Version:  2.0.40 2.2.26 2.4.37 3.8 3.9 3.10 3.11 3.12 3.13 3.14 3.15 3.16 3.17 3.18 3.19 4.0 4.1 4.2 4.3 4.4

Linux/block/ioctl.c

  1 #include <linux/capability.h>
  2 #include <linux/blkdev.h>
  3 #include <linux/export.h>
  4 #include <linux/gfp.h>
  5 #include <linux/blkpg.h>
  6 #include <linux/hdreg.h>
  7 #include <linux/backing-dev.h>
  8 #include <linux/fs.h>
  9 #include <linux/blktrace_api.h>
 10 #include <linux/pr.h>
 11 #include <asm/uaccess.h>
 12 
 13 static int blkpg_ioctl(struct block_device *bdev, struct blkpg_ioctl_arg __user *arg)
 14 {
 15         struct block_device *bdevp;
 16         struct gendisk *disk;
 17         struct hd_struct *part, *lpart;
 18         struct blkpg_ioctl_arg a;
 19         struct blkpg_partition p;
 20         struct disk_part_iter piter;
 21         long long start, length;
 22         int partno;
 23 
 24         if (!capable(CAP_SYS_ADMIN))
 25                 return -EACCES;
 26         if (copy_from_user(&a, arg, sizeof(struct blkpg_ioctl_arg)))
 27                 return -EFAULT;
 28         if (copy_from_user(&p, a.data, sizeof(struct blkpg_partition)))
 29                 return -EFAULT;
 30         disk = bdev->bd_disk;
 31         if (bdev != bdev->bd_contains)
 32                 return -EINVAL;
 33         partno = p.pno;
 34         if (partno <= 0)
 35                 return -EINVAL;
 36         switch (a.op) {
 37                 case BLKPG_ADD_PARTITION:
 38                         start = p.start >> 9;
 39                         length = p.length >> 9;
 40                         /* check for fit in a hd_struct */
 41                         if (sizeof(sector_t) == sizeof(long) &&
 42                             sizeof(long long) > sizeof(long)) {
 43                                 long pstart = start, plength = length;
 44                                 if (pstart != start || plength != length
 45                                     || pstart < 0 || plength < 0 || partno > 65535)
 46                                         return -EINVAL;
 47                         }
 48 
 49                         mutex_lock(&bdev->bd_mutex);
 50 
 51                         /* overlap? */
 52                         disk_part_iter_init(&piter, disk,
 53                                             DISK_PITER_INCL_EMPTY);
 54                         while ((part = disk_part_iter_next(&piter))) {
 55                                 if (!(start + length <= part->start_sect ||
 56                                       start >= part->start_sect + part->nr_sects)) {
 57                                         disk_part_iter_exit(&piter);
 58                                         mutex_unlock(&bdev->bd_mutex);
 59                                         return -EBUSY;
 60                                 }
 61                         }
 62                         disk_part_iter_exit(&piter);
 63 
 64                         /* all seems OK */
 65                         part = add_partition(disk, partno, start, length,
 66                                              ADDPART_FLAG_NONE, NULL);
 67                         mutex_unlock(&bdev->bd_mutex);
 68                         return PTR_ERR_OR_ZERO(part);
 69                 case BLKPG_DEL_PARTITION:
 70                         part = disk_get_part(disk, partno);
 71                         if (!part)
 72                                 return -ENXIO;
 73 
 74                         bdevp = bdget(part_devt(part));
 75                         disk_put_part(part);
 76                         if (!bdevp)
 77                                 return -ENOMEM;
 78 
 79                         mutex_lock(&bdevp->bd_mutex);
 80                         if (bdevp->bd_openers) {
 81                                 mutex_unlock(&bdevp->bd_mutex);
 82                                 bdput(bdevp);
 83                                 return -EBUSY;
 84                         }
 85                         /* all seems OK */
 86                         fsync_bdev(bdevp);
 87                         invalidate_bdev(bdevp);
 88 
 89                         mutex_lock_nested(&bdev->bd_mutex, 1);
 90                         delete_partition(disk, partno);
 91                         mutex_unlock(&bdev->bd_mutex);
 92                         mutex_unlock(&bdevp->bd_mutex);
 93                         bdput(bdevp);
 94 
 95                         return 0;
 96                 case BLKPG_RESIZE_PARTITION:
 97                         start = p.start >> 9;
 98                         /* new length of partition in bytes */
 99                         length = p.length >> 9;
100                         /* check for fit in a hd_struct */
101                         if (sizeof(sector_t) == sizeof(long) &&
102                             sizeof(long long) > sizeof(long)) {
103                                 long pstart = start, plength = length;
104                                 if (pstart != start || plength != length
105                                     || pstart < 0 || plength < 0)
106                                         return -EINVAL;
107                         }
108                         part = disk_get_part(disk, partno);
109                         if (!part)
110                                 return -ENXIO;
111                         bdevp = bdget(part_devt(part));
112                         if (!bdevp) {
113                                 disk_put_part(part);
114                                 return -ENOMEM;
115                         }
116                         mutex_lock(&bdevp->bd_mutex);
117                         mutex_lock_nested(&bdev->bd_mutex, 1);
118                         if (start != part->start_sect) {
119                                 mutex_unlock(&bdevp->bd_mutex);
120                                 mutex_unlock(&bdev->bd_mutex);
121                                 bdput(bdevp);
122                                 disk_put_part(part);
123                                 return -EINVAL;
124                         }
125                         /* overlap? */
126                         disk_part_iter_init(&piter, disk,
127                                             DISK_PITER_INCL_EMPTY);
128                         while ((lpart = disk_part_iter_next(&piter))) {
129                                 if (lpart->partno != partno &&
130                                    !(start + length <= lpart->start_sect ||
131                                    start >= lpart->start_sect + lpart->nr_sects)
132                                    ) {
133                                         disk_part_iter_exit(&piter);
134                                         mutex_unlock(&bdevp->bd_mutex);
135                                         mutex_unlock(&bdev->bd_mutex);
136                                         bdput(bdevp);
137                                         disk_put_part(part);
138                                         return -EBUSY;
139                                 }
140                         }
141                         disk_part_iter_exit(&piter);
142                         part_nr_sects_write(part, (sector_t)length);
143                         i_size_write(bdevp->bd_inode, p.length);
144                         mutex_unlock(&bdevp->bd_mutex);
145                         mutex_unlock(&bdev->bd_mutex);
146                         bdput(bdevp);
147                         disk_put_part(part);
148                         return 0;
149                 default:
150                         return -EINVAL;
151         }
152 }
153 
154 /*
155  * This is an exported API for the block driver, and will not
156  * acquire bd_mutex. This API should be used in case that
157  * caller has held bd_mutex already.
158  */
159 int __blkdev_reread_part(struct block_device *bdev)
160 {
161         struct gendisk *disk = bdev->bd_disk;
162 
163         if (!disk_part_scan_enabled(disk) || bdev != bdev->bd_contains)
164                 return -EINVAL;
165         if (!capable(CAP_SYS_ADMIN))
166                 return -EACCES;
167 
168         lockdep_assert_held(&bdev->bd_mutex);
169 
170         return rescan_partitions(disk, bdev);
171 }
172 EXPORT_SYMBOL(__blkdev_reread_part);
173 
174 /*
175  * This is an exported API for the block driver, and will
176  * try to acquire bd_mutex. If bd_mutex has been held already
177  * in current context, please call __blkdev_reread_part().
178  *
179  * Make sure the held locks in current context aren't required
180  * in open()/close() handler and I/O path for avoiding ABBA deadlock:
181  * - bd_mutex is held before calling block driver's open/close
182  *   handler
183  * - reading partition table may submit I/O to the block device
184  */
185 int blkdev_reread_part(struct block_device *bdev)
186 {
187         int res;
188 
189         mutex_lock(&bdev->bd_mutex);
190         res = __blkdev_reread_part(bdev);
191         mutex_unlock(&bdev->bd_mutex);
192 
193         return res;
194 }
195 EXPORT_SYMBOL(blkdev_reread_part);
196 
197 static int blk_ioctl_discard(struct block_device *bdev, fmode_t mode,
198                 unsigned long arg, unsigned long flags)
199 {
200         uint64_t range[2];
201         uint64_t start, len;
202 
203         if (!(mode & FMODE_WRITE))
204                 return -EBADF;
205 
206         if (copy_from_user(range, (void __user *)arg, sizeof(range)))
207                 return -EFAULT;
208 
209         start = range[0];
210         len = range[1];
211 
212         if (start & 511)
213                 return -EINVAL;
214         if (len & 511)
215                 return -EINVAL;
216         start >>= 9;
217         len >>= 9;
218 
219         if (start + len > (i_size_read(bdev->bd_inode) >> 9))
220                 return -EINVAL;
221         return blkdev_issue_discard(bdev, start, len, GFP_KERNEL, flags);
222 }
223 
224 static int blk_ioctl_zeroout(struct block_device *bdev, fmode_t mode,
225                 unsigned long arg)
226 {
227         uint64_t range[2];
228         uint64_t start, len;
229 
230         if (!(mode & FMODE_WRITE))
231                 return -EBADF;
232 
233         if (copy_from_user(range, (void __user *)arg, sizeof(range)))
234                 return -EFAULT;
235 
236         start = range[0];
237         len = range[1];
238 
239         if (start & 511)
240                 return -EINVAL;
241         if (len & 511)
242                 return -EINVAL;
243         start >>= 9;
244         len >>= 9;
245 
246         if (start + len > (i_size_read(bdev->bd_inode) >> 9))
247                 return -EINVAL;
248 
249         return blkdev_issue_zeroout(bdev, start, len, GFP_KERNEL, false);
250 }
251 
252 static int put_ushort(unsigned long arg, unsigned short val)
253 {
254         return put_user(val, (unsigned short __user *)arg);
255 }
256 
257 static int put_int(unsigned long arg, int val)
258 {
259         return put_user(val, (int __user *)arg);
260 }
261 
262 static int put_uint(unsigned long arg, unsigned int val)
263 {
264         return put_user(val, (unsigned int __user *)arg);
265 }
266 
267 static int put_long(unsigned long arg, long val)
268 {
269         return put_user(val, (long __user *)arg);
270 }
271 
272 static int put_ulong(unsigned long arg, unsigned long val)
273 {
274         return put_user(val, (unsigned long __user *)arg);
275 }
276 
277 static int put_u64(unsigned long arg, u64 val)
278 {
279         return put_user(val, (u64 __user *)arg);
280 }
281 
282 int __blkdev_driver_ioctl(struct block_device *bdev, fmode_t mode,
283                         unsigned cmd, unsigned long arg)
284 {
285         struct gendisk *disk = bdev->bd_disk;
286 
287         if (disk->fops->ioctl)
288                 return disk->fops->ioctl(bdev, mode, cmd, arg);
289 
290         return -ENOTTY;
291 }
292 /*
293  * For the record: _GPL here is only because somebody decided to slap it
294  * on the previous export.  Sheer idiocy, since it wasn't copyrightable
295  * at all and could be open-coded without any exports by anybody who cares.
296  */
297 EXPORT_SYMBOL_GPL(__blkdev_driver_ioctl);
298 
299 static int blkdev_pr_register(struct block_device *bdev,
300                 struct pr_registration __user *arg)
301 {
302         const struct pr_ops *ops = bdev->bd_disk->fops->pr_ops;
303         struct pr_registration reg;
304 
305         if (!capable(CAP_SYS_ADMIN))
306                 return -EPERM;
307         if (!ops || !ops->pr_register)
308                 return -EOPNOTSUPP;
309         if (copy_from_user(&reg, arg, sizeof(reg)))
310                 return -EFAULT;
311 
312         if (reg.flags & ~PR_FL_IGNORE_KEY)
313                 return -EOPNOTSUPP;
314         return ops->pr_register(bdev, reg.old_key, reg.new_key, reg.flags);
315 }
316 
317 static int blkdev_pr_reserve(struct block_device *bdev,
318                 struct pr_reservation __user *arg)
319 {
320         const struct pr_ops *ops = bdev->bd_disk->fops->pr_ops;
321         struct pr_reservation rsv;
322 
323         if (!capable(CAP_SYS_ADMIN))
324                 return -EPERM;
325         if (!ops || !ops->pr_reserve)
326                 return -EOPNOTSUPP;
327         if (copy_from_user(&rsv, arg, sizeof(rsv)))
328                 return -EFAULT;
329 
330         if (rsv.flags & ~PR_FL_IGNORE_KEY)
331                 return -EOPNOTSUPP;
332         return ops->pr_reserve(bdev, rsv.key, rsv.type, rsv.flags);
333 }
334 
335 static int blkdev_pr_release(struct block_device *bdev,
336                 struct pr_reservation __user *arg)
337 {
338         const struct pr_ops *ops = bdev->bd_disk->fops->pr_ops;
339         struct pr_reservation rsv;
340 
341         if (!capable(CAP_SYS_ADMIN))
342                 return -EPERM;
343         if (!ops || !ops->pr_release)
344                 return -EOPNOTSUPP;
345         if (copy_from_user(&rsv, arg, sizeof(rsv)))
346                 return -EFAULT;
347 
348         if (rsv.flags)
349                 return -EOPNOTSUPP;
350         return ops->pr_release(bdev, rsv.key, rsv.type);
351 }
352 
353 static int blkdev_pr_preempt(struct block_device *bdev,
354                 struct pr_preempt __user *arg, bool abort)
355 {
356         const struct pr_ops *ops = bdev->bd_disk->fops->pr_ops;
357         struct pr_preempt p;
358 
359         if (!capable(CAP_SYS_ADMIN))
360                 return -EPERM;
361         if (!ops || !ops->pr_preempt)
362                 return -EOPNOTSUPP;
363         if (copy_from_user(&p, arg, sizeof(p)))
364                 return -EFAULT;
365 
366         if (p.flags)
367                 return -EOPNOTSUPP;
368         return ops->pr_preempt(bdev, p.old_key, p.new_key, p.type, abort);
369 }
370 
371 static int blkdev_pr_clear(struct block_device *bdev,
372                 struct pr_clear __user *arg)
373 {
374         const struct pr_ops *ops = bdev->bd_disk->fops->pr_ops;
375         struct pr_clear c;
376 
377         if (!capable(CAP_SYS_ADMIN))
378                 return -EPERM;
379         if (!ops || !ops->pr_clear)
380                 return -EOPNOTSUPP;
381         if (copy_from_user(&c, arg, sizeof(c)))
382                 return -EFAULT;
383 
384         if (c.flags)
385                 return -EOPNOTSUPP;
386         return ops->pr_clear(bdev, c.key);
387 }
388 
389 /*
390  * Is it an unrecognized ioctl? The correct returns are either
391  * ENOTTY (final) or ENOIOCTLCMD ("I don't know this one, try a
392  * fallback"). ENOIOCTLCMD gets turned into ENOTTY by the ioctl
393  * code before returning.
394  *
395  * Confused drivers sometimes return EINVAL, which is wrong. It
396  * means "I understood the ioctl command, but the parameters to
397  * it were wrong".
398  *
399  * We should aim to just fix the broken drivers, the EINVAL case
400  * should go away.
401  */
402 static inline int is_unrecognized_ioctl(int ret)
403 {
404         return  ret == -EINVAL ||
405                 ret == -ENOTTY ||
406                 ret == -ENOIOCTLCMD;
407 }
408 
409 static int blkdev_flushbuf(struct block_device *bdev, fmode_t mode,
410                 unsigned cmd, unsigned long arg)
411 {
412         int ret;
413 
414         if (!capable(CAP_SYS_ADMIN))
415                 return -EACCES;
416 
417         ret = __blkdev_driver_ioctl(bdev, mode, cmd, arg);
418         if (!is_unrecognized_ioctl(ret))
419                 return ret;
420 
421         fsync_bdev(bdev);
422         invalidate_bdev(bdev);
423         return 0;
424 }
425 
426 static int blkdev_roset(struct block_device *bdev, fmode_t mode,
427                 unsigned cmd, unsigned long arg)
428 {
429         int ret, n;
430 
431         ret = __blkdev_driver_ioctl(bdev, mode, cmd, arg);
432         if (!is_unrecognized_ioctl(ret))
433                 return ret;
434         if (!capable(CAP_SYS_ADMIN))
435                 return -EACCES;
436         if (get_user(n, (int __user *)arg))
437                 return -EFAULT;
438         set_device_ro(bdev, n);
439         return 0;
440 }
441 
442 static int blkdev_getgeo(struct block_device *bdev,
443                 struct hd_geometry __user *argp)
444 {
445         struct gendisk *disk = bdev->bd_disk;
446         struct hd_geometry geo;
447         int ret;
448 
449         if (!argp)
450                 return -EINVAL;
451         if (!disk->fops->getgeo)
452                 return -ENOTTY;
453 
454         /*
455          * We need to set the startsect first, the driver may
456          * want to override it.
457          */
458         memset(&geo, 0, sizeof(geo));
459         geo.start = get_start_sect(bdev);
460         ret = disk->fops->getgeo(bdev, &geo);
461         if (ret)
462                 return ret;
463         if (copy_to_user(argp, &geo, sizeof(geo)))
464                 return -EFAULT;
465         return 0;
466 }
467 
468 /* set the logical block size */
469 static int blkdev_bszset(struct block_device *bdev, fmode_t mode,
470                 int __user *argp)
471 {
472         int ret, n;
473 
474         if (!capable(CAP_SYS_ADMIN))
475                 return -EACCES;
476         if (!argp)
477                 return -EINVAL;
478         if (get_user(n, argp))
479                 return -EFAULT;
480 
481         if (!(mode & FMODE_EXCL)) {
482                 bdgrab(bdev);
483                 if (blkdev_get(bdev, mode | FMODE_EXCL, &bdev) < 0)
484                         return -EBUSY;
485         }
486 
487         ret = set_blocksize(bdev, n);
488         if (!(mode & FMODE_EXCL))
489                 blkdev_put(bdev, mode | FMODE_EXCL);
490         return ret;
491 }
492 
493 /*
494  * always keep this in sync with compat_blkdev_ioctl()
495  */
496 int blkdev_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd,
497                         unsigned long arg)
498 {
499         struct backing_dev_info *bdi;
500         void __user *argp = (void __user *)arg;
501         loff_t size;
502         unsigned int max_sectors;
503 
504         switch (cmd) {
505         case BLKFLSBUF:
506                 return blkdev_flushbuf(bdev, mode, cmd, arg);
507         case BLKROSET:
508                 return blkdev_roset(bdev, mode, cmd, arg);
509         case BLKDISCARD:
510                 return blk_ioctl_discard(bdev, mode, arg, 0);
511         case BLKSECDISCARD:
512                 return blk_ioctl_discard(bdev, mode, arg,
513                                 BLKDEV_DISCARD_SECURE);
514         case BLKZEROOUT:
515                 return blk_ioctl_zeroout(bdev, mode, arg);
516         case HDIO_GETGEO:
517                 return blkdev_getgeo(bdev, argp);
518         case BLKRAGET:
519         case BLKFRAGET:
520                 if (!arg)
521                         return -EINVAL;
522                 bdi = blk_get_backing_dev_info(bdev);
523                 return put_long(arg, (bdi->ra_pages * PAGE_CACHE_SIZE) / 512);
524         case BLKROGET:
525                 return put_int(arg, bdev_read_only(bdev) != 0);
526         case BLKBSZGET: /* get block device soft block size (cf. BLKSSZGET) */
527                 return put_int(arg, block_size(bdev));
528         case BLKSSZGET: /* get block device logical block size */
529                 return put_int(arg, bdev_logical_block_size(bdev));
530         case BLKPBSZGET: /* get block device physical block size */
531                 return put_uint(arg, bdev_physical_block_size(bdev));
532         case BLKIOMIN:
533                 return put_uint(arg, bdev_io_min(bdev));
534         case BLKIOOPT:
535                 return put_uint(arg, bdev_io_opt(bdev));
536         case BLKALIGNOFF:
537                 return put_int(arg, bdev_alignment_offset(bdev));
538         case BLKDISCARDZEROES:
539                 return put_uint(arg, bdev_discard_zeroes_data(bdev));
540         case BLKSECTGET:
541                 max_sectors = min_t(unsigned int, USHRT_MAX,
542                                     queue_max_sectors(bdev_get_queue(bdev)));
543                 return put_ushort(arg, max_sectors);
544         case BLKROTATIONAL:
545                 return put_ushort(arg, !blk_queue_nonrot(bdev_get_queue(bdev)));
546         case BLKRASET:
547         case BLKFRASET:
548                 if(!capable(CAP_SYS_ADMIN))
549                         return -EACCES;
550                 bdi = blk_get_backing_dev_info(bdev);
551                 bdi->ra_pages = (arg * 512) / PAGE_CACHE_SIZE;
552                 return 0;
553         case BLKBSZSET:
554                 return blkdev_bszset(bdev, mode, argp);
555         case BLKPG:
556                 return blkpg_ioctl(bdev, argp);
557         case BLKRRPART:
558                 return blkdev_reread_part(bdev);
559         case BLKGETSIZE:
560                 size = i_size_read(bdev->bd_inode);
561                 if ((size >> 9) > ~0UL)
562                         return -EFBIG;
563                 return put_ulong(arg, size >> 9);
564         case BLKGETSIZE64:
565                 return put_u64(arg, i_size_read(bdev->bd_inode));
566         case BLKTRACESTART:
567         case BLKTRACESTOP:
568         case BLKTRACESETUP:
569         case BLKTRACETEARDOWN:
570                 return blk_trace_ioctl(bdev, cmd, argp);
571         case IOC_PR_REGISTER:
572                 return blkdev_pr_register(bdev, argp);
573         case IOC_PR_RESERVE:
574                 return blkdev_pr_reserve(bdev, argp);
575         case IOC_PR_RELEASE:
576                 return blkdev_pr_release(bdev, argp);
577         case IOC_PR_PREEMPT:
578                 return blkdev_pr_preempt(bdev, argp, false);
579         case IOC_PR_PREEMPT_ABORT:
580                 return blkdev_pr_preempt(bdev, argp, true);
581         case IOC_PR_CLEAR:
582                 return blkdev_pr_clear(bdev, argp);
583         default:
584                 return __blkdev_driver_ioctl(bdev, mode, cmd, arg);
585         }
586 }
587 EXPORT_SYMBOL_GPL(blkdev_ioctl);
588 

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