[Libguestfs] [nbdkit PATCH v2 12/13] filters: Move rdelay/wdelay from file plugin to new delay filter.

From: "Richard W.M. Jones" <rjones(a)redhat.com&gt; Previously the file plugin supported ‘rdelay’ and ‘wdelay’ parameters for injecting delays (for testing) into read and write requests. This moves the functionality to a new delay filter so that it can be used with any plugin. Message-Id: <20180117205356.8699-10-rjones(a)redhat.com&gt; [eblake: adjust for FUA flags] Signed-off-by: Eric Blake <eblake(a)redhat.com&gt; --- TODO | 3 - configure.ac | 1 + filters/Makefile.am | 1 + filters/delay/Makefile.am | 62 +++++++++++++ filters/delay/delay.c | 162 ++++++++++++++++++++++++++++++++++ filters/delay/nbdkit-delay-filter.pod | 88 ++++++++++++++++++ plugins/file/file.c | 76 ++-------------- plugins/file/nbdkit-file-plugin.pod | 14 +-- tests/test-parallel-file.sh | 4 +- tests/test-parallel-nbd.sh | 1 + 10 files changed, 325 insertions(+), 87 deletions(-) create mode 100644 filters/delay/Makefile.am create mode 100644 filters/delay/delay.c create mode 100644 filters/delay/nbdkit-delay-filter.pod diff --git a/TODO b/TODO index 8eda0d7..3ec45fd 100644 --- a/TODO +++ b/TODO @@ -37,9 +37,6 @@ directed to qemu-nbd for these use cases. Suggestions for filters ----------------------- -* adding artificial delays (see wdelay/rdelay options in the file - plugin) - * injecting artificial errors for testing clients * copy-on-write, a popular feature in other servers diff --git a/configure.ac b/configure.ac index 4892dc4..9376a2e 100644 --- a/configure.ac +++ b/configure.ac @@ -513,6 +513,7 @@ AC_CONFIG_FILES([Makefile plugins/vddk/Makefile plugins/xz/Makefile filters/Makefile + filters/delay/Makefile filters/offset/Makefile src/Makefile src/nbdkit.pc diff --git a/filters/Makefile.am b/filters/Makefile.am index 91fbe6c..d4aa6c0 100644 --- a/filters/Makefile.am +++ b/filters/Makefile.am @@ -31,4 +31,5 @@ # SUCH DAMAGE. SUBDIRS = \ + delay \ offset diff --git a/filters/delay/Makefile.am b/filters/delay/Makefile.am new file mode 100644 index 0000000..5b20b69 --- /dev/null +++ b/filters/delay/Makefile.am @@ -0,0 +1,62 @@ +# nbdkit +# Copyright (C) 2018 Red Hat Inc. +# All rights reserved. +# +# Redistribution and use in source and binary forms, with or without +# modification, are permitted provided that the following conditions are +# met: +# +# * Redistributions of source code must retain the above copyright +# notice, this list of conditions and the following disclaimer. +# +# * Redistributions in binary form must reproduce the above copyright +# notice, this list of conditions and the following disclaimer in the +# documentation and/or other materials provided with the distribution. +# +# * Neither the name of Red Hat nor the names of its contributors may be +# used to endorse or promote products derived from this software without +# specific prior written permission. +# +# THIS SOFTWARE IS PROVIDED BY RED HAT AND CONTRIBUTORS ''AS IS'' AND +# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, +# THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A +# PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL RED HAT OR +# CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT +# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF +# USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND +# ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, +# OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT +# OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF +# SUCH DAMAGE. + +EXTRA_DIST = nbdkit-delay-filter.pod + +CLEANFILES = *~ + +filterdir = $(libdir)/nbdkit/filters + +filter_LTLIBRARIES = nbdkit-delay-filter.la + +nbdkit_delay_filter_la_SOURCES = \ + delay.c \ + $(top_srcdir)/include/nbdkit-filter.h + +nbdkit_delay_filter_la_CPPFLAGS = \ + -I$(top_srcdir)/include +nbdkit_delay_filter_la_CFLAGS = \ + $(WARNINGS_CFLAGS) +nbdkit_delay_filter_la_LDFLAGS = \ + -module -avoid-version -shared + +if HAVE_POD2MAN + +man_MANS = nbdkit-delay-filter.1 +CLEANFILES += $(man_MANS) + +nbdkit-delay-filter.1: nbdkit-delay-filter.pod + $(POD2MAN) $(POD2MAN_ARGS) --section=1 --name=`basename $@ .1` $< $@.t && \ + if grep 'POD ERROR' $@.t; then rm $@.t; exit 1; fi && \ + mv $@.t $@ + +endif diff --git a/filters/delay/delay.c b/filters/delay/delay.c new file mode 100644 index 0000000..6049a20 --- /dev/null +++ b/filters/delay/delay.c @@ -0,0 +1,162 @@ +/* nbdkit + * Copyright (C) 2018 Red Hat Inc. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are + * met: + * + * * Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * + * * Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * * Neither the name of Red Hat nor the names of its contributors may be + * used to endorse or promote products derived from this software without + * specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY RED HAT AND CONTRIBUTORS ''AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, + * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A + * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL RED HAT OR + * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF + * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND + * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, + * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT + * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#include <config.h> + +#include <stdio.h> +#include <stdlib.h> +#include <stdint.h> +#include <string.h> +#include <time.h> + +#include <nbdkit-filter.h> + +static int rdelayms = 0; /* read delay (milliseconds) */ +static int wdelayms = 0; /* write delay (milliseconds) */ + +static int +parse_delay (const char *value) +{ + size_t len = strlen (value); + int r; + + if (len > 2 && strcmp (&value[len-2], "ms") == 0) { + if (sscanf (value, "%d", &r) == 1) + return r; + else { + nbdkit_error ("cannot parse rdelay/wdelay milliseconds parameter: %s", + value); + return -1; + } + } + else { + if (sscanf (value, "%d", &r) == 1) + return r * 1000; + else { + nbdkit_error ("cannot parse rdelay/wdelay seconds parameter: %s", + value); + return -1; + } + } +} + +static void +delay (int ms) +{ + if (ms > 0) { + const struct timespec ts = { + .tv_sec = ms / 1000, + .tv_nsec = (ms * 1000000) % 1000000000 + }; + nanosleep (&ts, NULL); + } +} + +static void +read_delay (void) +{ + delay (rdelayms); +} + +static void +write_delay (void) +{ + delay (wdelayms); +} + +/* Called for each key=value passed on the command line. */ +static int +delay_config (nbdkit_next_config *next, void *nxdata, + const char *key, const char *value) +{ + if (strcmp (key, "rdelay") == 0) { + rdelayms = parse_delay (value); + if (rdelayms == -1) + return -1; + return 0; + } + else if (strcmp (key, "wdelay") == 0) { + wdelayms = parse_delay (value); + if (wdelayms == -1) + return -1; + return 0; + } + else + return next (nxdata, key, value); +} + +#define delay_config_help \ + "rdelay=<NN>[ms] Read delay in seconds/milliseconds.\n" \ + "wdelay=<NN>[ms] Write delay in seconds/milliseconds." \ + +/* Read data. */ +static int +delay_pread (struct nbdkit_next *next, void *nxdata, + void *handle, void *buf, uint32_t count, uint64_t offset, + uint32_t flags) +{ + read_delay (); + return next->pread (nxdata, buf, count, offset, flags); +} + +/* Write data. */ +static int +delay_pwrite (struct nbdkit_next *next, void *nxdata, + void *handle, + const void *buf, uint32_t count, uint64_t offset, uint32_t flags) +{ + write_delay (); + return next->pwrite (nxdata, buf, count, offset, flags); +} + +/* Zero data. */ +static int +delay_zero (struct nbdkit_next *next, void *nxdata, + void *handle, uint32_t count, uint64_t offset, uint32_t flags) +{ + write_delay (); + return next->zero (nxdata, count, offset, flags); +} + +static struct nbdkit_filter filter = { + .name = "delay", + .longname = "nbdkit delay filter", + .version = PACKAGE_VERSION, + .config = delay_config, + .config_help = delay_config_help, + .pread = delay_pread, + .pwrite = delay_pwrite, + .zero = delay_zero, +}; + +NBDKIT_REGISTER_FILTER(filter) diff --git a/filters/delay/nbdkit-delay-filter.pod b/filters/delay/nbdkit-delay-filter.pod new file mode 100644 index 0000000..10aba94 --- /dev/null +++ b/filters/delay/nbdkit-delay-filter.pod @@ -0,0 +1,88 @@ +=encoding utf8 + +=head1 NAME + +nbdkit-delay-filter - nbdkit delay filter + +=head1 SYNOPSIS + + nbdkit --filter=delay plugin rdelay=SECS wdelay=SECS [plugin-args...] + + nbdkit --filter=delay plugin rdelay=<NN>ms wdelay=<NN>ms [plugin-args...] + +=head1 DESCRIPTION + +C<nbdkit-delay-filter> is a filter that delays read and write requests +by some seconds or milliseconds. This is used to simulate a slow or +remote server, or to test certain kinds of race conditions in Linux. + +=head1 PARAMETERS + +=over 4 + +=item B<rdelay=SECS> + +=item B<rdelay=E<lt>NNE<gt>ms> + +The optional read delay in seconds or milliseconds. + +=item B<wdelay=SECS> + +=item B<wdelay=E<lt>NNE<gt>ms> + +The optional write delay in seconds or milliseconds. + +=back + +=head1 SEE ALSO + +L<nbdkit(1)>, +L<nbdkit-filter(3)>. + +=head1 AUTHORS + +Richard W.M. Jones + +=head1 COPYRIGHT + +Copyright (C) 2018 Red Hat Inc. + +=head1 LICENSE + +Redistribution and use in source and binary forms, with or without +modification, are permitted provided that the following conditions are +met: + +=over 4 + +=item * + +Redistributions of source code must retain the above copyright +notice, this list of conditions and the following disclaimer. + +=item * + +Redistributions in binary form must reproduce the above copyright +notice, this list of conditions and the following disclaimer in the +documentation and/or other materials provided with the distribution. + +=item * + +Neither the name of Red Hat nor the names of its contributors may be +used to endorse or promote products derived from this software without +specific prior written permission. + +=back + +THIS SOFTWARE IS PROVIDED BY RED HAT AND CONTRIBUTORS ''AS IS'' AND +ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, +THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A +PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL RED HAT OR +CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT +LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF +USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND +ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, +OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT +OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF +SUCH DAMAGE. diff --git a/plugins/file/file.c b/plugins/file/file.c index 4a91251..1fe4191 100644 --- a/plugins/file/file.c +++ b/plugins/file/file.c @@ -40,7 +40,6 @@ #include <unistd.h> #include <sys/types.h> #include <sys/stat.h> -#include <time.h> #include <errno.h> #include <nbdkit-plugin.h> @@ -50,8 +49,6 @@ #endif static char *filename = NULL; -static int rdelayms = 0; /* read delay (milliseconds) */ -static int wdelayms = 0; /* write delay (milliseconds) */ static void file_unload (void) @@ -59,56 +56,6 @@ file_unload (void) free (filename); } -static int -parse_delay (const char *value) -{ - size_t len = strlen (value); - int r; - - if (len > 2 && strcmp (&value[len-2], "ms") == 0) { - if (sscanf (value, "%d", &r) == 1) - return r; - else { - nbdkit_error ("cannot parse rdelay/wdelay milliseconds parameter: %s", - value); - return -1; - } - } - else { - if (sscanf (value, "%d", &r) == 1) - return r * 1000; - else { - nbdkit_error ("cannot parse rdelay/wdelay seconds parameter: %s", - value); - return -1; - } - } -} - -static void -delay (int ms) -{ - if (ms > 0) { - const struct timespec ts = { - .tv_sec = ms / 1000, - .tv_nsec = (ms * 1000000) % 1000000000 - }; - nanosleep (&ts, NULL); - } -} - -static void -read_delay (void) -{ - delay (rdelayms); -} - -static void -write_delay (void) -{ - delay (wdelayms); -} - /* Called for each key=value passed on the command line. This plugin * only accepts file=<filename>, which is required. */ @@ -122,15 +69,10 @@ file_config (const char *key, const char *value) if (!filename) return -1; } - else if (strcmp (key, "rdelay") == 0) { - rdelayms = parse_delay (value); - if (rdelayms == -1) - return -1; - } - else if (strcmp (key, "wdelay") == 0) { - wdelayms = parse_delay (value); - if (wdelayms == -1) - return -1; + else if (strcmp (key, "rdelay") == 0 || + strcmp (key, "wdelay") == 0) { + nbdkit_error ("add --filter=delay on the command line"); + return -1; } else { nbdkit_error ("unknown parameter '%s'", key); @@ -157,9 +99,7 @@ file_config_complete (void) } #define file_config_help \ - "file=<FILENAME> (required) The filename to serve.\n" \ - "rdelay=<NN>[ms] Read delay in seconds/milliseconds.\n" \ - "wdelay=<NN>[ms] Write delay in seconds/milliseconds." \ + "file=<FILENAME> (required) The filename to serve." \ /* The per-connection handle. */ struct handle { @@ -241,8 +181,6 @@ file_pread (void *handle, void *buf, uint32_t count, uint64_t offset) { struct handle *h = handle; - read_delay (); - while (count > 0) { ssize_t r = pread (h->fd, buf, count, offset); if (r == -1) { @@ -267,8 +205,6 @@ file_pwrite (void *handle, const void *buf, uint32_t count, uint64_t offset) { struct handle *h = handle; - write_delay (); - while (count > 0) { ssize_t r = pwrite (h->fd, buf, count, offset); if (r == -1) { @@ -292,8 +228,6 @@ file_zero (void *handle, uint32_t count, uint64_t offset, int may_trim) #endif int r = -1; - write_delay (); - #ifdef FALLOC_FL_PUNCH_HOLE if (may_trim) { r = fallocate (h->fd, FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE, diff --git a/plugins/file/nbdkit-file-plugin.pod b/plugins/file/nbdkit-file-plugin.pod index a2d1e6a..016513a 100644 --- a/plugins/file/nbdkit-file-plugin.pod +++ b/plugins/file/nbdkit-file-plugin.pod @@ -31,21 +31,13 @@ This parameter is required. =item B<rdelay=E<lt>NNE<gt>ms> -Delay reads for C<SECS> seconds or C<NN> milliseconds. -This is used to simulate a slow or remote server, or to -test certain kinds of race conditions in Linux. - -The default is no delay. - =item B<wdelay=SECS> =item B<wdelay=E<lt>NNE<gt>ms> -Delay writes for C<SECS> seconds or C<NN> milliseconds. -This is used to simulate a slow or remote server, or to -test certain kinds of race conditions in Linux. - -The default is no delay. +These plugin parameters have been moved to the +L<nbdkit-delay-filter(1)> filter. Modify the command line to add +I<--filter=delay> in order to use these parameters. =back diff --git a/tests/test-parallel-file.sh b/tests/test-parallel-file.sh index 79a60ac..b9e5f40 100755 --- a/tests/test-parallel-file.sh +++ b/tests/test-parallel-file.sh @@ -49,7 +49,7 @@ $QEMU_IO -f raw -c "aio_write -P 2 1 1" -c "aio_read -P 1 0 1" -c aio_flush \ trap 'rm -f test-parallel-file.out' 0 1 2 3 15 # With --threads=1, the write should complete first because it was issued first -nbdkit -v -t 1 -U - file file=file-data wdelay=2 rdelay=1 --run ' +nbdkit -v -t 1 -U - --filter delay file file=file-data wdelay=2 rdelay=1 --run ' $QEMU_IO -f raw -c "aio_write -P 2 1 1" -c "aio_read -P 1 0 1" -c aio_flush $nbd ' | tee test-parallel-file.out if test "$(grep '1/1' test-parallel-file.out)" != \ @@ -59,7 +59,7 @@ read 1/1 bytes at offset 0"; then fi # With default --threads, the faster read should complete first -nbdkit -v -U - file file=file-data wdelay=2 rdelay=1 --run ' +nbdkit -v -U - --filter delay file file=file-data wdelay=2 rdelay=1 --run ' $QEMU_IO -f raw -c "aio_write -P 2 1 1" -c "aio_read -P 1 0 1" -c aio_flush $nbd ' | tee test-parallel-file.out if test "$(grep '1/1' test-parallel-file.out)" != \ diff --git a/tests/test-parallel-nbd.sh b/tests/test-parallel-nbd.sh index f8e5071..d87573d 100755 --- a/tests/test-parallel-nbd.sh +++ b/tests/test-parallel-nbd.sh @@ -54,6 +54,7 @@ trap 'rm -f test-parallel-nbd.out test-parallel-nbd.sock' 0 1 2 3 15 ( rm -f test-parallel-nbd.sock nbdkit --exit-with-parent -v -U test-parallel-nbd.sock \ + --filter delay \ file file=file-data wdelay=2 rdelay=1 & # With --threads=1, the write should complete first because it was issued first -- 2.14.3