Occassional "permission denied" in the middle of a large transfer over NFS

[Vincent Hoffman]

Hi,
After only one off-list reply from the author of kern/136865 (see below)
after asking -questions, I thought it worth asking -CURRENT.
Basically:

I seem to have run into the problems described in this old thread.
http://lists.freebsd.org/pipermail/freebsd-questions/2004-April/044927.html

tl:dr mountd may give incorrect permission denied errors when it is
refreshing the exports list due to non-atomic operations,  /sbin/mount has code that sends SIGHUP to
mountd on any mount operation, which implies that any manual mount
request would cause the problem.  

Currently I have still only tested on 8.3-RELEASE but the svn log doesnt
seem to mention a fix since then. I'm currently taking a VM up to
-CURRENT to test.

Looking though old PRs I see the following related.
kern/131342
kern/136865 (with patch for 7.2 and links to
http://nfse.sourceforge.net/ for -CURRENT )

Does anyone who is qualified (sadly not me) feel like looking at the
code to see if its suitable for inclusion in part/whole as not having
NFS transfers interrupted by local mount operations on the nfs server
would be very handy :)


thanks, Vince