diff --git a/block/compat_ioctl.c b/block/compat_ioctl.c index c23177e4623f..1e559fba7bdf 100644 --- a/block/compat_ioctl.c +++ b/block/compat_ioctl.c @@ -788,6 +788,7 @@ long compat_blkdev_ioctl(struct file *file, unsigned cmd, unsigned long arg) return compat_hdio_getgeo(disk, bdev, compat_ptr(arg)); case BLKFLSBUF: case BLKROSET: + case BLKDISCARD: /* * the ones below are implemented in blkdev_locked_ioctl, * but we call blkdev_ioctl, which gets the lock for us diff --git a/block/ioctl.c b/block/ioctl.c index 77185e5c026a..342298bb6080 100644 --- a/block/ioctl.c +++ b/block/ioctl.c @@ -111,6 +111,69 @@ static int blkdev_reread_part(struct block_device *bdev) 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); @@ -258,6 +321,19 @@ int blkdev_ioctl(struct inode *inode, struct file *file, unsigned cmd, 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; diff --git a/include/linux/fs.h b/include/linux/fs.h index eb0131319134..88358ca6af25 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -223,6 +223,7 @@ extern int dir_notify_enable; #define BLKTRACESTART _IO(0x12,116) #define BLKTRACESTOP _IO(0x12,117) #define BLKTRACETEARDOWN _IO(0x12,118) +#define BLKDISCARD _IO(0x12,119) #define BMAP_IOCTL 1 /* obsolete - kept for compatibility */ #define FIBMAP _IO(0x00,1) /* bmap access */