |
2608 | * goose the queue for this device. This routine assumes the | |
2609 | * host_lock is held upon entry. | |
eb44820c | 2610 | */ |
1da177e4 LT |
2611 | int |
2612 | scsi_internal_device_unblock(struct scsi_device *sdev) | |
2613 | { | |
165125e1 | 2614 | struct request_queue *q = sdev->request_queue; |
1da177e4 LT |
2615 | int err; |
2616 | unsigned long flags; | |
2617 | ||
2618 | /* | |
2619 | * Try to transition the scsi device to SDEV_RUNNING | |
2620 | * and goose the device queue if successful. | |
2621 | */ | |
2622 | err = scsi_device_set_state(sdev, SDEV_RUNNING); | |
6f4267e3 JB |
2623 | if (err) { |
2624 | err = scsi_device_set_state(sdev, SDEV_CREATED); | |
2625 | ||
2626 | if (err) | |
2627 | return err; | |
2628 | } | |
1da177e4 LT |
2629 | |
2630 | spin_lock_irqsave(q->queue_lock, flags); | |
2631 | blk_start_queue(q); | |
2632 | spin_unlock_irqrestore(q->queue_lock, flags); | |
2633 | ||
2634 | return 0; | |
2635 | } | |
2636 | EXPORT_SYMBOL_GPL(scsi_internal_device_unblock); | |
2637 | ||
2638 | static void | |
2639 | device_block(struct scsi_device *sdev, void *data) | |
2640 | { | |
2641 | scsi_internal_device_block(sdev); | |
2642 | } | |
2643 | ||
2644 | static int | |
2645 | target_block(struct device *dev, void *data) | |
2646 | { | |
2647 | if (scsi_is_target_device(dev)) | |
2648 | starget_for_each_device(to_scsi_target(dev), NULL, | |
2649 | device_block); | |
2650 | return 0; | |
2651 | } | |
2652 | ||
2653 | void | |
2654 | scsi_target_block(struct device *dev) | |
2655 | { | |
2656 | if (scsi_is_target_device(dev)) | |
2657 | starget_for_each_device(to_scsi_target(dev), NULL, | |
2658 | device_block); | |
2659 | else | |
2660 | device_for_each_child(dev, NULL, target_block); | |
2661 | } | |
2662 | EXPORT_SYMBOL_GPL(scsi_target_block); | |
2663 | ||
2664 | static void | |
2665 | device_unblock(struct scsi_device *sdev, void *data) | |
2666 | { | |
2667 | scsi_internal_device_unblock(sdev); | |
2668 | } | |
2669 | ||
2670 | static int | |
2671 | target_unblock(struct device *dev, void *data) | |
2672 | { | |
2673 | if (scsi_is_target_device(dev)) | |
2674 | starget_for_each_device(to_scsi_target(dev), NULL, | |
2675 | device_unblock); | |
2676 | return 0; | |
2677 | } | |
2678 | ||
2679 | void | |
2680 | scsi_target_unblock(struct device *dev) | |
2681 | { | |
2682 | if (scsi_is_target_device(dev)) | |
2683 | starget_for_each_device(to_scsi_target(dev), NULL, | |
2684 | device_unblock); | |
2685 | else | |
2686 | device_for_each_child(dev, NULL, target_unblock); | |
2687 | } | |
2688 | EXPORT_SYMBOL_GPL(scsi_target_unblock); | |
cdb8c2a6 GL |
2689 | |
2690 | /** | |
2691 | * scsi_kmap_atomic_sg - find and atomically map an sg-elemnt | |
eb44820c | 2692 | * @sgl: scatter-gather list |
cdb8c2a6 GL |
2693 | * @sg_count: number of segments in sg |
2694 | * @offset: offset in bytes into sg, on return offset into the mapped area | |
2695 | * @len: bytes to map, on return number of bytes mapped | |
2696 | * | |
2697 | * Returns virtual address of the start of the mapped page | |
2698 | */ | |
c6132da1 | 2699 | void *scsi_kmap_atomic_sg(struct scatterlist *sgl, int sg_count, |
cdb8c2a6 GL |
2700 | size_t *offset, size_t *len) |
2701 | { | |
2702 | int i; | |
2703 | size_t sg_len = 0, len_complete = 0; | |
c6132da1 | 2704 | struct scatterlist *sg; |
cdb8c2a6 GL |
2705 | struct page *page; |
2706 | ||
22cfefb5 AM |
2707 | WARN_ON(!irqs_disabled()); |
2708 | ||
c6132da1 | 2709 | for_each_sg(sgl, sg, sg_count, i) { |
cdb8c2a6 | 2710 | len_complete = sg_len; /* Complete sg-entries */ |
c6132da1 | 2711 | sg_len += sg->length; |
cdb8c2a6 GL |
2712 | if (sg_len > *offset) |
2713 | break; | |
2714 | } | |
2715 | ||
2716 | if (unlikely(i == sg_count)) { | |
169e1a2a AM |
2717 | printk(KERN_ERR "%s: Bytes in sg: %zu, requested offset %zu, " |
2718 | "elements %d\n", | |
cadbd4a5 | 2719 | __func__, sg_len, *offset, sg_count); |
cdb8c2a6 GL |
2720 | WARN_ON(1); |
2721 | return NULL; | |
2722 | } | |
2723 | ||
2724 | /* Offset starting from the beginning of first page in this sg-entry */ | |
c6132da1 | 2725 | *offset = *offset - len_complete + sg->offset; |
cdb8c2a6 GL |
2726 | |
2727 | /* Assumption: contiguous pages can be accessed as "page + i" */ | |
45711f1a | 2728 | page = nth_page(sg_page(sg), (*offset >> PAGE_SHIFT)); |
cdb8c2a6 GL |
2729 | *offset &= ~PAGE_MASK; |
2730 | ||
2731 | /* Bytes in this sg-entry from *offset to the end of the page */ | |
2732 | sg_len = PAGE_SIZE - *offset; | |
2733 | if (*len > sg_len) | |
2734 | *len = sg_len; | |
2735 | ||
2736 | return kmap_atomic(page, KM_BIO_SRC_IRQ); | |
2737 | } | |
2738 | EXPORT_SYMBOL(scsi_kmap_atomic_sg); | |
2739 | ||
2740 | /** | |
eb44820c | 2741 | * scsi_kunmap_atomic_sg - atomically unmap a virtual address, previously mapped with scsi_kmap_atomic_sg |
cdb8c2a6 GL |
2742 | * @virt: virtual address to be unmapped |
2743 | */ | |
2744 | void scsi_kunmap_atomic_sg(void *virt) | |
2745 | { | |
2746 | kunmap_atomic(virt, KM_BIO_SRC_IRQ); | |
2747 | } | |
2748 | EXPORT_SYMBOL(scsi_kunmap_atomic_sg); |