search for: plugin_trim

...if (backend->pwrite (backend, conn, buf, count, offset) == -1) return get_error (conn); break; case NBD_CMD_FLUSH: - if (plugin_flush (conn) == -1) + if (backend->flush (backend, conn) == -1) return get_error (conn); break; case NBD_CMD_TRIM: - if (plugin_trim (conn, count, offset) == -1) + if (backend->trim (backend, conn, count, offset) == -1) return get_error (conn); break; case NBD_CMD_WRITE_ZEROES: - if (plugin_zero (conn, count, offset, - !(flags & NBD_CMD_FLAG_NO_HOLE)) == -1) + if (backend->...

...if (backend->pwrite (backend, conn, buf, count, offset) == -1) return get_error (conn); break; case NBD_CMD_FLUSH: - if (plugin_flush (conn) == -1) + if (backend->flush (backend, conn) == -1) return get_error (conn); break; case NBD_CMD_TRIM: - if (plugin_trim (conn, count, offset) == -1) + if (backend->trim (backend, conn, count, offset) == -1) return get_error (conn); break; case NBD_CMD_WRITE_ZEROES: - if (plugin_zero (conn, count, offset, - !(flags & NBD_CMD_FLAG_NO_HOLE)) == -1) + if (backend->...

...if (backend->pwrite (backend, conn, buf, count, offset) == -1) return get_error (conn); break; case NBD_CMD_FLUSH: - if (plugin_flush (conn) == -1) + if (backend->flush (backend, conn) == -1) return get_error (conn); break; case NBD_CMD_TRIM: - if (plugin_trim (conn, count, offset) == -1) + if (backend->trim (backend, conn, count, offset) == -1) return get_error (conn); break; case NBD_CMD_WRITE_ZEROES: - if (plugin_zero (conn, count, offset, - !(flags & NBD_CMD_FLAG_NO_HOLE)) == -1) + if (backend->...

Tested via: term1$ qemu-nbd -k $PWD/sock -t -f raw -x foo junk --trace=nbd_\* term2$ ./nbdkit -f -v -e bar nbd socket=$PWD/sock export=foo term3$ qemu-io -t none -f raw nbd://localhost:10809/bar --trace=nbd_\* and checking the traces to see that 'w 0 1' vs. 'w -f 0 1' was able to influence whether the FUA flag showed up at the server in term1. Still to go: figure out how to

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.

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

...+++ b/src/plugins.c @@ -412,7 +412,7 @@ plugin_pwrite (struct backend *b, struct connection *conn, errno = EROFS; return -1; } - if (r == 0 && fua) { + if (r != -1 && fua) { assert (p->plugin.flush); r = plugin_flush (b, conn, 0); } @@ -439,7 +439,7 @@ plugin_trim (struct backend *b, struct connection *conn, errno = EINVAL; return -1; } - if (r == 0 && fua) { + if (r != -1 && fua) { assert (p->plugin.flush); r = plugin_flush (b, conn, 0); } @@ -503,7 +503,7 @@ plugin_zero (struct backend *b, struct connection *c...

The upstream protocol recently promoted NBD_CMD_WRITE_ZEROES from experimental to a documented extension. Exposing support for this allows plugin writers to create sparse files when driven by a client that knows how to use the extension; meanwhile, even if a plugin does not support this extension, the server benefits from less network traffic from the client. Eric Blake (5): protocol: Support

While working on improving the backend interface to allow filters to handle errors, I noticed that I've introduced some minor incompatibilities for filters that don't quite obey the documentation which states that a callback should return only 0/-1. Prior to my additions, we treated all plugin returns other than -1 as success (sort of makes sense for a positive return, particularly if a

...ion *conn); -extern bool plugin_is_parallel (void); extern int plugin_errno_is_preserved (void); extern int plugin_open (struct connection *conn, int readonly); extern void plugin_close (struct connection *conn); @@ -169,6 +165,14 @@ extern int plugin_flush (struct connection *conn); extern int plugin_trim (struct connection *conn, uint32_t count, uint64_t offset); extern int plugin_zero (struct connection *conn, uint32_t count, uint64_t offset, int may_trim); +/* locks.c */ +extern void lock_connection (void); +extern void unlock_connection (void); +extern void lock_request (struct connection *co...

...ion *conn); -extern bool plugin_is_parallel (void); extern int plugin_errno_is_preserved (void); extern int plugin_open (struct connection *conn, int readonly); extern void plugin_close (struct connection *conn); @@ -169,6 +165,14 @@ extern int plugin_flush (struct connection *conn); extern int plugin_trim (struct connection *conn, uint32_t count, uint64_t offset); extern int plugin_zero (struct connection *conn, uint32_t count, uint64_t offset, int may_trim); +/* locks.c */ +extern void lock_connection (void); +extern void unlock_connection (void); +extern void lock_request (struct connection *co...

...onnection_get_handle (conn, 0)); debug ("flush"); if (p->plugin.flush != NULL) - return p->plugin.flush (connection_get_handle (conn)); + return p->plugin.flush (connection_get_handle (conn, 0)); else { errno = EINVAL; return -1; @@ -394,12 +395,12 @@ plugin_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 ("trim count=%" PRIu32 " offset=%" PRIu64, count, o...

...est (struct connection *conn, case NBD_CMD_FLUSH: r = plugin_flush (conn); if (r == -1) { - *error = errno ? errno : EIO; + *error = _get_error (); return 0; } break; @@ -656,7 +674,7 @@ _handle_request (struct connection *conn, case NBD_CMD_TRIM: r = plugin_trim (conn, count, offset); if (r == -1) { - *error = errno ? errno : EIO; + *error = _get_error (); return 0; } break; @@ -664,7 +682,7 @@ _handle_request (struct connection *conn, case NBD_CMD_WRITE_ZEROES: r = plugin_zero (conn, count, offset, !(flags & NBD...

...); if (p->plugin.pwrite != NULL) - r = p->plugin.pwrite (connection_get_handle (conn), buf, count, offset); + r = p->plugin.pwrite (connection_get_handle (conn, 0), + buf, count, offset); else { errno = EROFS; return -1; @@ -407,14 +408,14 @@ plugin_trim (struct backend *b, struct connection *conn, struct backend_plugin *p = container_of (b, struct backend_plugin, backend); bool fua = flags & NBDKIT_FLAG_FUA; - assert (connection_get_handle (conn)); + assert (connection_get_handle (conn, 0)); assert (!(flags & ~NBDKIT_FLAG_FUA))...

...-1; } - if (r != -1 && fua) { - assert (p->plugin.flush); - r = p->plugin.flush (connection_get_handle (conn, 0)); - } + if (r != -1 && need_flush) + r = plugin_flush (b, conn, 0, err); if (r == -1) *err = get_error (p); return r; @@ -471,6 +495,7 @@ plugin_trim (struct backend *b, struct connection *conn, int r; struct backend_plugin *p = container_of (b, struct backend_plugin, backend); bool fua = flags & NBDKIT_FLAG_FUA; + bool need_flush = false; assert (connection_get_handle (conn, 0)); assert (!(flags & ~NBDKIT_FLAG_FUA)); @@...

...mulate 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

I ran into these while trying to prepare patches to add NBD_CMD_FLAG_FAST_ZERO, which will expose a new NBD_ENOTSUP wire value. Eric Blake (2): plugins: Don't lose original error when emulating FUA plugins: Permit ENOTSUP as synonym for EOPNOTSUPP docs/nbdkit-filter.pod | 11 ++++++----- docs/nbdkit-plugin.pod | 12 +++++++----- plugins/file/file.c | 16 +++++++++++-----

I still don't have .prepare/.finalize working cleanly across reopen, but did find a nasty bug where a botched assertion means we failed to notice reads beyond EOF in both the xz and retry filter. Refactoring backend.c will make .finalize work easier. Eric Blake (5): xz: Avoid reading beyond EOF retry: Check size before transactions tests: Test retry when get_size values change

...-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_pread, .pwrite = plugin_pwrite, .flush = plugin_flush, .trim = plugin_trim, .zero = plugin_zero, .extents = plugin_extents, + .cache = plugin_cache, }; /* Register and load a plugin. */ diff --git a/server/protocol-handshake.c b/server/protocol-handshake.c index 03377a9..af1cd18 100644 --- a/server/protocol-handshake.c +++ b/server/protocol-handshake.c @@ -109,7...