git: 1d97ad676d58 - main - lockmgr(9): add lockcanrecurse(9)

The branch main has been updated by kib:

URL: https://cgit.FreeBSD.org/src/commit/?id=1d97ad676d586aa5d91227ebaa39bd9c3b1d68fe

commit 1d97ad676d586aa5d91227ebaa39bd9c3b1d68fe
Author:     Konstantin Belousov <kib@FreeBSD.org>
AuthorDate: 2026-07-31 04:11:05 +0000
Commit:     Konstantin Belousov <kib@FreeBSD.org>
CommitDate: 2026-08-07 09:09:50 +0000

    lockmgr(9): add lockcanrecurse(9)
    
    Also add vnode locking wrappers for lockcanrecurse(9) and
    lockdisablerecurse(9).
    
    Reviewed by:    jah
    Sponsored by:   The FreeBSD Foundation
    MFC after:      1 week
    Differential revision:  https://reviews.freebsd.org/D58567
---
 sys/kern/kern_lock.c | 7 +++++++
 sys/sys/lockmgr.h    | 1 +
 sys/sys/vnode.h      | 2 ++
 3 files changed, 10 insertions(+)

diff --git a/sys/kern/kern_lock.c b/sys/kern/kern_lock.c
index 76f68677e292..b12d5bc2f12c 100644
--- a/sys/kern/kern_lock.c
+++ b/sys/kern/kern_lock.c
@@ -495,6 +495,13 @@ lockdisablerecurse(struct lock *lk)
 	lk->lock_object.lo_flags &= ~LO_RECURSABLE;
 }
 
+bool
+lockcanrecurse(struct lock *lk)
+{
+	lockmgr_assert(lk, KA_LOCKED);
+	return ((lk->lock_object.lo_flags & LO_RECURSABLE) != 0);
+}
+
 void
 lockdestroy(struct lock *lk)
 {
diff --git a/sys/sys/lockmgr.h b/sys/sys/lockmgr.h
index 48eea47c60da..ca066148d7d3 100644
--- a/sys/sys/lockmgr.h
+++ b/sys/sys/lockmgr.h
@@ -82,6 +82,7 @@ void	 _lockmgr_disown(struct lock *lk, const char *file, int line);
 
 void	 lockallowrecurse(struct lock *lk);
 void	 lockallowshare(struct lock *lk);
+bool	 lockcanrecurse(struct lock *lk);
 void	 lockdestroy(struct lock *lk);
 void	 lockdisablerecurse(struct lock *lk);
 void	 lockdisableshare(struct lock *lk);
diff --git a/sys/sys/vnode.h b/sys/sys/vnode.h
index 9d17dde1e73d..2fa1a51ce1cc 100644
--- a/sys/sys/vnode.h
+++ b/sys/sys/vnode.h
@@ -480,6 +480,8 @@ extern	u_int vn_lock_pair_pause_max;
 #define	VI_MTX(vp)	(&(vp)->v_interlock)
 
 #define	VN_LOCK_AREC(vp)	lockallowrecurse((vp)->v_vnlock)
+#define	VN_LOCK_DREC(vp)	lockdisablerecurse((vp)->v_vnlock)
+#define	VN_LOCK_CANREC(vp)	lockcanrecurse((vp)->v_vnlock)
 #define	VN_LOCK_ASHARE(vp)	lockallowshare((vp)->v_vnlock)
 #define	VN_LOCK_DSHARE(vp)	lockdisableshare((vp)->v_vnlock)