search for: plugin_functions

...*extents == NULL) { + *err = errno; + nbdkit_error ("calloc"); + return -1; + } + (*extents)[0].offset = offset; + (*extents)[0].length = count; + (*extents)[0].type = NBDKIT_EXTENT_TYPE_DATA; + *nr_extents = 1; + return 0; + } +} + static struct backend plugin_functions = { .free = plugin_free, .thread_model = plugin_thread_model, @@ -672,6 +740,7 @@ static struct backend plugin_functions = { .is_rotational = plugin_is_rotational, .can_trim = plugin_can_trim, .can_zero = plugin_can_zero, + .can_extents = plugin_can_extents, .can_fua = plugin_can...

...struct backend *); void (*usage) (struct backend *); const char *(*version) (struct backend *); void (*dump_fields) (struct backend *); diff --git a/src/plugins.c b/src/plugins.c index 6a2ef66..f0fe864 100644 --- a/src/plugins.c +++ b/src/plugins.c @@ -465,6 +465,7 @@ static struct backend plugin_functions = { .free = plugin_free, .thread_model = plugin_thread_model, .name = plugin_name, + .plugin_name = plugin_name, .usage = plugin_usage, .version = plugin_version, .dump_fields = plugin_dump_fields, -- 2.15.1

...if (r == -1) + *err = get_error (p); + return r; + } + else { + /* By default we assume that everything in the range is allocated. */ + return nbdkit_extent_add (extents_map, offset, count, + NBDKIT_EXTENT_TYPE_DATA); + } +} + static struct backend plugin_functions = { .free = plugin_free, .thread_model = plugin_thread_model, @@ -672,6 +731,7 @@ static struct backend plugin_functions = { .is_rotational = plugin_is_rotational, .can_trim = plugin_can_trim, .can_zero = plugin_can_zero, + .can_extents = plugin_can_extents, .can_fua = plugin_can...

...ection_get_handle (conn, 0)); + assert (!flags); + + debug ("cache count=%" PRIu32 " offset=%" PRIu64, count, offset); + + /* FIXME: assert plugin->cache and call it */ + assert (false); + + if (r == -1) + *err = get_error (p); + return r; +} + static struct backend plugin_functions = { .free = plugin_free, .thread_model = plugin_thread_model, @@ -717,12 +749,14 @@ static struct backend plugin_functions = { .can_extents = plugin_can_extents, .can_fua = plugin_can_fua, .can_multi_conn = plugin_can_multi_conn, + .can_cache = plugin_can_cache, .pread = plugin_p...

...t, + flags, extents_map); + if (r == -1) + *err = get_error (p); + return r; + } + else { + /* By default we assume that everything in the range is allocated. */ + return nbdkit_extent_add (extents_map, offset, count, 0); + } +} + static struct backend plugin_functions = { .free = plugin_free, .thread_model = plugin_thread_model, @@ -672,6 +730,7 @@ static struct backend plugin_functions = { .is_rotational = plugin_is_rotational, .can_trim = plugin_can_trim, .can_zero = plugin_can_zero, + .can_extents = plugin_can_extents, .can_fua = plugin_can...

...--- Just as .name and .plugin_name can differ for filters, should we also have a way to report independent version numbers (via .version) for the filter, compared to the version of the underlying plugin (via .plugin_version)? > +++ b/src/plugins.c > @@ -465,6 +465,7 @@ static struct backend plugin_functions = { > .free = plugin_free, > .thread_model = plugin_thread_model, > .name = plugin_name, > + .plugin_name = plugin_name, > .usage = plugin_usage, > .version = plugin_version, > .dump_fields = plugin_dump_fields, > -- Eric Blake, Principal Software Engin...

...lags, extents); + if (r >= 0 && nbdkit_extents_count (extents) < 1) { + nbdkit_error ("extents: plugin must return at least one extent"); + nbdkit_set_error (EINVAL); + r = -1; + } + if (r == -1) + *err = get_error (p); + return r; +} + static struct backend plugin_functions = { .free = plugin_free, .thread_model = plugin_thread_model, @@ -672,6 +722,7 @@ static struct backend plugin_functions = { .is_rotational = plugin_is_rotational, .can_trim = plugin_can_trim, .can_zero = plugin_can_zero, + .can_extents = plugin_can_extents, .can_fua = plugin_can...

This tentative commit implements extents/can_extents, roughly as discussed in the previous thread here: https://www.redhat.com/archives/libguestfs/2019-March/msg00017.html I can't say that I'm a big fan of having the plugin allocate an extents array. There are no other plugin callbacks currently where we require the plugin to allocate complex data structures (or indeed do any allocation

...return r; + } + else { + /* By default we assume that everything in the range is allocated. */ + errno = 0; + r = nbdkit_add_extent (extents, offset, count, 0 /* allocated data */); + if (r == -1) + *err = errno ? errno : EINVAL; + return r; + } +} + static struct backend plugin_functions = { .free = plugin_free, .thread_model = plugin_thread_model, @@ -672,6 +729,7 @@ static struct backend plugin_functions = { .is_rotational = plugin_is_rotational, .can_trim = plugin_can_trim, .can_zero = plugin_can_zero, + .can_extents = plugin_can_extents, .can_fua = plugin_can...

I'm not sure which version we're up to now. Anyway I believe this addresses all the points that Eric raised in: https://www.redhat.com/archives/libguestfs/2019-March/msg00038.html https://www.redhat.com/archives/libguestfs/2019-March/msg00040.html In particular: - default state of extents_map is all allocated disk - support hole + non-zero - you can now iterate with bounds -

...lags, extents); + if (r >= 0 && nbdkit_extents_count (extents) < 1) { + nbdkit_error ("extents: plugin must return at least one extent"); + nbdkit_set_error (EINVAL); + r = -1; + } + if (r == -1) + *err = get_error (p); + return r; +} + static struct backend plugin_functions = { .free = plugin_free, .thread_model = plugin_thread_model, @@ -672,6 +722,7 @@ static struct backend plugin_functions = { .is_rotational = plugin_is_rotational, .can_trim = plugin_can_trim, .can_zero = plugin_can_zero, + .can_extents = plugin_can_extents, .can_fua = plugin_can...

Second version based on nbdkit_extent* calls, as discussed here: https://www.redhat.com/archives/libguestfs/2019-March/msg00033.html Note in particular there is some subtlety about how filters would work in this implementation. See docs/nbdkit-filter.pod for the details. Rich.

...*err = get_error (p); + return r; + } + else { + /* By default we assume that everything in the range is allocated. + * However as that is the default state for the empty extents_map + * we don't need to do anything here. + */ + return 0; + } +} + static struct backend plugin_functions = { .free = plugin_free, .thread_model = plugin_thread_model, @@ -672,6 +724,7 @@ static struct backend plugin_functions = { .is_rotational = plugin_is_rotational, .can_trim = plugin_can_trim, .can_zero = plugin_can_zero, + .can_extents = plugin_can_extents, .can_fua = plugin_can...

...LL); - debug ("%s: open readonly=%d", p->name, readonly); + debug ("%s: open readonly=%d", b->name, readonly); handle = p->plugin.open (readonly); if (!handle) @@ -744,7 +724,6 @@ plugin_cache (struct backend *b, struct connection *conn, static struct backend plugin_functions = { .free = plugin_free, .thread_model = plugin_thread_model, - .name = plugin_name, .plugin_name = plugin_name, .usage = plugin_usage, .version = plugin_version, @@ -782,23 +761,16 @@ plugin_register (size_t index, const char *filename, { struct backend_plugin *p; const stru...

...(p->plugin.can_multi_conn) + return p->plugin.can_multi_conn (connection_get_handle (conn, 0)); + else + return 0; /* assume false */ +} + /* Plugins and filters can call this to set the true errno, in cases * where !errno_is_preserved. */ @@ -656,6 +672,7 @@ static struct backend plugin_functions = { .can_trim = plugin_can_trim, .can_zero = plugin_can_zero, .can_fua = plugin_can_fua, + .can_multi_conn = plugin_can_multi_conn, .pread = plugin_pread, .pwrite = plugin_pwrite, .flush = plugin_flush, diff --git a/tests/test-layers-filter.c b/tests/test-layers-filter.c index c5...

...s: ready_to_serve", b->name); + + if (!p->plugin.ready_to_serve) + return; + + if (p->plugin.ready_to_serve () == -1) + exit (EXIT_FAILURE); +} + static void * plugin_open (struct backend *b, struct connection *conn, int readonly) { @@ -656,6 +671,7 @@ static struct backend plugin_functions = { .config = plugin_config, .config_complete = plugin_config_complete, .magic_config_key = plugin_magic_config_key, + .ready_to_serve = plugin_ready_to_serve, .open = plugin_open, .prepare = plugin_prepare, .finalize = plugin_finalize, diff --git a/tests/test-layers-filter.c b/t...

...ame) printf (" (%s)", p->plugin.longname); printf ("\n"); + printf ("(%s)", p->filename); if (p->plugin.description) { printf ("\n"); printf ("%s\n", p->plugin.description); @@ -489,7 +490,7 @@ static struct backend plugin_functions = { /* Register and load a plugin. */ struct backend * -plugin_register (const char *filename, +plugin_register (size_t index, const char *filename, void *dl, struct nbdkit_plugin *(*plugin_init) (void)) { struct backend_plugin *p; @@ -504,11 +505,13 @@ plugin_register (co...

...en, this copies + // can_flush, since that's how we emulate FUA + return plugin_can_flush (b, conn); +} + static int plugin_pread (struct backend *b, struct connection *conn, void *buf, uint32_t count, uint64_t offset, uint32_t flags) @@ -535,6 +555,8 @@ static struct backend plugin_functions = { .flush = plugin_flush, .trim = plugin_trim, .zero = plugin_zero, + .can_zero = plugin_can_zero, + .can_fua = plugin_can_fua, }; /* Register and load a plugin. */ -- 2.14.3

...+ result = p->plugin.pwrite (connection_get_handle (conn), + buf, limit, offset); if (result < 0) break; count -= limit; @@ -538,3 +462,134 @@ plugin_zero (struct connection *conn, errno = err; return result; } + +static struct backend plugin_functions = { + .free = plugin_free, + .thread_model = plugin_thread_model, + .name = plugin_name, + .usage = plugin_usage, + .version = plugin_version, + .dump_fields = plugin_dump_fields, + .config = plugin_config, + .config_complete = plugin_config_complete, + .errno_is_preserved = plugin_errno_i...

...+ result = p->plugin.pwrite (connection_get_handle (conn), + buf, limit, offset); if (result < 0) break; count -= limit; @@ -538,3 +460,134 @@ plugin_zero (struct connection *conn, errno = err; return result; } + +static struct backend plugin_functions = { + .free = plugin_free, + .thread_model = plugin_thread_model, + .name = plugin_name, + .usage = plugin_usage, + .version = plugin_version, + .dump_fields = plugin_dump_fields, + .config = plugin_config, + .config_complete = plugin_config_complete, + .errno_is_preserved = plugin_errno_i...