diff options
Diffstat (limited to 'block/ioctl.c')
| -rw-r--r-- | block/ioctl.c | 275 |
1 files changed, 275 insertions, 0 deletions
diff --git a/block/ioctl.c b/block/ioctl.c new file mode 100644 index 000000000000..6e278474f9a8 --- /dev/null +++ b/block/ioctl.c @@ -0,0 +1,275 @@ +#include <linux/sched.h> /* for capable() */ +#include <linux/blkdev.h> +#include <linux/blkpg.h> +#include <linux/backing-dev.h> +#include <linux/buffer_head.h> +#include <linux/smp_lock.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? */ + down(&bdev->bd_sem); + if (disk->part[part - 1]) { + up(&bdev->bd_sem); + 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)) { + up(&bdev->bd_sem); + return -EBUSY; + } + } + /* all seems OK */ + add_partition(disk, part, start, length); + up(&bdev->bd_sem); + 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; + down(&bdevp->bd_sem); + if (bdevp->bd_openers) { + up(&bdevp->bd_sem); + bdput(bdevp); + return -EBUSY; + } + /* all seems OK */ + fsync_bdev(bdevp); + invalidate_bdev(bdevp, 0); + + down(&bdev->bd_sem); + delete_partition(disk, part); + up(&bdev->bd_sem); + up(&bdevp->bd_sem); + 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 (down_trylock(&bdev->bd_sem)) + return -EBUSY; + res = rescan_partitions(disk, bdev); + up(&bdev->bd_sem); + 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); + } + return -ENOIOCTLCMD; +} + +static 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; +} + +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, 0); + 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; + } + + 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); +} + +/* Most of the generic ioctls are handled in the normal fallback path. + This assumes the blkdev's low level compat_ioctl always returns + ENOIOCTLCMD for unknown ioctls. */ +long compat_blkdev_ioctl(struct file *file, unsigned cmd, unsigned long arg) +{ + struct block_device *bdev = file->f_dentry->d_inode->i_bdev; + struct gendisk *disk = bdev->bd_disk; + int ret = -ENOIOCTLCMD; + if (disk->fops->compat_ioctl) { + lock_kernel(); + ret = disk->fops->compat_ioctl(file, cmd, arg); + unlock_kernel(); + } + return ret; +} + +EXPORT_SYMBOL_GPL(blkdev_ioctl); |