On Mon, Jun 04, 2007 at 11:02:23AM -0600, Matthew Wilcox wrote: > On Mon, Jun 04, 2007 at 09:56:07AM -0700, Bryan Henderson wrote: > > Programs that assume a full transfer are fairly common, but are > > universally regarded as either broken or just lazy, and when it does cause > > a problem, it is far more common to fix the application than the kernel. > > Linus has explicitly forbidden short reads from being returned. The > original poster may get away with it for a specialised case, but for > example, signals may not cause a return to userspace with a short read > for exactly this reason. Hmm, I'm not sure I would go that far. Per the POSIX specification, we support the optional BSD-style restartable system calls for signals which will avoid short reads; but this is only true if SA_RESTART is passed to sigaction(). Without SA_RESTART, we will indeed return short reads, as required by POSIX. I don't think Linus has said that short reads are always evil; I certainly can't remember him ever making that statement. Do you have a pointer to a LKML message where he's said that? - Ted - To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
