Remove MaxConnsPerHost settings to avoid potential hangs (#10438)

MaxConnsPerHost can potentially hang a call without any
way to timeout, we do not need this setting for our proxy
and gateway implementations instead IdleConn settings are
good enough.

Also ensure to use NewRequestWithContext and make sure to
take the disks offline only for network errors.

Fixes #10304

cmd/rest/client.go

@@ -27,6 +27,7 @@ import (
 	"time"
 
 	xhttp "github.com/minio/minio/cmd/http"
+	xnet "github.com/minio/minio/pkg/net"
 )
 
 // DefaultRESTTimeout - default RPC timeout is one minute.
@@ -100,11 +101,13 @@ func (c *Client) Call(ctx context.Context, method string, values url.Values, bod
 	if !c.IsOnline() {
 		return nil, &NetworkError{Err: &url.Error{Op: method, URL: c.url.String(), Err: restError("remote server offline")}}
 	}
-	req, err := http.NewRequest(http.MethodPost, c.url.String()+method+querySep+values.Encode(), body)
+	req, err := http.NewRequestWithContext(ctx, http.MethodPost, c.url.String()+method+querySep+values.Encode(), body)
 	if err != nil {
+		if xnet.IsNetworkOrHostDown(err) {
+			c.MarkOffline()
+		}
 		return nil, &NetworkError{err}
 	}
-	req = req.WithContext(ctx)
 	req.Header.Set("Authorization", "Bearer "+c.newAuthToken(req.URL.Query().Encode()))
 	req.Header.Set("X-Minio-Time", time.Now().UTC().Format(time.RFC3339))
 	if length > 0 {
@@ -112,9 +115,7 @@ func (c *Client) Call(ctx context.Context, method string, values url.Values, bod
 	}
 	resp, err := c.httpClient.Do(req)
 	if err != nil {
-		// A canceled context doesn't always mean a network problem.
-		if !errors.Is(err, context.Canceled) {
-			// We are safe from recursion
+		if xnet.IsNetworkOrHostDown(err) || errors.Is(err, context.DeadlineExceeded) {
 			c.MarkOffline()
 		}
 		return nil, &NetworkError{err}