Hello again,
the previous patch had a typo in the manpage (it said "/lib/udev"
instead of "/usr/lib/udev" at one place), and also forgot to adjust
systemd-udev-hwdb-update.service.in. Both done now.
However, the latter currently has a gotcha:
+ConditionPathExists=!@udevlibexecdir@/hwdb.bin
This works correctly if you use this with the "factory reset"
semantics, i. e. start with an empty /etc. But it would not work if
you update /usr and have an already existing /etc/udev/hwdb.d/*. So
ideally the condition would be
ConditionPathExists=!@udevlibexecdir@/hwdb.bin OR
ConditionDirectoryNotEmpty=/etc/udev/hwdb.d/
but this isn't possible AFAIK. The alternative would be to change the
Exec= to call "hdwb --update --vendor" iff /etc/udev/hwdb.d/ is empty.
An alternative that was discussed at Plumbers was to make hwdb
--update automatically use @udevlibexecdir@ if there is no
/etc/udev/hwdb.d/, which would avoid this problem, avoid introducing a
new option, and still generally DTRT. I'd prefer this, so if you think
that's easier/better, I'm happy to update the patch accordingly.
Thanks,
Martin
--
Martin Pitt | http://www.piware.de
Ubuntu Developer (www.ubuntu.com) | Debian Developer (www.debian.org)
>From 5c093f2552d7ebbafe079eafe9b0a9bada7615ad Mon Sep 17 00:00:00 2001
From: Martin Pitt <martin.p...@ubuntu.com>
Date: Fri, 17 Oct 2014 15:01:01 +0200
Subject: [PATCH] udev hwdb: Support shipping pre-compiled database in system
images
In some cases it is preferable to ship system images with a pre-generated
binary hwdb database, to avoid having to build it at runtime, avoid shipping
the source hwdb files, or avoid storing large binary files in /etc.
So if hwdb.bin does not exist in /etc/udev/, fall back to looking for it in
UDEVLIBEXECDIR. This keeps the possibility to add files to /etc/udev/hwdb.d/
and re-generating the database which trumps the one in /usr/lib.
Add a new --vendor flag to "udevadm hwdb --update" which puts the database
into UDEVLIBEXECDIR.
Adjust systemd-udev-hwdb-update.service to not generate the file in /etc if we
already have it in /usr.
---
man/udev.xml | 4 +++-
man/udevadm.xml | 9 +++++++++
src/libudev/libudev-hwdb.c | 20 ++++++++++++++------
src/udev/udevadm-hwdb.c | 10 ++++++++--
units/systemd-udev-hwdb-update.service.in | 1 +
5 files changed, 35 insertions(+), 9 deletions(-)
diff --git a/man/udev.xml b/man/udev.xml
index d77cbb0..87c16c7 100644
--- a/man/udev.xml
+++ b/man/udev.xml
@@ -766,7 +766,9 @@
<para>The content of all hwdb files is read by
<citerefentry><refentrytitle>udevadm</refentrytitle><manvolnum>8</manvolnum></citerefentry>
- and compiled to a binary database located at <filename>/etc/udev/hwdb.bin</filename>.
+ and compiled to a binary database located at <filename>/etc/udev/hwdb.bin</filename>,
+ or alternatively <filename>/usr/lib/udev/hwdb.bin</filename> if you want ship the compiled
+ database in an immutable image.
During runtime only the binary database is used.</para>
</refsect1>
diff --git a/man/udevadm.xml b/man/udevadm.xml
index 749144d..571ef7d 100644
--- a/man/udevadm.xml
+++ b/man/udevadm.xml
@@ -494,6 +494,15 @@
</listitem>
</varlistentry>
<varlistentry>
+ <term><option>--vendor</option></term>
+ <listitem>
+ <para>Put the compiled database into <filename>/usr/lib/udev/hwdb.bin</filename> instead.
+ Use this if you want to ship a pre-compiled database in immutable system images, or
+ don't use <filename>/etc/udev/hwdb.d</filename> and want to avoid large binary files in
+ <filename>/etc</filename>.</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
<term><option>-t</option></term>
<term><option>--test=<replaceable>string</replaceable></option></term>
<listitem>
diff --git a/src/libudev/libudev-hwdb.c b/src/libudev/libudev-hwdb.c
index 8fb7240..91c05e8 100644
--- a/src/libudev/libudev-hwdb.c
+++ b/src/libudev/libudev-hwdb.c
@@ -256,6 +256,13 @@ static int trie_search_f(struct udev_hwdb *hwdb, const char *search) {
return 0;
}
+static const char *get_hwdb_bin_path(void) {
+ if (access("/etc/udev/hwdb.bin", F_OK) >= 0)
+ return "/etc/udev/hwdb.bin";
+ else
+ return UDEVLIBEXECDIR "/hwdb.bin";
+}
+
/**
* udev_hwdb_new:
* @udev: udev library context
@@ -267,6 +274,7 @@ static int trie_search_f(struct udev_hwdb *hwdb, const char *search) {
_public_ struct udev_hwdb *udev_hwdb_new(struct udev *udev) {
struct udev_hwdb *hwdb;
const char sig[] = HWDB_SIG;
+ const char *hwdb_bin_path = get_hwdb_bin_path();
hwdb = new0(struct udev_hwdb, 1);
if (!hwdb)
@@ -275,30 +283,30 @@ _public_ struct udev_hwdb *udev_hwdb_new(struct udev *udev) {
hwdb->refcount = 1;
udev_list_init(udev, &hwdb->properties_list, true);
- hwdb->f = fopen("/etc/udev/hwdb.bin", "re");
+ hwdb->f = fopen(hwdb_bin_path, "re");
if (!hwdb->f) {
- udev_dbg(udev, "error reading /etc/udev/hwdb.bin: %m");
+ udev_dbg(udev, "error reading %s: %m", hwdb_bin_path);
udev_hwdb_unref(hwdb);
return NULL;
}
if (fstat(fileno(hwdb->f), &hwdb->st) < 0 ||
(size_t)hwdb->st.st_size < offsetof(struct trie_header_f, strings_len) + 8) {
- udev_dbg(udev, "error reading /etc/udev/hwdb.bin: %m");
+ udev_dbg(udev, "error reading %s: %m", hwdb_bin_path);
udev_hwdb_unref(hwdb);
return NULL;
}
hwdb->map = mmap(0, hwdb->st.st_size, PROT_READ, MAP_SHARED, fileno(hwdb->f), 0);
if (hwdb->map == MAP_FAILED) {
- udev_dbg(udev, "error mapping /etc/udev/hwdb.bin: %m");
+ udev_dbg(udev, "error mapping %s: %m", hwdb_bin_path);
udev_hwdb_unref(hwdb);
return NULL;
}
if (memcmp(hwdb->map, sig, sizeof(hwdb->head->signature)) != 0 ||
(size_t)hwdb->st.st_size != le64toh(hwdb->head->file_size)) {
- udev_dbg(udev, "error recognizing the format of /etc/udev/hwdb.bin");
+ udev_dbg(udev, "error recognizing the format of %s", hwdb_bin_path);
udev_hwdb_unref(hwdb);
return NULL;
}
@@ -358,7 +366,7 @@ bool udev_hwdb_validate(struct udev_hwdb *hwdb) {
return false;
if (!hwdb->f)
return false;
- if (stat("/etc/udev/hwdb.bin", &st) < 0)
+ if (stat(get_hwdb_bin_path(), &st) < 0)
return true;
if (timespec_load(&hwdb->st.st_mtim) != timespec_load(&st.st_mtim))
return true;
diff --git a/src/udev/udevadm-hwdb.c b/src/udev/udevadm-hwdb.c
index 64273fb..2127213 100644
--- a/src/udev/udevadm-hwdb.c
+++ b/src/udev/udevadm-hwdb.c
@@ -536,6 +536,7 @@ static int import_file(struct udev *udev, struct trie *trie, const char *filenam
static void help(void) {
printf("Usage: udevadm hwdb OPTIONS\n"
" -u,--update update the hardware database\n"
+ " --vendor generate in " UDEVLIBEXECDIR " instead of /etc/udev\n"
" -t,--test=MODALIAS query database and print result\n"
" -r,--root=PATH alternative root path in the filesystem\n"
" -h,--help\n\n");
@@ -544,6 +545,7 @@ static void help(void) {
static int adm_hwdb(struct udev *udev, int argc, char *argv[]) {
static const struct option options[] = {
{ "update", no_argument, NULL, 'u' },
+ { "vendor", no_argument, NULL, 'V' },
{ "test", required_argument, NULL, 't' },
{ "root", required_argument, NULL, 'r' },
{ "help", no_argument, NULL, 'h' },
@@ -551,16 +553,20 @@ static int adm_hwdb(struct udev *udev, int argc, char *argv[]) {
};
const char *test = NULL;
const char *root = "";
+ const char *hwdb_bin_dir = "/etc/udev";
bool update = false;
struct trie *trie = NULL;
int err, c;
int rc = EXIT_SUCCESS;
- while ((c = getopt_long(argc, argv, "ut:r:h", options, NULL)) >= 0)
+ while ((c = getopt_long(argc, argv, "uVt:r:h", options, NULL)) >= 0)
switch(c) {
case 'u':
update = true;
break;
+ case 'V':
+ hwdb_bin_dir = UDEVLIBEXECDIR;
+ break;
case 't':
test = optarg;
break;
@@ -634,7 +640,7 @@ static int adm_hwdb(struct udev *udev, int argc, char *argv[]) {
log_debug("strings dedup'ed: %8zu bytes (%8zu)",
trie->strings->dedup_len, trie->strings->dedup_count);
- if (asprintf(&hwdb_bin, "%s/etc/udev/hwdb.bin", root) < 0) {
+ if (asprintf(&hwdb_bin, "%s/%s/hwdb.bin", root, hwdb_bin_dir) < 0) {
rc = EXIT_FAILURE;
goto out;
}
diff --git a/units/systemd-udev-hwdb-update.service.in b/units/systemd-udev-hwdb-update.service.in
index cdbcd83..4ee5025 100644
--- a/units/systemd-udev-hwdb-update.service.in
+++ b/units/systemd-udev-hwdb-update.service.in
@@ -13,6 +13,7 @@ Conflicts=shutdown.target
After=systemd-remount-fs.service
Before=sysinit.target shutdown.target systemd-update-done.service
ConditionNeedsUpdate=/etc
+ConditionPathExists=!@udevlibexecdir@/hwdb.bin
[Service]
Type=oneshot
--
2.1.0
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