SLUB: Alternate fast paths using cmpxchg_local
[linux-2.6/openmoko-kernel/knife-kernel.git] / block / scsi_ioctl.c
blob9675b34638d4824b566e9df643042239bbf04e05
1 /*
2 * Copyright (C) 2001 Jens Axboe <axboe@suse.de>
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.
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
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-
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/slab.h>
28 #include <linux/times.h>
29 #include <asm/uaccess.h>
31 #include <scsi/scsi.h>
32 #include <scsi/scsi_ioctl.h>
33 #include <scsi/scsi_cmnd.h>
35 /* Command group 3 is reserved and should never be used. */
36 const unsigned char scsi_command_size[8] =
38 6, 10, 10, 12,
39 16, 12, 10, 10
42 EXPORT_SYMBOL(scsi_command_size);
44 #include <scsi/sg.h>
46 static int sg_get_version(int __user *p)
48 static const int sg_version_num = 30527;
49 return put_user(sg_version_num, p);
52 static int scsi_get_idlun(struct request_queue *q, int __user *p)
54 return put_user(0, p);
57 static int scsi_get_bus(struct request_queue *q, int __user *p)
59 return put_user(0, p);
62 static int sg_get_timeout(struct request_queue *q)
64 return q->sg_timeout / (HZ / USER_HZ);
67 static int sg_set_timeout(struct request_queue *q, int __user *p)
69 int timeout, err = get_user(timeout, p);
71 if (!err)
72 q->sg_timeout = timeout * (HZ / USER_HZ);
74 return err;
77 static int sg_get_reserved_size(struct request_queue *q, int __user *p)
79 unsigned val = min(q->sg_reserved_size, q->max_sectors << 9);
81 return put_user(val, p);
84 static int sg_set_reserved_size(struct request_queue *q, int __user *p)
86 int size, err = get_user(size, p);
88 if (err)
89 return err;
91 if (size < 0)
92 return -EINVAL;
93 if (size > (q->max_sectors << 9))
94 size = q->max_sectors << 9;
96 q->sg_reserved_size = size;
97 return 0;
101 * will always return that we are ATAPI even for a real SCSI drive, I'm not
102 * so sure this is worth doing anything about (why would you care??)
104 static int sg_emulated_host(struct request_queue *q, int __user *p)
106 return put_user(1, p);
109 #define CMD_READ_SAFE 0x01
110 #define CMD_WRITE_SAFE 0x02
111 #define CMD_WARNED 0x04
112 #define safe_for_read(cmd) [cmd] = CMD_READ_SAFE
113 #define safe_for_write(cmd) [cmd] = CMD_WRITE_SAFE
115 int blk_verify_command(unsigned char *cmd, int has_write_perm)
117 static unsigned char cmd_type[256] = {
119 /* Basic read-only commands */
120 safe_for_read(TEST_UNIT_READY),
121 safe_for_read(REQUEST_SENSE),
122 safe_for_read(READ_6),
123 safe_for_read(READ_10),
124 safe_for_read(READ_12),
125 safe_for_read(READ_16),
126 safe_for_read(READ_BUFFER),
127 safe_for_read(READ_DEFECT_DATA),
128 safe_for_read(READ_LONG),
129 safe_for_read(INQUIRY),
130 safe_for_read(MODE_SENSE),
131 safe_for_read(MODE_SENSE_10),
132 safe_for_read(LOG_SENSE),
133 safe_for_read(START_STOP),
134 safe_for_read(GPCMD_VERIFY_10),
135 safe_for_read(VERIFY_16),
137 /* Audio CD commands */
138 safe_for_read(GPCMD_PLAY_CD),
139 safe_for_read(GPCMD_PLAY_AUDIO_10),
140 safe_for_read(GPCMD_PLAY_AUDIO_MSF),
141 safe_for_read(GPCMD_PLAY_AUDIO_TI),
142 safe_for_read(GPCMD_PAUSE_RESUME),
144 /* CD/DVD data reading */
145 safe_for_read(GPCMD_READ_BUFFER_CAPACITY),
146 safe_for_read(GPCMD_READ_CD),
147 safe_for_read(GPCMD_READ_CD_MSF),
148 safe_for_read(GPCMD_READ_DISC_INFO),
149 safe_for_read(GPCMD_READ_CDVD_CAPACITY),
150 safe_for_read(GPCMD_READ_DVD_STRUCTURE),
151 safe_for_read(GPCMD_READ_HEADER),
152 safe_for_read(GPCMD_READ_TRACK_RZONE_INFO),
153 safe_for_read(GPCMD_READ_SUBCHANNEL),
154 safe_for_read(GPCMD_READ_TOC_PMA_ATIP),
155 safe_for_read(GPCMD_REPORT_KEY),
156 safe_for_read(GPCMD_SCAN),
157 safe_for_read(GPCMD_GET_CONFIGURATION),
158 safe_for_read(GPCMD_READ_FORMAT_CAPACITIES),
159 safe_for_read(GPCMD_GET_EVENT_STATUS_NOTIFICATION),
160 safe_for_read(GPCMD_GET_PERFORMANCE),
161 safe_for_read(GPCMD_SEEK),
162 safe_for_read(GPCMD_STOP_PLAY_SCAN),
164 /* Basic writing commands */
165 safe_for_write(WRITE_6),
166 safe_for_write(WRITE_10),
167 safe_for_write(WRITE_VERIFY),
168 safe_for_write(WRITE_12),
169 safe_for_write(WRITE_VERIFY_12),
170 safe_for_write(WRITE_16),
171 safe_for_write(WRITE_LONG),
172 safe_for_write(WRITE_LONG_2),
173 safe_for_write(ERASE),
174 safe_for_write(GPCMD_MODE_SELECT_10),
175 safe_for_write(MODE_SELECT),
176 safe_for_write(LOG_SELECT),
177 safe_for_write(GPCMD_BLANK),
178 safe_for_write(GPCMD_CLOSE_TRACK),
179 safe_for_write(GPCMD_FLUSH_CACHE),
180 safe_for_write(GPCMD_FORMAT_UNIT),
181 safe_for_write(GPCMD_REPAIR_RZONE_TRACK),
182 safe_for_write(GPCMD_RESERVE_RZONE_TRACK),
183 safe_for_write(GPCMD_SEND_DVD_STRUCTURE),
184 safe_for_write(GPCMD_SEND_EVENT),
185 safe_for_write(GPCMD_SEND_KEY),
186 safe_for_write(GPCMD_SEND_OPC),
187 safe_for_write(GPCMD_SEND_CUE_SHEET),
188 safe_for_write(GPCMD_SET_SPEED),
189 safe_for_write(GPCMD_PREVENT_ALLOW_MEDIUM_REMOVAL),
190 safe_for_write(GPCMD_LOAD_UNLOAD),
191 safe_for_write(GPCMD_SET_STREAMING),
193 unsigned char type = cmd_type[cmd[0]];
195 /* Anybody who can open the device can do a read-safe command */
196 if (type & CMD_READ_SAFE)
197 return 0;
199 /* Write-safe commands just require a writable open.. */
200 if ((type & CMD_WRITE_SAFE) && has_write_perm)
201 return 0;
203 /* And root can do any command.. */
204 if (capable(CAP_SYS_RAWIO))
205 return 0;
207 if (!type) {
208 cmd_type[cmd[0]] = CMD_WARNED;
209 printk(KERN_WARNING "scsi: unknown opcode 0x%02x\n", cmd[0]);
212 /* Otherwise fail it with an "Operation not permitted" */
213 return -EPERM;
215 EXPORT_SYMBOL_GPL(blk_verify_command);
217 static int blk_fill_sghdr_rq(struct request_queue *q, struct request *rq,
218 struct sg_io_hdr *hdr, int has_write_perm)
220 memset(rq->cmd, 0, BLK_MAX_CDB); /* ATAPI hates garbage after CDB */
222 if (copy_from_user(rq->cmd, hdr->cmdp, hdr->cmd_len))
223 return -EFAULT;
224 if (blk_verify_command(rq->cmd, has_write_perm))
225 return -EPERM;
228 * fill in request structure
230 rq->cmd_len = hdr->cmd_len;
231 rq->cmd_type = REQ_TYPE_BLOCK_PC;
233 rq->timeout = msecs_to_jiffies(hdr->timeout);
234 if (!rq->timeout)
235 rq->timeout = q->sg_timeout;
236 if (!rq->timeout)
237 rq->timeout = BLK_DEFAULT_SG_TIMEOUT;
239 return 0;
243 * unmap a request that was previously mapped to this sg_io_hdr. handles
244 * both sg and non-sg sg_io_hdr.
246 static int blk_unmap_sghdr_rq(struct request *rq, struct sg_io_hdr *hdr)
248 blk_rq_unmap_user(rq->bio);
249 blk_put_request(rq);
250 return 0;
253 static int blk_complete_sghdr_rq(struct request *rq, struct sg_io_hdr *hdr,
254 struct bio *bio)
256 int r, ret = 0;
259 * fill in all the output members
261 hdr->status = rq->errors & 0xff;
262 hdr->masked_status = status_byte(rq->errors);
263 hdr->msg_status = msg_byte(rq->errors);
264 hdr->host_status = host_byte(rq->errors);
265 hdr->driver_status = driver_byte(rq->errors);
266 hdr->info = 0;
267 if (hdr->masked_status || hdr->host_status || hdr->driver_status)
268 hdr->info |= SG_INFO_CHECK;
269 hdr->resid = rq->data_len;
270 hdr->sb_len_wr = 0;
272 if (rq->sense_len && hdr->sbp) {
273 int len = min((unsigned int) hdr->mx_sb_len, rq->sense_len);
275 if (!copy_to_user(hdr->sbp, rq->sense, len))
276 hdr->sb_len_wr = len;
277 else
278 ret = -EFAULT;
281 rq->bio = bio;
282 r = blk_unmap_sghdr_rq(rq, hdr);
283 if (ret)
284 r = ret;
286 return r;
289 static int sg_io(struct file *file, struct request_queue *q,
290 struct gendisk *bd_disk, struct sg_io_hdr *hdr)
292 unsigned long start_time;
293 int writing = 0, ret = 0, has_write_perm = 0;
294 struct request *rq;
295 char sense[SCSI_SENSE_BUFFERSIZE];
296 struct bio *bio;
298 if (hdr->interface_id != 'S')
299 return -EINVAL;
300 if (hdr->cmd_len > BLK_MAX_CDB)
301 return -EINVAL;
303 if (hdr->dxfer_len > (q->max_hw_sectors << 9))
304 return -EIO;
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;
318 rq = blk_get_request(q, writing ? WRITE : READ, GFP_KERNEL);
319 if (!rq)
320 return -ENOMEM;
322 if (file)
323 has_write_perm = file->f_mode & FMODE_WRITE;
325 if (blk_fill_sghdr_rq(q, rq, hdr, has_write_perm)) {
326 blk_put_request(rq);
327 return -EFAULT;
330 if (hdr->iovec_count) {
331 const int size = sizeof(struct sg_iovec) * hdr->iovec_count;
332 struct sg_iovec *iov;
334 iov = kmalloc(size, GFP_KERNEL);
335 if (!iov) {
336 ret = -ENOMEM;
337 goto out;
340 if (copy_from_user(iov, hdr->dxferp, size)) {
341 kfree(iov);
342 ret = -EFAULT;
343 goto out;
346 ret = blk_rq_map_user_iov(q, rq, iov, hdr->iovec_count,
347 hdr->dxfer_len);
348 kfree(iov);
349 } else if (hdr->dxfer_len)
350 ret = blk_rq_map_user(q, rq, hdr->dxferp, hdr->dxfer_len);
352 if (ret)
353 goto out;
355 bio = rq->bio;
356 memset(sense, 0, sizeof(sense));
357 rq->sense = sense;
358 rq->sense_len = 0;
359 rq->retries = 0;
361 start_time = jiffies;
363 /* ignore return value. All information is passed back to caller
364 * (if he doesn't check that is his problem).
365 * N.B. a non-zero SCSI status is _not_ necessarily an error.
367 blk_execute_rq(q, bd_disk, rq, 0);
369 hdr->duration = jiffies_to_msecs(jiffies - start_time);
371 return blk_complete_sghdr_rq(rq, hdr, bio);
372 out:
373 blk_put_request(rq);
374 return ret;
378 * sg_scsi_ioctl -- handle deprecated SCSI_IOCTL_SEND_COMMAND ioctl
379 * @file: file this ioctl operates on (optional)
380 * @q: request queue to send scsi commands down
381 * @disk: gendisk to operate on (option)
382 * @sic: userspace structure describing the command to perform
384 * Send down the scsi command described by @sic to the device below
385 * the request queue @q. If @file is non-NULL it's used to perform
386 * fine-grained permission checks that allow users to send down
387 * non-destructive SCSI commands. If the caller has a struct gendisk
388 * available it should be passed in as @disk to allow the low level
389 * driver to use the information contained in it. A non-NULL @disk
390 * is only allowed if the caller knows that the low level driver doesn't
391 * need it (e.g. in the scsi subsystem).
393 * Notes:
394 * - This interface is deprecated - users should use the SG_IO
395 * interface instead, as this is a more flexible approach to
396 * performing SCSI commands on a device.
397 * - The SCSI command length is determined by examining the 1st byte
398 * of the given command. There is no way to override this.
399 * - Data transfers are limited to PAGE_SIZE
400 * - The length (x + y) must be at least OMAX_SB_LEN bytes long to
401 * accommodate the sense buffer when an error occurs.
402 * The sense buffer is truncated to OMAX_SB_LEN (16) bytes so that
403 * old code will not be surprised.
404 * - If a Unix error occurs (e.g. ENOMEM) then the user will receive
405 * a negative return and the Unix error code in 'errno'.
406 * If the SCSI command succeeds then 0 is returned.
407 * Positive numbers returned are the compacted SCSI error codes (4
408 * bytes in one int) where the lowest byte is the SCSI status.
410 #define OMAX_SB_LEN 16 /* For backward compatibility */
411 int sg_scsi_ioctl(struct file *file, struct request_queue *q,
412 struct gendisk *disk, struct scsi_ioctl_command __user *sic)
414 struct request *rq;
415 int err;
416 unsigned int in_len, out_len, bytes, opcode, cmdlen;
417 char *buffer = NULL, sense[SCSI_SENSE_BUFFERSIZE];
419 if (!sic)
420 return -EINVAL;
423 * get in an out lengths, verify they don't exceed a page worth of data
425 if (get_user(in_len, &sic->inlen))
426 return -EFAULT;
427 if (get_user(out_len, &sic->outlen))
428 return -EFAULT;
429 if (in_len > PAGE_SIZE || out_len > PAGE_SIZE)
430 return -EINVAL;
431 if (get_user(opcode, sic->data))
432 return -EFAULT;
434 bytes = max(in_len, out_len);
435 if (bytes) {
436 buffer = kzalloc(bytes, q->bounce_gfp | GFP_USER| __GFP_NOWARN);
437 if (!buffer)
438 return -ENOMEM;
442 rq = blk_get_request(q, in_len ? WRITE : READ, __GFP_WAIT);
444 cmdlen = COMMAND_SIZE(opcode);
447 * get command and data to send to device, if any
449 err = -EFAULT;
450 rq->cmd_len = cmdlen;
451 if (copy_from_user(rq->cmd, sic->data, cmdlen))
452 goto error;
454 if (in_len && copy_from_user(buffer, sic->data + cmdlen, in_len))
455 goto error;
457 err = blk_verify_command(rq->cmd, file->f_mode & FMODE_WRITE);
458 if (err)
459 goto error;
461 /* default. possible overriden later */
462 rq->retries = 5;
464 switch (opcode) {
465 case SEND_DIAGNOSTIC:
466 case FORMAT_UNIT:
467 rq->timeout = FORMAT_UNIT_TIMEOUT;
468 rq->retries = 1;
469 break;
470 case START_STOP:
471 rq->timeout = START_STOP_TIMEOUT;
472 break;
473 case MOVE_MEDIUM:
474 rq->timeout = MOVE_MEDIUM_TIMEOUT;
475 break;
476 case READ_ELEMENT_STATUS:
477 rq->timeout = READ_ELEMENT_STATUS_TIMEOUT;
478 break;
479 case READ_DEFECT_DATA:
480 rq->timeout = READ_DEFECT_DATA_TIMEOUT;
481 rq->retries = 1;
482 break;
483 default:
484 rq->timeout = BLK_DEFAULT_SG_TIMEOUT;
485 break;
488 if (bytes && blk_rq_map_kern(q, rq, buffer, bytes, __GFP_WAIT)) {
489 err = DRIVER_ERROR << 24;
490 goto out;
493 memset(sense, 0, sizeof(sense));
494 rq->sense = sense;
495 rq->sense_len = 0;
496 rq->cmd_type = REQ_TYPE_BLOCK_PC;
498 blk_execute_rq(q, disk, rq, 0);
500 out:
501 err = rq->errors & 0xff; /* only 8 bit SCSI status */
502 if (err) {
503 if (rq->sense_len && rq->sense) {
504 bytes = (OMAX_SB_LEN > rq->sense_len) ?
505 rq->sense_len : OMAX_SB_LEN;
506 if (copy_to_user(sic->data, rq->sense, bytes))
507 err = -EFAULT;
509 } else {
510 if (copy_to_user(sic->data, buffer, out_len))
511 err = -EFAULT;
514 error:
515 kfree(buffer);
516 blk_put_request(rq);
517 return err;
519 EXPORT_SYMBOL_GPL(sg_scsi_ioctl);
521 /* Send basic block requests */
522 static int __blk_send_generic(struct request_queue *q, struct gendisk *bd_disk,
523 int cmd, int data)
525 struct request *rq;
526 int err;
528 rq = blk_get_request(q, WRITE, __GFP_WAIT);
529 rq->cmd_type = REQ_TYPE_BLOCK_PC;
530 rq->data = NULL;
531 rq->data_len = 0;
532 rq->timeout = BLK_DEFAULT_SG_TIMEOUT;
533 memset(rq->cmd, 0, sizeof(rq->cmd));
534 rq->cmd[0] = cmd;
535 rq->cmd[4] = data;
536 rq->cmd_len = 6;
537 err = blk_execute_rq(q, bd_disk, rq, 0);
538 blk_put_request(rq);
540 return err;
543 static inline int blk_send_start_stop(struct request_queue *q,
544 struct gendisk *bd_disk, int data)
546 return __blk_send_generic(q, bd_disk, GPCMD_START_STOP_UNIT, data);
549 int scsi_cmd_ioctl(struct file *file, struct request_queue *q,
550 struct gendisk *bd_disk, unsigned int cmd, void __user *arg)
552 int err;
554 if (!q || blk_get_queue(q))
555 return -ENXIO;
557 switch (cmd) {
559 * new sgv3 interface
561 case SG_GET_VERSION_NUM:
562 err = sg_get_version(arg);
563 break;
564 case SCSI_IOCTL_GET_IDLUN:
565 err = scsi_get_idlun(q, arg);
566 break;
567 case SCSI_IOCTL_GET_BUS_NUMBER:
568 err = scsi_get_bus(q, arg);
569 break;
570 case SG_SET_TIMEOUT:
571 err = sg_set_timeout(q, arg);
572 break;
573 case SG_GET_TIMEOUT:
574 err = sg_get_timeout(q);
575 break;
576 case SG_GET_RESERVED_SIZE:
577 err = sg_get_reserved_size(q, arg);
578 break;
579 case SG_SET_RESERVED_SIZE:
580 err = sg_set_reserved_size(q, arg);
581 break;
582 case SG_EMULATED_HOST:
583 err = sg_emulated_host(q, arg);
584 break;
585 case SG_IO: {
586 struct sg_io_hdr hdr;
588 err = -EFAULT;
589 if (copy_from_user(&hdr, arg, sizeof(hdr)))
590 break;
591 err = sg_io(file, q, bd_disk, &hdr);
592 if (err == -EFAULT)
593 break;
595 if (copy_to_user(arg, &hdr, sizeof(hdr)))
596 err = -EFAULT;
597 break;
599 case CDROM_SEND_PACKET: {
600 struct cdrom_generic_command cgc;
601 struct sg_io_hdr hdr;
603 err = -EFAULT;
604 if (copy_from_user(&cgc, arg, sizeof(cgc)))
605 break;
606 cgc.timeout = clock_t_to_jiffies(cgc.timeout);
607 memset(&hdr, 0, sizeof(hdr));
608 hdr.interface_id = 'S';
609 hdr.cmd_len = sizeof(cgc.cmd);
610 hdr.dxfer_len = cgc.buflen;
611 err = 0;
612 switch (cgc.data_direction) {
613 case CGC_DATA_UNKNOWN:
614 hdr.dxfer_direction = SG_DXFER_UNKNOWN;
615 break;
616 case CGC_DATA_WRITE:
617 hdr.dxfer_direction = SG_DXFER_TO_DEV;
618 break;
619 case CGC_DATA_READ:
620 hdr.dxfer_direction = SG_DXFER_FROM_DEV;
621 break;
622 case CGC_DATA_NONE:
623 hdr.dxfer_direction = SG_DXFER_NONE;
624 break;
625 default:
626 err = -EINVAL;
628 if (err)
629 break;
631 hdr.dxferp = cgc.buffer;
632 hdr.sbp = cgc.sense;
633 if (hdr.sbp)
634 hdr.mx_sb_len = sizeof(struct request_sense);
635 hdr.timeout = cgc.timeout;
636 hdr.cmdp = ((struct cdrom_generic_command __user*) arg)->cmd;
637 hdr.cmd_len = sizeof(cgc.cmd);
639 err = sg_io(file, q, bd_disk, &hdr);
640 if (err == -EFAULT)
641 break;
643 if (hdr.status)
644 err = -EIO;
646 cgc.stat = err;
647 cgc.buflen = hdr.resid;
648 if (copy_to_user(arg, &cgc, sizeof(cgc)))
649 err = -EFAULT;
651 break;
655 * old junk scsi send command ioctl
657 case SCSI_IOCTL_SEND_COMMAND:
658 printk(KERN_WARNING "program %s is using a deprecated SCSI ioctl, please convert it to SG_IO\n", current->comm);
659 err = -EINVAL;
660 if (!arg)
661 break;
663 err = sg_scsi_ioctl(file, q, bd_disk, arg);
664 break;
665 case CDROMCLOSETRAY:
666 err = blk_send_start_stop(q, bd_disk, 0x03);
667 break;
668 case CDROMEJECT:
669 err = blk_send_start_stop(q, bd_disk, 0x02);
670 break;
671 default:
672 err = -ENOTTY;
675 blk_put_queue(q);
676 return err;
679 EXPORT_SYMBOL(scsi_cmd_ioctl);