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