Date: Wed, 27 Oct 1999 10:17:36 -0400 (EDT) From: Robert Watson <robert@cyrus.watson.org> To: Don <don@calis.blacksun.org> Cc: freebsd-fs@freebsd.org Subject: Re: Journaling Message-ID: <Pine.BSF.3.96.991027101306.22425A-100000@fledge.watson.org> In-Reply-To: <Pine.BSF.4.05.9910270014340.34406-100000@calis.blacksun.org>
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I would love to see full journaling/logging for meta-data -- softupdates is cool, but seems to be a hard-coding of the rules as opposed to a general journaling fs. Specifically, I'd love to see a journaling fs with extensible meta-data attributes, such as supported by XFS. This would put us in a situation where adding new structures to the fs didn't require understanding the internals of the journalling--this way someone (say me) could add new meta-data (say ACLs) and not have to deal with the realities of softupdates, or even fsck. IRIX XFS adds two new vops, a getexattr and setexattr for named extensions that are also logged. The Linux people, to add ACL support, are using extra blocks on the file system. The problem with this is that if the user can coerce a kernel failure (i.e., crash the system, cut the power, whatever), they can induce inconsistencies in the ACL and inode versions, meaning that if they time it right, they can influence the content of the ACLs, or other security data (MAC tags, etc). With a logged extensible meta-data system, this could not happen. Someone mentioned at one point that they were looking at porting XFS to FreeBSD. I assume XFS is under some sort of community license and not a BSD license, but it might be a good place to start. On Wed, 27 Oct 1999, Don wrote: > On the subject of a journaled file system for FreeBSD: > > I am sure a lot of people have pondered the construction of a journaled > file system for FreeBSD. I would like to see these pondering's become a > reality. > > I have been speaking to a variety of people who are very interested in > becoming involved in such a project should one be started. Basically I > would like to know if anyone here is interested in creating a journaled > file system and who would be willing to donate time and programming skills > to such a project. > > This would be a rather large undertaking but it would get FreeBSD a world > class file system. Also, some work along these lines was already done with > LFS and it does not look as if XFS is going to be strolling down the pike > any time soon. (And even if it did it wont have a copyright that FreeBSD > could really use) > > In summary: > I am assuming there is no journaled file system project already under way. > (If there is please let me know so that I can donate any help I can) > This project would need people willing to work hard and who would be > willing to use the BSD license for their work. > This project would not be meant to replace or usurp either softupdates or > UFS for a long time. It is meant to provide a more fault tolerant, > flexible, "free" (i.e. BSD license) file system for FreeBSD. > > Any information that anyone is willing to share would be very welcome. > > -don > > > > To Unsubscribe: send mail to majordomo@FreeBSD.org > with "unsubscribe freebsd-fs" in the body of the message > Robert N M Watson robert@fledge.watson.org http://www.watson.org/~robert/ PGP key fingerprint: AF B5 5F FF A6 4A 79 37 ED 5F 55 E9 58 04 6A B1 TIS Labs at Network Associates, Safeport Network Services To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-fs" in the body of the message
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