From 9d21c796712d4e1b22e62f79af0a63be166912ab Mon Sep 17 00:00:00 2001
From: Idan Horowitz <idan.horowitz@gmail.com>
Date: Sat, 7 Aug 2021 16:06:07 +0300
Subject: [PATCH] Kernel: Disable big process lock for sys$sync

This syscall doesn't touch any intra-process shared resources and only
calls VirtualFileSystem::sync, which is self-locking.
---
 Kernel/API/Syscall.h     | 2 +-
 Kernel/Syscalls/sync.cpp | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/Kernel/API/Syscall.h b/Kernel/API/Syscall.h
index 50f75daa06..e62cba8aa8 100644
--- a/Kernel/API/Syscall.h
+++ b/Kernel/API/Syscall.h
@@ -106,7 +106,7 @@ enum class NeedsBigProcessLock {
     S(mkdir, NeedsBigProcessLock::Yes)                      \
     S(times, NeedsBigProcessLock::Yes)                      \
     S(utime, NeedsBigProcessLock::Yes)                      \
-    S(sync, NeedsBigProcessLock::Yes)                       \
+    S(sync, NeedsBigProcessLock::No)                        \
     S(ptsname, NeedsBigProcessLock::Yes)                    \
     S(select, NeedsBigProcessLock::Yes)                     \
     S(unlink, NeedsBigProcessLock::Yes)                     \
diff --git a/Kernel/Syscalls/sync.cpp b/Kernel/Syscalls/sync.cpp
index 22174843f0..0e369e6ff8 100644
--- a/Kernel/Syscalls/sync.cpp
+++ b/Kernel/Syscalls/sync.cpp
@@ -11,7 +11,7 @@ namespace Kernel {
 
 KResultOr<FlatPtr> Process::sys$sync()
 {
-    VERIFY_PROCESS_BIG_LOCK_ACQUIRED(this)
+    VERIFY_NO_PROCESS_BIG_LOCK(this)
     REQUIRE_PROMISE(stdio);
     VirtualFileSystem::sync();
     return 0;