linux/device/class.h: No such file or directory

[Zabrane]

I'm unable to compile the kernel module on my Ubuntu 20.04 LTS.

$ make
make -C /lib/modules/5.4.0-128-generic/build M=/home/zab/fanout modules
make[1]: Entering directory '/usr/src/linux-headers-5.4.0-128-generic'
  CC [M]  /home/zab/fanout/fanout.o
/home/zab/fanout/fanout.c:28:12: fatal error: linux/device/class.h: No such file or directory
   28 | #  include <linux/device/class.h>
      |            ^~~~~~~~~~~~~~~~~~~~~~
compilation terminated.
make[2]: *** [scripts/Makefile.build:270: /home/zab/fanout/fanout.o] Error 1
make[1]: *** [Makefile:1762: /home/zab/fanout] Error 2
make[1]: Leaving directory '/usr/src/linux-headers-5.4.0-128-generic'
make: *** [Makefile:8: all] Error 2

Advice please?

[bob-linuxtoys]

Zabrane It builds and installs cleanly on Ubuntu 20.04 if you comment out the mknod define: //#define DEV_MKNOD Interestingly, it works unmodified on 22.04. This is not so much a coding bug as a documentation error, which I'll fix. Thanks for bring this to my attention. thanks Bob Smith

…

On 10/17/22 12:08, Zabrane wrote: I'm unable to compile the kernel module on my `Ubuntu 20.04 LTS`. ```bash $ make make -C /lib/modules/5.4.0-128-generic/build M=/home/zab/fanout modules make[1]: Entering directory '/usr/src/linux-headers-5.4.0-128-generic' CC [M] /home/zab/fanout/fanout.o /home/zab/fanout/fanout.c:28:12: fatal error: linux/device/class.h: No such file or directory 28 | # include <linux/device/class.h> | ^~~~~~~~~~~~~~~~~~~~~~ compilation terminated. make[2]: *** [scripts/Makefile.build:270: /home/zab/fanout/fanout.o] Error 1 make[1]: *** [Makefile:1762: /home/zab/fanout] Error 2 make[1]: Leaving directory '/usr/src/linux-headers-5.4.0-128-generic' make: *** [Makefile:8: all] Error 2 ``` Advice please?

[Zabrane]

@bob-linuxtoys thanks a lot. Now it compiles but i still can't see the 08 nodes:

$ sudo modprobe fanout
$ sudo lsmod | grep fanout
fanout                 16384  0
$ ls /dev/fanout*
"/dev/fanout*": No such file or directory (os error 2)

[bob-linuxtoys]

On 10/17/22 13:41, Zabrane wrote: @bob-linuxtoys thanks a lot. Now it compiles but i still can't see the 08 nodes: ```bash $ sudo modprobe fanout $ sudo lsmod | grep fanout fanout 16384 0 $ ls /dev/fanout* "/dev/fanout*": No such file or directory (os error 2)

Right, without the mknod define the fanout devices are not created automatically. You have to create them manually. As root... modprobe fanout grep fanout /proc/devices # note the major number mknod /dev/fanout0 c 242 0 # my major # was 242 Bob

[Zabrane]

Wow, real magic:

$ grep fanout /proc/devices
240 fanout
$ for i in `seq 0 7`; do mknod /dev/fanout$i c 240 $i; done

You could maybe update the doc for newcomers like myself ;-)

[Zabrane]

@bob-linuxtoys how fast this PubSub can be? I'm now really intrigued.