[dm-devel] [PATCH 30/31] kpartx/del-part-nodes.rules: new udev file

[Benjamin Marzinski]

On Sun, Sep 03, 2017 at 12:38:59AM +0200, Martin Wilck wrote:
> A new udev rules file "68-del-part-nodes.rules" is introduced,
> based on code from Ben Marzinki. This code deletes partitions on
> multipath member devices. The purpose of this is to avoid users
> accidentally accessing partitions of member devices rather than of the
> multipath devcice. The deletion is done only once for every disk
> device. If the user wants to get the partitions back, he can run "partx
> -a" or "partprobe" on the disk device.
> 
> This code could be extended to wipe partitions on member devices
> of non-multipath dm targets if desired.
> 
> Means to deactivate this behavior are provided via kernel parameter
> "dont_del_part_nodes", or a custom udev rules file setting the
> "DONT_DEL_PART_NODES" environment variable.

You need to uninstall 68-del-part-nodes.rules. Otherwise, this looks
fine.

-Ben

> 
> Signed-off-by: Martin Wilck <mwilck at suse.com>
> ---
>  kpartx/Makefile             |  1 +
>  kpartx/del-part-nodes.rules | 32 ++++++++++++++++++++++++++++++++
>  2 files changed, 33 insertions(+)
>  create mode 100644 kpartx/del-part-nodes.rules
> 
> diff --git a/kpartx/Makefile b/kpartx/Makefile
> index 7b75032e..7f5c1708 100644
> --- a/kpartx/Makefile
> +++ b/kpartx/Makefile
> @@ -30,6 +30,7 @@ install: $(EXEC) $(EXEC).8
>  	$(INSTALL_PROGRAM) -m 755 kpartx_id $(DESTDIR)$(libudevdir)
>  	$(INSTALL_PROGRAM) -d $(DESTDIR)$(libudevdir)/rules.d
>  	$(INSTALL_PROGRAM) -m 644 kpartx.rules $(DESTDIR)$(libudevdir)/rules.d/66-kpartx.rules
> +	$(INSTALL_PROGRAM) -m 644 del-part-nodes.rules $(DESTDIR)$(libudevdir)/rules.d/68-del-part-nodes.rules
>  	$(INSTALL_PROGRAM) -d $(DESTDIR)$(man8dir)
>  	$(INSTALL_PROGRAM) -m 644 $(EXEC).8.gz $(DESTDIR)$(man8dir)
>  
> diff --git a/kpartx/del-part-nodes.rules b/kpartx/del-part-nodes.rules
> new file mode 100644
> index 00000000..cee945d9
> --- /dev/null
> +++ b/kpartx/del-part-nodes.rules
> @@ -0,0 +1,32 @@
> +# These rules can delete partitions devnodes for slave devices
> +# for certain aggregate devices such as multipath.
> +# This is desirable to avoid confusion and keep the number
> +# of device nodes and symlinks within limits.
> +#
> +# This is done only once on the first "add" or "change" event for
> +# any given device.
> +#
> +# To suppress this, use the kernel parameter "dont_del_part_nodes",
> +# or create an udev rule file that sets ENV{DONT_DEL_PART_NODES}="1".
> +
> +SUBSYSTEM!="block", GOTO="end_del_part_nodes"
> +KERNEL!="sd*|dasd*|rbd*", GOTO="end_del_part_nodes"
> +ACTION!="add|change", GOTO="end_del_part_nodes"
> +
> +IMPORT{cmdline}="dont_del_part_nodes"
> +ENV{dont_del_part_nodes}=="1", GOTO="end_del_part_nodes"
> +ENV{DONT_DEL_PART_NODES}=="1", GOTO="end_del_part_nodes"
> +
> +# dm-multipath
> +ENV{DM_MULTIPATH_DEVICE_PATH}=="1", GOTO="del_part_nodes"
> +
> +# Other aggregate device types can be added here.
> +
> +GOTO="end_del_part_nodes"
> +
> +LABEL="del_part_nodes"
> +IMPORT{db}="DM_DEL_PART_NODES"
> +ENV{DM_DEL_PART_NODES}!="1", ENV{DM_DEL_PART_NODES}="1", \
> +	RUN+="/usr/sbin/partx -d --nr 1-1024 $env{DEVNAME}"
> +
> +LABEL="end_del_part_nodes"
> -- 
> 2.14.0