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CommitLineData
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
165125e1 139static int blk_fill_sgv4_hdr_rq(struct request_queue *q, struct request *rq,
abf54393 140 struct sg_io_v4 *hdr, struct bsg_device *bd,
aeb5d727 141 fmode_t has_write_perm)
70e36ece 142{
9f5de6b1
FT
143 if (hdr->request_len > BLK_MAX_CDB) {
144 rq->cmd = kzalloc(hdr->request_len, GFP_KERNEL);
145 if (!rq->cmd)
146 return -ENOMEM;
147 }
70e36ece 148
2b727c63 149 if (copy_from_user(rq->cmd, (void __user *)(unsigned long)hdr->request,
70e36ece
FT
150 hdr->request_len))
151 return -EFAULT;
15d10b61
FT
152
153 if (hdr->subprotocol == BSG_SUB_PROTOCOL_SCSI_CMD) {
018e0446 154 if (blk_verify_command(rq->cmd, has_write_perm))
15d10b61
FT
155 return -EPERM;
156 } else if (!capable(CAP_SYS_RAWIO))
70e36ece
FT
157 return -EPERM;
158
159 /*
160 * fill in request structure
161 */
162 rq->cmd_len = hdr->request_len;
70e36ece 163
ad5ebd2f 164 rq->timeout = msecs_to_jiffies(hdr->timeout);
70e36ece
FT
165 if (!rq->timeout)
166 rq->timeout = q->sg_timeout;
167 if (!rq->timeout)
168 rq->timeout = BLK_DEFAULT_SG_TIMEOUT;
f2f1fa78
LT
169 if (rq->timeout < BLK_MIN_SG_TIMEOUT)
170 rq->timeout = BLK_MIN_SG_TIMEOUT;
70e36ece
FT
171
172 return 0;
173}
174
3d6392cf 175/*
70e36ece 176 * Check if sg_io_v4 from user is allowed and valid
3d6392cf
JA
177 */
178static int
165125e1 179bsg_validate_sgv4_hdr(struct request_queue *q, struct sg_io_v4 *hdr, int *rw)
3d6392cf 180{
15d10b61
FT
181 int ret = 0;
182
70e36ece 183 if (hdr->guard != 'Q')
3d6392cf 184 return -EINVAL;
3d6392cf 185
15d10b61
FT
186 switch (hdr->protocol) {
187 case BSG_PROTOCOL_SCSI:
188 switch (hdr->subprotocol) {
189 case BSG_SUB_PROTOCOL_SCSI_CMD:
190 case BSG_SUB_PROTOCOL_SCSI_TRANSPORT:
191 break;
192 default:
193 ret = -EINVAL;
194 }
195 break;
196 default:
197 ret = -EINVAL;
198 }
70e36ece 199
70e36ece 200 *rw = hdr->dout_xfer_len ? WRITE : READ;
15d10b61 201 return ret;
3d6392cf
JA
202}
203
204/*
70e36ece 205 * map sg_io_v4 to a request.
3d6392cf
JA
206 */
207static struct request *
c1c20120
BH
208bsg_map_hdr(struct bsg_device *bd, struct sg_io_v4 *hdr, fmode_t has_write_perm,
209 u8 *sense)
3d6392cf 210{
165125e1 211 struct request_queue *q = bd->queue;
2c9ecdf4 212 struct request *rq, *next_rq = NULL;
25fd1643 213 int ret, rw;
70e36ece 214 unsigned int dxfer_len;
2b727c63 215 void __user *dxferp = NULL;
c7a841f3
JS
216 struct bsg_class_device *bcd = &q->bsg_dev;
217
218 /* if the LLD has been removed then the bsg_unregister_queue will
219 * eventually be called and the class_dev was freed, so we can no
220 * longer use this request_queue. Return no such address.
221 */
222 if (!bcd->class_dev)
223 return ERR_PTR(-ENXIO);
3d6392cf 224
70e36ece
FT
225 dprintk("map hdr %llx/%u %llx/%u\n", (unsigned long long) hdr->dout_xferp,
226 hdr->dout_xfer_len, (unsigned long long) hdr->din_xferp,
227 hdr->din_xfer_len);
3d6392cf 228
70e36ece 229 ret = bsg_validate_sgv4_hdr(q, hdr, &rw);
3d6392cf
JA
230 if (ret)
231 return ERR_PTR(ret);
232
233 /*
3ad2f3fb 234 * map scatter-gather elements separately and string them to request
3d6392cf
JA
235 */
236 rq = blk_get_request(q, rw, GFP_KERNEL);
a492f075
JL
237 if (IS_ERR(rq))
238 return rq;
f27b087b
JA
239 blk_rq_set_block_pc(rq);
240
abf54393 241 ret = blk_fill_sgv4_hdr_rq(q, rq, hdr, bd, has_write_perm);
2c9ecdf4
FT
242 if (ret)
243 goto out;
244
245 if (rw == WRITE && hdr->din_xfer_len) {
246 if (!test_bit(QUEUE_FLAG_BIDI, &q->queue_flags)) {
247 ret = -EOPNOTSUPP;
248 goto out;
249 }
250
251 next_rq = blk_get_request(q, READ, GFP_KERNEL);
a492f075
JL
252 if (IS_ERR(next_rq)) {
253 ret = PTR_ERR(next_rq);
55872c5a 254 next_rq = NULL;
2c9ecdf4
FT
255 goto out;
256 }
257 rq->next_rq = next_rq;
40f62028 258 next_rq->cmd_type = rq->cmd_type;
2c9ecdf4 259
2b727c63 260 dxferp = (void __user *)(unsigned long)hdr->din_xferp;
152e283f
FT
261 ret = blk_rq_map_user(q, next_rq, NULL, dxferp,
262 hdr->din_xfer_len, GFP_KERNEL);
2c9ecdf4
FT
263 if (ret)
264 goto out;
3d6392cf
JA
265 }
266
70e36ece
FT
267 if (hdr->dout_xfer_len) {
268 dxfer_len = hdr->dout_xfer_len;
2b727c63 269 dxferp = (void __user *)(unsigned long)hdr->dout_xferp;
70e36ece
FT
270 } else if (hdr->din_xfer_len) {
271 dxfer_len = hdr->din_xfer_len;
2b727c63 272 dxferp = (void __user *)(unsigned long)hdr->din_xferp;
70e36ece
FT
273 } else
274 dxfer_len = 0;
275
276 if (dxfer_len) {
152e283f
FT
277 ret = blk_rq_map_user(q, rq, NULL, dxferp, dxfer_len,
278 GFP_KERNEL);
2c9ecdf4
FT
279 if (ret)
280 goto out;
3d6392cf 281 }
c1c20120
BH
282
283 rq->sense = sense;
284 rq->sense_len = 0;
285
3d6392cf 286 return rq;
2c9ecdf4 287out:
9f5de6b1
FT
288 if (rq->cmd != rq->__cmd)
289 kfree(rq->cmd);
2c9ecdf4
FT
290 blk_put_request(rq);
291 if (next_rq) {
292 blk_rq_unmap_user(next_rq->bio);
293 blk_put_request(next_rq);
294 }
295 return ERR_PTR(ret);
3d6392cf
JA
296}
297
298/*
299 * async completion call-back from the block layer, when scsi/ide/whatever
300 * calls end_that_request_last() on a request
301 */
302static void bsg_rq_end_io(struct request *rq, int uptodate)
303{
304 struct bsg_command *bc = rq->end_io_data;
305 struct bsg_device *bd = bc->bd;
306 unsigned long flags;
307
5309cb38
JA
308 dprintk("%s: finished rq %p bc %p, bio %p stat %d\n",
309 bd->name, rq, bc, bc->bio, uptodate);
3d6392cf
JA
310
311 bc->hdr.duration = jiffies_to_msecs(jiffies - bc->hdr.duration);
312
313 spin_lock_irqsave(&bd->lock, flags);
25fd1643
JA
314 list_move_tail(&bc->list, &bd->done_list);
315 bd->done_cmds++;
3d6392cf 316 spin_unlock_irqrestore(&bd->lock, flags);
25fd1643
JA
317
318 wake_up(&bd->wq_done);
3d6392cf
JA
319}
320
321/*
322 * do final setup of a 'bc' and submit the matching 'rq' to the block
323 * layer for io
324 */
165125e1 325static void bsg_add_command(struct bsg_device *bd, struct request_queue *q,
3d6392cf
JA
326 struct bsg_command *bc, struct request *rq)
327{
05378940
BH
328 int at_head = (0 == (bc->hdr.flags & BSG_FLAG_Q_AT_TAIL));
329
3d6392cf
JA
330 /*
331 * add bc command to busy queue and submit rq for io
332 */
333 bc->rq = rq;
334 bc->bio = rq->bio;
2c9ecdf4
FT
335 if (rq->next_rq)
336 bc->bidi_bio = rq->next_rq->bio;
3d6392cf
JA
337 bc->hdr.duration = jiffies;
338 spin_lock_irq(&bd->lock);
339 list_add_tail(&bc->list, &bd->busy_list);
340 spin_unlock_irq(&bd->lock);
341
342 dprintk("%s: queueing rq %p, bc %p\n", bd->name, rq, bc);
343
344 rq->end_io_data = bc;
05378940 345 blk_execute_rq_nowait(q, NULL, rq, at_head, bsg_rq_end_io);
3d6392cf
JA
346}
347
25fd1643 348static struct bsg_command *bsg_next_done_cmd(struct bsg_device *bd)
3d6392cf
JA
349{
350 struct bsg_command *bc = NULL;
351
352 spin_lock_irq(&bd->lock);
353 if (bd->done_cmds) {
43ac9e62 354 bc = list_first_entry(&bd->done_list, struct bsg_command, list);
25fd1643
JA
355 list_del(&bc->list);
356 bd->done_cmds--;
3d6392cf
JA
357 }
358 spin_unlock_irq(&bd->lock);
359
360 return bc;
361}
362
363/*
364 * Get a finished command from the done list
365 */
e7d72173 366static struct bsg_command *bsg_get_done_cmd(struct bsg_device *bd)
3d6392cf
JA
367{
368 struct bsg_command *bc;
369 int ret;
370
371 do {
372 bc = bsg_next_done_cmd(bd);
373 if (bc)
374 break;
375
e7d72173
FT
376 if (!test_bit(BSG_F_BLOCK, &bd->flags)) {
377 bc = ERR_PTR(-EAGAIN);
378 break;
379 }
380
381 ret = wait_event_interruptible(bd->wq_done, bd->done_cmds);
3d6392cf 382 if (ret) {
e7d72173 383 bc = ERR_PTR(-ERESTARTSYS);
3d6392cf
JA
384 break;
385 }
386 } while (1);
387
388 dprintk("%s: returning done %p\n", bd->name, bc);
389
390 return bc;
391}
392
70e36ece 393static int blk_complete_sgv4_hdr_rq(struct request *rq, struct sg_io_v4 *hdr,
2c9ecdf4 394 struct bio *bio, struct bio *bidi_bio)
70e36ece
FT
395{
396 int ret = 0;
397
c1c20120 398 dprintk("rq %p bio %p 0x%x\n", rq, bio, rq->errors);
70e36ece
FT
399 /*
400 * fill in all the output members
401 */
47897160 402 hdr->device_status = rq->errors & 0xff;
70e36ece
FT
403 hdr->transport_status = host_byte(rq->errors);
404 hdr->driver_status = driver_byte(rq->errors);
405 hdr->info = 0;
406 if (hdr->device_status || hdr->transport_status || hdr->driver_status)
407 hdr->info |= SG_INFO_CHECK;
70e36ece
FT
408 hdr->response_len = 0;
409
410 if (rq->sense_len && hdr->response) {
25fd1643
JA
411 int len = min_t(unsigned int, hdr->max_response_len,
412 rq->sense_len);
70e36ece 413
2b727c63 414 ret = copy_to_user((void __user *)(unsigned long)hdr->response,
70e36ece
FT
415 rq->sense, len);
416 if (!ret)
417 hdr->response_len = len;
418 else
419 ret = -EFAULT;
420 }
421
2c9ecdf4 422 if (rq->next_rq) {
c3a4d78c
TH
423 hdr->dout_resid = rq->resid_len;
424 hdr->din_resid = rq->next_rq->resid_len;
2c9ecdf4
FT
425 blk_rq_unmap_user(bidi_bio);
426 blk_put_request(rq->next_rq);
0c6a89ba 427 } else if (rq_data_dir(rq) == READ)
c3a4d78c 428 hdr->din_resid = rq->resid_len;
0c6a89ba 429 else
c3a4d78c 430 hdr->dout_resid = rq->resid_len;
2c9ecdf4 431
2d507a01
JB
432 /*
433 * If the request generated a negative error number, return it
434 * (providing we aren't already returning an error); if it's
435 * just a protocol response (i.e. non negative), that gets
436 * processed above.
437 */
438 if (!ret && rq->errors < 0)
439 ret = rq->errors;
440
70e36ece 441 blk_rq_unmap_user(bio);
9f5de6b1
FT
442 if (rq->cmd != rq->__cmd)
443 kfree(rq->cmd);
70e36ece
FT
444 blk_put_request(rq);
445
446 return ret;
447}
448
2c561246
PZ
449static bool bsg_complete(struct bsg_device *bd)
450{
451 bool ret = false;
452 bool spin;
453
454 do {
455 spin_lock_irq(&bd->lock);
456
457 BUG_ON(bd->done_cmds > bd->queued_cmds);
458
459 /*
460 * All commands consumed.
461 */
462 if (bd->done_cmds == bd->queued_cmds)
463 ret = true;
464
465 spin = !test_bit(BSG_F_BLOCK, &bd->flags);
466
467 spin_unlock_irq(&bd->lock);
468 } while (!ret && spin);
469
470 return ret;
471}
472
3d6392cf
JA
473static int bsg_complete_all_commands(struct bsg_device *bd)
474{
475 struct bsg_command *bc;
476 int ret, tret;
477
478 dprintk("%s: entered\n", bd->name);
479
3d6392cf
JA
480 /*
481 * wait for all commands to complete
482 */
2c561246 483 io_wait_event(bd->wq_done, bsg_complete(bd));
3d6392cf
JA
484
485 /*
486 * discard done commands
487 */
488 ret = 0;
489 do {
e7d72173
FT
490 spin_lock_irq(&bd->lock);
491 if (!bd->queued_cmds) {
492 spin_unlock_irq(&bd->lock);
3d6392cf
JA
493 break;
494 }
efba1a31 495 spin_unlock_irq(&bd->lock);
3d6392cf 496
e7d72173
FT
497 bc = bsg_get_done_cmd(bd);
498 if (IS_ERR(bc))
499 break;
500
2c9ecdf4
FT
501 tret = blk_complete_sgv4_hdr_rq(bc->rq, &bc->hdr, bc->bio,
502 bc->bidi_bio);
3d6392cf
JA
503 if (!ret)
504 ret = tret;
505
506 bsg_free_command(bc);
507 } while (1);
508
509 return ret;
510}
511
25fd1643 512static int
e7d72173
FT
513__bsg_read(char __user *buf, size_t count, struct bsg_device *bd,
514 const struct iovec *iov, ssize_t *bytes_read)
3d6392cf
JA
515{
516 struct bsg_command *bc;
517 int nr_commands, ret;
518
70e36ece 519 if (count % sizeof(struct sg_io_v4))
3d6392cf
JA
520 return -EINVAL;
521
522 ret = 0;
70e36ece 523 nr_commands = count / sizeof(struct sg_io_v4);
3d6392cf 524 while (nr_commands) {
e7d72173 525 bc = bsg_get_done_cmd(bd);
3d6392cf
JA
526 if (IS_ERR(bc)) {
527 ret = PTR_ERR(bc);
528 break;
529 }
530
531 /*
532 * this is the only case where we need to copy data back
533 * after completing the request. so do that here,
534 * bsg_complete_work() cannot do that for us
535 */
2c9ecdf4
FT
536 ret = blk_complete_sgv4_hdr_rq(bc->rq, &bc->hdr, bc->bio,
537 bc->bidi_bio);
3d6392cf 538
25fd1643 539 if (copy_to_user(buf, &bc->hdr, sizeof(bc->hdr)))
3d6392cf
JA
540 ret = -EFAULT;
541
542 bsg_free_command(bc);
543
544 if (ret)
545 break;
546
70e36ece
FT
547 buf += sizeof(struct sg_io_v4);
548 *bytes_read += sizeof(struct sg_io_v4);
3d6392cf
JA
549 nr_commands--;
550 }
551
552 return ret;
553}
554
555static inline void bsg_set_block(struct bsg_device *bd, struct file *file)
556{
557 if (file->f_flags & O_NONBLOCK)
558 clear_bit(BSG_F_BLOCK, &bd->flags);
559 else
560 set_bit(BSG_F_BLOCK, &bd->flags);
561}
562
25fd1643
JA
563/*
564 * Check if the error is a "real" error that we should return.
565 */
3d6392cf
JA
566static inline int err_block_err(int ret)
567{
568 if (ret && ret != -ENOSPC && ret != -ENODATA && ret != -EAGAIN)
569 return 1;
570
571 return 0;
572}
573
574static ssize_t
575bsg_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
576{
577 struct bsg_device *bd = file->private_data;
578 int ret;
579 ssize_t bytes_read;
580
9e69fbb5 581 dprintk("%s: read %Zd bytes\n", bd->name, count);
3d6392cf
JA
582
583 bsg_set_block(bd, file);
0b07de85 584
3d6392cf 585 bytes_read = 0;
e7d72173 586 ret = __bsg_read(buf, count, bd, NULL, &bytes_read);
3d6392cf
JA
587 *ppos = bytes_read;
588
44194e3e 589 if (!bytes_read || err_block_err(ret))
3d6392cf
JA
590 bytes_read = ret;
591
592 return bytes_read;
593}
594
25fd1643 595static int __bsg_write(struct bsg_device *bd, const char __user *buf,
aeb5d727
AV
596 size_t count, ssize_t *bytes_written,
597 fmode_t has_write_perm)
3d6392cf
JA
598{
599 struct bsg_command *bc;
600 struct request *rq;
601 int ret, nr_commands;
602
70e36ece 603 if (count % sizeof(struct sg_io_v4))
3d6392cf
JA
604 return -EINVAL;
605
70e36ece 606 nr_commands = count / sizeof(struct sg_io_v4);
3d6392cf
JA
607 rq = NULL;
608 bc = NULL;
609 ret = 0;
610 while (nr_commands) {
165125e1 611 struct request_queue *q = bd->queue;
3d6392cf 612
e7d72173 613 bc = bsg_alloc_command(bd);
3d6392cf
JA
614 if (IS_ERR(bc)) {
615 ret = PTR_ERR(bc);
616 bc = NULL;
617 break;
618 }
619
3d6392cf
JA
620 if (copy_from_user(&bc->hdr, buf, sizeof(bc->hdr))) {
621 ret = -EFAULT;
622 break;
623 }
624
625 /*
626 * get a request, fill in the blanks, and add to request queue
627 */
c1c20120 628 rq = bsg_map_hdr(bd, &bc->hdr, has_write_perm, bc->sense);
3d6392cf
JA
629 if (IS_ERR(rq)) {
630 ret = PTR_ERR(rq);
631 rq = NULL;
632 break;
633 }
634
635 bsg_add_command(bd, q, bc, rq);
636 bc = NULL;
637 rq = NULL;
638 nr_commands--;
70e36ece 639 buf += sizeof(struct sg_io_v4);
25fd1643 640 *bytes_written += sizeof(struct sg_io_v4);
3d6392cf
JA
641 }
642
3d6392cf
JA
643 if (bc)
644 bsg_free_command(bc);
645
646 return ret;
647}
648
649static ssize_t
650bsg_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
651{
652 struct bsg_device *bd = file->private_data;
25fd1643 653 ssize_t bytes_written;
3d6392cf
JA
654 int ret;
655
9e69fbb5 656 dprintk("%s: write %Zd bytes\n", bd->name, count);
3d6392cf
JA
657
658 bsg_set_block(bd, file);
3d6392cf 659
25fd1643 660 bytes_written = 0;
abf54393
FT
661 ret = __bsg_write(bd, buf, count, &bytes_written,
662 file->f_mode & FMODE_WRITE);
663
25fd1643 664 *ppos = bytes_written;
3d6392cf
JA
665
666 /*
667 * return bytes written on non-fatal errors
668 */
44194e3e 669 if (!bytes_written || err_block_err(ret))
25fd1643 670 bytes_written = ret;
3d6392cf 671
25fd1643
JA
672 dprintk("%s: returning %Zd\n", bd->name, bytes_written);
673 return bytes_written;
3d6392cf
JA
674}
675
3d6392cf
JA
676static struct bsg_device *bsg_alloc_device(void)
677{
3d6392cf 678 struct bsg_device *bd;
3d6392cf
JA
679
680 bd = kzalloc(sizeof(struct bsg_device), GFP_KERNEL);
681 if (unlikely(!bd))
682 return NULL;
683
684 spin_lock_init(&bd->lock);
685
5309cb38 686 bd->max_queue = BSG_DEFAULT_CMDS;
3d6392cf
JA
687
688 INIT_LIST_HEAD(&bd->busy_list);
689 INIT_LIST_HEAD(&bd->done_list);
690 INIT_HLIST_NODE(&bd->dev_list);
691
692 init_waitqueue_head(&bd->wq_free);
693 init_waitqueue_head(&bd->wq_done);
694 return bd;
3d6392cf
JA
695}
696
97f46ae4
FT
697static void bsg_kref_release_function(struct kref *kref)
698{
699 struct bsg_class_device *bcd =
700 container_of(kref, struct bsg_class_device, ref);
8df5fc04 701 struct device *parent = bcd->parent;
97f46ae4
FT
702
703 if (bcd->release)
704 bcd->release(bcd->parent);
705
8df5fc04 706 put_device(parent);
97f46ae4
FT
707}
708
3d6392cf
JA
709static int bsg_put_device(struct bsg_device *bd)
710{
97f46ae4
FT
711 int ret = 0, do_free;
712 struct request_queue *q = bd->queue;
3d6392cf
JA
713
714 mutex_lock(&bsg_mutex);
715
97f46ae4 716 do_free = atomic_dec_and_test(&bd->ref_count);
3f27e3ed
FT
717 if (!do_free) {
718 mutex_unlock(&bsg_mutex);
3d6392cf 719 goto out;
3f27e3ed
FT
720 }
721
722 hlist_del(&bd->dev_list);
723 mutex_unlock(&bsg_mutex);
3d6392cf
JA
724
725 dprintk("%s: tearing down\n", bd->name);
726
727 /*
728 * close can always block
729 */
730 set_bit(BSG_F_BLOCK, &bd->flags);
731
732 /*
733 * correct error detection baddies here again. it's the responsibility
734 * of the app to properly reap commands before close() if it wants
735 * fool-proof error detection
736 */
737 ret = bsg_complete_all_commands(bd);
738
5309cb38 739 kfree(bd);
3d6392cf 740out:
97f46ae4
FT
741 kref_put(&q->bsg_dev.ref, bsg_kref_release_function);
742 if (do_free)
743 blk_put_queue(q);
3d6392cf
JA
744 return ret;
745}
746
747static struct bsg_device *bsg_add_device(struct inode *inode,
d351af01 748 struct request_queue *rq,
3d6392cf
JA
749 struct file *file)
750{
25fd1643 751 struct bsg_device *bd;
3d6392cf
JA
752#ifdef BSG_DEBUG
753 unsigned char buf[32];
754#endif
09ac46c4 755 if (!blk_get_queue(rq))
c3ff1b90 756 return ERR_PTR(-ENXIO);
3d6392cf
JA
757
758 bd = bsg_alloc_device();
c3ff1b90
FT
759 if (!bd) {
760 blk_put_queue(rq);
3d6392cf 761 return ERR_PTR(-ENOMEM);
c3ff1b90 762 }
3d6392cf 763
d351af01 764 bd->queue = rq;
0b07de85 765
3d6392cf
JA
766 bsg_set_block(bd, file);
767
768 atomic_set(&bd->ref_count, 1);
3d6392cf 769 mutex_lock(&bsg_mutex);
842ea771 770 hlist_add_head(&bd->dev_list, bsg_dev_idx_hash(iminor(inode)));
3d6392cf 771
3ada8b7e 772 strncpy(bd->name, dev_name(rq->bsg_dev.class_dev), sizeof(bd->name) - 1);
3d6392cf 773 dprintk("bound to <%s>, max queue %d\n",
9e69fbb5 774 format_dev_t(buf, inode->i_rdev), bd->max_queue);
3d6392cf
JA
775
776 mutex_unlock(&bsg_mutex);
777 return bd;
778}
779
842ea771 780static struct bsg_device *__bsg_get_device(int minor, struct request_queue *q)
3d6392cf 781{
43ac9e62 782 struct bsg_device *bd;
3d6392cf
JA
783
784 mutex_lock(&bsg_mutex);
785
b67bfe0d 786 hlist_for_each_entry(bd, bsg_dev_idx_hash(minor), dev_list) {
842ea771 787 if (bd->queue == q) {
3d6392cf 788 atomic_inc(&bd->ref_count);
43ac9e62 789 goto found;
3d6392cf 790 }
3d6392cf 791 }
43ac9e62
FT
792 bd = NULL;
793found:
3d6392cf
JA
794 mutex_unlock(&bsg_mutex);
795 return bd;
796}
797
798static struct bsg_device *bsg_get_device(struct inode *inode, struct file *file)
799{
598443a2
FT
800 struct bsg_device *bd;
801 struct bsg_class_device *bcd;
3d6392cf 802
3d6392cf
JA
803 /*
804 * find the class device
805 */
3d6392cf 806 mutex_lock(&bsg_mutex);
598443a2 807 bcd = idr_find(&bsg_minor_idr, iminor(inode));
d45ac4fa 808 if (bcd)
97f46ae4 809 kref_get(&bcd->ref);
3d6392cf
JA
810 mutex_unlock(&bsg_mutex);
811
812 if (!bcd)
813 return ERR_PTR(-ENODEV);
814
842ea771 815 bd = __bsg_get_device(iminor(inode), bcd->queue);
d45ac4fa
FT
816 if (bd)
817 return bd;
818
819 bd = bsg_add_device(inode, bcd->queue, file);
820 if (IS_ERR(bd))
97f46ae4 821 kref_put(&bcd->ref, bsg_kref_release_function);
d45ac4fa
FT
822
823 return bd;
3d6392cf
JA
824}
825
826static int bsg_open(struct inode *inode, struct file *file)
827{
75bd2ef1
JC
828 struct bsg_device *bd;
829
75bd2ef1 830 bd = bsg_get_device(inode, file);
3d6392cf
JA
831
832 if (IS_ERR(bd))
833 return PTR_ERR(bd);
834
835 file->private_data = bd;
836 return 0;
837}
838
839static int bsg_release(struct inode *inode, struct file *file)
840{
841 struct bsg_device *bd = file->private_data;
842
843 file->private_data = NULL;
844 return bsg_put_device(bd);
845}
846
847static unsigned int bsg_poll(struct file *file, poll_table *wait)
848{
849 struct bsg_device *bd = file->private_data;
850 unsigned int mask = 0;
851
852 poll_wait(file, &bd->wq_done, wait);
853 poll_wait(file, &bd->wq_free, wait);
854
855 spin_lock_irq(&bd->lock);
856 if (!list_empty(&bd->done_list))
857 mask |= POLLIN | POLLRDNORM;
80ceb057 858 if (bd->queued_cmds < bd->max_queue)
3d6392cf
JA
859 mask |= POLLOUT;
860 spin_unlock_irq(&bd->lock);
861
862 return mask;
863}
864
25fd1643 865static long bsg_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
3d6392cf
JA
866{
867 struct bsg_device *bd = file->private_data;
868 int __user *uarg = (int __user *) arg;
2d507a01 869 int ret;
3d6392cf 870
3d6392cf
JA
871 switch (cmd) {
872 /*
873 * our own ioctls
874 */
875 case SG_GET_COMMAND_Q:
876 return put_user(bd->max_queue, uarg);
5309cb38 877 case SG_SET_COMMAND_Q: {
3d6392cf
JA
878 int queue;
879
880 if (get_user(queue, uarg))
881 return -EFAULT;
5309cb38 882 if (queue < 1)
3d6392cf
JA
883 return -EINVAL;
884
5309cb38 885 spin_lock_irq(&bd->lock);
3d6392cf 886 bd->max_queue = queue;
5309cb38 887 spin_unlock_irq(&bd->lock);
3d6392cf
JA
888 return 0;
889 }
890
891 /*
892 * SCSI/sg ioctls
893 */
894 case SG_GET_VERSION_NUM:
895 case SCSI_IOCTL_GET_IDLUN:
896 case SCSI_IOCTL_GET_BUS_NUMBER:
897 case SG_SET_TIMEOUT:
898 case SG_GET_TIMEOUT:
899 case SG_GET_RESERVED_SIZE:
900 case SG_SET_RESERVED_SIZE:
901 case SG_EMULATED_HOST:
3d6392cf
JA
902 case SCSI_IOCTL_SEND_COMMAND: {
903 void __user *uarg = (void __user *) arg;
74f3c8af 904 return scsi_cmd_ioctl(bd->queue, NULL, file->f_mode, cmd, uarg);
3d6392cf 905 }
10e8855b
FT
906 case SG_IO: {
907 struct request *rq;
2c9ecdf4 908 struct bio *bio, *bidi_bio = NULL;
10e8855b 909 struct sg_io_v4 hdr;
05378940 910 int at_head;
c1c20120 911 u8 sense[SCSI_SENSE_BUFFERSIZE];
10e8855b
FT
912
913 if (copy_from_user(&hdr, uarg, sizeof(hdr)))
914 return -EFAULT;
915
c1c20120 916 rq = bsg_map_hdr(bd, &hdr, file->f_mode & FMODE_WRITE, sense);
10e8855b
FT
917 if (IS_ERR(rq))
918 return PTR_ERR(rq);
919
920 bio = rq->bio;
2c9ecdf4
FT
921 if (rq->next_rq)
922 bidi_bio = rq->next_rq->bio;
05378940
BH
923
924 at_head = (0 == (hdr.flags & BSG_FLAG_Q_AT_TAIL));
925 blk_execute_rq(bd->queue, NULL, rq, at_head);
2d507a01 926 ret = blk_complete_sgv4_hdr_rq(rq, &hdr, bio, bidi_bio);
10e8855b
FT
927
928 if (copy_to_user(uarg, &hdr, sizeof(hdr)))
929 return -EFAULT;
b711afa6 930
2d507a01 931 return ret;
10e8855b 932 }
3d6392cf
JA
933 /*
934 * block device ioctls
935 */
936 default:
937#if 0
938 return ioctl_by_bdev(bd->bdev, cmd, arg);
939#else
940 return -ENOTTY;
941#endif
942 }
943}
944
7344be05 945static const struct file_operations bsg_fops = {
3d6392cf
JA
946 .read = bsg_read,
947 .write = bsg_write,
948 .poll = bsg_poll,
949 .open = bsg_open,
950 .release = bsg_release,
25fd1643 951 .unlocked_ioctl = bsg_ioctl,
3d6392cf 952 .owner = THIS_MODULE,
6038f373 953 .llseek = default_llseek,
3d6392cf
JA
954};
955
d351af01 956void bsg_unregister_queue(struct request_queue *q)
3d6392cf 957{
d351af01 958 struct bsg_class_device *bcd = &q->bsg_dev;
3d6392cf 959
df468820
FT
960 if (!bcd->class_dev)
961 return;
3d6392cf
JA
962
963 mutex_lock(&bsg_mutex);
598443a2 964 idr_remove(&bsg_minor_idr, bcd->minor);
37b40adf
SG
965 if (q->kobj.sd)
966 sysfs_remove_link(&q->kobj, "bsg");
ee959b00 967 device_unregister(bcd->class_dev);
3d6392cf 968 bcd->class_dev = NULL;
97f46ae4 969 kref_put(&bcd->ref, bsg_kref_release_function);
3d6392cf
JA
970 mutex_unlock(&bsg_mutex);
971}
4cf0723a 972EXPORT_SYMBOL_GPL(bsg_unregister_queue);
3d6392cf 973
97f46ae4
FT
974int bsg_register_queue(struct request_queue *q, struct device *parent,
975 const char *name, void (*release)(struct device *))
3d6392cf 976{
598443a2 977 struct bsg_class_device *bcd;
3d6392cf 978 dev_t dev;
bab998d6 979 int ret;
ee959b00 980 struct device *class_dev = NULL;
39dca558
JB
981 const char *devname;
982
983 if (name)
984 devname = name;
985 else
3ada8b7e 986 devname = dev_name(parent);
3d6392cf
JA
987
988 /*
989 * we need a proper transport to send commands, not a stacked device
990 */
49fd524f 991 if (!queue_is_rq_based(q))
3d6392cf
JA
992 return 0;
993
d351af01 994 bcd = &q->bsg_dev;
3d6392cf 995 memset(bcd, 0, sizeof(*bcd));
3d6392cf
JA
996
997 mutex_lock(&bsg_mutex);
292b7f27 998
bab998d6
TH
999 ret = idr_alloc(&bsg_minor_idr, bcd, 0, BSG_MAX_DEVS, GFP_KERNEL);
1000 if (ret < 0) {
1001 if (ret == -ENOSPC) {
1002 printk(KERN_ERR "bsg: too many bsg devices\n");
1003 ret = -EINVAL;
1004 }
598443a2 1005 goto unlock;
598443a2
FT
1006 }
1007
bab998d6 1008 bcd->minor = ret;
d351af01 1009 bcd->queue = q;
97f46ae4
FT
1010 bcd->parent = get_device(parent);
1011 bcd->release = release;
1012 kref_init(&bcd->ref);
46f6ef4a 1013 dev = MKDEV(bsg_major, bcd->minor);
1ff9f542 1014 class_dev = device_create(bsg_class, parent, dev, NULL, "%s", devname);
4e2872d6
FT
1015 if (IS_ERR(class_dev)) {
1016 ret = PTR_ERR(class_dev);
598443a2 1017 goto put_dev;
4e2872d6
FT
1018 }
1019 bcd->class_dev = class_dev;
1020
abce891a 1021 if (q->kobj.sd) {
4e2872d6
FT
1022 ret = sysfs_create_link(&q->kobj, &bcd->class_dev->kobj, "bsg");
1023 if (ret)
598443a2 1024 goto unregister_class_dev;
4e2872d6
FT
1025 }
1026
3d6392cf
JA
1027 mutex_unlock(&bsg_mutex);
1028 return 0;
6826ee4f 1029
598443a2 1030unregister_class_dev:
ee959b00 1031 device_unregister(class_dev);
598443a2 1032put_dev:
97f46ae4 1033 put_device(parent);
bab998d6 1034 idr_remove(&bsg_minor_idr, bcd->minor);
598443a2 1035unlock:
264a0472 1036 mutex_unlock(&bsg_mutex);
4e2872d6
FT
1037 return ret;
1038}
4cf0723a 1039EXPORT_SYMBOL_GPL(bsg_register_queue);
4e2872d6 1040
7e7654a9 1041static struct cdev bsg_cdev;
292b7f27 1042
2c9ede55 1043static char *bsg_devnode(struct device *dev, umode_t *mode)
2bdf9149
KS
1044{
1045 return kasprintf(GFP_KERNEL, "bsg/%s", dev_name(dev));
1046}
1047
3d6392cf
JA
1048static int __init bsg_init(void)
1049{
1050 int ret, i;
46f6ef4a 1051 dev_t devid;
3d6392cf 1052
5309cb38 1053 bsg_cmd_cachep = kmem_cache_create("bsg_cmd",
20c2df83 1054 sizeof(struct bsg_command), 0, 0, NULL);
5309cb38
JA
1055 if (!bsg_cmd_cachep) {
1056 printk(KERN_ERR "bsg: failed creating slab cache\n");
1057 return -ENOMEM;
1058 }
1059
25fd1643 1060 for (i = 0; i < BSG_LIST_ARRAY_SIZE; i++)
3d6392cf
JA
1061 INIT_HLIST_HEAD(&bsg_device_list[i]);
1062
1063 bsg_class = class_create(THIS_MODULE, "bsg");
5309cb38 1064 if (IS_ERR(bsg_class)) {
9b9f770c
FT
1065 ret = PTR_ERR(bsg_class);
1066 goto destroy_kmemcache;
5309cb38 1067 }
e454cea2 1068 bsg_class->devnode = bsg_devnode;
3d6392cf 1069
46f6ef4a 1070 ret = alloc_chrdev_region(&devid, 0, BSG_MAX_DEVS, "bsg");
9b9f770c
FT
1071 if (ret)
1072 goto destroy_bsg_class;
292b7f27 1073
46f6ef4a
JA
1074 bsg_major = MAJOR(devid);
1075
292b7f27 1076 cdev_init(&bsg_cdev, &bsg_fops);
46f6ef4a 1077 ret = cdev_add(&bsg_cdev, MKDEV(bsg_major, 0), BSG_MAX_DEVS);
9b9f770c
FT
1078 if (ret)
1079 goto unregister_chrdev;
3d6392cf 1080
5d3a8cd3 1081 printk(KERN_INFO BSG_DESCRIPTION " version " BSG_VERSION
0ed081ce 1082 " loaded (major %d)\n", bsg_major);
3d6392cf 1083 return 0;
9b9f770c
FT
1084unregister_chrdev:
1085 unregister_chrdev_region(MKDEV(bsg_major, 0), BSG_MAX_DEVS);
1086destroy_bsg_class:
1087 class_destroy(bsg_class);
1088destroy_kmemcache:
1089 kmem_cache_destroy(bsg_cmd_cachep);
1090 return ret;
3d6392cf
JA
1091}
1092
1093MODULE_AUTHOR("Jens Axboe");
0ed081ce 1094MODULE_DESCRIPTION(BSG_DESCRIPTION);
3d6392cf
JA
1095MODULE_LICENSE("GPL");
1096
4e2872d6 1097device_initcall(bsg_init);