Pull block fixes from Jens Axboe:
- Series for zloop, fixing a variety of issues
- t10-pi code cleanup
- Fix for a merge window regression with the bio memory allocation mask
- Fix for a merge window regression in ublk, caused by an issue with
the maple tree iteration code at teardown
- ublk self tests additions
- Zoned device pgmap fixes
- Various little cleanups and fixes
* tag 'block-7.1-20260424' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux: (21 commits)
Revert "floppy: fix reference leak on platform_device_register() failure"
ublk: avoid unpinning pages under maple tree spinlock
ublk: refactor common helper ublk_shmem_remove_ranges()
ublk: fix maple tree lockdep warning in ublk_buf_cleanup
selftests: ublk: add ublk auto integrity test
selftests: ublk: enable test_integrity_02.sh on fio 3.42
selftests: ublk: remove unused argument to _cleanup
block: only restrict bio allocation gfp mask asked to block
block/blk-throttle: Add WQ_PERCPU to alloc_workqueue users
block: Add WQ_PERCPU to alloc_workqueue users
block: relax pgmap check in bio_add_page for compatible zone device pages
block: add pgmap check to biovec_phys_mergeable
floppy: fix reference leak on platform_device_register() failure
ublk: use unchecked copy helpers for bio page data
t10-pi: reduce ref tag code duplication
zloop: remove irq-safe locking
zloop: factor out zloop_mark_{full,empty} helpers
zloop: set RQF_QUIET when completing requests on deleted devices
zloop: improve the unaligned write pointer warning
zloop: use vfs_truncate
...
Pull ceph updates from Ilya Dryomov:
"We have a series from Alex which extends CephFS client metrics with
support for per-subvolume data I/O performance and latency tracking
(metadata operations aren't included) and a good variety of fixes and
cleanups across RBD and CephFS"
* tag 'ceph-for-7.1-rc1' of https://github.com/ceph/ceph-client:
ceph: add subvolume metrics collection and reporting
ceph: parse subvolume_id from InodeStat v9 and store in inode
ceph: handle InodeStat v8 versioned field in reply parsing
libceph: Fix slab-out-of-bounds access in auth message processing
rbd: fix null-ptr-deref when device_add_disk() fails
crush: cleanup in crush_do_rule() method
ceph: clear s_cap_reconnect when ceph_pagelist_encode_32() fails
ceph: only d_add() negative dentries when they are unhashed
libceph: update outdated comment in ceph_sock_write_space()
libceph: Remove obsolete session key alignment logic
ceph: fix num_ops off-by-one when crypto allocation fails
libceph: Prevent potential null-ptr-deref in ceph_handle_auth_reply()
ublk_shmem_remove_ranges() calls unpin_user_pages() while holding the
maple tree spinlock (mas_lock). Although unpin_user_pages() is safe in
atomic context, holding the spinlock across potentially many page
unpinning operations is not ideal.
Split into __ublk_shmem_remove_ranges() which erases up to 64 ranges
under mas_lock, collecting base_pfn and nr_pages into a temporary
xarray. Then drop the lock and unpin pages outside spinlock context.
ublk_shmem_remove_ranges() loops until all matching ranges are
processed.
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Link: https://patch.msgid.link/20260423033058.2805135-4-tom.leiming@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Extract the shared walk+erase+unpin+kfree loop into
ublk_shmem_remove_ranges(). When buf_index >= 0, only ranges matching
that index are removed; when buf_index < 0, all ranges are removed.
Also extract ublk_unpin_range_pages() to share the page unpinning
loop.
Convert both __ublk_ctrl_unreg_buf() and ublk_buf_cleanup() to use
the new helper.
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Link: https://patch.msgid.link/20260423033058.2805135-3-tom.leiming@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Pull more MM updates from Andrew Morton:
- "Eliminate Dying Memory Cgroup" (Qi Zheng and Muchun Song)
Address the longstanding "dying memcg problem". A situation wherein a
no-longer-used memory control group will hang around for an extended
period pointlessly consuming memory
- "fix unexpected type conversions and potential overflows" (Qi Zheng)
Fix a couple of potential 32-bit/64-bit issues which were identified
during review of the "Eliminate Dying Memory Cgroup" series
- "kho: history: track previous kernel version and kexec boot count"
(Breno Leitao)
Use Kexec Handover (KHO) to pass the previous kernel's version string
and the number of kexec reboots since the last cold boot to the next
kernel, and print it at boot time
- "liveupdate: prevent double preservation" (Pasha Tatashin)
Teach LUO to avoid managing the same file across different active
sessions
- "liveupdate: Fix module unloading and unregister API" (Pasha
Tatashin)
Address an issue with how LUO handles module reference counting and
unregistration during module unloading
- "zswap pool per-CPU acomp_ctx simplifications" (Kanchana Sridhar)
Simplify and clean up the zswap crypto compression handling and
improve the lifecycle management of zswap pool's per-CPU acomp_ctx
resources
- "mm/damon/core: fix damon_call()/damos_walk() vs kdmond exit race"
(SeongJae Park)
Address unlikely but possible leaks and deadlocks in damon_call() and
damon_walk()
- "mm/damon/core: validate damos_quota_goal->nid" (SeongJae Park)
Fix a couple of root-only wild pointer dereferences
- "Docs/admin-guide/mm/damon: warn commit_inputs vs other params race"
(SeongJae Park)
Update the DAMON documentation to warn operators about potential
races which can occur if the commit_inputs parameter is altered at
the wrong time
- "Minor hmm_test fixes and cleanups" (Alistair Popple)
Bugfixes and a cleanup for the HMM kernel selftests
- "Modify memfd_luo code" (Chenghao Duan)
Cleanups, simplifications and speedups to the memfd_lou code
- "mm, kvm: allow uffd support in guest_memfd" (Mike Rapoport)
Support for userfaultfd in guest_memfd
- "selftests/mm: skip several tests when thp is not available" (Chunyu
Hu)
Fix several issues in the selftests code which were causing breakage
when the tests were run on CONFIG_THP=n kernels
- "mm/mprotect: micro-optimization work" (Pedro Falcato)
A couple of nice speedups for mprotect()
- "MAINTAINERS: update KHO and LIVE UPDATE entries" (Pratyush Yadav)
Document upcoming changes in the maintenance of KHO, LUO, memfd_luo,
kexec, crash, kdump and probably other kexec-based things - they are
being moved out of mm.git and into a new git tree
* tag 'mm-stable-2026-04-18-02-14' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (121 commits)
MAINTAINERS: add page cache reviewer
mm/vmscan: avoid false-positive -Wuninitialized warning
MAINTAINERS: update Dave's kdump reviewer email address
MAINTAINERS: drop include/linux/liveupdate from LIVE UPDATE
MAINTAINERS: drop include/linux/kho/abi/ from KHO
MAINTAINERS: update KHO and LIVE UPDATE maintainers
MAINTAINERS: update kexec/kdump maintainers entries
mm/migrate_device: remove dead migration entry check in migrate_vma_collect_huge_pmd()
selftests: mm: skip charge_reserved_hugetlb without killall
userfaultfd: allow registration of ranges below mmap_min_addr
mm/vmstat: fix vmstat_shepherd double-scheduling vmstat_update
mm/hugetlb: fix early boot crash on parameters without '=' separator
zram: reject unrecognized type= values in recompress_store()
docs: proc: document ProtectionKey in smaps
mm/mprotect: special-case small folios when applying permissions
mm/mprotect: move softleaf code out of the main function
mm: remove '!root_reclaim' checking in should_abort_scan()
mm/sparse: fix comment for section map alignment
mm/page_io: use sio->len for PSWPIN accounting in sio_read_complete()
selftests/mm: transhuge_stress: skip the test when thp not available
...
When platform_device_register() fails in do_floppy_init(), the embedded
struct device in floppy_device[drive] has already been initialized by
device_initialize(), but the failure path jumps to out_remove_drives
without dropping the device reference for the current drive.
Previously registered floppy devices are cleaned up in out_remove_drives,
but the device for the drive that fails registration is not, leading to
a reference leak.
The issue was identified by a static analysis tool I developed and
confirmed by manual review. Fix this by calling put_device() for the
current floppy device before jumping to the common cleanup path.
Fixes: 94fd0db7bf ("[PATCH] Floppy: Add cmos attribute to floppy driver")
Cc: stable@vger.kernel.org
Signed-off-by: Guangshuo Li <lgs201920130244@gmail.com>
Link: https://patch.msgid.link/20260415145708.3331818-1-lgs201920130244@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Bio pages may originate from slab caches that lack a usercopy region
(e.g. jbd2 frozen metadata buffers allocated via jbd2_alloc()).
When CONFIG_HARDENED_USERCOPY is enabled, copy_to_iter() calls
check_copy_size() which rejects these slab pages, triggering a
kernel BUG in usercopy_abort().
This is a false positive: the data is ordinary block I/O content —
the same data the loop driver writes to its backing file via
vfs_iter_write(). The bvec length is always trusted, so the size
check in check_copy_size() is not needed either.
Switch to _copy_to_iter()/_copy_from_iter() which skip the
check_copy_size() wrapper while the underlying copy_to_user()
remains unchanged.
Acked-by: Caleb Sander Mateos <csander@purestorage.com>
Fixes: 2299ceec36 ("ublk: use copy_{to,from}_iter() for user copy")
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://patch.msgid.link/20260415230246.808176-1-tom.leiming@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Pull MM updates from Andrew Morton:
- "maple_tree: Replace big node with maple copy" (Liam Howlett)
Mainly prepararatory work for ongoing development but it does reduce
stack usage and is an improvement.
- "mm, swap: swap table phase III: remove swap_map" (Kairui Song)
Offers memory savings by removing the static swap_map. It also yields
some CPU savings and implements several cleanups.
- "mm: memfd_luo: preserve file seals" (Pratyush Yadav)
File seal preservation to LUO's memfd code
- "mm: zswap: add per-memcg stat for incompressible pages" (Jiayuan
Chen)
Additional userspace stats reportng to zswap
- "arch, mm: consolidate empty_zero_page" (Mike Rapoport)
Some cleanups for our handling of ZERO_PAGE() and zero_pfn
- "mm/kmemleak: Improve scan_should_stop() implementation" (Zhongqiu
Han)
A robustness improvement and some cleanups in the kmemleak code
- "Improve khugepaged scan logic" (Vernon Yang)
Improve khugepaged scan logic and reduce CPU consumption by
prioritizing scanning tasks that access memory frequently
- "Make KHO Stateless" (Jason Miu)
Simplify Kexec Handover by transitioning KHO from an xarray-based
metadata tracking system with serialization to a radix tree data
structure that can be passed directly to the next kernel
- "mm: vmscan: add PID and cgroup ID to vmscan tracepoints" (Thomas
Ballasi and Steven Rostedt)
Enhance vmscan's tracepointing
- "mm: arch/shstk: Common shadow stack mapping helper and
VM_NOHUGEPAGE" (Catalin Marinas)
Cleanup for the shadow stack code: remove per-arch code in favour of
a generic implementation
- "Fix KASAN support for KHO restored vmalloc regions" (Pasha Tatashin)
Fix a WARN() which can be emitted the KHO restores a vmalloc area
- "mm: Remove stray references to pagevec" (Tal Zussman)
Several cleanups, mainly udpating references to "struct pagevec",
which became folio_batch three years ago
- "mm: Eliminate fake head pages from vmemmap optimization" (Kiryl
Shutsemau)
Simplify the HugeTLB vmemmap optimization (HVO) by changing how tail
pages encode their relationship to the head page
- "mm/damon/core: improve DAMOS quota efficiency for core layer
filters" (SeongJae Park)
Improve two problematic behaviors of DAMOS that makes it less
efficient when core layer filters are used
- "mm/damon: strictly respect min_nr_regions" (SeongJae Park)
Improve DAMON usability by extending the treatment of the
min_nr_regions user-settable parameter
- "mm/page_alloc: pcp locking cleanup" (Vlastimil Babka)
The proper fix for a previously hotfixed SMP=n issue. Code
simplifications and cleanups ensued
- "mm: cleanups around unmapping / zapping" (David Hildenbrand)
A bunch of cleanups around unmapping and zapping. Mostly
simplifications, code movements, documentation and renaming of
zapping functions
- "support batched checking of the young flag for MGLRU" (Baolin Wang)
Batched checking of the young flag for MGLRU. It's part cleanups; one
benchmark shows large performance benefits for arm64
- "memcg: obj stock and slab stat caching cleanups" (Johannes Weiner)
memcg cleanup and robustness improvements
- "Allow order zero pages in page reporting" (Yuvraj Sakshith)
Enhance free page reporting - it is presently and undesirably order-0
pages when reporting free memory.
- "mm: vma flag tweaks" (Lorenzo Stoakes)
Cleanup work following from the recent conversion of the VMA flags to
a bitmap
- "mm/damon: add optional debugging-purpose sanity checks" (SeongJae
Park)
Add some more developer-facing debug checks into DAMON core
- "mm/damon: test and document power-of-2 min_region_sz requirement"
(SeongJae Park)
An additional DAMON kunit test and makes some adjustments to the
addr_unit parameter handling
- "mm/damon/core: make passed_sample_intervals comparisons
overflow-safe" (SeongJae Park)
Fix a hard-to-hit time overflow issue in DAMON core
- "mm/damon: improve/fixup/update ratio calculation, test and
documentation" (SeongJae Park)
A batch of misc/minor improvements and fixups for DAMON
- "mm: move vma_(kernel|mmu)_pagesize() out of hugetlb.c" (David
Hildenbrand)
Fix a possible issue with dax-device when CONFIG_HUGETLB=n. Some code
movement was required.
- "zram: recompression cleanups and tweaks" (Sergey Senozhatsky)
A somewhat random mix of fixups, recompression cleanups and
improvements in the zram code
- "mm/damon: support multiple goal-based quota tuning algorithms"
(SeongJae Park)
Extend DAMOS quotas goal auto-tuning to support multiple tuning
algorithms that users can select
- "mm: thp: reduce unnecessary start_stop_khugepaged()" (Breno Leitao)
Fix the khugpaged sysfs handling so we no longer spam the logs with
reams of junk when starting/stopping khugepaged
- "mm: improve map count checks" (Lorenzo Stoakes)
Provide some cleanups and slight fixes in the mremap, mmap and vma
code
- "mm/damon: support addr_unit on default monitoring targets for
modules" (SeongJae Park)
Extend the use of DAMON core's addr_unit tunable
- "mm: khugepaged cleanups and mTHP prerequisites" (Nico Pache)
Cleanups to khugepaged and is a base for Nico's planned khugepaged
mTHP support
- "mm: memory hot(un)plug and SPARSEMEM cleanups" (David Hildenbrand)
Code movement and cleanups in the memhotplug and sparsemem code
- "mm: remove CONFIG_ARCH_ENABLE_MEMORY_HOTREMOVE and cleanup
CONFIG_MIGRATION" (David Hildenbrand)
Rationalize some memhotplug Kconfig support
- "change young flag check functions to return bool" (Baolin Wang)
Cleanups to change all young flag check functions to return bool
- "mm/damon/sysfs: fix memory leak and NULL dereference issues" (Josh
Law and SeongJae Park)
Fix a few potential DAMON bugs
- "mm/vma: convert vm_flags_t to vma_flags_t in vma code" (Lorenzo
Stoakes)
Convert a lot of the existing use of the legacy vm_flags_t data type
to the new vma_flags_t type which replaces it. Mainly in the vma
code.
- "mm: expand mmap_prepare functionality and usage" (Lorenzo Stoakes)
Expand the mmap_prepare functionality, which is intended to replace
the deprecated f_op->mmap hook which has been the source of bugs and
security issues for some time. Cleanups, documentation, extension of
mmap_prepare into filesystem drivers
- "mm/huge_memory: refactor zap_huge_pmd()" (Lorenzo Stoakes)
Simplify and clean up zap_huge_pmd(). Additional cleanups around
vm_normal_folio_pmd() and the softleaf functionality are performed.
* tag 'mm-stable-2026-04-13-21-45' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (369 commits)
mm: fix deferred split queue races during migration
mm/khugepaged: fix issue with tracking lock
mm/huge_memory: add and use has_deposited_pgtable()
mm/huge_memory: add and use normal_or_softleaf_folio_pmd()
mm: add softleaf_is_valid_pmd_entry(), pmd_to_softleaf_folio()
mm/huge_memory: separate out the folio part of zap_huge_pmd()
mm/huge_memory: use mm instead of tlb->mm
mm/huge_memory: remove unnecessary sanity checks
mm/huge_memory: deduplicate zap deposited table call
mm/huge_memory: remove unnecessary VM_BUG_ON_PAGE()
mm/huge_memory: add a common exit path to zap_huge_pmd()
mm/huge_memory: handle buggy PMD entry in zap_huge_pmd()
mm/huge_memory: have zap_huge_pmd return a boolean, add kdoc
mm/huge: avoid big else branch in zap_huge_pmd()
mm/huge_memory: simplify vma_is_specal_huge()
mm: on remap assert that input range within the proposed VMA
mm: add mmap_action_map_kernel_pages[_full]()
uio: replace deprecated mmap hook with mmap_prepare in uio_info
drivers: hv: vmbus: replace deprecated mmap hook with mmap_prepare
mm: allow handling of stacked mmap_prepare hooks in more drivers
...
Pull x86 cleanups from Ingo Molnar:
- Consolidate AMD and Hygon cases in parse_topology() (Wei Wang)
- asm constraints cleanups in __iowrite32_copy() (Uros Bizjak)
- Drop AMD Extended Interrupt LVT macros (Naveen N Rao)
- Don't use REALLY_SLOW_IO for delays (Juergen Gross)
- paravirt cleanups (Juergen Gross)
- FPU code cleanups (Borislav Petkov)
- split-lock handling code cleanups (Borislav Petkov, Ronan Pigott)
* tag 'x86-cleanups-2026-04-13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/fpu: Correct the comment explaining what xfeatures_in_use() does
x86/split_lock: Don't warn about unknown split_lock_detect parameter
x86/fpu: Correct misspelled xfeaures_to_write local var
x86/apic: Drop AMD Extended Interrupt LVT macros
x86/cpu/topology: Consolidate AMD and Hygon cases in parse_topology()
block/floppy: Don't use REALLY_SLOW_IO for delays
x86/paravirt: Replace io_delay() hook with a bool
x86/irqflags: Preemptively move include paravirt.h directive where it belongs
x86/split_lock: Restructure the unwieldy switch-case in sld_state_show()
x86/local: Remove trailing semicolon from _ASM_XADD in local_add_return()
x86/asm: Use inout "+" asm onstraint modifiers in __iowrite32_copy()
Pull block updates from Jens Axboe:
- Add shared memory zero-copy I/O support for ublk, bypassing per-I/O
copies between kernel and userspace by matching registered buffer
PFNs at I/O time. Includes selftests.
- Refactor bio integrity to support filesystem initiated integrity
operations and arbitrary buffer alignment.
- Clean up bio allocation, splitting bio_alloc_bioset() into clear fast
and slow paths. Add bio_await() and bio_submit_or_kill() helpers,
unify synchronous bi_end_io callbacks.
- Fix zone write plug refcount handling and plug removal races. Add
support for serializing zone writes at QD=1 for rotational zoned
devices, yielding significant throughput improvements.
- Add SED-OPAL ioctls for Single User Mode management and a STACK_RESET
command.
- Add io_uring passthrough (uring_cmd) support to the BSG layer.
- Replace pp_buf in partition scanning with struct seq_buf.
- zloop improvements and cleanups.
- drbd genl cleanup, switching to pre_doit/post_doit.
- NVMe pull request via Keith:
- Fabrics authentication updates
- Enhanced block queue limits support
- Workqueue usage updates
- A new write zeroes device quirk
- Tagset cleanup fix for loop device
- MD pull requests via Yu Kuai:
- Fix raid5 soft lockup in retry_aligned_read()
- Fix raid10 deadlock with check operation and nowait requests
- Fix raid1 overlapping writes on writemostly disks
- Fix sysfs deadlock on array_state=clear
- Proactive RAID-5 parity building with llbitmap, with
write_zeroes_unmap optimization for initial sync
- Fix llbitmap barrier ordering, rdev skipping, and bitmap_ops
version mismatch fallback
- Fix bcache use-after-free and uninitialized closure
- Validate raid5 journal metadata payload size
- Various cleanups
- Various other fixes, improvements, and cleanups
* tag 'for-7.1/block-20260411' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux: (146 commits)
ublk: fix tautological comparison warning in ublk_ctrl_reg_buf
scsi: bsg: fix buffer overflow in scsi_bsg_uring_cmd()
block: refactor blkdev_zone_mgmt_ioctl
MAINTAINERS: update ublk driver maintainer email
Documentation: ublk: address review comments for SHMEM_ZC docs
ublk: allow buffer registration before device is started
ublk: replace xarray with IDA for shmem buffer index allocation
ublk: simplify PFN range loop in __ublk_ctrl_reg_buf
ublk: verify all pages in multi-page bvec fall within registered range
ublk: widen ublk_shmem_buf_reg.len to __u64 for 4GB buffer support
xfs: use bio_await in xfs_zone_gc_reset_sync
block: add a bio_submit_or_kill helper
block: factor out a bio_await helper
block: unify the synchronous bi_end_io callbacks
xfs: fix number of GC bvecs
selftests/ublk: add read-only buffer registration test
selftests/ublk: add filesystem fio verify test for shmem_zc
selftests/ublk: add hugetlbfs shmem_zc test for loop target
selftests/ublk: add shared memory zero-copy test
selftests/ublk: add UBLK_F_SHMEM_ZC support for loop target
...
Before START_DEV, there is no disk, no queue, no I/O dispatch, so
the maple tree can be safely modified under ub->mutex alone without
freezing the queue.
Add ublk_lock_buf_tree()/ublk_unlock_buf_tree() helpers that take
ub->mutex first, then freeze the queue if device is started. This
ordering (mutex -> freeze) is safe because ublk_stop_dev_unlocked()
already holds ub->mutex when calling del_gendisk() which freezes
the queue.
Suggested-by: Caleb Sander Mateos <csander@purestorage.com>
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Link: https://patch.msgid.link/20260409133020.3780098-6-tom.leiming@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Remove struct ublk_buf which only contained nr_pages that was never
read after registration. Use IDA for pure index allocation instead
of xarray. Make __ublk_ctrl_unreg_buf() return int so the caller
can detect invalid index without a separate lookup.
Simplify ublk_buf_cleanup() to walk the maple tree directly and
unpin all pages in one pass, instead of iterating the xarray by
buffer index.
Suggested-by: Caleb Sander Mateos <csander@purestorage.com>
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Link: https://patch.msgid.link/20260409133020.3780098-5-tom.leiming@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
rq_for_each_bvec() yields multi-page bvecs where bv_page is only the
first page. ublk_try_buf_match() only validated the start PFN against
the maple tree, but a bvec can span multiple pages past the end of a
registered range.
Use mas_walk() instead of mtree_load() to obtain the range boundaries
stored in the maple tree, and check that the bvec's end PFN does not
exceed the range. Also remove base_pfn from struct ublk_buf_range
since mas.index already provides the range start PFN.
Reported-by: Caleb Sander Mateos <csander@purestorage.com>
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Link: https://patch.msgid.link/20260409133020.3780098-3-tom.leiming@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The __u32 len field cannot represent a 4GB buffer (0x100000000
overflows to 0). Change it to __u64 so buffers up to 4GB can be
registered. Add a reserved field for alignment and validate it
is zero.
The kernel enforces a default max of 4GB (UBLK_SHMEM_BUF_SIZE_MAX)
which may be increased in future.
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Link: https://patch.msgid.link/20260409133020.3780098-2-tom.leiming@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The pages[] array (kvmalloc'd, 8 bytes per page = 2MB for a 1GB buffer)
was stored permanently in struct ublk_buf but only needed during
pin_user_pages_fast() and maple tree construction. Since the maple tree
already stores PFN ranges via ublk_buf_range, struct page pointers can
be recovered via pfn_to_page() during unregistration.
Make pages[] a temporary allocation in ublk_ctrl_reg_buf(), freed
immediately after the maple tree is built. Rewrite __ublk_ctrl_unreg_buf()
to iterate the maple tree for matching buf_index entries, recovering
struct page pointers via pfn_to_page() and unpinning in batches of 32.
Simplify ublk_buf_erase_ranges() to iterate the maple tree by buf_index
instead of walking the now-removed pages[] array.
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://patch.msgid.link/20260331153207.3635125-5-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Add UBLK_F_SHMEM_ZC (1ULL << 19) to the UAPI header and UBLK_F_ALL.
Switch ublk_support_shmem_zc() and ublk_dev_support_shmem_zc() from
returning false to checking the actual flag, enabling the shared
memory zero-copy feature for devices that request it.
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://patch.msgid.link/20260331153207.3635125-4-ming.lei@redhat.com
[axboe: ublk_buf_reg -> ublk_shmem_buf_reg errors]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Add ublk_try_buf_match() which walks a request's bio_vecs, looks up
each page's PFN in the per-device maple tree, and verifies all pages
belong to the same registered buffer at contiguous offsets.
Add ublk_iod_is_shmem_zc() inline helper for checking whether a
request uses the shmem zero-copy path.
Integrate into the I/O path:
- ublk_setup_iod(): if pages match a registered buffer, set
UBLK_IO_F_SHMEM_ZC and encode buffer index + offset in addr
- ublk_start_io(): skip ublk_map_io() for zero-copy requests
- __ublk_complete_rq(): skip ublk_unmap_io() for zero-copy requests
The feature remains disabled (ublk_support_shmem_zc() returns false)
until the UBLK_F_SHMEM_ZC flag is enabled in the next patch.
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://patch.msgid.link/20260331153207.3635125-3-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Add control commands for registering and unregistering shared memory
buffers for zero-copy I/O:
- UBLK_U_CMD_REG_BUF (0x18): pins pages from userspace, inserts PFN
ranges into a per-device maple tree for O(log n) lookup during I/O.
Buffer pointers are tracked in a per-device xarray. Returns the
assigned buffer index.
- UBLK_U_CMD_UNREG_BUF (0x19): removes PFN entries and unpins pages.
Queue freeze/unfreeze is handled internally so userspace need not
quiesce the device during registration.
Also adds:
- UBLK_IO_F_SHMEM_ZC flag and addr encoding helpers in UAPI header
(16-bit buffer index supporting up to 65536 buffers)
- Data structures (ublk_buf, ublk_buf_range) and xarray/maple tree
- __ublk_ctrl_reg_buf() helper for PFN insertion with error unwinding
- __ublk_ctrl_unreg_buf() helper for cleanup reuse
- ublk_support_shmem_zc() / ublk_dev_support_shmem_zc() stubs
(returning false — feature not enabled yet)
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://patch.msgid.link/20260331153207.3635125-2-ming.lei@redhat.com
[axboe: fixup ublk_buf_reg -> ublk_shmem_buf_reg errors, comments]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
DRBD used a custom mechanism to mark netlink attributes as "mandatory":
bit 14 of nla_type was repurposed as DRBD_GENLA_F_MANDATORY. Attributes
sent from userspace that had this bit present and that were unknown
to the kernel would lead to an error.
Since commit ef6243acb4 ("genetlink: optionally validate strictly/dumps"),
the generic netlink layer rejects unknown top-level attributes when
strict validation is enabled. DRBD never opted out of strict
validation, so unknown top-level attributes are already rejected by
the netlink core.
The mandatory flag mechanism was required for nested attributes, because
these are parsed liberally, silently dropping attributes unknown to the
kernel.
This prepares for the move to a new YNL-based family, which will use the
now-default strict parsing.
The current family is not expected to gain any new attributes, which
makes this change safe.
Old userspace that still sets bit 14 is unaffected: nla_type()
strips it before __nla_validate_parse() performs attribute validation,
so the bit never reaches DRBD.
Remove all references to the mandatory flag in DRBD.
Cc: Johannes Berg <johannes.berg@intel.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Christoph Böhmwalder <christoph.boehmwalder@linbit.com>
Link: https://patch.msgid.link/20260403132953.2248751-1-christoph.boehmwalder@linbit.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
If a ublk server starts recovering devices but dies before issuing fetch
commands for all IOs, cancellation of the fetch commands that were
successfully issued may never complete. This is because the per-IO
canceled flag can remain set even after the fetch for that IO has been
submitted - the per-IO canceled flags for all IOs in a queue are reset
together only once all IOs for that queue have been fetched. So if a
nonempty proper subset of the IOs for a queue are fetched when the ublk
server dies, the IOs in that subset will never successfully be canceled,
as their canceled flags remain set, and this prevents ublk_cancel_cmd
from actually calling io_uring_cmd_done on the commands, despite the
fact that they are outstanding.
Fix this by resetting the per-IO cancel flags immediately when each IO
is fetched instead of waiting for all IOs for the queue (which may never
happen).
Signed-off-by: Uday Shankar <ushankar@purestorage.com>
Fixes: 728cbac5fe ("ublk: move device reset into ublk_ch_release()")
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: zhang, the-essence-of-life <zhangweize9@gmail.com>
Link: https://patch.msgid.link/20260405-cancel-v2-1-02d711e643c2@purestorage.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
scan_slots_for_writeback() and scan_slots_for_recompress() work in a "best
effort" fashion, if they cannot allocate memory for a new pp-slot
candidate they just return and post-processing selects slots that were
successfully scanned thus far. scan_slots functions never return errors
and their callers never check the return status, so convert them to return
void.
Link: https://lkml.kernel.org/r/20260317032349.753645-1-senozhatsky@chromium.org
Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Reviewed-by: SeongJae Park <sj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Calling `LZ4_loadDict()` repeatedly in Zram causes significant overhead
due to its internal dictionary pre-processing. This commit introduces a
template stream mechanism to pre-process the dictionary only once when the
dictionary is initially set or modified. It then efficiently copies this
state for subsequent compressions.
Verification Test Items:
Test Platform: android16-6.12
1. Collect Anonymous Page Dataset
1) Apply the following patch:
static bool zram_meta_alloc(struct zram *zram, u64 disksize)
if (!huge_class_size)
- huge_class_size = zs_huge_class_size(zram->mem_pool);
+ huge_class_size = 0;
2）Install multiple apps and monkey testing until SwapFree is close to 0.
3）Execute the following command to export data:
dd if=/dev/block/zram0 of=/data/samples/zram_dump.img bs=4K
2. Train Dictionary
Since LZ4 does not have a dedicated dictionary training tool, the zstd
tool can be used for training[1]. The command is as follows:
zstd --train /data/samples/* --split=4096 --maxdict=64KB -o /vendor/etc/dict_data
3. Test Code
adb shell "dd if=/data/samples/zram_dump.img of=/dev/test_pattern bs=4096 count=131072 conv=fsync"
adb shell "swapoff /dev/block/zram0"
adb shell "echo 1 > /sys/block/zram0/reset"
adb shell "echo lz4 > /sys/block/zram0/comp_algorithm"
adb shell "echo dict=/vendor/etc/dict_data > /sys/block/zram0/algorithm_params"
adb shell "echo 6G > /sys/block/zram0/disksize"
echo "Start Compression"
adb shell "taskset 80 dd if=/dev/test_pattern of=/dev/block/zram0 bs=4096 count=131072 conv=fsync"
echo.
echo "Start Decompression"
adb shell "taskset 80 dd if=/dev/block/zram0 of=/dev/output_result bs=4096 count=131072 conv=fsync"
echo "mm_stat:"
adb shell "cat /sys/block/zram0/mm_stat"
echo.
Note: To ensure stable test results, it is best to lock the CPU frequency
before executing the test.
LZ4 supports dictionaries up to 64KB. Below are the test results for
compression rates at various dictionary sizes:
dict_size base patch
4 KB 156M/s 219M/s
8 KB 136M/s 217M/s
16KB 98M/s 214M/s
32KB 66M/s 225M/s
64KB 38M/s 224M/s
When an LZ4 compression dictionary is enabled, compression speed is
negatively impacted by the dictionary's size; larger dictionaries result
in slower compression. This patch eliminates the influence of dictionary
size on compression speed, ensuring consistent performance regardless of
dictionary scale.
Link: https://lkml.kernel.org/r/698181478c9c4b10aa21b4a847bdc706@honor.com
Link: https://github.com/lz4/lz4?tab=readme-ov-file [1]
Signed-off-by: gao xu <gaoxu2@honor.com>
Acked-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
We have two functions that accept algo= and priority= params -
algorithm_params_store() and recompress_store(). This patch unifies and
hardens handling of those parameters.
There are 4 possible cases:
- only priority= provided [recommended]
We need to verify that provided priority value is
within permitted range for each particular function.
- both algo= and priority= provided
We cannot prioritize one over another. All we should
do is to verify that zram is configured in the way
that user-space expects it to be. Namely that zram
indeed has compressor algo= setup at given priority=.
- only algo= provided [not recommended]
We should lookup priority in compressors list.
- none provided [not recommended]
Just use function's defaults.
Link: https://lkml.kernel.org/r/20260311084312.1766036-7-senozhatsky@chromium.org
Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Suggested-by: Minchan Kim <minchan@kernel.org>
Cc: Brian Geffon <bgeffon@google.com>
Cc: gao xu <gaoxu2@honor.com>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Chained recompression has unpredictable behavior and is not useful in
practice.
First, systems usually configure just one alternative recompression
algorithm, which has slower compression/decompression but better
compression ratio. A single alternative algorithm doesn't need chaining.
Second, even with multiple recompression algorithms, chained recompression
is suboptimal. If a lower priority algorithm succeeds, the page is never
attempted with a higher priority algorithm, leading to worse memory
savings. If a lower priority algorithm fails, the page is still attempted
with a higher priority algorithm, wasting resources on the failed lower
priority attempt.
In either case, the system would be better off targeting a specific
priority directly.
Chained recompression also significantly complicates the code. Remove it.
Link: https://lkml.kernel.org/r/20260311084312.1766036-6-senozhatsky@chromium.org
Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Brian Geffon <bgeffon@google.com>
Cc: gao xu <gaoxu2@honor.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "zram: recompression cleanups and tweaks", v2.
This series is a somewhat random mix of fixups, recompression cleanups and
improvements partly based on internal conversations. A few patches in the
series remove unexpected or confusing behaviour, e.g. auto correction of
bad priority= param for recompression, which should have always been just
an error. Then it also removes "chain recompression" which has a tricky,
unexpected and confusing behaviour at times. We also unify and harden the
handling of algo/priority params. There is also an addition of missing
device lock in algorithm_params_store() which previously permitted
modification of algo params while the device is active.
This patch (of 6):
First, algorithm_params_store(), like any sysfs handler, should grab
device lock.
Second, like any write() sysfs handler, it should grab device lock in
exclusive mode.
Third, it should not permit change of algos' parameters after device init,
as this doesn't make sense - we cannot compress with one C/D dict and then
just change C/D dict to a different one, for example.
Another thing to notice is that algorithm_params_store() accesses device's
->comp_algs for algo priority lookup, which should be protected by device
lock in exclusive mode in general.
Link: https://lkml.kernel.org/r/20260311084312.1766036-1-senozhatsky@chromium.org
Link: https://lkml.kernel.org/r/20260311084312.1766036-2-senozhatsky@chromium.org
Fixes: 4eac932103 ("zram: introduce algorithm_params device attribute")
Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Acked-by: Brian Geffon <bgeffon@google.com>
Cc: gao xu <gaoxu2@honor.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Currently, zram dynamically allocates memory for compressor algorithm
names when they are set by the user. This requires careful memory
management, including explicit `kfree` calls and special handling to avoid
freeing statically defined default compressor names.
This patch refactors the way zram handles compression algorithm names.
Instead of storing dynamically allocated copies, `zram->comp_algs` will
now store pointers directly to the static name strings defined within the
`zcomp_ops` backend structures, thereby removing the need for conditional
`kfree` calls.
Link: https://lkml.kernel.org/r/5bb2e9318d124dbcb2b743dcdce6a950@honor.com
Signed-off-by: gao xu <gaoxu2@honor.com>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Introduce the new max_open_zones option to allow specifying a limit on
the maximum number of open zones of a zloop device. This change allows
creating a zloop device that can more closely mimick the characteristics
of a physical SMR drive.
When set to a non zero value, only up to max_open_zones zones can be in
the implicit open (BLK_ZONE_COND_IMP_OPEN) and explicit open
(BLK_ZONE_COND_EXP_OPEN) conditions at any time. The transition to the
implicit open condition of a zone on a write operation can result in an
implicit close of an already implicitly open zone. This is handled in
the function zloop_do_open_zone(). This function also handles
transitions to the explicit open condition. Implicit close transitions
are handled using an LRU ordered list of open zones which is managed
using the helper functions zloop_lru_rotate_open_zone() and
zloop_lru_remove_open_zone().
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://patch.msgid.link/20260326203245.946830-1-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Every doit handler followed the same pattern: stack-allocate an
adm_ctx, call drbd_adm_prepare() at the top, call drbd_adm_finish()
at the bottom. This duplicated boilerplate across 25 handlers and
made error paths inconsistent, since some handlers could miss sending
the reply skb on early-exit paths.
The generic netlink framework already provides pre_doit/post_doit
hooks for exactly this purpose. An old comment even noted "this
would be a good candidate for a pre_doit hook".
Use them:
- pre_doit heap-allocates adm_ctx, looks up per-command flags from a
new drbd_genl_cmd_flags[] table, runs drbd_adm_prepare(), and
stores the context in info->user_ptr[0].
- post_doit sends the reply, drops kref references for
device/connection/resource, and frees the adm_ctx.
- Handlers just receive adm_ctx from info->user_ptr[0], set
reply_dh->ret_code, and return. All teardown is in post_doit.
- drbd_adm_finish() is removed, superseded by post_doit.
Signed-off-by: Christoph Böhmwalder <christoph.boehmwalder@linbit.com>
Link: https://patch.msgid.link/20260324152907.2840984-1-christoph.boehmwalder@linbit.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Mark ublk_filter_unused_tags() as noinline since it is only called from
the unlikely(needs_filter) branch. Extract the error-handling block from
__ublk_batch_dispatch() into a new noinline ublk_batch_dispatch_fail()
function to keep the hot path compact and icache-friendly. This also
makes __ublk_batch_dispatch() more readable by separating the error
recovery logic from the normal dispatch flow.
Before: __ublk_batch_dispatch is ~1419 bytes
After: __ublk_batch_dispatch is ~1090 bytes (-329 bytes, -23%)
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://patch.msgid.link/20260318014112.3125432-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Instead of defining REALLY_SLOW_IO before including io.h, add the
required additional calls of native_io_delay() to the related functions
in arch/x86/include/asm/floppy.h.
Drop REALLY_SLOW_IO now too as it has no users.
[ bp: Merge the REALLY_SLOW_IO removal into this patch. ]
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://patch.msgid.link/20260119182632.596369-4-jgross@suse.com
