search for: plugin_flush

...c index 699e9c5..1b0816c 100644 --- a/src/plugins.c +++ 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 @@ p...

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

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 +++++++++++-----

...disk. You should write C<$count> bytes to the disk starting at +C<$offset>. + +NBD only supports whole writes, so your function should try to write +the whole region (perhaps requiring a loop). If the write fails or is +partial, your function should call C<error>. + +=item C<plugin_flush> + +(Optional) + + proc plugin_flush {h} { + # No return value + } + +The body of your C<plugin_flush> function should do a L<sync(2)> or +L<fdatasync(2)> or equivalent on the backing store. + +=item C<trim> + +(Optional) + + proc trim {h count offset} { + # No re...

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

...f, count, offset) == -1) return get_error (conn); break; case NBD_CMD_WRITE: - if (plugin_pwrite (conn, buf, count, offset) == -1) + 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...

...f, count, offset) == -1) return get_error (conn); break; case NBD_CMD_WRITE: - if (plugin_pwrite (conn, buf, count, offset) == -1) + 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...

...f, count, offset) == -1) return get_error (conn); break; case NBD_CMD_WRITE: - if (plugin_pwrite (conn, buf, count, offset) == -1) + 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...

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

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.

...*conn, case NBD_CMD_WRITE: r = plugin_pwrite (conn, buf, count, offset); if (r == -1) { - *error = errno ? errno : EIO; + *error = _get_error (); return 0; } break; @@ -648,7 +666,7 @@ _handle_request (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 = err...

...ugin.pread (connection_get_handle (conn, 0), buf, count, offset, + 0); + else + r = p->plugin._pread_old (connection_get_handle (conn, 0), buf, count, + offset); if (r == -1) *err = get_error (p); return r; @@ -421,16 +438,17 @@ plugin_flush (struct backend *b, struct connection *conn, uint32_t flags, debug ("flush"); - if (p->plugin.flush != NULL) { - r = p->plugin.flush (connection_get_handle (conn, 0)); - if (r == -1) - *err = get_error (p); - return r; - } + if (p->plugin.flush) + r = p-&...

...t=%" PRIu32 " offset=%" PRIu64, count, offset); - return p->plugin.pread (connection_get_handle (conn, 0), buf, count, offset); + r = p->plugin.pread (connection_get_handle (conn, 0), buf, count, offset); + if (r < 0) + r = get_error (p); + return r; } static int plugin_flush (struct backend *b, struct connection *conn, uint32_t flags) { struct backend_plugin *p = container_of (b, struct backend_plugin, backend); + int r; assert (connection_get_handle (conn, 0)); assert (!flags); debug ("flush"); - if (p->plugin.flush != NULL) - return...

..._command; struct operation *op = (struct operation *) vop; flush_after_command = (op->flags & NBD_CMD_FLAG_FUA) != 0; if (!op->conn->can_flush || op->conn->readonly) flush_after_command = false; if (flush_after_command) { op->flags = 0; // clear flags r = plugin_flush_lowlevel (op, op->conn->handle); if (r == -1) // do error stuff; } else if (op->cmd == NBD_CMD_READ) send_reply(op, op->buf, op->count, 0); else send_reply(op, NULL, 0, 0); } int my_plugin_pwrite_lowlevel (void *op, void *handle, void *buf,...

...onn, case NBD_CMD_WRITE: r = plugin_pwrite (conn, buf, count, offset); if (r == -1) { - *error = errno ? errno : EIO; + *error = get_error (conn); return 0; } break; @@ -648,7 +662,7 @@ _handle_request (struct connection *conn, case NBD_CMD_FLUSH: r = plugin_flush (conn); if (r == -1) { - *error = errno ? errno : EIO; + *error = get_error (conn); return 0; } break; @@ -656,7 +670,7 @@ _handle_request (struct connection *conn, case NBD_CMD_TRIM: r = plugin_trim (conn, count, offset); if (r == -1) { - *error =...

...struct connection *conn, void *handle, +plugin_pread (struct backend *b, void *handle, void *buf, uint32_t count, uint64_t offset, uint32_t flags, int *err) { @@ -473,7 +473,7 @@ plugin_pread (struct backend *b, struct connection *conn, void *handle, } static int -plugin_flush (struct backend *b, struct connection *conn, void *handle, +plugin_flush (struct backend *b, void *handle, uint32_t flags, int *err) { struct backend_plugin *p = container_of (b, struct backend_plugin, backend); @@ -493,7 +493,7 @@ plugin_flush (struct backend *b, struct connecti...

v1 was here: https://www.redhat.com/archives/libguestfs/2020-February/msg00081.html v2 replaces struct connection *conn = GET_CONN; with GET_CONN; which sets conn implicitly and asserts that it is non-NULL. If we actually want to test if conn is non-NULL or behave differently, then you must use threadlocal_get_conn() instead, and some existing uses do that. Rich.

The third patch is a large but mechanical change which gets rid of passing around struct connection * entirely within the server, preferring instead to reference the connection through thread-local storage. I hope this is a gateway to simplifying other parts of the code. Rich.

A combination of the work that both Rich and I have been doing lately, where filters use only the new API with flags on every command that the client can send over the wire (we can then add support for more flags in nbdkit without having to add new callbacks, as NBD adds more flags upstream). Eric Blake (4): protocol: Split flags from cmd field in requests backend: Pass flags argument through