[LTP] [PATCH v8 0/1] statx: Add regression test for STATX_WRITE_ATOMIC on regular files

[Gaurav Pathak]

From: Gaurav Pathak <gaurav.pathak@suse.com>

    This series adds syscalls/statx13, an LTP test exercising statx(2)'s
    STATX_WRITE_ATOMIC reporting on regular files for XFS and ext4.
    It covers the hardware-backed atomic write path (shared by both
    filesystems, where the underlying block device itself advertises
    atomic write support) as well as XFS's newer software/CoW-based
    atomic write path (Linux v6.16+), which works even on devices without
    hardware atomic write support, such as loop devices.
    
    ---
    Changes in v8:
    - Query the test device's own atomic write capability via statx()
      before formatting, instead of assuming fixed mkfs options always apply.
    - Derive the XFS/ext4 mkfs block size (and ext4 bigalloc cluster size)
      from the device's reported atomic write limits at runtime, capped at
      the 64KiB xfsprogs/e2fsprogs ceiling and at the page size unless THP
      (xfs) or blocksize_gt_pagesize (ext4) allows larger blocks.
    - Add support for XFS's software (CoW/reflink-based) atomic write path
      (Linux v6.16+), so the test produces meaningful results on loop
      devices too, not just on real or scsi_debug-emulated hardware.
    - Keep ext4 on the hardware-only path, since it has no software
      fallback; TCONF cleanly when the device lacks atomic write support.
    - Switch from .mount_device with static per-filesystem mkfs_opts to
      .needs_device + .needs_root with explicit setup()/cleanup(), to
      support the new dynamic mkfs/mount logic and TCONF branching.
    - Drop the hardcoded xfs-only .min_kver = "6.12" override; gate
      behavior on runtime statx() results instead of a fixed kernel
      version.
    - Expand the file's top comment to document the hardware vs.
      software atomic write mechanisms and the block-size constraints
      involved.
    - Link to v7: https://lore.kernel.org/r/20261016-statx-atomic-write-v7-1-d9cd4e1f1bcd@suse.com

Gaurav Pathak (1):
  statx: Add regression test for STATX_WRITE_ATOMIC on regular files


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2.51.0