Initial import

1 files changed, 430 insertions, 0 deletions

diff --git a/block/ioctl.c b/block/ioctl.c
new file mode 100644
index 000000000..7d8befde2
--- /dev/null
+++ b/block/ioctl.c
@@ -0,0 +1,430 @@
+#include <linux/capability.h>
+#include <linux/blkdev.h>
+#include <linux/export.h>
+#include <linux/gfp.h>
+#include <linux/blkpg.h>
+#include <linux/hdreg.h>
+#include <linux/backing-dev.h>
+#include <linux/fs.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 hd_struct *part, *lpart;
+	struct blkpg_ioctl_arg a;
+	struct blkpg_partition p;
+	struct disk_part_iter piter;
+	long long start, length;
+	int partno;
+
+	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;
+	partno = p.pno;
+	if (partno <= 0)
+		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 || partno > 65535)
+					return -EINVAL;
+			}
+
+			mutex_lock(&bdev->bd_mutex);
+
+			/* overlap? */
+			disk_part_iter_init(&piter, disk,
+					    DISK_PITER_INCL_EMPTY);
+			while ((part = disk_part_iter_next(&piter))) {
+				if (!(start + length <= part->start_sect ||
+				      start >= part->start_sect + part->nr_sects)) {
+					disk_part_iter_exit(&piter);
+					mutex_unlock(&bdev->bd_mutex);
+					return -EBUSY;
+				}
+			}
+			disk_part_iter_exit(&piter);
+
+			/* all seems OK */
+			part = add_partition(disk, partno, start, length,
+					     ADDPART_FLAG_NONE, NULL);
+			mutex_unlock(&bdev->bd_mutex);
+			return PTR_ERR_OR_ZERO(part);
+		case BLKPG_DEL_PARTITION:
+			part = disk_get_part(disk, partno);
+			if (!part)
+				return -ENXIO;
+
+			bdevp = bdget(part_devt(part));
+			disk_put_part(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, partno);
+			mutex_unlock(&bdev->bd_mutex);
+			mutex_unlock(&bdevp->bd_mutex);
+			bdput(bdevp);
+
+			return 0;
+		case BLKPG_RESIZE_PARTITION:
+			start = p.start >> 9;
+			/* new length of partition in bytes */
+			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;
+			}
+			part = disk_get_part(disk, partno);
+			if (!part)
+				return -ENXIO;
+			bdevp = bdget(part_devt(part));
+			if (!bdevp) {
+				disk_put_part(part);
+				return -ENOMEM;
+			}
+			mutex_lock(&bdevp->bd_mutex);
+			mutex_lock_nested(&bdev->bd_mutex, 1);
+			if (start != part->start_sect) {
+				mutex_unlock(&bdevp->bd_mutex);
+				mutex_unlock(&bdev->bd_mutex);
+				bdput(bdevp);
+				disk_put_part(part);
+				return -EINVAL;
+			}
+			/* overlap? */
+			disk_part_iter_init(&piter, disk,
+					    DISK_PITER_INCL_EMPTY);
+			while ((lpart = disk_part_iter_next(&piter))) {
+				if (lpart->partno != partno &&
+				   !(start + length <= lpart->start_sect ||
+				   start >= lpart->start_sect + lpart->nr_sects)
+				   ) {
+					disk_part_iter_exit(&piter);
+					mutex_unlock(&bdevp->bd_mutex);
+					mutex_unlock(&bdev->bd_mutex);
+					bdput(bdevp);
+					disk_put_part(part);
+					return -EBUSY;
+				}
+			}
+			disk_part_iter_exit(&piter);
+			part_nr_sects_write(part, (sector_t)length);
+			i_size_write(bdevp->bd_inode, p.length);
+			mutex_unlock(&bdevp->bd_mutex);
+			mutex_unlock(&bdev->bd_mutex);
+			bdput(bdevp);
+			disk_put_part(part);
+			return 0;
+		default:
+			return -EINVAL;
+	}
+}
+
+static int blkdev_reread_part(struct block_device *bdev)
+{
+	struct gendisk *disk = bdev->bd_disk;
+	int res;
+
+	if (!disk_part_scan_enabled(disk) || 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 blk_ioctl_discard(struct block_device *bdev, uint64_t start,
+			     uint64_t len, int secure)
+{
+	unsigned long flags = 0;
+
+	if (start & 511)
+		return -EINVAL;
+	if (len & 511)
+		return -EINVAL;
+	start >>= 9;
+	len >>= 9;
+
+	if (start + len > (i_size_read(bdev->bd_inode) >> 9))
+		return -EINVAL;
+	if (secure)
+		flags |= BLKDEV_DISCARD_SECURE;
+	return blkdev_issue_discard(bdev, start, len, GFP_KERNEL, flags);
+}
+
+static int blk_ioctl_zeroout(struct block_device *bdev, uint64_t start,
+			     uint64_t len)
+{
+	if (start & 511)
+		return -EINVAL;
+	if (len & 511)
+		return -EINVAL;
+	start >>= 9;
+	len >>= 9;
+
+	if (start + len > (i_size_read(bdev->bd_inode) >> 9))
+		return -EINVAL;
+
+	return blkdev_issue_zeroout(bdev, start, len, GFP_KERNEL, false);
+}
+
+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_uint(unsigned long arg, unsigned int val)
+{
+	return put_user(val, (unsigned 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);
+}
+
+int __blkdev_driver_ioctl(struct block_device *bdev, fmode_t mode,
+			unsigned cmd, unsigned long arg)
+{
+	struct gendisk *disk = bdev->bd_disk;
+
+	if (disk->fops->ioctl)
+		return disk->fops->ioctl(bdev, mode, cmd, arg);
+
+	return -ENOTTY;
+}
+/*
+ * For the record: _GPL here is only because somebody decided to slap it
+ * on the previous export.  Sheer idiocy, since it wasn't copyrightable
+ * at all and could be open-coded without any exports by anybody who cares.
+ */
+EXPORT_SYMBOL_GPL(__blkdev_driver_ioctl);
+
+/*
+ * Is it an unrecognized ioctl? The correct returns are either
+ * ENOTTY (final) or ENOIOCTLCMD ("I don't know this one, try a
+ * fallback"). ENOIOCTLCMD gets turned into ENOTTY by the ioctl
+ * code before returning.
+ *
+ * Confused drivers sometimes return EINVAL, which is wrong. It
+ * means "I understood the ioctl command, but the parameters to
+ * it were wrong".
+ *
+ * We should aim to just fix the broken drivers, the EINVAL case
+ * should go away.
+ */
+static inline int is_unrecognized_ioctl(int ret)
+{
+	return	ret == -EINVAL ||
+		ret == -ENOTTY ||
+		ret == -ENOIOCTLCMD;
+}
+
+/*
+ * always keep this in sync with compat_blkdev_ioctl()
+ */
+int blkdev_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd,
+			unsigned long arg)
+{
+	struct gendisk *disk = bdev->bd_disk;
+	struct backing_dev_info *bdi;
+	loff_t size;
+	int ret, n;
+	unsigned int max_sectors;
+
+	switch(cmd) {
+	case BLKFLSBUF:
+		if (!capable(CAP_SYS_ADMIN))
+			return -EACCES;
+
+		ret = __blkdev_driver_ioctl(bdev, mode, cmd, arg);
+		if (!is_unrecognized_ioctl(ret))
+			return ret;
+
+		fsync_bdev(bdev);
+		invalidate_bdev(bdev);
+		return 0;
+
+	case BLKROSET:
+		ret = __blkdev_driver_ioctl(bdev, mode, cmd, arg);
+		if (!is_unrecognized_ioctl(ret))
+			return ret;
+		if (!capable(CAP_SYS_ADMIN))
+			return -EACCES;
+		if (get_user(n, (int __user *)(arg)))
+			return -EFAULT;
+		set_device_ro(bdev, n);
+		return 0;
+
+	case BLKDISCARD:
+	case BLKSECDISCARD: {
+		uint64_t range[2];
+
+		if (!(mode & FMODE_WRITE))
+			return -EBADF;
+
+		if (copy_from_user(range, (void __user *)arg, sizeof(range)))
+			return -EFAULT;
+
+		return blk_ioctl_discard(bdev, range[0], range[1],
+					 cmd == BLKSECDISCARD);
+	}
+	case BLKZEROOUT: {
+		uint64_t range[2];
+
+		if (!(mode & FMODE_WRITE))
+			return -EBADF;
+
+		if (copy_from_user(range, (void __user *)arg, sizeof(range)))
+			return -EFAULT;
+
+		return blk_ioctl_zeroout(bdev, range[0], range[1]);
+	}
+
+	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.
+		 */
+		memset(&geo, 0, sizeof(geo));
+		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;
+	}
+	case BLKRAGET:
+	case BLKFRAGET:
+		if (!arg)
+			return -EINVAL;
+		bdi = blk_get_backing_dev_info(bdev);
+		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 block device soft block size (cf. BLKSSZGET) */
+		return put_int(arg, block_size(bdev));
+	case BLKSSZGET: /* get block device logical block size */
+		return put_int(arg, bdev_logical_block_size(bdev));
+	case BLKPBSZGET: /* get block device physical block size */
+		return put_uint(arg, bdev_physical_block_size(bdev));
+	case BLKIOMIN:
+		return put_uint(arg, bdev_io_min(bdev));
+	case BLKIOOPT:
+		return put_uint(arg, bdev_io_opt(bdev));
+	case BLKALIGNOFF:
+		return put_int(arg, bdev_alignment_offset(bdev));
+	case BLKDISCARDZEROES:
+		return put_uint(arg, bdev_discard_zeroes_data(bdev));
+	case BLKSECTGET:
+		max_sectors = min_t(unsigned int, USHRT_MAX,
+				    queue_max_sectors(bdev_get_queue(bdev)));
+		return put_ushort(arg, max_sectors);
+	case BLKROTATIONAL:
+		return put_ushort(arg, !blk_queue_nonrot(bdev_get_queue(bdev)));
+	case BLKRASET:
+	case BLKFRASET:
+		if(!capable(CAP_SYS_ADMIN))
+			return -EACCES;
+		bdi = blk_get_backing_dev_info(bdev);
+		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 (!(mode & FMODE_EXCL)) {
+			bdgrab(bdev);
+			if (blkdev_get(bdev, mode | FMODE_EXCL, &bdev) < 0)
+				return -EBUSY;
+		}
+		ret = set_blocksize(bdev, n);
+		if (!(mode & FMODE_EXCL))
+			blkdev_put(bdev, mode | FMODE_EXCL);
+		return ret;
+	case BLKPG:
+		ret = blkpg_ioctl(bdev, (struct blkpg_ioctl_arg __user *) arg);
+		break;
+	case BLKRRPART:
+		ret = blkdev_reread_part(bdev);
+		break;
+	case BLKGETSIZE:
+		size = i_size_read(bdev->bd_inode);
+		if ((size >> 9) > ~0UL)
+			return -EFBIG;
+		return put_ulong(arg, size >> 9);
+	case BLKGETSIZE64:
+		return put_u64(arg, i_size_read(bdev->bd_inode));
+	case BLKTRACESTART:
+	case BLKTRACESTOP:
+	case BLKTRACESETUP:
+	case BLKTRACETEARDOWN:
+		ret = blk_trace_ioctl(bdev, cmd, (char __user *) arg);
+		break;
+	default:
+		ret = __blkdev_driver_ioctl(bdev, mode, cmd, arg);
+	}
+	return ret;
+}
+EXPORT_SYMBOL_GPL(blkdev_ioctl);