Our main fileserver here (which is based on dapper, but uses an edgy 2.6.17 kernel (version 2.6.17-11-server, backported to dapper) because we need NFSv4 with working krb5p support) is also hit by the problem. Using "no_subtree_check" as export option seems to work around the problem, but as I consider this to be just a better hack, a more thorough solution is needed (see below for my analysis and suggestion).
The problem manifests itself not only in "permission denied" errors, but also stale NFS handles. Googling around finally leads to Novell's bug 195040 in SuSE Linux (https://bugzilla.novell.com/show_bug.cgi?id=195040), for which a patch is already available (https://bugzilla.novell.com/attachment.cgi?id=94729&action=view). We are currently preparing a kernel rebuild using this patch and have thus not yet verified it (rebooting is currently not an option, as we have active users and the functioning workaround in place), but from the comments found on Novell's page it seems to work fine, and I thought it made sense to share this information; additionally, the patch seems to have found its way into Linus' git version of the kernel (commit d1bbf14f37261c2c0dba71404602e1ddcec069d2 from NeilBrown <[EMAIL PROTECTED]>, dating Sun, 30 Jul 2006 10:03:16 +0000, just one month after the commit introducing the problem), and it resembles the situation of fs/nfsd/nfsfh.c in dapper, which is known to be working without these problems. So, for a quick workaround, I suggest using the "no_subtree_check" export option; it would certainly be nice to have above (simple!) patch (which I also added as an attachment to this comment) or (even better) the correcting commit mentioned above included in some updated kernel in edgy in the near (!) future, as the need to have this workaround makes ubuntu look less professional than we might want it to. (SuSE has it included for *quite some time* now...) ** Attachment added: "Patch for NFS problems in 2.6.17 (from Novell's SUSE, may need some modifications)" http://librarian.launchpad.net/6582193/patch -- Permission Denied on nfs clients for only some files https://launchpad.net/bugs/62308 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
