similar to: [PATCH libnbd] api: New nbd_kill_command API for sending a signal to the command subprocess.

One API change, some small documentation changes.

Rich recently patched things to generate one man page per function rather than libnbd-api.3 (nice), but in doing so got stumped by a problem with a fresh git clone (automake fails for any 'include' directive that does not already exist). I've figured out how to hack around it, but the hack requires GNU make. We already use GNU make constructs elsewhere (such as $(wildcard)), but

As mentioned in commits 176fc4ea and 609c25f0, our original plan in adding a flags argument to nbd_shutdown was to let us specify different behaviors at the libnbd level, rather than NBD protocol flags (for that, the user has nbd_aio_disconnect). But when we later parameterized OFlags to accept various bitmasks (commit f891340b), we failed to mark nbd_shutdown as using a different bitmask than

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

This applies on top of the OClosure v2 series posted a few minutes ago. Rich.

On 8/15/19 4:56 AM, Richard W.M. Jones wrote: > --- > generator/generator | 25 +++++++++++++++++++++++++ > 1 file changed, 25 insertions(+) > > diff --git a/generator/generator b/generator/generator > index 1252bdb..13cb0b9 100755 > --- a/generator/generator > +++ b/generator/generator > @@ -3121,6 +3121,31 @@ let () = > failwithf "%s: first_version

Noticed while thinking about the recent threads wondering if we need a more efficient lookup from cookie back to command. Both of these fix bugs, but are tricky enough that I'm posting for review. Eric Blake (2): lib: Decrement in_flight at response, not retirement lib: Do O(1) rather than O(n) queue insertion generator/states-issue-command.c | 2 ++ generator/states-reply.c |

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 @@

On 7/25/19 2:15 PM, Richard W.M. Jones wrote: > Reverts commit 387cbe67c3db27e8a61117fedb6e7fad76e409ef. > --- > generator/generator | 18 +++++++++++++++++- > lib/handle.c | 28 +++++++++++++++++++++++++++- > tests/closure-lifetimes.c | 4 +++- > 3 files changed, 47 insertions(+), 3 deletions(-) tests/server-death.c can be simplified (no longer has to use

This is a simple renaming to avoid confusion over "command" when used to mean an asynchronous request to the server and "command" meaning the subprocess forked previously by libnbd. --- generator/generator | 4 ++-- lib/handle.c | 2 +- tests/closure-lifetimes.c | 4 ++-- tests/server-death.c | 4 ++-- 4 files changed, 7 insertions(+), 7 deletions(-)

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 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

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

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

** 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.

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

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

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

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 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