Commit 08ace1d7 authored by Eric Blake's avatar Eric Blake
Browse files

nbd: Don't crash when server reports NBD_CMD_READ failure 



If a server fails a read, for example with EIO, but the connection
is still live, then we would crash trying to print a non-existent
error message in nbd_client_co_preadv().  For consistency, also
change the error printout in nbd_read_reply_entry(), although that
instance does not crash.  Bug introduced in commit f140e300.

Signed-off-by: default avatarEric Blake <eblake@redhat.com>
Message-Id: <20171112013936.5942-1-eblake@redhat.com>
Reviewed-by: default avatarVladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
parent fec035a5

block/nbd-client.c

+2 −2
Original line number Diff line number Diff line
@@ -78,7 +78,7 @@ static coroutine_fn void nbd_read_reply_entry(void *opaque) 
    while (!s->quit) {

        assert(s->reply.handle == 0);

        ret = nbd_receive_reply(s->ioc, &s->reply, &local_err);

        if (ret < 0) {

        if (local_err) {

            error_report_err(local_err);

        }

        if (ret <= 0) {
@@ -691,7 +691,7 @@ int nbd_client_co_preadv(BlockDriverState *bs, uint64_t offset, 


    ret = nbd_co_receive_cmdread_reply(client, request.handle, offset, qiov,

                                       &local_err);

    if (ret < 0) {

    if (local_err) {

        error_report_err(local_err);

    }

    return ret;