From d8de6fc3530b5cfa05485f24e14af4ce44a8b72d Mon Sep 17 00:00:00 2001
From: Max Reitz <mreitz@redhat.com>
Date: Tue, 19 Nov 2019 15:30:00 +0000
Subject: [PATCH 8/8] curl: Check curl_multi_add_handle()'s return code
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RH-Author: Max Reitz <mreitz@redhat.com>
Message-id: <20191119153000.101646-8-mreitz@redhat.com>
Patchwork-id: 92521
O-Subject: [RHEL-8.2.0 qemu-kvm PATCH 7/7] curl: Check curl_multi_add_handle()'s return code
Bugzilla: 1744602
RH-Acked-by: Maxim Levitsky <mlevitsk@redhat.com>
RH-Acked-by: Philippe Mathieu-Daudé <philmd@redhat.com>
RH-Acked-by: Stefano Garzarella <sgarzare@redhat.com>

If we had done that all along, debugging would have been much simpler.
(Also, I/O errors are better than hangs.)

Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20190910124136.10565-8-mreitz@redhat.com
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
(cherry picked from commit c34dc07f9f01cf686e512f939aece744723072cd)
Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Danilo C. L. de Paula <ddepaula@redhat.com>
---
 block/curl.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/block/curl.c b/block/curl.c
index b5899e1..5d05d30 100644
--- a/block/curl.c
+++ b/block/curl.c
@@ -891,7 +891,13 @@ static void curl_setup_preadv(BlockDriverState *bs, CURLAIOCB *acb)
             acb->bytes, start, state->range);
     curl_easy_setopt(state->curl, CURLOPT_RANGE, state->range);
 
-    curl_multi_add_handle(s->multi, state->curl);
+    if (curl_multi_add_handle(s->multi, state->curl) != CURLM_OK) {
+        state->acb[0] = NULL;
+        acb->ret = -EIO;
+
+        curl_clean_state(state);
+        goto out;
+    }
 
     /* Tell curl it needs to kick things off */
     curl_multi_socket_action(s->multi, CURL_SOCKET_TIMEOUT, 0, &running);
-- 
1.8.3.1