From 172f5f1a4058c361bfcd19317b0e3151556b3edb Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Thu, 14 Apr 2022 19:57:50 +0200 Subject: nbd: remove peppering of nbd_client_connected It is unnecessary to check nbd_client_connected() because every time s->state is moved out of NBD_CLIENT_CONNECTED the socket is shut down and all coroutines are resumed. The only case where it was actually needed is when the NBD server disconnects and there is no reconnect-delay. In that case, nbd_receive_replies() does not set s->reply.handle and nbd_co_do_receive_one_chunk() cannot continue. For that one case, check the return value of nbd_receive_replies(). As to the others: * nbd_receive_replies() can put the current coroutine to sleep if another reply is ongoing; then it will be woken by nbd_channel_error(), called by the ongoing reply. Or it can try itself to read a reply header and fail, thus calling nbd_channel_error() itself. * nbd_co_send_request() will write the body of the request and fail * nbd_reply_chunk_iter_receive() will call nbd_co_receive_one_chunk() and then nbd_co_do_receive_one_chunk(), which will handle the failure as above; or it will just detect a previous call to nbd_iter_channel_error() via iter->ret < 0. Reviewed-by: Eric Blake Signed-off-by: Paolo Bonzini Message-Id: <20220414175756.671165-4-pbonzini@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy Reviewed-by: Lukas Straub Signed-off-by: Eric Blake --- block/nbd.c | 17 ++++------------- 1 file changed, 4 insertions(+), 13 deletions(-) (limited to 'block') diff --git a/block/nbd.c b/block/nbd.c index 3a6e609203..326546f6cd 100644 --- a/block/nbd.c +++ b/block/nbd.c @@ -409,10 +409,6 @@ static coroutine_fn int nbd_receive_replies(BDRVNBDState *s, uint64_t handle) return 0; } - if (!nbd_client_connected(s)) { - return -EIO; - } - if (s->reply.handle != 0) { /* * Some other request is being handled now. It should already be @@ -512,7 +508,7 @@ static int coroutine_fn nbd_co_send_request(BlockDriverState *bs, if (qiov) { qio_channel_set_cork(s->ioc, true); rc = nbd_send_request(s->ioc, request); - if (nbd_client_connected(s) && rc >= 0) { + if (rc >= 0) { if (qio_channel_writev_all(s->ioc, qiov->iov, qiov->niov, NULL) < 0) { rc = -EIO; @@ -829,8 +825,8 @@ static coroutine_fn int nbd_co_do_receive_one_chunk( } *request_ret = 0; - nbd_receive_replies(s, handle); - if (!nbd_client_connected(s)) { + ret = nbd_receive_replies(s, handle); + if (ret < 0) { error_setg(errp, "Connection closed"); return -EIO; } @@ -982,11 +978,6 @@ static bool nbd_reply_chunk_iter_receive(BDRVNBDState *s, NBDReply local_reply; NBDStructuredReplyChunk *chunk; Error *local_err = NULL; - if (!nbd_client_connected(s)) { - error_setg(&local_err, "Connection closed"); - nbd_iter_channel_error(iter, -EIO, &local_err); - goto break_loop; - } if (iter->done) { /* Previous iteration was last. */ @@ -1007,7 +998,7 @@ static bool nbd_reply_chunk_iter_receive(BDRVNBDState *s, } /* Do not execute the body of NBD_FOREACH_REPLY_CHUNK for simple reply. */ - if (nbd_reply_is_simple(reply) || !nbd_client_connected(s)) { + if (nbd_reply_is_simple(reply) || iter->ret < 0) { goto break_loop; } -- cgit v1.2.3