diff --git a/source3/modules/vfs_virusfilter_utils.c b/source3/modules/vfs_virusfilter_utils.c
index c7f8089ffc7..a76017abf73 100644
--- a/source3/modules/vfs_virusfilter_utils.c
+++ b/source3/modules/vfs_virusfilter_utils.c
@@ -553,6 +553,7 @@ bool virusfilter_io_readl(TALLOC_CTX *ctx,
 	/* Search for an existing complete line. */
 	ok = return_existing_line(ctx, io_h, read_line);
 	if (ok) {
+		DBG_ERR("return_existing_line success with readline=\"%s\"\n");
 		goto finish;
 	}
 
@@ -569,20 +570,28 @@ bool virusfilter_io_readl(TALLOC_CTX *ctx,
 	/* Error return - must be talloc'ed. */
 	perror = talloc_zero(frame, uint64_t);
 	if (perror == NULL) {
+		ok = false;
+		DBG_ERR("talloc_zero failed\n");
 		goto finish;
 	}
 
-	for (;;) {
+	for (int i=0;;i++) {
 		ssize_t pending = 0;
 		size_t read_size = 0;
 		struct iovec iov;
 		struct tevent_req *req = NULL;
 
+		DBG_ERR("virusfilter_io_readl loop with index i=%d.\n",
+			i);
+
 		/*
 		 * How much can we read ?
 		 */
 		pending = tstream_pending_bytes(io_h->stream);
+		DBG_ERR("tstream_pending_bytes pending=%zu.\n",
+			pending);
 		if (pending < 0) {
+			ok = false;
 			DBG_ERR("tstream_pending_bytes failed (%s).\n",
 				strerror(errno));
 			goto finish;
@@ -596,7 +605,11 @@ bool virusfilter_io_readl(TALLOC_CTX *ctx,
 		read_size = MAX(read_size,
 				(sizeof(io_h->r_buffer) - io_h->r_len));
 
+		DBG_ERR("virusfilter_io_readl read_size=%zu.\n",
+			read_size);
+
 		if (read_size == 0) {
+			ok = false;
 			/* Buffer is full with no EOL. Error out. */
 			DBG_ERR("Line buffer full.\n");
 			goto finish;
@@ -612,6 +625,7 @@ bool virusfilter_io_readl(TALLOC_CTX *ctx,
 					&iov,
 					1);
 		if (req == NULL) {
+			ok = false;
 			DBG_ERR("out of memory.\n");
 			goto finish;
 		}
@@ -628,7 +642,9 @@ bool virusfilter_io_readl(TALLOC_CTX *ctx,
 		}
 
 		/* Loop waiting for req to finish. */
+		DBG_DEBUG("Enter tevent_req_poll\n");
 		ok = tevent_req_poll(req, ev);
+		DBG_DEBUG("Leave tevent_req_poll ok=%d\n", ok);
 		if (!ok) {
 			DBG_ERR("tevent_req_poll failed\n");
 			goto finish;
@@ -642,6 +658,7 @@ bool virusfilter_io_readl(TALLOC_CTX *ctx,
 		 * EPIPE may be success so, don't exit.
 		 */
 		if (*perror != 0 && *perror != EPIPE) {
+			ok = false;
 			DBG_DEBUG("Error %s\n", strerror((int)*perror));
 			errno = (int)*perror;
 			goto finish;
@@ -661,11 +678,13 @@ bool virusfilter_io_readl(TALLOC_CTX *ctx,
 		if (ok) {
 			goto finish;
 		}
+		DBG_DEBUG("return_existing_line %s\n", read_line);
 		/* No eol - keep reading. */
 	}
 
   finish:
 
+	DBG_DEBUG("virusfilter_io_readl ok=%d\n", ok);
 	TALLOC_FREE(frame);
 	return ok;
 }