mirror of
https://github.com/systemd/systemd-stable.git
synced 2024-12-31 17:17:43 +03:00
[PATCH] finally solve the bad sysfs-timing for all of us
On Tue, Sep 21, 2004 at 07:17:34PM +0200, Kay Sievers wrote: > During the integration of HAL into the linux hotplug system, we dicover > every week a new signaling path that fails cause of the delayed > population of the sysfs files, which are connected by symlinks and > appear in something like a random order in userspace. > > It's pretty complicated to understand the connection between all these > files for all the different subsystems with all the exceptions, so most > of the users simply sleep a few seconds, but that is not acceptable for > our integration work. > > Here I try to get all the special knowledge about that behavior together > and place that in a simple binary. That program _must_ run first of all > other hotplug processsing and every later script, udev or HAL all can get > rid of the wild guesses about the right time sysfs is ready. > > It will not only wait for the "dev"-file events we handle with udev, also > for every /device-device with the corresponding bus link. > > It is provided as a patch against the current udev tree and a "install" will > place the new program in the hotplug.d directory: > > [kay@pim ~]$ tree /etc/hotplug.d/ > /etc/hotplug.d/ > `-- default > |-- 00-wait_for_sysfs.hotplug -> /sbin/wait_for_sysfs > |-- 10-udev.hotplug -> /sbin/udevsend > |-- 20-hal.hotplug -> /usr/libexec/hal.hotplug > |-- default.hotplug > `-- log.hotplug > > > For now, it logs the result of the waiting to syslog, to catch any > device, that needs special treatment. All newly discovered delay problems, > device black/whitelist updates should go into that program and we may remove > that kind of specialisation from all the other hotplug programs. > > Any patches, reports, testing is more than welcome. > > Sample debug: > Sep 21 18:44:07 localhost kernel: usb 3-2: new full speed USB device using address 12 > Sep 21 18:44:07 localhost kernel: hub 3-2:1.0: USB hub found > Sep 21 18:44:07 localhost kernel: hub 3-2:1.0: 2 ports detected > Sep 21 18:44:07 localhost 00-wait_for_sysfs.hotplug: result: waiting for sysfs successful '/devices/pci0000:00/0000:00:1d.1/usb3/3-2' > Sep 21 18:44:07 localhost 00-wait_for_sysfs.hotplug: result: waiting for sysfs successful '/devices/pci0000:00/0000:00:1d.1/usb3/3-2/3-2:1.0' > Sep 21 18:44:08 localhost kernel: usb 3-2.1: new full speed USB device using address 13 > Sep 21 18:44:08 localhost 00-wait_for_sysfs.hotplug: result: waiting for sysfs successful '/class/usb/lp0' > Sep 21 18:44:08 localhost kernel: drivers/usb/class/usblp.c: usblp0: USB Bidirectional printer dev 13 if 0 alt 1 proto 2 vid 0x067B pid 0x2305 > Sep 21 18:44:08 localhost 00-wait_for_sysfs.hotplug: result: waiting for sysfs successful '/devices/pci0000:00/0000:00:1d.1/usb3/3-2/3-2.1/3-2.1:1.0' > Sep 21 18:44:08 localhost 00-wait_for_sysfs.hotplug: result: waiting for sysfs successful '/devices/pci0000:00/0000:00:1d.1/usb3/3-2/3-2.1' > Sep 21 18:44:08 localhost udev: configured rule in '/etc/udev/rules.d/50-udev.rules' at line 29 applied, 'lp0' becomes 'usb/%k' > Sep 21 18:44:08 localhost udev: creating device node '/udev/usb/lp0' > Sep 21 18:44:09 localhost kernel: usb 3-2.2: new full speed USB device using address 14 > Sep 21 18:44:09 localhost kernel: pl2303 3-2.2:1.0: PL-2303 converter detected > Sep 21 18:44:09 localhost kernel: usb 3-2.2: PL-2303 converter now attached to ttyUSB0 > Sep 21 18:44:09 localhost 00-wait_for_sysfs.hotplug: result: waiting for sysfs successful '/devices/pci0000:00/0000:00:1d.1/usb3/3-2/3-2.2' > Sep 21 18:44:09 localhost 00-wait_for_sysfs.hotplug: result: waiting for sysfs successful '/devices/pci0000:00/0000:00:1d.1/usb3/3-2/3-2.2/3-2.2:1.0' > Sep 21 18:44:09 localhost 00-wait_for_sysfs.hotplug: result: waiting for sysfs successful '/devices/pci0000:00/0000:00:1d.1/usb3/3-2/3-2.2/3-2.2:1.0/ttyUSB0' > Sep 21 18:44:09 localhost 00-wait_for_sysfs.hotplug: result: waiting for sysfs successful '/class/tty/ttyUSB0' > Sep 21 18:44:09 localhost udev: creating device node '/udev/ttyUSB0' New version with more devices excluded from /device-link saerch and a better maching for device names.
This commit is contained in:
kay.sievers@vrfy.org
Greg KH
parent
01f950e2eb
commit
a8b5267a62
15
Makefile
15
Makefile
@ -33,6 +33,7 @@ INFO = udevinfo
|
||||
TESTER = udevtest
|
||||
STARTER = udevstart
|
||||
RULER = udevruler
|
||||
WAIT = wait_for_sysfs
|
||||
VERSION = 032_bk
|
||||
INSTALL_DIR = /usr/local/bin
|
||||
RELEASE_NAME = $(ROOT)-$(VERSION)
|
||||
@ -171,7 +172,7 @@ endif
|
||||
|
||||
CFLAGS += -I$(PWD)/libsysfs
|
||||
|
||||
all: $(ROOT) $(SENDER) $(DAEMON) $(INFO) $(TESTER)
|
||||
all: $(ROOT) $(SENDER) $(DAEMON) $(INFO) $(TESTER) $(WAIT)
|
||||
@extras="$(EXTRAS)" ; for target in $$extras ; do \
|
||||
echo $$target ; \
|
||||
$(MAKE) prefix=$(prefix) \
|
||||
@ -287,10 +288,14 @@ $(RULER): $(LIBC) $(RULER).o $(OBJS) $(HEADERS)
|
||||
$(LD) $(LDFLAGS) -o $@ $(CRT0) udevruler.o udev_lib.o udev_config.o udevdb.o $(SYSFS) $(TDB) $(LIB_OBJS) $(ARCH_LIB_OBJS) -lnewt
|
||||
$(STRIPCMD) $@
|
||||
|
||||
$(WAIT): $(WAIT).o $(OBJS) $(HEADERS) $(LIBC)
|
||||
$(LD) $(LDFLAGS) -o $@ $(CRT0) $(WAIT).o $(SYSFS) $(LIB_OBJS) $(ARCH_LIB_OBJS)
|
||||
$(STRIPCMD) $@
|
||||
|
||||
clean:
|
||||
-find . \( -not -type d \) -and \( -name '*~' -o -name '*.[oas]' \) -type f -print \
|
||||
| xargs rm -f
|
||||
-rm -f core $(ROOT) $(GEN_HEADERS) $(GEN_CONFIGS) $(GEN_MANPAGES) $(INFO) $(DAEMON) $(SENDER) $(TESTER) $(RULER)
|
||||
-rm -f core $(ROOT) $(GEN_HEADERS) $(GEN_CONFIGS) $(GEN_MANPAGES) $(INFO) $(DAEMON) $(SENDER) $(TESTER) $(RULER) $(WAIT)
|
||||
$(MAKE) -C klibc clean
|
||||
@extras="$(EXTRAS)" ; for target in $$extras ; do \
|
||||
echo $$target ; \
|
||||
@ -391,8 +396,10 @@ install: install-initscript install-config install-man install-dev.d all
|
||||
$(INSTALL_PROGRAM) -D $(SENDER) $(DESTDIR)$(sbindir)/$(SENDER)
|
||||
$(INSTALL_PROGRAM) -D $(INFO) $(DESTDIR)$(usrbindir)/$(INFO)
|
||||
$(INSTALL_PROGRAM) -D $(TESTER) $(DESTDIR)$(usrbindir)/$(TESTER)
|
||||
ln -sf $(sbindir)/udev $(DESTDIR)$(sbindir)/$(STARTER)
|
||||
$(INSTALL_PROGRAM) -D $(WAIT) $(DESTDIR)$(sbindir)/$(WAIT)
|
||||
- ln -f -s $(sbindir)/udev $(DESTDIR)$(sbindir)/$(STARTER)
|
||||
- ln -f -s $(sbindir)/$(SENDER) $(DESTDIR)$(hotplugdir)/10-udev.hotplug
|
||||
- ln -f -s $(sbindir)/$(WAIT) $(DESTDIR)$(hotplugdir)/00-wait_for_sysfs.hotplug
|
||||
ifndef DESTDIR
|
||||
- killall udevd
|
||||
- rm -f $(udevdir)/.udev.tdb
|
||||
@ -405,6 +412,7 @@ endif
|
||||
|
||||
uninstall: uninstall-man uninstall-dev.d
|
||||
- rm $(hotplugdir)/10-udev.hotplug
|
||||
- rm $(hotplugdir)/00-wait_for_sysfs.hotplug
|
||||
- rm $(configdir)/rules.d/50-udev.rules
|
||||
- rm $(configdir)/permissions.d/50-udev.permissions
|
||||
- rm $(configdir)/udev.conf
|
||||
@ -418,6 +426,7 @@ uninstall: uninstall-man uninstall-dev.d
|
||||
- rm $(sbindir)/$(STARTER)
|
||||
- rm $(usrbindir)/$(INFO)
|
||||
- rm $(usrbindir)/$(TESTER)
|
||||
- rm $(usrbindir)/$(WAIT)
|
||||
- rmdir $(hotplugdir)
|
||||
- rm $(udevdir)/.udev.tdb
|
||||
- rmdir $(udevdir)
|
||||
|
||||
334
wait_for_sysfs.c
Normal file
334
wait_for_sysfs.c
Normal file
@ -0,0 +1,334 @@
|
||||
/*
|
||||
* wait_for_sysfs.c - small program to delay the execution
|
||||
* of /etc/hotplug.d/ programs, until sysfs
|
||||
* is populated by the kernel. Depending on
|
||||
* the type of device, we wait for all expected
|
||||
* directories and then just exit.
|
||||
*
|
||||
* Copyright (C) 2004 Kay Sievers <kay.sievers@vrfy.org>
|
||||
*
|
||||
* 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 version 2 of the License.
|
||||
*
|
||||
* 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, write to the Free Software Foundation, Inc.,
|
||||
* 675 Mass Ave, Cambridge, MA 02139, USA.
|
||||
*
|
||||
*/
|
||||
|
||||
#include <stdio.h>
|
||||
#include <stddef.h>
|
||||
#include <stdlib.h>
|
||||
#include <unistd.h>
|
||||
#include <string.h>
|
||||
#include <ctype.h>
|
||||
#include <errno.h>
|
||||
#include <sys/stat.h>
|
||||
|
||||
#include "logging.h"
|
||||
#include "libsysfs/sysfs/libsysfs.h"
|
||||
|
||||
#ifdef LOG
|
||||
unsigned char logname[LOGNAME_SIZE];
|
||||
void log_message(int level, const char *format, ...)
|
||||
{
|
||||
va_list args;
|
||||
|
||||
va_start(args, format);
|
||||
vsyslog(level, format, args);
|
||||
va_end(args);
|
||||
}
|
||||
#endif
|
||||
|
||||
#define WAIT_MAX_SECONDS 5
|
||||
#define WAIT_LOOP_PER_SECOND 20
|
||||
|
||||
static int wait_for_class_device_attributes(struct sysfs_class_device *class_dev)
|
||||
{
|
||||
static struct class_file {
|
||||
char *subsystem;
|
||||
char *file;
|
||||
} class_files[] = {
|
||||
{ .subsystem = "net", .file = "ifindex" },
|
||||
{ .subsystem = "usb_host", .file = NULL },
|
||||
{ .subsystem = "pcmcia_socket", .file = NULL },
|
||||
{ NULL, NULL }
|
||||
};
|
||||
struct class_file *classfile;
|
||||
const char *file = "dev";
|
||||
int loop;
|
||||
|
||||
/* look if we want to look for another file instead of "dev" */
|
||||
for (classfile = class_files; classfile->subsystem != NULL; classfile++) {
|
||||
if (strcmp(class_dev->classname, classfile->subsystem) == 0) {
|
||||
if (classfile->file == NULL) {
|
||||
dbg("class '%s' has no file to wait for", class_dev->classname);
|
||||
return 0;
|
||||
}
|
||||
file = classfile->file;
|
||||
break;
|
||||
}
|
||||
}
|
||||
dbg("looking at class '%s' for specific file '%s'", class_dev->classname, file);
|
||||
|
||||
loop = WAIT_MAX_SECONDS * WAIT_LOOP_PER_SECOND;
|
||||
while (--loop) {
|
||||
if (sysfs_get_classdev_attr(class_dev, file) != NULL) {
|
||||
dbg("class '%s' specific file '%s' found", class_dev->classname, file);
|
||||
return 0;
|
||||
}
|
||||
}
|
||||
|
||||
dbg("error: getting bus '%s' specific file '%s'", class_dev->classname, file);
|
||||
return -1;
|
||||
}
|
||||
|
||||
static int class_device_expect_no_device_link(struct sysfs_class_device *class_dev)
|
||||
{
|
||||
char **device;
|
||||
|
||||
static char *devices_without_link[] = {
|
||||
"nb",
|
||||
"ram",
|
||||
"loop",
|
||||
"fd",
|
||||
"md",
|
||||
"dos_cd",
|
||||
"double",
|
||||
"flash",
|
||||
"msd",
|
||||
"rflash",
|
||||
"rom",
|
||||
"rrom",
|
||||
"sbpcd",
|
||||
"pcd",
|
||||
"pf",
|
||||
"scd",
|
||||
"sit",
|
||||
"lp",
|
||||
"ubd",
|
||||
"vcs",
|
||||
"vcsa",
|
||||
"console",
|
||||
"tty",
|
||||
"ttyS",
|
||||
NULL
|
||||
};
|
||||
|
||||
for (device = devices_without_link; *device != NULL; device++) {
|
||||
int len = strlen(*device);
|
||||
|
||||
/* look if name matches */
|
||||
if (strncmp(class_dev->name, *device, len) != 0)
|
||||
continue;
|
||||
|
||||
/* exact match */
|
||||
if (strlen(class_dev->name) == len)
|
||||
return 1;
|
||||
|
||||
/* instance numbers are matching too */
|
||||
if (isdigit(class_dev->name[len]))
|
||||
return 1;
|
||||
}
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
static int wait_for_bus_device(struct sysfs_device *device_dev)
|
||||
{
|
||||
static struct bus_file {
|
||||
char *bus;
|
||||
char *file;
|
||||
} bus_files[] = {
|
||||
{ .bus = "scsi", .file = "vendor" },
|
||||
{ .bus = "usb", .file = "idVendor" },
|
||||
{ .bus = "usb", .file = "iInterface" },
|
||||
{ .bus = "usb-serial", .file = "detach_state" },
|
||||
{ .bus = "ide", .file = "detach_state" },
|
||||
{ .bus = "pci", .file = "vendor" },
|
||||
{ NULL }
|
||||
};
|
||||
struct bus_file *busfile;
|
||||
int loop;
|
||||
|
||||
/* wait for the /bus-device link to the /device-device */
|
||||
loop = WAIT_MAX_SECONDS * WAIT_LOOP_PER_SECOND;
|
||||
while (--loop) {
|
||||
if (sysfs_get_device_bus(device_dev) == 0)
|
||||
break;
|
||||
|
||||
usleep(1000 * 1000 / WAIT_LOOP_PER_SECOND);
|
||||
}
|
||||
if (loop == 0) {
|
||||
dbg("error: getting /bus-device link");
|
||||
return -1;
|
||||
}
|
||||
dbg("/bus-device link found for bus '%s'", device_dev->bus);
|
||||
|
||||
/* wait for a bus specific file to show up */
|
||||
loop = WAIT_MAX_SECONDS * WAIT_LOOP_PER_SECOND;
|
||||
while (--loop) {
|
||||
for (busfile = bus_files; busfile->bus != NULL; busfile++) {
|
||||
if (strcmp(device_dev->bus, busfile->bus) == 0) {
|
||||
dbg("looking at bus '%s' for specific file '%s'", device_dev->bus, busfile->file);
|
||||
if (sysfs_get_device_attr(device_dev, busfile->file) != NULL) {
|
||||
dbg("bus '%s' specific file '%s' found", device_dev->bus, busfile->file);
|
||||
return 0;
|
||||
}
|
||||
if (busfile->bus == NULL) {
|
||||
info("error: unknown bus, update the build-in list '%s'", device_dev->bus);
|
||||
return -1;
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
dbg("error: getting bus '%s' specific file '%s'", device_dev->bus, busfile->file);
|
||||
return -1;
|
||||
}
|
||||
|
||||
int main(int argc, char *argv[], char *envp[])
|
||||
{
|
||||
const char *devpath = "";
|
||||
const char *action;
|
||||
const char *subsystem;
|
||||
char sysfs_path[SYSFS_PATH_MAX];
|
||||
char filename[SYSFS_PATH_MAX];
|
||||
struct sysfs_class_device *class_dev;
|
||||
struct sysfs_class_device *class_dev_parent;
|
||||
struct sysfs_device *device_dev = NULL;
|
||||
int loop;
|
||||
int rc = 0;
|
||||
|
||||
if (argc != 2) {
|
||||
dbg("error: subsystem");
|
||||
return 1;
|
||||
}
|
||||
subsystem = argv[1];
|
||||
|
||||
devpath = getenv ("DEVPATH");
|
||||
if (!devpath) {
|
||||
dbg("error: no DEVPATH");
|
||||
return 1;
|
||||
}
|
||||
|
||||
action = getenv ("ACTION");
|
||||
if (!action) {
|
||||
dbg("error: no ACTION");
|
||||
return 1;
|
||||
}
|
||||
|
||||
if (strcmp(action, "add") != 0)
|
||||
return 0;
|
||||
|
||||
if (sysfs_get_mnt_path(sysfs_path, SYSFS_PATH_MAX) != 0) {
|
||||
dbg("error: no sysfs path");
|
||||
return 2;
|
||||
}
|
||||
|
||||
if ((strncmp(devpath, "/block/", 7) == 0) || (strncmp(devpath, "/class/", 7) == 0)) {
|
||||
/* open the class device we are called for */
|
||||
snprintf(filename, SYSFS_PATH_MAX-1, "%s%s", sysfs_path, devpath);
|
||||
filename[SYSFS_PATH_MAX-1] = '\0';
|
||||
|
||||
loop = WAIT_MAX_SECONDS * WAIT_LOOP_PER_SECOND;
|
||||
while (--loop) {
|
||||
class_dev = sysfs_open_class_device_path(filename);
|
||||
if (class_dev)
|
||||
break;
|
||||
}
|
||||
if (class_dev == NULL) {
|
||||
dbg("error: getting class_device");
|
||||
rc = 4;
|
||||
goto exit;
|
||||
}
|
||||
dbg("class_device opened '%s'", filename);
|
||||
|
||||
wait_for_class_device_attributes(class_dev);
|
||||
|
||||
if (class_device_expect_no_device_link(class_dev)) {
|
||||
dbg("no device symlink expected");
|
||||
sysfs_close_class_device(class_dev);
|
||||
goto exit;
|
||||
}
|
||||
|
||||
/* the symlink may be on the parent device */
|
||||
class_dev_parent = sysfs_get_classdev_parent(class_dev);
|
||||
if (class_dev_parent)
|
||||
dbg("looking at parent device for device link '%s'", class_dev_parent->path);
|
||||
|
||||
/* wait for the symlink to the /device-device */
|
||||
dbg("waiting for symlink to /device-device");
|
||||
loop = WAIT_MAX_SECONDS * WAIT_LOOP_PER_SECOND;
|
||||
while (--loop) {
|
||||
if (class_dev_parent)
|
||||
device_dev = sysfs_get_classdev_device(class_dev_parent);
|
||||
else
|
||||
device_dev = sysfs_get_classdev_device(class_dev);
|
||||
|
||||
if (device_dev)
|
||||
break;
|
||||
|
||||
usleep(1000 * 1000 / WAIT_LOOP_PER_SECOND);
|
||||
}
|
||||
if (device_dev == NULL) {
|
||||
dbg("error: getting /device-device");
|
||||
sysfs_close_class_device(class_dev);
|
||||
rc = 5;
|
||||
goto exit;
|
||||
}
|
||||
dbg("device symlink found pointing to '%s'", device_dev->path);
|
||||
|
||||
/* wait for the bus value */
|
||||
if (wait_for_bus_device(device_dev) != 0)
|
||||
rc = 6;
|
||||
sysfs_close_class_device(class_dev);
|
||||
|
||||
/* finished */
|
||||
goto exit;
|
||||
|
||||
} else if ((strncmp(devpath, "/devices/", 9) == 0)) {
|
||||
/* open the path we are called for */
|
||||
snprintf(filename, SYSFS_PATH_MAX-1, "%s%s", sysfs_path, devpath);
|
||||
filename[SYSFS_PATH_MAX-1] = '\0';
|
||||
|
||||
loop = WAIT_MAX_SECONDS * WAIT_LOOP_PER_SECOND;
|
||||
while (--loop) {
|
||||
device_dev = sysfs_open_device_path(filename);
|
||||
if (device_dev)
|
||||
break;
|
||||
}
|
||||
if (device_dev == NULL) {
|
||||
dbg("error: getting /device-device");
|
||||
rc = 4;
|
||||
goto exit;
|
||||
}
|
||||
dbg("device_device opened '%s'", filename);
|
||||
|
||||
/* wait for the bus value */
|
||||
if (wait_for_bus_device(device_dev) != 0)
|
||||
rc = 9;
|
||||
|
||||
sysfs_close_device(device_dev);
|
||||
|
||||
/* finished */
|
||||
goto exit;
|
||||
|
||||
} else {
|
||||
dbg("unhandled sysfs path, no need to wait");
|
||||
}
|
||||
|
||||
exit:
|
||||
if (rc == 0)
|
||||
info("result: waiting for sysfs successful '%s'", devpath);
|
||||
else
|
||||
info("result: waiting for sysfs failed '%s'", devpath);
|
||||
|
||||
return rc;
|
||||
}
|
||||
Loading…
Reference in New Issue
Block a user