btrfs tests: create more loopback devices automatically so we can run btrfs unit tests in parallel

Author: williamstein

src/packages/file-server/btrfs/test/setup.ts

@@ -3,7 +3,7 @@ import {
   type Filesystem,
 } from "@cocalc/file-server/btrfs/filesystem";
 import process from "node:process";
-import { chmod, mkdtemp, mkdir, rm } from "node:fs/promises";
+import { chmod, mkdtemp, mkdir, rm, stat } from "node:fs/promises";
 import { tmpdir } from "node:os";
 import { join } from "path";
 import { until } from "@cocalc/util/async-utils";
@@ -16,12 +16,29 @@ let tempDir;
 
 const TEMP_PREFIX = "cocalc-test-btrfs-";
 
+async function ensureMoreLoops() {
+  // to run tests, this is helpful
+  //for i in $(seq 8 63); do sudo mknod -m660 /dev/loop$i b 7 $i; sudo chown root:disk /dev/loop$i; done
+  for (let i = 0; i < 64; i++) {
+    try {
+      await stat(`/dev/loop${i}`);
+      continue;
+    } catch {}
+    await sudo({
+      command: "mknod",
+      args: ["-m660", `/dev/loop${i}`, "b", "7", `${i}`],
+    });
+    await sudo({ command: "chown", args: ["root:disk", `/dev/loop${i}`] });
+  }
+}
+
 export async function before() {
   try {
     const command = `umount ${join(tmpdir(), TEMP_PREFIX)}*/mnt`;
     // attempt to unmount any mounts left from previous runs
     await sudo({ command, bash: true });
   } catch {}
+  await ensureMoreLoops();
   tempDir = await mkdtemp(join(tmpdir(), TEMP_PREFIX));
   // Set world read/write/execute
   await chmod(tempDir, 0o777);

src/packages/file-server/btrfs/test/subvolume.test.ts

@@ -152,4 +152,4 @@ describe("test bup backups", () => {
   });
 });
 
-//afterAll(after);
+afterAll(after);

src/packages/file-server/package.json

@@ -10,7 +10,7 @@
     "preinstall": "npx only-allow pnpm",
     "build": "pnpm exec tsc --build",
     "tsc": "pnpm exec tsc  --watch  --pretty --preserveWatchOutput",
-    "test": "pnpm exec jest  --runInBand",
+    "test": "pnpm exec jest",
     "depcheck": "pnpx depcheck",
     "clean": "rm -rf node_modules dist"
   },