In addition to Eric's review:
Kevin Wolf <kw...@redhat.com> writes:
> This adds a new binary qemu-storage-daemon that doesn't yet do more than
> some typical initialisation for tools and parsing the basic command
> options --version, --help and --trace.
>
> Signed-off-by: Kevin Wolf <kw...@redhat.com>
> ---
> configure | 2 +-
> qemu-storage-daemon.c | 141 ++++++++++++++++++++++++++++++++++++++++++
> Makefile | 1 +
> 3 files changed, 143 insertions(+), 1 deletion(-)
> create mode 100644 qemu-storage-daemon.c
>
> diff --git a/configure b/configure
> index 08ca4bcb46..bb3d55fb25 100755
> --- a/configure
> +++ b/configure
> @@ -6034,7 +6034,7 @@ tools=""
> if test "$want_tools" = "yes" ; then
> tools="qemu-img\$(EXESUF) qemu-io\$(EXESUF) qemu-edid\$(EXESUF) $tools"
> if [ "$linux" = "yes" -o "$bsd" = "yes" -o "$solaris" = "yes" ] ; then
> - tools="qemu-nbd\$(EXESUF) $tools"
> + tools="qemu-nbd\$(EXESUF) qemu-storage-daemon\$(EXESUF) $tools"
> fi
> if [ "$ivshmem" = "yes" ]; then
> tools="ivshmem-client\$(EXESUF) ivshmem-server\$(EXESUF) $tools"
> diff --git a/qemu-storage-daemon.c b/qemu-storage-daemon.c
> new file mode 100644
> index 0000000000..a251dc255c
> --- /dev/null
> +++ b/qemu-storage-daemon.c
> @@ -0,0 +1,141 @@
> +/*
> + * QEMU storage daemon
> + *
> + * Copyright (c) 2019 Kevin Wolf <kw...@redhat.com>
> + *
> + * Permission is hereby granted, free of charge, to any person obtaining a
> copy
> + * of this software and associated documentation files (the "Software"), to
> deal
> + * in the Software without restriction, including without limitation the
> rights
> + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
> + * copies of the Software, and to permit persons to whom the Software is
> + * furnished to do so, subject to the following conditions:
> + *
> + * The above copyright notice and this permission notice shall be included in
> + * all copies or substantial portions of the Software.
> + *
> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
> + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
> + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
> FROM,
> + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
> + * THE SOFTWARE.
> + */
Standard request for new code: please make this GPLv2+, or tell us why
it has to be something else.
> +
> +#include "qemu/osdep.h"
> +
> +#include "block/block.h"
> +#include "crypto/init.h"
> +
> +#include "qapi/error.h"
> +#include "qemu-common.h"
> +#include "qemu-version.h"
> +#include "qemu/config-file.h"
> +#include "qemu/error-report.h"
> +#include "qemu/log.h"
> +#include "qemu/main-loop.h"
> +#include "qemu/module.h"
> +
> +#include "trace/control.h"
> +
> +#include <getopt.h>
> +
> +static void help(void)
> +{
> + printf(
> +"Usage: %s [options]\n"
> +"QEMU storage daemon\n"
> +"\n"
> +" -h, --help display this help and exit\n"
> +" -T, --trace [[enable=]<pattern>][,events=<file>][,file=<file>]\n"
> +" specify tracing options\n"
> +" -V, --version output version information and exit\n"
> +"\n"
> +QEMU_HELP_BOTTOM "\n",
> + error_get_progname());
> +}
> +
> +static int process_options(int argc, char *argv[], Error **errp)
> +{
> + int c;
> + char *trace_file = NULL;
> + int ret = -EINVAL;
> +
> + static const struct option long_options[] = {
> + {"help", no_argument, 0, 'h'},
You initialize member int *flag with 0 here, ....
> + {"version", no_argument, 0, 'V'},
> + {"trace", required_argument, NULL, 'T'},
... and with NULL here. Recommend to pick one and stick to it.
> + {0, 0, 0, 0}
{0} or {} would do.
> + };
> +
> + while ((c = getopt_long(argc, argv, ":hT:V", long_options, NULL)) != -1)
> {
> + switch (c) {
> + case '?':
> + error_setg(errp, "Unknown option '%s'", argv[optind - 1]);
> + goto out;
> + case ':':
> + error_setg(errp, "Missing option argument for '%s'",
> + argv[optind - 1]);
> + goto out;
> + case 'h':
> + help();
> + exit(EXIT_SUCCESS);
> + case 'V':
> + printf("qemu-storage-daemon version "
> + QEMU_FULL_VERSION "\n" QEMU_COPYRIGHT "\n");
> + exit(EXIT_SUCCESS);
> + case 'T':
> + g_free(trace_file);
> + trace_file = trace_opt_parse(optarg);
This is QemuOpts below the hood. Fact, not criticism :)
> + break;
> + }
Suggest (your preferred variation of) default: assert(0) to catch
omissions.
> + }
> + if (optind != argc) {
> + error_setg(errp, "Unexpected argument: %s", argv[optind]);
> + goto out;
> + }
> +
> + if (!trace_init_backends()) {
> + error_setg(errp, "Could not initialize trace backends");
> + goto out;
> + }
> + trace_init_file(trace_file);
> + qemu_set_log(LOG_TRACE);
I suspect the only reason for hiding trace initialization within
process_options() is avoiding a global variable @trace_file. I'd prefer
the global variable over the hiding.
> +
> + ret = 0;
> +out:
> + g_free(trace_file);
> + return ret;
> +}
Since the function exit(0)s on -h and -V anyway, let's exit(1) on error
instead of mucking around with error_setg(). You can then leave
reporting unknown options and missing option arguments to getopt_long().
Saves you the trouble of fixing the bug Max pointed out.
> +
> +int main(int argc, char *argv[])
> +{
> + Error *local_err = NULL;
> + int ret;
> +
> +#ifdef CONFIG_POSIX
> + signal(SIGPIPE, SIG_IGN);
> +#endif
> +
> + error_init(argv[0]);
> + qemu_init_exec_dir(argv[0]);
> +
> + module_call_init(MODULE_INIT_QOM);
> + module_call_init(MODULE_INIT_TRACE);
> + qemu_add_opts(&qemu_trace_opts);
> + qcrypto_init(&error_fatal);
> + bdrv_init();
Out of curiosity: how did you come up with this set of initializations?
> +
> + if (qemu_init_main_loop(&local_err)) {
> + error_report_err(local_err);
> + return EXIT_FAILURE;
What's wrong with
qemu_init_main_loop(&error_fatal)
?
> + }
> +
> + ret = process_options(argc, argv, &local_err);
> + if (ret < 0) {
> + error_report_err(local_err);
> + return EXIT_FAILURE;
> + }
> +
> + return EXIT_SUCCESS;
> +}
> diff --git a/Makefile b/Makefile
> index 30f0abfb42..76338d0ab4 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -558,6 +558,7 @@ qemu-img.o: qemu-img-cmds.h
> qemu-img$(EXESUF): qemu-img.o $(authz-obj-y) $(block-obj-y) $(crypto-obj-y)
> $(io-obj-y) $(qom-obj-y) $(COMMON_LDADDS)
> qemu-nbd$(EXESUF): qemu-nbd.o $(authz-obj-y) $(block-obj-y) $(crypto-obj-y)
> $(io-obj-y) $(qom-obj-y) $(COMMON_LDADDS)
> qemu-io$(EXESUF): qemu-io.o $(authz-obj-y) $(block-obj-y) $(crypto-obj-y)
> $(io-obj-y) $(qom-obj-y) $(COMMON_LDADDS)
> +qemu-storage-daemon$(EXESUF): qemu-storage-daemon.o $(authz-obj-y)
> $(block-obj-y) $(crypto-obj-y) $(io-obj-y) $(qom-obj-y) $(COMMON_LDADDS)
>
> qemu-bridge-helper$(EXESUF): qemu-bridge-helper.o $(COMMON_LDADDS)
