Date: Tue, 7 Oct 2008 03:50:04 GMT From: Maxim Konovalov <maxim@macomnet.ru> To: freebsd-fs@FreeBSD.org Subject: Re: kern/127213: [tmpfs] sendfile on tmpfs data corruption Message-ID: <200810070350.m973o411017984@freefall.freebsd.org>
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The following reply was made to PR kern/127213; it has been noted by GNATS. From: Maxim Konovalov <maxim@macomnet.ru> To: Nate Eldredge <neldredge@math.ucsd.edu> Cc: bug-followup@freebsd.org, JH <jh275@s6.sector6.net> Subject: Re: kern/127213: [tmpfs] sendfile on tmpfs data corruption Date: Tue, 7 Oct 2008 07:43:17 +0400 (MSD) On Mon, 6 Oct 2008, 15:22-0700, Nate Eldredge wrote: > On Mon, 6 Oct 2008, Maxim Konovalov wrote: > > > Hello, > > > > On Mon, 6 Oct 2008, 06:40-0000, Nate Eldredge wrote: > > > > [...] > > > Incidentally, to the initial reporter, what application do you have > > > that requires sendfile? In my experience, most things will fall > > > back to a read/write loop if sendfile fails, since sendfile isn't > > > available on all systems or under all circumstances. So if you > > > apply the quick fix so that sendfile always fails, it might at > > > least get your application working again. > > > > > As stated in the PR Andrey used nginx (ports/www/nginx). But I could > > easily reproduce the bug with the stock ftpd(8) with the ftproot on > > tmpfs. > > To simplify matters further, here is the testcase I used when > testing this, which uses sendfile to send some data over a unix > domain socket. Do: > > ./server /tmpfs/data mysocket & > ./client mysocket >data.out > cmp /tmpfs/data data.out > > If things work right, data and data.out should be identical. But if > data is a file on a tmpfs, data.out contains apparently random > kernel memory contents. > Hi Nate, It'd be really nice if you extend src/tools/regression/sockets/sendfile regression test for this bug. Now it doesn't detect this case. -- Maxim Konovalov
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