git: 46811949797b - main - tmpfs_destroy_vobject(): clear v_object under the object lock
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Date: Mon, 13 May 2024 18:34:26 UTC
The branch main has been updated by kib: URL: https://cgit.FreeBSD.org/src/commit/?id=46811949797b7e44521cd56cfa61b6c8378c4600 commit 46811949797b7e44521cd56cfa61b6c8378c4600 Author: Konstantin Belousov <kib@FreeBSD.org> AuthorDate: 2024-05-12 01:26:32 +0000 Commit: Konstantin Belousov <kib@FreeBSD.org> CommitDate: 2024-05-13 18:33:59 +0000 tmpfs_destroy_vobject(): clear v_object under the object lock Which allows tmpfs_pager_writecount_recalc() to reliably detect reclaimed vnode and make its accesses to object->un_pager.swp.private (== vp) safe against reclaim. Note that vnode instantiation already assigns v_object under the object lock. Reviewed by: markj Reported and tested by: pho Sponsored by: The FreeBSD Foundation MFC after: 1 week Differential revision: https://reviews.freebsd.org/D45119 --- sys/fs/tmpfs/tmpfs_subr.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/sys/fs/tmpfs/tmpfs_subr.c b/sys/fs/tmpfs/tmpfs_subr.c index 4ddf2b4ba5ff..53781202b066 100644 --- a/sys/fs/tmpfs/tmpfs_subr.c +++ b/sys/fs/tmpfs/tmpfs_subr.c @@ -120,7 +120,7 @@ tmpfs_pager_writecount_recalc(vm_object_t object, vm_offset_t old, /* * Forced unmount? */ - if (vp == NULL) { + if (vp == NULL || vp->v_object == NULL) { KASSERT((object->flags & OBJ_TMPFS_VREF) == 0, ("object %p with OBJ_TMPFS_VREF but without vnode", object)); @@ -957,6 +957,8 @@ tmpfs_destroy_vobject(struct vnode *vp, vm_object_t obj) VM_OBJECT_WLOCK(obj); VI_LOCK(vp); + vp->v_object = NULL; + /* * May be going through forced unmount. */