#pragma section-numbers on
#pragma keywords Linux, kernel, operating system, changes, changelog, file system, Linus Torvalds, open source, device drivers
#pragma description Summary of the changes and new features merged in the Linux kernel during the 4.0 development cycle

Linux 4.0 [https://lkml.org/lkml/2015/4/12/178 has been released] on Sun, 12 Apr 2015.


This page is not complete. It will be completed in the next few days. Meanwhile, you can read about Linux 4.0 in other sites:
 * LWN: [http://lwn.net/Articles/632761/ The merge window opens], [http://lwn.net/Articles/633096/ merge window part 2], [http://lwn.net/Articles/634471/ The end of the 4.0 merge window]



= File systems =
 * UBIFS
  * Add security.* XATTR support for the UBIFS [http://git.kernel.org/linus/d7f0b70d30ffb9bbe6b8a3e1035cf0b79965ef53 commit]
  * Add xattr support for symlinks [http://git.kernel.org/linus/895d9db253a0b0b1f8a6e635fb2460d80bf72d5a commit]


= Block =
 * loop: Add blk-mq support, which greatly improves performance for sequential and random reads [http://git.kernel.org/linus/b5dd2f6047ca108001328aac0e8588edd15f1778 commit]
 * UBI: Add blk-mq support [http://git.kernel.org/linus/ff1f48ee3bb3af226f1f8993af0103794b4d4eab commit]
 * UBI: Implement UBI_METAONLY, a new open mode for UBI volumes, it indicates that only meta data is being changed [http://git.kernel.org/linus/fafdd2bf2638157670f28462b641150d16dbaeca commit]

= Virtualization =

 * vmxnet3: Make Rx ring 2 size configurable [http://git.kernel.org/linus/53831aa12538f8753fb77b7ab6408cce54973b30 commit]


= Security =
 * Add security hooks to the Android binder that enable security modules such as SELinux to implement controls over binder IPC. The security hooks include support for controlling what process can become the binder context manager, invoke a binder transaction/IPC to another process, transfer a binder reference to another process , transfer an open file to another process. These hooks have been included in the Android kernel trees since Android 4.3 [http://git.kernel.org/linus/79af73079d753b2d04e46f7445716d3b5f914dbd commit]
 * Smack: secmark support for netfilter [http://git.kernel.org/linus/69f287ae6fc8357e0bc561353a2d585b89ee8cdc commit]

= Networking =
 * Infiniband: Add support for extensible query device capabilities verb to allow adding new features [http://git.kernel.org/linus/02d1aa7af17ef0e0655745ce32cab369ed040a67 commit]

 * SUNRPC: Set SO_REUSEPORT socket option for TCP connections to bind multiple TCP connections to the same source address+port combination [http://git.kernel.org/linus/4dda9c8a5e34773b290c6b5938ccb36e7fcdf35c commit]

 * bridge
  * offload bridge port attributes to switch asic if feature flag set [http://git.kernel.org/linus/68e331c785b85b78f4155e2ab6f90e976b609dc1 commit]
  * Support for allowing userspace to pack multiple vlans and vlan ranges in setlink and dellink requests for improved performance [http://git.kernel.org/linus/bdced7ef7838c1c4aebe9f295e44b7f0dcae2109 commit]
  * Add ability to enable TSO [http://git.kernel.org/linus/f902e8812ef657c6cf744ac25e21865217155460 commit]

 * Near Field Communication (NFC)
  * HCI over NCI protocol support (Some secure elements only understand HCI and thus we need to send them HCI frames) [http://git.kernel.org/linus/11f54f228643d0248ec00ce8c9fb8d872f87e7b8 commit]
  * NCI NFCEE (NFC Execution Environment, typically an embedded or external secure element) discovery and enabling/disabling support [http://git.kernel.org/linus/8277f6937ae97c51ced5b54faa4934613c76999c commit], [http://git.kernel.org/linus/af9c8aa67d07adcd3b41fb2934af7af056eabecf commit], [http://git.kernel.org/linus/f7f793f31378d5e83276871339c2a8374b0e8657 commit], [http://git.kernel.org/linus/a41bb8448ebaebe1d0d9a268d340fad73c247e09 commit], [http://git.kernel.org/linus/4aeee6871e8c3b043ef02996db8ac70a1af8be92 commit], [http://git.kernel.org/linus/6095b0f07d9b1abd98484bc33b329e06a684115b commit], [http://git.kernel.org/linus/736bb9577407d3556d81c3c3cd57581cd3ae10ea commit]
  * NFC_EVT_TRANSACTION userspace API addition, it is sent through netlink in order for a specific application running on a secure element to notify userspace of an event [http://git.kernel.org/linus/447b27c4f29b510b98e99395120d635f009ed563 commit]