- BUF_REFCNT() seems to be the preferred method for verifying a locked buf.

   Tell vop_strategy_pre() to use this instead.
 - Ignore B_CLUSTER bufs.  Their components are locked but they don't really
   exist so they don't have to be.  This isn't ideal but it is safe.

1 files changed, 9 insertions, 3 deletions

diff --git a/sys/kern/vfs_subr.c b/sys/kern/vfs_subr.c
index 83c7bec..059b50b 100644
--- a/sys/kern/vfs_subr.c
+++ b/sys/kern/vfs_subr.c
@@ -257,11 +257,17 @@ void
 vop_strategy_pre(void *ap)
 {
 	struct vop_strategy_args *a = ap;
-	int status;
+	struct buf *bp;
 
-	status = lockstatus(&a->a_bp->b_lock, curthread);
+	bp = a->a_bp;
 
-	if (status != LK_SHARED && status != LK_EXCLUSIVE) {
+	/*
+	 * Cluster ops lock their component buffers but not the IO container.
+	 */
+	if ((bp->b_flags & B_CLUSTER) != 0)
+		return;
+
+	if (BUF_REFCNT(bp) < 1) {
 		if (vfs_badlock_print)
 			printf("VOP_STRATEGY: bp is not locked but should be.\n");
 		if (vfs_badlock_panic)