search for: nbd_can_multi_conn

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

...tions"); return -1; } diff --git a/tests/aio-parallel-load.c b/tests/aio-parallel-load.c index ce39140..f4ba635 100644 --- a/tests/aio-parallel-load.c +++ b/tests/aio-parallel-load.c @@ -231,7 +231,7 @@ start_thread (void *arg) assert (nbd_get_size (nbd) == EXPORTSIZE); assert (nbd_can_multi_conn (nbd) > 0); - assert (nbd_read_only (nbd) == 0); + assert (nbd_is_read_only (nbd) == 0); /* Issue commands. */ assert (nbd_aio_in_flight (nbd) == 0); diff --git a/tests/aio-parallel.c b/tests/aio-parallel.c index 166b560..f8d4891 100644 --- a/tests/aio-parallel.c +++ b/tests/aio-parall...

...conn(), it would be nice if we could automatically kill off the losers, swap the winning connection into conns[0], and then behave as if we implicitly called set_multi_conn(nbd, 1), so that the synchronous connect command will succeed after all. In such a case, the user can learn after the fact via nbd_can_multi_conn and nbd_get_multi_conn that things were changed because multi_conn was not supported after all. Or maybe we want both 'set_multi_conn' (connect hard-fails if the FIRST connection reports !can_multi_conn) vs. 'request_multi_conn' (connect downgrades gracefully), similar to how reque...

One API change, some small documentation changes.

...urn !!(h->flags & NBD_FLAG_SEND_TRIM); } static int @@ -1199,7 +1199,7 @@ nbd_can_zero (void *handle) { struct handle *h = handle; - return h->flags & NBD_FLAG_SEND_WRITE_ZEROES; + return !!(h->flags & NBD_FLAG_SEND_WRITE_ZEROES); } static int @@ -1215,7 +1215,7 @@ nbd_can_multi_conn (void *handle) { struct handle *h = handle; - return h->flags & NBD_FLAG_CAN_MULTI_CONN; + return !!(h->flags & NBD_FLAG_CAN_MULTI_CONN); } static int -- 2.25.1

...an_fast_zero, can_flush, can_fua, can_multi_conn, can_trim, can_zero; + int64_t block_minimum, block_preferred, block_maximum; /* Collect the metadata we are going to display. */ size = nbd_get_size (nbd); @@ -288,6 +289,9 @@ list_one_export (struct nbd_handle *nbd) can_multi_conn = nbd_can_multi_conn (nbd); can_trim = nbd_can_trim (nbd); can_zero = nbd_can_zero (nbd); + block_minimum = nbd_get_block_size (nbd, LIBNBD_SIZE_MINIMUM); + block_preferred = nbd_get_block_size (nbd, LIBNBD_SIZE_PREFERRED); + block_maximum = nbd_get_block_size (nbd, LIBNBD_SIZE_MAXIMUM); if (!json_output)...

..._username \ - nbd_get_tls_username \ - nbd_set_tls_psk_file \ - nbd_add_meta_context \ - nbd_connect_uri \ - nbd_connect_unix \ - nbd_connect_tcp \ - nbd_connect_command \ - nbd_is_read_only \ - nbd_can_flush \ - nbd_can_fua \ - nbd_is_rotational \ - nbd_can_trim \ - nbd_can_zero \ - nbd_can_df \ - nbd_can_multi_conn \ - nbd_can_cache \ - nbd_can_meta_context \ - nbd_get_size \ - nbd_pread \ - nbd_pread_structured \ - nbd_pwrite \ - nbd_shutdown \ - nbd_flush \ - nbd_trim \ - nbd_cache \ - nbd_zero \ - nbd_block_status \ - nbd_poll \ - nbd_aio_connect \ - nbd_aio_connect_uri \ - nbd_aio_connect_unix \ - nbd_aio...

..._username \ + nbd_get_tls_username \ + nbd_set_tls_psk_file \ + nbd_add_meta_context \ + nbd_connect_uri \ + nbd_connect_unix \ + nbd_connect_tcp \ + nbd_connect_command \ + nbd_is_read_only \ + nbd_can_flush \ + nbd_can_fua \ + nbd_is_rotational \ + nbd_can_trim \ + nbd_can_zero \ + nbd_can_df \ + nbd_can_multi_conn \ + nbd_can_cache \ + nbd_can_meta_context \ + nbd_get_size \ + nbd_pread \ + nbd_pread_structured \ + nbd_pwrite \ + nbd_shutdown \ + nbd_flush \ + nbd_trim \ + nbd_cache \ + nbd_zero \ + nbd_block_status \ + nbd_poll \ + nbd_aio_connect \ + nbd_aio_connect_uri \ + nbd_aio_connect_unix \ + nbd_aio...

...static int > @@ -1199,7 +1199,7 @@ nbd_can_zero (void *handle) > { > struct handle *h = handle; > > - return h->flags & NBD_FLAG_SEND_WRITE_ZEROES; > + return !!(h->flags & NBD_FLAG_SEND_WRITE_ZEROES); > } > > static int > @@ -1215,7 +1215,7 @@ nbd_can_multi_conn (void *handle) > { > struct handle *h = handle; > > - return h->flags & NBD_FLAG_CAN_MULTI_CONN; > + return !!(h->flags & NBD_FLAG_CAN_MULTI_CONN); > } > > static int While I don't like the idea of modifying plugins to fix broken nbdkit behaviour...

...exportsize == -1) { + fprintf (stderr, "%s\n", nbd_get_error ()); + exit (EXIT_FAILURE); + } + + if (nbd_read_only (nbd) == 1) { + fprintf (stderr, "%s: error: this NBD export is read-only\n", argv[0]); + exit (EXIT_FAILURE); + } + +#if NR_MULTI_CONN > 1 + if (nbd_can_multi_conn (nbd) == 0) { + fprintf (stderr, "%s: error: " + "this NBD export does not support multi-conn\n", argv[0]); + exit (EXIT_FAILURE); + } +#endif + + nbd_close (nbd); + + /* Start the reader threads. */ + for (i = 0; i < NR_MULTI_CONN; ++i) { + status[i]...

...bd_get_size (nbd); + if (exportsize == -1) { + fprintf (stderr, "%s\n", nbd_get_error ()); + exit (EXIT_FAILURE); + } + + if (nbd_read_only (nbd) == 1) { + fprintf (stderr, "%s: error: this NBD export is read-only\n", argv[0]); + exit (EXIT_FAILURE); + } + + if (nbd_can_multi_conn (nbd) == 0) { + fprintf (stderr, "%s: error: " + "this NBD export does not support multi-conn\n", argv[0]); + exit (EXIT_FAILURE); + } + + nbd_close (nbd); + + /* Start the reader threads. */ + for (i = 0; i < NR_MULTI_CONN; ++i) { + reader_status[i]....

First thing to say is that I need to do a *lot* more testing on this, so this is just an early peek. In particular, although it passed ‘make check && make check-valgrind’ I have *not* tested it against a multi-conn-aware client such as the Linux kernel >= 4.9. This implements NBD_FLAG_CAN_MULTI_CONN, described in the protocol doc as: "NBD_FLAG_CAN_MULTI_CONN: Indicates that

Patch 1 played with an early draft of Rich's Fedora 30 libnbd package: https://bugzilla.redhat.com/show_bug.cgi?id=1713767#c17 Note that comment 21 provides a newer package 0.1.1-1 with a different API; and that libnbd has more unreleased API changes in the pipeline (whether that will be called 0.2 or 0.1.2); so we'll have to tweak things based on what is actually available in distros.

Updated based on other changes that have happened in the meantime: - rely more on cleanup.h (throughout) - split structured read for easier review (patch 2 and 3 were combined in v1) - rely on nbdkit not leaking a server's partial answer (patch 3) - add tests (patch 5) - other bug fixes I found while testing it - drop EOVERFLOW patch for now; it will be separate once upstream NBD protocol

libnbd-0.1.2-1 is now available in Fedora 29/30 updates-testing, although it was not compiled against libxml2 so it lacks uri support (I ended up testing patch 4 with a self-built libnbd). Diffs since v1 - rebase to master, bump from libnbd 0.1 to 0.1.2, add URI support, better timing results Still not done - patch 5 needs associated tests Eric Blake (5): nbd: Check for libnbd nbd:

For existing commits, this is almost identical to v1, except that I updated some commit messages and reordered the commits in a somewhat more logical sequence. The main changes are the extra commits: [06/11] plugins: Return NBD_FLAG_CAN_MULTI_CONN from some readonly plugins. - Readonly plugins that can set the flag unconditionally. [09/11] partitioning: Return NBD_FLAG_CAN_MULTI_CONN. [10/11]

Necessary when writing a client that wants to avoid unnecessary EINVAL errors from sending unaligned requests. At some point, we may want to add synchronous convenience API wrappers that do request splitting or read-modify-write to obey server constraints while still appearing to the library client as accepting any possible request. But such a wrapper should only be synchronous and not copied to

...n_zero (void *handle) -{ - struct handle *h = handle; - - return !!(h->flags & NBD_FLAG_SEND_WRITE_ZEROES); -} - -static int -nbd_can_fua (void *handle) -{ - struct handle *h = handle; - - return h->flags & NBD_FLAG_SEND_FUA ? NBDKIT_FUA_NATIVE : NBDKIT_FUA_NONE; -} - -static int -nbd_can_multi_conn (void *handle) -{ - struct handle *h = handle; - - return !!(h->flags & NBD_FLAG_CAN_MULTI_CONN); -} - -static int -nbd_can_cache (void *handle) -{ - struct handle *h = handle; - - if (h->flags & NBD_FLAG_SEND_CACHE) - return NBDKIT_CACHE_NATIVE; - return NBDKIT_CACHE_NONE; -}...

libnbd-0.1.4-1 is now available in Fedora 29/30 updates testing. Diffs since v2 - rebase to master, bump from libnbd 0.1.2 to 0.1.3+, add tests to TLS usage which flushed out the need to turn relative pathnames into absolute, doc tweaks Now that the testsuite covers TLS and libnbd has been fixed to provide the things I found lacking when developing v2, I'm leaning towards pushing this on

I'm hoping to implement .extents for the nbd plugin; this is a prerequisite. I'm not sure about patch 3 - if we like it, I'll squash it to 2, if we don't, I think we are okay just dropping it. I'm also wondering if we have to worry about malicious plugins that don't populate the entire .pread buffer in an effort to get nbdkit to expose portions of the heap; my patch 7 loses