- 03 Feb, 2023 40 commits
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David Hildenbrand authored
nios2 disables swap for a good reason: it doesn't even provide sufficient type bits as required by core MM. However, swap entries are nowadays also used for other purposes (migration entries, PTE markers, HWPoison, ...), and accidential use could be problematic. Let's properly use 5 bits for the swap type and document the layout. Bits 26--31 should get ignored by hardware completely, so they can be used. Link: https://lkml.kernel.org/r/20230113171026.582290-14-david@redhat.comSigned-off-by:
David Hildenbrand <david@redhat.com> Cc: Dinh Nguyen <dinguyen@kernel.org> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org>
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David Hildenbrand authored
Let's support __HAVE_ARCH_PTE_SWP_EXCLUSIVE. On 64bit, steal one bit from the type. Generic MM currently only uses 5 bits for the type (MAX_SWAPFILES_SHIFT), so the stolen bit is effectively unused. On 32bit we're able to locate unused bits. As the PTE layout for 32 bit is very confusing, document it a bit better. While at it, mask the type in __swp_entry()/mk_swap_pte(). Link: https://lkml.kernel.org/r/20230113171026.582290-13-david@redhat.comSigned-off-by:
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David Hildenbrand authored
Let's support __HAVE_ARCH_PTE_SWP_EXCLUSIVE by stealing one bit from the type. Generic MM currently only uses 5 bits for the type (MAX_SWAPFILES_SHIFT), so the stolen bit is effectively unused. The shift by 2 when converting between PTE and arch-specific swap entry makes the swap PTE layout a little bit harder to decipher. While at it, drop the comment from paulus---copy-and-paste leftover from powerpc where we actually have _PAGE_HASHPTE---and mask the type in __swp_entry_to_pte() as well. Link: https://lkml.kernel.org/r/20230113171026.582290-12-david@redhat.comSigned-off-by:
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David Hildenbrand authored
Let's support __HAVE_ARCH_PTE_SWP_EXCLUSIVE by stealing one bit from the type. Generic MM currently only uses 5 bits for the type (MAX_SWAPFILES_SHIFT), so the stolen bit is effectively unused. While at it, make sure for sun3 that the valid bit never gets set by properly masking it off and mask the type in __swp_entry(). Link: https://lkml.kernel.org/r/20230113171026.582290-11-david@redhat.comSigned-off-by:
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David Hildenbrand authored
The definitions are not required, let's remove them. Link: https://lkml.kernel.org/r/20230113171026.582290-10-david@redhat.comSigned-off-by:
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David Hildenbrand authored
Let's support __HAVE_ARCH_PTE_SWP_EXCLUSIVE by stealing one bit from the type. Generic MM currently only uses 5 bits for the type (MAX_SWAPFILES_SHIFT), so the stolen bit is effectively unused. While at it, also mask the type in mk_swap_pte(). Note that this bit does not conflict with swap PMDs and could also be used in swap PMD context later. Link: https://lkml.kernel.org/r/20230113171026.582290-9-david@redhat.comSigned-off-by:
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David Hildenbrand authored
Let's support __HAVE_ARCH_PTE_SWP_EXCLUSIVE by stealing one bit from the type. Generic MM currently only uses 5 bits for the type (MAX_SWAPFILES_SHIFT), so the stolen bit is effectively unused. While at it, also mask the type in __swp_entry(). Link: https://lkml.kernel.org/r/20230113171026.582290-8-david@redhat.comSigned-off-by:
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David Hildenbrand authored
Let's support __HAVE_ARCH_PTE_SWP_EXCLUSIVE by stealing one bit from the offset. This reduces the maximum swap space per file to 16 GiB (was 32 GiB). While at it, mask the type in __swp_entry(). Link: https://lkml.kernel.org/r/20230113171026.582290-7-david@redhat.comSigned-off-by:
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David Hildenbrand authored
Let's support __HAVE_ARCH_PTE_SWP_EXCLUSIVE by stealing one bit from the offset. This reduces the maximum swap space per file to 16 GiB (was 32 GiB). We might actually be able to reuse one of the other software bits (_PAGE_READ / PAGE_WRITE) instead, because we only have to keep pte_present(), pte_none() and HW happy. For now, let's keep it simple because there might be something non-obvious. Link: https://lkml.kernel.org/r/20230113171026.582290-6-david@redhat.comSigned-off-by:
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David Hildenbrand authored
Let's support __HAVE_ARCH_PTE_SWP_EXCLUSIVE by stealing one bit from the offset. This reduces the maximum swap space per file to 64 GiB (was 128 GiB). While at it drop the PTE_TYPE_FAULT from __swp_entry_to_pte() which is defined to be 0 and is rather confusing because we should be dealing with "Linux PTEs" not "hardware PTEs". Also, properly mask the type in __swp_entry(). Link: https://lkml.kernel.org/r/20230113171026.582290-5-david@redhat.comSigned-off-by:
Russell King (Oracle) <rmk+kernel@armlinux.org.uk> Signed-off-by:
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David Hildenbrand authored
Let's support __HAVE_ARCH_PTE_SWP_EXCLUSIVE by using bit 5, which is yet unused. The only important parts seems to be to not use _PAGE_PRESENT (bit 9). Link: https://lkml.kernel.org/r/20230113171026.582290-4-david@redhat.comSigned-off-by:
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David Hildenbrand authored
Let's support __HAVE_ARCH_PTE_SWP_EXCLUSIVE by stealing one bit from the type. Generic MM currently only uses 5 bits for the type (MAX_SWAPFILES_SHIFT), so the stolen bit is effectively unused. While at it, mask the type in mk_swap_pte() as well. Link: https://lkml.kernel.org/r/20230113171026.582290-3-david@redhat.comSigned-off-by:
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David Hildenbrand authored
Patch series "mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE on all architectures with swap PTEs". This is the follow-up on [1]: [PATCH v2 0/8] mm: COW fixes part 3: reliable GUP R/W FOLL_GET of anonymous pages After we implemented __HAVE_ARCH_PTE_SWP_EXCLUSIVE on most prominent enterprise architectures, implement __HAVE_ARCH_PTE_SWP_EXCLUSIVE on all remaining architectures that support swap PTEs. This makes sure that exclusive anonymous pages will stay exclusive, even after they were swapped out -- for example, making GUP R/W FOLL_GET of anonymous pages reliable. Details can be found in [1]. This primarily fixes remaining known O_DIRECT memory corruptions that can happen on concurrent swapout, whereby we can lose DMA reads to a page (modifying the user page by writing to it). To verify, there are two test cases (requiring swap space, obviously): (1) The O_DIRECT+swapout test case [2] from Andrea. This test case tries triggering a race condition. (2) My vmsplice() test case [3] that tries to detect if the exclusive marker was lost during swapout, not relying on a race condition. For example, on 32bit x86 (with and without PAE), my test case fails without these patches: $ ./test_swp_exclusive FAIL: page was replaced during COW But succeeds with these patches: $ ./test_swp_exclusive PASS: page was not replaced during COW Why implement __HAVE_ARCH_PTE_SWP_EXCLUSIVE for all architectures, even the ones where swap support might be in a questionable state? This is the first step towards removing "readable_exclusive" migration entries, and instead using pte_swp_exclusive() also with (readable) migration entries instead (as suggested by Peter). The only missing piece for that is supporting pmd_swp_exclusive() on relevant architectures with THP migration support. As all relevant architectures now implement __HAVE_ARCH_PTE_SWP_EXCLUSIVE,, we can drop __HAVE_ARCH_PTE_SWP_EXCLUSIVE in the last patch. I tried cross-compiling all relevant setups and tested on x86 and sparc64 so far. CCing arch maintainers only on this cover letter and on the respective patch(es). [1] https://lkml.kernel.org/r/20220329164329.208407-1-david@redhat.com [2] https://gitlab.com/aarcange/kernel-testcases-for-v5.11/-/blob/main/page_count_do_wp_page-swap.c [3] https://gitlab.com/davidhildenbrand/scratchspace/-/blob/main/test_swp_exclusive.c This patch (of 26): We want to implement __HAVE_ARCH_PTE_SWP_EXCLUSIVE on all architectures. Let's extend our sanity checks, especially testing that our PTE bit does not affect: * is_swap_pte() -> pte_present() and pte_none() * the swap entry + type * pte_swp_soft_dirty() Especially, the pfn_pte() is dodgy when the swap PTE layout differs heavily from ordinary PTEs. Let's properly construct a swap PTE from swap type+offset. [david@redhat.com: fix build] Link: https://lkml.kernel.org/r/6aaad548-cf48-77fa-9d6c-db83d724b2eb@redhat.com Link: https://lkml.kernel.org/r/20230113171026.582290-1-david@redhat.com Link: https://lkml.kernel.org/r/20230113171026.582290-2-david@redhat.comSigned-off-by: -
Vishal Moola (Oracle) authored
Converts release_pte_pages() to use folios instead of pages. Link: https://lkml.kernel.org/r/20230114001556.43795-2-vishal.moola@gmail.comSigned-off-by:
Vishal Moola (Oracle) <vishal.moola@gmail.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mike Kravetz <mike.kravetz@oracle.com> Signed-off-by:
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Vishal Moola (Oracle) authored
release_pte_page() is converted to be a wrapper for release_pte_folio() to help facilitate the khugepaged conversion to folios. This replaces 3 calls to compound_head() with 1, and saves 85 bytes of kernel text. Link: https://lkml.kernel.org/r/20230114001556.43795-1-vishal.moola@gmail.comSigned-off-by:
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Alexander Potapenko authored
When building the kernel with W=1, the compiler reports numerous warnings about the missing prototypes for KMSAN instrumentation hooks. Because these functions are not supposed to be called explicitly by the kernel code (calls to them are emitted by the compiler), they do not have to be declared in the headers. Instead, we add forward declarations right before the definitions to silence the warnings produced by -Wmissing-prototypes. Link: https://lkml.kernel.org/r/20230112103147.382416-1-glider@google.comSigned-off-by:
Alexander Potapenko <glider@google.com> Reported-by:
Vlastimil Babka <vbabka@suse.cz> Suggested-by:
Marco Elver <elver@google.com> Reviewed-by:
kernel test robot <lkp@intel.com> Link: https://lore.kernel.org/lkml/202301020356.dFruA4I5-lkp@intel.com/T/ Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by:
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Lorenzo Stoakes authored
We now pass folios to these functions, so update the documentation accordingly. Additionally, correct the outdated reference to __pagevec_lru_add_fn(), the referenced action occurs in __munlock_folio() directly now, replace reference to lru_cache_add_inactive_or_unevictable() with the modern folio equivalent folio_add_lru_vma() and reference folio flags by the flag name rather than accessor. Link: https://lkml.kernel.org/r/898c487169d98a7f09c1c1e57a7dfdc2b3f6bf0f.1673526881.git.lstoakes@gmail.comSigned-off-by:
Lorenzo Stoakes <lstoakes@gmail.com> Acked-by:
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Lorenzo Stoakes authored
Update the mlock interface to accept folios rather than pages, bringing the interface in line with the internal implementation. munlock_vma_page() still requires a page_folio() conversion, however this is consistent with the existent mlock_vma_page() implementation and a product of rmap still dealing in pages rather than folios. Link: https://lkml.kernel.org/r/cba12777c5544305014bc0cbec56bb4cc71477d8.1673526881.git.lstoakes@gmail.comSigned-off-by:
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Lorenzo Stoakes authored
Failing to specify a specific type here breaks anything that relies on the type being explicitly known, such as page_folio(). Make explicit the type of null pointer returned here. Link: https://lkml.kernel.org/r/ad6be2821bbd6af10966b3704568ff458b270d9c.1673526881.git.lstoakes@gmail.comSigned-off-by:
Geert Uytterhoeven <geert@linux-m68k.org> Acked-by:
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Lorenzo Stoakes authored
This brings mlock in line with the folio batches declared in mm/swap.c and makes the code more consistent across the two. The existing mechanism for identifying which operation each folio in the batch is undergoing is maintained, i.e. using the lower 2 bits of the struct folio address (previously struct page address). This should continue to function correctly as folios remain at least system word-aligned. All invocations of mlock() pass either a non-compound page or the head of a THP-compound page and no tail pages need updating so this functionality works with struct folios being used internally rather than struct pages. In this patch the external interface is kept identical to before in order to maintain separation between patches in the series, using a rather awkward conversion from struct page to struct folio in relevant functions. However, this maintenance of the existing interface is intended to be temporary - the next patch in the series will update the interfaces to accept folios directly. Link: https://lkml.kernel.org/r/9f894d54d568773f4ed3cb0eef5f8932f62c95f4.1673526881.git.lstoakes@gmail.comSigned-off-by:
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Lorenzo Stoakes authored
Patch series "update mlock to use folios", v4. This series updates mlock to use folios, converting the internal interface to using folios exclusively and exposing the folio interface externally. As a product of this we move to using a folio batch rather than a pagevec for mlock folios, which brings it in line with the core folio batches contained in mm/swap.c. This patch (of 5): This performs the same task as pagevec_reinit(), only modifying a folio batch rather than a pagevec. Link: https://lkml.kernel.org/r/cover.1673526881.git.lstoakes@gmail.com Link: https://lkml.kernel.org/r/9018cecacb39e34c883540f997f9be8281153613.1673526881.git.lstoakes@gmail.comSigned-off-by:
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Kefeng Wang authored
There is already a vm_normal_folio(), use it to make madvise_free_pte_range() only use a folio. Link: https://lkml.kernel.org/r/20230112124028.16964-1-wangkefeng.wang@huawei.comSigned-off-by:
Kefeng Wang <wangkefeng.wang@huawei.com> Reviewed-by:
Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com> Signed-off-by:
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Matthew Wilcox (Oracle) authored
Use a folio internally to shmem_write_end() which saves a number of calls to compound_head() and lets us get rid of the custom code to zero out the rest of a THP and supports folios of arbitrary size. Link: https://lkml.kernel.org/r/20230112131031.1209553-1-willy@infradead.orgSigned-off-by:
William Kucharski <william.kucharski@oracle.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by:
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Sidhartha Kumar authored
Use a folio inside unpoison_memory which replaces a compound_head() call with a call to page_folio(). Link: https://lkml.kernel.org/r/20230112204608.80136-9-sidhartha.kumar@oracle.comSigned-off-by:
Sidhartha Kumar <sidhartha.kumar@oracle.com> Acked-by:
Naoya Horiguchi <naoya.horiguchi@nec.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Miaohe Lin <linmiaohe@huawei.com> Signed-off-by:
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Sidhartha Kumar authored
Change hugetlb_set_page_hwpoison() to folio_set_hugetlb_hwpoison() and use a folio internally. Link: https://lkml.kernel.org/r/20230112204608.80136-8-sidhartha.kumar@oracle.comSigned-off-by:
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Sidhartha Kumar authored
Change __free_raw_hwp_pages() to __folio_free_raw_hwp() and modify its callers to pass in a folio. Link: https://lkml.kernel.org/r/20230112204608.80136-7-sidhartha.kumar@oracle.comSigned-off-by:
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Sidhartha Kumar authored
Change raw_hwp_list_head() to take in a folio and modify its callers to pass in a folio. Also converts two users of hugetlb specific page macro users to their folio equivalents. Link: https://lkml.kernel.org/r/20230112204608.80136-6-sidhartha.kumar@oracle.comSigned-off-by:
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Sidhartha Kumar authored
Change free_raw_hwp_pages() to folio_free_raw_hwp(), converts two users of hugetlb specific page macro users to their folio equivalents. Link: https://lkml.kernel.org/r/20230112204608.80136-5-sidhartha.kumar@oracle.comSigned-off-by:
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Sidhartha Kumar authored
Change hugetlb_clear_page_hwpoison() to folio_clear_hugetlb_hwpoison() by changing the function to take in a folio. This converts one use of ClearPageHWPoison and HPageRawHwpUnreliable to their folio equivalents. Link: https://lkml.kernel.org/r/20230112204608.80136-4-sidhartha.kumar@oracle.comSigned-off-by:
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Sidhartha Kumar authored
Use a struct folio rather than a head page in try_memory_failure_hugetlb. This converts one user of SetHPageMigratable to the folio equivalent. Link: https://lkml.kernel.org/r/20230112204608.80136-3-sidhartha.kumar@oracle.comSigned-off-by:
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Sidhartha Kumar authored
Patch series "convert hugepage memory failure functions to folios". This series contains a 1:1 straightforward page to folio conversion for memory failure functions which deal with huge pages. I renamed a few functions to fit with how other folio operating functions are named. These include: hugetlb_clear_page_hwpoison -> folio_clear_hugetlb_hwpoison free_raw_hwp_pages -> folio_free_raw_hwp __free_raw_hwp_pages -> __folio_free_raw_hwp hugetlb_set_page_hwpoison -> folio_set_hugetlb_hwpoison The goal of this series was to reduce users of the hugetlb specific page flag macros which take in a page so users are protected by the compiler to make sure they are operating on a head page. This patch (of 8): Use a folio throughout the function rather than using a head page. This also reduces the users of the page version of hugetlb specific page flags. Link: https://lkml.kernel.org/r/20230112204608.80136-2-sidhartha.kumar@oracle.comSigned-off-by:
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Alexander Potapenko authored
This reverts commit 3f1e2c7a. As noticed by Qun-Wei Lin, arch_sync_kernel_mappings() in arch/x86/mm/fault.c is only used with CONFIG_X86_32, whereas KMSAN is only supported on x86_64, where this code is not compiled. The patch in question dates back to downstream KMSAN branch based on v5.8-rc5, it sneaked into upstream unnoticed in v6.1. Link: https://lkml.kernel.org/r/20230111101806.3236991-1-glider@google.comSigned-off-by:
Qun-Wei Lin <qun-wei.lin@mediatek.com> Link: https://github.com/google/kmsan/issues/91 Cc: Andy Lutomirski <luto@kernel.org> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Marco Elver <elver@google.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by:
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Vernon Yang authored
The low_limit of unmapped area information is inclusive, and the hight_limit is not, so make symbol to be [ instead of (. And replace hight_limit to high_limit. Link: https://lkml.kernel.org/r/20230111132036.801404-1-vernon2gm@gmail.com Fixes: 3499a131 ("mm/mmap: use maple tree for unmapped_area{_topdown}") Signed-off-by:
Vernon Yang <vernon2gm@gmail.com> Cc: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Matthew Wilcox <willy@infradead.org> Signed-off-by:
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Vernon Yang authored
The parameter name of maple tree is mt, make the comment be mt instead of mn, and the separator between the parameter name and the description to be : instead of -. Link: https://lkml.kernel.org/r/20230111135348.803181-1-vernon2gm@gmail.com Fixes: 54a611b6 ("Maple Tree: add new data structure") Signed-off-by:
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Sidhartha Kumar authored
Patch series "Get rid of tail page fields". Continue the shrinkage of the struct page definition by getting rid of the 'first tail page' and 'second tail page' fields. I originally did this patch set before Hugh's rewrite of the subpages_mapcount, so it needed substantial updates; hope I didn't miss anything. This patch (of 28): commit dad6a5eb(mm,hugetlb: use folio fields in second tail page) added a transitional hugetlb field to struct page and struct folio to make room for another int in the first tail of a compound page. Hugetlb folio conversions have changed all page users of this field to use the fields within the folio so struct page no longer needs this hugetlb specific field. Link: https://lkml.kernel.org/r/20230111142915.1001531-1-willy@infradead.org Link: https://lkml.kernel.org/r/20230111142915.1001531-29-willy@infradead.orgSigned-off-by:
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Matthew Wilcox (Oracle) authored
Now that both callers use a folio, pass the folio in and save a call to compound_head(). Link: https://lkml.kernel.org/r/20230111142915.1001531-28-willy@infradead.orgSigned-off-by:
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Matthew Wilcox (Oracle) authored
Removes a few calls to compound_head(). Link: https://lkml.kernel.org/r/20230111142915.1001531-27-willy@infradead.orgSigned-off-by:
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Matthew Wilcox (Oracle) authored
Use folio->_deferred_list directly. Link: https://lkml.kernel.org/r/20230111142915.1001531-26-willy@infradead.orgSigned-off-by:
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Matthew Wilcox (Oracle) authored
Remove the entire block of definitions for the second tail page, and add the deferred list to the struct folio. This actually moves _deferred_list to a different offset in struct folio because I don't see a need to include the padding. This lets us use list_for_each_entry_safe() in deferred_split_scan() and avoid a number of calls to compound_head(). Link: https://lkml.kernel.org/r/20230111142915.1001531-25-willy@infradead.orgSigned-off-by:
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Matthew Wilcox (Oracle) authored
Insert appropriate public: and private: markers to make the generated kernel-doc look right. Link: https://lkml.kernel.org/r/20230111142915.1001531-24-willy@infradead.orgSigned-off-by:
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