Merge tag 'locking-urgent-2026-09-20' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipgrafted

Pull futex fix from Ingo Molnar:

 - Also allocate a default private futex hash on vfork() as well, to
   avoid races with (private) futex waiters (Peter Zijlstra)

* tag 'locking-urgent-2026-09-20' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  futex: Also allocate private hash on vfork()

1 files changed, 39 insertions, 0 deletions

diff --git a/fs/lockd/share.h b/fs/lockd/share.h
new file mode 100644
index 000000000..a12b6c454
--- /dev/null
+++ b/fs/lockd/share.h
@@ -0,0 +1,39 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * DOS share management for lockd.
+ *
+ * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
+ */
+
+#ifndef _LOCKD_SHARE_H
+#define _LOCKD_SHARE_H
+
+#include <linux/bits.h>
+
+/* Synthetic svid for lockowner lookup during share operations */
+#define LOCKD_SHARE_SVID	(~(u32)0)
+
+/* One bit per (access, deny) pair; index = (access << 2) | deny */
+#define LOCKD_FSH_BIT(a, d)	BIT(((a) << 2) | (d))
+
+/*
+ * DOS share for a specific file
+ */
+struct lockd_share {
+	struct lockd_share *	s_next;		/* linked list */
+	struct nlm_host *	s_host;		/* client host */
+	struct nlm_file *	s_file;		/* shared file */
+	struct xdr_netobj	s_owner;	/* owner handle */
+	u32			s_access;	/* access mode */
+	u32			s_mode;		/* deny mode */
+	u16			s_access_deny_bmap;	/* held (access, deny) pairs */
+};
+
+__be32	nlmsvc_share_file(struct nlm_host *host, struct nlm_file *file,
+			  struct xdr_netobj *oh, u32 access, u32 mode);
+__be32	nlmsvc_unshare_file(struct nlm_host *host, struct nlm_file *file,
+			    struct xdr_netobj *oh, u32 access, u32 mode);
+void	nlmsvc_traverse_shares(struct nlm_host *, struct nlm_file *,
+					       nlm_host_match_fn_t);
+
+#endif /* _LOCKD_SHARE_H */