o dev_write

lib/device/dev-io.c

@@ -38,6 +38,10 @@ int dev_get_size(struct device *dev, uint64_t *size)
 	return 1;
 }
 
+/*
+ *  FIXME: factor common code out.
+ */
+
 int _read(int fd, void *buf, size_t count)
 {
 	size_t n = 0;
@@ -77,9 +81,41 @@ int64_t dev_read(struct device *dev, uint64_t offset,
 	return r;
 }
 
+int _write(int fd, const void *buf, size_t count)
+{
+	size_t n = 0;
+	int tot = 0;
+
+	while (tot < count) {
+		n = write(fd, buf, count - tot);
+
+		if (n <= 0)
+			return tot ? tot : n;
+
+		tot += n;
+		buf += n;
+	}
+
+	return tot;
+}
+
 int64_t dev_write(struct device *dev, uint64_t offset,
 		  int64_t len, void *buffer)
 {
-	// FIXME: lazy programmer
+	int64_t r;
+	int fd = open(dev->name, O_WRONLY);
+
+	if (fd < 0) {
+		log_sys_err("open");
 		return 0;
+	}
+
+	if (lseek(fd, offset, SEEK_SET) < 0) {
+		log_sys_err("lseek");
+		return 0;
+	}
+
+	r = _write(fd, buffer, len);
+	close(fd);
+	return r;
 }

lib/format1/disk-rep.c

@@ -239,7 +239,7 @@ struct disk_list *read_pv(struct device *dev, struct pool *mem,
 		goto bad;
 	}
 
-	if (!(_munge_formats(&data->pv))) {
+	if (!_munge_formats(&data->pv)) {
 		log_verbose("Unknown metadata version %d found on %s", 
 			    data->pv.version, dev->name);
 		goto bad;