[Libguestfs] [nbdkit PATCH 0/5] Use shared context to make ext2 filter parallel

[Eric Blake]

I've been working on this one for a while, and finally got it working
well enough to post.  I'm probably still going to work on adding
another unit test proving that you can open multiple NBD clients in
parallel, and that they can interleave I/O, but my immediate test was
setting up:

nbdkit -f --filter=ext2 --filter=exportname file tests/ext2.img \
  ext2file=exportname exportname-list=explicit exportname=hidden

then running two simultaneous nbdsh, one visiting
nbd://localhost:10809/manifest and the other
nbd://localhost:10809/disks/disk.img.  Pre-series, the second nbdsh
stalls until the first exits, post-series, both can read their
respective file out of the overall image at the same time.

Eric Blake (5):
  filters: Tighter rules on .get_ready/.after_fork
  threadlocal: Add way to store current context
  filters: Allow nbdkit_next_context_open outside client connection
  api: Add .cleanup callback
  ext2: Support parallel requests and connections

 docs/nbdkit-filter.pod              |  65 ++++++--
 docs/nbdkit-plugin.pod              |  33 +++-
 include/nbdkit-filter.h             |  10 +-
 include/nbdkit-plugin.h             |   4 +-
 server/internal.h                   |  14 +-
 server/backend.c                    |  48 +++++-
 server/filters.c                    |  49 +++---
 server/main.c                       |   1 +
 server/plugins.c                    |  32 ++--
 server/protocol-handshake.c         |   2 +-
 server/public.c                     |  24 ++-
 server/test-public.c                |  12 +-
 server/threadlocal.c                |  36 ++++-
 filters/exitwhen/exitwhen.c         |   9 +-
 filters/ext2/ext2.c                 | 225 ++++++++++++++++------------
 filters/extentlist/extentlist.c     |   5 +-
 filters/log/log.c                   |   9 +-
 filters/multi-conn/multi-conn.c     |   5 +-
 filters/pause/pause.c               |   4 +-
 filters/rate/rate.c                 |   5 +-
 filters/retry/retry.c               |   2 +-
 filters/stats/stats.c               |   5 +-
 filters/tls-fallback/tls-fallback.c |   5 +-
 tests/test-layers-filter.c          |  22 ++-
 tests/test-layers-plugin.c          |   9 +-
 tests/test-layers.c                 |  42 ++++--
 26 files changed, 453 insertions(+), 224 deletions(-)

-- 
2.31.1