file_write: Fix NULL pointer dereference.

[paraslash.git] / file_write.c

diff --git a/file_write.c b/file_write.c
index 4a4dc66e52d61b2a5e632bbadd67f26a5f42ed27..7497dfaa0f00e6be8c8856a2659bcaaa65938100 100644 (file)
--- a/file_write.c
+++ b/file_write.c
@@ -52,9 +52,17 @@ __must_check __malloc static char *random_filename(void)
 
 static int file_write_open(struct writer_node *wn)
 {
-       struct private_file_write_data *pfwd = para_calloc(
-               sizeof(struct private_file_write_data));
+       struct private_file_write_data *pfwd = para_calloc(sizeof(*pfwd));
+
+       wn->private_data = pfwd;
+       pfwd->fd = -1;
+       return 0;
+}
+
+static int prepare_output_file(struct writer_node *wn)
+{
        struct file_write_args_info *conf = wn->conf;
+       struct private_file_write_data *pfwd = wn->private_data;
        char *filename;
        int ret;
 
@@ -62,7 +70,6 @@ static int file_write_open(struct writer_node *wn)
                filename = conf->filename_arg;
        else
                filename = random_filename();
-       wn->private_data = pfwd;
        ret = para_open(filename, O_WRONLY | O_CREAT, S_IRUSR | S_IWUSR);
        if (!conf->filename_given)
                free(filename);
@@ -86,9 +93,9 @@ static void file_write_pre_select(struct sched *s, struct task *t)
 
        t->error = 0;
        ret = btr_node_status(wn->btrn, wn->min_iqs, BTR_NT_LEAF);
-       if (ret > 0)
+       if (ret > 0 && pfwd->fd >= 0)
                para_fd_set(pfwd->fd, &s->wfds, &s->max_fileno);
-       else if (ret < 0)
+       else if (ret != 0) /* error or bos and fd not yet open */
                sched_min_delay(s);
 }
 
@@ -96,7 +103,8 @@ static void file_write_close(struct writer_node *wn)
 {
        struct private_file_write_data *pfwd = wn->private_data;
 
-       close(pfwd->fd);
+       if (pfwd->fd >= 0)
+               close(pfwd->fd);
        free(pfwd);
 }
 
@@ -114,6 +122,11 @@ static void file_write_post_select(__a_unused struct sched *s,
        ret = btr_node_status(btrn, wn->min_iqs, BTR_NT_LEAF);
        if (ret <= 0)
                goto out;
+       if (pfwd->fd < 0) {
+               ret = prepare_output_file(wn);
+               if (ret < 0)
+                       goto out;
+       }
        if (!FD_ISSET(pfwd->fd, &s->wfds))
                return;
        bytes = btr_next_buffer(btrn, &buf);