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Now that we have a way to pass Mutable(Int "error") to callbacks, that's a much nicer way for language bindings to use than relying on the value of errno after returning -1. Update the semantics for block status to match what pread_structured does, getting errno out of the equation, and changing things to call the callback for a second context even after an earlier callback failure

A rather trivial decoding; we may enhance it further if qemu extends things to give an integer depth alongside its tri-state encoding. --- I'll wait to push this to libnbd until the counterpart qemu patches land upstream, although it looks like I've got positive review. info/nbdinfo.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/info/nbdinfo.c b/info/nbdinfo.c index

...Servers MUST NOT > > + advertise this bit unless the client successfully negotiates > > + extended headers via `NBD_OPT_EXTENDED_HEADERS`, and SHOULD NOT > > + advertise this bit in response to `NBD_OPT_EXPORT_NAME` or > > + `NBD_OPT_GO` if the client does not negotiate metacontexts with > > + `NBD_OPT_SET_META_CONTEXT`; clients SHOULD NOT set the > > + `NBD_CMD_FLAG_PAYLOAD_LEN` flag for `NBD_CMD_BLOCK_STATUS` unless > > + this transmission flag is set. > > Given that we are introducing this at the same time as the extended > headers (and given...

On 6/27/19 5:07 AM, Martin Kletzander wrote: > This just defines the namespace, its contexts and related constants and the only > supported one is currently base:allocation. The names of the constants are not > very future-proof, but shorter than LIBNBD_META_NS_CONTEXT_BASE_ALLOCATION or > similar. > > Currently the output looks like this: > > /* "base"

Callback functions now return an int instead of a void. This allows in some cases for the callback to indicate that there was an error. This is a small change to the API: For nbd_set_debug_callback the signature has changed, but the return value is ignored. For nbd_block_status and nbd_aio_block_status the extent function can return an error, which causes the block status command to return an

On 10/16/20 10:23 AM, Eric Blake wrote: > A rather trivial decoding; we may enhance it further if qemu extends > things to give an integer depth alongside its tri-state encoding. > --- > > I'll wait to push this to libnbd until the counterpart qemu patches > land upstream, although it looks like I've got positive review. Whoops, I accidentally pushed this before qemu

If the user's extent_fn callback fails, we want to fail the overall block status command with the same errno, but not give up on the server. Do this by skipping any further context chunks from the server, and relying on the previous patch's ability to preserve the first error encountered. Update the interop test with qemu's dirty bitmap context to provoke callback failure, as well as

This just defines the namespace, its contexts and related constants and the only supported one is currently base:allocation. The names of the constants are not very future-proof, but shorter than LIBNBD_META_NS_CONTEXT_BASE_ALLOCATION or similar. Currently the output looks like this: /* "base" namespace */ /* "base" namespace contexts */ /* "base:allocation"

This is a rough-and-ready implementation of nbdinfo --map option, to display the allocation and other metadata of NBD exports. I only tested it lightly against nbdkit. It needs at least some tests. Command like these should work: nbdinfo --map nbd://localhost nbdinfo --map=qemu:dirty-bitmap nbd://localhost Rich.

Rather than moving the connection to DEAD, we can just ignore further contexts to the existing command handle, and fail the overall command with the same errno as the failed callback. Eric Blake (2): states: Track cmd->error as errno, not wire value api: Recover from block status callback failure generator/generator | 5 ++- generator/states-reply-simple.c | 2 +-

Fixes bugs with JSON output in the previous patch, and adds some tests. Rich.

Previously closures had a crude flag which tells if they are persistent or transient. Transient closures (flag = false) last for the lifetime of the currently called libnbd function. Persistent closures had an indefinite lifetime which could last for as long as the handle. In language bindings handling persistent closures was wasteful as we needed to register a "close callback" to

On 6/4/19 4:59 AM, Richard W.M. Jones wrote: > Callback functions now return an int instead of a void. This allows > in some cases for the callback to indicate that there was an error. > > This is a small change to the API: Indeed; and my work to let nbdkit-nbd use libnbd is slightly impacted. If I want to support both 0.1.2 and 0.1.x, I now have to do a conditional compilation

On 9/26/20 11:36 AM, Richard W.M. Jones wrote: > --- > info/Makefile.am | 4 + > info/info-map-base-allocation-json.sh | 52 ++++++++++ > info/info-map-base-allocation.sh | 49 ++++++++++ > info/nbdinfo.c | 134 ++++++++++++++++++++++++-- > info/nbdinfo.pod | 39 +++++++- > 5 files changed, 271

Previously closures had a crude flag which tells if they are persistent or transient. Transient closures (flag = false) last for the lifetime of the currently called libnbd function. Persistent closures had an indefinite lifetime which could last for as long as the handle. In language bindings handling persistent closures was wasteful as we needed to register a "close callback" to

--- info/Makefile.am | 4 + info/info-map-base-allocation-json.sh | 52 ++++++++++ info/info-map-base-allocation.sh | 49 ++++++++++ info/nbdinfo.c | 134 ++++++++++++++++++++++++-- info/nbdinfo.pod | 39 +++++++- 5 files changed, 271 insertions(+), 7 deletions(-) diff --git a/info/Makefile.am b/info/Makefile.am index

This change does not affect the output of the generator. Note this requires that all Closure args have the same parameter name whichever method they appear in. An alternate refactoring could work the same way as Flags and Enum where the parameter name is part of the arg, eg: type arg = ... | Closure of string * closure (* name, type *) ... "set_debug_callback", {

This is an API/ABI break, but we have not yet declared stable API. In order to use optional arguments in languages that support that, any optional arguments must be last. Let's be consistent in this by rearranging the arguments to block_status so that flags is always last. --- generator/generator | 10 ++++++---- interop/dirty-bitmap.c | 6 +++--- lib/rw.c

** INCOMPLETE ** This is the generator change as discussed on the list already. The Python and OCaml bindings are not yet done. It passes all [C only] tests and valgrind. Note that nbd_add_close_callback is inconsistent with other closure types because it passes the user_data parameter after the function. (This is not caused by the current patch, it was already inconsistent). We decided that

Previously closures had a crude flag which tells if they are persistent or transient. Transient closures (flag = false) last for the lifetime of the currently called libnbd function. Persistent closures had an indefinite lifetime which could last for as long as the handle. In language bindings handling persistent closures was wasteful as we needed to register a "close callback" to