Version:  2.0.40 2.2.26 2.4.37 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 4.10

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 <linux/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                         /* check if partition is aligned to blocksize */
 49                         if (p.start & (bdev_logical_block_size(bdev) - 1))
 50                                 return -EINVAL;
 51 
 52                         mutex_lock(&bdev->bd_mutex);
 53 
 54                         /* overlap? */
 55                         disk_part_iter_init(&piter, disk,
 56                                             DISK_PITER_INCL_EMPTY);
 57                         while ((part = disk_part_iter_next(&piter))) {
 58                                 if (!(start + length <= part->start_sect ||
 59                                       start >= part->start_sect + part->nr_sects)) {
 60                                         disk_part_iter_exit(&piter);
 61                                         mutex_unlock(&bdev->bd_mutex);
 62                                         return -EBUSY;
 63                                 }
 64                         }
 65                         disk_part_iter_exit(&piter);
 66 
 67                         /* all seems OK */
 68                         part = add_partition(disk, partno, start, length,
 69                                              ADDPART_FLAG_NONE, NULL);
 70                         mutex_unlock(&bdev->bd_mutex);
 71                         return PTR_ERR_OR_ZERO(part);
 72                 case BLKPG_DEL_PARTITION:
 73                         part = disk_get_part(disk, partno);
 74                         if (!part)
 75                                 return -ENXIO;
 76 
 77                         bdevp = bdget(part_devt(part));
 78                         disk_put_part(part);
 79                         if (!bdevp)
 80                                 return -ENOMEM;
 81 
 82                         mutex_lock(&bdevp->bd_mutex);
 83                         if (bdevp->bd_openers) {
 84                                 mutex_unlock(&bdevp->bd_mutex);
 85                                 bdput(bdevp);
 86                                 return -EBUSY;
 87                         }
 88                         /* all seems OK */
 89                         fsync_bdev(bdevp);
 90                         invalidate_bdev(bdevp);
 91 
 92                         mutex_lock_nested(&bdev->bd_mutex, 1);
 93                         delete_partition(disk, partno);
 94                         mutex_unlock(&bdev->bd_mutex);
 95                         mutex_unlock(&bdevp->bd_mutex);
 96                         bdput(bdevp);
 97 
 98                         return 0;
 99                 case BLKPG_RESIZE_PARTITION:
100                         start = p.start >> 9;
101                         /* new length of partition in bytes */
102                         length = p.length >> 9;
103                         /* check for fit in a hd_struct */
104                         if (sizeof(sector_t) == sizeof(long) &&
105                             sizeof(long long) > sizeof(long)) {
106                                 long pstart = start, plength = length;
107                                 if (pstart != start || plength != length
108                                     || pstart < 0 || plength < 0)
109                                         return -EINVAL;
110                         }
111                         part = disk_get_part(disk, partno);
112                         if (!part)
113                                 return -ENXIO;
114                         bdevp = bdget(part_devt(part));
115                         if (!bdevp) {
116                                 disk_put_part(part);
117                                 return -ENOMEM;
118                         }
119                         mutex_lock(&bdevp->bd_mutex);
120                         mutex_lock_nested(&bdev->bd_mutex, 1);
121                         if (start != part->start_sect) {
122                                 mutex_unlock(&bdevp->bd_mutex);
123                                 mutex_unlock(&bdev->bd_mutex);
124                                 bdput(bdevp);
125                                 disk_put_part(part);
126                                 return -EINVAL;
127                         }
128                         /* overlap? */
129                         disk_part_iter_init(&piter, disk,
130                                             DISK_PITER_INCL_EMPTY);
131                         while ((lpart = disk_part_iter_next(&piter))) {
132                                 if (lpart->partno != partno &&
133                                    !(start + length <= lpart->start_sect ||
134                                    start >= lpart->start_sect + lpart->nr_sects)
135                                    ) {
136                                         disk_part_iter_exit(&piter);
137                                         mutex_unlock(&bdevp->bd_mutex);
138                                         mutex_unlock(&bdev->bd_mutex);
139                                         bdput(bdevp);
140                                         disk_put_part(part);
141                                         return -EBUSY;
142                                 }
143                         }
144                         disk_part_iter_exit(&piter);
145                         part_nr_sects_write(part, (sector_t)length);
146                         i_size_write(bdevp->bd_inode, p.length);
147                         mutex_unlock(&bdevp->bd_mutex);
148                         mutex_unlock(&bdev->bd_mutex);
149                         bdput(bdevp);
150                         disk_put_part(part);
151                         return 0;
152                 default:
153                         return -EINVAL;
154         }
155 }
156 
157 /*
158  * This is an exported API for the block driver, and will not
159  * acquire bd_mutex. This API should be used in case that
160  * caller has held bd_mutex already.
161  */
162 int __blkdev_reread_part(struct block_device *bdev)
163 {
164         struct gendisk *disk = bdev->bd_disk;
165 
166         if (!disk_part_scan_enabled(disk) || bdev != bdev->bd_contains)
167                 return -EINVAL;
168         if (!capable(CAP_SYS_ADMIN))
169                 return -EACCES;
170 
171         lockdep_assert_held(&bdev->bd_mutex);
172 
173         return rescan_partitions(disk, bdev);
174 }
175 EXPORT_SYMBOL(__blkdev_reread_part);
176 
177 /*
178  * This is an exported API for the block driver, and will
179  * try to acquire bd_mutex. If bd_mutex has been held already
180  * in current context, please call __blkdev_reread_part().
181  *
182  * Make sure the held locks in current context aren't required
183  * in open()/close() handler and I/O path for avoiding ABBA deadlock:
184  * - bd_mutex is held before calling block driver's open/close
185  *   handler
186  * - reading partition table may submit I/O to the block device
187  */
188 int blkdev_reread_part(struct block_device *bdev)
189 {
190         int res;
191 
192         mutex_lock(&bdev->bd_mutex);
193         res = __blkdev_reread_part(bdev);
194         mutex_unlock(&bdev->bd_mutex);
195 
196         return res;
197 }
198 EXPORT_SYMBOL(blkdev_reread_part);
199 
200 static int blk_ioctl_discard(struct block_device *bdev, fmode_t mode,
201                 unsigned long arg, unsigned long flags)
202 {
203         uint64_t range[2];
204         uint64_t start, len;
205 
206         if (!(mode & FMODE_WRITE))
207                 return -EBADF;
208 
209         if (copy_from_user(range, (void __user *)arg, sizeof(range)))
210                 return -EFAULT;
211 
212         start = range[0];
213         len = range[1];
214 
215         if (start & 511)
216                 return -EINVAL;
217         if (len & 511)
218                 return -EINVAL;
219         start >>= 9;
220         len >>= 9;
221 
222         if (start + len > (i_size_read(bdev->bd_inode) >> 9))
223                 return -EINVAL;
224         return blkdev_issue_discard(bdev, start, len, GFP_KERNEL, flags);
225 }
226 
227 static int blk_ioctl_zeroout(struct block_device *bdev, fmode_t mode,
228                 unsigned long arg)
229 {
230         uint64_t range[2];
231         struct address_space *mapping;
232         uint64_t start, end, len;
233 
234         if (!(mode & FMODE_WRITE))
235                 return -EBADF;
236 
237         if (copy_from_user(range, (void __user *)arg, sizeof(range)))
238                 return -EFAULT;
239 
240         start = range[0];
241         len = range[1];
242         end = start + len - 1;
243 
244         if (start & 511)
245                 return -EINVAL;
246         if (len & 511)
247                 return -EINVAL;
248         if (end >= (uint64_t)i_size_read(bdev->bd_inode))
249                 return -EINVAL;
250         if (end < start)
251                 return -EINVAL;
252 
253         /* Invalidate the page cache, including dirty pages */
254         mapping = bdev->bd_inode->i_mapping;
255         truncate_inode_pages_range(mapping, start, end);
256 
257         return blkdev_issue_zeroout(bdev, start >> 9, len >> 9, GFP_KERNEL,
258                                     false);
259 }
260 
261 static int put_ushort(unsigned long arg, unsigned short val)
262 {
263         return put_user(val, (unsigned short __user *)arg);
264 }
265 
266 static int put_int(unsigned long arg, int val)
267 {
268         return put_user(val, (int __user *)arg);
269 }
270 
271 static int put_uint(unsigned long arg, unsigned int val)
272 {
273         return put_user(val, (unsigned int __user *)arg);
274 }
275 
276 static int put_long(unsigned long arg, long val)
277 {
278         return put_user(val, (long __user *)arg);
279 }
280 
281 static int put_ulong(unsigned long arg, unsigned long val)
282 {
283         return put_user(val, (unsigned long __user *)arg);
284 }
285 
286 static int put_u64(unsigned long arg, u64 val)
287 {
288         return put_user(val, (u64 __user *)arg);
289 }
290 
291 int __blkdev_driver_ioctl(struct block_device *bdev, fmode_t mode,
292                         unsigned cmd, unsigned long arg)
293 {
294         struct gendisk *disk = bdev->bd_disk;
295 
296         if (disk->fops->ioctl)
297                 return disk->fops->ioctl(bdev, mode, cmd, arg);
298 
299         return -ENOTTY;
300 }
301 /*
302  * For the record: _GPL here is only because somebody decided to slap it
303  * on the previous export.  Sheer idiocy, since it wasn't copyrightable
304  * at all and could be open-coded without any exports by anybody who cares.
305  */
306 EXPORT_SYMBOL_GPL(__blkdev_driver_ioctl);
307 
308 static int blkdev_pr_register(struct block_device *bdev,
309                 struct pr_registration __user *arg)
310 {
311         const struct pr_ops *ops = bdev->bd_disk->fops->pr_ops;
312         struct pr_registration reg;
313 
314         if (!capable(CAP_SYS_ADMIN))
315                 return -EPERM;
316         if (!ops || !ops->pr_register)
317                 return -EOPNOTSUPP;
318         if (copy_from_user(&reg, arg, sizeof(reg)))
319                 return -EFAULT;
320 
321         if (reg.flags & ~PR_FL_IGNORE_KEY)
322                 return -EOPNOTSUPP;
323         return ops->pr_register(bdev, reg.old_key, reg.new_key, reg.flags);
324 }
325 
326 static int blkdev_pr_reserve(struct block_device *bdev,
327                 struct pr_reservation __user *arg)
328 {
329         const struct pr_ops *ops = bdev->bd_disk->fops->pr_ops;
330         struct pr_reservation rsv;
331 
332         if (!capable(CAP_SYS_ADMIN))
333                 return -EPERM;
334         if (!ops || !ops->pr_reserve)
335                 return -EOPNOTSUPP;
336         if (copy_from_user(&rsv, arg, sizeof(rsv)))
337                 return -EFAULT;
338 
339         if (rsv.flags & ~PR_FL_IGNORE_KEY)
340                 return -EOPNOTSUPP;
341         return ops->pr_reserve(bdev, rsv.key, rsv.type, rsv.flags);
342 }
343 
344 static int blkdev_pr_release(struct block_device *bdev,
345                 struct pr_reservation __user *arg)
346 {
347         const struct pr_ops *ops = bdev->bd_disk->fops->pr_ops;
348         struct pr_reservation rsv;
349 
350         if (!capable(CAP_SYS_ADMIN))
351                 return -EPERM;
352         if (!ops || !ops->pr_release)
353                 return -EOPNOTSUPP;
354         if (copy_from_user(&rsv, arg, sizeof(rsv)))
355                 return -EFAULT;
356 
357         if (rsv.flags)
358                 return -EOPNOTSUPP;
359         return ops->pr_release(bdev, rsv.key, rsv.type);
360 }
361 
362 static int blkdev_pr_preempt(struct block_device *bdev,
363                 struct pr_preempt __user *arg, bool abort)
364 {
365         const struct pr_ops *ops = bdev->bd_disk->fops->pr_ops;
366         struct pr_preempt p;
367 
368         if (!capable(CAP_SYS_ADMIN))
369                 return -EPERM;
370         if (!ops || !ops->pr_preempt)
371                 return -EOPNOTSUPP;
372         if (copy_from_user(&p, arg, sizeof(p)))
373                 return -EFAULT;
374 
375         if (p.flags)
376                 return -EOPNOTSUPP;
377         return ops->pr_preempt(bdev, p.old_key, p.new_key, p.type, abort);
378 }
379 
380 static int blkdev_pr_clear(struct block_device *bdev,
381                 struct pr_clear __user *arg)
382 {
383         const struct pr_ops *ops = bdev->bd_disk->fops->pr_ops;
384         struct pr_clear c;
385 
386         if (!capable(CAP_SYS_ADMIN))
387                 return -EPERM;
388         if (!ops || !ops->pr_clear)
389                 return -EOPNOTSUPP;
390         if (copy_from_user(&c, arg, sizeof(c)))
391                 return -EFAULT;
392 
393         if (c.flags)
394                 return -EOPNOTSUPP;
395         return ops->pr_clear(bdev, c.key);
396 }
397 
398 /*
399  * Is it an unrecognized ioctl? The correct returns are either
400  * ENOTTY (final) or ENOIOCTLCMD ("I don't know this one, try a
401  * fallback"). ENOIOCTLCMD gets turned into ENOTTY by the ioctl
402  * code before returning.
403  *
404  * Confused drivers sometimes return EINVAL, which is wrong. It
405  * means "I understood the ioctl command, but the parameters to
406  * it were wrong".
407  *
408  * We should aim to just fix the broken drivers, the EINVAL case
409  * should go away.
410  */
411 static inline int is_unrecognized_ioctl(int ret)
412 {
413         return  ret == -EINVAL ||
414                 ret == -ENOTTY ||
415                 ret == -ENOIOCTLCMD;
416 }
417 
418 static int blkdev_flushbuf(struct block_device *bdev, fmode_t mode,
419                 unsigned cmd, unsigned long arg)
420 {
421         int ret;
422 
423         if (!capable(CAP_SYS_ADMIN))
424                 return -EACCES;
425 
426         ret = __blkdev_driver_ioctl(bdev, mode, cmd, arg);
427         if (!is_unrecognized_ioctl(ret))
428                 return ret;
429 
430         fsync_bdev(bdev);
431         invalidate_bdev(bdev);
432         return 0;
433 }
434 
435 static int blkdev_roset(struct block_device *bdev, fmode_t mode,
436                 unsigned cmd, unsigned long arg)
437 {
438         int ret, n;
439 
440         ret = __blkdev_driver_ioctl(bdev, mode, cmd, arg);
441         if (!is_unrecognized_ioctl(ret))
442                 return ret;
443         if (!capable(CAP_SYS_ADMIN))
444                 return -EACCES;
445         if (get_user(n, (int __user *)arg))
446                 return -EFAULT;
447         set_device_ro(bdev, n);
448         return 0;
449 }
450 
451 static int blkdev_getgeo(struct block_device *bdev,
452                 struct hd_geometry __user *argp)
453 {
454         struct gendisk *disk = bdev->bd_disk;
455         struct hd_geometry geo;
456         int ret;
457 
458         if (!argp)
459                 return -EINVAL;
460         if (!disk->fops->getgeo)
461                 return -ENOTTY;
462 
463         /*
464          * We need to set the startsect first, the driver may
465          * want to override it.
466          */
467         memset(&geo, 0, sizeof(geo));
468         geo.start = get_start_sect(bdev);
469         ret = disk->fops->getgeo(bdev, &geo);
470         if (ret)
471                 return ret;
472         if (copy_to_user(argp, &geo, sizeof(geo)))
473                 return -EFAULT;
474         return 0;
475 }
476 
477 /* set the logical block size */
478 static int blkdev_bszset(struct block_device *bdev, fmode_t mode,
479                 int __user *argp)
480 {
481         int ret, n;
482 
483         if (!capable(CAP_SYS_ADMIN))
484                 return -EACCES;
485         if (!argp)
486                 return -EINVAL;
487         if (get_user(n, argp))
488                 return -EFAULT;
489 
490         if (!(mode & FMODE_EXCL)) {
491                 bdgrab(bdev);
492                 if (blkdev_get(bdev, mode | FMODE_EXCL, &bdev) < 0)
493                         return -EBUSY;
494         }
495 
496         ret = set_blocksize(bdev, n);
497         if (!(mode & FMODE_EXCL))
498                 blkdev_put(bdev, mode | FMODE_EXCL);
499         return ret;
500 }
501 
502 /*
503  * always keep this in sync with compat_blkdev_ioctl()
504  */
505 int blkdev_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd,
506                         unsigned long arg)
507 {
508         struct backing_dev_info *bdi;
509         void __user *argp = (void __user *)arg;
510         loff_t size;
511         unsigned int max_sectors;
512 
513         switch (cmd) {
514         case BLKFLSBUF:
515                 return blkdev_flushbuf(bdev, mode, cmd, arg);
516         case BLKROSET:
517                 return blkdev_roset(bdev, mode, cmd, arg);
518         case BLKDISCARD:
519                 return blk_ioctl_discard(bdev, mode, arg, 0);
520         case BLKSECDISCARD:
521                 return blk_ioctl_discard(bdev, mode, arg,
522                                 BLKDEV_DISCARD_SECURE);
523         case BLKZEROOUT:
524                 return blk_ioctl_zeroout(bdev, mode, arg);
525         case BLKREPORTZONE:
526                 return blkdev_report_zones_ioctl(bdev, mode, cmd, arg);
527         case BLKRESETZONE:
528                 return blkdev_reset_zones_ioctl(bdev, mode, cmd, arg);
529         case HDIO_GETGEO:
530                 return blkdev_getgeo(bdev, argp);
531         case BLKRAGET:
532         case BLKFRAGET:
533                 if (!arg)
534                         return -EINVAL;
535                 bdi = blk_get_backing_dev_info(bdev);
536                 return put_long(arg, (bdi->ra_pages * PAGE_SIZE) / 512);
537         case BLKROGET:
538                 return put_int(arg, bdev_read_only(bdev) != 0);
539         case BLKBSZGET: /* get block device soft block size (cf. BLKSSZGET) */
540                 return put_int(arg, block_size(bdev));
541         case BLKSSZGET: /* get block device logical block size */
542                 return put_int(arg, bdev_logical_block_size(bdev));
543         case BLKPBSZGET: /* get block device physical block size */
544                 return put_uint(arg, bdev_physical_block_size(bdev));
545         case BLKIOMIN:
546                 return put_uint(arg, bdev_io_min(bdev));
547         case BLKIOOPT:
548                 return put_uint(arg, bdev_io_opt(bdev));
549         case BLKALIGNOFF:
550                 return put_int(arg, bdev_alignment_offset(bdev));
551         case BLKDISCARDZEROES:
552                 return put_uint(arg, bdev_discard_zeroes_data(bdev));
553         case BLKSECTGET:
554                 max_sectors = min_t(unsigned int, USHRT_MAX,
555                                     queue_max_sectors(bdev_get_queue(bdev)));
556                 return put_ushort(arg, max_sectors);
557         case BLKROTATIONAL:
558                 return put_ushort(arg, !blk_queue_nonrot(bdev_get_queue(bdev)));
559         case BLKRASET:
560         case BLKFRASET:
561                 if(!capable(CAP_SYS_ADMIN))
562                         return -EACCES;
563                 bdi = blk_get_backing_dev_info(bdev);
564                 bdi->ra_pages = (arg * 512) / PAGE_SIZE;
565                 return 0;
566         case BLKBSZSET:
567                 return blkdev_bszset(bdev, mode, argp);
568         case BLKPG:
569                 return blkpg_ioctl(bdev, argp);
570         case BLKRRPART:
571                 return blkdev_reread_part(bdev);
572         case BLKGETSIZE:
573                 size = i_size_read(bdev->bd_inode);
574                 if ((size >> 9) > ~0UL)
575                         return -EFBIG;
576                 return put_ulong(arg, size >> 9);
577         case BLKGETSIZE64:
578                 return put_u64(arg, i_size_read(bdev->bd_inode));
579         case BLKTRACESTART:
580         case BLKTRACESTOP:
581         case BLKTRACESETUP:
582         case BLKTRACETEARDOWN:
583                 return blk_trace_ioctl(bdev, cmd, argp);
584         case IOC_PR_REGISTER:
585                 return blkdev_pr_register(bdev, argp);
586         case IOC_PR_RESERVE:
587                 return blkdev_pr_reserve(bdev, argp);
588         case IOC_PR_RELEASE:
589                 return blkdev_pr_release(bdev, argp);
590         case IOC_PR_PREEMPT:
591                 return blkdev_pr_preempt(bdev, argp, false);
592         case IOC_PR_PREEMPT_ABORT:
593                 return blkdev_pr_preempt(bdev, argp, true);
594         case IOC_PR_CLEAR:
595                 return blkdev_pr_clear(bdev, argp);
596         default:
597                 return __blkdev_driver_ioctl(bdev, mode, cmd, arg);
598         }
599 }
600 EXPORT_SYMBOL_GPL(blkdev_ioctl);
601 

This page was automatically generated by LXR 0.3.1 (source).  •  Linux is a registered trademark of Linus Torvalds  •  Contact us