rest client: Expect context timeouts for locks (#10782)

Add option for rest clients to not mark a remote offline for context timeouts.

This can be used if context timeouts are expected on the call.

cmd/rest/client.go

@@ -77,6 +77,10 @@ type Client struct {
 	// Should only be modified before any calls are made.
 	MaxErrResponseSize int64
 
+	// ExpectTimeouts indicates if context timeouts are expected.
+	// This will not mark the client offline in these cases.
+	ExpectTimeouts bool
+
 	httpClient   *http.Client
 	url          *url.URL
 	newAuthToken func(audience string) string
@@ -114,7 +118,7 @@ func (c *Client) Call(ctx context.Context, method string, values url.Values, bod
 	}
 	resp, err := c.httpClient.Do(req)
 	if err != nil {
-		if xnet.IsNetworkOrHostDown(err) {
+		if xnet.IsNetworkOrHostDown(err, c.ExpectTimeouts) {
 			logger.LogIf(ctx, err, "marking disk offline")
 			c.MarkOffline()
 		}
@@ -144,7 +148,7 @@ func (c *Client) Call(ctx context.Context, method string, values url.Values, bod
 		// Limit the ReadAll(), just in case, because of a bug, the server responds with large data.
 		b, err := ioutil.ReadAll(io.LimitReader(resp.Body, c.MaxErrResponseSize))
 		if err != nil {
-			if xnet.IsNetworkOrHostDown(err) {
+			if xnet.IsNetworkOrHostDown(err, c.ExpectTimeouts) {
 				logger.LogIf(ctx, err, "marking disk offline")
 				c.MarkOffline()
 			}