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Date: Wed, 20 Apr 2005 13:16:05 -0400
To: Marc Olzheim <marcolz@stack.nl>
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Subject: Re: NFS client/buffer cache deadlock
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<<On Wed, 20 Apr 2005 16:38:42 +0200, Marc Olzheim <marcolz@stack.nl> said:

> Btw.: I'm not sure write(),writev() and pwrite() are allowed to do short
> writes on regular files... ?

I believe it is the intent of the Standard to prohibit this (a
paragraph in the rationale says that short writes can only happen if
O_NONBLOCK is set, but this is clearly wrong because the normative
text says end-of-medium also results in a short write) but there does
not appear to be any language which requires atomic behavior for
descriptors other than pipes and FIFOs.

As a quality-of-implementation matter, for writes to regular files not
to be atomic would be considered surprising.

-GAWollman