Commit | Line | Data |
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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 | 36 | struct bsg_device { |
3d6392cf JA |
37 | request_queue_t *queue; |
38 | spinlock_t lock; | |
39 | struct list_head busy_list; | |
40 | struct list_head done_list; | |
41 | struct hlist_node dev_list; | |
42 | atomic_t ref_count; | |
43 | int minor; | |
44 | int queued_cmds; | |
45 | int done_cmds; | |
3d6392cf JA |
46 | wait_queue_head_t wq_done; |
47 | wait_queue_head_t wq_free; | |
d351af01 | 48 | char name[BUS_ID_SIZE]; |
3d6392cf JA |
49 | int max_queue; |
50 | unsigned long flags; | |
51 | }; | |
52 | ||
53 | enum { | |
54 | BSG_F_BLOCK = 1, | |
55 | BSG_F_WRITE_PERM = 2, | |
56 | }; | |
57 | ||
5309cb38 | 58 | #define BSG_DEFAULT_CMDS 64 |
3d6392cf JA |
59 | |
60 | #undef BSG_DEBUG | |
61 | ||
62 | #ifdef BSG_DEBUG | |
63 | #define dprintk(fmt, args...) printk(KERN_ERR "%s: " fmt, __FUNCTION__, ##args) | |
64 | #else | |
65 | #define dprintk(fmt, args...) | |
66 | #endif | |
67 | ||
68 | #define list_entry_bc(entry) list_entry((entry), struct bsg_command, list) | |
69 | ||
70 | /* | |
71 | * just for testing | |
72 | */ | |
73 | #define BSG_MAJOR (240) | |
74 | ||
75 | static DEFINE_MUTEX(bsg_mutex); | |
76 | static int bsg_device_nr; | |
77 | ||
78 | #define BSG_LIST_SIZE (8) | |
79 | #define bsg_list_idx(minor) ((minor) & (BSG_LIST_SIZE - 1)) | |
80 | static struct hlist_head bsg_device_list[BSG_LIST_SIZE]; | |
81 | ||
82 | static struct class *bsg_class; | |
83 | static LIST_HEAD(bsg_class_list); | |
84 | ||
5309cb38 JA |
85 | static struct kmem_cache *bsg_cmd_cachep; |
86 | ||
3d6392cf JA |
87 | /* |
88 | * our internal command type | |
89 | */ | |
90 | struct bsg_command { | |
91 | struct bsg_device *bd; | |
92 | struct list_head list; | |
93 | struct request *rq; | |
94 | struct bio *bio; | |
95 | int err; | |
70e36ece FT |
96 | struct sg_io_v4 hdr; |
97 | struct sg_io_v4 __user *uhdr; | |
3d6392cf JA |
98 | char sense[SCSI_SENSE_BUFFERSIZE]; |
99 | }; | |
100 | ||
101 | static void bsg_free_command(struct bsg_command *bc) | |
102 | { | |
103 | struct bsg_device *bd = bc->bd; | |
3d6392cf JA |
104 | unsigned long flags; |
105 | ||
5309cb38 | 106 | kmem_cache_free(bsg_cmd_cachep, bc); |
3d6392cf JA |
107 | |
108 | spin_lock_irqsave(&bd->lock, flags); | |
109 | bd->queued_cmds--; | |
3d6392cf JA |
110 | spin_unlock_irqrestore(&bd->lock, flags); |
111 | ||
112 | wake_up(&bd->wq_free); | |
113 | } | |
114 | ||
115 | static struct bsg_command *__bsg_alloc_command(struct bsg_device *bd) | |
116 | { | |
117 | struct bsg_command *bc = NULL; | |
3d6392cf JA |
118 | |
119 | spin_lock_irq(&bd->lock); | |
120 | ||
121 | if (bd->queued_cmds >= bd->max_queue) | |
122 | goto out; | |
123 | ||
3d6392cf | 124 | bd->queued_cmds++; |
3d6392cf JA |
125 | spin_unlock_irq(&bd->lock); |
126 | ||
5309cb38 JA |
127 | bc = kmem_cache_alloc(bsg_cmd_cachep, GFP_USER); |
128 | if (unlikely(!bc)) { | |
129 | spin_lock_irq(&bd->lock); | |
7e75d730 FT |
130 | bd->queued_cmds--; |
131 | goto out; | |
5309cb38 JA |
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 JA |
138 | return bc; |
139 | out: | |
3d6392cf JA |
140 | spin_unlock_irq(&bd->lock); |
141 | return bc; | |
142 | } | |
143 | ||
144 | static inline void | |
145 | bsg_del_done_cmd(struct bsg_device *bd, struct bsg_command *bc) | |
146 | { | |
147 | bd->done_cmds--; | |
148 | list_del(&bc->list); | |
149 | } | |
150 | ||
151 | static inline void | |
152 | bsg_add_done_cmd(struct bsg_device *bd, struct bsg_command *bc) | |
153 | { | |
154 | bd->done_cmds++; | |
155 | list_add_tail(&bc->list, &bd->done_list); | |
156 | wake_up(&bd->wq_done); | |
157 | } | |
158 | ||
159 | static inline int bsg_io_schedule(struct bsg_device *bd, int state) | |
160 | { | |
161 | DEFINE_WAIT(wait); | |
162 | int ret = 0; | |
163 | ||
164 | spin_lock_irq(&bd->lock); | |
165 | ||
166 | BUG_ON(bd->done_cmds > bd->queued_cmds); | |
167 | ||
168 | /* | |
169 | * -ENOSPC or -ENODATA? I'm going for -ENODATA, meaning "I have no | |
170 | * work to do", even though we return -ENOSPC after this same test | |
171 | * during bsg_write() -- there, it means our buffer can't have more | |
172 | * bsg_commands added to it, thus has no space left. | |
173 | */ | |
174 | if (bd->done_cmds == bd->queued_cmds) { | |
175 | ret = -ENODATA; | |
176 | goto unlock; | |
177 | } | |
178 | ||
179 | if (!test_bit(BSG_F_BLOCK, &bd->flags)) { | |
180 | ret = -EAGAIN; | |
181 | goto unlock; | |
182 | } | |
183 | ||
184 | prepare_to_wait(&bd->wq_done, &wait, state); | |
185 | spin_unlock_irq(&bd->lock); | |
186 | io_schedule(); | |
187 | finish_wait(&bd->wq_done, &wait); | |
188 | ||
189 | if ((state == TASK_INTERRUPTIBLE) && signal_pending(current)) | |
190 | ret = -ERESTARTSYS; | |
191 | ||
192 | return ret; | |
193 | unlock: | |
194 | spin_unlock_irq(&bd->lock); | |
195 | return ret; | |
196 | } | |
197 | ||
198 | /* | |
199 | * get a new free command, blocking if needed and specified | |
200 | */ | |
201 | static struct bsg_command *bsg_get_command(struct bsg_device *bd) | |
202 | { | |
203 | struct bsg_command *bc; | |
204 | int ret; | |
205 | ||
206 | do { | |
207 | bc = __bsg_alloc_command(bd); | |
208 | if (bc) | |
209 | break; | |
210 | ||
211 | ret = bsg_io_schedule(bd, TASK_INTERRUPTIBLE); | |
212 | if (ret) { | |
213 | bc = ERR_PTR(ret); | |
214 | break; | |
215 | } | |
216 | ||
217 | } while (1); | |
218 | ||
219 | return bc; | |
220 | } | |
221 | ||
70e36ece FT |
222 | static int blk_fill_sgv4_hdr_rq(request_queue_t *q, struct request *rq, |
223 | struct sg_io_v4 *hdr, int has_write_perm) | |
224 | { | |
225 | memset(rq->cmd, 0, BLK_MAX_CDB); /* ATAPI hates garbage after CDB */ | |
226 | ||
227 | if (copy_from_user(rq->cmd, (void *)(unsigned long)hdr->request, | |
228 | hdr->request_len)) | |
229 | return -EFAULT; | |
230 | if (blk_verify_command(rq->cmd, has_write_perm)) | |
231 | return -EPERM; | |
232 | ||
233 | /* | |
234 | * fill in request structure | |
235 | */ | |
236 | rq->cmd_len = hdr->request_len; | |
237 | rq->cmd_type = REQ_TYPE_BLOCK_PC; | |
238 | ||
239 | rq->timeout = (hdr->timeout * HZ) / 1000; | |
240 | if (!rq->timeout) | |
241 | rq->timeout = q->sg_timeout; | |
242 | if (!rq->timeout) | |
243 | rq->timeout = BLK_DEFAULT_SG_TIMEOUT; | |
244 | ||
245 | return 0; | |
246 | } | |
247 | ||
3d6392cf | 248 | /* |
70e36ece | 249 | * Check if sg_io_v4 from user is allowed and valid |
3d6392cf JA |
250 | */ |
251 | static int | |
70e36ece | 252 | bsg_validate_sgv4_hdr(request_queue_t *q, struct sg_io_v4 *hdr, int *rw) |
3d6392cf | 253 | { |
70e36ece | 254 | if (hdr->guard != 'Q') |
3d6392cf | 255 | return -EINVAL; |
70e36ece | 256 | if (hdr->request_len > BLK_MAX_CDB) |
3d6392cf | 257 | return -EINVAL; |
70e36ece FT |
258 | if (hdr->dout_xfer_len > (q->max_sectors << 9) || |
259 | hdr->din_xfer_len > (q->max_sectors << 9)) | |
3d6392cf JA |
260 | return -EIO; |
261 | ||
70e36ece FT |
262 | /* not supported currently */ |
263 | if (hdr->protocol || hdr->subprotocol) | |
264 | return -EINVAL; | |
265 | ||
3d6392cf JA |
266 | /* |
267 | * looks sane, if no data then it should be fine from our POV | |
268 | */ | |
70e36ece | 269 | if (!hdr->dout_xfer_len && !hdr->din_xfer_len) |
3d6392cf JA |
270 | return 0; |
271 | ||
70e36ece FT |
272 | /* not supported currently */ |
273 | if (hdr->dout_xfer_len && hdr->din_xfer_len) | |
274 | return -EINVAL; | |
275 | ||
276 | *rw = hdr->dout_xfer_len ? WRITE : READ; | |
3d6392cf JA |
277 | |
278 | return 0; | |
279 | } | |
280 | ||
281 | /* | |
70e36ece | 282 | * map sg_io_v4 to a request. |
3d6392cf JA |
283 | */ |
284 | static struct request * | |
70e36ece | 285 | bsg_map_hdr(struct bsg_device *bd, struct sg_io_v4 *hdr) |
3d6392cf JA |
286 | { |
287 | request_queue_t *q = bd->queue; | |
3d6392cf | 288 | struct request *rq; |
2ef7086a | 289 | int ret, rw = 0; /* shut up gcc */ |
70e36ece FT |
290 | unsigned int dxfer_len; |
291 | void *dxferp = NULL; | |
3d6392cf | 292 | |
70e36ece FT |
293 | dprintk("map hdr %llx/%u %llx/%u\n", (unsigned long long) hdr->dout_xferp, |
294 | hdr->dout_xfer_len, (unsigned long long) hdr->din_xferp, | |
295 | hdr->din_xfer_len); | |
3d6392cf | 296 | |
70e36ece | 297 | ret = bsg_validate_sgv4_hdr(q, hdr, &rw); |
3d6392cf JA |
298 | if (ret) |
299 | return ERR_PTR(ret); | |
300 | ||
301 | /* | |
302 | * map scatter-gather elements seperately and string them to request | |
303 | */ | |
304 | rq = blk_get_request(q, rw, GFP_KERNEL); | |
70e36ece FT |
305 | ret = blk_fill_sgv4_hdr_rq(q, rq, hdr, test_bit(BSG_F_WRITE_PERM, |
306 | &bd->flags)); | |
3d6392cf JA |
307 | if (ret) { |
308 | blk_put_request(rq); | |
309 | return ERR_PTR(ret); | |
310 | } | |
311 | ||
70e36ece FT |
312 | if (hdr->dout_xfer_len) { |
313 | dxfer_len = hdr->dout_xfer_len; | |
314 | dxferp = (void*)(unsigned long)hdr->dout_xferp; | |
315 | } else if (hdr->din_xfer_len) { | |
316 | dxfer_len = hdr->din_xfer_len; | |
317 | dxferp = (void*)(unsigned long)hdr->din_xferp; | |
318 | } else | |
319 | dxfer_len = 0; | |
320 | ||
321 | if (dxfer_len) { | |
322 | ret = blk_rq_map_user(q, rq, dxferp, dxfer_len); | |
323 | if (ret) { | |
324 | dprintk("failed map at %d\n", ret); | |
325 | blk_put_request(rq); | |
326 | rq = ERR_PTR(ret); | |
3d6392cf | 327 | } |
3d6392cf JA |
328 | } |
329 | ||
330 | return rq; | |
331 | } | |
332 | ||
333 | /* | |
334 | * async completion call-back from the block layer, when scsi/ide/whatever | |
335 | * calls end_that_request_last() on a request | |
336 | */ | |
337 | static void bsg_rq_end_io(struct request *rq, int uptodate) | |
338 | { | |
339 | struct bsg_command *bc = rq->end_io_data; | |
340 | struct bsg_device *bd = bc->bd; | |
341 | unsigned long flags; | |
342 | ||
5309cb38 JA |
343 | dprintk("%s: finished rq %p bc %p, bio %p stat %d\n", |
344 | bd->name, rq, bc, bc->bio, uptodate); | |
3d6392cf JA |
345 | |
346 | bc->hdr.duration = jiffies_to_msecs(jiffies - bc->hdr.duration); | |
347 | ||
348 | spin_lock_irqsave(&bd->lock, flags); | |
349 | list_del(&bc->list); | |
350 | bsg_add_done_cmd(bd, bc); | |
351 | spin_unlock_irqrestore(&bd->lock, flags); | |
352 | } | |
353 | ||
354 | /* | |
355 | * do final setup of a 'bc' and submit the matching 'rq' to the block | |
356 | * layer for io | |
357 | */ | |
358 | static void bsg_add_command(struct bsg_device *bd, request_queue_t *q, | |
359 | struct bsg_command *bc, struct request *rq) | |
360 | { | |
361 | rq->sense = bc->sense; | |
362 | rq->sense_len = 0; | |
363 | ||
364 | /* | |
365 | * add bc command to busy queue and submit rq for io | |
366 | */ | |
367 | bc->rq = rq; | |
368 | bc->bio = rq->bio; | |
369 | bc->hdr.duration = jiffies; | |
370 | spin_lock_irq(&bd->lock); | |
371 | list_add_tail(&bc->list, &bd->busy_list); | |
372 | spin_unlock_irq(&bd->lock); | |
373 | ||
374 | dprintk("%s: queueing rq %p, bc %p\n", bd->name, rq, bc); | |
375 | ||
376 | rq->end_io_data = bc; | |
d351af01 | 377 | blk_execute_rq_nowait(q, NULL, rq, 1, bsg_rq_end_io); |
3d6392cf JA |
378 | } |
379 | ||
380 | static inline struct bsg_command *bsg_next_done_cmd(struct bsg_device *bd) | |
381 | { | |
382 | struct bsg_command *bc = NULL; | |
383 | ||
384 | spin_lock_irq(&bd->lock); | |
385 | if (bd->done_cmds) { | |
386 | bc = list_entry_bc(bd->done_list.next); | |
387 | bsg_del_done_cmd(bd, bc); | |
388 | } | |
389 | spin_unlock_irq(&bd->lock); | |
390 | ||
391 | return bc; | |
392 | } | |
393 | ||
394 | /* | |
395 | * Get a finished command from the done list | |
396 | */ | |
397 | static struct bsg_command *__bsg_get_done_cmd(struct bsg_device *bd, int state) | |
398 | { | |
399 | struct bsg_command *bc; | |
400 | int ret; | |
401 | ||
402 | do { | |
403 | bc = bsg_next_done_cmd(bd); | |
404 | if (bc) | |
405 | break; | |
406 | ||
407 | ret = bsg_io_schedule(bd, state); | |
408 | if (ret) { | |
409 | bc = ERR_PTR(ret); | |
410 | break; | |
411 | } | |
412 | } while (1); | |
413 | ||
414 | dprintk("%s: returning done %p\n", bd->name, bc); | |
415 | ||
416 | return bc; | |
417 | } | |
418 | ||
419 | static struct bsg_command * | |
420 | bsg_get_done_cmd(struct bsg_device *bd, const struct iovec *iov) | |
421 | { | |
422 | return __bsg_get_done_cmd(bd, TASK_INTERRUPTIBLE); | |
423 | } | |
424 | ||
425 | static struct bsg_command * | |
426 | bsg_get_done_cmd_nosignals(struct bsg_device *bd) | |
427 | { | |
428 | return __bsg_get_done_cmd(bd, TASK_UNINTERRUPTIBLE); | |
429 | } | |
430 | ||
70e36ece FT |
431 | static int blk_complete_sgv4_hdr_rq(struct request *rq, struct sg_io_v4 *hdr, |
432 | struct bio *bio) | |
433 | { | |
434 | int ret = 0; | |
435 | ||
436 | dprintk("rq %p bio %p %u\n", rq, bio, rq->errors); | |
437 | /* | |
438 | * fill in all the output members | |
439 | */ | |
440 | hdr->device_status = status_byte(rq->errors); | |
441 | hdr->transport_status = host_byte(rq->errors); | |
442 | hdr->driver_status = driver_byte(rq->errors); | |
443 | hdr->info = 0; | |
444 | if (hdr->device_status || hdr->transport_status || hdr->driver_status) | |
445 | hdr->info |= SG_INFO_CHECK; | |
446 | hdr->din_resid = rq->data_len; | |
447 | hdr->response_len = 0; | |
448 | ||
449 | if (rq->sense_len && hdr->response) { | |
450 | int len = min((unsigned int) hdr->max_response_len, | |
451 | rq->sense_len); | |
452 | ||
453 | ret = copy_to_user((void*)(unsigned long)hdr->response, | |
454 | rq->sense, len); | |
455 | if (!ret) | |
456 | hdr->response_len = len; | |
457 | else | |
458 | ret = -EFAULT; | |
459 | } | |
460 | ||
461 | blk_rq_unmap_user(bio); | |
462 | blk_put_request(rq); | |
463 | ||
464 | return ret; | |
465 | } | |
466 | ||
3d6392cf JA |
467 | static int bsg_complete_all_commands(struct bsg_device *bd) |
468 | { | |
469 | struct bsg_command *bc; | |
470 | int ret, tret; | |
471 | ||
472 | dprintk("%s: entered\n", bd->name); | |
473 | ||
474 | set_bit(BSG_F_BLOCK, &bd->flags); | |
475 | ||
476 | /* | |
477 | * wait for all commands to complete | |
478 | */ | |
479 | ret = 0; | |
480 | do { | |
481 | ret = bsg_io_schedule(bd, TASK_UNINTERRUPTIBLE); | |
482 | /* | |
483 | * look for -ENODATA specifically -- we'll sometimes get | |
484 | * -ERESTARTSYS when we've taken a signal, but we can't | |
485 | * return until we're done freeing the queue, so ignore | |
486 | * it. The signal will get handled when we're done freeing | |
487 | * the bsg_device. | |
488 | */ | |
489 | } while (ret != -ENODATA); | |
490 | ||
491 | /* | |
492 | * discard done commands | |
493 | */ | |
494 | ret = 0; | |
495 | do { | |
496 | bc = bsg_get_done_cmd_nosignals(bd); | |
497 | ||
498 | /* | |
499 | * we _must_ complete before restarting, because | |
500 | * bsg_release can't handle this failing. | |
501 | */ | |
502 | if (PTR_ERR(bc) == -ERESTARTSYS) | |
503 | continue; | |
504 | if (IS_ERR(bc)) { | |
505 | ret = PTR_ERR(bc); | |
506 | break; | |
507 | } | |
508 | ||
70e36ece | 509 | tret = blk_complete_sgv4_hdr_rq(bc->rq, &bc->hdr, bc->bio); |
3d6392cf JA |
510 | if (!ret) |
511 | ret = tret; | |
512 | ||
513 | bsg_free_command(bc); | |
514 | } while (1); | |
515 | ||
516 | return ret; | |
517 | } | |
518 | ||
519 | typedef struct bsg_command *(*bsg_command_callback)(struct bsg_device *bd, const struct iovec *iov); | |
520 | ||
521 | static ssize_t | |
522 | __bsg_read(char __user *buf, size_t count, bsg_command_callback get_bc, | |
523 | struct bsg_device *bd, const struct iovec *iov, ssize_t *bytes_read) | |
524 | { | |
525 | struct bsg_command *bc; | |
526 | int nr_commands, ret; | |
527 | ||
70e36ece | 528 | if (count % sizeof(struct sg_io_v4)) |
3d6392cf JA |
529 | return -EINVAL; |
530 | ||
531 | ret = 0; | |
70e36ece | 532 | nr_commands = count / sizeof(struct sg_io_v4); |
3d6392cf JA |
533 | while (nr_commands) { |
534 | bc = get_bc(bd, iov); | |
535 | if (IS_ERR(bc)) { | |
536 | ret = PTR_ERR(bc); | |
537 | break; | |
538 | } | |
539 | ||
540 | /* | |
541 | * this is the only case where we need to copy data back | |
542 | * after completing the request. so do that here, | |
543 | * bsg_complete_work() cannot do that for us | |
544 | */ | |
70e36ece | 545 | ret = blk_complete_sgv4_hdr_rq(bc->rq, &bc->hdr, bc->bio); |
3d6392cf JA |
546 | |
547 | if (copy_to_user(buf, (char *) &bc->hdr, sizeof(bc->hdr))) | |
548 | ret = -EFAULT; | |
549 | ||
550 | bsg_free_command(bc); | |
551 | ||
552 | if (ret) | |
553 | break; | |
554 | ||
70e36ece FT |
555 | buf += sizeof(struct sg_io_v4); |
556 | *bytes_read += sizeof(struct sg_io_v4); | |
3d6392cf JA |
557 | nr_commands--; |
558 | } | |
559 | ||
560 | return ret; | |
561 | } | |
562 | ||
563 | static inline void bsg_set_block(struct bsg_device *bd, struct file *file) | |
564 | { | |
565 | if (file->f_flags & O_NONBLOCK) | |
566 | clear_bit(BSG_F_BLOCK, &bd->flags); | |
567 | else | |
568 | set_bit(BSG_F_BLOCK, &bd->flags); | |
569 | } | |
570 | ||
571 | static inline void bsg_set_write_perm(struct bsg_device *bd, struct file *file) | |
572 | { | |
573 | if (file->f_mode & FMODE_WRITE) | |
574 | set_bit(BSG_F_WRITE_PERM, &bd->flags); | |
575 | else | |
576 | clear_bit(BSG_F_WRITE_PERM, &bd->flags); | |
577 | } | |
578 | ||
579 | static inline int err_block_err(int ret) | |
580 | { | |
581 | if (ret && ret != -ENOSPC && ret != -ENODATA && ret != -EAGAIN) | |
582 | return 1; | |
583 | ||
584 | return 0; | |
585 | } | |
586 | ||
587 | static ssize_t | |
588 | bsg_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) | |
589 | { | |
590 | struct bsg_device *bd = file->private_data; | |
591 | int ret; | |
592 | ssize_t bytes_read; | |
593 | ||
9e69fbb5 | 594 | dprintk("%s: read %Zd bytes\n", bd->name, count); |
3d6392cf JA |
595 | |
596 | bsg_set_block(bd, file); | |
597 | bytes_read = 0; | |
598 | ret = __bsg_read(buf, count, bsg_get_done_cmd, | |
599 | bd, NULL, &bytes_read); | |
600 | *ppos = bytes_read; | |
601 | ||
602 | if (!bytes_read || (bytes_read && err_block_err(ret))) | |
603 | bytes_read = ret; | |
604 | ||
605 | return bytes_read; | |
606 | } | |
607 | ||
608 | static ssize_t __bsg_write(struct bsg_device *bd, const char __user *buf, | |
609 | size_t count, ssize_t *bytes_read) | |
610 | { | |
611 | struct bsg_command *bc; | |
612 | struct request *rq; | |
613 | int ret, nr_commands; | |
614 | ||
70e36ece | 615 | if (count % sizeof(struct sg_io_v4)) |
3d6392cf JA |
616 | return -EINVAL; |
617 | ||
70e36ece | 618 | nr_commands = count / sizeof(struct sg_io_v4); |
3d6392cf JA |
619 | rq = NULL; |
620 | bc = NULL; | |
621 | ret = 0; | |
622 | while (nr_commands) { | |
623 | request_queue_t *q = bd->queue; | |
3d6392cf JA |
624 | |
625 | bc = bsg_get_command(bd); | |
626 | if (!bc) | |
627 | break; | |
628 | if (IS_ERR(bc)) { | |
629 | ret = PTR_ERR(bc); | |
630 | bc = NULL; | |
631 | break; | |
632 | } | |
633 | ||
70e36ece | 634 | bc->uhdr = (struct sg_io_v4 __user *) buf; |
3d6392cf JA |
635 | if (copy_from_user(&bc->hdr, buf, sizeof(bc->hdr))) { |
636 | ret = -EFAULT; | |
637 | break; | |
638 | } | |
639 | ||
640 | /* | |
641 | * get a request, fill in the blanks, and add to request queue | |
642 | */ | |
70e36ece | 643 | rq = bsg_map_hdr(bd, &bc->hdr); |
3d6392cf JA |
644 | if (IS_ERR(rq)) { |
645 | ret = PTR_ERR(rq); | |
646 | rq = NULL; | |
647 | break; | |
648 | } | |
649 | ||
650 | bsg_add_command(bd, q, bc, rq); | |
651 | bc = NULL; | |
652 | rq = NULL; | |
653 | nr_commands--; | |
70e36ece FT |
654 | buf += sizeof(struct sg_io_v4); |
655 | *bytes_read += sizeof(struct sg_io_v4); | |
3d6392cf JA |
656 | } |
657 | ||
3d6392cf JA |
658 | if (bc) |
659 | bsg_free_command(bc); | |
660 | ||
661 | return ret; | |
662 | } | |
663 | ||
664 | static ssize_t | |
665 | bsg_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) | |
666 | { | |
667 | struct bsg_device *bd = file->private_data; | |
668 | ssize_t bytes_read; | |
669 | int ret; | |
670 | ||
9e69fbb5 | 671 | dprintk("%s: write %Zd bytes\n", bd->name, count); |
3d6392cf JA |
672 | |
673 | bsg_set_block(bd, file); | |
674 | bsg_set_write_perm(bd, file); | |
675 | ||
676 | bytes_read = 0; | |
677 | ret = __bsg_write(bd, buf, count, &bytes_read); | |
678 | *ppos = bytes_read; | |
679 | ||
680 | /* | |
681 | * return bytes written on non-fatal errors | |
682 | */ | |
683 | if (!bytes_read || (bytes_read && err_block_err(ret))) | |
684 | bytes_read = ret; | |
685 | ||
9e69fbb5 | 686 | dprintk("%s: returning %Zd\n", bd->name, bytes_read); |
3d6392cf JA |
687 | return bytes_read; |
688 | } | |
689 | ||
3d6392cf JA |
690 | static struct bsg_device *bsg_alloc_device(void) |
691 | { | |
3d6392cf | 692 | struct bsg_device *bd; |
3d6392cf JA |
693 | |
694 | bd = kzalloc(sizeof(struct bsg_device), GFP_KERNEL); | |
695 | if (unlikely(!bd)) | |
696 | return NULL; | |
697 | ||
698 | spin_lock_init(&bd->lock); | |
699 | ||
5309cb38 | 700 | bd->max_queue = BSG_DEFAULT_CMDS; |
3d6392cf JA |
701 | |
702 | INIT_LIST_HEAD(&bd->busy_list); | |
703 | INIT_LIST_HEAD(&bd->done_list); | |
704 | INIT_HLIST_NODE(&bd->dev_list); | |
705 | ||
706 | init_waitqueue_head(&bd->wq_free); | |
707 | init_waitqueue_head(&bd->wq_done); | |
708 | return bd; | |
3d6392cf JA |
709 | } |
710 | ||
711 | static int bsg_put_device(struct bsg_device *bd) | |
712 | { | |
713 | int ret = 0; | |
714 | ||
715 | mutex_lock(&bsg_mutex); | |
716 | ||
717 | if (!atomic_dec_and_test(&bd->ref_count)) | |
718 | goto out; | |
719 | ||
720 | dprintk("%s: tearing down\n", bd->name); | |
721 | ||
722 | /* | |
723 | * close can always block | |
724 | */ | |
725 | set_bit(BSG_F_BLOCK, &bd->flags); | |
726 | ||
727 | /* | |
728 | * correct error detection baddies here again. it's the responsibility | |
729 | * of the app to properly reap commands before close() if it wants | |
730 | * fool-proof error detection | |
731 | */ | |
732 | ret = bsg_complete_all_commands(bd); | |
733 | ||
734 | blk_put_queue(bd->queue); | |
735 | hlist_del(&bd->dev_list); | |
5309cb38 | 736 | kfree(bd); |
3d6392cf JA |
737 | out: |
738 | mutex_unlock(&bsg_mutex); | |
739 | return ret; | |
740 | } | |
741 | ||
742 | static struct bsg_device *bsg_add_device(struct inode *inode, | |
d351af01 | 743 | struct request_queue *rq, |
3d6392cf JA |
744 | struct file *file) |
745 | { | |
746 | struct bsg_device *bd = NULL; | |
747 | #ifdef BSG_DEBUG | |
748 | unsigned char buf[32]; | |
749 | #endif | |
750 | ||
751 | bd = bsg_alloc_device(); | |
752 | if (!bd) | |
753 | return ERR_PTR(-ENOMEM); | |
754 | ||
d351af01 FT |
755 | bd->queue = rq; |
756 | kobject_get(&rq->kobj); | |
3d6392cf JA |
757 | bsg_set_block(bd, file); |
758 | ||
759 | atomic_set(&bd->ref_count, 1); | |
760 | bd->minor = iminor(inode); | |
761 | mutex_lock(&bsg_mutex); | |
d351af01 | 762 | hlist_add_head(&bd->dev_list, &bsg_device_list[bsg_list_idx(bd->minor)]); |
3d6392cf | 763 | |
d351af01 | 764 | strncpy(bd->name, rq->bsg_dev.class_dev->class_id, sizeof(bd->name) - 1); |
3d6392cf | 765 | dprintk("bound to <%s>, max queue %d\n", |
9e69fbb5 | 766 | format_dev_t(buf, inode->i_rdev), bd->max_queue); |
3d6392cf JA |
767 | |
768 | mutex_unlock(&bsg_mutex); | |
769 | return bd; | |
770 | } | |
771 | ||
772 | static struct bsg_device *__bsg_get_device(int minor) | |
773 | { | |
774 | struct hlist_head *list = &bsg_device_list[bsg_list_idx(minor)]; | |
775 | struct bsg_device *bd = NULL; | |
776 | struct hlist_node *entry; | |
777 | ||
778 | mutex_lock(&bsg_mutex); | |
779 | ||
780 | hlist_for_each(entry, list) { | |
781 | bd = hlist_entry(entry, struct bsg_device, dev_list); | |
782 | if (bd->minor == minor) { | |
783 | atomic_inc(&bd->ref_count); | |
784 | break; | |
785 | } | |
786 | ||
787 | bd = NULL; | |
788 | } | |
789 | ||
790 | mutex_unlock(&bsg_mutex); | |
791 | return bd; | |
792 | } | |
793 | ||
794 | static struct bsg_device *bsg_get_device(struct inode *inode, struct file *file) | |
795 | { | |
796 | struct bsg_device *bd = __bsg_get_device(iminor(inode)); | |
797 | struct bsg_class_device *bcd, *__bcd; | |
798 | ||
799 | if (bd) | |
800 | return bd; | |
801 | ||
802 | /* | |
803 | * find the class device | |
804 | */ | |
805 | bcd = NULL; | |
806 | mutex_lock(&bsg_mutex); | |
807 | list_for_each_entry(__bcd, &bsg_class_list, list) { | |
808 | if (__bcd->minor == iminor(inode)) { | |
809 | bcd = __bcd; | |
810 | break; | |
811 | } | |
812 | } | |
813 | mutex_unlock(&bsg_mutex); | |
814 | ||
815 | if (!bcd) | |
816 | return ERR_PTR(-ENODEV); | |
817 | ||
d351af01 | 818 | return bsg_add_device(inode, bcd->queue, file); |
3d6392cf JA |
819 | } |
820 | ||
821 | static int bsg_open(struct inode *inode, struct file *file) | |
822 | { | |
823 | struct bsg_device *bd = bsg_get_device(inode, file); | |
824 | ||
825 | if (IS_ERR(bd)) | |
826 | return PTR_ERR(bd); | |
827 | ||
828 | file->private_data = bd; | |
829 | return 0; | |
830 | } | |
831 | ||
832 | static int bsg_release(struct inode *inode, struct file *file) | |
833 | { | |
834 | struct bsg_device *bd = file->private_data; | |
835 | ||
836 | file->private_data = NULL; | |
837 | return bsg_put_device(bd); | |
838 | } | |
839 | ||
840 | static unsigned int bsg_poll(struct file *file, poll_table *wait) | |
841 | { | |
842 | struct bsg_device *bd = file->private_data; | |
843 | unsigned int mask = 0; | |
844 | ||
845 | poll_wait(file, &bd->wq_done, wait); | |
846 | poll_wait(file, &bd->wq_free, wait); | |
847 | ||
848 | spin_lock_irq(&bd->lock); | |
849 | if (!list_empty(&bd->done_list)) | |
850 | mask |= POLLIN | POLLRDNORM; | |
851 | if (bd->queued_cmds >= bd->max_queue) | |
852 | mask |= POLLOUT; | |
853 | spin_unlock_irq(&bd->lock); | |
854 | ||
855 | return mask; | |
856 | } | |
857 | ||
858 | static int | |
859 | bsg_ioctl(struct inode *inode, struct file *file, unsigned int cmd, | |
860 | unsigned long arg) | |
861 | { | |
862 | struct bsg_device *bd = file->private_data; | |
863 | int __user *uarg = (int __user *) arg; | |
864 | ||
865 | if (!bd) | |
866 | return -ENXIO; | |
867 | ||
868 | switch (cmd) { | |
869 | /* | |
870 | * our own ioctls | |
871 | */ | |
872 | case SG_GET_COMMAND_Q: | |
873 | return put_user(bd->max_queue, uarg); | |
5309cb38 | 874 | case SG_SET_COMMAND_Q: { |
3d6392cf JA |
875 | int queue; |
876 | ||
877 | if (get_user(queue, uarg)) | |
878 | return -EFAULT; | |
5309cb38 | 879 | if (queue < 1) |
3d6392cf JA |
880 | return -EINVAL; |
881 | ||
5309cb38 | 882 | spin_lock_irq(&bd->lock); |
3d6392cf | 883 | bd->max_queue = queue; |
5309cb38 | 884 | spin_unlock_irq(&bd->lock); |
3d6392cf JA |
885 | return 0; |
886 | } | |
887 | ||
888 | /* | |
889 | * SCSI/sg ioctls | |
890 | */ | |
891 | case SG_GET_VERSION_NUM: | |
892 | case SCSI_IOCTL_GET_IDLUN: | |
893 | case SCSI_IOCTL_GET_BUS_NUMBER: | |
894 | case SG_SET_TIMEOUT: | |
895 | case SG_GET_TIMEOUT: | |
896 | case SG_GET_RESERVED_SIZE: | |
897 | case SG_SET_RESERVED_SIZE: | |
898 | case SG_EMULATED_HOST: | |
3d6392cf JA |
899 | case SCSI_IOCTL_SEND_COMMAND: { |
900 | void __user *uarg = (void __user *) arg; | |
d351af01 | 901 | return scsi_cmd_ioctl(file, bd->queue, NULL, cmd, uarg); |
3d6392cf | 902 | } |
10e8855b FT |
903 | case SG_IO: { |
904 | struct request *rq; | |
905 | struct bio *bio; | |
906 | struct sg_io_v4 hdr; | |
907 | ||
908 | if (copy_from_user(&hdr, uarg, sizeof(hdr))) | |
909 | return -EFAULT; | |
910 | ||
911 | rq = bsg_map_hdr(bd, &hdr); | |
912 | if (IS_ERR(rq)) | |
913 | return PTR_ERR(rq); | |
914 | ||
915 | bio = rq->bio; | |
d351af01 | 916 | blk_execute_rq(bd->queue, NULL, rq, 0); |
10e8855b FT |
917 | blk_complete_sgv4_hdr_rq(rq, &hdr, bio); |
918 | ||
919 | if (copy_to_user(uarg, &hdr, sizeof(hdr))) | |
920 | return -EFAULT; | |
b711afa6 JA |
921 | |
922 | return 0; | |
10e8855b | 923 | } |
3d6392cf JA |
924 | /* |
925 | * block device ioctls | |
926 | */ | |
927 | default: | |
928 | #if 0 | |
929 | return ioctl_by_bdev(bd->bdev, cmd, arg); | |
930 | #else | |
931 | return -ENOTTY; | |
932 | #endif | |
933 | } | |
934 | } | |
935 | ||
936 | static struct file_operations bsg_fops = { | |
937 | .read = bsg_read, | |
938 | .write = bsg_write, | |
939 | .poll = bsg_poll, | |
940 | .open = bsg_open, | |
941 | .release = bsg_release, | |
942 | .ioctl = bsg_ioctl, | |
943 | .owner = THIS_MODULE, | |
944 | }; | |
945 | ||
d351af01 | 946 | void bsg_unregister_queue(struct request_queue *q) |
3d6392cf | 947 | { |
d351af01 | 948 | struct bsg_class_device *bcd = &q->bsg_dev; |
3d6392cf JA |
949 | |
950 | if (!bcd->class_dev) | |
951 | return; | |
952 | ||
953 | mutex_lock(&bsg_mutex); | |
d351af01 | 954 | sysfs_remove_link(&q->kobj, "bsg"); |
3d6392cf JA |
955 | class_device_destroy(bsg_class, MKDEV(BSG_MAJOR, bcd->minor)); |
956 | bcd->class_dev = NULL; | |
957 | list_del_init(&bcd->list); | |
958 | mutex_unlock(&bsg_mutex); | |
959 | } | |
960 | ||
d351af01 | 961 | int bsg_register_queue(struct request_queue *q, char *name) |
3d6392cf | 962 | { |
3d6392cf JA |
963 | struct bsg_class_device *bcd; |
964 | dev_t dev; | |
965 | ||
966 | /* | |
967 | * we need a proper transport to send commands, not a stacked device | |
968 | */ | |
969 | if (!q->request_fn) | |
970 | return 0; | |
971 | ||
d351af01 | 972 | bcd = &q->bsg_dev; |
3d6392cf JA |
973 | memset(bcd, 0, sizeof(*bcd)); |
974 | INIT_LIST_HEAD(&bcd->list); | |
975 | ||
976 | mutex_lock(&bsg_mutex); | |
977 | dev = MKDEV(BSG_MAJOR, bsg_device_nr); | |
978 | bcd->minor = bsg_device_nr; | |
979 | bsg_device_nr++; | |
d351af01 FT |
980 | bcd->queue = q; |
981 | bcd->class_dev = class_device_create(bsg_class, NULL, dev, bcd->dev, "%s", name); | |
264a0472 JA |
982 | if (!bcd->class_dev) |
983 | goto err; | |
3d6392cf | 984 | list_add_tail(&bcd->list, &bsg_class_list); |
264a0472 JA |
985 | if (sysfs_create_link(&q->kobj, &bcd->class_dev->kobj, "bsg")) |
986 | goto err; | |
3d6392cf JA |
987 | mutex_unlock(&bsg_mutex); |
988 | return 0; | |
264a0472 JA |
989 | err: |
990 | bsg_device_nr--; | |
991 | if (bcd->class_dev) | |
992 | class_device_destroy(bsg_class, MKDEV(BSG_MAJOR, bcd->minor)); | |
993 | mutex_unlock(&bsg_mutex); | |
994 | return -ENOMEM; | |
3d6392cf JA |
995 | } |
996 | ||
997 | static int __init bsg_init(void) | |
998 | { | |
999 | int ret, i; | |
1000 | ||
5309cb38 JA |
1001 | bsg_cmd_cachep = kmem_cache_create("bsg_cmd", |
1002 | sizeof(struct bsg_command), 0, 0, NULL, NULL); | |
1003 | if (!bsg_cmd_cachep) { | |
1004 | printk(KERN_ERR "bsg: failed creating slab cache\n"); | |
1005 | return -ENOMEM; | |
1006 | } | |
1007 | ||
3d6392cf JA |
1008 | for (i = 0; i < BSG_LIST_SIZE; i++) |
1009 | INIT_HLIST_HEAD(&bsg_device_list[i]); | |
1010 | ||
1011 | bsg_class = class_create(THIS_MODULE, "bsg"); | |
5309cb38 JA |
1012 | if (IS_ERR(bsg_class)) { |
1013 | kmem_cache_destroy(bsg_cmd_cachep); | |
3d6392cf | 1014 | return PTR_ERR(bsg_class); |
5309cb38 | 1015 | } |
3d6392cf JA |
1016 | |
1017 | ret = register_chrdev(BSG_MAJOR, "bsg", &bsg_fops); | |
1018 | if (ret) { | |
5309cb38 | 1019 | kmem_cache_destroy(bsg_cmd_cachep); |
3d6392cf JA |
1020 | class_destroy(bsg_class); |
1021 | return ret; | |
1022 | } | |
1023 | ||
1024 | printk(KERN_INFO "%s loaded\n", bsg_version); | |
1025 | return 0; | |
1026 | } | |
1027 | ||
1028 | MODULE_AUTHOR("Jens Axboe"); | |
1029 | MODULE_DESCRIPTION("Block layer SGSI generic (sg) driver"); | |
1030 | MODULE_LICENSE("GPL"); | |
1031 | ||
1032 | subsys_initcall(bsg_init); |