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 int put_ushort(unsigned long arg, unsigned short val)
 115 {
 116         return put_user(val, (unsigned short __user *)arg);
 117 }
 118
 119 static int put_int(unsigned long arg, int val)
 120 {
 121         return put_user(val, (int __user *)arg);
 122 }
 123
 124 static int put_long(unsigned long arg, long val)
 125 {
 126         return put_user(val, (long __user *)arg);
 127 }
 128
 129 static int put_ulong(unsigned long arg, unsigned long val)
 130 {
 131         return put_user(val, (unsigned long __user *)arg);
 132 }
 133
 134 static int put_u64(unsigned long arg, u64 val)
 135 {
 136         return put_user(val, (u64 __user *)arg);
 137 }
 138
 139 static int blkdev_locked_ioctl(struct file *file, struct block_device *bdev,
 140                                 unsigned cmd, unsigned long arg)
 141 {
 142         struct backing_dev_info *bdi;
 143         int ret, n;
 144
 145         switch (cmd) {
 146         case BLKRAGET:
 147         case BLKFRAGET:
 148                 if (!arg)
 149                         return -EINVAL;
 150                 bdi = blk_get_backing_dev_info(bdev);
 151                 if (bdi == NULL)
 152                         return -ENOTTY;
 153                 return put_long(arg, (bdi->ra_pages * PAGE_CACHE_SIZE) / 512);
 154         case BLKROGET:
 155                 return put_int(arg, bdev_read_only(bdev) != 0);
 156         case BLKBSZGET: /* get the logical block size (cf. BLKSSZGET) */
 157                 return put_int(arg, block_size(bdev));
 158         case BLKSSZGET: /* get block device hardware sector size */
 159                 return put_int(arg, bdev_hardsect_size(bdev));
 160         case BLKSECTGET:
 161                 return put_ushort(arg, bdev_get_queue(bdev)->max_sectors);
 162         case BLKRASET:
 163         case BLKFRASET:
 164                 if(!capable(CAP_SYS_ADMIN))
 165                         return -EACCES;
 166                 bdi = blk_get_backing_dev_info(bdev);
 167                 if (bdi == NULL)
 168                         return -ENOTTY;
 169                 bdi->ra_pages = (arg * 512) / PAGE_CACHE_SIZE;
 170                 return 0;
 171         case BLKBSZSET:
 172                 /* set the logical block size */
 173                 if (!capable(CAP_SYS_ADMIN))
 174                         return -EACCES;
 175                 if (!arg)
 176                         return -EINVAL;
 177                 if (get_user(n, (int __user *) arg))
 178                         return -EFAULT;
 179                 if (bd_claim(bdev, file) < 0)
 180                         return -EBUSY;
 181                 ret = set_blocksize(bdev, n);
 182                 bd_release(bdev);
 183                 return ret;
 184         case BLKPG:
 185                 return blkpg_ioctl(bdev, (struct blkpg_ioctl_arg __user *) arg);
 186         case BLKRRPART:
 187                 return blkdev_reread_part(bdev);
 188         case BLKGETSIZE:
 189                 if ((bdev->bd_inode->i_size >> 9) > ~0UL)
 190                         return -EFBIG;
 191                 return put_ulong(arg, bdev->bd_inode->i_size >> 9);
 192         case BLKGETSIZE64:
 193                 return put_u64(arg, bdev->bd_inode->i_size);
 194         case BLKTRACESTART:
 195         case BLKTRACESTOP:
 196         case BLKTRACESETUP:
 197         case BLKTRACETEARDOWN:
 198                 return blk_trace_ioctl(bdev, cmd, (char __user *) arg);
 199         }
 200         return -ENOIOCTLCMD;
 201 }
 202
 203 int blkdev_driver_ioctl(struct inode *inode, struct file *file,
 204                         struct gendisk *disk, unsigned cmd, unsigned long arg)
 205 {
 206         int ret;
 207         if (disk->fops->unlocked_ioctl)
 208                 return disk->fops->unlocked_ioctl(file, cmd, arg);
 209
 210         if (disk->fops->ioctl) {
 211                 lock_kernel();
 212                 ret = disk->fops->ioctl(inode, file, cmd, arg);
 213                 unlock_kernel();
 214                 return ret;
 215         }
 216
 217         return -ENOTTY;
 218 }
 219 EXPORT_SYMBOL_GPL(blkdev_driver_ioctl);
 220
 221 /*
 222  * always keep this in sync with compat_blkdev_ioctl() and
 223  * compat_blkdev_locked_ioctl()
 224  */
 225 int blkdev_ioctl(struct inode *inode, struct file *file, unsigned cmd,
 226                         unsigned long arg)
 227 {
 228         struct block_device *bdev = inode->i_bdev;
 229         struct gendisk *disk = bdev->bd_disk;
 230         int ret, n;
 231
 232         switch(cmd) {
 233         case BLKFLSBUF:
 234                 if (!capable(CAP_SYS_ADMIN))
 235                         return -EACCES;
 236
 237                 ret = blkdev_driver_ioctl(inode, file, disk, cmd, arg);
 238                 /* -EINVAL to handle old uncorrected drivers */
 239                 if (ret != -EINVAL && ret != -ENOTTY)
 240                         return ret;
 241
 242                 lock_kernel();
 243                 fsync_bdev(bdev);
 244                 invalidate_bdev(bdev);
 245                 unlock_kernel();
 246                 return 0;
 247
 248         case BLKROSET:
 249                 ret = blkdev_driver_ioctl(inode, file, disk, cmd, arg);
 250                 /* -EINVAL to handle old uncorrected drivers */
 251                 if (ret != -EINVAL && ret != -ENOTTY)
 252                         return ret;
 253                 if (!capable(CAP_SYS_ADMIN))
 254                         return -EACCES;
 255                 if (get_user(n, (int __user *)(arg)))
 256                         return -EFAULT;
 257                 lock_kernel();
 258                 set_device_ro(bdev, n);
 259                 unlock_kernel();
 260                 return 0;
 261         case HDIO_GETGEO: {
 262                 struct hd_geometry geo;
 263
 264                 if (!arg)
 265                         return -EINVAL;
 266                 if (!disk->fops->getgeo)
 267                         return -ENOTTY;
 268
 269                 /*
 270                  * We need to set the startsect first, the driver may
 271                  * want to override it.
 272                  */
 273                 geo.start = get_start_sect(bdev);
 274                 ret = disk->fops->getgeo(bdev, &geo);
 275                 if (ret)
 276                         return ret;
 277                 if (copy_to_user((struct hd_geometry __user *)arg, &geo,
 278                                         sizeof(geo)))
 279                         return -EFAULT;
 280                 return 0;
 281         }
 282         }
 283
 284         lock_kernel();
 285         ret = blkdev_locked_ioctl(file, bdev, cmd, arg);
 286         unlock_kernel();
 287         if (ret != -ENOIOCTLCMD)
 288                 return ret;
 289
 290         return blkdev_driver_ioctl(inode, file, disk, cmd, arg);
 291 }
 292 EXPORT_SYMBOL_GPL(blkdev_ioctl);