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3d6392cf 1/*
0c6a89ba 2 * bsg.c - block layer implementation of the sg v4 interface
3d6392cf
JA
3 *
4 * Copyright (C) 2004 Jens Axboe <axboe@suse.de> SUSE Labs
5 * Copyright (C) 2004 Peter M. Jones <pjones@redhat.com>
6 *
7 * This file is subject to the terms and conditions of the GNU General Public
8 * License version 2. See the file "COPYING" in the main directory of this
9 * archive for more details.
10 *
11 */
3d6392cf
JA
12#include <linux/module.h>
13#include <linux/init.h>
14#include <linux/file.h>
15#include <linux/blkdev.h>
16#include <linux/poll.h>
17#include <linux/cdev.h>
ad5ebd2f 18#include <linux/jiffies.h>
3d6392cf
JA
19#include <linux/percpu.h>
20#include <linux/uio.h>
598443a2 21#include <linux/idr.h>
3d6392cf 22#include <linux/bsg.h>
5a0e3ad6 23#include <linux/slab.h>
3d6392cf
JA
24
25#include <scsi/scsi.h>
26#include <scsi/scsi_ioctl.h>
27#include <scsi/scsi_cmnd.h>
4e2872d6
FT
28#include <scsi/scsi_device.h>
29#include <scsi/scsi_driver.h>
3d6392cf
JA
30#include <scsi/sg.h>
31
0ed081ce
FT
32#define BSG_DESCRIPTION "Block layer SCSI generic (bsg) driver"
33#define BSG_VERSION "0.4"
3d6392cf 34
3d6392cf 35struct bsg_device {
165125e1 36 struct request_queue *queue;
3d6392cf
JA
37 spinlock_t lock;
38 struct list_head busy_list;
39 struct list_head done_list;
40 struct hlist_node dev_list;
41 atomic_t ref_count;
3d6392cf
JA
42 int queued_cmds;
43 int done_cmds;
3d6392cf
JA
44 wait_queue_head_t wq_done;
45 wait_queue_head_t wq_free;
3ada8b7e 46 char name[20];
3d6392cf
JA
47 int max_queue;
48 unsigned long flags;
49};
50
51enum {
52 BSG_F_BLOCK = 1,
3d6392cf
JA
53};
54
5309cb38 55#define BSG_DEFAULT_CMDS 64
292b7f27 56#define BSG_MAX_DEVS 32768
3d6392cf
JA
57
58#undef BSG_DEBUG
59
60#ifdef BSG_DEBUG
24c03d47 61#define dprintk(fmt, args...) printk(KERN_ERR "%s: " fmt, __func__, ##args)
3d6392cf
JA
62#else
63#define dprintk(fmt, args...)
64#endif
65
3d6392cf 66static DEFINE_MUTEX(bsg_mutex);
598443a2 67static DEFINE_IDR(bsg_minor_idr);
3d6392cf 68
25fd1643 69#define BSG_LIST_ARRAY_SIZE 8
25fd1643 70static struct hlist_head bsg_device_list[BSG_LIST_ARRAY_SIZE];
3d6392cf
JA
71
72static struct class *bsg_class;
46f6ef4a 73static int bsg_major;
3d6392cf 74
5309cb38
JA
75static struct kmem_cache *bsg_cmd_cachep;
76
3d6392cf
JA
77/*
78 * our internal command type
79 */
80struct bsg_command {
81 struct bsg_device *bd;
82 struct list_head list;
83 struct request *rq;
84 struct bio *bio;
2c9ecdf4 85 struct bio *bidi_bio;
3d6392cf 86 int err;
70e36ece 87 struct sg_io_v4 hdr;
3d6392cf
JA
88 char sense[SCSI_SENSE_BUFFERSIZE];
89};
90
91static void bsg_free_command(struct bsg_command *bc)
92{
93 struct bsg_device *bd = bc->bd;
3d6392cf
JA
94 unsigned long flags;
95
5309cb38 96 kmem_cache_free(bsg_cmd_cachep, bc);
3d6392cf
JA
97
98 spin_lock_irqsave(&bd->lock, flags);
99 bd->queued_cmds--;
3d6392cf
JA
100 spin_unlock_irqrestore(&bd->lock, flags);
101
102 wake_up(&bd->wq_free);
103}
104
e7d72173 105static struct bsg_command *bsg_alloc_command(struct bsg_device *bd)
3d6392cf 106{
e7d72173 107 struct bsg_command *bc = ERR_PTR(-EINVAL);
3d6392cf
JA
108
109 spin_lock_irq(&bd->lock);
110
111 if (bd->queued_cmds >= bd->max_queue)
112 goto out;
113
3d6392cf 114 bd->queued_cmds++;
3d6392cf
JA
115 spin_unlock_irq(&bd->lock);
116
25fd1643 117 bc = kmem_cache_zalloc(bsg_cmd_cachep, GFP_KERNEL);
5309cb38
JA
118 if (unlikely(!bc)) {
119 spin_lock_irq(&bd->lock);
7e75d730 120 bd->queued_cmds--;
e7d72173 121 bc = ERR_PTR(-ENOMEM);
7e75d730 122 goto out;
5309cb38
JA
123 }
124
3d6392cf
JA
125 bc->bd = bd;
126 INIT_LIST_HEAD(&bc->list);
5309cb38 127 dprintk("%s: returning free cmd %p\n", bd->name, bc);
3d6392cf
JA
128 return bc;
129out:
3d6392cf
JA
130 spin_unlock_irq(&bd->lock);
131 return bc;
132}
133
1c1133e1 134static inline struct hlist_head *bsg_dev_idx_hash(int index)
3d6392cf 135{
1c1133e1 136 return &bsg_device_list[index & (BSG_LIST_ARRAY_SIZE - 1)];
3d6392cf
JA
137}
138
25fd1643 139static int bsg_io_schedule(struct bsg_device *bd)
3d6392cf
JA
140{
141 DEFINE_WAIT(wait);
142 int ret = 0;
143
144 spin_lock_irq(&bd->lock);
145
146 BUG_ON(bd->done_cmds > bd->queued_cmds);
147
148 /*
149 * -ENOSPC or -ENODATA? I'm going for -ENODATA, meaning "I have no
150 * work to do", even though we return -ENOSPC after this same test
151 * during bsg_write() -- there, it means our buffer can't have more
152 * bsg_commands added to it, thus has no space left.
153 */
154 if (bd->done_cmds == bd->queued_cmds) {
155 ret = -ENODATA;
156 goto unlock;
157 }
158
159 if (!test_bit(BSG_F_BLOCK, &bd->flags)) {
160 ret = -EAGAIN;
161 goto unlock;
162 }
163
25fd1643 164 prepare_to_wait(&bd->wq_done, &wait, TASK_UNINTERRUPTIBLE);
3d6392cf
JA
165 spin_unlock_irq(&bd->lock);
166 io_schedule();
167 finish_wait(&bd->wq_done, &wait);
168
3d6392cf
JA
169 return ret;
170unlock:
171 spin_unlock_irq(&bd->lock);
172 return ret;
173}
174
165125e1 175static int blk_fill_sgv4_hdr_rq(struct request_queue *q, struct request *rq,
abf54393 176 struct sg_io_v4 *hdr, struct bsg_device *bd,
aeb5d727 177 fmode_t has_write_perm)
70e36ece 178{
9f5de6b1
FT
179 if (hdr->request_len > BLK_MAX_CDB) {
180 rq->cmd = kzalloc(hdr->request_len, GFP_KERNEL);
181 if (!rq->cmd)
182 return -ENOMEM;
183 }
70e36ece 184
2b727c63 185 if (copy_from_user(rq->cmd, (void __user *)(unsigned long)hdr->request,
70e36ece
FT
186 hdr->request_len))
187 return -EFAULT;
15d10b61
FT
188
189 if (hdr->subprotocol == BSG_SUB_PROTOCOL_SCSI_CMD) {
018e0446 190 if (blk_verify_command(rq->cmd, has_write_perm))
15d10b61
FT
191 return -EPERM;
192 } else if (!capable(CAP_SYS_RAWIO))
70e36ece
FT
193 return -EPERM;
194
195 /*
196 * fill in request structure
197 */
198 rq->cmd_len = hdr->request_len;
70e36ece 199
ad5ebd2f 200 rq->timeout = msecs_to_jiffies(hdr->timeout);
70e36ece
FT
201 if (!rq->timeout)
202 rq->timeout = q->sg_timeout;
203 if (!rq->timeout)
204 rq->timeout = BLK_DEFAULT_SG_TIMEOUT;
f2f1fa78
LT
205 if (rq->timeout < BLK_MIN_SG_TIMEOUT)
206 rq->timeout = BLK_MIN_SG_TIMEOUT;
70e36ece
FT
207
208 return 0;
209}
210
3d6392cf 211/*
70e36ece 212 * Check if sg_io_v4 from user is allowed and valid
3d6392cf
JA
213 */
214static int
165125e1 215bsg_validate_sgv4_hdr(struct request_queue *q, struct sg_io_v4 *hdr, int *rw)
3d6392cf 216{
15d10b61
FT
217 int ret = 0;
218
70e36ece 219 if (hdr->guard != 'Q')
3d6392cf 220 return -EINVAL;
3d6392cf 221
15d10b61
FT
222 switch (hdr->protocol) {
223 case BSG_PROTOCOL_SCSI:
224 switch (hdr->subprotocol) {
225 case BSG_SUB_PROTOCOL_SCSI_CMD:
226 case BSG_SUB_PROTOCOL_SCSI_TRANSPORT:
227 break;
228 default:
229 ret = -EINVAL;
230 }
231 break;
232 default:
233 ret = -EINVAL;
234 }
70e36ece 235
70e36ece 236 *rw = hdr->dout_xfer_len ? WRITE : READ;
15d10b61 237 return ret;
3d6392cf
JA
238}
239
240/*
70e36ece 241 * map sg_io_v4 to a request.
3d6392cf
JA
242 */
243static struct request *
c1c20120
BH
244bsg_map_hdr(struct bsg_device *bd, struct sg_io_v4 *hdr, fmode_t has_write_perm,
245 u8 *sense)
3d6392cf 246{
165125e1 247 struct request_queue *q = bd->queue;
2c9ecdf4 248 struct request *rq, *next_rq = NULL;
25fd1643 249 int ret, rw;
70e36ece 250 unsigned int dxfer_len;
2b727c63 251 void __user *dxferp = NULL;
c7a841f3
JS
252 struct bsg_class_device *bcd = &q->bsg_dev;
253
254 /* if the LLD has been removed then the bsg_unregister_queue will
255 * eventually be called and the class_dev was freed, so we can no
256 * longer use this request_queue. Return no such address.
257 */
258 if (!bcd->class_dev)
259 return ERR_PTR(-ENXIO);
3d6392cf 260
70e36ece
FT
261 dprintk("map hdr %llx/%u %llx/%u\n", (unsigned long long) hdr->dout_xferp,
262 hdr->dout_xfer_len, (unsigned long long) hdr->din_xferp,
263 hdr->din_xfer_len);
3d6392cf 264
70e36ece 265 ret = bsg_validate_sgv4_hdr(q, hdr, &rw);
3d6392cf
JA
266 if (ret)
267 return ERR_PTR(ret);
268
269 /*
3ad2f3fb 270 * map scatter-gather elements separately and string them to request
3d6392cf
JA
271 */
272 rq = blk_get_request(q, rw, GFP_KERNEL);
a492f075
JL
273 if (IS_ERR(rq))
274 return rq;
f27b087b
JA
275 blk_rq_set_block_pc(rq);
276
abf54393 277 ret = blk_fill_sgv4_hdr_rq(q, rq, hdr, bd, has_write_perm);
2c9ecdf4
FT
278 if (ret)
279 goto out;
280
281 if (rw == WRITE && hdr->din_xfer_len) {
282 if (!test_bit(QUEUE_FLAG_BIDI, &q->queue_flags)) {
283 ret = -EOPNOTSUPP;
284 goto out;
285 }
286
287 next_rq = blk_get_request(q, READ, GFP_KERNEL);
a492f075
JL
288 if (IS_ERR(next_rq)) {
289 ret = PTR_ERR(next_rq);
55872c5a 290 next_rq = NULL;
2c9ecdf4
FT
291 goto out;
292 }
293 rq->next_rq = next_rq;
40f62028 294 next_rq->cmd_type = rq->cmd_type;
2c9ecdf4 295
2b727c63 296 dxferp = (void __user *)(unsigned long)hdr->din_xferp;
152e283f
FT
297 ret = blk_rq_map_user(q, next_rq, NULL, dxferp,
298 hdr->din_xfer_len, GFP_KERNEL);
2c9ecdf4
FT
299 if (ret)
300 goto out;
3d6392cf
JA
301 }
302
70e36ece
FT
303 if (hdr->dout_xfer_len) {
304 dxfer_len = hdr->dout_xfer_len;
2b727c63 305 dxferp = (void __user *)(unsigned long)hdr->dout_xferp;
70e36ece
FT
306 } else if (hdr->din_xfer_len) {
307 dxfer_len = hdr->din_xfer_len;
2b727c63 308 dxferp = (void __user *)(unsigned long)hdr->din_xferp;
70e36ece
FT
309 } else
310 dxfer_len = 0;
311
312 if (dxfer_len) {
152e283f
FT
313 ret = blk_rq_map_user(q, rq, NULL, dxferp, dxfer_len,
314 GFP_KERNEL);
2c9ecdf4
FT
315 if (ret)
316 goto out;
3d6392cf 317 }
c1c20120
BH
318
319 rq->sense = sense;
320 rq->sense_len = 0;
321
3d6392cf 322 return rq;
2c9ecdf4 323out:
9f5de6b1
FT
324 if (rq->cmd != rq->__cmd)
325 kfree(rq->cmd);
2c9ecdf4
FT
326 blk_put_request(rq);
327 if (next_rq) {
328 blk_rq_unmap_user(next_rq->bio);
329 blk_put_request(next_rq);
330 }
331 return ERR_PTR(ret);
3d6392cf
JA
332}
333
334/*
335 * async completion call-back from the block layer, when scsi/ide/whatever
336 * calls end_that_request_last() on a request
337 */
338static void bsg_rq_end_io(struct request *rq, int uptodate)
339{
340 struct bsg_command *bc = rq->end_io_data;
341 struct bsg_device *bd = bc->bd;
342 unsigned long flags;
343
5309cb38
JA
344 dprintk("%s: finished rq %p bc %p, bio %p stat %d\n",
345 bd->name, rq, bc, bc->bio, uptodate);
3d6392cf
JA
346
347 bc->hdr.duration = jiffies_to_msecs(jiffies - bc->hdr.duration);
348
349 spin_lock_irqsave(&bd->lock, flags);
25fd1643
JA
350 list_move_tail(&bc->list, &bd->done_list);
351 bd->done_cmds++;
3d6392cf 352 spin_unlock_irqrestore(&bd->lock, flags);
25fd1643
JA
353
354 wake_up(&bd->wq_done);
3d6392cf
JA
355}
356
357/*
358 * do final setup of a 'bc' and submit the matching 'rq' to the block
359 * layer for io
360 */
165125e1 361static void bsg_add_command(struct bsg_device *bd, struct request_queue *q,
3d6392cf
JA
362 struct bsg_command *bc, struct request *rq)
363{
05378940
BH
364 int at_head = (0 == (bc->hdr.flags & BSG_FLAG_Q_AT_TAIL));
365
3d6392cf
JA
366 /*
367 * add bc command to busy queue and submit rq for io
368 */
369 bc->rq = rq;
370 bc->bio = rq->bio;
2c9ecdf4
FT
371 if (rq->next_rq)
372 bc->bidi_bio = rq->next_rq->bio;
3d6392cf
JA
373 bc->hdr.duration = jiffies;
374 spin_lock_irq(&bd->lock);
375 list_add_tail(&bc->list, &bd->busy_list);
376 spin_unlock_irq(&bd->lock);
377
378 dprintk("%s: queueing rq %p, bc %p\n", bd->name, rq, bc);
379
380 rq->end_io_data = bc;
05378940 381 blk_execute_rq_nowait(q, NULL, rq, at_head, bsg_rq_end_io);
3d6392cf
JA
382}
383
25fd1643 384static struct bsg_command *bsg_next_done_cmd(struct bsg_device *bd)
3d6392cf
JA
385{
386 struct bsg_command *bc = NULL;
387
388 spin_lock_irq(&bd->lock);
389 if (bd->done_cmds) {
43ac9e62 390 bc = list_first_entry(&bd->done_list, struct bsg_command, list);
25fd1643
JA
391 list_del(&bc->list);
392 bd->done_cmds--;
3d6392cf
JA
393 }
394 spin_unlock_irq(&bd->lock);
395
396 return bc;
397}
398
399/*
400 * Get a finished command from the done list
401 */
e7d72173 402static struct bsg_command *bsg_get_done_cmd(struct bsg_device *bd)
3d6392cf
JA
403{
404 struct bsg_command *bc;
405 int ret;
406
407 do {
408 bc = bsg_next_done_cmd(bd);
409 if (bc)
410 break;
411
e7d72173
FT
412 if (!test_bit(BSG_F_BLOCK, &bd->flags)) {
413 bc = ERR_PTR(-EAGAIN);
414 break;
415 }
416
417 ret = wait_event_interruptible(bd->wq_done, bd->done_cmds);
3d6392cf 418 if (ret) {
e7d72173 419 bc = ERR_PTR(-ERESTARTSYS);
3d6392cf
JA
420 break;
421 }
422 } while (1);
423
424 dprintk("%s: returning done %p\n", bd->name, bc);
425
426 return bc;
427}
428
70e36ece 429static int blk_complete_sgv4_hdr_rq(struct request *rq, struct sg_io_v4 *hdr,
2c9ecdf4 430 struct bio *bio, struct bio *bidi_bio)
70e36ece
FT
431{
432 int ret = 0;
433
c1c20120 434 dprintk("rq %p bio %p 0x%x\n", rq, bio, rq->errors);
70e36ece
FT
435 /*
436 * fill in all the output members
437 */
47897160 438 hdr->device_status = rq->errors & 0xff;
70e36ece
FT
439 hdr->transport_status = host_byte(rq->errors);
440 hdr->driver_status = driver_byte(rq->errors);
441 hdr->info = 0;
442 if (hdr->device_status || hdr->transport_status || hdr->driver_status)
443 hdr->info |= SG_INFO_CHECK;
70e36ece
FT
444 hdr->response_len = 0;
445
446 if (rq->sense_len && hdr->response) {
25fd1643
JA
447 int len = min_t(unsigned int, hdr->max_response_len,
448 rq->sense_len);
70e36ece 449
2b727c63 450 ret = copy_to_user((void __user *)(unsigned long)hdr->response,
70e36ece
FT
451 rq->sense, len);
452 if (!ret)
453 hdr->response_len = len;
454 else
455 ret = -EFAULT;
456 }
457
2c9ecdf4 458 if (rq->next_rq) {
c3a4d78c
TH
459 hdr->dout_resid = rq->resid_len;
460 hdr->din_resid = rq->next_rq->resid_len;
2c9ecdf4
FT
461 blk_rq_unmap_user(bidi_bio);
462 blk_put_request(rq->next_rq);
0c6a89ba 463 } else if (rq_data_dir(rq) == READ)
c3a4d78c 464 hdr->din_resid = rq->resid_len;
0c6a89ba 465 else
c3a4d78c 466 hdr->dout_resid = rq->resid_len;
2c9ecdf4 467
2d507a01
JB
468 /*
469 * If the request generated a negative error number, return it
470 * (providing we aren't already returning an error); if it's
471 * just a protocol response (i.e. non negative), that gets
472 * processed above.
473 */
474 if (!ret && rq->errors < 0)
475 ret = rq->errors;
476
70e36ece 477 blk_rq_unmap_user(bio);
9f5de6b1
FT
478 if (rq->cmd != rq->__cmd)
479 kfree(rq->cmd);
70e36ece
FT
480 blk_put_request(rq);
481
482 return ret;
483}
484
3d6392cf
JA
485static int bsg_complete_all_commands(struct bsg_device *bd)
486{
487 struct bsg_command *bc;
488 int ret, tret;
489
490 dprintk("%s: entered\n", bd->name);
491
3d6392cf
JA
492 /*
493 * wait for all commands to complete
494 */
495 ret = 0;
496 do {
25fd1643 497 ret = bsg_io_schedule(bd);
3d6392cf
JA
498 /*
499 * look for -ENODATA specifically -- we'll sometimes get
500 * -ERESTARTSYS when we've taken a signal, but we can't
501 * return until we're done freeing the queue, so ignore
502 * it. The signal will get handled when we're done freeing
503 * the bsg_device.
504 */
505 } while (ret != -ENODATA);
506
507 /*
508 * discard done commands
509 */
510 ret = 0;
511 do {
e7d72173
FT
512 spin_lock_irq(&bd->lock);
513 if (!bd->queued_cmds) {
514 spin_unlock_irq(&bd->lock);
3d6392cf
JA
515 break;
516 }
efba1a31 517 spin_unlock_irq(&bd->lock);
3d6392cf 518
e7d72173
FT
519 bc = bsg_get_done_cmd(bd);
520 if (IS_ERR(bc))
521 break;
522
2c9ecdf4
FT
523 tret = blk_complete_sgv4_hdr_rq(bc->rq, &bc->hdr, bc->bio,
524 bc->bidi_bio);
3d6392cf
JA
525 if (!ret)
526 ret = tret;
527
528 bsg_free_command(bc);
529 } while (1);
530
531 return ret;
532}
533
25fd1643 534static int
e7d72173
FT
535__bsg_read(char __user *buf, size_t count, struct bsg_device *bd,
536 const struct iovec *iov, ssize_t *bytes_read)
3d6392cf
JA
537{
538 struct bsg_command *bc;
539 int nr_commands, ret;
540
70e36ece 541 if (count % sizeof(struct sg_io_v4))
3d6392cf
JA
542 return -EINVAL;
543
544 ret = 0;
70e36ece 545 nr_commands = count / sizeof(struct sg_io_v4);
3d6392cf 546 while (nr_commands) {
e7d72173 547 bc = bsg_get_done_cmd(bd);
3d6392cf
JA
548 if (IS_ERR(bc)) {
549 ret = PTR_ERR(bc);
550 break;
551 }
552
553 /*
554 * this is the only case where we need to copy data back
555 * after completing the request. so do that here,
556 * bsg_complete_work() cannot do that for us
557 */
2c9ecdf4
FT
558 ret = blk_complete_sgv4_hdr_rq(bc->rq, &bc->hdr, bc->bio,
559 bc->bidi_bio);
3d6392cf 560
25fd1643 561 if (copy_to_user(buf, &bc->hdr, sizeof(bc->hdr)))
3d6392cf
JA
562 ret = -EFAULT;
563
564 bsg_free_command(bc);
565
566 if (ret)
567 break;
568
70e36ece
FT
569 buf += sizeof(struct sg_io_v4);
570 *bytes_read += sizeof(struct sg_io_v4);
3d6392cf
JA
571 nr_commands--;
572 }
573
574 return ret;
575}
576
577static inline void bsg_set_block(struct bsg_device *bd, struct file *file)
578{
579 if (file->f_flags & O_NONBLOCK)
580 clear_bit(BSG_F_BLOCK, &bd->flags);
581 else
582 set_bit(BSG_F_BLOCK, &bd->flags);
583}
584
25fd1643
JA
585/*
586 * Check if the error is a "real" error that we should return.
587 */
3d6392cf
JA
588static inline int err_block_err(int ret)
589{
590 if (ret && ret != -ENOSPC && ret != -ENODATA && ret != -EAGAIN)
591 return 1;
592
593 return 0;
594}
595
596static ssize_t
597bsg_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
598{
599 struct bsg_device *bd = file->private_data;
600 int ret;
601 ssize_t bytes_read;
602
9e69fbb5 603 dprintk("%s: read %Zd bytes\n", bd->name, count);
3d6392cf
JA
604
605 bsg_set_block(bd, file);
0b07de85 606
3d6392cf 607 bytes_read = 0;
e7d72173 608 ret = __bsg_read(buf, count, bd, NULL, &bytes_read);
3d6392cf
JA
609 *ppos = bytes_read;
610
44194e3e 611 if (!bytes_read || err_block_err(ret))
3d6392cf
JA
612 bytes_read = ret;
613
614 return bytes_read;
615}
616
25fd1643 617static int __bsg_write(struct bsg_device *bd, const char __user *buf,
aeb5d727
AV
618 size_t count, ssize_t *bytes_written,
619 fmode_t has_write_perm)
3d6392cf
JA
620{
621 struct bsg_command *bc;
622 struct request *rq;
623 int ret, nr_commands;
624
70e36ece 625 if (count % sizeof(struct sg_io_v4))
3d6392cf
JA
626 return -EINVAL;
627
70e36ece 628 nr_commands = count / sizeof(struct sg_io_v4);
3d6392cf
JA
629 rq = NULL;
630 bc = NULL;
631 ret = 0;
632 while (nr_commands) {
165125e1 633 struct request_queue *q = bd->queue;
3d6392cf 634
e7d72173 635 bc = bsg_alloc_command(bd);
3d6392cf
JA
636 if (IS_ERR(bc)) {
637 ret = PTR_ERR(bc);
638 bc = NULL;
639 break;
640 }
641
3d6392cf
JA
642 if (copy_from_user(&bc->hdr, buf, sizeof(bc->hdr))) {
643 ret = -EFAULT;
644 break;
645 }
646
647 /*
648 * get a request, fill in the blanks, and add to request queue
649 */
c1c20120 650 rq = bsg_map_hdr(bd, &bc->hdr, has_write_perm, bc->sense);
3d6392cf
JA
651 if (IS_ERR(rq)) {
652 ret = PTR_ERR(rq);
653 rq = NULL;
654 break;
655 }
656
657 bsg_add_command(bd, q, bc, rq);
658 bc = NULL;
659 rq = NULL;
660 nr_commands--;
70e36ece 661 buf += sizeof(struct sg_io_v4);
25fd1643 662 *bytes_written += sizeof(struct sg_io_v4);
3d6392cf
JA
663 }
664
3d6392cf
JA
665 if (bc)
666 bsg_free_command(bc);
667
668 return ret;
669}
670
671static ssize_t
672bsg_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
673{
674 struct bsg_device *bd = file->private_data;
25fd1643 675 ssize_t bytes_written;
3d6392cf
JA
676 int ret;
677
9e69fbb5 678 dprintk("%s: write %Zd bytes\n", bd->name, count);
3d6392cf
JA
679
680 bsg_set_block(bd, file);
3d6392cf 681
25fd1643 682 bytes_written = 0;
abf54393
FT
683 ret = __bsg_write(bd, buf, count, &bytes_written,
684 file->f_mode & FMODE_WRITE);
685
25fd1643 686 *ppos = bytes_written;
3d6392cf
JA
687
688 /*
689 * return bytes written on non-fatal errors
690 */
44194e3e 691 if (!bytes_written || err_block_err(ret))
25fd1643 692 bytes_written = ret;
3d6392cf 693
25fd1643
JA
694 dprintk("%s: returning %Zd\n", bd->name, bytes_written);
695 return bytes_written;
3d6392cf
JA
696}
697
3d6392cf
JA
698static struct bsg_device *bsg_alloc_device(void)
699{
3d6392cf 700 struct bsg_device *bd;
3d6392cf
JA
701
702 bd = kzalloc(sizeof(struct bsg_device), GFP_KERNEL);
703 if (unlikely(!bd))
704 return NULL;
705
706 spin_lock_init(&bd->lock);
707
5309cb38 708 bd->max_queue = BSG_DEFAULT_CMDS;
3d6392cf
JA
709
710 INIT_LIST_HEAD(&bd->busy_list);
711 INIT_LIST_HEAD(&bd->done_list);
712 INIT_HLIST_NODE(&bd->dev_list);
713
714 init_waitqueue_head(&bd->wq_free);
715 init_waitqueue_head(&bd->wq_done);
716 return bd;
3d6392cf
JA
717}
718
97f46ae4
FT
719static void bsg_kref_release_function(struct kref *kref)
720{
721 struct bsg_class_device *bcd =
722 container_of(kref, struct bsg_class_device, ref);
8df5fc04 723 struct device *parent = bcd->parent;
97f46ae4
FT
724
725 if (bcd->release)
726 bcd->release(bcd->parent);
727
8df5fc04 728 put_device(parent);
97f46ae4
FT
729}
730
3d6392cf
JA
731static int bsg_put_device(struct bsg_device *bd)
732{
97f46ae4
FT
733 int ret = 0, do_free;
734 struct request_queue *q = bd->queue;
3d6392cf
JA
735
736 mutex_lock(&bsg_mutex);
737
97f46ae4 738 do_free = atomic_dec_and_test(&bd->ref_count);
3f27e3ed
FT
739 if (!do_free) {
740 mutex_unlock(&bsg_mutex);
3d6392cf 741 goto out;
3f27e3ed
FT
742 }
743
744 hlist_del(&bd->dev_list);
745 mutex_unlock(&bsg_mutex);
3d6392cf
JA
746
747 dprintk("%s: tearing down\n", bd->name);
748
749 /*
750 * close can always block
751 */
752 set_bit(BSG_F_BLOCK, &bd->flags);
753
754 /*
755 * correct error detection baddies here again. it's the responsibility
756 * of the app to properly reap commands before close() if it wants
757 * fool-proof error detection
758 */
759 ret = bsg_complete_all_commands(bd);
760
5309cb38 761 kfree(bd);
3d6392cf 762out:
97f46ae4
FT
763 kref_put(&q->bsg_dev.ref, bsg_kref_release_function);
764 if (do_free)
765 blk_put_queue(q);
3d6392cf
JA
766 return ret;
767}
768
769static struct bsg_device *bsg_add_device(struct inode *inode,
d351af01 770 struct request_queue *rq,
3d6392cf
JA
771 struct file *file)
772{
25fd1643 773 struct bsg_device *bd;
3d6392cf
JA
774#ifdef BSG_DEBUG
775 unsigned char buf[32];
776#endif
09ac46c4 777 if (!blk_get_queue(rq))
c3ff1b90 778 return ERR_PTR(-ENXIO);
3d6392cf
JA
779
780 bd = bsg_alloc_device();
c3ff1b90
FT
781 if (!bd) {
782 blk_put_queue(rq);
3d6392cf 783 return ERR_PTR(-ENOMEM);
c3ff1b90 784 }
3d6392cf 785
d351af01 786 bd->queue = rq;
0b07de85 787
3d6392cf
JA
788 bsg_set_block(bd, file);
789
790 atomic_set(&bd->ref_count, 1);
3d6392cf 791 mutex_lock(&bsg_mutex);
842ea771 792 hlist_add_head(&bd->dev_list, bsg_dev_idx_hash(iminor(inode)));
3d6392cf 793
3ada8b7e 794 strncpy(bd->name, dev_name(rq->bsg_dev.class_dev), sizeof(bd->name) - 1);
3d6392cf 795 dprintk("bound to <%s>, max queue %d\n",
9e69fbb5 796 format_dev_t(buf, inode->i_rdev), bd->max_queue);
3d6392cf
JA
797
798 mutex_unlock(&bsg_mutex);
799 return bd;
800}
801
842ea771 802static struct bsg_device *__bsg_get_device(int minor, struct request_queue *q)
3d6392cf 803{
43ac9e62 804 struct bsg_device *bd;
3d6392cf
JA
805
806 mutex_lock(&bsg_mutex);
807
b67bfe0d 808 hlist_for_each_entry(bd, bsg_dev_idx_hash(minor), dev_list) {
842ea771 809 if (bd->queue == q) {
3d6392cf 810 atomic_inc(&bd->ref_count);
43ac9e62 811 goto found;
3d6392cf 812 }
3d6392cf 813 }
43ac9e62
FT
814 bd = NULL;
815found:
3d6392cf
JA
816 mutex_unlock(&bsg_mutex);
817 return bd;
818}
819
820static struct bsg_device *bsg_get_device(struct inode *inode, struct file *file)
821{
598443a2
FT
822 struct bsg_device *bd;
823 struct bsg_class_device *bcd;
3d6392cf 824
3d6392cf
JA
825 /*
826 * find the class device
827 */
3d6392cf 828 mutex_lock(&bsg_mutex);
598443a2 829 bcd = idr_find(&bsg_minor_idr, iminor(inode));
d45ac4fa 830 if (bcd)
97f46ae4 831 kref_get(&bcd->ref);
3d6392cf
JA
832 mutex_unlock(&bsg_mutex);
833
834 if (!bcd)
835 return ERR_PTR(-ENODEV);
836
842ea771 837 bd = __bsg_get_device(iminor(inode), bcd->queue);
d45ac4fa
FT
838 if (bd)
839 return bd;
840
841 bd = bsg_add_device(inode, bcd->queue, file);
842 if (IS_ERR(bd))
97f46ae4 843 kref_put(&bcd->ref, bsg_kref_release_function);
d45ac4fa
FT
844
845 return bd;
3d6392cf
JA
846}
847
848static int bsg_open(struct inode *inode, struct file *file)
849{
75bd2ef1
JC
850 struct bsg_device *bd;
851
75bd2ef1 852 bd = bsg_get_device(inode, file);
3d6392cf
JA
853
854 if (IS_ERR(bd))
855 return PTR_ERR(bd);
856
857 file->private_data = bd;
858 return 0;
859}
860
861static int bsg_release(struct inode *inode, struct file *file)
862{
863 struct bsg_device *bd = file->private_data;
864
865 file->private_data = NULL;
866 return bsg_put_device(bd);
867}
868
869static unsigned int bsg_poll(struct file *file, poll_table *wait)
870{
871 struct bsg_device *bd = file->private_data;
872 unsigned int mask = 0;
873
874 poll_wait(file, &bd->wq_done, wait);
875 poll_wait(file, &bd->wq_free, wait);
876
877 spin_lock_irq(&bd->lock);
878 if (!list_empty(&bd->done_list))
879 mask |= POLLIN | POLLRDNORM;
80ceb057 880 if (bd->queued_cmds < bd->max_queue)
3d6392cf
JA
881 mask |= POLLOUT;
882 spin_unlock_irq(&bd->lock);
883
884 return mask;
885}
886
25fd1643 887static long bsg_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
3d6392cf
JA
888{
889 struct bsg_device *bd = file->private_data;
890 int __user *uarg = (int __user *) arg;
2d507a01 891 int ret;
3d6392cf 892
3d6392cf
JA
893 switch (cmd) {
894 /*
895 * our own ioctls
896 */
897 case SG_GET_COMMAND_Q:
898 return put_user(bd->max_queue, uarg);
5309cb38 899 case SG_SET_COMMAND_Q: {
3d6392cf
JA
900 int queue;
901
902 if (get_user(queue, uarg))
903 return -EFAULT;
5309cb38 904 if (queue < 1)
3d6392cf
JA
905 return -EINVAL;
906
5309cb38 907 spin_lock_irq(&bd->lock);
3d6392cf 908 bd->max_queue = queue;
5309cb38 909 spin_unlock_irq(&bd->lock);
3d6392cf
JA
910 return 0;
911 }
912
913 /*
914 * SCSI/sg ioctls
915 */
916 case SG_GET_VERSION_NUM:
917 case SCSI_IOCTL_GET_IDLUN:
918 case SCSI_IOCTL_GET_BUS_NUMBER:
919 case SG_SET_TIMEOUT:
920 case SG_GET_TIMEOUT:
921 case SG_GET_RESERVED_SIZE:
922 case SG_SET_RESERVED_SIZE:
923 case SG_EMULATED_HOST:
3d6392cf
JA
924 case SCSI_IOCTL_SEND_COMMAND: {
925 void __user *uarg = (void __user *) arg;
74f3c8af 926 return scsi_cmd_ioctl(bd->queue, NULL, file->f_mode, cmd, uarg);
3d6392cf 927 }
10e8855b
FT
928 case SG_IO: {
929 struct request *rq;
2c9ecdf4 930 struct bio *bio, *bidi_bio = NULL;
10e8855b 931 struct sg_io_v4 hdr;
05378940 932 int at_head;
c1c20120 933 u8 sense[SCSI_SENSE_BUFFERSIZE];
10e8855b
FT
934
935 if (copy_from_user(&hdr, uarg, sizeof(hdr)))
936 return -EFAULT;
937
c1c20120 938 rq = bsg_map_hdr(bd, &hdr, file->f_mode & FMODE_WRITE, sense);
10e8855b
FT
939 if (IS_ERR(rq))
940 return PTR_ERR(rq);
941
942 bio = rq->bio;
2c9ecdf4
FT
943 if (rq->next_rq)
944 bidi_bio = rq->next_rq->bio;
05378940
BH
945
946 at_head = (0 == (hdr.flags & BSG_FLAG_Q_AT_TAIL));
947 blk_execute_rq(bd->queue, NULL, rq, at_head);
2d507a01 948 ret = blk_complete_sgv4_hdr_rq(rq, &hdr, bio, bidi_bio);
10e8855b
FT
949
950 if (copy_to_user(uarg, &hdr, sizeof(hdr)))
951 return -EFAULT;
b711afa6 952
2d507a01 953 return ret;
10e8855b 954 }
3d6392cf
JA
955 /*
956 * block device ioctls
957 */
958 default:
959#if 0
960 return ioctl_by_bdev(bd->bdev, cmd, arg);
961#else
962 return -ENOTTY;
963#endif
964 }
965}
966
7344be05 967static const struct file_operations bsg_fops = {
3d6392cf
JA
968 .read = bsg_read,
969 .write = bsg_write,
970 .poll = bsg_poll,
971 .open = bsg_open,
972 .release = bsg_release,
25fd1643 973 .unlocked_ioctl = bsg_ioctl,
3d6392cf 974 .owner = THIS_MODULE,
6038f373 975 .llseek = default_llseek,
3d6392cf
JA
976};
977
d351af01 978void bsg_unregister_queue(struct request_queue *q)
3d6392cf 979{
d351af01 980 struct bsg_class_device *bcd = &q->bsg_dev;
3d6392cf 981
df468820
FT
982 if (!bcd->class_dev)
983 return;
3d6392cf
JA
984
985 mutex_lock(&bsg_mutex);
598443a2 986 idr_remove(&bsg_minor_idr, bcd->minor);
37b40adf
SG
987 if (q->kobj.sd)
988 sysfs_remove_link(&q->kobj, "bsg");
ee959b00 989 device_unregister(bcd->class_dev);
3d6392cf 990 bcd->class_dev = NULL;
97f46ae4 991 kref_put(&bcd->ref, bsg_kref_release_function);
3d6392cf
JA
992 mutex_unlock(&bsg_mutex);
993}
4cf0723a 994EXPORT_SYMBOL_GPL(bsg_unregister_queue);
3d6392cf 995
97f46ae4
FT
996int bsg_register_queue(struct request_queue *q, struct device *parent,
997 const char *name, void (*release)(struct device *))
3d6392cf 998{
598443a2 999 struct bsg_class_device *bcd;
3d6392cf 1000 dev_t dev;
bab998d6 1001 int ret;
ee959b00 1002 struct device *class_dev = NULL;
39dca558
JB
1003 const char *devname;
1004
1005 if (name)
1006 devname = name;
1007 else
3ada8b7e 1008 devname = dev_name(parent);
3d6392cf
JA
1009
1010 /*
1011 * we need a proper transport to send commands, not a stacked device
1012 */
49fd524f 1013 if (!queue_is_rq_based(q))
3d6392cf
JA
1014 return 0;
1015
d351af01 1016 bcd = &q->bsg_dev;
3d6392cf 1017 memset(bcd, 0, sizeof(*bcd));
3d6392cf
JA
1018
1019 mutex_lock(&bsg_mutex);
292b7f27 1020
bab998d6
TH
1021 ret = idr_alloc(&bsg_minor_idr, bcd, 0, BSG_MAX_DEVS, GFP_KERNEL);
1022 if (ret < 0) {
1023 if (ret == -ENOSPC) {
1024 printk(KERN_ERR "bsg: too many bsg devices\n");
1025 ret = -EINVAL;
1026 }
598443a2 1027 goto unlock;
598443a2
FT
1028 }
1029
bab998d6 1030 bcd->minor = ret;
d351af01 1031 bcd->queue = q;
97f46ae4
FT
1032 bcd->parent = get_device(parent);
1033 bcd->release = release;
1034 kref_init(&bcd->ref);
46f6ef4a 1035 dev = MKDEV(bsg_major, bcd->minor);
1ff9f542 1036 class_dev = device_create(bsg_class, parent, dev, NULL, "%s", devname);
4e2872d6
FT
1037 if (IS_ERR(class_dev)) {
1038 ret = PTR_ERR(class_dev);
598443a2 1039 goto put_dev;
4e2872d6
FT
1040 }
1041 bcd->class_dev = class_dev;
1042
abce891a 1043 if (q->kobj.sd) {
4e2872d6
FT
1044 ret = sysfs_create_link(&q->kobj, &bcd->class_dev->kobj, "bsg");
1045 if (ret)
598443a2 1046 goto unregister_class_dev;
4e2872d6
FT
1047 }
1048
3d6392cf
JA
1049 mutex_unlock(&bsg_mutex);
1050 return 0;
6826ee4f 1051
598443a2 1052unregister_class_dev:
ee959b00 1053 device_unregister(class_dev);
598443a2 1054put_dev:
97f46ae4 1055 put_device(parent);
bab998d6 1056 idr_remove(&bsg_minor_idr, bcd->minor);
598443a2 1057unlock:
264a0472 1058 mutex_unlock(&bsg_mutex);
4e2872d6
FT
1059 return ret;
1060}
4cf0723a 1061EXPORT_SYMBOL_GPL(bsg_register_queue);
4e2872d6 1062
7e7654a9 1063static struct cdev bsg_cdev;
292b7f27 1064
2c9ede55 1065static char *bsg_devnode(struct device *dev, umode_t *mode)
2bdf9149
KS
1066{
1067 return kasprintf(GFP_KERNEL, "bsg/%s", dev_name(dev));
1068}
1069
3d6392cf
JA
1070static int __init bsg_init(void)
1071{
1072 int ret, i;
46f6ef4a 1073 dev_t devid;
3d6392cf 1074
5309cb38 1075 bsg_cmd_cachep = kmem_cache_create("bsg_cmd",
20c2df83 1076 sizeof(struct bsg_command), 0, 0, NULL);
5309cb38
JA
1077 if (!bsg_cmd_cachep) {
1078 printk(KERN_ERR "bsg: failed creating slab cache\n");
1079 return -ENOMEM;
1080 }
1081
25fd1643 1082 for (i = 0; i < BSG_LIST_ARRAY_SIZE; i++)
3d6392cf
JA
1083 INIT_HLIST_HEAD(&bsg_device_list[i]);
1084
1085 bsg_class = class_create(THIS_MODULE, "bsg");
5309cb38 1086 if (IS_ERR(bsg_class)) {
9b9f770c
FT
1087 ret = PTR_ERR(bsg_class);
1088 goto destroy_kmemcache;
5309cb38 1089 }
e454cea2 1090 bsg_class->devnode = bsg_devnode;
3d6392cf 1091
46f6ef4a 1092 ret = alloc_chrdev_region(&devid, 0, BSG_MAX_DEVS, "bsg");
9b9f770c
FT
1093 if (ret)
1094 goto destroy_bsg_class;
292b7f27 1095
46f6ef4a
JA
1096 bsg_major = MAJOR(devid);
1097
292b7f27 1098 cdev_init(&bsg_cdev, &bsg_fops);
46f6ef4a 1099 ret = cdev_add(&bsg_cdev, MKDEV(bsg_major, 0), BSG_MAX_DEVS);
9b9f770c
FT
1100 if (ret)
1101 goto unregister_chrdev;
3d6392cf 1102
5d3a8cd3 1103 printk(KERN_INFO BSG_DESCRIPTION " version " BSG_VERSION
0ed081ce 1104 " loaded (major %d)\n", bsg_major);
3d6392cf 1105 return 0;
9b9f770c
FT
1106unregister_chrdev:
1107 unregister_chrdev_region(MKDEV(bsg_major, 0), BSG_MAX_DEVS);
1108destroy_bsg_class:
1109 class_destroy(bsg_class);
1110destroy_kmemcache:
1111 kmem_cache_destroy(bsg_cmd_cachep);
1112 return ret;
3d6392cf
JA
1113}
1114
1115MODULE_AUTHOR("Jens Axboe");
0ed081ce 1116MODULE_DESCRIPTION(BSG_DESCRIPTION);
3d6392cf
JA
1117MODULE_LICENSE("GPL");
1118
4e2872d6 1119device_initcall(bsg_init);