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: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 17 insertions, 21 deletions

diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index 0722a25a3a33..ec68e1c05b85 100644
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -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;