Version:  2.0.40 2.2.26 2.4.37 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 4.5 4.6 4.7 4.8 4.9

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         struct address_space *mapping;
229         uint64_t start, end, len;
230 
231         if (!(mode & FMODE_WRITE))
232                 return -EBADF;
233 
234         if (copy_from_user(range, (void __user *)arg, sizeof(range)))
235                 return -EFAULT;
236 
237         start = range[0];
238         len = range[1];
239         end = start + len - 1;
240 
241         if (start & 511)
242                 return -EINVAL;
243         if (len & 511)
244                 return -EINVAL;
245         if (end >= (uint64_t)i_size_read(bdev->bd_inode))
246                 return -EINVAL;
247         if (end < start)
248                 return -EINVAL;
249 
250         /* Invalidate the page cache, including dirty pages */
251         mapping = bdev->bd_inode->i_mapping;
252         truncate_inode_pages_range(mapping, start, end);
253 
254         return blkdev_issue_zeroout(bdev, start >> 9, len >> 9, GFP_KERNEL,
255                                     false);
256 }
257 
258 static int put_ushort(unsigned long arg, unsigned short val)
259 {
260         return put_user(val, (unsigned short __user *)arg);
261 }
262 
263 static int put_int(unsigned long arg, int val)
264 {
265         return put_user(val, (int __user *)arg);
266 }
267 
268 static int put_uint(unsigned long arg, unsigned int val)
269 {
270         return put_user(val, (unsigned int __user *)arg);
271 }
272 
273 static int put_long(unsigned long arg, long val)
274 {
275         return put_user(val, (long __user *)arg);
276 }
277 
278 static int put_ulong(unsigned long arg, unsigned long val)
279 {
280         return put_user(val, (unsigned long __user *)arg);
281 }
282 
283 static int put_u64(unsigned long arg, u64 val)
284 {
285         return put_user(val, (u64 __user *)arg);
286 }
287 
288 int __blkdev_driver_ioctl(struct block_device *bdev, fmode_t mode,
289                         unsigned cmd, unsigned long arg)
290 {
291         struct gendisk *disk = bdev->bd_disk;
292 
293         if (disk->fops->ioctl)
294                 return disk->fops->ioctl(bdev, mode, cmd, arg);
295 
296         return -ENOTTY;
297 }
298 /*
299  * For the record: _GPL here is only because somebody decided to slap it
300  * on the previous export.  Sheer idiocy, since it wasn't copyrightable
301  * at all and could be open-coded without any exports by anybody who cares.
302  */
303 EXPORT_SYMBOL_GPL(__blkdev_driver_ioctl);
304 
305 static int blkdev_pr_register(struct block_device *bdev,
306                 struct pr_registration __user *arg)
307 {
308         const struct pr_ops *ops = bdev->bd_disk->fops->pr_ops;
309         struct pr_registration reg;
310 
311         if (!capable(CAP_SYS_ADMIN))
312                 return -EPERM;
313         if (!ops || !ops->pr_register)
314                 return -EOPNOTSUPP;
315         if (copy_from_user(&reg, arg, sizeof(reg)))
316                 return -EFAULT;
317 
318         if (reg.flags & ~PR_FL_IGNORE_KEY)
319                 return -EOPNOTSUPP;
320         return ops->pr_register(bdev, reg.old_key, reg.new_key, reg.flags);
321 }
322 
323 static int blkdev_pr_reserve(struct block_device *bdev,
324                 struct pr_reservation __user *arg)
325 {
326         const struct pr_ops *ops = bdev->bd_disk->fops->pr_ops;
327         struct pr_reservation rsv;
328 
329         if (!capable(CAP_SYS_ADMIN))
330                 return -EPERM;
331         if (!ops || !ops->pr_reserve)
332                 return -EOPNOTSUPP;
333         if (copy_from_user(&rsv, arg, sizeof(rsv)))
334                 return -EFAULT;
335 
336         if (rsv.flags & ~PR_FL_IGNORE_KEY)
337                 return -EOPNOTSUPP;
338         return ops->pr_reserve(bdev, rsv.key, rsv.type, rsv.flags);
339 }
340 
341 static int blkdev_pr_release(struct block_device *bdev,
342                 struct pr_reservation __user *arg)
343 {
344         const struct pr_ops *ops = bdev->bd_disk->fops->pr_ops;
345         struct pr_reservation rsv;
346 
347         if (!capable(CAP_SYS_ADMIN))
348                 return -EPERM;
349         if (!ops || !ops->pr_release)
350                 return -EOPNOTSUPP;
351         if (copy_from_user(&rsv, arg, sizeof(rsv)))
352                 return -EFAULT;
353 
354         if (rsv.flags)
355                 return -EOPNOTSUPP;
356         return ops->pr_release(bdev, rsv.key, rsv.type);
357 }
358 
359 static int blkdev_pr_preempt(struct block_device *bdev,
360                 struct pr_preempt __user *arg, bool abort)
361 {
362         const struct pr_ops *ops = bdev->bd_disk->fops->pr_ops;
363         struct pr_preempt p;
364 
365         if (!capable(CAP_SYS_ADMIN))
366                 return -EPERM;
367         if (!ops || !ops->pr_preempt)
368                 return -EOPNOTSUPP;
369         if (copy_from_user(&p, arg, sizeof(p)))
370                 return -EFAULT;
371 
372         if (p.flags)
373                 return -EOPNOTSUPP;
374         return ops->pr_preempt(bdev, p.old_key, p.new_key, p.type, abort);
375 }
376 
377 static int blkdev_pr_clear(struct block_device *bdev,
378                 struct pr_clear __user *arg)
379 {
380         const struct pr_ops *ops = bdev->bd_disk->fops->pr_ops;
381         struct pr_clear c;
382 
383         if (!capable(CAP_SYS_ADMIN))
384                 return -EPERM;
385         if (!ops || !ops->pr_clear)
386                 return -EOPNOTSUPP;
387         if (copy_from_user(&c, arg, sizeof(c)))
388                 return -EFAULT;
389 
390         if (c.flags)
391                 return -EOPNOTSUPP;
392         return ops->pr_clear(bdev, c.key);
393 }
394 
395 /*
396  * Is it an unrecognized ioctl? The correct returns are either
397  * ENOTTY (final) or ENOIOCTLCMD ("I don't know this one, try a
398  * fallback"). ENOIOCTLCMD gets turned into ENOTTY by the ioctl
399  * code before returning.
400  *
401  * Confused drivers sometimes return EINVAL, which is wrong. It
402  * means "I understood the ioctl command, but the parameters to
403  * it were wrong".
404  *
405  * We should aim to just fix the broken drivers, the EINVAL case
406  * should go away.
407  */
408 static inline int is_unrecognized_ioctl(int ret)
409 {
410         return  ret == -EINVAL ||
411                 ret == -ENOTTY ||
412                 ret == -ENOIOCTLCMD;
413 }
414 
415 static int blkdev_flushbuf(struct block_device *bdev, fmode_t mode,
416                 unsigned cmd, unsigned long arg)
417 {
418         int ret;
419 
420         if (!capable(CAP_SYS_ADMIN))
421                 return -EACCES;
422 
423         ret = __blkdev_driver_ioctl(bdev, mode, cmd, arg);
424         if (!is_unrecognized_ioctl(ret))
425                 return ret;
426 
427         fsync_bdev(bdev);
428         invalidate_bdev(bdev);
429         return 0;
430 }
431 
432 static int blkdev_roset(struct block_device *bdev, fmode_t mode,
433                 unsigned cmd, unsigned long arg)
434 {
435         int ret, n;
436 
437         ret = __blkdev_driver_ioctl(bdev, mode, cmd, arg);
438         if (!is_unrecognized_ioctl(ret))
439                 return ret;
440         if (!capable(CAP_SYS_ADMIN))
441                 return -EACCES;
442         if (get_user(n, (int __user *)arg))
443                 return -EFAULT;
444         set_device_ro(bdev, n);
445         return 0;
446 }
447 
448 static int blkdev_getgeo(struct block_device *bdev,
449                 struct hd_geometry __user *argp)
450 {
451         struct gendisk *disk = bdev->bd_disk;
452         struct hd_geometry geo;
453         int ret;
454 
455         if (!argp)
456                 return -EINVAL;
457         if (!disk->fops->getgeo)
458                 return -ENOTTY;
459 
460         /*
461          * We need to set the startsect first, the driver may
462          * want to override it.
463          */
464         memset(&geo, 0, sizeof(geo));
465         geo.start = get_start_sect(bdev);
466         ret = disk->fops->getgeo(bdev, &geo);
467         if (ret)
468                 return ret;
469         if (copy_to_user(argp, &geo, sizeof(geo)))
470                 return -EFAULT;
471         return 0;
472 }
473 
474 /* set the logical block size */
475 static int blkdev_bszset(struct block_device *bdev, fmode_t mode,
476                 int __user *argp)
477 {
478         int ret, n;
479 
480         if (!capable(CAP_SYS_ADMIN))
481                 return -EACCES;
482         if (!argp)
483                 return -EINVAL;
484         if (get_user(n, argp))
485                 return -EFAULT;
486 
487         if (!(mode & FMODE_EXCL)) {
488                 bdgrab(bdev);
489                 if (blkdev_get(bdev, mode | FMODE_EXCL, &bdev) < 0)
490                         return -EBUSY;
491         }
492 
493         ret = set_blocksize(bdev, n);
494         if (!(mode & FMODE_EXCL))
495                 blkdev_put(bdev, mode | FMODE_EXCL);
496         return ret;
497 }
498 
499 /*
500  * always keep this in sync with compat_blkdev_ioctl()
501  */
502 int blkdev_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd,
503                         unsigned long arg)
504 {
505         struct backing_dev_info *bdi;
506         void __user *argp = (void __user *)arg;
507         loff_t size;
508         unsigned int max_sectors;
509 
510         switch (cmd) {
511         case BLKFLSBUF:
512                 return blkdev_flushbuf(bdev, mode, cmd, arg);
513         case BLKROSET:
514                 return blkdev_roset(bdev, mode, cmd, arg);
515         case BLKDISCARD:
516                 return blk_ioctl_discard(bdev, mode, arg, 0);
517         case BLKSECDISCARD:
518                 return blk_ioctl_discard(bdev, mode, arg,
519                                 BLKDEV_DISCARD_SECURE);
520         case BLKZEROOUT:
521                 return blk_ioctl_zeroout(bdev, mode, arg);
522         case HDIO_GETGEO:
523                 return blkdev_getgeo(bdev, argp);
524         case BLKRAGET:
525         case BLKFRAGET:
526                 if (!arg)
527                         return -EINVAL;
528                 bdi = blk_get_backing_dev_info(bdev);
529                 return put_long(arg, (bdi->ra_pages * PAGE_SIZE) / 512);
530         case BLKROGET:
531                 return put_int(arg, bdev_read_only(bdev) != 0);
532         case BLKBSZGET: /* get block device soft block size (cf. BLKSSZGET) */
533                 return put_int(arg, block_size(bdev));
534         case BLKSSZGET: /* get block device logical block size */
535                 return put_int(arg, bdev_logical_block_size(bdev));
536         case BLKPBSZGET: /* get block device physical block size */
537                 return put_uint(arg, bdev_physical_block_size(bdev));
538         case BLKIOMIN:
539                 return put_uint(arg, bdev_io_min(bdev));
540         case BLKIOOPT:
541                 return put_uint(arg, bdev_io_opt(bdev));
542         case BLKALIGNOFF:
543                 return put_int(arg, bdev_alignment_offset(bdev));
544         case BLKDISCARDZEROES:
545                 return put_uint(arg, bdev_discard_zeroes_data(bdev));
546         case BLKSECTGET:
547                 max_sectors = min_t(unsigned int, USHRT_MAX,
548                                     queue_max_sectors(bdev_get_queue(bdev)));
549                 return put_ushort(arg, max_sectors);
550         case BLKROTATIONAL:
551                 return put_ushort(arg, !blk_queue_nonrot(bdev_get_queue(bdev)));
552         case BLKRASET:
553         case BLKFRASET:
554                 if(!capable(CAP_SYS_ADMIN))
555                         return -EACCES;
556                 bdi = blk_get_backing_dev_info(bdev);
557                 bdi->ra_pages = (arg * 512) / PAGE_SIZE;
558                 return 0;
559         case BLKBSZSET:
560                 return blkdev_bszset(bdev, mode, argp);
561         case BLKPG:
562                 return blkpg_ioctl(bdev, argp);
563         case BLKRRPART:
564                 return blkdev_reread_part(bdev);
565         case BLKGETSIZE:
566                 size = i_size_read(bdev->bd_inode);
567                 if ((size >> 9) > ~0UL)
568                         return -EFBIG;
569                 return put_ulong(arg, size >> 9);
570         case BLKGETSIZE64:
571                 return put_u64(arg, i_size_read(bdev->bd_inode));
572         case BLKTRACESTART:
573         case BLKTRACESTOP:
574         case BLKTRACESETUP:
575         case BLKTRACETEARDOWN:
576                 return blk_trace_ioctl(bdev, cmd, argp);
577         case IOC_PR_REGISTER:
578                 return blkdev_pr_register(bdev, argp);
579         case IOC_PR_RESERVE:
580                 return blkdev_pr_reserve(bdev, argp);
581         case IOC_PR_RELEASE:
582                 return blkdev_pr_release(bdev, argp);
583         case IOC_PR_PREEMPT:
584                 return blkdev_pr_preempt(bdev, argp, false);
585         case IOC_PR_PREEMPT_ABORT:
586                 return blkdev_pr_preempt(bdev, argp, true);
587         case IOC_PR_CLEAR:
588                 return blkdev_pr_clear(bdev, argp);
589         default:
590                 return __blkdev_driver_ioctl(bdev, mode, cmd, arg);
591         }
592 }
593 EXPORT_SYMBOL_GPL(blkdev_ioctl);
594 

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