When mounting with modefromsid mount option, it was possible to
get the error on stat of a fifo or char or block device:
"cannot stat <filename>: Operation not supported"
Special devices can be stored as reparse points by some servers
(e.g. Windows NFS server and when using the SMB3.1.1 POSIX
Extensions) but when the modefromsid mount option is used
the client attempts to get the ACL for the file which requires
opening with OPEN_REPARSE_POINT create option.
--
Thanks,
Steve
From de3fe18663801dded6987441664cd54b3276703a Mon Sep 17 00:00:00 2001
From: Steve French <stfrench@xxxxxxxxxxxxx>
Date: Tue, 20 Oct 2020 22:53:57 -0500
Subject: [PATCH] smb3: fix stat when special device file and mounted with
modefromsid
When mounting with modefromsid mount option, it was possible to
get the error on stat of a fifo or char or block device:
"cannot stat <filename>: Operation not supported"
Special devices can be stored as reparse points by some servers
(e.g. Windows NFS server and when using the SMB3.1.1 POSIX
Extensions) but when the modefromsid mount option is used
the client attempts to get the ACL for the file which requires
opening with OPEN_REPARSE_POINT create option.
Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx>
---
fs/cifs/smb2ops.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
index 2c3cfb2e8e72..7e3edcda054e 100644
--- a/fs/cifs/smb2ops.c
+++ b/fs/cifs/smb2ops.c
@@ -3099,6 +3099,12 @@ get_smb2_acl_by_path(struct cifs_sb_info *cifs_sb,
rc = SMB2_open(xid, &oparms, utf16_path, &oplock, NULL, NULL, NULL,
NULL);
+ if (rc == -EOPNOTSUPP) {
+ oparms.create_options |= OPEN_REPARSE_POINT;
+ rc = SMB2_open(xid, &oparms, utf16_path, &oplock, NULL, NULL,
+ NULL, NULL);
+ cifs_dbg(VFS, "open retry rc %d\n", rc); /* BB removeme */
+ }
kfree(utf16_path);
if (!rc) {
rc = SMB2_query_acl(xid, tlink_tcon(tlink), fid.persistent_fid,
--
2.25.1
