search for: meta_contexts

...e-swap the entries returned, but apart from that we - * don't validate them. - */ - for (i = 0; i < length/4; ++i) - h->bs_entries[i] = be32toh (h->bs_entries[i]); - - /* Look up the context ID. */ - context_id = h->bs_entries[0]; - for (meta_context = h->meta_contexts; - meta_context; - meta_context = meta_context->next) - if (context_id == meta_context->context_id) - break; - - if (meta_context) { - /* Call the caller's extent function. */ - if (cmd->extent_fn (cmd->data, meta_context->name, cmd->of...

...e-swap the entries returned, but apart from that we + * don't validate them. + */ + for (i = 0; i < length/4; ++i) + h->bs_entries[i] = be32toh (h->bs_entries[i]); + + /* Look up the context ID. */ + context_id = h->bs_entries[0]; + for (meta_context = h->meta_contexts; + meta_context; + meta_context = meta_context->next) + if (context_id == meta_context->context_id) + break; + + if (meta_context) { + /* Call the caller's extent function. */ + int error = cmd->error; + + if (cmd->cb.fn.extent (cmd->...

Rather than moving the connection to DEAD, we can just ignore further contexts to the existing command handle, and fail the overall command with the same errno as the failed callback. Eric Blake (2): states: Track cmd->error as errno, not wire value api: Recover from block status callback failure generator/generator | 5 ++- generator/states-reply-simple.c | 2 +-

...tion mode. + +The NBD protocol allows a client to decide how many queries to ask +the server. Rather than taking that list of queries as a parameter +to this function, libnbd reuses the current list of requested meta +contexts as set by L<nbd_add_meta_context(3)>; you can use +L<nbd_clear_meta_contexts(3)> to set up a different list of queries. +When the list is empty, a server will typically reply with all +contexts that it supports; when the list is non-empty, the server +will reply only with supported contexts that match the client's +request. Note that a reply by the server might be e...

...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 (3): api: Add get_nr_meta_contexts, clear_meta_contexts generator: Rename OPT_SET_META_CONTEXT states api: Add nbd_opt_list_meta_context lib/internal.h | 1 + generator/API.ml | 162 +++++++++++++++++- generator/Makefile.am | 4 +- generato...

On 6/4/19 4:59 AM, Richard W.M. Jones wrote: > Callback functions now return an int instead of a void. This allows > in some cases for the callback to indicate that there was an error. > > This is a small change to the API: Indeed; and my work to let nbdkit-nbd use libnbd is slightly impacted. If I want to support both 0.1.2 and 0.1.x, I now have to do a conditional compilation

...const char *name; > + uint32_t orig_len, len, flags; > + uint64_t total, cap; > + bool stop; > > switch (recv_into_rbuf (h)) { > case -1: SET_NEXT_STATE (%.DEAD); return 0; > @@ -481,30 +486,63 @@ REPLY.CHUNK_REPLY.RECV_BS_ENTRIES: > if (context_id == h->meta_contexts.ptr[i].context_id) > break; > > - if (i < h->meta_contexts.len) { > - int error = cmd->error; > - const char *name = h->meta_contexts.ptr[i].name; > - > - /* Need to byte-swap the entries returned, but apart from that > - * we do...

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

...*h) if (h->debug_fn) h->debug_fn (LIBNBD_CALLBACK_FREE, h->debug_data, NULL, NULL); - for (cc = h->close_callbacks; cc != NULL; cc = cc_next) { - cc_next = cc->next; - cc->cb (cc->user_data); - free (cc); - } - free (h->bs_entries); for (m = h->meta_contexts; m != NULL; m = m_next) { m_next = m->next; @@ -202,34 +195,6 @@ nbd_unlocked_add_meta_context (struct nbd_handle *h, const char *name) return 0; } -/* This is not generated because we don't want to offer it to other - * programming languages. - */ -int -nbd_add_close_callback (st...

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 ++++++++-

--- plugins/python/nbdkit-python-plugin.pod | 19 ++++++- plugins/python/python.c | 75 +++++++++++++++++++++++++ tests/test-python-plugin.py | 8 ++- tests/test_python.py | 73 +++++++++++++++++++++++- 4 files changed, 169 insertions(+), 6 deletions(-) diff --git a/plugins/python/nbdkit-python-plugin.pod b/plugins/python/nbdkit-python-plugin.pod

Callback functions now return an int instead of a void. This allows in some cases for the callback to indicate that there was an error. This is a small change to the API: For nbd_set_debug_callback the signature has changed, but the return value is ignored. For nbd_block_status and nbd_aio_block_status the extent function can return an error, which causes the block status command to return an

Instead of repeating a check for valid reply headers in each sub-state machine, let's have a common helper function do all the work. Additionally, a central location will make it easier to uniformly capture any NBD_REP_ERR message payloads. --- generator/generator | 8 +-- generator/states-newstyle-opt-go.c | 40 +++----------

The next patch will add a new 'nbd_aio_pread_callback' function for allowing the user more immediate access as each chunk of a structured reply read is received. But before we do that, let's refactor the command code. This includes a revert of 12843a1a, since the read callback will need both a buffer and the user's opaque object at the same time. ---

On Mon, Aug 10, 2020 at 1:51 PM Richard W.M. Jones <rjones@redhat.com> wrote: > > --- > plugins/python/nbdkit-python-plugin.pod | 19 ++++++- > plugins/python/python.c | 75 +++++++++++++++++++++++++ > tests/test-python-plugin.py | 8 ++- > tests/test_python.py | 73 +++++++++++++++++++++++- > 4 files changed, 169

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

...; @@ -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 @@...

When the server sets NBD_REPLY_FLAG_DONE on a data or block status chunk, we can use that fact to pass (VALID|FREE) and avoid a separate callback later just for FREE. --- As I've been promising in other threads... generator/states-reply-structured.c | 33 +++++++++++++++++++++++++---- 1 file changed, 29 insertions(+), 4 deletions(-) diff --git a/generator/states-reply-structured.c

This adds a C-only semi-private function for freeing various types of persistent data passed to libnbd. There are some similarities with nbd_add_close_callback which we removed in commit 7f191b150b52ed50098976309a6af883d245fc56. --- generator/generator | 57 ++++++++++++++++++++ lib/Makefile.am | 1 + lib/free.c | 129 ++++++++++++++++++++++++++++++++++++++++++++ lib/handle.c

When we introduced valid_flags, there was an incentive to do as few callbacks as possible, favoring cb(VALID|FREE) calls over the sequence cb(VALID);cb(FREE). To make it work, we set .callback=NULL after an early free, so that the later check during retirement didn't free again. But now that our .free callback is distinct from our other callbacks, there is no longer an advantage to bundling