From 8a59b15cd4a7ed7ba2939ab95f153e0b4ac0e060 Mon Sep 17 00:00:00 2001 From: Alan Cox Date: Mon, 2 Sep 2002 04:04:12 +0000 Subject: [PATCH] o Synchronize updates to struct vm_page::cow with the page queues lock. --- sys/kern/uipc_cow.c | 4 +++- sys/vm/vm_page.c | 11 +++++------ 2 files changed, 8 insertions(+), 7 deletions(-) diff --git a/sys/kern/uipc_cow.c b/sys/kern/uipc_cow.c index 14231a253e0..f57067782ca 100644 --- a/sys/kern/uipc_cow.c +++ b/sys/kern/uipc_cow.c @@ -96,7 +96,9 @@ socow_iodone(void *addr, void *args) pp = PHYS_TO_VM_PAGE(paddr); s = splvm(); /* remove COW mapping */ + vm_page_lock_queues(); vm_page_cowclear(pp); + vm_page_unlock_queues(); vm_object_deallocate(pp->object); splx(s); /* note that sf_buf_free() unwires the page for us*/ @@ -141,12 +143,12 @@ socow_setup(struct mbuf *m0, struct uio *uio) /* * set up COW */ + vm_page_lock_queues(); vm_page_cowsetup(pp); /* * wire the page for I/O */ - vm_page_lock_queues(); vm_page_wire(pp); vm_page_unlock_queues(); diff --git a/sys/vm/vm_page.c b/sys/vm/vm_page.c index 637d2c095aa..535f566e8ab 100644 --- a/sys/vm/vm_page.c +++ b/sys/vm/vm_page.c @@ -1812,10 +1812,9 @@ void vm_page_cowclear(vm_page_t m) { - /* XXX KDM find out if giant is required here. */ - GIANT_REQUIRED; + mtx_assert(&vm_page_queue_mtx, MA_OWNED); if (m->cow) { - atomic_subtract_int(&m->cow, 1); + m->cow--; /* * let vm_fault add back write permission lazily */ @@ -1828,9 +1827,9 @@ vm_page_cowclear(vm_page_t m) void vm_page_cowsetup(vm_page_t m) { - /* XXX KDM find out if giant is required here */ - GIANT_REQUIRED; - atomic_add_int(&m->cow, 1); + + mtx_assert(&vm_page_queue_mtx, MA_OWNED); + m->cow++; vm_page_protect(m, VM_PROT_READ); }