From d1cbf3eeea671a36a16f1606e4d68f78d8708608 Mon Sep 17 00:00:00 2001 From: Mateusz Guzik Date: Sun, 13 Oct 2019 15:40:34 +0000 Subject: [PATCH] vfs: add MNTK_NOMSYNC On many filesystems the traversal is effectively a no-op. Add a way to avoid the overhead. Reviewed by: kib Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D22009 --- sys/kern/vfs_subr.c | 3 +++ sys/sys/mount.h | 1 + 2 files changed, 4 insertions(+) diff --git a/sys/kern/vfs_subr.c b/sys/kern/vfs_subr.c index 22c6065e2c5..d9541cde7bc 100644 --- a/sys/kern/vfs_subr.c +++ b/sys/kern/vfs_subr.c @@ -4395,6 +4395,9 @@ vfs_msync(struct mount *mp, int flags) CTR2(KTR_VFS, "%s: mp %p", __func__, mp); + if ((mp->mnt_kern_flag & MNTK_NOMSYNC) != 0) + return; + MNT_VNODE_FOREACH_ACTIVE(vp, mp, mvp) { obj = vp->v_object; if (obj != NULL && (obj->flags & OBJ_MIGHTBEDIRTY) != 0 && diff --git a/sys/sys/mount.h b/sys/sys/mount.h index e9cdd63e37f..53a776454bc 100644 --- a/sys/sys/mount.h +++ b/sys/sys/mount.h @@ -396,6 +396,7 @@ void __mnt_vnode_markerfree_active(struct vnode **mvp, struct mount *); #define MNTK_UNMOUNTF 0x00000001 /* forced unmount in progress */ #define MNTK_ASYNC 0x00000002 /* filtered async flag */ #define MNTK_SOFTDEP 0x00000004 /* async disabled by softdep */ +#define MNTK_NOMSYNC 0x00000008 /* don't do vfs_msync */ #define MNTK_DRAINING 0x00000010 /* lock draining is happening */ #define MNTK_REFEXPIRE 0x00000020 /* refcount expiring is happening */ #define MNTK_EXTENDED_SHARED 0x00000040 /* Allow shared locking for more ops */ -- 2.45.0