git: 90314c04f10f - main - makedev(9): drop an additional note about cdevpriv dtors

From: Kyle Evans <kevans_at_FreeBSD.org>
Date: Wed, 05 Nov 2025 00:28:13 UTC
The branch main has been updated by kevans:

URL: https://cgit.FreeBSD.org/src/commit/?id=90314c04f10f583c37c59ec51fd628e3deaf3622

commit 90314c04f10f583c37c59ec51fd628e3deaf3622
Author:     Kyle Evans <kevans@FreeBSD.org>
AuthorDate: 2025-11-05 00:28:02 +0000
Commit:     Kyle Evans <kevans@FreeBSD.org>
CommitDate: 2025-11-05 00:28:02 +0000

    makedev(9): drop an additional note about cdevpriv dtors
    
    These were previously somewhat safe to call destroy_dev(9), but will now
    also cause a deadlock in the same fashion that d_close doing so would
    previously.  Amend the note to point it out, in case it's useful for
    someone.
    
    Reviewed by:    imp, kib, markj
    Differential Revision:  https://reviews.freebsd.org/D53439
---
 share/man/man9/make_dev.9 | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/share/man/man9/make_dev.9 b/share/man/man9/make_dev.9
index de56f350faa5..9f2c36fb39a4 100644
--- a/share/man/man9/make_dev.9
+++ b/share/man/man9/make_dev.9
@@ -25,7 +25,7 @@
 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 .\" SUCH DAMAGE.
 .\"
-.Dd January 19, 2025
+.Dd November 4, 2025
 .Dt MAKE_DEV 9
 .Os
 .Sh NAME
@@ -387,14 +387,18 @@ function is the same as:
 destroy_dev_sched_cb(cdev, NULL, NULL);
 .Ed
 .Pp
-The
+Neither the
 .Fn d_close
-driver method cannot call
+driver method, nor a
+.Xr devfs_cdevpriv 9
+.Fa dtr
+method can
 .Fn destroy_dev
 directly.
 Doing so causes deadlock when
 .Fn destroy_dev
-waits for all threads to leave the driver methods.
+waits for all threads to leave the driver methods and finish executing any
+per-open destructors.
 Also, because
 .Fn destroy_dev
 sleeps, no non-sleepable locks may be held over the call.