CVS commit: [ad-namecache] src/sys/miscfs/genfs

[Andrew Doran]

Module Name:    src
Committed By:   ad
Date:           Wed Jan 22 12:00:18 UTC 2020

Modified Files:
        src/sys/miscfs/genfs [ad-namecache]: genfs_vnops.c

Log Message:
Make sure LK_UPGRADE always comes with LK_NOWAIT; dropping the lock in here
is unclean and I wonder if it could screw over fstrans.


To generate a diff of this commit:
cvs rdiff -u -r1.200.2.1 -r1.200.2.2 src/sys/miscfs/genfs/genfs_vnops.c

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.


Modified files:

Index: src/sys/miscfs/genfs/genfs_vnops.c
diff -u src/sys/miscfs/genfs/genfs_vnops.c:1.200.2.1 src/sys/miscfs/genfs/genfs_vnops.c:1.200.2.2
--- src/sys/miscfs/genfs/genfs_vnops.c:1.200.2.1	Sat Jan 18 17:12:59 2020
+++ src/sys/miscfs/genfs/genfs_vnops.c	Wed Jan 22 12:00:18 2020
@@ -1,4 +1,4 @@
-/*	$NetBSD: genfs_vnops.c,v 1.200.2.1 2020/01/18 17:12:59 ad Exp $	*/
+/*	$NetBSD: genfs_vnops.c,v 1.200.2.2 2020/01/22 12:00:18 ad Exp $	*/
 
 /*-
  * Copyright (c) 2008 The NetBSD Foundation, Inc.
@@ -57,7 +57,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: genfs_vnops.c,v 1.200.2.1 2020/01/18 17:12:59 ad Exp $");
+__KERNEL_RCSID(0, "$NetBSD: genfs_vnops.c,v 1.200.2.2 2020/01/22 12:00:18 ad Exp $");
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -295,11 +295,9 @@ genfs_deadlock(void *v)
 	if (ISSET(flags, LK_DOWNGRADE)) {
 		rw_downgrade(vip->vi_lock);
 	} else if (ISSET(flags, LK_UPGRADE)) {
+		KASSERT(ISSET(flags, LK_NOWAIT));
 		if (!rw_tryupgrade(vip->vi_lock)) {
-			if (ISSET(flags, LK_NOWAIT))
-				return EBUSY;
-			rw_exit(vip->vi_lock);
-			rw_enter(vip->vi_lock, RW_WRITER);
+			return EBUSY;
 		}
 	} else if ((flags & (LK_EXCLUSIVE | LK_SHARED)) != 0) {
 		op = (ISSET(flags, LK_EXCLUSIVE) ? RW_WRITER : RW_READER);
@@ -349,11 +347,9 @@ genfs_lock(void *v)
 	if (ISSET(flags, LK_DOWNGRADE)) {
 		rw_downgrade(vip->vi_lock);
 	} else if (ISSET(flags, LK_UPGRADE)) {
+		KASSERT(ISSET(flags, LK_NOWAIT));
 		if (!rw_tryupgrade(vip->vi_lock)) {
-			if (ISSET(flags, LK_NOWAIT))
-				return EBUSY;
-			rw_exit(vip->vi_lock);
-			rw_enter(vip->vi_lock, RW_WRITER);
+			return EBUSY;
 		}
 	} else if ((flags & (LK_EXCLUSIVE | LK_SHARED)) != 0) {
 		op = (ISSET(flags, LK_EXCLUSIVE) ? RW_WRITER : RW_READER);