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Linus Torvalds 5903c871e2 New features and improvements for the ext4 file system
* Avoid unnecessary cache invadiation in the extent status cache
     (es_cache) when adding extents to be cached in the es_cache and we
     are not changing the extent tree.
   * Add a sysfs parameter, err_report_sec, to control how frequently
     to log a warning message that file system inconsistency has been
     detected.  (Previously we logged the warning message every 24
     hours.)
   * Avoid unnecessary forced ordered writes when appending to a file
     when delayed allocation is enabled.
   * Defer splitting unwritten extents to I/O completion to improve
     write performance of concurrent direct I/O writes to multiple
     files.
   * Refactor and add kunit tests to the extent splitting and
     conversion code paths.
 
 Various Bug Fixes
 
   * Fix a panic when the debugging DOUBLE_CHECK macro is defined.
   * Avoid using fast commit for rare and complex file system
     operations to make fast commit easier to reason about.  This can
     also avoid some corner cases that could result in file system
     inconsistency if there is a crash between the fast commit before a
     subsequent full commit.
   * Fix memory leaks in error paths
   * Fix a false positive reports caused when running stress tests
     using mixed huge-page workloads caused by a race between page
     migration and bitmap updates.
   * Fix a potential recursion into file system reclaim when evicting
     an inode when fast commit is enabled.
   * Fix a warning caused by a potential double decrement to the dirty
     clusters counter when executing FS_IOC_SHUTDOWN when running a
     stress test.
   * Enable mballoc optimzied scanning regardless whether the inode is
     using indirect blocks or extent trees to map blocks.
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Merge tag 'ext4_for_linus-7.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

Pull ext4 updates from Ted Ts'o:
 "New features and improvements for the ext4 file system

   - Avoid unnecessary cache invalidation in the extent status cache
     (es_cache) when adding extents to be cached in the es_cache and we
     are not changing the extent tree

   - Add a sysfs parameter, err_report_sec, to control how frequently to
     log a warning message that file system inconsistency has been
     detected (Previously we logged the warning message every 24 hours)

   - Avoid unnecessary forced ordered writes when appending to a file
     when delayed allocation is enabled

   - Defer splitting unwritten extents to I/O completion to improve
     write performance of concurrent direct I/O writes to multiple files

   - Refactor and add kunit tests to the extent splitting and conversion
     code paths

  Various Bug Fixes:

   - Fix a panic when the debugging DOUBLE_CHECK macro is defined

   - Avoid using fast commit for rare and complex file system operations
     to make fast commit easier to reason about. This can also avoid
     some corner cases that could result in file system inconsistency if
     there is a crash between the fast commit before a subsequent full
     commit

   - Fix memory leaks in error paths

   - Fix a false positive reports caused when running stress tests using
     mixed huge-page workloads caused by a race between page migration
     and bitmap updates

   - Fix a potential recursion into file system reclaim when evicting an
     inode when fast commit is enabled

   - Fix a warning caused by a potential double decrement to the dirty
     clusters counter when executing FS_IOC_SHUTDOWN when running a
     stress test

   - Enable mballoc optimized scanning regardless whether the inode is
     using indirect blocks or extent trees to map blocks"

* tag 'ext4_for_linus-7.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (45 commits)
  et4: allow zeroout when doing written to unwritten split
  ext4: refactor split and convert extents
  ext4: refactor zeroout path and handle all cases
  ext4: propagate flags to ext4_convert_unwritten_extents_endio()
  ext4: propagate flags to convert_initialized_extent()
  ext4: add extent status cache support to kunit tests
  ext4: kunit tests for higher level extent manipulation functions
  ext4: kunit tests for extent splitting and conversion
  ext4: use optimized mballoc scanning regardless of inode format
  ext4: always allocate blocks only from groups inode can use
  ext4: fix dirtyclusters double decrement on fs shutdown
  ext4: fast commit: make s_fc_lock reclaim-safe
  ext4: fix e4b bitmap inconsistency reports
  ext4: remove redundant NULL check after __GFP_NOFAIL
  ext4: remove EXT4_GET_BLOCKS_IO_CREATE_EXT
  ext4: simplify the mapping query logic in ext4_iomap_begin()
  ext4: remove unused unwritten parameter in ext4_dio_write_iter()
  ext4: remove useless ext4_iomap_overwrite_ops
  ext4: avoid starting handle when dio writing an unwritten extent
  ext4: don't split extent before submitting I/O
  ...
2026-02-12 10:19:58 -08:00
Documentation NFSD 7.0 Release Notes 2026-02-12 08:23:53 -08:00
LICENSES LICENSES: Add modern form of the LGPL-2.1 tags to the usage guide section 2025-10-22 07:58:19 +02:00
arch Networking changes for 7.0 2026-02-11 19:31:52 -08:00
block The kthread code provides an infrastructure which manages the preferred 2026-02-09 19:57:30 -08:00
certs modsign: Enable ML-DSA module signing 2026-02-02 16:57:39 +00:00
crypto Locking updates for v6.20: 2026-02-10 12:28:44 -08:00
drivers 32 ksmbd and smbdirect fixes 2026-02-12 08:31:12 -08:00
fs New features and improvements for the ext4 file system 2026-02-12 10:19:58 -08:00
include New features and improvements for the ext4 file system 2026-02-12 10:19:58 -08:00
init Kbuild/Kconfig updates for 7.0 2026-02-11 13:40:35 -08:00
io_uring for-7.0/block-20260206 2026-02-09 17:57:21 -08:00
ipc mqueue: switch to CLASS(filename) 2026-01-16 12:52:04 -05:00
kernel Networking changes for 7.0 2026-02-11 19:31:52 -08:00
lib Networking changes for 7.0 2026-02-11 19:31:52 -08:00
mm IOMMU Updates for Linux v7.0 2026-02-11 16:36:08 -08:00
net NFSD 7.0 Release Notes 2026-02-12 08:23:53 -08:00
rust Networking changes for 7.0 2026-02-11 19:31:52 -08:00
samples Driver core changes for 7.0-rc1 2026-02-11 17:43:59 -08:00
scripts Devicetree updates for v7.0: 2026-02-11 18:27:08 -08:00
security Landlock update for v7.0-rc1 2026-02-11 15:57:08 -08:00
sound sound updates for 7.0-rc1 2026-02-11 11:43:00 -08:00
tools NFSD 7.0 Release Notes 2026-02-12 08:23:53 -08:00
usr kbuild: uapi: drop dependency on CC_CAN_LINK 2026-01-16 15:02:11 -07:00
virt Performance events changes for v7.0: 2026-02-10 12:00:46 -08:00
.clang-format Devicetree updates for v7.0: 2026-02-11 18:27:08 -08:00
.clippy.toml rust: clean Rust 1.88.0's warning about `clippy::disallowed_macros` configuration 2025-05-07 00:11:47 +02:00
.cocciconfig
.editorconfig .editorconfig: remove trim_trailing_whitespace option 2024-06-13 16:47:52 +02:00
.get_maintainer.ignore MAINTAINERS: remove Alyssa Rosenzweig 2025-09-18 21:17:31 +02:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore rust: kbuild: add proc macro library support 2025-11-24 17:15:36 +01:00
.mailmap Landlock update for v7.0-rc1 2026-02-11 15:57:08 -08:00
.pylintrc docs: Move the python libraries to tools/lib/python 2025-11-18 09:22:40 -07:00
.rustfmt.toml rust: add `.rustfmt.toml` 2022-09-28 09:02:20 +02:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS Networking changes for 7.0 2026-02-11 19:31:52 -08:00
Kbuild sched: Make migrate_{en,dis}able() inline 2025-09-25 09:57:16 +02:00
Kconfig io_uring: Rename KConfig to Kconfig 2025-02-19 14:53:27 -07:00
MAINTAINERS Networking changes for 7.0 2026-02-11 19:31:52 -08:00
Makefile Devicetree updates for v7.0: 2026-02-11 18:27:08 -08:00
README docs: add AI Coding Assistants documentation 2026-01-06 14:55:06 -07:00

README

Linux kernel
============

The Linux kernel is the core of any Linux operating system. It manages hardware,
system resources, and provides the fundamental services for all other software.

Quick Start
-----------

* Report a bug: See Documentation/admin-guide/reporting-issues.rst
* Get the latest kernel: https://kernel.org
* Build the kernel: See Documentation/admin-guide/quickly-build-trimmed-linux.rst
* Join the community: https://lore.kernel.org/

Essential Documentation
-----------------------

All users should be familiar with:

* Building requirements: Documentation/process/changes.rst
* Code of Conduct: Documentation/process/code-of-conduct.rst
* License: See COPYING

Documentation can be built with make htmldocs or viewed online at:
https://www.kernel.org/doc/html/latest/


Who Are You?
============

Find your role below:

* New Kernel Developer - Getting started with kernel development
* Academic Researcher - Studying kernel internals and architecture
* Security Expert - Hardening and vulnerability analysis
* Backport/Maintenance Engineer - Maintaining stable kernels
* System Administrator - Configuring and troubleshooting
* Maintainer - Leading subsystems and reviewing patches
* Hardware Vendor - Writing drivers for new hardware
* Distribution Maintainer - Packaging kernels for distros
* AI Coding Assistant - LLMs and AI-powered development tools


For Specific Users
==================

New Kernel Developer
--------------------

Welcome! Start your kernel development journey here:

* Getting Started: Documentation/process/development-process.rst
* Your First Patch: Documentation/process/submitting-patches.rst
* Coding Style: Documentation/process/coding-style.rst
* Build System: Documentation/kbuild/index.rst
* Development Tools: Documentation/dev-tools/index.rst
* Kernel Hacking Guide: Documentation/kernel-hacking/hacking.rst
* Core APIs: Documentation/core-api/index.rst

Academic Researcher
-------------------

Explore the kernel's architecture and internals:

* Researcher Guidelines: Documentation/process/researcher-guidelines.rst
* Memory Management: Documentation/mm/index.rst
* Scheduler: Documentation/scheduler/index.rst
* Networking Stack: Documentation/networking/index.rst
* Filesystems: Documentation/filesystems/index.rst
* RCU (Read-Copy Update): Documentation/RCU/index.rst
* Locking Primitives: Documentation/locking/index.rst
* Power Management: Documentation/power/index.rst

Security Expert
---------------

Security documentation and hardening guides:

* Security Documentation: Documentation/security/index.rst
* LSM Development: Documentation/security/lsm-development.rst
* Self Protection: Documentation/security/self-protection.rst
* Reporting Vulnerabilities: Documentation/process/security-bugs.rst
* CVE Procedures: Documentation/process/cve.rst
* Embargoed Hardware Issues: Documentation/process/embargoed-hardware-issues.rst
* Security Features: Documentation/userspace-api/seccomp_filter.rst

Backport/Maintenance Engineer
-----------------------------

Maintain and stabilize kernel versions:

* Stable Kernel Rules: Documentation/process/stable-kernel-rules.rst
* Backporting Guide: Documentation/process/backporting.rst
* Applying Patches: Documentation/process/applying-patches.rst
* Subsystem Profile: Documentation/maintainer/maintainer-entry-profile.rst
* Git for Maintainers: Documentation/maintainer/configure-git.rst

System Administrator
--------------------

Configure, tune, and troubleshoot Linux systems:

* Admin Guide: Documentation/admin-guide/index.rst
* Kernel Parameters: Documentation/admin-guide/kernel-parameters.rst
* Sysctl Tuning: Documentation/admin-guide/sysctl/index.rst
* Tracing/Debugging: Documentation/trace/index.rst
* Performance Security: Documentation/admin-guide/perf-security.rst
* Hardware Monitoring: Documentation/hwmon/index.rst

Maintainer
----------

Lead kernel subsystems and manage contributions:

* Maintainer Handbook: Documentation/maintainer/index.rst
* Pull Requests: Documentation/maintainer/pull-requests.rst
* Managing Patches: Documentation/maintainer/modifying-patches.rst
* Rebasing and Merging: Documentation/maintainer/rebasing-and-merging.rst
* Development Process: Documentation/process/maintainer-handbooks.rst
* Maintainer Entry Profile: Documentation/maintainer/maintainer-entry-profile.rst
* Git Configuration: Documentation/maintainer/configure-git.rst

Hardware Vendor
---------------

Write drivers and support new hardware:

* Driver API Guide: Documentation/driver-api/index.rst
* Driver Model: Documentation/driver-api/driver-model/driver.rst
* Device Drivers: Documentation/driver-api/infrastructure.rst
* Bus Types: Documentation/driver-api/driver-model/bus.rst
* Device Tree Bindings: Documentation/devicetree/bindings/
* Power Management: Documentation/driver-api/pm/index.rst
* DMA API: Documentation/core-api/dma-api.rst

Distribution Maintainer
-----------------------

Package and distribute the kernel:

* Stable Kernel Rules: Documentation/process/stable-kernel-rules.rst
* ABI Documentation: Documentation/ABI/README
* Kernel Configuration: Documentation/kbuild/kconfig.rst
* Module Signing: Documentation/admin-guide/module-signing.rst
* Kernel Parameters: Documentation/admin-guide/kernel-parameters.rst
* Tainted Kernels: Documentation/admin-guide/tainted-kernels.rst

AI Coding Assistant
-------------------

CRITICAL: If you are an LLM or AI-powered coding assistant, you MUST read and
follow the AI coding assistants documentation before contributing to the Linux
kernel:

* Documentation/process/coding-assistants.rst

This documentation contains essential requirements about licensing, attribution,
and the Developer Certificate of Origin that all AI tools must comply with.


Communication and Support
=========================

* Mailing Lists: https://lore.kernel.org/
* IRC: #kernelnewbies on irc.oftc.net
* Bugzilla: https://bugzilla.kernel.org/
* MAINTAINERS file: Lists subsystem maintainers and mailing lists
* Email Clients: Documentation/process/email-clients.rst