Commit 2ad94ae6 authored by Al Viro's avatar Al Viro

[PATCH] new (local) helper: user_path_parent()

Preparation to untangling intents mess: reduce the number of do_path_lookup()
callers.
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 2d8f3038
......@@ -1352,6 +1352,24 @@ int user_path_at(int dfd, const char __user *name, unsigned flags,
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 @@ static int may_mknod(mode_t mode)
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 @@ asmlinkage long sys_mknodat(int dfd, const char __user *filename, int mode,
out_unlock:
mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
path_put(&nd.path);
out:
putname(tmp);
return error;
......@@ -2074,14 +2089,10 @@ asmlinkage long sys_mkdirat(int dfd, const char __user *pathname, int mode)
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 @@ asmlinkage long sys_mkdirat(int dfd, const char __user *pathname, int mode)
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 @@ static long do_rmdir(int dfd, const char __user *pathname)
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 @@ static long do_rmdir(int dfd, const char __user *pathname)
mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
exit1:
path_put(&nd.path);
exit:
putname(name);
return error;
}
......@@ -2261,19 +2266,16 @@ int vfs_unlink(struct inode *dir, struct dentry *dentry)
*/
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 @@ static long do_unlinkat(int dfd, const char __user *pathname)
iput(inode); /* truncate the inode here */
exit1:
path_put(&nd.path);
exit:
putname(name);
return error;
......@@ -2350,23 +2351,20 @@ int vfs_symlink(struct inode *dir, struct dentry *dentry, const char *oldname)
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))
goto out_putname;
error = do_path_lookup(newdfd, to, LOOKUP_PARENT, &nd);
error = user_path_parent(newdfd, newname, &nd, &to);
if (error)
goto out;
goto out_putname;
dentry = lookup_create(&nd, 0);
error = PTR_ERR(dentry);
if (IS_ERR(dentry))
......@@ -2382,7 +2380,6 @@ asmlinkage long sys_symlinkat(const char __user *oldname,
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 @@ asmlinkage long sys_linkat(int olddfd, const char __user *oldname,
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 @@ asmlinkage long sys_linkat(int olddfd, const char __user *oldname,
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 @@ int vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
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 @@ static int do_rename(int olddfd, const char *oldname,
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;
}
......
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