Commit Graph

8976 Commits

Author SHA1 Message Date
Linus Torvalds
18fbf5151d mm.git review status for linus..mm-stable
Everything:
 
 Total patches:       171
 Reviews/patch:       1.83
 Reviewed rate:       82%
 
 Excluding selftests:
 
 Total patches:       149
 Reviews/patch:       1.77
 Reviewed rate:       80%
 
 Excluding selftests and maple_tree:
 
 Total patches:       129
 Reviews/patch:       1.99
 Reviewed rate:       89%
 
 Summary of patch series in this merge:
 
 - "mm/rmap: index MAP_PRIVATE file-backed folios by anonymous pgoff"
   (Lorenzo Stoakes):
 
   Index MAP_PRIVATE file-backed folios by their anonymous page offset to
   resolve confusion around reverse mapping for zeroed and CoW'd
   file-backed memory.
 
   Use this new VMA anonymous page offset tracking to eliminate index
   conflicts and lay the foundation for scalable CoW performance
   improvements.
 
 - "promote mapped executable folios after first usage for MGLRU" (Baolin
   Wang):
 
   Make MGLRU's protection of mapped executable file folios more
   reliable.  Follow the classical LRU's logic, promoting mapped executable
   file folios after their first usage to give executable code a better
   chance to stay in memory and improve workload performance.
 
 - "mm: vmscan: fix node reclaim ignoring swappiness parameter" (Ridong Chen):
 
   Fix per-node proactive reclaim interface's ignoring the swappiness
   parameter when CONFIG_MEMCG is disabled by consolidating sc_swappiness()
   into a single function that checks proactive_swappiness regardless of
   kernel configuration.
 
 - "mm/vmscan: reduce lru_lock contention via vmstat-derived scan-balance
   cost" (Usama Arif):
 
   Reduce lru_lock contention in the reclaim path by deriving
   scan-balance costs from vmstat counters rather than lock-acquired
   producer updates.
 
   Read and decay these cost signals on the reclaim side under a
   dedicated per-lruvec lock, reducing total LRU lock wait time by over 60%
   without impacting scan throughput.
 
 - "zram: fix zram issues reported by sashiko" (Sergey Senozhatsky):
 
   Fix two low-risk zram bugs which Sashiko spotted in drive-by review.
 
 - "Honor XA_FLAGS_ACCOUNT in xas_split_alloc() and charge to folio's
   memcg" (Zi Yan):
 
   Fix xas_split_alloc() by enabling target folio memcg charging during
   splits and adding the missing __GFP_ACCOUNT flag for proper XArray node
   memory accounting.
 
 - "selftests/mm: use pattern matching in .gitignore" (Pratyush Mallick):
 
   Replace hardcoded binary names in selftests/mm/.gitignore with a
   generic pattern-matching rule to automatically ignore generated test
   files and avoid manual updates when adding new tests.
 
 - "mm/page_ext: remove pgdat_page_ext_init()" (Sang-Heon Jeon):
 
   Make the incompatibility between FLATMEM and NUMA explicit in
   mm/Kconfig and remove the unused pgdat_page_ext_init() function.
 
 - "zram: fix zstd error paths and add parameter validation" (Haoqin Huang):
 
   Clean up zram compression backends by removing redundant error
   cleanup, adding parameter and dictionary validation, auto-prefixing
   algorithm error logs, and resetting parameters prior to
   reinitialization.
 
 - "zram: fix stale scan bounds after reinitialization" (Longlong Xia):
 
   Prevent out-of-bounds slot accesses during concurrent zram resets by
   moving table scan bound calculations under dev_lock in writeback_store()
   and read_block_state().
 
 - "add anon mTHP collapse test cases" (Baolin Wang):
 
   Extend selftests helper functions to support arbitrary page orders and
   add new test cases and options for mTHP collapse in khugepaged.
 
 - "selftests/mm: Handle unsupported and transient test conditions"
   (Muhammad Usama Anjum):
 
   Update MM selftests to report a SKIP status instead of a failure when
   required kernel or filesystem features are unsupported, while adding
   retry logic for transient page migration errors.
 
 - "mm/zswap: Fixes and improves the zswap shrink" (Hao Jia):
 
   Fix the missing zswap global shrinker when CONFIG_MEMCG is disabled
   and extend shrink_memcg() to support batch writeback for improved
   writeback efficiency.
 
 - "alloc_tag: introduce IOCTL-based filtering for MAP" (Suren Baghdasaryan):
 
   Introduce an IOCTL-based binary interface for memory allocation
   profiling that enables kernel-side filtering before per-CPU counter
   aggregation.
 
   This eliminates the text-parsing overhead of /proc/allocinfo and
   provides up to a 20x speedup by transferring only filtered allocation
   data to userspace.
 
 - "better block swap batching and a different take on swap_ops v5"
   (Christoph Hellwig):
 
   Refactor block swap I/O to use swap_iocb for batching instead of
   single-bio requests and rebase the swap_ops interface, achieving faster
   swap throughput during kernel builds.
 
 - "mm: kmemleak: reduce transient false positives by confirming leaks"
   (Catalin Marinas):
 
   Reduce false-positive kmemleak reports by combining two kmemleak
   enhancements that add a second confirmation scan and a configurable
   minimum unreferenced scan count module parameter.
 
 - "mm: kmemleak: default min_unref_scans to 2 for verbose kernels"
   (Breno Leitao):
 
   Auto-scanning kernels can generate false-positive memory leak reports
   on single scans, so this patch defaults min_unref_scans to 2 when
   CONFIG_DEBUG_KMEMLEAK_VERBOSE is enabled to require a second confirming
   scan.
 
 - "swap_ops updates" (Christoph Hellwig):
 
   Batching I/O for synchronous swap devices causes performance
   regressions and filesystem-based swap suffers from double-indirection
   overhead.  This series resolves both issues by reintroducing per-folio
   writes for synchronous swap and allowing filesystems to directly export
   their own swap_ops.
 
 - "mm/khugepaged: several cleanups" (Nico Pache):
 
   khugepaged accumulated redundant state-checking patterns and outdated
   comments following mTHP integration.  Introduce dedicated helpers for
   PTE validation and event counting while refreshing the internal
   documentation.
 
 - "maple_tree: lock checking and clean ups" (Liam Howlett):
 
   Syzbot reports incorrectly blame memory management exit paths for
   locking bugs, maple tree erase operations risk allocation failures
   without gfp flags and internal documentation lacks clarity.
 
   Improve lock error detection, update docs, fix race and allocation
   edge cases and optimize erase allocations using a fallback to GFP_KERNEL
   | GFP_NOFAIL.
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Merge tag 'mm-stable-2026-08-26-15-22' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull more MM updates from Andrew Morton:

 - "mm/rmap: index MAP_PRIVATE file-backed folios by anonymous pgoff"
   (Lorenzo Stoakes)

   Index MAP_PRIVATE file-backed folios by their anonymous page offset
   to resolve confusion around reverse mapping for zeroed and CoW'd
   file-backed memory.

   Use this new VMA anonymous page offset tracking to eliminate index
   conflicts and lay the foundation for scalable CoW performance
   improvements.

 - "promote mapped executable folios after first usage for MGLRU"
   (Baolin Wang)

   Make MGLRU's protection of mapped executable file folios more
   reliable. Follow the classical LRU's logic, promoting mapped
   executable file folios after their first usage to give executable
   code a better chance to stay in memory and improve workload
   performance.

 - "mm: vmscan: fix node reclaim ignoring swappiness parameter" (Ridong
   Chen)

   Fix per-node proactive reclaim interface's ignoring the swappiness
   parameter when CONFIG_MEMCG is disabled by consolidating
   sc_swappiness() into a single function that checks
   proactive_swappiness regardless of kernel configuration.

 - "mm/vmscan: reduce lru_lock contention via vmstat-derived
   scan-balance cost" (Usama Arif)

   Reduce lru_lock contention in the reclaim path by deriving
   scan-balance costs from vmstat counters rather than lock-acquired
   producer updates.

   Read and decay these cost signals on the reclaim side under a
   dedicated per-lruvec lock, reducing total LRU lock wait time by over
   60% without impacting scan throughput.

 - "zram: fix zram issues reported by sashiko" (Sergey Senozhatsky)

   Fix two low-risk zram bugs which Sashiko spotted in drive-by review.

 - "Honor XA_FLAGS_ACCOUNT in xas_split_alloc() and charge to folio's
   memcg" (Zi Yan)

   Fix xas_split_alloc() by enabling target folio memcg charging during
   splits and adding the missing __GFP_ACCOUNT flag for proper XArray
   node memory accounting.

 - "selftests/mm: use pattern matching in .gitignore" (Pratyush Mallick)

   Replace hardcoded binary names in selftests/mm/.gitignore with a
   generic pattern-matching rule to automatically ignore generated test
   files and avoid manual updates when adding new tests.

 - "mm/page_ext: remove pgdat_page_ext_init()" (Sang-Heon Jeon)

   Make the incompatibility between FLATMEM and NUMA explicit in
   mm/Kconfig and remove the unused pgdat_page_ext_init() function.

 - "zram: fix zstd error paths and add parameter validation" (Haoqin
   Huang)

   Clean up zram compression backends by removing redundant error
   cleanup, adding parameter and dictionary validation, auto-prefixing
   algorithm error logs, and resetting parameters prior to
   reinitialization.

 - "zram: fix stale scan bounds after reinitialization" (Longlong Xia)

   Prevent out-of-bounds slot accesses during concurrent zram resets by
   moving table scan bound calculations under dev_lock in
   writeback_store() and read_block_state().

 - "add anon mTHP collapse test cases" (Baolin Wang)

   Extend selftests helper functions to support arbitrary page orders
   and add new test cases and options for mTHP collapse in khugepaged.

 - "selftests/mm: Handle unsupported and transient test conditions"
   (Muhammad Usama Anjum)

   Update MM selftests to report a SKIP status instead of a failure when
   required kernel or filesystem features are unsupported, while adding
   retry logic for transient page migration errors.

 - "mm/zswap: Fixes and improves the zswap shrink" (Hao Jia)

   Fix the missing zswap global shrinker when CONFIG_MEMCG is disabled
   and extend shrink_memcg() to support batch writeback for improved
   writeback efficiency.

 - "alloc_tag: introduce IOCTL-based filtering for MAP" (Suren
   Baghdasaryan)

   Introduce an IOCTL-based binary interface for memory allocation
   profiling that enables kernel-side filtering before per-CPU counter
   aggregation.

   This eliminates the text-parsing overhead of /proc/allocinfo and
   provides up to a 20x speedup by transferring only filtered allocation
   data to userspace.

 - "better block swap batching and a different take on swap_ops v5"
   (Christoph Hellwig)

   Refactor block swap I/O to use swap_iocb for batching instead of
   single-bio requests and rebase the swap_ops interface, achieving
   faster swap throughput during kernel builds.

 - "mm: kmemleak: reduce transient false positives by confirming leaks"
   (Catalin Marinas)

   Reduce false-positive kmemleak reports by combining two kmemleak
   enhancements that add a second confirmation scan and a configurable
   minimum unreferenced scan count module parameter.

 - "mm: kmemleak: default min_unref_scans to 2 for verbose kernels"
   (Breno Leitao)

   Auto-scanning kernels can generate false-positive memory leak reports
   on single scans, so this patch defaults min_unref_scans to 2 when
   CONFIG_DEBUG_KMEMLEAK_VERBOSE is enabled to require a second
   confirming scan.

 - "swap_ops updates" (Christoph Hellwig)

   Batching I/O for synchronous swap devices causes performance
   regressions and filesystem-based swap suffers from double-indirection
   overhead. This series resolves both issues by reintroducing per-folio
   writes for synchronous swap and allowing filesystems to directly
   export their own swap_ops.

 - "mm/khugepaged: several cleanups" (Nico Pache)

   khugepaged accumulated redundant state-checking patterns and outdated
   comments following mTHP integration. Introduce dedicated helpers for
   PTE validation and event counting while refreshing the internal
   documentation.

 - "maple_tree: lock checking and clean ups" (Liam Howlett)

   Syzbot reports incorrectly blame memory management exit paths for
   locking bugs, maple tree erase operations risk allocation failures
   without gfp flags and internal documentation lacks clarity.

   Improve lock error detection, update docs, fix race and allocation
   edge cases and optimize erase allocations using a fallback to
   GFP_KERNEL | GFP_NOFAIL.

* tag 'mm-stable-2026-08-26-15-22' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (172 commits)
  selftests/proc: make proc-maps-race work with READ_IMPLIES_EXEC
  memcg: move LRU size accounting on reparenting instead of copying it
  mm/vmscan: fix comment logic in balance_pgdat
  maple_tree: add helper mas_make_walkable()
  maple_tree: avoid extra gap calculation
  maple_tree: fix argument name in header
  maple_tree: change two GFP flags in tests
  maple_tree: document erase and allocations better
  maple_tree: avoid mas_erase() and mtree_erase() failures
  maple_tree: document that erase may use GFP_KERNEL for allocations
  maple_tree: catch race in mas_alloc_cyclic()
  maple_tree: add bulk parent set helper
  maple_tree: micro optimisation of mas_wr_store_type()
  maple_tree: optimise mas_wr_node_store() when not in rcu mode
  maple_tree: use prefetched value in mas_wr_store_type()
  maple_tree: clarify comments on mas_nomem()
  maple_tree: drop MAPLE_ALLOC_SLOTS
  maple_tree: drop dead code from mas_extend_spanning_null()
  maple_tree: documentation fix
  maple_tree: add write lock checking with lockdep sequence numbers
  ...
2026-08-27 09:17:06 -07:00
Linus Torvalds
9cebfe6504 fuse update for 7.3
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Merge tag 'fuse-update-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse

Pull fuse updates from Miklos Szeredi:

 - Improve performance of the io-uring transport by introducing buffer
   pools and zero-copy (Joanne)

 - Fix lots of bugs (Baokun Li)

 - Fix io-uring initialization issues (Joanne, Bernd)

 - More prep work for large folios (Joanne)

 - Don't limit buffered read to 128k (Jim Harris)

 - Fix zeroing of page end (dirtied with mmap) on file size extension
   (Jimmy Zuber)

 - Improve performance in certain cases with wake_up_sync() when queuing
   request (Xuewen Yan)

 - Misc fixes and cleanups (Xuewen Yan)

* tag 'fuse-update-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse: (35 commits)
  fuse: zero the partial EOF page when extending a file
  io_uring: Add missing include for ITER_SOURCE and ITER_DEST
  fuse: Fix the condition to enable over-io-uring
  fuse: invalidate the correct range after O_APPEND direct write
  selftests/fuse: test post-EOF page zeroing when a file is extended
  fuse: wake one waiter per freed slot when raising max_background
  fuse: use min_not_zero() in fuse_init_server_timeout()
  fuse: copy request headers via a stack buffer for io-uring
  fuse: give wakeup hints to the scheduler for synchronous requests
  fuse: check for NULL root inode in fuse_fill_super_submount
  fuse: reject a duplicate fd= mount option
  cuse: wait for pending RCU callbacks on module exit
  fuse: fix invalidate lock leak on open O_TRUNC DAX failure
  fuse: fix invalidate lock leak on setattr writeback failure
  fuse: wait for FR_FINISHED on abort_on_kill to prevent use-after-free
  fuse: make dentry_tree_work static
  docs: fuse: document io-uring buffer pool and zero-copy uapi
  fuse: add zero-copy over io-uring
  fuse: support registered buffer pools in io-uring
  fuse: add io-uring buffer pools
  ...
2026-08-25 07:59:44 -07:00
David Carlier
a8b5875741 zram: fix slot lock bit position on big-endian 64-bit
The slot lock is a bit operation on the whole __lock word, which flags and
ac_time alias as two u32s.  On little-endian the lock bit lands in the
position ZRAM_ENTRY_LOCK reserves in flags, so the aliasing works out.  On
64-bit big-endian it lands in ac_time instead: with
ZRAM_TRACK_ENTRY_ACTIME enabled, storing the access time from
mark_slot_accessed() or slot_free() wipes out the held lock bit, letting
another CPU take the same slot lock; an access time value with that bit
set makes the slot look locked forever.

Shift the lock bit into the flags half of the word on big-endian 64-bit.

Link: https://lore.kernel.org/20260810202241.2436603-1-devnexen@gmail.com
Fixes: 2e8ff2f51d ("zram: use u32 for entry ac_time tracking")
Signed-off-by: David Carlier <devnexen@gmail.com>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-08-24 18:43:19 -07:00
Sergey Senozhatsky
184bf187c4 zram: switch to unsigned long indexing
zram has always used "unsigned int" for (page) index calculations, which
unnecessarily limited max zram disksize.

Switch to "unsigned long" and permit much larger zram devices.

Link: https://lore.kernel.org/20260806031640.536615-1-senozhatsky@chromium.org
Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Suggested-by: Andrew Morton <akpm@linux-foundation.org>
Co-developed-by: Longlong Xia <xialonglong2025@163.com>
Cc: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-08-24 18:43:06 -07:00
Longlong Xia
391f057f44 zram: fix out-of-bounds access in read_block_state()
read_block_state() calculates nr_pages before taking dev_lock.  If the
device is reset and reinitialized with a smaller disksize before lock
acquisition, nr_pages still describes the old table.  The subsequent loop
can then call slot_lock() past the end of the newly allocated table.

Read disksize after acquiring dev_lock and checking that the device is
initialized.  The read lock then keeps the table and its bound stable for
the duration of the scan.

Link: https://lore.kernel.org/20260804065919.3970386-3-xialonglong2025@163.com
Fixes: c0265342bf ("zram: introduce zram memory tracking")
Assisted-by: Codex:gpt-5.6-sol
Signed-off-by: Longlong Xia <xialonglong@kylinos.cn>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Minchan Kim <minchan@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-08-24 18:43:05 -07:00
Longlong Xia
894913e2d3 zram: fix out-of-bounds access in writeback_store()
Patch series "zram: fix stale scan bounds after reinitialization".

Both writeback_store() and read_block_state() derive their table scan
bounds from zram->disksize before acquiring dev_lock.  If the device is
reset and reinitialized with a smaller disksize between that read and lock
acquisition, the bound can describe the old table while the scan operates
on the new one.  This can lead to out-of-bounds slot accesses.

Move both bound calculations under dev_lock so each bound remains
consistent with the table throughout its scan.  Keep the fixes separate
because the affected interfaces originate from different commits and can
be backported independently.


This patch (of 2):

writeback_store() calculates the table scan bounds before taking dev_lock.
A reset followed by reconfiguration with a smaller disksize can therefore
replace zram->table while writeback_store() is waiting for the lock.  Once
it acquires the lock, it sees an initialized device but scans the new
table using the old upper bound, resulting in an out-of-bounds access.

Calculate the number of pages while holding dev_lock so the scan bound
matches the table protected by the lock.

Link: https://lore.kernel.org/20260804065919.3970386-1-xialonglong2025@163.com
Link: https://lore.kernel.org/20260804065919.3970386-2-xialonglong2025@163.com
Fixes: a939888ec3 ("zram: support idle/huge page writeback")
Assisted-by: Codex:gpt-5.6-sol
Signed-off-by: Longlong Xia <xialonglong@kylinos.cn>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Minchan Kim <minchan@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-08-24 18:43:05 -07:00
Haoqin Huang
702c5a799d zram: reset per-priority params when changing algorithm before init
Parameters validated against one algorithm may be invalid for another
(e.g.  lz4 accepts level=65535 but zstd does not).  Although algorithm
changes are blocked after disksize is set, they are allowed before device
initialization.  Reset per-priority params on algorithm change so that
stale parameters do not silently carry over.

Link: https://lore.kernel.org/20260804093841.67920-6-haoqinhuang7@gmail.com
Signed-off-by: Haoqin Huang <haoqinhuang@tencent.com>
Signed-off-by: Rongwei Wang <zigiwang@tencent.com>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Tested-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: David Sterba <dsterba@suse.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Nick Terrell <terrelln@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-08-24 18:43:05 -07:00
Haoqin Huang
7b0f677c7b zram: validate parameters in each backend's setup_params
Dict and level parameters are silently accepted even for backends that do
not support them.  Validate these parameters in each backend's
.setup_params() to reject unsupported combinations and out-of-range levels
with a specific error message.

Link: https://lore.kernel.org/20260804093841.67920-5-haoqinhuang7@gmail.com
Signed-off-by: Haoqin Huang <haoqinhuang@tencent.com>
Signed-off-by: Rongwei Wang <zigiwang@tencent.com>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Tested-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: David Sterba <dsterba@suse.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Nick Terrell <terrelln@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-08-24 18:43:04 -07:00
Haoqin Huang
70922d5ef8 zram: add pr_fmt to backend files
Add pr_fmt to each backend so that pr_err() messages are auto-prefixed
with the algorithm name.  While at it, tweak the deflate winbits pr_err to
avoid a duplicated "deflate" prefix.

Link: https://lore.kernel.org/20260804093841.67920-4-haoqinhuang7@gmail.com
Signed-off-by: Haoqin Huang <haoqinhuang@tencent.com>
Signed-off-by: Rongwei Wang <zigiwang@tencent.com>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Tested-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: David Sterba <dsterba@suse.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Nick Terrell <terrelln@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-08-24 18:43:04 -07:00
Haoqin Huang
6dc404d433 zram: reject zero-size dictionary
kernel_read_file_from_path() already rejects empty files (i_size <= 0) and
returns -EINVAL, but the current implementation only checks for sz < 0
without logging any information.  Use sz == 0 to reject the zero-size case
and print distinct error messages for each failure type.

Link: https://lore.kernel.org/20260804093841.67920-3-haoqinhuang7@gmail.com
Signed-off-by: Haoqin Huang <haoqinhuang@tencent.com>
Signed-off-by: Rongwei Wang <zigiwang@tencent.com>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Tested-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: David Sterba <dsterba@suse.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Nick Terrell <terrelln@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-08-24 18:43:04 -07:00
Haoqin Huang
45214458d6 zram: do not release zstd global params from error paths
Patch series "zram: fix zstd error paths and add parameter validation", v6,

Patch 1 removes zstd_release_params() from both zstd_create() and
zstd_setup_params() error paths -- the former is a layering violation
in a per-CPU callback, the latter is redundant as zcomp_init() already
calls release_params() on setup failure.

Patch 2 rejects zero-size dictionaries and prints distinct error
messages for sz < 0 (returns the original error code) and sz == 0
("empty file"). Currently errors are silently swallowed.

Patch 3 adds pr_fmt to each backend file so that pr_err() messages
are auto-prefixed with the algorithm name.

Patch 4 validates dict and level parameters in each backend's
.setup_params(), rejecting unsupported combinations and out-of-range
levels.

Patch 5 resets per-priority params on algorithm change before init.


This patch (of 5):

zstd_setup_params() creates global cdict and ddict stored in
params->drv_data, shared across all per-CPU contexts.  The per-CPU
zstd_create() error path called zstd_release_params(), which freed those
globally-shared objects.  This is a layering violation: a per-CPU callback
should only clean up its own context, not release resources owned by the
compression lifecycle.

zstd_setup_params() called zstd_release_params() on its own error path as
well, but zcomp_init() already calls release_params() when setup fails, so
this is redundant.

Remove zstd_release_params() from both error paths.

Link: https://lore.kernel.org/20260804093841.67920-1-haoqinhuang7@gmail.com
Link: https://lore.kernel.org/20260804093841.67920-2-haoqinhuang7@gmail.com
Signed-off-by: Haoqin Huang <haoqinhuang@tencent.com>
Signed-off-by: Rongwei Wang <zigiwang@tencent.com>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Tested-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: David Sterba <dsterba@suse.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Nick Terrell <terrelln@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-08-24 18:43:04 -07:00
Sergey Senozhatsky
ec7607ac47 zram: validate deflate params
We must validate user-supplied deflate winbits before we pass it to
zlib_deflate_workspacesize(), which triggers BUG_ON() if winbits value is
outside of valid ranges.

Link: https://lore.kernel.org/20260729045745.775973-3-senozhatsky@chromium.org
Fixes: dc75a0d93b ("zram: support deflate-specific params")
Link: https://sashiko.dev/#/patchset/20260728092935.31139-1-haoqinhuang7@gmail.com
Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Haoqin Huang <haoqinhuang7@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-08-24 18:42:56 -07:00
Sergey Senozhatsky
dde75313ee zram: set default primary compressor in zram_destroy_comps()
Patch series "zram: fix zram issues reported by sashiko".

Sashiko drove by and reported [1] a couple of zram issues:
a possible BUG_ON() in zlib code due to missing winbits range
validation and one possible NULL-ptr dereference in zcomp.
Both are low risk yet still worth fixing.


This patch (of 2):

zram_destroy_comps() resets all compressors and leaves them set to NULL,
including the primary one, which is invalid device state, as now
comp_algorithm_show()->strcmp() can be called on a NULL compressor.  Set
default primary compressor in zram_destroy_comps().

Link: https://lore.kernel.org/20260729045745.775973-2-senozhatsky@chromium.org
Fixes: 486fd58af7 ("zram: don't free statically defined names")
Link: https://sashiko.dev/#/patchset/20260728092935.31139-1-haoqinhuang7@gmail.com [1]
Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Haoqin Huang <haoqinhuang7@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-08-24 18:42:56 -07:00
Linus Torvalds
ed3b875bea mm.git review status for mm-hotfixes-stable..mm-stable
Everything:
 
 Total patches:       501
 Reviews/patch:       1.66
 Reviewed rate:       70%
 
 Excluding DAMON:
 
 Total patches:       356
 Reviews/patch:       2.26
 Reviewed rate:       90%
 
 Excluding DAMON and selftests:
 
 Total patches:       329
 Reviews/patch:       2.31
 Reviewed rate:       92%
 
 Excluding DAMON, selftests and maple_tree:
 
 Total patches:       328
 Reviews/patch:       2.31
 Reviewed rate:       92%
 
 Summary of patch series in this merge:
 
 - The 2 patch series "mm: drop "sub" prefix from various places" from
   Dev Jain implements some page->folio conversion and a naming cleanup.
 
 - The 2 patch series "mm/kasan: remove redundant initialization for
   kasan_flag_write_only" from Igor Putko provides some KASAN cleanup work.
 
 - The 2 patch series "mm/filemap: reduce unnecessary xarray lookups"
   from Chi Zhiling provides a small speedup in the pagecaache read code.
 
 - The 4 patch series "mm/percpu: Fix possible NOFS/NOIO reclaim
   recursion" from Kaitao Cheng improves a few things in the vmalloc code -
   mainly the avoidance of GFP_KERNEL allocations when the caller asked for
   GFP_NOFS or GFP_NOIO.
 
 - The 3 patch series "mm/kmemleak: avoid soft lockup when scanning task
   stacks" from Breno Leitao avoids a soft lockup watchdog trigger from the
   kmemleak scanning code in extreme situations.
 
 - The 6 patch series "mm/page_owner: misc cleanups" from Ye Liu is a
   collection of unrelated cleanups to the page_owner code.  For some
   reason lots of people have been working on the page_owner code this
   cycle.
 
 - The 4 patch series "mm: convert to walk_page_range_vma() to eliminate
   find_vma()" from Kefeng Wang simplifies and accelerates the page walking
   library function.
 
 - The 3 patch series "mm/migrate: preparatory cleanups for batch copy
   and offload" from Shivank Garg implements cleanups in the migration
   code.
 
 - The 4 patch series "mm/page_owner: add per-fd filter infrastructure
   for print_mode and NUMA filtering" from Zhen Ni provides per-fd
   filtering to page_owner in order to reduce the sometimes vast amount of
   output it can produce.
 
 - The 19 patch series "mm: Refactor bootmem gigantic hugepage
   allocation" from Muchun Song is a "set of fixes and preparatory cleanups
   around bootmem HugeTLB handling, sparse initialization ordering, and
   related vmemmap setup".
 
 - The 4 patch series "mm/zsmalloc: reduce lock contention in zs_free()"
   from Wenchao Hao reduces lock contention in zs_free(), which dominates
   the unmap path under memory pressure on Android (LMK kills) and on x86
   servers running zswap-heavy workloads.  Up to 1.83x improvement in
   microbenchmarking.
 
 - The 2 patch series "move alloc_tag.c file under mm/" from Suren
   Baghdasaryan does that.
 
 - The 6 patch series "samples/damon: handle damon_{start,stop}()
   failures" from SJ Park fixes improper handling of damon_start(),
   damon_stop(), and damon_call() failures across DAMON sample modules to
   prevent potential memory leaks, operation disruptions and use-after-free
   bugs.
 
 - The 11 patch series "mm/damon/sysfs: kobject_del() directories that
   users can create/remove" from SJ Park resolves an issue where delayed
   sysfs directory removal under CONFIG_DEBUG_KOBJECT_RELEASE causes
   creation failures due to duplicate directory names by adding missing
   kobject_del() calls before creating new directories.
 
 - The 3 patch series "mm: cleanup clear_not_present_full_ptes()" from
   David Hildenbrand cleans up the core pte handling code.
 
 - The 3 patch series "selftests/damon: misc fixes for test bugs" from
   Kunwu Chan fixes several bugs in the DAMON selftests.
 
 - The 2 patch series "selftests/damon: fix memcg_path staging handling"
   from Cheng Nie fixes a bug in _damon_sysfs.py for damos_filter
   memcg_path setup, and adds a test case for it in sysfs.py.
 
 - The 2 patch series "selftests/damon: test kdamond refresh_ms" from
   Ruslan Valiyev introduces selftest coverage for DAMON's refresh_ms sysfs
   feature by updating the test control module and verifying that scheme
   stats update automatically without manual intervention.
 
 - The 5 patch series "mm/damon: five misc fixups" from Akinobu Mita
   contains miscellaneous DAMON fixups.
 
 - The 2 patch series "mm/damon/core: detect internal variation above
   max_nr_regions/2" from Jiayuan Chen fixes DAMON's region splitting
   behavior when region counts exceed half the maximum budget by
   dynamically scaling down the split fraction as the limit approaches,
   preventing large regions from staying un-split, and adds corresponding
   KUnit test coverage.
 
 - The 6 patch series "mm: preparatory patches for PMD level swap
   entries" from Usama Arif refactors and cleans up PMD softleaf helpers,
   call sites, and architecture flags to lay the groundwork for a follow-up
   series that introduces PMD page table swap entries.
 
 - The 11 patch series "mm/damon: update, optimize, and clean up doc,
   tests, and code" from SJ Park updates DAMON design and ABI
   documentation, expands unit and selftest coverage, optimizes
   damon_commit_target_regions(), and cleans up recently added sysfs
   interface code for better readability.
 
 - The 2 patch series "mm/vmpressure: reduce CPU, memory and code
   overhead on cgroup v2" from Usama Arif optimizes vmpressure() by
   skipping unnecessary work on cgroup v2 for userspace event notifications
   and refactors v1-only eventfd handling into mm/memcontrol-v1.c to reduce
   memory overhead and code complexity.
 
 - The 10 patch series "selftests/mm: refactor pkey helpers and fix mmap
   error handling" from Hongfu Li refactors pkeys shared tracing and
   assertion helpers into a common file, unifies protection key selftests
   to use consistent diagnostic logging and assertions, and enforces
   standardized MAP_FAILED return checks for mmap() calls across the tests.
 
 - The 18 patch series "mm/damon: optimize out nr_accesses_bp" from SJ
   Park replaces the error-prone, continuously updated nr_accesses_bp field
   in damon_region with an on-demand moving sum function
   (damon_nr_accesses_mvsum()), reducing structure memory overhead and
   avoiding state corruption bugs.
 
 - The 6 patch series "Open HugeTLB allocation routine for more generic
   use" from Ackerley Tng decouples HugeTLB folio allocation from VMA
   dependencies by introducing hugetlb_alloc_folio(), enabling subsystems
   like guest_memfd to allocate HugeTLB folios without standard VMA
   reservations or pseudo-VMAs.
 
 - The 3 patch series "mm/damon: provide pseudo moving sum probe_hits"
   from SJ Park integrates DAMON's probe_hits attribute counter into the
   pseudo moving sum infrastructure, enabling real-time, online monitoring
   without waiting for full aggregation intervals.
 
 - The 18 patch series "mm: Some cleanups for page allocator APIs" from
   Brendan Jackman simplifies and refactors the page allocator entry points
   and flags by unifying allocation paths, adding internal alloc_flags
   arguments, and eliminating redundant __ prefixed alloc_pages variants.
 
 - The 5 patch series "Fix incorrect access of hugetlb pte entries" from
   Dev Jain enforces the consistent use of huge_ptep_get() instead of
   ptep_get() for HugeTLB entries and fixes an unaligned address issue in
   arm64's huge_ptep_get() implementation.
 
 - The 8 patch series "mm/damon: validate all parameters in the core"
   from SJ Park consolidates parameter validation into the DAMON core
   specifically within damon_start() and damon_commit_ctx() to centralize
   error checking, eliminate caller-side redundant checks and to improve
   maintenance efficiency.
 
 - The 3 patch series "tools/mm/page_owner_sort: fix filtering and
   cleanup issues" from Yichong Chen renames is_need() to filter_record()
   for clearer return semantics, fixes per-record allocation memory leaks
   and bounds output copies in search_pattern() to address an existing
   buffer issue.
 
 - The 4 patch series "memcg: bail out reclaim when memcg is dying" from
   Jiayuan Chen mitigates a system-wide stall which occurs when a cgroup is
   removed while one of its memory control files is doing synchronous
   reclaim.
 
 - The 5 patch series "mm/memory-failure: add panic option for
   unrecoverable pages" from Breno Leitao introduces an opt-in
   vm.panic_on_unrecoverable_memory_failure sysctl that immediately panics
   the kernel on unrecoverable memory errors in kernel-owned pages to
   preserve error context and prevent delayed, silent data corruption.
 
 - The 11 patch series "mm/damon: refactor damon_{start,stop,commit}()
   for simple error handling" from SJ Park refactors the DAMON core API
   functions to guarantee that all contexts are fully stopped when
   damon_start(), damon_stop(), or damon_commit() fail, eliminating the
   need for complex and error-prone caller-side cleanup code.
 
 - The 5 patch series "Keep tail page private zero at free and folio
   split" from Zi Yan adds checks to ensure tail_page->private is zero when
   freeing compound or high-order pages and when promoting tail pages
   during large folio splits.  By validating these fields at free and split
   time, it allows the removal of redundant private field clearing inside
   prep_compound_tail().
 
 - The 4 patch series "mm: drop redundant lru_add_drain in anon folio
   reuse paths" from Barry Song eliminates redundant lru_add_drain() calls
   in wp_can_reuse_anon_folio() and do_swap_page() to reduce LRU lock
   contention and system overhead.
 
   By validating folio refcounts against the LRU cache before draining
   and removing unnecessary drains in the swap path, it achieves up to a
   30.5% reduction in drain calls during heavy swap workloads.
 
 - The 3 patch series "mm: clean up folio LRU and swap declarations" from
   Jianyue Wu reorganizes folio LRU and swap code by relocating
   page-cluster state to mm/swap_state.c, renaming mm/swap.c to mm/folio.c,
   and moving MM-internal reclaim declarations into mm/internal.h.
 
 - The 15 patch series "userfaultfd: working set tracking for VM guest
   memory" from Kiryl Shutsemau adds userfaultfd support for tracking the
   working set of VM guest memory, so a VMM can identify hot pages and
   reclaim cold ones to tiered or remote storage.
 
 - The 10 patch series "mm: remove CONFIG_HAVE_BOOTMEM_INFO_NODE (Part
   2)" from David Hildenbrand removes the remaining pieces of
   CONFIG_HAVE_BOOTMEM_INFO_NODE, performing some smaller cleanups around
   freeing of reserved vmemmap pages on the way.
 
 - The 7 patch series "mm/damon: update probe hits for runtime parameter
   commits" from SJ Park ensures that DAMON's probe_hits attribute counter
   is properly updated when monitoring intervals are changed at runtime,
   matching the behavior of nr_accesses.  To achieve this, it refactors and
   renames existing helper functions for shared use, applies the updates to
   probe_hits, and handles edge cases in damon_probe_hits_mvsum() to
   maintain measurement accuracy.
 
 - The 3 patch series "KSM: performance optimizations for rmap_walk_ksm"
   from xu xin resolves a severe KSM reverse-mapping performance bottleneck
   where thousands of split VMAs sharing a single anon_vma cause extended
   lock contention.  By adding an interval-filtering check during the rmap
   walk, it reduces worst-case anon_vma lock hold times from over 500ms
   down to under 2ms, preventing application freezes and latency spikes
   under memory pressure.
 
 - The 3 patch series "mm: split a couple of headers from internal.h"
   from Mike Rapoport splits declarations related to mm_init, memblock,
   vmalloc and sparse into new headers.
 
 - The 2 patch series "KSM: use linear_page_index in collect_procs_ksm()"
   from xu xin applies the interval tree optimization from rmap_walk_ksm()
   to collect_procs_ksm() to avoid iterating over non-matching VMAs during
   KSM memory error handling.  It hoists loop-invariant address
   initialization and restricts the anon_vma_interval_tree_foreach walk to
   a targeted page offset range, reducing redundant checks and improving
   lookup efficiency.
 
 - The 3 patch series "selftests/mm: avoid false failures in hugetlb and
   KSM tests" from Sayali Patil fixes issues in the hugetlb and KSM MM
   selftest categories that can report failures when the prerequisites for
   the tests are not satisfied.
 
 - The 19 patch series "mm/damon: introduce data attributes only
   monitoring" from SJ Park introduces attribute-weighted region management
   in DAMON, allowing users to prioritize specific data attributes (such as
   page sizes or cgroups) over or instead of access monitoring.
 
   By assigning weights to attribute probes, DAMON can completely disable
   access tracking and adjust monitoring regions based on weighted
   probe-hit counters to optimize monitoring quality for attribute-focused
   workloads.
 
 - The 8 patch series "mm/hmm: Add mmap lock-drop support for
   userfaultfd-backed mappings" from Stanislav Kinsburskii extends
   hmm_range_fault() to support userfaultfd-backed regions by allowing the
   mmap lock to be dropped during fault handling via a new
   hmm_range_fault_locked() helper.
 
   By accepting a locked pointer and signaling retry status when lock
   release occurs, it enables page fault resolution in userfaultfd regions
   while preserving backward compatibility for existing callers.
 
 - The 33 patch series "mm: make VMA page offset handling more
   consistent" from Lorenzo Stoakes cleans up and standardizes how
   vma->vm_pgoff is accessed and manipulated across file-backed and
   anonymous mappings in the kernel.
 
   It introduces dedicated helper functions such as vma_start_pgoff(),
   vma_end_pgoff(), vma_set_pgoff() and linear_page_delta() while renaming
   rmap interval tree helpers to better reflect their functionality.
 
   These changes establish a cleaner foundation for future work that will
   unify virtual page offset indexing for all anonymous and CoW'd folios.
 
 - The 3 patch series "mm: handle device-private PMDs in walk callbacks"
   from Usama Arif addresses kernel panics and state corruption caused by
   MM walk callbacks reaching non-present device-private PMD swap entries
   created during HMM migrations.
 
   It ensures that functions which acquire pmd_trans_huge_lock() properly
   recognize device-private PMDs instead of assuming a present THP or a
   standard migration entry.
 
 - The 5 patch series "mm/rmap: Refactor try_to_unmap_one" from Dev Jain
   refactors try_to_unmap_one by modularizing Hugetlb, anonymous-lazyfree,
   and anonymous-swapbacked logic into dedicated functions, laying the
   structural groundwork for batched anonymous large folio unmapping.
 
 - The 4 patch series "Docs/ABI/damon: sysfs ABI document fixes and
   additions" from Song Hu fixes typos and fills in missing entries in the
   DAMON sysfs ABI document.
 
 - The 10 patch series "dax/kmem: atomic whole-device hotplug via sysfs"
   from Gregory Price introduces an atomic sysfs state attribute and
   supporting DAX/MM infrastructure to prevent userland races when
   offlining and removing entire memory regions.
 
   By adding an unplugged state alongside standard online modes, it
   enables whole-device atomic hotplug control while preserving backward
   compatibility.
 
 - The 13 patch series "mm: convert more vm_flags_t users to vma_flags_t"
   from Lorenzo Stoakes continues transitioning the kernel from the
   deprecated vm_flags_t type to vma_flags_t across core memory management
   infrastructure.
 
   It replaces legacy type usage in core functions such as do_mmap(),
   unmapped area allocation, mm->def_vma_flags, and VMA operations like
   mlock, mprotect, and mremap.
 
 - The 2 patch series "Two small patches to clean up mm/mm_slot.h" from
   xu xin refactors mm_slot.h by introducing mm_slot_remove() to unify
   duplicate slot deletion sequences in khugepaged and KSM.  It also adds
   code documentation explaining why mm_slot_lookup and mm_slot_insert must
   remain as preprocessor macros rather than static inline functions.
 
 - The 10 patch series "mm/damon/core: hide core-private struct fields"
   from SJ Park cleans up DAMON core structures by consistently marking
   internal-only fields with private: comment tags to prevent improper
   direct access from outer layers.
 
   It enforces encapsulation across core structures including
   damon_region, damon_target, and damon_ctx and updates DAMON_SYSFS to
   interact through approved access APIs instead of exposing raw struct
   members.
 
 - The 6 patch series "mm/damon: unurgent fixes for infinite loop, NULL
   de-ref and races" from SJ Park addresses potential infinite loops, NULL
   dereferences, and race conditions identified in DAMON.
 
   It fixes an infinite loop triggered by extreme user configurations, a
   NULL pointer dereference within unit tests and minor monitoring
   accuracy degradation caused by subtle runtime races.
 
 - The 2 patch series "mm/page_alloc: fixes for free_pages_nolock() on
   RT/UP" from Brendan Jackman fixes an NMI safety flaw in
   __free_frozen_pages() where freeing pages on non-SMP or PREEMPT_RT
   kernels can bypass can_spin_trylock() checks via non-PCP or isolated
   migration paths.
 
   It also resolves potential kernel crashes and privilege escalation
   risks triggered when BPF tracing runs in NMI context alongside memory
   hotplug or large allocation frees.
 
 - The 4 patch series "mm/page_alloc: couple of followups for recent
   cleanups" from Brendan Jackman cleans up and updates page allocator
   nomenclature, documentation, and debug assertions.
 
   It aligns internal FPI_ flags with the public "nolock" naming
   convention, removes outdated internal implementation details from
   high-level page allocator comments, and eliminates obsolete VM_BUG_ON()
   assertions in allocation paths.
 
 - The 3 patch series "mm/mseal: further cleanups" from Lorenzo Stoakes
   refactors and simplifies the mseal implementation by clarifying API
   boundaries and removing unnecessary code complexity.
 
   It replaces generic do_mseal() usage outside the syscall with a
   dedicated mseal_mmap_page_zero() helper for MMAP_PAGE_ZERO, eliminates
   mm_struct parameters to enforce that sealing applies only to
   current->mm, and streamlines overall logic and comments with no
   functional changes intended.
 
 - The 4 patch series "mm/vmscan: fix swappiness=max and clean up
   per-node proactive reclaim" from Ridong Chen resolves reclaim behavior
   bugs and cleans up function parameters across memory reclaim paths.
 
   It fixes swappiness=max in both standard reclaim and MGLRU so
   unswappable anonymous memory no longer falls back to evicting page
   cache, ensures reclaim_store() returns accurate error codes instead of
   collapsing all failures into -EAGAIN, and removes the obsolete gfp_mask
   parameter from __node_reclaim().
 
 - The 6 patch series "mm: mincore: misc cleanups" from Kefeng Wang
   cleans up and simplifies the mincore code.  Most importantly, it removes
   the historical special behavior that always reports VM_PFNMAP pages as
   non-resident.
 
 - The 2 patch series "mm/huge_memory: drop dead split helper variants"
   from Kiryl Shutsemau implements two trivial cleanups in the folio split
   API.
 
 - The 7 patch series "mm/damon: fix uninitialized DAMOS field and kunit
   exec expectation bugs" from SJ Park resolves minor operational and
   testing bugs in DAMON identified by Sashiko.  It initializes the
   damos->last_applied field to prevent occasional efficiency degradation
   and fixes invalid memory accesses in DAMON KUnit tests during test
   failure handling.
 
 - The 3 patch series "cleanup for stable_page_flags()" from Jinjiang Tu
   cleans up and refactors stable_page_flags() used by /proc/kpageflags
   without altering functionality.
 
   It uses BIT_ULL() to prevent shift-overflow warnings on 64-bit flag
   bits, converts folio-specific flag checks to standard folio_test_*()
   helpers, and removes redundant CONFIG_PAGE_IDLE_FLAG handling.
 
 - The 3 patch series "Batch unmap of uffd-wp file folios" from Dev Jain
   extends batched folio unmapping support to file folios within
   userfaultfd write-protect (uffd-wp) VMAs by adding batching capabilities
   to pte_install_uffd_wp_if_needed().
 
   This removes special-case restrictions on uffd-wp VMAs in
   try_to_unmap_one(), significantly simplifying the function's control
   flow and complexity.
 
 - The 3 patch series "mm/early_ioremap: clarify and clean up
   early_ioremap_reset()" from Sang-Heon Jeon clarifies and cleans up the
   architecture-specific usage of __late_set_fixmap() and
   __late_clear_fixmap() after early_ioremap_reset().
 
   It adds explicit documentation regarding when early_ioremap_reset()
   must be called and removes redundant macro definitions and reset calls
   in the RISC-V and ARM64 architectures.
 
 - The 4 patch series "mm: fix reclaim storms in defrag_mode" from
   Johannes Weiner addresses severe performance regressions, swap storms,
   and spurious OOMs caused by vm.defrag_mode=1 under high memory pressure
   in Meta production.
 
   It updates the page allocator slowpath so non-movable allocation
   requests actively trigger direct reclaim and direct compaction at
   pageblock_order scale, allowing them to claim whole pageblocks rather
   than spinning unproductively.
 
 - The 2 patch series "zram: lockmap tweaks" from Sebastian Siewior
   optimizes and fixes lockdep tracking for zram devices by consolidating
   per-entry lockmaps and isolating lock classes across multiple instances.
 
   It reduces memory overhead by replacing per-entry lockdep_map instances
   with a single map per struct zram, and assigns a dynamic lock_class_key
   to each instance to prevent false deadlock reports when different zram
   devices are backed by distinct filesystems.
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Merge tag 'mm-stable-2026-08-18-18-39' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:

 - "mm: drop "sub" prefix from various places" (Dev Jain)

   page->folio conversion and a naming cleanup

 - "mm/kasan: remove redundant initialization for kasan_flag_write_only"
   (Igor Putko)

   KASAN cleanup work

 - "mm/filemap: reduce unnecessary xarray lookups" (Chi Zhiling)

   Small speedup in the pagecaache read code

 - "mm/percpu: Fix possible NOFS/NOIO reclaim recursion" (Kaitao Cheng)

   Improve the vmalloc code - mainly the avoidance of GFP_KERNEL
   allocations when the caller asked for GFP_NOFS or GFP_NOIO

 - "mm/kmemleak: avoid soft lockup when scanning task stacks" (Breno
   Leitao)

   Avoid a soft lockup watchdog trigger from the kmemleak scanning code
   in extreme situations

 - "mm/page_owner: misc cleanups" (Ye Liu)

   Cleanups to the page_owner code. For some reason lots of people have
   been working on the page_owner code this cycle.

 - "mm: convert to walk_page_range_vma() to eliminate find_vma()"
   (Kefeng Wang)

   Simplify and accelerate the page walking library function

 - "mm/migrate: preparatory cleanups for batch copy and offload"
   (Shivank Garg)

   Cleanups in the migration code

 - "mm/page_owner: add per-fd filter infrastructure for print_mode and
   NUMA filtering" (Zhen Ni)

   Per-fd filtering to page_owner in order to reduce the sometimes vast
   amount of output it can produce

 - "mm: Refactor bootmem gigantic hugepage allocation" (Muchun Song)

   Fixes and preparatory cleanups around bootmem HugeTLB handling,
   sparse initialization ordering, and related vmemmap setup

 - "mm/zsmalloc: reduce lock contention in zs_free()" (Wenchao Hao)

   Reduce lock contention in zs_free(), which dominates the unmap path
   under memory pressure on Android (LMK kills) and on x86 servers
   running zswap-heavy workloads.

   Up to 1.83x improvement in microbenchmarking.

 - "move alloc_tag.c file under mm/" (Suren Baghdasaryan)

 - "samples/damon: handle damon_{start,stop}() failures" (SJ Park)

   Fix improper handling of damon_start(), damon_stop(), and
   damon_call() failures across DAMON sample modules to prevent
   potential memory leaks, operation disruptions and use-after-free
   bugs

 - "mm/damon/sysfs: kobject_del() directories that users can
   create/remove" (SJ Park)

   Fix delayed sysfs directory removal under DEBUG_KOBJECT_RELEASE
   causeing creation failures due to duplicate directory names by adding
   missing kobject_del() calls before creating new directories

 - "mm: cleanup clear_not_present_full_ptes()" (David Hildenbrand)

   Clean up the core pte handling code

 - "selftests/damon: misc fixes for test bugs" (Kunwu Chan)

   Fix several bugs in the DAMON selftests

 - "selftests/damon: fix memcg_path staging handling" (Cheng Nie)

   Fix a bug in _damon_sysfs.py for damos_filter memcg_path setup, and
   add a test case for it in sysfs.py.

 - "selftests/damon: test kdamond refresh_ms" (Ruslan Valiyev)

   Selftest coverage for DAMON's refresh_ms sysfs feature by updating
   the test control module and verifying that scheme stats update
   automatically without manual intervention

 - "mm/damon: five misc fixups" (Akinobu Mita)

   Miscellaneous DAMON fixups.

 - "mm/damon/core: detect internal variation above max_nr_regions/2"
   (Jiayuan Chen)

   Fix DAMON's region splitting behavior when region counts exceed half
   the maximum budget by dynamically scaling down the split fraction as
   the limit approaches, preventing large regions from staying un-split,
   and add corresponding KUnit test coverage

 - "mm: preparatory patches for PMD level swap entries" (Usama Arif)

   Refactor and clean up PMD softleaf helpers, call sites, and
   architecture flags to lay the groundwork for a follow-up series that
   introduces PMD page table swap entries

 - "mm/damon: update, optimize, and clean up doc, tests, and code" (SJ
   Park)

   Update DAMON design and ABI documentation, expands unit and selftest
   coverage, optimize damon_commit_target_regions(), and clean up
   recently added sysfs interface code for better readability

 - "mm/vmpressure: reduce CPU, memory and code overhead on cgroup v2"
   (Usama Arif)

   Optimize vmpressure() by skipping unnecessary work on cgroup v2 for
   userspace event notifications and refactor v1-only eventfd handling
   into mm/memcontrol-v1.c to reduce memory overhead and code complexity

 - "selftests/mm: refactor pkey helpers and fix mmap error handling"
   (Hongfu Li)

   Refactor pkeys shared tracing and assertion helpers into a common
   file, unify protection key selftests to use consistent diagnostic
   logging and assertions, and enforce standardized MAP_FAILED return
   checks for mmap() calls across the tests

 - "mm/damon: optimize out nr_accesses_bp" (SJ Park)

   Replace the error-prone, continuously updated nr_accesses_bp field in
   damon_region with an on-demand moving sum function, reducing
   structure memory overhead and avoiding state corruption bugs

 - "Open HugeTLB allocation routine for more generic use" (Ackerley Tng)

   Decouple HugeTLB folio allocation from VMA dependencies by
   introducing hugetlb_alloc_folio(), enabling subsystems like
   guest_memfd to allocate HugeTLB folios without standard VMA
   reservations or pseudo-VMAs

 - "mm/damon: provide pseudo moving sum probe_hits" (SJ Park)

   Integrate DAMON's probe_hits attribute counter into the pseudo moving
   sum infrastructure, enabling real-time, online monitoring without
   waiting for full aggregation intervals

 - "mm: Some cleanups for page allocator APIs" (Brendan Jackman)

   Simplify and refactor the page allocator entry points and flags by
   unifying allocation paths, adding internal alloc_flags arguments, and
   eliminating redundant __ prefixed alloc_pages variants.

 - "Fix incorrect access of hugetlb pte entries" (Dev Jain)

   Enforce the consistent use of huge_ptep_get() instead of ptep_get()
   for HugeTLB entries and fixes an unaligned address issue in arm64's
   huge_ptep_get() implementation

 - "mm/damon: validate all parameters in the core" (SJ Park)

   Consolidate parameter validation into the DAMON core specifically
   within damon_start() and damon_commit_ctx() to centralize error
   checking, eliminate caller-side redundant checks and to improve
   maintenance efficiency

 - "tools/mm/page_owner_sort: fix filtering and cleanup issues" (Yichong
   Chen)

   Rename is_need() to filter_record() for clearer return semantics, fix
   per-record allocation memory leaks and bound output copies in
   search_pattern() to address an existing buffer issue

 - "memcg: bail out reclaim when memcg is dying" (Jiayuan Chen)

   Mitigate a system-wide stall which occurs when a cgroup is removed
   while one of its memory control files is doing synchronous reclaim

 - "mm/memory-failure: add panic option for unrecoverable pages" (Breno
   Leitao)

   Introduce an opt-in vm.panic_on_unrecoverable_memory_failure sysctl
   that immediately panics the kernel on unrecoverable memory errors in
   kernel-owned pages to preserve error context and prevent delayed,
   silent data corruption

 - "mm/damon: refactor damon_{start,stop,commit}() for simple error
   handling" (SJ Park)

   Refactor the DAMON core API functions to guarantee that all contexts
   are fully stopped when damon_start(), damon_stop(), or damon_commit()
   fail, eliminating the need for complex and error-prone caller-side
   cleanup code

 - "Keep tail page private zero at free and folio split" (Zi Yan)

   Add checks to ensure tail_page->private is zero when freeing compound
   or high-order pages and when promoting tail pages during large folio
   splits. By validating these fields at free and split time, it allows
   the removal of redundant private field clearing inside
   prep_compound_tail()

 - "mm: drop redundant lru_add_drain in anon folio reuse paths" (Barry
   Song)

   Eliminate redundant lru_add_drain() calls in
   wp_can_reuse_anon_folio() and do_swap_page() to reduce LRU lock
   contention and system overhead

   By validating folio refcounts against the LRU cache before draining
   and removing unnecessary drains in the swap path, it achieves up to a
   30.5% reduction in drain calls during heavy swap workloads

 - "mm: clean up folio LRU and swap declarations" (Jianyue Wu)

   Reorganize folio LRU and swap code by relocating page-cluster state
   to mm/swap_state.c, renaming mm/swap.c to mm/folio.c, and moving
   MM-internal reclaim declarations into mm/internal.h.

 - "userfaultfd: working set tracking for VM guest memory" (Kiryl
   Shutsemau)

   Add userfaultfd support for tracking the working set of VM guest
   memory, so a VMM can identify hot pages and reclaim cold ones to
   tiered or remote storage

 - "mm: remove CONFIG_HAVE_BOOTMEM_INFO_NODE (Part 2)" (David
   Hildenbrand)

   Remove the remaining pieces of CONFIG_HAVE_BOOTMEM_INFO_NODE,
   performing some smaller cleanups around freeing of reserved vmemmap
   pages on the way.

 - "mm/damon: update probe hits for runtime parameter commits" (SJ Park)

   Ensure that DAMON's probe_hits attribute counter is properly updated
   when monitoring intervals are changed at runtime, matching the
   behavior of nr_accesses. To achieve this, it refactors and renames
   existing helper functions for shared use, applies the updates to
   probe_hits, and handles edge cases in damon_probe_hits_mvsum() to
   maintain measurement accuracy.

 - "KSM: performance optimizations for rmap_walk_ksm" (xu xin)

   Resolve a severe KSM reverse-mapping performance bottleneck where
   thousands of split VMAs sharing a single anon_vma cause extended lock
   contention.

   By adding an interval-filtering check during the rmap walk, it
   reduces worst-case anon_vma lock hold times from over 500ms down to
   under 2ms, preventing application freezes and latency spikes under
   memory pressure.

 - "mm: split a couple of headers from internal.h" (Mike Rapoport)

   Split declarations related to mm_init, memblock, vmalloc and sparse
   into new headers

 - "KSM: use linear_page_index in collect_procs_ksm()" (xu xin)

   Apply the interval tree optimization from rmap_walk_ksm() to
   collect_procs_ksm() to avoid iterating over non-matching VMAs during
   KSM memory error handling.

   It hoists loop-invariant address initialization and restricts the
   anon_vma_interval_tree_foreach walk to a targeted page offset range,
   reducing redundant checks and improving lookup efficiency.

 - "selftests/mm: avoid false failures in hugetlb and KSM tests" (Sayali
   Patil)

   Fix issues in the hugetlb and KSM MM selftest categories that can
   report failures when the prerequisites for the tests are not
   satisfied

 - "mm/damon: introduce data attributes only monitoring" (SJ Park)

   Introduce attribute-weighted region management in DAMON, allowing
   users to prioritize specific data attributes (such as page sizes or
   cgroups) over or instead of access monitoring.

   By assigning weights to attribute probes, DAMON can completely
   disable access tracking and adjust monitoring regions based on
   weighted probe-hit counters to optimize monitoring quality for
   attribute-focused workloads.

 - "mm/hmm: Add mmap lock-drop support for userfaultfd-backed mappings"
   (Stanislav Kinsburskii)

   Extend hmm_range_fault() to support userfaultfd-backed regions by
   allowing the mmap lock to be dropped during fault handling via a new
   hmm_range_fault_locked() helper.

   By accepting a locked pointer and signaling retry status when lock
   release occurs, it enables page fault resolution in userfaultfd
   regions while preserving backward compatibility for existing callers.

 - "mm: make VMA page offset handling more consistent" (Lorenzo Stoakes)

   Clean up and standardize how vma->vm_pgoff is accessed and
   manipulated across file-backed and anonymous mappings in the kernel

   It introduces dedicated helper functions such as vma_start_pgoff(),
   vma_end_pgoff(), vma_set_pgoff() and linear_page_delta() while
   renaming rmap interval tree helpers to better reflect their
   functionality.

   These changes establish a cleaner foundation for future work that
   will unify virtual page offset indexing for all anonymous and CoW'd
   folios.

 - "mm: handle device-private PMDs in walk callbacks" (Usama Arif)

   Address kernel panics and state corruption caused by MM walk
   callbacks reaching non-present device-private PMD swap entries
   created during HMM migrations

   It ensures that functions which acquire pmd_trans_huge_lock()
   properly recognize device-private PMDs instead of assuming a present
   THP or a standard migration entry.

 - "mm/rmap: Refactor try_to_unmap_one" (Dev Jain)

   Refactor try_to_unmap_one by modularizing Hugetlb,
   anonymous-lazyfree, and anonymous-swapbacked logic into dedicated
   functions, laying the structural groundwork for batched anonymous
   large folio unmapping.

 - "Docs/ABI/damon: sysfs ABI document fixes and additions" (Song Hu)

   Fix typos and fills in missing entries in the DAMON sysfs ABI
   document

 - "dax/kmem: atomic whole-device hotplug via sysfs" (Gregory Price)

   Introduce an atomic sysfs state attribute and supporting DAX/MM
   infrastructure to prevent userland races when offlining and removing
   entire memory regions

   By adding an unplugged state alongside standard online modes, it
   enables whole-device atomic hotplug control while preserving backward
   compatibility.

 - "mm: convert more vm_flags_t users to vma_flags_t" (Lorenzo Stoakes)

   Continue transitioning the kernel from the deprecated vm_flags_t type
   to vma_flags_t across core memory management infrastructure.

   It replaces legacy type usage in core functions such as do_mmap(),
   unmapped area allocation, mm->def_vma_flags, and VMA operations like
   mlock, mprotect, and mremap.

 - "Two small patches to clean up mm/mm_slot.h" (xu xin)

   Refactor mm_slot.h by introducing mm_slot_remove() to unify duplicate
   slot deletion sequences in khugepaged and KSM. It also adds code
   documentation explaining why mm_slot_lookup and mm_slot_insert must
   remain as preprocessor macros rather than static inline functions.

 - "mm/damon/core: hide core-private struct fields" (SJ Park)

   Clean up DAMON core structures by consistently marking internal-only
   fields with private: comment tags to prevent improper direct access
   from outer layers.

   It enforces encapsulation across core structures including
   damon_region, damon_target, and damon_ctx and updates DAMON_SYSFS to
   interact through approved access APIs instead of exposing raw struct
   members.

 - "mm/damon: unurgent fixes for infinite loop, NULL de-ref and races"
   (SJ Park)

   Address potential infinite loops, NULL dereferences, and race
   conditions identified in DAMON

   It fixes an infinite loop triggered by extreme user configurations, a
   NULL pointer dereference within unit tests and minor monitoring
   accuracy degradation caused by subtle runtime races.

 - "mm/page_alloc: fixes for free_pages_nolock() on RT/UP" (Brendan
   Jackman)

   Fix an NMI safety flaw in __free_frozen_pages() where freeing pages
   on non-SMP or PREEMPT_RT kernels can bypass can_spin_trylock() checks
   via non-PCP or isolated migration paths.

   It also resolves potential kernel crashes and privilege escalation
   risks triggered when BPF tracing runs in NMI context alongside memory
   hotplug or large allocation frees.

 - "mm/page_alloc: couple of followups for recent cleanups" (Brendan
   Jackman)

   Clean up and update page allocator nomenclature, documentation, and
   debug assertions.

   It aligns internal FPI_ flags with the public "nolock" naming
   convention, removes outdated internal implementation details from
   high-level page allocator comments, and eliminates obsolete
   VM_BUG_ON() assertions in allocation paths.

 - "mm/mseal: further cleanups" (Lorenzo Stoakes)

   Refactor and simplify the mseal implementation by clarifying API
   boundaries and removing unnecessary code complexity.

   It replaces generic do_mseal() usage outside the syscall with a
   dedicated mseal_mmap_page_zero() helper for MMAP_PAGE_ZERO,
   eliminates mm_struct parameters to enforce that sealing applies only
   to current->mm, and streamlines overall logic and comments with no
   functional changes intended.

 - "mm/vmscan: fix swappiness=max and clean up per-node proactive
   reclaim" (Ridong Chen)

   Resolve reclaim behavior bugs and clean up function parameters across
   memory reclaim paths

   It fixes swappiness=max in both standard reclaim and MGLRU so
   unswappable anonymous memory no longer falls back to evicting page
   cache, ensures reclaim_store() returns accurate error codes instead
   of collapsing all failures into -EAGAIN, and removes the obsolete
   gfp_mask parameter from __node_reclaim().

 - "mm: mincore: misc cleanups" (Kefeng Wang)

   Clean up and simplifies the mincore code. Most importantly, it
   removes the historical special behavior that always reports VM_PFNMAP
   pages as non-resident.

 - "mm/huge_memory: drop dead split helper variants" (Kiryl Shutsemau)

   Two trivial cleanups in the folio split API

 - "mm/damon: fix uninitialized DAMOS field and kunit exec expectation
   bugs" (SJ Park)

   Resolve minor operational and testing bugs in DAMON identified by
   Sashiko. It initializes the damos->last_applied field to prevent
   occasional efficiency degradation and fixes invalid memory accesses
   in DAMON KUnit tests during test failure handling.

 - "cleanup for stable_page_flags()" (Jinjiang Tu)

   Clean up and refactor stable_page_flags() used by /proc/kpageflags
   without altering functionality.

   It uses BIT_ULL() to prevent shift-overflow warnings on 64-bit flag
   bits, converts folio-specific flag checks to standard folio_test_*()
   helpers, and removes redundant CONFIG_PAGE_IDLE_FLAG handling.

 - "Batch unmap of uffd-wp file folios" (Dev Jain)

   Extend batched folio unmapping support to file folios within
   userfaultfd write-protect (uffd-wp) VMAs by adding batching
   capabilities to pte_install_uffd_wp_if_needed().

   This removes special-case restrictions on uffd-wp VMAs in
   try_to_unmap_one(), significantly simplifying the function's control
   flow and complexity.

 - "mm/early_ioremap: clarify and clean up early_ioremap_reset()"
   (Sang-Heon Jeon)

   Clarify and clean up the architecture-specific usage of
   __late_set_fixmap() and __late_clear_fixmap() after
   early_ioremap_reset()

   It adds explicit documentation regarding when early_ioremap_reset()
   must be called and removes redundant macro definitions and reset
   calls in the RISC-V and ARM64 architectures.

 - "mm: fix reclaim storms in defrag_mode" (Johannes Weiner)

   Address severe performance regressions, swap storms, and spurious
   OOMs caused by vm.defrag_mode=1 under high memory pressure in Meta
   production

   It updates the page allocator slowpath so non-movable allocation
   requests actively trigger direct reclaim and direct compaction at
   pageblock_order scale, allowing them to claim whole pageblocks rather
   than spinning unproductively.

 - "zram: lockmap tweaks" (Sebastian Siewior)

   Optimize and fix lockdep tracking for zram devices by consolidating
   per-entry lockmaps and isolate lock classes across multiple instances

   This reduces memory overhead by replacing per-entry lockdep_map
   instances with a single map per struct zram, and assigns a dynamic
   lock_class_key to each instance to prevent false deadlock reports
   when different zram devices are backed by distinct filesystems.

* tag 'mm-stable-2026-08-18-18-39' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (501 commits)
  selftests/mm: thuge-gen: fix test_shmget() for PAGE_SIZE check
  selftests/mm: unpoison pages in memory-failure teardown
  mm/shmem: downgrade final i_blocks check in shmem_evict_inode() to pr_warn()
  mm/khugepaged: replace mutex_lock/mutex_unlock usage with guard macro
  mm/zsmalloc: fix release order of locks in zs_page_migrate()
  Documentation: zram: remove sections numbering
  ksm: stop iterating VMAs when ksm_test_exit returns true
  mm: fold userfaultfd_rwp() to false without CONFIG_ARCH_HAS_PTE_PROTNONE
  mm/migrate: report RCU-tasks quiescent states in migrate_pages_batch()
  zram: use a custom key for each zram object
  zram: move lockmap to be per-zram instead per table
  selftests/mm: fix gup_longterm EINVAL error message
  mm: page_alloc: fix non-movable reclaim storm in defrag_mode
  mm: page_alloc: move capture_control to the page allocator
  mm: compaction: support non-movable compaction for pageblock requests
  mm: page_alloc: __GFP_FS lockdep annotation for direct compaction
  hugetlb: evaluate subpool free state while locked
  mm/damon: remove trailing semicolons after function definitions
  mm/damon/ops-common: prevent migration fallback to non-target nodes
  mm/damon: update outdated comment about DAMOS filter handling
  ...
2026-08-20 18:17:08 -07:00
Linus Torvalds
55ab7e1422 for-7.3/block-20260819
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Merge tag 'for-7.3/block-20260819' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux

Pull block updates from Jens Axboe:

 - NVMe updates via Keith:
     - Enable Clang context analysis for the nvme host driver, adding
       context annotations across core, fabrics, rdma, tcp and pci
     - nvmet reservation state exposed through a new namespace-level
       debugfs directory, plus ABI documentation for the host sysfs and
       target configfs interfaces
     - nvme-tcp host memory disclosure fixes on the read path: reject a
       read that transferred too few bytes, don't accept C2HData based
       on blk_rq_payload_bytes() alone, and fix the R2T case for a read
       command
     - Parallelize nvme-rdma I/O queue allocation and startup (Surabhi)
     - Apple nvme fixes and quirks: page aligned admin queue buffers,
       destroy the admin queue on removal, and various DMA/NVMMU
       correctness fixes
     - A large pile of nvmet and host fixes for out-of-bounds reads,
       refcount/resource leaks, and NULL derefs across auth, zns,
       passthru, pci-epf, rdma and configfs
     - Various other fixes and cleanups

 - MD updates via Yu Kuai:
     - llbitmap reshape support, the large series wiring exact bitmap
       mapping and reshape lifecycle through raid5 and raid10, growing
       the page cache in place, and remapping checkpointed bits as
       reshape progresses
     - raid5 fixes for lockless max_nr_stripes and recovery_offset
       accesses, a reshape deadlock with more failed devices than max
       degraded, and bitmap batch counter consistency
     - Atomic write handling for raid1/raid10, and removal of the
       REQ_NOWAIT support from raid1/10/456
     - raid5-ppl use-after-free fix in ppl_do_flush()
     - A batch of smaller fixes across md core and the bitmap code

 - s390/dasd ESE full-track write support and the surrounding
   infrastructure, plus enabling CONTEXT_ANALYSIS for s390/block

 - RWF_DONTCACHE support for block devices, built on new task-context
   bio completion infrastructure, and wiring it up for the iomap and
   buffer dropbehind writeback paths

 - Async io_uring zone reset all, plus zone management command cleanups
   allowing REQ_NOWAIT and tightening conventional zone rejection

 - Block integrity refactoring: lift BIP_CHECK_FLAGS to the shared
   header, handle nogenerate/noverify properly in fs-integrity, and drop
   the blk-integrity.h include from bdev.c

 - Split out a new blk_plug.h header

 - ublk improvements: add UBLK_F_IO_DESC_SIZE, split request validation
   from io_desc init, reject non-power-of-2 zone sizes in SET_PARAMS,
   and a series of hardening fixes around map/unmap and auto buf reg

 - null_blk cleanups and configfs serialization fixes

 - nbd queue freeze removal on the setup paths, and a new
   pre_defined_connections module parameter for pre-created devices

 - blk-cgroup fixes for the race between policy activation and blkg
   destruction, and accounting per-cpu stats over possible CPUs across
   blk-stat, iolatency, iocost and kyber

 - Various dio fixes: leak on metadata mapping error, validate user
   space vectors during extraction, and set dma_alignment from the
   backing file for loop and zloop direct I/O

 - bio cleanups

 - Various other fixes and cleanups all over

* tag 'for-7.3/block-20260819' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux: (241 commits)
  nbd: add pre_defined_connections module parameter for pre-created devices
  nbd: remove queue freeze for newly created nbd from netlink path
  nbd: factor out a nbd_genl_foreach_sock
  nbd: skip queue freeze when setting size at device startup
  nbd: remove queue freeze in nbd_add_socket
  nbd: clear queue limits on disconnect
  nbd: disallow NBD_SET_SOCK on an active device
  nbd: simplify find_fallback() by removing redundant logic
  blk-mq: add missing call to srcu_barrier() in blk_mq_free_tag_set()
  block: mtip32xx: synchronize ioctls with device removal
  ublk: avoid teardown retry loop on xarray allocation failure
  null_blk: fix UBSAN shift-out-of-bounds when zone_size is 0 or overflows
  block: don't include blk-integrity.h in bdev.c
  xfs: avoid double deferrals for RWF_DONTCACHE writes
  loop: Fix recently introduced lock inversion
  block: set QUEUE_FLAG_DYING unconditionally in blk_mark_disk_dead()
  swim3: Add missing MODULE_DESCRIPTION
  selftests: ublk: add SET_PARAMS validation test
  selftests: ublk: add helper for SET_PARAMS
  ublk: reject non-power-of-2 zone sizes in SET_PARAMS
  ...
2026-08-20 13:55:16 -07:00
Linus Torvalds
d24f5cdbef Rust changes for v7.3
Toolchain and infrastructure:
 
  - Warn when using 'bindgen' < 0.72.1 with 'libclang' >= 22, since that
    combination may fail to build. It includes a probe for the bug in
    case 'bindgen' happens to be patched, and tests.
 
    In parallel, Nathan updated the instructions for the kernel.org
    LLVM+Rust toolchains so that the latest version of 'bindgen' is
    installed, which should avoid some of these situations.
 
  - Support testing 'rust_is_available.sh' with 'bash' as '/bin/sh'.
 
  - Fix an objtool warning by adding one more 'noreturn' function for
    Rust 1.99.0 (expected 2026-10-01).
 
  - Fix build error in the 'rusttest' target due to ambiguity when the
    'rustc-dev' component is installed, which was uncovered by the work
    to support Rust's GCC backend ('rustc_codegen_gcc').
 
  - Fix future Clang warnings in the upcoming powerpc support due to
    macro redefinitions in the UAPI helper header by including the
    arch-aware 'ioctl.h' header.
 
 'kernel' crate:
 
  - Rework module ownership support:
 
      - Move the module-related types into a new 'module' module and make
        the 'THIS_MODULE' pointer a constant of 'ModuleMetadata' so that
        modules can provide the pointer in const contexts, and add a
        'this_module' 'const fn' to retrieve it.
 
        This was enabled by upstream Rust's work on the 'const_mut_refs'
        and 'const_refs_to_static' features which were stabilized back
        in Rust 1.83.0.
 
      - Teach '#[vtable]' to associate implementations with their owning
        module, defaulting to the local one, including fallbacks for
        doctests, uses within the 'kernel' crate (like upcoming KUnit
        '#[test]'s for DRM) and 'rusttest'.
 
      - Set 'fops.owner' from the module pointer for DRM and miscdevice.
 
      - Migrate Rust Binder and configfs away from the old 'THIS_MODULE'
        'static' and finally remove it from the 'module!' macro.
 
  - 'num' module:
 
      - Add the new 'casts' module for lossless integer conversions.
 
        Rust's 'core' library's 'From' implementations do not cover
        conversions that are not portable or future-proof. However, the
        kernel supports a narrower set of architectures, which makes it
        helpful to provide more infallible conversions, instead of having
        developers use 'as' casts, which carry the risk of silently
        losing data.
 
        This goes along with previous work we did to avoid casts in Rust
        kernel code since they are more powerful than needed.
 
        Thus, provide safe 'const' conversion functions (e.g.
        'usize_as_u64' and 'u64_into_u8'), as well as the 'FromSafeCast'
        and 'IntoSafeCast' extension traits that provide conversions that
        are known to be lossless in the kernel, and an 'arch' submodule
        defining conversions that are known to be lossless on particular
        architectures (e.g. 64-bit platforms). For instance:
 
            // Conversion in const context.
            const USIZED_CONST: usize = u8_as_usize(255u8);
 
            // Non-const conversions.
            let a = u64::from_safe_cast(4096usize);
            let b: u64 = 4096usize.into_safe_cast();
 
      - Add 'Bounded::shr_exact' method in the vein of 'try_shrink' which
        shifts a bounded right only if it loses no set bits.
 
      - Fix unsoundness issue in the 'Bounded::shr' method by rejecting,
        at compile-time, shifts of at least the type's bit width.
 
  - 'fmt' module:
 
      - Route '{:p}' raw pointer formatting through the kernel's hashed
        '%p' format to prevent address leaks, including support for width
        and padding. Include tests for both 'no_hash_pointers' case and
        the default (hashed) one.
 
      - Fix the '{:p}' forwarding implementation, which could print the
        address of a temporary stack variable.
 
  - 'time' module:
 
      - Make 'Delta' generic over its time unit, with a default unit of
        nanoseconds ('Nsec'), preserving the existing behavior. Then, add
        a 'Jiffy' time unit.
 
      - Add the 'Delta::as_millis_ceil()' method.
 
      - Fix 'as_micros_ceil()' rounding near 'i64::MAX', which could
        yield a result one microsecond too small.
 
  - 'sync' module:
 
      - Implement 'ForeignOwnable' for 'ARef<T>', allowing C code to own
        an 'ARef<T>'.
 
      - Add a safe abstraction for 'rcu_barrier()'.
 
  - 'error' module: add all of the remaining error codes, except the
    deprecated compatibility aliases.
 
  - 'bug' module:
 
      - Fix build error on UML in 'warn_on!' for callers from within
        the 'kernel' crate.
 
      - Fix future 'dead_code' warning on arm and loongarch64 and under
        'CONFIG_BUG=n' in 'warn_on!', which would trigger with the
        upcoming SRCU abstractions.
 
      - Fix future build error in 'rusttest' on cross-compilation cases,
        which would trigger when 'warn_on!' has callers inside the
        'kernel' crate.
 
  - 'bitfield' module: fix build error for the upcoming support for
    Rust's GCC backend ('rustc_codegen_gcc') by always inlining a couple
    conversions used in tests.
 
 'pin-init' crate:
 
  - User-visible changes:
 
      - Merge the '__pinned_init' and '__init' methods and make 'Init'
        a marker trait.
 
      - Introduce public APIs 'raw_init' and 'raw_try_init' to prevent
        users from needing to invoke the internal
        '__pinned_init'/'__init' methods.
 
      - Emit errors for duplicate '#[pin]' attributes.
 
      - Link 'Zeroable::zeroed' and 'pin_init::zeroed' in documentation.
 
  - Other changes:
 
      - Fix unwind safety issues.
 
      - Clean up lint 'allow' and 'expect's.
 
      - Overhaul '#[cfg]' handling to pave the way for tuple structs and
        self-referential structs.
 
      - Mark many functions as '#[inline]' for better codegen with '-C
        opt-level=s' ('CC_OPTIMIZE_FOR_SIZE').
 
 'MAINTAINERS':
 
  - Update 'MODULE SUPPORT' to cover the new 'module' module.
 
 And some other fixes, cleanups and improvements.
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Merge tag 'rust-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux

Pull Rust updates from Miguel Ojeda:
 "Toolchain and infrastructure:

   - Warn when using 'bindgen' < 0.72.1 with 'libclang' >= 22, since
     that combination may fail to build. It includes a probe for the bug
     in case 'bindgen' happens to be patched, and tests

     In parallel, Nathan updated the instructions for the kernel.org
     LLVM+Rust toolchains so that the latest version of 'bindgen' is
     installed, which should avoid some of these situations

   - Support testing 'rust_is_available.sh' with 'bash' as '/bin/sh'

   - Fix an objtool warning by adding one more 'noreturn' function for
     Rust 1.99.0 (expected 2026-10-01)

   - Fix build error in the 'rusttest' target due to ambiguity when the
     'rustc-dev' component is installed, which was uncovered by the work
     to support Rust's GCC backend ('rustc_codegen_gcc')

   - Fix future Clang warnings in the upcoming powerpc support due to
     macro redefinitions in the UAPI helper header by including the
     arch-aware 'ioctl.h' header

  'kernel' crate:

   - Rework module ownership support:

       - Move the module-related types into a new 'module' module and
         make the 'THIS_MODULE' pointer a constant of 'ModuleMetadata'
         so that modules can provide the pointer in const contexts, and
         add a 'this_module' 'const fn' to retrieve it

         This was enabled by upstream Rust's work on the 'const_mut_refs'
         and 'const_refs_to_static' features which were stabilized back
         in Rust 1.83.0

       - Teach '#[vtable]' to associate implementations with their
         owning module, defaulting to the local one, including fallbacks
         for doctests, uses within the 'kernel' crate (like upcoming
         KUnit '#[test]'s for DRM) and 'rusttest'

       - Set 'fops.owner' from the module pointer for DRM and
         miscdevice

       - Migrate Rust Binder and configfs away from the old
         'THIS_MODULE' 'static' and finally remove it from the 'module!'
         macro

   - 'num' module:

       - Add the new 'casts' module for lossless integer conversions

         Rust's 'core' library's 'From' implementations do not cover
         conversions that are not portable or future-proof. However, the
         kernel supports a narrower set of architectures, which makes it
         helpful to provide more infallible conversions, instead of
         having developers use 'as' casts, which carry the risk of
         silently losing data

         This goes along with previous work we did to avoid casts in
         Rust kernel code since they are more powerful than needed

         Thus, provide safe 'const' conversion functions (e.g.
         'usize_as_u64' and 'u64_into_u8'), as well as the
         'FromSafeCast' and 'IntoSafeCast' extension traits that provide
         conversions that are known to be lossless in the kernel, and an
         'arch' submodule defining conversions that are known to be
         lossless on particular architectures (e.g. 64-bit platforms).
         For instance:

             // Conversion in const context.
             const USIZED_CONST: usize = u8_as_usize(255u8);

             // Non-const conversions.
             let a = u64::from_safe_cast(4096usize);
             let b: u64 = 4096usize.into_safe_cast();

       - Add 'Bounded::shr_exact' method in the vein of 'try_shrink'
         which shifts a bounded right only if it loses no set bits

       - Fix unsoundness issue in the 'Bounded::shr' method by
         rejecting, at compile-time, shifts of at least the type's bit
         width

   - 'fmt' module:

       - Route '{:p}' raw pointer formatting through the kernel's hashed
         '%p' format to prevent address leaks, including support for
         width and padding. Include tests for both 'no_hash_pointers'
         case and the default (hashed) one

       - Fix the '{:p}' forwarding implementation, which could print the
         address of a temporary stack variable

   - 'time' module:

       - Make 'Delta' generic over its time unit, with a default unit of
         nanoseconds ('Nsec'), preserving the existing behavior. Then,
         add a 'Jiffy' time unit

       - Add the 'Delta::as_millis_ceil()' method

       - Fix 'as_micros_ceil()' rounding near 'i64::MAX', which could
         yield a result one microsecond too small

   - 'sync' module:

       - Implement 'ForeignOwnable' for 'ARef<T>', allowing C code to
         own an 'ARef<T>'

       - Add a safe abstraction for 'rcu_barrier()'

   - 'error' module: add all of the remaining error codes, except the
     deprecated compatibility aliases

   - 'bug' module:

       - Fix build error on UML in 'warn_on!' for callers from within
         the 'kernel' crate

       - Fix future 'dead_code' warning on arm and loongarch64 and under
         'CONFIG_BUG=n' in 'warn_on!', which would trigger with the
         upcoming SRCU abstractions

       - Fix future build error in 'rusttest' on cross-compilation
         cases, which would trigger when 'warn_on!' has callers inside
         the 'kernel' crate

   - 'bitfield' module: fix build error for the upcoming support for
     Rust's GCC backend ('rustc_codegen_gcc') by always inlining a
     couple conversions used in tests

  'pin-init' crate:

   - User-visible changes:

       - Merge the '__pinned_init' and '__init' methods and make 'Init'
         a marker trait

       - Introduce public APIs 'raw_init' and 'raw_try_init' to prevent
         users from needing to invoke the internal '__pinned_init' and
         '__init' methods

       - Emit errors for duplicate '#[pin]' attributes

       - Link 'Zeroable::zeroed' and 'pin_init::zeroed' in documentation

   - Other changes:

       - Fix unwind safety issues

       - Clean up lint 'allow' and 'expect's

       - Overhaul '#[cfg]' handling to pave the way for tuple structs
         and self-referential structs

       - Mark many functions as '#[inline]' for better codegen with '-C
         opt-level=s' ('CC_OPTIMIZE_FOR_SIZE')

  'MAINTAINERS':

   - Update 'MODULE SUPPORT' to cover the new 'module' module

  And some other fixes, cleanups and improvements"

* tag 'rust-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux: (54 commits)
  rust: add functions and traits for lossless integer conversions
  rust: kernel: add `LocalModule` fallback for `#[vtable]` `impl`s
  rust: fmt: route {:p} through HashedPtr to prevent address leaks
  rust: fmt: fix {:p} printing stack addresses
  rust: module: update MAINTAINERS to cover module.rs
  rust: macros: remove `THIS_MODULE` static from `module!`
  rust_binder: use `LocalModule` for `THIS_MODULE`
  rust: configfs: use `LocalModule` for `THIS_MODULE`
  rust: miscdevice: set fops.owner from driver module pointer
  rust: drm: set fops.owner from driver module pointer
  rust: macros: auto-insert OwnerModule in #[vtable]
  rust: doctest: add LocalModule fallback for #[vtable] ThisModule
  rust: module: add `THIS_MODULE` const to `ModuleMetadata` trait
  rust: module: move module types into `module.rs`
  rust: num: add Bounded::shr_exact
  rust: num: reject Bounded::shr overshifts at build time
  rust: num: use const_assert! in Bounded
  rust: uapi: replace direct asm-generic/ioctl.h include with linux/ioctl.h
  rust: time: add Delta::as_millis_ceil()
  rust: time: add jiffies time unit for Delta
  ...
2026-08-18 11:25:09 -07:00
Linus Torvalds
fff0150b02 vfs-7.3-rc1.kthread
Please consider pulling these changes from the signed vfs-7.3-rc1.kthread tag.
 
 Thanks!
 Christian
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Merge tag 'vfs-7.3-rc1.kthread' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

Pull kthread vfs updates from Christian Brauner:
 "This stops kernel threads from sharing filesystem state with
  userspace. This work is about 3 cycles old and has been in -next
  for about that time.

  When the kernel boots init_task creates PID 1 and then kthreadd. From
  that point every kthread and PID 1 share the same fs_struct. That is
  why pivot_root() has to rewrite the fs_struct of all kthreads. The
  rewriting exists so that kthreads can use init's filesystem state when
  they want to. It also means userspace can move the ground out from
  under the kernel.

  PID 1 now gets a completely separate fs_struct. All kthreads are
  anchored in a private SB_KERNMOUNT instance of nullfs that cannot be
  mounted on and cannot be used to follow other mounts. Userspace init
  can no longer affect kthread filesystem state and kthreads can no
  longer affect userspace fs state without explicit opting in to that.

  Path lookup from a kthread now fails by default. It makes it
  deliberately hard to offload security sensitive operations into init's
  filesystem state from a kthread.

  Places that legitimately need to look something up there opt in
  through the new scoped_with_init_fs() which temporarily overrides the
  caller's fs_struct with init's. usermodehelpers remain the only kernel
  tasks that genuinely share init's filesystem state, since they execute
  random binaries in the root filesystem (excellent...).

  The visible result is that /proc/2/root is a nullfs with an empty
  mountinfo while /proc/1/root is the real root"

* tag 'vfs-7.3-rc1.kthread' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (26 commits)
  initramfs_test: use test init/exit hooks to override init fs
  fs: stop rewriting paths for PF_EXITING | PF_DUMPCORE
  fs: stop rewriting kthread fs structs
  fs: start all kthreads in nullfs
  nullfs: make nullfs multi-instance
  devtmpfs: create private mount namespace
  fs: add umh argument to struct kernel_clone_args
  fs: stop sharing fs_struct between init_task and pid 1
  af_unix: use scoped_with_init_fs() for coredump socket lookup
  initramfs: use scoped_with_init_fs() for rootfs unpacking
  pnfs/blocklayout: use scoped_with_init_fs() for SCSI device lookup
  ksmbd: use scoped_with_init_fs() for VFS path operations
  ksmbd: use scoped_with_init_fs() for filesystem info path lookup
  ksmbd: use scoped_with_init_fs() for share path resolution
  fs: use scoped_with_init_fs() for kernel_read_file_from_path_initns()
  coredump: use scoped_with_init_fs() for coredump path resolution
  btrfs: use scoped_with_init_fs() for update_dev_time()
  scsi: target: use scoped_with_init_fs() for APTPL metadata
  scsi: target: use scoped_with_init_fs() for ALUA metadata
  crypto: ccp: use scoped_with_init_fs() for SEV file access
  ...
2026-08-17 11:35:12 -07:00
Joanne Koong
51e08eaf95 io_uring/rsrc: rename io_buffer_register_bvec()/io_buffer_unregister_bvec()
Currently, io_buffer_register_bvec() takes in a request. In preparation
for supporting kernel-populated buffers in fuse io-uring (which will
need to register bvecs directly, not through a struct request), rename
this to io_buffer_register_request().

A subsequent patch will commandeer the "io_buffer_register_bvec()"
function name to support registering bvecs directly.

Rename io_buffer_unregister_bvec() to a more generic name,
io_buffer_unregister(), as both io_buffer_register_request() and
io_buffer_register_bvec() callers will use it for unregistration.

Signed-off-by: Joanne Koong <joannelkoong@gmail.com>
Reviewed-by: Caleb Sander Mateos <csander@purestorage.com>
Link: https://patch.msgid.link/20260612184840.4058966-2-joannelkoong@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2026-08-17 17:02:09 +02:00
Linus Torvalds
dcb68831ea block-7.2-20260815
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Merge tag 'block-7.2-20260815' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux

Pull block fix from Jens Axboe:
 "A single fix for a regression in this cycle, where drbd would leak
  shared secrets over netlink. This restores the behavior to match
  what we had before"

* tag 'block-7.2-20260815' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux:
  drbd: don't leak the shared secret to unprivileged netlink dumps
2026-08-16 07:00:40 -07:00
Yang Erkun
326d49039c nbd: add pre_defined_connections module parameter for pre-created devices
blk_mq_update_nr_hw_queues() in nbd_start_device() may cause a queue
freeze.  The previous commit addressed this for newly created nbd
devices by setting the expected nr_hw_queues in nbd_dev_add().  However,
when reusing an old inactive nbd device, the queue freeze can still
occur if the old nbd->tag_set->nr_hw_queues does not match the new
socket connection count.  Inactive nbd devices can originate from two
sources: loading the nbd module with nbds_max, which sets the default
nr_hw_queues to 1, and the netlink method, which sets nr_hw_queues
according to the expected number of socket connections.  For the first
case, add a module parameter so the default nr_hw_queues can be
changed.  Users who know their expected number of connections can then
prevent queue freezes on pre-created devices via nbds_max.

Before this patchset:
real    0m2.195s
user    0m0.005s
sys     0m0.022s

After this patchset:
real    0m0.090s
user    0m0.004s
sys     0m0.018s

Signed-off-by: Yang Erkun <yangerkun@huawei.com>
Reviewed-by: Yu Kuai <yukuai@fygo.io>
Link: https://patch.msgid.link/20260805122930.57647-9-yangerkun@huawei.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-08-15 20:01:20 -06:00
Yang Erkun
a9d414b4a1 nbd: remove queue freeze for newly created nbd from netlink path
Previous commits has removed the queue freeze in nbd_add_socket and
nbd_set_size during nbd device setup. However, a queue freeze can still
occur when nbd_start_device calls blk_mq_update_nr_hw_queues if the
socket connection count does not match nbd->tag_set->nr_hw_queues.

The nbd_start_device function can be invoked through either the ioctl or
netlink paths. The ioctl path only allows reusing an existing inactivate
nbd device, there is nothing more we can do to prevent the queue freeze
since the old nbd->tag_set->nr_hw_queues may not match the new socket
connection count. Similarly, the netlink path can reuse a preferred
inactivate nbd device, and again, we cannot do more in this scenario.
However, the netlink path can also add a new nbd device using
nbd_dev_add. In this case, we can obtain the new number of socket
connections, and by adding a new argument representing the expected
nr_hw_queues in nbd_dev_add, we can ensure the queue freeze is avoided
for this situation.

Reviewed-by: Yu Kuai <yukuai@fygo.io>
Signed-off-by: Yang Erkun <yangerkun@huawei.com>
Link: https://patch.msgid.link/20260805122930.57647-8-yangerkun@huawei.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-08-15 20:01:20 -06:00
Yang Erkun
f8d21c590e nbd: factor out a nbd_genl_foreach_sock
The NBD_ATTR_SOCKETS walk is duplicated in nbd_genl_connect (add sockets)
and nbd_genl_reconfigure (reconnect).  Factor out a single helper that
walks the list and calls a callback per fd; with a NULL callback it is a
pure counter, used by a later patch to learn nr_hw_queues before the
device exists.  Returns the number of fds walked (>= 0) or a negative
errno; a callback >0 will stops early.

Reviewed-by: Yu Kuai <yukuai@fygo.io>
Signed-off-by: Yang Erkun <yangerkun@huawei.com>
Link: https://patch.msgid.link/20260805122930.57647-7-yangerkun@huawei.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-08-15 20:01:20 -06:00
Yang Erkun
db285268df nbd: skip queue freeze when setting size at device startup
Commit 242a49e5c8 ("nbd: freeze the queue for queue limits updates")
added the freeze to keep in-flight commands from seeing
torn queue_limits.  But at startup the capacity is still 0
(invalidate_disk cleared it) and the write cache is off (the previous
patch cleared it on disconnect, and nbd_set_size sets it back only after
the commit), so submit_bio_noacct() rejects any bio before it reaches
the driver and no I/O is in flight.  Drop the freeze by checking
capacity and write cache state in nbd_set_size.

Reviewed-by: Yu Kuai <yukuai@fygo.io>
Signed-off-by: Yang Erkun <yangerkun@huawei.com>
Link: https://patch.msgid.link/20260805122930.57647-6-yangerkun@huawei.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-08-15 20:01:20 -06:00
Yang Erkun
285908f554 nbd: remove queue freeze in nbd_add_socket
nbd_add_socket() kreallocs config->socks, which a concurrent reader in
nbd_handle_cmd() could UAF; commit b98e762e3d ("nbd: freeze the queue
while we're adding connections")froze the queue to block that.  But the
freeze costs an RCU grace period on every socket added, and setup adds
them one by one.

After the previous patch, nbd_add_socket() is rejected once nbd->pid is
set, so it only runs during setup.  There the capacity is 0 and the
write cache is off (cleared on disconnect by the preceding patch, and
re-enabled only later in nbd_set_size), so submit_bio_noacct() rejects
every bio before it reaches the driver -- non-zero-sector ones via
bio_check_eod(), and flush-only ones via the !bdev_write_cache() branch.
No I/O is in flight, so the freeze is unnecessary.

Reviewed-by: Yu Kuai <yukuai@fygo.io>
Signed-off-by: Yang Erkun <yangerkun@huawei.com>
Link: https://patch.msgid.link/20260805122930.57647-5-yangerkun@huawei.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-08-15 20:01:20 -06:00
Yang Erkun
0fdee7c5fa nbd: clear queue limits on disconnect
An inactive nbd device may refuse any I/O operations. The nbd_config_put
function calls invalidate_disk, which sets the device capacity to zero
to reject all read and write I/O. For zero-sector flush I/O requests
from blkdev_issue_flush, if the write cache is disabled, the zero-sector
flush I/O immediately returns 0 in submit_bio_noacct. However, since
nbd_config_put does not clear the write cache state, an inactive nbd
device might still have the write cache enabled. In this situation,
zero-sector flush I/O will return -EIO because there is no active socket.
Additionally, BLK_FEAT_FUA and BLK_FEAT_ROTATIONAL flags may also remain
stale, resetting all of them ensures consistent behavior.

The limits update uses queue_limits_commit_update() (the non-freezing
variant) because config_refs == 0 here means every fd is closed and recv
threads have drained, so no in-flight I/O can read q->limits concurrently.

Reviewed-by: Yu Kuai <yukuai@fygo.io>
Signed-off-by: Yang Erkun <yangerkun@huawei.com>
Link: https://patch.msgid.link/20260805122930.57647-4-yangerkun@huawei.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-08-15 20:01:19 -06:00
Yang Erkun
04d8fb23e5 nbd: disallow NBD_SET_SOCK on an active device
We cannot add a socket to an already running nbd device, the reconfigure
for netlink can only active an inactive socket. But for ioctl path, we can
call NBD_SET_SOCK after NBD_DO_IT, reject this using nbd->pid which has
been setted when NBD_DO_IT. Besides, it is the root cause for commit
b98e762e3d ("nbd: freeze the queue while we're adding connections").

Reviewed-by: Yu Kuai <yukuai@fygo.io>
Signed-off-by: Yang Erkun <yangerkun@huawei.com>
Link: https://patch.msgid.link/20260805122930.57647-3-yangerkun@huawei.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-08-15 20:01:19 -06:00
Long Li
fe247030f1 nbd: simplify find_fallback() by removing redundant logic
The second conditional checking nsock->fallback_index validity is the
logical inverse of the first, so drop it and let execution fall through
naturally. Consolidate the two identical dev_err_ratelimited() + return
paths into a single no_fallback label to reduce duplication.

Reviewed-by: Yu Kuai <yukuai@fygo.io>
Signed-off-by: Long Li <leo.lilong@huawei.com>
Link: https://patch.msgid.link/20260805122930.57647-2-yangerkun@huawei.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-08-15 20:01:19 -06:00
Christoph Böhmwalder
c71bf113df drbd: don't leak the shared secret to unprivileged netlink dumps
The conversion to explicit netlink serialization dropped the
exclude_sensitive parameter from net_conf_to_skb(), so each caller has
to sanitize by hand. Two dump paths were missed:
drbd_nl_get_connections_dumpit() and the volume-less connection branch
of get_one_status(). Neither op carries GENL_ADMIN_PERM, so any
unprivileged local user could read the CRAM-HMAC secret.

Add a net_conf_to_skb_sanitized() wrapper and route all three callers
through it.

Fixes: 8098eeb693 ("drbd: replace genl_magic with explicit netlink serialization")
Reported-by: Vivek Parikh <vivek.parikh@breachx.ai>
Signed-off-by: Christoph Böhmwalder <christoph.boehmwalder@linbit.com>
Link: https://patch.msgid.link/20260814151617.73752-1-christoph.boehmwalder@linbit.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-08-15 20:00:10 -06:00
Hongyan Xu
68940f841d block: mtip32xx: synchronize ioctls with device removal
The ioctl handlers only test REMOVE_PENDING before entering
mtip_hw_ioctl(). Removal can set that bit immediately afterwards and free
dd->port in mtip_hw_exit() while an ioctl still dereferences it. An already
open block device can reach the handlers while del_gendisk() is in
progress.

Serialize both native and compat ioctls with removal. Set REMOVE_PENDING
before taking the mutex so new callers fail after an in-flight ioctl has
drained, and hold the mutex until the port has been torn down.

Fixes: 88523a6155 ("block: Add driver for Micron RealSSD pcie flash cards")
Signed-off-by: Hongyan Xu <getshell@seu.edu.cn>
Link: https://patch.msgid.link/20260806060441.676-1-getshell@seu.edu.cn
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-08-15 17:45:38 -06:00
Yao Sang
4fd66a7f82 ublk: avoid teardown retry loop on xarray allocation failure
__ublk_shmem_remove_ranges() removes matching maple tree ranges in
batches, but first stores each range into a temporary xarray so that the
pages can be unpinned after dropping the maple tree lock.

That temporary xarray is filled under the maple tree lock with
xa_store(..., GFP_ATOMIC). If the store fails before mas_erase(), the
current range is left in the tree and the helper returns false. The
outer ublk_shmem_remove_ranges() loop then immediately retries the same
range. While the atomic allocation keeps failing, the teardown path has
no forward progress.

The issue can be reproduced with radix_tree_node failslab injection after
a SHMEM_ZC buffer has already been registered:

  # Kernel config:
  #   CONFIG_BLK_DEV_UBLK=y
  #   CONFIG_DEBUG_FS=y
  #   CONFIG_FAULT_INJECTION=y
  #   CONFIG_FAULT_INJECTION_DEBUG_FS=y
  #   CONFIG_FAILSLAB=y

  echo 10 > /proc/sys/vm/nr_hugepages
  mkdir -p /tmp/htlb
  mount -t hugetlbfs none /tmp/htlb
  fallocate -l 4M /tmp/htlb/ublk_buf

  dev_id=$(kublk add -t null --shmem_zc \
		--htlb /tmp/htlb/ublk_buf |
	   awk -F '[ :]' '/dev id/ {print $3}')

  echo 1 > /sys/kernel/slab/radix_tree_node/failslab
  echo Y > /sys/kernel/debug/failslab/cache-filter
  echo Y > /sys/kernel/debug/failslab/ignore-gfp-wait
  echo 1 > /sys/kernel/debug/failslab/interval
  echo -1 > /sys/kernel/debug/failslab/times
  echo 100 > /sys/kernel/debug/failslab/probability

  kublk del -n "$dev_id"

On the unfixed kernel the delete command was still running after 3
seconds. Disabling failslab made it return. The fault-injection stack
showed:

  should_failslab
  kmem_cache_alloc_lru_noprof
  __xas_nomem
  __xa_store
  xa_store
  __ublk_shmem_remove_ranges
  ublk_cdev_rel
  ublk_ctrl_del_dev

Remove the allocation from the teardown loop. Keep the existing batch
limit, but collect {base_pfn, nr_pages} pairs in a fixed-size stack array.
Once a matching range is found, the range is erased from the maple tree
before dropping the lock, so each successful scan makes progress without
depending on any GFP_ATOMIC allocation.

With the same failslab settings, the fixed kernel completed
"kublk del -n $dev_id" successfully in about 45 ms.

Fixes: 309e02dccf ("ublk: avoid unpinning pages under maple tree spinlock")
Signed-off-by: Yao Sang <sangyao@kylinos.cn>
Reviewed-by: Ming Lei <tom.leiming@gmail.com>
Link: https://patch.msgid.link/20260804125736.2011774-1-sangyao@kylinos.cn
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-08-15 17:44:21 -06:00
Rik van Riel
95491fb051 null_blk: fix UBSAN shift-out-of-bounds when zone_size is 0 or overflows
null_zone_no() does sect >> ilog2(dev->zone_size_sects). When
zone_size_sects is 0, ilog2(0) returns -1, producing shift exponent -1
which UBSAN reports as shift-out-of-bounds.

  UBSAN: shift-out-of-bounds in drivers/block/null_blk/zoned.c:21:14
  shift exponent -1 is negative
  Call Trace:
   null_zone_no drivers/block/null_blk/zoned.c:21 [inline]
   null_process_zoned_cmd+0xf76/0xf80 drivers/block/null_blk/zoned.c:728
   null_handle_cmd drivers/block/null_blk/main.c:1455 [inline]
   null_queue_rq+0x8bc/0xe70 drivers/block/null_blk/main.c:1703
   __blk_mq_issue_directly block/blk-mq.c:2694 [inline]
   blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2754
   blk_mq_submit_bio+0x20c0/0x2a40 block/blk-mq.c:3208
   submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
   block_read_full_folio+0x7a6/0x810 fs/buffer.c:2463
   filemap_read_folio+0x12c/0x3a0 mm/filemap.c:2510
   read_part_sector+0xb6/0x2b0 block/partitions/core.c:724
   adfspart_check_ICS+0xb1/0x960 block/partitions/acorn.c:357
   check_partition block/partitions/core.c:143 [inline]
   blk_add_partitions block/partitions/core.c:591 [inline]
   bdev_disk_changed+0x851/0x17a0 block/partitions/core.c:695
   blkdev_get_whole+0x372/0x510 block/bdev.c:751
   add_disk_final block/genhd.c:412 [inline]
   add_disk_fwnode+0x24b/0x3a0 block/genhd.c:606
   null_add_dev+0x130b/0x1d70 drivers/block/null_blk/main.c:2052
   nullb_device_power_store+0x240/0x380 drivers/block/null_blk/main.c:501
   configfs_write_iter+0x337/0x430 fs/configfs/file.c:229

Syzkaller triggers this by creating a zoned null_blk device via
configfs. The Call Trace shows configfs_write_iter in configfs/file.c
handling a write to power file, which calls nullb_device_power_store in
main.c, which calls null_add_dev in main.c, which calls add_disk in
genhd.c, which triggers partition scan via bdev_disk_changed in
partitions/core.c.

A zoned null_blk device with zone_size 0 should not be legal. Existing
code tries to reject it via is_power_of_2() check in zoned.c and
!zone_size check in main.c, but syzkaller can still reach
null_zone_no() with zone_size_sects 0 via two paths:

1. Direct 0 via configfs: zone_size attribute store in main.c has
NULLB_DEVICE_ATTR(zone_size, ulong, NULL) with no validation callback,
so echo 0 > zone_size succeeds before power store. If zoned is false
at power store time, the !zone_size check in main.c is skipped, and
later zoned set true leaves zone_size 0.

2. Large value overflow: mb_to_sects() in zoned.c does
(sector_t)mb * SZ_1M >> SECTOR_SHIFT which is mb * 2048. If mb is
1UL << 53 (9PB), mb * 2048 overflows 64-bit to 0. The value is
power-of-two so is_power_of_2() passes, but mb_to_sects() returns 0.

Check for zero zone_size explicitly in null_init_zoned_dev() in
zoned.c, returning -EINVAL with "must be non-zero power-of-two".
Check for zero zone_size_sects after mb_to_sects() conversion,
returning -EINVAL for overflow case. Keep defensive check in
null_zone_no() returning 0 for zero sectors to avoid shift out-of-bounds
even if  zero slips through.

This change should be safe because zone_size is set once in
null_init_zoned_dev() under device lock and never changes after, and 0
is never valid for a zoned device. Returning -EINVAL at init time fails
device creation early with clear error, while defensive return 0 in
null_zone_no() makes zoned command fail via offline zone check.
No new locking is introduced.

Reported-by: syzbot+abd6a8dca0f2b7726060@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=abd6a8dca0f2b7726060
Link: https://lore.kernel.org/all/6a75205c.01d0871a.3a0d52.0033.GAE@google.com/
Fixes: 8a3cf049af68 ("null_blk: add zoned block device emulation")
Cc: stable@vger.kernel.org
Assisted-by: Hermes:muse-spark-1.2 syzkaller
Signed-off-by: Rik van Riel <riel@surriel.com>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Link: https://patch.msgid.link/20260808114239.69167f68@fangorn
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-08-15 17:39:23 -06:00
Bart Van Assche
06a2ff603f loop: Fix recently introduced lock inversion
All block driver code except loop_set_dio() calls
queue_limits_start_update() before it freezes the request queue. Make
loop_set_dio() follow this convention. This patch fixes the following
lockdep complaint:

======================================================
WARNING: possible circular locking dependency detected
7.2.0-rc5-dbg #11 Not tainted
------------------------------------------------------
losetup/2924 is trying to acquire lock:
ffff88816c76da68 (&q->limits_lock){+.+.}-{4:4}, at: loop_set_dio+0x318/0x720 [loop]

but task is already holding lock:
ffff88816c76d430 (&q->q_usage_counter(io)#24){++++}-{0:0}, at: blk_mq_freeze_queue_nomemsave+0x1a/0x30

which lock already depends on the new lock.

Cc: Keith Busch <kbusch@kernel.org>
Fixes: 6c8dec275c ("loop: set dma_alignment from the backing file for direct I/O")
Reported-by: syzbot+cc0de396bac84da51919@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/linux-block/6a7d5368.d5f0ebe7.22d851.0013.GAE@google.com/
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Link: https://patch.msgid.link/d919f5285d16afbec6c51ecdf201692a484566e5.1786637565.git.bvanassche@acm.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-08-15 17:33:52 -06:00
Nathan Chancellor
f9820056e4 swim3: Add missing MODULE_DESCRIPTION
Since commit 6c6c1fc09d ("modpost: require a MODULE_DESCRIPTION()"),
modpost complains that swim3.ko is missing a module description.

  WARNING: modpost: drivers/block/swim3.ko: missing MODULE_DESCRIPTION()

Add one to clear up the warning.

Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://patch.msgid.link/20260811-swim3-module-description-v1-1-28398c5a0e32@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-08-15 17:17:58 -06:00
Yao Sang
2707acf185 ublk: reject non-power-of-2 zone sizes in SET_PARAMS
UBLK_F_ZONED uses params.basic.chunk_sectors as zone size. ublk uses
ilog2(chunk_sectors) to get number of zones, so the value must be power
of 2.

If chunk_sectors is 96 and dev_sectors is 96 * 16, userspace asks for
16 zones. But the shift calculation gets 24 zones.

Block layer rejects such zone size when the disk is started. But
SET_PARAMS has already returned success, which is confusing for
userspace. Reject it in SET_PARAMS with other zoned parameter checks.

Fixes: 29802d7ca3 ("ublk: enable zoned storage support")
Signed-off-by: Yao Sang <sangyao@kylinos.cn>
Link: https://patch.msgid.link/20260814023226.354288-2-sangyao@kylinos.cn
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-08-15 17:17:11 -06:00
Niklas Cassel
4e1f23f9c3 null_blk: serialize configfs attribute updates with device setup
The attribute store methods generated with NULLB_DEVICE_ATTR() refuse to
change the configuration of a live device by testing
NULLB_DEV_FL_CONFIGURED, but that flag is only set by
nullb_device_power_store() after null_add_dev() has returned, and the
store methods take no lock at all. configfs only serializes writes to
the same open file (buffer->mutex), so a write to any attribute can run
concurrently with null_add_dev() and change the device configuration
while it is being used.

null_add_dev() reads the configuration several times, e.g. dev->zoned is
read once to set up the queue limits and once to initialize the zone
resources:

  CPU0: echo 1 > nullb0/power         CPU1: echo 1 > nullb0/zoned
  nullb_device_power_store()
    mutex_lock(&lock)
    null_add_dev()
      if (dev->zoned) -> false
        /* no BLK_FEAT_ZONED */       nullb_device_zoned_store()
                                        test_bit(FL_CONFIGURED) -> 0
                                        dev->zoned = true
      blk_mq_alloc_disk()
        /* queue is not zoned */
      if (nullb->dev->zoned) -> true
        null_register_zoned_dev()
          blk_revalidate_disk_zones()

blk_revalidate_disk_zones() is then called for a queue that does not
have BLK_FEAT_ZONED set, which triggers its WARN_ON_ONCE() and fails the
device setup with -EIO:

  WARNING: CPU: 2 PID: 322 at block/blk-zoned.c:2357 blk_revalidate_disk_zones+0x4c/0x560

Clearing dev->zoned in the same window is worse: the queue is created
with BLK_FEAT_ZONED but the zone resources are never initialized, so
add_disk() succeeds for a zoned disk that has no zones. And a store that
lands after the last dev->zoned test leaves dev->zoned set while
dev->zones is still NULL, which null_process_zoned_cmd() dereferences on
the first write.

Fix this by taking the global lock, which nullb_device_power_store()
already holds across null_add_dev() and null_del_dev(), around both the
NULLB_DEV_FL_CONFIGURED test and the update of the device configuration.
The submit_queues and poll_queues apply callbacks are now called with
that lock held, so remove the locking they did themselves.

Since the store methods can run as soon as configfs_register_subsystem()
returns, that is, before null_init() gets to mutex_init(&lock), also
initialize the lock statically with DEFINE_MUTEX().

Fixes: 3bf2bd2073 ("nullb: add configfs interface")
Reported-by: syzbot+643a6dd130546afdf1fb@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/linux-block/6a7d0b3f.ac361c09.22ff0a.004c.GAE@google.com/
Signed-off-by: Niklas Cassel <cassel@kernel.org>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Link: https://patch.msgid.link/20260813141456.1625857-2-cassel@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-08-15 17:13:39 -06:00
Zizhi Wo
2cd9e14abe null_blk: serialize configfs attribute shows with the lock
The _show callback in the NULLB_DEVICE_ATTR macro reads dev->NAME and the
_store path writes it. configfs does not serialize accesses across separate
open file descriptions (buffer->mutex is per-fd), and _show takes no lock,
so a concurrent read and write on the same attribute is a data race. The
_show readers also race against writes to these fields that run after the
configfs item becomes visible, e.g. in nullb_update_nr_hw_queues().

All of those writers now run under the file-scope lock: _store takes it
unconditionally, and the setup-side writers run under power_store() which
holds the same lock. The only remaining unsynchronized accesses are the
plain reads in _show. Rather than annotating every field with
READ_ONCE()/WRITE_ONCE() across files, simply take the file-scope lock in
_show (and in power_show) as well. This closes the remaining _show-vs-write
data races with a single lock and keeps the writers as plain assignments.

configfs attribute access is not on the I/O hot path, so taking the mutex
in _show is acceptable from a performance standpoint. The dev fields
written in null_alloc_dev() and dev->power in nullb_group_drop_item() need
no locking: the former runs from .make_group before the item is published,
and the latter is serialized by configfs frag_sem/frag_dead against
attribute show/store.

Suggested-by: Nilay Shroff <nilay@linux.ibm.com>
Suggested-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Zizhi Wo <wozizhi@huawei.com>
Reviewed-by: Nilay Shroff <nilay@linux.ibm.com>
Link: https://patch.msgid.link/20260725022509.714271-11-wozizhi@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-08-15 17:06:51 -06:00
Zizhi Wo
7e7fff5180 null_blk: serialize configfs attribute stores with the lock
The NULLB_DEVICE_ATTR _store takes no lock: apply_fn attributes
(submit_queues, poll_queues) get dev->NAME written again after apply_fn
returns, outside its lock; APPLY=NULL attributes are entirely lockless.
configfs only serializes stores per-open-file, so concurrent stores on
separate fds race.

For apply_fn attributes, once one store's apply_fn has reconfigured the
hardware, a second (losing) store can still overwrite dev->NAME
afterwards. This leaves dev->submit_queues out of sync with the live
queue count, which is later caught by the WARN_ON_ONCE() in
null_map_queues().

For !apply_fn attributes, power_store()'s null_add_dev() validates and
builds the device under "lock" but only sets CONFIGURED afterwards. A store
slipping in during this window can change a field mid-setup -- for example,
zone_nr_conv can be pushed above nr_zones after it has already been
clamped, leading to an out-of-bounds dev->zones[] access.

Take "lock" in the macro around the apply_fn call, the CONFIGURED test and
the field write, and move it out of nullb_apply_submit_queues()/
nullb_apply_poll_queues() so both paths are covered once. This serializes
stores with power_store's setup and with each other.

Fixes: 45919fbfe1 ("null_blk: Enable modifying 'submit_queues' after an instance has been configured")
Suggested-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Zizhi Wo <wozizhi@huawei.com>
Reviewed-by: Nilay Shroff <nilay@linux.ibm.com>
Link: https://patch.msgid.link/20260725022509.714271-10-wozizhi@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-08-15 17:06:51 -06:00
Zizhi Wo
e3ef4b1b76 null_blk: convert file-scope mutex users to guard(mutex)
Using guard()/scoped_guard() ties lock release to scope exit, removing the
need for manual mutex_unlock() calls and preventing missed unlocks on error
paths.

The per-attribute apply wrappers are left untouched, as those are reworked
separately by the configfs show/store serialization patches.

Signed-off-by: Zizhi Wo <wozizhi@huawei.com>
Link: https://patch.msgid.link/20260725022509.714271-9-wozizhi@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-08-15 17:06:51 -06:00
Zizhi Wo
1cdfe2fa62 null_blk: reject per-device queue resize for shared tag set
When shared_tags is enabled, null_setup_tagset() makes the device use the
global tag_set, whose driver_data stays NULL. null_map_queues() therefore
falls back to the module-wide g_submit_queues/g_poll_queues instead of any
per-device value.

Resizing submit_queues or poll_queues via configfs on such a device calls
blk_mq_update_nr_hw_queues() on the shared set, shrinking
set->nr_hw_queues.  __blk_mq_realloc_hw_ctxs() only grows the
q->queue_hw_ctx[] allocation, so on shrink it merely exits and NULLs the
now-excess hctx slots. null_map_queues(), however, keeps mapping CPUs with
the unchanged g_submit_queues/g_poll_queues, so mq_map[] ends up pointing
at those NULLed hctx slots. blk_mq_map_swqueue() then dereferences the NULL
hctx (hctx->cpumask), crashing the kernel:

[  460.218374] KASAN: null-ptr-deref in range [0x0000000000000098-0x000000000000009f]
[  460.219003] CPU: 24 UID: 0 PID: 1492 Comm: sh Not tainted 7.2.0-rc2+ #67 PREEMPT(full)
[  460.219792] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.17.0-4.fc41 04/01/2014
[  460.220452] RIP: 0010:blk_mq_map_swqueue+0x4db/0x1430
......
[  460.228977] Call Trace:
[  460.229175]  <TASK>
[  460.229354]  blk_mq_update_nr_hw_queues+0xd49/0x11c0
[  460.229779]  ? __pfx_blk_mq_update_nr_hw_queues+0x10/0x10
[  460.230200]  nullb_update_nr_hw_queues+0x1a9/0x370 [null_blk]
[  460.230694]  nullb_device_submit_queues_store+0xd9/0x170 [null_blk]
[  460.231190]  ? __pfx_nullb_device_submit_queues_store+0x10/0x10 [null_blk]
[  460.231776]  ? configfs_write_iter+0x35c/0x4e0
[  460.232122]  configfs_write_iter+0x286/0x4e0
[  460.232460]  vfs_write+0x52d/0xd00
[  460.232779]  ? __x64_sys_openat+0x108/0x1d0
[  460.233106]  ? __pfx_vfs_write+0x10/0x10
[  460.233413]  ? fdget_pos+0x1cf/0x4c0
[  460.233745]  ? fput_close+0x133/0x190
[  460.234038]  ? __pfx_expand_files+0x10/0x10
[  460.234368]  ksys_write+0xfc/0x1d0

Reproducer:
modprobe null_blk shared_tags=1 submit_queues=64 poll_queues=1
mkdir /sys/kernel/config/nullb/dev
echo 1 > /sys/kernel/config/nullb/dev/power
echo 1 > /sys/kernel/config/nullb/dev/submit_queues

A per-device resize of a shared tag set is meaningless anyway, so reject it
with -EINVAL in nullb_update_nr_hw_queues() when the device is bound to the
global tag_set.

Fixes: 45919fbfe1 ("null_blk: Enable modifying 'submit_queues' after an instance has been configured")
Suggested-by: Nilay Shroff <nilay@linux.ibm.com>
Assisted-by: Claude-Code:GLM-5.2
Signed-off-by: Zizhi Wo <wozizhi@huawei.com>
Reviewed-by: Nilay Shroff <nilay@linux.ibm.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Link: https://patch.msgid.link/20260725022509.714271-8-wozizhi@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-08-15 17:06:51 -06:00
Zizhi Wo
5bce98f9e7 null_blk: clean up null_del_dev() to use cached dev pointer
Replace remaining nullb->dev dereferences with the already-cached
local dev variable. No functional change.

Signed-off-by: Zizhi Wo <wozizhi@huawei.com>
Reviewed-by: Nilay Shroff <nilay@linux.ibm.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Link: https://patch.msgid.link/20260725022509.714271-7-wozizhi@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-08-15 17:06:50 -06:00
Zizhi Wo
2a6357a9b9 null_blk: free zones array on device power-off
null_init_zoned_dev() allocates dev->zones when a zoned device is powered
on, but null_del_dev() never frees it on power-off; dev->zones is only
freed later in null_free_dev(), when the configfs directory is removed. If
the device is powered off and then on again, null_init_zoned_dev()
allocates a new array and overwrites the dev->zones pointer, leaking the
previous allocation each power cycle.

Free dev->zones in null_del_dev() via null_free_zoned_dev() to solve it.
And calling null_free_zoned_dev() in null_free_dev() is no longer necessary
because every caller already invokes null_del_dev() first: via
nullb_group_drop_item() before nullb_device_release(), in the
null_add_dev() error path of null_create_dev(), and in null_destroy_dev().
Remove the redundant call.

And take &lock around zone_cond_store() in the two store wrappers to
serialize dev->zones check-and-deref against its alloc/free, which already
run under &lock. The reason there was no problem before is that only
nullb_device_release() or null_exit() frees the dev->zones, which
guarantees that subsequent users won't access the configfs interface.

Fixes: ca4b2a0119 ("null_blk: add zone support")
Assisted-by: Claude-Code:GLM-5.2
Signed-off-by: Zizhi Wo <wozizhi@huawei.com>
Reviewed-by: Nilay Shroff <nilay@linux.ibm.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Link: https://patch.msgid.link/20260725022509.714271-6-wozizhi@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-08-15 17:06:50 -06:00
Zizhi Wo
5a1c5ff3a4 null_blk: free global tag_set on init error path
If shared_tags is enabled, null_setup_tagset() allocates the global tag_set
via null_init_global_tag_set(). If device creation later fails, err_dev
destroys the default devices and calls unregister_blkdev(), but never frees
the global tag_set. Since module init failed, null_exit() is never invoked,
so the global tag_set's tags and maps are permanently leaked.

Free the global tag_set in err_dev, matching null_exit() which does
if (tag_set.ops) blk_mq_free_tag_set(&tag_set).

Fixes: 82f402fefa ("null_blk: add support for shared tags")
Signed-off-by: Zizhi Wo <wozizhi@huawei.com>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Nilay Shroff <nilay@linux.ibm.com>
Link: https://patch.msgid.link/20260725022509.714271-5-wozizhi@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-08-15 17:06:50 -06:00
Zizhi Wo
4ec26e8885 null_blk: move unregister_blkdev() after destroying dev in null_exit()
In null_exit(), unregister_blkdev() is called before the null_blk instances
are destroyed, which is inconsistent with the cleanup order in null_init().
Move it after null_destroy_dev() so that teardown happens in the reverse
order of initialization.

No functional change intended.

Suggested-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Zizhi Wo <wozizhi@huawei.com>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Nilay Shroff <nilay@linux.ibm.com>
Link: https://patch.msgid.link/20260725022509.714271-4-wozizhi@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-08-15 17:06:50 -06:00
Zizhi Wo
c9d293d6bb null_blk: register configfs subsystem after creating default devices
In null_init(), configfs_register_subsystem() currently runs before
register_blkdev(), so when null_blk is built as a module, a racing mkdir()
+ poweron from userspace can reach null_add_dev() while null_major is still
0. __add_disk() then hits WARN_ON(disk->minors) (major=0 with minors!=0)
and fails:

[root@fedora ~]# [ 2366.521436] WARNING: block/genhd.c:476 at __add_disk+0x8a7/0xde0,
[ 2366.523552] Modules linked in: null_blk(+) nft_fib_inet nft_fib_ipv4 nft_fib_ipv6 nft_fib
[ 2366.529081] CPU: 26 UID: 0 PID: 1600 Comm: sh Not tainted 7.2.0-rc1+ #66 PREEMPT(full)
......
[ 2366.547251] Call Trace:
[ 2366.547575]  <TASK>
[ 2366.547831]  ? _raw_spin_lock+0x84/0xe0
[ 2366.548260]  add_disk_fwnode+0x114/0x560
[ 2366.548739]  null_add_dev+0x102d/0x1b80 [null_blk]
[ 2366.549310]  ? __pfx_null_add_dev+0x10/0x10 [null_blk]
[ 2366.549906]  ? mutex_lock+0xde/0x1c0
[ 2366.550361]  ? __pfx_mutex_lock+0x10/0x10
[ 2366.550827]  nullb_device_power_store+0x1e7/0x280 [null_blk]
[ 2366.551499]  ? __pfx_nullb_device_power_store+0x10/0x10 [null_blk]
[ 2366.552177]  ? __kmalloc_cache_noprof+0x1f5/0x470
[ 2366.552748]  ? configfs_write_iter+0x35c/0x4e0
[ 2366.553242]  configfs_write_iter+0x286/0x4e0
[ 2366.553787]  vfs_write+0x52d/0xd00
[ 2366.554169]  ? __pfx_vfs_write+0x10/0x10
[ 2366.554679]  ? __pfx___css_rstat_updated+0x10/0x10
[ 2366.555196]  ? fdget_pos+0x1cf/0x4c0
[ 2366.555649]  ksys_write+0xfc/0x1d0
......

Additionally, the err_dev path destroys all devices on nullb_list while
configfs is still registered. If a racing mkdir() + poweron puts a user
device on the list, null_destroy_dev()->null_free_dev() kfrees the user
device's nullb_device but /sys/kernel/config/nullb/<name> is still
reachable. Any userspace access to the item will trigger a UAF.

For simplicity, move configfs_register_subsystem() to the end to solve
the problems above.

Fixes: 3bf2bd2073 ("nullb: add configfs interface")
Signed-off-by: Zizhi Wo <wozizhi@huawei.com>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Nilay Shroff <nilay@linux.ibm.com>
Link: https://patch.msgid.link/20260725022509.714271-3-wozizhi@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-08-15 17:06:50 -06:00
Zizhi Wo
017dac7670 null_blk: use DEFINE_MUTEX for the file-scope mutex
In null_init(), mutex_init(&lock) currently happens after
configfs_register_subsystem(), which exposes the nullb subsystem to
userspace. A racing mkdir() into /sys/kernel/config/nullb/ can reach
null_find_dev_by_name() -> mutex_lock(&lock) before the mutex is
initialized, trigger warning:

[  123.137788] DEBUG_LOCKS_WARN_ON(lock->magic != lock)
[  123.137796] WARNING: kernel/locking/mutex.c:159 at mutex_lock+0x171/0x1c0, CPU#13: mkdir/1301
[  123.140090] Modules linked in: null_blk(+) nft_fib_inet nft_fib_ipv4
......
[  123.154926] Call Trace:
[  123.155172]  <TASK>
[  123.155419]  ? __pfx_mutex_lock+0x10/0x10
[  123.156181]  ? __pfx__raw_spin_lock+0x10/0x10
[  123.156571]  nullb_group_make_group+0x20/0x100 [null_blk]
[  123.157011]  configfs_mkdir+0x47b/0xc70
[  123.157337]  ? __pfx_configfs_mkdir+0x10/0x10
[  123.157719]  ? may_create_dentry+0x242/0x2e0
[  123.158061]  vfs_mkdir+0x2a9/0x6c0
[  123.158352]  filename_mkdirat+0x3dc/0x500
[  123.158710]  ? __pfx_filename_mkdirat+0x10/0x10
[  123.159070]  ? strncpy_from_user+0x3a/0x1d0
[  123.159413]  __x64_sys_mkdir+0x6b/0x90
[  123.159760]  do_syscall_64+0xea/0x600

Replace the runtime mutex_init(&lock) with a static DEFINE_MUTEX(lock)
declaration to fix this issue.

Fixes: 49c3b9266a ("block: null_blk: Improve device creation with configfs")
Suggested-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Zizhi Wo <wozizhi@huawei.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Nilay Shroff <nilay@linux.ibm.com>
Link: https://patch.msgid.link/20260725022509.714271-2-wozizhi@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-08-15 17:06:50 -06:00
Alvin Sun
003c01b2f0 rust: configfs: use LocalModule for THIS_MODULE
Replace the `THIS_MODULE` static reference in the `configfs_attrs!`
macro with `this_module::<LocalModule>()`, and update
rnull to import `LocalModule` instead of `THIS_MODULE`, consistent
with the move of `THIS_MODULE` into the `ModuleMetadata` trait.

Assisted-by: opencode:glm-5.2
Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org>
Acked-by: Danilo Krummrich <dakr@kernel.org>
Reviewed-by: Gary Guo <gary@garyguo.net>
Acked-by: Andreas Hindborg <a.hindborg@kernel.org>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Alvin Sun <alvin.sun@linux.dev>
Link: https://patch.msgid.link/20260811-fix-fops-owner-v10-7-7e71776f9dbe@linux.dev
[ Rebased to avoid the imports cleanup patch. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2026-08-12 09:36:26 +02:00
Sebastian Andrzej Siewior
d56a82aa87 zram: use a custom key for each zram object
Each struct zram uses the same key for its struct lockdep_map which is
used for locking analysis.

According to Sergey the lock chains might be different if zram1 is used
for and zram2 is for ext4.  This might lead to false dead lock reports if
it mixes a zram1 chain with a zram2.  This can be avoided if each lockmap
gets its own unique key.c

Use a dynamic lock_class_key for the table_lock_map.

Link: https://lore.kernel.org/20260714141300.3945672-3-bigeasy@linutronix.de
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Tested-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-08-06 18:57:25 -07:00
Sebastian Andrzej Siewior
dbb7ba9c7f zram: move lockmap to be per-zram instead per table
Patch series "zram: lockmap tweaks".


This patch (of 2):

The zram object contains an array zram_table_entry.  Each one has a `lock'
variable and each has a matching struct lockdep_map.  This mimics a struct
mutex.

It uses always the same key for all lockdep_map instances.  This makes it
look like the same lock to lockdep.  Therefore it could be reduced to have
one lockdep_map per struct zram.

Use only one struct lockdep_map per struct zram.

Link: https://lore.kernel.org/20260714141300.3945672-1-bigeasy@linutronix.de
Link: https://lore.kernel.org/20260714141300.3945672-2-bigeasy@linutronix.de
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Tested-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-08-06 18:57:24 -07:00
Pavel Begunkov
b539aeacf8 block: rename bi_bvec_done
struct bvec_iter::bi_bvec_done is used an offset in the current bvec,
let's rename it accordingly for better clarity. I also plan to use it
for non-bvec based iteration in the future like dma-buf, so drop the
"bvec" part.

Suggested-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://patch.msgid.link/4e4c21858705a200bd8848ffe4080522e3eb5c1c.1786018753.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-08-06 06:47:33 -06:00
Yang Xiuwei
af0955c8f2 ublk: clear auto buf reg before updating io->buf in batch commit
ublk_batch_commit_io() stored the new auto_buf into io->buf before
calling ublk_clear_auto_buf_reg(). Clear takes the unregister index
from io->buf.auto_reg, so it could drop the new slot and leave the
old registered buffer behind.

Fixes: 1e500e106d ("ublk: handle UBLK_U_IO_COMMIT_IO_CMDS")
Signed-off-by: Yang Xiuwei <yangxiuwei@kylinos.cn>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-08-04 07:00:06 -06:00