Revert "af_unix: Fix splice-bind deadlock"

[linux-2.6-block.git] / net / unix / af_unix.c

diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index f1dffe84f0d5e56b0c57271831a427ee137a37c4..433ae1bbef97fd4168fb872b56d0910f00c60cdd 100644 (file)
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -954,20 +954,32 @@ fail:
        return NULL;
 }
 
-static int unix_mknod(struct dentry *dentry, const struct path *path, umode_t mode,
-                     struct path *res)
+static int unix_mknod(const char *sun_path, umode_t mode, struct path *res)
 {
-       int err;
+       struct dentry *dentry;
+       struct path path;
+       int err = 0;
+       /*
+        * Get the parent directory, calculate the hash for last
+        * component.
+        */
+       dentry = kern_path_create(AT_FDCWD, sun_path, &path, 0);
+       err = PTR_ERR(dentry);
+       if (IS_ERR(dentry))
+               return err;
 
-       err = security_path_mknod(path, dentry, mode, 0);
+       /*
+        * All right, let's create it.
+        */
+       err = security_path_mknod(&path, dentry, mode, 0);
        if (!err) {
-               err = vfs_mknod(d_inode(path->dentry), dentry, mode, 0);
+               err = vfs_mknod(d_inode(path.dentry), dentry, mode, 0);
                if (!err) {
-                       res->mnt = mntget(path->mnt);
+                       res->mnt = mntget(path.mnt);
                        res->dentry = dget(dentry);
                }
        }
-
+       done_path_create(&path, dentry);
        return err;
 }
 
@@ -978,12 +990,10 @@ static int unix_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
        struct unix_sock *u = unix_sk(sk);
        struct sockaddr_un *sunaddr = (struct sockaddr_un *)uaddr;
        char *sun_path = sunaddr->sun_path;
-       int err, name_err;
+       int err;
        unsigned int hash;
        struct unix_address *addr;
        struct hlist_head *list;
-       struct path path;
-       struct dentry *dentry;
 
        err = -EINVAL;
        if (sunaddr->sun_family != AF_UNIX)
@@ -999,34 +1009,14 @@ static int unix_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
                goto out;
        addr_len = err;
 
-       name_err = 0;
-       dentry = NULL;
-       if (sun_path[0]) {
-               /* Get the parent directory, calculate the hash for last
-                * component.
-                */
-               dentry = kern_path_create(AT_FDCWD, sun_path, &path, 0);
-
-               if (IS_ERR(dentry)) {
-                       /* delay report until after 'already bound' check */
-                       name_err = PTR_ERR(dentry);
-                       dentry = NULL;
-               }
-       }
-
        err = mutex_lock_interruptible(&u->readlock);
        if (err)
-               goto out_path;
+               goto out;
 
        err = -EINVAL;
        if (u->addr)
                goto out_up;
 
-       if (name_err) {
-               err = name_err == -EEXIST ? -EADDRINUSE : name_err;
-               goto out_up;
-       }
-
        err = -ENOMEM;
        addr = kmalloc(sizeof(*addr)+addr_len, GFP_KERNEL);
        if (!addr)
@@ -1037,11 +1027,11 @@ 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 (dentry) {
-               struct path u_path;
+       if (sun_path[0]) {
+               struct path path;
                umode_t mode = S_IFSOCK |
                       (SOCK_INODE(sock)->i_mode & ~current_umask());
-               err = unix_mknod(dentry, &path, mode, &u_path);
+               err = unix_mknod(sun_path, mode, &path);
                if (err) {
                        if (err == -EEXIST)
                                err = -EADDRINUSE;
@@ -1049,9 +1039,9 @@ static int unix_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
                        goto out_up;
                }
                addr->hash = UNIX_HASH_SIZE;
-               hash = d_real_inode(dentry)->i_ino & (UNIX_HASH_SIZE - 1);
+               hash = d_real_inode(path.dentry)->i_ino & (UNIX_HASH_SIZE - 1);
                spin_lock(&unix_table_lock);
-               u->path = u_path;
+               u->path = path;
                list = &unix_socket_table[hash];
        } else {
                spin_lock(&unix_table_lock);
@@ -1074,10 +1064,6 @@ out_unlock:
        spin_unlock(&unix_table_lock);
 out_up:
        mutex_unlock(&u->readlock);
-out_path:
-       if (dentry)
-               done_path_create(&path, dentry);
-
 out:
        return err;
 }