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-rw-r--r--block/ioctl.c275
1 files changed, 275 insertions, 0 deletions
diff --git a/block/ioctl.c b/block/ioctl.c
new file mode 100644
index 0000000..6e27847
--- /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);