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authorTrond Myklebust <Trond.Myklebust@netapp.com>2011-08-02 14:46:52 -0400
committerGreg Kroah-Hartman <gregkh@suse.de>2011-08-29 13:29:08 -0700
commite25d2c749d25fc559f374766af66d267c97e0877 (patch)
tree8f04bd2605641a7c887158aa8d149c36d74646d9
parentf4bc412bc2f46d644375403b601f42d8487949da (diff)
NFSv4.1: Return NFS4ERR_BADSESSION to callbacks during session resets
commit 910ac68a2b80c7de95bc8488734067b1bb15d583 upstream. If the client is in the process of resetting the session when it receives a callback, then returning NFS4ERR_DELAY may cause a deadlock with the DESTROY_SESSION call. Basically, if the client returns NFS4ERR_DELAY in response to the CB_SEQUENCE call, then the server is entitled to believe that the client is busy because it is already processing that call. In that case, the server is perfectly entitled to respond with a NFS4ERR_BACK_CHAN_BUSY to any DESTROY_SESSION call. Fix this by having the client reply with a NFS4ERR_BADSESSION in response to the callback if it is resetting the session. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
-rw-r--r--fs/nfs/callback_proc.c5
1 files changed, 5 insertions, 0 deletions
diff --git a/fs/nfs/callback_proc.c b/fs/nfs/callback_proc.c
index 31407ecd0e56..aaa09e948a9c 100644
--- a/fs/nfs/callback_proc.c
+++ b/fs/nfs/callback_proc.c
@@ -437,6 +437,11 @@ __be32 nfs4_callback_sequence(struct cb_sequenceargs *args,
if (test_bit(NFS4_SESSION_DRAINING, &clp->cl_session->session_state)) {
spin_unlock(&tbl->slot_tbl_lock);
status = htonl(NFS4ERR_DELAY);
+ /* Return NFS4ERR_BADSESSION if we're draining the session
+ * in order to reset it.
+ */
+ if (test_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state))
+ status = htonl(NFS4ERR_BADSESSION);
goto out;
}