block/ioctl.c

   1 #include <linux/capability.h>
   2 #include <linux/blkdev.h>
   3 #include <linux/blkpg.h>
   4 #include <linux/hdreg.h>
   5 #include <linux/backing-dev.h>
   6 #include <linux/buffer_head.h>
   7 #include <linux/smp_lock.h>
   8 #include <linux/blktrace_api.h>
   9 #include <asm/uaccess.h>
  10
  11 static int blkpg_ioctl(struct block_device *bdev, struct blkpg_ioctl_arg __user *arg)
  12 {
  13         struct block_device *bdevp;
  14         struct gendisk *disk;
  15         struct blkpg_ioctl_arg a;
  16         struct blkpg_partition p;
  17         long long start, length;
  18         int part;
  19         int i;
  20         int err;
  21
  22         if (!capable(CAP_SYS_ADMIN))
  23                 return -EACCES;
  24         if (copy_from_user(&a, arg, sizeof(struct blkpg_ioctl_arg)))
  25                 return -EFAULT;
  26         if (copy_from_user(&p, a.data, sizeof(struct blkpg_partition)))
  27                 return -EFAULT;
  28         disk = bdev->bd_disk;
  29         if (bdev != bdev->bd_contains)
  30                 return -EINVAL;
  31         part = p.pno;
  32         if (part <= 0 || part >= disk->minors)
  33                 return -EINVAL;
  34         switch (a.op) {
  35                 case BLKPG_ADD_PARTITION:
  36                         start = p.start >> 9;
  37                         length = p.length >> 9;
  38                         /* check for fit in a hd_struct */
  39                         if (sizeof(sector_t) == sizeof(long) &&
  40                             sizeof(long long) > sizeof(long)) {
  41                                 long pstart = start, plength = length;
  42                                 if (pstart != start || plength != length
  43                                     || pstart < 0 || plength < 0)
  44                                         return -EINVAL;
  45                         }
  46                         /* partition number in use? */
  47                         mutex_lock(&bdev->bd_mutex);
  48                         if (disk->part[part - 1]) {
  49                                 mutex_unlock(&bdev->bd_mutex);
  50                                 return -EBUSY;
  51                         }
  52                         /* overlap? */
  53                         for (i = 0; i < disk->minors - 1; i++) {
  54                                 struct hd_struct *s = disk->part[i];
  55
  56                                 if (!s)
  57                                         continue;
  58                                 if (!(start+length <= s->start_sect ||
  59                                       start >= s->start_sect + s->nr_sects)) {
  60                                         mutex_unlock(&bdev->bd_mutex);
  61                                         return -EBUSY;
  62                                 }
  63                         }
  64                         /* all seems OK */
  65                         err = add_partition(disk, part, start, length, ADDPART_FLAG_NONE);
  66                         mutex_unlock(&bdev->bd_mutex);
  67                         return err;
  68                 case BLKPG_DEL_PARTITION:
  69                         if (!disk->part[part-1])
  70                                 return -ENXIO;
  71                         if (disk->part[part - 1]->nr_sects == 0)
  72                                 return -ENXIO;
  73                         bdevp = bdget_disk(disk, part);
  74                         if (!bdevp)
  75                                 return -ENOMEM;
  76                         mutex_lock(&bdevp->bd_mutex);
  77                         if (bdevp->bd_openers) {
  78                                 mutex_unlock(&bdevp->bd_mutex);
  79                                 bdput(bdevp);
  80                                 return -EBUSY;
  81                         }
  82                         /* all seems OK */
  83                         fsync_bdev(bdevp);
  84                         invalidate_bdev(bdevp);
  85
  86                         mutex_lock_nested(&bdev->bd_mutex, 1);
  87                         delete_partition(disk, part);
  88                         mutex_unlock(&bdev->bd_mutex);
  89                         mutex_unlock(&bdevp->bd_mutex);
  90                         bdput(bdevp);
  91
  92                         return 0;
  93                 default:
  94                         return -EINVAL;
  95         }
  96 }
  97
  98 static int blkdev_reread_part(struct block_device *bdev)
  99 {
 100         struct gendisk *disk = bdev->bd_disk;
 101         int res;
 102
 103         if (disk->minors == 1 || bdev != bdev->bd_contains)
 104                 return -EINVAL;
 105         if (!capable(CAP_SYS_ADMIN))
 106                 return -EACCES;
 107         if (!mutex_trylock(&bdev->bd_mutex))
 108                 return -EBUSY;
 109         res = rescan_partitions(disk, bdev);
 110         mutex_unlock(&bdev->bd_mutex);
 111         return res;
 112 }
 113
 114 static void blk_ioc_discard_endio(struct bio *bio, int err)
 115 {
 116         if (err) {
 117                 if (err == -EOPNOTSUPP)
 118                         set_bit(BIO_EOPNOTSUPP, &bio->bi_flags);
 119                 clear_bit(BIO_UPTODATE, &bio->bi_flags);
 120         }
 121         complete(bio->bi_private);
 122 }
 123
 124 static int blk_ioctl_discard(struct block_device *bdev, uint64_t start,
 125                              uint64_t len)
 126 {
 127         struct request_queue *q = bdev_get_queue(bdev);
 128         int ret = 0;
 129
 130         if (start & 511)
 131                 return -EINVAL;
 132         if (len & 511)
 133                 return -EINVAL;
 134         start >>= 9;
 135         len >>= 9;
 136
 137         if (start + len > (bdev->bd_inode->i_size >> 9))
 138                 return -EINVAL;
 139
 140         if (!q->prepare_discard_fn)
 141                 return -EOPNOTSUPP;
 142
 143         while (len && !ret) {
 144                 DECLARE_COMPLETION_ONSTACK(wait);
 145                 struct bio *bio;
 146
 147                 bio = bio_alloc(GFP_KERNEL, 0);
 148                 if (!bio)
 149                         return -ENOMEM;
 150
 151                 bio->bi_end_io = blk_ioc_discard_endio;
 152                 bio->bi_bdev = bdev;
 153                 bio->bi_private = &wait;
 154                 bio->bi_sector = start;
 155
 156                 if (len > q->max_hw_sectors) {
 157                         bio->bi_size = q->max_hw_sectors << 9;
 158                         len -= q->max_hw_sectors;
 159                         start += q->max_hw_sectors;
 160                 } else {
 161                         bio->bi_size = len << 9;
 162                         len = 0;
 163                 }
 164                 submit_bio(DISCARD_NOBARRIER, bio);
 165
 166                 wait_for_completion(&wait);
 167
 168                 if (bio_flagged(bio, BIO_EOPNOTSUPP))
 169                         ret = -EOPNOTSUPP;
 170                 else if (!bio_flagged(bio, BIO_UPTODATE))
 171                         ret = -EIO;
 172                 bio_put(bio);
 173         }
 174         return ret;
 175 }
 176
 177 static int put_ushort(unsigned long arg, unsigned short val)
 178 {
 179         return put_user(val, (unsigned short __user *)arg);
 180 }
 181
 182 static int put_int(unsigned long arg, int val)
 183 {
 184         return put_user(val, (int __user *)arg);
 185 }
 186
 187 static int put_long(unsigned long arg, long val)
 188 {
 189         return put_user(val, (long __user *)arg);
 190 }
 191
 192 static int put_ulong(unsigned long arg, unsigned long val)
 193 {
 194         return put_user(val, (unsigned long __user *)arg);
 195 }
 196
 197 static int put_u64(unsigned long arg, u64 val)
 198 {
 199         return put_user(val, (u64 __user *)arg);
 200 }
 201
 202 static int blkdev_locked_ioctl(struct file *file, struct block_device *bdev,
 203                                 unsigned cmd, unsigned long arg)
 204 {
 205         struct backing_dev_info *bdi;
 206         int ret, n;
 207
 208         switch (cmd) {
 209         case BLKRAGET:
 210         case BLKFRAGET:
 211                 if (!arg)
 212                         return -EINVAL;
 213                 bdi = blk_get_backing_dev_info(bdev);
 214                 if (bdi == NULL)
 215                         return -ENOTTY;
 216                 return put_long(arg, (bdi->ra_pages * PAGE_CACHE_SIZE) / 512);
 217         case BLKROGET:
 218                 return put_int(arg, bdev_read_only(bdev) != 0);
 219         case BLKBSZGET: /* get the logical block size (cf. BLKSSZGET) */
 220                 return put_int(arg, block_size(bdev));
 221         case BLKSSZGET: /* get block device hardware sector size */
 222                 return put_int(arg, bdev_hardsect_size(bdev));
 223         case BLKSECTGET:
 224                 return put_ushort(arg, bdev_get_queue(bdev)->max_sectors);
 225         case BLKRASET:
 226         case BLKFRASET:
 227                 if(!capable(CAP_SYS_ADMIN))
 228                         return -EACCES;
 229                 bdi = blk_get_backing_dev_info(bdev);
 230                 if (bdi == NULL)
 231                         return -ENOTTY;
 232                 bdi->ra_pages = (arg * 512) / PAGE_CACHE_SIZE;
 233                 return 0;
 234         case BLKBSZSET:
 235                 /* set the logical block size */
 236                 if (!capable(CAP_SYS_ADMIN))
 237                         return -EACCES;
 238                 if (!arg)
 239                         return -EINVAL;
 240                 if (get_user(n, (int __user *) arg))
 241                         return -EFAULT;
 242                 if (bd_claim(bdev, file) < 0)
 243                         return -EBUSY;
 244                 ret = set_blocksize(bdev, n);
 245                 bd_release(bdev);
 246                 return ret;
 247         case BLKPG:
 248                 return blkpg_ioctl(bdev, (struct blkpg_ioctl_arg __user *) arg);
 249         case BLKRRPART:
 250                 return blkdev_reread_part(bdev);
 251         case BLKGETSIZE:
 252                 if ((bdev->bd_inode->i_size >> 9) > ~0UL)
 253                         return -EFBIG;
 254                 return put_ulong(arg, bdev->bd_inode->i_size >> 9);
 255         case BLKGETSIZE64:
 256                 return put_u64(arg, bdev->bd_inode->i_size);
 257         case BLKTRACESTART:
 258         case BLKTRACESTOP:
 259         case BLKTRACESETUP:
 260         case BLKTRACETEARDOWN:
 261                 return blk_trace_ioctl(bdev, cmd, (char __user *) arg);
 262         }
 263         return -ENOIOCTLCMD;
 264 }
 265
 266 int blkdev_driver_ioctl(struct inode *inode, struct file *file,
 267                         struct gendisk *disk, unsigned cmd, unsigned long arg)
 268 {
 269         int ret;
 270         if (disk->fops->unlocked_ioctl)
 271                 return disk->fops->unlocked_ioctl(file, cmd, arg);
 272
 273         if (disk->fops->ioctl) {
 274                 lock_kernel();
 275                 ret = disk->fops->ioctl(inode, file, cmd, arg);
 276                 unlock_kernel();
 277                 return ret;
 278         }
 279
 280         return -ENOTTY;
 281 }
 282 EXPORT_SYMBOL_GPL(blkdev_driver_ioctl);
 283
 284 /*
 285  * always keep this in sync with compat_blkdev_ioctl() and
 286  * compat_blkdev_locked_ioctl()
 287  */
 288 int blkdev_ioctl(struct inode *inode, struct file *file, unsigned cmd,
 289                         unsigned long arg)
 290 {
 291         struct block_device *bdev = inode->i_bdev;
 292         struct gendisk *disk = bdev->bd_disk;
 293         int ret, n;
 294
 295         switch(cmd) {
 296         case BLKFLSBUF:
 297                 if (!capable(CAP_SYS_ADMIN))
 298                         return -EACCES;
 299
 300                 ret = blkdev_driver_ioctl(inode, file, disk, cmd, arg);
 301                 /* -EINVAL to handle old uncorrected drivers */
 302                 if (ret != -EINVAL && ret != -ENOTTY)
 303                         return ret;
 304
 305                 lock_kernel();
 306                 fsync_bdev(bdev);
 307                 invalidate_bdev(bdev);
 308                 unlock_kernel();
 309                 return 0;
 310
 311         case BLKROSET:
 312                 ret = blkdev_driver_ioctl(inode, file, disk, cmd, arg);
 313                 /* -EINVAL to handle old uncorrected drivers */
 314                 if (ret != -EINVAL && ret != -ENOTTY)
 315                         return ret;
 316                 if (!capable(CAP_SYS_ADMIN))
 317                         return -EACCES;
 318                 if (get_user(n, (int __user *)(arg)))
 319                         return -EFAULT;
 320                 lock_kernel();
 321                 set_device_ro(bdev, n);
 322                 unlock_kernel();
 323                 return 0;
 324
 325         case BLKDISCARD: {
 326                 uint64_t range[2];
 327
 328                 if (!(file->f_mode & FMODE_WRITE))
 329                         return -EBADF;
 330
 331                 if (copy_from_user(range, (void __user *)arg, sizeof(range)))
 332                         return -EFAULT;
 333
 334                 return blk_ioctl_discard(bdev, range[0], range[1]);
 335         }
 336
 337         case HDIO_GETGEO: {
 338                 struct hd_geometry geo;
 339
 340                 if (!arg)
 341                         return -EINVAL;
 342                 if (!disk->fops->getgeo)
 343                         return -ENOTTY;
 344
 345                 /*
 346                  * We need to set the startsect first, the driver may
 347                  * want to override it.
 348                  */
 349                 geo.start = get_start_sect(bdev);
 350                 ret = disk->fops->getgeo(bdev, &geo);
 351                 if (ret)
 352                         return ret;
 353                 if (copy_to_user((struct hd_geometry __user *)arg, &geo,
 354                                         sizeof(geo)))
 355                         return -EFAULT;
 356                 return 0;
 357         }
 358         }
 359
 360         lock_kernel();
 361         ret = blkdev_locked_ioctl(file, bdev, cmd, arg);
 362         unlock_kernel();
 363         if (ret != -ENOIOCTLCMD)
 364                 return ret;
 365
 366         return blkdev_driver_ioctl(inode, file, disk, cmd, arg);
 367 }
 368 EXPORT_SYMBOL_GPL(blkdev_ioctl);