Date: Tue, 22 Jan 2002 10:44:31 -0800 From: Alfred Perlstein <bright@mu.org> To: David Greenman <dg@FreeBSD.org> Cc: cvs-committers@FreeBSD.org, cvs-all@FreeBSD.org Subject: Re: cvs commit: src/sys/kern uipc_syscalls.c Message-ID: <20020122104431.X13686@elvis.mu.org> In-Reply-To: <200201221732.g0MHWAR50160@freefall.freebsd.org>; from dg@FreeBSD.org on Tue, Jan 22, 2002 at 09:32:10AM -0800 References: <200201221732.g0MHWAR50160@freefall.freebsd.org>
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* David Greenman <dg@FreeBSD.org> [020122 09:32] wrote: > dg 2002/01/22 09:32:10 PST > > Modified files: > sys/kern uipc_syscalls.c > Log: > Fixed bug in calculation of amount of file to send when nbytes !=0 and > headers or trailers are supplied. Reported by Vladislav Shabanov > <vs@rambler-co.ru>. There's a problem here where people actually figured out this buggy behaviour and worked around it, however now you've broken their workarounds. This is why in a previous email (private I think) I suggested you use the flags argument or make a new syscall to implement the proper behaviour. see revision 1.6 of src/lib/libc_r/uthread/uthread_sendfile.c. -or- http://www.freebsd.org/cgi/cvsweb.cgi/src/lib/libc_r/uthread/uthread_sendfile.c?rev=1.6&content-type=text/x-cvsweb-markup Apache 2.x depends on the old behaviour as well. While you're here, you realize that sendfile's sideways return is pretty confusing, specifically the case where non-blocking IO is being done you can get back EAGAIN along with sbytes != 0. Most other syscalls, (write(2), read(2)) will return a short count and no error if they would block. I don't strongly object to MFC'ing this fix, but I think at least: 1) FreeBSD version needs to be bumped in both 5.x and 4.x. 2) If MFC'd please provide a osendfile function to not break applications. 3) consider fixing the sideways return as well to just return a partial count in sbytes and not an error? (ret == -1 && errno == EAGAIN && sbytes != 0) thanks, -- -Alfred Perlstein [alfred@freebsd.org] 'Instead of asking why a piece of software is using "1970s technology," start asking why software is ignoring 30 years of accumulated wisdom.' Tax deductable donations for FreeBSD: http://www.freebsdfoundation.org/ To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe cvs-all" in the body of the message
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