Ameer Hamza 825dc41ad4 L2ARC: Preserve L2HDR in arc_release() for in-flight writes
When arc_release() is called on a header with a single buffer and
L2_WRITING set, the L2HDR must be preserved for ABD cleanup (similar
to the arc_hdr_destroy() case). If we destroy the L2HDR here, later
arc_write() will allocate a new ABD and call arc_hdr_free_abd(),
which needs b_l2hdr.b_dev to properly defer ABD cleanup, causing
VERIFY(HDR_HAS_L2HDR(hdr)) to fail.

Allocate a new header for the buffer in the single_buf_l2writing
case (single buffer + L2_WRITING), leaving the original header with
L2HDR intact. The original header becomes an "orphan" (no buffers, no
b_pabd) but retains device association for ABD cleanup when
l2arc_write_done() completes.

The shared buffer case (HDR_SHARED_DATA) is excluded because L2ARC
makes its own transformed copy via l2arc_apply_transforms(), so the
original ABD is not used by the L2 write. The header can be safely
reused without allocating a new one.

For proper evictable space accounting, arc_buf_remove() must be
called before remove_reference() in the single_buf_l2writing path.
This ensures arc_evictable_space_increment() (during remove_reference)
and arc_evictable_space_decrement() (during destruction) see the
same state (b_buf=NULL), preventing accounting leaks that cause
module unload to hang with non-zero esize.

Reviewed-by: Alexander Motin <alexander.motin@TrueNAS.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ameer Hamza <ahamza@ixsystems.com>
Closes #18093
2026-02-04 10:06:57 -08:00
2022-12-22 11:34:28 -08:00
2020-06-09 21:24:09 -07:00
2025-12-10 09:04:24 -08:00
2020-08-26 21:44:41 -07:00
2025-11-03 16:37:58 -08:00

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OpenZFS is an advanced file system and volume manager which was originally developed for Solaris and is now maintained by the OpenZFS community. This repository contains the code for running OpenZFS on Linux and FreeBSD.

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Official Resources

Installation

Full documentation for installing OpenZFS on your favorite operating system can be found at the Getting Started Page.

Contribute & Develop

We have a separate document with contribution guidelines.

We have a Code of Conduct.

Release

OpenZFS is released under a CDDL license. For more details see the NOTICE, LICENSE and COPYRIGHT files; UCRL-CODE-235197

Supported Kernels

  • The META file contains the officially recognized supported Linux kernel versions.
  • Supported FreeBSD versions are any supported branches and releases starting from 13.0-RELEASE.
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