]>
Commit | Line | Data |
---|---|---|
3d6392cf JA |
1 | /* |
2 | * bsg.c - block layer implementation of the sg v3 interface | |
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 | */ | |
12 | /* | |
13 | * TODO | |
14 | * - Should this get merged, block/scsi_ioctl.c will be migrated into | |
15 | * this file. To keep maintenance down, it's easier to have them | |
16 | * seperated right now. | |
17 | * | |
18 | */ | |
3d6392cf JA |
19 | #include <linux/module.h> |
20 | #include <linux/init.h> | |
21 | #include <linux/file.h> | |
22 | #include <linux/blkdev.h> | |
23 | #include <linux/poll.h> | |
24 | #include <linux/cdev.h> | |
25 | #include <linux/percpu.h> | |
26 | #include <linux/uio.h> | |
27 | #include <linux/bsg.h> | |
28 | ||
29 | #include <scsi/scsi.h> | |
30 | #include <scsi/scsi_ioctl.h> | |
31 | #include <scsi/scsi_cmnd.h> | |
32 | #include <scsi/sg.h> | |
33 | ||
34 | static char bsg_version[] = "block layer sg (bsg) 0.4"; | |
35 | ||
3d6392cf JA |
36 | struct bsg_device { |
37 | struct gendisk *disk; | |
38 | request_queue_t *queue; | |
39 | spinlock_t lock; | |
40 | struct list_head busy_list; | |
41 | struct list_head done_list; | |
42 | struct hlist_node dev_list; | |
43 | atomic_t ref_count; | |
44 | int minor; | |
45 | int queued_cmds; | |
46 | int done_cmds; | |
3d6392cf JA |
47 | wait_queue_head_t wq_done; |
48 | wait_queue_head_t wq_free; | |
49 | char name[BDEVNAME_SIZE]; | |
50 | int max_queue; | |
51 | unsigned long flags; | |
52 | }; | |
53 | ||
54 | enum { | |
55 | BSG_F_BLOCK = 1, | |
56 | BSG_F_WRITE_PERM = 2, | |
57 | }; | |
58 | ||
5309cb38 | 59 | #define BSG_DEFAULT_CMDS 64 |
3d6392cf JA |
60 | |
61 | #undef BSG_DEBUG | |
62 | ||
63 | #ifdef BSG_DEBUG | |
64 | #define dprintk(fmt, args...) printk(KERN_ERR "%s: " fmt, __FUNCTION__, ##args) | |
65 | #else | |
66 | #define dprintk(fmt, args...) | |
67 | #endif | |
68 | ||
69 | #define list_entry_bc(entry) list_entry((entry), struct bsg_command, list) | |
70 | ||
71 | /* | |
72 | * just for testing | |
73 | */ | |
74 | #define BSG_MAJOR (240) | |
75 | ||
76 | static DEFINE_MUTEX(bsg_mutex); | |
77 | static int bsg_device_nr; | |
78 | ||
79 | #define BSG_LIST_SIZE (8) | |
80 | #define bsg_list_idx(minor) ((minor) & (BSG_LIST_SIZE - 1)) | |
81 | static struct hlist_head bsg_device_list[BSG_LIST_SIZE]; | |
82 | ||
83 | static struct class *bsg_class; | |
84 | static LIST_HEAD(bsg_class_list); | |
85 | ||
5309cb38 JA |
86 | static struct kmem_cache *bsg_cmd_cachep; |
87 | ||
3d6392cf JA |
88 | /* |
89 | * our internal command type | |
90 | */ | |
91 | struct bsg_command { | |
92 | struct bsg_device *bd; | |
93 | struct list_head list; | |
94 | struct request *rq; | |
95 | struct bio *bio; | |
96 | int err; | |
70e36ece FT |
97 | struct sg_io_v4 hdr; |
98 | struct sg_io_v4 __user *uhdr; | |
3d6392cf JA |
99 | char sense[SCSI_SENSE_BUFFERSIZE]; |
100 | }; | |
101 | ||
102 | static void bsg_free_command(struct bsg_command *bc) | |
103 | { | |
104 | struct bsg_device *bd = bc->bd; | |
3d6392cf JA |
105 | unsigned long flags; |
106 | ||
5309cb38 | 107 | kmem_cache_free(bsg_cmd_cachep, bc); |
3d6392cf JA |
108 | |
109 | spin_lock_irqsave(&bd->lock, flags); | |
110 | bd->queued_cmds--; | |
3d6392cf JA |
111 | spin_unlock_irqrestore(&bd->lock, flags); |
112 | ||
113 | wake_up(&bd->wq_free); | |
114 | } | |
115 | ||
116 | static struct bsg_command *__bsg_alloc_command(struct bsg_device *bd) | |
117 | { | |
118 | struct bsg_command *bc = NULL; | |
3d6392cf JA |
119 | |
120 | spin_lock_irq(&bd->lock); | |
121 | ||
122 | if (bd->queued_cmds >= bd->max_queue) | |
123 | goto out; | |
124 | ||
3d6392cf | 125 | bd->queued_cmds++; |
3d6392cf JA |
126 | spin_unlock_irq(&bd->lock); |
127 | ||
5309cb38 JA |
128 | bc = kmem_cache_alloc(bsg_cmd_cachep, GFP_USER); |
129 | if (unlikely(!bc)) { | |
130 | spin_lock_irq(&bd->lock); | |
131 | goto alloc_fail; | |
132 | } | |
133 | ||
3d6392cf JA |
134 | memset(bc, 0, sizeof(*bc)); |
135 | bc->bd = bd; | |
136 | INIT_LIST_HEAD(&bc->list); | |
5309cb38 | 137 | dprintk("%s: returning free cmd %p\n", bd->name, bc); |
3d6392cf | 138 | return bc; |
5309cb38 JA |
139 | alloc_fail: |
140 | bd->queued_cmds--; | |
3d6392cf | 141 | out: |
3d6392cf JA |
142 | spin_unlock_irq(&bd->lock); |
143 | return bc; | |
144 | } | |
145 | ||
146 | static inline void | |
147 | bsg_del_done_cmd(struct bsg_device *bd, struct bsg_command *bc) | |
148 | { | |
149 | bd->done_cmds--; | |
150 | list_del(&bc->list); | |
151 | } | |
152 | ||
153 | static inline void | |
154 | bsg_add_done_cmd(struct bsg_device *bd, struct bsg_command *bc) | |
155 | { | |
156 | bd->done_cmds++; | |
157 | list_add_tail(&bc->list, &bd->done_list); | |
158 | wake_up(&bd->wq_done); | |
159 | } | |
160 | ||
161 | static inline int bsg_io_schedule(struct bsg_device *bd, int state) | |
162 | { | |
163 | DEFINE_WAIT(wait); | |
164 | int ret = 0; | |
165 | ||
166 | spin_lock_irq(&bd->lock); | |
167 | ||
168 | BUG_ON(bd->done_cmds > bd->queued_cmds); | |
169 | ||
170 | /* | |
171 | * -ENOSPC or -ENODATA? I'm going for -ENODATA, meaning "I have no | |
172 | * work to do", even though we return -ENOSPC after this same test | |
173 | * during bsg_write() -- there, it means our buffer can't have more | |
174 | * bsg_commands added to it, thus has no space left. | |
175 | */ | |
176 | if (bd->done_cmds == bd->queued_cmds) { | |
177 | ret = -ENODATA; | |
178 | goto unlock; | |
179 | } | |
180 | ||
181 | if (!test_bit(BSG_F_BLOCK, &bd->flags)) { | |
182 | ret = -EAGAIN; | |
183 | goto unlock; | |
184 | } | |
185 | ||
186 | prepare_to_wait(&bd->wq_done, &wait, state); | |
187 | spin_unlock_irq(&bd->lock); | |
188 | io_schedule(); | |
189 | finish_wait(&bd->wq_done, &wait); | |
190 | ||
191 | if ((state == TASK_INTERRUPTIBLE) && signal_pending(current)) | |
192 | ret = -ERESTARTSYS; | |
193 | ||
194 | return ret; | |
195 | unlock: | |
196 | spin_unlock_irq(&bd->lock); | |
197 | return ret; | |
198 | } | |
199 | ||
200 | /* | |
201 | * get a new free command, blocking if needed and specified | |
202 | */ | |
203 | static struct bsg_command *bsg_get_command(struct bsg_device *bd) | |
204 | { | |
205 | struct bsg_command *bc; | |
206 | int ret; | |
207 | ||
208 | do { | |
209 | bc = __bsg_alloc_command(bd); | |
210 | if (bc) | |
211 | break; | |
212 | ||
213 | ret = bsg_io_schedule(bd, TASK_INTERRUPTIBLE); | |
214 | if (ret) { | |
215 | bc = ERR_PTR(ret); | |
216 | break; | |
217 | } | |
218 | ||
219 | } while (1); | |
220 | ||
221 | return bc; | |
222 | } | |
223 | ||
70e36ece FT |
224 | static int blk_fill_sgv4_hdr_rq(request_queue_t *q, struct request *rq, |
225 | struct sg_io_v4 *hdr, int has_write_perm) | |
226 | { | |
227 | memset(rq->cmd, 0, BLK_MAX_CDB); /* ATAPI hates garbage after CDB */ | |
228 | ||
229 | if (copy_from_user(rq->cmd, (void *)(unsigned long)hdr->request, | |
230 | hdr->request_len)) | |
231 | return -EFAULT; | |
232 | if (blk_verify_command(rq->cmd, has_write_perm)) | |
233 | return -EPERM; | |
234 | ||
235 | /* | |
236 | * fill in request structure | |
237 | */ | |
238 | rq->cmd_len = hdr->request_len; | |
239 | rq->cmd_type = REQ_TYPE_BLOCK_PC; | |
240 | ||
241 | rq->timeout = (hdr->timeout * HZ) / 1000; | |
242 | if (!rq->timeout) | |
243 | rq->timeout = q->sg_timeout; | |
244 | if (!rq->timeout) | |
245 | rq->timeout = BLK_DEFAULT_SG_TIMEOUT; | |
246 | ||
247 | return 0; | |
248 | } | |
249 | ||
3d6392cf | 250 | /* |
70e36ece | 251 | * Check if sg_io_v4 from user is allowed and valid |
3d6392cf JA |
252 | */ |
253 | static int | |
70e36ece | 254 | bsg_validate_sgv4_hdr(request_queue_t *q, struct sg_io_v4 *hdr, int *rw) |
3d6392cf | 255 | { |
70e36ece | 256 | if (hdr->guard != 'Q') |
3d6392cf | 257 | return -EINVAL; |
70e36ece | 258 | if (hdr->request_len > BLK_MAX_CDB) |
3d6392cf | 259 | return -EINVAL; |
70e36ece FT |
260 | if (hdr->dout_xfer_len > (q->max_sectors << 9) || |
261 | hdr->din_xfer_len > (q->max_sectors << 9)) | |
3d6392cf JA |
262 | return -EIO; |
263 | ||
70e36ece FT |
264 | /* not supported currently */ |
265 | if (hdr->protocol || hdr->subprotocol) | |
266 | return -EINVAL; | |
267 | ||
3d6392cf JA |
268 | /* |
269 | * looks sane, if no data then it should be fine from our POV | |
270 | */ | |
70e36ece | 271 | if (!hdr->dout_xfer_len && !hdr->din_xfer_len) |
3d6392cf JA |
272 | return 0; |
273 | ||
70e36ece FT |
274 | /* not supported currently */ |
275 | if (hdr->dout_xfer_len && hdr->din_xfer_len) | |
276 | return -EINVAL; | |
277 | ||
278 | *rw = hdr->dout_xfer_len ? WRITE : READ; | |
3d6392cf JA |
279 | |
280 | return 0; | |
281 | } | |
282 | ||
283 | /* | |
70e36ece | 284 | * map sg_io_v4 to a request. |
3d6392cf JA |
285 | */ |
286 | static struct request * | |
70e36ece | 287 | bsg_map_hdr(struct bsg_device *bd, struct sg_io_v4 *hdr) |
3d6392cf JA |
288 | { |
289 | request_queue_t *q = bd->queue; | |
3d6392cf | 290 | struct request *rq; |
2ef7086a | 291 | int ret, rw = 0; /* shut up gcc */ |
70e36ece FT |
292 | unsigned int dxfer_len; |
293 | void *dxferp = NULL; | |
3d6392cf | 294 | |
70e36ece FT |
295 | dprintk("map hdr %llx/%u %llx/%u\n", (unsigned long long) hdr->dout_xferp, |
296 | hdr->dout_xfer_len, (unsigned long long) hdr->din_xferp, | |
297 | hdr->din_xfer_len); | |
3d6392cf | 298 | |
70e36ece | 299 | ret = bsg_validate_sgv4_hdr(q, hdr, &rw); |
3d6392cf JA |
300 | if (ret) |
301 | return ERR_PTR(ret); | |
302 | ||
303 | /* | |
304 | * map scatter-gather elements seperately and string them to request | |
305 | */ | |
306 | rq = blk_get_request(q, rw, GFP_KERNEL); | |
70e36ece FT |
307 | ret = blk_fill_sgv4_hdr_rq(q, rq, hdr, test_bit(BSG_F_WRITE_PERM, |
308 | &bd->flags)); | |
3d6392cf JA |
309 | if (ret) { |
310 | blk_put_request(rq); | |
311 | return ERR_PTR(ret); | |
312 | } | |
313 | ||
70e36ece FT |
314 | if (hdr->dout_xfer_len) { |
315 | dxfer_len = hdr->dout_xfer_len; | |
316 | dxferp = (void*)(unsigned long)hdr->dout_xferp; | |
317 | } else if (hdr->din_xfer_len) { | |
318 | dxfer_len = hdr->din_xfer_len; | |
319 | dxferp = (void*)(unsigned long)hdr->din_xferp; | |
320 | } else | |
321 | dxfer_len = 0; | |
322 | ||
323 | if (dxfer_len) { | |
324 | ret = blk_rq_map_user(q, rq, dxferp, dxfer_len); | |
325 | if (ret) { | |
326 | dprintk("failed map at %d\n", ret); | |
327 | blk_put_request(rq); | |
328 | rq = ERR_PTR(ret); | |
3d6392cf | 329 | } |
3d6392cf JA |
330 | } |
331 | ||
332 | return rq; | |
333 | } | |
334 | ||
335 | /* | |
336 | * async completion call-back from the block layer, when scsi/ide/whatever | |
337 | * calls end_that_request_last() on a request | |
338 | */ | |
339 | static void bsg_rq_end_io(struct request *rq, int uptodate) | |
340 | { | |
341 | struct bsg_command *bc = rq->end_io_data; | |
342 | struct bsg_device *bd = bc->bd; | |
343 | unsigned long flags; | |
344 | ||
5309cb38 JA |
345 | dprintk("%s: finished rq %p bc %p, bio %p stat %d\n", |
346 | bd->name, rq, bc, bc->bio, uptodate); | |
3d6392cf JA |
347 | |
348 | bc->hdr.duration = jiffies_to_msecs(jiffies - bc->hdr.duration); | |
349 | ||
350 | spin_lock_irqsave(&bd->lock, flags); | |
351 | list_del(&bc->list); | |
352 | bsg_add_done_cmd(bd, bc); | |
353 | spin_unlock_irqrestore(&bd->lock, flags); | |
354 | } | |
355 | ||
356 | /* | |
357 | * do final setup of a 'bc' and submit the matching 'rq' to the block | |
358 | * layer for io | |
359 | */ | |
360 | static void bsg_add_command(struct bsg_device *bd, request_queue_t *q, | |
361 | struct bsg_command *bc, struct request *rq) | |
362 | { | |
363 | rq->sense = bc->sense; | |
364 | rq->sense_len = 0; | |
365 | ||
366 | /* | |
367 | * add bc command to busy queue and submit rq for io | |
368 | */ | |
369 | bc->rq = rq; | |
370 | bc->bio = rq->bio; | |
371 | bc->hdr.duration = jiffies; | |
372 | spin_lock_irq(&bd->lock); | |
373 | list_add_tail(&bc->list, &bd->busy_list); | |
374 | spin_unlock_irq(&bd->lock); | |
375 | ||
376 | dprintk("%s: queueing rq %p, bc %p\n", bd->name, rq, bc); | |
377 | ||
378 | rq->end_io_data = bc; | |
379 | blk_execute_rq_nowait(q, bd->disk, rq, 1, bsg_rq_end_io); | |
380 | } | |
381 | ||
382 | static inline struct bsg_command *bsg_next_done_cmd(struct bsg_device *bd) | |
383 | { | |
384 | struct bsg_command *bc = NULL; | |
385 | ||
386 | spin_lock_irq(&bd->lock); | |
387 | if (bd->done_cmds) { | |
388 | bc = list_entry_bc(bd->done_list.next); | |
389 | bsg_del_done_cmd(bd, bc); | |
390 | } | |
391 | spin_unlock_irq(&bd->lock); | |
392 | ||
393 | return bc; | |
394 | } | |
395 | ||
396 | /* | |
397 | * Get a finished command from the done list | |
398 | */ | |
399 | static struct bsg_command *__bsg_get_done_cmd(struct bsg_device *bd, int state) | |
400 | { | |
401 | struct bsg_command *bc; | |
402 | int ret; | |
403 | ||
404 | do { | |
405 | bc = bsg_next_done_cmd(bd); | |
406 | if (bc) | |
407 | break; | |
408 | ||
409 | ret = bsg_io_schedule(bd, state); | |
410 | if (ret) { | |
411 | bc = ERR_PTR(ret); | |
412 | break; | |
413 | } | |
414 | } while (1); | |
415 | ||
416 | dprintk("%s: returning done %p\n", bd->name, bc); | |
417 | ||
418 | return bc; | |
419 | } | |
420 | ||
421 | static struct bsg_command * | |
422 | bsg_get_done_cmd(struct bsg_device *bd, const struct iovec *iov) | |
423 | { | |
424 | return __bsg_get_done_cmd(bd, TASK_INTERRUPTIBLE); | |
425 | } | |
426 | ||
427 | static struct bsg_command * | |
428 | bsg_get_done_cmd_nosignals(struct bsg_device *bd) | |
429 | { | |
430 | return __bsg_get_done_cmd(bd, TASK_UNINTERRUPTIBLE); | |
431 | } | |
432 | ||
70e36ece FT |
433 | static int blk_complete_sgv4_hdr_rq(struct request *rq, struct sg_io_v4 *hdr, |
434 | struct bio *bio) | |
435 | { | |
436 | int ret = 0; | |
437 | ||
438 | dprintk("rq %p bio %p %u\n", rq, bio, rq->errors); | |
439 | /* | |
440 | * fill in all the output members | |
441 | */ | |
442 | hdr->device_status = status_byte(rq->errors); | |
443 | hdr->transport_status = host_byte(rq->errors); | |
444 | hdr->driver_status = driver_byte(rq->errors); | |
445 | hdr->info = 0; | |
446 | if (hdr->device_status || hdr->transport_status || hdr->driver_status) | |
447 | hdr->info |= SG_INFO_CHECK; | |
448 | hdr->din_resid = rq->data_len; | |
449 | hdr->response_len = 0; | |
450 | ||
451 | if (rq->sense_len && hdr->response) { | |
452 | int len = min((unsigned int) hdr->max_response_len, | |
453 | rq->sense_len); | |
454 | ||
455 | ret = copy_to_user((void*)(unsigned long)hdr->response, | |
456 | rq->sense, len); | |
457 | if (!ret) | |
458 | hdr->response_len = len; | |
459 | else | |
460 | ret = -EFAULT; | |
461 | } | |
462 | ||
463 | blk_rq_unmap_user(bio); | |
464 | blk_put_request(rq); | |
465 | ||
466 | return ret; | |
467 | } | |
468 | ||
3d6392cf JA |
469 | static int bsg_complete_all_commands(struct bsg_device *bd) |
470 | { | |
471 | struct bsg_command *bc; | |
472 | int ret, tret; | |
473 | ||
474 | dprintk("%s: entered\n", bd->name); | |
475 | ||
476 | set_bit(BSG_F_BLOCK, &bd->flags); | |
477 | ||
478 | /* | |
479 | * wait for all commands to complete | |
480 | */ | |
481 | ret = 0; | |
482 | do { | |
483 | ret = bsg_io_schedule(bd, TASK_UNINTERRUPTIBLE); | |
484 | /* | |
485 | * look for -ENODATA specifically -- we'll sometimes get | |
486 | * -ERESTARTSYS when we've taken a signal, but we can't | |
487 | * return until we're done freeing the queue, so ignore | |
488 | * it. The signal will get handled when we're done freeing | |
489 | * the bsg_device. | |
490 | */ | |
491 | } while (ret != -ENODATA); | |
492 | ||
493 | /* | |
494 | * discard done commands | |
495 | */ | |
496 | ret = 0; | |
497 | do { | |
498 | bc = bsg_get_done_cmd_nosignals(bd); | |
499 | ||
500 | /* | |
501 | * we _must_ complete before restarting, because | |
502 | * bsg_release can't handle this failing. | |
503 | */ | |
504 | if (PTR_ERR(bc) == -ERESTARTSYS) | |
505 | continue; | |
506 | if (IS_ERR(bc)) { | |
507 | ret = PTR_ERR(bc); | |
508 | break; | |
509 | } | |
510 | ||
70e36ece | 511 | tret = blk_complete_sgv4_hdr_rq(bc->rq, &bc->hdr, bc->bio); |
3d6392cf JA |
512 | if (!ret) |
513 | ret = tret; | |
514 | ||
515 | bsg_free_command(bc); | |
516 | } while (1); | |
517 | ||
518 | return ret; | |
519 | } | |
520 | ||
521 | typedef struct bsg_command *(*bsg_command_callback)(struct bsg_device *bd, const struct iovec *iov); | |
522 | ||
523 | static ssize_t | |
524 | __bsg_read(char __user *buf, size_t count, bsg_command_callback get_bc, | |
525 | struct bsg_device *bd, const struct iovec *iov, ssize_t *bytes_read) | |
526 | { | |
527 | struct bsg_command *bc; | |
528 | int nr_commands, ret; | |
529 | ||
70e36ece | 530 | if (count % sizeof(struct sg_io_v4)) |
3d6392cf JA |
531 | return -EINVAL; |
532 | ||
533 | ret = 0; | |
70e36ece | 534 | nr_commands = count / sizeof(struct sg_io_v4); |
3d6392cf JA |
535 | while (nr_commands) { |
536 | bc = get_bc(bd, iov); | |
537 | if (IS_ERR(bc)) { | |
538 | ret = PTR_ERR(bc); | |
539 | break; | |
540 | } | |
541 | ||
542 | /* | |
543 | * this is the only case where we need to copy data back | |
544 | * after completing the request. so do that here, | |
545 | * bsg_complete_work() cannot do that for us | |
546 | */ | |
70e36ece | 547 | ret = blk_complete_sgv4_hdr_rq(bc->rq, &bc->hdr, bc->bio); |
3d6392cf JA |
548 | |
549 | if (copy_to_user(buf, (char *) &bc->hdr, sizeof(bc->hdr))) | |
550 | ret = -EFAULT; | |
551 | ||
552 | bsg_free_command(bc); | |
553 | ||
554 | if (ret) | |
555 | break; | |
556 | ||
70e36ece FT |
557 | buf += sizeof(struct sg_io_v4); |
558 | *bytes_read += sizeof(struct sg_io_v4); | |
3d6392cf JA |
559 | nr_commands--; |
560 | } | |
561 | ||
562 | return ret; | |
563 | } | |
564 | ||
565 | static inline void bsg_set_block(struct bsg_device *bd, struct file *file) | |
566 | { | |
567 | if (file->f_flags & O_NONBLOCK) | |
568 | clear_bit(BSG_F_BLOCK, &bd->flags); | |
569 | else | |
570 | set_bit(BSG_F_BLOCK, &bd->flags); | |
571 | } | |
572 | ||
573 | static inline void bsg_set_write_perm(struct bsg_device *bd, struct file *file) | |
574 | { | |
575 | if (file->f_mode & FMODE_WRITE) | |
576 | set_bit(BSG_F_WRITE_PERM, &bd->flags); | |
577 | else | |
578 | clear_bit(BSG_F_WRITE_PERM, &bd->flags); | |
579 | } | |
580 | ||
581 | static inline int err_block_err(int ret) | |
582 | { | |
583 | if (ret && ret != -ENOSPC && ret != -ENODATA && ret != -EAGAIN) | |
584 | return 1; | |
585 | ||
586 | return 0; | |
587 | } | |
588 | ||
589 | static ssize_t | |
590 | bsg_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) | |
591 | { | |
592 | struct bsg_device *bd = file->private_data; | |
593 | int ret; | |
594 | ssize_t bytes_read; | |
595 | ||
9e69fbb5 | 596 | dprintk("%s: read %Zd bytes\n", bd->name, count); |
3d6392cf JA |
597 | |
598 | bsg_set_block(bd, file); | |
599 | bytes_read = 0; | |
600 | ret = __bsg_read(buf, count, bsg_get_done_cmd, | |
601 | bd, NULL, &bytes_read); | |
602 | *ppos = bytes_read; | |
603 | ||
604 | if (!bytes_read || (bytes_read && err_block_err(ret))) | |
605 | bytes_read = ret; | |
606 | ||
607 | return bytes_read; | |
608 | } | |
609 | ||
610 | static ssize_t __bsg_write(struct bsg_device *bd, const char __user *buf, | |
611 | size_t count, ssize_t *bytes_read) | |
612 | { | |
613 | struct bsg_command *bc; | |
614 | struct request *rq; | |
615 | int ret, nr_commands; | |
616 | ||
70e36ece | 617 | if (count % sizeof(struct sg_io_v4)) |
3d6392cf JA |
618 | return -EINVAL; |
619 | ||
70e36ece | 620 | nr_commands = count / sizeof(struct sg_io_v4); |
3d6392cf JA |
621 | rq = NULL; |
622 | bc = NULL; | |
623 | ret = 0; | |
624 | while (nr_commands) { | |
625 | request_queue_t *q = bd->queue; | |
3d6392cf JA |
626 | |
627 | bc = bsg_get_command(bd); | |
628 | if (!bc) | |
629 | break; | |
630 | if (IS_ERR(bc)) { | |
631 | ret = PTR_ERR(bc); | |
632 | bc = NULL; | |
633 | break; | |
634 | } | |
635 | ||
70e36ece | 636 | bc->uhdr = (struct sg_io_v4 __user *) buf; |
3d6392cf JA |
637 | if (copy_from_user(&bc->hdr, buf, sizeof(bc->hdr))) { |
638 | ret = -EFAULT; | |
639 | break; | |
640 | } | |
641 | ||
642 | /* | |
643 | * get a request, fill in the blanks, and add to request queue | |
644 | */ | |
70e36ece | 645 | rq = bsg_map_hdr(bd, &bc->hdr); |
3d6392cf JA |
646 | if (IS_ERR(rq)) { |
647 | ret = PTR_ERR(rq); | |
648 | rq = NULL; | |
649 | break; | |
650 | } | |
651 | ||
652 | bsg_add_command(bd, q, bc, rq); | |
653 | bc = NULL; | |
654 | rq = NULL; | |
655 | nr_commands--; | |
70e36ece FT |
656 | buf += sizeof(struct sg_io_v4); |
657 | *bytes_read += sizeof(struct sg_io_v4); | |
3d6392cf JA |
658 | } |
659 | ||
3d6392cf JA |
660 | if (bc) |
661 | bsg_free_command(bc); | |
662 | ||
663 | return ret; | |
664 | } | |
665 | ||
666 | static ssize_t | |
667 | bsg_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) | |
668 | { | |
669 | struct bsg_device *bd = file->private_data; | |
670 | ssize_t bytes_read; | |
671 | int ret; | |
672 | ||
9e69fbb5 | 673 | dprintk("%s: write %Zd bytes\n", bd->name, count); |
3d6392cf JA |
674 | |
675 | bsg_set_block(bd, file); | |
676 | bsg_set_write_perm(bd, file); | |
677 | ||
678 | bytes_read = 0; | |
679 | ret = __bsg_write(bd, buf, count, &bytes_read); | |
680 | *ppos = bytes_read; | |
681 | ||
682 | /* | |
683 | * return bytes written on non-fatal errors | |
684 | */ | |
685 | if (!bytes_read || (bytes_read && err_block_err(ret))) | |
686 | bytes_read = ret; | |
687 | ||
9e69fbb5 | 688 | dprintk("%s: returning %Zd\n", bd->name, bytes_read); |
3d6392cf JA |
689 | return bytes_read; |
690 | } | |
691 | ||
3d6392cf JA |
692 | static struct bsg_device *bsg_alloc_device(void) |
693 | { | |
3d6392cf | 694 | struct bsg_device *bd; |
3d6392cf JA |
695 | |
696 | bd = kzalloc(sizeof(struct bsg_device), GFP_KERNEL); | |
697 | if (unlikely(!bd)) | |
698 | return NULL; | |
699 | ||
700 | spin_lock_init(&bd->lock); | |
701 | ||
5309cb38 | 702 | bd->max_queue = BSG_DEFAULT_CMDS; |
3d6392cf JA |
703 | |
704 | INIT_LIST_HEAD(&bd->busy_list); | |
705 | INIT_LIST_HEAD(&bd->done_list); | |
706 | INIT_HLIST_NODE(&bd->dev_list); | |
707 | ||
708 | init_waitqueue_head(&bd->wq_free); | |
709 | init_waitqueue_head(&bd->wq_done); | |
710 | return bd; | |
3d6392cf JA |
711 | } |
712 | ||
713 | static int bsg_put_device(struct bsg_device *bd) | |
714 | { | |
715 | int ret = 0; | |
716 | ||
717 | mutex_lock(&bsg_mutex); | |
718 | ||
719 | if (!atomic_dec_and_test(&bd->ref_count)) | |
720 | goto out; | |
721 | ||
722 | dprintk("%s: tearing down\n", bd->name); | |
723 | ||
724 | /* | |
725 | * close can always block | |
726 | */ | |
727 | set_bit(BSG_F_BLOCK, &bd->flags); | |
728 | ||
729 | /* | |
730 | * correct error detection baddies here again. it's the responsibility | |
731 | * of the app to properly reap commands before close() if it wants | |
732 | * fool-proof error detection | |
733 | */ | |
734 | ret = bsg_complete_all_commands(bd); | |
735 | ||
736 | blk_put_queue(bd->queue); | |
737 | hlist_del(&bd->dev_list); | |
5309cb38 | 738 | kfree(bd); |
3d6392cf JA |
739 | out: |
740 | mutex_unlock(&bsg_mutex); | |
741 | return ret; | |
742 | } | |
743 | ||
744 | static struct bsg_device *bsg_add_device(struct inode *inode, | |
745 | struct gendisk *disk, | |
746 | struct file *file) | |
747 | { | |
748 | struct bsg_device *bd = NULL; | |
749 | #ifdef BSG_DEBUG | |
750 | unsigned char buf[32]; | |
751 | #endif | |
752 | ||
753 | bd = bsg_alloc_device(); | |
754 | if (!bd) | |
755 | return ERR_PTR(-ENOMEM); | |
756 | ||
757 | bd->disk = disk; | |
758 | bd->queue = disk->queue; | |
759 | kobject_get(&disk->queue->kobj); | |
760 | bsg_set_block(bd, file); | |
761 | ||
762 | atomic_set(&bd->ref_count, 1); | |
763 | bd->minor = iminor(inode); | |
764 | mutex_lock(&bsg_mutex); | |
765 | hlist_add_head(&bd->dev_list,&bsg_device_list[bsg_list_idx(bd->minor)]); | |
766 | ||
767 | strncpy(bd->name, disk->disk_name, sizeof(bd->name) - 1); | |
768 | dprintk("bound to <%s>, max queue %d\n", | |
9e69fbb5 | 769 | format_dev_t(buf, inode->i_rdev), bd->max_queue); |
3d6392cf JA |
770 | |
771 | mutex_unlock(&bsg_mutex); | |
772 | return bd; | |
773 | } | |
774 | ||
775 | static struct bsg_device *__bsg_get_device(int minor) | |
776 | { | |
777 | struct hlist_head *list = &bsg_device_list[bsg_list_idx(minor)]; | |
778 | struct bsg_device *bd = NULL; | |
779 | struct hlist_node *entry; | |
780 | ||
781 | mutex_lock(&bsg_mutex); | |
782 | ||
783 | hlist_for_each(entry, list) { | |
784 | bd = hlist_entry(entry, struct bsg_device, dev_list); | |
785 | if (bd->minor == minor) { | |
786 | atomic_inc(&bd->ref_count); | |
787 | break; | |
788 | } | |
789 | ||
790 | bd = NULL; | |
791 | } | |
792 | ||
793 | mutex_unlock(&bsg_mutex); | |
794 | return bd; | |
795 | } | |
796 | ||
797 | static struct bsg_device *bsg_get_device(struct inode *inode, struct file *file) | |
798 | { | |
799 | struct bsg_device *bd = __bsg_get_device(iminor(inode)); | |
800 | struct bsg_class_device *bcd, *__bcd; | |
801 | ||
802 | if (bd) | |
803 | return bd; | |
804 | ||
805 | /* | |
806 | * find the class device | |
807 | */ | |
808 | bcd = NULL; | |
809 | mutex_lock(&bsg_mutex); | |
810 | list_for_each_entry(__bcd, &bsg_class_list, list) { | |
811 | if (__bcd->minor == iminor(inode)) { | |
812 | bcd = __bcd; | |
813 | break; | |
814 | } | |
815 | } | |
816 | mutex_unlock(&bsg_mutex); | |
817 | ||
818 | if (!bcd) | |
819 | return ERR_PTR(-ENODEV); | |
820 | ||
821 | return bsg_add_device(inode, bcd->disk, file); | |
822 | } | |
823 | ||
824 | static int bsg_open(struct inode *inode, struct file *file) | |
825 | { | |
826 | struct bsg_device *bd = bsg_get_device(inode, file); | |
827 | ||
828 | if (IS_ERR(bd)) | |
829 | return PTR_ERR(bd); | |
830 | ||
831 | file->private_data = bd; | |
832 | return 0; | |
833 | } | |
834 | ||
835 | static int bsg_release(struct inode *inode, struct file *file) | |
836 | { | |
837 | struct bsg_device *bd = file->private_data; | |
838 | ||
839 | file->private_data = NULL; | |
840 | return bsg_put_device(bd); | |
841 | } | |
842 | ||
843 | static unsigned int bsg_poll(struct file *file, poll_table *wait) | |
844 | { | |
845 | struct bsg_device *bd = file->private_data; | |
846 | unsigned int mask = 0; | |
847 | ||
848 | poll_wait(file, &bd->wq_done, wait); | |
849 | poll_wait(file, &bd->wq_free, wait); | |
850 | ||
851 | spin_lock_irq(&bd->lock); | |
852 | if (!list_empty(&bd->done_list)) | |
853 | mask |= POLLIN | POLLRDNORM; | |
854 | if (bd->queued_cmds >= bd->max_queue) | |
855 | mask |= POLLOUT; | |
856 | spin_unlock_irq(&bd->lock); | |
857 | ||
858 | return mask; | |
859 | } | |
860 | ||
861 | static int | |
862 | bsg_ioctl(struct inode *inode, struct file *file, unsigned int cmd, | |
863 | unsigned long arg) | |
864 | { | |
865 | struct bsg_device *bd = file->private_data; | |
866 | int __user *uarg = (int __user *) arg; | |
867 | ||
868 | if (!bd) | |
869 | return -ENXIO; | |
870 | ||
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; | |
904 | return scsi_cmd_ioctl(file, bd->disk, cmd, uarg); | |
905 | } | |
10e8855b FT |
906 | case SG_IO: { |
907 | struct request *rq; | |
908 | struct bio *bio; | |
909 | struct sg_io_v4 hdr; | |
910 | ||
911 | if (copy_from_user(&hdr, uarg, sizeof(hdr))) | |
912 | return -EFAULT; | |
913 | ||
914 | rq = bsg_map_hdr(bd, &hdr); | |
915 | if (IS_ERR(rq)) | |
916 | return PTR_ERR(rq); | |
917 | ||
918 | bio = rq->bio; | |
919 | blk_execute_rq(bd->queue, bd->disk, rq, 0); | |
920 | blk_complete_sgv4_hdr_rq(rq, &hdr, bio); | |
921 | ||
922 | if (copy_to_user(uarg, &hdr, sizeof(hdr))) | |
923 | return -EFAULT; | |
b711afa6 JA |
924 | |
925 | return 0; | |
10e8855b | 926 | } |
3d6392cf JA |
927 | /* |
928 | * block device ioctls | |
929 | */ | |
930 | default: | |
931 | #if 0 | |
932 | return ioctl_by_bdev(bd->bdev, cmd, arg); | |
933 | #else | |
934 | return -ENOTTY; | |
935 | #endif | |
936 | } | |
937 | } | |
938 | ||
939 | static struct file_operations bsg_fops = { | |
940 | .read = bsg_read, | |
941 | .write = bsg_write, | |
942 | .poll = bsg_poll, | |
943 | .open = bsg_open, | |
944 | .release = bsg_release, | |
945 | .ioctl = bsg_ioctl, | |
946 | .owner = THIS_MODULE, | |
947 | }; | |
948 | ||
949 | void bsg_unregister_disk(struct gendisk *disk) | |
950 | { | |
951 | struct bsg_class_device *bcd = &disk->bsg_dev; | |
952 | ||
953 | if (!bcd->class_dev) | |
954 | return; | |
955 | ||
956 | mutex_lock(&bsg_mutex); | |
957 | sysfs_remove_link(&bcd->disk->queue->kobj, "bsg"); | |
958 | class_device_destroy(bsg_class, MKDEV(BSG_MAJOR, bcd->minor)); | |
959 | bcd->class_dev = NULL; | |
960 | list_del_init(&bcd->list); | |
961 | mutex_unlock(&bsg_mutex); | |
962 | } | |
963 | ||
964 | int bsg_register_disk(struct gendisk *disk) | |
965 | { | |
966 | request_queue_t *q = disk->queue; | |
967 | struct bsg_class_device *bcd; | |
968 | dev_t dev; | |
969 | ||
970 | /* | |
971 | * we need a proper transport to send commands, not a stacked device | |
972 | */ | |
973 | if (!q->request_fn) | |
974 | return 0; | |
975 | ||
976 | bcd = &disk->bsg_dev; | |
977 | memset(bcd, 0, sizeof(*bcd)); | |
978 | INIT_LIST_HEAD(&bcd->list); | |
979 | ||
980 | mutex_lock(&bsg_mutex); | |
981 | dev = MKDEV(BSG_MAJOR, bsg_device_nr); | |
982 | bcd->minor = bsg_device_nr; | |
983 | bsg_device_nr++; | |
984 | bcd->disk = disk; | |
985 | bcd->class_dev = class_device_create(bsg_class, NULL, dev, bcd->dev, "%s", disk->disk_name); | |
264a0472 JA |
986 | if (!bcd->class_dev) |
987 | goto err; | |
3d6392cf | 988 | list_add_tail(&bcd->list, &bsg_class_list); |
264a0472 JA |
989 | if (sysfs_create_link(&q->kobj, &bcd->class_dev->kobj, "bsg")) |
990 | goto err; | |
3d6392cf JA |
991 | mutex_unlock(&bsg_mutex); |
992 | return 0; | |
264a0472 JA |
993 | err: |
994 | bsg_device_nr--; | |
995 | if (bcd->class_dev) | |
996 | class_device_destroy(bsg_class, MKDEV(BSG_MAJOR, bcd->minor)); | |
997 | mutex_unlock(&bsg_mutex); | |
998 | return -ENOMEM; | |
3d6392cf JA |
999 | } |
1000 | ||
1001 | static int __init bsg_init(void) | |
1002 | { | |
1003 | int ret, i; | |
1004 | ||
5309cb38 JA |
1005 | bsg_cmd_cachep = kmem_cache_create("bsg_cmd", |
1006 | sizeof(struct bsg_command), 0, 0, NULL, NULL); | |
1007 | if (!bsg_cmd_cachep) { | |
1008 | printk(KERN_ERR "bsg: failed creating slab cache\n"); | |
1009 | return -ENOMEM; | |
1010 | } | |
1011 | ||
3d6392cf JA |
1012 | for (i = 0; i < BSG_LIST_SIZE; i++) |
1013 | INIT_HLIST_HEAD(&bsg_device_list[i]); | |
1014 | ||
1015 | bsg_class = class_create(THIS_MODULE, "bsg"); | |
5309cb38 JA |
1016 | if (IS_ERR(bsg_class)) { |
1017 | kmem_cache_destroy(bsg_cmd_cachep); | |
3d6392cf | 1018 | return PTR_ERR(bsg_class); |
5309cb38 | 1019 | } |
3d6392cf JA |
1020 | |
1021 | ret = register_chrdev(BSG_MAJOR, "bsg", &bsg_fops); | |
1022 | if (ret) { | |
5309cb38 | 1023 | kmem_cache_destroy(bsg_cmd_cachep); |
3d6392cf JA |
1024 | class_destroy(bsg_class); |
1025 | return ret; | |
1026 | } | |
1027 | ||
1028 | printk(KERN_INFO "%s loaded\n", bsg_version); | |
1029 | return 0; | |
1030 | } | |
1031 | ||
1032 | MODULE_AUTHOR("Jens Axboe"); | |
1033 | MODULE_DESCRIPTION("Block layer SGSI generic (sg) driver"); | |
1034 | MODULE_LICENSE("GPL"); | |
1035 | ||
1036 | subsys_initcall(bsg_init); |