From a4962e21d10a2da40118f8a68d4c08032e3fded8 Mon Sep 17 00:00:00 2001
From: dougal <dougal.craigwood@gmail.com>
Date: Mon, 1 Sep 2025 12:14:57 +0100
Subject: [PATCH] vfs: fix SIGHUP killing serve instead of flushing directory
 caches

Before, rclone serve would crash when sent a SIGHUP which contradicts
the documentation - saying it should flush the directory caches.

Moved signal handling from the mount into the vfs layer, which now
handles SIGHUP on all uses of the VFS including mount and serve.

Fixes #8607
---
 cmd/mountlib/mount.go                       | 22 +-------------
 cmd/serve/docker/driver.go                  |  1 -
 {cmd/mountlib => vfs}/sighup.go             |  2 +-
 {cmd/mountlib => vfs}/sighup_unsupported.go |  2 +-
 vfs/vfs.go                                  | 32 ++++++++++++++++++++-
 5 files changed, 34 insertions(+), 25 deletions(-)
 rename {cmd/mountlib => vfs}/sighup.go (93%)
 rename {cmd/mountlib => vfs}/sighup_unsupported.go (90%)

diff --git a/cmd/mountlib/mount.go b/cmd/mountlib/mount.go
index c14eed789..7a7974ba4 100644
--- a/cmd/mountlib/mount.go
+++ b/cmd/mountlib/mount.go
@@ -403,27 +403,7 @@ func (m *MountPoint) Wait() error {
 	fnHandle := atexit.Register(finalise)
 	defer atexit.Unregister(fnHandle)
 
-	// Reload VFS cache on SIGHUP
-	sigHup := make(chan os.Signal, 1)
-	NotifyOnSigHup(sigHup)
-	var err error
-
-	waiting := true
-	for waiting {
-		select {
-		// umount triggered outside the app
-		case err = <-m.ErrChan:
-			waiting = false
-		// user sent SIGHUP to clear the cache
-		case <-sigHup:
-			root, err := m.VFS.Root()
-			if err != nil {
-				fs.Errorf(m.VFS.Fs(), "Error reading root: %v", err)
-			} else {
-				root.ForgetAll()
-			}
-		}
-	}
+	err := <-m.ErrChan
 
 	finalise()
 
diff --git a/cmd/serve/docker/driver.go b/cmd/serve/docker/driver.go
index 86885d336..804a8bc02 100644
--- a/cmd/serve/docker/driver.go
+++ b/cmd/serve/docker/driver.go
@@ -76,7 +76,6 @@ func NewDriver(ctx context.Context, root string, mntOpt *mountlib.Options, vfsOp
 	// start mount monitoring
 	drv.hupChan = make(chan os.Signal, 1)
 	drv.monChan = make(chan bool, 1)
-	mountlib.NotifyOnSigHup(drv.hupChan)
 	go drv.monitor()
 
 	// unmount all volumes on exit
diff --git a/cmd/mountlib/sighup.go b/vfs/sighup.go
similarity index 93%
rename from cmd/mountlib/sighup.go
rename to vfs/sighup.go
index 2dfbf9621..fadcbcdda 100644
--- a/cmd/mountlib/sighup.go
+++ b/vfs/sighup.go
@@ -1,6 +1,6 @@
 //go:build !plan9 && !js
 
-package mountlib
+package vfs
 
 import (
 	"os"
diff --git a/cmd/mountlib/sighup_unsupported.go b/vfs/sighup_unsupported.go
similarity index 90%
rename from cmd/mountlib/sighup_unsupported.go
rename to vfs/sighup_unsupported.go
index 8e786f696..19e08a34b 100644
--- a/cmd/mountlib/sighup_unsupported.go
+++ b/vfs/sighup_unsupported.go
@@ -1,6 +1,6 @@
 //go:build plan9 || js
 
-package mountlib
+package vfs
 
 import (
 	"os"
diff --git a/vfs/vfs.go b/vfs/vfs.go
index ecde90b19..1d2f71dd1 100644
--- a/vfs/vfs.go
+++ b/vfs/vfs.go
@@ -179,6 +179,7 @@ type VFS struct {
 	root        *Dir
 	Opt         vfscommon.Options
 	cache       *vfscache.Cache
+	cancel      context.CancelFunc
 	cancelCache context.CancelFunc
 	usageMu     sync.Mutex
 	usageTime   time.Time
@@ -197,8 +198,10 @@ var (
 // DefaultOpt will be used
 func New(f fs.Fs, opt *vfscommon.Options) *VFS {
 	fsDir := fs.NewDir("", time.Now())
+	ctx, cancel := context.WithCancel(context.Background())
 	vfs := &VFS{
-		f: f,
+		f:      f,
+		cancel: cancel,
 	}
 	vfs.inUse.Store(1)
 
@@ -259,6 +262,9 @@ func New(f fs.Fs, opt *vfscommon.Options) *VFS {
 		go vfs.refresh()
 	}
 
+	// Handle supported signals
+	go vfs.signalHandler(ctx)
+
 	// This can take some time so do it after the Pin
 	vfs.SetCacheMode(vfs.Opt.CacheMode)
 
@@ -274,6 +280,27 @@ func (vfs *VFS) refresh() {
 	}
 }
 
+// Reload VFS cache on SIGHUP
+func (vfs *VFS) signalHandler(ctx context.Context) {
+	sigHup := make(chan os.Signal, 1)
+	NotifyOnSigHup(sigHup)
+
+	waiting := true
+	for waiting {
+		select {
+		case <-ctx.Done():
+			waiting = false
+		case <-sigHup:
+			root, err := vfs.Root()
+			if err != nil {
+				fs.Errorf(vfs.Fs(), "Error reading root: %v", err)
+			} else {
+				root.ForgetAll()
+			}
+		}
+	}
+}
+
 // Stats returns info about the VFS
 func (vfs *VFS) Stats() (out rc.Params) {
 	out = make(rc.Params)
@@ -372,6 +399,9 @@ func (vfs *VFS) Shutdown() {
 		close(vfs.pollChan)
 		vfs.pollChan = nil
 	}
+
+	// Cancel any background go routines
+	vfs.cancel()
 }
 
 // CleanUp deletes the contents of the on disk cache