> -----Original Message----- > From: Matteo Croce <mcroce@xxxxxxxxxxxxxxxxxxx> > Sent: Sunday, July 11, 2021 12:54 PM ... > Subject: [PATCH v4 3/5] block: add ioctl to read the disk sequence number > > From: Matteo Croce <mcroce@xxxxxxxxxxxxx> > > Add a new BLKGETDISKSEQ ioctl which retrieves the disk sequence number > from the genhd structure. ... Given: static int put_u64(u64 __user *argp, u64 val) { return put_user(val, argp); } > diff --git a/block/ioctl.c b/block/ioctl.c > index 24beec9ca9c9..0c3a4a53fa11 100644 > --- a/block/ioctl.c > +++ b/block/ioctl.c > @@ -469,6 +469,8 @@ static int blkdev_common_ioctl(struct block_device > *bdev, fmode_t mode, > BLKDEV_DISCARD_SECURE); ... > + case BLKGETDISKSEQ: > + return put_u64(argp, bdev->bd_disk->diskseq); How does that work on a system in which int is 32 bits?