lkml.org 
[lkml]   [2001]   [Oct]   [3]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH] Cleanup LOOKUP_PARENT handling in fs/namei.c
Date

The attached patch (against 2.4.10) adds a user_path_walk_parent() macro
in fs.h, and uses it to clean up some repetitive code in fs/namei.c.
Basically, variations on the sequence:

tmp = getname(path)
if(!IS_ERR(tmp)) {
if(!path_init(tmp, LOOKUP_PARENT, &nd))
error = path_walk(tmp, &nd);
if(!error) {
error = do_stuff_with_parentdir();
path_release(&nd);
}
putname(tmp);
}

are replaced with:

error = user_path_walk_parent(path, &nd);
if(!error) {
error = do_stuff_with_parentdir();
path_release(&nd);
}

Paul

--- linux.orig/include/linux/fs.h Sun Sep 23 10:31:02 2001
+++ linux/include/linux/fs.h Wed Oct 3 09:37:19 2001
@@ -1297,6 +1297,7 @@
extern struct dentry * lookup_hash(struct qstr *, struct dentry *);
#define user_path_walk(name,nd) __user_walk(name, LOOKUP_FOLLOW|LOOKUP_POSITIVE, nd)
#define user_path_walk_link(name,nd) __user_walk(name, LOOKUP_POSITIVE, nd)
+#define user_path_walk_parent(name, nd) __user_walk(name, LOOKUP_PARENT, nd)

extern void iput(struct inode *);
extern void force_delete(struct inode *);
--- linux.orig/fs/namei.c Tue Sep 18 11:01:47 2001
+++ linux/fs/namei.c Wed Oct 3 14:11:18 2001
@@ -1216,18 +1216,13 @@
asmlinkage long sys_mknod(const char * filename, int mode, dev_t dev)
{
int error = 0;
- char * tmp;
struct dentry * dentry;
struct nameidata nd;

if (S_ISDIR(mode))
return -EPERM;
- tmp = getname(filename);
- if (IS_ERR(tmp))
- return PTR_ERR(tmp);

- if (path_init(tmp, LOOKUP_PARENT, &nd))
- error = path_walk(tmp, &nd);
+ error = user_path_walk_parent(filename, &nd);
if (error)
goto out;
dentry = lookup_create(&nd, 0);
@@ -1253,7 +1248,6 @@
up(&nd.dentry->d_inode->i_sem);
path_release(&nd);
out:
- putname(tmp);

return error;
}
@@ -1287,30 +1281,21 @@
asmlinkage long sys_mkdir(const char * pathname, int mode)
{
int error = 0;
- char * tmp;
-
- tmp = getname(pathname);
- error = PTR_ERR(tmp);
- if (!IS_ERR(tmp)) {
- struct dentry *dentry;
- struct nameidata nd;
-
- if (path_init(tmp, LOOKUP_PARENT, &nd))
- error = path_walk(tmp, &nd);
- if (error)
- goto out;
- dentry = lookup_create(&nd, 1);
- error = PTR_ERR(dentry);
- if (!IS_ERR(dentry)) {
- error = vfs_mkdir(nd.dentry->d_inode, dentry,
- mode & ~current->fs->umask);
- dput(dentry);
- }
- up(&nd.dentry->d_inode->i_sem);
- path_release(&nd);
-out:
- putname(tmp);
+ struct dentry *dentry;
+ struct nameidata nd;
+ error = user_path_walk_parent(pathname, &nd);
+ if (error)
+ goto out;
+ dentry = lookup_create(&nd, 1);
+ error = PTR_ERR(dentry);
+ if (!IS_ERR(dentry)) {
+ error = vfs_mkdir(nd.dentry->d_inode, dentry,
+ mode & ~current->fs->umask);
+ dput(dentry);
}
+ up(&nd.dentry->d_inode->i_sem);
+ path_release(&nd);
+out:

return error;
}
@@ -1382,29 +1367,23 @@
asmlinkage long sys_rmdir(const char * pathname)
{
int error = 0;
- char * name;
struct dentry *dentry;
struct nameidata nd;

- name = getname(pathname);
- if(IS_ERR(name))
- return PTR_ERR(name);
-
- if (path_init(name, LOOKUP_PARENT, &nd))
- error = path_walk(name, &nd);
+ error = user_path_walk_parent(pathname, &nd);
if (error)
goto exit;

switch(nd.last_type) {
case LAST_DOTDOT:
error = -ENOTEMPTY;
- goto exit1;
+ goto exit_release;
case LAST_DOT:
error = -EINVAL;
- goto exit1;
+ goto exit_release;
case LAST_ROOT:
error = -EBUSY;
- goto exit1;
+ goto exit_release;
}
down(&nd.dentry->d_inode->i_sem);
dentry = lookup_hash(&nd.last, nd.dentry);
@@ -1414,10 +1393,9 @@
dput(dentry);
}
up(&nd.dentry->d_inode->i_sem);
-exit1:
+exit_release:
path_release(&nd);
exit:
- putname(name);
return error;
}

@@ -1451,21 +1429,15 @@
asmlinkage long sys_unlink(const char * pathname)
{
int error = 0;
- char * name;
struct dentry *dentry;
struct nameidata nd;

- name = getname(pathname);
- if(IS_ERR(name))
- return PTR_ERR(name);
-
- if (path_init(name, LOOKUP_PARENT, &nd))
- error = path_walk(name, &nd);
+ error = user_path_walk_parent(pathname, &nd);
if (error)
goto exit;
error = -EISDIR;
if (nd.last_type != LAST_NORM)
- goto exit1;
+ goto exit_path_release;
down(&nd.dentry->d_inode->i_sem);
dentry = lookup_hash(&nd.last, nd.dentry);
error = PTR_ERR(dentry);
@@ -1474,21 +1446,20 @@
if (nd.last.name[nd.last.len])
goto slashes;
error = vfs_unlink(nd.dentry->d_inode, dentry);
- exit2:
+ exit_dput:
dput(dentry);
}
up(&nd.dentry->d_inode->i_sem);
-exit1:
+exit_path_release:
path_release(&nd);
exit:
- putname(name);

return error;

slashes:
error = !dentry->d_inode ? -ENOENT :
S_ISDIR(dentry->d_inode->i_mode) ? -EISDIR : -ENOTDIR;
- goto exit2;
+ goto exit_dput;
}

int vfs_symlink(struct inode *dir, struct dentry *dentry, const char *oldname)
@@ -1518,35 +1489,34 @@

asmlinkage long sys_symlink(const char * oldname, const char * newname)
{
- int error = 0;
+ int error;
char * from;
- char * to;
+ struct dentry *dentry;
+ struct nameidata nd;

from = getname(oldname);
- if(IS_ERR(from))
- return PTR_ERR(from);
- to = getname(newname);
- error = PTR_ERR(to);
- if (!IS_ERR(to)) {
- struct dentry *dentry;
- struct nameidata nd;
-
- if (path_init(to, LOOKUP_PARENT, &nd))
- error = path_walk(to, &nd);
- if (error)
- goto out;
- dentry = lookup_create(&nd, 0);
- error = PTR_ERR(dentry);
- if (!IS_ERR(dentry)) {
- error = vfs_symlink(nd.dentry->d_inode, dentry, from);
- dput(dentry);
- }
- up(&nd.dentry->d_inode->i_sem);
- path_release(&nd);
-out:
- putname(to);
+ if(IS_ERR(from)) {
+ error = PTR_ERR(from);
+ goto out;
}
+
+ error = user_path_walk_parent(newname, &nd);
+ if (error)
+ goto out_putname;
+
+ dentry = lookup_create(&nd, 0);
+ error = PTR_ERR(dentry);
+ if (!IS_ERR(dentry)) {
+ error = vfs_symlink(nd.dentry->d_inode, dentry, from);
+ dput(dentry);
+ }
+ up(&nd.dentry->d_inode->i_sem);
+ path_release(&nd);
+
+ out_putname:
putname(from);
+
+ out:
return error;
}

@@ -1602,46 +1572,34 @@
asmlinkage long sys_link(const char * oldname, const char * newname)
{
int error;
- char * from;
- char * to;
+ struct dentry *new_dentry;
+ struct nameidata nd, old_nd;

- 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);
- if (error)
- goto exit;
- if (path_init(to, LOOKUP_PARENT, &nd))
- error = path_walk(to, &nd);
- if (error)
- goto out;
- error = -EXDEV;
- if (old_nd.mnt != nd.mnt)
- goto out_release;
- new_dentry = lookup_create(&nd, 0);
- error = PTR_ERR(new_dentry);
- if (!IS_ERR(new_dentry)) {
- error = vfs_link(old_nd.dentry, nd.dentry->d_inode, new_dentry);
- dput(new_dentry);
- }
- up(&nd.dentry->d_inode->i_sem);
-out_release:
- path_release(&nd);
-out:
- path_release(&old_nd);
-exit:
- putname(to);
+ error = user_path_walk_link(oldname, &old_nd);
+ if (error)
+ goto out;
+ error = user_path_walk_parent(newname, &nd);
+ if (error)
+ goto out_release_old;
+ error = -EXDEV;
+ if (old_nd.mnt != nd.mnt)
+ goto out_release_both;
+
+ new_dentry = lookup_create(&nd, 0);
+ error = PTR_ERR(new_dentry);
+ if (!IS_ERR(new_dentry)) {
+ error = vfs_link(old_nd.dentry, nd.dentry->d_inode, new_dentry);
+ dput(new_dentry);
}
- putname(from);
+ up(&nd.dentry->d_inode->i_sem);
+
+out_release_both:
+ path_release(&nd);
+
+out_release_old:
+ path_release(&old_nd);

+out:
return error;
}
\
 
 \ /
  Last update: 2005-03-22 13:03    [W:0.052 / U:0.480 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site