[PATCH] Add scatter-gather support for the block layer SG_IO
[linux-3.10.git] / drivers / 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/completion.h>
25 #include <linux/cdrom.h>
26 #include <linux/slab.h>
27 #include <linux/times.h>
28 #include <asm/uaccess.h>
29
30 #include <scsi/scsi.h>
31 #include <scsi/scsi_ioctl.h>
32 #include <scsi/scsi_cmnd.h>
33
34 /* Command group 3 is reserved and should never be used.  */
35 const unsigned char scsi_command_size[8] =
36 {
37         6, 10, 10, 12,
38         16, 12, 10, 10
39 };
40
41 EXPORT_SYMBOL(scsi_command_size);
42
43 #define BLK_DEFAULT_TIMEOUT     (60 * HZ)
44
45 #include <scsi/sg.h>
46
47 static int sg_get_version(int __user *p)
48 {
49         static int sg_version_num = 30527;
50         return put_user(sg_version_num, p);
51 }
52
53 static int scsi_get_idlun(request_queue_t *q, int __user *p)
54 {
55         return put_user(0, p);
56 }
57
58 static int scsi_get_bus(request_queue_t *q, int __user *p)
59 {
60         return put_user(0, p);
61 }
62
63 static int sg_get_timeout(request_queue_t *q)
64 {
65         return q->sg_timeout / (HZ / USER_HZ);
66 }
67
68 static int sg_set_timeout(request_queue_t *q, int __user *p)
69 {
70         int timeout, err = get_user(timeout, p);
71
72         if (!err)
73                 q->sg_timeout = timeout * (HZ / USER_HZ);
74
75         return err;
76 }
77
78 static int sg_get_reserved_size(request_queue_t *q, int __user *p)
79 {
80         return put_user(q->sg_reserved_size, p);
81 }
82
83 static int sg_set_reserved_size(request_queue_t *q, int __user *p)
84 {
85         int size, err = get_user(size, p);
86
87         if (err)
88                 return err;
89
90         if (size < 0)
91                 return -EINVAL;
92         if (size > (q->max_sectors << 9))
93                 size = q->max_sectors << 9;
94
95         q->sg_reserved_size = size;
96         return 0;
97 }
98
99 /*
100  * will always return that we are ATAPI even for a real SCSI drive, I'm not
101  * so sure this is worth doing anything about (why would you care??)
102  */
103 static int sg_emulated_host(request_queue_t *q, int __user *p)
104 {
105         return put_user(1, p);
106 }
107
108 #define CMD_READ_SAFE   0x01
109 #define CMD_WRITE_SAFE  0x02
110 #define CMD_WARNED      0x04
111 #define safe_for_read(cmd)      [cmd] = CMD_READ_SAFE
112 #define safe_for_write(cmd)     [cmd] = CMD_WRITE_SAFE
113
114 static int verify_command(struct file *file, unsigned char *cmd)
115 {
116         static unsigned char cmd_type[256] = {
117
118                 /* Basic read-only commands */
119                 safe_for_read(TEST_UNIT_READY),
120                 safe_for_read(REQUEST_SENSE),
121                 safe_for_read(READ_6),
122                 safe_for_read(READ_10),
123                 safe_for_read(READ_12),
124                 safe_for_read(READ_16),
125                 safe_for_read(READ_BUFFER),
126                 safe_for_read(READ_LONG),
127                 safe_for_read(INQUIRY),
128                 safe_for_read(MODE_SENSE),
129                 safe_for_read(MODE_SENSE_10),
130                 safe_for_read(LOG_SENSE),
131                 safe_for_read(START_STOP),
132                 safe_for_read(GPCMD_VERIFY_10),
133                 safe_for_read(VERIFY_16),
134
135                 /* Audio CD commands */
136                 safe_for_read(GPCMD_PLAY_CD),
137                 safe_for_read(GPCMD_PLAY_AUDIO_10),
138                 safe_for_read(GPCMD_PLAY_AUDIO_MSF),
139                 safe_for_read(GPCMD_PLAY_AUDIO_TI),
140                 safe_for_read(GPCMD_PAUSE_RESUME),
141
142                 /* CD/DVD data reading */
143                 safe_for_read(GPCMD_READ_BUFFER_CAPACITY),
144                 safe_for_read(GPCMD_READ_CD),
145                 safe_for_read(GPCMD_READ_CD_MSF),
146                 safe_for_read(GPCMD_READ_DISC_INFO),
147                 safe_for_read(GPCMD_READ_CDVD_CAPACITY),
148                 safe_for_read(GPCMD_READ_DVD_STRUCTURE),
149                 safe_for_read(GPCMD_READ_HEADER),
150                 safe_for_read(GPCMD_READ_TRACK_RZONE_INFO),
151                 safe_for_read(GPCMD_READ_SUBCHANNEL),
152                 safe_for_read(GPCMD_READ_TOC_PMA_ATIP),
153                 safe_for_read(GPCMD_REPORT_KEY),
154                 safe_for_read(GPCMD_SCAN),
155                 safe_for_read(GPCMD_GET_CONFIGURATION),
156                 safe_for_read(GPCMD_READ_FORMAT_CAPACITIES),
157                 safe_for_read(GPCMD_GET_EVENT_STATUS_NOTIFICATION),
158                 safe_for_read(GPCMD_GET_PERFORMANCE),
159                 safe_for_read(GPCMD_SEEK),
160                 safe_for_read(GPCMD_STOP_PLAY_SCAN),
161
162                 /* Basic writing commands */
163                 safe_for_write(WRITE_6),
164                 safe_for_write(WRITE_10),
165                 safe_for_write(WRITE_VERIFY),
166                 safe_for_write(WRITE_12),
167                 safe_for_write(WRITE_VERIFY_12),
168                 safe_for_write(WRITE_16),
169                 safe_for_write(WRITE_LONG),
170                 safe_for_write(ERASE),
171                 safe_for_write(GPCMD_MODE_SELECT_10),
172                 safe_for_write(MODE_SELECT),
173                 safe_for_write(LOG_SELECT),
174                 safe_for_write(GPCMD_BLANK),
175                 safe_for_write(GPCMD_CLOSE_TRACK),
176                 safe_for_write(GPCMD_FLUSH_CACHE),
177                 safe_for_write(GPCMD_FORMAT_UNIT),
178                 safe_for_write(GPCMD_REPAIR_RZONE_TRACK),
179                 safe_for_write(GPCMD_RESERVE_RZONE_TRACK),
180                 safe_for_write(GPCMD_SEND_DVD_STRUCTURE),
181                 safe_for_write(GPCMD_SEND_EVENT),
182                 safe_for_write(GPCMD_SEND_KEY),
183                 safe_for_write(GPCMD_SEND_OPC),
184                 safe_for_write(GPCMD_SEND_CUE_SHEET),
185                 safe_for_write(GPCMD_SET_SPEED),
186                 safe_for_write(GPCMD_PREVENT_ALLOW_MEDIUM_REMOVAL),
187                 safe_for_write(GPCMD_LOAD_UNLOAD),
188                 safe_for_write(GPCMD_SET_STREAMING),
189         };
190         unsigned char type = cmd_type[cmd[0]];
191
192         /* Anybody who can open the device can do a read-safe command */
193         if (type & CMD_READ_SAFE)
194                 return 0;
195
196         /* Write-safe commands just require a writable open.. */
197         if (type & CMD_WRITE_SAFE) {
198                 if (file->f_mode & FMODE_WRITE)
199                         return 0;
200         }
201
202         if (!type) {
203                 cmd_type[cmd[0]] = CMD_WARNED;
204                 printk(KERN_WARNING "scsi: unknown opcode 0x%02x\n", cmd[0]);
205         }
206
207         /* And root can do any command.. */
208         if (capable(CAP_SYS_RAWIO))
209                 return 0;
210
211         /* Otherwise fail it with an "Operation not permitted" */
212         return -EPERM;
213 }
214
215 static int sg_io(struct file *file, request_queue_t *q,
216                 struct gendisk *bd_disk, struct sg_io_hdr *hdr)
217 {
218         unsigned long start_time;
219         int reading, writing, ret;
220         struct request *rq;
221         struct bio *bio;
222         char sense[SCSI_SENSE_BUFFERSIZE];
223         unsigned char cmd[BLK_MAX_CDB];
224
225         if (hdr->interface_id != 'S')
226                 return -EINVAL;
227         if (hdr->cmd_len > BLK_MAX_CDB)
228                 return -EINVAL;
229         if (copy_from_user(cmd, hdr->cmdp, hdr->cmd_len))
230                 return -EFAULT;
231         if (verify_command(file, cmd))
232                 return -EPERM;
233
234         if (hdr->dxfer_len > (q->max_sectors << 9))
235                 return -EIO;
236
237         reading = writing = 0;
238         if (hdr->dxfer_len)
239                 switch (hdr->dxfer_direction) {
240                 default:
241                         return -EINVAL;
242                 case SG_DXFER_TO_FROM_DEV:
243                         reading = 1;
244                         /* fall through */
245                 case SG_DXFER_TO_DEV:
246                         writing = 1;
247                         break;
248                 case SG_DXFER_FROM_DEV:
249                         reading = 1;
250                         break;
251                 }
252         }
253
254         rq = blk_get_request(q, writing ? WRITE : READ, GFP_KERNEL);
255         if (!rq)
256                 return -ENOMEM;
257
258         if (hdr->iovec_count) {
259                 const int size = sizeof(struct sg_iovec) * hdr->iovec_count;
260                 struct sg_iovec *iov;
261
262                 iov = kmalloc(size, GFP_KERNEL);
263                 if (!iov) {
264                         ret = -ENOMEM;
265                         goto out;
266                 }
267
268                 if (copy_from_user(iov, hdr->dxferp, size)) {
269                         kfree(iov);
270                         ret = -EFAULT;
271                         goto out;
272                 }
273
274                 ret = blk_rq_map_user_iov(q, rq, iov, hdr->iovec_count);
275                 kfree(iov);
276         } else if (hdr->dxfer_len)
277                 ret = blk_rq_map_user(q, rq, hdr->dxferp, hdr->dxfer_len);
278
279         if (ret)
280                 goto out;
281
282         /*
283          * fill in request structure
284          */
285         rq->cmd_len = hdr->cmd_len;
286         memcpy(rq->cmd, cmd, hdr->cmd_len);
287         if (sizeof(rq->cmd) != hdr->cmd_len)
288                 memset(rq->cmd + hdr->cmd_len, 0, sizeof(rq->cmd) - hdr->cmd_len);
289
290         memset(sense, 0, sizeof(sense));
291         rq->sense = sense;
292         rq->sense_len = 0;
293
294         rq->flags |= REQ_BLOCK_PC;
295         bio = rq->bio;
296
297         /*
298          * bounce this after holding a reference to the original bio, it's
299          * needed for proper unmapping
300          */
301         if (rq->bio)
302                 blk_queue_bounce(q, &rq->bio);
303
304         rq->timeout = (hdr->timeout * HZ) / 1000;
305         if (!rq->timeout)
306                 rq->timeout = q->sg_timeout;
307         if (!rq->timeout)
308                 rq->timeout = BLK_DEFAULT_TIMEOUT;
309
310         start_time = jiffies;
311
312         /* ignore return value. All information is passed back to caller
313          * (if he doesn't check that is his problem).
314          * N.B. a non-zero SCSI status is _not_ necessarily an error.
315          */
316         blk_execute_rq(q, bd_disk, rq);
317
318         /* write to all output members */
319         hdr->status = 0xff & rq->errors;
320         hdr->masked_status = status_byte(rq->errors);
321         hdr->msg_status = msg_byte(rq->errors);
322         hdr->host_status = host_byte(rq->errors);
323         hdr->driver_status = driver_byte(rq->errors);
324         hdr->info = 0;
325         if (hdr->masked_status || hdr->host_status || hdr->driver_status)
326                 hdr->info |= SG_INFO_CHECK;
327         hdr->resid = rq->data_len;
328         hdr->duration = ((jiffies - start_time) * 1000) / HZ;
329         hdr->sb_len_wr = 0;
330
331         if (rq->sense_len && hdr->sbp) {
332                 int len = min((unsigned int) hdr->mx_sb_len, rq->sense_len);
333
334                 if (!copy_to_user(hdr->sbp, rq->sense, len))
335                         hdr->sb_len_wr = len;
336         }
337
338         if (blk_rq_unmap_user(rq, bio, hdr->dxfer_len))
339                 ret = -EFAULT;
340
341         /* may not have succeeded, but output values written to control
342          * structure (struct sg_io_hdr).  */
343 out:
344         blk_put_request(rq);
345         return ret;
346 }
347
348 #define OMAX_SB_LEN 16          /* For backward compatibility */
349
350 static int sg_scsi_ioctl(struct file *file, request_queue_t *q,
351                          struct gendisk *bd_disk, Scsi_Ioctl_Command __user *sic)
352 {
353         struct request *rq;
354         int err;
355         unsigned int in_len, out_len, bytes, opcode, cmdlen;
356         char *buffer = NULL, sense[SCSI_SENSE_BUFFERSIZE];
357
358         /*
359          * get in an out lengths, verify they don't exceed a page worth of data
360          */
361         if (get_user(in_len, &sic->inlen))
362                 return -EFAULT;
363         if (get_user(out_len, &sic->outlen))
364                 return -EFAULT;
365         if (in_len > PAGE_SIZE || out_len > PAGE_SIZE)
366                 return -EINVAL;
367         if (get_user(opcode, sic->data))
368                 return -EFAULT;
369
370         bytes = max(in_len, out_len);
371         if (bytes) {
372                 buffer = kmalloc(bytes, q->bounce_gfp | GFP_USER| __GFP_NOWARN);
373                 if (!buffer)
374                         return -ENOMEM;
375
376                 memset(buffer, 0, bytes);
377         }
378
379         rq = blk_get_request(q, in_len ? WRITE : READ, __GFP_WAIT);
380
381         cmdlen = COMMAND_SIZE(opcode);
382
383         /*
384          * get command and data to send to device, if any
385          */
386         err = -EFAULT;
387         rq->cmd_len = cmdlen;
388         if (copy_from_user(rq->cmd, sic->data, cmdlen))
389                 goto error;
390
391         if (copy_from_user(buffer, sic->data + cmdlen, in_len))
392                 goto error;
393
394         err = verify_command(file, rq->cmd);
395         if (err)
396                 goto error;
397
398         switch (opcode) {
399                 case SEND_DIAGNOSTIC:
400                 case FORMAT_UNIT:
401                         rq->timeout = FORMAT_UNIT_TIMEOUT;
402                         break;
403                 case START_STOP:
404                         rq->timeout = START_STOP_TIMEOUT;
405                         break;
406                 case MOVE_MEDIUM:
407                         rq->timeout = MOVE_MEDIUM_TIMEOUT;
408                         break;
409                 case READ_ELEMENT_STATUS:
410                         rq->timeout = READ_ELEMENT_STATUS_TIMEOUT;
411                         break;
412                 case READ_DEFECT_DATA:
413                         rq->timeout = READ_DEFECT_DATA_TIMEOUT;
414                         break;
415                 default:
416                         rq->timeout = BLK_DEFAULT_TIMEOUT;
417                         break;
418         }
419
420         memset(sense, 0, sizeof(sense));
421         rq->sense = sense;
422         rq->sense_len = 0;
423
424         rq->data = buffer;
425         rq->data_len = bytes;
426         rq->flags |= REQ_BLOCK_PC;
427
428         blk_execute_rq(q, bd_disk, rq);
429         err = rq->errors & 0xff;        /* only 8 bit SCSI status */
430         if (err) {
431                 if (rq->sense_len && rq->sense) {
432                         bytes = (OMAX_SB_LEN > rq->sense_len) ?
433                                 rq->sense_len : OMAX_SB_LEN;
434                         if (copy_to_user(sic->data, rq->sense, bytes))
435                                 err = -EFAULT;
436                 }
437         } else {
438                 if (copy_to_user(sic->data, buffer, out_len))
439                         err = -EFAULT;
440         }
441         
442 error:
443         kfree(buffer);
444         blk_put_request(rq);
445         return err;
446 }
447
448 int scsi_cmd_ioctl(struct file *file, struct gendisk *bd_disk, unsigned int cmd, void __user *arg)
449 {
450         request_queue_t *q;
451         struct request *rq;
452         int close = 0, err;
453
454         q = bd_disk->queue;
455         if (!q)
456                 return -ENXIO;
457
458         if (blk_get_queue(q))
459                 return -ENXIO;
460
461         switch (cmd) {
462                 /*
463                  * new sgv3 interface
464                  */
465                 case SG_GET_VERSION_NUM:
466                         err = sg_get_version(arg);
467                         break;
468                 case SCSI_IOCTL_GET_IDLUN:
469                         err = scsi_get_idlun(q, arg);
470                         break;
471                 case SCSI_IOCTL_GET_BUS_NUMBER:
472                         err = scsi_get_bus(q, arg);
473                         break;
474                 case SG_SET_TIMEOUT:
475                         err = sg_set_timeout(q, arg);
476                         break;
477                 case SG_GET_TIMEOUT:
478                         err = sg_get_timeout(q);
479                         break;
480                 case SG_GET_RESERVED_SIZE:
481                         err = sg_get_reserved_size(q, arg);
482                         break;
483                 case SG_SET_RESERVED_SIZE:
484                         err = sg_set_reserved_size(q, arg);
485                         break;
486                 case SG_EMULATED_HOST:
487                         err = sg_emulated_host(q, arg);
488                         break;
489                 case SG_IO: {
490                         struct sg_io_hdr hdr;
491
492                         err = -EFAULT;
493                         if (copy_from_user(&hdr, arg, sizeof(hdr)))
494                                 break;
495                         err = sg_io(file, q, bd_disk, &hdr);
496                         if (err == -EFAULT)
497                                 break;
498
499                         if (copy_to_user(arg, &hdr, sizeof(hdr)))
500                                 err = -EFAULT;
501                         break;
502                 }
503                 case CDROM_SEND_PACKET: {
504                         struct cdrom_generic_command cgc;
505                         struct sg_io_hdr hdr;
506
507                         err = -EFAULT;
508                         if (copy_from_user(&cgc, arg, sizeof(cgc)))
509                                 break;
510                         cgc.timeout = clock_t_to_jiffies(cgc.timeout);
511                         memset(&hdr, 0, sizeof(hdr));
512                         hdr.interface_id = 'S';
513                         hdr.cmd_len = sizeof(cgc.cmd);
514                         hdr.dxfer_len = cgc.buflen;
515                         err = 0;
516                         switch (cgc.data_direction) {
517                                 case CGC_DATA_UNKNOWN:
518                                         hdr.dxfer_direction = SG_DXFER_UNKNOWN;
519                                         break;
520                                 case CGC_DATA_WRITE:
521                                         hdr.dxfer_direction = SG_DXFER_TO_DEV;
522                                         break;
523                                 case CGC_DATA_READ:
524                                         hdr.dxfer_direction = SG_DXFER_FROM_DEV;
525                                         break;
526                                 case CGC_DATA_NONE:
527                                         hdr.dxfer_direction = SG_DXFER_NONE;
528                                         break;
529                                 default:
530                                         err = -EINVAL;
531                         }
532                         if (err)
533                                 break;
534
535                         hdr.dxferp = cgc.buffer;
536                         hdr.sbp = cgc.sense;
537                         if (hdr.sbp)
538                                 hdr.mx_sb_len = sizeof(struct request_sense);
539                         hdr.timeout = cgc.timeout;
540                         hdr.cmdp = ((struct cdrom_generic_command __user*) arg)->cmd;
541                         hdr.cmd_len = sizeof(cgc.cmd);
542
543                         err = sg_io(file, q, bd_disk, &hdr);
544                         if (err == -EFAULT)
545                                 break;
546
547                         if (hdr.status)
548                                 err = -EIO;
549
550                         cgc.stat = err;
551                         cgc.buflen = hdr.resid;
552                         if (copy_to_user(arg, &cgc, sizeof(cgc)))
553                                 err = -EFAULT;
554
555                         break;
556                 }
557
558                 /*
559                  * old junk scsi send command ioctl
560                  */
561                 case SCSI_IOCTL_SEND_COMMAND:
562                         printk(KERN_WARNING "program %s is using a deprecated SCSI ioctl, please convert it to SG_IO\n", current->comm);
563                         err = -EINVAL;
564                         if (!arg)
565                                 break;
566
567                         err = sg_scsi_ioctl(file, q, bd_disk, arg);
568                         break;
569                 case CDROMCLOSETRAY:
570                         close = 1;
571                 case CDROMEJECT:
572                         rq = blk_get_request(q, WRITE, __GFP_WAIT);
573                         rq->flags |= REQ_BLOCK_PC;
574                         rq->data = NULL;
575                         rq->data_len = 0;
576                         rq->timeout = BLK_DEFAULT_TIMEOUT;
577                         memset(rq->cmd, 0, sizeof(rq->cmd));
578                         rq->cmd[0] = GPCMD_START_STOP_UNIT;
579                         rq->cmd[4] = 0x02 + (close != 0);
580                         rq->cmd_len = 6;
581                         err = blk_execute_rq(q, bd_disk, rq);
582                         blk_put_request(rq);
583                         break;
584                 default:
585                         err = -ENOTTY;
586         }
587
588         blk_put_queue(q);
589         return err;
590 }
591
592 EXPORT_SYMBOL(scsi_cmd_ioctl);