Change 208382 by pjd@pjd_slayer on 2012/03/22 17:57:29

	Currently on each record write we call VFS_STATFS() to get available
	space on the file system as well as VOP_GETATTR() to get trail file
	size.
	
	We can assume that trail file is only updated by the audit worker,
	so instead of asking for file size on every write, get file size
	on trail switch only (it should be zero, but it's not expensive)
	and use global variable audit_size protected by the audit worker
	lock to keep track of trail file's size.
	
	This eliminates VOP_GETATTR() call for every write.

Affected files ...

... //depot/user/pjd/auditdistd/sys/security/audit/audit_worker.c#3 edit

Differences ...

==== //depot/user/pjd/auditdistd/sys/security/audit/audit_worker.c#3 (text) ====

@@ -88,6 +88,7 @@
 static int		 audit_file_rotate_wait;
 static struct ucred	*audit_cred;
 static struct vnode	*audit_vp;
+static off_t		 audit_size;
 static struct sx	 audit_worker_lock;
 
 #define	AUDIT_WORKER_LOCK_INIT()	sx_init(&audit_worker_lock, \
@@ -115,7 +116,6 @@
 	struct statfs *mnt_stat;
 	int error, vfslocked;
 	static int cur_fail;
-	struct vattr vattr;
 	long temp;
 
 	AUDIT_WORKER_LOCK_ASSERT();
@@ -134,12 +134,6 @@
 	error = VFS_STATFS(vp->v_mount, mnt_stat);
 	if (error)
 		goto fail;
-	vn_lock(vp, LK_SHARED | LK_RETRY);
-	error = VOP_GETATTR(vp, &vattr, cred);
-	VOP_UNLOCK(vp, 0);
-	if (error)
-		goto fail;
-	audit_fstat.af_currsz = vattr.va_size;
 
 	/*
 	 * We handle four different space-related limits:
@@ -197,7 +191,7 @@
 	 * records may be generated before the daemon rotates the file.
 	 */
 	if ((audit_fstat.af_filesz != 0) && (audit_file_rotate_wait == 0) &&
-	    (vattr.va_size >= audit_fstat.af_filesz)) {
+	    (audit_size >= audit_fstat.af_filesz)) {
 		AUDIT_WORKER_LOCK_ASSERT();
 
 		audit_file_rotate_wait = 1;
@@ -239,6 +233,8 @@
 		goto fail_enospc;
 	else if (error)
 		goto fail;
+	AUDIT_WORKER_LOCK_ASSERT();
+	audit_size += len;
 
 	/*
 	 * Catch completion of a queue drain here; if we're draining and the
@@ -451,11 +447,21 @@
 {
 	struct ucred *old_audit_cred;
 	struct vnode *old_audit_vp;
+	struct vattr vattr;
 	int vfslocked;
 
 	KASSERT((cred != NULL && vp != NULL) || (cred == NULL && vp == NULL),
 	    ("audit_rotate_vnode: cred %p vp %p", cred, vp));
 
+	if (vp != NULL) {
+		vn_lock(vp, LK_SHARED | LK_RETRY);
+		if (VOP_GETATTR(vp, &vattr, cred) != 0)
+			vattr.va_size = 0;
+		VOP_UNLOCK(vp, 0);
+	} else {
+		vattr.va_size = 0;
+	}
+
 	/*
 	 * Rotate the vnode/cred, and clear the rotate flag so that we will
 	 * send a rotate trigger if the new file fills.
@@ -465,6 +471,7 @@
 	old_audit_vp = audit_vp;
 	audit_cred = cred;
 	audit_vp = vp;
+	audit_size = vattr.va_size;
 	audit_file_rotate_wait = 0;
 	audit_enabled = (audit_vp != NULL);
 	AUDIT_WORKER_UNLOCK();