Re: [RFC] sane access to per-fs metadata (was Re: [PATCH] Documentation/ioctl-number.txt)

Matthew Wilcox
2001-03-23T17:17:19Z

On Fri, Mar 23, 2001 at 09:56:47AM -0700, Bryan Henderson wrote:
> There's a lot of cool simplicity in this, both in implementation and
> application, but it leaves something to be desired in functionality. This
> is partly because the price you pay for being able to use existing,
> well-worn Unix interfaces is the ancient limitations of those interfaces
> -- like the inability to return adequate error information.

hmm... open("defrag-error") first, then read from it if it fails?

> effective the defrag was? And bear in mind that multiple processes may be
> issuing commands to /mnt/control simultaneously.

you should probably serialise them. you probably have to do this anyway.

> With ioctl, I can easily match a response of any kind to a request. I can
> even return an English text message if I want to be friendly.

yes, one of the nice plan9 changes was the change to returning strings
instead of numerics.

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