The slow logging facilites on some systems are a reason for
the reported slowness of udevstart. On one of my boxes udevstart
is down from 9 second to 0.3 seconds.
Remove the overwriting of main_argv[] hack and use the values
from the udev object.
Pass the udev object to call_foreach_file().
In the udevstart case, export SUBSYSTEM and UDEVSTART to the
environment.
This makes the udev operation completely lockless by storing a
file for every node in /dev/.udevdb/* This solved the problem
with deadlocking concurrent udev processes waiting for each other
to release the file lock under heavy load.
This patch exposes the wait_for_sysfs functions to all possible users,
so we need to maintain only one list of exceptions. The last list is
hereby removed from udev.c.
Here we supress the dev.d/ execution if we didn't change a network
interface's name with a rule. This should solve the issue of two
running dhclients for the same interface, cause the
/etc/dev.d/net/hotplug.dev script that fakes the hotplug event runs
with every udevstart for every interface and fakes a second identical
hotplug event on bootup.
With this patch netif interfaces are no longer stored in the udevdb.
It is not needed, cause we don't have permissions or symlinks :) and
all information is available in sysfs.
This patch also moves the dev_d execution calls out of the
udev_add/udev_remove. As with the former api-cleanup-patch we have
all processed data in one udev struct and can place the execution
calls where needed.
Here is the first patch to cleanup the internal processing of the
various stages of an udev event. It should not change any behavior,
but if your system depends on udev, please always test it before reboot :)
We pass only one generic structure around between add, remove,
namedev, db and dev_d handling and make all relevant data available
to all internal stages. All udev structures are renamed to "udev".
We replace the fake parameter by a flag in the udev structure.
We open the class device in the main binaries and not in udev_add, to
make it possible to use libsysfs for udevstart directory crawling.
The last sleep parameters are removed.
Here we remove all the sysfs sleep loops from udev as wait_for_sysfs
will do this for us and any other hotplug user. We still keep a small
blacklist of subsystems we don't care about but any missing entry here
will no longer lead to a spinning udev waiting for files.
This patch fixes the reintroduced bug with the
sig_handler(), if we link against a -mregparm=3 compiled
klibc on i386.
It also fixes some compiler warnings about redefined
asmlinkage on some systems.
Also some (broken?) compilers on distros throw out warnings
if asmlinkage is before "static void". This fixes it, too.
This patch fixes two
warning: assignment from incompatible pointer type
asmlinkage is the reason for the warning. We can
simply cast to avoid it.
It also fixes this warning:
warning: implicit declaration of function `umask'
Here is the patch, that should prevent all of the known deadlocks with
corrupt tdb databases we discovered.
Thanks to Frank Steiner <fsteiner-mail@bio.ifi.lmu.de>, who tested all this
endlessly with a NFS mounted /dev. The conclusion is, that udev will not work
on filesystems without proper record locking, but we should prevent the
endless loops anyway. This patch implements:
o recovery from a corrupted udev database. udev will continue
without database support now, instead of doing nothing. So the node should
be generated in any case, remove will obviously not work for custom names.
o added iteration limits to the tdb-code at the places we discovered endless
loops. In the case tdb tries to find more than 100.000 entries with the
same hash, we better give up :)
o prevent a {all_partitions} loop caused by corrupt db data
o log all tdb errors to syslog
o switch sleep() to usleep() cause we want to use alarm()
On Tue, Sep 07, 2004 at 12:46:43PM +0200, Kay Sievers wrote:
> On Mon, 2004-09-06 at 20:18 -0700, Tom Rini wrote:
> > I noticed somewhat recently that my enet devices weren't being renamed
> > on boot anymore. I don't quite know when this got broken (or rather, if
> > it was supposed to be working. I swear it worked for me once..), but
> > the following seems to do it.
>
> I think it never worked in the udevstart case. It worked only with the
> hotplug-event-udev, I expect.
>
> > In udev_scan_class(), look for not just
> > %s/%s/dev (which everything with a dev node has), but %s/%s/dev* (both
> > of my enet devices, sis900 & 3c59x only have device) and if that
> > exists, pass this along to udev.
>
> Yeah, network devices don't have a devnode and therefore no "dev", but
> they are all in /sys/class/net/. We may just test if we are there
> instead of the "device" match.
How about something like this. It adds all the net devices without
looking at the attributes and keeps the remaining logic like it is.
It also removes certain levels of indirection and much simplifies the
udevstart process. We surely don't need to open and close the udevdb
for every node while iterating over the list. (We are about 5% faster on
my box)
It's not well tested, so it would be nice if someone can have a look
at it, before a broken udevstart renders any system unbootable.
Move setting UDEV_NO_SLEEP into main(). I thought about moving
udev_init_config() around, but it still must be invoked in both udev and
udevstart cases, and before udev_hotplug() is called. An alternative
would be to have main() do:
if (is_udevstart) {
... current ...
} else {
udev_init_config();
return udev_hotplug();
}
And move setting UDEV_NO_SLEEP into udev_start(). I can redo it that
way, if you prefer.
Signed-off-by: Tom Rini <trini@kernel.crashing.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>
Hi,
The following patch makes udev/udevstart be a common binary. First,
doing this grows udev by a total of 1.8kB (ppc32, stripped) whereas
udevstart by itself is 6.4kB. I know you mentioned being able to
replace udevstart with a script, but at 1.8kB I don't think it'll be
easy to beat this with size there. Next, the following are by-eye
timings of before, after, and with devfs on a slow, but still usable
embedded platform (config stripped down to more-or-less bare for
ramdisk):
-- Embedded Planet RPX LITE, 64Mhz MPC 823e --
devfs : 15.333s, 15.253s, 14.988s (15.191s avg)
udev-pristine : 18.675s, 18.079s, 18.418s (18.390s avg)
udev-multi : 14.587s, 14.747s, 14.868s (14.734s avg)
The patch ends up being rather large to add this, as in doing so I ended
up making all refs (that I hit..) to devpath/subsystem be marked as
'const'.
Signed-off-by: Tom Rini <trini@kernel.crashing.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>
The following patch adds 'asmlinkage' defines to udev, to kill off 2
warnings on !i386.
Signed-off-by: Tom Rini <trini@kernel.crashing.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>
The recent version of klibc switched to -mregparm=3. This broke the
signal handlers parameter, cause it is called directly from the kernel
with the parameter on the stack not in a register.
Hmm, Arndt Bergmann sent a patch like this one a few weeks ago and
I want to bring the question back, if we want to handle net device
naming with udev.
With this patch it is actually possible to specify something like this
in udev.rules:
KERNEL="dummy*", SYSFS{address}="00:00:00:00:00:00", SYSFS{features}="0x0", NAME="blind%n"
KERNEL="eth*", SYSFS{address}="00:0d:60:77:30:91", NAME="private"
and you will get:
[root@pim udev.kay]# cat /proc/net/dev
Inter-| Receive | Transmit
face |bytes packets errs drop fifo frame compressed multicast|bytes packets errs drop fifo colls carrier compressed
lo: 1500 30 0 0 0 0 0 0 1500 30 0 0 0 0 0 0
private: 278393 1114 0 0 0 0 0 0 153204 1468 0 0 0 0 0 0
sit0: 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
blind0: 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
The udevinfo program is also working:
[root@pim udev.kay]# ./udevinfo -a -p /sys/class/net/private
looking at class device '/sys/class/net/private':
SYSFS{addr_len}="6"
SYSFS{address}="00:0d:60:77:30:91"
SYSFS{broadcast}="ff:ff:ff:ff:ff:ff"
SYSFS{features}="0x3a9"
SYSFS{flags}="0x1003"
SYSFS{ifindex}="2"
SYSFS{iflink}="2"
SYSFS{mtu}="1500"
SYSFS{tx_queue_len}="1000"
SYSFS{type}="1"
follow the class device's "device"
looking at the device chain at '/sys/devices/pci0000:00/0000:00:1e.0/0000:02:01.0':
BUS="pci"
ID="0000:02:01.0"
SYSFS{class}="0x020000"
SYSFS{detach_state}="0"
SYSFS{device}="0x101e"
SYSFS{irq}="11"
SYSFS{subsystem_device}="0x0549"
SYSFS{subsystem_vendor}="0x1014"
SYSFS{vendor}="0x8086"
The matching device will be renamed to the given name. The device name
will not be put into the udev database, cause the kernel renames the
device and the sysfs name disappears.
I like it, cause it plugs in nicely. We have all the naming features
and sysfs queries and walks inside of udev. The sysfs timing races
are already solved and the management tools are working for net devices
too. nameif can only match the MAC address now. udev can match any sysfs
value of the device tree the net device is connected to.
But right, net devices do not have device nodes :)
Is there any reason to parse the rules for a remove event?
Without it, our test script needs only 2.1 seconds instead of 2.5,
so we have 19 percent more time for testing now :)
Here we replace the various fgets() with a mmap() call for the config
file reading, due to the reported performance problems with klibc.
Thanks to Patrick's testing, it makes a very small, close to nothing
speed gain for libc users, but a 6 times speed increase for klibc users
with a 1000 line config file.
I've created a udev_lib.[hc] for this and also moved all the generic
stuff from udev.h in there and uninlined the functions.
Here I try to make the style a bit more consistant in the different
files, so that new patches just copy the 'right' one :)
Some "magic" numbers are replaced and udevtest.c is catched up with udev.
Mainly a cleanup of the earlier patches with a few missing pieces
and some cosmetical changes.
I've moved the udev_init_config() to very early init, otherwise we
don't get any logging for the processing of the input. What would I
do without gdb :)
Greg, it's the 7th patch in your box to apply. I will stop now and
wait for you :)
Here we truncate our input strings from the environment to our
defined limit. It's a bit theroretical but better check for it.
It cleans up some magic length definitions and removes the code
duplication in udev, udevtest and udevsend.
udevd needs to be killed after installation, cause the message size
is changed with this patch.
Should we do this with the 'make install', like we do with the '.udevdb'?
I was on the train for 5 hours today and the TODO is almost empty :)
So, at least four people wanted this feature, then here is a actual
working patch.
We may specify now in udev.conf:
udev_rules="/etc/udev/"
and udev will scan the whole directory for files ending with *.rules,
sort it in lexical order and create our rule list from all of the files.
A plain given file will still work and the same applies to the *.permissions.
I sort the files in our usual linked list, cause klibc has no scandir().
On Mon, Feb 09, 2004 at 05:41:15AM +0100, Kay Sievers wrote:
> It seems that today was just another udev-sunday for me :)
>
> Here is a working patch to compile udevd with klibc.
>
> It's sweet the static binary takes 6 kbytes and it runs
> with only 80 kbytes virtual memory.
>
> I changed a few peaces and added a siginterrupt.c file to klibc.
> We may check with hpa to get the changes upstream?
So here is the next try :)
hpa, for good reason, didn't like my changes to klibc.
He will dump signal() completely from klibc instead, so here we switch to
sigaction() and keep udevd working with klibc.
Here is the next round. We have three queues now. All incoming messages
are queued in msg_list and if nothing is missing we move it to the
running_list and exec in the background.
If the exec comes back, it removes the message from the running_list and
frees the message.
Before we exec, we check the running_list if there is a udev running on
the same device path. If yes, we move the message to the delay_list. If
the former exec comes back, we move the message to the running_list and
exec it.
The very first event is delayed now to catch possible earlier sequences,
every following event is executed without delay if no sequence is missing.
The daemon doesn't exit by itself any longer, cause we don't want to
delay every first exec.
I've put a $(PWD) for now in the Makefile for testing this beast. Only
the local binaries are executed, not the /sbin/udev. We can change it
if we are ready for real testing.
And SIGKILL can't be cought, so I removed it from the handler :)
06:58:36 sig_handler: caught signal 15
06:58:36 main: using ipc queue 0x2d548
06:58:37 message is still in the ipc queue, starting daemon...
06:58:37 work: received sequence 3, expected sequence 0
06:58:37 msg_dump_queue: sequence 3 in queue
06:58:37 set_timeout: set timeout in 1 seconds
06:58:37 main: using ipc queue 0x2d548
06:58:37 main: using ipc queue 0x2d548
06:58:37 work: received sequence 1, expected sequence 1
06:58:37 msg_dump_queue: sequence 1 in queue
06:58:37 msg_dump_queue: sequence 3 in queue
06:58:37 msg_dump: sequence 1, 'add', '/block/sda', 'block'
06:58:37 msg_exec: child [8038] created
06:58:37 running_moveto_queue: move sequence 1 [8038] to running queue '/block/sda'
06:58:37 set_timeout: set timeout in 5 seconds
06:58:37 work: received sequence 2, expected sequence 2
06:58:37 msg_dump_queue: sequence 2 in queue
06:58:37 msg_dump_queue: sequence 3 in queue
06:58:37 msg_dump: sequence 2, 'add', '/block/sdb', 'block'
06:58:37 msg_exec: child [8039] created
06:58:37 running_moveto_queue: move sequence 2 [8039] to running queue '/block/sdb'
06:58:37 msg_dump: sequence 3, 'add', '/block/sdc', 'block'
06:58:37 msg_exec: child [8040] created
06:58:37 running_moveto_queue: move sequence 3 [8040] to running queue '/block/sdc'
06:58:37 main: using ipc queue 0x2d548
06:58:37 main: using ipc queue 0x2d548
06:58:37 work: received sequence 4, expected sequence 4
06:58:37 msg_dump_queue: sequence 4 in queue
06:58:37 msg_dump: sequence 4, 'remove', '/block/sdc', 'block'
06:58:37 msg_exec: delay exec of sequence 4, [8040] already working on '/block/sdc'
06:58:37 delayed_moveto_queue: move event to delayed queue '/block/sdc'
06:58:37 msg_exec: child [8043] created
06:58:37 running_moveto_queue: move sequence 4 [8043] to running queue '/block/sdc'
06:58:37 work: received sequence 5, expected sequence 5
06:58:37 msg_dump_queue: sequence 5 in queue
06:58:37 msg_dump: sequence 5, 'remove', '/block/sdb', 'block'
06:58:37 msg_exec: delay exec of sequence 5, [8039] already working on '/block/sdb'
06:58:37 delayed_moveto_queue: move event to delayed queue '/block/sdb'
06:58:37 msg_exec: child [8044] created
06:58:37 running_moveto_queue: move sequence 5 [8044] to running queue '/block/sdb'
06:58:37 main: using ipc queue 0x2d548
06:58:37 main: using ipc queue 0x2d548
06:58:37 work: received sequence 8, expected sequence 6
06:58:37 msg_dump_queue: sequence 8 in queue
06:58:37 set_timeout: set timeout in 5 seconds
06:58:37 work: received sequence 6, expected sequence 6
06:58:37 msg_dump_queue: sequence 6 in queue
06:58:37 msg_dump_queue: sequence 8 in queue
06:58:37 msg_dump: sequence 6, 'remove', '/block/sda', 'block'
06:58:37 msg_exec: delay exec of sequence 6, [8038] already working on '/block/sda'
06:58:37 delayed_moveto_queue: move event to delayed queue '/block/sda'
06:58:37 msg_exec: child [8047] created
06:58:37 running_moveto_queue: move sequence 6 [8047] to running queue '/block/sda'
06:58:37 set_timeout: set timeout in 5 seconds
06:58:38 sig_handler: caught signal 17
06:58:38 sig_handler: exec finished, pid 8038
06:58:38 set_timeout: set timeout in 4 seconds
06:58:38 msg_dump_queue: sequence 8 in queue
06:58:38 sig_handler: caught signal 17
06:58:38 sig_handler: exec finished, pid 8039
06:58:38 set_timeout: set timeout in 4 seconds
06:58:38 msg_dump_queue: sequence 8 in queue
06:58:38 sig_handler: caught signal 17
06:58:38 sig_handler: exec finished, pid 8040
06:58:38 set_timeout: set timeout in 4 seconds
06:58:38 msg_dump_queue: sequence 8 in queue
06:58:38 sig_handler: caught signal 17
06:58:38 sig_handler: exec finished, pid 8043
06:58:38 set_timeout: set timeout in 4 seconds
06:58:38 msg_dump_queue: sequence 8 in queue
06:58:38 sig_handler: caught signal 17
06:58:38 sig_handler: exec finished, pid 8044
06:58:38 set_timeout: set timeout in 4 seconds
06:58:38 msg_dump_queue: sequence 8 in queue
06:58:38 sig_handler: caught signal 17
06:58:38 sig_handler: exec finished, pid 8047
06:58:38 set_timeout: set timeout in 4 seconds
06:58:38 msg_dump_queue: sequence 8 in queue
06:58:39 main: using ipc queue 0x2d548
06:58:39 main: using ipc queue 0x2d548
06:58:39 work: received sequence 9, expected sequence 7
06:58:39 msg_dump_queue: sequence 8 in queue
06:58:39 msg_dump_queue: sequence 9 in queue
06:58:39 set_timeout: set timeout in 3 seconds
06:58:39 work: received sequence 11, expected sequence 7
06:58:39 msg_dump_queue: sequence 8 in queue
06:58:39 msg_dump_queue: sequence 9 in queue
06:58:39 msg_dump_queue: sequence 11 in queue
06:58:39 set_timeout: set timeout in 3 seconds
06:58:39 main: using ipc queue 0x2d548
06:58:39 work: received sequence 10, expected sequence 7
06:58:39 msg_dump_queue: sequence 8 in queue
06:58:39 msg_dump_queue: sequence 9 in queue
06:58:39 msg_dump_queue: sequence 10 in queue
06:58:39 msg_dump_queue: sequence 11 in queue
06:58:39 set_timeout: set timeout in 3 seconds
06:58:39 main: using ipc queue 0x2d548
06:58:39 work: received sequence 13, expected sequence 7
06:58:39 msg_dump_queue: sequence 8 in queue
06:58:39 msg_dump_queue: sequence 9 in queue
06:58:39 msg_dump_queue: sequence 10 in queue
06:58:39 msg_dump_queue: sequence 11 in queue
06:58:39 msg_dump_queue: sequence 13 in queue
06:58:39 set_timeout: set timeout in 3 seconds
06:58:39 main: using ipc queue 0x2d548
06:58:39 work: received sequence 14, expected sequence 7
06:58:39 msg_dump_queue: sequence 8 in queue
06:58:39 msg_dump_queue: sequence 9 in queue
06:58:39 msg_dump_queue: sequence 10 in queue
06:58:39 msg_dump_queue: sequence 11 in queue
06:58:39 msg_dump_queue: sequence 13 in queue
06:58:39 msg_dump_queue: sequence 14 in queue
06:58:39 set_timeout: set timeout in 3 seconds
06:58:39 main: using ipc queue 0x2d548
06:58:39 work: received sequence 15, expected sequence 7
06:58:39 msg_dump_queue: sequence 8 in queue
06:58:39 msg_dump_queue: sequence 9 in queue
06:58:39 msg_dump_queue: sequence 10 in queue
06:58:39 msg_dump_queue: sequence 11 in queue
06:58:39 msg_dump_queue: sequence 13 in queue
06:58:39 msg_dump_queue: sequence 14 in queue
06:58:39 msg_dump_queue: sequence 15 in queue
06:58:39 set_timeout: set timeout in 3 seconds
06:58:41 main: using ipc queue 0x2d548
06:58:41 work: received sequence 12, expected sequence 7
06:58:41 msg_dump_queue: sequence 8 in queue
06:58:41 msg_dump_queue: sequence 9 in queue
06:58:41 msg_dump_queue: sequence 10 in queue
06:58:41 msg_dump_queue: sequence 11 in queue
06:58:41 msg_dump_queue: sequence 12 in queue
06:58:41 msg_dump_queue: sequence 13 in queue
06:58:41 msg_dump_queue: sequence 14 in queue
06:58:41 msg_dump_queue: sequence 15 in queue
06:58:41 set_timeout: set timeout in 1 seconds
06:58:42 sig_handler: caught signal 14
06:58:42 sig_handler: event timeout reached
06:58:42 event 8, age 5 seconds, skip event 7-7
06:58:42 msg_dump: sequence 8, 'add', '/block/sdb', 'block'
06:58:42 msg_exec: child [8057] created
06:58:42 running_moveto_queue: move sequence 8 [8057] to running queue '/block/sdb'
06:58:42 msg_dump: sequence 9, 'add', '/block/sdc', 'block'
06:58:42 msg_exec: child [8058] created
06:58:42 running_moveto_queue: move sequence 9 [8058] to running queue '/block/sdc'
06:58:42 msg_dump: sequence 10, 'remove', '/block/sdc', 'block'
06:58:42 msg_exec: delay exec of sequence 10, [8058] already working on '/block/sdc'
06:58:42 delayed_moveto_queue: move event to delayed queue '/block/sdc'
06:58:42 msg_exec: child [8059] created
06:58:42 running_moveto_queue: move sequence 10 [8059] to running queue '/block/sdc'
06:58:42 msg_dump: sequence 11, 'remove', '/block/sdb', 'block'
06:58:42 msg_exec: delay exec of sequence 11, [8057] already working on '/block/sdb'
06:58:42 delayed_moveto_queue: move event to delayed queue '/block/sdb'
06:58:42 msg_exec: child [8060] created
06:58:42 running_moveto_queue: move sequence 11 [8060] to running queue '/block/sdb'
06:58:42 msg_dump: sequence 12, 'remove', '/block/sda', 'block'
06:58:42 msg_exec: child [8061] created
06:58:42 running_moveto_queue: move sequence 12 [8061] to running queue '/block/sda'
06:58:42 msg_dump: sequence 13, 'add', '/block/sda', 'block'
06:58:42 msg_exec: delay exec of sequence 13, [8061] already working on '/block/sda'
06:58:42 delayed_moveto_queue: move event to delayed queue '/block/sda'
06:58:42 msg_exec: child [8062] created
06:58:42 running_moveto_queue: move sequence 13 [8062] to running queue '/block/sda'
06:58:42 msg_dump: sequence 14, 'add', '/block/sdb', 'block'
06:58:42 msg_exec: delay exec of sequence 14, [8057] already working on '/block/sdb'
06:58:42 delayed_moveto_queue: move event to delayed queue '/block/sdb'
06:58:42 msg_exec: child [8063] created
06:58:42 running_moveto_queue: move sequence 14 [8063] to running queue '/block/sdb'
06:58:42 msg_dump: sequence 15, 'add', '/block/sdc', 'block'
06:58:42 msg_exec: delay exec of sequence 15, [8058] already working on '/block/sdc'
06:58:42 delayed_moveto_queue: move event to delayed queue '/block/sdc'
06:58:42 msg_exec: child [8064] created
06:58:42 running_moveto_queue: move sequence 15 [8064] to running queue '/block/sdc'
06:58:43 sig_handler: caught signal 17
06:58:43 sig_handler: exec finished, pid 8057
06:58:43 sig_handler: exec finished, pid 8058
06:58:43 sig_handler: caught signal 17
06:58:43 sig_handler: exec finished, pid 8059
06:58:43 sig_handler: caught signal 17
06:58:43 sig_handler: exec finished, pid 8060
06:58:43 sig_handler: exec finished, pid 8061
06:58:43 sig_handler: caught signal 17
06:58:43 sig_handler: exec finished, pid 8062
06:58:43 sig_handler: caught signal 17
06:58:43 sig_handler: exec finished, pid 8063
06:58:43 sig_handler: caught signal 17
06:58:43 sig_handler: exec finished, pid 8064
Here we get the ability to query with the name of the node instead of
the device path. It uses a linear search over the whole database.
kay@pim:~/src/udev.kay$ ./udev -q path -n video/webcam0
/class/video4linux/video0
New version, with better function return codes for error handling.
On Thu, Jan 15, 2004 at 05:14:16AM +0100, Kay Sievers wrote:
> On Wed, Jan 14, 2004 at 01:10:43PM -0800, Greg KH wrote:
> > On Wed, Jan 14, 2004 at 02:34:26PM -0600, Clay Haapala wrote:
> > > On Wed, 14 Jan 2004, Chris Friesen spake thusly:
> > > >
> > > > Maybe for ones with a matching rule, you could print something like:
> > > >
> > > >
> > > Is the act of printing/syslogging a rule in an of itself?
> >
> > No, as currently the only way stuff ends up in the syslog is if
> > DEBUG=true is used on the build line.
> >
> > But it's sounding like we might want to change that... :)
>
> How about this in the syslog after connect/disconnect?
>
> Jan 15 05:07:45 pim udev[28007]: configured rule in '/etc/udev/udev.rules' at line 17 applied, 'video*' becomes 'video/webcam%n'
> Jan 15 05:07:45 pim udev[28007]: creating device node '/udev/video/webcam0'
> Jan 15 05:07:47 pim udev[28015]: removing device node '/udev/video/webcam0'
Here is a slightly better version. I've created a logging.h file and
moved the debug macros from udev.h in there.
If you type:
'make' - you will get a binary that prints one or two lines to syslog
if a device node is created or deleted
'make LOG=false' - you get a binary that prints asolutely nothing
'make DEBUG=true' - the same as today, it will print all debug lines
