Revert r253939:

We cannot busy a page before doing pagefaults.
Infact, it can deadlock against vnode lock, as it tries to vget().
Other functions, right now, have an opposite lock ordering, like
vm_object_sync(), which acquires the vnode lock first and then
sleeps on the busy mechanism.

Before this patch is reinserted we need to break this ordering.

Sponsored by:	EMC / Isilon storage division
Reported by:	kib

1 files changed, 2 insertions, 2 deletions

diff --git a/sys/kern/kern_exec.c b/sys/kern/kern_exec.c
index 0c8b0c1..c0e1435 100644
--- a/sys/kern/kern_exec.c
+++ b/sys/kern/kern_exec.c
@@ -973,7 +973,7 @@ exec_map_first_page(imgp)
 		vm_page_wakeup(ma[0]);
 	}
 	vm_page_lock(ma[0]);
-	vm_page_wire(ma[0]);
+	vm_page_hold(ma[0]);
 	vm_page_unlock(ma[0]);
 	VM_OBJECT_WUNLOCK(object);
 
@@ -994,7 +994,7 @@ exec_unmap_first_page(imgp)
 		sf_buf_free(imgp->firstpage);
 		imgp->firstpage = NULL;
 		vm_page_lock(m);
-		vm_page_unwire(m, 0);
+		vm_page_unhold(m);
 		vm_page_unlock(m);
 	}
 }