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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; | |
e18b890b | 36 | static struct kmem_cache *scsi_tgt_cmd_cache; |
5a55c259 FT |
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 | ||
06328b4f | 188 | static void scsi_tgt_cmd_destroy(struct work_struct *work) |
5a55c259 | 189 | { |
06328b4f DH |
190 | struct scsi_tgt_cmd *tcmd = |
191 | container_of(work, struct scsi_tgt_cmd, work); | |
192 | struct scsi_cmnd *cmd = tcmd->rq->special; | |
5a55c259 FT |
193 | |
194 | dprintk("cmd %p %d %lu\n", cmd, cmd->sc_data_direction, | |
195 | rq_data_dir(cmd->request)); | |
196 | /* | |
197 | * We fix rq->cmd_flags here since when we told bio_map_user | |
198 | * to write vm for WRITE commands, blk_rq_bio_prep set | |
199 | * rq_data_dir the flags to READ. | |
200 | */ | |
201 | if (cmd->sc_data_direction == DMA_TO_DEVICE) | |
202 | cmd->request->cmd_flags |= REQ_RW; | |
203 | else | |
204 | cmd->request->cmd_flags &= ~REQ_RW; | |
205 | ||
206 | scsi_unmap_user_pages(tcmd); | |
207 | scsi_host_put_command(scsi_tgt_cmd_to_host(cmd), cmd); | |
208 | } | |
209 | ||
210 | static void init_scsi_tgt_cmd(struct request *rq, struct scsi_tgt_cmd *tcmd, | |
211 | u64 tag) | |
212 | { | |
213 | struct scsi_tgt_queuedata *qdata = rq->q->queuedata; | |
214 | unsigned long flags; | |
215 | struct list_head *head; | |
216 | ||
217 | tcmd->tag = tag; | |
06328b4f | 218 | INIT_WORK(&tcmd->work, scsi_tgt_cmd_destroy); |
5a55c259 FT |
219 | spin_lock_irqsave(&qdata->cmd_hash_lock, flags); |
220 | head = &qdata->cmd_hash[cmd_hashfn(tag)]; | |
221 | list_add(&tcmd->hash_list, head); | |
222 | spin_unlock_irqrestore(&qdata->cmd_hash_lock, flags); | |
223 | } | |
224 | ||
225 | /* | |
226 | * scsi_tgt_alloc_queue - setup queue used for message passing | |
227 | * shost: scsi host | |
228 | * | |
229 | * This should be called by the LLD after host allocation. | |
230 | * And will be released when the host is released. | |
231 | */ | |
232 | int scsi_tgt_alloc_queue(struct Scsi_Host *shost) | |
233 | { | |
234 | struct scsi_tgt_queuedata *queuedata; | |
235 | struct request_queue *q; | |
236 | int err, i; | |
237 | ||
238 | /* | |
239 | * Do we need to send a netlink event or should uspace | |
240 | * just respond to the hotplug event? | |
241 | */ | |
242 | q = __scsi_alloc_queue(shost, NULL); | |
243 | if (!q) | |
244 | return -ENOMEM; | |
245 | ||
246 | queuedata = kzalloc(sizeof(*queuedata), GFP_KERNEL); | |
247 | if (!queuedata) { | |
248 | err = -ENOMEM; | |
249 | goto cleanup_queue; | |
250 | } | |
251 | queuedata->shost = shost; | |
252 | q->queuedata = queuedata; | |
253 | ||
254 | /* | |
255 | * this is a silly hack. We should probably just queue as many | |
256 | * command as is recvd to userspace. uspace can then make | |
257 | * sure we do not overload the HBA | |
258 | */ | |
259 | q->nr_requests = shost->hostt->can_queue; | |
260 | /* | |
261 | * We currently only support software LLDs so this does | |
262 | * not matter for now. Do we need this for the cards we support? | |
263 | * If so we should make it a host template value. | |
264 | */ | |
265 | blk_queue_dma_alignment(q, 0); | |
266 | shost->uspace_req_q = q; | |
267 | ||
268 | for (i = 0; i < ARRAY_SIZE(queuedata->cmd_hash); i++) | |
269 | INIT_LIST_HEAD(&queuedata->cmd_hash[i]); | |
270 | spin_lock_init(&queuedata->cmd_hash_lock); | |
271 | ||
272 | return 0; | |
273 | ||
274 | cleanup_queue: | |
275 | blk_cleanup_queue(q); | |
276 | return err; | |
277 | } | |
278 | EXPORT_SYMBOL_GPL(scsi_tgt_alloc_queue); | |
279 | ||
280 | void scsi_tgt_free_queue(struct Scsi_Host *shost) | |
281 | { | |
282 | int i; | |
283 | unsigned long flags; | |
284 | struct request_queue *q = shost->uspace_req_q; | |
285 | struct scsi_cmnd *cmd; | |
286 | struct scsi_tgt_queuedata *qdata = q->queuedata; | |
287 | struct scsi_tgt_cmd *tcmd, *n; | |
288 | LIST_HEAD(cmds); | |
289 | ||
290 | spin_lock_irqsave(&qdata->cmd_hash_lock, flags); | |
291 | ||
292 | for (i = 0; i < ARRAY_SIZE(qdata->cmd_hash); i++) { | |
293 | list_for_each_entry_safe(tcmd, n, &qdata->cmd_hash[i], | |
294 | hash_list) { | |
295 | list_del(&tcmd->hash_list); | |
296 | list_add(&tcmd->hash_list, &cmds); | |
297 | } | |
298 | } | |
299 | ||
300 | spin_unlock_irqrestore(&qdata->cmd_hash_lock, flags); | |
301 | ||
302 | while (!list_empty(&cmds)) { | |
303 | tcmd = list_entry(cmds.next, struct scsi_tgt_cmd, hash_list); | |
304 | list_del(&tcmd->hash_list); | |
305 | cmd = tcmd->rq->special; | |
306 | ||
307 | shost->hostt->eh_abort_handler(cmd); | |
06328b4f | 308 | scsi_tgt_cmd_destroy(&tcmd->work); |
5a55c259 FT |
309 | } |
310 | } | |
311 | EXPORT_SYMBOL_GPL(scsi_tgt_free_queue); | |
312 | ||
313 | struct Scsi_Host *scsi_tgt_cmd_to_host(struct scsi_cmnd *cmd) | |
314 | { | |
315 | struct scsi_tgt_queuedata *queue = cmd->request->q->queuedata; | |
316 | return queue->shost; | |
317 | } | |
318 | EXPORT_SYMBOL_GPL(scsi_tgt_cmd_to_host); | |
319 | ||
320 | /* | |
321 | * scsi_tgt_queue_command - queue command for userspace processing | |
322 | * @cmd: scsi command | |
323 | * @scsilun: scsi lun | |
324 | * @tag: unique value to identify this command for tmf | |
325 | */ | |
326 | int scsi_tgt_queue_command(struct scsi_cmnd *cmd, struct scsi_lun *scsilun, | |
327 | u64 tag) | |
328 | { | |
329 | struct scsi_tgt_cmd *tcmd = cmd->request->end_io_data; | |
330 | int err; | |
331 | ||
332 | init_scsi_tgt_cmd(cmd->request, tcmd, tag); | |
333 | err = scsi_tgt_uspace_send_cmd(cmd, scsilun, tag); | |
334 | if (err) | |
335 | cmd_hashlist_del(cmd); | |
336 | ||
337 | return err; | |
338 | } | |
339 | EXPORT_SYMBOL_GPL(scsi_tgt_queue_command); | |
340 | ||
341 | /* | |
342 | * This is run from a interrpt handler normally and the unmap | |
343 | * needs process context so we must queue | |
344 | */ | |
345 | static void scsi_tgt_cmd_done(struct scsi_cmnd *cmd) | |
346 | { | |
347 | struct scsi_tgt_cmd *tcmd = cmd->request->end_io_data; | |
348 | ||
349 | dprintk("cmd %p %lu\n", cmd, rq_data_dir(cmd->request)); | |
350 | ||
351 | scsi_tgt_uspace_send_status(cmd, tcmd->tag); | |
5a55c259 FT |
352 | queue_work(scsi_tgtd, &tcmd->work); |
353 | } | |
354 | ||
355 | static int __scsi_tgt_transfer_response(struct scsi_cmnd *cmd) | |
356 | { | |
357 | struct Scsi_Host *shost = scsi_tgt_cmd_to_host(cmd); | |
358 | int err; | |
359 | ||
360 | dprintk("cmd %p %lu\n", cmd, rq_data_dir(cmd->request)); | |
361 | ||
362 | err = shost->hostt->transfer_response(cmd, scsi_tgt_cmd_done); | |
363 | switch (err) { | |
364 | case SCSI_MLQUEUE_HOST_BUSY: | |
365 | case SCSI_MLQUEUE_DEVICE_BUSY: | |
366 | return -EAGAIN; | |
367 | } | |
368 | ||
369 | return 0; | |
370 | } | |
371 | ||
372 | static void scsi_tgt_transfer_response(struct scsi_cmnd *cmd) | |
373 | { | |
374 | struct scsi_tgt_cmd *tcmd = cmd->request->end_io_data; | |
375 | int err; | |
376 | ||
377 | err = __scsi_tgt_transfer_response(cmd); | |
378 | if (!err) | |
379 | return; | |
380 | ||
381 | cmd->result = DID_BUS_BUSY << 16; | |
382 | err = scsi_tgt_uspace_send_status(cmd, tcmd->tag); | |
383 | if (err <= 0) | |
384 | /* the eh will have to pick this up */ | |
385 | printk(KERN_ERR "Could not send cmd %p status\n", cmd); | |
386 | } | |
387 | ||
388 | static int scsi_tgt_init_cmd(struct scsi_cmnd *cmd, gfp_t gfp_mask) | |
389 | { | |
390 | struct request *rq = cmd->request; | |
391 | struct scsi_tgt_cmd *tcmd = rq->end_io_data; | |
392 | int count; | |
393 | ||
394 | cmd->use_sg = rq->nr_phys_segments; | |
395 | cmd->request_buffer = scsi_alloc_sgtable(cmd, gfp_mask); | |
396 | if (!cmd->request_buffer) | |
397 | return -ENOMEM; | |
398 | ||
399 | cmd->request_bufflen = rq->data_len; | |
400 | ||
401 | dprintk("cmd %p addr %p cnt %d %lu\n", cmd, tcmd->buffer, cmd->use_sg, | |
402 | rq_data_dir(rq)); | |
403 | count = blk_rq_map_sg(rq->q, rq, cmd->request_buffer); | |
404 | if (likely(count <= cmd->use_sg)) { | |
405 | cmd->use_sg = count; | |
406 | return 0; | |
407 | } | |
408 | ||
409 | eprintk("cmd %p addr %p cnt %d\n", cmd, tcmd->buffer, cmd->use_sg); | |
410 | scsi_free_sgtable(cmd->request_buffer, cmd->sglist_len); | |
411 | return -EINVAL; | |
412 | } | |
413 | ||
414 | /* TODO: test this crap and replace bio_map_user with new interface maybe */ | |
415 | static int scsi_map_user_pages(struct scsi_tgt_cmd *tcmd, struct scsi_cmnd *cmd, | |
416 | int rw) | |
417 | { | |
418 | struct request_queue *q = cmd->request->q; | |
419 | struct request *rq = cmd->request; | |
420 | void *uaddr = tcmd->buffer; | |
421 | unsigned int len = tcmd->bufflen; | |
422 | struct bio *bio; | |
423 | int err; | |
424 | ||
425 | while (len > 0) { | |
426 | dprintk("%lx %u\n", (unsigned long) uaddr, len); | |
427 | bio = bio_map_user(q, NULL, (unsigned long) uaddr, len, rw); | |
428 | if (IS_ERR(bio)) { | |
429 | err = PTR_ERR(bio); | |
430 | dprintk("fail to map %lx %u %d %x\n", | |
431 | (unsigned long) uaddr, len, err, cmd->cmnd[0]); | |
432 | goto unmap_bios; | |
433 | } | |
434 | ||
435 | uaddr += bio->bi_size; | |
436 | len -= bio->bi_size; | |
437 | ||
438 | /* | |
439 | * The first bio is added and merged. We could probably | |
440 | * try to add others using scsi_merge_bio() but for now | |
441 | * we keep it simple. The first bio should be pretty large | |
442 | * (either hitting the 1 MB bio pages limit or a queue limit) | |
443 | * already but for really large IO we may want to try and | |
444 | * merge these. | |
445 | */ | |
446 | if (!rq->bio) { | |
447 | blk_rq_bio_prep(q, rq, bio); | |
448 | rq->data_len = bio->bi_size; | |
449 | } else | |
450 | /* put list of bios to transfer in next go around */ | |
451 | bio_list_add(&tcmd->xfer_list, bio); | |
452 | } | |
453 | ||
454 | cmd->offset = 0; | |
455 | err = scsi_tgt_init_cmd(cmd, GFP_KERNEL); | |
456 | if (err) | |
457 | goto unmap_bios; | |
458 | ||
459 | return 0; | |
460 | ||
461 | unmap_bios: | |
462 | if (rq->bio) { | |
463 | bio_unmap_user(rq->bio); | |
464 | while ((bio = bio_list_pop(&tcmd->xfer_list))) | |
465 | bio_unmap_user(bio); | |
466 | } | |
467 | ||
468 | return err; | |
469 | } | |
470 | ||
471 | static int scsi_tgt_transfer_data(struct scsi_cmnd *); | |
472 | ||
473 | static void scsi_tgt_data_transfer_done(struct scsi_cmnd *cmd) | |
474 | { | |
475 | struct scsi_tgt_cmd *tcmd = cmd->request->end_io_data; | |
476 | struct bio *bio; | |
477 | int err; | |
478 | ||
479 | /* should we free resources here on error ? */ | |
480 | if (cmd->result) { | |
481 | send_uspace_err: | |
482 | err = scsi_tgt_uspace_send_status(cmd, tcmd->tag); | |
483 | if (err <= 0) | |
484 | /* the tgt uspace eh will have to pick this up */ | |
485 | printk(KERN_ERR "Could not send cmd %p status\n", cmd); | |
486 | return; | |
487 | } | |
488 | ||
489 | dprintk("cmd %p request_bufflen %u bufflen %u\n", | |
490 | cmd, cmd->request_bufflen, tcmd->bufflen); | |
491 | ||
492 | scsi_free_sgtable(cmd->request_buffer, cmd->sglist_len); | |
493 | bio_list_add(&tcmd->xfer_done_list, cmd->request->bio); | |
494 | ||
495 | tcmd->buffer += cmd->request_bufflen; | |
496 | cmd->offset += cmd->request_bufflen; | |
497 | ||
498 | if (!tcmd->xfer_list.head) { | |
499 | scsi_tgt_transfer_response(cmd); | |
500 | return; | |
501 | } | |
502 | ||
503 | dprintk("cmd2 %p request_bufflen %u bufflen %u\n", | |
504 | cmd, cmd->request_bufflen, tcmd->bufflen); | |
505 | ||
506 | bio = bio_list_pop(&tcmd->xfer_list); | |
507 | BUG_ON(!bio); | |
508 | ||
509 | blk_rq_bio_prep(cmd->request->q, cmd->request, bio); | |
510 | cmd->request->data_len = bio->bi_size; | |
511 | err = scsi_tgt_init_cmd(cmd, GFP_ATOMIC); | |
512 | if (err) { | |
513 | cmd->result = DID_ERROR << 16; | |
514 | goto send_uspace_err; | |
515 | } | |
516 | ||
517 | if (scsi_tgt_transfer_data(cmd)) { | |
518 | cmd->result = DID_NO_CONNECT << 16; | |
519 | goto send_uspace_err; | |
520 | } | |
521 | } | |
522 | ||
523 | static int scsi_tgt_transfer_data(struct scsi_cmnd *cmd) | |
524 | { | |
525 | int err; | |
526 | struct Scsi_Host *host = scsi_tgt_cmd_to_host(cmd); | |
527 | ||
528 | err = host->hostt->transfer_data(cmd, scsi_tgt_data_transfer_done); | |
529 | switch (err) { | |
530 | case SCSI_MLQUEUE_HOST_BUSY: | |
531 | case SCSI_MLQUEUE_DEVICE_BUSY: | |
532 | return -EAGAIN; | |
533 | default: | |
534 | return 0; | |
535 | } | |
536 | } | |
537 | ||
538 | static int scsi_tgt_copy_sense(struct scsi_cmnd *cmd, unsigned long uaddr, | |
539 | unsigned len) | |
540 | { | |
541 | char __user *p = (char __user *) uaddr; | |
542 | ||
543 | if (copy_from_user(cmd->sense_buffer, p, | |
544 | min_t(unsigned, SCSI_SENSE_BUFFERSIZE, len))) { | |
545 | printk(KERN_ERR "Could not copy the sense buffer\n"); | |
546 | return -EIO; | |
547 | } | |
548 | return 0; | |
549 | } | |
550 | ||
551 | static int scsi_tgt_abort_cmd(struct Scsi_Host *shost, struct scsi_cmnd *cmd) | |
552 | { | |
06328b4f | 553 | struct scsi_tgt_cmd *tcmd; |
5a55c259 FT |
554 | int err; |
555 | ||
556 | err = shost->hostt->eh_abort_handler(cmd); | |
557 | if (err) | |
558 | eprintk("fail to abort %p\n", cmd); | |
559 | ||
06328b4f DH |
560 | tcmd = cmd->request->end_io_data; |
561 | scsi_tgt_cmd_destroy(&tcmd->work); | |
5a55c259 FT |
562 | return err; |
563 | } | |
564 | ||
565 | static struct request *tgt_cmd_hash_lookup(struct request_queue *q, u64 tag) | |
566 | { | |
567 | struct scsi_tgt_queuedata *qdata = q->queuedata; | |
568 | struct request *rq = NULL; | |
569 | struct list_head *head; | |
570 | struct scsi_tgt_cmd *tcmd; | |
571 | unsigned long flags; | |
572 | ||
573 | head = &qdata->cmd_hash[cmd_hashfn(tag)]; | |
574 | spin_lock_irqsave(&qdata->cmd_hash_lock, flags); | |
575 | list_for_each_entry(tcmd, head, hash_list) { | |
576 | if (tcmd->tag == tag) { | |
577 | rq = tcmd->rq; | |
578 | list_del(&tcmd->hash_list); | |
579 | break; | |
580 | } | |
581 | } | |
582 | spin_unlock_irqrestore(&qdata->cmd_hash_lock, flags); | |
583 | ||
584 | return rq; | |
585 | } | |
586 | ||
587 | int scsi_tgt_kspace_exec(int host_no, u64 tag, int result, u32 len, | |
588 | unsigned long uaddr, u8 rw) | |
589 | { | |
590 | struct Scsi_Host *shost; | |
591 | struct scsi_cmnd *cmd; | |
592 | struct request *rq; | |
593 | struct scsi_tgt_cmd *tcmd; | |
594 | int err = 0; | |
595 | ||
596 | dprintk("%d %llu %d %u %lx %u\n", host_no, (unsigned long long) tag, | |
597 | result, len, uaddr, rw); | |
598 | ||
599 | /* TODO: replace with a O(1) alg */ | |
600 | shost = scsi_host_lookup(host_no); | |
601 | if (IS_ERR(shost)) { | |
602 | printk(KERN_ERR "Could not find host no %d\n", host_no); | |
603 | return -EINVAL; | |
604 | } | |
605 | ||
606 | if (!shost->uspace_req_q) { | |
607 | printk(KERN_ERR "Not target scsi host %d\n", host_no); | |
608 | goto done; | |
609 | } | |
610 | ||
611 | rq = tgt_cmd_hash_lookup(shost->uspace_req_q, tag); | |
612 | if (!rq) { | |
613 | printk(KERN_ERR "Could not find tag %llu\n", | |
614 | (unsigned long long) tag); | |
615 | err = -EINVAL; | |
616 | goto done; | |
617 | } | |
618 | cmd = rq->special; | |
619 | ||
620 | dprintk("cmd %p result %d len %d bufflen %u %lu %x\n", cmd, | |
621 | result, len, cmd->request_bufflen, rq_data_dir(rq), cmd->cmnd[0]); | |
622 | ||
623 | if (result == TASK_ABORTED) { | |
624 | scsi_tgt_abort_cmd(shost, cmd); | |
625 | goto done; | |
626 | } | |
627 | /* | |
628 | * store the userspace values here, the working values are | |
629 | * in the request_* values | |
630 | */ | |
631 | tcmd = cmd->request->end_io_data; | |
632 | tcmd->buffer = (void *)uaddr; | |
633 | tcmd->bufflen = len; | |
634 | cmd->result = result; | |
635 | ||
636 | if (!tcmd->bufflen || cmd->request_buffer) { | |
637 | err = __scsi_tgt_transfer_response(cmd); | |
638 | goto done; | |
639 | } | |
640 | ||
641 | /* | |
642 | * TODO: Do we need to handle case where request does not | |
643 | * align with LLD. | |
644 | */ | |
645 | err = scsi_map_user_pages(rq->end_io_data, cmd, rw); | |
646 | if (err) { | |
647 | eprintk("%p %d\n", cmd, err); | |
648 | err = -EAGAIN; | |
649 | goto done; | |
650 | } | |
651 | ||
652 | /* userspace failure */ | |
653 | if (cmd->result) { | |
654 | if (status_byte(cmd->result) == CHECK_CONDITION) | |
655 | scsi_tgt_copy_sense(cmd, uaddr, len); | |
656 | err = __scsi_tgt_transfer_response(cmd); | |
657 | goto done; | |
658 | } | |
659 | /* ask the target LLD to transfer the data to the buffer */ | |
660 | err = scsi_tgt_transfer_data(cmd); | |
661 | ||
662 | done: | |
663 | scsi_host_put(shost); | |
664 | return err; | |
665 | } | |
666 | ||
667 | int scsi_tgt_tsk_mgmt_request(struct Scsi_Host *shost, int function, u64 tag, | |
668 | struct scsi_lun *scsilun, void *data) | |
669 | { | |
670 | int err; | |
671 | ||
672 | /* TODO: need to retry if this fails. */ | |
673 | err = scsi_tgt_uspace_send_tsk_mgmt(shost->host_no, function, | |
674 | tag, scsilun, data); | |
675 | if (err < 0) | |
676 | eprintk("The task management request lost!\n"); | |
677 | return err; | |
678 | } | |
679 | EXPORT_SYMBOL_GPL(scsi_tgt_tsk_mgmt_request); | |
680 | ||
681 | int scsi_tgt_kspace_tsk_mgmt(int host_no, u64 mid, int result) | |
682 | { | |
683 | struct Scsi_Host *shost; | |
684 | int err = -EINVAL; | |
685 | ||
686 | dprintk("%d %d %llx\n", host_no, result, (unsigned long long) mid); | |
687 | ||
688 | shost = scsi_host_lookup(host_no); | |
689 | if (IS_ERR(shost)) { | |
690 | printk(KERN_ERR "Could not find host no %d\n", host_no); | |
691 | return err; | |
692 | } | |
693 | ||
694 | if (!shost->uspace_req_q) { | |
695 | printk(KERN_ERR "Not target scsi host %d\n", host_no); | |
696 | goto done; | |
697 | } | |
698 | ||
699 | err = shost->hostt->tsk_mgmt_response(mid, result); | |
700 | done: | |
701 | scsi_host_put(shost); | |
702 | return err; | |
703 | } | |
704 | ||
705 | static int __init scsi_tgt_init(void) | |
706 | { | |
707 | int err; | |
708 | ||
709 | scsi_tgt_cmd_cache = kmem_cache_create("scsi_tgt_cmd", | |
710 | sizeof(struct scsi_tgt_cmd), | |
711 | 0, 0, NULL, NULL); | |
712 | if (!scsi_tgt_cmd_cache) | |
713 | return -ENOMEM; | |
714 | ||
715 | scsi_tgtd = create_workqueue("scsi_tgtd"); | |
716 | if (!scsi_tgtd) { | |
717 | err = -ENOMEM; | |
718 | goto free_kmemcache; | |
719 | } | |
720 | ||
721 | err = scsi_tgt_if_init(); | |
722 | if (err) | |
723 | goto destroy_wq; | |
724 | ||
725 | return 0; | |
726 | ||
727 | destroy_wq: | |
728 | destroy_workqueue(scsi_tgtd); | |
729 | free_kmemcache: | |
730 | kmem_cache_destroy(scsi_tgt_cmd_cache); | |
731 | return err; | |
732 | } | |
733 | ||
734 | static void __exit scsi_tgt_exit(void) | |
735 | { | |
736 | destroy_workqueue(scsi_tgtd); | |
737 | scsi_tgt_if_exit(); | |
738 | kmem_cache_destroy(scsi_tgt_cmd_cache); | |
739 | } | |
740 | ||
741 | module_init(scsi_tgt_init); | |
742 | module_exit(scsi_tgt_exit); | |
743 | ||
744 | MODULE_DESCRIPTION("SCSI target core"); | |
745 | MODULE_LICENSE("GPL"); |