[PATCH] path_lookup for 2.4.20-pre4

Hanna Linder (hannal@us.ibm.com)
Fri, 23 Aug 2002 13:44:03 -0700


This patch cleans up vfs path lookup code by combining
path_init and path_walk into one function. This patch has
not changed since Alan Cox included it in 2.4.19-pre5-ac2.
I have ported it to 2.4.20-pre4.

Hanna

----------
diff -Nru -Xdontdiff linux-2.4.20-pre4/fs/exec.c linux-path_lookup/fs/exec.c
--- linux-2.4.20-pre4/fs/exec.c Fri Aug 23 13:30:18 2002
+++ linux-path_lookup/fs/exec.c Fri Aug 23 13:27:33 2002
@@ -364,8 +364,7 @@
struct file *file;
int err = 0;

- if (path_init(name, LOOKUP_FOLLOW|LOOKUP_POSITIVE, &nd))
- err = path_walk(name, &nd);
+ err = path_lookup(name, LOOKUP_FOLLOW|LOOKUP_POSITIVE, &nd);
file = ERR_PTR(err);
if (!err) {
inode = nd.dentry->d_inode;
diff -Nru -Xdontdiff linux-2.4.20-pre4/fs/namei.c linux-path_lookup/fs/namei.c
--- linux-2.4.20-pre4/fs/namei.c Fri Aug 2 17:39:45 2002
+++ linux-path_lookup/fs/namei.c Fri Aug 23 13:27:33 2002
@@ -739,6 +739,16 @@
}

/* SMP-safe */
+int path_lookup(const char *path, unsigned flags, struct nameidata *nd)
+{
+ int error = 0;
+ if (path_init(path, flags, nd))
+ error = path_walk(path, nd);
+ return error;
+}
+
+
+/* SMP-safe */
int path_init(const char *name, unsigned int flags, struct nameidata *nd)
{
nd->last_type = LAST_ROOT; /* if there are only slashes... */
@@ -844,8 +854,7 @@
err = PTR_ERR(tmp);
if (!IS_ERR(tmp)) {
err = 0;
- if (path_init(tmp, flags, nd))
- err = path_walk(tmp, nd);
+ err = path_lookup(tmp, flags, nd);
putname(tmp);
}
return err;
@@ -1001,8 +1010,7 @@
* The simplest case - just a plain lookup.
*/
if (!(flag & O_CREAT)) {
- if (path_init(pathname, lookup_flags(flag), nd))
- error = path_walk(pathname, nd);
+ error = path_lookup(pathname, lookup_flags(flag), nd);
if (error)
return error;
dentry = nd->dentry;
@@ -1012,8 +1020,7 @@
/*
* Create - we need to know the parent.
*/
- if (path_init(pathname, LOOKUP_PARENT, nd))
- error = path_walk(pathname, nd);
+ error = path_lookup(pathname, LOOKUP_PARENT, nd);
if (error)
return error;

@@ -1265,8 +1272,7 @@
if (IS_ERR(tmp))
return PTR_ERR(tmp);

- if (path_init(tmp, LOOKUP_PARENT, &nd))
- error = path_walk(tmp, &nd);
+ error = path_lookup(tmp, LOOKUP_PARENT, &nd);
if (error)
goto out;
dentry = lookup_create(&nd, 0);
@@ -1334,8 +1340,7 @@
struct dentry *dentry;
struct nameidata nd;

- if (path_init(tmp, LOOKUP_PARENT, &nd))
- error = path_walk(tmp, &nd);
+ error = path_lookup(tmp, LOOKUP_PARENT, &nd);
if (error)
goto out;
dentry = lookup_create(&nd, 1);
@@ -1431,8 +1436,7 @@
if(IS_ERR(name))
return PTR_ERR(name);

- if (path_init(name, LOOKUP_PARENT, &nd))
- error = path_walk(name, &nd);
+ error = path_lookup(name, LOOKUP_PARENT, &nd);
if (error)
goto exit;

@@ -1500,8 +1504,7 @@
if(IS_ERR(name))
return PTR_ERR(name);

- if (path_init(name, LOOKUP_PARENT, &nd))
- error = path_walk(name, &nd);
+ error = path_lookup(name, LOOKUP_PARENT, &nd);
if (error)
goto exit;
error = -EISDIR;
@@ -1572,8 +1575,7 @@
struct dentry *dentry;
struct nameidata nd;

- if (path_init(to, LOOKUP_PARENT, &nd))
- error = path_walk(to, &nd);
+ error = path_lookup(to, LOOKUP_PARENT, &nd);
if (error)
goto out;
dentry = lookup_create(&nd, 0);
@@ -1643,25 +1645,18 @@
asmlinkage long sys_link(const char * oldname, const char * newname)
{
int error;
- char * from;
char * to;

- from = getname(oldname);
- if(IS_ERR(from))
- return PTR_ERR(from);
to = getname(newname);
error = PTR_ERR(to);
if (!IS_ERR(to)) {
struct dentry *new_dentry;
struct nameidata nd, old_nd;

- error = 0;
- if (path_init(from, LOOKUP_POSITIVE, &old_nd))
- error = path_walk(from, &old_nd);
+ error = __user_walk(oldname, LOOKUP_POSITIVE, &old_nd);
if (error)
goto exit;
- if (path_init(to, LOOKUP_PARENT, &nd))
- error = path_walk(to, &nd);
+ error = path_lookup(to, LOOKUP_PARENT, &nd);
if (error)
goto out;
error = -EXDEV;
@@ -1681,8 +1676,6 @@
exit:
putname(to);
}
- putname(from);
-
return error;
}

@@ -1859,14 +1852,11 @@
struct dentry * old_dentry, *new_dentry;
struct nameidata oldnd, newnd;

- if (path_init(oldname, LOOKUP_PARENT, &oldnd))
- error = path_walk(oldname, &oldnd);
-
+ error = path_lookup(oldname, LOOKUP_PARENT, &oldnd);
if (error)
goto exit;

- if (path_init(newname, LOOKUP_PARENT, &newnd))
- error = path_walk(newname, &newnd);
+ error = path_lookup(newname, LOOKUP_PARENT, &newnd);
if (error)
goto exit1;

diff -Nru -Xdontdiff linux-2.4.20-pre4/fs/namespace.c linux-path_lookup/fs/namespace.c
--- linux-2.4.20-pre4/fs/namespace.c Fri Aug 23 13:30:19 2002
+++ linux-path_lookup/fs/namespace.c Fri Aug 23 13:27:33 2002
@@ -361,17 +361,9 @@
asmlinkage long sys_umount(char * name, int flags)
{
struct nameidata nd;
- char *kname;
int retval;

- kname = getname(name);
- retval = PTR_ERR(kname);
- if (IS_ERR(kname))
- goto out;
- retval = 0;
- if (path_init(kname, LOOKUP_POSITIVE|LOOKUP_FOLLOW, &nd))
- retval = path_walk(kname, &nd);
- putname(kname);
+ retval = __user_walk(name, LOOKUP_POSITIVE|LOOKUP_FOLLOW, &nd);
if (retval)
goto out;
retval = -EINVAL;
@@ -498,8 +490,7 @@
return err;
if (!old_name || !*old_name)
return -EINVAL;
- if (path_init(old_name, LOOKUP_POSITIVE|LOOKUP_FOLLOW, &old_nd))
- err = path_walk(old_name, &old_nd);
+ err = path_lookup(old_name, LOOKUP_POSITIVE|LOOKUP_FOLLOW, &old_nd);
if (err)
return err;

@@ -565,8 +556,7 @@
return -EPERM;
if (!old_name || !*old_name)
return -EINVAL;
- if (path_init(old_name, LOOKUP_POSITIVE|LOOKUP_FOLLOW, &old_nd))
- err = path_walk(old_name, &old_nd);
+ err = path_lookup(old_name, LOOKUP_POSITIVE|LOOKUP_FOLLOW, &old_nd);
if (err)
return err;

@@ -732,8 +722,7 @@
flags &= ~(MS_NOSUID|MS_NOEXEC|MS_NODEV);

/* ... and get the mountpoint */
- if (path_init(dir_name, LOOKUP_FOLLOW|LOOKUP_POSITIVE, &nd))
- retval = path_walk(dir_name, &nd);
+ retval = path_lookup(dir_name, LOOKUP_FOLLOW|LOOKUP_POSITIVE, &nd);
if (retval)
return retval;

@@ -912,7 +901,6 @@
{
struct vfsmount *tmp;
struct nameidata new_nd, old_nd, parent_nd, root_parent, user_nd;
- char *name;
int error;

if (!capable(CAP_SYS_ADMIN))
@@ -920,28 +908,14 @@

lock_kernel();

- name = getname(new_root);
- error = PTR_ERR(name);
- if (IS_ERR(name))
- goto out0;
- error = 0;
- if (path_init(name, LOOKUP_POSITIVE|LOOKUP_FOLLOW|LOOKUP_DIRECTORY, &new_nd))
- error = path_walk(name, &new_nd);
- putname(name);
+ error = __user_walk(new_root, LOOKUP_POSITIVE|LOOKUP_FOLLOW|LOOKUP_DIRECTORY, &new_nd);
if (error)
goto out0;
error = -EINVAL;
if (!check_mnt(new_nd.mnt))
goto out1;

- name = getname(put_old);
- error = PTR_ERR(name);
- if (IS_ERR(name))
- goto out1;
- error = 0;
- if (path_init(name, LOOKUP_POSITIVE|LOOKUP_FOLLOW|LOOKUP_DIRECTORY, &old_nd))
- error = path_walk(name, &old_nd);
- putname(name);
+ error = __user_walk(put_old, LOOKUP_POSITIVE|LOOKUP_FOLLOW|LOOKUP_DIRECTORY, &old_nd);
if (error)
goto out1;

diff -Nru -Xdontdiff linux-2.4.20-pre4/fs/open.c linux-path_lookup/fs/open.c
--- linux-2.4.20-pre4/fs/open.c Fri Aug 2 17:39:45 2002
+++ linux-path_lookup/fs/open.c Fri Aug 23 13:27:33 2002
@@ -385,17 +385,8 @@
{
int error;
struct nameidata nd;
- char *name;

- name = getname(filename);
- error = PTR_ERR(name);
- if (IS_ERR(name))
- goto out;
-
- error = 0;
- if (path_init(name,LOOKUP_POSITIVE|LOOKUP_FOLLOW|LOOKUP_DIRECTORY,&nd))
- error = path_walk(name, &nd);
- putname(name);
+ error = __user_walk(filename,LOOKUP_POSITIVE|LOOKUP_FOLLOW|LOOKUP_DIRECTORY,&nd);
if (error)
goto out;

@@ -445,17 +436,9 @@
{
int error;
struct nameidata nd;
- char *name;
-
- name = getname(filename);
- error = PTR_ERR(name);
- if (IS_ERR(name))
- goto out;

- path_init(name, LOOKUP_POSITIVE | LOOKUP_FOLLOW |
+ error = __user_walk(filename, LOOKUP_POSITIVE | LOOKUP_FOLLOW |
LOOKUP_DIRECTORY | LOOKUP_NOALT, &nd);
- error = path_walk(name, &nd);
- putname(name);
if (error)
goto out;

diff -Nru -Xdontdiff linux-2.4.20-pre4/fs/super.c linux-path_lookup/fs/super.c
--- linux-2.4.20-pre4/fs/super.c Fri Aug 2 17:39:45 2002
+++ linux-path_lookup/fs/super.c Fri Aug 23 13:27:33 2002
@@ -659,8 +659,7 @@
/* What device it is? */
if (!dev_name || !*dev_name)
return ERR_PTR(-EINVAL);
- if (path_init(dev_name, LOOKUP_FOLLOW|LOOKUP_POSITIVE, &nd))
- error = path_walk(dev_name, &nd);
+ error = path_lookup(dev_name, LOOKUP_FOLLOW|LOOKUP_POSITIVE, &nd);
if (error)
return ERR_PTR(error);
inode = nd.dentry->d_inode;
diff -Nru -Xdontdiff linux-2.4.20-pre4/include/linux/fs.h linux-path_lookup/include/linux/fs.h
--- linux-2.4.20-pre4/include/linux/fs.h Fri Aug 23 13:30:25 2002
+++ linux-path_lookup/include/linux/fs.h Fri Aug 23 13:27:33 2002
@@ -1329,6 +1329,7 @@
extern int FASTCALL(__user_walk(const char *, unsigned, struct nameidata *));
extern int FASTCALL(path_init(const char *, unsigned, struct nameidata *));
extern int FASTCALL(path_walk(const char *, struct nameidata *));
+extern int FASTCALL(path_lookup(const char *, unsigned, struct nameidata *));
extern int FASTCALL(link_path_walk(const char *, struct nameidata *));
extern void path_release(struct nameidata *);
extern int follow_down(struct vfsmount **, struct dentry **);

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