From 34e11da3eb4022c42a6cc89990733607eb53d19e Mon Sep 17 00:00:00 2001
From: Steve French <stfrench@microsoft.com>
Date: Thu, 19 Oct 2023 23:01:49 -0500
Subject: [PATCH] smb3: fix creating FIFOs when mounting with "sfu" mount
 option

commit 72bc63f5e23a38b65ff2a201bdc11401d4223fa9 upstream.

Fixes some xfstests including generic/564 and generic/157

The "sfu" mount option can be useful for creating special files (character
and block devices in particular) but could not create FIFOs. It did
recognize existing empty files with the "system" attribute flag as FIFOs
but this is too general, so to support creating FIFOs more safely use a new
tag (but the same length as those for char and block devices ie "IntxLNK"
and "IntxBLK") "LnxFIFO" to indicate that the file should be treated as a
FIFO (when mounted with the "sfu").   For some additional context note that
"sfu" followed the way that "Services for Unix" on Windows handled these
special files (at least for character and block devices and symlinks),
which is different than newer Windows which can handle special files
as reparse points (which isn't an option to many servers).

Cc: stable@vger.kernel.org
Reviewed-by: Paulo Alcantara (SUSE) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 fs/smb/client/cifspdu.h | 2 +-
 fs/smb/client/inode.c   | 4 ++++
 fs/smb/client/smb2ops.c | 8 +++++++-
 3 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/fs/smb/client/cifspdu.h b/fs/smb/client/cifspdu.h
index e17222fec9d29..a75220db5c1e1 100644
--- a/fs/smb/client/cifspdu.h
+++ b/fs/smb/client/cifspdu.h
@@ -2570,7 +2570,7 @@ typedef struct {
 
 
 struct win_dev {
-	unsigned char type[8]; /* IntxCHR or IntxBLK */
+	unsigned char type[8]; /* IntxCHR or IntxBLK or LnxFIFO*/
 	__le64 major;
 	__le64 minor;
 } __attribute__((packed));
diff --git a/fs/smb/client/inode.c b/fs/smb/client/inode.c
index cb85d7977b1e3..9e242b0f48fcd 100644
--- a/fs/smb/client/inode.c
+++ b/fs/smb/client/inode.c
@@ -567,6 +567,10 @@ cifs_sfu_type(struct cifs_fattr *fattr, const char *path,
 			cifs_dbg(FYI, "Symlink\n");
 			fattr->cf_mode |= S_IFLNK;
 			fattr->cf_dtype = DT_LNK;
+		} else if (memcmp("LnxFIFO", pbuf, 8) == 0) {
+			cifs_dbg(FYI, "FIFO\n");
+			fattr->cf_mode |= S_IFIFO;
+			fattr->cf_dtype = DT_FIFO;
 		} else {
 			fattr->cf_mode |= S_IFREG; /* file? */
 			fattr->cf_dtype = DT_REG;
diff --git a/fs/smb/client/smb2ops.c b/fs/smb/client/smb2ops.c
index a5cba71c30aed..0b71a1cc22980 100644
--- a/fs/smb/client/smb2ops.c
+++ b/fs/smb/client/smb2ops.c
@@ -5212,7 +5212,7 @@ smb2_make_node(unsigned int xid, struct inode *inode,
 	 * over SMB2/SMB3 and Samba will do this with SMB3.1.1 POSIX Extensions
 	 */
 
-	if (!S_ISCHR(mode) && !S_ISBLK(mode))
+	if (!S_ISCHR(mode) && !S_ISBLK(mode) && !S_ISFIFO(mode))
 		return rc;
 
 	cifs_dbg(FYI, "sfu compat create special file\n");
@@ -5260,6 +5260,12 @@ smb2_make_node(unsigned int xid, struct inode *inode,
 		pdev->minor = cpu_to_le64(MINOR(dev));
 		rc = tcon->ses->server->ops->sync_write(xid, &fid, &io_parms,
 							&bytes_written, iov, 1);
+	} else if (S_ISFIFO(mode)) {
+		memcpy(pdev->type, "LnxFIFO", 8);
+		pdev->major = 0;
+		pdev->minor = 0;
+		rc = tcon->ses->server->ops->sync_write(xid, &fid, &io_parms,
+							&bytes_written, iov, 1);
 	}
 	tcon->ses->server->ops->close(xid, tcon, &fid);
 	d_drop(dentry);
-- 
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