4.331. udev

Updated udev packages that fix various bugs and add an enhancement are now available for Red Hat Enterprise Linux 6.
The udev packages implement a dynamic device-directory, providing only the devices present on the system. This dynamic directory runs in user space, dynamically creates and removes devices, provides consistent naming, and a user-space API. The udev package replaces the devfs package and provides better hot plug functionality.

Bug Fixes

BZ#632646
Previously, a udev rule used the modem-modeswitch callout on the Vodafone K3565-Z 3G modem. As a consequence, a medium in a virtual CD-ROM drive could not be ejected to activate the modem functionality. Now, the modem-modeswitch callout is no longer used for this device and a medium is automatically ejected instead, thus fixing this bug.
BZ#698540
The path_id utility did not create symbolic links for SAS (Serial Attached SCSI) devices without enclosures. Consequently, udev did not create a symbolic link in the /dev/disk/by-path/ directory and the device could not be accessed by this path. This bug has been fixed, udev now follows the naming scheme of its upstream version 171, and symbolic links for SAS devices are now created in the following format: sas-[sas_address]-[lun]". In this format, [sas_address] stands for the contents of the sas_address file of the device, located in the /sys subdirectory, and [lun] represents the logical unit number of the device.
BZ#714951
The path_id utility did not create symbolic links for iSCSI (Internet SCSI) devices. Consequently, udev did not create a symbolic link in the /dev/disk/by-path/ directory and the device could not be accessed by this path. This bug has been fixed, udev now follows the naming scheme of its upstream version 171, and symbolic links for iSCSI devices are now created in the following format: "ip-[address]:[port]-iscsi-[target]-[lun]". In this format, [lun] represents the logical unit number of the device.
BZ#701265
When udev renamed a network interface and encountered a naming conflict, it renamed the interface to "[initial name]-[desired name]". Sometimes, this name was not unique and the naming conflict persisted. This bug has been fixed, udev now uses the unique interface index for renaming, and temporary names for interfaces are now of the following format: "rename[ifindex]".
BZ#727500
Prior to this update, the libgudev1 package had no explicit package version requirement on the libudev library. As a consequence, it was possible to update libudev without updating libgudev1, which could lead to inconsistencies, if the ABI (application binary interface) changed in libudev. With this update, the libgudev1 spec file has been updated, and the package now requires libudev explicitly, thus fixing this bug.
BZ#726566
Previously, the result buffer to store the output of programs started with the IMPORT directive was too short in some cases. Consequently, the "ERR udevd-work: ressize 4096 too short" error messages were returned, and the system sometimes became non-operational. Now, the result buffer has been increased to 16kB, thus fixing this bug.
BZ#696651
Previously, when traversing the list of devices internal to udev, the libvirtd daemon terminated unexpectedly in the udev_enumerate_get_list_entry() function. This bug has been fixed and libvirtd no longer crashes in the described scenario.
BZ#731400
Previously, for Xen block devices, udev did not provide information acquired by the blkid utility, such as the filesystem label or UUID. Consequently, no symbolic links in the /dev/disk/{by-uuid,by-label,by-id} directories were created. With this update, these symbolic links are created for Xen block devices as expected, thus fixing this bug.

Enhancement

BZ#711254
The default I/O scheduler (CFQ) parameters for all disk types, except SATA disks, have been changed as follows:
slice_idle=0 
quantum=32
All users of udev are advised to upgrade to these updated packages, which fix these bugs and add this enhancement.