2005-08-26 Kevin Coffman <kwc@citi.umich.edu>

2005-08-26 Kevin Coffman <kwc@citi.umich.edu>
	*utils/mountd/mountd.c:
	mountd currently always returns AUTH_NULL and AUTH_SYS as the
	allowable flavors in mount replies.  We want it to also return gss
	flavors when appropriate. For now as a hack we just have it always
	return the KRB5 flavors as well.

	*utils/mountd/cache.c:

	When attempting to mount an NFSv4 pseudofilesystem (fsid=0) and the
	actual exported directory does not exist on the server, rpc.mountd
	doesn't check the directory exists (when fsidtype=1, i.e. using fsid,
	but does check for fsidtype=0, i.e. using dev/ino).  The non-existent
	exported directory path with fsid=0 is written to the kernel via
	/proc/net/rpc/nfsd.export/channel, which leads to path_lookup() to
	return ENOENT (seems appropriate).  Unfortunately, the new_cache
	approach ignores errors returned when writing via the channel file so
	that particular error is lost and the mount request is silently ignored.

	Assuming it doesn't make sense to revamp the new_cache/up-call method to
	not ignore returned errors, it seems appropriate to fix the case where
	rpc.mountd doesn't check for the existence of an exported directory with
	fsid= semantics.  The following patch does this by moving the stat() up
	so it is done for both fsidtype's.  I'm not certain whether the other
	tests need to be executed for fsidtype=1, but it doesn't appear to hurt
	[Not exactly true: the comparison of inode numbers caused problems so
	now it's kept for fsidtype=0 only].

	Would it be also desirable to log a warning for every error, if any,
	returned by a write to any of the /proc/net/rpc/*/channel files which
	would otherwise be ignored (maybe under a debug flag)?

	* gssd/mountd/svcgssd: Changes gssd, svcgssd, and mountd to ignore a
	SIGHUP rather than dying.

	* many: Remove the gssapi code and rely on an external library instead.