search for: opt_cb

...| - nbd_internal_string_list_length (h->request_meta_contexts) == 0) { - SET_NEXT_STATE (%^OPT_GO.START); - return 0; + if (h->opt_current == NBD_OPT_LIST_META_CONTEXT) { + assert (h->opt_mode); + assert (h->structured_replies); + assert (CALLBACK_IS_NOT_NULL (h->opt_cb.fn.context)); + opt = h->opt_current; + } + else { + assert (CALLBACK_IS_NULL (h->opt_cb.fn.context)); + opt = NBD_OPT_SET_META_CONTEXT; + if (!h->structured_replies || + nbd_internal_string_list_length (h->request_meta_contexts) == 0) { + SET_NEXT_STATE (%^OPT...

...llback list) /* Issue NBD_OPT_GO (or NBD_OPT_EXPORT_NAME) without waiting. */ int nbd_unlocked_aio_opt_go (struct nbd_handle *h, - nbd_completion_callback complete) + nbd_completion_callback *complete) { h->opt_current = NBD_OPT_GO; - h->opt_cb.completion = complete; + h->opt_cb.completion = *complete; if (nbd_internal_run (h, cmd_issue) == -1) debug (h, "option queued, ignoring state machine failure"); @@ -181,7 +181,7 @@ nbd_unlocked_aio_opt_go (struct nbd_handle *h, /* Issue NBD_OPT_INFO without waiting. */ int...

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

As promised in my earlier thread on libnbd completion callback question. Eric Blake (2): generator: Refactor handling of closures in unlocked functions generator: Free closures on failure docs/libnbd.pod | 2 +- generator/C.ml | 48 +++++++++++------ generator/C.mli | 1 + lib/debug.c | 7 +-- lib/opt.c | 31 ++++++-----

...handle for debug messages * (to avoid having to print actual pointers). @@ -102,10 +111,7 @@ struct nbd_handle { /* Option negotiation mode. */ bool opt_mode; uint8_t current_opt; - - /* Results of nbd_opt_list. */ - size_t nr_exports; - struct export *exports; + struct command_cb opt_cb; /* Full info mode. */ bool full_info; @@ -186,7 +192,7 @@ struct nbd_handle { union { struct { struct nbd_fixed_new_option_reply_server server; - char str[NBD_MAX_STRING * 2]; /* name and description */ + char str[NBD_MAX_STRING * 2 + 1]; /* name...

...ck *list) if (nbd_unlocked_aio_opt_list (h, &l, &c) == -1) return -1; + SET_CALLBACK_TO_NULL (*list); if (wait_for_option (h) == -1) return -1; if (s.err) { @@ -172,6 +173,7 @@ nbd_unlocked_aio_opt_go (struct nbd_handle *h, { h->opt_current = NBD_OPT_GO; h->opt_cb.completion = *complete; + SET_CALLBACK_TO_NULL (*complete); if (nbd_internal_run (h, cmd_issue) == -1) debug (h, "option queued, ignoring state machine failure"); @@ -190,6 +192,7 @@ nbd_unlocked_aio_opt_info (struct nbd_handle *h, h->opt_current = NBD_OPT_INFO; h->...

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 ++++++++-

...* (to avoid having to print actual pointers). @@ -102,10 +111,7 @@ struct nbd_handle { /* Option negotiation mode. */ bool opt_mode; uint8_t opt_current; /* 0 or one of NBD_OPT_* */ - - /* Results of nbd_opt_list. */ - size_t nr_exports; - struct export *exports; + struct command_cb opt_cb; /* Full info mode. */ bool full_info; @@ -186,7 +192,7 @@ struct nbd_handle { union { struct { struct nbd_fixed_new_option_reply_server server; - char str[NBD_MAX_STRING * 2]; /* name and description */ + char str[NBD_MAX_STRING * 2 + 1]; /* name...

...reply); } nbd_internal_reset_size_and_flags (h); - if (h->opt_mode) - SET_NEXT_STATE (%.NEGOTIATING); - else - SET_NEXT_STATE (%^PREPARE_OPT_ABORT); + err = nbd_get_errno (); break; case NBD_REP_ACK: + err = 0; + break; + } + + CALL_CALLBACK (h->opt_cb.completion, &err); + nbd_internal_free_option (h); + if (err == 0) SET_NEXT_STATE (%^FINISHED); - break; - } + else if (h->opt_mode) + SET_NEXT_STATE (%.NEGOTIATING); + else + SET_NEXT_STATE (%^PREPARE_OPT_ABORT); return 0; } /* END STATE MACHINE */ diff --git a/lib/o...

This is a subset of my v2 posting, but limited to just the NBD_OPT_LIST handling. The biggest change since v2 is the addition of added unit testing in all four language bindings (C, python, ocaml, golang). The tests require nbdkit built from git on PATH, and may not be entirely idiomatic, but I at least validated that they catch issues (for example, adding an exit statement near the end of the

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):

...1301 USA + */ + +/* State machine for negotiating NBD_OPT_EXTENDED_HEADERS. */ + +STATE_MACHINE { + NEWSTYLE.OPT_EXTENDED_HEADERS.START: + assert (h->gflags & LIBNBD_HANDSHAKE_FLAG_FIXED_NEWSTYLE); + assert (h->opt_current != NBD_OPT_EXTENDED_HEADERS); + assert (CALLBACK_IS_NULL (h->opt_cb.completion)); + if (!h->request_eh || !h->request_sr) { + SET_NEXT_STATE (%^OPT_STRUCTURED_REPLY.START); + return 0; + } + + h->sbuf.option.version = htobe64 (NBD_NEW_VERSION); + h->sbuf.option.option = htobe32 (NBD_OPT_EXTENDED_HEADERS); + h->sbuf.option.optlen = htobe32...

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

This adds coalescing of adjacent extents of the same type, as mentioned by Eric Blake in the commit message here: https://github.com/libguestfs/libnbd/commit/46072f6611f80245846a445766da071e457b00cd The patch series is rather long because it detours through adding the <vector.h> library from nbdkit into libnbd and replacing ad hoc uses of realloc, char ** etc in various places. Rich.