From a8b5267a629f21c30d4e94ec82be193009803ddd Mon Sep 17 00:00:00 2001 From: "kay.sievers@vrfy.org" Date: Tue, 5 Oct 2004 21:35:39 -0700 Subject: [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. --- Makefile | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) (limited to 'Makefile') diff --git a/Makefile b/Makefile index bc2f852614..67a7d46525 100644 --- a/Makefile +++ b/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) -- cgit v1.2.3-54-g00ecf