Bug#629994: sendfile returns early without user-visible reason

[Jonathan Nieder <jrnieder@gmail.com>]

clone 629994 -1
reassign -1 manpages-dev 3.27-1
severity -1 = minor
tags -1 = upstream lfs
retitle -1 read/write/readv/writev/sendfile(2): undocumented cap on number of bytes read/written
quit

Marc Lehmann wrote:
(out of order for convenience)

> I am really busy with writing and maintaining a LOT of free software. I
> consider it my duty to report bugs, but if upstream doesn't feel like
> fixing it, that's not really my problem.

Indeed, thanks for reporting it.

>> If you'd like, you can retitle this bug. :)
>
> I don't know how.

http://www.debian.org/Bugs/Developer

> Well, the relevant posix manpage for read is read, not the one for write.
> read is clear.

I looked at both.  I suppose we will have to agree to disagree here ---
in standardese "may" and "shall" both have clear meanings, and unless I
missed something obvious the wording you pointed to did not place the
requirement we are talking about on the implementation.

Not that it matters much, since on one hand the text is obviously less
clear than ideal and there are people in the Austin Group who would be
glad to improve it if asked (presumably by making it match the intent
better) and on the other hand, Linux does not follow Posix rigidly
anyway.

But I had thought I could point to that easy avenue for improving
documentation and portability in the wider world.

Cloning the bug so the confusing behavior can be documented.  I will
leave it to the kernel maintainers to decide whether the kernel bug
should be left open.

Regards,
Jonathan