The patch titled Subject: mm: add folio_flush_mapping() has been added to the -mm mm-unstable branch. Its filename is mm-add-folio_flush_mapping.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-add-folio_flush_mapping.patch This patch will later appear in the mm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx> Subject: mm: add folio_flush_mapping() Date: Wed, 2 Aug 2023 16:13:32 +0100 This is the folio equivalent of page_mapping_file(), but rename it to make it clear that it's very different from page_file_mapping(). Theoretically, there's nothing flush-only about it, but there are no other users today, and I doubt there will be; it's almost always more useful to know the swapfile's mapping or the swapcache's mapping. Link: https://lkml.kernel.org/r/20230802151406.3735276-5-willy@xxxxxxxxxxxxx Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx> Acked-by: Mike Rapoport (IBM) <rppt@xxxxxxxxxx> Reviewed-by: Anshuman Khandual <anshuman.khandual@xxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- include/linux/pagemap.h | 26 +++++++++++++++++++++----- 1 file changed, 21 insertions(+), 5 deletions(-) --- a/include/linux/pagemap.h~mm-add-folio_flush_mapping +++ a/include/linux/pagemap.h @@ -389,6 +389,26 @@ static inline struct address_space *foli return folio->mapping; } +/** + * folio_flush_mapping - Find the file mapping this folio belongs to. + * @folio: The folio. + * + * For folios which are in the page cache, return the mapping that this + * page belongs to. Anonymous folios return NULL, even if they're in + * the swap cache. Other kinds of folio also return NULL. + * + * This is ONLY used by architecture cache flushing code. If you aren't + * writing cache flushing code, you want either folio_mapping() or + * folio_file_mapping(). + */ +static inline struct address_space *folio_flush_mapping(struct folio *folio) +{ + if (unlikely(folio_test_swapcache(folio))) + return NULL; + + return folio_mapping(folio); +} + static inline struct address_space *page_file_mapping(struct page *page) { return folio_file_mapping(page_folio(page)); @@ -399,11 +419,7 @@ static inline struct address_space *page */ static inline struct address_space *page_mapping_file(struct page *page) { - struct folio *folio = page_folio(page); - - if (unlikely(folio_test_swapcache(folio))) - return NULL; - return folio_mapping(folio); + return folio_flush_mapping(page_folio(page)); } /** _ Patches currently in -mm which might be from willy@xxxxxxxxxxxxx are mm-drop-per-vma-lock-when-returning-vm_fault_retry-or-vm_fault_completed-fix.patch rmap-pass-the-folio-to-__page_check_anon_rmap.patch highmem-add-memcpy_to_folio-and-memcpy_from_folio.patch affs-convert-affs_symlink_read_folio-to-use-the-folio.patch affs-convert-data-read-and-write-to-use-folios.patch migrate-use-folio_set_bh-instead-of-set_bh_page.patch ntfs3-convert-ntfs_get_block_vbo-to-use-a-folio.patch jbd2-use-a-folio-in-jbd2_journal_write_metadata_buffer.patch buffer-remove-set_bh_page.patch zswap-make-zswap_store-take-a-folio.patch memcg-convert-get_obj_cgroup_from_page-to-get_obj_cgroup_from_folio.patch swap-remove-some-calls-to-compound_head-in-swap_readpage.patch zswap-make-zswap_load-take-a-folio.patch mm-remove-config_per_vma_lock-ifdefs.patch mm-allow-per-vma-locks-on-file-backed-vmas.patch mm-move-fault_flag_vma_lock-check-from-handle_mm_fault.patch mm-handle-pud-faults-under-the-vma-lock.patch mm-handle-some-pmd-faults-under-the-vma-lock.patch mm-move-fault_flag_vma_lock-check-down-in-handle_pte_fault.patch mm-move-fault_flag_vma_lock-check-down-from-do_fault.patch mm-run-the-fault-around-code-under-the-vma-lock.patch mm-handle-swap-and-numa-pte-faults-under-the-vma-lock.patch mm-handle-faults-that-merely-update-the-accessed-bit-under-the-vma-lock.patch mm-handle-faults-that-merely-update-the-accessed-bit-under-the-vma-lock-fix.patch mm-improve-the-comment-in-isolate_migratepages_block.patch minmax-add-in_range-macro.patch mm-convert-page_table_check_pte_set-to-page_table_check_ptes_set.patch mm-add-generic-flush_icache_pages-and-documentation.patch mm-add-folio_flush_mapping.patch mm-remove-arch_implements_flush_dcache_folio.patch mm-add-default-definition-of-set_ptes.patch alpha-implement-the-new-page-table-range-api.patch arc-implement-the-new-page-table-range-api.patch arm-implement-the-new-page-table-range-api.patch arm64-implement-the-new-page-table-range-api.patch csky-implement-the-new-page-table-range-api.patch hexagon-implement-the-new-page-table-range-api.patch ia64-implement-the-new-page-table-range-api.patch loongarch-implement-the-new-page-table-range-api.patch m68k-implement-the-new-page-table-range-api.patch microblaze-implement-the-new-page-table-range-api.patch mips-implement-the-new-page-table-range-api.patch nios2-implement-the-new-page-table-range-api.patch openrisc-implement-the-new-page-table-range-api.patch parisc-implement-the-new-page-table-range-api.patch powerpc-implement-the-new-page-table-range-api.patch riscv-implement-the-new-page-table-range-api.patch s390-implement-the-new-page-table-range-api.patch sh-implement-the-new-page-table-range-api.patch sparc32-implement-the-new-page-table-range-api.patch sparc64-implement-the-new-page-table-range-api.patch um-implement-the-new-page-table-range-api.patch x86-implement-the-new-page-table-range-api.patch xtensa-implement-the-new-page-table-range-api.patch mm-remove-page_mapping_file.patch mm-rationalise-flush_icache_pages-and-flush_icache_page.patch mm-tidy-up-set_ptes-definition.patch mm-use-flush_icache_pages-in-do_set_pmd.patch mm-call-update_mmu_cache_range-in-more-page-fault-handling-paths.patch