block: allow WRITE_SAME commands with the SG_IO ioctl
[platform/kernel/linux-rpi.git] / block / scsi_ioctl.c
1 /*
2  * Copyright (C) 2001 Jens Axboe <axboe@suse.de>
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License version 2 as
6  * published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope that it will be useful,
9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
10  *
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  * GNU General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public Licens
15  * along with this program; if not, write to the Free Software
16  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-
17  *
18  */
19 #include <linux/kernel.h>
20 #include <linux/errno.h>
21 #include <linux/string.h>
22 #include <linux/module.h>
23 #include <linux/blkdev.h>
24 #include <linux/capability.h>
25 #include <linux/completion.h>
26 #include <linux/cdrom.h>
27 #include <linux/ratelimit.h>
28 #include <linux/slab.h>
29 #include <linux/times.h>
30 #include <linux/uio.h>
31 #include <asm/uaccess.h>
32
33 #include <scsi/scsi.h>
34 #include <scsi/scsi_ioctl.h>
35 #include <scsi/scsi_cmnd.h>
36
37 struct blk_cmd_filter {
38         unsigned long read_ok[BLK_SCSI_CMD_PER_LONG];
39         unsigned long write_ok[BLK_SCSI_CMD_PER_LONG];
40 };
41
42 static struct blk_cmd_filter blk_default_cmd_filter;
43
44 /* Command group 3 is reserved and should never be used.  */
45 const unsigned char scsi_command_size_tbl[8] =
46 {
47         6, 10, 10, 12,
48         16, 12, 10, 10
49 };
50 EXPORT_SYMBOL(scsi_command_size_tbl);
51
52 #include <scsi/sg.h>
53
54 static int sg_get_version(int __user *p)
55 {
56         static const int sg_version_num = 30527;
57         return put_user(sg_version_num, p);
58 }
59
60 static int scsi_get_idlun(struct request_queue *q, int __user *p)
61 {
62         return put_user(0, p);
63 }
64
65 static int scsi_get_bus(struct request_queue *q, int __user *p)
66 {
67         return put_user(0, p);
68 }
69
70 static int sg_get_timeout(struct request_queue *q)
71 {
72         return jiffies_to_clock_t(q->sg_timeout);
73 }
74
75 static int sg_set_timeout(struct request_queue *q, int __user *p)
76 {
77         int timeout, err = get_user(timeout, p);
78
79         if (!err)
80                 q->sg_timeout = clock_t_to_jiffies(timeout);
81
82         return err;
83 }
84
85 static int max_sectors_bytes(struct request_queue *q)
86 {
87         unsigned int max_sectors = queue_max_sectors(q);
88
89         max_sectors = min_t(unsigned int, max_sectors, INT_MAX >> 9);
90
91         return max_sectors << 9;
92 }
93
94 static int sg_get_reserved_size(struct request_queue *q, int __user *p)
95 {
96         int val = min_t(int, q->sg_reserved_size, max_sectors_bytes(q));
97
98         return put_user(val, p);
99 }
100
101 static int sg_set_reserved_size(struct request_queue *q, int __user *p)
102 {
103         int size, err = get_user(size, p);
104
105         if (err)
106                 return err;
107
108         if (size < 0)
109                 return -EINVAL;
110
111         q->sg_reserved_size = min(size, max_sectors_bytes(q));
112         return 0;
113 }
114
115 /*
116  * will always return that we are ATAPI even for a real SCSI drive, I'm not
117  * so sure this is worth doing anything about (why would you care??)
118  */
119 static int sg_emulated_host(struct request_queue *q, int __user *p)
120 {
121         return put_user(1, p);
122 }
123
124 static void blk_set_cmd_filter_defaults(struct blk_cmd_filter *filter)
125 {
126         /* Basic read-only commands */
127         __set_bit(TEST_UNIT_READY, filter->read_ok);
128         __set_bit(REQUEST_SENSE, filter->read_ok);
129         __set_bit(READ_6, filter->read_ok);
130         __set_bit(READ_10, filter->read_ok);
131         __set_bit(READ_12, filter->read_ok);
132         __set_bit(READ_16, filter->read_ok);
133         __set_bit(READ_BUFFER, filter->read_ok);
134         __set_bit(READ_DEFECT_DATA, filter->read_ok);
135         __set_bit(READ_CAPACITY, filter->read_ok);
136         __set_bit(READ_LONG, filter->read_ok);
137         __set_bit(INQUIRY, filter->read_ok);
138         __set_bit(MODE_SENSE, filter->read_ok);
139         __set_bit(MODE_SENSE_10, filter->read_ok);
140         __set_bit(LOG_SENSE, filter->read_ok);
141         __set_bit(START_STOP, filter->read_ok);
142         __set_bit(GPCMD_VERIFY_10, filter->read_ok);
143         __set_bit(VERIFY_16, filter->read_ok);
144         __set_bit(REPORT_LUNS, filter->read_ok);
145         __set_bit(SERVICE_ACTION_IN_16, filter->read_ok);
146         __set_bit(RECEIVE_DIAGNOSTIC, filter->read_ok);
147         __set_bit(MAINTENANCE_IN, filter->read_ok);
148         __set_bit(GPCMD_READ_BUFFER_CAPACITY, filter->read_ok);
149
150         /* Audio CD commands */
151         __set_bit(GPCMD_PLAY_CD, filter->read_ok);
152         __set_bit(GPCMD_PLAY_AUDIO_10, filter->read_ok);
153         __set_bit(GPCMD_PLAY_AUDIO_MSF, filter->read_ok);
154         __set_bit(GPCMD_PLAY_AUDIO_TI, filter->read_ok);
155         __set_bit(GPCMD_PAUSE_RESUME, filter->read_ok);
156
157         /* CD/DVD data reading */
158         __set_bit(GPCMD_READ_CD, filter->read_ok);
159         __set_bit(GPCMD_READ_CD_MSF, filter->read_ok);
160         __set_bit(GPCMD_READ_DISC_INFO, filter->read_ok);
161         __set_bit(GPCMD_READ_CDVD_CAPACITY, filter->read_ok);
162         __set_bit(GPCMD_READ_DVD_STRUCTURE, filter->read_ok);
163         __set_bit(GPCMD_READ_HEADER, filter->read_ok);
164         __set_bit(GPCMD_READ_TRACK_RZONE_INFO, filter->read_ok);
165         __set_bit(GPCMD_READ_SUBCHANNEL, filter->read_ok);
166         __set_bit(GPCMD_READ_TOC_PMA_ATIP, filter->read_ok);
167         __set_bit(GPCMD_REPORT_KEY, filter->read_ok);
168         __set_bit(GPCMD_SCAN, filter->read_ok);
169         __set_bit(GPCMD_GET_CONFIGURATION, filter->read_ok);
170         __set_bit(GPCMD_READ_FORMAT_CAPACITIES, filter->read_ok);
171         __set_bit(GPCMD_GET_EVENT_STATUS_NOTIFICATION, filter->read_ok);
172         __set_bit(GPCMD_GET_PERFORMANCE, filter->read_ok);
173         __set_bit(GPCMD_SEEK, filter->read_ok);
174         __set_bit(GPCMD_STOP_PLAY_SCAN, filter->read_ok);
175
176         /* Basic writing commands */
177         __set_bit(WRITE_6, filter->write_ok);
178         __set_bit(WRITE_10, filter->write_ok);
179         __set_bit(WRITE_VERIFY, filter->write_ok);
180         __set_bit(WRITE_12, filter->write_ok);
181         __set_bit(WRITE_VERIFY_12, filter->write_ok);
182         __set_bit(WRITE_16, filter->write_ok);
183         __set_bit(WRITE_LONG, filter->write_ok);
184         __set_bit(WRITE_LONG_2, filter->write_ok);
185         __set_bit(WRITE_SAME, filter->write_ok);
186         __set_bit(WRITE_SAME_16, filter->write_ok);
187         __set_bit(WRITE_SAME_32, filter->write_ok);
188         __set_bit(ERASE, filter->write_ok);
189         __set_bit(GPCMD_MODE_SELECT_10, filter->write_ok);
190         __set_bit(MODE_SELECT, filter->write_ok);
191         __set_bit(LOG_SELECT, filter->write_ok);
192         __set_bit(GPCMD_BLANK, filter->write_ok);
193         __set_bit(GPCMD_CLOSE_TRACK, filter->write_ok);
194         __set_bit(GPCMD_FLUSH_CACHE, filter->write_ok);
195         __set_bit(GPCMD_FORMAT_UNIT, filter->write_ok);
196         __set_bit(GPCMD_REPAIR_RZONE_TRACK, filter->write_ok);
197         __set_bit(GPCMD_RESERVE_RZONE_TRACK, filter->write_ok);
198         __set_bit(GPCMD_SEND_DVD_STRUCTURE, filter->write_ok);
199         __set_bit(GPCMD_SEND_EVENT, filter->write_ok);
200         __set_bit(GPCMD_SEND_KEY, filter->write_ok);
201         __set_bit(GPCMD_SEND_OPC, filter->write_ok);
202         __set_bit(GPCMD_SEND_CUE_SHEET, filter->write_ok);
203         __set_bit(GPCMD_SET_SPEED, filter->write_ok);
204         __set_bit(GPCMD_PREVENT_ALLOW_MEDIUM_REMOVAL, filter->write_ok);
205         __set_bit(GPCMD_LOAD_UNLOAD, filter->write_ok);
206         __set_bit(GPCMD_SET_STREAMING, filter->write_ok);
207         __set_bit(GPCMD_SET_READ_AHEAD, filter->write_ok);
208 }
209
210 int blk_verify_command(unsigned char *cmd, fmode_t has_write_perm)
211 {
212         struct blk_cmd_filter *filter = &blk_default_cmd_filter;
213
214         /* root can do any command. */
215         if (capable(CAP_SYS_RAWIO))
216                 return 0;
217
218         /* Anybody who can open the device can do a read-safe command */
219         if (test_bit(cmd[0], filter->read_ok))
220                 return 0;
221
222         /* Write-safe commands require a writable open */
223         if (test_bit(cmd[0], filter->write_ok) && has_write_perm)
224                 return 0;
225
226         return -EPERM;
227 }
228 EXPORT_SYMBOL(blk_verify_command);
229
230 static int blk_fill_sghdr_rq(struct request_queue *q, struct request *rq,
231                              struct sg_io_hdr *hdr, fmode_t mode)
232 {
233         if (copy_from_user(rq->cmd, hdr->cmdp, hdr->cmd_len))
234                 return -EFAULT;
235         if (blk_verify_command(rq->cmd, mode & FMODE_WRITE))
236                 return -EPERM;
237
238         /*
239          * fill in request structure
240          */
241         rq->cmd_len = hdr->cmd_len;
242
243         rq->timeout = msecs_to_jiffies(hdr->timeout);
244         if (!rq->timeout)
245                 rq->timeout = q->sg_timeout;
246         if (!rq->timeout)
247                 rq->timeout = BLK_DEFAULT_SG_TIMEOUT;
248         if (rq->timeout < BLK_MIN_SG_TIMEOUT)
249                 rq->timeout = BLK_MIN_SG_TIMEOUT;
250
251         return 0;
252 }
253
254 static int blk_complete_sghdr_rq(struct request *rq, struct sg_io_hdr *hdr,
255                                  struct bio *bio)
256 {
257         int r, ret = 0;
258
259         /*
260          * fill in all the output members
261          */
262         hdr->status = rq->errors & 0xff;
263         hdr->masked_status = status_byte(rq->errors);
264         hdr->msg_status = msg_byte(rq->errors);
265         hdr->host_status = host_byte(rq->errors);
266         hdr->driver_status = driver_byte(rq->errors);
267         hdr->info = 0;
268         if (hdr->masked_status || hdr->host_status || hdr->driver_status)
269                 hdr->info |= SG_INFO_CHECK;
270         hdr->resid = rq->resid_len;
271         hdr->sb_len_wr = 0;
272
273         if (rq->sense_len && hdr->sbp) {
274                 int len = min((unsigned int) hdr->mx_sb_len, rq->sense_len);
275
276                 if (!copy_to_user(hdr->sbp, rq->sense, len))
277                         hdr->sb_len_wr = len;
278                 else
279                         ret = -EFAULT;
280         }
281
282         r = blk_rq_unmap_user(bio);
283         if (!ret)
284                 ret = r;
285
286         return ret;
287 }
288
289 static int sg_io(struct request_queue *q, struct gendisk *bd_disk,
290                 struct sg_io_hdr *hdr, fmode_t mode)
291 {
292         unsigned long start_time;
293         ssize_t ret = 0;
294         int writing = 0;
295         int at_head = 0;
296         struct request *rq;
297         char sense[SCSI_SENSE_BUFFERSIZE];
298         struct bio *bio;
299
300         if (hdr->interface_id != 'S')
301                 return -EINVAL;
302
303         if (hdr->dxfer_len > (queue_max_hw_sectors(q) << 9))
304                 return -EIO;
305
306         if (hdr->dxfer_len)
307                 switch (hdr->dxfer_direction) {
308                 default:
309                         return -EINVAL;
310                 case SG_DXFER_TO_DEV:
311                         writing = 1;
312                         break;
313                 case SG_DXFER_TO_FROM_DEV:
314                 case SG_DXFER_FROM_DEV:
315                         break;
316                 }
317         if (hdr->flags & SG_FLAG_Q_AT_HEAD)
318                 at_head = 1;
319
320         ret = -ENOMEM;
321         rq = blk_get_request(q, writing ? WRITE : READ, GFP_KERNEL);
322         if (IS_ERR(rq))
323                 return PTR_ERR(rq);
324         blk_rq_set_block_pc(rq);
325
326         if (hdr->cmd_len > BLK_MAX_CDB) {
327                 rq->cmd = kzalloc(hdr->cmd_len, GFP_KERNEL);
328                 if (!rq->cmd)
329                         goto out_put_request;
330         }
331
332         ret = blk_fill_sghdr_rq(q, rq, hdr, mode);
333         if (ret < 0)
334                 goto out_free_cdb;
335
336         ret = 0;
337         if (hdr->iovec_count) {
338                 struct iov_iter i;
339                 struct iovec *iov = NULL;
340
341                 ret = import_iovec(rq_data_dir(rq),
342                                    hdr->dxferp, hdr->iovec_count,
343                                    0, &iov, &i);
344                 if (ret < 0)
345                         goto out_free_cdb;
346
347                 /* SG_IO howto says that the shorter of the two wins */
348                 iov_iter_truncate(&i, hdr->dxfer_len);
349
350                 ret = blk_rq_map_user_iov(q, rq, NULL, &i, GFP_KERNEL);
351                 kfree(iov);
352         } else if (hdr->dxfer_len)
353                 ret = blk_rq_map_user(q, rq, NULL, hdr->dxferp, hdr->dxfer_len,
354                                       GFP_KERNEL);
355
356         if (ret)
357                 goto out_free_cdb;
358
359         bio = rq->bio;
360         memset(sense, 0, sizeof(sense));
361         rq->sense = sense;
362         rq->sense_len = 0;
363         rq->retries = 0;
364
365         start_time = jiffies;
366
367         /* ignore return value. All information is passed back to caller
368          * (if he doesn't check that is his problem).
369          * N.B. a non-zero SCSI status is _not_ necessarily an error.
370          */
371         blk_execute_rq(q, bd_disk, rq, at_head);
372
373         hdr->duration = jiffies_to_msecs(jiffies - start_time);
374
375         ret = blk_complete_sghdr_rq(rq, hdr, bio);
376
377 out_free_cdb:
378         if (rq->cmd != rq->__cmd)
379                 kfree(rq->cmd);
380 out_put_request:
381         blk_put_request(rq);
382         return ret;
383 }
384
385 /**
386  * sg_scsi_ioctl  --  handle deprecated SCSI_IOCTL_SEND_COMMAND ioctl
387  * @file:       file this ioctl operates on (optional)
388  * @q:          request queue to send scsi commands down
389  * @disk:       gendisk to operate on (option)
390  * @sic:        userspace structure describing the command to perform
391  *
392  * Send down the scsi command described by @sic to the device below
393  * the request queue @q.  If @file is non-NULL it's used to perform
394  * fine-grained permission checks that allow users to send down
395  * non-destructive SCSI commands.  If the caller has a struct gendisk
396  * available it should be passed in as @disk to allow the low level
397  * driver to use the information contained in it.  A non-NULL @disk
398  * is only allowed if the caller knows that the low level driver doesn't
399  * need it (e.g. in the scsi subsystem).
400  *
401  * Notes:
402  *   -  This interface is deprecated - users should use the SG_IO
403  *      interface instead, as this is a more flexible approach to
404  *      performing SCSI commands on a device.
405  *   -  The SCSI command length is determined by examining the 1st byte
406  *      of the given command. There is no way to override this.
407  *   -  Data transfers are limited to PAGE_SIZE
408  *   -  The length (x + y) must be at least OMAX_SB_LEN bytes long to
409  *      accommodate the sense buffer when an error occurs.
410  *      The sense buffer is truncated to OMAX_SB_LEN (16) bytes so that
411  *      old code will not be surprised.
412  *   -  If a Unix error occurs (e.g. ENOMEM) then the user will receive
413  *      a negative return and the Unix error code in 'errno'.
414  *      If the SCSI command succeeds then 0 is returned.
415  *      Positive numbers returned are the compacted SCSI error codes (4
416  *      bytes in one int) where the lowest byte is the SCSI status.
417  */
418 #define OMAX_SB_LEN 16          /* For backward compatibility */
419 int sg_scsi_ioctl(struct request_queue *q, struct gendisk *disk, fmode_t mode,
420                 struct scsi_ioctl_command __user *sic)
421 {
422         struct request *rq;
423         int err;
424         unsigned int in_len, out_len, bytes, opcode, cmdlen;
425         char *buffer = NULL, sense[SCSI_SENSE_BUFFERSIZE];
426
427         if (!sic)
428                 return -EINVAL;
429
430         /*
431          * get in an out lengths, verify they don't exceed a page worth of data
432          */
433         if (get_user(in_len, &sic->inlen))
434                 return -EFAULT;
435         if (get_user(out_len, &sic->outlen))
436                 return -EFAULT;
437         if (in_len > PAGE_SIZE || out_len > PAGE_SIZE)
438                 return -EINVAL;
439         if (get_user(opcode, sic->data))
440                 return -EFAULT;
441
442         bytes = max(in_len, out_len);
443         if (bytes) {
444                 buffer = kzalloc(bytes, q->bounce_gfp | GFP_USER| __GFP_NOWARN);
445                 if (!buffer)
446                         return -ENOMEM;
447
448         }
449
450         rq = blk_get_request(q, in_len ? WRITE : READ, __GFP_RECLAIM);
451         if (IS_ERR(rq)) {
452                 err = PTR_ERR(rq);
453                 goto error_free_buffer;
454         }
455         blk_rq_set_block_pc(rq);
456
457         cmdlen = COMMAND_SIZE(opcode);
458
459         /*
460          * get command and data to send to device, if any
461          */
462         err = -EFAULT;
463         rq->cmd_len = cmdlen;
464         if (copy_from_user(rq->cmd, sic->data, cmdlen))
465                 goto error;
466
467         if (in_len && copy_from_user(buffer, sic->data + cmdlen, in_len))
468                 goto error;
469
470         err = blk_verify_command(rq->cmd, mode & FMODE_WRITE);
471         if (err)
472                 goto error;
473
474         /* default.  possible overriden later */
475         rq->retries = 5;
476
477         switch (opcode) {
478         case SEND_DIAGNOSTIC:
479         case FORMAT_UNIT:
480                 rq->timeout = FORMAT_UNIT_TIMEOUT;
481                 rq->retries = 1;
482                 break;
483         case START_STOP:
484                 rq->timeout = START_STOP_TIMEOUT;
485                 break;
486         case MOVE_MEDIUM:
487                 rq->timeout = MOVE_MEDIUM_TIMEOUT;
488                 break;
489         case READ_ELEMENT_STATUS:
490                 rq->timeout = READ_ELEMENT_STATUS_TIMEOUT;
491                 break;
492         case READ_DEFECT_DATA:
493                 rq->timeout = READ_DEFECT_DATA_TIMEOUT;
494                 rq->retries = 1;
495                 break;
496         default:
497                 rq->timeout = BLK_DEFAULT_SG_TIMEOUT;
498                 break;
499         }
500
501         if (bytes && blk_rq_map_kern(q, rq, buffer, bytes, __GFP_RECLAIM)) {
502                 err = DRIVER_ERROR << 24;
503                 goto error;
504         }
505
506         memset(sense, 0, sizeof(sense));
507         rq->sense = sense;
508         rq->sense_len = 0;
509
510         blk_execute_rq(q, disk, rq, 0);
511
512         err = rq->errors & 0xff;        /* only 8 bit SCSI status */
513         if (err) {
514                 if (rq->sense_len && rq->sense) {
515                         bytes = (OMAX_SB_LEN > rq->sense_len) ?
516                                 rq->sense_len : OMAX_SB_LEN;
517                         if (copy_to_user(sic->data, rq->sense, bytes))
518                                 err = -EFAULT;
519                 }
520         } else {
521                 if (copy_to_user(sic->data, buffer, out_len))
522                         err = -EFAULT;
523         }
524         
525 error:
526         blk_put_request(rq);
527
528 error_free_buffer:
529         kfree(buffer);
530
531         return err;
532 }
533 EXPORT_SYMBOL_GPL(sg_scsi_ioctl);
534
535 /* Send basic block requests */
536 static int __blk_send_generic(struct request_queue *q, struct gendisk *bd_disk,
537                               int cmd, int data)
538 {
539         struct request *rq;
540         int err;
541
542         rq = blk_get_request(q, WRITE, __GFP_RECLAIM);
543         if (IS_ERR(rq))
544                 return PTR_ERR(rq);
545         blk_rq_set_block_pc(rq);
546         rq->timeout = BLK_DEFAULT_SG_TIMEOUT;
547         rq->cmd[0] = cmd;
548         rq->cmd[4] = data;
549         rq->cmd_len = 6;
550         err = blk_execute_rq(q, bd_disk, rq, 0);
551         blk_put_request(rq);
552
553         return err;
554 }
555
556 static inline int blk_send_start_stop(struct request_queue *q,
557                                       struct gendisk *bd_disk, int data)
558 {
559         return __blk_send_generic(q, bd_disk, GPCMD_START_STOP_UNIT, data);
560 }
561
562 int scsi_cmd_ioctl(struct request_queue *q, struct gendisk *bd_disk, fmode_t mode,
563                    unsigned int cmd, void __user *arg)
564 {
565         int err;
566
567         if (!q)
568                 return -ENXIO;
569
570         switch (cmd) {
571                 /*
572                  * new sgv3 interface
573                  */
574                 case SG_GET_VERSION_NUM:
575                         err = sg_get_version(arg);
576                         break;
577                 case SCSI_IOCTL_GET_IDLUN:
578                         err = scsi_get_idlun(q, arg);
579                         break;
580                 case SCSI_IOCTL_GET_BUS_NUMBER:
581                         err = scsi_get_bus(q, arg);
582                         break;
583                 case SG_SET_TIMEOUT:
584                         err = sg_set_timeout(q, arg);
585                         break;
586                 case SG_GET_TIMEOUT:
587                         err = sg_get_timeout(q);
588                         break;
589                 case SG_GET_RESERVED_SIZE:
590                         err = sg_get_reserved_size(q, arg);
591                         break;
592                 case SG_SET_RESERVED_SIZE:
593                         err = sg_set_reserved_size(q, arg);
594                         break;
595                 case SG_EMULATED_HOST:
596                         err = sg_emulated_host(q, arg);
597                         break;
598                 case SG_IO: {
599                         struct sg_io_hdr hdr;
600
601                         err = -EFAULT;
602                         if (copy_from_user(&hdr, arg, sizeof(hdr)))
603                                 break;
604                         err = sg_io(q, bd_disk, &hdr, mode);
605                         if (err == -EFAULT)
606                                 break;
607
608                         if (copy_to_user(arg, &hdr, sizeof(hdr)))
609                                 err = -EFAULT;
610                         break;
611                 }
612                 case CDROM_SEND_PACKET: {
613                         struct cdrom_generic_command cgc;
614                         struct sg_io_hdr hdr;
615
616                         err = -EFAULT;
617                         if (copy_from_user(&cgc, arg, sizeof(cgc)))
618                                 break;
619                         cgc.timeout = clock_t_to_jiffies(cgc.timeout);
620                         memset(&hdr, 0, sizeof(hdr));
621                         hdr.interface_id = 'S';
622                         hdr.cmd_len = sizeof(cgc.cmd);
623                         hdr.dxfer_len = cgc.buflen;
624                         err = 0;
625                         switch (cgc.data_direction) {
626                                 case CGC_DATA_UNKNOWN:
627                                         hdr.dxfer_direction = SG_DXFER_UNKNOWN;
628                                         break;
629                                 case CGC_DATA_WRITE:
630                                         hdr.dxfer_direction = SG_DXFER_TO_DEV;
631                                         break;
632                                 case CGC_DATA_READ:
633                                         hdr.dxfer_direction = SG_DXFER_FROM_DEV;
634                                         break;
635                                 case CGC_DATA_NONE:
636                                         hdr.dxfer_direction = SG_DXFER_NONE;
637                                         break;
638                                 default:
639                                         err = -EINVAL;
640                         }
641                         if (err)
642                                 break;
643
644                         hdr.dxferp = cgc.buffer;
645                         hdr.sbp = cgc.sense;
646                         if (hdr.sbp)
647                                 hdr.mx_sb_len = sizeof(struct request_sense);
648                         hdr.timeout = jiffies_to_msecs(cgc.timeout);
649                         hdr.cmdp = ((struct cdrom_generic_command __user*) arg)->cmd;
650                         hdr.cmd_len = sizeof(cgc.cmd);
651
652                         err = sg_io(q, bd_disk, &hdr, mode);
653                         if (err == -EFAULT)
654                                 break;
655
656                         if (hdr.status)
657                                 err = -EIO;
658
659                         cgc.stat = err;
660                         cgc.buflen = hdr.resid;
661                         if (copy_to_user(arg, &cgc, sizeof(cgc)))
662                                 err = -EFAULT;
663
664                         break;
665                 }
666
667                 /*
668                  * old junk scsi send command ioctl
669                  */
670                 case SCSI_IOCTL_SEND_COMMAND:
671                         printk(KERN_WARNING "program %s is using a deprecated SCSI ioctl, please convert it to SG_IO\n", current->comm);
672                         err = -EINVAL;
673                         if (!arg)
674                                 break;
675
676                         err = sg_scsi_ioctl(q, bd_disk, mode, arg);
677                         break;
678                 case CDROMCLOSETRAY:
679                         err = blk_send_start_stop(q, bd_disk, 0x03);
680                         break;
681                 case CDROMEJECT:
682                         err = blk_send_start_stop(q, bd_disk, 0x02);
683                         break;
684                 default:
685                         err = -ENOTTY;
686         }
687
688         return err;
689 }
690 EXPORT_SYMBOL(scsi_cmd_ioctl);
691
692 int scsi_verify_blk_ioctl(struct block_device *bd, unsigned int cmd)
693 {
694         if (bd && bd == bd->bd_contains)
695                 return 0;
696
697         /* Actually none of these is particularly useful on a partition,
698          * but they are safe.
699          */
700         switch (cmd) {
701         case SCSI_IOCTL_GET_IDLUN:
702         case SCSI_IOCTL_GET_BUS_NUMBER:
703         case SCSI_IOCTL_GET_PCI:
704         case SCSI_IOCTL_PROBE_HOST:
705         case SG_GET_VERSION_NUM:
706         case SG_SET_TIMEOUT:
707         case SG_GET_TIMEOUT:
708         case SG_GET_RESERVED_SIZE:
709         case SG_SET_RESERVED_SIZE:
710         case SG_EMULATED_HOST:
711                 return 0;
712         case CDROM_GET_CAPABILITY:
713                 /* Keep this until we remove the printk below.  udev sends it
714                  * and we do not want to spam dmesg about it.   CD-ROMs do
715                  * not have partitions, so we get here only for disks.
716                  */
717                 return -ENOIOCTLCMD;
718         default:
719                 break;
720         }
721
722         if (capable(CAP_SYS_RAWIO))
723                 return 0;
724
725         /* In particular, rule out all resets and host-specific ioctls.  */
726         printk_ratelimited(KERN_WARNING
727                            "%s: sending ioctl %x to a partition!\n", current->comm, cmd);
728
729         return -ENOIOCTLCMD;
730 }
731 EXPORT_SYMBOL(scsi_verify_blk_ioctl);
732
733 int scsi_cmd_blk_ioctl(struct block_device *bd, fmode_t mode,
734                        unsigned int cmd, void __user *arg)
735 {
736         int ret;
737
738         ret = scsi_verify_blk_ioctl(bd, cmd);
739         if (ret < 0)
740                 return ret;
741
742         return scsi_cmd_ioctl(bd->bd_disk->queue, bd->bd_disk, mode, cmd, arg);
743 }
744 EXPORT_SYMBOL(scsi_cmd_blk_ioctl);
745
746 static int __init blk_scsi_ioctl_init(void)
747 {
748         blk_set_cmd_filter_defaults(&blk_default_cmd_filter);
749         return 0;
750 }
751 fs_initcall(blk_scsi_ioctl_init);