Logo Search packages:      
Sourcecode: linux version File versions  Download package

ioctl.c

#include <linux/capability.h>
#include <linux/blkdev.h>
#include <linux/blkpg.h>
#include <linux/hdreg.h>
#include <linux/backing-dev.h>
#include <linux/buffer_head.h>
#include <linux/smp_lock.h>
#include <linux/blktrace_api.h>
#include <asm/uaccess.h>

static int blkpg_ioctl(struct block_device *bdev, struct blkpg_ioctl_arg __user *arg)
{
      struct block_device *bdevp;
      struct gendisk *disk;
      struct blkpg_ioctl_arg a;
      struct blkpg_partition p;
      long long start, length;
      int part;
      int i;

      if (!capable(CAP_SYS_ADMIN))
            return -EACCES;
      if (copy_from_user(&a, arg, sizeof(struct blkpg_ioctl_arg)))
            return -EFAULT;
      if (copy_from_user(&p, a.data, sizeof(struct blkpg_partition)))
            return -EFAULT;
      disk = bdev->bd_disk;
      if (bdev != bdev->bd_contains)
            return -EINVAL;
      part = p.pno;
      if (part <= 0 || part >= disk->minors)
            return -EINVAL;
      switch (a.op) {
            case BLKPG_ADD_PARTITION:
                  start = p.start >> 9;
                  length = p.length >> 9;
                  /* check for fit in a hd_struct */ 
                  if (sizeof(sector_t) == sizeof(long) && 
                      sizeof(long long) > sizeof(long)) {
                        long pstart = start, plength = length;
                        if (pstart != start || plength != length
                            || pstart < 0 || plength < 0)
                              return -EINVAL;
                  }
                  /* partition number in use? */
                  mutex_lock(&bdev->bd_mutex);
                  if (disk->part[part - 1]) {
                        mutex_unlock(&bdev->bd_mutex);
                        return -EBUSY;
                  }
                  /* overlap? */
                  for (i = 0; i < disk->minors - 1; i++) {
                        struct hd_struct *s = disk->part[i];

                        if (!s)
                              continue;
                        if (!(start+length <= s->start_sect ||
                              start >= s->start_sect + s->nr_sects)) {
                              mutex_unlock(&bdev->bd_mutex);
                              return -EBUSY;
                        }
                  }
                  /* all seems OK */
                  add_partition(disk, part, start, length, ADDPART_FLAG_NONE);
                  mutex_unlock(&bdev->bd_mutex);
                  return 0;
            case BLKPG_DEL_PARTITION:
                  if (!disk->part[part-1])
                        return -ENXIO;
                  if (disk->part[part - 1]->nr_sects == 0)
                        return -ENXIO;
                  bdevp = bdget_disk(disk, part);
                  if (!bdevp)
                        return -ENOMEM;
                  mutex_lock(&bdevp->bd_mutex);
                  if (bdevp->bd_openers) {
                        mutex_unlock(&bdevp->bd_mutex);
                        bdput(bdevp);
                        return -EBUSY;
                  }
                  /* all seems OK */
                  fsync_bdev(bdevp);
                  invalidate_bdev(bdevp);

                  mutex_lock_nested(&bdev->bd_mutex, 1);
                  delete_partition(disk, part);
                  mutex_unlock(&bdev->bd_mutex);
                  mutex_unlock(&bdevp->bd_mutex);
                  bdput(bdevp);

                  return 0;
            default:
                  return -EINVAL;
      }
}

static int blkdev_reread_part(struct block_device *bdev)
{
      struct gendisk *disk = bdev->bd_disk;
      int res;

      if (disk->minors == 1 || bdev != bdev->bd_contains)
            return -EINVAL;
      if (!capable(CAP_SYS_ADMIN))
            return -EACCES;
      if (!mutex_trylock(&bdev->bd_mutex))
            return -EBUSY;
      res = rescan_partitions(disk, bdev);
      mutex_unlock(&bdev->bd_mutex);
      return res;
}

static int put_ushort(unsigned long arg, unsigned short val)
{
      return put_user(val, (unsigned short __user *)arg);
}

static int put_int(unsigned long arg, int val)
{
      return put_user(val, (int __user *)arg);
}

static int put_long(unsigned long arg, long val)
{
      return put_user(val, (long __user *)arg);
}

static int put_ulong(unsigned long arg, unsigned long val)
{
      return put_user(val, (unsigned long __user *)arg);
}

static int put_u64(unsigned long arg, u64 val)
{
      return put_user(val, (u64 __user *)arg);
}

static int blkdev_locked_ioctl(struct file *file, struct block_device *bdev,
                        unsigned cmd, unsigned long arg)
{
      struct backing_dev_info *bdi;
      int ret, n;

      switch (cmd) {
      case BLKRAGET:
      case BLKFRAGET:
            if (!arg)
                  return -EINVAL;
            bdi = blk_get_backing_dev_info(bdev);
            if (bdi == NULL)
                  return -ENOTTY;
            return put_long(arg, (bdi->ra_pages * PAGE_CACHE_SIZE) / 512);
      case BLKROGET:
            return put_int(arg, bdev_read_only(bdev) != 0);
      case BLKBSZGET: /* get the logical block size (cf. BLKSSZGET) */
            return put_int(arg, block_size(bdev));
      case BLKSSZGET: /* get block device hardware sector size */
            return put_int(arg, bdev_hardsect_size(bdev));
      case BLKSECTGET:
            return put_ushort(arg, bdev_get_queue(bdev)->max_sectors);
      case BLKRASET:
      case BLKFRASET:
            if(!capable(CAP_SYS_ADMIN))
                  return -EACCES;
            bdi = blk_get_backing_dev_info(bdev);
            if (bdi == NULL)
                  return -ENOTTY;
            bdi->ra_pages = (arg * 512) / PAGE_CACHE_SIZE;
            return 0;
      case BLKBSZSET:
            /* set the logical block size */
            if (!capable(CAP_SYS_ADMIN))
                  return -EACCES;
            if (!arg)
                  return -EINVAL;
            if (get_user(n, (int __user *) arg))
                  return -EFAULT;
            if (bd_claim(bdev, file) < 0)
                  return -EBUSY;
            ret = set_blocksize(bdev, n);
            bd_release(bdev);
            return ret;
      case BLKPG:
            return blkpg_ioctl(bdev, (struct blkpg_ioctl_arg __user *) arg);
      case BLKRRPART:
            return blkdev_reread_part(bdev);
      case BLKGETSIZE:
            if ((bdev->bd_inode->i_size >> 9) > ~0UL)
                  return -EFBIG;
            return put_ulong(arg, bdev->bd_inode->i_size >> 9);
      case BLKGETSIZE64:
            return put_u64(arg, bdev->bd_inode->i_size);
      case BLKTRACESTART:
      case BLKTRACESTOP:
      case BLKTRACESETUP:
      case BLKTRACETEARDOWN:
            return blk_trace_ioctl(bdev, cmd, (char __user *) arg);
      }
      return -ENOIOCTLCMD;
}

int blkdev_driver_ioctl(struct inode *inode, struct file *file,
                  struct gendisk *disk, unsigned cmd, unsigned long arg)
{
      int ret;
      if (disk->fops->unlocked_ioctl)
            return disk->fops->unlocked_ioctl(file, cmd, arg);

      if (disk->fops->ioctl) {
            lock_kernel();
            ret = disk->fops->ioctl(inode, file, cmd, arg);
            unlock_kernel();
            return ret;
      }

      return -ENOTTY;
}
EXPORT_SYMBOL_GPL(blkdev_driver_ioctl);

/*
 * always keep this in sync with compat_blkdev_ioctl() and
 * compat_blkdev_locked_ioctl()
 */
int blkdev_ioctl(struct inode *inode, struct file *file, unsigned cmd,
                  unsigned long arg)
{
      struct block_device *bdev = inode->i_bdev;
      struct gendisk *disk = bdev->bd_disk;
      int ret, n;

      switch(cmd) {
      case BLKFLSBUF:
            if (!capable(CAP_SYS_ADMIN))
                  return -EACCES;

            ret = blkdev_driver_ioctl(inode, file, disk, cmd, arg);
            /* -EINVAL to handle old uncorrected drivers */
            if (ret != -EINVAL && ret != -ENOTTY)
                  return ret;

            lock_kernel();
            fsync_bdev(bdev);
            invalidate_bdev(bdev);
            unlock_kernel();
            return 0;

      case BLKROSET:
            ret = blkdev_driver_ioctl(inode, file, disk, cmd, arg);
            /* -EINVAL to handle old uncorrected drivers */
            if (ret != -EINVAL && ret != -ENOTTY)
                  return ret;
            if (!capable(CAP_SYS_ADMIN))
                  return -EACCES;
            if (get_user(n, (int __user *)(arg)))
                  return -EFAULT;
            lock_kernel();
            set_device_ro(bdev, n);
            unlock_kernel();
            return 0;
      case HDIO_GETGEO: {
            struct hd_geometry geo;

            if (!arg)
                  return -EINVAL;
            if (!disk->fops->getgeo)
                  return -ENOTTY;

            /*
             * We need to set the startsect first, the driver may
             * want to override it.
             */
            geo.start = get_start_sect(bdev);
            ret = disk->fops->getgeo(bdev, &geo);
            if (ret)
                  return ret;
            if (copy_to_user((struct hd_geometry __user *)arg, &geo,
                              sizeof(geo)))
                  return -EFAULT;
            return 0;
      }
      }

      lock_kernel();
      ret = blkdev_locked_ioctl(file, bdev, cmd, arg);
      unlock_kernel();
      if (ret != -ENOIOCTLCMD)
            return ret;

      return blkdev_driver_ioctl(inode, file, disk, cmd, arg);
}
EXPORT_SYMBOL_GPL(blkdev_ioctl);

Generated by  Doxygen 1.6.0   Back to index