git: 5c41d888de1a - main - kcmp(2): implement for devfs files

From: Konstantin Belousov <kib_at_FreeBSD.org>
Date: Wed, 24 Jan 2024 05:12:21 UTC
The branch main has been updated by kib:

URL: https://cgit.FreeBSD.org/src/commit/?id=5c41d888de1aba0e82531fb6df4cc3b6989d37bd

commit 5c41d888de1aba0e82531fb6df4cc3b6989d37bd
Author:     Konstantin Belousov <kib@FreeBSD.org>
AuthorDate: 2024-01-19 21:36:50 +0000
Commit:     Konstantin Belousov <kib@FreeBSD.org>
CommitDate: 2024-01-24 05:11:26 +0000

    kcmp(2): implement for devfs files
    
    Compare not vnodes, which are different between mount points, but
    actual cdev referenced by the devfs node.
    
    Reviewed by:    brooks, markj
    Sponsored by:   The FreeBSD Foundation
    MFC after:      1 week
    Differential revision:  https://reviews.freebsd.org/D43518
---
 sys/fs/devfs/devfs_vnops.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/sys/fs/devfs/devfs_vnops.c b/sys/fs/devfs/devfs_vnops.c
index fbb314dbbe79..3b8a624fe620 100644
--- a/sys/fs/devfs/devfs_vnops.c
+++ b/sys/fs/devfs/devfs_vnops.c
@@ -2010,6 +2010,14 @@ dev2udev(struct cdev *x)
 	return (cdev2priv(x)->cdp_inode);
 }
 
+static int
+devfs_cmp_f(struct file *fp1, struct file *fp2, struct thread *td)
+{
+	if (fp2->f_type != DTYPE_VNODE || fp2->f_ops != &devfs_ops_f)
+		return (3);
+	return (kcmp_cmp((uintptr_t)fp1->f_data, (uintptr_t)fp2->f_data));
+}
+
 static struct fileops devfs_ops_f = {
 	.fo_read =	devfs_read_f,
 	.fo_write =	devfs_write_f,
@@ -2025,6 +2033,7 @@ static struct fileops devfs_ops_f = {
 	.fo_seek =	vn_seek,
 	.fo_fill_kinfo = vn_fill_kinfo,
 	.fo_mmap =	devfs_mmap_f,
+	.fo_cmp =	devfs_cmp_f,
 	.fo_flags =	DFLAG_PASSABLE | DFLAG_SEEKABLE
 };