From b0c34890309b39625d33a7d2b57b965ab252520c Mon Sep 17 00:00:00 2001
From: Andrew Osheroff <andrewosh@gmail.com>
Date: Fri, 24 Jan 2020 11:39:52 +0100
Subject: [PATCH] Added force option + static unmount

---
 index.js     | 39 +++++++++++++++++--------------
 test/misc.js | 66 +++++++++++++++++++++++++++++++++++++++++++++++++++-
 2 files changed, 87 insertions(+), 18 deletions(-)

diff --git a/index.js b/index.js
index 8e23b29..4b94b7f 100644
--- a/index.js
+++ b/index.js
@@ -9,6 +9,7 @@ const { beforeMount, beforeUnmount, configure, unconfigure, isConfigured } = req
 const binding = require('node-gyp-build')(__dirname)
 
 const IS_OSX = os.platform() === 'darwin'
+const ENOTCONN = IS_OSX ? -57 : -107
 const OSX_FOLDER_ICON = '/System/Library/CoreServices/CoreTypes.bundle/Contents/Resources/GenericFolderIcon.icns'
 const HAS_FOLDER_ICON = IS_OSX && fs.existsSync(OSX_FOLDER_ICON)
 
@@ -227,8 +228,9 @@ class Fuse extends Nanoresource {
   }
 
   // Static methods
+
   static unmount (mnt, cb) {
-    const mnt = JSON.stringify(mnt)
+    mnt = JSON.stringify(mnt)
     const cmd = IS_OSX ? `diskutil umount ${mnt}` : `fusermount -uz ${mnt}`
     exec(cmd, err => {
       if (err) return cb(err)
@@ -236,30 +238,37 @@ class Fuse extends Nanoresource {
     })
   }
 
+  // Debugging methods
+
   // Lifecycle methods
 
   _open (cb) {
     const self = this
 
-    if (this._force) return Fuse.unmount(this.mnt, open)
+    if (this._force) {
+      return fs.stat(path.join(this.mnt), (err, st) => {
+        if (err && err.errno === ENOTCONN) return Fuse.unmount(this.mnt, open)
+        return open()
+      })
+    }
     return open()
 
-    function open (err) {
-      if (err) return cb(err)
-      this._thread = Buffer.alloc(binding.sizeof_fuse_thread_t)
-      this._openCallback = cb
+    function open () {
+      // If there was an unmount error, continue attempting to mount (this is the best we can do)
+      self._thread = Buffer.alloc(binding.sizeof_fuse_thread_t)
+      self._openCallback = cb
 
-      const opts = this._fuseOptions()
-      const implemented = this._getImplementedArray()
+      const opts = self._fuseOptions()
+      const implemented = self._getImplementedArray()
 
-      return fs.stat(this.mnt, (err, stat) => {
+      return fs.stat(self.mnt, (err, stat) => {
         if (err) return cb(new Error('Mountpoint does not exist'))
         if (!stat.isDirectory()) return cb(new Error('Mountpoint is not a directory'))
-        return fs.stat(path.join(this.mnt, '..'), (_, parent) => {
+        return fs.stat(path.join(self.mnt, '..'), (_, parent) => {
           if (parent && parent.dev !== stat.dev) return cb(new Error('Mountpoint in use'))
           try {
             // TODO: asyncify
-            binding.fuse_native_mount(this.mnt, opts, this._thread, this, this._handlers, implemented)
+            binding.fuse_native_mount(self.mnt, opts, self._thread, self, self._handlers, implemented)
           } catch (err) {
             return cb(err)
           }
@@ -269,13 +278,10 @@ class Fuse extends Nanoresource {
   }
 
   _close (cb) {
-    if (this._closed) return process.nextTick(cb, null)
     const self = this
-    const mnt = JSON.stringify(this.mnt)
-    const cmd = IS_OSX ? `diskutil umount ${mnt}` : `fusermount -uz ${mnt}`
 
-    Fuse.unmount(mnt, err => {
-      if (err) return cb(err)
+    Fuse.unmount(this.mnt, () => {
+      // Even if the unmount command fails, do the native unmount.
       nativeUnmount()
     })
 
@@ -285,7 +291,6 @@ class Fuse extends Nanoresource {
       } catch (err) {
         return cb(err)
       }
-      self._closed = true
       return cb(null)
     }
   }
diff --git a/test/misc.js b/test/misc.js
index 53644b4..8039439 100644
--- a/test/misc.js
+++ b/test/misc.js
@@ -1,5 +1,6 @@
 const mnt = require('./fixtures/mnt')
 const tape = require('tape')
+const { spawnSync } = require('child_process')
 
 const Fuse = require('../')
 const { unmount } = require('./helpers')
@@ -39,7 +40,7 @@ tape('mount + unmount + mount with same instance fails', function (t) {
 
   fuse.mount(function (err) {
     t.error(err, 'no error')
-    t.ok(true, 'works')
+    t.pass('works')
     unmount(fuse, function () {
       fuse.mount(function (err) {
         t.ok(err, 'had error')
@@ -64,3 +65,66 @@ tape('mnt point must be directory', function (t) {
     t.end()
   })
 })
+
+tape('mounting twice without force fails', function (t) {
+  const fuse1 = new Fuse(mnt, {}, { force: true, debug: false })
+  const fuse2 = new Fuse(mnt, {}, { force: false, debug: false })
+
+  fuse1.mount(function (err) {
+    t.error(err, 'no error')
+    t.pass('works')
+    fuse2.mount(function (err) {
+      t.true(err, 'cannot mount over existing mountpoint')
+      unmount(fuse1, function () {
+        t.end()
+      })
+    })
+  })
+})
+
+tape('mounting twice with force fail if mountpoint is not broken', function (t) {
+  const fuse1 = new Fuse(mnt, {}, { force: true, debug: false })
+  const fuse2 = new Fuse(mnt, {}, { force: true, debug: false })
+
+  fuse1.mount(function (err) {
+    t.error(err, 'no error')
+    t.pass('works')
+    fuse2.mount(function (err) {
+      t.true(err, 'cannot mount over existing mountpoint')
+      unmount(fuse1, function () {
+        t.end()
+      })
+    })
+  })
+})
+
+tape('mounting over a broken mountpoint with force succeeds', function (t) {
+  createBrokenMountpoint(mnt)
+
+  const fuse = new Fuse(mnt, {}, { force: true, debug: false })
+  fuse.mount(function (err) {
+    t.error(err, 'no error')
+    t.pass('works')
+    unmount(fuse, function (err) {
+      t.end()
+    })
+  })
+})
+
+tape('static unmounting', function (t) {
+  t.end()
+})
+
+function createBrokenMountpoint (mnt) {
+  spawnSync(process.execPath, ['-e', `
+    const Fuse = require('..')
+    const mnt = ${JSON.stringify(mnt)}
+    const fuse = new Fuse(mnt, {}, { force: true, debug: false })
+    fuse.mount(() => {
+      process.exit(0)
+    })
+  `], {
+    cwd: __dirname,
+    stdio: 'inherit'
+  })
+}