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authorAlan Cox <alc@FreeBSD.org>2012-05-24 04:09:47 +0000
committerAlan Cox <alc@FreeBSD.org>2012-05-24 04:09:47 +0000
commit0ba66380cd392ac11b7bd447ae7128f0e5a7837d (patch)
tree76a5a08ad90e25fb885068602981159a030387fe /sys/vm/vm_map.c
parent6646b90c1364b89e17b3f232b0dc4436cc8dd7ad (diff)
Notes
Diffstat (limited to 'sys/vm/vm_map.c')
-rw-r--r--sys/vm/vm_map.c24
1 files changed, 10 insertions, 14 deletions
diff --git a/sys/vm/vm_map.c b/sys/vm/vm_map.c
index e6e04345074a..45a9d9020cff 100644
--- a/sys/vm/vm_map.c
+++ b/sys/vm/vm_map.c
@@ -3087,27 +3087,25 @@ struct vmspace *
vmspace_fork(struct vmspace *vm1, vm_ooffset_t *fork_charge)
{
struct vmspace *vm2;
- vm_map_t old_map = &vm1->vm_map;
- vm_map_t new_map;
- vm_map_entry_t old_entry;
- vm_map_entry_t new_entry;
+ vm_map_t new_map, old_map;
+ vm_map_entry_t new_entry, old_entry;
vm_object_t object;
int locked;
- vm_map_lock(old_map);
- if (old_map->busy)
- vm_map_wait_busy(old_map);
- new_map = NULL; /* silence gcc */
+ old_map = &vm1->vm_map;
+ /* Copy immutable fields of vm1 to vm2. */
vm2 = vmspace_alloc(old_map->min_offset, old_map->max_offset);
if (vm2 == NULL)
- goto unlock_and_return;
+ return (NULL);
vm2->vm_taddr = vm1->vm_taddr;
vm2->vm_daddr = vm1->vm_daddr;
vm2->vm_maxsaddr = vm1->vm_maxsaddr;
- new_map = &vm2->vm_map; /* XXX */
+ vm_map_lock(old_map);
+ if (old_map->busy)
+ vm_map_wait_busy(old_map);
+ new_map = &vm2->vm_map;
locked = vm_map_trylock(new_map); /* trylock to silence WITNESS */
KASSERT(locked, ("vmspace_fork: lock failed"));
- new_map->timestamp = 1;
old_entry = old_map->header.next;
@@ -3228,15 +3226,13 @@ vmspace_fork(struct vmspace *vm1, vm_ooffset_t *fork_charge)
}
old_entry = old_entry->next;
}
-unlock_and_return:
/*
* Use inlined vm_map_unlock() to postpone handling the deferred
* map entries, which cannot be done until both old_map and
* new_map locks are released.
*/
sx_xunlock(&old_map->lock);
- if (vm2 != NULL)
- sx_xunlock(&new_map->lock);
+ sx_xunlock(&new_map->lock);
vm_map_process_deferred();
return (vm2);