similar to: [PATCH libnbd 0/3] One API and small documentation changes.

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

On 8/6/19 8:38 AM, Richard W.M. Jones wrote: > This makes it consistent with other nbd_is_* and nbd_can_* APIs. > > Suggested by Thomas Haller. > --- > docs/libnbd.pod | 2 +- > examples/batched-read-write.c | 2 +- > examples/simple-reads-and-writes.c | 2 +- > examples/threaded-reads-and-writes.c | 2 +- > generator/generator

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):

This patch is a straightforward refactoring of libnbd?s nbdcopy program, and not very interesting. However I have plans for nbdcopy (see full todo below). I would like to use this utility for virt-v2v as a replacement for ?qemu-img convert?. qemu-img has caused us a series of problems: - change in zeroing behaviour caused a big performance regression - qemu-img reads extents up-front which

Since v2: - rebase to Rich's new API calls - more refactoring in patch 1 (retitled) - new patches 3 and 4 - fix data corruption in patch 6 (was 4) - more tweaks to the reproducer example (including using new API from 3) Eric Blake (7): lib: Refactor command_common() to do more common work commands: Allow for a command queue commands: Expose FIFO ordering of server completions

This might not be the final solution, but it certainly seems to solve a deadlock for me that I could trigger by using 'nbdkit --filter=noparallel memory 512k' and calling nbd_aio_pread for a request larger than 256k (enough for the Linux kernel to block the server until libnbd read()s), immediately followed by nbd_aio_pwrite for a request larger than 256k (enough to block libnbd until the

We have been inconsistent on how much we reject client-side without even consulting the server, vs. how much we depend on the server to detect failure (even if our request can be deemed undefined per NBD protocol). I'd like to change it so that by default, we reject as much as we can client-side for less traffic, but where the user can also change things on the fly for server-side integration

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 ++++++++-

v1: https://www.redhat.com/archives/libguestfs/2019-June/msg00014.html I pushed a few bits which are uncontroversial. The main changes since v1 are: An extra patch removes the want_to_send / check for nbd_aio_is_ready in examples/threaded-reads-and-writes.c. This logic was wrong since commit 6af72b87 as was pointed out by Eric in his review. Comments and structure of

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

This makes it consistent with other nbd_is_* and nbd_can_* APIs. Suggested by Thomas Haller. --- docs/libnbd.pod | 2 +- examples/batched-read-write.c | 2 +- examples/simple-reads-and-writes.c | 2 +- examples/threaded-reads-and-writes.c | 2 +- generator/generator | 2 +- lib/flags.c | 2 +- lib/rw.c

This works, but there's no time saving and I'm still investigating whether it does what I think it does. Nevertheless I thought I would post it because it (probably) implements the idea I had last night outlined in: https://www.redhat.com/archives/libguestfs/2019-June/msg00010.html The meat of the change is patch 4. Patch 5 is an example which I would probably fold into patch 4 for

This is my proposal for fixing the documentation to match practice (namely, that completion.callback is not invoked in the cases where the aio call itself reports errors); we could instead try to go the other direction and tweak the generator to guarantee that both completion.callback and completion.free are reached no matter what, but that felt more invasive to me. Eric Blake (2): api: Tighten

Reverts commit 387cbe67c3db27e8a61117fedb6e7fad76e409ef. --- generator/generator | 18 +++++++++++++++++- lib/handle.c | 28 +++++++++++++++++++++++++++- tests/closure-lifetimes.c | 4 +++- 3 files changed, 47 insertions(+), 3 deletions(-) diff --git a/generator/generator b/generator/generator index 2cd83f1..25e4aa5 100755 --- a/generator/generator +++ b/generator/generator

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

In v2: - now based on my proposal to add LIBNBD_SHUTDOWN_IMMEDIATE - four flags instead of two: STRICT_FLAGS is new (patch 4), and STRICT_BOUNDS is separate from STRICT_ZERO_SIZE (patch 5) - various refactorings for more shared code and less duplication Eric Blake (5): api: Add xxx_MASK constant for each Flags type generator: Refactor filtering of accepted OFlags api: Add

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.

If the user calls nbd_kill_subprocess, we shouldn't kill the process again when we close the handle (since the process has likely gone and we might be killing a different process). --- lib/handle.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/lib/handle.c b/lib/handle.c index 2af25fe..5ad818e 100644 --- a/lib/handle.c +++ b/lib/handle.c @@ -315,6 +315,8 @@

** NOT WORKING ** This patch shows how to integrate libnbd and the glib main loop. Posted mainly as a point of discussion as it doesn't quite work yet. Rich.

Patches 1 & 2 are rather complex, but the end result is that we pass closures + user_data + free function in single struct parameters as I described previously in this email: https://www.redhat.com/archives/libguestfs/2019-August/msg00210.html Patch 3 adds a convenient FREE_CALLBACK macro which seems a worthwhile simplification if you buy into 1 & 2. Patch 4 adds another macro which is