s3 oplocks: Add capabilites flags field to the kernel_oplocks struct

Here is a short description for each of the new capability flags:

KOPLOCKS_LEVEL2_SUPPORTED: Level 2 oplocks are supported natively in
the kernel.

KOPLOCKS_DEFERRED_OPEN_NOTIFICATION: The kernel notifies deferred
openers when they can retry the open.

KOPLOCKS_TIMEOUT_NOTIFICATION: The kernel notifies smbds when an
oplock break times out.

KOPLOCKS_OPLOCK_BROKEN_NOTIFICATION: The kernel notifies smbds when an
oplock is broken.

4 files changed, 50 insertions, 2 deletions

diff --git a/source3/include/proto.h b/source3/include/proto.h
index ceea97bf56..f553f7625e 100644
--- a/source3/include/proto.h
+++ b/source3/include/proto.h
@@ -6898,6 +6898,7 @@ bool set_file_oplock(files_struct *fsp, int oplock_type);
 void release_file_oplock(files_struct *fsp);
 bool remove_oplock(files_struct *fsp);
 bool downgrade_oplock(files_struct *fsp);
+bool should_notify_deferred_opens(void);
 void reply_to_oplock_break_requests(files_struct *fsp);
 void process_oplock_async_level2_break_message(struct messaging_context *msg_ctx,
 						      void *private_data,
diff --git a/source3/include/smb.h b/source3/include/smb.h
index 557489f211..bef0fd177b 100644
--- a/source3/include/smb.h
+++ b/source3/include/smb.h
@@ -1689,9 +1689,26 @@ enum smbd_capability {
     LEASE_CAPABILITY
 };
 
+/*
+ * Kernel oplocks capability flags.
+ */
+
+/* Level 2 oplocks are supported natively by kernel oplocks. */
+#define KOPLOCKS_LEVEL2_SUPPORTED		0x1
+
+/* The kernel notifies deferred openers when they can retry the open. */
+#define KOPLOCKS_DEFERRED_OPEN_NOTIFICATION	0x2
+
+/* The kernel notifies smbds when an oplock break times out. */
+#define KOPLOCKS_TIMEOUT_NOTIFICATION		0x4
+
+/* The kernel notifies smbds when an oplock is broken. */
+#define KOPLOCKS_OPLOCK_BROKEN_NOTIFICATION	0x8
+
 struct kernel_oplocks_ops;
 struct kernel_oplocks {
 	const struct kernel_oplocks_ops *ops;
+	uint32_t flags;
 	void *private_data;
 };
 
diff --git a/source3/smbd/close.c b/source3/smbd/close.c
index 2fb8ec2bb5..e484fa8e01 100644
--- a/source3/smbd/close.c
+++ b/source3/smbd/close.c
@@ -134,6 +134,10 @@ static NTSTATUS close_filestruct(files_struct *fsp)
 static void notify_deferred_opens(struct share_mode_lock *lck)
 {
  	int i;
+
+	if (!should_notify_deferred_opens()) {
+		return;
+	}
  
  	for (i=0; i<lck->num_share_modes; i++) {
  		struct share_mode_entry *e = &lck->share_modes[i];
diff --git a/source3/smbd/oplock.c b/source3/smbd/oplock.c
index 4c84fd41ed..a6ec9cfa2d 100644
--- a/source3/smbd/oplock.c
+++ b/source3/smbd/oplock.c
@@ -188,6 +188,15 @@ bool downgrade_oplock(files_struct *fsp)
 	return ret;
 }
 
+/*
+ * Some kernel oplock implementations handle the notification themselves.
+ */
+bool should_notify_deferred_opens()
+{
+	return !(koplocks &&
+		(koplocks->flags & KOPLOCKS_DEFERRED_OPEN_NOTIFICATION));
+}
+
 /****************************************************************************
  Set up an oplock break message.
 ****************************************************************************/
@@ -306,6 +315,15 @@ static void oplock_timeout_handler(struct event_context *ctx,
 
 static void add_oplock_timeout_handler(files_struct *fsp)
 {
+	/*
+	 * If kernel oplocks already notifies smbds when an oplock break times
+	 * out, just return.
+	 */
+	if (koplocks &&
+	    (koplocks->flags & KOPLOCKS_TIMEOUT_NOTIFICATION)) {
+		return;
+	}
+
 	if (fsp->oplock_timeout != NULL) {
 		DEBUG(0, ("Logic problem -- have an oplock event hanging "
 			  "around\n"));
@@ -491,8 +509,7 @@ static void process_oplock_break_message(struct messaging_context *msg_ctx,
 
 	if ((global_client_caps & CAP_LEVEL_II_OPLOCKS) && 
 	    !(msg.op_type & FORCE_OPLOCK_BREAK_TO_NONE) &&
-	    !koplocks && /* NOTE: we force levelII off for kernel oplocks -
-			  * this will change when it is supported */
+	    !(koplocks && !(koplocks->flags & KOPLOCKS_LEVEL2_SUPPORTED)) &&
 	    lp_level2_oplocks(SNUM(fsp->conn))) {
 		break_to_level2 = True;
 	}
@@ -613,6 +630,15 @@ void reply_to_oplock_break_requests(files_struct *fsp)
 {
 	int i;
 
+	/*
+	 * If kernel oplocks already notifies smbds when oplocks are
+	 * broken/removed, just return.
+	 */
+	if (koplocks &&
+	    (koplocks->flags & KOPLOCKS_OPLOCK_BROKEN_NOTIFICATION)) {
+		return;
+	}
+
 	for (i=0; i<fsp->num_pending_break_messages; i++) {
 		struct share_mode_entry *e = &fsp->pending_break_messages[i];
 		char msg[MSG_SMB_SHARE_MODE_ENTRY_SIZE];