LKML Summary Podcast

Audio: http://media.libsyn.com/media/jcm/linux_kernel_podcast_20090701.mp3

For Canada Day (Wednesday, July 1st 2009), I’m Jon Masters with a summary of today’s LKML traffic.

In today’s issue: Encrypting the page cache, VFAT, and XFS.

Encrypting the page cache. There is an RFC floating around from Jeremy Maitin-Shepard for TuxOnIce (the out-of-tree alternative suspend code) concerning encrypting the page cache in RAM on suspend-to-RAM so that the system cannot be cold booted into another kernel and its memory content analyzed. Such an attack is not too far fetched – research over the past few years has shown that it is not only feasible but is also actively being used. The only real concern surrounding this seems to be the overhead involved, though it is likely to be a configurable option, if Jeremy follows up to the RFC with some patches.

VFAT. Ongoing discussion of the VFAT patch proposed by Andrew Tridgell seems to have headed toward changes to VFAT support possibly necessitating that the additional configuration options be part of a new (perhaps aptly named) alternative VFAT filesystem. Posters have pointed out that some windows systems choke when working with these patches and we probably don’t want those systems to bluescreen when reading from disks written to using Linux systems. As an aside, this author is always amused by the configurable nature of the Windows bluescreen – I recall a much younger version of myself in college winding up Microsoft support one day by inquiring about the registry codes to set the bluescreen background colour. Childish for sure, but I recall it being quite fun at the time – there are sixteen glorious color options!

XFS. Christoph Hellwig posted an updated about XFS support, in which he noted that the 2.6.30 kernel had incorporated fixes for ENOSPC handling, and had additionally shrunk by 500 lines in the latest release. He notes that in the current merge window, quotaops went away (which simplifies quotas), and XFS dropped its own POSIX ACL implementation in favor of the generic in-kernel one. This author recently noticed Andreas updated his acl git tree with a note that the official location for those bits is now Savannaih, as Christoph mentions in his summary also. Seems like an exciting time for XFS again.

Miscellaneous fixes include: fixes to round_up/down from H Peter Anvin, some minor Super-H updates from Paul Mundt, some race fixes for irqfd/eventfd from Gregory Haskins, some fixes for FUSE (Miklos Szeredi) that include a couple of minor features which might not be allowed in rc2, cache events in perf from Jaswinder Singh Rajput (kudos to you, jaswinder, for your continued efforts to make cleanups and fixes to the kernel – it doesn’t all go unnoticed either), a per-GPIO sysfs symlinking naming patch from Jani Nikula, a scheduling while atomic bug introduced by kmemleak is fixed by a patch from Ingo Molnar, a disabling of CLONE_PARENT for the init task from Sukadev Bhattiprolu, a large number of networking bits from David Miller (including an important SCTP fix), some md updates from Neil Brown (implementing mostly the new ‘topology’ numbers), version 6 of the Intel Trusted Execution (Boot) Technology covered several times previously in this podcast, and some block bits for 2.6.31-rc2 from Jens Axboe (incuding a removal of __GFP_NOFAIL misuse in CFQ that was debated a little over last week). Steven Rostedt noticed that the gcov patches don’t protect against modification to vsyscall memory (as his ftrace patches do) so fail to boot on his test system, falling over inside the initrd init.

This podcast is now two months old. You’ll notice we’re a little behind again this week (it won’t get any easier next week as your author is in Japan only from Monday to Friday and will be fighting severe jetlag over the next two weekends in addition to being on planes for 32 hours and trying to write a chapter on the plane). It’s tricky to do a podcast every day, but I enjoy it, so I plan instead to continue to make a best effort – and occasionally live with being a few days out of sync. If you would like to see a guaranteed daily service, feel free to volunteer to help do that. Meanwhile, I’ll keep the podcasts coming, you just keep listening and sending me those nice mails. And if you happen to be in Tokyo on an evening next week, let’s have some coffee!

In today’s announcements: LTTng 0.142. Mathieu Desnoyers announced version 0.142 of LTTng. This includes a fix to text poke he posted about previously. Also, the Linux Test Project has been released for June 2009. Subrata Modak posted to let us know that 6 testcases have been added covering 5 new system calls, major syscall and powermanagement test fixes have been added, and a number of additional test fixes have been added. The healthy number of contributors to June 2009 LTP include the ever-involved Darren Hart and a large number of others also. And this is certainly a worthy project to help out on if you’ve got some spare cycles these days.

The latest kernel release is 2.6.31-rc1, which was released by Linus last week.

Greg Kroah-Hartman is preparing new .27, .29, and .30 stable releases for which he sent out 30, 35 and a whopping 108 proposed patches respectively for review on Tuesday evening ahead of a deadline on Friday morning.

Stephen Rothwell posted a linux-next tree for July 1st. He dropped the new “sfi” tree due to build problems, powerpc still fails allyesconfig, and the tree overall gained conflicts over the previous day. The total sub-tree count is now up to 132 trees in the current linux-next compose.

That’s a summary of today’s Linux Kernel Mailing List traffic, for further information visit www.kernel.org. I’m Jon Masters.