« previous 1 2 3 4 5 6 next »

Data Storage

Kernel developer David Miller, known for his work as maintainer of the networking subsystem and for SPARC support, has now also taken over the IDE subsystem from Bartlomiej Zolnierkiewicz in a handover that was preceded by some disagreement between the two hackers.

Miller has intimated that he is not planning on implementing any major changes to the IDE subsystem, "I'm going to treat IDE as pure legacy." The future now belongs to the PATA drives in the Libata subsystem which were introduced in Linux 2.6.19. The modern IDE/PATA driver ata_piix for Intel controllers, which forms part of the Libata subsystem, now scans for drives in parallel, halving initialisation time on the developer's Eee PC.

As a result of one of many changes to the block layer, the layer now exports information on I/O topology using data supplied by the SCSI subsystem – this includes a drive's physical sector size. This is, for example, of interest when allocating storage media with sector sizes other than 512 bytes or for optimal arrangement of data in RAID arrays. The developer behind this code explores some of the issues involved in a recently released presentation (see pages 235-238). The MD code responsible for software RAIDs is already able to make use of this topology information.

Wirelessly happy

This time around, there are again many Wi-Fi related changes. The kernel developers have added support for data transfer using 802.11n to the basic infrastructure of the RT2X00 family of drivers for driving various Ralink Wi-Fi chips. Changes adding support for Ralink's RT2770, RT2870 and RT3070 USB Wi-Fi chips have also moved into the kernel. This code is, however, far from mature, with the commit comments listing a number of major problems, so users may be better served by the staging drivers for these chips, or by the vendor's own drivers.

Hot on the heels of the first complete revamp in 2.6.27 comes a new 'rewrite' of the Rfkill framework, which deals with switching Wi-Fi or Bluetooth on or off using the slide switch or keyboard short-cut usually found on laptops. The rewrite is aimed at improving the interaction between hardware, kernel and userspace programs such as NetworkManager, and finally fixing numerous problems in this area.

There have been many improvements and a few new drivers in the Controller Area Network (CAN) subsystem (e.g. 1, 2, 3, 4, 5, 6). Developed primarily by developers working for Siemens, support for the IEEE 802.15.4 data transfer protocol for Personal Area Networks (WPAN) has also now found its way into the main Linux development tree (e.g. 1, 2, 3, 4, documentation).

Network hardware and packet filtering

Another new arrival is the int51x1 driver for Intellon's USB-connected 14 Mbit/s INT51x1 and INT5200 chips, used by devices for transferring data via the power grid (power line communication/PLC), such as develo's dLAN. One new arrival is the cnic driver for Broadcom's NetXtremeII series Gigabit Ethernet cards. Thanks to a number of changes to the bnx2 driver for Broadcom chips, Broadcom hardware now takes care of much of the iSCSI work itself, thereby reducing CPU load ("iSCSI offload").

Thanks to passive OS fingerprinting, the Netfilter code can now partially detect the operating system deployed on the system from which network packets originate and can then subject packets to operating system-specific rule sets. The OSF project website includes example usages and links to a fingerprint collection. There is also a short LWN.net article with background information on the technology.

Next: The Dodgy Corner

« previous 1 2 3 4 5 6 next »