RFC: chattr/lsattr +DS? was: ext3-2.4-0.9.4

Matthias Andree
2001-07-26T15:08:00Z

On Fri, 27 Jul 2001, Andrew Morton wrote:

> > Would you deem it
> > possible to get such an option done before ext3fs 1.0.0?
>
> We'd prefer not - we're trying to stabilise things quite
> sternly at present. However that doesn't prevent work
> on 1.1.0 :)
>
> Seems like a worthwhile thing to do - I'll cut a branch
> and do this. It'll take a couple of weeks - as usual, most
> of the work is in development and use of test tools...
> But I can't predict at this time when we'll merge it into
> the mainline fs.

So the summary of all this is, as I understand it: for ext3fs 1.0, treat
it with chattr +S and the like as if it was ext2fs, it may or may not be
faster with "mount -o data=journalled" and is well worthwhile for an MTA
to try, a weaker sync option may be introduced after ext3fs 1.0.

Sounds good.

I'm dropping the ext3-users mailing list for now since this is getting
more general.

However, since the ReiserFS team also showed interest in a similar
functionality, and they don't yet support chattr, would it be useful to
specify a "D" option for chattr already?

I have a suggestion: if D is set, but S isn't, no effect. If S is set,
but D is unset, treat S as in the past. If S is set, and D is set,
directory updates are synchronous like with S, but data updates are
asynchronous in spite of S.

This way, booting a kernel without chattr "D" flag support or mounting
the file system as ext2 would have it default to the safer
everything-synchronously mode.

--
Matthias Andree