search for: nbd_aio_is_connected

Patch 1/6 was posted before and I didn't change it: https://www.redhat.com/archives/libguestfs/2019-May/thread.html#00134 That doesn't necessarily mean I shouldn't change it, I'm posting it again because the other patches depend on it. The main change in this series is we add three new API functions: nbd_aio_is_created - connection has just been created

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

Squash this into opt_go? into opt_info? Standalone? Testing: why does python not throw an exception: $ ./run nbdsh Welcome to nbdsh, the shell for interacting with Network Block Device (NBD) servers. The ‘nbd’ module has already been imported and there is an open NBD handle called ‘h’. h.connect_tcp ("remote", "10809") # Connect to a remote server. h.get_size ()

This allows us to connect directly to a connected socket. How exactly the socket is created and connected to the NBD server is left up to the main program. The only real complexity in this patch is allowing file descriptors to be passed to libnbd APIs. Luckily in C and Python we can treat them exactly as integers, and in OCaml they are also integers but with a different type. ---

...d custom NBD_OPT_ commands during handshake, or even to emulate 'qemu-nbd --list' where the client can make queries to see what the server supports before finally settling on whether to run NBD_OPT_GO or NBD_OPT_ABORT, we'll need to add an external event after nbd_aio_connect but before nbd_aio_is_connected for doing those additional handshake steps. It's easier to think about adding a mandatory nbd_aio_go() called in between nbd_aio_connect*() and the first nbd_aio_pread now, before we have to start worrying about back-compat issues to all existing AIO clients. > @@ -2866,8 +2866,11 @@ let g...

For commands with long names and/or short descriptors, you can end up going over 72 characters in the first line of the man page (causing podwrapper to complain). Wrap these lines. --- generator/generator | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/generator/generator b/generator/generator index 7d3f656..ad1cb6b 100755 --- a/generator/generator +++ b/generator/generator

This adds new APIs for running a local NBD server and connecting to it using systemd socket activation (instead of stdin/stdout). This includes interop tests against nbdkit and qemu-nbd which I believe are the only NBD servers supporting socket activation. (If we find others then we can add more interop tests in future.) The upstream spec for systemd socket activation is here:

On 6/5/19 6:15 AM, Richard W.M. Jones wrote: > For each nbd_(unlocked_)?aio_is_* function, split it into an internal > function that tests the state and a public visible API function. > > For calls within the library, use the internal function. > > This is simple refactoring. > > As a side effect this fixes a race condition identified by Eric Blake: > > Thread A

Automake insists that any file present in a Makefile.am 'include' must be present, but it has no idea about the GNU make extension 'sinclude'. Use this to our advantage: as long as Makefile.inc has nothing other than variable modifications (done in the previous patch), and our rules properly generate it when needed (thanks to generator_built), then running 'make' will

This adds new APIs for running a local NBD server and connecting to it using systemd socket activation (instead of stdin/stdout). This includes interop tests against nbdkit and qemu-nbd which I believe are the only NBD servers supporting socket activation. (If we find others then we can add more interop tests in future.) The upstream spec for systemd socket activation is here:

‘make clean && make’ was not rebuilding the docs/*.3 files. The reason is obscure: - docs/Makefile has rules: MANS = $(man_MANS) all: all-am all-am: Makefile $(MANS) - sinclude docs/Makefile.inc happened long after MANS is defined, so MANS held the earlier version of $(man_MANS) without the api-built man pages listed. This was confirmed by looking at the output of

...mmands during handshake, or even to emulate 'qemu-nbd > --list' where the client can make queries to see what the server > supports before finally settling on whether to run NBD_OPT_GO or > NBD_OPT_ABORT, we'll need to add an external event after nbd_aio_connect > but before nbd_aio_is_connected for doing those additional handshake > steps. It's easier to think about adding a mandatory nbd_aio_go() called > in between nbd_aio_connect*() and the first nbd_aio_pread now, before we > have to start worrying about back-compat issues to all existing AIO clients. I envisaged that we...

Well, I'm not quite done (I still want to get nbdinfo to work on a single nbd connection for all cases when reading the heads of the file is not required), but I'm happy with patches 1-11, and 12-13 show where I'm headed for getting NBD_OPT_INFO to work. Posting now to see if some of the earlier patches are ready to commit while I continue working on the latter half. Eric Blake (13):

This is the culmination of the previous patches' preparation work for using extended headers when possible. The new states in the state machine are copied extensively from our handling of OPT_STRUCTURED_REPLY. The next patch will then expose a new API nbd_opt_extended_headers() for manual control. At the same time I posted this patch, I had patches for qemu-nbd to support extended headers

For each nbd_(unlocked_)?aio_is_* function, split it into an internal function that tests the state and a public visible API function. For calls within the library, use the internal function. This is simple refactoring. As a side effect this fixes a race condition identified by Eric Blake: Thread A Thread B (in a call that holds h->lock) (calling nbd_aio_pread)

I need to think about this patch series a bit more, but it does at least pass the tests. Rich.

This adds a new API for connecting to AF_VSOCK protocol (https://wiki.qemu.org/Features/VirtioVsock). For example: nbd_connect_vsock (nbd, 2, 10809); There is no test of this feature because it only works between guest and host. You cannot start a server and client on the host and talk between them, which is what we'd need to write a sane test. --- configure.ac | 2 ++

This continues the changes for adding NBD_OPT_LIST support. Now, instead of libnbd malloc'ing storage itself, the user passes a callback that can handle name/description pairs however it likes, and we get rid of the artificial cap at 10000 exports. However, the user will probably end up malloc'ing a list themselves, as we can't call nbd_set_export_name, or even request NBD_OPT_INFO

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 @@

v1 was posted here: https://www.redhat.com/archives/libguestfs/2019-September/thread.html#00337 v2: - Drop the first patch. - Hopefully fix the multiple issues with fork-safety and general behaviour on error paths. Note this requires execvpe for which there seems to be no equivalent on FreeBSD, except some kind of tedious path parsing (but can we assign to environ?) Rich.