From ea028ac92541ac30bf202ed94cb53eec2ea0c9d6 Mon Sep 17 00:00:00 2001 From: Andy Adamson Date: Fri, 4 Dec 2009 15:55:38 -0500 Subject: nfs41: nfs41: fix state manager deadlock in session reset If the session is reset during state recovery, the state manager thread can sleep on the slot_tbl_waitq causing a deadlock. Add a completion framework to the session. Have the state manager thread set a new session state (NFS4CLNT_SESSION_DRAINING) and wait for the session slot table to drain. Signal the state manager thread in nfs41_sequence_free_slot when the NFS4CLNT_SESSION_DRAINING bit is set and the session is drained. Reported-by: Trond Myklebust Signed-off-by: Andy Adamson Signed-off-by: Trond Myklebust --- fs/nfs/nfs4state.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) (limited to 'fs/nfs/nfs4state.c') diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c index f56f6be..3c14335 100644 --- a/fs/nfs/nfs4state.c +++ b/fs/nfs/nfs4state.c @@ -1181,8 +1181,23 @@ static void nfs4_session_recovery_handle_error(struct nfs_client *clp, int err) static int nfs4_reset_session(struct nfs_client *clp) { + struct nfs4_session *ses = clp->cl_session; + struct nfs4_slot_table *tbl = &ses->fc_slot_table; int status; + INIT_COMPLETION(ses->complete); + spin_lock(&tbl->slot_tbl_lock); + if (tbl->highest_used_slotid != -1) { + set_bit(NFS4CLNT_SESSION_DRAINING, &clp->cl_state); + spin_unlock(&tbl->slot_tbl_lock); + status = wait_for_completion_interruptible(&ses->complete); + clear_bit(NFS4CLNT_SESSION_DRAINING, &clp->cl_state); + if (status) /* -ERESTARTSYS */ + goto out; + } else { + spin_unlock(&tbl->slot_tbl_lock); + } + status = nfs4_proc_destroy_session(clp->cl_session); if (status && status != -NFS4ERR_BADSESSION && status != -NFS4ERR_DEADSESSION) { -- cgit v1.1