search for: 421a7d2

...}; "pwrite", { @@ -1774,6 +1790,7 @@ let constants = [ "CMD_FLAG_FUA", 1 lsl 0; "CMD_FLAG_NO_HOLE", 1 lsl 1; + "CMD_FLAG_DF", 1 lsl 2; "CMD_FLAG_REQ_ONE", 1 lsl 3; ] diff --git a/lib/flags.c b/lib/flags.c index 421a7d2..cdbc28f 100644 --- a/lib/flags.c +++ b/lib/flags.c @@ -42,6 +42,11 @@ nbd_internal_set_size_and_flags (struct nbd_handle *h, return -1; } + if (eflags & NBD_FLAG_SEND_DF && !h->structured_replies) { + debug (h, "server lacks structured replies, ignoring claim of df...

...\n", nbd_get_error ()); + exit (EXIT_FAILURE); + } + assert (data.seen_data && !data.seen_hole); /* Trigger a failed callback, to prove connection stays up. With * reads, all chunks trigger a callback even after failure, but the diff --git a/lib/flags.c b/lib/flags.c index 421a7d2..cdbc28f 100644 --- a/lib/flags.c +++ b/lib/flags.c @@ -42,6 +42,11 @@ nbd_internal_set_size_and_flags (struct nbd_handle *h, return -1; } + if (eflags & NBD_FLAG_SEND_DF && !h->structured_replies) { + debug (h, "server lacks structured replies, ignoring claim of df...

RFC because this is an API break, but we haven't declared stable API yet. If we like it, I'm working on using libnbd to implement the nbdkit-nbd plugin; knowing whether it is API version 0.1 or 0.2 will be useful. I also dabbled with allowing optional parameters in python, although my OCaml is weak enough that there may be cleaner ways to approach that. Eric Blake (4): api: Add flags

Since v1: - rebase to applied patches - split out support for Int in callbacks - sort of test that callbacks work in OCaml (see comment in patch 5) - rename API to nbd_pread_structured - expose error as explicit parameter to callback Eric Blake (5): generator: Allow Int in callbacks states: Wire in a read callback states: Add nbd_pread_structured API states: Add tests for

I've mentioned this topic before (in fact, the idea of adding NBD_CMD_FLAG_DF was first mentioned at [1]), but finally finished enough of an implementation to feel confident in posting it. I'd still like to add something under examples/ that uses the new API to implement strict checking of a server's structured replies read implementation (ensure that a server never sends data after

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