block/ioctl.c - maze/linux - Git at Google

 #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;
 	int err;

 	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 */
 			err = add_partition(disk, part, start, length, ADDPART_FLAG_NONE);
 			mutex_unlock(&bdev->bd_mutex);
 			return err;
 		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 void blk_ioc_discard_endio(struct bio *bio, int err)
 {
 	if (err) {
 		if (err == -EOPNOTSUPP)
 			set_bit(BIO_EOPNOTSUPP, &bio->bi_flags);
 		clear_bit(BIO_UPTODATE, &bio->bi_flags);
 	}
 	complete(bio->bi_private);
 }

 static int blk_ioctl_discard(struct block_device *bdev, uint64_t start,
 			     uint64_t len)
 {
 	struct request_queue *q = bdev_get_queue(bdev);
 	int ret = 0;

 	if (start & 511)
 		return -EINVAL;
 	if (len & 511)
 		return -EINVAL;
 	start >>= 9;
 	len >>= 9;

 	if (start + len > (bdev->bd_inode->i_size >> 9))
 		return -EINVAL;

 	if (!q->prepare_discard_fn)
 		return -EOPNOTSUPP;

 	while (len && !ret) {
 		DECLARE_COMPLETION_ONSTACK(wait);
 		struct bio *bio;

 		bio = bio_alloc(GFP_KERNEL, 0);
 		if (!bio)
 			return -ENOMEM;

 		bio->bi_end_io = blk_ioc_discard_endio;
 		bio->bi_bdev = bdev;
 		bio->bi_private = &wait;
 		bio->bi_sector = start;

 		if (len > q->max_hw_sectors) {
 			bio->bi_size = q->max_hw_sectors << 9;
 			len -= q->max_hw_sectors;
 			start += q->max_hw_sectors;
 		} else {
 			bio->bi_size = len << 9;
 			len = 0;
 		}
 		submit_bio(WRITE_DISCARD, bio);

 		wait_for_completion(&wait);

 		if (bio_flagged(bio, BIO_EOPNOTSUPP))
 			ret = -EOPNOTSUPP;
 		else if (!bio_flagged(bio, BIO_UPTODATE))
 			ret = -EIO;
 		bio_put(bio);
 	}
 	return ret;
 }

 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 BLKDISCARD: {
 		uint64_t range[2];

 		if (!(file->f_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]);
 	}

 	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);
	#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;
	int err;

	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 */
	err = add_partition(disk, part, start, length, ADDPART_FLAG_NONE);
	mutex_unlock(&bdev->bd_mutex);
	return err;
	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 void blk_ioc_discard_endio(struct bio *bio, int err)
	{
	if (err) {
	if (err == -EOPNOTSUPP)
	set_bit(BIO_EOPNOTSUPP, &bio->bi_flags);
	clear_bit(BIO_UPTODATE, &bio->bi_flags);
	}
	complete(bio->bi_private);
	}

	static int blk_ioctl_discard(struct block_device *bdev, uint64_t start,
	uint64_t len)
	{
	struct request_queue *q = bdev_get_queue(bdev);
	int ret = 0;

	if (start & 511)
	return -EINVAL;
	if (len & 511)
	return -EINVAL;
	start >>= 9;
	len >>= 9;

	if (start + len > (bdev->bd_inode->i_size >> 9))
	return -EINVAL;

	if (!q->prepare_discard_fn)
	return -EOPNOTSUPP;

	while (len && !ret) {
	DECLARE_COMPLETION_ONSTACK(wait);
	struct bio *bio;

	bio = bio_alloc(GFP_KERNEL, 0);
	if (!bio)
	return -ENOMEM;

	bio->bi_end_io = blk_ioc_discard_endio;
	bio->bi_bdev = bdev;
	bio->bi_private = &wait;
	bio->bi_sector = start;

	if (len > q->max_hw_sectors) {
	bio->bi_size = q->max_hw_sectors << 9;
	len -= q->max_hw_sectors;
	start += q->max_hw_sectors;
	} else {
	bio->bi_size = len << 9;
	len = 0;
	}
	submit_bio(WRITE_DISCARD, bio);

	wait_for_completion(&wait);

	if (bio_flagged(bio, BIO_EOPNOTSUPP))
	ret = -EOPNOTSUPP;
	else if (!bio_flagged(bio, BIO_UPTODATE))
	ret = -EIO;
	bio_put(bio);
	}
	return ret;
	}

	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 BLKDISCARD: {
	uint64_t range[2];

	if (!(file->f_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]);
	}

	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);