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 | ||
36 | struct bsg_command; | |
37 | ||
38 | struct bsg_device { | |
39 | struct gendisk *disk; | |
40 | request_queue_t *queue; | |
41 | spinlock_t lock; | |
42 | struct list_head busy_list; | |
43 | struct list_head done_list; | |
44 | struct hlist_node dev_list; | |
45 | atomic_t ref_count; | |
46 | int minor; | |
47 | int queued_cmds; | |
48 | int done_cmds; | |
49 | unsigned long *cmd_bitmap; | |
50 | struct bsg_command *cmd_map; | |
51 | wait_queue_head_t wq_done; | |
52 | wait_queue_head_t wq_free; | |
53 | char name[BDEVNAME_SIZE]; | |
54 | int max_queue; | |
55 | unsigned long flags; | |
56 | }; | |
57 | ||
58 | enum { | |
59 | BSG_F_BLOCK = 1, | |
60 | BSG_F_WRITE_PERM = 2, | |
61 | }; | |
62 | ||
63 | /* | |
64 | * command allocation bitmap defines | |
65 | */ | |
66 | #define BSG_CMDS_PAGE_ORDER (1) | |
67 | #define BSG_CMDS_PER_LONG (sizeof(unsigned long) * 8) | |
68 | #define BSG_CMDS_MASK (BSG_CMDS_PER_LONG - 1) | |
69 | #define BSG_CMDS_BYTES (PAGE_SIZE * (1 << BSG_CMDS_PAGE_ORDER)) | |
70 | #define BSG_CMDS (BSG_CMDS_BYTES / sizeof(struct bsg_command)) | |
71 | ||
72 | #undef BSG_DEBUG | |
73 | ||
74 | #ifdef BSG_DEBUG | |
75 | #define dprintk(fmt, args...) printk(KERN_ERR "%s: " fmt, __FUNCTION__, ##args) | |
76 | #else | |
77 | #define dprintk(fmt, args...) | |
78 | #endif | |
79 | ||
80 | #define list_entry_bc(entry) list_entry((entry), struct bsg_command, list) | |
81 | ||
82 | /* | |
83 | * just for testing | |
84 | */ | |
85 | #define BSG_MAJOR (240) | |
86 | ||
87 | static DEFINE_MUTEX(bsg_mutex); | |
88 | static int bsg_device_nr; | |
89 | ||
90 | #define BSG_LIST_SIZE (8) | |
91 | #define bsg_list_idx(minor) ((minor) & (BSG_LIST_SIZE - 1)) | |
92 | static struct hlist_head bsg_device_list[BSG_LIST_SIZE]; | |
93 | ||
94 | static struct class *bsg_class; | |
95 | static LIST_HEAD(bsg_class_list); | |
96 | ||
97 | /* | |
98 | * our internal command type | |
99 | */ | |
100 | struct bsg_command { | |
101 | struct bsg_device *bd; | |
102 | struct list_head list; | |
103 | struct request *rq; | |
104 | struct bio *bio; | |
105 | int err; | |
70e36ece FT |
106 | struct sg_io_v4 hdr; |
107 | struct sg_io_v4 __user *uhdr; | |
3d6392cf JA |
108 | char sense[SCSI_SENSE_BUFFERSIZE]; |
109 | }; | |
110 | ||
111 | static void bsg_free_command(struct bsg_command *bc) | |
112 | { | |
113 | struct bsg_device *bd = bc->bd; | |
114 | unsigned long bitnr = bc - bd->cmd_map; | |
115 | unsigned long flags; | |
116 | ||
117 | dprintk("%s: command bit offset %lu\n", bd->name, bitnr); | |
118 | ||
119 | spin_lock_irqsave(&bd->lock, flags); | |
120 | bd->queued_cmds--; | |
121 | __clear_bit(bitnr, bd->cmd_bitmap); | |
122 | spin_unlock_irqrestore(&bd->lock, flags); | |
123 | ||
124 | wake_up(&bd->wq_free); | |
125 | } | |
126 | ||
127 | static struct bsg_command *__bsg_alloc_command(struct bsg_device *bd) | |
128 | { | |
129 | struct bsg_command *bc = NULL; | |
130 | unsigned long *map; | |
131 | int free_nr; | |
132 | ||
133 | spin_lock_irq(&bd->lock); | |
134 | ||
135 | if (bd->queued_cmds >= bd->max_queue) | |
136 | goto out; | |
137 | ||
138 | for (free_nr = 0, map = bd->cmd_bitmap; *map == ~0UL; map++) | |
139 | free_nr += BSG_CMDS_PER_LONG; | |
140 | ||
141 | BUG_ON(*map == ~0UL); | |
142 | ||
143 | bd->queued_cmds++; | |
144 | free_nr += ffz(*map); | |
145 | __set_bit(free_nr, bd->cmd_bitmap); | |
146 | spin_unlock_irq(&bd->lock); | |
147 | ||
148 | bc = bd->cmd_map + free_nr; | |
149 | memset(bc, 0, sizeof(*bc)); | |
150 | bc->bd = bd; | |
151 | INIT_LIST_HEAD(&bc->list); | |
152 | dprintk("%s: returning free cmd %p (bit %d)\n", bd->name, bc, free_nr); | |
153 | return bc; | |
154 | out: | |
155 | dprintk("%s: failed (depth %d)\n", bd->name, bd->queued_cmds); | |
156 | spin_unlock_irq(&bd->lock); | |
157 | return bc; | |
158 | } | |
159 | ||
160 | static inline void | |
161 | bsg_del_done_cmd(struct bsg_device *bd, struct bsg_command *bc) | |
162 | { | |
163 | bd->done_cmds--; | |
164 | list_del(&bc->list); | |
165 | } | |
166 | ||
167 | static inline void | |
168 | bsg_add_done_cmd(struct bsg_device *bd, struct bsg_command *bc) | |
169 | { | |
170 | bd->done_cmds++; | |
171 | list_add_tail(&bc->list, &bd->done_list); | |
172 | wake_up(&bd->wq_done); | |
173 | } | |
174 | ||
175 | static inline int bsg_io_schedule(struct bsg_device *bd, int state) | |
176 | { | |
177 | DEFINE_WAIT(wait); | |
178 | int ret = 0; | |
179 | ||
180 | spin_lock_irq(&bd->lock); | |
181 | ||
182 | BUG_ON(bd->done_cmds > bd->queued_cmds); | |
183 | ||
184 | /* | |
185 | * -ENOSPC or -ENODATA? I'm going for -ENODATA, meaning "I have no | |
186 | * work to do", even though we return -ENOSPC after this same test | |
187 | * during bsg_write() -- there, it means our buffer can't have more | |
188 | * bsg_commands added to it, thus has no space left. | |
189 | */ | |
190 | if (bd->done_cmds == bd->queued_cmds) { | |
191 | ret = -ENODATA; | |
192 | goto unlock; | |
193 | } | |
194 | ||
195 | if (!test_bit(BSG_F_BLOCK, &bd->flags)) { | |
196 | ret = -EAGAIN; | |
197 | goto unlock; | |
198 | } | |
199 | ||
200 | prepare_to_wait(&bd->wq_done, &wait, state); | |
201 | spin_unlock_irq(&bd->lock); | |
202 | io_schedule(); | |
203 | finish_wait(&bd->wq_done, &wait); | |
204 | ||
205 | if ((state == TASK_INTERRUPTIBLE) && signal_pending(current)) | |
206 | ret = -ERESTARTSYS; | |
207 | ||
208 | return ret; | |
209 | unlock: | |
210 | spin_unlock_irq(&bd->lock); | |
211 | return ret; | |
212 | } | |
213 | ||
214 | /* | |
215 | * get a new free command, blocking if needed and specified | |
216 | */ | |
217 | static struct bsg_command *bsg_get_command(struct bsg_device *bd) | |
218 | { | |
219 | struct bsg_command *bc; | |
220 | int ret; | |
221 | ||
222 | do { | |
223 | bc = __bsg_alloc_command(bd); | |
224 | if (bc) | |
225 | break; | |
226 | ||
227 | ret = bsg_io_schedule(bd, TASK_INTERRUPTIBLE); | |
228 | if (ret) { | |
229 | bc = ERR_PTR(ret); | |
230 | break; | |
231 | } | |
232 | ||
233 | } while (1); | |
234 | ||
235 | return bc; | |
236 | } | |
237 | ||
70e36ece FT |
238 | static int blk_fill_sgv4_hdr_rq(request_queue_t *q, struct request *rq, |
239 | struct sg_io_v4 *hdr, int has_write_perm) | |
240 | { | |
241 | memset(rq->cmd, 0, BLK_MAX_CDB); /* ATAPI hates garbage after CDB */ | |
242 | ||
243 | if (copy_from_user(rq->cmd, (void *)(unsigned long)hdr->request, | |
244 | hdr->request_len)) | |
245 | return -EFAULT; | |
246 | if (blk_verify_command(rq->cmd, has_write_perm)) | |
247 | return -EPERM; | |
248 | ||
249 | /* | |
250 | * fill in request structure | |
251 | */ | |
252 | rq->cmd_len = hdr->request_len; | |
253 | rq->cmd_type = REQ_TYPE_BLOCK_PC; | |
254 | ||
255 | rq->timeout = (hdr->timeout * HZ) / 1000; | |
256 | if (!rq->timeout) | |
257 | rq->timeout = q->sg_timeout; | |
258 | if (!rq->timeout) | |
259 | rq->timeout = BLK_DEFAULT_SG_TIMEOUT; | |
260 | ||
261 | return 0; | |
262 | } | |
263 | ||
3d6392cf | 264 | /* |
70e36ece | 265 | * Check if sg_io_v4 from user is allowed and valid |
3d6392cf JA |
266 | */ |
267 | static int | |
70e36ece | 268 | bsg_validate_sgv4_hdr(request_queue_t *q, struct sg_io_v4 *hdr, int *rw) |
3d6392cf | 269 | { |
70e36ece | 270 | if (hdr->guard != 'Q') |
3d6392cf | 271 | return -EINVAL; |
70e36ece | 272 | if (hdr->request_len > BLK_MAX_CDB) |
3d6392cf | 273 | return -EINVAL; |
70e36ece FT |
274 | if (hdr->dout_xfer_len > (q->max_sectors << 9) || |
275 | hdr->din_xfer_len > (q->max_sectors << 9)) | |
3d6392cf JA |
276 | return -EIO; |
277 | ||
70e36ece FT |
278 | /* not supported currently */ |
279 | if (hdr->protocol || hdr->subprotocol) | |
280 | return -EINVAL; | |
281 | ||
3d6392cf JA |
282 | /* |
283 | * looks sane, if no data then it should be fine from our POV | |
284 | */ | |
70e36ece | 285 | if (!hdr->dout_xfer_len && !hdr->din_xfer_len) |
3d6392cf JA |
286 | return 0; |
287 | ||
70e36ece FT |
288 | /* not supported currently */ |
289 | if (hdr->dout_xfer_len && hdr->din_xfer_len) | |
290 | return -EINVAL; | |
291 | ||
292 | *rw = hdr->dout_xfer_len ? WRITE : READ; | |
3d6392cf JA |
293 | |
294 | return 0; | |
295 | } | |
296 | ||
297 | /* | |
70e36ece | 298 | * map sg_io_v4 to a request. |
3d6392cf JA |
299 | */ |
300 | static struct request * | |
70e36ece | 301 | bsg_map_hdr(struct bsg_device *bd, struct sg_io_v4 *hdr) |
3d6392cf JA |
302 | { |
303 | request_queue_t *q = bd->queue; | |
3d6392cf | 304 | struct request *rq; |
70e36ece FT |
305 | int ret, rw; |
306 | unsigned int dxfer_len; | |
307 | void *dxferp = NULL; | |
3d6392cf | 308 | |
70e36ece FT |
309 | dprintk("map hdr %llx/%u %llx/%u\n", (unsigned long long) hdr->dout_xferp, |
310 | hdr->dout_xfer_len, (unsigned long long) hdr->din_xferp, | |
311 | hdr->din_xfer_len); | |
3d6392cf | 312 | |
70e36ece | 313 | ret = bsg_validate_sgv4_hdr(q, hdr, &rw); |
3d6392cf JA |
314 | if (ret) |
315 | return ERR_PTR(ret); | |
316 | ||
317 | /* | |
318 | * map scatter-gather elements seperately and string them to request | |
319 | */ | |
320 | rq = blk_get_request(q, rw, GFP_KERNEL); | |
70e36ece FT |
321 | ret = blk_fill_sgv4_hdr_rq(q, rq, hdr, test_bit(BSG_F_WRITE_PERM, |
322 | &bd->flags)); | |
3d6392cf JA |
323 | if (ret) { |
324 | blk_put_request(rq); | |
325 | return ERR_PTR(ret); | |
326 | } | |
327 | ||
70e36ece FT |
328 | if (hdr->dout_xfer_len) { |
329 | dxfer_len = hdr->dout_xfer_len; | |
330 | dxferp = (void*)(unsigned long)hdr->dout_xferp; | |
331 | } else if (hdr->din_xfer_len) { | |
332 | dxfer_len = hdr->din_xfer_len; | |
333 | dxferp = (void*)(unsigned long)hdr->din_xferp; | |
334 | } else | |
335 | dxfer_len = 0; | |
336 | ||
337 | if (dxfer_len) { | |
338 | ret = blk_rq_map_user(q, rq, dxferp, dxfer_len); | |
339 | if (ret) { | |
340 | dprintk("failed map at %d\n", ret); | |
341 | blk_put_request(rq); | |
342 | rq = ERR_PTR(ret); | |
3d6392cf | 343 | } |
3d6392cf JA |
344 | } |
345 | ||
346 | return rq; | |
347 | } | |
348 | ||
349 | /* | |
350 | * async completion call-back from the block layer, when scsi/ide/whatever | |
351 | * calls end_that_request_last() on a request | |
352 | */ | |
353 | static void bsg_rq_end_io(struct request *rq, int uptodate) | |
354 | { | |
355 | struct bsg_command *bc = rq->end_io_data; | |
356 | struct bsg_device *bd = bc->bd; | |
357 | unsigned long flags; | |
358 | ||
70e36ece | 359 | dprintk("%s: finished rq %p bc %p, bio %p offset %Zd stat %d\n", |
9e69fbb5 | 360 | bd->name, rq, bc, bc->bio, bc - bd->cmd_map, uptodate); |
3d6392cf JA |
361 | |
362 | bc->hdr.duration = jiffies_to_msecs(jiffies - bc->hdr.duration); | |
363 | ||
364 | spin_lock_irqsave(&bd->lock, flags); | |
365 | list_del(&bc->list); | |
366 | bsg_add_done_cmd(bd, bc); | |
367 | spin_unlock_irqrestore(&bd->lock, flags); | |
368 | } | |
369 | ||
370 | /* | |
371 | * do final setup of a 'bc' and submit the matching 'rq' to the block | |
372 | * layer for io | |
373 | */ | |
374 | static void bsg_add_command(struct bsg_device *bd, request_queue_t *q, | |
375 | struct bsg_command *bc, struct request *rq) | |
376 | { | |
377 | rq->sense = bc->sense; | |
378 | rq->sense_len = 0; | |
379 | ||
380 | /* | |
381 | * add bc command to busy queue and submit rq for io | |
382 | */ | |
383 | bc->rq = rq; | |
384 | bc->bio = rq->bio; | |
385 | bc->hdr.duration = jiffies; | |
386 | spin_lock_irq(&bd->lock); | |
387 | list_add_tail(&bc->list, &bd->busy_list); | |
388 | spin_unlock_irq(&bd->lock); | |
389 | ||
390 | dprintk("%s: queueing rq %p, bc %p\n", bd->name, rq, bc); | |
391 | ||
392 | rq->end_io_data = bc; | |
393 | blk_execute_rq_nowait(q, bd->disk, rq, 1, bsg_rq_end_io); | |
394 | } | |
395 | ||
396 | static inline struct bsg_command *bsg_next_done_cmd(struct bsg_device *bd) | |
397 | { | |
398 | struct bsg_command *bc = NULL; | |
399 | ||
400 | spin_lock_irq(&bd->lock); | |
401 | if (bd->done_cmds) { | |
402 | bc = list_entry_bc(bd->done_list.next); | |
403 | bsg_del_done_cmd(bd, bc); | |
404 | } | |
405 | spin_unlock_irq(&bd->lock); | |
406 | ||
407 | return bc; | |
408 | } | |
409 | ||
410 | /* | |
411 | * Get a finished command from the done list | |
412 | */ | |
413 | static struct bsg_command *__bsg_get_done_cmd(struct bsg_device *bd, int state) | |
414 | { | |
415 | struct bsg_command *bc; | |
416 | int ret; | |
417 | ||
418 | do { | |
419 | bc = bsg_next_done_cmd(bd); | |
420 | if (bc) | |
421 | break; | |
422 | ||
423 | ret = bsg_io_schedule(bd, state); | |
424 | if (ret) { | |
425 | bc = ERR_PTR(ret); | |
426 | break; | |
427 | } | |
428 | } while (1); | |
429 | ||
430 | dprintk("%s: returning done %p\n", bd->name, bc); | |
431 | ||
432 | return bc; | |
433 | } | |
434 | ||
435 | static struct bsg_command * | |
436 | bsg_get_done_cmd(struct bsg_device *bd, const struct iovec *iov) | |
437 | { | |
438 | return __bsg_get_done_cmd(bd, TASK_INTERRUPTIBLE); | |
439 | } | |
440 | ||
441 | static struct bsg_command * | |
442 | bsg_get_done_cmd_nosignals(struct bsg_device *bd) | |
443 | { | |
444 | return __bsg_get_done_cmd(bd, TASK_UNINTERRUPTIBLE); | |
445 | } | |
446 | ||
70e36ece FT |
447 | static int blk_complete_sgv4_hdr_rq(struct request *rq, struct sg_io_v4 *hdr, |
448 | struct bio *bio) | |
449 | { | |
450 | int ret = 0; | |
451 | ||
452 | dprintk("rq %p bio %p %u\n", rq, bio, rq->errors); | |
453 | /* | |
454 | * fill in all the output members | |
455 | */ | |
456 | hdr->device_status = status_byte(rq->errors); | |
457 | hdr->transport_status = host_byte(rq->errors); | |
458 | hdr->driver_status = driver_byte(rq->errors); | |
459 | hdr->info = 0; | |
460 | if (hdr->device_status || hdr->transport_status || hdr->driver_status) | |
461 | hdr->info |= SG_INFO_CHECK; | |
462 | hdr->din_resid = rq->data_len; | |
463 | hdr->response_len = 0; | |
464 | ||
465 | if (rq->sense_len && hdr->response) { | |
466 | int len = min((unsigned int) hdr->max_response_len, | |
467 | rq->sense_len); | |
468 | ||
469 | ret = copy_to_user((void*)(unsigned long)hdr->response, | |
470 | rq->sense, len); | |
471 | if (!ret) | |
472 | hdr->response_len = len; | |
473 | else | |
474 | ret = -EFAULT; | |
475 | } | |
476 | ||
477 | blk_rq_unmap_user(bio); | |
478 | blk_put_request(rq); | |
479 | ||
480 | return ret; | |
481 | } | |
482 | ||
3d6392cf JA |
483 | static int bsg_complete_all_commands(struct bsg_device *bd) |
484 | { | |
485 | struct bsg_command *bc; | |
486 | int ret, tret; | |
487 | ||
488 | dprintk("%s: entered\n", bd->name); | |
489 | ||
490 | set_bit(BSG_F_BLOCK, &bd->flags); | |
491 | ||
492 | /* | |
493 | * wait for all commands to complete | |
494 | */ | |
495 | ret = 0; | |
496 | do { | |
497 | ret = bsg_io_schedule(bd, TASK_UNINTERRUPTIBLE); | |
498 | /* | |
499 | * look for -ENODATA specifically -- we'll sometimes get | |
500 | * -ERESTARTSYS when we've taken a signal, but we can't | |
501 | * return until we're done freeing the queue, so ignore | |
502 | * it. The signal will get handled when we're done freeing | |
503 | * the bsg_device. | |
504 | */ | |
505 | } while (ret != -ENODATA); | |
506 | ||
507 | /* | |
508 | * discard done commands | |
509 | */ | |
510 | ret = 0; | |
511 | do { | |
512 | bc = bsg_get_done_cmd_nosignals(bd); | |
513 | ||
514 | /* | |
515 | * we _must_ complete before restarting, because | |
516 | * bsg_release can't handle this failing. | |
517 | */ | |
518 | if (PTR_ERR(bc) == -ERESTARTSYS) | |
519 | continue; | |
520 | if (IS_ERR(bc)) { | |
521 | ret = PTR_ERR(bc); | |
522 | break; | |
523 | } | |
524 | ||
70e36ece | 525 | tret = blk_complete_sgv4_hdr_rq(bc->rq, &bc->hdr, bc->bio); |
3d6392cf JA |
526 | if (!ret) |
527 | ret = tret; | |
528 | ||
529 | bsg_free_command(bc); | |
530 | } while (1); | |
531 | ||
532 | return ret; | |
533 | } | |
534 | ||
535 | typedef struct bsg_command *(*bsg_command_callback)(struct bsg_device *bd, const struct iovec *iov); | |
536 | ||
537 | static ssize_t | |
538 | __bsg_read(char __user *buf, size_t count, bsg_command_callback get_bc, | |
539 | struct bsg_device *bd, const struct iovec *iov, ssize_t *bytes_read) | |
540 | { | |
541 | struct bsg_command *bc; | |
542 | int nr_commands, ret; | |
543 | ||
70e36ece | 544 | if (count % sizeof(struct sg_io_v4)) |
3d6392cf JA |
545 | return -EINVAL; |
546 | ||
547 | ret = 0; | |
70e36ece | 548 | nr_commands = count / sizeof(struct sg_io_v4); |
3d6392cf JA |
549 | while (nr_commands) { |
550 | bc = get_bc(bd, iov); | |
551 | if (IS_ERR(bc)) { | |
552 | ret = PTR_ERR(bc); | |
553 | break; | |
554 | } | |
555 | ||
556 | /* | |
557 | * this is the only case where we need to copy data back | |
558 | * after completing the request. so do that here, | |
559 | * bsg_complete_work() cannot do that for us | |
560 | */ | |
70e36ece | 561 | ret = blk_complete_sgv4_hdr_rq(bc->rq, &bc->hdr, bc->bio); |
3d6392cf JA |
562 | |
563 | if (copy_to_user(buf, (char *) &bc->hdr, sizeof(bc->hdr))) | |
564 | ret = -EFAULT; | |
565 | ||
566 | bsg_free_command(bc); | |
567 | ||
568 | if (ret) | |
569 | break; | |
570 | ||
70e36ece FT |
571 | buf += sizeof(struct sg_io_v4); |
572 | *bytes_read += sizeof(struct sg_io_v4); | |
3d6392cf JA |
573 | nr_commands--; |
574 | } | |
575 | ||
576 | return ret; | |
577 | } | |
578 | ||
579 | static inline void bsg_set_block(struct bsg_device *bd, struct file *file) | |
580 | { | |
581 | if (file->f_flags & O_NONBLOCK) | |
582 | clear_bit(BSG_F_BLOCK, &bd->flags); | |
583 | else | |
584 | set_bit(BSG_F_BLOCK, &bd->flags); | |
585 | } | |
586 | ||
587 | static inline void bsg_set_write_perm(struct bsg_device *bd, struct file *file) | |
588 | { | |
589 | if (file->f_mode & FMODE_WRITE) | |
590 | set_bit(BSG_F_WRITE_PERM, &bd->flags); | |
591 | else | |
592 | clear_bit(BSG_F_WRITE_PERM, &bd->flags); | |
593 | } | |
594 | ||
595 | static inline int err_block_err(int ret) | |
596 | { | |
597 | if (ret && ret != -ENOSPC && ret != -ENODATA && ret != -EAGAIN) | |
598 | return 1; | |
599 | ||
600 | return 0; | |
601 | } | |
602 | ||
603 | static ssize_t | |
604 | bsg_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) | |
605 | { | |
606 | struct bsg_device *bd = file->private_data; | |
607 | int ret; | |
608 | ssize_t bytes_read; | |
609 | ||
9e69fbb5 | 610 | dprintk("%s: read %Zd bytes\n", bd->name, count); |
3d6392cf JA |
611 | |
612 | bsg_set_block(bd, file); | |
613 | bytes_read = 0; | |
614 | ret = __bsg_read(buf, count, bsg_get_done_cmd, | |
615 | bd, NULL, &bytes_read); | |
616 | *ppos = bytes_read; | |
617 | ||
618 | if (!bytes_read || (bytes_read && err_block_err(ret))) | |
619 | bytes_read = ret; | |
620 | ||
621 | return bytes_read; | |
622 | } | |
623 | ||
624 | static ssize_t __bsg_write(struct bsg_device *bd, const char __user *buf, | |
625 | size_t count, ssize_t *bytes_read) | |
626 | { | |
627 | struct bsg_command *bc; | |
628 | struct request *rq; | |
629 | int ret, nr_commands; | |
630 | ||
70e36ece | 631 | if (count % sizeof(struct sg_io_v4)) |
3d6392cf JA |
632 | return -EINVAL; |
633 | ||
70e36ece | 634 | nr_commands = count / sizeof(struct sg_io_v4); |
3d6392cf JA |
635 | rq = NULL; |
636 | bc = NULL; | |
637 | ret = 0; | |
638 | while (nr_commands) { | |
639 | request_queue_t *q = bd->queue; | |
3d6392cf JA |
640 | |
641 | bc = bsg_get_command(bd); | |
642 | if (!bc) | |
643 | break; | |
644 | if (IS_ERR(bc)) { | |
645 | ret = PTR_ERR(bc); | |
646 | bc = NULL; | |
647 | break; | |
648 | } | |
649 | ||
70e36ece | 650 | bc->uhdr = (struct sg_io_v4 __user *) buf; |
3d6392cf JA |
651 | if (copy_from_user(&bc->hdr, buf, sizeof(bc->hdr))) { |
652 | ret = -EFAULT; | |
653 | break; | |
654 | } | |
655 | ||
656 | /* | |
657 | * get a request, fill in the blanks, and add to request queue | |
658 | */ | |
70e36ece | 659 | rq = bsg_map_hdr(bd, &bc->hdr); |
3d6392cf JA |
660 | if (IS_ERR(rq)) { |
661 | ret = PTR_ERR(rq); | |
662 | rq = NULL; | |
663 | break; | |
664 | } | |
665 | ||
666 | bsg_add_command(bd, q, bc, rq); | |
667 | bc = NULL; | |
668 | rq = NULL; | |
669 | nr_commands--; | |
70e36ece FT |
670 | buf += sizeof(struct sg_io_v4); |
671 | *bytes_read += sizeof(struct sg_io_v4); | |
3d6392cf JA |
672 | } |
673 | ||
3d6392cf JA |
674 | if (bc) |
675 | bsg_free_command(bc); | |
676 | ||
677 | return ret; | |
678 | } | |
679 | ||
680 | static ssize_t | |
681 | bsg_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) | |
682 | { | |
683 | struct bsg_device *bd = file->private_data; | |
684 | ssize_t bytes_read; | |
685 | int ret; | |
686 | ||
9e69fbb5 | 687 | dprintk("%s: write %Zd bytes\n", bd->name, count); |
3d6392cf JA |
688 | |
689 | bsg_set_block(bd, file); | |
690 | bsg_set_write_perm(bd, file); | |
691 | ||
692 | bytes_read = 0; | |
693 | ret = __bsg_write(bd, buf, count, &bytes_read); | |
694 | *ppos = bytes_read; | |
695 | ||
696 | /* | |
697 | * return bytes written on non-fatal errors | |
698 | */ | |
699 | if (!bytes_read || (bytes_read && err_block_err(ret))) | |
700 | bytes_read = ret; | |
701 | ||
9e69fbb5 | 702 | dprintk("%s: returning %Zd\n", bd->name, bytes_read); |
3d6392cf JA |
703 | return bytes_read; |
704 | } | |
705 | ||
706 | static void bsg_free_device(struct bsg_device *bd) | |
707 | { | |
708 | if (bd->cmd_map) | |
709 | free_pages((unsigned long) bd->cmd_map, BSG_CMDS_PAGE_ORDER); | |
710 | ||
711 | kfree(bd->cmd_bitmap); | |
712 | kfree(bd); | |
713 | } | |
714 | ||
715 | static struct bsg_device *bsg_alloc_device(void) | |
716 | { | |
717 | struct bsg_command *cmd_map; | |
718 | unsigned long *cmd_bitmap; | |
719 | struct bsg_device *bd; | |
720 | int bits; | |
721 | ||
722 | bd = kzalloc(sizeof(struct bsg_device), GFP_KERNEL); | |
723 | if (unlikely(!bd)) | |
724 | return NULL; | |
725 | ||
726 | spin_lock_init(&bd->lock); | |
727 | ||
728 | bd->max_queue = BSG_CMDS; | |
729 | ||
730 | bits = (BSG_CMDS / BSG_CMDS_PER_LONG) + 1; | |
731 | cmd_bitmap = kzalloc(bits * sizeof(unsigned long), GFP_KERNEL); | |
732 | if (!cmd_bitmap) | |
733 | goto out_free_bd; | |
734 | bd->cmd_bitmap = cmd_bitmap; | |
735 | ||
736 | cmd_map = (void *) __get_free_pages(GFP_KERNEL | __GFP_ZERO, | |
737 | BSG_CMDS_PAGE_ORDER); | |
738 | if (!cmd_map) | |
739 | goto out_free_bitmap; | |
740 | bd->cmd_map = cmd_map; | |
741 | ||
742 | INIT_LIST_HEAD(&bd->busy_list); | |
743 | INIT_LIST_HEAD(&bd->done_list); | |
744 | INIT_HLIST_NODE(&bd->dev_list); | |
745 | ||
746 | init_waitqueue_head(&bd->wq_free); | |
747 | init_waitqueue_head(&bd->wq_done); | |
748 | return bd; | |
749 | ||
750 | out_free_bitmap: | |
751 | kfree(cmd_bitmap); | |
752 | out_free_bd: | |
753 | kfree(bd); | |
754 | return NULL; | |
755 | } | |
756 | ||
757 | static int bsg_put_device(struct bsg_device *bd) | |
758 | { | |
759 | int ret = 0; | |
760 | ||
761 | mutex_lock(&bsg_mutex); | |
762 | ||
763 | if (!atomic_dec_and_test(&bd->ref_count)) | |
764 | goto out; | |
765 | ||
766 | dprintk("%s: tearing down\n", bd->name); | |
767 | ||
768 | /* | |
769 | * close can always block | |
770 | */ | |
771 | set_bit(BSG_F_BLOCK, &bd->flags); | |
772 | ||
773 | /* | |
774 | * correct error detection baddies here again. it's the responsibility | |
775 | * of the app to properly reap commands before close() if it wants | |
776 | * fool-proof error detection | |
777 | */ | |
778 | ret = bsg_complete_all_commands(bd); | |
779 | ||
780 | blk_put_queue(bd->queue); | |
781 | hlist_del(&bd->dev_list); | |
782 | bsg_free_device(bd); | |
783 | out: | |
784 | mutex_unlock(&bsg_mutex); | |
785 | return ret; | |
786 | } | |
787 | ||
788 | static struct bsg_device *bsg_add_device(struct inode *inode, | |
789 | struct gendisk *disk, | |
790 | struct file *file) | |
791 | { | |
792 | struct bsg_device *bd = NULL; | |
793 | #ifdef BSG_DEBUG | |
794 | unsigned char buf[32]; | |
795 | #endif | |
796 | ||
797 | bd = bsg_alloc_device(); | |
798 | if (!bd) | |
799 | return ERR_PTR(-ENOMEM); | |
800 | ||
801 | bd->disk = disk; | |
802 | bd->queue = disk->queue; | |
803 | kobject_get(&disk->queue->kobj); | |
804 | bsg_set_block(bd, file); | |
805 | ||
806 | atomic_set(&bd->ref_count, 1); | |
807 | bd->minor = iminor(inode); | |
808 | mutex_lock(&bsg_mutex); | |
809 | hlist_add_head(&bd->dev_list,&bsg_device_list[bsg_list_idx(bd->minor)]); | |
810 | ||
811 | strncpy(bd->name, disk->disk_name, sizeof(bd->name) - 1); | |
812 | dprintk("bound to <%s>, max queue %d\n", | |
9e69fbb5 | 813 | format_dev_t(buf, inode->i_rdev), bd->max_queue); |
3d6392cf JA |
814 | |
815 | mutex_unlock(&bsg_mutex); | |
816 | return bd; | |
817 | } | |
818 | ||
819 | static struct bsg_device *__bsg_get_device(int minor) | |
820 | { | |
821 | struct hlist_head *list = &bsg_device_list[bsg_list_idx(minor)]; | |
822 | struct bsg_device *bd = NULL; | |
823 | struct hlist_node *entry; | |
824 | ||
825 | mutex_lock(&bsg_mutex); | |
826 | ||
827 | hlist_for_each(entry, list) { | |
828 | bd = hlist_entry(entry, struct bsg_device, dev_list); | |
829 | if (bd->minor == minor) { | |
830 | atomic_inc(&bd->ref_count); | |
831 | break; | |
832 | } | |
833 | ||
834 | bd = NULL; | |
835 | } | |
836 | ||
837 | mutex_unlock(&bsg_mutex); | |
838 | return bd; | |
839 | } | |
840 | ||
841 | static struct bsg_device *bsg_get_device(struct inode *inode, struct file *file) | |
842 | { | |
843 | struct bsg_device *bd = __bsg_get_device(iminor(inode)); | |
844 | struct bsg_class_device *bcd, *__bcd; | |
845 | ||
846 | if (bd) | |
847 | return bd; | |
848 | ||
849 | /* | |
850 | * find the class device | |
851 | */ | |
852 | bcd = NULL; | |
853 | mutex_lock(&bsg_mutex); | |
854 | list_for_each_entry(__bcd, &bsg_class_list, list) { | |
855 | if (__bcd->minor == iminor(inode)) { | |
856 | bcd = __bcd; | |
857 | break; | |
858 | } | |
859 | } | |
860 | mutex_unlock(&bsg_mutex); | |
861 | ||
862 | if (!bcd) | |
863 | return ERR_PTR(-ENODEV); | |
864 | ||
865 | return bsg_add_device(inode, bcd->disk, file); | |
866 | } | |
867 | ||
868 | static int bsg_open(struct inode *inode, struct file *file) | |
869 | { | |
870 | struct bsg_device *bd = bsg_get_device(inode, file); | |
871 | ||
872 | if (IS_ERR(bd)) | |
873 | return PTR_ERR(bd); | |
874 | ||
875 | file->private_data = bd; | |
876 | return 0; | |
877 | } | |
878 | ||
879 | static int bsg_release(struct inode *inode, struct file *file) | |
880 | { | |
881 | struct bsg_device *bd = file->private_data; | |
882 | ||
883 | file->private_data = NULL; | |
884 | return bsg_put_device(bd); | |
885 | } | |
886 | ||
887 | static unsigned int bsg_poll(struct file *file, poll_table *wait) | |
888 | { | |
889 | struct bsg_device *bd = file->private_data; | |
890 | unsigned int mask = 0; | |
891 | ||
892 | poll_wait(file, &bd->wq_done, wait); | |
893 | poll_wait(file, &bd->wq_free, wait); | |
894 | ||
895 | spin_lock_irq(&bd->lock); | |
896 | if (!list_empty(&bd->done_list)) | |
897 | mask |= POLLIN | POLLRDNORM; | |
898 | if (bd->queued_cmds >= bd->max_queue) | |
899 | mask |= POLLOUT; | |
900 | spin_unlock_irq(&bd->lock); | |
901 | ||
902 | return mask; | |
903 | } | |
904 | ||
905 | static int | |
906 | bsg_ioctl(struct inode *inode, struct file *file, unsigned int cmd, | |
907 | unsigned long arg) | |
908 | { | |
909 | struct bsg_device *bd = file->private_data; | |
910 | int __user *uarg = (int __user *) arg; | |
911 | ||
912 | if (!bd) | |
913 | return -ENXIO; | |
914 | ||
915 | switch (cmd) { | |
916 | /* | |
917 | * our own ioctls | |
918 | */ | |
919 | case SG_GET_COMMAND_Q: | |
920 | return put_user(bd->max_queue, uarg); | |
921 | case SG_SET_COMMAND_Q: { | |
922 | int queue; | |
923 | ||
924 | if (get_user(queue, uarg)) | |
925 | return -EFAULT; | |
926 | if (queue > BSG_CMDS || queue < 1) | |
927 | return -EINVAL; | |
928 | ||
929 | bd->max_queue = queue; | |
930 | return 0; | |
931 | } | |
932 | ||
933 | /* | |
934 | * SCSI/sg ioctls | |
935 | */ | |
936 | case SG_GET_VERSION_NUM: | |
937 | case SCSI_IOCTL_GET_IDLUN: | |
938 | case SCSI_IOCTL_GET_BUS_NUMBER: | |
939 | case SG_SET_TIMEOUT: | |
940 | case SG_GET_TIMEOUT: | |
941 | case SG_GET_RESERVED_SIZE: | |
942 | case SG_SET_RESERVED_SIZE: | |
943 | case SG_EMULATED_HOST: | |
3d6392cf JA |
944 | case SCSI_IOCTL_SEND_COMMAND: { |
945 | void __user *uarg = (void __user *) arg; | |
946 | return scsi_cmd_ioctl(file, bd->disk, cmd, uarg); | |
947 | } | |
10e8855b FT |
948 | case SG_IO: { |
949 | struct request *rq; | |
950 | struct bio *bio; | |
951 | struct sg_io_v4 hdr; | |
952 | ||
953 | if (copy_from_user(&hdr, uarg, sizeof(hdr))) | |
954 | return -EFAULT; | |
955 | ||
956 | rq = bsg_map_hdr(bd, &hdr); | |
957 | if (IS_ERR(rq)) | |
958 | return PTR_ERR(rq); | |
959 | ||
960 | bio = rq->bio; | |
961 | blk_execute_rq(bd->queue, bd->disk, rq, 0); | |
962 | blk_complete_sgv4_hdr_rq(rq, &hdr, bio); | |
963 | ||
964 | if (copy_to_user(uarg, &hdr, sizeof(hdr))) | |
965 | return -EFAULT; | |
966 | else | |
967 | return 0; | |
968 | } | |
3d6392cf JA |
969 | /* |
970 | * block device ioctls | |
971 | */ | |
972 | default: | |
973 | #if 0 | |
974 | return ioctl_by_bdev(bd->bdev, cmd, arg); | |
975 | #else | |
976 | return -ENOTTY; | |
977 | #endif | |
978 | } | |
979 | } | |
980 | ||
981 | static struct file_operations bsg_fops = { | |
982 | .read = bsg_read, | |
983 | .write = bsg_write, | |
984 | .poll = bsg_poll, | |
985 | .open = bsg_open, | |
986 | .release = bsg_release, | |
987 | .ioctl = bsg_ioctl, | |
988 | .owner = THIS_MODULE, | |
989 | }; | |
990 | ||
991 | void bsg_unregister_disk(struct gendisk *disk) | |
992 | { | |
993 | struct bsg_class_device *bcd = &disk->bsg_dev; | |
994 | ||
995 | if (!bcd->class_dev) | |
996 | return; | |
997 | ||
998 | mutex_lock(&bsg_mutex); | |
999 | sysfs_remove_link(&bcd->disk->queue->kobj, "bsg"); | |
1000 | class_device_destroy(bsg_class, MKDEV(BSG_MAJOR, bcd->minor)); | |
1001 | bcd->class_dev = NULL; | |
1002 | list_del_init(&bcd->list); | |
1003 | mutex_unlock(&bsg_mutex); | |
1004 | } | |
1005 | ||
1006 | int bsg_register_disk(struct gendisk *disk) | |
1007 | { | |
1008 | request_queue_t *q = disk->queue; | |
1009 | struct bsg_class_device *bcd; | |
1010 | dev_t dev; | |
1011 | ||
1012 | /* | |
1013 | * we need a proper transport to send commands, not a stacked device | |
1014 | */ | |
1015 | if (!q->request_fn) | |
1016 | return 0; | |
1017 | ||
1018 | bcd = &disk->bsg_dev; | |
1019 | memset(bcd, 0, sizeof(*bcd)); | |
1020 | INIT_LIST_HEAD(&bcd->list); | |
1021 | ||
1022 | mutex_lock(&bsg_mutex); | |
1023 | dev = MKDEV(BSG_MAJOR, bsg_device_nr); | |
1024 | bcd->minor = bsg_device_nr; | |
1025 | bsg_device_nr++; | |
1026 | bcd->disk = disk; | |
1027 | bcd->class_dev = class_device_create(bsg_class, NULL, dev, bcd->dev, "%s", disk->disk_name); | |
1028 | list_add_tail(&bcd->list, &bsg_class_list); | |
1029 | sysfs_create_link(&q->kobj, &bcd->class_dev->kobj, "bsg"); | |
1030 | mutex_unlock(&bsg_mutex); | |
1031 | return 0; | |
1032 | } | |
1033 | ||
1034 | static int __init bsg_init(void) | |
1035 | { | |
1036 | int ret, i; | |
1037 | ||
1038 | for (i = 0; i < BSG_LIST_SIZE; i++) | |
1039 | INIT_HLIST_HEAD(&bsg_device_list[i]); | |
1040 | ||
1041 | bsg_class = class_create(THIS_MODULE, "bsg"); | |
1042 | if (IS_ERR(bsg_class)) | |
1043 | return PTR_ERR(bsg_class); | |
1044 | ||
1045 | ret = register_chrdev(BSG_MAJOR, "bsg", &bsg_fops); | |
1046 | if (ret) { | |
1047 | class_destroy(bsg_class); | |
1048 | return ret; | |
1049 | } | |
1050 | ||
1051 | printk(KERN_INFO "%s loaded\n", bsg_version); | |
1052 | return 0; | |
1053 | } | |
1054 | ||
1055 | MODULE_AUTHOR("Jens Axboe"); | |
1056 | MODULE_DESCRIPTION("Block layer SGSI generic (sg) driver"); | |
1057 | MODULE_LICENSE("GPL"); | |
1058 | ||
1059 | subsys_initcall(bsg_init); |