kernel/linux.git/mm/shmem.c, branch v7.0.10

Convert 'alloc_obj' family to use the new default GFP_KERNEL argument

2026-02-22T01:09:51+00:00

This was done entirely with mindless brute force, using git grep -l '\

treewide: Replace kmalloc with kmalloc_obj for non-scalar types

2026-02-21T09:02:28+00:00

This is the result of running the Coccinelle script from scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to avoid scalar types (which need careful case-by-case checking), and instead replace kmalloc-family calls that allocate struct or union object instances: Single allocations: kmalloc(sizeof(TYPE), ...) are replaced with: kmalloc_obj(TYPE, ...) Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...) are replaced with: kmalloc_objs(TYPE, COUNT, ...) Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...) are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...) (where TYPE may also be *VAR) The resulting allocations no longer return "void *", instead returning "TYPE *". Signed-off-by: Kees Cook

Merge tag 'mm-stable-2026-02-18-19-48' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2026-02-19T04:50:32+00:00

Pull more MM updates from Andrew Morton: - "mm/vmscan: fix demotion targets checks in reclaim/demotion" fixes a couple of issues in the demotion code - pages were failed demotion and were finding themselves demoted into disallowed nodes (Bing Jiao) - "Remove XA_ZERO from error recovery of dup_mmap()" fixes a rare mapledtree race and performs a number of cleanups (Liam Howlett) - "mm: add bitmap VMA flag helpers and convert all mmap_prepare to use them" implements a lot of cleanups following on from the conversion of the VMA flags into a bitmap (Lorenzo Stoakes) - "support batch checking of references and unmapping for large folios" implements batching to greatly improve the performance of reclaiming clean file-backed large folios (Baolin Wang) - "selftests/mm: add memory failure selftests" does as claimed (Miaohe Lin) * tag 'mm-stable-2026-02-18-19-48' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (36 commits) mm/page_alloc: clear page->private in free_pages_prepare() selftests/mm: add memory failure dirty pagecache test selftests/mm: add memory failure clean pagecache test selftests/mm: add memory failure anonymous page test mm: rmap: support batched unmapping for file large folios arm64: mm: implement the architecture-specific clear_flush_young_ptes() arm64: mm: support batch clearing of the young flag for large folios arm64: mm: factor out the address and ptep alignment into a new helper mm: rmap: support batched checks of the references for large folios tools/testing/vma: add VMA userland tests for VMA flag functions tools/testing/vma: separate out vma_internal.h into logical headers tools/testing/vma: separate VMA userland tests into separate files mm: make vm_area_desc utilise vma_flags_t only mm: update all remaining mmap_prepare users to use vma_flags_t mm: update shmem_[kernel]_file_*() functions to use vma_flags_t mm: update secretmem to use VMA flags on mmap_prepare mm: update hugetlbfs to use VMA flags on mmap_prepare mm: add basic VMA flag operation helper functions tools: bitmap: add missing bitmap_[subset(), andnot()] mm: add mk_vma_flags() bitmap flag macro helper ...

mm: update shmem_[kernel]_file_*() functions to use vma_flags_t

2026-02-12T23:42:58+00:00

In order to be able to use only vma_flags_t in vm_area_desc we must adjust shmem file setup functions to operate in terms of vma_flags_t rather than vm_flags_t. This patch makes this change and updates all callers to use the new functions. No functional changes intended. [akpm@linux-foundation.org: comment fixes, per Baolin] Link: https://lkml.kernel.org/r/736febd280eb484d79cef5cf55b8a6f79ad832d2.1769097829.git.lorenzo.stoakes@oracle.com Signed-off-by: Lorenzo Stoakes Reviewed-by: Baolin Wang Reviewed-by: Jarkko Sakkinen Reviewed-by: Liam R. Howlett Cc: Barry Song Cc: David Hildenbrand Cc: Dev Jain Cc: Jason Gunthorpe Cc: Suren Baghdasaryan Cc: Vlastimil Babka Cc: Zi Yan Cc: "Darrick J. Wong" Cc: Damien Le Moal Cc: Yury Norov Cc: Chris Mason Cc: Pedro Falcato Signed-off-by: Andrew Morton

Merge tag 'mm-stable-2026-02-11-19-22' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2026-02-12T19:32:37+00:00

Pull MM updates from Andrew Morton: - "powerpc/64s: do not re-activate batched TLB flush" makes arch_{enter|leave}_lazy_mmu_mode() nest properly (Alexander Gordeev) It adds a generic enter/leave layer and switches architectures to use it. Various hacks were removed in the process. - "zram: introduce compressed data writeback" implements data compression for zram writeback (Richard Chang and Sergey Senozhatsky) - "mm: folio_zero_user: clear page ranges" adds clearing of contiguous page ranges for hugepages. Large improvements during demand faulting are demonstrated (David Hildenbrand) - "memcg cleanups" tidies up some memcg code (Chen Ridong) - "mm/damon: introduce {,max_}nr_snapshots and tracepoint for damos stats" improves DAMOS stat's provided information, deterministic control, and readability (SeongJae Park) - "selftests/mm: hugetlb cgroup charging: robustness fixes" fixes a few issues in the hugetlb cgroup charging selftests (Li Wang) - "Fix va_high_addr_switch.sh test failure - again" addresses several issues in the va_high_addr_switch test (Chunyu Hu) - "mm/damon/tests/core-kunit: extend existing test scenarios" improves the KUnit test coverage for DAMON (Shu Anzai) - "mm/khugepaged: fix dirty page handling for MADV_COLLAPSE" fixes a glitch in khugepaged which was causing madvise(MADV_COLLAPSE) to transiently return -EAGAIN (Shivank Garg) - "arch, mm: consolidate hugetlb early reservation" reworks and consolidates a pile of straggly code related to reservation of hugetlb memory from bootmem and creation of CMA areas for hugetlb (Mike Rapoport) - "mm: clean up anon_vma implementation" cleans up the anon_vma implementation in various ways (Lorenzo Stoakes) - "tweaks for __alloc_pages_slowpath()" does a little streamlining of the page allocator's slowpath code (Vlastimil Babka) - "memcg: separate private and public ID namespaces" cleans up the memcg ID code and prevents the internal-only private IDs from being exposed to userspace (Shakeel Butt) - "mm: hugetlb: allocate frozen gigantic folio" cleans up the allocation of frozen folios and avoids some atomic refcount operations (Kefeng Wang) - "mm/damon: advance DAMOS-based LRU sorting" improves DAMOS's movement of memory betewwn the active and inactive LRUs and adds auto-tuning of the ratio-based quotas and of monitoring intervals (SeongJae Park) - "Support page table check on PowerPC" makes CONFIG_PAGE_TABLE_CHECK_ENFORCED work on powerpc (Andrew Donnellan) - "nodemask: align nodes_and{,not} with underlying bitmap ops" makes nodes_and() and nodes_andnot() propagate the return values from the underlying bit operations, enabling some cleanup in calling code (Yury Norov) - "mm/damon: hide kdamond and kdamond_lock from API callers" cleans up some DAMON internal interfaces (SeongJae Park) - "mm/khugepaged: cleanups and scan limit fix" does some cleanup work in khupaged and fixes a scan limit accounting issue (Shivank Garg) - "mm: balloon infrastructure cleanups" goes to town on the balloon infrastructure and its page migration function. Mainly cleanups, also some locking simplification (David Hildenbrand) - "mm/vmscan: add tracepoint and reason for kswapd_failures reset" adds additional tracepoints to the page reclaim code (Jiayuan Chen) - "Replace wq users and add WQ_PERCPU to alloc_workqueue() users" is part of Marco's kernel-wide migration from the legacy workqueue APIs over to the preferred unbound workqueues (Marco Crivellari) - "Various mm kselftests improvements/fixes" provides various unrelated improvements/fixes for the mm kselftests (Kevin Brodsky) - "mm: accelerate gigantic folio allocation" greatly speeds up gigantic folio allocation, mainly by avoiding unnecessary work in pfn_range_valid_contig() (Kefeng Wang) - "selftests/damon: improve leak detection and wss estimation reliability" improves the reliability of two of the DAMON selftests (SeongJae Park) - "mm/damon: cleanup kdamond, damon_call(), damos filter and DAMON_MIN_REGION" does some cleanup work in the core DAMON code (SeongJae Park) - "Docs/mm/damon: update intro, modules, maintainer profile, and misc" performs maintenance work on the DAMON documentation (SeongJae Park) - "mm: add and use vma_assert_stabilised() helper" refactors and cleans up the core VMA code. The main aim here is to be able to use the mmap write lock's lockdep state to perform various assertions regarding the locking which the VMA code requires (Lorenzo Stoakes) - "mm, swap: swap table phase II: unify swapin use" removes some old swap code (swap cache bypassing and swap synchronization) which wasn't working very well. Various other cleanups and simplifications were made. The end result is a 20% speedup in one benchmark (Kairui Song) - "enable PT_RECLAIM on more 64-bit architectures" makes PT_RECLAIM available on 64-bit alpha, loongarch, mips, parisc, and um. Various cleanups were performed along the way (Qi Zheng) * tag 'mm-stable-2026-02-11-19-22' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (325 commits) mm/memory: handle non-split locks correctly in zap_empty_pte_table() mm: move pte table reclaim code to memory.c mm: make PT_RECLAIM depends on MMU_GATHER_RCU_TABLE_FREE mm: convert __HAVE_ARCH_TLB_REMOVE_TABLE to CONFIG_HAVE_ARCH_TLB_REMOVE_TABLE config um: mm: enable MMU_GATHER_RCU_TABLE_FREE parisc: mm: enable MMU_GATHER_RCU_TABLE_FREE mips: mm: enable MMU_GATHER_RCU_TABLE_FREE LoongArch: mm: enable MMU_GATHER_RCU_TABLE_FREE alpha: mm: enable MMU_GATHER_RCU_TABLE_FREE mm: change mm/pt_reclaim.c to use asm/tlb.h instead of asm-generic/tlb.h mm/damon/stat: remove __read_mostly from memory_idle_ms_percentiles zsmalloc: make common caches global mm: add SPDX id lines to some mm source files mm/zswap: use %pe to print error pointers mm/vmscan: use %pe to print error pointers mm/readahead: fix typo in comment mm: khugepaged: fix NR_FILE_PAGES and NR_SHMEM in collapse_file() mm: refactor vma_map_pages to use vm_insert_pages mm/damon: unify address range representation with damon_addr_range mm/cma: replace snprintf with strscpy in cma_new_area ...

Merge tag 'vfs-7.0-rc1.leases' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

2026-02-09T19:59:07+00:00

Pull vfs lease updates from Christian Brauner: "This contains updates for lease support to require filesystems to explicitly opt-in to lease support Currently kernel_setlease() falls through to generic_setlease() when a a filesystem does not define ->setlease(), silently granting lease support to every filesystem regardless of whether it is prepared for it. This is a poor default: most filesystems never intended to support leases, and the silent fallthrough makes it impossible to distinguish "supports leases" from "never thought about it". This inverts the default. It adds explicit .setlease = generic_setlease; assignments to every in-tree filesystem that should retain lease support, then changes kernel_setlease() to return -EINVAL when ->setlease is NULL. With the new default in place, simple_nosetlease() is redundant and is removed along with all references to it" * tag 'vfs-7.0-rc1.leases' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (25 commits) fuse: add setlease file operation fs: remove simple_nosetlease() filelock: default to returning -EINVAL when ->setlease operation is NULL xfs: add setlease file operation ufs: add setlease file operation udf: add setlease file operation tmpfs: add setlease file operation squashfs: add setlease file operation overlayfs: add setlease file operation orangefs: add setlease file operation ocfs2: add setlease file operation ntfs3: add setlease file operation nilfs2: add setlease file operation jfs: add setlease file operation jffs2: add setlease file operation gfs2: add a setlease file operation fat: add setlease file operation f2fs: add setlease file operation exfat: add setlease file operation ext4: add setlease file operation ...

mm: add SPDX id lines to some mm source files

2026-02-06T23:47:16+00:00

Some of the memory management source files are missing SPDX-License-Identifier lines. Add appropriate IDs to these files (mostly GPL-2.0, but one LGPL-2.1). Link: https://lkml.kernel.org/r/20260204213101.1754183-1-tim.bird@sony.com Signed-off-by: Tim Bird Signed-off-by: Andrew Morton

mm, shmem: prevent infinite loop on truncate race

2026-02-03T02:43:55+00:00

When truncating a large swap entry, shmem_free_swap() returns 0 when the entry's index doesn't match the given index due to lookup alignment. The failure fallback path checks if the entry crosses the end border and aborts when it happens, so truncate won't erase an unexpected entry or range. But one scenario was ignored. When `index` points to the middle of a large swap entry, and the large swap entry doesn't go across the end border, find_get_entries() will return that large swap entry as the first item in the batch with `indices[0]` equal to `index`. The entry's base index will be smaller than `indices[0]`, so shmem_free_swap() will fail and return 0 due to the "base < index" check. The code will then call shmem_confirm_swap(), get the order, check if it crosses the END boundary (which it doesn't), and retry with the same index. The next iteration will find the same entry again at the same index with same indices, leading to an infinite loop. Fix this by retrying with a round-down index, and abort if the index is smaller than the truncate range. Link: https://lkml.kernel.org/r/aXo6ltB5iqAKJzY8@KASONG-MC4 Fixes: 809bc86517cc ("mm: shmem: support large folio swap out") Fixes: 8a1968bd997f ("mm/shmem, swap: fix race of truncate and swap entry split") Signed-off-by: Kairui Song Reported-by: Chris Mason Closes: https://lore.kernel.org/linux-mm/20260128130336.727049-1-clm@meta.com/ Reviewed-by: Baolin Wang Cc: Baoquan He Cc: Barry Song Cc: Chris Li Cc: Hugh Dickins Cc: Kemeng Shi Cc: Nhat Pham Cc: Signed-off-by: Andrew Morton

mm, swap: cleanup swap entry management workflow

2026-01-31T22:22:56+00:00

The current swap entry allocation/freeing workflow has never had a clear definition. This makes it hard to debug or add new optimizations. This commit introduces a proper definition of how swap entries would be allocated and freed. Now, most operations are folio based, so they will never exceed one swap cluster, and we now have a cleaner border between swap and the rest of mm, making it much easier to follow and debug, especially with new added sanity checks. Also making more optimization possible. Swap entry will be mostly freed and free with a folio bound. The folio lock will be useful for resolving many swap related races. Now swap allocation (except hibernation) always starts with a folio in the swap cache, and gets duped/freed protected by the folio lock: - folio_alloc_swap() - The only allocation entry point now. Context: The folio must be locked. This allocates one or a set of continuous swap slots for a folio and binds them to the folio by adding the folio to the swap cache. The swap slots' swap count start with zero value. - folio_dup_swap() - Increase the swap count of one or more entries. Context: The folio must be locked and in the swap cache. For now, the caller still has to lock the new swap entry owner (e.g., PTL). This increases the ref count of swap entries allocated to a folio. Newly allocated swap slots' count has to be increased by this helper as the folio got unmapped (and swap entries got installed). - folio_put_swap() - Decrease the swap count of one or more entries. Context: The folio must be locked and in the swap cache. For now, the caller still has to lock the new swap entry owner (e.g., PTL). This decreases the ref count of swap entries allocated to a folio. Typically, swapin will decrease the swap count as the folio got installed back and the swap entry got uninstalled This won't remove the folio from the swap cache and free the slot. Lazy freeing of swap cache is helpful for reducing IO. There is already a folio_free_swap() for immediate cache reclaim. This part could be further optimized later. The above locking constraints could be further relaxed when the swap table is fully implemented. Currently dup still needs the caller to lock the swap entry container (e.g. PTL), or a concurrent zap may underflow the swap count. Some swap users need to interact with swap count without involving folio (e.g. forking/zapping the page table or mapping truncate without swapin). In such cases, the caller has to ensure there is no race condition on whatever owns the swap count and use the below helpers: - swap_put_entries_direct() - Decrease the swap count directly. Context: The caller must lock whatever is referencing the slots to avoid a race. Typically the page table zapping or shmem mapping truncate will need to free swap slots directly. If a slot is cached (has a folio bound), this will also try to release the swap cache. - swap_dup_entry_direct() - Increase the swap count directly. Context: The caller must lock whatever is referencing the entries to avoid race, and the entries must already have a swap count > 1. Typically, forking will need to copy the page table and hence needs to increase the swap count of the entries in the table. The page table is locked while referencing the swap entries, so the entries all have a swap count > 1 and can't be freed. Hibernation subsystem is a bit different, so two special wrappers are here: - swap_alloc_hibernation_slot() - Allocate one entry from one device. - swap_free_hibernation_slot() - Free one entry allocated by the above helper. All hibernation entries are exclusive to the hibernation subsystem and should not interact with ordinary swap routines. By separating the workflows, it will be possible to bind folio more tightly with swap cache and get rid of the SWAP_HAS_CACHE as a temporary pin. This commit should not introduce any behavior change [kasong@tencent.com: fix leak, per Chris Mason. Remove WARN_ON, per Lai Yi] Link: https://lkml.kernel.org/r/CAMgjq7AUz10uETVm8ozDWcB3XohkOqf0i33KGrAquvEVvfp5cg@mail.gmail.com [ryncsn@gmail.com: fix KSM copy pages for swapoff, per Chris] Link: https://lkml.kernel.org/r/aXxkANcET3l2Xu6J@KASONG-MC4 Link: https://lkml.kernel.org/r/20251220-swap-table-p2-v5-14-8862a265a033@tencent.com Signed-off-by: Kairui Song Signed-off-by: Kairui Song Acked-by: Rafael J. Wysocki (Intel) Reviewed-by: Baoquan He Cc: Baolin Wang Cc: Barry Song Cc: Chris Li Cc: Nhat Pham Cc: Yosry Ahmed Cc: Deepanshu Kartikey Cc: Johannes Weiner Cc: Kairui Song Cc: Chris Mason Cc: Chris Mason Cc: Lai Yi Signed-off-by: Andrew Morton

mm/shmem, swap: remove SWAP_MAP_SHMEM

2026-01-31T22:22:55+00:00

The SWAP_MAP_SHMEM state was introduced in the commit aaa468653b4a ("swap_info: note SWAP_MAP_SHMEM"), to quickly determine if a swap entry belongs to shmem during swapoff. However, swapoff has since been rewritten in the commit b56a2d8af914 ("mm: rid swapoff of quadratic complexity"). Now having swap count == SWAP_MAP_SHMEM value is basically the same as having swap count == 1, and swap_shmem_alloc() behaves analogously to swap_duplicate(). The only difference of note is that swap_shmem_alloc() does not check for -ENOMEM returned from __swap_duplicate(), but it is OK because shmem never re-duplicates any swap entry it owns. This will stil be safe if we use (batched) swap_duplicate() instead. This commit adds swap_duplicate_nr(), the batched variant of swap_duplicate(), and removes the SWAP_MAP_SHMEM state and the associated swap_shmem_alloc() helper to simplify the state machine (both mentally and in terms of actual code). We will also have an extra state/special value that can be repurposed (for swap entries that never gets re-duplicated). Link: https://lkml.kernel.org/r/20251220-swap-table-p2-v5-8-8862a265a033@tencent.com Signed-off-by: Kairui Song Signed-off-by: Nhat Pham Reviewed-by: Baolin Wang Tested-by: Baolin Wang Cc: Baoquan He Cc: Barry Song Cc: Chris Li Cc: Rafael J. Wysocki (Intel) Cc: Yosry Ahmed Cc: Deepanshu Kartikey Cc: Johannes Weiner Cc: Kairui Song Signed-off-by: Andrew Morton