From 93ff911473a8a6f1c2e8fb70359f8e8acbb77f20 Mon Sep 17 00:00:00 2001
From: Sergey Bugaev <bugaevc@gmail.com>
Date: Sun, 12 Jan 2020 19:22:24 +0300
Subject: [PATCH] Kernel: Properly propagate bind mount flags

Previously, when performing a bind mount flags other than MS_BIND were ignored.
Now, they're properly propagated the same way a for any other mount.
---
 Kernel/FileSystem/VirtualFileSystem.cpp | 8 ++++----
 Kernel/FileSystem/VirtualFileSystem.h   | 4 ++--
 Kernel/Process.cpp                      | 2 +-
 3 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/Kernel/FileSystem/VirtualFileSystem.cpp b/Kernel/FileSystem/VirtualFileSystem.cpp
index 3b7c52f11db..af91c3d21e9 100644
--- a/Kernel/FileSystem/VirtualFileSystem.cpp
+++ b/Kernel/FileSystem/VirtualFileSystem.cpp
@@ -49,11 +49,11 @@ KResult VFS::mount(FS& file_system, Custody& mount_point, int flags)
     return KSuccess;
 }
 
-KResult VFS::bind_mount(Custody& source, Custody& mount_point)
+KResult VFS::bind_mount(Custody& source, Custody& mount_point, int flags)
 {
     dbg() << "VFS: Bind-mounting " << source.absolute_path() << " at " << mount_point.absolute_path();
     // FIXME: check that this is not already a mount point
-    Mount mount { source.inode(), mount_point };
+    Mount mount { source.inode(), mount_point, flags };
     m_mounts.append(move(mount));
     mount_point.did_mount_on({});
     return KSuccess;
@@ -631,11 +631,11 @@ VFS::Mount::Mount(FS& guest_fs, Custody* host_custody, int flags)
 {
 }
 
-VFS::Mount::Mount(Inode& source, Custody& host_custody)
+VFS::Mount::Mount(Inode& source, Custody& host_custody, int flags)
     : m_guest(source.identifier())
     , m_guest_fs(source.fs())
     , m_host_custody(host_custody)
-    , m_flags(MS_BIND)
+    , m_flags(flags)
 {
 }
 
diff --git a/Kernel/FileSystem/VirtualFileSystem.h b/Kernel/FileSystem/VirtualFileSystem.h
index c062d7bba17..2fa748487d4 100644
--- a/Kernel/FileSystem/VirtualFileSystem.h
+++ b/Kernel/FileSystem/VirtualFileSystem.h
@@ -48,7 +48,7 @@ public:
     class Mount {
     public:
         Mount(FS&, Custody* host_custody, int flags);
-        Mount(Inode& source, Custody& host_custody);
+        Mount(Inode& source, Custody& host_custody, int flags);
 
         InodeIdentifier host() const;
         InodeIdentifier guest() const { return m_guest; }
@@ -74,7 +74,7 @@ public:
 
     bool mount_root(FS&);
     KResult mount(FS&, Custody& mount_point, int flags);
-    KResult bind_mount(Custody& source, Custody& mount_point);
+    KResult bind_mount(Custody& source, Custody& mount_point, int flags);
     KResult unmount(InodeIdentifier guest_inode_id);
 
     KResultOr<NonnullRefPtr<FileDescription>> open(StringView path, int options, mode_t mode, Custody& base, Optional<UidAndGid> = {});
diff --git a/Kernel/Process.cpp b/Kernel/Process.cpp
index 87f52dda081..6e1d34dce81 100644
--- a/Kernel/Process.cpp
+++ b/Kernel/Process.cpp
@@ -3753,7 +3753,7 @@ int Process::sys$mount(const Syscall::SC_mount_params* user_params)
         if (source_or_error.is_error())
             return source_or_error.error();
         auto& source_custody = source_or_error.value();
-        return VFS::the().bind_mount(source_custody, target_custody);
+        return VFS::the().bind_mount(source_custody, target_custody, params.flags);
     }
 
     if (fs_type == "ext2" || fs_type == "Ext2FS") {