search for: prepare_for_reply_payload

...is short enough to fit in the - * static buffer. If it's too long, skip it. - */ - len = be32toh (h->sbuf.or.option_reply.replylen); - if (len <= maxpayload) - h->rbuf = &h->sbuf.or.payload; - else - h->rbuf = NULL; - h->rlen = len; + if (prepare_for_reply_payload (h, NBD_OPT_GO) == -1) { + SET_NEXT_STATE (%.DEAD); + return -1; + } SET_NEXT_STATE (%RECV_REPLY_PAYLOAD); } return 0; @@ -104,8 +96,6 @@ return 0; NEWSTYLE.OPT_GO.CHECK_REPLY: - uint64_t magic; - uint32_t option; uint32_t reply; uint32_t len; const size_t m...

I'm still playing with ideas on how to split rstate from wstate (so that we can send a request without waiting for POLLIN to complete a pending reply), but this is some preliminary refactoring I found useful. I also fixed a couple of bugs while in the area (already pushed). There's a question of whether we want nbd_handle to be nearly 5k, or if we should instead keep it small and add one

...; case 0: h->rbuf = &h->sbuf; h->rlen = sizeof h->sbuf.or.option_reply; @@ -78,11 +78,11 @@ NEWSTYLE.OPT_GO.RECV_REPLY: switch (recv_into_rbuf (h)) { - case -1: SET_NEXT_STATE (%.DEAD); return -1; + case -1: SET_NEXT_STATE (%.DEAD); return 0; case 0: if (prepare_for_reply_payload (h, NBD_OPT_GO) == -1) { SET_NEXT_STATE (%.DEAD); - return -1; + return 0; } SET_NEXT_STATE (%RECV_REPLY_PAYLOAD); } @@ -90,7 +90,7 @@ NEWSTYLE.OPT_GO.RECV_REPLY_PAYLOAD: switch (recv_into_rbuf (h)) { - case -1: SET_NEXT_STATE (%.DEAD); return -1; + case -1: SE...

...errors, it's worth > logging (at least through debug) any error messages that the server > sends alongside NBD_REP_ERR. And given our earlier changes, it > doesn't really impact the size of struct nbd_handle. > --- > +++ b/generator/states-newstyle.c > @@ -77,6 +77,35 @@ prepare_for_reply_payload (struct nbd_handle *h, uint32_t opt) > return 0; > } > > +/* Check an unexpected server reply. If it is an error, log any > + * message from the server and return 0; otherwise, return -1. > + */ > +static int > +handle_reply_error (struct nbd_handle *h) > +{ > +...

...+-- generator/states-reply-structured.c | 13 +++++++++++++ 2 files changed, 18 insertions(+), 2 deletions(-) diff --git a/generator/states-newstyle.c b/generator/states-newstyle.c index e86282b..369df0f 100644 --- a/generator/states-newstyle.c +++ b/generator/states-newstyle.c @@ -64,9 +64,12 @@ prepare_for_reply_payload (struct nbd_handle *h, uint32_t opt) /* Read the following payload if it is short enough to fit in the * static buffer. If it's too long, skip it. */ - /* XXX Move to DEAD if len > MAX_REQUEST_SIZE */ len = be32toh (h->sbuf.or.option_reply.replylen); - if (len <= maxpa...

...turn 0; NEWSTYLE.OPT_META_CONTEXT.RECV_REPLY: + uint32_t opt; + + if (h->opt_current == NBD_OPT_LIST_META_CONTEXT) + opt = h->opt_current; + else + opt = NBD_OPT_SET_META_CONTEXT; + switch (recv_into_rbuf (h)) { case -1: SET_NEXT_STATE (%.DEAD); return 0; case 0: - if (prepare_for_reply_payload (h, NBD_OPT_SET_META_CONTEXT) == -1) { + if (prepare_for_reply_payload (h, opt) == -1) { SET_NEXT_STATE (%.DEAD); return 0; } @@ -163,12 +181,25 @@ STATE_MACHINE { uint32_t len; const size_t maxpayload = sizeof h->sbuf.or.payload.context; struct meta_context *meta_...

...;structured replies are not supported by this server"); h->structured_replies = false; break; diff --git a/generator/states-newstyle.c b/generator/states-newstyle.c index 369df0f..8a4eec6 100644 --- a/generator/states-newstyle.c +++ b/generator/states-newstyle.c @@ -77,6 +77,35 @@ prepare_for_reply_payload (struct nbd_handle *h, uint32_t opt) return 0; } +/* Check an unexpected server reply. If it is an error, log any + * message from the server and return 0; otherwise, return -1. + */ +static int +handle_reply_error (struct nbd_handle *h) +{ + uint32_t len; + uint32_t reply; + + len = be32to...

I'm posting this now, as I'm at the end of a workday and I got things working for manual experimentation. Still to do: - write interop tests for qemu-nbd and nbdkit (including my proposed patch addition of qemu-nbd -A to show qemu:allocation-depth) - figure out if we can make 'nbdinfo --map' use the new API to automatically select all contexts advertised by the server Eric Blake

...; return 0; + case 0: + h->rbuf = &h->sbuf; + h->rlen = sizeof (h->sbuf.or.option_reply); + SET_NEXT_STATE (%RECV_REPLY); + } + return 0; + + NEWSTYLE.OPT_LIST.RECV_REPLY: + switch (recv_into_rbuf (h)) { + case -1: SET_NEXT_STATE (%.DEAD); return 0; + case 0: + if (prepare_for_reply_payload (h, NBD_OPT_LIST) == -1) { + SET_NEXT_STATE (%.DEAD); + return 0; + } + SET_NEXT_STATE (%RECV_REPLY_PAYLOAD); + } + return 0; + + NEWSTYLE.OPT_LIST.RECV_REPLY_PAYLOAD: + switch (recv_into_rbuf (h)) { + case -1: SET_NEXT_STATE (%.DEAD); return 0; + case 0: SET_NEXT_STATE (%CHEC...

In v2: ack'ed preliminary patches have been pushed, and I've added a lot of testsuite coverage as well as putting the new API to use in nbdinfo. Eric Blake (2): api: Add nbd_opt_list_meta_context info: List available meta-contexts lib/internal.h | 1 + generator/API.ml | 84 ++++++++-

...; + case 0: + h->rbuf = &h->sbuf; + h->rlen = sizeof h->sbuf.or.option_reply; + SET_NEXT_STATE (%RECV_REPLY); + } + return 0; + + NEWSTYLE.OPT_EXTENDED_HEADERS.RECV_REPLY: + switch (recv_into_rbuf (h)) { + case -1: SET_NEXT_STATE (%.DEAD); return 0; + case 0: + if (prepare_for_reply_payload (h, NBD_OPT_EXTENDED_HEADERS) == -1) { + SET_NEXT_STATE (%.DEAD); + return 0; + } + SET_NEXT_STATE (%RECV_REPLY_PAYLOAD); + } + return 0; + + NEWSTYLE.OPT_EXTENDED_HEADERS.RECV_REPLY_PAYLOAD: + switch (recv_into_rbuf (h)) { + case -1: SET_NEXT_STATE (%.DEAD); return 0; + case 0...

This replaces 13/13 of my v2 series; and now that it has pretty good testsuite coverage and demonstrable performance improvement to nbdinfo, I'm going ahead and pushing this now. We may still want to add further nbd_opt_* commands for other fine-grained tuning of negotiation, but for now, I think things have stabilized on this end, and I can return to polishing .list_exports on the nbdkit

I still need to wire in the use of *_notify functions into nbdkit to prove whether it makes the code any faster or easier to maintain, but at least the added example shows one good use case for the new API. Eric Blake (6): api: Add nbd_aio_in_flight generator: Allow DEAD state actions to run generator: Allow Int64 in callbacks states: Prepare for aio notify callback api: Add new

Proposal for new APIs to list exports. The general shape of the API can probably best be seen from the examples/list-exports.c example. Rich.

Well, I'm not quite done (I still want to get nbdinfo to work on a single nbd connection for all cases when reading the heads of the file is not required), but I'm happy with patches 1-11, and 12-13 show where I'm headed for getting NBD_OPT_INFO to work. Posting now to see if some of the earlier patches are ready to commit while I continue working on the latter half. Eric Blake (13):