[systemd-devel] [PATCH v2] tools: add static-nodes tool
Lucas De Marchi
lucas.demarchi at profusion.mobi
Mon Apr 15 16:20:00 PDT 2013
Hi Tom,
On Fri, Apr 12, 2013 at 9:15 PM, Tom Gundersen <teg at jklm.no> wrote:
> This tool reads modules.devname from the current kernel directory and outputs
> the information.
>
> For now only the tmpfiles.d(5) format is supported, but more could easily be
> added in the future if there is a need.
>
> When booting with systemd, the new tool is called at boot to instruct
> systemd-tmpfiles to create the necessary static modules before starting
> systemd-udevd.
>
> This means nothing but kmod needs to reads the private files under /lib/modules/.
For me this would be the main goal of this patch or anything similar to this.
>
> Cc: <linux-hotplug at vger.kernel.org>
> Cc: <systemd-devel at lists.freedesktop.org>
> ---
>
> v2: adressed concerns raised by Dave, and made the tool a bit more generic so
> more output formats may be added in the future as suggested by Lucas. Also
> included the systemd unit file to hook this up with systemd.
>
> Makefile.am | 20 ++++-
> configure.ac | 8 ++
> tools/kmod-static-nodes.service.in | 16 ++++
> tools/kmod.c | 1 +
> tools/kmod.h | 1 +
> tools/static-nodes.c | 163 +++++++++++++++++++++++++++++++++++++
> 6 files changed, 207 insertions(+), 2 deletions(-)
> create mode 100644 tools/kmod-static-nodes.service.in
> create mode 100644 tools/static-nodes.c
>
> diff --git a/Makefile.am b/Makefile.am
> index 9feaf96..333e861 100644
> --- a/Makefile.am
> +++ b/Makefile.am
> @@ -36,6 +36,9 @@ SED_PROCESS = \
> %.pc: %.pc.in Makefile
> $(SED_PROCESS)
>
> +%.service: %.service.in Makefile
> + $(SED_PROCESS)
> +
> LIBKMOD_CURRENT=4
> LIBKMOD_REVISION=2
> LIBKMOD_AGE=2
> @@ -88,6 +91,17 @@ pkgconfig_DATA = libkmod/libkmod.pc
> EXTRA_DIST += libkmod/libkmod.pc.in
> CLEANFILES += libkmod/libkmod.pc
>
> +if HAVE_SYSTEMD
> +systemdsystemunit_DATA = tools/kmod-static-nodes.service
> +EXTRA_DIST += tools/kmod-static-nodes.service.in
> +CLEANFILES += tools/kmod-static-nodes.service
> +
> +install-data-hook:
> + $(MKDIR_P) $(DESTDIR)$(systemdsystemunitdir)/sysinit.target.wants
> + ln -sf ../kmod-static-nodes.service \
> + $(DESTDIR)$(systemdsystemunitdir)/sysinit.target.wants/kmod-static-nodes.service
> +endif
> +
> install-exec-hook:
> if test "$(libdir)" != "$(rootlibdir)"; then \
> $(MKDIR_P) $(DESTDIR)$(rootlibdir) && \
> @@ -109,7 +123,8 @@ noinst_SCRIPTS = tools/insmod tools/rmmod tools/lsmod \
> tools_kmod_SOURCES = tools/kmod.c tools/kmod.h tools/lsmod.c \
> tools/rmmod.c tools/insmod.c \
> tools/modinfo.c tools/modprobe.c \
> - tools/depmod.c tools/log.h tools/log.c
> + tools/depmod.c tools/log.h tools/log.c \
> + tools/static-nodes.c
> tools_kmod_LDADD = libkmod/libkmod-util.la \
> libkmod/libkmod.la
>
> @@ -211,7 +226,8 @@ testsuite-distclean:
> DISTCLEAN_LOCAL_HOOKS += testsuite-distclean
> EXTRA_DIST += testsuite/rootfs-pristine
>
> -DISTCHECK_CONFIGURE_FLAGS=--enable-gtk-doc --sysconfdir=/etc --with-zlib
> +DISTCHECK_CONFIGURE_FLAGS=--enable-gtk-doc --sysconfdir=/etc --with-zlib \
> + --with-systemdsystemunitdir=$$dc_install_base/$(systemdsystemunitdir)
>
> distclean-local: $(DISTCLEAN_LOCAL_HOOKS)
>
> diff --git a/configure.ac b/configure.ac
> index 566b317..af5ed52 100644
> --- a/configure.ac
> +++ b/configure.ac
> @@ -76,6 +76,13 @@ AS_IF([test "x$with_zlib" != "xno"], [
> AC_MSG_NOTICE([zlib support not requested])
> ])
>
> +AC_ARG_WITH([systemdsystemunitdir],
> + AS_HELP_STRING([--with-systemdsystemunitdir=DIR], [Directory for systemd service files]),
> + [], [with_systemdsystemunitdir=$($PKG_CONFIG --variable=systemdsystemunitdir systemd)])
> +if test "x$with_systemdsystemunitdir" != xno; then
> + AC_SUBST([systemdsystemunitdir], [$with_systemdsystemunitdir])
> +fi
> +AM_CONDITIONAL(HAVE_SYSTEMD, [test -n "$with_systemdsystemunitdir" -a "x$with_systemdsystemunitdir" != xno ])
>
> #####################################################################
> # --enable-
> @@ -200,6 +207,7 @@ AC_MSG_RESULT([
> compiler: ${CC}
> cflags: ${with_cflags} ${CFLAGS}
> ldflags: ${with_ldflags} ${LDFLAGS}
> + systemdsystemunitdir: ${with_systemdsystemunitdir}
>
> tools: ${enable_tools}
> logging: ${enable_logging}
> diff --git a/tools/kmod-static-nodes.service.in b/tools/kmod-static-nodes.service.in
> new file mode 100644
> index 0000000..be8482e
> --- /dev/null
> +++ b/tools/kmod-static-nodes.service.in
I'm not sure we want the service file to live in kmod repository.
Maybe we could let this in systemd and in kmod we only add the support
to create this type of information?
> @@ -0,0 +1,16 @@
> +# This file is part of kmod.
> +#
> +# kmod is free software; you can redistribute it and/or modify it
> +# under the terms of the GNU Lesser General Public License as published by
> +# the Free Software Foundation; either version 2.1 of the License, or
> +# (at your option) any later version.
> +
> +[Unit]
> +Description=Create list of static nodes to be created in /dev
> +DefaultDependencies=no
> +Before=sysinit.target systemd-static-nodes.service
> +
> +[Service]
> +Type=oneshot
> +ExecStart=/bin/mkdir -p /run/tmpfiles.d
> +ExecStart=@prefix@/bin/kmod static-nodes tmpfiles --output=/run/tmpfiles.d/kmod.conf
The syntax is a bit cumbersome too, but since we still don't have any
command (except from the test-only "list") I think we could let this
as is and change later, before a new release.
IMO it should be kmod static-nodes --format=...
It's ok to implement only the tmpfiles output, though the default
should be an human readable format, just like git commands are.
> diff --git a/tools/kmod.c b/tools/kmod.c
> index ebb8875..347bb7d 100644
> --- a/tools/kmod.c
> +++ b/tools/kmod.c
> @@ -37,6 +37,7 @@ static const struct kmod_cmd kmod_cmd_help;
> static const struct kmod_cmd *kmod_cmds[] = {
> &kmod_cmd_help,
> &kmod_cmd_list,
> + &kmod_cmd_static_nodes,
> };
>
> static const struct kmod_cmd *kmod_compat_cmds[] = {
> diff --git a/tools/kmod.h b/tools/kmod.h
> index 80fa4c2..68a646a 100644
> --- a/tools/kmod.h
> +++ b/tools/kmod.h
> @@ -35,5 +35,6 @@ extern const struct kmod_cmd kmod_cmd_compat_modprobe;
> extern const struct kmod_cmd kmod_cmd_compat_depmod;
>
> extern const struct kmod_cmd kmod_cmd_list;
> +extern const struct kmod_cmd kmod_cmd_static_nodes;
>
> #include "log.h"
> diff --git a/tools/static-nodes.c b/tools/static-nodes.c
> new file mode 100644
> index 0000000..a79fc3d
> --- /dev/null
> +++ b/tools/static-nodes.c
> @@ -0,0 +1,163 @@
> +/*
> + * kmod-static-nodes - manage modules.devname
> + *
> + * Copyright (C) 2004-2012 Kay Sievers <kay at vrfy.org>
> + * Copyright (C) 2011-2013 ProFUSION embedded systems
> + * Copyright (C) 2013 Tom Gundersen <teg at jklm.no>
> + *
> + * This program is free software: you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation, either version 2 of the License, or
> + * (at your option) any later version.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program. If not, see <http://www.gnu.org/licenses/>.
> + */
> +
> +#include <stdio.h>
> +#include <stdlib.h>
> +#include <stddef.h>
> +#include <getopt.h>
> +#include <errno.h>
> +#include <unistd.h>
> +#include <string.h>
> +#include <limits.h>
> +#include <sys/utsname.h>
> +#include <sys/stat.h>
> +#include <sys/types.h>
> +#include "libkmod-util.h"
> +
> +#include "kmod.h"
> +
> +static const char cmdopts_s[] = "o:h";
> +static const struct option cmdopts[] = {
> + { "output", required_argument, 0, 'o'},
> + { "help", no_argument, 0, 'h'},
> + { },
> +};
> +
> +static void help(void)
> +{
> + printf("Usage:\n"
> + "\t%s static-nodes format [options]\n"
> + "\n"
> + "kmod static-nodes outputs the static-node information of the currently running kernel.\n"
> + "\n"
> + "Options:\n"
> + "\t-o, --output=FILE write output to file\n"
> + "\t-h, --help show this help\n"
> + "\n"
> + "Formats:\n"
> + " tmpfiles the tmpfiles.d(5) used by systemd-tmpfiles.\n",
> + program_invocation_short_name);
> +}
> +
> +static int write_tmpfile(FILE *in, FILE *out) {
> + char buf[4096];
> + int ret = EXIT_SUCCESS;
> +
> + while (fgets(buf, sizeof(buf), in) != NULL) {
> + char devname[PATH_MAX];
> + char type;
> + unsigned int maj, min;
> + int matches;
> +
> + if (buf[0] == '#')
> + continue;
> +
> + matches = sscanf(buf, "%*s %s %c%u:%u", devname, &type, &maj, &min);
> + if (matches != 4 || (type != 'c' && type != 'b')) {
> + fprintf(stderr, "Error: invalid devname entry: %s", buf);
> + ret = EXIT_FAILURE;
> + continue;
> + }
> +
> + fprintf(out, "%c /dev/%s 0600 - - - %u:%u\n", type, devname, maj, min);
> + }
> +
> + return ret;
> +}
> +
> +static int do_static_nodes(int argc, char *argv[])
> +{
> + struct utsname kernel;
> + char modules[PATH_MAX];
> + FILE *in = NULL, *out = stdout;
> + int ret = EXIT_SUCCESS;
> +
> + for (;;) {
> + int c, idx = 0;
> +
> + c = getopt_long(argc - 1, argv + 1, cmdopts_s, cmdopts, &idx);
> + if (c == -1) {
> + break;
> + }
> + switch (c) {
> + case 'o':
> + out = fopen(optarg, "we");
> + if (out == NULL) {
> + fprintf(stderr, "Error: could not create %s!\n", optarg);
> + ret = EXIT_FAILURE;
> + goto finish;
> + }
> + break;
> + case 'h':
> + help();
> + goto finish;
> + case '?':
> + ret = EXIT_FAILURE;
> + goto finish;
> + default:
> + fprintf(stderr, "Unexpected commandline option '%c'.\n", c);
> + help();
> + ret = EXIT_FAILURE;
> + goto finish;
> + }
> + }
> +
> + if (argc < 2) {
> + help();
> + ret = EXIT_FAILURE;
> + goto finish;
> + }
> +
> + if (!streq(argv[1], "tmpfiles")) {
> + fprintf(stderr, "Unknown format: '%s'.\n", argv[1]);
> + help();
> + ret = EXIT_FAILURE;
> + goto finish;
> + }
> +
> + if (uname(&kernel) < 0) {
> + fputs("Error: uname failed!\n", stderr);
> + ret = EXIT_FAILURE;
> + goto finish;
> + }
> + snprintf(modules, sizeof(modules), "/lib/modules/%s/modules.devname", kernel.release);
> + in = fopen(modules, "re");
> + if (in == NULL && errno != ENOENT) {
> + fprintf(stderr, "Error: could not open /lib/modules/%s/modules.devname!\n", kernel.release);
> + ret = EXIT_FAILURE;
> + goto finish;
> + }
> +
> + ret = write_tmpfile(in, out);
> +
> +finish:
> + if (in)
> + fclose(in);
> + if (out)
> + fclose(out);
> + return ret;
> +}
> +
> +const struct kmod_cmd kmod_cmd_static_nodes = {
> + .name = "static-nodes",
> + .cmd = do_static_nodes,
> + .help = "outputs the static-node information of the currently running kernel",
> +};
> --
Lucas De Marchi
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