linux-kernel - [PATCH] cifs: Check if server supports EAs before trying to set it for WSL

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Message-Id: <20250712160732.17580-1-pali@kernel.org>
Date: Sat, 12 Jul 2025 18:07:32 +0200
From: Pali Rohár <pali@...nel.org>
To: Steve French <sfrench@...ba.org>,
	Paulo Alcantara <pc@...guebit.com>
Cc: linux-cifs@...r.kernel.org,
	linux-kernel@...r.kernel.org
Subject: [PATCH] cifs: Check if server supports EAs before trying to set it for WSL

WSL special files store information into EAs. When EAs are not supported
on the server filesystem then fast fail in mknod_wsl() function.

Signed-off-by: Pali Rohár <pali@...nel.org>
---
 fs/smb/client/reparse.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/fs/smb/client/reparse.c b/fs/smb/client/reparse.c
index faf208bef926..ee4af153e7af 100644
--- a/fs/smb/client/reparse.c
+++ b/fs/smb/client/reparse.c
@@ -665,6 +665,13 @@ static int mknod_wsl(unsigned int xid, struct inode *inode,
 	struct kvec reparse_iov, xattr_iov;
 	int rc;
 
+	/*
+	 * WSL special files store information into EAs. When EAs are not
+	 * supported on the server filesystem then fast fail.
+	 */
+	if (!(le32_to_cpu(tcon->fsAttrInfo.Attributes) & FILE_SUPPORTS_EXTENDED_ATTRIBUTES))
+		return -EOPNOTSUPP;
+
 	rc = wsl_set_reparse_buf(&buf, mode, symname, cifs_sb, &reparse_iov);
 	if (rc)
 		return rc;
-- 
2.20.1