linux-kernel - [PATCH 5/7] cifs: Improve guard for excluding $LXDEV xattr

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Message-Id: <20241006100046.30772-6-pali@kernel.org>
Date: Sun,  6 Oct 2024 12:00:44 +0200
From: Pali Rohár <pali@...nel.org>
To: Steve French <sfrench@...ba.org>,
	Paulo Alcantara <pc@...guebit.com>,
	Ronnie Sahlberg <ronniesahlberg@...il.com>
Cc: linux-cifs@...r.kernel.org,
	linux-kernel@...r.kernel.org
Subject: [PATCH 5/7] cifs: Improve guard for excluding $LXDEV xattr

$LXDEV xattr is for storing block/char device's major and minor number.
Change guard which excludes storing $LXDEV xattr to explicitly filter
everything except block and char device. Current guard is opposite, which
is currently correct but is less-safe. This change is required for adding
support for creating WSL-style symlinks as symlinks also do not use
device's major and minor numbers.

Signed-off-by: Pali Rohár <pali@...nel.org>
---
 fs/smb/client/reparse.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/smb/client/reparse.c b/fs/smb/client/reparse.c
index 41f91613e7f2..402eb568f466 100644
--- a/fs/smb/client/reparse.c
+++ b/fs/smb/client/reparse.c
@@ -578,8 +578,8 @@ static int wsl_set_xattrs(struct inode *inode, umode_t _mode,
 
 	memset(iov, 0, sizeof(*iov));
 
-	/* Exclude $LXDEV xattr for sockets and fifos */
-	if (S_ISSOCK(_mode) || S_ISFIFO(_mode))
+	/* Exclude $LXDEV xattr for non-device files */
+	if (!S_ISBLK(_mode) && !S_ISCHR(_mode))
 		num_xattrs = ARRAY_SIZE(xattrs) - 1;
 	else
 		num_xattrs = ARRAY_SIZE(xattrs);
-- 
2.20.1