block: ioctl to zero block ranges

Introduce a BLKZEROOUT ioctl which can be used to clear block ranges by
way of blkdev_issue_zeroout().

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Acked-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Martin K. Petersen 2012-09-18 12:19:29 -04:00 committed by Jens Axboe
parent 579e8f3c7b
commit 66ba32dc16
2 changed files with 28 additions and 0 deletions

View File

@ -185,6 +185,22 @@ static int blk_ioctl_discard(struct block_device *bdev, uint64_t start,
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);
}
static int put_ushort(unsigned long arg, unsigned short val)
{
return put_user(val, (unsigned short __user *)arg);
@ -300,6 +316,17 @@ int blkdev_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd,
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;

View File

@ -335,6 +335,7 @@ struct inodes_stat_t {
#define BLKDISCARDZEROES _IO(0x12,124)
#define BLKSECDISCARD _IO(0x12,125)
#define BLKROTATIONAL _IO(0x12,126)
#define BLKZEROOUT _IO(0x12,127)
#define BMAP_IOCTL 1 /* obsolete - kept for compatibility */
#define FIBMAP _IO(0x00,1) /* bmap access */