tests: Fix tools::is_hdd unit tests

Correct the unit tests for tools::is_hdd to avoid making assumptions
about the configuration of a particular device based solely on the
value of the __GLIBC__ preprocessor flag. Instead, rely on the
test invoker to provide paths for devices of specific types via
the process environment, thereby avoiding faulty assumptions and
improving the specificity of test assertions. To ensure appropriate
devices exist, add a script, tests/create_test_disks.sh, which
configures loopback devices mirroring relevant configurations.

.github/workflows/build.yml

@@ -213,6 +213,8 @@ jobs:
       run: sudo ${{env.APT_INSTALL_LINUX}}
     - name: install Python dependencies
       run: pip install requests psutil monotonic zmq deepdiff
+    - name: create dummy disk drives for testing
+      run: tests/create_test_disks.sh >> $GITHUB_ENV
     - name: tests
       env:
         CTEST_OUTPUT_ON_FAILURE: ON

tests/create_test_disks.sh

@@ -0,0 +1,98 @@
+#!/bin/bash
+
+set -e
+
+LOOP_DEVICE_MAJOR=7
+LOOP_DEVICE_MIN_ID=100
+
+echo_err() {
+    echo "$@" >&2
+}
+
+root_exec() {
+    if [[ $EUID -ne 0 ]]; then
+        ${ROOT_EXEC_CMD:-sudo} "$@"
+    else
+        "$@"
+    fi
+}
+
+create_device_node() {
+    local -r last_id=$(find /dev/ -name 'loop[0-9]*' -printf '%f\n' | sed 's/^loop//' | sort -r -n | head -1)
+    local id=$((last_id + 1))
+    if [[ "$id" -lt "$LOOP_DEVICE_MIN_ID" ]]; then
+        id="$LOOP_DEVICE_MIN_ID"
+    fi
+    local path
+    for (( i=0; i<10; i++ )); do
+        path="/dev/loop$id"
+        if [[ ! -e "$path" ]] && root_exec mknod "$path" b "$LOOP_DEVICE_MAJOR" "$id"; then
+            echo "$path"
+            return 0
+        fi
+        $((id++))
+    done
+    return 1
+}
+
+device_mountpoint() {
+    local -r datadir="$1"
+    local -r dev="$2"
+    if [[ -z "$datadir" || -z "$dev" ]]; then
+        echo_err "Usage: device_mountpoint <data dir> <device>"
+        return 1
+    fi
+    echo "$datadir/mnt-$(basename "$dev")"
+}
+
+create_device() {
+    local -r datadir="$1"
+    if [[ -z "$datadir" ]]; then
+        echo_err "Usage: create_device <data dir>"
+        return 1
+    fi
+    local -r dev=$(create_device_node)
+    local -r fs="$datadir/$(basename "$dev").vhd"
+    local -r mountpoint=$(device_mountpoint "$datadir" "$dev")
+    echo_err
+    echo_err "# Device $dev"
+    dd if=/dev/zero of="$fs" bs=64K count=128 >/dev/null 2>&1
+    root_exec losetup "$dev" "$fs"
+    root_exec mkfs.ext4 "$dev" >/dev/null 2>&1
+    mkdir "$mountpoint"
+    root_exec mount "$dev" "$mountpoint"
+    echo "$dev"
+}
+
+# Unused by default, but helpful for local development
+destroy_device() {
+    local -r datadir="$1"
+    local -r dev="$2"
+    if [[ -z "$datadir" || -z "$dev" ]]; then
+        echo_err "Usage: destroy_device <data dir> <device>"
+        return 1
+    fi
+    echo_err "Destroying device $dev"
+    root_exec umount $(device_mountpoint "$datadir" "$dev")
+    root_exec losetup -d "$dev"
+    root_exec rm "$dev"
+}
+
+block_device_path() {
+    device_name=$(basename "$1")
+    device_minor=${device_name/#loop}
+    echo "/sys/dev/block/$LOOP_DEVICE_MAJOR:$device_minor"
+}
+
+tmpdir=$(mktemp --tmpdir -d monerotest.XXXXXXXX)
+echo_err "Creating devices using temporary directory: $tmpdir"
+
+dev_rot=$(create_device "$tmpdir")
+bdev_rot=$(block_device_path "$dev_rot")
+echo 1 | root_exec tee "$bdev_rot/queue/rotational" >/dev/null
+echo MONERO_TEST_DEVICE_HDD=$(device_mountpoint "$tmpdir" "$dev_rot")
+
+dev_ssd=$(create_device "$tmpdir")
+bdev_ssd=$(block_device_path "$dev_ssd")
+echo 0 | root_exec tee "$bdev_ssd/queue/rotational" >/dev/null
+echo MONERO_TEST_DEVICE_SSD=$(device_mountpoint "$tmpdir" "$dev_ssd")

tests/unit_tests/is_hdd.cpp

@@ -1,17 +1,29 @@
 #include "common/util.h"
+#include <cstdlib>
 #include <string>
 #include <gtest/gtest.h>
+#include <boost/optional/optional_io.hpp> /* required to output boost::optional in assertions */
 
 #if defined(__GLIBC__)
-TEST(is_hdd, linux_os_root)
-{
-  std::string path = "/";
-  EXPECT_TRUE(tools::is_hdd(path.c_str()) != boost::none);
+TEST(is_hdd, rotational_drive) {
+  const char *hdd = std::getenv("MONERO_TEST_DEVICE_HDD");
+  if (hdd == nullptr)
+    GTEST_SKIP() << "No rotational disk device configured";
+  EXPECT_EQ(tools::is_hdd(hdd), boost::optional<bool>(true));
 }
-#else
-TEST(is_hdd, unknown_os)
-{
-  std::string path = "";
-  EXPECT_FALSE(tools::is_hdd(path.c_str()) != boost::none);
+
+TEST(is_hdd, ssd) {
+  const char *ssd = std::getenv("MONERO_TEST_DEVICE_SSD");
+  if (ssd == nullptr)
+    GTEST_SKIP() << "No SSD device configured";
+  EXPECT_EQ(tools::is_hdd(ssd), boost::optional<bool>(false));
+}
+
+TEST(is_hdd, unknown_attrs) {
+  EXPECT_EQ(tools::is_hdd("/dev/null"), boost::none);
 }
 #endif
+TEST(is_hdd, stability)
+{
+  EXPECT_NO_THROW(tools::is_hdd(""));
+}