WORK IN PROGRESS

Summary: Linux 2.6.35

This page contains details about the main features included in the kernel core and the main subsystems. For details on architecture-specific changes and driver changes, check the page [wiki:Linux_2_6_35-DriversArch Linux_2_6_35-DriversArch]

TableOfContents()

1. Prominent features (the cool stuff)

1.1. Btrfs improvements

• Direct I/O support: Direct I/O is a technique used to bypass the filesystem cache. This harms performance, but it's widely used by high performance software like some databases, which like to implement their own cache. Code: [http://git.kernel.org/linus/4b46fce23349bfca781a32e2707a18328ca5ae22 (commit)]

• Complete -ENOSPC support: Linux 2.6.32 already added reliable -ENOSPC support for common filesystem usage, but some corner cases hit by volume management operations were not handled. The -ENOSPC code added in this version handles all difficult corner cases like space balancing, drive management, fsync logging and many others. Code: [http://git.kernel.org/linus/b742bb82f1676d50103ade0ba89bfb79debabe73 (commit 1], [http://git.kernel.org/linus/424499dbd0c4d88742bf581b5714b27fb44b9fef 2], [http://git.kernel.org/linus/5da9d01b66458b180a6bee0e637a1d0a3effc622 3], [http://git.kernel.org/linus/f0486c68e4bd9a06a5904d3eeb3a0d73a83befb8 4], [http://git.kernel.org/linus/a22285a6a32390195235171b89d157ed1a1fe932 5], [http://git.kernel.org/linus/0ca1f7ceb1991099ed5273885ebcf4323948c72e 6], [http://git.kernel.org/linus/8929ecfa50f266163832eeacfbc3642ed5eb83b6 7], [http://git.kernel.org/linus/d68fc57b7e3245cfacf2e3b47acfed1946a11786 8], [http://git.kernel.org/linus/4a500fd178c89b96fa166a2d9e7855df33429841 9], [http://git.kernel.org/linus/3fd0a5585eb98e074fb9934549c8d85c49756c0d 10] ,[http://git.kernel.org/linus/efa56464562991b8c24f965199888806bd8c4b38 11)]

1.2. XFS Delayed logging

• This version adds a logging (journaling) mode called delayed logging, which is very briefly modeled after the journaling mode in the ext3/4 and reiserfs filesystems. It allows to accumulated multiple asynchronous transactions in memory instead of possibly writing them out many times. The I/O bandwidth used for the log decreases by orders of magnitude and performance on metadata intensive workloads increases massively. The log disk format is not changed, only the in-memory data structures and code. This feature is experimental, so it's not recommended for final users or production servers. Those who want to test it can enable it with the "-o delaylog" mount option. Code: [http://git.kernel.org/linus/a9a745daadab26f13884ff26a50fa38247c11ce9 (commit 1], [http://git.kernel.org/linus/71e330b593905e40d6c5afa824d38ee02d70ce5f 2)]

2. Various core changes

• sysfs: Implement sysfs tagged directory support. [http://git.kernel.org/linus/3ff195b011d7decf501a4d55aeed312731094796 (commit)]

3. Filesystems

• OCFS2

  • Implement allocation reservations [http://git.kernel.org/linus/d02f00cc057809d96c044cc72d5b9809d59f7d49 (commit)], [http://git.kernel.org/linus/4fe370afaae49c57619bb0bedb75de7e7c168308 (commit)], [http://git.kernel.org/linus/e3b4a97dbe9741a3227c3ed857a0632532fcd386 (commit)], [http://git.kernel.org/linus/6b82021b9e91cd689fdffadbcdb9a42597bbe764 (commit)], [http://git.kernel.org/linus/83f92318fa33cc084e14e64dc903e605f75884c1 (commit)],

  • Optimize punching-hole code. [http://git.kernel.org/linus/c1631d4a484fbb498e35d661f1aebd64c86b66bf (commit)]

  • Discontiguous block groups. [http://git.kernel.org/linus/798db35f4649eac2778381c390ed7d12de9ec767 (commit)], [http://git.kernel.org/linus/4cbe4249d6586d5d88ef271e07302407a14c8443 (commit)], [http://git.kernel.org/linus/1a934c3e57594588c373aea858e4593cdfcba4f4 (commit)]

  • Make nointr a default mount option [http://git.kernel.org/linus/4b37fcb7d41ce3b9264b9562d6ffd62db9294bd1 (commit)]

• Squashfs: XATTR support [http://git.kernel.org/linus/67f66cc6c728de183d9d43c243cb163c1ebd8e04 (commit)], [http://git.kernel.org/linus/f41d207cbedecd82f797adcce83890aa96f1c9e9 (commit)], [http://git.kernel.org/linus/4b5397dc24ab12afaac85be3d0863b7f6eb8b0f0 (commit)], [http://git.kernel.org/linus/01e5b4e4e897fce8c7e6236bc933c9721c7ee237 (commit)]

• Ext2: Remove BKL from ext2 filesystem [http://git.kernel.org/linus/e0a5cbac029db69032758000c67465c2ed7a5736 (commit)]

• Ext4: check for a good block group before loading buddy pages [http://git.kernel.org/linus/8a57d9d61a6e361c7bb159dda797672c1df1a691 (commit)]

• UFS: permit mounting of Borderware filesystems [http://git.kernel.org/linus/d27d7a9a7838587fcdcc6f2b042f5610eb4984a1 (commit)]

4. Networking

5. Tracing/Profiling

6. Crypto

7. Virtualization

8. Block

9. Security

• TOMOYO: Add pathname grouping support. [http://git.kernel.org/linus/7762fbfffdbce8191f5236d5053b290035d3d749 (commit)]