From 608362facd2d0f2667f68b7f42207707d59a0071 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Pali=20Roh=C3=A1r?= Date: Tue, 7 Jul 2026 11:03:56 +0200 Subject: [PATCH] cifs: Fix support for creating SFU fifo MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit SFU fifos are natively supported (created and recognized) at least by: - Microsoft POSIX subsystem - OpenNT/Interix subsystem - Microsoft SFU (Windows Services for UNIX) - Microsoft SUA (Subsystem for UNIX-based Applications) - Windows NFS server (up to the Windows Server 2008 R2) Windows NFS server since Windows Server 2012 uses new reparse point format for storing new fifos, but still can recognize this old format (also in the latest Windows Server 2022 version). SFU-style fifo is empty regular file which has system attribute set. These SFU-style fifos are already recognized by Linux SMB client. But Linux SMB client is currently creating new SFU fifos in different format which is not compatible with all those SFU-style consumers. Fix this by creating new fifos in correct SFU format which would be recognized by all those applications and also by existing Linux SMB clients. This change affects only creating new fifos when mount option -o sfu is used. Signed-off-by: Pali Rohár Acked-by: Paulo Alcantara (Red Hat) Signed-off-by: Steve French --- fs/smb/client/smb2ops.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/fs/smb/client/smb2ops.c b/fs/smb/client/smb2ops.c index b4fa43f32e51..15b3ae45c833 100644 --- a/fs/smb/client/smb2ops.c +++ b/fs/smb/client/smb2ops.c @@ -5291,10 +5291,8 @@ int __cifs_sfu_make_node(unsigned int xid, struct inode *inode, type[0] = '\0'; break; case S_IFIFO: - type_len = 8; - strscpy(type, "LnxFIFO"); - data = (u8 *)&pdev; - data_len = sizeof(pdev); + /* SFU fifo is system file which is empty */ + type_len = 0; break; default: rc = -EPERM; -- 2.47.3