The branch main has been updated by kib:
URL:
https://cgit.FreeBSD.org/src/commit/?id=3f05bbdbd80f2eefb647e595dc73e80d6186d6a5
commit 3f05bbdbd80f2eefb647e595dc73e80d6186d6a5
Author: Konstantin Belousov <k...@freebsd.org>
AuthorDate: 2025-07-24 10:47:52 +0000
Commit: Konstantin Belousov <k...@freebsd.org>
CommitDate: 2025-09-14 19:12:58 +0000
vm_fault: add helper vm_fault_can_cow_rename()
Reviewed by: alc, markj
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D51474
---
sys/vm/vm_fault.c | 20 +++++++++++---------
1 file changed, 11 insertions(+), 9 deletions(-)
diff --git a/sys/vm/vm_fault.c b/sys/vm/vm_fault.c
index 226cf34b3ca4..27b5f72ec945 100644
--- a/sys/vm/vm_fault.c
+++ b/sys/vm/vm_fault.c
@@ -1006,6 +1006,16 @@ vm_fault_relookup(struct faultstate *fs)
return (KERN_SUCCESS);
}
+static bool
+vm_fault_can_cow_rename(struct faultstate *fs)
+{
+ return (
+ /* Only one shadow object and no other refs. */
+ fs->object->shadow_count == 1 && fs->object->ref_count == 1 &&
+ /* No other ways to look the object up. */
+ fs->object->handle == NULL && (fs->object->flags & OBJ_ANON) != 0);
+}
+
static void
vm_fault_cow(struct faultstate *fs)
{
@@ -1023,15 +1033,7 @@ vm_fault_cow(struct faultstate *fs)
* object so that it will go out to swap when needed.
*/
is_first_object_locked = false;
- if (
- /*
- * Only one shadow object and no other refs.
- */
- fs->object->shadow_count == 1 && fs->object->ref_count == 1 &&
- /*
- * No other ways to look the object up
- */
- fs->object->handle == NULL && (fs->object->flags & OBJ_ANON) != 0 &&
+ if (vm_fault_can_cow_rename(fs) &&
/*
* We don't chase down the shadow chain and we can acquire locks.
*/
