similar to: [PATCH nbdkit] server: When using --run, wait for captive nbdkit to exit.

I like this change. I think we were overloading the config_complete method before to do two different things (complete configuration; do any allocation/housekeeping necessary before we can start serving). The only questions in my mind are whether we want this before 1.18, and whether the name ("get_ready") is a good one. Rich.

This happened on s390 in Koji, once. The key lines from the log are: + start_t=0 nbdkit: sh[1]: debug: retry 1: waiting 1 seconds before retrying nbdkit: sh[1]: debug: retry 1: waiting 1 seconds before retrying + end_t=1 Somehow nbdkit did wait 2 seconds (or at least, nbdkit_nanosleep (1, 0) was called twice by the retry filter). But in the bash script, time (as measured by $SECONDS) advanced

Eric: Did you want to take this one any further? It might be one that we save for > 1.18: https://www.redhat.com/archives/libguestfs/2020-February/thread.html#00206 Another thing I've been thinking about for some time is splitting .config_complete into .config_complete + .get_ready (new name TBD). At the moment .config_complete is both the place where we finish processing config, and

This picks up python and ocaml. Some of our languages are lacking a number of bindings (for example, lua and perl lack .extents, so I didn't have anything to copy from), and I felt less comfortable with golang and rust. But for python and ocaml, I was able to test a working implementation. Eric Blake (2): python: Implement .list_exports and friends ocaml: Implement .list_exports and

It's been several weeks since I posted v2 (I got distracted by improving libnbd to better test things, which in turn surfaced some major memory leak problems in nbdsh that are now fixed). Many of the patches are minor rebases from v2, with the biggest changes being fallout from: - patch 2: rename nbdkit_add_default_export to nbdkit_use_default_export - overall: this missed 1.22, so update

Patch 3 still needs tests added, but it is at least working from my simple command line tests. Eric Blake (3): server: Implement nbdkit_is_tls for use during .open server: Expose final thread_model to filter's .get_ready tlsdummy: New filter docs/nbdkit-filter.pod | 21 +- docs/nbdkit-plugin.pod | 34 ++- docs/nbdkit-tls.pod

This is a revision of my .default_export work, plus new work on .export_descriptions and a new exportname filter. I think it is now ready to check in. Things I'd still like in 1.22: - the file plugin should implement .list_exports (patch already posted, but it needs rebasing on this series) - the ext2 filter should override .list_exports when in exportname mode - the nbd plugin should be

If you have a plugin which either creates background threads itself or uses a library that creates background threads, it turns out you cannot create these in .get_ready (or earlier). The reason is that nbdkit forks when either daemonizing itself or using the --run option, and fork cancels all the background threads in the child process (the daemonized or captive nbdkit). The only good solution

Since v1: - patch 1: check size limits - patch 2: better handling of default export name canonicalization - patch 3: support filters as well as plugins - patch 4: new - patch 5: rewrite sh parser, fix testsuite to actually work and cover more cases (now that libnbd.git is fixed) Eric Blake (4): server: Add exports list functions server: Prepare to use export list from plugin log: Add

v1 -> v2: - Fixed everything mentioned in the review. Rich.

Somewhat invasive but mostly mechanical change to how plugins are called. This patch is in preparation for adding a second backend subtype for filters. Rich.

This is working for me now, although possibly only on Python 3.9. Dan suggested PyEval_InitThreads but that was deprecated in Python 3.7. Rich.

Somewhat of a mishmash between .open (in that it takes a bool readonly parameter) and .config_complete (in that the C code returns an int, but the Ocaml code either throws an exception or completes with unit). I did not spot any existing testsuite coverage to modify for this, and am relying on the fact that it compiles cleanly. Signed-off-by: Eric Blake <eblake@redhat.com> ---

The first three patches are identical to: https://www.redhat.com/archives/libguestfs/2018-January/msg00079.html "[PATCH nbdkit v2 0/3] Refactor plugin_* functions into a backend" The rest of the patches add filters using the new filter API previously described here: https://www.redhat.com/archives/libguestfs/2018-January/msg00073.html This needs a lot more testing -- and tests --

On Sat, Feb 22, 2020 at 05:11:01AM -0600, Eric Blake wrote: > On 2/22/20 4:37 AM, Richard W.M. Jones wrote: > >Another thing I've been thinking about for some time is splitting > >.config_complete into .config_complete + .get_ready (new name TBD). > >At the moment .config_complete is both the place where we finish > >processing config, and also the last chance we get

This is what I've been playing with in response to my earlier question about what to do with 'nbdkit -s sh -' (https://www.redhat.com/archives/libguestfs/2020-April/msg00032.html) I'm still open to ideas on a better name, and/or whether adding <stdbool.h> to our public include files is a good idea (if not, returning int instead of bool is tolerable). Eric Blake (2):

In v2: - use int instead of bool in the public header - split the tests from the code - don't overload test-layers; instead, add new tests - add a missing fflush exposed by the new tests - other minor cleanups Eric Blake (3): server: Add nbdkit_stdio_safe server: Sanitize stdin/out before running plugin code server: More tests of stdin/out handling docs/nbdkit-plugin.pod |

This incomplete patch adds a new filter allowing more control over when nbdkit exits. You can now get nbdkit to exit gracefully on certain events, such as a file being created, a pipe held open by another process going away, or when another PID exits. There is also a script option to allow for completely custom events. It is untested at the moment, I'm posting it to get feedback on the

This takes Rich's API proposal and starts fleshing it out with enough meat that I was able to test 'nbdkit eval' advertising multiple exports with descriptions paired with 'qemu-nbd --list'. Eric Blake (3): server: Add exports list functions server: Prepare to use export list from plugin sh, eval: Add .list_exports support Richard W.M. Jones (1): server: Implement

A combination of the work that both Rich and I have been doing lately, where filters use only the new API with flags on every command that the client can send over the wire (we can then add support for more flags in nbdkit without having to add new callbacks, as NBD adds more flags upstream). Eric Blake (4): protocol: Split flags from cmd field in requests backend: Pass flags argument through