kernel/linux
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ synced 2026-11-06 18:57:23 +00:00
Code Issues Releases Packages Activity
No description
1,351,530 commits 117 branches 5,824 tags 6.2 GiB
  • C 96.8%
  • Assembly 0.9%
  • Rust 0.7%
  • Shell 0.6%
  • Python 0.5%
  • Other 0.3%
Find a file
Carlos Maiolino 4abb9052a7 large atomic writes for xfs [v12.1] 
Currently atomic write support for xfs is limited to writing a single
 block as we have no way to guarantee alignment and that the write covers
 a single extent.
 
 This series introduces a method to issue atomic writes via a
 software-based method.
 
 The software-based method is used as a fallback for when attempting to
 issue an atomic write over misaligned or multiple extents.
 
 For xfs, this support is based on reflink CoW support.
 
 The basic idea of this CoW method is to alloc a range in the CoW fork,
 write the data, and atomically update the mapping.
 
 Initial mysql performance testing has shown this method to perform ok.
 However, there we are only using 16K atomic writes (and 4K block size),
 so typically - and thankfully - this software fallback method won't be
 used often.
 
 For other FSes which want large atomics writes and don't support CoW, I
 think that they can follow the example in [0].
 
 Catherine is currently working on further xfstests for this feature,
 which we hope to share soon.
 
 About 17/17, maybe it can be omitted as there is no strong demand to have
 it included.
 
 Based on bfecc4091e (xfs/next-rc, xfs/for-next) xfs: allow ro mounts
 if rtdev or logdev are read-only
 
 [0] https://lore.kernel.org/linux-xfs/20250102140411.14617-1-john.g.garry@oracle.com/
 
 Differences to v12:
 - add more review tags
 
 Differences to v11:
 - split "xfs: ignore ..." patch
 - inline sync_blockdev() in xfs_alloc_buftarg() (Christoph)
 - fix xfs_calc_rtgroup_awu_max() for 0 block count (Darrick)
 - Add RB tag from Christoph (thanks!)
 
 Differences to v10:
 - add "xfs: only call xfs_setsize_buftarg once ..." by Darrick
 - symbol renames in "xfs: ignore HW which cannot..." by Darrick
 
 Differences to v9:
 - rework "ignore HW which cannot .." patch by Darrick
 - Ensure power-of-2 max always for unit min/max when no HW support
 
 With a bit of luck, this should all go splendidly.
 
 Signed-off-by: "Darrick J. Wong" <djwong@kernel.org>
 -----BEGIN PGP SIGNATURE-----
 
 iHUEABYKAB0WIQQ2qTKExjcn+O1o2YRKO3ySh0YRpgUCaBvPzwAKCRBKO3ySh0YR
 pkDWAP9Znh9MKUMGDDTn0LH2V57VbZXjtwv9MjBomWcc4yVL0AD9HpAv38+zjInL
 OGgrUvEk4HxdDtGtPkYIOlXoegpioAc=
 =D/6o
 -----END PGP SIGNATURE-----

Merge tag 'atomic-writes-6.16_2025-05-07' of https://git.kernel.org/pub/scm/linux/kernel/git/djwong/xfs-linux into atomic_writes

large atomic writes for xfs [v12.1]

Currently atomic write support for xfs is limited to writing a single
block as we have no way to guarantee alignment and that the write covers
a single extent.

This series introduces a method to issue atomic writes via a
software-based method.

The software-based method is used as a fallback for when attempting to
issue an atomic write over misaligned or multiple extents.

For xfs, this support is based on reflink CoW support.

The basic idea of this CoW method is to alloc a range in the CoW fork,
write the data, and atomically update the mapping.

Initial mysql performance testing has shown this method to perform ok.
However, there we are only using 16K atomic writes (and 4K block size),
so typically - and thankfully - this software fallback method won't be
used often.

For other FSes which want large atomics writes and don't support CoW, I
think that they can follow the example in [0].

Catherine is currently working on further xfstests for this feature,
which we hope to share soon.

About 17/17, maybe it can be omitted as there is no strong demand to have
it included.

Based on bfecc4091e (xfs/next-rc, xfs/for-next) xfs: allow ro mounts
if rtdev or logdev are read-only

[0] https://lore.kernel.org/linux-xfs/20250102140411.14617-1-john.g.garry@oracle.com/

Differences to v12:
- add more review tags

Differences to v11:
- split "xfs: ignore ..." patch
- inline sync_blockdev() in xfs_alloc_buftarg() (Christoph)
- fix xfs_calc_rtgroup_awu_max() for 0 block count (Darrick)
- Add RB tag from Christoph (thanks!)

Differences to v10:
- add "xfs: only call xfs_setsize_buftarg once ..." by Darrick
- symbol renames in "xfs: ignore HW which cannot..." by Darrick

Differences to v9:
- rework "ignore HW which cannot .." patch by Darrick
- Ensure power-of-2 max always for unit min/max when no HW support

With a bit of luck, this should all go splendidly.

Signed-off-by: "Darrick J. Wong" <djwong@kernel.org>
History 2025-05-09 09:15:39 +02:00
arch
block
certs
crypto
Documentation
drivers
fs
include
init
io_uring
ipc
kernel
lib
LICENSES
mm
net
rust
samples
scripts
security
sound
tools
usr
virt
.clang-format
.clippy.toml
.cocciconfig
.editorconfig
.get_maintainer.ignore
.gitattributes
.gitignore
.mailmap
.rustfmt.toml
COPYING
CREDITS
Kbuild
Kconfig
MAINTAINERS
Makefile
README

README 

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

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.