--- info/nbdinfo.c | 132 ++++++++++++++++++++++++++++++++++++++++++++--- info/nbdinfo.pod | 39 +++++++++++++- 2 files changed, 164 insertions(+), 7 deletions(-) diff --git a/info/nbdinfo.c b/info/nbdinfo.c index 647a24c..d1648b8 100644 --- a/info/nbdinfo.c +++ b/info/nbdinfo.c @@ -34,6 +34,7 @@ static bool list_all = false; static bool probe_content, content_flag, no_content_flag; static bool json_output = false; +static const char *map = NULL; static bool size_only = false; static struct export_list { @@ -49,6 +50,10 @@ static void list_one_export (struct nbd_handle *nbd, const char *desc, static void list_all_exports (struct nbd_handle *nbd1, const char *uri); static void print_json_string (const char *); static char *get_content (struct nbd_handle *, int64_t size); +static int extent_callback (void *user_data, const char *metacontext, + uint64_t offset, + uint32_t *entries, size_t nr_entries, + int *error); static void __attribute__((noreturn)) usage (FILE *fp, int exitcode) @@ -60,6 +65,7 @@ usage (FILE *fp, int exitcode) " nbdinfo nbd://localhost\n" " nbdinfo \"nbd+unix:///?socket=/tmp/unixsock\"\n" " nbdinfo --size nbd://example.com\n" +" nbdinfo --map nbd://example.com\n" " nbdinfo --json nbd://example.com\n" " nbdinfo --list nbd://example.com\n" "\n" @@ -85,6 +91,7 @@ main (int argc, char *argv[]) CONTENT_OPTION, NO_CONTENT_OPTION, JSON_OPTION, + MAP_OPTION, SIZE_OPTION, }; const char *short_options = "LV"; @@ -95,6 +102,7 @@ main (int argc, char *argv[]) { "json", no_argument, NULL, JSON_OPTION }, { "list", no_argument, NULL, 'L' }, { "long-options", no_argument, NULL, LONG_OPTIONS }, + { "map", optional_argument, NULL, MAP_OPTION }, { "short-options", no_argument, NULL, SHORT_OPTIONS }, { "size", no_argument, NULL, SIZE_OPTION }, { "version", no_argument, NULL, 'V' }, @@ -143,6 +151,10 @@ main (int argc, char *argv[]) no_content_flag = true; break; + case MAP_OPTION: + map = optarg ? optarg : "base:allocation"; + break; + case SIZE_OPTION: size_only = true; break; @@ -164,10 +176,11 @@ main (int argc, char *argv[]) if (argc - optind != 1) usage (stderr, EXIT_FAILURE); - /* You can combine certain options. */ - if (list_all && size_only) { - fprintf (stderr, "%s: you cannot use %s and %s together.\n", - argv[0], "--list", "--size"); + /* You cannot combine certain options. */ + if (!!list_all + !!map + !!size_only > 1) { + fprintf (stderr, + "%s: you cannot use --list, --map and --size together.\n", + argv[0]); exit (EXIT_FAILURE); } if (content_flag && no_content_flag) { @@ -182,6 +195,8 @@ main (int argc, char *argv[]) probe_content = true; if (no_content_flag) probe_content = false; + if (map) + probe_content = false; /* Open the NBD side. */ nbd = nbd_create (); @@ -191,11 +206,13 @@ main (int argc, char *argv[]) } nbd_set_uri_allow_local_file (nbd, true); /* Allow ?tls-psk-file. */ - /* If using --list then we need opt mode in the handle. */ + /* Set optional modes in the handle. */ if (list_all) nbd_set_opt_mode (nbd, true); - if (!size_only) + if (!map && !size_only) nbd_set_full_info (nbd, true); + if (map) + nbd_add_meta_context (nbd, map); if (nbd_connect_uri (nbd, argv[optind]) == -1) { fprintf (stderr, "%s\n", nbd_get_error ()); @@ -225,6 +242,43 @@ main (int argc, char *argv[]) printf ("%" PRIi64 "\n", size); } + else if (map) { + uint64_t offset, prev_offset; + + /* Did we get the requested map? */ + if (!nbd_can_meta_context (nbd, map)) { + fprintf (stderr, + "%s: --map: server does not support metadata context \"%s\"\n", + argv[0], map); + exit (EXIT_FAILURE); + } + + size = nbd_get_size (nbd); + if (size == -1) { + fprintf (stderr, "%s\n", nbd_get_error ()); + exit (EXIT_FAILURE); + } + + for (offset = 0; offset < size;) { + prev_offset = offset; + if (nbd_block_status (nbd, size - offset, offset, + (nbd_extent_callback) { .callback = extent_callback, + .user_data = &offset }, + 0) == -1) { + fprintf (stderr, "%s\n", nbd_get_error ()); + exit (EXIT_FAILURE); + } + /* We expect extent_callback to increment the offset. If it did + * not then probably the server is not returning any extents. + */ + if (offset <= prev_offset) { + fprintf (stderr, "%s: --map: server did not return any extents\n", + argv[0]); + exit (EXIT_FAILURE); + } + } + if (json_output) printf ("\n"); + } else { /* Print per-connection fields. */ protocol = nbd_get_protocol (nbd); @@ -591,3 +645,69 @@ get_content (struct nbd_handle *nbd, int64_t size) free (cmd); return ret; /* caller frees */ } + +/* Callback handling --map. */ +static const char * +extent_description (const char *metacontext, uint32_t type) +{ + if (strcmp (metacontext, "base:allocation") == 0) { + switch (type) { + case 0: return "allocated"; + case 1: return "zero"; + case 2: return "hole"; + case 3: return "hole,zero"; + } + } + else if (strcmp (metacontext, "qemu:dirty-bitmap") == 0) { + switch (type) { + case 0: return "dirty"; + case 1: return "clean"; + } + } + + return "unknown"; +} + +static int +extent_callback (void *user_data, const char *metacontext, + uint64_t offset, + uint32_t *entries, size_t nr_entries, + int *error) +{ + size_t i; + uint64_t *ret_offset = user_data; + static bool comma = false; + + if (strcmp (metacontext, map) != 0) + return 0; + + /* Print the entries received. */ + for (i = 0; i < nr_entries; i += 2) { + const char *descr = extent_description (map, entries[i+1]); + + if (!json_output) { + printf ("%" PRIu64 " " + "%" PRIu32 " " + "%" PRIu32 " " + "%s\n", + offset, entries[i], entries[i+1], descr); + } + else { + if (comma) + printf (",\n"); + + printf ("[%" PRIu64 ", " + "%" PRIu32 ", " + "%" PRIu32 ", ", + offset, entries[i], entries[i+1]); + print_json_string (descr); + printf ("]"); + comma = true; + } + + offset += entries[i]; + } + + *ret_offset = offset; + return 0; +} diff --git a/info/nbdinfo.pod b/info/nbdinfo.pod index 19305bf..dbfb62f 100644 --- a/info/nbdinfo.pod +++ b/info/nbdinfo.pod @@ -4,7 +4,7 @@ nbdinfo - display information and metadata about NBD servers and exports =head1 SYNOPSIS - nbdinfo [--json] [--size] NBD-URI + nbdinfo [--json] [--map] [--size] NBD-URI nbdinfo -L|--list NBD-URI @@ -20,6 +20,8 @@ nbdinfo - display information and metadata about NBD servers and exports nbdinfo --size nbd://example.com + nbdinfo --map nbd://example.com + nbdinfo --json nbd://example.com nbdinfo --list nbd://example.com @@ -84,6 +86,32 @@ the I<--json> parameter: ] } +=head3 Map + +To show a map which areas of the disk are allocated and sparse, use +the I<--map> option: + + $ nbdinfo --map nbd://localhost/ + 0 1048576 0 allocated + 1048576 2097152 3 hole,zero + +The fields are: start size type description. + +The type field is an integer showing the raw value from the NBD +protocol. For some maps nbdinfo knows how to translate the type into +a printable description. + +By default this shows the C<"base:allocation"> map, but you can show +other maps too: + + $ nbdinfo --map=qemu:dirty-bitmap nbd://localhost/ + 0 1048576 dirty + +For more information on NBD maps, see I<Metadata querying> in the NBD +protocol. I<--json> can also be used here for parsable JSON output. + +=head3 List of exports + To list all the exports available on an NBD server use the I<--list> (I<-L>) option. @@ -122,6 +150,15 @@ use I<--list --content>. The output is displayed in JSON format. +=item B<--map> + +=item B<--map=>MAP + +Display the map (usually whether parts of the disk are allocated or +sparse) of the given export. This displays the C<"base:allocation"> +map by default, you can choose a different map with the optional +parameter. + =item B<-L> =item B<--list> -- 2.27.0