[PATCH] new (local) helper: user_path_parent()
Preparation to untangling intents mess: reduce the number of do_path_lookup()
callers.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/namei.c b/fs/namei.c
index edb5e97..38ceb6e 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -1352,6 +1352,24 @@
return err;
}
+static int user_path_parent(int dfd, const char __user *path,
+ struct nameidata *nd, char **name)
+{
+ char *s = getname(path);
+ int error;
+
+ if (IS_ERR(s))
+ return PTR_ERR(s);
+
+ error = do_path_lookup(dfd, s, LOOKUP_PARENT, nd);
+ if (error)
+ putname(s);
+ else
+ *name = s;
+
+ return error;
+}
+
/*
* It's inline, so penalty for filesystems that don't use sticky bit is
* minimal.
@@ -1989,20 +2007,18 @@
asmlinkage long sys_mknodat(int dfd, const char __user *filename, int mode,
unsigned dev)
{
- int error = 0;
- char * tmp;
- struct dentry * dentry;
+ int error;
+ 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);
- error = do_path_lookup(dfd, tmp, LOOKUP_PARENT, &nd);
+ error = user_path_parent(dfd, filename, &nd, &tmp);
if (error)
- goto out;
+ return error;
+
dentry = lookup_create(&nd, 0);
if (IS_ERR(dentry)) {
error = PTR_ERR(dentry);
@@ -2034,7 +2050,6 @@
out_unlock:
mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
path_put(&nd.path);
-out:
putname(tmp);
return error;
@@ -2074,14 +2089,10 @@
struct dentry *dentry;
struct nameidata nd;
- tmp = getname(pathname);
- error = PTR_ERR(tmp);
- if (IS_ERR(tmp))
+ error = user_path_parent(dfd, pathname, &nd, &tmp);
+ if (error)
goto out_err;
- error = do_path_lookup(dfd, tmp, LOOKUP_PARENT, &nd);
- if (error)
- goto out;
dentry = lookup_create(&nd, 1);
error = PTR_ERR(dentry);
if (IS_ERR(dentry))
@@ -2099,7 +2110,6 @@
out_unlock:
mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
path_put(&nd.path);
-out:
putname(tmp);
out_err:
return error;
@@ -2177,13 +2187,9 @@
struct dentry *dentry;
struct nameidata nd;
- name = getname(pathname);
- if(IS_ERR(name))
- return PTR_ERR(name);
-
- error = do_path_lookup(dfd, name, LOOKUP_PARENT, &nd);
+ error = user_path_parent(dfd, pathname, &nd, &name);
if (error)
- goto exit;
+ return error;
switch(nd.last_type) {
case LAST_DOTDOT:
@@ -2212,7 +2218,6 @@
mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
exit1:
path_put(&nd.path);
-exit:
putname(name);
return error;
}
@@ -2261,19 +2266,16 @@
*/
static long do_unlinkat(int dfd, const char __user *pathname)
{
- int error = 0;
- char * name;
+ int error;
+ char *name;
struct dentry *dentry;
struct nameidata nd;
struct inode *inode = NULL;
- name = getname(pathname);
- if(IS_ERR(name))
- return PTR_ERR(name);
-
- error = do_path_lookup(dfd, name, LOOKUP_PARENT, &nd);
+ error = user_path_parent(dfd, pathname, &nd, &name);
if (error)
- goto exit;
+ return error;
+
error = -EISDIR;
if (nd.last_type != LAST_NORM)
goto exit1;
@@ -2300,7 +2302,6 @@
iput(inode); /* truncate the inode here */
exit1:
path_put(&nd.path);
-exit:
putname(name);
return error;
@@ -2350,23 +2351,20 @@
asmlinkage long sys_symlinkat(const char __user *oldname,
int newdfd, const char __user *newname)
{
- int error = 0;
- char * from;
- char * to;
+ int error;
+ char *from;
+ char *to;
struct dentry *dentry;
struct nameidata nd;
from = getname(oldname);
- if(IS_ERR(from))
+ if (IS_ERR(from))
return PTR_ERR(from);
- to = getname(newname);
- error = PTR_ERR(to);
- if (IS_ERR(to))
+
+ error = user_path_parent(newdfd, newname, &nd, &to);
+ if (error)
goto out_putname;
- error = do_path_lookup(newdfd, to, LOOKUP_PARENT, &nd);
- if (error)
- goto out;
dentry = lookup_create(&nd, 0);
error = PTR_ERR(dentry);
if (IS_ERR(dentry))
@@ -2382,7 +2380,6 @@
out_unlock:
mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
path_put(&nd.path);
-out:
putname(to);
out_putname:
putname(from);
@@ -2449,21 +2446,18 @@
struct nameidata nd;
struct path old_path;
int error;
- char * to;
+ char *to;
if ((flags & ~AT_SYMLINK_FOLLOW) != 0)
return -EINVAL;
- to = getname(newname);
- if (IS_ERR(to))
- return PTR_ERR(to);
-
error = user_path_at(olddfd, oldname,
flags & AT_SYMLINK_FOLLOW ? LOOKUP_FOLLOW : 0,
&old_path);
if (error)
- goto exit;
- error = do_path_lookup(newdfd, to, LOOKUP_PARENT, &nd);
+ return error;
+
+ error = user_path_parent(newdfd, newname, &nd, &to);
if (error)
goto out;
error = -EXDEV;
@@ -2484,10 +2478,9 @@
mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
out_release:
path_put(&nd.path);
+ putname(to);
out:
path_put(&old_path);
-exit:
- putname(to);
return error;
}
@@ -2643,20 +2636,22 @@
return error;
}
-static int do_rename(int olddfd, const char *oldname,
- int newdfd, const char *newname)
+asmlinkage long sys_renameat(int olddfd, const char __user *oldname,
+ int newdfd, const char __user *newname)
{
- int error = 0;
- struct dentry * old_dir, * new_dir;
- struct dentry * old_dentry, *new_dentry;
- struct dentry * trap;
+ struct dentry *old_dir, *new_dir;
+ struct dentry *old_dentry, *new_dentry;
+ struct dentry *trap;
struct nameidata oldnd, newnd;
+ char *from;
+ char *to;
+ int error;
- error = do_path_lookup(olddfd, oldname, LOOKUP_PARENT, &oldnd);
+ error = user_path_parent(olddfd, oldname, &oldnd, &from);
if (error)
goto exit;
- error = do_path_lookup(newdfd, newname, LOOKUP_PARENT, &newnd);
+ error = user_path_parent(newdfd, newname, &newnd, &to);
if (error)
goto exit1;
@@ -2718,29 +2713,11 @@
unlock_rename(new_dir, old_dir);
exit2:
path_put(&newnd.path);
+ putname(to);
exit1:
path_put(&oldnd.path);
-exit:
- return error;
-}
-
-asmlinkage long sys_renameat(int olddfd, const char __user *oldname,
- int newdfd, const char __user *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)) {
- error = do_rename(olddfd, from, newdfd, to);
- putname(to);
- }
putname(from);
+exit:
return error;
}