fix(fuse): a new file closed empty reaches Drive at once (B192)

crates/pdfs-fuse/src/lib.rs

@@ -3334,6 +3334,12 @@ impl Core {
         if !h.dirty {
             self.cache.clear_scratch_durable(&h.path);
             let _ = std::fs::remove_file(&h.path);
+            // A new file's create waits for this release to wake the drain
+            // (`Core::queue_local_node`). Closed empty, it attached nothing
+            // that would, and sat until the idle poll (`docs/BUGS.md` B192).
+            if is_local_uid(&h.uid) {
+                self.wake_drain();
+            }
             return Ok(());
         }
         preserve_on_access_denied(self.require_uid_writable(&h.uid), h.dirty, || {
@@ -3828,7 +3834,7 @@ impl Core {
         debug!(%uid, %parent_uid, name, is_dir, "created node offline; queued");
         // A folder is due now; without this the workers slept through it to
         // the idle poll (B160). A file is not: its bytes ride on the create, and
-        // the release that attaches them wakes the drain.
+        // its release wakes the drain, with bytes or without (B192).
         if is_dir {
             self.wake_drain();
         }

crates/pdfs-fuse/src/sim/daemon.rs

@@ -383,6 +383,34 @@ mod tests {
         let _ = std::fs::remove_dir_all(&dir);
     }
 
+    #[test]
+    #[ignore = "mounts FUSE: run with `cargo test -p pdfs-fuse sim:: -- --ignored`"]
+    fn a_file_made_empty_while_the_drain_is_idle_reaches_drive_at_once() {
+        // A new file's create waits for the release that attaches its bytes
+        // to wake the drain. A file closed without any attached none, so it
+        // sat until the workers' 30 s idle poll (B192).
+        let drive = FakeDrive::new();
+        let dir = scratch("idle-empty-create");
+        let daemon = Daemon::start(&dir, drive.client(1, Faults::lan())).unwrap();
+        assert!(wait_until(Duration::from_secs(30), || {
+            daemon.pending().is_ok_and(|items| items.is_empty())
+        }));
+
+        std::fs::write(daemon.mountpoint.join("e.md"), b"").unwrap();
+        assert!(
+            wait_until(Duration::from_secs(10), || {
+                daemon.pending().is_ok_and(|items| items.is_empty())
+                    && drive.lookup("e.md").is_some()
+            }),
+            "{:?} {:?}",
+            daemon.pending(),
+            drive.tree()
+        );
+
+        assert!(matches!(daemon.stop(), Ok(MountOutcome::Shutdown)));
+        let _ = std::fs::remove_dir_all(&dir);
+    }
+
     #[test]
     #[ignore = "mounts FUSE: run with `cargo test -p pdfs-fuse sim:: -- --ignored`"]
     fn a_file_whose_upload_was_not_read_back_takes_two_writes_at_once() {

docs/BUGS.md

@@ -12,6 +12,23 @@ Conventions:
 
 ---
 
+## B192 — A new file closed empty reaches Drive only half a minute later
+
+**Status:** Fixed.
+**Found:** 2026-10-05, while writing the test for B193. An empty file made on an idle mount was
+still queued 30 s later.
+
+**Where:** `Core::queue_revision` in `crates/pdfs-fuse/src/lib.rs`.
+
+**Cause.** Queueing a file's create does not wake the drain: its bytes ride on the create, and
+the release that attaches them wakes it (B160). A file closed without a write (`touch`, `: > f`)
+attaches nothing, so its create waited for the workers' 30 s idle poll.
+
+**Fix.** Closing a clean handle of a file whose create is queued wakes the drain.
+
+**Test:** simulation test `a_file_made_empty_while_the_drain_is_idle_reaches_drive_at_once`
+(failed before the fix: the file was still queued after 10 s).
+
 ## B191 — A file deleted after its create failed and was written again can stay on Drive
 
 **Status:** Fixed (unverified).

docs/CHANGELOG.md

@@ -54,7 +54,8 @@ by its local id, in the queue, the stored tree and pins alike.
   (B158).
 - **Opening a file right after the daemon restarts no longer fails with "Resource temporarily
   unavailable"** (B159).
-- **A new folder reaches Drive at once**, not up to half a minute later (B160).
+- **A new folder, or a new empty file, reaches Drive at once**, not up to half a minute later
+  (B160, B192).
 - **A file moved while it was still being uploaded keeps its new name in the mount** on a slow
   link (B161).
 - **A folder removed and made again at once keeps what goes into it.** It used to be created

docs/MILESTONE-3.0.0-STATUS.md

@@ -9,7 +9,7 @@ Tracks `docs/MILESTONE-3.0.0.md`. Update it with every commit that moves a phase
 - **Phase 2**: local ids, inode = local id, one tree for every mount (2.10.0).
 - **Phase 3, first part**: mkdir, create, rename, unlink and rmdir on the mount are recorded
   locally and sent from the queue; `"local_first": false` brings back the old path (5e0f30c).
-- Fixes from the simulation and account runs since then: B125, B127, B130 and B141 to B191.
+- Fixes from the simulation and account runs since then: B125, B127, B130 and B141 to B192.
 - **Sync issues, first cut** (§6.2): refusals sorted into issues, shown at once in the app,
   tray and CLI; Export button and `pdfs sync export`; `pdfs sync issues`; Discard button and
   `pdfs sync discard`; a warning badge on the node in the file browser.
@@ -118,7 +118,8 @@ Tracks `docs/MILESTONE-3.0.0.md`. Update it with every commit that moves a phase
          after an outage only the drain had met (B189, fixed; older than 3.0.0), and a file
          saved just before a stop whose release the stop dropped (B190, fixed; older too). The run
          on 1436c5f found a file deleted after its failed create was written again left on Drive
-         (B191, fixed).
+         (B191, fixed). Its test for B193 found a new empty file waiting out the idle poll (B192,
+         fixed).
    - [ ] A clean account run. The one on a6f36d5 (2026-10-04, LAN: 427 passed, 12 failed)
          failed B113 and B121 on every on-demand mount, two mirror-to-mirror move cases, and
          the journal check. B121 was a bug (B149, fixed); B113's case still expected creates