NFSv4: Fix buggy nfs_wait_on_sequence()

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

1 files changed, 10 insertions, 10 deletions

diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c
index 0675f3215e0a..5ef4c57618fe 100644
--- a/fs/nfs/nfs4state.c
+++ b/fs/nfs/nfs4state.c
@@ -644,12 +644,15 @@ void nfs4_copy_stateid(nfs4_stateid *dst, struct nfs4_state *state, fl_owner_t f
 
 struct nfs_seqid *nfs_alloc_seqid(struct nfs_seqid_counter *counter)
 {
+        struct rpc_sequence *sequence = counter->sequence;
         struct nfs_seqid *new;
 
         new = kmalloc(sizeof(*new), GFP_KERNEL);
         if (new != NULL) {
                 new->sequence = counter;
-                INIT_LIST_HEAD(&new->list);
+                spin_lock(&sequence->lock);
+                list_add_tail(&new->list, &sequence->list);
+                spin_unlock(&sequence->lock);
         }
         return new;
 }
@@ -658,12 +661,10 @@ void nfs_free_seqid(struct nfs_seqid *seqid)
 {
         struct rpc_sequence *sequence = seqid->sequence->sequence;
 
-        if (!list_empty(&seqid->list)) {
-                spin_lock(&sequence->lock);
-                list_del(&seqid->list);
-                spin_unlock(&sequence->lock);
-        }
-        rpc_wake_up_next(&sequence->wait);
+        spin_lock(&sequence->lock);
+        list_del(&seqid->list);
+        spin_unlock(&sequence->lock);
+        rpc_wake_up(&sequence->wait);
         kfree(seqid);
 }
 
@@ -722,11 +723,10 @@ int nfs_wait_on_sequence(struct nfs_seqid *seqid, struct rpc_task *task)
         if (sequence->list.next == &seqid->list)
                 goto out;
         spin_lock(&sequence->lock);
-        if (!list_empty(&sequence->list)) {
+        if (sequence->list.next != &seqid->list) {
                 rpc_sleep_on(&sequence->wait, task, NULL, NULL);
                 status = -EAGAIN;
-        } else
-                list_add(&seqid->list, &sequence->list);
+        }
         spin_unlock(&sequence->lock);
 out:
         return status;