From d33ad2d8f357d83dfdc14c3358e3956aac76a9b0 Mon Sep 17 00:00:00 2001 From: Jes Cok Date: Wed, 15 Nov 2023 13:08:23 +0000 Subject: [PATCH] syscall: support O_SYNC flag for os.OpenFile on windows os.OpenFile on windows did not use the O_SYNC flag. This meant that even if the user set O_SYNC, os.OpenFile would ignore it. This change adds a new flag FILE_FLAG_WRITE_THROUGH, which is the equivalent of O_SYNC flag on Linux and is documented in https://docs.microsoft.com/en-us/windows/win32/api/fileapi/nf-fileapi-createfilea Fixes #35358 Change-Id: Ib338caed5bb2f215723bfe30a2551a83998d92c9 GitHub-Last-Rev: 82c6275cb49602d7903b2bff7d60b7c772a5d91a GitHub-Pull-Request: golang/go#64027 Reviewed-on: https://go-review.googlesource.com/c/go/+/541015 Reviewed-by: Than McIntosh Reviewed-by: Emmanuel Odeke Run-TryBot: Jes Cok TryBot-Result: Gopher Robot Reviewed-by: David Chase Reviewed-by: Quim Muntal --- src/syscall/syscall_windows.go | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/src/syscall/syscall_windows.go b/src/syscall/syscall_windows.go index 33876c7fe03..d13acc5c441 100644 --- a/src/syscall/syscall_windows.go +++ b/src/syscall/syscall_windows.go @@ -409,6 +409,10 @@ func Open(path string, mode int, perm uint32) (fd Handle, err error) { // Necessary for opening directory handles. attrs |= FILE_FLAG_BACKUP_SEMANTICS } + if mode&O_SYNC != 0 { + const _FILE_FLAG_WRITE_THROUGH = 0x80000000 + attrs |= _FILE_FLAG_WRITE_THROUGH + } return CreateFile(pathp, access, sharemode, sa, createmode, attrs, 0) }