similar to: [nbdkit PATCH 0/3] More responsive shutdown

The previous incomplete patch was here: https://www.redhat.com/archives/libguestfs/2019-September/msg00049.html based on earlier discussion here: https://www.redhat.com/archives/libguestfs/2019-September/msg00047.html In v2: - The previous patch was incomplete. This version completes it by adding tests and extending nbdkit-sh-plugin. - nbdkit_export_name now returns NULL for error,

On 3/24/20 3:12 PM, Eric Blake wrote: >> (For non-mingw platforms) this breaks the source API promises rather >> seriously, so if I understand your proposal correctly I don't think >> this is a good idea.  It's possibly something we can consider for >> internal plugins, or for the V3 API. > > How does it break API to request that someone link against a

On 8/3/19 11:01 AM, Eric Blake wrote: > There are a couple of problems with filters trying to sleep. First, > when it is time to shut down nbdkit, we wait until all pending > transactions have had a chance to wind down. But consider what > happens if one or more of those pending transactions are blocked in a > sleep. POSIX says nanosleep is interrupted with EINTR if that thread

The third patch is a large but mechanical change which gets rid of passing around struct connection * entirely within the server, preferring instead to reference the connection through thread-local storage. I hope this is a gateway to simplifying other parts of the code. Rich.

On 2/11/20 11:15 AM, Richard W.M. Jones wrote: > Since we're going to be calling this function a lot, add a short alias > for it. > --- > server/internal.h | 1 + > server/public.c | 6 +++--- > 2 files changed, 4 insertions(+), 3 deletions(-) > > diff --git a/server/internal.h b/server/internal.h > index a1fa7309..1e7b4cf0 100644 > --- a/server/internal.h

This is the previous 5/9 patch posted earlier today, split into reviewable chunks. This passes bisection with -x 'make && make check', but I didn't work very hard on the commit messages, so I refer you back to the original patch to explain how it works: https://www.redhat.com/archives/libguestfs/2020-March/msg00248.html Rich.

On 3/25/20 7:16 AM, Richard W.M. Jones wrote: > I think I understand now that libnbdkit.so won't break the ABI for > existing plugins. Does it require that plugins for newer nbdkit use > -lnbdkit (which would be a source API break) or would it still be > possible to compile without this? I guess as long as plugins do not > start using -no-undefined then it would still work, so

There are a couple of problems with filters trying to sleep. First, when it is time to shut down nbdkit, we wait until all pending transactions have had a chance to wind down. But consider what happens if one or more of those pending transactions are blocked in a sleep. POSIX says nanosleep is interrupted with EINTR if that thread handles a signal, but wiring up signal masks just to ensure a

Patch itself is not controversial. However I do wonder if we want to change all these constructs so that instead of using #ifdef we use something like: if (HAVE_PIPE2) { // normal path } else { // fallback } (It wouldn't actually work as written above because HAVE_PIPE2 is not always defined, but you get the idea.) This would allow us to test that the fallback paths still

I pushed a few of the msys2 patches upstream. I changed the way that $(SHARED_LDFLAGS) works so it's more to my liking, and the others were pushed unchanged. Three patches remain which I'm posting on the mailing list for proper review. Rich.

Since the v1 series (0/4, at [1]), I've applied patches 1 and 2, rewritten patch 3 [Forbid NUL in export and context names] into patch 4 here, patch 4 there turned into patch 6 here, and everything else here is new. [1]https://www.redhat.com/archives/libguestfs/2019-September/msg00180.html I don't know if there is a handy reusable function for checking whether a string contains valid

Rather than failing to compile on platforms which lack POLLRDHUP such as FreeBSD, simply fallback to the old method of sleeping. This leaves the porting suggestions as a comment in case someone wants to implement a better solution for particular platforms. --- server/public.c | 38 ++++++++++++++++++++++++-------------- 1 file changed, 24 insertions(+), 14 deletions(-) diff --git

v1 was here: https://www.redhat.com/archives/libguestfs/2020-February/msg00081.html v2 replaces struct connection *conn = GET_CONN; with GET_CONN; which sets conn implicitly and asserts that it is non-NULL. If we actually want to test if conn is non-NULL or behave differently, then you must use threadlocal_get_conn() instead, and some existing uses do that. Rich.

I want to make my nbd forwarding plugin fully parallel - but to do that, I first need to make nbdkit itself fully parallel ;) With this series, I was finally able to demonstrate out-of-order responses when using qemu-io (which is great at sending back-to-back requests prior to waiting for responses) coupled with the nbd file plugin (which has a great feature of rdelay and wdelay, to make it

This fixes the long-standing crash on close when nbdkit exits. I did try first to fix threads so we're using a proper thread pool, but that's difficult to implement. So this does the minimal change needed to fix the crash instead. There are still two segfaults that happen during running the test suite. One is deliberately caused (tests/test-captive.sh). The other appears to be an

The test relies on the timeout program. Also, since the nbdkit_nanosleep code relies on the Linux extension POLLRDHUP to detect early client closure, we may have to relax that part of the test when porting to platforms that lack ppoll/POLLRDHUP. (That is, while we should still be able to let a signal to the server shut down nbdkit quickly, it's harder to let a client close()ing its end cause

I've posted some of these patches or ideas before; but now I'm confident enough with the series that it should be ready to push; at any rate, I can now run test-socket-activation in a tight loop without triggering any crashes or hangs. With this in place, I'm going back to work on making the nbd forwarder wort with the parallel thread model. Eric Blake (8): sockets: Use

This is the sort of thing I had in mind for option (1) here: https://www.redhat.com/archives/libguestfs/2019-September/msg00047.html It does reveal that the way we currently list exports is naive to say the least ... Rich.

I do have a question about whether patch 2 is right, or whether I've exposed a bigger problem in the truncate (and possibly other) filter, but the rest seem fairly straightforward. Eric Blake (4): server: Check for pthread lock failures truncate: Factor out reading real_size under mutex plugins: Check for mutex failures filters: Check for mutex failures filters/cache/cache.c

Version 1 was here: https://www.redhat.com/archives/libguestfs/2019-April/msg00144.html Version 2 makes a couple of much larger changes: The OCaml patch changes the API of the pread method so it matches what other language bindings are already doing, ie. get the language plugin to return a newly allocated buffer, check it is long enough, copy out the data. The server patch implements a