[PATCH v2 0/7] large atomic writes for xfs

John Garry
2024-12-10T12:58:06Z

Currently the atomic write unit min and max is fixed at the FS blocksize
for xfs and ext4.

This series expands support to allow multiple FS blocks to be written
atomically.

To allow multiple blocks be written atomically, the fs must ensure blocks
are allocated with some alignment and granularity. For xfs, today only
rtvol provides this through rt_extsize. So initial support for large
atomic writes will be for rtvol here. Support can easily be expanded to
regular files through the proposed forcealign feature.

An atomic write which spans mixed unwritten and mapped extents will be
required to have the unwritten extents pre-zeroed, which will be supported
in iomap.

Based on v6.13-rc2.

Patches available at the following:
https://github.com/johnpgarry/linux/tree/atomic-write-large-atomics-v6.13-v2

Changes since v1:
- Add extent zeroing support
- Rebase

John Garry (6):
iomap: Increase iomap_dio_zero() size limit
iomap: Add zero unwritten mappings dio support
xfs: Add extent zeroing support for atomic writes
xfs: Switch atomic write size check in xfs_file_write_iter()
xfs: Add RT atomic write unit max to xfs_mount
xfs: Update xfs_get_atomic_write_attr() for large atomic writes

Ritesh Harjani (IBM) (1):
iomap: Lift blocksize restriction on atomic writes

fs/iomap/direct-io.c | 100 +++++++++++++++++++++++++++++++++++++----
fs/xfs/libxfs/xfs_sb.c | 3 ++
fs/xfs/xfs_file.c | 97 ++++++++++++++++++++++++++++++++++++---
fs/xfs/xfs_iops.c | 21 ++++++++-
fs/xfs/xfs_iops.h | 2 +
fs/xfs/xfs_mount.h | 1 +
fs/xfs/xfs_rtalloc.c | 25 +++++++++++
fs/xfs/xfs_rtalloc.h | 4 ++
include/linux/iomap.h | 3 ++
9 files changed, 239 insertions(+), 17 deletions(-)

--
2.31.1