Commit dae6ad8f authored by Al Viro's avatar Al Viro
Browse files

new helpers: kern_path_create/user_path_create 



combination of kern_path_parent() and lookup_create().  Does *not*
expose struct nameidata to caller.  Syscalls converted to that...

Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 49084c3b

fs/namei.c

+76 −78
Original line number Diff line number Diff line
@@ -2311,6 +2311,35 @@ fail: 
}

EXPORT_SYMBOL_GPL(lookup_create);



struct dentry *kern_path_create(int dfd, const char *pathname, struct path *path, int is_dir)

{

	struct nameidata nd;

	struct dentry *res;

	int error = do_path_lookup(dfd, pathname, LOOKUP_PARENT, &nd);

	if (error)

		return ERR_PTR(error);

	res = lookup_create(&nd, is_dir);

	if (IS_ERR(res)) {

		mutex_unlock(&nd.path.dentry->d_inode->i_mutex);

		path_put(&nd.path);

	}

	*path = nd.path;

	return res;

}

EXPORT_SYMBOL(kern_path_create);



struct dentry *user_path_create(int dfd, const char __user *pathname, struct path *path, int is_dir)

{

	char *tmp = getname(pathname);

	struct dentry *res;

	if (IS_ERR(tmp))

		return ERR_CAST(tmp);

	res = kern_path_create(dfd, tmp, path, is_dir);

	putname(tmp);

	return res;

}

EXPORT_SYMBOL(user_path_create);



int vfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev)

{

	int error = may_create(dir, dentry);
@@ -2359,54 +2388,46 @@ static int may_mknod(mode_t mode) 
SYSCALL_DEFINE4(mknodat, int, dfd, const char __user *, filename, int, mode,

		unsigned, dev)

{

	int error;

	char *tmp;

	struct dentry *dentry;

	struct nameidata nd;

	struct path path;

	int error;



	if (S_ISDIR(mode))

		return -EPERM;



	error = user_path_parent(dfd, filename, &nd, &tmp);

	if (error)

		return error;

	dentry = user_path_create(dfd, filename, &path, 0);

	if (IS_ERR(dentry))

		return PTR_ERR(dentry);



	dentry = lookup_create(&nd, 0);

	if (IS_ERR(dentry)) {

		error = PTR_ERR(dentry);

		goto out_unlock;

	}

	if (!IS_POSIXACL(nd.path.dentry->d_inode))

	if (!IS_POSIXACL(path.dentry->d_inode))

		mode &= ~current_umask();

	error = may_mknod(mode);

	if (error)

		goto out_dput;

	error = mnt_want_write(nd.path.mnt);

	error = mnt_want_write(path.mnt);

	if (error)

		goto out_dput;

	error = security_path_mknod(&nd.path, dentry, mode, dev);

	error = security_path_mknod(&path, dentry, mode, dev);

	if (error)

		goto out_drop_write;

	switch (mode & S_IFMT) {

		case 0: case S_IFREG:

			error = vfs_create(nd.path.dentry->d_inode,dentry,mode,NULL);

			error = vfs_create(path.dentry->d_inode,dentry,mode,NULL);

			break;

		case S_IFCHR: case S_IFBLK:

			error = vfs_mknod(nd.path.dentry->d_inode,dentry,mode,

			error = vfs_mknod(path.dentry->d_inode,dentry,mode,

					new_decode_dev(dev));

			break;

		case S_IFIFO: case S_IFSOCK:

			error = vfs_mknod(nd.path.dentry->d_inode,dentry,mode,0);

			error = vfs_mknod(path.dentry->d_inode,dentry,mode,0);

			break;

	}

out_drop_write:

	mnt_drop_write(nd.path.mnt);

	mnt_drop_write(path.mnt);

out_dput:

	dput(dentry);

out_unlock:

	mutex_unlock(&nd.path.dentry->d_inode->i_mutex);

	path_put(&nd.path);

	putname(tmp);

	mutex_unlock(&path.dentry->d_inode->i_mutex);

	path_put(&path);



	return error;

}
@@ -2439,38 +2460,29 @@ int vfs_mkdir(struct inode *dir, struct dentry *dentry, int mode) 


SYSCALL_DEFINE3(mkdirat, int, dfd, const char __user *, pathname, int, mode)

{

	int error = 0;

	char * tmp;

	struct dentry *dentry;

	struct nameidata nd;



	error = user_path_parent(dfd, pathname, &nd, &tmp);

	if (error)

		goto out_err;

	struct path path;

	int error;



	dentry = lookup_create(&nd, 1);

	error = PTR_ERR(dentry);

	dentry = user_path_create(dfd, pathname, &path, 1);

	if (IS_ERR(dentry))

		goto out_unlock;

		return PTR_ERR(dentry);



	if (!IS_POSIXACL(nd.path.dentry->d_inode))

	if (!IS_POSIXACL(path.dentry->d_inode))

		mode &= ~current_umask();

	error = mnt_want_write(nd.path.mnt);

	error = mnt_want_write(path.mnt);

	if (error)

		goto out_dput;

	error = security_path_mkdir(&nd.path, dentry, mode);

	error = security_path_mkdir(&path, dentry, mode);

	if (error)

		goto out_drop_write;

	error = vfs_mkdir(nd.path.dentry->d_inode, dentry, mode);

	error = vfs_mkdir(path.dentry->d_inode, dentry, mode);

out_drop_write:

	mnt_drop_write(nd.path.mnt);

	mnt_drop_write(path.mnt);

out_dput:

	dput(dentry);

out_unlock:

	mutex_unlock(&nd.path.dentry->d_inode->i_mutex);

	path_put(&nd.path);

	putname(tmp);

out_err:

	mutex_unlock(&path.dentry->d_inode->i_mutex);

	path_put(&path);

	return error;

}
@@ -2730,38 +2742,31 @@ SYSCALL_DEFINE3(symlinkat, const char __user *, oldname, 
{

	int error;

	char *from;

	char *to;

	struct dentry *dentry;

	struct nameidata nd;

	struct path path;



	from = getname(oldname);

	if (IS_ERR(from))

		return PTR_ERR(from);



	error = user_path_parent(newdfd, newname, &nd, &to);

	if (error)

		goto out_putname;



	dentry = lookup_create(&nd, 0);

	dentry = user_path_create(newdfd, newname, &path, 0);

	error = PTR_ERR(dentry);

	if (IS_ERR(dentry))

		goto out_unlock;

		goto out_putname;



	error = mnt_want_write(nd.path.mnt);

	error = mnt_want_write(path.mnt);

	if (error)

		goto out_dput;

	error = security_path_symlink(&nd.path, dentry, from);

	error = security_path_symlink(&path, dentry, from);

	if (error)

		goto out_drop_write;

	error = vfs_symlink(nd.path.dentry->d_inode, dentry, from);

	error = vfs_symlink(path.dentry->d_inode, dentry, from);

out_drop_write:

	mnt_drop_write(nd.path.mnt);

	mnt_drop_write(path.mnt);

out_dput:

	dput(dentry);

out_unlock:

	mutex_unlock(&nd.path.dentry->d_inode->i_mutex);

	path_put(&nd.path);

	putname(to);

	mutex_unlock(&path.dentry->d_inode->i_mutex);

	path_put(&path);

out_putname:

	putname(from);

	return error;
@@ -2826,11 +2831,9 @@ SYSCALL_DEFINE5(linkat, int, olddfd, const char __user *, oldname, 
		int, newdfd, const char __user *, newname, int, flags)

{

	struct dentry *new_dentry;

	struct nameidata nd;

	struct path old_path;

	struct path old_path, new_path;

	int how = 0;

	int error;

	char *to;



	if ((flags & ~(AT_SYMLINK_FOLLOW | AT_EMPTY_PATH)) != 0)

		return -EINVAL;
@@ -2852,32 +2855,27 @@ SYSCALL_DEFINE5(linkat, int, olddfd, const char __user *, oldname, 
	if (error)

		return error;



	error = user_path_parent(newdfd, newname, &nd, &to);

	if (error)

		goto out;

	error = -EXDEV;

	if (old_path.mnt != nd.path.mnt)

		goto out_release;

	new_dentry = lookup_create(&nd, 0);

	new_dentry = user_path_create(newdfd, newname, &new_path, 0);

	error = PTR_ERR(new_dentry);

	if (IS_ERR(new_dentry))

		goto out_unlock;

	error = mnt_want_write(nd.path.mnt);

		goto out;



	error = -EXDEV;

	if (old_path.mnt != new_path.mnt)

		goto out_dput;

	error = mnt_want_write(new_path.mnt);

	if (error)

		goto out_dput;

	error = security_path_link(old_path.dentry, &nd.path, new_dentry);

	error = security_path_link(old_path.dentry, &new_path, new_dentry);

	if (error)

		goto out_drop_write;

	error = vfs_link(old_path.dentry, nd.path.dentry->d_inode, new_dentry);

	error = vfs_link(old_path.dentry, new_path.dentry->d_inode, new_dentry);

out_drop_write:

	mnt_drop_write(nd.path.mnt);

	mnt_drop_write(new_path.mnt);

out_dput:

	dput(new_dentry);

out_unlock:

	mutex_unlock(&nd.path.dentry->d_inode->i_mutex);

out_release:

	path_put(&nd.path);

	putname(to);

	mutex_unlock(&new_path.dentry->d_inode->i_mutex);

	path_put(&new_path);

out:

	path_put(&old_path);

fs/ocfs2/refcounttree.c

+11 −38
Original line number Diff line number Diff line
@@ -4368,25 +4368,6 @@ static inline int ocfs2_may_create(struct inode *dir, struct dentry *child) 
	return inode_permission(dir, MAY_WRITE | MAY_EXEC);

}



/* copied from user_path_parent. */

static int ocfs2_user_path_parent(const char __user *path,

				  struct nameidata *nd, char **name)

{

	char *s = getname(path);

	int error;



	if (IS_ERR(s))

		return PTR_ERR(s);



	error = kern_path_parent(s, nd);

	if (error)

		putname(s);

	else

		*name = s;



	return error;

}



/**

 * ocfs2_vfs_reflink - Create a reference-counted link

 *
@@ -4460,10 +4441,8 @@ int ocfs2_reflink_ioctl(struct inode *inode, 
			bool preserve)

{

	struct dentry *new_dentry;

	struct nameidata nd;

	struct path old_path;

	struct path old_path, new_path;

	int error;

	char *to = NULL;



	if (!ocfs2_refcount_tree(OCFS2_SB(inode->i_sb)))

		return -EOPNOTSUPP;
@@ -4474,39 +4453,33 @@ int ocfs2_reflink_ioctl(struct inode *inode, 
		return error;

	}



	error = ocfs2_user_path_parent(newname, &nd, &to);

	if (error) {

	new_dentry = user_path_create(AT_FDCWD, newname, &new_path, 0);

	error = PTR_ERR(new_dentry);

	if (IS_ERR(new_dentry)) {

		mlog_errno(error);

		goto out;

	}



	error = -EXDEV;

	if (old_path.mnt != nd.path.mnt)

		goto out_release;

	new_dentry = lookup_create(&nd, 0);

	error = PTR_ERR(new_dentry);

	if (IS_ERR(new_dentry)) {

	if (old_path.mnt != new_path.mnt) {

		mlog_errno(error);

		goto out_unlock;

		goto out_dput;

	}



	error = mnt_want_write(nd.path.mnt);

	error = mnt_want_write(new_path.mnt);

	if (error) {

		mlog_errno(error);

		goto out_dput;

	}



	error = ocfs2_vfs_reflink(old_path.dentry,

				  nd.path.dentry->d_inode,

				  new_path.dentry->d_inode,

				  new_dentry, preserve);

	mnt_drop_write(nd.path.mnt);

	mnt_drop_write(new_path.mnt);

out_dput:

	dput(new_dentry);

out_unlock:

	mutex_unlock(&nd.path.dentry->d_inode->i_mutex);

out_release:

	path_put(&nd.path);

	putname(to);

	mutex_unlock(&new_path.dentry->d_inode->i_mutex);

	path_put(&new_path);

out:

	path_put(&old_path);

include/linux/namei.h

+2 −0
Original line number Diff line number Diff line
@@ -74,6 +74,8 @@ extern int user_path_at(int, const char __user *, unsigned, struct path *); 


extern int kern_path(const char *, unsigned, struct path *);



extern struct dentry *kern_path_create(int, const char *, struct path *, int);

extern struct dentry *user_path_create(int, const char __user *, struct path *, int);

extern int kern_path_parent(const char *, struct nameidata *);

extern int vfs_path_lookup(struct dentry *, struct vfsmount *,

			   const char *, unsigned int, struct nameidata *);

net/unix/af_unix.c

+17 −21
Original line number Diff line number Diff line
@@ -808,8 +808,9 @@ static int unix_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len) 
	struct net *net = sock_net(sk);

	struct unix_sock *u = unix_sk(sk);

	struct sockaddr_un *sunaddr = (struct sockaddr_un *)uaddr;

	char *sun_path = sunaddr->sun_path;

	struct dentry *dentry = NULL;

	struct nameidata nd;

	struct path path;

	int err;

	unsigned hash;

	struct unix_address *addr;
@@ -845,48 +846,44 @@ static int unix_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len) 
	addr->hash = hash ^ sk->sk_type;

	atomic_set(&addr->refcnt, 1);



	if (sunaddr->sun_path[0]) {

	if (sun_path[0]) {

		unsigned int mode;

		err = 0;

		/*

		 * Get the parent directory, calculate the hash for last

		 * component.

		 */

		err = kern_path_parent(sunaddr->sun_path, &nd);

		if (err)

			goto out_mknod_parent;



		dentry = lookup_create(&nd, 0);

		dentry = kern_path_create(AT_FDCWD, sun_path, &path, 0);

		err = PTR_ERR(dentry);

		if (IS_ERR(dentry))

			goto out_mknod_unlock;

			goto out_mknod_parent;



		/*

		 * All right, let's create it.

		 */

		mode = S_IFSOCK |

		       (SOCK_INODE(sock)->i_mode & ~current_umask());

		err = mnt_want_write(nd.path.mnt);

		err = mnt_want_write(path.mnt);

		if (err)

			goto out_mknod_dput;

		err = security_path_mknod(&nd.path, dentry, mode, 0);

		err = security_path_mknod(&path, dentry, mode, 0);

		if (err)

			goto out_mknod_drop_write;

		err = vfs_mknod(nd.path.dentry->d_inode, dentry, mode, 0);

		err = vfs_mknod(path.dentry->d_inode, dentry, mode, 0);

out_mknod_drop_write:

		mnt_drop_write(nd.path.mnt);

		mnt_drop_write(path.mnt);

		if (err)

			goto out_mknod_dput;

		mutex_unlock(&nd.path.dentry->d_inode->i_mutex);

		dput(nd.path.dentry);

		nd.path.dentry = dentry;

		mutex_unlock(&path.dentry->d_inode->i_mutex);

		dput(path.dentry);

		path.dentry = dentry;



		addr->hash = UNIX_HASH_SIZE;

	}



	spin_lock(&unix_table_lock);



	if (!sunaddr->sun_path[0]) {

	if (!sun_path[0]) {

		err = -EADDRINUSE;

		if (__unix_find_socket_byname(net, sunaddr, addr_len,

					      sk->sk_type, hash)) {
@@ -897,8 +894,8 @@ out_mknod_drop_write: 
		list = &unix_socket_table[addr->hash];

	} else {

		list = &unix_socket_table[dentry->d_inode->i_ino & (UNIX_HASH_SIZE-1)];

		u->dentry = nd.path.dentry;

		u->mnt    = nd.path.mnt;

		u->dentry = path.dentry;

		u->mnt    = path.mnt;

	}



	err = 0;
@@ -915,9 +912,8 @@ out: 


out_mknod_dput:

	dput(dentry);

out_mknod_unlock:

	mutex_unlock(&nd.path.dentry->d_inode->i_mutex);

	path_put(&nd.path);

	mutex_unlock(&path.dentry->d_inode->i_mutex);

	path_put(&path);

out_mknod_parent:

	if (err == -EEXIST)

		err = -EADDRINUSE;