SAFE public projects git trees. - safe/jmp/linux-2.6/blob - 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                         bdevp = bdget_disk(disk, part);
  72                         if (!bdevp)
  73                                 return -ENOMEM;
  74                         mutex_lock(&bdevp->bd_mutex);
  75                         if (bdevp->bd_openers) {
  76                                 mutex_unlock(&bdevp->bd_mutex);
  77                                 bdput(bdevp);
  78                                 return -EBUSY;
  79                         }
  80                         /* all seems OK */
  81                         fsync_bdev(bdevp);
  82                         invalidate_bdev(bdevp);
  83
  84                         mutex_lock_nested(&bdev->bd_mutex, 1);
  85                         delete_partition(disk, part);
  86                         mutex_unlock(&bdev->bd_mutex);
  87                         mutex_unlock(&bdevp->bd_mutex);
  88                         bdput(bdevp);
  89
  90                         return 0;
  91                 default:
  92                         return -EINVAL;
  93         }
  94 }
  95
  96 static int blkdev_reread_part(struct block_device *bdev)
  97 {
  98         struct gendisk *disk = bdev->bd_disk;
  99         int res;
 100
 101         if (disk->minors == 1 || bdev != bdev->bd_contains)
 102                 return -EINVAL;
 103         if (!capable(CAP_SYS_ADMIN))
 104                 return -EACCES;
 105         if (!mutex_trylock(&bdev->bd_mutex))
 106                 return -EBUSY;
 107         res = rescan_partitions(disk, bdev);
 108         mutex_unlock(&bdev->bd_mutex);
 109         return res;
 110 }
 111
 112 static void blk_ioc_discard_endio(struct bio *bio, int err)
 113 {
 114         if (err) {
 115                 if (err == -EOPNOTSUPP)
 116                         set_bit(BIO_EOPNOTSUPP, &bio->bi_flags);
 117                 clear_bit(BIO_UPTODATE, &bio->bi_flags);
 118         }
 119         complete(bio->bi_private);
 120 }
 121
 122 static int blk_ioctl_discard(struct block_device *bdev, uint64_t start,
 123                              uint64_t len)
 124 {
 125         struct request_queue *q = bdev_get_queue(bdev);
 126         int ret = 0;
 127
 128         if (start & 511)
 129                 return -EINVAL;
 130         if (len & 511)
 131                 return -EINVAL;
 132         start >>= 9;
 133         len >>= 9;
 134
 135         if (start + len > (bdev->bd_inode->i_size >> 9))
 136                 return -EINVAL;
 137
 138         if (!q->prepare_discard_fn)
 139                 return -EOPNOTSUPP;
 140
 141         while (len && !ret) {
 142                 DECLARE_COMPLETION_ONSTACK(wait);
 143                 struct bio *bio;
 144
 145                 bio = bio_alloc(GFP_KERNEL, 0);
 146                 if (!bio)
 147                         return -ENOMEM;
 148
 149                 bio->bi_end_io = blk_ioc_discard_endio;
 150                 bio->bi_bdev = bdev;
 151                 bio->bi_private = &wait;
 152                 bio->bi_sector = start;
 153
 154                 if (len > q->max_hw_sectors) {
 155                         bio->bi_size = q->max_hw_sectors << 9;
 156                         len -= q->max_hw_sectors;
 157                         start += q->max_hw_sectors;
 158                 } else {
 159                         bio->bi_size = len << 9;
 160                         len = 0;
 161                 }
 162                 submit_bio(DISCARD_NOBARRIER, bio);
 163
 164                 wait_for_completion(&wait);
 165
 166                 if (bio_flagged(bio, BIO_EOPNOTSUPP))
 167                         ret = -EOPNOTSUPP;
 168                 else if (!bio_flagged(bio, BIO_UPTODATE))
 169                         ret = -EIO;
 170                 bio_put(bio);
 171         }
 172         return ret;
 173 }
 174
 175 static int put_ushort(unsigned long arg, unsigned short val)
 176 {
 177         return put_user(val, (unsigned short __user *)arg);
 178 }
 179
 180 static int put_int(unsigned long arg, int val)
 181 {
 182         return put_user(val, (int __user *)arg);
 183 }
 184
 185 static int put_long(unsigned long arg, long val)
 186 {
 187         return put_user(val, (long __user *)arg);
 188 }
 189
 190 static int put_ulong(unsigned long arg, unsigned long val)
 191 {
 192         return put_user(val, (unsigned long __user *)arg);
 193 }
 194
 195 static int put_u64(unsigned long arg, u64 val)
 196 {
 197         return put_user(val, (u64 __user *)arg);
 198 }
 199
 200 static int blkdev_locked_ioctl(struct file *file, struct block_device *bdev,
 201                                 unsigned cmd, unsigned long arg)
 202 {
 203         struct backing_dev_info *bdi;
 204         int ret, n;
 205
 206         switch (cmd) {
 207         case BLKRAGET:
 208         case BLKFRAGET:
 209                 if (!arg)
 210                         return -EINVAL;
 211                 bdi = blk_get_backing_dev_info(bdev);
 212                 if (bdi == NULL)
 213                         return -ENOTTY;
 214                 return put_long(arg, (bdi->ra_pages * PAGE_CACHE_SIZE) / 512);
 215         case BLKROGET:
 216                 return put_int(arg, bdev_read_only(bdev) != 0);
 217         case BLKBSZGET: /* get the logical block size (cf. BLKSSZGET) */
 218                 return put_int(arg, block_size(bdev));
 219         case BLKSSZGET: /* get block device hardware sector size */
 220                 return put_int(arg, bdev_hardsect_size(bdev));
 221         case BLKSECTGET:
 222                 return put_ushort(arg, bdev_get_queue(bdev)->max_sectors);
 223         case BLKRASET:
 224         case BLKFRASET:
 225                 if(!capable(CAP_SYS_ADMIN))
 226                         return -EACCES;
 227                 bdi = blk_get_backing_dev_info(bdev);
 228                 if (bdi == NULL)
 229                         return -ENOTTY;
 230                 bdi->ra_pages = (arg * 512) / PAGE_CACHE_SIZE;
 231                 return 0;
 232         case BLKBSZSET:
 233                 /* set the logical block size */
 234                 if (!capable(CAP_SYS_ADMIN))
 235                         return -EACCES;
 236                 if (!arg)
 237                         return -EINVAL;
 238                 if (get_user(n, (int __user *) arg))
 239                         return -EFAULT;
 240                 if (bd_claim(bdev, file) < 0)
 241                         return -EBUSY;
 242                 ret = set_blocksize(bdev, n);
 243                 bd_release(bdev);
 244                 return ret;
 245         case BLKPG:
 246                 return blkpg_ioctl(bdev, (struct blkpg_ioctl_arg __user *) arg);
 247         case BLKRRPART:
 248                 return blkdev_reread_part(bdev);
 249         case BLKGETSIZE:
 250                 if ((bdev->bd_inode->i_size >> 9) > ~0UL)
 251                         return -EFBIG;
 252                 return put_ulong(arg, bdev->bd_inode->i_size >> 9);
 253         case BLKGETSIZE64:
 254                 return put_u64(arg, bdev->bd_inode->i_size);
 255         case BLKTRACESTART:
 256         case BLKTRACESTOP:
 257         case BLKTRACESETUP:
 258         case BLKTRACETEARDOWN:
 259                 return blk_trace_ioctl(bdev, cmd, (char __user *) arg);
 260         }
 261         return -ENOIOCTLCMD;
 262 }
 263
 264 int blkdev_driver_ioctl(struct inode *inode, struct file *file,
 265                         struct gendisk *disk, unsigned cmd, unsigned long arg)
 266 {
 267         int ret;
 268         if (disk->fops->unlocked_ioctl)
 269                 return disk->fops->unlocked_ioctl(file, cmd, arg);
 270
 271         if (disk->fops->ioctl) {
 272                 lock_kernel();
 273                 ret = disk->fops->ioctl(inode, file, cmd, arg);
 274                 unlock_kernel();
 275                 return ret;
 276         }
 277
 278         return -ENOTTY;
 279 }
 280 EXPORT_SYMBOL_GPL(blkdev_driver_ioctl);
 281
 282 /*
 283  * always keep this in sync with compat_blkdev_ioctl() and
 284  * compat_blkdev_locked_ioctl()
 285  */
 286 int blkdev_ioctl(struct inode *inode, struct file *file, unsigned cmd,
 287                         unsigned long arg)
 288 {
 289         struct block_device *bdev = inode->i_bdev;
 290         struct gendisk *disk = bdev->bd_disk;
 291         int ret, n;
 292
 293         switch(cmd) {
 294         case BLKFLSBUF:
 295                 if (!capable(CAP_SYS_ADMIN))
 296                         return -EACCES;
 297
 298                 ret = blkdev_driver_ioctl(inode, file, disk, cmd, arg);
 299                 /* -EINVAL to handle old uncorrected drivers */
 300                 if (ret != -EINVAL && ret != -ENOTTY)
 301                         return ret;
 302
 303                 lock_kernel();
 304                 fsync_bdev(bdev);
 305                 invalidate_bdev(bdev);
 306                 unlock_kernel();
 307                 return 0;
 308
 309         case BLKROSET:
 310                 ret = blkdev_driver_ioctl(inode, file, disk, cmd, arg);
 311                 /* -EINVAL to handle old uncorrected drivers */
 312                 if (ret != -EINVAL && ret != -ENOTTY)
 313                         return ret;
 314                 if (!capable(CAP_SYS_ADMIN))
 315                         return -EACCES;
 316                 if (get_user(n, (int __user *)(arg)))
 317                         return -EFAULT;
 318                 lock_kernel();
 319                 set_device_ro(bdev, n);
 320                 unlock_kernel();
 321                 return 0;
 322
 323         case BLKDISCARD: {
 324                 uint64_t range[2];
 325
 326                 if (!(file->f_mode & FMODE_WRITE))
 327                         return -EBADF;
 328
 329                 if (copy_from_user(range, (void __user *)arg, sizeof(range)))
 330                         return -EFAULT;
 331
 332                 return blk_ioctl_discard(bdev, range[0], range[1]);
 333         }
 334
 335         case HDIO_GETGEO: {
 336                 struct hd_geometry geo;
 337
 338                 if (!arg)
 339                         return -EINVAL;
 340                 if (!disk->fops->getgeo)
 341                         return -ENOTTY;
 342
 343                 /*
 344                  * We need to set the startsect first, the driver may
 345                  * want to override it.
 346                  */
 347                 geo.start = get_start_sect(bdev);
 348                 ret = disk->fops->getgeo(bdev, &geo);
 349                 if (ret)
 350                         return ret;
 351                 if (copy_to_user((struct hd_geometry __user *)arg, &geo,
 352                                         sizeof(geo)))
 353                         return -EFAULT;
 354                 return 0;
 355         }
 356         }
 357
 358         lock_kernel();
 359         ret = blkdev_locked_ioctl(file, bdev, cmd, arg);
 360         unlock_kernel();
 361         if (ret != -ENOIOCTLCMD)
 362                 return ret;
 363
 364         return blkdev_driver_ioctl(inode, file, disk, cmd, arg);
 365 }
 366 EXPORT_SYMBOL_GPL(blkdev_ioctl);