NFSv4: Clean up nfs4_select_rw_stateid()

Ensure that we select delegation stateids first, then
lock stateids and then open stateids.

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

1 files changed, 33 insertions, 12 deletions

diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c
index 7adc46b..de44804 100644
--- a/fs/nfs/nfs4state.c
+++ b/fs/nfs/nfs4state.c
@@ -886,28 +886,49 @@ int nfs4_set_lock_state(struct nfs4_state *state, struct file_lock *fl)
 	return 0;
 }
 
-/*
- * Byte-range lock aware utility to initialize the stateid of read/write
- * requests.
- */
-void nfs4_select_rw_stateid(nfs4_stateid *dst, struct nfs4_state *state, fl_owner_t fl_owner, pid_t fl_pid)
+static bool nfs4_copy_lock_stateid(nfs4_stateid *dst, struct nfs4_state *state,
+		fl_owner_t fl_owner, pid_t fl_pid)
 {
 	struct nfs4_lock_state *lsp;
-	int seq;
+	bool ret = false;
 
-	do {
-		seq = read_seqbegin(&state->seqlock);
-		nfs4_stateid_copy(dst, &state->stateid);
-	} while (read_seqretry(&state->seqlock, seq));
 	if (test_bit(LK_STATE_IN_USE, &state->flags) == 0)
-		return;
+		goto out;
 
 	spin_lock(&state->state_lock);
 	lsp = __nfs4_find_lock_state(state, fl_owner, fl_pid, NFS4_ANY_LOCK_TYPE);
-	if (lsp != NULL && (lsp->ls_flags & NFS_LOCK_INITIALIZED) != 0)
+	if (lsp != NULL && (lsp->ls_flags & NFS_LOCK_INITIALIZED) != 0) {
 		nfs4_stateid_copy(dst, &lsp->ls_stateid);
+		ret = true;
+	}
 	spin_unlock(&state->state_lock);
 	nfs4_put_lock_state(lsp);
+out:
+	return ret;
+}
+
+static void nfs4_copy_open_stateid(nfs4_stateid *dst, struct nfs4_state *state)
+{
+	int seq;
+
+	do {
+		seq = read_seqbegin(&state->seqlock);
+		nfs4_stateid_copy(dst, &state->stateid);
+	} while (read_seqretry(&state->seqlock, seq));
+}
+
+/*
+ * Byte-range lock aware utility to initialize the stateid of read/write
+ * requests.
+ */
+void nfs4_select_rw_stateid(nfs4_stateid *dst, struct nfs4_state *state,
+		fmode_t fmode, fl_owner_t fl_owner, pid_t fl_pid)
+{
+	if (nfs4_copy_delegation_stateid(dst, state->inode, fmode))
+		return;
+	if (nfs4_copy_lock_stateid(dst, state, fl_owner, fl_pid))
+		return;
+	nfs4_copy_open_stateid(dst, state);
 }
 
 struct nfs_seqid *nfs_alloc_seqid(struct nfs_seqid_counter *counter, gfp_t gfp_mask)