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Lock the vm_object when updating its shadow list.

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This commit is contained in:
alc 2003-05-02 04:55:21 +00:00
parent dbd34846bd
commit 3b6c8feea3
1 changed files with 10 additions and 2 deletions
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12
sys/vm/vm_object.c
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@ -1529,8 +1529,8 @@ vm_object_collapse(vm_object_t object)
/*
* Move the pager from backing_object to object.
*/
VM_OBJECT_LOCK(backing_object);
if (backing_object->type == OBJT_SWAP) {
VM_OBJECT_LOCK(backing_object);
vm_object_pip_add(backing_object, 1);
VM_OBJECT_UNLOCK(backing_object);
/*
@ -1554,7 +1554,6 @@ vm_object_collapse(vm_object_t object)
VM_OBJECT_LOCK(backing_object);
vm_object_pip_wakeup(backing_object);
VM_OBJECT_UNLOCK(backing_object);
}
/*
* Object now shadows whatever backing_object did.
@ -1570,6 +1569,7 @@ vm_object_collapse(vm_object_t object)
backing_object->shadow_count--;
backing_object->generation++;
if (backing_object->backing_object) {
VM_OBJECT_LOCK(backing_object->backing_object);
TAILQ_REMOVE(
&backing_object->backing_object->shadow_head,
backing_object,
@ -1577,9 +1577,11 @@ vm_object_collapse(vm_object_t object)
);
backing_object->backing_object->shadow_count--;
backing_object->backing_object->generation++;
VM_OBJECT_UNLOCK(backing_object->backing_object);
}
object->backing_object = backing_object->backing_object;
if (object->backing_object) {
VM_OBJECT_LOCK(object->backing_object);
TAILQ_INSERT_TAIL(
&object->backing_object->shadow_head,
object,
@ -1587,6 +1589,7 @@ vm_object_collapse(vm_object_t object)
);
object->backing_object->shadow_count++;
object->backing_object->generation++;
VM_OBJECT_UNLOCK(object->backing_object);
}
object->backing_object_offset +=
@ -1601,6 +1604,7 @@ vm_object_collapse(vm_object_t object)
*/
KASSERT(backing_object->ref_count == 1, ("backing_object %p was somehow re-referenced during collapse!", backing_object));
KASSERT(TAILQ_FIRST(&backing_object->memq) == NULL, ("backing_object %p somehow has left over pages during collapse!", backing_object));
VM_OBJECT_UNLOCK(backing_object);
mtx_lock(&vm_object_list_mtx);
TAILQ_REMOVE(
@ -1629,6 +1633,7 @@ vm_object_collapse(vm_object_t object)
* chain. Deallocating backing_object will not remove
* it, since its reference count is at least 2.
*/
VM_OBJECT_LOCK(backing_object);
TAILQ_REMOVE(
&backing_object->shadow_head,
object,
@ -1636,10 +1641,12 @@ vm_object_collapse(vm_object_t object)
);
backing_object->shadow_count--;
backing_object->generation++;
VM_OBJECT_UNLOCK(backing_object);
new_backing_object = backing_object->backing_object;
if ((object->backing_object = new_backing_object) != NULL) {
vm_object_reference(new_backing_object);
VM_OBJECT_LOCK(new_backing_object);
TAILQ_INSERT_TAIL(
&new_backing_object->shadow_head,
object,
@ -1647,6 +1654,7 @@ vm_object_collapse(vm_object_t object)
);
new_backing_object->shadow_count++;
new_backing_object->generation++;
VM_OBJECT_UNLOCK(new_backing_object);
object->backing_object_offset +=
backing_object->backing_object_offset;
}