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Linus Torvalds fbeea4db51 New features and improvements for the ext4 file system
* Optimize online defragmentation by using folios instead of individual
   buffer heads
 * Improve error codes stored in the superblock when the journal aborts
 * Minor cleanups and clarifications in ext4_map_blocks()
 * Add documentation of the casefold and encrypt flags
 * Add support for file systems with a blocksize greater than the pagesize
 * Improve performance by enabling the caching the fact that an inode does
   not have a Posix ACL.
 
 Various Bug Fixes
 
 * Fix false positive compliants from smatch
 * Fix error code which is returned by ext4fs_dirhash() when Siphash is
   used without the encryption key
 * Fix races when writing to inline data files which could trigger a BUG
 * Fix potential NULL dereference when there is an corrupt file system with
   an extended attribute value stored in a inode
 * Fix false positive lockdep report when syzbot uses ext4 and ocfs2 together
 * Fix false positive reported by DEPT by adjusting lock annotation
 * Avoid a potential BUG_ON in jbd2 when a file system is massively corrupted
 * Fix a WARN_ON when superblock is corrupted with a non-NULL terminated
   mount options field
 * Add check if the userspace passes in a non-NULL terminated mount options
   field to EXT4_IOC_SET_TUNE_SB_PARAM
 * Fix a potential journal checksum failure whena file system is copied while
   it is mounted read-only
 * Fix a potential potential orphan file tracking error which only showed
   on 32-bit systems
 * Fix assertion checks in mballoc (which have to be explicitly enbled by
   manually enabling AGGRESSIVE_CHECKS and recompiling)
 * Avoid complaining about overly large orphan files created by mke2fs with
   with file systems with a 64k block size
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Merge tag 'ext4_for_linus-6.19-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:
   - Optimize online defragmentation by using folios instead of
     individual buffer heads
   - Improve error codes stored in the superblock when the journal
     aborts
   - Minor cleanups and clarifications in ext4_map_blocks()
   - Add documentation of the casefold and encrypt flags
   - Add support for file systems with a blocksize greater than the
     pagesize
   - Improve performance by enabling the caching the fact that an inode
     does not have a Posix ACL

  Various Bug Fixes:
   - Fix false positive complaints from smatch
   - Fix error code which is returned by ext4fs_dirhash() when Siphash
     is used without the encryption key
   - Fix races when writing to inline data files which could trigger a
     BUG
   - Fix potential NULL dereference when there is an corrupt file system
     with an extended attribute value stored in a inode
   - Fix false positive lockdep report when syzbot uses ext4 and ocfs2
     together
   - Fix false positive reported by DEPT by adjusting lock annotation
   - Avoid a potential BUG_ON in jbd2 when a file system is massively
     corrupted
   - Fix a WARN_ON when superblock is corrupted with a non-NULL
     terminated mount options field
   - Add check if the userspace passes in a non-NULL terminated mount
     options field to EXT4_IOC_SET_TUNE_SB_PARAM
   - Fix a potential journal checksum failure whena file system is
     copied while it is mounted read-only
   - Fix a potential potential orphan file tracking error which only
     showed on 32-bit systems
   - Fix assertion checks in mballoc (which have to be explicitly enbled
     by manually enabling AGGRESSIVE_CHECKS and recompiling)
   - Avoid complaining about overly large orphan files created by mke2fs
     with with file systems with a 64k block size"

* tag 'ext4_for_linus-6.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (58 commits)
  ext4: mark inodes without acls in __ext4_iget()
  ext4: enable block size larger than page size
  ext4: add checks for large folio incompatibilities when BS > PS
  ext4: support verifying data from large folios with fs-verity
  ext4: make data=journal support large block size
  ext4: support large block size in __ext4_block_zero_page_range()
  ext4: support large block size in mpage_prepare_extent_to_map()
  ext4: support large block size in mpage_map_and_submit_buffers()
  ext4: support large block size in ext4_block_write_begin()
  ext4: support large block size in ext4_mpage_readpages()
  ext4: rename 'page' references to 'folio' in multi-block allocator
  ext4: prepare buddy cache inode for BS > PS with large folios
  ext4: support large block size in ext4_mb_init_cache()
  ext4: support large block size in ext4_mb_get_buddy_page_lock()
  ext4: support large block size in ext4_mb_load_buddy_gfp()
  ext4: add EXT4_LBLK_TO_PG and EXT4_PG_TO_LBLK for block/page conversion
  ext4: add EXT4_LBLK_TO_B macro for logical block to bytes conversion
  ext4: support large block size in ext4_readdir()
  ext4: support large block size in ext4_calculate_overhead()
  ext4: introduce s_min_folio_order for future BS > PS support
  ...
2025-12-03 20:37:15 -08:00
Documentation New features and improvements for the ext4 file system 2025-12-03 20:37:15 -08:00
LICENSES LICENSES: Replace the obsolete address of the FSF in the GFDL-1.2 2025-07-24 11:15:39 +02:00
arch Networking changes for 6.19. 2025-12-03 17:24:33 -08:00
block for-6.19/block-20251201 2025-12-03 19:26:18 -08:00
certs sign-file,extract-cert: use pkcs11 provider for OPENSSL MAJOR >= 3 2024-09-20 19:52:48 +03:00
crypto Networking changes for 6.19. 2025-12-03 17:24:33 -08:00
drivers for-6.19/block-20251201 2025-12-03 19:26:18 -08:00
fs New features and improvements for the ext4 file system 2025-12-03 20:37:15 -08:00
include New features and improvements for the ext4 file system 2025-12-03 20:37:15 -08:00
init Kbuild updates for v6.19 2025-12-03 14:42:21 -08:00
io_uring for-6.19/io_uring-20251201 2025-12-03 18:58:57 -08:00
ipc vfs-6.19-rc1.fd_prepare.fs 2025-12-01 17:32:07 -08:00
kernel for-6.19/block-20251201 2025-12-03 19:26:18 -08:00
lib for-6.19/block-20251201 2025-12-03 19:26:18 -08:00
mm slab updates for 6.19 2025-12-03 11:53:47 -08:00
net for-6.19/io_uring-20251201 2025-12-03 18:58:57 -08:00
rust for-6.19/block-20251201 2025-12-03 19:26:18 -08:00
samples Networking changes for 6.19. 2025-12-03 17:24:33 -08:00
scripts Kbuild updates for v6.19 2025-12-03 14:42:21 -08:00
security This update includes the following changes: 2025-12-03 11:28:38 -08:00
sound ALSA: hda/realtek: Add quirk for HP ProBook 450 G8 2025-11-26 07:26:56 +01:00
tools for-6.19/block-20251201 2025-12-03 19:26:18 -08:00
usr initramfs: add gen_init_cpio to hostprogs unconditionally 2025-11-26 21:55:40 +01:00
virt A large overhaul of the restartable sequences and CID management: 2025-12-02 08:48:53 -08:00
.clang-format memblock: drop for_each_free_mem_pfn_range_in_zone_from() 2025-09-14 08:49:03 +03:00
.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 Kbuild updates for v6.19 2025-12-03 14:42:21 -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
CREDITS MAINTAINERS: mark ISDN subsystem as orphan 2025-10-27 17:49:45 -07:00
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 gfs2 changes 2025-12-03 20:28:50 -08:00
Makefile Kbuild updates for v6.19 2025-12-03 14:42:21 -08:00
README README: restructure with role-based documentation and guidelines 2025-11-29 08:40:33 -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


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



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