retrieving CIFS ACLs when mounted with SMB2 fails dropping session

The get/set ACL xattr support for CIFS ACLs attempts to send old
cifs dialect protocol requests even when mounted with SMB2 or later
dialects. Sending cifs requests on an smb2 session causes problems -
the server drops the session due to the illegal request.

This patch makes CIFS ACL operations protocol specific to fix that.

Attempting to query/set CIFS ACLs for SMB2 will now return
EOPNOTSUPP (until we add worker routines for sending query
ACL requests via SMB2) instead of sending invalid (cifs)
requests.

A separate followon patch will be needed to fix cifs_acl_to_fattr
(which takes a cifs specific u16 fid so can't be abstracted
to work with SMB2 until that is changed) and will be needed
to fix mount problems when "cifsacl" is specified on mount
with e.g. vers=2.1

Signed-off-by: Steve French <smfrench@gmail.com>
Reviewed-by: Shirish Pargaonkar <spargaonkar@suse.com>
CC: Stable <stable@kernel.org>

1 files changed, 24 insertions, 4 deletions

diff --git a/fs/cifs/cifsacl.c b/fs/cifs/cifsacl.c
index 8f9b4f710d4a..c819b0bd491a 100644
--- a/fs/cifs/cifsacl.c
+++ b/fs/cifs/cifsacl.c
@@ -1043,15 +1043,30 @@ id_mode_to_cifs_acl(struct inode *inode, const char *path, __u64 nmode,
 	__u32 secdesclen = 0;
 	struct cifs_ntsd *pntsd = NULL; /* acl obtained from server */
 	struct cifs_ntsd *pnntsd = NULL; /* modified acl to be sent to server */
+	struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
+	struct tcon_link *tlink = cifs_sb_tlink(cifs_sb);
+	struct cifs_tcon *tcon;
+
+	if (IS_ERR(tlink))
+		return PTR_ERR(tlink);
+	tcon = tlink_tcon(tlink);
 
 	cifs_dbg(NOISY, "set ACL from mode for %s\n", path);
 
 	/* Get the security descriptor */
-	pntsd = get_cifs_acl(CIFS_SB(inode->i_sb), inode, path, &secdesclen);
+
+	if (tcon->ses->server->ops->get_acl == NULL) {
+		cifs_put_tlink(tlink);
+		return -EOPNOTSUPP;
+	}
+
+	pntsd = tcon->ses->server->ops->get_acl(cifs_sb, inode, path,
+						&secdesclen);
 	if (IS_ERR(pntsd)) {
 		rc = PTR_ERR(pntsd);
 		cifs_dbg(VFS, "%s: error %d getting sec desc\n", __func__, rc);
-		goto out;
+		cifs_put_tlink(tlink);
+		return rc;
 	}
 
 	/*
@@ -1064,6 +1079,7 @@ id_mode_to_cifs_acl(struct inode *inode, const char *path, __u64 nmode,
 	pnntsd = kmalloc(secdesclen, GFP_KERNEL);
 	if (!pnntsd) {
 		kfree(pntsd);
+		cifs_put_tlink(tlink);
 		return -ENOMEM;
 	}
 
@@ -1072,14 +1088,18 @@ id_mode_to_cifs_acl(struct inode *inode, const char *path, __u64 nmode,
 
 	cifs_dbg(NOISY, "build_sec_desc rc: %d\n", rc);
 
+	if (tcon->ses->server->ops->set_acl == NULL)
+		rc = -EOPNOTSUPP;
+
 	if (!rc) {
 		/* Set the security descriptor */
-		rc = set_cifs_acl(pnntsd, secdesclen, inode, path, aclflag);
+		rc = tcon->ses->server->ops->set_acl(pnntsd, secdesclen, inode,
+						     path, aclflag);
 		cifs_dbg(NOISY, "set_cifs_acl rc: %d\n", rc);
 	}
+	cifs_put_tlink(tlink);
 
 	kfree(pnntsd);
 	kfree(pntsd);
-out:
 	return rc;
 }