[PVFS-developers] Minor pvfs-1.6.3 pre1 patch (don't close stdout in do_restart)

[White Stuart - stwhit]

In the iod during startup, the code opens the logfile, and then calls dup2()
on stdout and stderr, so that anything printed to stdout or stderr will get
printed to the log file:

if ((fd = open(logfile, logflags, 0700)) == -1) return -1;
#endif
fchmod(fd, 0755);
dup2(fd, 2);
dup2(fd, 1);

Later, in do_restart(), which gets called when the manager gets bounced, the
IOD closes all open file descriptors, except for the "accept" socket and
stderr.  It closes stdout.

for (i=0; i < sysconf(_SC_OPEN_MAX); i++) {
   if (i != acc && i != 2) close(i);
}

So, stdout (fd 1) will get reused later when opening local data files.  If a
developer puts some debug code into the IOD which calls printf(), it works
properly until the manager gets bounced, at which point the printf's start
getting printed to one of the data files!  You can imagine my surprise when
my data files started getting corrupted by my debug printf's! :-)

I have attached a patch that simply adds file descriptor 1 to the list of
"special" file descriptors that do not get closed in do_restart().

Thanks!

Stuart White



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