afs: Use op->nr_iterations=-1 to indicate to begin fileserver iteration

Set op->nr_iterations to -1 to indicate that we need to begin fileserver
iteration rather than setting error to SHRT_MAX.  This makes it easier to
eliminate the address cursor.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org

fs/afs/fs_operation.c

@@ -41,7 +41,7 @@ struct afs_operation *afs_alloc_operation(struct key *key, struct afs_volume *vo
 	op->cb_v_break	= volume->cb_v_break;
 	op->debug_id	= atomic_inc_return(&afs_operation_debug_counter);
 	op->error	= -EDESTADDRREQ;
-	op->ac.error	= SHRT_MAX;
+	op->nr_iterations = -1;
 
 	_leave(" = [op=%08x]", op->debug_id);
 	return op;

fs/afs/internal.h

@@ -859,7 +859,7 @@ struct afs_operation {
 	struct afs_call		*call;
 	unsigned long		untried;	/* Bitmask of untried servers */
 	short			index;		/* Current server */
-	unsigned short		nr_iterations;	/* Number of server iterations */
+	short			nr_iterations;	/* Number of server iterations */
 
 	unsigned int		flags;
 #define AFS_OPERATION_STOP		0x0001	/* Set to cease iteration */

fs/afs/rotate.c

@@ -116,7 +116,10 @@ bool afs_select_fileserver(struct afs_operation *op)
 	unsigned int rtt;
 	int error = op->ac.error, i;
 
-	_enter("%lx[%d],%lx[%d],%d,%d",
+	op->nr_iterations++;
+
+	_enter("OP=%x+%x,%llx,%lx[%d],%lx[%d],%d,%d",
+	       op->debug_id, op->nr_iterations, op->volume->vid,
 	       op->untried, op->index,
 	       op->ac.tried, op->ac.index,
 	       error, op->ac.abort_code);
@@ -126,13 +129,11 @@ bool afs_select_fileserver(struct afs_operation *op)
 		return false;
 	}
 
-	op->nr_iterations++;
+	if (op->nr_iterations == 0)
+		goto start;
 
 	/* Evaluate the result of the previous operation, if there was one. */
 	switch (error) {
-	case SHRT_MAX:
-		goto start;
-
 	case 0:
 	default:
 		/* Success or local failure.  Stop. */