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author | Paolo Bonzini <pbonzini@redhat.com> | 2022-04-14 19:57:50 +0200 |
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committer | Eric Blake <eblake@redhat.com> | 2022-04-26 13:16:36 -0500 |
commit | 172f5f1a4058c361bfcd19317b0e3151556b3edb (patch) | |
tree | 75b8b2e04cef5dfe4954ff5a51c32e0e71c5097f | |
parent | 0c43c6fc896ff0894627b9464c3db94a33c8c7ac (diff) | |
download | qemu-172f5f1a4058c361bfcd19317b0e3151556b3edb.zip qemu-172f5f1a4058c361bfcd19317b0e3151556b3edb.tar.gz qemu-172f5f1a4058c361bfcd19317b0e3151556b3edb.tar.bz2 |
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 <eblake@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20220414175756.671165-4-pbonzini@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@openvz.org>
Reviewed-by: Lukas Straub <lukasstraub2@web.de>
Signed-off-by: Eric Blake <eblake@redhat.com>
-rw-r--r-- | block/nbd.c | 17 |
1 files changed, 4 insertions, 13 deletions
diff --git a/block/nbd.c b/block/nbd.c index 3a6e609..326546f 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; } |