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NFSv4.1 fix infinite loop on I/O. 

commit 994b15b983 upstream.

The previous fix broke recovery of delegated stateids because it assumes
that if we did not mark the delegation as suspect, then the delegation has
effectively been revoked, and so it removes that delegation irrespectively
of whether or not it is valid and still in use. While this is "mostly
harmless" for ordinary I/O, we've seen pNFS fail with LAYOUTGET spinning
in an infinite loop while complaining that we're using an invalid stateid
(in this case the all-zero stateid).

What we rather want to do here is ensure that the delegation is always
correctly marked as needing testing when that is the case. So we want
to close the loophole offered by nfs4_schedule_stateid_recovery(),
which marks the state as needing to be reclaimed, but not the
delegation that may be backing it.

Fixes: 0e3d3e5df0 ("NFSv4.1 fix infinite loop on IO BAD_STATEID error")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: stable@vger.kernel.org # v4.11+
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
pull/10/head
Trond Myklebust 2018-09-05 14:07:14 -04:00 committed by Greg Kroah-Hartman
parent 9995545163
commit 948f1a7f76
2 changed files with 9 additions and 3 deletions
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10
fs/nfs/nfs4proc.c
View File

@ -2533,14 +2533,18 @@ static void nfs41_check_delegation_stateid(struct nfs4_state *state)
}
nfs4_stateid_copy(&stateid, &delegation->stateid);
if (test_bit(NFS_DELEGATION_REVOKED, &delegation->flags) ||
!test_and_clear_bit(NFS_DELEGATION_TEST_EXPIRED,
&delegation->flags)) {
if (test_bit(NFS_DELEGATION_REVOKED, &delegation->flags)) {
rcu_read_unlock();
nfs_finish_clear_delegation_stateid(state, &stateid);
return;
}
if (!test_and_clear_bit(NFS_DELEGATION_TEST_EXPIRED,
&delegation->flags)) {
rcu_read_unlock();
return;
}
cred = get_rpccred(delegation->cred);
rcu_read_unlock();
status = nfs41_test_and_free_expired_stateid(server, &stateid, cred);

2
fs/nfs/nfs4state.c
View File

@ -1354,6 +1354,8 @@ int nfs4_schedule_stateid_recovery(const struct nfs_server *server, struct nfs4_
if (!nfs4_state_mark_reclaim_nograce(clp, state))
return -EBADF;
nfs_inode_find_delegation_state_and_recover(state->inode,
&state->stateid);
dprintk("%s: scheduling stateid recovery for server %s\n", __func__,
clp->cl_hostname);
nfs4_schedule_state_manager(clp);