From 0e2d6cc899f79446c0b77c608a93d50d91c255a3 Mon Sep 17 00:00:00 2001
From: Jeff Roberson <jeff@FreeBSD.org>
Date: Tue, 14 May 2002 21:59:49 +0000
Subject: [PATCH] Disable the shared locking namei() code for now.  It breaks
 several stacking filesystems.  This is on hold until the rest of VFS Locking
 is reviewed and deemed safe.  It can be enabled with 'options LOOKUP_SHARED'.

---
 sys/conf/options        |  2 +-
 sys/kern/vfs_cache.c    |  8 ++++----
 sys/kern/vfs_extattr.c  |  2 +-
 sys/kern/vfs_syscalls.c |  2 +-
 sys/kern/vfs_vnops.c    | 10 +++++-----
 5 files changed, 12 insertions(+), 12 deletions(-)

diff --git a/sys/conf/options b/sys/conf/options
index dc617f34d82..29984680593 100644
--- a/sys/conf/options
+++ b/sys/conf/options
@@ -389,7 +389,7 @@ BLKDEV_IOSIZE		opt_global.h
 DEBUG			opt_global.h
 DEBUG_LOCKS		opt_global.h
 DEBUG_VFS_LOCKS		opt_global.h
-LOOKUP_EXCLUSIVE	opt_global.h
+LOOKUP_SHARED		opt_global.h
 DIAGNOSTIC		opt_global.h
 ENABLE_VFS_IOOPT	opt_global.h
 INVARIANT_SUPPORT	opt_global.h
diff --git a/sys/kern/vfs_cache.c b/sys/kern/vfs_cache.c
index 49bd83f0b08..6fd537f90b2 100644
--- a/sys/kern/vfs_cache.c
+++ b/sys/kern/vfs_cache.c
@@ -566,7 +566,7 @@ vfs_cache_lookup(ap)
 
 	error = cache_lookup(dvp, vpp, cnp);
 
-#ifndef LOOKUP_EXCLUSIVE
+#ifdef LOOKUP_SHARED
 	if (!error) {
 		/* We do this because the rest of the system now expects to get
 		 * a shared lock, which is later upgraded if LOCKSHARED is not
@@ -608,7 +608,7 @@ vfs_cache_lookup(ap)
 	} else if (flags & ISDOTDOT) {
 		VOP_UNLOCK(dvp, 0, td);
 		cnp->cn_flags |= PDIRUNLOCK;
-#ifndef LOOKUP_EXCLUSIVE
+#ifdef LOOKUP_SHARED
 		if ((flags & ISLASTCN) && (flags & LOCKSHARED))
 			error = vget(vp, LK_SHARED, td);
 		else
@@ -622,7 +622,7 @@ vfs_cache_lookup(ap)
 				cnp->cn_flags &= ~PDIRUNLOCK;
 		}
 	} else {
-#ifndef LOOKUP_EXCLUSIVE
+#ifdef LOOKUP_SHARED
 		if ((flags & ISLASTCN) && (flags & LOCKSHARED))
 			error = vget(vp, LK_SHARED, td);
 		else
@@ -654,7 +654,7 @@ vfs_cache_lookup(ap)
 			return (error);
 		cnp->cn_flags &= ~PDIRUNLOCK;
 	}
-#ifndef LOOKUP_EXCLUSIVE
+#ifdef LOOKUP_SHARED
 	error = VOP_CACHEDLOOKUP(dvp, vpp, cnp);
 
 	if (!error) {
diff --git a/sys/kern/vfs_extattr.c b/sys/kern/vfs_extattr.c
index f256e9e4484..44dec6d4d84 100644
--- a/sys/kern/vfs_extattr.c
+++ b/sys/kern/vfs_extattr.c
@@ -2585,7 +2585,7 @@ stat(td, uap)
 	int error;
 	struct nameidata nd;
 
-#ifndef LOOKUP_EXCLUSIVE
+#ifdef LOOKUP_SHARED
 	NDINIT(&nd, LOOKUP, FOLLOW | LOCKSHARED | LOCKLEAF | NOOBJ,
 	    UIO_USERSPACE, SCARG(uap, path), td);
 #else
diff --git a/sys/kern/vfs_syscalls.c b/sys/kern/vfs_syscalls.c
index f256e9e4484..44dec6d4d84 100644
--- a/sys/kern/vfs_syscalls.c
+++ b/sys/kern/vfs_syscalls.c
@@ -2585,7 +2585,7 @@ stat(td, uap)
 	int error;
 	struct nameidata nd;
 
-#ifndef LOOKUP_EXCLUSIVE
+#ifdef LOOKUP_SHARED
 	NDINIT(&nd, LOOKUP, FOLLOW | LOCKSHARED | LOCKLEAF | NOOBJ,
 	    UIO_USERSPACE, SCARG(uap, path), td);
 #else
diff --git a/sys/kern/vfs_vnops.c b/sys/kern/vfs_vnops.c
index d2d735d480b..64e26be32ff 100644
--- a/sys/kern/vfs_vnops.c
+++ b/sys/kern/vfs_vnops.c
@@ -106,7 +106,7 @@ vn_open_cred(ndp, flagp, cmode, cred)
 	struct vattr vat;
 	struct vattr *vap = &vat;
 	int mode, fmode, error;
-#ifndef LOOKUP_EXCLUSIVE
+#ifdef LOOKUP_SHARED
 	int exclusive;	/* The current intended lock state */
 
 	exclusive = 0;
@@ -149,7 +149,7 @@ restart:
 			ASSERT_VOP_LOCKED(ndp->ni_vp, "create");
 			fmode &= ~O_TRUNC;
 			vp = ndp->ni_vp;
-#ifndef LOOKUP_EXCLUSIVE
+#ifdef LOOKUP_SHARED
 			exclusive = 1;
 #endif
 		} else {
@@ -167,7 +167,7 @@ restart:
 		}
 	} else {
 		ndp->ni_cnd.cn_nameiop = LOOKUP;
-#ifndef LOOKUP_EXCLUSIVE
+#ifdef LOOKUP_SHARED
 		ndp->ni_cnd.cn_flags =
 		    ((fmode & O_NOFOLLOW) ? NOFOLLOW : FOLLOW) |
 		    LOCKSHARED | LOCKLEAF;
@@ -213,7 +213,7 @@ restart:
 	 * Make sure that a VM object is created for VMIO support.
 	 */
 	if (vn_canvmio(vp) == TRUE) {
-#ifndef LOOKUP_EXCLUSIVE
+#ifdef LOOKUP_SHARED
 		int flock;
 
 		if (!exclusive && VOP_GETVOBJECT(vp, NULL) != 0)
@@ -236,7 +236,7 @@ restart:
 			*flagp = fmode;
 			return (error);
 		}
-#ifndef LOOKUP_EXCLUSIVE
+#ifdef LOOKUP_SHARED
 		flock = VOP_ISLOCKED(vp, td);
 		if (!exclusive && flock == LK_EXCLUSIVE)
 			VOP_LOCK(vp, LK_DOWNGRADE, td);