curl: Report only ready sockets

Instead of reporting all sockets to cURL, only report the one that has
caused curl_multi_do_locked() to be called.  This lets us get rid of the
QLIST_FOREACH_SAFE() list, which was actually wrong: SAFE foreaches are
only safe when the current element is removed in each iteration.  If it
possible for the list to be concurrently modified, we cannot guarantee
that only the current element will be removed.  Therefore, we must not
use QLIST_FOREACH_SAFE() here.

Fixes: ff5ca1664a
Cc: qemu-stable@nongnu.org
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20190910124136.10565-6-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 9abaf9fc47)
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
stable-4.0
Max Reitz 2019-09-10 14:41:34 +02:00 committed by Michael Roth
parent 076796fd39
commit deea66dc61
1 changed files with 6 additions and 11 deletions

View File

@ -391,24 +391,19 @@ static void curl_multi_check_completion(BDRVCURLState *s)
}
/* Called with s->mutex held. */
static void curl_multi_do_locked(CURLSocket *ready_socket)
static void curl_multi_do_locked(CURLSocket *socket)
{
CURLSocket *socket, *next_socket;
CURLState *s = ready_socket->state;
BDRVCURLState *s = socket->state->s;
int running;
int r;
if (!s->s->multi) {
if (!s->multi) {
return;
}
/* Need to use _SAFE because curl_multi_socket_action() may trigger
* curl_sock_cb() which might modify this list */
QLIST_FOREACH_SAFE(socket, &s->sockets, next, next_socket) {
do {
r = curl_multi_socket_action(s->s->multi, socket->fd, 0, &running);
} while (r == CURLM_CALL_MULTI_PERFORM);
}
do {
r = curl_multi_socket_action(s->multi, socket->fd, 0, &running);
} while (r == CURLM_CALL_MULTI_PERFORM);
}
static void curl_multi_do(void *arg)