NFSv4: Ensure that nfs4_reclaim_open_state() doesn't depend on cl_sem

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c
index 7dcca23167ddaf7712e3dbf384671f53f9906d82..beade5570b5690403fc8b8ccef84135a76abd014 100644 (file)
--- a/fs/nfs/nfs4state.c
+++ b/fs/nfs/nfs4state.c
@@ -893,11 +893,15 @@ static int nfs4_reclaim_open_state(struct nfs4_state_owner *sp, const struct nfs
         * recovering after a network partition or a reboot from a
         * server that doesn't support a grace period.
         */
+restart:
+       spin_lock(&sp->so_lock);
        list_for_each_entry(state, &sp->so_states, open_states) {
                if (!test_and_clear_bit(ops->state_flag_bit, &state->flags))
                        continue;
                if (state->state == 0)
                        continue;
+               atomic_inc(&state->count);
+               spin_unlock(&sp->so_lock);
                status = ops->recover_open(sp, state);
                if (status >= 0) {
                        status = nfs4_reclaim_locks(state, ops);
@@ -907,7 +911,8 @@ static int nfs4_reclaim_open_state(struct nfs4_state_owner *sp, const struct nfs
                                                printk("%s: Lock reclaim failed!\n",
                                                        __func__);
                                }
-                               continue;
+                               nfs4_put_open_state(state);
+                               goto restart;
                        }
                }
                switch (status) {
@@ -935,9 +940,13 @@ static int nfs4_reclaim_open_state(struct nfs4_state_owner *sp, const struct nfs
                        case -NFS4ERR_STALE_CLIENTID:
                                goto out_err;
                }
+               nfs4_put_open_state(state);
+               goto restart;
        }
+       spin_unlock(&sp->so_lock);
        return 0;
 out_err:
+       nfs4_put_open_state(state);
        return status;
 }