14866 SMB oplock not recalled when there is a request from NFS

Reviewed by: Prashanth Badari <prbadari@tintri.com>
Reviewed by: Suresh Jayaraman <sjayaraman@tintri.com>
Reviewed by: Jerry Jelinek <gjelinek@gmail.com>
Reviewed by: Garrett D'Amore <garrett@damore.org>
Reviewed by: Matt Barden <mbarden@tintri.com>
Approved by: Dan McDonald <danmcd@mnx.io>

4 files changed, 75 insertions, 8 deletions

diff --git a/usr/src/cmd/smbsrv/testoplock/smbsrv/smb_kproto.h b/usr/src/cmd/smbsrv/testoplock/smbsrv/smb_kproto.h
index 4ccf839f51..f743dcd179 100644
--- a/usr/src/cmd/smbsrv/testoplock/smbsrv/smb_kproto.h
+++ b/usr/src/cmd/smbsrv/testoplock/smbsrv/smb_kproto.h
@@ -21,7 +21,7 @@
 
 /*
  * Copyright (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
- * Copyright 2018 Nexenta Systems, Inc.  All rights reserved.
+ * Copyright 2020 Tintri by DDN, Inc.  All rights reserved.
  */
 
 /*
@@ -103,6 +103,8 @@ uint32_t smb_oplock_wait_break(smb_node_t *, int);
 int smb_lock_range_access(smb_request_t *, smb_node_t *,
     uint64_t, uint64_t, boolean_t);
 
+int smb_fem_oplock_install(smb_node_t *);
+void smb_fem_oplock_uninstall(smb_node_t *);
 
 #ifdef	__cplusplus
 }
diff --git a/usr/src/cmd/smbsrv/testoplock/tol_main.c b/usr/src/cmd/smbsrv/testoplock/tol_main.c
index 5382802b82..f78729a9d6 100644
--- a/usr/src/cmd/smbsrv/testoplock/tol_main.c
+++ b/usr/src/cmd/smbsrv/testoplock/tol_main.c
@@ -10,7 +10,7 @@
  */
 
 /*
- * Copyright 2018 Nexenta Systems, Inc.  All rights reserved.
+ * Copyright 2020 Tintri by DDN, Inc.  All rights reserved.
  * Copyright 2019 Joyent, Inc.
  * Copyright 2022 RackTop Systems, Inc.
  */
@@ -645,6 +645,17 @@ smb_oplock_wait_break(smb_node_t *node, int timeout)
 	return (0);
 }
 
+int
+smb_fem_oplock_install(smb_node_t *node)
+{
+	return (0);
+}
+
+void
+smb_fem_oplock_uninstall(smb_node_t *node)
+{
+}
+
 /*
  * There are a couple DTRACE_PROBE* in smb_cmn_oplock.c but we're
  * not linking with the user-level dtrace support, so just
diff --git a/usr/src/uts/common/fs/smbsrv/smb_cmn_oplock.c b/usr/src/uts/common/fs/smbsrv/smb_cmn_oplock.c
index 1b9ccce688..0afd313281 100644
--- a/usr/src/uts/common/fs/smbsrv/smb_cmn_oplock.c
+++ b/usr/src/uts/common/fs/smbsrv/smb_cmn_oplock.c
@@ -977,7 +977,9 @@ smb_oplock_req_excl(
 		 * This operation MUST be made cancelable...
 		 * This operation waits until the oplock is
 		 * broken or canceled, as specified in
-		 * section 2.1.5.17.3.
+		 * section 2.1.5.17.3. Note: This function
+		 * does not cause breaks that require a wait,
+		 * so never returns ..._BREAK_IN_PROGRESS.
 		 *
 		 * When the operation specified in section
 		 * 2.1.5.17.3 is called, its following input
@@ -990,11 +992,18 @@ smb_oplock_req_excl(
 		 * section 2.1.5.17.3.
 		 */
 		/* Keep *rop = ... from caller. */
-		if ((node->n_oplock.ol_state & BREAK_ANY) != 0) {
-			status = NT_STATUS_OPLOCK_BREAK_IN_PROGRESS;
-			/* Caller does smb_oplock_wait_break() */
-		} else {
-			status = NT_STATUS_SUCCESS;
+		status = NT_STATUS_SUCCESS;
+
+		/*
+		 * First oplock grant installs FEM hooks.
+		 */
+		if (node->n_oplock.ol_fem == B_FALSE) {
+			if (smb_fem_oplock_install(node) != 0) {
+				cmn_err(CE_NOTE,
+				    "smb_fem_oplock_install failed");
+			} else {
+				node->n_oplock.ol_fem =	B_TRUE;
+			}
 		}
 	}
 
@@ -1387,6 +1396,18 @@ smb_oplock_req_shared(
 		} else {
 			status = NT_STATUS_SUCCESS;
 		}
+
+		/*
+		 * First oplock grant installs FEM hooks.
+		 */
+		if (node->n_oplock.ol_fem == B_FALSE) {
+			if (smb_fem_oplock_install(node) != 0) {
+				cmn_err(CE_NOTE,
+				    "smb_fem_oplock_install failed");
+			} else {
+				node->n_oplock.ol_fem =	B_TRUE;
+			}
+		}
 	}
 
 out:
@@ -2075,6 +2096,18 @@ out:
 	}
 
 	/*
+	 * If this node no longer has any oplock grants, let's
+	 * go ahead and remove the FEM hooks now. We could leave
+	 * that until close, but this lets access outside of SMB
+	 * be free of FEM oplock work after a "break to none".
+	 */
+	if (node->n_oplock.ol_state == NO_OPLOCK &&
+	    node->n_oplock.ol_fem == B_TRUE) {
+		smb_fem_oplock_uninstall(node);
+		node->n_oplock.ol_fem = B_FALSE;
+	}
+
+	/*
 	 * The spec. describes waiting for a break here,
 	 * but we let the caller do that (when needed) if
 	 * status == NT_STATUS_OPLOCK_BREAK_IN_PROGRESS
@@ -2506,6 +2539,14 @@ smb_oplock_break_CLOSE(smb_node_t *node, smb_ofile_t *ofile)
 	if ((node->n_oplock.ol_state & BREAK_ANY) == 0)
 		cv_broadcast(&node->n_oplock.WaitingOpenCV);
 
+	/*
+	 * If no longer any oplock, remove FEM hooks.
+	 */
+	if (node->n_oplock.ol_state == NO_OPLOCK &&
+	    node->n_oplock.ol_fem == B_TRUE) {
+		smb_fem_oplock_uninstall(node);
+		node->n_oplock.ol_fem = B_FALSE;
+	}
 }
 
 /*
diff --git a/usr/src/uts/common/fs/smbsrv/smb_node.c b/usr/src/uts/common/fs/smbsrv/smb_node.c
index a204326514..fd37c2b328 100644
--- a/usr/src/uts/common/fs/smbsrv/smb_node.c
+++ b/usr/src/uts/common/fs/smbsrv/smb_node.c
@@ -21,6 +21,7 @@
 /*
  * Copyright (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
  * Copyright 2020 Tintri by DDN, Inc. All rights reserved.
+ * Copyright 2021 RackTop Systems, Inc.
  */
 /*
  * SMB Node State Machine
@@ -492,6 +493,18 @@ smb_node_release(smb_node_t *node)
 
 			mutex_exit(&node->n_mutex);
 
+			/*
+			 * Out of caution, make sure FEM hooks
+			 * used by oplocks are also gone.
+			 */
+			mutex_enter(&node->n_oplock.ol_mutex);
+			ASSERT(node->n_oplock.ol_fem == B_FALSE);
+			if (node->n_oplock.ol_fem == B_TRUE) {
+				smb_fem_oplock_uninstall(node);
+				node->n_oplock.ol_fem = B_FALSE;
+			}
+			mutex_exit(&node->n_oplock.ol_mutex);
+
 			smb_llist_enter(node->n_hash_bucket, RW_WRITER);
 			smb_llist_remove(node->n_hash_bucket, node);
 			smb_llist_exit(node->n_hash_bucket);