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5a55c259 FT |
1 | /* |
2 | * SCSI target lib functions | |
3 | * | |
4 | * Copyright (C) 2005 Mike Christie <michaelc@cs.wisc.edu> | |
5 | * Copyright (C) 2005 FUJITA Tomonori <tomof@acm.org> | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or | |
8 | * modify it under the terms of the GNU General Public License as | |
9 | * published by the Free Software Foundation; either version 2 of the | |
10 | * License, or (at your option) any later version. | |
11 | * | |
12 | * This program is distributed in the hope that it will be useful, but | |
13 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
15 | * General Public License for more details. | |
16 | * | |
17 | * You should have received a copy of the GNU General Public License | |
18 | * along with this program; if not, write to the Free Software | |
19 | * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA | |
20 | * 02110-1301 USA | |
21 | */ | |
22 | #include <linux/blkdev.h> | |
23 | #include <linux/hash.h> | |
24 | #include <linux/module.h> | |
25 | #include <linux/pagemap.h> | |
26 | #include <scsi/scsi.h> | |
27 | #include <scsi/scsi_cmnd.h> | |
28 | #include <scsi/scsi_device.h> | |
29 | #include <scsi/scsi_host.h> | |
30 | #include <scsi/scsi_tgt.h> | |
31 | #include <../drivers/md/dm-bio-list.h> | |
32 | ||
33 | #include "scsi_tgt_priv.h" | |
34 | ||
35 | static struct workqueue_struct *scsi_tgtd; | |
36 | static kmem_cache_t *scsi_tgt_cmd_cache; | |
37 | ||
38 | /* | |
39 | * TODO: this struct will be killed when the block layer supports large bios | |
40 | * and James's work struct code is in | |
41 | */ | |
42 | struct scsi_tgt_cmd { | |
43 | /* TODO replace work with James b's code */ | |
44 | struct work_struct work; | |
45 | /* TODO replace the lists with a large bio */ | |
46 | struct bio_list xfer_done_list; | |
47 | struct bio_list xfer_list; | |
48 | ||
49 | struct list_head hash_list; | |
50 | struct request *rq; | |
51 | u64 tag; | |
52 | ||
53 | void *buffer; | |
54 | unsigned bufflen; | |
55 | }; | |
56 | ||
57 | #define TGT_HASH_ORDER 4 | |
58 | #define cmd_hashfn(tag) hash_long((unsigned long) (tag), TGT_HASH_ORDER) | |
59 | ||
60 | struct scsi_tgt_queuedata { | |
61 | struct Scsi_Host *shost; | |
62 | struct list_head cmd_hash[1 << TGT_HASH_ORDER]; | |
63 | spinlock_t cmd_hash_lock; | |
64 | }; | |
65 | ||
66 | /* | |
67 | * Function: scsi_host_get_command() | |
68 | * | |
69 | * Purpose: Allocate and setup a scsi command block and blk request | |
70 | * | |
71 | * Arguments: shost - scsi host | |
72 | * data_dir - dma data dir | |
73 | * gfp_mask- allocator flags | |
74 | * | |
75 | * Returns: The allocated scsi command structure. | |
76 | * | |
77 | * This should be called by target LLDs to get a command. | |
78 | */ | |
79 | struct scsi_cmnd *scsi_host_get_command(struct Scsi_Host *shost, | |
80 | enum dma_data_direction data_dir, | |
81 | gfp_t gfp_mask) | |
82 | { | |
83 | int write = (data_dir == DMA_TO_DEVICE); | |
84 | struct request *rq; | |
85 | struct scsi_cmnd *cmd; | |
86 | struct scsi_tgt_cmd *tcmd; | |
87 | ||
88 | /* Bail if we can't get a reference to the device */ | |
89 | if (!get_device(&shost->shost_gendev)) | |
90 | return NULL; | |
91 | ||
92 | tcmd = kmem_cache_alloc(scsi_tgt_cmd_cache, GFP_ATOMIC); | |
93 | if (!tcmd) | |
94 | goto put_dev; | |
95 | ||
96 | rq = blk_get_request(shost->uspace_req_q, write, gfp_mask); | |
97 | if (!rq) | |
98 | goto free_tcmd; | |
99 | ||
100 | cmd = __scsi_get_command(shost, gfp_mask); | |
101 | if (!cmd) | |
102 | goto release_rq; | |
103 | ||
104 | memset(cmd, 0, sizeof(*cmd)); | |
105 | cmd->sc_data_direction = data_dir; | |
106 | cmd->jiffies_at_alloc = jiffies; | |
107 | cmd->request = rq; | |
108 | ||
109 | rq->special = cmd; | |
110 | rq->cmd_type = REQ_TYPE_SPECIAL; | |
111 | rq->cmd_flags |= REQ_TYPE_BLOCK_PC; | |
112 | rq->end_io_data = tcmd; | |
113 | ||
114 | bio_list_init(&tcmd->xfer_list); | |
115 | bio_list_init(&tcmd->xfer_done_list); | |
116 | tcmd->rq = rq; | |
117 | ||
118 | return cmd; | |
119 | ||
120 | release_rq: | |
121 | blk_put_request(rq); | |
122 | free_tcmd: | |
123 | kmem_cache_free(scsi_tgt_cmd_cache, tcmd); | |
124 | put_dev: | |
125 | put_device(&shost->shost_gendev); | |
126 | return NULL; | |
127 | ||
128 | } | |
129 | EXPORT_SYMBOL_GPL(scsi_host_get_command); | |
130 | ||
131 | /* | |
132 | * Function: scsi_host_put_command() | |
133 | * | |
134 | * Purpose: Free a scsi command block | |
135 | * | |
136 | * Arguments: shost - scsi host | |
137 | * cmd - command block to free | |
138 | * | |
139 | * Returns: Nothing. | |
140 | * | |
141 | * Notes: The command must not belong to any lists. | |
142 | */ | |
143 | void scsi_host_put_command(struct Scsi_Host *shost, struct scsi_cmnd *cmd) | |
144 | { | |
145 | struct request_queue *q = shost->uspace_req_q; | |
146 | struct request *rq = cmd->request; | |
147 | struct scsi_tgt_cmd *tcmd = rq->end_io_data; | |
148 | unsigned long flags; | |
149 | ||
150 | kmem_cache_free(scsi_tgt_cmd_cache, tcmd); | |
151 | ||
152 | spin_lock_irqsave(q->queue_lock, flags); | |
153 | __blk_put_request(q, rq); | |
154 | spin_unlock_irqrestore(q->queue_lock, flags); | |
155 | ||
156 | __scsi_put_command(shost, cmd, &shost->shost_gendev); | |
157 | } | |
158 | EXPORT_SYMBOL_GPL(scsi_host_put_command); | |
159 | ||
160 | static void scsi_unmap_user_pages(struct scsi_tgt_cmd *tcmd) | |
161 | { | |
162 | struct bio *bio; | |
163 | ||
164 | /* must call bio_endio in case bio was bounced */ | |
165 | while ((bio = bio_list_pop(&tcmd->xfer_done_list))) { | |
166 | bio_endio(bio, bio->bi_size, 0); | |
167 | bio_unmap_user(bio); | |
168 | } | |
169 | ||
170 | while ((bio = bio_list_pop(&tcmd->xfer_list))) { | |
171 | bio_endio(bio, bio->bi_size, 0); | |
172 | bio_unmap_user(bio); | |
173 | } | |
174 | } | |
175 | ||
176 | static void cmd_hashlist_del(struct scsi_cmnd *cmd) | |
177 | { | |
178 | struct request_queue *q = cmd->request->q; | |
179 | struct scsi_tgt_queuedata *qdata = q->queuedata; | |
180 | unsigned long flags; | |
181 | struct scsi_tgt_cmd *tcmd = cmd->request->end_io_data; | |
182 | ||
183 | spin_lock_irqsave(&qdata->cmd_hash_lock, flags); | |
184 | list_del(&tcmd->hash_list); | |
185 | spin_unlock_irqrestore(&qdata->cmd_hash_lock, flags); | |
186 | } | |
187 | ||
188 | static void scsi_tgt_cmd_destroy(void *data) | |
189 | { | |
190 | struct scsi_cmnd *cmd = data; | |
191 | struct scsi_tgt_cmd *tcmd = cmd->request->end_io_data; | |
192 | ||
193 | dprintk("cmd %p %d %lu\n", cmd, cmd->sc_data_direction, | |
194 | rq_data_dir(cmd->request)); | |
195 | /* | |
196 | * We fix rq->cmd_flags here since when we told bio_map_user | |
197 | * to write vm for WRITE commands, blk_rq_bio_prep set | |
198 | * rq_data_dir the flags to READ. | |
199 | */ | |
200 | if (cmd->sc_data_direction == DMA_TO_DEVICE) | |
201 | cmd->request->cmd_flags |= REQ_RW; | |
202 | else | |
203 | cmd->request->cmd_flags &= ~REQ_RW; | |
204 | ||
205 | scsi_unmap_user_pages(tcmd); | |
206 | scsi_host_put_command(scsi_tgt_cmd_to_host(cmd), cmd); | |
207 | } | |
208 | ||
209 | static void init_scsi_tgt_cmd(struct request *rq, struct scsi_tgt_cmd *tcmd, | |
210 | u64 tag) | |
211 | { | |
212 | struct scsi_tgt_queuedata *qdata = rq->q->queuedata; | |
213 | unsigned long flags; | |
214 | struct list_head *head; | |
215 | ||
216 | tcmd->tag = tag; | |
217 | spin_lock_irqsave(&qdata->cmd_hash_lock, flags); | |
218 | head = &qdata->cmd_hash[cmd_hashfn(tag)]; | |
219 | list_add(&tcmd->hash_list, head); | |
220 | spin_unlock_irqrestore(&qdata->cmd_hash_lock, flags); | |
221 | } | |
222 | ||
223 | /* | |
224 | * scsi_tgt_alloc_queue - setup queue used for message passing | |
225 | * shost: scsi host | |
226 | * | |
227 | * This should be called by the LLD after host allocation. | |
228 | * And will be released when the host is released. | |
229 | */ | |
230 | int scsi_tgt_alloc_queue(struct Scsi_Host *shost) | |
231 | { | |
232 | struct scsi_tgt_queuedata *queuedata; | |
233 | struct request_queue *q; | |
234 | int err, i; | |
235 | ||
236 | /* | |
237 | * Do we need to send a netlink event or should uspace | |
238 | * just respond to the hotplug event? | |
239 | */ | |
240 | q = __scsi_alloc_queue(shost, NULL); | |
241 | if (!q) | |
242 | return -ENOMEM; | |
243 | ||
244 | queuedata = kzalloc(sizeof(*queuedata), GFP_KERNEL); | |
245 | if (!queuedata) { | |
246 | err = -ENOMEM; | |
247 | goto cleanup_queue; | |
248 | } | |
249 | queuedata->shost = shost; | |
250 | q->queuedata = queuedata; | |
251 | ||
252 | /* | |
253 | * this is a silly hack. We should probably just queue as many | |
254 | * command as is recvd to userspace. uspace can then make | |
255 | * sure we do not overload the HBA | |
256 | */ | |
257 | q->nr_requests = shost->hostt->can_queue; | |
258 | /* | |
259 | * We currently only support software LLDs so this does | |
260 | * not matter for now. Do we need this for the cards we support? | |
261 | * If so we should make it a host template value. | |
262 | */ | |
263 | blk_queue_dma_alignment(q, 0); | |
264 | shost->uspace_req_q = q; | |
265 | ||
266 | for (i = 0; i < ARRAY_SIZE(queuedata->cmd_hash); i++) | |
267 | INIT_LIST_HEAD(&queuedata->cmd_hash[i]); | |
268 | spin_lock_init(&queuedata->cmd_hash_lock); | |
269 | ||
270 | return 0; | |
271 | ||
272 | cleanup_queue: | |
273 | blk_cleanup_queue(q); | |
274 | return err; | |
275 | } | |
276 | EXPORT_SYMBOL_GPL(scsi_tgt_alloc_queue); | |
277 | ||
278 | void scsi_tgt_free_queue(struct Scsi_Host *shost) | |
279 | { | |
280 | int i; | |
281 | unsigned long flags; | |
282 | struct request_queue *q = shost->uspace_req_q; | |
283 | struct scsi_cmnd *cmd; | |
284 | struct scsi_tgt_queuedata *qdata = q->queuedata; | |
285 | struct scsi_tgt_cmd *tcmd, *n; | |
286 | LIST_HEAD(cmds); | |
287 | ||
288 | spin_lock_irqsave(&qdata->cmd_hash_lock, flags); | |
289 | ||
290 | for (i = 0; i < ARRAY_SIZE(qdata->cmd_hash); i++) { | |
291 | list_for_each_entry_safe(tcmd, n, &qdata->cmd_hash[i], | |
292 | hash_list) { | |
293 | list_del(&tcmd->hash_list); | |
294 | list_add(&tcmd->hash_list, &cmds); | |
295 | } | |
296 | } | |
297 | ||
298 | spin_unlock_irqrestore(&qdata->cmd_hash_lock, flags); | |
299 | ||
300 | while (!list_empty(&cmds)) { | |
301 | tcmd = list_entry(cmds.next, struct scsi_tgt_cmd, hash_list); | |
302 | list_del(&tcmd->hash_list); | |
303 | cmd = tcmd->rq->special; | |
304 | ||
305 | shost->hostt->eh_abort_handler(cmd); | |
306 | scsi_tgt_cmd_destroy(cmd); | |
307 | } | |
308 | } | |
309 | EXPORT_SYMBOL_GPL(scsi_tgt_free_queue); | |
310 | ||
311 | struct Scsi_Host *scsi_tgt_cmd_to_host(struct scsi_cmnd *cmd) | |
312 | { | |
313 | struct scsi_tgt_queuedata *queue = cmd->request->q->queuedata; | |
314 | return queue->shost; | |
315 | } | |
316 | EXPORT_SYMBOL_GPL(scsi_tgt_cmd_to_host); | |
317 | ||
318 | /* | |
319 | * scsi_tgt_queue_command - queue command for userspace processing | |
320 | * @cmd: scsi command | |
321 | * @scsilun: scsi lun | |
322 | * @tag: unique value to identify this command for tmf | |
323 | */ | |
324 | int scsi_tgt_queue_command(struct scsi_cmnd *cmd, struct scsi_lun *scsilun, | |
325 | u64 tag) | |
326 | { | |
327 | struct scsi_tgt_cmd *tcmd = cmd->request->end_io_data; | |
328 | int err; | |
329 | ||
330 | init_scsi_tgt_cmd(cmd->request, tcmd, tag); | |
331 | err = scsi_tgt_uspace_send_cmd(cmd, scsilun, tag); | |
332 | if (err) | |
333 | cmd_hashlist_del(cmd); | |
334 | ||
335 | return err; | |
336 | } | |
337 | EXPORT_SYMBOL_GPL(scsi_tgt_queue_command); | |
338 | ||
339 | /* | |
340 | * This is run from a interrpt handler normally and the unmap | |
341 | * needs process context so we must queue | |
342 | */ | |
343 | static void scsi_tgt_cmd_done(struct scsi_cmnd *cmd) | |
344 | { | |
345 | struct scsi_tgt_cmd *tcmd = cmd->request->end_io_data; | |
346 | ||
347 | dprintk("cmd %p %lu\n", cmd, rq_data_dir(cmd->request)); | |
348 | ||
349 | scsi_tgt_uspace_send_status(cmd, tcmd->tag); | |
350 | INIT_WORK(&tcmd->work, scsi_tgt_cmd_destroy, cmd); | |
351 | queue_work(scsi_tgtd, &tcmd->work); | |
352 | } | |
353 | ||
354 | static int __scsi_tgt_transfer_response(struct scsi_cmnd *cmd) | |
355 | { | |
356 | struct Scsi_Host *shost = scsi_tgt_cmd_to_host(cmd); | |
357 | int err; | |
358 | ||
359 | dprintk("cmd %p %lu\n", cmd, rq_data_dir(cmd->request)); | |
360 | ||
361 | err = shost->hostt->transfer_response(cmd, scsi_tgt_cmd_done); | |
362 | switch (err) { | |
363 | case SCSI_MLQUEUE_HOST_BUSY: | |
364 | case SCSI_MLQUEUE_DEVICE_BUSY: | |
365 | return -EAGAIN; | |
366 | } | |
367 | ||
368 | return 0; | |
369 | } | |
370 | ||
371 | static void scsi_tgt_transfer_response(struct scsi_cmnd *cmd) | |
372 | { | |
373 | struct scsi_tgt_cmd *tcmd = cmd->request->end_io_data; | |
374 | int err; | |
375 | ||
376 | err = __scsi_tgt_transfer_response(cmd); | |
377 | if (!err) | |
378 | return; | |
379 | ||
380 | cmd->result = DID_BUS_BUSY << 16; | |
381 | err = scsi_tgt_uspace_send_status(cmd, tcmd->tag); | |
382 | if (err <= 0) | |
383 | /* the eh will have to pick this up */ | |
384 | printk(KERN_ERR "Could not send cmd %p status\n", cmd); | |
385 | } | |
386 | ||
387 | static int scsi_tgt_init_cmd(struct scsi_cmnd *cmd, gfp_t gfp_mask) | |
388 | { | |
389 | struct request *rq = cmd->request; | |
390 | struct scsi_tgt_cmd *tcmd = rq->end_io_data; | |
391 | int count; | |
392 | ||
393 | cmd->use_sg = rq->nr_phys_segments; | |
394 | cmd->request_buffer = scsi_alloc_sgtable(cmd, gfp_mask); | |
395 | if (!cmd->request_buffer) | |
396 | return -ENOMEM; | |
397 | ||
398 | cmd->request_bufflen = rq->data_len; | |
399 | ||
400 | dprintk("cmd %p addr %p cnt %d %lu\n", cmd, tcmd->buffer, cmd->use_sg, | |
401 | rq_data_dir(rq)); | |
402 | count = blk_rq_map_sg(rq->q, rq, cmd->request_buffer); | |
403 | if (likely(count <= cmd->use_sg)) { | |
404 | cmd->use_sg = count; | |
405 | return 0; | |
406 | } | |
407 | ||
408 | eprintk("cmd %p addr %p cnt %d\n", cmd, tcmd->buffer, cmd->use_sg); | |
409 | scsi_free_sgtable(cmd->request_buffer, cmd->sglist_len); | |
410 | return -EINVAL; | |
411 | } | |
412 | ||
413 | /* TODO: test this crap and replace bio_map_user with new interface maybe */ | |
414 | static int scsi_map_user_pages(struct scsi_tgt_cmd *tcmd, struct scsi_cmnd *cmd, | |
415 | int rw) | |
416 | { | |
417 | struct request_queue *q = cmd->request->q; | |
418 | struct request *rq = cmd->request; | |
419 | void *uaddr = tcmd->buffer; | |
420 | unsigned int len = tcmd->bufflen; | |
421 | struct bio *bio; | |
422 | int err; | |
423 | ||
424 | while (len > 0) { | |
425 | dprintk("%lx %u\n", (unsigned long) uaddr, len); | |
426 | bio = bio_map_user(q, NULL, (unsigned long) uaddr, len, rw); | |
427 | if (IS_ERR(bio)) { | |
428 | err = PTR_ERR(bio); | |
429 | dprintk("fail to map %lx %u %d %x\n", | |
430 | (unsigned long) uaddr, len, err, cmd->cmnd[0]); | |
431 | goto unmap_bios; | |
432 | } | |
433 | ||
434 | uaddr += bio->bi_size; | |
435 | len -= bio->bi_size; | |
436 | ||
437 | /* | |
438 | * The first bio is added and merged. We could probably | |
439 | * try to add others using scsi_merge_bio() but for now | |
440 | * we keep it simple. The first bio should be pretty large | |
441 | * (either hitting the 1 MB bio pages limit or a queue limit) | |
442 | * already but for really large IO we may want to try and | |
443 | * merge these. | |
444 | */ | |
445 | if (!rq->bio) { | |
446 | blk_rq_bio_prep(q, rq, bio); | |
447 | rq->data_len = bio->bi_size; | |
448 | } else | |
449 | /* put list of bios to transfer in next go around */ | |
450 | bio_list_add(&tcmd->xfer_list, bio); | |
451 | } | |
452 | ||
453 | cmd->offset = 0; | |
454 | err = scsi_tgt_init_cmd(cmd, GFP_KERNEL); | |
455 | if (err) | |
456 | goto unmap_bios; | |
457 | ||
458 | return 0; | |
459 | ||
460 | unmap_bios: | |
461 | if (rq->bio) { | |
462 | bio_unmap_user(rq->bio); | |
463 | while ((bio = bio_list_pop(&tcmd->xfer_list))) | |
464 | bio_unmap_user(bio); | |
465 | } | |
466 | ||
467 | return err; | |
468 | } | |
469 | ||
470 | static int scsi_tgt_transfer_data(struct scsi_cmnd *); | |
471 | ||
472 | static void scsi_tgt_data_transfer_done(struct scsi_cmnd *cmd) | |
473 | { | |
474 | struct scsi_tgt_cmd *tcmd = cmd->request->end_io_data; | |
475 | struct bio *bio; | |
476 | int err; | |
477 | ||
478 | /* should we free resources here on error ? */ | |
479 | if (cmd->result) { | |
480 | send_uspace_err: | |
481 | err = scsi_tgt_uspace_send_status(cmd, tcmd->tag); | |
482 | if (err <= 0) | |
483 | /* the tgt uspace eh will have to pick this up */ | |
484 | printk(KERN_ERR "Could not send cmd %p status\n", cmd); | |
485 | return; | |
486 | } | |
487 | ||
488 | dprintk("cmd %p request_bufflen %u bufflen %u\n", | |
489 | cmd, cmd->request_bufflen, tcmd->bufflen); | |
490 | ||
491 | scsi_free_sgtable(cmd->request_buffer, cmd->sglist_len); | |
492 | bio_list_add(&tcmd->xfer_done_list, cmd->request->bio); | |
493 | ||
494 | tcmd->buffer += cmd->request_bufflen; | |
495 | cmd->offset += cmd->request_bufflen; | |
496 | ||
497 | if (!tcmd->xfer_list.head) { | |
498 | scsi_tgt_transfer_response(cmd); | |
499 | return; | |
500 | } | |
501 | ||
502 | dprintk("cmd2 %p request_bufflen %u bufflen %u\n", | |
503 | cmd, cmd->request_bufflen, tcmd->bufflen); | |
504 | ||
505 | bio = bio_list_pop(&tcmd->xfer_list); | |
506 | BUG_ON(!bio); | |
507 | ||
508 | blk_rq_bio_prep(cmd->request->q, cmd->request, bio); | |
509 | cmd->request->data_len = bio->bi_size; | |
510 | err = scsi_tgt_init_cmd(cmd, GFP_ATOMIC); | |
511 | if (err) { | |
512 | cmd->result = DID_ERROR << 16; | |
513 | goto send_uspace_err; | |
514 | } | |
515 | ||
516 | if (scsi_tgt_transfer_data(cmd)) { | |
517 | cmd->result = DID_NO_CONNECT << 16; | |
518 | goto send_uspace_err; | |
519 | } | |
520 | } | |
521 | ||
522 | static int scsi_tgt_transfer_data(struct scsi_cmnd *cmd) | |
523 | { | |
524 | int err; | |
525 | struct Scsi_Host *host = scsi_tgt_cmd_to_host(cmd); | |
526 | ||
527 | err = host->hostt->transfer_data(cmd, scsi_tgt_data_transfer_done); | |
528 | switch (err) { | |
529 | case SCSI_MLQUEUE_HOST_BUSY: | |
530 | case SCSI_MLQUEUE_DEVICE_BUSY: | |
531 | return -EAGAIN; | |
532 | default: | |
533 | return 0; | |
534 | } | |
535 | } | |
536 | ||
537 | static int scsi_tgt_copy_sense(struct scsi_cmnd *cmd, unsigned long uaddr, | |
538 | unsigned len) | |
539 | { | |
540 | char __user *p = (char __user *) uaddr; | |
541 | ||
542 | if (copy_from_user(cmd->sense_buffer, p, | |
543 | min_t(unsigned, SCSI_SENSE_BUFFERSIZE, len))) { | |
544 | printk(KERN_ERR "Could not copy the sense buffer\n"); | |
545 | return -EIO; | |
546 | } | |
547 | return 0; | |
548 | } | |
549 | ||
550 | static int scsi_tgt_abort_cmd(struct Scsi_Host *shost, struct scsi_cmnd *cmd) | |
551 | { | |
552 | int err; | |
553 | ||
554 | err = shost->hostt->eh_abort_handler(cmd); | |
555 | if (err) | |
556 | eprintk("fail to abort %p\n", cmd); | |
557 | ||
558 | scsi_tgt_cmd_destroy(cmd); | |
559 | return err; | |
560 | } | |
561 | ||
562 | static struct request *tgt_cmd_hash_lookup(struct request_queue *q, u64 tag) | |
563 | { | |
564 | struct scsi_tgt_queuedata *qdata = q->queuedata; | |
565 | struct request *rq = NULL; | |
566 | struct list_head *head; | |
567 | struct scsi_tgt_cmd *tcmd; | |
568 | unsigned long flags; | |
569 | ||
570 | head = &qdata->cmd_hash[cmd_hashfn(tag)]; | |
571 | spin_lock_irqsave(&qdata->cmd_hash_lock, flags); | |
572 | list_for_each_entry(tcmd, head, hash_list) { | |
573 | if (tcmd->tag == tag) { | |
574 | rq = tcmd->rq; | |
575 | list_del(&tcmd->hash_list); | |
576 | break; | |
577 | } | |
578 | } | |
579 | spin_unlock_irqrestore(&qdata->cmd_hash_lock, flags); | |
580 | ||
581 | return rq; | |
582 | } | |
583 | ||
584 | int scsi_tgt_kspace_exec(int host_no, u64 tag, int result, u32 len, | |
585 | unsigned long uaddr, u8 rw) | |
586 | { | |
587 | struct Scsi_Host *shost; | |
588 | struct scsi_cmnd *cmd; | |
589 | struct request *rq; | |
590 | struct scsi_tgt_cmd *tcmd; | |
591 | int err = 0; | |
592 | ||
593 | dprintk("%d %llu %d %u %lx %u\n", host_no, (unsigned long long) tag, | |
594 | result, len, uaddr, rw); | |
595 | ||
596 | /* TODO: replace with a O(1) alg */ | |
597 | shost = scsi_host_lookup(host_no); | |
598 | if (IS_ERR(shost)) { | |
599 | printk(KERN_ERR "Could not find host no %d\n", host_no); | |
600 | return -EINVAL; | |
601 | } | |
602 | ||
603 | if (!shost->uspace_req_q) { | |
604 | printk(KERN_ERR "Not target scsi host %d\n", host_no); | |
605 | goto done; | |
606 | } | |
607 | ||
608 | rq = tgt_cmd_hash_lookup(shost->uspace_req_q, tag); | |
609 | if (!rq) { | |
610 | printk(KERN_ERR "Could not find tag %llu\n", | |
611 | (unsigned long long) tag); | |
612 | err = -EINVAL; | |
613 | goto done; | |
614 | } | |
615 | cmd = rq->special; | |
616 | ||
617 | dprintk("cmd %p result %d len %d bufflen %u %lu %x\n", cmd, | |
618 | result, len, cmd->request_bufflen, rq_data_dir(rq), cmd->cmnd[0]); | |
619 | ||
620 | if (result == TASK_ABORTED) { | |
621 | scsi_tgt_abort_cmd(shost, cmd); | |
622 | goto done; | |
623 | } | |
624 | /* | |
625 | * store the userspace values here, the working values are | |
626 | * in the request_* values | |
627 | */ | |
628 | tcmd = cmd->request->end_io_data; | |
629 | tcmd->buffer = (void *)uaddr; | |
630 | tcmd->bufflen = len; | |
631 | cmd->result = result; | |
632 | ||
633 | if (!tcmd->bufflen || cmd->request_buffer) { | |
634 | err = __scsi_tgt_transfer_response(cmd); | |
635 | goto done; | |
636 | } | |
637 | ||
638 | /* | |
639 | * TODO: Do we need to handle case where request does not | |
640 | * align with LLD. | |
641 | */ | |
642 | err = scsi_map_user_pages(rq->end_io_data, cmd, rw); | |
643 | if (err) { | |
644 | eprintk("%p %d\n", cmd, err); | |
645 | err = -EAGAIN; | |
646 | goto done; | |
647 | } | |
648 | ||
649 | /* userspace failure */ | |
650 | if (cmd->result) { | |
651 | if (status_byte(cmd->result) == CHECK_CONDITION) | |
652 | scsi_tgt_copy_sense(cmd, uaddr, len); | |
653 | err = __scsi_tgt_transfer_response(cmd); | |
654 | goto done; | |
655 | } | |
656 | /* ask the target LLD to transfer the data to the buffer */ | |
657 | err = scsi_tgt_transfer_data(cmd); | |
658 | ||
659 | done: | |
660 | scsi_host_put(shost); | |
661 | return err; | |
662 | } | |
663 | ||
664 | int scsi_tgt_tsk_mgmt_request(struct Scsi_Host *shost, int function, u64 tag, | |
665 | struct scsi_lun *scsilun, void *data) | |
666 | { | |
667 | int err; | |
668 | ||
669 | /* TODO: need to retry if this fails. */ | |
670 | err = scsi_tgt_uspace_send_tsk_mgmt(shost->host_no, function, | |
671 | tag, scsilun, data); | |
672 | if (err < 0) | |
673 | eprintk("The task management request lost!\n"); | |
674 | return err; | |
675 | } | |
676 | EXPORT_SYMBOL_GPL(scsi_tgt_tsk_mgmt_request); | |
677 | ||
678 | int scsi_tgt_kspace_tsk_mgmt(int host_no, u64 mid, int result) | |
679 | { | |
680 | struct Scsi_Host *shost; | |
681 | int err = -EINVAL; | |
682 | ||
683 | dprintk("%d %d %llx\n", host_no, result, (unsigned long long) mid); | |
684 | ||
685 | shost = scsi_host_lookup(host_no); | |
686 | if (IS_ERR(shost)) { | |
687 | printk(KERN_ERR "Could not find host no %d\n", host_no); | |
688 | return err; | |
689 | } | |
690 | ||
691 | if (!shost->uspace_req_q) { | |
692 | printk(KERN_ERR "Not target scsi host %d\n", host_no); | |
693 | goto done; | |
694 | } | |
695 | ||
696 | err = shost->hostt->tsk_mgmt_response(mid, result); | |
697 | done: | |
698 | scsi_host_put(shost); | |
699 | return err; | |
700 | } | |
701 | ||
702 | static int __init scsi_tgt_init(void) | |
703 | { | |
704 | int err; | |
705 | ||
706 | scsi_tgt_cmd_cache = kmem_cache_create("scsi_tgt_cmd", | |
707 | sizeof(struct scsi_tgt_cmd), | |
708 | 0, 0, NULL, NULL); | |
709 | if (!scsi_tgt_cmd_cache) | |
710 | return -ENOMEM; | |
711 | ||
712 | scsi_tgtd = create_workqueue("scsi_tgtd"); | |
713 | if (!scsi_tgtd) { | |
714 | err = -ENOMEM; | |
715 | goto free_kmemcache; | |
716 | } | |
717 | ||
718 | err = scsi_tgt_if_init(); | |
719 | if (err) | |
720 | goto destroy_wq; | |
721 | ||
722 | return 0; | |
723 | ||
724 | destroy_wq: | |
725 | destroy_workqueue(scsi_tgtd); | |
726 | free_kmemcache: | |
727 | kmem_cache_destroy(scsi_tgt_cmd_cache); | |
728 | return err; | |
729 | } | |
730 | ||
731 | static void __exit scsi_tgt_exit(void) | |
732 | { | |
733 | destroy_workqueue(scsi_tgtd); | |
734 | scsi_tgt_if_exit(); | |
735 | kmem_cache_destroy(scsi_tgt_cmd_cache); | |
736 | } | |
737 | ||
738 | module_init(scsi_tgt_init); | |
739 | module_exit(scsi_tgt_exit); | |
740 | ||
741 | MODULE_DESCRIPTION("SCSI target core"); | |
742 | MODULE_LICENSE("GPL"); |