Re: ext3-2.4-0.9.4

From: Richard A Nelson (
Date: Thu Jul 26 2001 - 15:04:13 EST

On Thu, 26 Jul 2001, Linus Torvalds wrote:

> > 1) Does fsync() of a directory work on most/all current FS?
> Modulo bugs, yes.

Great, that was a big concern

> Now, there's another issue, of course: if you have an important mail-spool
> on some of the less tested filesystems, I would consider you crazy
> regardless of fsync() working ;). I don't think anybody has ever verified
> that fsync() (or much anything else wrt writing) does the right thing on
> NTFS, for example.

Caveat Emptor ;-)

> > 2) Does it work on 2.2.x as well as 2.4.x?
> Yes. However, there may be performance issues. As with just about
> anything, we didn't start optimizing things until it became a real issue,
> and in some cases at least historically the filesystems fell back on just
> doing a whole "fsync_dev()" if they had nothing better to do.
> I think later 2.2.x kernels (ie the ones past the point where Alan took
> over) probably have the fsync() optimizations at least for ext2.

That should be recent enough - I push 2.2.19 for shm support and security
reasons anyway - though I see alot of folk on 2.2.16/17.

Are the optimizations more than writing out only changed blocks?
Has anyone any information on the performance differences between
optimized vs non-optimized?

Thanks, I'm feeling much better about getting this support added

Rick Nelson
Life'll kill ya                         -- Warren Zevon
Then you'll be dead                     -- Life'll kill ya

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This archive was generated by hypermail 2b29 : Tue Jul 31 2001 - 21:00:29 EST