diff mbox

[1/1] NFS add session back channel draining

Message ID 1291393741-2851-1-git-send-email-andros@netapp.com (mailing list archive)
State Superseded, archived
Delegated to: Trond Myklebust
Headers show

Commit Message

Andy Adamson Dec. 3, 2010, 4:29 p.m. UTC
None
diff mbox

Patch

diff --git a/fs/nfs/callback_proc.c b/fs/nfs/callback_proc.c
index aa62342..bcad3c1 100644
--- a/fs/nfs/callback_proc.c
+++ b/fs/nfs/callback_proc.c
@@ -251,6 +251,12 @@  __be32 nfs4_callback_sequence(struct cb_sequenceargs *args,
 	if (clp == NULL)
 		goto out;
 
+	/* state manager is resetting the session */
+	if (test_bit(NFS4_SESSION_DRAINING, &clp->cl_session->session_state)) {
+		status = NFS4ERR_DELAY;
+		goto err_putclient;
+	}
+
 	status = validate_seqid(&clp->cl_session->bc_slot_table, args);
 	if (status)
 		goto err_putclient;
diff --git a/fs/nfs/callback_xdr.c b/fs/nfs/callback_xdr.c
index 85cbb8f..d21f17c 100644
--- a/fs/nfs/callback_xdr.c
+++ b/fs/nfs/callback_xdr.c
@@ -596,6 +596,22 @@  preprocess_nfs41_op(int nop, unsigned int op_nr, struct callback_op **op)
 	return htonl(NFS_OK);
 }
 
+static void nfs4_callback_free_slot(struct nfs4_session *session)
+{
+	struct nfs4_slot_table *tbl = &session->bc_slot_table;
+
+	spin_lock(&tbl->slot_tbl_lock);
+	/*
+	 * Let the state manager know callback processing done.
+	 * A single slot, so highest used slotid is either 0 or -1
+	 */
+	tbl->highest_used_slotid--;
+	nfs4_check_drain_bc_complete(session);
+	spin_unlock(&tbl->slot_tbl_lock);
+	dprintk("%s highest_used_slotid %d\n", __func__,
+	tbl->highest_used_slotid);
+}
+
 #else /* CONFIG_NFS_V4_1 */
 
 static __be32
@@ -604,6 +620,9 @@  preprocess_nfs41_op(int nop, unsigned int op_nr, struct callback_op **op)
 	return htonl(NFS4ERR_MINOR_VERS_MISMATCH);
 }
 
+static void nfs4_callback_free_slot(struct nfs4_session *session)
+{
+}
 #endif /* CONFIG_NFS_V4_1 */
 
 static __be32
diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
index f65602c..0b5d99e 100644
--- a/fs/nfs/internal.h
+++ b/fs/nfs/internal.h
@@ -281,6 +281,7 @@  extern int _nfs4_call_sync_session(struct nfs_server *server,
 				   struct nfs4_sequence_res *res,
 				   int cache_reply);
 
+void nfs4_check_drain_bc_complete(struct nfs4_session *ses);
 /*
  * Determine the device name as a string
  */
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index a241957..c244000 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -355,9 +355,9 @@  nfs4_free_slot(struct nfs4_slot_table *tbl, struct nfs4_slot *free_slot)
 }
 
 /*
- * Signal state manager thread if session is drained
+ * Signal state manager thread if session fore channel is drained
  */
-static void nfs41_check_drain_session_complete(struct nfs4_session *ses)
+static void nfs4_check_drain_fc_complete(struct nfs4_session *ses)
 {
 	struct rpc_task *task;
 
@@ -371,8 +371,20 @@  static void nfs41_check_drain_session_complete(struct nfs4_session *ses)
 	if (ses->fc_slot_table.highest_used_slotid != -1)
 		return;
 
-	dprintk("%s COMPLETE: Session Drained\n", __func__);
-	complete(&ses->complete);
+	dprintk("%s COMPLETE: Session Fore Channel Drained\n", __func__);
+	complete(&ses->fc_slot_table.complete);
+}
+
+/*
+ * Signal state manager thread if session back channel is drained
+ */
+void nfs4_check_drain_bc_complete(struct nfs4_session *ses)
+{
+	if (!test_bit(NFS4_SESSION_DRAINING, &ses->session_state) ||
+	    ses->bc_slot_table.highest_used_slotid != -1)
+		return;
+	dprintk("%s COMPLETE: Session Back Channel Drained\n", __func__);
+	complete(&ses->bc_slot_table.complete);
 }
 
 static void nfs41_sequence_free_slot(struct nfs4_sequence_res *res)
@@ -389,7 +401,7 @@  static void nfs41_sequence_free_slot(struct nfs4_sequence_res *res)
 
 	spin_lock(&tbl->slot_tbl_lock);
 	nfs4_free_slot(tbl, res->sr_slot);
-	nfs41_check_drain_session_complete(res->sr_session);
+	nfs4_check_drain_fc_complete(res->sr_session);
 	spin_unlock(&tbl->slot_tbl_lock);
 	res->sr_slot = NULL;
 }
@@ -4772,17 +4784,17 @@  struct nfs4_session *nfs4_alloc_session(struct nfs_client *clp)
 	if (!session)
 		return NULL;
 
-	init_completion(&session->complete);
-
 	tbl = &session->fc_slot_table;
 	tbl->highest_used_slotid = -1;
 	spin_lock_init(&tbl->slot_tbl_lock);
 	rpc_init_priority_wait_queue(&tbl->slot_tbl_waitq, "ForeChannel Slot table");
+	init_completion(&tbl->complete);
 
 	tbl = &session->bc_slot_table;
 	tbl->highest_used_slotid = -1;
 	spin_lock_init(&tbl->slot_tbl_lock);
 	rpc_init_wait_queue(&tbl->slot_tbl_waitq, "BackChannel Slot table");
+	init_completion(&tbl->complete);
 
 	session->session_state = 1<<NFS4_SESSION_INITING;
 
diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c
index 11290de..3445b01 100644
--- a/fs/nfs/nfs4state.c
+++ b/fs/nfs/nfs4state.c
@@ -143,6 +143,11 @@  static int nfs41_setup_state_renewal(struct nfs_client *clp)
 	return status;
 }
 
+/*
+ * Back channel returns NFS4ERR_DELAY for new requests when
+ * NFS4_SESSION_DRAINING is set so there is no work to be done when draining
+ * is ended.
+ */
 static void nfs4_end_drain_session(struct nfs_client *clp)
 {
 	struct nfs4_session *ses = clp->cl_session;
@@ -170,16 +175,32 @@  static int nfs4_begin_drain_session(struct nfs_client *clp)
 {
 	struct nfs4_session *ses = clp->cl_session;
 	struct nfs4_slot_table *tbl = &ses->fc_slot_table;
+	int ret = 0;
 
-	spin_lock(&tbl->slot_tbl_lock);
 	set_bit(NFS4_SESSION_DRAINING, &ses->session_state);
+	/* back channel */
+	tbl = &ses->bc_slot_table;
+	spin_lock(&tbl->slot_tbl_lock);
 	if (tbl->highest_used_slotid != -1) {
-		INIT_COMPLETION(ses->complete);
+		INIT_COMPLETION(tbl->complete);
 		spin_unlock(&tbl->slot_tbl_lock);
-		return wait_for_completion_interruptible(&ses->complete);
+		ret = wait_for_completion_interruptible(&tbl->complete);
+		if (ret)
+			goto out;
+		goto forechannel;
 	}
 	spin_unlock(&tbl->slot_tbl_lock);
-	return 0;
+forechannel:
+	/* fore channel */
+	spin_lock(&tbl->slot_tbl_lock);
+	if (tbl->highest_used_slotid != -1) {
+		INIT_COMPLETION(tbl->complete);
+		spin_unlock(&tbl->slot_tbl_lock);
+		return wait_for_completion_interruptible(&tbl->complete);
+	}
+	spin_unlock(&tbl->slot_tbl_lock);
+out:
+	return ret;
 }
 
 int nfs41_init_clientid(struct nfs_client *clp, struct rpc_cred *cred)
diff --git a/include/linux/nfs_fs_sb.h b/include/linux/nfs_fs_sb.h
index 1eaa054..e93ada0 100644
--- a/include/linux/nfs_fs_sb.h
+++ b/include/linux/nfs_fs_sb.h
@@ -197,6 +197,7 @@  struct nfs4_slot_table {
 						 * op for dynamic resizing */
 	int		target_max_slots;	/* Set by CB_RECALL_SLOT as
 						 * the new max_slots */
+	struct completion complete;
 };
 
 static inline int slot_idx(struct nfs4_slot_table *tbl, struct nfs4_slot *sp)
@@ -213,7 +214,6 @@  struct nfs4_session {
 	unsigned long			session_state;
 	u32				hash_alg;
 	u32				ssv_len;
-	struct completion		complete;
 
 	/* The fore and back channel */
 	struct nfs4_channel_attrs	fc_attrs;