dofs, wsd, script: unlink symlinks without following targets

Resolve paths for rm with the final symlink preserved so unlink removes the link entry rather than the target it points at. Treat symlinks as leaves during recursive removal and cover the FUSE unlink path plus the fs-tests rm -rf scenario.

Author: aron-cf

packages/dofs/src/fs/rm.test.ts

@@ -5,6 +5,7 @@ import { mkdir } from "./mkdir.js";
 import { readdir } from "./readdir.js";
 import { resolveInode } from "./resolve.js";
 import { rm } from "./rm.js";
+import { symlink } from "./symlink.js";
 import { withDB } from "./with-db.js";
 import { writeFile } from "./writeFile.js";
 
@@ -60,6 +61,31 @@ describe("rm", () => {
     });
   });
 
+  it("removes a symlink itself rather than its target", async () => {
+    await withDB(async (db) => {
+      await writeFile(db, "/target.txt", "still here", {}, () => 0);
+      symlink(db, "/target.txt", "/link.txt", () => 0);
+
+      rm(db, "/link.txt", {});
+
+      expect(resolveInode(db, "/link.txt", { followSymlinks: false })).toBeNull();
+      expect(resolveInode(db, "/target.txt")).not.toBeNull();
+    });
+  });
+
+  it("recursive rm does not follow symlinks out of the removed tree", async () => {
+    await withDB(async (db) => {
+      await writeFile(db, "/outside.txt", "still here", {}, () => 0);
+      mkdir(db, "/d", {}, () => 0);
+      symlink(db, "/outside.txt", "/d/link.txt", () => 0);
+
+      rm(db, "/d", { recursive: true });
+
+      expect(resolveInode(db, "/d", { followSymlinks: false })).toBeNull();
+      expect(resolveInode(db, "/outside.txt")).not.toBeNull();
+    });
+  });
+
   it("rejects ENOENT for a missing path", async () => {
     await withDB((db) => {
       expect(() => rm(db, "/missing", {})).toThrowError(

packages/dofs/src/fs/rm.ts

@@ -32,7 +32,7 @@ function* walkPostOrder(
 
   while (stack.length > 0) {
     const top = stack[stack.length - 1];
-    if (top.type === "file" || top.expanded) {
+    if (top.type !== "dir" || top.expanded) {
       stack.pop();
       yield { path: top.path, inode: top.inode, type: top.type };
       continue;
@@ -76,7 +76,7 @@ export function rm(db: Database, path: string, options: RmOptions): void {
   const recursive = options.recursive === true;
 
   db.transactionSync(() => {
-    const node = resolveInode(db, canonical);
+    const node = resolveInode(db, canonical, { followSymlinks: false });
     if (node === null) {
       if (force) return;
       throw createWorkspaceError("ENOENT", `no such path: ${canonical}`, canonical);

packages/wsd/src/fuse/driver.test.ts

@@ -199,6 +199,19 @@ test("FUSE ops return errno values instead of throwing for expected filesystem e
   expect(await status((cb) => ops.unlink("/missing", cb))).toBe(-2);
 });
 
+test("FUSE unlink removes a symlink itself rather than its target", async () => {
+  const { vfs } = await createNodeVirtualFileSystem();
+  const ops = makeFUSEOps(vfs);
+
+  vfs.writeFileSync("/target.txt", Buffer.from("still here"));
+  expect(await status((cb) => ops.symlink("/target.txt", "/link.txt", cb))).toBe(0);
+
+  expect(await status((cb) => ops.unlink("/link.txt", cb))).toBe(0);
+
+  expect(() => vfs.lstatSync("/link.txt")).toThrow();
+  expect(Buffer.from(vfs.readFileSync("/target.txt")).toString("utf8")).toBe("still here");
+});
+
 test("write past the per-file cap returns EFBIG instead of growing unbounded", async () => {
   // The driver keeps an in-memory buffer per file and doubles its
   // capacity on demand. Without a ceiling, a runaway client can OOM

script/fs-tests.sh

@@ -141,6 +141,15 @@ run "follow symlink"              -- 'echo content > target && ln -s target link
 run "stat -L follows"             -- 'echo x > target && ln -s target link && [ -f link ]'
 run "lstat shows symlink"         -- 'echo x > target && ln -s target link && [ -L link ]'
 run "dangling symlink"            -- 'ln -s nowhere d && [ -L d ] && [ ! -e d ]'
+run "rm -rf removes symlink entry" -- '
+  echo content > target
+  mkdir d
+  ln -s ../target d/link
+  rm -rf d
+  [ ! -e d ]
+  [ -f target ]
+  [ "$(cat target)" = "content" ]
+'
 
 section "hard links"
 run "create hard link"            -- 'echo content > a && ln a b && [ "$(cat b)" = "content" ]'