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 hd_struct *part;
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)
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);
mutex_unlock(&bdev->bd_mutex);
return IS_ERR(part) ? PTR_ERR(part) : 0;
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;
default:
return -EINVAL;
}
}
static int blkdev_reread_part(struct block_device *bdev)
{
struct gendisk *disk = bdev->bd_disk;
int res;
if (!disk_partitionable(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 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);
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(DISCARD_NOBARRIER, 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);
}
int __blkdev_driver_ioctl(struct block_device *bdev, fmode_t mode,
unsigned cmd, unsigned long arg)
{
struct gendisk *disk = bdev->bd_disk;
int ret;
if (disk->fops->ioctl)
return disk->fops->ioctl(bdev, mode, cmd, arg);
if (disk->fops->locked_ioctl) {
lock_kernel();
ret = disk->fops->locked_ioctl(bdev, mode, cmd, arg);
unlock_kernel();
return ret;
}
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);
/*
* always keep this in sync with compat_blkdev_ioctl() and
* compat_blkdev_locked_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;
switch(cmd) {
case BLKFLSBUF:
if (!capable(CAP_SYS_ADMIN))
return -EACCES;
ret = __blkdev_driver_ioctl(bdev, mode, 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(bdev, mode, 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 (!(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;
}
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 (!(mode & FMODE_EXCL) && bd_claim(bdev, &bdev) < 0)
return -EBUSY;
ret = set_blocksize(bdev, n);
if (!(mode & FMODE_EXCL))
bd_release(bdev);
return ret;
case BLKPG:
lock_kernel();
ret = blkpg_ioctl(bdev, (struct blkpg_ioctl_arg __user *) arg);
unlock_kernel();
break;
case BLKRRPART:
lock_kernel();
ret = blkdev_reread_part(bdev);
unlock_kernel();
break;
case BLKGETSIZE:
size = bdev->bd_inode->i_size;
if ((size >> 9) > ~0UL)
return -EFBIG;
return put_ulong(arg, size >> 9);
case BLKGETSIZE64:
return put_u64(arg, bdev->bd_inode->i_size);
case BLKTRACESTART:
case BLKTRACESTOP:
case BLKTRACESETUP:
case BLKTRACETEARDOWN:
lock_kernel();
ret = blk_trace_ioctl(bdev, cmd, (char __user *) arg);
unlock_kernel();
break;
default:
ret = __blkdev_driver_ioctl(bdev, mode, cmd, arg);
}
return ret;
}
EXPORT_SYMBOL_GPL(blkdev_ioctl);
