afs: Make error on cell lookup failure consistent with OpenAFS

[ Upstream commit 2a4ca1b4b77850544408595e2433f5d7811a9daa ]

When kafs tries to look up a cell in the DNS or the local config, it will
translate a lookup failure into EDESTADDRREQ whereas OpenAFS translates it
into ENOENT.  Applications such as West expect the latter behaviour and
fail if they see the former.

This can be seen by trying to mount an unknown cell:

   # mount -t afs %example.com:cell.root /mnt
   mount: /mnt: mount(2) system call failed: Destination address required.

Fixes: 4d673da14533 ("afs: Support the AFS dynamic root")
Reported-by: Markus Suvanto <markus.suvanto@gmail.com>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=216637
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeffrey Altman <jaltman@auristor.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/fs/afs/dynroot.c b/fs/afs/dynroot.c
index 95bcbd7..8081d68 100644 (file)
--- a/fs/afs/dynroot.c
+++ b/fs/afs/dynroot.c
@@ -132,8 +132,8 @@ static int afs_probe_cell_name(struct dentry *dentry)
 
        ret = dns_query(net->net, "afsdb", name, len, "srv=1",
                        NULL, NULL, false);
-       if (ret == -ENODATA)
-               ret = -EDESTADDRREQ;
+       if (ret == -ENODATA || ret == -ENOKEY)
+               ret = -ENOENT;
        return ret;
 }