Messages in this thread | | | Date | Thu, 1 Aug 2002 15:40:56 -0700 (PDT) | From | Linus Torvalds <> | Subject | Re: manipulating sigmask from filesystems and drivers |
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On Thu, 1 Aug 2002, David Woodhouse wrote: > > torvalds@transmeta.com said: > > Any regular file IO is supposed to give you the full result. > > read(2) is permitted to return -EINTR.
It is _not_ allowed to do that for regular UNIX filesystems.
It is allowed to return it for things like pipes, sockets, etc, and for filesystems that do not have UNIX behaviour.
> Regular file I/O through the page cache is inherently restartable, anyway, > as long as you're careful about fpos.
It's not the kernel side that is not restartable. It's the _user_ side. There is 30 _years_ of history on this, and there are programs that have been programmed to follow the existing documentation.
And the existing documentation says that if you return a partial read from a normal file, that means EOF for that file.
You may not like it, but that doesn't make it less so. Linux has UNIX semantics for read(). Linux is not a research project where we change fundamental semantics just because we don't like it. That's final.
Linus
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