search for: plugin_can_trim

...(fl == -1) + return -1; + if (fl) { + eflags |= NBD_FLAG_SEND_FLUSH | NBD_FLAG_SEND_FUA; + conn->can_flush = 1; + } + + fl = plugin_is_rotational (conn); + if (fl == -1) + return -1; + if (fl) { + eflags |= NBD_FLAG_ROTATIONAL; + conn->is_rotational = 1; + } + + fl = plugin_can_trim (conn); + if (fl == -1) + return -1; + if (fl) { + eflags |= NBD_FLAG_SEND_TRIM; + conn->can_trim = 1; + } + + *flags = eflags; + return 0; +} + +static int _negotiate_handshake_oldstyle (struct connection *conn) { struct old_handshake handshake; int64_t r; uint64_t expo...

...ue) plugin_config_complete (void) plugin_open (struct connection *conn, int readonly) plugin_close (struct connection *conn) plugin_get_size (struct connection *conn) plugin_can_write (struct connection *conn) plugin_can_flush (struct connection *conn) plugin_is_rotational (struct connection *conn) plugin_can_trim (struct connection *conn) That means dumping the plugin-internal data on connection close is not locked against the requests within that connection, and any garbage collection triggered by the last request may still be running while plugin_close runs. Boom. In general, when working with python an...

...gs) conn->can_flush = 1; } - fl = plugin_is_rotational (conn); + fl = backend->is_rotational (backend, conn); if (fl == -1) return -1; if (fl) { @@ -379,7 +381,7 @@ compute_eflags (struct connection *conn, uint16_t *flags) conn->is_rotational = 1; } - fl = plugin_can_trim (conn); + fl = backend->can_trim (backend, conn); if (fl == -1) return -1; if (fl) { @@ -407,7 +409,7 @@ _negotiate_handshake_oldstyle (struct connection *conn) return -1; } - r = plugin_get_size (conn); + r = backend->get_size (backend, conn); if (r == -1) ret...

...gs) conn->can_flush = 1; } - fl = plugin_is_rotational (conn); + fl = backend->is_rotational (backend, conn); if (fl == -1) return -1; if (fl) { @@ -379,7 +381,7 @@ compute_eflags (struct connection *conn, uint16_t *flags) conn->is_rotational = 1; } - fl = plugin_can_trim (conn); + fl = backend->can_trim (backend, conn); if (fl == -1) return -1; if (fl) { @@ -407,7 +409,7 @@ _negotiate_handshake_oldstyle (struct connection *conn) return -1; } - r = plugin_get_size (conn); + r = backend->get_size (backend, conn); if (r == -1) ret...

...gs) conn->can_flush = 1; } - fl = plugin_is_rotational (conn); + fl = backend->is_rotational (backend, conn); if (fl == -1) return -1; if (fl) { @@ -379,7 +381,7 @@ compute_eflags (struct connection *conn, uint16_t *flags) conn->is_rotational = 1; } - fl = plugin_can_trim (conn); + fl = backend->can_trim (backend, conn); if (fl == -1) return -1; if (fl) { @@ -407,7 +409,7 @@ _negotiate_handshake_oldstyle (struct connection *conn) return -1; } - r = plugin_get_size (conn); + r = backend->get_size (backend, conn); if (r == -1) ret...

v1 -> v2: - Fixed everything mentioned in the review. Rich.

Somewhat invasive but mostly mechanical change to how plugins are called. This patch is in preparation for adding a second backend subtype for filters. Rich.

...le) struct backend_plugin *p = container_of (b, struct backend_plugin, backend); if (p->plugin.is_rotational) - return p->plugin.is_rotational (handle); + return normalize_bool (p->plugin.is_rotational (handle)); else return 0; /* assume false */ } @@ -347,7 +355,7 @@ plugin_can_trim (struct backend *b, void *handle) struct backend_plugin *p = container_of (b, struct backend_plugin, backend); if (p->plugin.can_trim) - return p->plugin.can_trim (handle); + return normalize_bool (p->plugin.can_trim (handle)); else return p->plugin.trim || p->pl...

...ner_of (b, struct backend_plugin, backend); > > if (p->plugin.is_rotational) > - return p->plugin.is_rotational (handle); > + return normalize_bool (p->plugin.is_rotational (handle)); > else > return 0; /* assume false */ > } > @@ -347,7 +355,7 @@ plugin_can_trim (struct backend *b, void *handle) > struct backend_plugin *p = container_of (b, struct backend_plugin, backend); > > if (p->plugin.can_trim) > - return p->plugin.can_trim (handle); > + return normalize_bool (p->plugin.can_trim (handle)); > else > r...

...conn, 0)); debug ("is_rotational"); if (p->plugin.is_rotational) - return p->plugin.is_rotational (connection_get_handle (conn)); + return p->plugin.is_rotational (connection_get_handle (conn, 0)); else return 0; /* assume false */ } @@ -329,12 +329,12 @@ plugin_can_trim (struct backend *b, struct connection *conn) { struct backend_plugin *p = container_of (b, struct backend_plugin, backend); - assert (connection_get_handle (conn)); + assert (connection_get_handle (conn, 0)); debug ("can_trim"); if (p->plugin.can_trim) - return p-&...

...(conn, 0)); debug ("is_rotational"); if (p->plugin.is_rotational) - return p->plugin.is_rotational (connection_get_handle (conn)); + return p->plugin.is_rotational (connection_get_handle (conn, 0)); else return 0; /* assume false */ } @@ -329,12 +329,12 @@ plugin_can_trim (struct backend *b, struct connection *conn) { struct backend_plugin *p = container_of (b, struct backend_plugin, backend); - assert (connection_get_handle (conn)); + assert (connection_get_handle (conn, 0)); debug ("can_trim"); if (p->plugin.can_trim) - return p->...

The concern is a client is blocked while processing a request. The nbdkit server design requires a thread per request being processed regardless of the number of connections or clients. We want to run 1000's of requests in parallel without needing a thread at nbdkit layer per request in flight. Our plugin layer is built around boost asio and a few threads in a worker pool running an io

...eturn 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 c5a96e7..6da6ee6 100644 --- a/tests/t...

...uint32_t flags); + int (*can_zero) (struct backend *, struct connection *conn); + int (*can_fua) (struct backend *, struct connection *conn); }; /* plugins.c */ diff --git a/src/plugins.c b/src/plugins.c index dba3e24..3468b6d 100644 --- a/src/plugins.c +++ b/src/plugins.c @@ -358,6 +358,26 @@ plugin_can_trim (struct backend *b, struct connection *conn) return p->plugin.trim != NULL; } +static int +plugin_can_zero (struct backend *b, struct connection *conn) +{ + debug ("can_zero"); + + // We always allow .zero to fall back to .write, so plugins don't + // need to override thi...

...); + *err = EOPNOTSUPP; + goto done; + } + assert (p->plugin.pwrite || p->plugin._pwrite_old); flags &= ~NBDKIT_FLAG_MAY_TRIM; threadlocal_set_error (0); @@ -762,6 +783,7 @@ static struct backend plugin_functions = { .is_rotational = plugin_is_rotational, .can_trim = plugin_can_trim, .can_zero = plugin_can_zero, + .can_fast_zero = plugin_can_fast_zero, .can_extents = plugin_can_extents, .can_fua = plugin_can_fua, .can_multi_conn = plugin_can_multi_conn, diff --git a/server/protocol-handshake.c b/server/protocol-handshake.c index 0f3bd280..84fcacfd 100644 --- a/ser...

I still need to add testsuite coverage. Perhaps it might be easier if I create a new '--filter=log logfile=foo' filter that produces a log of which commands a client sent, then compare the log using a known client that uses write_zeroes (qemu-io works well) both with and without --filter=nozero to prove that the change in advertisement changes the commands sent over the wire (that would

...ith no exposure + * to the plugin interface; only filters can change it. + */ + return 1; +} + static int plugin_can_extents (struct backend *b, struct connection *conn) { @@ -761,6 +772,7 @@ static struct backend plugin_functions = { .is_rotational = plugin_is_rotational, .can_trim = plugin_can_trim, .can_zero = plugin_can_zero, + .can_sr = plugin_can_sr, .can_extents = plugin_can_extents, .can_fua = plugin_can_fua, .can_multi_conn = plugin_can_multi_conn, diff --git a/server/protocol-handshake-newstyle.c b/server/protocol-handshake-newstyle.c index e0136de1..518de703 100644 --- a...

...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_fua, .can_multi_conn = plugin_can_multi_conn, .pread = plugin_pread, @@ -679,6 +748,7 @@ static struct backend plugin_functions = { .flush = plugin_flush, .trim = plugin_trim, .zero = plug...

Experimental and only very lightly tested so far. Rich.

The first three patches are identical to: https://www.redhat.com/archives/libguestfs/2018-January/msg00079.html "[PATCH nbdkit v2 0/3] Refactor plugin_* functions into a backend" The rest of the patches add filters using the new filter API previously described here: https://www.redhat.com/archives/libguestfs/2018-January/msg00073.html This needs a lot more testing -- and tests --