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Fix the assertions for the state of the object under the map entry

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with the MAP_ENTRY_VN_WRITECNT flag:
- Move the assertion that verifies the state of the v_writecount and
  vnp.writecount, under the block where the object is locked.
- Check that the object type is OBJT_VNODE before asserting.

Reported by:	avg
Reviewed by:	alc
MFC after:	1 week
This commit is contained in:
kib 2013-04-09 10:04:10 +00:00
parent 99469b7e8a
commit d5061cb1cd
1 changed files with 16 additions and 6 deletions
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22
sys/vm/vm_map.c
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@ -3160,6 +3160,22 @@ vmspace_fork(struct vmspace *vm1, vm_ooffset_t *fork_charge)
object->charge = old_entry->end - old_entry->start;
old_entry->cred = NULL;
}
/*
* Assert the correct state of the vnode
* v_writecount while the object is locked, to
* not relock it later for the assertion
* correctness.
*/
if (old_entry->eflags & MAP_ENTRY_VN_WRITECNT &&
object->type == OBJT_VNODE) {
KASSERT(((struct vnode *)object->handle)->
v_writecount > 0,
("vmspace_fork: v_writecount %p", object));
KASSERT(object->un_pager.vnp.writemappings > 0,
("vmspace_fork: vnp.writecount %p",
object));
}
VM_OBJECT_WUNLOCK(object);
/*
@ -3171,12 +3187,6 @@ vmspace_fork(struct vmspace *vm1, vm_ooffset_t *fork_charge)
MAP_ENTRY_IN_TRANSITION);
new_entry->wired_count = 0;
if (new_entry->eflags & MAP_ENTRY_VN_WRITECNT) {
object = new_entry->object.vm_object;
KASSERT(((struct vnode *)object->handle)->
v_writecount > 0,
("vmspace_fork: v_writecount"));
KASSERT(object->un_pager.vnp.writemappings > 0,
("vmspace_fork: vnp.writecount"));
vnode_pager_update_writecount(object,
new_entry->start, new_entry->end);
}