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