svn commit: r250909 - head/sys/vm
Attilio Rao
attilio at FreeBSD.org
Wed May 22 15:11:01 UTC 2013
Author: attilio
Date: Wed May 22 15:11:00 2013
New Revision: 250909
URL: http://svnweb.freebsd.org/changeset/base/250909
Log:
Acquire read lock on the src object for vm_fault_copy_entry().
Sponsored by: EMC / Isilon storage division
Reviewed by: alc
Modified:
head/sys/vm/vm_fault.c
Modified: head/sys/vm/vm_fault.c
==============================================================================
--- head/sys/vm/vm_fault.c Wed May 22 12:59:39 2013 (r250908)
+++ head/sys/vm/vm_fault.c Wed May 22 15:11:00 2013 (r250909)
@@ -1318,7 +1318,7 @@ vm_fault_copy_entry(vm_map_t dst_map, vm
* (Because the source is wired down, the page will be in
* memory.)
*/
- VM_OBJECT_WLOCK(src_object);
+ VM_OBJECT_RLOCK(src_object);
object = src_object;
pindex = src_pindex + dst_pindex;
while ((src_m = vm_page_lookup(object, pindex)) == NULL &&
@@ -1327,15 +1327,15 @@ vm_fault_copy_entry(vm_map_t dst_map, vm
/*
* Allow fallback to backing objects if we are reading.
*/
- VM_OBJECT_WLOCK(backing_object);
+ VM_OBJECT_RLOCK(backing_object);
pindex += OFF_TO_IDX(object->backing_object_offset);
- VM_OBJECT_WUNLOCK(object);
+ VM_OBJECT_RUNLOCK(object);
object = backing_object;
}
if (src_m == NULL)
panic("vm_fault_copy_wired: page missing");
pmap_copy_page(src_m, dst_m);
- VM_OBJECT_WUNLOCK(object);
+ VM_OBJECT_RUNLOCK(object);
dst_m->valid = VM_PAGE_BITS_ALL;
dst_m->dirty = VM_PAGE_BITS_ALL;
VM_OBJECT_WUNLOCK(dst_object);
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