Recent OpenZFS work, by @robn.

(Summary by the AI 🤖, read more about that).

• Current Focus Areas
• Pull requests: Active · Recently completed
• Day journal

Current Focus Areas

• Mounts / snapshot automounting — A colleague’s report of bind mount failures after zfs recv -F opened into structural work on ZFS dataset mount handling. #18415 landed a targeted fix for the z_teardown_lock / namespace_sem deadlock. #18705 (ZTS tests for snapshot directory edge cases) and #18722 (ctldir cleanups) have both landed as prep. The snapmount-rewrite branch is the current active work — a fresh approach implementing in-kernel snapshot mounting via d_automount, inverting the automount flow to thread user intent (flags, no-setuid) through to the actual mount, and managing expiry at zfsctl_destroy. The snapmount-cleanup branch carries the ctldir state machine cleanup forward.

• NFS4 change cookie — A user report of random EINVAL on NFS4 clients after kernel 6.18.14 (#18487) pointed at a locking gap in ZFS’s STATX_CHANGE_COOKIE path. The change cookie combines coarse ctime with a per-object z_seq counter; z_seq was not always read or written under lock, and was also reset on every znode eviction, allowing regressed cookies. Two complementary fixes are in flight: #18573 (ixhamza) persists z_seq via a new SA_ZPL_SEQ SA attribute so it survives znode eviction; the statx-cookie-seq-lock branch addresses the locking gap. User bisect has since narrowed the issue to kernels 6.19+; 6.18 LTS is unaffected.

• ZAP subsystem — A series of improvements to the ZFS Attribute Processor (ZAP) key-value store. Source reorganisation, internal locking uplift, _by_dnode() API uplift, a µnit-based unit test framework with mocks, and core/cursor/misc function tests have all landed (#18516, #18546, #18551, #18564, #18586, #18603, #18619, #18630, #18654), building a test suite now at 64 tests. The pipeline ahead fills remaining gaps: zap-unit-fatzap (fatzap: shrink, collision, pointer table growth, cursor cross-leaf) and zap-backend-api (a zap_ops vtable); community contributors are active in this area — #18638 (chrislongros, mixed-case ZAP tests), #18639 (chrislongros, uint64-key tests), #18643 (namecheck tests), #18670 (dedicated CI workflow), and #18690 (chrislongros, btree unit tests) have all merged; #18701 (tim-day-387) removes deprecated zap_cursor fields, approved and open. #7633, the old ZTS casenorm integration test tracking issue, is assigned to robn.

• ACL/idmap cleanup — A refactor of how ZFS handles user namespace and idmap mapping in the Linux platform layer. #18736 removed zidmap_t from core and FreeBSD platform code — FreeBSD’s stub idmap API was doing nothing useful; the first step before a deeper disentanglement of the Linux platform #ifdef maze around userns/idmap handling.

• zstats — New work to unify ZFS statistics across platforms. ZFS currently uses OS-specific kstat/sysctl/procfs APIs throughout, making cross-platform work and statistics introspection inconsistent. The zstats branch introduces a zstats abstraction layer with a unified API for counters, gauges, and atomic operations, with initial conversions of abd_os (Linux and FreeBSD) and dbufstats.

• ztable — New work to unify ZFS CLI tabular output. ZFS commands currently use inconsistent ad-hoc formatting throughout cmd/zfs.c and cmd/zpool.c; the ztable branch introduces a ztable abstraction with a unified API for column definition, auto-width-fitting, text color and effects, and scripted/parseable output modes. zfs list, zpool list, zfs allow, zfs holds, zfs usage, and zpool usage have been converted to the new layer so far.

Pull requests

Active

Recently completed

Gone Cold

Day journal

8 Jul (Tuesday)

• Crypto — Opened and published #18762 from crypto-no-tmpfile — “libzfs/crypto: keep in-flight key from network in memory”; for keylocation=https://... datasets, keys fetched via libcurl were being written to a tempfile that could land on durable storage even without a directory link; replaced with fmemopen() over a stack buffer, keeping key material entirely in RAM

• #18762 (libzfs/crypto: keep in-flight key from network in memory) applied directly by behlendorf

7 Jul (Monday)

• #18736 (Remove idmap/userns concept from core & FreeBSD platform code) applied directly by behlendorf

3 Jul (Thursday)

• ACL/idmap cleanup — Opened #18736 from acl-idmap-split — “Remove idmap/userns concept from core & FreeBSD platform code”; removes zidmap_t from core and FreeBSD platform code entirely; FreeBSD’s stub idmap API was doing nothing useful; first step in disentangling the Linux platform idmap/userns maze — more refactors ahead

2 Jul (Wednesday)

• Reviewed and approved #18732 — “FreeBSD: Wire sha512 offload to the build” (amotin); now that FreeBSD main has CPUID_STDEXT4_SHA512, wires up SHA-512 hardware offload for FreeBSD builds; completes the FreeBSD side of #18233
• Commented on #18731 — “kernel BUG at mm/vmalloc.c:3212 on 7.0.11” (dp1140a, Pop!_OS); triage: bug originates inside the kernel, need a full backtrace before anything useful can be said; labeled “Feedback requested”

1 Jul (Tuesday)

• Mounts — Opened #18722 from snapdir-cleanup — “snapdir: misc cleanups”; preparatory cleanups in Linux zfs_ctldir.c ahead of the snapshot automounting rewrite; compile-checked on 5.4–7.0, ZTS run on 6.12.86

• #18722 (snapdir: misc cleanups) applied directly by behlendorf

30 Jun (Monday)

• Opened #18719 from remove-abd-bio — “linux/abd: remove BIO support functions”; removes abd_bio_map_off(), abd_nr_pages_off() and related dead code unused since the classic vdev_disk implementation was removed

• #16747 (On-demand log-spacemap flush; zpool condense command) applied by behlendorf — “Merged. Thanks @robn for iterating on this, I’m happy to see it get across the finish line.”

• #18677 (Linux 7.2 compat) merged by behlendorf

• #18710 ([2.4] delegate: add send:encrypted permission) merged by behlendorf

• #18705 (ZTS: add snapdir test group) applied directly by behlendorf

• #18719 (linux/abd: remove BIO support functions) merged by behlendorf

29 Jun (Sunday)

• Reviewed and approved #18690 — “unit/btree: test basic B-Tree operations” (chrislongros); adds four tests for the btree public API (empty, add_find, remove, walk); behlendorf had flagged btree as a next target in #18643 feedback

• Reviewed and approved #18701 — “Remove zc_objset / zc_zapobj from zap_cursor” (tim-day-387); removes zc_objset/zc_zapobj fields deprecated in #18603; Lustre’s osd-zfs, the last user, has already migrated upstream

• send permissions — Opened #18710 — “[2.4] delegate: add send:encrypted permission”; backport of #18672 and #18673 to the 2.4 branch, ahead of FreeBSD 16

• Linux 7.2 compat — Addressed review comments on #18677; pushed final update and removed draft label — ready for review

• Log spacemap condense — Addressed final inline review comments on #16747 from three reviewers; pushed final update: CI run clean with two unrelated failures; dropped the zloop commit; marked as final product

• #18690 (unit/btree: test basic B-Tree operations) merged by behlendorf

28 Jun (Saturday)

• Log spacemap condense — Pushed update to condense-log-spacemaps for #16747; addressed reviewer comments and continued CI flake investigation
• Responded to review comments on #18705 (snapdir test group)

26 Jun (Thursday)

• Reviewed and approved #18706 — “ddt_log: Fix ref holder tagging for begin/commit” (ihoro); extends #18536: ddt_log_begin() and ddt_log_commit() shared a dbuf array but used mismatched FTAG holders — both should use a consistent tag across begin/commit

• Log spacemap condense — Multiple pushes to condense-log-spacemaps for #16747; CI flake investigation; addressed inline review comments

• Mounts — Created snapdir-tests branch and opened #18705 — “ZTS: add snapdir test group”; new ZTS test group covering snapshot directory behavior and automounting edge cases (no-setuid tunable, expiry, admin ops, mount-only-on-access); tests written to work with both current behavior and the upcoming snapmount rewrite

• #18706 (ddt_log: Fix ref holder tagging for begin/commit) merged by behlendorf

25 Jun (Wednesday)

• #18652 (zbookmark_compare: handle “marker” bookmarks with negative levels) merged by behlendorf

24 Jun (Tuesday)

• Reviewed and approved #18687 — “Avoid lookup overhead for nonexistent xattr directories” (ixhamza); adds a z_xattr_dir_absent flag to skip the xattr directory lookup for files known to have no xattr directory; common trigger is the security.capability probe issued on every file access

23 Jun (Monday)

• Commented on #18690 — “unit/btree: test basic B-Tree operations” (chrislongros); suggested pairing with a test_avl suite to cover the AVL layer; noted open question about where stress and performance tests fit in the unit test framework

• send permissions — Addressed behlendorf’s nits on #18673; rebased and force-pushed

• #18673 (delegate: add send:encrypted permission) approved by amotin and applied directly by behlendorf

22 Jun (Sunday)

• Mounts — Started snapmount-rewrite — fresh approach to snapshot automounting: in-kernel mount returned directly from d_automount (eliminating the userspace round-trip), inverted automount flow to thread user intent through to the actual mount, lookup intent tracking, expiry managed at zfsctl_destroy; ZTS tests for zfs_snapshot_no_setuid behavior and for ensuring snapdir-only ops do not trigger automount

• Mounts — Created snapmount-cleanup — continuation of ctldir state machine cleanup

• #18672 (zts: add test for send sub-permissions) applied directly by behlendorf

• #18673 (delegate: add send:encrypted permission) approved by behlendorf; nits to address before landing

21 Jun (Saturday)

• Commented on #18694 — “short path for zfs/zpool upgrade -v before libzfs_init” (tiehexue); pushed back on the premise: FreeBSD’s module feature query functions are stub implementations that don’t interrogate the kernel, so moving the commands before libzfs_init wouldn’t change what upgrade -v reports

18 Jun (Thursday)

• Commented on #18684 — “true async io in linux” (tiehexue); provided guidance on what it takes to get large changes reviewed and merged; discussed the standard for LLM-assisted contributions: the author must be able to explain what they’ve done and how it works, and show reasonable confidence it won’t lose data

17 Jun (Wednesday)

• Reviewed and approved #18682 — “Linux 7.1 compat: META” (tonyhutter); updates META to mark 7.1 kernel support; tested via CI on Fedora 43-44 with 7.1 kernel RPMs

• #18682 (Linux 7.1 compat: META) merged by tonyhutter

16 Jun (Tuesday)

• Reviewed and approved #18668 — “Avoid more abd_t allocations in RAIDZ/dRAID” (amotin); introduces abd_alloc_linear_struct(), abd_alloc_gang_struct(), abd_get_zeros_struct() to eliminate redundant per-column abd_t allocations for parity columns in RAIDZ/dRAID

15 Jun (Monday)

• ztable — Published ztable branch: zfs list, zpool list, zfs allow, zfs holds, zfs usage, and zpool usage all converted to the new table abstraction; ztable supports column definitions, auto-width fitting, text color/effects, and scripted/parseable output
• Linux 7.2 compat — Opened #18677 — “Linux 7.2 compat” (draft); getting ahead of 7.2 support against next-20260612; replaces sget() with sget_fc(), the fs_context-native superblock API; ZTS run completed on next-20260612

14 Jun (Sunday)

• send permissions — Opened #18673 from send-encrypted — “delegate: add send:encrypted permission”; new permission narrower than send:raw — restricts a delegated user to raw send only on encrypted datasets, ensuring no unencrypted data can leave via delegation by any means; refactors zfs_secpolicy_send_impl() as shared logic for both send IOCTs; tests layer on #18672; prompted by @bellhyve

13 Jun (Saturday)

• Reviewed and approved #18670 — “Add a unit-tests workflow to our CI infrastructure” (chrislongros); adds a dedicated GitHub Actions workflow for the unit test suite (now 64 tests); enables standalone CI verification of unit tests independent of the full ZTS run
• Opened #18672 from zts-delegate-send-subperms — “zts: add test for send sub-permissions”; consolidates send and send:raw permission testing into the delegate test framework with a new zfs_allow_send test; replaces the unnecessarily complicated zfs_send_delegation and zfs_send_delegation_user tests

12 Jun (Friday)

• dsl_scan — Continued review discussion on #18652 — acknowledged reviewer suggestion to renumber ZB_* marker constants; agreed current approach is right (renumbering is a large, invasive change for limited benefit)

11 Jun (Thursday)

• dsl_scan — Pushed update to #18652 branch zbookmark-compare-marker: rewrote comparison to handle all three marker bookmark levels explicitly; responded to reviewer’s question about whether ZB_DNODE_LEVEL can reach zbookmark_compare (argues it mostly can’t — it is a sentinel for TRAVERSE_PRE/TRAVERSE_POST rather than a real block reference)

• Log spacemap condense — Commented on #16747: zloop runs consistently locally to completion in ~12 min; noted CI pool uses autotrim which is absent in local testing; investigating whether that is the source of the CI flake

• NFS4 change cookie — Reviewed and approved #18573 — “Persist z_seq across znode eviction” (ixhamza); persists z_seq via new SA_ZPL_SEQ SA attribute so the NFS4 change cookie survives znode eviction; directly addresses the root cause identified in #18487 analysis; ixhamza had briefed robn early

• Reviewed and approved #18638 — “unit/zap: add MT_MATCH_CASE mixed-case test” (chrislongros); adds ZAP mixed-case table test coverage; noted U8_TEXTPREP_TOUPPER is also valid for Unicode normalization forms and MT_MATCH_CASE defangs it

• #18652 (zbookmark_compare: handle “marker” bookmarks with negative levels) approved by amotin

10 Jun (Wednesday)

• Log spacemap condense — Pushed two updates to condense-log-spacemaps for #16747: reworked the debug condense target to properly track and cancel the delay task; added a ztest hook for the regular condense path (ztest exercises the actual condense, not the debug target)

• Assigned #7633 — “Test case: casenorm test group”; old tracking issue for ZTS casenorm integration tests needing update for Linux, directly relevant to ongoing ZAP casenorm work

• #18643 (unit/namecheck: test name validation by chrislongros) merged by behlendorf

9 Jun (Tuesday)

• dsl_scan — Opened #18652 — “zbookmark_compare: handle ‘marker’ bookmarks with negative levels”; correct fix for #14777, superseding #18598 and #18612; marker bookmarks (ZB_ROOT_LEVEL, ZB_ZIL_LEVEL, ZB_DNODE_LEVEL) represent valid dataset-level blocks but negative levels make BP_SPANB unsafe; fix sorts them ahead of “true” object blocks without performing any level arithmetic — they’re typically dataset metadata needed first anyway; ZTS running

• Log spacemap condense — Pushed fix to condense-log-spacemaps and responded to review on #16747: the debug condense target had a quirk where spa_condense_debug_task tasks linger on the delay taskq for up to 1s after condense completes; the task exits without re-arming on the next tick; documented the behaviour in-source

• ZAP — Commented on #18639 — “unit/zap: uint64 keys” (chrislongros); adds test_zap_uint64_keys covering ZAP_FLAG_UINT64_KEY fatzap (the key format used by DDT and BRT); robn had overlapping WIP in zap-unit-uint64-keys and pushed that branch; noted the PR covers the core operations well

• ZAP — Commented on #18638 (chrislongros, unit/zap: zap_lookup_norm) — noted overlap with own zap-unit-casenorm work; was about to post own PR today but #18638 had turned up first; coordinated and posted #18654 as a companion

• Reviewed and approved #18643 — “unit/namecheck: test name validation” (chrislongros); first unit test suite contributed independently of the test framework author — tests pool, dataset, snapshot, bookmark, component, permset, mountpoint, and depth namecheck functions; inline suggestions on naming style, avoiding unnecessary state restoration in forked tests

• ZAP — Opened #18654 — “unit/zap: key case normalization tests”; extends mock ZAP creation to accept normalisation flags; tests MT_NORMALIZE lookups across five Unicode normalization forms (U8_TEXTPREP_TOUPPER, NFC, NFD, NFKC, NFKD); tests conflict flag and real-name return in zap_lookup_norm_by_dnode(); tests zap_remove_norm_by_dnode()

• #18654 (unit/zap: key case normalization tests) applied directly by behlendorf

• #18643 (unit/namecheck: test name validation) approved and merged by behlendorf — “great to see the unit testing getting fleshed out”; suggested test_btree, test_range_tree, or test_raidz as next candidates

• #16747 (On-demand log-spacemap flush; zpool condense command) approved by behlendorf

6 Jun (Saturday)

• dsl_scan — Withdrew #18612 — confirmed with amotin that skipping ZB_ROOT_LEVEL prefetch entirely was wrong; these bookmarks do point to data the prefetcher needs; working on correct approach

5 Jun (Friday)

• ZAP — Opened #18630 — “zap: misc function removal / uplift / tests”; removes zap_increment_int() (long unused, potentially buggy) and zap_join()/zap_join_key()/zap_join_increment() (last seen 2017, too narrowly focused); adds zap_increment_by_dnode(), _by_dnode() variants for the zap_*_int and zap_*_int_key families, and zap_value_search_by_dnode(); all new API variants get unit tests; adds unit_rand_uint64() and unit_rand_str() helpers to the test framework; ZAP test suite now at 40 tests

• #18630 (zap: misc function removal / uplift / tests) applied directly by behlendorf

4 Jun (Thursday)

• ZAP — Updated #18619 — pushed unit-coverage-pretty branch with lcov 1.x support (lcov 1.14 / Alma 8.10 compatibility); worked around several 1.x quirks to produce the same text report from older tooling; responded to behlendorf’s review

• dsl_scan — Responded to amotin’s inline review on #18612 — agreed with amotin’s analysis; had forgotten that the prefetcher and scanner are separate threads each walking the tree, not a single pass where prefetch is set up ahead of each visit; that means rootbp is meaningful to prefetch and the fix is wrong; planning to withdraw #18612 once amotin weighs in with a better approach

• Reviewed #18625 — “PG_writeback may stuck with writeback_iter” (tiehexue, related to #18454); pushed back on the analysis — the claim that writeback_iter and write_cache_pages coexist and conflict applies only to a narrow HWE window (6.17 on Ubuntu 24.04); the proposed fix applies 6.18+ writeback code back to 6.10 where it isn’t needed

• #18619 (unit: produce a text coverage report) approved by behlendorf

• #18619 (unit: produce a text coverage report) applied directly by behlendorf

3 Jun (Wednesday)

• ZAP — Opened #18619 — “unit: produce a text coverage report”; adds scripts/coverage_report.pl which parses lcov/geninfo tracefiles and emits a text report immediately after make unit-coverage, showing per-file line/branch/function coverage; splits coverage targets into unit-coverage (text) and unit-coverage-html (full HTML); truecolor terminal colouring with fallback; Makefile improvements and doc updates

• #18603 (zap: add zap_cursor_init_by_dnode; cursor unit tests; mock dnode refcounts) applied directly by behlendorf

• amotin raised question on #18612 — whether the ZB_ROOT_LEVEL bookmark’s rootbp points to objset_phys_t and should still be prefetched to allow dsl_scan_prefetch_cb() to queue object prefetches

2 Jun (Tuesday)

• ZAP — Traced zpool_error_scrub_001_pos test hang on #18603 CI to error scrub carrying a live cursor in dsl_scan_t that is reinitialised on resume but not finalised on cancel; added dsl_scan: close errorscrub cursor on pause as a new first commit; final rebase to master; also restored zc_objset/zc_zapobj fields in zap_cursor_t for source compatibility (annotated “do not use” to document the ABI break)

• ZAP — Restructured additional ZAP unit test work into focused branches: zap-unit-misc (test additions for zap_join and zap_value_search), zap-unit-casenorm (case normalisation), zap-unit-fatzap (fatzap: shrink, collision, pointer table growth, cursor cross-leaf)

• Log spacemap condense — Rebased condense-log-spacemaps to master; behlendorf responded to naming concern on #16747 — considered extending zpool sync instead of a new zpool condense subcommand but is leaning toward keeping “condense” as it’s descriptive and likely to accumulate more data structures

• #18612 (dsl_scan_prefetch: don’t prefetch ZB_ROOT_LEVEL bookmarks) approved by behlendorf

1 Jun (Monday)

• Closed #18598 — withdrew zbookmark PR after amotin’s review prompted deeper analysis; the observed UBSAN shift values (-5, -7, -10) are explained by negative level constants (ZB_ROOT_LEVEL = -1, ZB_ZIL_LEVEL = -2, ZB_DNODE_LEVEL = -3) combined with valid ibs values, which bypass the existing IMPLY assertions; the ibs == 0 guard was addressing the wrong root cause

• Opened #18612 — “dsl_scan_prefetch: don’t prefetch ZB_ROOT_LEVEL bookmarks”; correct fix for #14777; dsl_scan_visit_rootbp() creates a marker bookmark with level == ZB_ROOT_LEVEL (-1) and passes it to dsl_scan_prefetch(), which sorts the list via zbookmark_compare() — that calls BP_SPANB() with a negative level, producing the undefined shift; fix: skip prefetch when level == ZB_ROOT_LEVEL (nothing to prefetch anyway, matching how traverse_prefetcher() handles ZB_DNODE_LEVEL); also asserts level >= 0 in zbookmark_compare() for future protection; full ZTS passed

• Published zio-crypt-common — initial work on a cross-platform encryption interface for zio_crypt; establishes an OS abstraction layer, lifts common code, and adds adapters for Linux/userspace (ICP) and FreeBSD

• #18603 (zap: add zap_cursor_init_by_dnode; cursor unit tests) approved by amotin

31 May (Sunday)

• ZAP — Responded to amotin’s review on #18603 about always taking the dnode and zap_t hold in _init() rather than deferring; pushed updated zap-unit-cursor making zap_cursor_init() and friends return int; adopted a deferred-error model where a failed init zeros the cursor enough that zap_cursor_retrieve() returns EIO and zap_cursor_fini() is a no-op, preserving existing call-site patterns while still handling init failures

30 May (Saturday)

• Commented on #18593 — continued discussion on auto-loading the kernel module when zpool list/status is invoked; outlined the behavioural ambiguity introduced if the module is not loaded (“no pools available” currently gives a definitive answer from the kernel; without loading it would be ambiguous between “no pools” and “module not loaded”)

• Reviewed (changes requested) #18605 — “fix: add buffer-length check in rdwr_efi.c” (orbisai0security); pushed back on “high severity” framing — strcpy is not a security issue in itself and the author’s own analysis showed the path is not exploitable; requested appropriate severity description and squash to a single commit

• #18603 (zap: add zap_cursor_init_by_dnode; cursor unit tests) reviewed by amotin — suggested always taking the dnode hold in _init() to allow assertions in cursor operations

29 May (Thursday)

• ZAP — Created zap-unit-cursor branch and opened #18603 — “zap: add zap_cursor_init_by_dnode; cursor unit tests; mock dnode refcounts”; adds zap_cursor_init_by_dnode() and zap_cursor_init_serialized_by_dnode(), which must hold the dnode until the first zap_cursor_retrieve() call; adds light refcounting to mock dnodes so tests can verify all holds are released on cleanup; cursor tests cover walking, multiple scenarios, and serialization (applied directly by behlendorf 3 Jun)
• Pushed splice-read — WIP: Linux splice_read file operation to support sendfile(), splice(), and tee() on ZFS files; reviving earlier exploratory work

28 May (Wednesday)

• Opened #18598 from zbookmark-compare-underflow-fix — “zbookmark_compare: avoid negative shift in block span calculation”; BP_SPANB subtracts SPA_BLKPTRSHIFT from ibs before using it as a shift count; ibs=0 is a legal value and with unsigned math the subtract underflows, making the shift amount undefined behaviour; fix only calls BP_SPANB when ibs is non-zero, otherwise uses the block id directly; ZTS passed; fixes #14777
• bootenv — Rebased bootenv-cleanup onto master for #17985; commented asking FreeBSD loader maintainers (@bsdimp, @kevans91, @tsoome) to weigh in ahead of the 2.5 betas; noted the upcoming FreeBSD dev summit as an opportunity
• Closed #17951 — “compat 6.18 clang - build failing”; already fixed
• Closed #16680 — “block clone and bulk deletions (Veeam)”; concluded the throttling side was addressed by #18043 and remaining design notes are captured elsewhere

27 May (Wednesday)

• Log spacemap condense — Added basic zpool condense tests to #16747: introduced a debug condense type (compiled only with ZFS_DEBUG) that runs a series of delay tasks to bump stats then completes after 10s, used as a hook for test observation; raised naming concern on #16747 — “condense” may be confusing given other unrelated condense operations in ZFS (indirect, metaslab, livelist); proposed the operation might be better described as a log-to-primary flush

• Investigated #18593 — “zpool list/status should not force the zfs kernel to be loaded” (thegushi, FreeBSD 15); located the relevant libzfs_load_module() function on Linux and FreeBSD; noted the behaviour has been present since 2010 on Linux and 2007 on FreeBSD and would be a visible change; offered strace -f zpool list for further diagnosis

• #18586 (unit/zap: test “core” ZAP operations) applied directly by behlendorf

• #18588 (config: detect the right way to get pthreads) merged by behlendorf

26 May (Tuesday)

• Log spacemap condense — Responded to behlendorf’s inline review comments on #16747; rebased condense-log-spacemaps onto current master

25 May (Sunday)

• Opened #18588 from pthread-linkage — “config: detect the right way to get pthreads”; replaces the ad-hoc mix of -pthread/-lpthread flags with the AX_PTHREAD autoconf macro, which produces the correct CFLAGS and LIBS for the target platform; ensures consistent thread state across compilation units regardless of whether they were compiled with -pthread (on Linux, -pthread defines _REENTRANT while -lpthread does not); also avoids undefined behaviour when two units — one compiled with -pthread, one without — call across each other; tested on Linux (gcc+glibc) and FreeBSD (clang) (merged by behlendorf 26 May)
• ZAP — Opened #18586 from zap-unit-core — “unit/zap: test ‘core’ ZAP operations”; extends ZAP unit tests to cover core operations (add, update, remove, count, contains, length); tests are constrained to single-uint64_t values since that’s what both ZAP types share; adds zap_contains_by_dnode() and exposes zap_update_by_dnode(), zap_length_by_dnode(), and zap_get_stats_by_dnode(); also includes two unit framework improvements: zero coverage counters before a coverage run, and a TOPT Makefile arg to pass options through to the test binary (applied directly by behlendorf 26 May)
• Reviewed (changes requested) #18585 — fs_parse API compatibility shim for kernel 5.4.0 (tiehexue); adds m4 macro to detect changed fs_parse signature and wrapper in zpl_super.c; acknowledged as a good start, requested changes and squash to a single commit

23 May (Saturday)

• ZAP — Fixed packaging issues surfaced during #18564 CI runs: added FreeBSD 15.0-RELEASE to the CI matrix, reduced CI scope on push events (skip full run; only run full CI when workflow files change), updated ZTS sanity.run for the new unit test binary; then rebased zap-unit-redux, zap-by-dnode-more, zap-backend-api, and zap-unit-more onto master; deleted zap-unit branch

• #18564 (Unit testing framework: µnit framework, dnode/dbuf/dmu_tx mocks, initial ZAP test suite) applied directly by behlendorf

22 May (Friday)

• ZAP — Triaged #18572 — ZAP-leaf chunk-chain corruption causing soft lockup in zfs_readdir/zap_lookup (happyaron, Debian 2.3.2); le->le_next walks into freelist chunks because l_hash[] entries can point at chunks on the freelist, looping forever with no termination guard; the ASSERT3U guards are debug-only and compile away in production; recognised as a patch from a prior customer recovery scenario that was never upstreamed; pushed zap-chunk-loop-stopper with the defensive fix: zap_leaf: defend against chunk lists with no end marker; noted the root issue appears to be behind #10825, #5346 and several other historical corruption reports
• Reviewed (changes requested) #18568 — zap: TinyZAP for multi-uint64 entries (akashb-22); new on-disk ZAP format between MicroZAP and FatZAP for multi-integer values and long keys (Lustre FID use case); on-board with the concept but the implementation approach is convoluted — requested simplification; behlendorf also engaged positively on direction
• Commented on #18488 — Ubuntu 26.04 ZFS-with-7.0 thread: engaged with john-cabaj (Ubuntu ZFS package maintainer); explained the “experimental” warning mechanism; 2.3.7/2.4.2 releases (in review now) will add official 7.0 support

21 May (Thursday)

• Reviewed and approved #18570 — zpl_xattr: stop heap-allocating prefixed xattr names (anodos325); replaces kmem_asprintf with stack buffer for xattr name construction (bounded by XATTR_NAME_MAX=255), avoiding 3% overhead seen in samba profiling; ixhamza and behlendorf also approved; noted additional refactor opportunity

• #18563 (linux/super: properly apply ro/rw mount option to superblock) applied directly by behlendorf

20 May (Wednesday)

• Mounts — Created mount-ro-rw branch and opened #18563 — “linux/super: properly apply ro/rw mount option to superblock”; regression from #18339: commit f5a9e3a622 changed how SB_RDONLY was applied — it set readonly when a mount had ro, but never cleared it when the mount had rw, so the dataset’s readonly= property always won over an explicit mount -o rw; fix checks fc->sb_flags_mask to detect whether the option set or cleared readonly; includes lifted ZTS helpers and a new consistency test; fixes #18557

• ZAP — Opened #18564 — “Unit testing framework”; introduces µnit as an in-tree unit test framework (two files, no external dependency; each test runs in an isolated fork); three commits: framework itself, dnode/dbuf/dmu_tx mock infrastructure, and an initial ZAP test suite; groundwork from #18516/#18546/#18551 already landed; behlendorf positive: “exactly the kind of infrastructure we want” (applied directly by behlendorf 23 May)

• #18558 (spl_kvmalloc: remove __GFP_COMP before calling vmalloc()) merged by behlendorf

19 May (Tuesday)

• Opened #18558 from spl-kvmalloc-no-gfp-comp — “spl_kvmalloc: remove __GFP_COMP before calling vmalloc()”; fixes #18556; a prior commit stopped passing __GFP_COMP for KM_VMEM allocations, but the fallback path for non-KM_VMEM allocations to vmalloc() still passed it, generating a warning on Linux 7.0; full ZTS on 7.0.8 passed (merged by behlendorf same day)

• Triage on #18557 — mount -o rw not granting write access on readonly=on datasets since 2.4.2; confirmed as own regression from #18339; started working up a test case

• ZAP — Rebased zap-unit, zap-by-dnode-more, zap-backend-api, and zap-unit-redux after #18551 was applied; deleted zap-by-dnode branch

• #18551 (zap: make _by_dnode() API variants be the primary implementation) applied directly by behlendorf

• #18554 (config: show progress output for kernel API checks) merged by behlendorf

18 May (Monday)

• Opened #18554 from configure-kernel-check-progress — “config: show progress output for kernel API checks”; adds a background job in ZFS_LINUX_TEST_COMPILE_ALL that watches build.log and prints a running counter as modules compile; inactive in silent mode or when stdout is not a terminal; prompted by a user asking why configure appeared to hang at checking for available kernel interfaces... (merged by behlendorf same day)

17 May (Sunday)

• Commented on #18549 — user report (alex-moch) of UBSAN array-index-out-of-bounds in zap.c on Linux 7.0 with CONFIG_UBSAN; explained no actual memory bug — UBSAN doesn’t understand the full-block allocation pattern where mz_chunks[] covers the rest of the block past the header; pointed to fix
• ZAP — Created mz-chunks-flex branch and opened #18550 — “zap_impl: use flex array field for mzap_phys_t.mz_chunks[]”; mzap_phys_t is always a full-block allocation with mz_chunks[] as an array over the remaining block; UBSAN complains because the declared size is [1]; fix converts to a C99 flexible array member — pure type annotation, no behavior change; fixes #18549 (merged by behlendorf same day)
• ZAP — Opened #18551 — “zap: make _by_dnode() API variants be the primary implementation”; PR 3/N in the ZAP cleanup series following #18546; reorganises so _by_dnode() functions are the actual implementation, with objset+object variants as thin wrappers around them — same pattern as the zap_lock()/zap_lock_by_dnode() change from #18546; rebased zap-unit, zap-by-dnode, zap-by-dnode-more, zap-backend-api, and zap-unit-redux on top

16 May (Saturday)

• ZAP — Continued zap-unit branch: reorganised mock DMU infrastructure — split mock helpers into mock_dmu.c/mock_dmu.h, separating test fixtures from test cases in test_zap.c; rebased dependent branches (zap-by-dnode, zap-by-dnode-more, zap-backend-api)

• #18535 (zstream: fix crashes when refcount tracking enabled) applied directly by behlendorf

• #18546 (zap: internal locking uplift) applied directly by behlendorf

15 May (Friday)

• ZAP — Created zap-lock branch and opened #18546 — “zap: internal locking uplift”: renames lockdir/unlockdir to lock/unlock; makes zap_lock() a simple wrapper around zap_lock_by_dnode(), reducing repetition and error scope; simplifies mzap_create_impl() and the fatzap lock upgrade dance; cleans up refcount tags now that zap_lock_by_dnode() is the sole locking path; PR 2/N in the ZAP cleanup series; rebased zap-unit on top (applied directly by behlendorf 15 May)

• Log spacemap condense — amotin reported a VERIFY0(nvlist_add_nvlist) crash in #16747 testing; fixed the nvlist bug in spa_log_spacemap.c, pushed to condense-log-spacemaps, and responded to amotin’s inline review comment

• zstream — Fixed amotin’s review nit on #18535: missing signal.h include; pushed fix and confirmed it compiles on FreeBSD 15+; PR now has approvals from both amotin and behlendorf

• Responded to behlendorf’s question (on #18536 thread) about enabling reference_tracking_enable=1 by default in debug builds — shared timing comparison from recent ZTS runs

• #18536 (refcount tag fixups: three mismatched hold/rele tags across zap, ddt_log, dsl_bookmark) applied directly by behlendorf

14 May (Thursday)

• Log spacemap condense — Continued inline review discussion on #16747: addressed amotin’s comments about spa_estimate_metaslabs_to_flush() complexity inside MAX() and txg targeting; changed to spa_syncing_txg(spa) + 1 to ensure at least one flush round; rebased and pushed condense-log-spacemaps

• zstream — Created zstream-refcount-crash branch and opened #18535 — running tests with ABD refcount tracking enabled found crashes in zstream’s compress and decompress paths: zfs_refcount_init() had not been called, so the kmem cache used for tracking was not set up; two commits: signal handler setup (matching zdb/ztest) and zfs_refcount_init()/_fini() calls around the main work (applied directly by behlendorf 15 May)

• Created refcount-fixups branch and opened #18536 — “refcount tag fixups”; same ZTS run with refcount tracking surfaced three mismatched hold/rele tags: zap_lookup_length_uint64_impl()/zap_prefetch_uint64_impl() used FTAG for zap_unlockdir() when the matching zap_lockdir() was called by their caller (fixed by threading the caller’s tag through); ddt_log_begin()/ddt_log_commit() both used FTAG for a shared dbuf array (fixed by using the ddt_log_update_t * as tag); dsl_bookmark_create_sync_impl_snap() used FTAG for an internal redaction list hold that didn’t match the caller-provided tag (applied directly by behlendorf 15 May)

• zstats — Created zstats branch: initial work on a cross-platform ZFS statistics abstraction layer — a zstats API to replace the mix of OS-specific kstat/sysctl/procfs implementations with a unified interface; first conversions of abd_os (Linux and FreeBSD) and dbufstats to the new API; adds atomic counter support, grouping, and a macro layer to reduce boilerplate

13 May (Tuesday)

• Approved #18520 — Fix double free for blocks cloned after DDT prune (amotin); amotin incorporated the zfs_valstr.c update and added DDT/BRT CI tests

• Mounts — Opened #18529 from mount-source-option — zpl_super: handle ‘source’ mount option directly; vfs_parse_fs_param_source() was not available before 5.14 and not backported to LTS kernels; handling it directly in zfs removes the need for a configure check; fixes #18528 (merged by behlendorf same day)

• ZAP — Created zap-by-dnode-more branch extending zap-by-dnode with additional _by_dnode() variants; cleaned up zap-api-split branch now that #18516 has landed

• #18520 (Fix double free for blocks cloned after DDT prune) applied directly by behlendorf

12 May (Monday)

• Reviewed (changes requested) #18520 — Fix double free for blocks cloned after DDT prune (amotin); suggested picking a zfs_valstr.c update commit from robn/zfs to go with the fix

• Log spacemap condense — Addressed amotin’s inline review comments on #16747: bounds safety of condense-type array, stats macro approach, txg_kick semantics, metaslab estimation inside MAX(), and a superfluous conditional; pushed updated condense-log-spacemaps branch

• #18516 (zap: reorganise and improve documentation) applied directly by behlendorf

11 May (Sunday)

• ZAP — Created zap-backend-api branch: adds microzap unit test coverage (lookup, length, remove, count, cursor retrieve, stats) and introduces a ZAP backend operations API — a zap_ops vtable with function pointers for open/close/prefetch/add/update/remove/byteswap, making the backend switchable between microzap and fatzap without conditional dispatch through the frontend

10 May (Sunday)

• ZAP — Opened #18516 from zap-api-split — “zap: reorganise and improve documentation”; PR 1/N in a planned series for comprehensive ZAP unit tests and a modular backend; splits the existing zap.c/zap_micro.c into five files: frontend API, common internals, microzap, fatzap core, and fatzap leaf (applied directly by behlendorf 12 May)

9 May (Saturday)

• ZAP — Continued zap-api-split: public and internal interface cleanup

8 May (Friday)

• ZAP — Started zap-api-split branch: split ZAP implementation out from two source files into five, separating frontend, common internals, and the two storage backends (microzap and fatzap)

7 May (Thursday)

• Commented on #18454 — user report of permanent system hangs on kernel 6.12 (Debian 13): folio_end_writeback() not called in all exit paths of zpl_writepages, leaving folios stuck in PG_writeback state; acknowledged and noted it’s in queue

6 May (Wednesday)

• ZAP API — Continued zap-unit-redux branch: expanding fatzap coverage — cursor iteration and cross-leaf transitions, case normalisation, uint64 key type, fatzap_remove, format sanity checks, and upgrade path tests

5 May (Tuesday)

• NFS4 change cookie — Continued triage on #18487: user bisect narrowed issue to kernels 6.19+, 6.18 LTS series unaffected — reduces urgency; planning to set up local reproduction environment
• ZAP API — Restructured ZAP work into named branches: created zap-by-dnode (holding the _by_dnode() API additions: zap_join, zap_value_search, int-key family, zap_contains, zap_stats, zap_remove_norm) and zap-unit-redux (fresh approach to the unit test structure, split from zap-unit)

4 May (Monday)

• NFS4 change cookie — Continued statx-cookie-seq-lock branch: second commit ensures all ctime/z_seq updates are done atomically under lock; commented on #18487 with full root cause analysis — insufficient locking in the STATX_CHANGE_COOKIE path allows z_seq reads to race with updates, producing a stale change cookie that NFS interprets as “no change”, causing EINVAL on cached directory entries; kernel 6.18.14 change likely shifted timing to expose it more reliably
• ZAP API — Created zap-unit branch: initial unit test infrastructure for ZAP covering fatzap multi-leaf remove, shrink/reclamation, normalization (NFD, NFKC, NFKD), and initial tests for the new _by_dnode() function family

3 May (Sunday)

• Commented on #18487 — NFS4 random EINVAL on clients after kernel ~6.18.14; initial triage, suspecting locking issue around NFS change cookie (STATX_CHANGE_COOKIE / z_seq); created statx-cookie-seq-lock branch with first fix: zfs_getattr_fast now reads z_seq under lock; posted initial patch for community testing
• Closed #18488 — Ubuntu 26.04 shipping ZFS 2.4.1 with kernel 7.0 “SERIOUS DATA LOSS” warning; explained the warning is correct: there are no official OpenZFS releases for kernel 7.0, the package is an unofficial Ubuntu build

2 May (Saturday)

• #18466 (libzfs/mnttab: restore ability to enable/disable cache) applied directly by behlendorf
• #18471 (Linux 7.1 compat: revert d_u.d_alias rename back to d_alias) merged by behlendorf

1 May (Friday)

• Commented on #18471 — responded to reviewer question about including 7.1 patches under a 7.0 META for 2.4.2 build compatibility
• Mounts — Continued snapshot-mount-cleanup branch: snapentry state machine completeness — unmounting entries always transition through the dead state rather than jumping directly to inactive; matched snapentry lifetime to the parent snapdir dentry

30 Apr (Thursday)

• Mounts — Created snapshot-mount-cleanup branch — ctldir locking refactor: mounting flag replaced with a state enum, states added for unmounting and inactive, unmount split into named and snapentry variants, expiry moved under entry lock with snapshot lock reduced to AVL-only scope

• #18475 (AUTHORS: add names of recent new contributors) merged by behlendorf

29 Apr (Wednesday)

• Opened #18475 — AUTHORS: add names of recent new contributors; routine update_authors.pl run (merged 30 Apr)
• Mounts — Pushed final mnttab-cache-enable-disable update for #18466: added repro from #18464 as a libzfs test case, verified fix passes
• Commented on #18464 — explained rationale for keeping libzfs_mnttab_cache() callable but as a no-op for upgrade compatibility

28 Apr (Tuesday)

• Linux 7.1 compat — Opened #18471 — Linux 7.1 compat: struct dentry’s d_u.d_alias field reverts to plain d_alias in 7.1-rc1 (reverting a 3.18 rename); single-commit fix, compile-checked on 4.18+/5.15+/6.8+, ZTS running (merged 2 May)
• Mounts — Continued snapshot-mount-direct: restore refcounts via dentry holds
• Mounts — Started snapentry-dentry-lifecycle branch: ctldir interface cleanup (remove flags arg to zfsctl_snapshot_unmount(), delay param from zfsctl_snapshot_unmount_delay(), unused args from zfsctl_snapshot_alloc); implemented concurrent mounter holding in manage_transit and direct mount creation in the automount graft path

27 Apr (Sunday)

• Mounts — Continued snapshot-mount-direct: tracking pathwalk intent through the VFS layer

• #18466 (libzfs/mnttab: restore ability to enable/disable cache) approved by prakashsurya

25 Apr (Saturday)

• Commented on #18464 — regression in #18296: libzfs_mnttab_cache(hdl, B_FALSE) became a no-op after “always enable the cache” change; Delphix’s multi-handle pool breaks because mounts via one handle populate its AVL, making ZFS_PROP_MOUNTED return wrong answers on other handles; acknowledged regression and referenced #18466 as fix

• Opened #18466 — libzfs/mnttab: restore ability to enable/disable cache; restores disabled mode by flushing AVL on each libzfs_mnttab_find() call when disabled; cache defaults to off, zfs explicitly re-enables (applied directly by behlendorf 2 May)

• Mounts — Continued snapshot-mount-direct: basic teardown function for zfsctl_destroy; separated dentry and parent mount tracking; expiry shape and noop stub

• #18466 (libzfs/mnttab: restore ability to enable/disable cache) approved by ixhamza and behlendorf

24 Apr (Friday)

• Mounts — Continued snapshot-mount-direct: passing back mount flags through manage_transit; lifted and renamed zpl_snapdir_t to zpl_snapentry_t; initial unified snapentry shape

23 Apr (Thursday)

• Mounts — Continued snapshot-mount-direct: manage_transit callback writeup; dentry private management fixup

17 Apr (Friday)

• Mounts — Continued snapshot-mount-direct: working toward hooking automount via the manage_transit kernel callback — initial trigger implementation and struct scaffolding for transit state

• Created casenorm branch — WIP: ZFS case normalization; ZTS helper program and initial test conversion

• #18435 (Linux 7.0 compat: META, by behlendorf) merged; commented confirming all 7.0 release candidates and the final release tested clean

15 Apr (Wednesday)

• Mounts — Continued snapshot-mount-direct: debug on ioctl unmount paths; investigating invalidate flow and delayed-work scheduling; extensive tracing added

14 Apr (Tuesday)

• Mounts — Continued snapshot-mount-direct: extra ref on returned automount; discovered zfs_parse_fs_string() takes 3 args in Linux 6.18 and added a compat fix on the branch; debug on automount lifecycle

11 Apr (Saturday)

• Commented on #18422 — zfs, zpool: ignore SIGPIPE in main() (chrislongros); argued the blanket approach is too broad — interval and long-running modes (zpool iostat <pool> 1, zpool events -f) should not ignore SIGPIPE; questioned whether the motivating scenario actually produces exit 141

10 Apr (Friday)

• Mounts — Continued snapshot-mount-direct: substantial locking and lifecycle rework — restored MNT_INTERNAL with zfsctl_destroy() support; direct snapshot unmount at parent teardown; timer disarm on detach; reimplemented rename around the new locking structure; ref counting fixes and mount ownership checks
• Linux 7.1 compat — Created linux-7.1-compat branch — initial investigation: d_u.d_alias renamed back to d_alias in upcoming kernels

8 Apr (Wednesday)

• Mounts — Continued snapshot-mount-direct: reverted to single lock model, fixing lock bugs, extensive locking debug work; getting close

• Reviewed and approved #18415 — fix snapshot automount deadlock during concurrent zfs recv (ixhamza); drops z_teardown_lock before call_usermodehelper() to break the deadlock cycle with namespace_sem; fixes #18409 and #18073

• Commented on #18409 — snapshot automount deadlock during concurrent zfs recv; this is exactly the deadlock class snapshot-mount-direct eliminates (snapshot automount holds z_teardown_lock(R) across call_usermodehelper, blocking on namespace_sem(W) while /proc/self/mountinfo readers hold namespace_sem(R) and wait on z_teardown_lock); noted #18073 as possible duplicate

• Commented on #18333 — zfs_resume_fs() bail path deadlock and use-after-free; asked whether now resolved by #18310 merging

• #18407 (add ability to set user properties while changing encryption key) merged by behlendorf

• #18415 (fix snapshot automount deadlock during concurrent zfs recv) applied directly by behlendorf

7 Apr (Tuesday)

• Mounts — Continued snapshot-mount-direct: reworking locking model — new locking theory and initial implementation
• Opened #18407 — add ability to set user properties while changing encryption key; port of illumos change by @ahrens; extends zfs change-key -o ... to apply user properties in the same transaction as the key change, using the existing properties nvlist already threaded through to ZFS_IOC_CHANGE_KEY (merged 8 Apr)
• Commented on #18402 — continued discussion on “RFE: speed up SEEK_DATA syscalls”; real improvement requires considering dirty/uncommitted buffers which is very difficult; practical advice is tuning via zfs_dmu_offset_next_sync

6 Apr (Monday)

• Log spacemap condense — Agreed with amotin that metaslabs are the natural unit of flushing; reworked #16747 to count dirty metaslabs at condense start and flush N% per txg (default 5%, ~20s total); pushed log_spacemap: add counter for unflushed metaslabs to condense-log-spacemaps and commented with updated approach
• Commented on #18402 — “RFE: speed up SEEK_DATA syscalls”; explained zfs_dmu_offset_next_sync tunable: disabling it trades hole-detection accuracy for performance by skipping the txg sync

3 Apr (Friday)

• fs_context — Responded to behlendorf’s follow-up question on #18377; pushed rebase of kernel-mount-params-direct

• Mounts — Continued snapshot-mount-direct: mnt mismatch protection, MNT_NOSUID handling, cancel expire time on force unmount

• #18377 (linux/super: reimplement in-kernel mount options parser for fs_context) approved and applied directly by behlendorf

2 Apr (Thursday)

• Mounts — Continued snapshot-mount-direct branch: reworked snapshot entry model for multiple snapentries per snapshot; locking rejig; unmounting by snapentry rather than snapname — progressing toward proper vfsmount-backed snapshot lifecycle management

1 Apr (Wednesday)

• fs_context — Commented on #18377 — responded to behlendorf’s review question about using GFP_KERNEL in the fs_context callback
• Commented on #15918 — kernel BUG at mm/usercopy.c report; pointed to #17129 as potentially related (worker thread spinning in EFAULT loop after parent thread destroyed)

31 Mar (Tuesday)

• fs_context — Rebased #18377 onto current master and added a new commit to kernel-mount-params-direct: workaround for kernels that enforce “forbidden” mount options and reject them before zpl_get_tree() sees them; commented on PR to describe the new commit

• #18376 (Linux 7.0: ensure LSMs get to process mount options) merged by behlendorf

30 Mar (Monday)

• Log spacemap condense — Addressed amotin’s review comments on #16747: fixed metaslab sorting, made -t target argument optional (defaults to all), added -a for all-pools support following scrub/resilver precedent; pushed ABI bump on condense-log-spacemaps
• Log spacemap condense — Asked amotin on #16747 about how to pace incremental spacemap flushing — per-metaslab and per-block approaches both feel too arbitrary; wondering if the right answer is some central IO scheduling layer (the same structural problem FDT had)

28 Mar (Saturday)

• Commented on #18381 — user crash report from USB device removal; user on ZFS 2.1, which is well out of support; advised upgrade to 2.3/2.4 series, noting zed OOM fix and disk detection improvements since 2.2

27 Mar (Friday)

• fs_context — Opened #18377 from kernel-mount-params-direct — linux/super: reimplement in-kernel mount options parser for fs_context; removes old monolithic parser, moves options setup onto fs_context as a structured “intent” before mount/remount; foundational for snapshot automounting without userspace round-trips, libmount integration, and eventual removal of mount.zfs
• fs_context — Opened #18376 from new lsm-mount-opts branch — Linux 7.0: ensure LSMs get to process mount options; when a filesystem provides .parse_monolithic, the kernel skips LSM option processing entirely — breaking SELinux context/fscontext/defcontext/rootcontext properties since #18339; fix by calling security_sb_eat_lsm_opts() before stashing remaining options for zfs_domount() (merged 31 Mar)

26 Mar (Thursday)

• fs_context — Continued kernel-mount-params-direct branch: added vfs_t allocator and made it public; matched vfs_t lifetime to fs_context; removed zfs_mnt_t (passing mount params directly instead); removed parse_monolithic — further simplification of the mount parameter stack, aligning object lifetimes with the fs_context model and removing intermediate structures

25 Mar (Wednesday)

• Mounts — Continued mountset branch: introduced zfs_mountset_iter iterator API and libzfs_mountset_apply; migrated zpool_disable_datasets, zfs_iter_mounted, unshare_unmount, and mount-list callers to use the new iterator; removed zfs_mountset_foreach; marked zfs_mount/zfs_unmount as deprecated — the iterator-based model is becoming the primary interface

23 Mar (Monday)

• #18356 (pyzfs: update license tags/classifiers) merged by behlendorf

22 Mar (Sunday)

• Created header-split branch — WIP: exploring moving ZFS/SPL headers out of sys/ to new zfs/ and spl/ namespaces

21 Mar (Saturday)

• fs_context — Continued kernel-mount-params-direct branch — added better lifetime control and dup-on-copy for context; removed old options parser; mount parameter parsing in the kernel via fs_context params API taking cleaner shape

20 Mar (Friday)

• fs_context — Created kernel-mount-params-direct branch — reworking mount parameter parsing to happen directly in the kernel via the fs_context params API, continuing the flattening work from the always-fs-context branch
• Log spacemap — Re-lifed #16747 — on-demand log-spacemap flush and zpool condense command; reworked to close txg immediately during condense (like scrub) and flush based on % of dirty unflushed blocks rather than a fixed metaslab count
• Opened #18356 — pyzfs: update license tags/classifiers; fix deprecated setuptools license classifier warning by switching to SPDX identifier and adding spdxcheck tag (merged 23 Mar)
• Reviewed and approved #18354 — Linux 7.0: autoconf: remove copy-from-user-inatomic API checks (john-cabaj); PowerPC build fix removing an unnecessary API check that now pulls in a GPL-only symbol

18 Mar (Wednesday)

• Mounts — Created snapshot-mount-direct branch — reworking zfs_ctldir snapshot mounting to hold a vfsmount directly in the snapshot entry; refactoring snap/snapmount paths, removing chroot handling, options allocation, and se_path/mountpoint generation; exploring autoexpiry via dentry invalidation and investigating a leaked zfsvfs reference

• #18339 (linux/super: require fs_context, remove support for old mount API) approved by behlendorf and applied directly

17 Mar (Tuesday)

• fs_context — Opened #18339 — linux/super: require fs_context, remove support for old mount API; first PR from the always-fs-context branch — drops the HAVE_FS_CONTEXT-gated old entry points, flattens the call chain into zpl_get_tree() and zpl_reconfigure(); full ZTS on 6.12.63, compile-checked back to 4.18; note scoped to zpl_super.c only, further cleanup in subsequent PRs

• Responded to amotin’s review comment on #18331 — explained that generic_setlease predates filelock.h: it has always existed but its declaration moved from fs.h to filelock.h at some point, so the #ifdef HAVE_FILELOCK_HEADER guard is for the include only, not the symbol

• #18331 (Linux 7.0: also set setlease handler on directories) approved by amotin and behlendorf; merged by tonyhutter

16 Mar (Monday)

• Mounts — Continued mountset branch: pushed zfs_mountset_apply prototype and initial hacks wiring it into mount callers — exploring an apply-based model for executing a set of mount operations as a unit

• Mounts — Created always-fs-context branch — full init_fs_context adoption: drops HAVE_FS_CONTEXT compatibility shims entirely and refuses to build without fs_context; follow-through on #18260’s groundwork and the 2.5 goal flagged by behlendorf

• Commented on #18316 — statx requires <sys/stat.h> include file (wbx-github/uClibc-ng build failure in Buildroot); suggested using configure to detect statx and skip the test binary if absent; then retracted in favour of @jolivain’s similar-but-better solution

• #18331 (Linux 7.0: also set setlease handler on directories) confirmed working by satmandu on 7.0.0-rc3

15 Mar (Sunday)

• Opened #18331 — Linux 7.0: also set setlease handler on directories; prompted by @satmandu’s report of NFS access failures on 7.0 (worked on 6.19); #18215 added the regular-file setlease handler but missed directory file ops, causing EINVAL when the NFS server tries to take a directory lease

14 Mar (Saturday)

• Mounts — Continued mountset branch: added initial mountbuilder/mountopt APIs — a structured layer for constructing mount operations and managing mount options, building on top of the zfs_mountset abstraction

13 Mar (Friday)

• Mounts — Continued mountset branch: converted zpool_disable_datasets to mountset; reworked zfs_unmount and zfs_unshare for the new API; migration through the remaining libzfs/cmd mount callers continuing

12 Mar (Thursday)

• Mounts — Continued mountset branch: converted unshare_unmount_path, zfs_do_userspace, zfs_for_each, zfs_path_to_zhandle, and zinject to the mountset API; removed legacy getextmntent from libspl; branch migrating steadily through the remaining libzfs/cmd mount callers

• Opened #18312 — config: fix STATX_MNT_ID detection; _GNU_SOURCE was not defined in the configure check, so sys/stat.h wouldn’t produce struct statx or STATX_* defines; missed when a prior change switched from linux/stat.h to sys/stat.h

• Opened #18313 — contrib/debian: add zilstat.1 to Debian packaging install lists; CI fix following #18303 (zilstat: add man page) which caused Debian packaging to fail

• Commented on #18310 — s_active leak fix in zfsvfs_hold() when z_unmounted is true (mischivus); agreed a leak exists but raised questions about whether zfsvfs_rele() would be more appropriate and what happens in the zfsvfs_create() fallback path

• #18312 (config: fix STATX_MNT_ID detection) approved by ixhamza; merged by behlendorf

• #18313 (contrib/debian: add zilstat.1 manpage to installation list) approved by ixhamza; merged by behlendorf

11 Mar (Wednesday)

• Mounts — Continued mountset branch: converted unshare_unmount and zfs_iter_mounted to use the mountset iterator, migrating more of libzfs off the legacy mnttab API
• Reviewed (changes requested) #18304 — README: add FreeBSD 14.4-RELEASE alongside 15.0 (grahamperrin); suggested listing only the latest release of each series rather than accumulating every version

10 Mar (Tuesday)

• Mounts — Started mountset branch — concrete implementation of the zfs_mountset abstraction sketched in the #18296 design discussion: interface definition, libmount-based Linux backend, libzfs global mountset instance, and migration of zfs_is_mounted and the legacy libzfs_mnttab API to use the new interface

• #18295 (Linux: remove minimum version requirement) applied directly by behlendorf

• #18296 (libzfs: mnttab cleanup) applied directly by behlendorf

9 Mar (Monday)

• Linux support — Opened #18295 — remove minimum Linux kernel version requirement; prefer configure checks over a version gate; document actually-supported distros and kernels in README instead

• Mounts — Opened #18296 — libzfs mnttab cleanup; pulls libzfs_mnttab_* functions into libzfs_mnttab.c, general modernisation (SPL mutexes, alloc/free helpers), removes unused legacy struct extmnttab and gettmntany(); preparatory cleanup carried across every mount management prototype, sent separately since it stands on its own

• Mounts — Commented on #18296 in response to @lundman — sketched design direction for mount abstraction: opaque mntent object representing a dataset/mountpoint pair, with OS-specific methods (mount, unmount, property changes, sort); libmount wrapping on Linux, direct implementation on FreeBSD/Windows; libzfs and tools would only ever interact through the abstraction

• Mounts — Started libzfs-mnttab-libmount branch — WIP initial shape of OS-specific mount API, integrating mnttab cleanup changes with the libmount work into a new branch; first cut at the opaque object abstraction described in the design comment

• Reviewed and approved #18290 — FreeBSD: improve dmesg kernel message prefix (concussious); noted Linux mixes ZFS: and zfs: prefixes too, consistency wouldn’t hurt

• Closed #17351 — rename zed binary to zfs-zed; no compelling case made; resolving namespace clashes in a global shared namespace is out of scope

• Linux support — Responded to review nit on #18295 — fixed “prioritise” spelling; pushed updated branch

• Mounts — Responded to review nit from @ixhamza on #18296 — fixed commit title typos (mnntab/gettmntany); pushed updated branch

• #18295 (Linux: remove minimum version requirement) approved by behlendorf

• #18296 (libzfs: mnttab cleanup) approved by behlendorf and ixhamza

8 Mar (Sunday)

• Linux support — Started linux-no-minimum branch — prompted by fs-context adoption work; investigated minimum kernel version requirement; found 4.18 minimum is RHEL8-derived, no longer compiles with modern toolchains, and doesn’t reflect actual support commitments

7 Mar (Saturday)

• Mounts — Split mountcache-initial branch off mountcache — isolating the initial mountcache infrastructure (the /proc/mountinfo parser, dual-tree cache, zfs_is_mounted integration) as a discrete unit for submission as a PR

6 Mar (Friday)

• Commented on #17000 — design discussion on zfs create -pp syntax for creating parents with canmount=no; suggested -O canmount=no as a general “properties for implicitly-created parents” alternative (intelfx); conceded it was a stretch; behlendorf resolved to proceed with -pp (intelfx)

• #18281 (libzpool: lift zfs_file ops out to separate source file) merged by behlendorf

5 Mar (Thursday)

• SHA-512 / SIMD build — Opened #18285 — separate SIMD compile checks for userspace and kernel toolchains; HAVE_SIMD() selector macro picks the right set at compile time; eliminates Ubuntu 24.04 builder failures where objtool rejects SHA512EXT in the kernel module even though the host compiler supports it

• #18285 (separate SIMD compile checks for userspace and kernel) approved by behlendorf and directly applied

4 Mar (Wednesday)

• SHA-512 / SIMD build — Investigated behlendorf’s report of Ubuntu 24.04 build failure in #18233; diagnosed as toolchain/kernel mismatch: compiler supports SHA512EXT but objtool in the kernel rejects it; responded with intent to fix properly; started simd-config branch — refactoring SIMD feature detection to test against both host and kernel toolchains separately

• Opened #18281 — split zfs_file_* ops out of libzpool/kernel.c into a new libzpool/zfs_file_os.c source file; cleanup requested by @lundman to ease porting work (merged 6 Mar)

• #18259 (more consistent TREE_* macro use in AVL comparators) merged by behlendorf

• #18281 (libzpool: lift zfs_file ops out to separate source file) approved by lundman

3 Mar (Tuesday)

• Mounts — Created libmount branch — WIP: reworking ZFS userspace mount management to use Linux’s libmount library; detect and link libmount, initial mount/unmount through it, mnttab_cache remade as a libmount wrapper, zfs_iter_mounted reimplemented over mtab

• Responded to amotin’s review nits on #18259 — removed unneeded lvb != rvb redundancy (good catch); defended belt-and-suspenders wrapping of zbookmark_compare() (AVL comparators must return -1/0/1, non-AVL functions could break at distance if changed); pushed updated branch

• #18259 (more consistent TREE_* macro use in AVL comparators) reviewed by amotin with nits

2 Mar (Monday)

• Commented on #18259 — responded to amotin’s Clang disassembly feedback; pushed rebase to master with || → | in zfs_refcount_compare to eliminate extra branch (tradeoff: load instead, on same cacheline); noted potential for separate search vs insertion comparator as a future idea

27 Feb (Friday)

• Mounts — Created fs-context-uplift branch — WIP: beginning full init_fs_context mount API adoption, next step following #18260
• Commented on #18259 — posted annotated disassembly showing macro changes produce identical codegen in kernel and userspace builds; noted spa_mapping_key_compare() as another candidate for the same treatment

26 Feb (Thursday)

• #18233 (SHA-512 via Intel SHA512 extension) merged by behlendorf
• #18260 (prefer fs_context mount API when available, groundwork for full init_fs_context adoption) merged by behlendorf

25 Feb (Wednesday)

• Mounts — Continued progress on mountcache branch: built out core mountcache infrastructure — alloc/free, locking (rrwlock), /proc/mountinfo refresh, dual-tree lookup (by dataset and by mountpoint), integrated cache into libzfs_handle_t, wired up zfs_is_mounted to use it; then filtered non-ZFS mount entries out of cache, generalised foreach iterator
• SHA-512 performance — Responded to review comment on #18233 — clarified 0.00 CPB values in sha2_test output when the CPU MHz argument is omitted; not a regression
• SHA-512 performance — Posted performance results on Core Ultra 9 285K VM for #18233: sha512ext at 1.82 CPB vs avx2 at 3.18 CPB (~1.75x faster on Arrow Lake desktop)
• Reviewed and approved #18261 — remove deprecated Fedora 41 from CI (tonyhutter)

24 Feb (Tuesday)

• Linux 7.0 compat — Commented on #18216: confirmed full ZTS pass on 7.0-rc1; maintainer flagged init_fs_context full adoption as a 2.5 goal

• SHA-512 performance — Rebased #18233 to master; shared first real hardware test results (Core Ultra 7 258V, ThinkPad X1 gen 13): sha512ext hashes 1GiB in 205ms vs avx2 at 945ms — ~4.6x faster; in-kernel test to follow

• Opened #18259 — more consistent use of TREE_CMP()/TREE_ISIGN()/TREE_PCMP() macros in AVL comparators; ZTS pass on Linux; notes a few curious constructions worth discussing (merged 4 Mar)

• Linux 7.0 compat — Opened #18260 — prefer new fs_context mount API when available (compiles back to 5.2), inverting the 7.0 compat shim check; sending to CI to verify support range before full init_fs_context adoption (merged 26 Feb)

• #18216 (Linux 7.0 compat: blk_queue_nonrot, posix_acl_to_xattr, legacy mount API removal) merged by behlendorf

• #18233 (SHA-512 via Intel SHA512 extension) approved by tonyhutter

23 Feb (Monday)

• Mounts — Started new mountcache branch — fresh approach to mount caching, starting with an initial /proc/mountinfo parser
• Mounts — Started kernel-mount-direct branch — reworking zfs_ctldir snapshot mounting to hold a vfsmount directly in the snapshot entry rather than going through the automount path
• Started superblock-experiments branch — early WIP: reimagining superblock vs inode relationship

22 Feb (Sunday)

• #18215 (F_SETLEASE compatibility fix) merged
• #18233 (SHA-512 via Intel SHA512 extension) approved by AttilaFueloep; nit about .byte directives in zfs_sha512_transform_sha512ext

20 Feb (Friday)

• #18230 (zdb --key crash fix and test harness improvements) merged by behlendorf
• #18216 (blk_queue_nonrot/posix_acl_to_xattr/legacy mount API changes) approved by behlendorf

19 Feb (Thursday)

• SHA-512 performance — Responded to two review comments on #18233 — fixed bugs in cpuid detection logic caught by reviewer; pushed sha512ext (multiple iterations)

• SHA-512 performance — Fixed $NF awk bug; pushed sha2-test-all-correct (final)

• Mounts — Commented on #18205 — investigated full unmount/remount approach; concluded it needs more work; PR left as safety-check only for now

• Mounts — Created mnttab-cache-highlander branch (WIP: mount table caching)

• #18232 (sha2_test correctness checks for all implementations) merged by behlendorf

• #18216 (Linux 7.0 compat) approved by tonyhutter

18 Feb (Wednesday)

• SHA-512 performance — Created sha512ext and sha2-test-all-correct branches
• SHA-512 performance — Opened #18232 — extend sha2_test correctness checks to all implementations; fix output formatting and get_cpu_freq for variable-frequency CPUs (merged 19 Feb)
• SHA-512 performance — Opened #18233 — icp: SHA-512 via Intel SHA512 extension; tested via Intel SDE with Arrow Lake emulation; requesting community testing on real hardware (merged 26 Feb)
• SHA-512 performance — Pushed sha512ext and sha2-test-all-correct branches (iteration)
• Linux 7.0 compat — Pushed setlease branch; commented on #18215 — addressed review feedback on commit structure
• Mounts — Commented on #18207 — discussed canonical vs. use-time normalisation of mountpoint=; noted cross-OS implications
• SHA-512 performance — Responded to review on #18230 — leftover error-threading code in zdb_derive_key()

17 Feb (Tuesday)

• SHA-512 performance — Created sha512-avx512 branch and pushed — deleted same day (AVX-512 approach abandoned)
• SHA-512 performance — Created zdb-load-key-smarter branch; opened #18230 — fix zdb --key crash on unencrypted datasets; fix test harness to catch silent zdb assertion failures (merged 20 Feb)

16 Feb (Monday)

• Linux 7.0 compat — Pushed setlease branch; responded to review on #18215, fixed commit split
• Code review: #18222, #18133

15 Feb (Sunday)

• Linux 7.0 compat — Created setlease branch; opened #18215 — explicitly set .setlease = generic_setlease to survive removal of kernel fallback in 7.0 (merged 22 Feb)
• Linux 7.0 compat — Pushed linux-7.0-compat branch; opened #18216 — handle blk_queue_nonrot rename, new posix_acl_to_xattr signature, legacy mount API removal
• Code review: #18214

14 Feb (Saturday)

• Linux 7.0 compat — Created linux-7.0-compat branch

13 Feb (Friday)

• Mounts — Commented on #18205 — worked out root cause (outstanding long holds prevent destroy); updated PR description

12 Feb (Thursday)

• Mounts — Created flatten-mount-point branch; opened #18207 — flatten mountpoint= parameter before sort in mountpoint_cmp, fixing mount ordering when trailing slashes present
• Mounts — Commented on #18205 responding to CI failures

11 Feb (Wednesday)

• Linux 6.19 compat — Approved #18197 META update to mark 6.19 support (tonyhutter) — merged; 6.19 work now fully landed
• Mounts — Created no-busy-receive-destroy branch; opened #18205 — abort zfs recv -F with EBUSY when dataset has outstanding bind mounts

9 Feb (Monday)

• Linux 6.19 compat — Confirmed ZTS run passed on 6.19 release day; #18053 effectively complete
• Opened and merged #18189 — AUTHORS update

6 Feb (Friday)

• Code review: #18179, #18180