Re: [bug-grep] [patch] getting '--devices=skip' to work

[Tim Waugh]

On Fri, Nov 19, 2004 at 01:10:30PM -0500, Paul Jarc wrote:

> Tim Waugh <address@hidden> wrote:
> > Stop the bus!  There is a kernel change to do with opening normal
> > files with O_NONBLOCK having unexpected consequences.
> 
> The Linux kernel, I assume?  What sort of consequences?  Would it work
> to change the descriptor back to blocking mode after opening?

Yes, Linux kernel.  I *think* it was that read() would set errno to
EAGAIN unless the requested data was actually in memory: i.e. it
wouldn't necessarily take steps to read from disk.

I don't know the details, and I don't know if the change was reverted
or is still present.  I believe it was still within POSIX, the idea
being to actually support O_NONBLOCK properly for regular files.

Tim.
*/

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