Properly synchronize access to the page's hold_count in vfs_vmio_release().

Reviewed by:	kib

1 files changed, 6 insertions, 6 deletions

diff --git a/sys/kern/vfs_bio.c b/sys/kern/vfs_bio.c
index dbcd6e8..1048998 100644
--- a/sys/kern/vfs_bio.c
+++ b/sys/kern/vfs_bio.c
@@ -1563,7 +1563,6 @@ vfs_vmio_release(struct buf *bp)
 	vm_page_t m;
 
 	VM_OBJECT_LOCK(bp->b_bufobj->bo_object);
-	vm_page_lock_queues();
 	for (i = 0; i < bp->b_npages; i++) {
 		m = bp->b_pages[i];
 		bp->b_pages[i] = NULL;
@@ -1571,16 +1570,16 @@ vfs_vmio_release(struct buf *bp)
 		 * In order to keep page LRU ordering consistent, put
 		 * everything on the inactive queue.
 		 */
+		vm_page_lock(m);
+		vm_page_lock_queues();
 		vm_page_unwire(m, 0);
 		/*
 		 * We don't mess with busy pages, it is
 		 * the responsibility of the process that
 		 * busied the pages to deal with them.
 		 */
-		if ((m->oflags & VPO_BUSY) || (m->busy != 0))
-			continue;
-			
-		if (m->wire_count == 0) {
+		if ((m->oflags & VPO_BUSY) == 0 && m->busy == 0 &&
+		    m->wire_count == 0) {
 			/*
 			 * Might as well free the page if we can and it has
 			 * no valid data.  We also free the page if the
@@ -1595,8 +1594,9 @@ vfs_vmio_release(struct buf *bp)
 				vm_page_try_to_cache(m);
 			}
 		}
+		vm_page_unlock_queues();
+		vm_page_unlock(m);
 	}
-	vm_page_unlock_queues();
 	VM_OBJECT_UNLOCK(bp->b_bufobj->bo_object);
 	pmap_qremove(trunc_page((vm_offset_t) bp->b_data), bp->b_npages);