aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/scsi/scsi_tgt_lib.c
diff options
context:
space:
mode:
authorFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>2006-11-16 05:24:13 -0500
committerJames Bottomley <jejb@mulgrave.il.steeleye.com>2006-11-25 14:17:18 -0500
commit5a55c2596f55e3a60f7502d0dfcfa0d20241e5ac (patch)
tree30bee283b134036d67b15e597270f3718a5e41e5 /drivers/scsi/scsi_tgt_lib.c
parentb58d91547fb17c65ad621f3f98b1f2c228c812a5 (diff)
[SCSI] scsi tgt: scsi target lib functionality
The core scsi target lib functions. TODO: - mv md/dm-bio-list.h to linux/bio-list.h so md and us do not have to do that weird include. - convert scsi_tgt_cmd's work struct to James's execute code. And try to kill our scsi_tgt_cmd. - add host state checking. We do refcouting so hotplug is partially supported, but we need to add state checking to make it easier on the LLD. Signed-off-by: Mike Christie <michaelc@cs.wisc.edu> Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Diffstat (limited to 'drivers/scsi/scsi_tgt_lib.c')
-rw-r--r--drivers/scsi/scsi_tgt_lib.c742
1 files changed, 742 insertions, 0 deletions
diff --git a/drivers/scsi/scsi_tgt_lib.c b/drivers/scsi/scsi_tgt_lib.c
new file mode 100644
index 000000000000..39da5cd6fb6f
--- /dev/null
+++ b/drivers/scsi/scsi_tgt_lib.c
@@ -0,0 +1,742 @@
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
35static struct workqueue_struct *scsi_tgtd;
36static 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 */
42struct 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
60struct 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 */
79struct 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
120release_rq:
121 blk_put_request(rq);
122free_tcmd:
123 kmem_cache_free(scsi_tgt_cmd_cache, tcmd);
124put_dev:
125 put_device(&shost->shost_gendev);
126 return NULL;
127
128}
129EXPORT_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 */
143void 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}
158EXPORT_SYMBOL_GPL(scsi_host_put_command);
159
160static 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
176static 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
188static 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
209static 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 */
230int 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
272cleanup_queue:
273 blk_cleanup_queue(q);
274 return err;
275}
276EXPORT_SYMBOL_GPL(scsi_tgt_alloc_queue);
277
278void 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}
309EXPORT_SYMBOL_GPL(scsi_tgt_free_queue);
310
311struct 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}
316EXPORT_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 */
324int 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}
337EXPORT_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 */
343static 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
354static 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
371static 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
387static 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 */
414static 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
460unmap_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
470static int scsi_tgt_transfer_data(struct scsi_cmnd *);
471
472static 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) {
480send_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
522static 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
537static 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
550static 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
562static 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
584int 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
659done:
660 scsi_host_put(shost);
661 return err;
662}
663
664int 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}
676EXPORT_SYMBOL_GPL(scsi_tgt_tsk_mgmt_request);
677
678int 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);
697done:
698 scsi_host_put(shost);
699 return err;
700}
701
702static 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
724destroy_wq:
725 destroy_workqueue(scsi_tgtd);
726free_kmemcache:
727 kmem_cache_destroy(scsi_tgt_cmd_cache);
728 return err;
729}
730
731static 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
738module_init(scsi_tgt_init);
739module_exit(scsi_tgt_exit);
740
741MODULE_DESCRIPTION("SCSI target core");
742MODULE_LICENSE("GPL");