#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 4.2 development cycle Linux 4.2 [https://lkml.org/lkml/2015/8/30/96 has been released] on 30 Aug 2015 /!\ /!\ Warning /!\ /!\ This page will be completed in the future (it will, really) = Prominent features = = Drivers and architectures = All the driver and architecture-specific changes can be found in the [http://kernelnewbies.org/Linux_4.2-DriversArch Linux_4.2-DriversArch] page. = Core (various) = * FS-Cache: Count culled objects and objects rejected due to lack of space, and the number of initialised operations, and show them in /proc/fs/fscache/stats [https://git.kernel.org/torvalds/c/03cdd0e4b9a98ae995b81cd8f58e992ec3f44ae2 commit], [https://git.kernel.org/torvalds/c/182d919b84902eece162c63ed3d476c8016b4197 commit] = File systems = * BTRFS * Show "subvol=" and "subvolid=" in /proc/mounts [https://git.kernel.org/torvalds/c/c8d3fe028f64054d75c72566efb9ecf3c75ee161 commit] * CIFS * Add (minimal) support for the new protocol dialect, SMB3.1.1 [https://git.kernel.org/torvalds/c/aab1893d5fbeb7c931e97189f54a71ab0ecbf4c7 commit], [https://git.kernel.org/torvalds/c/eed0e1753cbe7a30758ad2ee5e2742dd7fda2c41 commit], [https://git.kernel.org/torvalds/c/ebb3a9d4ba3babd19c83b96fc88fc9b0d2f7d2d6 commit], [https://git.kernel.org/torvalds/c/5f7fbf733c9dd6b58d40fa394313a5949b696f84 commit] * Add reflink copy support (cp --reflink ) over SMB3.11 [https://git.kernel.org/torvalds/c/02b1666544c08e245cb4e2253ed575f8128943d6 commit] * Add ioctl CIFS_IOC_SET_INTEGRITY to set integrity. Set integrity increases reliability of files stored on SMB3 servers [https://git.kernel.org/torvalds/c/b3152e2c7aa9ad0c50085738d048fbf16d01d32d commit] * GFS2 * Add support for rename2 and RENAME_EXCHANGE [https://git.kernel.org/torvalds/c/a63b7bbc2175901d79fa36ba734499655c077f0d commit] * NFS * NFSv4.2 LAYOUTSTATS functionality for pnfs flexfiles [https://git.kernel.org/torvalds/c/122d328d303afaa06ad530ca0b2e5be3cd50a1a5 (merge)] * NILFS2 * Support NFSv2 export [https://git.kernel.org/torvalds/c/f73c2f1f83ca1c4e2f4515f987973bfe56c86973 commit] * UDF * Support NFSv2 export [https://git.kernel.org/torvalds/c/92acca45428f28c0b387f85b52b230d526dd0ecc commit] = Memory management = = Block layer = * Make CFQ default to IOPS mode on SSDs [https://git.kernel.org/torvalds/c/41c0126b3f22ef36b97b3c38b8f29569848a5ce2 commit] * Addition of policy specific data to blkcg for block cgroups [https://git.kernel.org/torvalds/c/e48453c386f39ca9ea29e9df6efef78f56746af0 commit] * Add support for DAX reads/writes to block devices [https://git.kernel.org/torvalds/c/bbab37ddc20bae4709bca8745c128c4f46fe63c5 commit] * UBI: Dynamically allocate minor numbers [https://git.kernel.org/torvalds/c/2bf50d42f3a418153d2964ca0f25655177f36445 commit] = Cryptography = = Security = * selinux: enable genfscon labeling for sysfs and pstore files [https://git.kernel.org/torvalds/c/8e01472078763ebc1eaea089a1adab75dd982ccd commit] * selinux: enable per-file labeling for debugfs files. [https://git.kernel.org/torvalds/c/134509d54e4e98888be2697a92cb4b48957b792b commit] * Smack: allow multiple labels in onlycap [https://git.kernel.org/torvalds/c/c0d77c884461fc0dec0411e49797dc3f3651c31b commit] = Tracing and perf tool = * BPF * BPF based latency tracing [https://git.kernel.org/torvalds/c/0fb1170ee68a6aa14eca0666e02c4b62cbf1251d commit] * Allow BPF programs access skb->skb_iif and skb->dev->ifindex fields [https://git.kernel.org/torvalds/c/37e82c2f974b72c9ab49c787ef7b5bb1aec12768 commit] * Allow bpf programs to tail-call other bpf programs [https://git.kernel.org/torvalds/c/04fd61ab36ec065e194ab5e74ae34a5240d992bb commit] * Allow programs to write to certain skb fields [https://git.kernel.org/torvalds/c/d691f9e8d4405c334aa10d556e73c8bf44cb0e01 commit] * Disallow bpf tc programs access current->pid,uid [https://git.kernel.org/torvalds/c/89d256bb69f2596c3a31ac51466eac9e1791c388 commit] = Virtualization = * KVM * Implement multiple address spaces [https://git.kernel.org/torvalds/c/f481b069e674378758c73761827e83ab05c46b52 commit] * Hyper-V * file copy service: full handshake support [https://git.kernel.org/torvalds/c/a4d1ee5b0255a135fead1d62a7fc7e6fe718b66e commit] * vmbus: Implement NUMA aware CPU affinity for channels [https://git.kernel.org/torvalds/c/1f656ff3fdddc2f59649cc84b633b799908f1f7b commit] * vmbus: Implement the protocol for tearing down vmbus state [https://git.kernel.org/torvalds/c/2db84eff127e3f4b3635edc589cd6a56db8755a3 commit] * vss: full handshake support [https://git.kernel.org/torvalds/c/cd8dc0548511efff7a97d978f989ce67a883f9a5 commit] * Tools: kvp: use misc char device to communicate with kernel [https://git.kernel.org/torvalds/c/8ddca8088586303cfe3db4209a4682f7a4cf7d2d commit], vss: use misc char device to communicate with kernel [https://git.kernel.org/torvalds/c/f5722b9bd418e29b7429bd9a43bd100599b26d4f commit] = Networking = * bonding * Add netlink support for sys prio, actor sys mac, and port key, until now they were only exported via bond's proc entry [https://git.kernel.org/torvalds/c/171a42c38c6e1a5a076d6276e94e55a0b5b7868c commit] * Allow userspace to set actors' macaddr in an AD-system. [https://git.kernel.org/torvalds/c/74514957552edd4661a4608618121f3c71d4e891 commit] * Allow userspace to set actors' system_priority in AD system [https://git.kernel.org/torvalds/c/6791e4661c4bd3e9f193a84247f2c389578a4336 commit] * Implement user key part of port_key in an AD system. [https://git.kernel.org/torvalds/c/d22a5fc0c32edcf5c3bb973ee8c9a2606ba500a8 commit] * bridge: allow setting hash_max + multicast_router if interface is down [https://git.kernel.org/torvalds/c/6ae4ae8e512bd229f806c22f8a2cd751e4f987c2 commit] * wireless * cfg80211: allow the plink state blocking for user managed mesh [https://git.kernel.org/torvalds/c/4292504044a4fd4c5d9155dcb5c7b09ed6cbf611 commit] * Bluetooth * hci_core/mgmt: Introduce multi-adv list [https://git.kernel.org/torvalds/c/d2609b345ebf0547015a78588c4d7ad68c9ccf26 commit] * mgmt: program multi-adv on power on [https://git.kernel.org/torvalds/c/320b3bf7027b89821030e5e7c5fbd1f6aecb4af0 commit] * NFC: netlink: Implement vendor-specific command support [https://git.kernel.org/torvalds/c/9e58095f9660f88d6a2febe87d5073a6b2e9c399 commit] = List of merges = = Other news sites = * LWN merge window [https://lwn.net/Articles/648995/ part 1], [https://lwn.net/Articles/649652/ part 2], [https://lwn.net/Articles/650299/ part 3]