Module Name: src
Committed By: dholland
Date: Mon Jun 29 05:00:15 UTC 2009
Modified Files:
src/sys/kern: vfs_lookup.c
src/sys/sys: namei.src
Log Message:
Add namei_simple_kernel and namei_simple_user. These provide the common
case functionality of namei in a simple package with only a couple flags.
A substantial majority of the namei call sites in the kernel can use
this interface; this will isolate those areas from the changes arising
as the internals of namei are fumigated.
To generate a diff of this commit:
cvs rdiff -u -r1.115 -r1.116 src/sys/kern/vfs_lookup.c
cvs rdiff -u -r1.10 -r1.11 src/sys/sys/namei.src
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/kern/vfs_lookup.c
diff -u src/sys/kern/vfs_lookup.c:1.115 src/sys/kern/vfs_lookup.c:1.116
--- src/sys/kern/vfs_lookup.c:1.115 Fri Jun 26 15:49:03 2009
+++ src/sys/kern/vfs_lookup.c Mon Jun 29 05:00:14 2009
@@ -1,4 +1,4 @@
-/* $NetBSD: vfs_lookup.c,v 1.115 2009/06/26 15:49:03 christos Exp $ */
+/* $NetBSD: vfs_lookup.c,v 1.116 2009/06/29 05:00:14 dholland Exp $ */
/*
* Copyright (c) 1982, 1986, 1989, 1993
@@ -37,7 +37,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: vfs_lookup.c,v 1.115 2009/06/26 15:49:03 christos Exp $");
+__KERNEL_RCSID(0, "$NetBSD: vfs_lookup.c,v 1.116 2009/06/29 05:00:14 dholland Exp $");
#include "opt_magiclinks.h"
@@ -1010,3 +1010,76 @@
*vpp = NULL;
return (error);
}
+
+/*
+ * namei_simple - simple forms of namei.
+ *
+ * These are wrappers to allow the simple case callers of namei to be
+ * left alone while everything else changes under them.
+ */
+
+/* Flags */
+struct namei_simple_flags_type {
+ int dummy;
+};
+static const struct namei_simple_flags_type ns_nn, ns_nt, ns_fn, ns_ft;
+const namei_simple_flags_t NSM_NOFOLLOW_NOEMULROOT = &ns_nn;
+const namei_simple_flags_t NSM_NOFOLLOW_TRYEMULROOT = &ns_nt;
+const namei_simple_flags_t NSM_FOLLOW_NOEMULROOT = &ns_fn;
+const namei_simple_flags_t NSM_FOLLOW_TRYEMULROOT = &ns_ft;
+
+static
+int
+namei_simple_convert_flags(namei_simple_flags_t sflags)
+{
+ if (sflags == NSM_NOFOLLOW_NOEMULROOT)
+ return NOFOLLOW | 0;
+ if (sflags == NSM_NOFOLLOW_TRYEMULROOT)
+ return NOFOLLOW | TRYEMULROOT;
+ if (sflags == NSM_FOLLOW_NOEMULROOT)
+ return FOLLOW | 0;
+ if (sflags == NSM_FOLLOW_TRYEMULROOT)
+ return FOLLOW | TRYEMULROOT;
+ panic("namei_simple_convert_flags: bogus sflags\n");
+ return 0;
+}
+
+int
+namei_simple_kernel(const char *path, namei_simple_flags_t sflags,
+ struct vnode **vp_ret)
+{
+ struct nameidata nd;
+ int err;
+
+ NDINIT(&nd,
+ LOOKUP,
+ namei_simple_convert_flags(sflags),
+ UIO_SYSSPACE,
+ path);
+ err = namei(&nd);
+ if (err != 0) {
+ return err;
+ }
+ *vp_ret = nd.ni_vp;
+ return 0;
+}
+
+int
+namei_simple_user(const char *path, namei_simple_flags_t sflags,
+ struct vnode **vp_ret)
+{
+ struct nameidata nd;
+ int err;
+
+ NDINIT(&nd,
+ LOOKUP,
+ namei_simple_convert_flags(sflags),
+ UIO_USERSPACE,
+ path);
+ err = namei(&nd);
+ if (err != 0) {
+ return err;
+ }
+ *vp_ret = nd.ni_vp;
+ return 0;
+}
Index: src/sys/sys/namei.src
diff -u src/sys/sys/namei.src:1.10 src/sys/sys/namei.src:1.11
--- src/sys/sys/namei.src:1.10 Wed Feb 11 00:19:11 2009
+++ src/sys/sys/namei.src Mon Jun 29 05:00:14 2009
@@ -1,4 +1,4 @@
-/* $NetBSD: namei.src,v 1.10 2009/02/11 00:19:11 enami Exp $ */
+/* $NetBSD: namei.src,v 1.11 2009/06/29 05:00:14 dholland Exp $ */
/*
* Copyright (c) 1985, 1989, 1991, 1993
@@ -196,6 +196,36 @@
#define PNBUF_GET() pool_cache_get(pnbuf_cache, PR_WAITOK)
#define PNBUF_PUT(pnb) pool_cache_put(pnbuf_cache, (pnb))
+/*
+ * Typesafe flags for namei_simple.
+ *
+ * This encoding is not optimal but serves the important purpose of
+ * not being type-compatible with the regular namei flags.
+ */
+struct namei_simple_flags_type; /* Opaque. */
+typedef const struct namei_simple_flags_type *namei_simple_flags_t; /* Gross. */
+extern const namei_simple_flags_t
+ NSM_NOFOLLOW_NOEMULROOT,
+ NSM_NOFOLLOW_TRYEMULROOT,
+ NSM_FOLLOW_NOEMULROOT,
+ NSM_FOLLOW_TRYEMULROOT;
+
+/*
+ * namei_simple_* - the simple cases of namei, with no struct
+ * nameidata involved.
+ *
+ * namei_simple_kernel takes a kernel-space path as the first argument.
+ * namei_simple_user takes a user-space path as the first argument.
+ *
+ * A namei call can be converted to namei_simple_* if:
+ * - the second arg to NDINIT is LOOKUP;
+ * - it does not need the parent vnode, nd.ni_dvp;
+ * - the only flags it uses are (NO)FOLLOW and TRYEMULROOT;
+ * - it does not do anything else gross with the contents of nd.
+ */
+int namei_simple_kernel(const char *, namei_simple_flags_t, struct vnode **);
+int namei_simple_user(const char *, namei_simple_flags_t, struct vnode **);
+
int namei(struct nameidata *);
uint32_t namei_hash(const char *, const char **);
int lookup(struct nameidata *);
