On 2009-09-10, Michael Burk <bur...@gmail.com> wrote: > We have been working for a couple weeks with the Amanda developers to get > their latest release working on OpenBSD 4.5. Amanda stopped working with > OpenBSD somewhere around version 2.5.1 (3 years ago). We've been focusing on > a failure in the dump process on the client.
Does newer Amanda use threads? With pthread, stdio will be silently changed to _non_ blocking. > > On the client side, dump(8) is started with its output to a blocking pipe. > However, dump fails with EAGAIN, which we understand should be impossible. > One of the developers outlined the basic process as follows: > > In amandad process: > pipe(pipefd) > dup2(pipefd[1],b) > fork > in the child: > exec sendbackup process > dup2(b,c) > write c #fail with EAGAIN > > We added some debug messages to verify that the pipe was blocking. In so > doing, we discovered that the debug messages "fixed" the problem, and the > dump succeeded. Narrowing this down, we found the absolute minimal patch was > simply inserting the following line before the dup2 above: > fcntl(datafd, F_GETFL, 0); > > This adds to the mystery; why would doing a call that simply returns a flag > change the behavior of the program? Is there some side effect of this call? > > We have tried this on several machines (at least the sparc64, amd64 > platforms), all running 4.5. dump is invoked as follows: > /sbin/dump dump 0usf 1048576 - /dev/rsd0a > > I don't know what other details might be helpful; let me know and I'll send > them. > > Thank you for any insight. > > -- Michael
