[Libguestfs] [nbdkit PATCH 0/3] Add nozero filter

I still need to add testsuite coverage. Perhaps it might be easier if I create a new '--filter=log logfile=foo' filter that produces a log of which commands a client sent, then compare the log using a known client that uses write_zeroes (qemu-io works well) both with and without --filter=nozero to prove that the change in advertisement changes the commands sent over the wire (that would also test the log filter at the same time...). I'll wait for a review on this series, particularly since patch 2 intentionally breaks filter ABI (more ABI/API breaks on the way when I resubmit my FUA work; it would be nice to make all the API breaks before v1.1.29, rather than releasing versions while things are still in flux). Note that even if we try hard to let newer nbdkit load an older filter (which I did not do here), we absolutely cannot let older nbdkit load a newer filter - while we have sizing limits to guarantee we don't call beyond the end of an older filter's smaller struct, there are no sizing limits in the other direction to prevent a newer filter to know that it cannot call beyond the end of our smaller nbdkit_next_ops. Eric Blake (3): connections: Don't advertise TRIM on readonly connection filter: Add .can_zero/.can_fua overrides filters: Add nozero filter TODO | 2 +- configure.ac | 3 +- docs/nbdkit-filter.pod | 30 +++++++++++- docs/nbdkit.pod | 1 + filters/Makefile.am | 1 + filters/nozero/Makefile.am | 62 ++++++++++++++++++++++++ filters/nozero/nbdkit-nozero-filter.pod | 84 +++++++++++++++++++++++++++++++++ filters/nozero/nozero.c | 68 ++++++++++++++++++++++++++ include/nbdkit-filter.h | 8 +++- src/connections.c | 45 +++++++++++++----- src/filters.c | 70 ++++++++++++++++++++++++--- src/internal.h | 2 + src/plugins.c | 22 +++++++++ 13 files changed, 376 insertions(+), 22 deletions(-) create mode 100644 filters/nozero/Makefile.am create mode 100644 filters/nozero/nbdkit-nozero-filter.pod create mode 100644 filters/nozero/nozero.c -- 2.14.3