search for: nbdplug_notifi

libnbd 0.1.7 was released today, which breaks compilation of nbdkit-nbd-plugin. We could work around it by using #ifdef LIBNBD_HAVE_XXX to learn about the renamed functions, but supporting older versions is not all that important when we don't yet have API stability. So patch 1 copes by just bumping the minimum version instead, except that we have yet another pending libnbd patch with an API

libnbd 0.1.8 is due out soon, which reorders several function arguments. Signed-off-by: Eric Blake <eblake@redhat.com> --- configure.ac | 4 ++-- plugins/nbd/nbd.c | 17 +++++++++-------- 2 files changed, 11 insertions(+), 10 deletions(-) diff --git a/configure.ac b/configure.ac index 3b355667..77f08f46 100644 --- a/configure.ac +++ b/configure.ac @@ -718,12 +718,12 @@

The 0.9.8 release breaks API, requiring a number of changes: - Use symbolic constants instead of magic numbers/open-coded strings (well, the string for "base:allocation" was present before this libnbd bump) - Change callbacks to drop the valid_flag parameter - Add _is to nbd_read_only call - Drop the _callback suffix on nbd_aio_FOO calls - Add a struct for managing callback/user_data

We no longer have to track a linked list of in-flight transactions that are pending resolution, but rely instead on libnbd 0.1.6+ doing it on our behalf. Normally, we will get to call nbdplug_register() prior to the notify callback being reached, but under a heavily-loaded system, it is conceivable that the libnbd state machine can manage to fire off our request and receive a server reply all

--- configure.ac | 4 ++-- plugins/nbd/nbd.c | 12 +++++++++--- README | 2 +- 3 files changed, 12 insertions(+), 6 deletions(-) diff --git a/configure.ac b/configure.ac index 8c7ee8b..0ce78c7 100644 --- a/configure.ac +++ b/configure.ac @@ -718,12 +718,12 @@ AC_ARG_WITH([libnbd], [], [with_libnbd=check]) AS_IF([test "$with_libnbd" != "no"],[ -

I'm not observing any noticeable performance differences, but I'm liking the diffstat. I can't push this patch until we release a new libnbd version with the _notify API addition, but am posting it now for playing with things. Eric Blake (2): nbd: Move transaction info from heap to stack nbd: Use nbdkit aio_*_notify variants plugins/nbd/nbd.c | 217

When using the nbd_aio_FOO_callback commands, there is nothing further to be learned about the command by calling nbd_aio_command_completed() compared to what the callback already had access to. There are still scenarios where manually retiring the command after the fact is useful (whether the return was 0 to keep the status unchanged, or -1 to alter the retirement status to *error), but by