From: andros@netapp.com Subject: [PATCH 2/2] nfs41: fix race on session reset Date: Wed, 21 Oct 2009 14:24:52 -0400 Message-ID: <1256149492-25481-3-git-send-email-andros@netapp.com> References: <1256149492-25481-1-git-send-email-andros@netapp.com> <1256149492-25481-2-git-send-email-andros@netapp.com> Cc: linux-nfs@vger.kernel.org, Andy Adamson To: pnfs@linux-nfs.org Return-path: Received: from mx2.netapp.com ([216.240.18.37]:6584 "EHLO mx2.netapp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754353AbZJUSYu (ORCPT ); Wed, 21 Oct 2009 14:24:50 -0400 In-Reply-To: <1256149492-25481-2-git-send-email-andros@netapp.com> Sender: linux-nfs-owner@vger.kernel.org List-ID: From: Andy Adamson Do not clear the NFS4CLNT_SESSION_SETUP bit until after the session has been reset (a possible EXCHANGE_ID, a DESTROY_SESSION, and a CREATE_SESSION) to prevent a race with nfs41_setup_sequence assigning a slot on a partially reset session. Signed-off-by: Andy Adamson --- fs/nfs/nfs4proc.c | 3 +++ fs/nfs/nfs4state.c | 15 +++++++++------ 2 files changed, 12 insertions(+), 6 deletions(-) diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index eb245a1..80764e2 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -4788,6 +4788,9 @@ int nfs4_proc_create_session(struct nfs_client *clp, int reset) if (status) goto out; + /* Signal nfs41_setup_sequence that the session is ready for use */ + clear_bit(NFS4CLNT_SESSION_SETUP, &clp->cl_state); + ptr = (unsigned *)&session->sess_id.data[0]; dprintk("%s client>seqid %d sessionid %u:%u:%u:%u\n", __func__, clp->cl_seqid, ptr[0], ptr[1], ptr[2], ptr[3]); diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c index 1394dfb..09ca30b 100644 --- a/fs/nfs/nfs4state.c +++ b/fs/nfs/nfs4state.c @@ -1252,17 +1252,20 @@ static void nfs4_state_manager(struct nfs_client *clp) continue; } /* Initialize or reset the session */ - if (test_and_clear_bit(NFS4CLNT_SESSION_SETUP, &clp->cl_state) - && nfs4_has_session(clp)) { + if (test_bit(NFS4CLNT_SESSION_SETUP, &clp->cl_state) + && nfs4_has_session(clp)) { if (clp->cl_cons_state == NFS_CS_SESSION_INITING) status = nfs4_initialize_session(clp); else status = nfs4_reset_session(clp); - if (status) { - if (status == -NFS4ERR_STALE_CLIENTID) - continue; + if (status == -NFS4ERR_STALE_CLIENTID) + continue; + /* For error case. On success the bit is cleared in + * nfs4_proc_create_session */ + clear_bit(NFS4CLNT_SESSION_SETUP, &clp->cl_state); + + if (status) goto out_error; - } } /* First recover reboot state... */ if (test_and_clear_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state)) { -- 1.6.2.5