git: 6d0a335aaa81 - main - fcntl.h: warn that bits for O_* flags are scarce

The branch main has been updated by brooks:

URL: https://cgit.FreeBSD.org/src/commit/?id=6d0a335aaa81d3ddce95de8d862a23c97bb038a6

commit 6d0a335aaa81d3ddce95de8d862a23c97bb038a6
Author:     Brooks Davis <brooks@FreeBSD.org>
AuthorDate: 2025-06-12 13:33:35 +0000
Commit:     Brooks Davis <brooks@FreeBSD.org>
CommitDate: 2025-06-12 13:34:05 +0000

    fcntl.h: warn that bits for O_* flags are scarce
    
    Running out of O_* flag bits will end out ability to make additions that
    are source compatible with other operating systems.
    
    Add a warning to coordinate all additions with srcmgr@.
    
    Reviewed by:    markj, emaste
    Differential Revision:  https://reviews.freebsd.org/D50703
---
 sys/sys/fcntl.h | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/sys/sys/fcntl.h b/sys/sys/fcntl.h
index 08aa26fbce02..c23c7eba0544 100644
--- a/sys/sys/fcntl.h
+++ b/sys/sys/fcntl.h
@@ -143,6 +143,16 @@ typedef	__pid_t		pid_t;
 #define	O_NAMEDATTR	0x04000000	/* NFSv4 named attributes */
 #endif
 
+/*
+ * !!! DANGER !!!
+ *
+ * There are very few bits left for O_* flags.  Every bit we consume for
+ * local features is one bit we can't use for future source compatibility
+ * with other operating systems.
+ *
+ * All additions should be coordinated with srcmgr@.
+ */
+
 /*
  * XXX missing O_RSYNC.
  */