search for: opt_mode

...d a completion closure, for the same reason that aio_disconnect does not have one - the whole point of this command is a clean shutdown, so you aren't going to rely on a server reply, and there are no parameters that need cleanup. Yes, it's a bit awkward that with just this patch, enabling opt_mode means you HAVE to kill the connection without a data phase; that will be rectified in the next patch adding nbd_opt_go. But breaking the patches up makes review easier. --- lib/internal.h | 1 + generator/API.ml | 35 ++++++- generator/...

These patches aren't related to each other, but both are quite simple. The second one requires particular attention - it's my experience that printing out the state transitions in debug mode has never helped me to diagnose a bug, but it has made the debug logs huge and hard to follow. However that might just be me! Has it helped anyone else? Also I'm open to the concept of debug

This is the bare minimum needed to allow the user to take control over the rest of option negotiating. This patch adds several new API: nbd_set_opt_mode() - called during Created to enable the new mode nbd_get_opt_mode() - query whether opt mode is enabled nbd_opt_go() - used in Negotiating state to attempt to use export nbd_opt_abort() - used in Negotiating state to skip Connected state nbd_aio_is_negotiating() - used to detect Negotiating state...

On Fri, Aug 14, 2020 at 05:00:25PM -0500, Eric Blake wrote: > diff --git a/lib/internal.h b/lib/internal.h > index 5f495fb..03baacd 100644 > --- a/lib/internal.h > +++ b/lib/internal.h > @@ -101,6 +101,7 @@ struct nbd_handle { > > /* Option negotiation mode. */ > bool opt_mode; > + uint8_t current_opt; Be nice to add a comment here about what current_opt can contain, which would also explain why it has this somewhat unexpected type. Something like: + uint8_t current_opt; /* 0 or NBD_OPT_* */ (Can it only contain NBD_OPT_ABORT or are other options added in late...

...arlier patches are ready to commit while I continue working on the latter half. Eric Blake (13): api: Add nbd_set_full_info and friends info: Improve info without --list api: Add nbd_is_state_negotiating for new state api: Permit several existing API in Negotiating state api: Add nbd_set_opt_mode api: Add nbd_opt_abort and nbd_aio_opt_abort api: Add nbd_opt_go and nbd_aio_opt_go examples: Update list-exports to demonstrate nbd_opt_go info: Simplify by using nbd_opt_go api: Add nbd_opt_list api: Add nbd_aio_opt_list wip: api: Give aio_opt_go a completion callback wip: api: ad...

...0809") # Connect to a remote server. h.get_size () # Get size of the remote disk. buf = h.pread (512, 0, 0) # Read the first sector. exit() or Ctrl-D # Quit the shell help (nbd) # Display documentation nbd> h.set_opt_mode(True) nbd> h.connect_command(["nbdkit","-s","--exit-","eval", "open=echo ENOENT >&2; exit 1"]) nbd> h.aio_is_negotiating() True nbd> h.set_export_name('a') nbd> h.opt_go() nbdkit: eval: error: /tmp/nbdkitNyQD8J/open: ENOEN...

v1 was here: https://listman.redhat.com/archives/libguestfs/2022-October/030216.html Since then, I've incorporated changes based on Rich's feedback: swap order of patches 2 and 3 less change in patch 1 (including no unsafe eval(%s) for --uri) in patch 2, include -c in list of snippets to store, and use dict of lambdas to map back to the desired action Eric Blake (3): nbdsh:

This is a subset of my v2 posting, but limited to just the NBD_OPT_LIST handling. The biggest change since v2 is the addition of added unit testing in all four language bindings (C, python, ocaml, golang). The tests require nbdkit built from git on PATH, and may not be entirely idiomatic, but I at least validated that they catch issues (for example, adding an exit statement near the end of the

I think this needs extra documentation in docs/libnbd.pod because it's definitely not clear just from the rather thin manual page for set_opt_mode how it works. docs/libnbd.pod is a good place for a broader description of how it works. IIUC let me try to explain: we get through as far as the end of group OPT_STRUCTURED_REPLY before we check the opt flag, and then the remainder of opt negotiation can be controlled by the caller. (I really n...

...; + nbd_list_callback list; + } fn; + nbd_completion_callback completion; +}; + struct nbd_handle { /* Unique name assigned to this handle for debug messages * (to avoid having to print actual pointers). @@ -102,10 +111,7 @@ struct nbd_handle { /* Option negotiation mode. */ bool opt_mode; uint8_t current_opt; - - /* Results of nbd_opt_list. */ - size_t nr_exports; - struct export *exports; + struct command_cb opt_cb; /* Full info mode. */ bool full_info; @@ -186,7 +192,7 @@ struct nbd_handle { union { struct { struct nbd_fixed_new_option_rep...

...WSTYLE.OPT_STRUCTURED_REPLY.START: assert (h->gflags & LIBNBD_HANDSHAKE_FLAG_FIXED_NEWSTYLE); if (!h->request_sr) { - SET_NEXT_STATE (%^OPT_SET_META_CONTEXT.START); + SET_NEXT_STATE (%^OPT_META_CONTEXT.START); return 0; } @@ -87,7 +87,7 @@ STATE_MACHINE { if (h->opt_mode) SET_NEXT_STATE (%.NEGOTIATING); else - SET_NEXT_STATE (%^OPT_SET_META_CONTEXT.START); + SET_NEXT_STATE (%^OPT_META_CONTEXT.START); return 0; } /* END STATE MACHINE */ diff --git a/generator/states-newstyle.c b/generator/states-newstyle.c index 92cf5c9..a0a5928 100644 --- a/gener...

...tiple times in order to run multiple commands. +=item B<--opt-mode> + +Request that option mode be enabled, which gives fine-grained control +over option negotiation after initially contacting the server but +prior to actually using the export. This is equivalent to calling +S<C<h.set_opt_mode(True)>> in the shell prior to connecting, and works +even when combined with C<--uri> (while attempting the same with C<-c> +would be too late). + =item B<-c -> =item B<--command -> @@ -85,6 +96,12 @@ Read standard input and execute it as a command. Connect to the...

...; + nbd_list_callback list; + } fn; + nbd_completion_callback completion; +}; + struct nbd_handle { /* Unique name assigned to this handle for debug messages * (to avoid having to print actual pointers). @@ -102,10 +111,7 @@ struct nbd_handle { /* Option negotiation mode. */ bool opt_mode; uint8_t opt_current; /* 0 or one of NBD_OPT_* */ - - /* Results of nbd_opt_list. */ - size_t nr_exports; - struct export *exports; + struct command_cb opt_cb; /* Full info mode. */ bool full_info; @@ -186,7 +192,7 @@ struct nbd_handle { union { struct { str...

...e the just-added nbd_opt_list_meta_context() API to give more details about each export (matching what 'qemu-nbd --list' already does). Note that this requires some shuffling: listing meta exports requires being in opt mode, but is easiest to do in list_one_export(), which requires setting opt_mode in more code paths, and deferring ready mode until the last possible minute during get_content(). As written, the code displays the list in reverse order from how the server presented it, thanks to my use of a simple linked list. We could use a different data type if we don't like the data be...

In v2: ack'ed preliminary patches have been pushed, and I've added a lot of testsuite coverage as well as putting the new API to use in nbdinfo. Eric Blake (2): api: Add nbd_opt_list_meta_context info: List available meta-contexts lib/internal.h | 1 + generator/API.ml | 84 ++++++++-

I'm posting this now, as I'm at the end of a workday and I got things working for manual experimentation. Still to do: - write interop tests for qemu-nbd and nbdkit (including my proposed patch addition of qemu-nbd -A to show qemu:allocation-depth) - figure out if we can make 'nbdinfo --map' use the new API to automatically select all contexts advertised by the server Eric Blake

This replaces 13/13 of my v2 series; and now that it has pretty good testsuite coverage and demonstrable performance improvement to nbdinfo, I'm going ahead and pushing this now. We may still want to add further nbd_opt_* commands for other fine-grained tuning of negotiation, but for now, I think things have stabilized on this end, and I can return to polishing .list_exports on the nbdkit

...debug_closure; extent_closure; list_closure; + context_closure ] (* Enums. *) let tls_enum = { @@ -852,7 +857,7 @@ to end the connection without finishing negotiation."; example = Some "examples/list-exports.c"; see_also = [Link "get_opt_mode"; Link "aio_is_negotiating"; Link "opt_abort"; Link "opt_go"; Link "opt_list"; - Link "opt_info"]; + Link "opt_info"; Link "opt_list_meta_context"]; }; "get_opt_mode...

On 8/11/20 12:12 PM, Richard W.M. Jones wrote: > I think this needs extra documentation in docs/libnbd.pod because it's > definitely not clear just from the rather thin manual page for > set_opt_mode how it works. docs/libnbd.pod is a good place for a > broader description of how it works. Yes, good idea. State-wise, the existing flow was: Created - Progress only by command issue - namely one of nbd_connect_* Connecting - Progress by aio_notify_read/aio_notify_write (as driven by a...

Another series on top of my exportname filter, marking off another todo bullet point. With this, you can now use the NBD plugin as a transparent passthrough of all export names served by the remote server in both directions (list advertisement server to client, and export name from client to server). Eric Blake (3): nbd: Implement .default_export, .export_description nbd: Add