+ goto err_file;
+
+ this.len = sprintf(name, "[%lu]", inode->i_ino);
+ this.name = name;
+ this.hash = 0;
+ err = -ENOMEM;
+ dentry = d_alloc(pipe_mnt->mnt_sb->s_root, &this);
+ if (!dentry)
+ goto err_inode;
+
+ dentry->d_op = &pipefs_dentry_operations;
+ /*
+ * We dont want to publish this dentry into global dentry hash table.
+ * We pretend dentry is already hashed, by unsetting DCACHE_UNHASHED
+ * This permits a working /proc/$pid/fd/XXX on pipes
+ */
+ dentry->d_flags &= ~DCACHE_UNHASHED;
+ d_instantiate(dentry, inode);
+ f->f_path.mnt = mntget(pipe_mnt);
+ f->f_path.dentry = dentry;
+ f->f_mapping = inode->i_mapping;
+
+ f->f_flags = O_WRONLY;
+ f->f_op = &write_pipe_fops;
+ f->f_mode = FMODE_WRITE;
+ f->f_version = 0;
+
+ return f;
+
+ err_inode:
+ free_pipe_info(inode);
+ iput(inode);
+ err_file:
+ put_filp(f);
+ return ERR_PTR(err);
+}
+
+void free_write_pipe(struct file *f)
+{
+ free_pipe_info(f->f_dentry->d_inode);
+ dput(f->f_path.dentry);
+ mntput(f->f_path.mnt);
+ put_filp(f);
+}
+
+struct file *create_read_pipe(struct file *wrf)
+{
+ struct file *f = get_empty_filp();
+ if (!f)
+ return ERR_PTR(-ENFILE);
+
+ /* Grab pipe from the writer */
+ f->f_path.mnt = mntget(wrf->f_path.mnt);
+ f->f_path.dentry = dget(wrf->f_path.dentry);
+ f->f_mapping = wrf->f_path.dentry->d_inode->i_mapping;
+
+ f->f_pos = 0;
+ f->f_flags = O_RDONLY;
+ f->f_op = &read_pipe_fops;
+ f->f_mode = FMODE_READ;
+ f->f_version = 0;
+
+ return f;
+}
+
+int do_pipe(int *fd)
+{
+ struct file *fw, *fr;
+ int error;
+ int fdw, fdr;
+
+ fw = create_write_pipe();
+ if (IS_ERR(fw))
+ return PTR_ERR(fw);
+ fr = create_read_pipe(fw);
+ error = PTR_ERR(fr);
+ if (IS_ERR(fr))
+ goto err_write_pipe;