kernel/include/linux/highmem.h, branch linux-6.17.y

mm: remove unmap_and_put_page()

2025-07-20T01:59:51Z

There are no callers of unmap_and_put_page() left. Remove it. Link: https://lkml.kernel.org/r/20250709194017.927978-6-vishal.moola@gmail.com Signed-off-by: Vishal Moola (Oracle) Acked-by: David Hildenbrand Cc: Jordan Rome Cc: Matthew Wilcox (Oracle) Signed-off-by: Andrew Morton

mm: remove zero_user()

2025-07-10T05:42:09Z

All users have now been converted to either memzero_page() or folio_zero_range(). Link: https://lkml.kernel.org/r/20250612143443.2848197-6-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) Reviewed-by: Alex Markuze Cc: Christoph Hellwig Cc: Ilya Dryomov Cc: Ira Weiny Cc: Jens Axboe Cc: Xiubo Li Cc: Dan Carpenter Cc: Viacheslav Dubeyko Signed-off-by: Andrew Morton

Merge tag 'f2fs-for-6.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs

2025-05-30T15:40:25Z

Pull f2fs updates from Jaegeuk Kim: "In this round, Matthew converted most of page operations to using folio. Beyond the work, we've applied some performance tunings such as GC and linear lookup, in addition to enhancing fault injection and sanity checks. Enhancements: - large number of folio conversions - add a control to turn on/off the linear lookup for performance - tune GC logics for zoned block device - improve fault injection and sanity checks Bug fixes: - handle error cases of memory donation - fix to correct check conditions in f2fs_cross_rename - fix to skip f2fs_balance_fs() if checkpoint is disabled - don't over-report free space or inodes in statvfs - prevent the current section from being selected as a victim during GC - fix to calculate first_zoned_segno correctly - fix to avoid inconsistence between SIT and SSA for zoned block device As usual, there are several debugging patches and clean-ups as well" * tag 'f2fs-for-6.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs: (195 commits) f2fs: fix to correct check conditions in f2fs_cross_rename f2fs: use d_inode(dentry) cleanup dentry->d_inode f2fs: fix to skip f2fs_balance_fs() if checkpoint is disabled f2fs: clean up to check bi_status w/ BLK_STS_OK f2fs: introduce is_{meta,node}_folio f2fs: add ckpt_valid_blocks to the section entry f2fs: add a method for calculating the remaining blocks in the current segment in LFS mode. f2fs: introduce FAULT_VMALLOC f2fs: use vmalloc instead of kvmalloc in .init_{,de}compress_ctx f2fs: add f2fs_bug_on() in f2fs_quota_read() f2fs: add f2fs_bug_on() to detect potential bug f2fs: remove unused sbi argument from checksum functions f2fs: fix 32-bits hexademical number in fault injection doc f2fs: don't over-report free space or inodes in statvfs f2fs: return bool from __write_node_folio f2fs: simplify return value handling in f2fs_fsync_node_pages f2fs: always unlock the page in f2fs_write_single_data_page f2fs: remove wbc->for_reclaim handling f2fs: return bool from __f2fs_write_meta_folio f2fs: fix to return correct error number in f2fs_sync_node_pages() ...

highmem: add folio_test_partial_kmap()

2025-05-21T05:49:39Z

In commit c749d9b7ebbc ("iov_iter: fix copy_page_from_iter_atomic() if KMAP_LOCAL_FORCE_MAP"), Hugh correctly noted that if KMAP_LOCAL_FORCE_MAP is enabled, we must limit ourselves to PAGE_SIZE bytes per call to kmap_local(). The same problem exists in memcpy_from_folio(), memcpy_to_folio(), folio_zero_tail(), folio_fill_tail() and memcpy_from_file_folio(), so add folio_test_partial_kmap() to do this more succinctly. Link: https://lkml.kernel.org/r/20250514170607.3000994-2-willy@infradead.org Fixes: 00cdf76012ab ("mm: add memcpy_from_file_folio()") Signed-off-by: Matthew Wilcox (Oracle) Cc: Al Viro Cc: Hugh Dickins Cc: Signed-off-by: Andrew Morton

highmem: Add memcpy_folio()

2025-04-28T15:26:33Z

The folio equivalent of memcpy_page(). It should correctly and efficiently manage large folios: - If one, neither or both is highmem - If (either or both) offset+len crosses a page boundary - If the two offsets are congruent or not Signed-off-by: Matthew Wilcox (Oracle) Reviewed-by: Chao Yu Signed-off-by: Jaegeuk Kim

mm: use clear_user_(high)page() for arch with special user folio handling

2024-12-19T03:04:43Z

Some architectures have special handling after clearing user folios: architectures, which set cpu_dcache_is_aliasing() to true, require flushing dcache; arc, which sets cpu_icache_is_aliasing() to true, changes folio->flags to make icache coherent to dcache. So __GFP_ZERO using only clear_page() is not enough to zero user folios and clear_user_(high)page() must be used. Otherwise, user data will be corrupted. Fix it by always clearing user folios with clear_user_(high)page() when cpu_dcache_is_aliasing() is true or cpu_icache_is_aliasing() is true. Rename alloc_zeroed() to user_alloc_needs_zeroing() and invert the logic to clarify its intend. Link: https://lkml.kernel.org/r/20241209182326.2955963-2-ziy@nvidia.com Fixes: 5708d96da20b ("mm: avoid zeroing user movable page twice with init_on_alloc=1") Signed-off-by: Zi Yan Reported-by: Geert Uytterhoeven Closes: https://lore.kernel.org/linux-mm/CAMuHMdV1hRp_NtR5YnJo=HsfgKQeH91J537Gh4gKk3PFZhSkbA@mail.gmail.com/ Tested-by: Geert Uytterhoeven Acked-by: Vlastimil Babka Cc: Alexander Potapenko Cc: David Hildenbrand Cc: John Hubbard Cc: Kees Cook Cc: Kefeng Wang Cc: Mathieu Desnoyers Cc: Matthew Wilcox Cc: Miaohe Lin Cc: Ryan Roberts Cc: Vineet Gupta Signed-off-by: Andrew Morton

mm: avoid zeroing user movable page twice with init_on_alloc=1

2024-11-07T04:11:13Z

Commit 6471384af2a6 ("mm: security: introduce init_on_alloc=1 and init_on_free=1 boot options") forces allocated page to be zeroed in post_alloc_hook() when init_on_alloc=1. For order-0 folios, if arch does not define vma_alloc_zeroed_movable_folio(), the default implementation again zeros the page return from the buddy allocator. So the page is zeroed twice. Fix it by passing __GFP_ZERO instead to avoid double page zeroing. At the moment, s390,arm64,x86,alpha,m68k are not impacted since they define their own vma_alloc_zeroed_movable_folio(). For >0 order folios (mTHP and PMD THP), folio_zero_user() is called to zero the folio again. Fix it by calling folio_zero_user() only if init_on_alloc is set. All arch are impacted. Add alloc_zeroed() helper to encapsulate the init_on_alloc check. [ziy@nvidia.com: comment fixes, per David] Link: https://lkml.kernel.org/r/97DB52E1-C594-49B5-9736-89AC302FAB01@nvidia.com Link: https://lkml.kernel.org/r/20241011150304.709590-1-ziy@nvidia.com Signed-off-by: Zi Yan Acked-by: Vlastimil Babka Acked-by: David Hildenbrand Cc: Alexander Potapenko Cc: "Huang, Ying" Cc: John Hubbard Cc: Kees Cook Cc: Kefeng Wang Cc: Matthew Wilcox Cc: Miaohe Lin Cc: Ryan Roberts Signed-off-by: Andrew Morton

mm: remove unused hugepage for vma_alloc_folio()

2024-11-07T04:11:12Z

The hugepage parameter was deprecated since commit ddc1a5cbc05d ("mempolicy: alloc_pages_mpol() for NUMA policy without vma"), for PMD-sized THP, it still tries only preferred node if possible in vma_alloc_folio() by checking the order of the folio allocation. Link: https://lkml.kernel.org/r/20241010061556.1846751-1-wangkefeng.wang@huawei.com Signed-off-by: Kefeng Wang Acked-by: David Hildenbrand Reviewed-by: Zi Yan Reviewed-by: Barry Song Cc: Hugh Dickins Cc: Matthew Wilcox Cc: Ryan Roberts Signed-off-by: Andrew Morton

mm: move memory_failure_queue() into copy_mc_[user]_highpage()

2024-07-06T18:53:19Z

Patch series "mm: migrate: support poison recover from migrate folio", v5. The folio migration is widely used in kernel, memory compaction, memory hotplug, soft offline page, numa balance, memory demote/promotion, etc, but once access a poisoned source folio when migrating, the kernel will panic. There is a mechanism in the kernel to recover from uncorrectable memory errors, ARCH_HAS_COPY_MC(eg, Machine Check Safe Memory Copy on x86), which is already used in NVDIMM or core-mm paths(eg, CoW, khugepaged, coredump, ksm copy), see copy_mc_to_{user,kernel}, copy_mc_{user_}highpage callers. This series of patches provide the recovery mechanism from folio copy for the widely used folio migration. Please note, because folio migration is no guarantee of success, so we could chose to make folio migration tolerant of memory failures, adding folio_mc_copy() which is a #MC versions of folio_copy(), once accessing a poisoned source folio, we could return error and make the folio migration fail, and this could avoid the similar panic shown below. CPU: 1 PID: 88343 Comm: test_softofflin Kdump: loaded Not tainted 6.6.0 pc : copy_page+0x10/0xc0 lr : copy_highpage+0x38/0x50 ... Call trace: copy_page+0x10/0xc0 folio_copy+0x78/0x90 migrate_folio_extra+0x54/0xa0 move_to_new_folio+0xd8/0x1f0 migrate_folio_move+0xb8/0x300 migrate_pages_batch+0x528/0x788 migrate_pages_sync+0x8c/0x258 migrate_pages+0x440/0x528 soft_offline_in_use_page+0x2ec/0x3c0 soft_offline_page+0x238/0x310 soft_offline_page_store+0x6c/0xc0 dev_attr_store+0x20/0x40 sysfs_kf_write+0x4c/0x68 kernfs_fop_write_iter+0x130/0x1c8 new_sync_write+0xa4/0x138 vfs_write+0x238/0x2d8 ksys_write+0x74/0x110 This patch (of 5): There is a memory_failure_queue() call after copy_mc_[user]_highpage(), see callers, eg, CoW/KSM page copy, it is used to mark the source page as h/w poisoned and unmap it from other tasks, and the upcomming poison recover from migrate folio will do the similar thing, so let's move the memory_failure_queue() into the copy_mc_[user]_highpage() instead of adding it into each user, this should also enhance the handling of poisoned page in khugepaged. Link: https://lkml.kernel.org/r/20240626085328.608006-1-wangkefeng.wang@huawei.com Link: https://lkml.kernel.org/r/20240626085328.608006-2-wangkefeng.wang@huawei.com Signed-off-by: Kefeng Wang Reviewed-by: Jane Chu Reviewed-by: Miaohe Lin Cc: Alistair Popple Cc: Benjamin LaHaise Cc: David Hildenbrand Cc: Hugh Dickins Cc: Jérôme Glisse Cc: Jiaqi Yan Cc: Lance Yang Cc: Matthew Wilcox (Oracle) Cc: Muchun Song Cc: Naoya Horiguchi Cc: Oscar Salvador Cc: Tony Luck Cc: Vishal Moola (Oracle) Signed-off-by: Andrew Morton

mm/highmem: make nr_free_highpages() return "unsigned long"

2024-07-04T02:30:06Z

It looks rather weird that totalhigh_pages() returns an "unsigned long" but nr_free_highpages() returns an "unsigned int". Let's return an "unsigned long" from nr_free_highpages() to be consistent. While at it, use a plain "0" instead of a "0UL" in the !CONFIG_HIGHMEM totalhigh_pages() implementation, to make these look alike as well. Link: https://lkml.kernel.org/r/20240607083711.62833-3-david@redhat.com Signed-off-by: David Hildenbrand Reviewed-by: Wei Yang Signed-off-by: Andrew Morton