search for: request_meta_context

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.

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

...andle.c index a6b2172..e0047b7 100644 --- a/lib/handle.c +++ b/lib/handle.c @@ -313,6 +313,38 @@ nbd_unlocked_add_meta_context (struct nbd_handle *h, const char *name) return 0; } +int +nbd_unlocked_get_nr_meta_contexts (struct nbd_handle *h) +{ + return nbd_internal_string_list_length (h->request_meta_contexts); +} + +char * +nbd_unlocked_get_meta_context (struct nbd_handle *h, int i) +{ + size_t len = nbd_internal_string_list_length (h->request_meta_contexts); + char *ret; + + if (i < 0 || i >= len) { + set_error (EINVAL, "meta context request out of range"); + return NULL;...

...;t request any metadata - * contexts. + * contexts, when doing SET (but an empty LIST is okay). */ assert (h->gflags & LIBNBD_HANDSHAKE_FLAG_FIXED_NEWSTYLE); nbd_internal_reset_size_and_flags (h); - if (!h->structured_replies || - 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 { +...

...TA_CONTEXT.SEND_NRQUERIES: switch (send_from_wbuf (h)) { case -1: SET_NEXT_STATE (%.DEAD); return 0; case 0: @@ -97,7 +97,7 @@ STATE_MACHINE { } return 0; - NEWSTYLE.OPT_SET_META_CONTEXT.PREPARE_NEXT_QUERY: + NEWSTYLE.OPT_META_CONTEXT.PREPARE_NEXT_QUERY: const char *query = h->request_meta_contexts[h->querynum]; if (query == NULL) { /* end of list of requested meta contexts */ @@ -112,7 +112,7 @@ STATE_MACHINE { SET_NEXT_STATE (%SEND_QUERYLEN); return 0; - NEWSTYLE.OPT_SET_META_CONTEXT.SEND_QUERYLEN: + NEWSTYLE.OPT_META_CONTEXT.SEND_QUERYLEN: const char *query = h->reques...

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 ++++++++-

...dle.c +++ b/lib/handle.c @@ -320,12 +320,12 @@ nbd_unlocked_get_nr_meta_contexts (struct nbd_handle *h) } char * -nbd_unlocked_get_meta_context (struct nbd_handle *h, int i) +nbd_unlocked_get_meta_context (struct nbd_handle *h, size_t i) { size_t len = nbd_internal_string_list_length (h->request_meta_contexts); char *ret; - if (i < 0 || i >= len) { + if (i >= len) { set_error (EINVAL, "meta context request out of range"); return NULL; } -- 2.28.0.rc2

..._conn and nbd_get_multi_conn that things were changed because multi_conn was not supported after all. Or maybe we want both 'set_multi_conn' (connect hard-fails if the FIRST connection reports !can_multi_conn) vs. 'request_multi_conn' (connect downgrades gracefully), similar to how request_meta_context downgrades gracefully if the server lacks SR or a particular meta context. On IRC we were chatting about how multi-conn > 1 makes no sense with connect_command() (where we are limited to exactly one channel over stdin/stdout), so it may also be worth adding some logic to have connect_command fa...

...AMELEN); } return 0; @@ -67,6 +69,7 @@ case 0: h->wbuf = h->export_name; h->wlen = strlen (h->export_name); + h->wflags = MSG_MORE; SET_NEXT_STATE (%SEND_EXPORTNAME); } return 0; @@ -79,6 +82,7 @@ htobe32 (nbd_internal_string_list_length (h->request_meta_contexts)); h->wbuf = &h->sbuf; h->wlen = sizeof h->sbuf.nrqueries; + h->wflags = MSG_MORE; SET_NEXT_STATE (%SEND_NRQUERIES); } return 0; @@ -103,6 +107,7 @@ h->sbuf.len = htobe32 (strlen (query)); h->wbuf = &h->sbuf.len; h->wlen = sizeof...

...uri_allow_local_file (struct nbd_handle *h, bool allow) +{ + h->uri_allow_local_file = allow; + return 0; +} diff --git a/lib/internal.h b/lib/internal.h index 435cd36..50c0a9b 100644 --- a/lib/internal.h +++ b/lib/internal.h @@ -76,6 +76,11 @@ struct nbd_handle { bool request_sr; char **request_meta_contexts; + /* Allowed in URIs, see lib/uri.c. */ + uint32_t uri_allow_transports; + int uri_allow_tls; + bool uri_allow_local_file; + /* Global flags from the server. */ uint16_t gflags; diff --git a/lib/uri.c b/lib/uri.c index b3dfe7d..704641c 100644 --- a/lib/uri.c +++ b/lib/uri.c @@ -216,...

This isn't quite finished because not all of the tests or examples have been updated, but it demonstrates an idea: Should we forget about the concept of having multiple connections managed under a single handle? In this patch there is a single ‘struct nbd_handle *’ which manages a single state machine and connection (and therefore no nbd_connection). To connect to a multi-conn server you must

...letion(-) diff --git a/lib/internal.h b/lib/internal.h index 581777a..a48edff 100644 --- a/lib/internal.h +++ b/lib/internal.h @@ -73,6 +73,7 @@ struct nbd_handle { char *tls_psk_file; /* PSK filename, NULL = no PSK */ /* Desired metadata contexts. */ + bool request_sr; char **request_meta_contexts; /* Global flags from the server. */ diff --git a/generator/generator b/generator/generator index 1cc5c19..5c32afa 100755 --- a/generator/generator +++ b/generator/generator @@ -1243,6 +1243,36 @@ Get the current TLS PSK filename."; }; *) + "set_request_structured_replies"...

...rt_name); @@ -76,7 +76,7 @@ NEWSTYLE.OPT_SET_META_CONTEXT.SEND_EXPORTNAME: switch (send_from_wbuf (h)) { - case -1: SET_NEXT_STATE (%.DEAD); return -1; + case -1: SET_NEXT_STATE (%.DEAD); return 0; case 0: h->sbuf.nrqueries = htobe32 (nbd_internal_string_list_length (h->request_meta_contexts)); @@ -89,7 +89,7 @@ NEWSTYLE.OPT_SET_META_CONTEXT.SEND_NRQUERIES: switch (send_from_wbuf (h)) { - case -1: SET_NEXT_STATE (%.DEAD); return -1; + case -1: SET_NEXT_STATE (%.DEAD); return 0; case 0: h->querynum = 0; SET_NEXT_STATE (%PREPARE_NEXT_QUERY); @@ -115,7 +115,7 @@...

Previous discussion: https://www.redhat.com/archives/libguestfs/2019-August/msg00102.html Last night I experimentally added support for URIs that contain the query parameter tls-psk-file, as part of rewriting the tests to cover more of the URI code. So you can now have a URI like: nbds://alice@localhost/?tls-psk-file=keys.psk However there's an obvious security problem here because now

Appears to have a measurable benefit, see 3/3 for test results. Rich.

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

Patch 1/6 was posted before and I didn't change it: https://www.redhat.com/archives/libguestfs/2019-May/thread.html#00134 That doesn't necessarily mean I shouldn't change it, I'm posting it again because the other patches depend on it. The main change in this series is we add three new API functions: nbd_aio_is_created - connection has just been created

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):

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