Changing the cmb_enable attribute of a CCW device can cause a blocked
chzdev process or udev rule. This problem occurs when the device is
offline, cmb_enable is 0, and chzdev is used to set cmb_enable=1 and
online=1 at the same time.
The following call will block:
chzdev 190d -a cmb_enable=1 online=1
The following call will generate a udev rule that will block subsequent
calls to 'udevadm settle':
chzdev 190d -p online=1 cmb_enable=1
Fix this by ensuring that cmb_enable is only set when the CCW device
is not online.
Reported-by: André Wild <wild@linux.vnet.ibm.com>
Signed-off-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
Auto-configuration is the name of a new configuration target that is
supported by chzdev and lszdev besides the existing active and
persistent configuration targets. Directives created in this new
configuration are stored as udev rules in the /run/udev/rules.d
directory.
Auto-configuration directives are only in effect if there are no
directives for the same device in the user-provided persistent
configuration. This allows users to override auto-configuration
directives if necessary.
Due to the volatile nature of the /run directory, auto-configuration
directives are cleared on reboot. Therefore mechanisms that generate
auto-configuration directives must recreate them on every boot.
The lszdev tool displays auto-configuration data both in list view
as well as in detail view. Users can specify the new option --auto-conf
to only show data from this configuration target.
Mechanisms that generate automated configuration directives can use
chzdev together with the --auto-conf option to create the corresponding
udev rules.
Note: This change does not include a mechanism that generates
auto-configuration directives.
Signed-off-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
This commit is based on the s390-tools-1.39.0 version.
Changes on top of s390-tools-1.39.0:
- Add MIT license to all source files
- Add LICENSE file
- Transform REAMDE to README.md (markdown)
- Add AUTHORS.md file
- Add CONTRIBUTING.md file
- Move changelog from README to CHANGELOG.md file
Reviewed-by: Stefan Haberland <sth@linux.vnet.ibm.com>
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
