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| author | Leonardo Bras | 2022-07-11 23:11:11 +0200 |
|---|---|---|
| committer | Dr. David Alan Gilbert | 2022-07-20 13:15:09 +0200 |
| commit | 927f93e099c4f9184e60a1bc61624ac2d04d0223 (patch) | |
| tree | fdc23458934876fe4fe162689be5004f2ee75981 | |
| parent | migration: remove unreachable code after reading data (diff) | |
| download | qemu-927f93e099c4f9184e60a1bc61624ac2d04d0223.tar.gz qemu-927f93e099c4f9184e60a1bc61624ac2d04d0223.tar.xz qemu-927f93e099c4f9184e60a1bc61624ac2d04d0223.zip | |
QIOChannelSocket: Fix zero-copy flush returning code 1 when nothing sent
If flush is called when no buffer was sent with MSG_ZEROCOPY, it currently
returns 1. This return code should be used only when Linux fails to use
MSG_ZEROCOPY on a lot of sendmsg().
Fix this by returning early from flush if no sendmsg(...,MSG_ZEROCOPY)
was attempted.
Fixes: 2bc58ffc2926 ("QIOChannelSocket: Implement io_writev zero copy flag & io_flush for CONFIG_LINUX")
Signed-off-by: Leonardo Bras <leobras@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Acked-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Message-Id: <20220711211112.18951-2-leobras@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
| -rw-r--r-- | io/channel-socket.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/io/channel-socket.c b/io/channel-socket.c index 4466bb1cd4..74a936cc1f 100644 --- a/io/channel-socket.c +++ b/io/channel-socket.c @@ -716,12 +716,18 @@ static int qio_channel_socket_flush(QIOChannel *ioc, struct cmsghdr *cm; char control[CMSG_SPACE(sizeof(*serr))]; int received; - int ret = 1; + int ret; + + if (sioc->zero_copy_queued == sioc->zero_copy_sent) { + return 0; + } msg.msg_control = control; msg.msg_controllen = sizeof(control); memset(control, 0, sizeof(control)); + ret = 1; + while (sioc->zero_copy_sent < sioc->zero_copy_queued) { received = recvmsg(sioc->fd, &msg, MSG_ERRQUEUE); if (received < 0) { |