From: Jeremy Allison <jra@samba.org>
Date: Wed, 3 Jan 2018 17:52:33 +0000 (-0800)
Subject: s3: smbd: Use identical logic to test for kernel oplocks on a share.
X-Git-Tag: samba-4.6.13~10
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=579b6a4f603c97480a319353dcd7319dcbcb521e;p=thirdparty%2Fsamba.git

s3: smbd: Use identical logic to test for kernel oplocks on a share.

Due to inconsistent use of lp_kernel_oplocks() we could miss kernel
oplocks being on/off in some of our oplock handling code, and thus
use the wrong logic.

Ensure all logic around koplocks and lp_kernel_oplocks() is consistent.

BUG: https://bugzilla.samba.org/show_bug.cgi?id=13193

Signed-off-by: Jeremy Allison <jra@samba.org>
Reviewed-by: Volker Lendecke <vl@samba.org>

Autobuild-User(master): Volker Lendecke <vl@samba.org>
Autobuild-Date(master): Thu Jan  4 16:03:38 CET 2018 on sn-devel-144

(cherry picked from commit 114f5da2fab6f587de77e792274b396fb3d7ce71)

Autobuild-User(v4-6-test): Karolin Seeger <kseeger@samba.org>
Autobuild-Date(v4-6-test): Fri Jan  5 13:40:55 CET 2018 on sn-devel-144
---

diff --git a/source3/smbd/oplock.c b/source3/smbd/oplock.c
index d30de6a69e9..dc1159886ed 100644
--- a/source3/smbd/oplock.c
+++ b/source3/smbd/oplock.c
@@ -55,7 +55,8 @@ NTSTATUS set_file_oplock(files_struct *fsp)
 {
 	struct smbd_server_connection *sconn = fsp->conn->sconn;
 	struct kernel_oplocks *koplocks = sconn->oplocks.kernel_ops;
-	bool use_kernel = lp_kernel_oplocks(SNUM(fsp->conn)) && koplocks;
+	bool use_kernel = lp_kernel_oplocks(SNUM(fsp->conn)) &&
+			(koplocks != NULL);
 
 	if (fsp->oplock_type == LEVEL_II_OPLOCK) {
 		if (use_kernel &&
@@ -97,7 +98,8 @@ static void release_file_oplock(files_struct *fsp)
 {
 	struct smbd_server_connection *sconn = fsp->conn->sconn;
 	struct kernel_oplocks *koplocks = sconn->oplocks.kernel_ops;
-	bool use_kernel = lp_kernel_oplocks(SNUM(fsp->conn)) && koplocks;
+	bool use_kernel = lp_kernel_oplocks(SNUM(fsp->conn)) &&
+			(koplocks != NULL);
 
 	if ((fsp->oplock_type != NO_OPLOCK) &&
 	    use_kernel) {
@@ -130,13 +132,15 @@ static void downgrade_file_oplock(files_struct *fsp)
 {
 	struct smbd_server_connection *sconn = fsp->conn->sconn;
 	struct kernel_oplocks *koplocks = sconn->oplocks.kernel_ops;
+	bool use_kernel = lp_kernel_oplocks(SNUM(fsp->conn)) &&
+			(koplocks != NULL);
 
 	if (!EXCLUSIVE_OPLOCK_TYPE(fsp->oplock_type)) {
 		DEBUG(0, ("trying to downgrade an already-downgraded oplock!\n"));
 		return;
 	}
 
-	if (koplocks) {
+	if (use_kernel) {
 		koplocks->ops->release_oplock(koplocks, fsp, LEVEL_II_OPLOCK);
 	}
 	fsp->oplock_type = LEVEL_II_OPLOCK;
@@ -728,12 +732,14 @@ static void add_oplock_timeout_handler(files_struct *fsp)
 {
 	struct smbd_server_connection *sconn = fsp->conn->sconn;
 	struct kernel_oplocks *koplocks = sconn->oplocks.kernel_ops;
+	bool use_kernel = lp_kernel_oplocks(SNUM(fsp->conn)) &&
+			(koplocks != NULL);
 
 	/*
 	 * If kernel oplocks already notifies smbds when an oplock break times
 	 * out, just return.
 	 */
-	if (koplocks &&
+	if (use_kernel &&
 	    (koplocks->flags & KOPLOCKS_TIMEOUT_NOTIFICATION)) {
 		return;
 	}
@@ -844,7 +850,8 @@ static void process_oplock_break_message(struct messaging_context *msg_ctx,
 		break_to &= ~SMB2_LEASE_READ;
 	}
 
-	use_kernel = lp_kernel_oplocks(SNUM(fsp->conn)) && koplocks;
+	use_kernel = lp_kernel_oplocks(SNUM(fsp->conn)) &&
+			(koplocks != NULL);
 	if (use_kernel && !(koplocks->flags & KOPLOCKS_LEVEL2_SUPPORTED)) {
 		DEBUG(10, ("Kernel oplocks don't allow level2\n"));
 		break_to &= ~SMB2_LEASE_READ;
@@ -1254,8 +1261,10 @@ void smbd_contend_level2_oplocks_begin(files_struct *fsp,
 {
 	struct smbd_server_connection *sconn = fsp->conn->sconn;
 	struct kernel_oplocks *koplocks = sconn->oplocks.kernel_ops;
+	bool use_kernel = lp_kernel_oplocks(SNUM(fsp->conn)) &&
+			(koplocks != NULL);
 
-	if (koplocks && koplocks->ops->contend_level2_oplocks_begin) {
+	if (use_kernel && koplocks->ops->contend_level2_oplocks_begin) {
 		koplocks->ops->contend_level2_oplocks_begin(fsp, type);
 		return;
 	}
@@ -1268,9 +1277,11 @@ void smbd_contend_level2_oplocks_end(files_struct *fsp,
 {
 	struct smbd_server_connection *sconn = fsp->conn->sconn;
 	struct kernel_oplocks *koplocks = sconn->oplocks.kernel_ops;
+	bool use_kernel = lp_kernel_oplocks(SNUM(fsp->conn)) &&
+			(koplocks != NULL);
 
 	/* Only kernel oplocks implement this so far */
-	if (koplocks && koplocks->ops->contend_level2_oplocks_end) {
+	if (use_kernel && koplocks->ops->contend_level2_oplocks_end) {
 		koplocks->ops->contend_level2_oplocks_end(fsp, type);
 	}
 }