dm vdo: add basic logging and support utilities

Add various support utilities for the vdo target and deduplication index,
including logging utilities, string and time management, and index-specific
error codes.

Co-developed-by: J. corwin Coburn <[email protected]>
Signed-off-by: J. corwin Coburn <[email protected]>
Co-developed-by: Michael Sclafani <[email protected]>
Signed-off-by: Michael Sclafani <[email protected]>
Co-developed-by: Thomas Jaskiewicz <[email protected]>
Signed-off-by: Thomas Jaskiewicz <[email protected]>
Co-developed-by: Ken Raeburn <[email protected]>
Signed-off-by: Ken Raeburn <[email protected]>
Signed-off-by: Matthew Sakai <[email protected]>
Signed-off-by: Mike Snitzer <[email protected]>

1 files changed, 28 insertions, 0 deletions

diff --git a/drivers/md/dm-vdo/string-utils.c b/drivers/md/dm-vdo/string-utils.c
new file mode 100644
index 000000000000..a584b37bb70c
--- /dev/null
+++ b/drivers/md/dm-vdo/string-utils.c
@@ -0,0 +1,28 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright 2023 Red Hat
+ */
+
+#include "string-utils.h"
+
+#include "errors.h"
+#include "logger.h"
+#include "memory-alloc.h"
+#include "permassert.h"
+#include "uds.h"
+
+char *uds_append_to_buffer(char *buffer, char *buf_end, const char *fmt, ...)
+{
+	va_list args;
+	size_t n;
+
+	va_start(args, fmt);
+	n = vsnprintf(buffer, buf_end - buffer, fmt, args);
+	if (n >= (size_t) (buf_end - buffer))
+		buffer = buf_end;
+	else
+		buffer += n;
+	va_end(args);
+
+	return buffer;
+}