[PATCH] lock_kernel optimization

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Hi Linus

sys_{link, symlink, unlink, mkmod} acquired the kernel lock earlier than
needed. The patch below moves these calls as near as possible to the
actual VFS calls.

It's tested on SMP i386 with 2.3.39, and 2.3.40-1 doesn't touch
fs/namei.c.

--
	Manfred
------------------------
diff -ur 2.3/fs/namei.c build-2.3/fs/namei.c
--- 2.3/fs/namei.c	Thu Jan  6 22:57:20 2000
+++ build-2.3/fs/namei.c	Wed Jan 12 19:53:59 2000
@@ -780,16 +780,14 @@
 	char * tmp;
 	struct dentry * dentry;
 
-	lock_kernel();
-	error = -EPERM;
 	if (S_ISDIR(mode) || (!S_ISFIFO(mode) && !capable(CAP_MKNOD)))
-		goto out;
+		return -EPERM;
 	tmp = getname(filename);
-	error = PTR_ERR(tmp);
 	if (IS_ERR(tmp))
-		goto out;
+		return PTR_ERR(tmp);
 
 	error = -EINVAL;
+	lock_kernel();
 	switch (mode & S_IFMT) {
 	case 0:
 		mode |= S_IFREG;	/* fallthrough */
@@ -815,10 +813,9 @@
 		}
 		break;
 	}
+	unlock_kernel();
 	putname(tmp);
 
-out:
-	unlock_kernel();
 	return error;
 }
 
@@ -870,14 +867,14 @@
 	int error;
 	char * tmp;
 
-	lock_kernel();
 	tmp = getname(pathname);
-	error = PTR_ERR(tmp);
-	if (!IS_ERR(tmp)) {
-		error = do_mkdir(tmp,mode);
-		putname(tmp);
-	}
+	if(IS_ERR(tmp))
+		return PTR_ERR(tmp);
+	lock_kernel();
+	error = do_mkdir(tmp,mode);
 	unlock_kernel();
+	putname(tmp);
+
 	return error;
 }
 
@@ -965,14 +962,15 @@
 	int error;
 	char * tmp;
 
-	lock_kernel();
 	tmp = getname(pathname);
-	error = PTR_ERR(tmp);
-	if (!IS_ERR(tmp)) {
-		error = do_rmdir(tmp);
-		putname(tmp);
-	}
+	if(IS_ERR(tmp))
+		return PTR_ERR(tmp);
+	lock_kernel();
+	error = do_rmdir(tmp);
 	unlock_kernel();
+
+	putname(tmp);
+
 	return error;
 }
 
@@ -1018,14 +1016,14 @@
 	int error;
 	char * tmp;
 
-	lock_kernel();
 	tmp = getname(pathname);
-	error = PTR_ERR(tmp);
-	if (!IS_ERR(tmp)) {
-		error = do_unlink(tmp);
-		putname(tmp);
-	}
+	if(IS_ERR(tmp))
+		return PTR_ERR(tmp);
+	lock_kernel();
+	error = do_unlink(tmp);
 	unlock_kernel();
+	putname(tmp);
+
 	return error;
 }
 
@@ -1068,21 +1066,20 @@
 {
 	int error;
 	char * from;
+	char * to;
 
-	lock_kernel();
 	from = getname(oldname);
-	error = PTR_ERR(from);
-	if (!IS_ERR(from)) {
-		char * to;
-		to = getname(newname);
-		error = PTR_ERR(to);
-		if (!IS_ERR(to)) {
-			error = do_symlink(from,to);
-			putname(to);
-		}
-		putname(from);
+	if(IS_ERR(from))
+		return PTR_ERR(from);
+	to = getname(newname);
+	error = PTR_ERR(to);
+	if (!IS_ERR(to)) {
+		lock_kernel();
+		error = do_symlink(from,to);
+		unlock_kernel();
+		putname(to);
 	}
-	unlock_kernel();
+	putname(from);
 	return error;
 }
 
@@ -1156,21 +1153,21 @@
 {
 	int error;
 	char * from;
+		char * to;
 
-	lock_kernel();
 	from = getname(oldname);
-	error = PTR_ERR(from);
-	if (!IS_ERR(from)) {
-		char * to;
-		to = getname(newname);
-		error = PTR_ERR(to);
-		if (!IS_ERR(to)) {
-			error = do_link(from,to);
-			putname(to);
-		}
-		putname(from);
+	if(IS_ERR(from))
+		return PTR_ERR(from);
+	to = getname(newname);
+	error = PTR_ERR(to);
+	if (!IS_ERR(to)) {
+		lock_kernel();
+		error = do_link(from,to);
+		unlock_kernel();
+		putname(to);
 	}
-	unlock_kernel();
+	putname(from);
+
 	return error;
 }
 
@@ -1327,21 +1324,20 @@
 {
 	int error;
 	char * from;
+	char * to;
 
-	lock_kernel();
 	from = getname(oldname);
-	error = PTR_ERR(from);
-	if (!IS_ERR(from)) {
-		char * to;
-		to = getname(newname);
-		error = PTR_ERR(to);
-		if (!IS_ERR(to)) {
-			error = do_rename(from,to);
-			putname(to);
-		}
-		putname(from);
+	if(IS_ERR(from))
+		return PTR_ERR(from);
+	to = getname(newname);
+	error = PTR_ERR(to);
+	if (!IS_ERR(to)) {
+		lock_kernel();
+		error = do_rename(from,to);
+		unlock_kernel();
+		putname(to);
 	}
-	unlock_kernel();
+	putname(from);
 	return error;
 }
 
------------------------
-
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• Next message: Jim Studt: "[PATCH] fs/nfs, kernel 2.3.35 (and others including current)"
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