search for: nbd_get_nr_list_export

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

...t all exports that it supports. This can only be used if L<nbd_set_opt_mode(3)> enabled option mode. -In this mode, during connection we query the server for the list -of NBD exports and collect them in the handle. You can query -the list of exports provided by the server by calling -L<nbd_get_nr_list_exports(3)> and L<nbd_get_list_export_name(3)>. -After choosing the export you want, set the export name -(L<nbd_set_export_name(3)>), then finish connecting with L<nbd_opt_go(3)>. +The <list> function is called once per advertised export, with any +C<user_data> passed to...

...re are 0 or more than 1 exports. We need to move the '"exports":[' and ']' into list_all_exports(), not list_one_export(), and manage correct trailing comma output. (We only tested nbdinfo with qemu-nbd, which only lists one export, explaining how we missed this) Bug 2: nbd_get_nr_list_exports() fails if the handle is still in READY state, even though there were exports listed and available in that case. I see no reason to forbid this during READY; but I've also mentioned that there are probably more changes coming to the way we do list export handling in libnbd to allow the reuse...

This rounds up the remaining bugs that I originally identified in: https://www.redhat.com/archives/libguestfs/2020-July/msg00153.html Eric Blake (4): api: Permit export list APIs when Connected info: Support --list with serializing servers info: Fix --json output when list size != 1 info: Permit --size --json generator/API.ml | 6 +++--- info/info-list-json.sh | 9 +++++++++

...t all exports that it supports. This can only be used if L<nbd_set_opt_mode(3)> enabled option mode. -In this mode, during connection we query the server for the list -of NBD exports and collect them in the handle. You can query -the list of exports provided by the server by calling -L<nbd_get_nr_list_exports(3)> and L<nbd_get_list_export_name(3)>. -After choosing the export you want, set the export name -(L<nbd_set_export_name(3)>), then finish connecting with L<nbd_opt_go(3)>. +The <list> function is called once per advertised export, with any +C<user_data> passed to...

Proposal for new APIs to list exports. The general shape of the API can probably best be seen from the examples/list-exports.c example. Rich.

...9,6 @@ #include <limits.h> #include <errno.h> -#include <libxml/uri.h> #include <libnbd.h> static bool list_all = false; @@ -422,7 +421,6 @@ static void list_all_exports (struct nbd_handle *nbd1, const char *uri) { int i; - xmlURIPtr xmluri = NULL; int count = nbd_get_nr_list_exports (nbd1); if (count == -1) { @@ -434,49 +432,38 @@ list_all_exports (struct nbd_handle *nbd1, const char *uri) printf ("\t\"exports\": []\n"); for (i = 0; i < count; ++i) { - char *name, *desc, *new_path, *new_uri; + char *name, *desc; struct nbd_handle...

An incremental improvement on top of listing exports. I still think it's worth experimenting with revisiting how our API for list mode should actually work [1] (so that we can reuse a single connection for both grabbing the list and finally using NBD_OPT_GO), but this change was easier to whip together while still thinking about that. [1]

..._string (desc); + printf (",\n"); + } + if (content) { printf ("\t\"content\": "); print_json_string (content); @@ -402,7 +411,7 @@ list_all_exports (struct nbd_handle *nbd1, const char *uri) xmlURIPtr xmluri = NULL; for (i = 0; i < nbd_get_nr_list_exports (nbd1); ++i) { - char *name, *new_path, *new_uri; + char *name, *desc, *new_path, *new_uri; struct nbd_handle *nbd2; name = nbd_get_list_export_name (nbd1, i); @@ -437,10 +446,12 @@ list_all_exports (struct nbd_handle *nbd1, const char *uri) } /* List the metadata o...

...is operation can fail normally, so + * we need to check the return value and + * error code. + */ + r = nbd_connect_unix (nbd, argv[1]); + if (r == -1 && nbd_get_errno () == ENOTSUP) { + fprintf (stderr, "%s\n", nbd_get_error ()); + exit (EXIT_FAILURE); + } + + if (nbd_get_nr_list_exports (nbd) == 0) { + fprintf (stderr, "Server does not support " + "listing exports.\n"); + exit (EXIT_FAILURE); + } + + /* Display the list of exports. */ + for (i = 0; + i < nbd_get_nr_list_exports (nbd); + i++) { + name = nbd_get_list_export...

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):

...eed to check the return value and > + * error code. > + */ > + r = nbd_connect_unix (nbd, argv[1]); > + if (r == -1 && nbd_get_errno () == ENOTSUP) { > + fprintf (stderr, "%s\n", nbd_get_error ()); > + exit (EXIT_FAILURE); > + } > + > + if (nbd_get_nr_list_exports (nbd) == 0) { > + fprintf (stderr, "Server does not support " > + "listing exports.\n"); > + exit (EXIT_FAILURE); > + } > + > + /* Display the list of exports. */ > + for (i = 0; > + i < nbd_get_nr_list_exports (nbd); > +...

...Set opt mode and request list exports. */ + nbd_set_opt_mode (nbd, true); nbd_set_list_exports (nbd, true); /* Connect to the NBD server over a @@ -52,8 +71,8 @@ main (int argc, char *argv[]) fprintf (stderr, "%s\n", nbd_get_error ()); exit (EXIT_FAILURE); } - - if (nbd_get_nr_list_exports (nbd) == 0) { + if (!nbd_aio_is_negotiating (nbd) || + nbd_get_nr_list_exports (nbd) == 0) { fprintf (stderr, "Server does not support " "listing exports.\n"); exit (EXIT_FAILURE); @@ -73,29 +92,34 @@ main (int argc, char *argv[]) } printf (&...