Messages in this thread | | | From | "H. Peter Anvin" <> | Subject | Re: linux-2.4.0 breaks grub install into partition | Date | 8 Jul 2000 22:55:58 -0700 |
| |
Followup to: <20000709124906O.okuji@kuicr.kyoto-u.ac.jp> By author: OKUJI Yoshinori <okuji@gnu.org> In newsgroup: linux.dev.kernel > > I don't think what GRUB does is a wrong thing basically. Some types > of software always need (or want) to access raw devices, for example, > FDISK programs, filesystem resizers, and fast database servers. So, > AFAIK, all the realistic operating systems export raw devices to > user-level programs and support one or more system calls to keep > anything in the kernel consistent. >
That's a pretty ridiculous assertion! When you have a kernel filesystem mounted, it belongs to the kernel. However, in the past Linux has allowed the boot block -- not being used by the in-kernel filesystem -- to be accessed via the block device. Breaking this without introducing an API to write the boot block was a bad idea.
> For now, the grub shell calls sync() (twice before any operation) > and ioctl(fd, BLKFLSBUF, 0) (after and before operations) under > Linux. I thought that was enough, since sync should make filesystems > and buffer caches consistent, and BLKFLSBUF should flush buffer caches > to actual disks. I even thought that was overkill.
There operations don't change a thing. At all. They're not merely overkill, they're useless. You're changing tires because you're out of gas.
-hpa -- <hpa@transmeta.com> at work, <hpa@zytor.com> in private! "Unix gives you enough rope to shoot yourself in the foot." http://www.zytor.com/~hpa/puzzle.txt
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.rutgers.edu Please read the FAQ at http://www.tux.org/lkml/
| |