[v14,38/39] mm/filemap: Add filemap_get_folio

Message ID	20210715200030.899216-39-willy@infradead.org (mailing list archive)
State	New
Headers	show Return-Path: <SRS0=osCV=MH=kvack.org=owner-linux-mm@kernel.org> DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5395F613D2 From: "Matthew Wilcox (Oracle)" <willy@infradead.org> To: linux-mm@kvack.org, linux-fsdevel@vger.kernel.org Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org> Subject: [PATCH v14 38/39] mm/filemap: Add filemap_get_folio Date: Thu, 15 Jul 2021 21:00:29 +0100 Message-Id: <20210715200030.899216-39-willy@infradead.org> In-Reply-To: <20210715200030.899216-1-willy@infradead.org> References: <20210715200030.899216-1-willy@infradead.org> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Sender: owner-linux-mm@kvack.org Precedence: bulk
Series	Memory folios: Pagecache edition \| expand [v14c,00/39] Memory folios: Pagecache edition [v14,01/39] mm: Add folio_pfn() [v14,02/39] mm: Add folio_raw_mapping() [v14,03/39] mm: Add flush_dcache_folio() [v14,04/39] mm: Add kmap_local_folio() [v14,05/39] mm: Add arch_make_folio_accessible() [v14,06/39] mm: Add folio_young and folio_idle [v14,07/39] mm/swap: Add folio_activate() [v14,08/39] mm/swap: Add folio_mark_accessed() [v14,09/39] mm/rmap: Add folio_mkclean() [v14,10/39] mm/migrate: Add folio_migrate_mapping() [v14,11/39] mm/migrate: Add folio_migrate_flags() [v14,12/39] mm/migrate: Add folio_migrate_copy() [v14,13/39] mm/writeback: Rename __add_wb_stat() to wb_stat_mod() [v14,14/39] flex_proportions: Allow N events instead of 1 [v14,15/39] mm/writeback: Change __wb_writeout_inc() to __wb_writeout_add() [v14,16/39] mm/writeback: Add __folio_end_writeback() [v14,17/39] mm/writeback: Add folio_start_writeback() [v14,18/39] mm/writeback: Add folio_mark_dirty() [v14,19/39] mm/writeback: Add __folio_mark_dirty() [v14,20/39] mm/writeback: Convert tracing writeback_page_template to folios [v14,21/39] mm/writeback: Add filemap_dirty_folio() [v14,22/39] mm/writeback: Add folio_account_cleaned() [v14,23/39] mm/writeback: Add folio_cancel_dirty() [v14,24/39] mm/writeback: Add folio_clear_dirty_for_io() [v14,25/39] mm/writeback: Add folio_account_redirty() [v14,26/39] mm/writeback: Add folio_redirty_for_writepage() [v14,27/39] mm/filemap: Add i_blocks_per_folio() [v14,28/39] mm/filemap: Add folio_mkwrite_check_truncate() [v14,29/39] mm/filemap: Add readahead_folio() [v14,30/39] mm/workingset: Convert workingset_refault() to take a folio [v14,31/39] mm: Add folio_evictable() [v14,32/39] mm/lru: Convert __pagevec_lru_add_fn to take a folio [v14,33/39] mm/lru: Add folio_add_lru() [v14,34/39] mm/page_alloc: Add folio allocation functions [v14,35/39] mm/filemap: Add filemap_alloc_folio [v14,36/39] mm/filemap: Add filemap_add_folio() [v14,37/39] mm/filemap: Convert mapping_get_entry to return a folio [v14,38/39] mm/filemap: Add filemap_get_folio [v14,39/39] mm/filemap: Add FGP_STABLE

diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h index 19b2e3bea14c..b24933eced18 100644 --- a/include/linux/pagemap.h +++ b/include/linux/pagemap.h @@ -302,8 +302,26 @@ pgoff_t page_cache_prev_miss(struct address_space *mapping, #define FGP_HEAD 0x00000080 #define FGP_ENTRY 0x00000100 -struct page *pagecache_get_page(struct address_space *mapping, pgoff_t offset, - int fgp_flags, gfp_t cache_gfp_mask); +struct folio *__filemap_get_folio(struct address_space *mapping, pgoff_t index, + int fgp_flags, gfp_t gfp); +struct page *pagecache_get_page(struct address_space *mapping, pgoff_t index, + int fgp_flags, gfp_t gfp); + +/** + * filemap_get_folio - Find and get a folio. + * @mapping: The address_space to search. + * @index: The page index. + * + * Looks up the page cache entry at @mapping & @index. If a folio is + * present, it is returned with an increased refcount. + * + * Otherwise, %NULL is returned. + */ +static inline struct folio *filemap_get_folio(struct address_space *mapping, + pgoff_t index) +{ + return __filemap_get_folio(mapping, index, 0, 0); +} /** * find_get_page - find and get a page reference @@ -346,25 +364,6 @@ static inline struct page *find_lock_page(struct address_space *mapping, return pagecache_get_page(mapping, index, FGP_LOCK, 0); } -/** - * find_lock_head - Locate, pin and lock a pagecache page. - * @mapping: The address_space to search. - * @index: The page index. - * - * Looks up the page cache entry at @mapping & @index. If there is a - * page cache page, its head page is returned locked and with an increased - * refcount. - * - * Context: May sleep. - * Return: A struct page which is !PageTail, or %NULL if there is no page - * in the cache for this index. - */ -static inline struct page *find_lock_head(struct address_space *mapping, - pgoff_t index) -{ - return pagecache_get_page(mapping, index, FGP_LOCK | FGP_HEAD, 0); -} - /** * find_or_create_page - locate or add a pagecache page * @mapping: the page's address_space diff --git a/mm/filemap.c b/mm/filemap.c index 85a457c7b7a7..061e285aae21 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -1794,93 +1794,89 @@ static void *mapping_get_entry(struct address_space *mapping, pgoff_t index) } /** - * pagecache_get_page - Find and get a reference to a page. + * __filemap_get_folio - Find and get a reference to a folio. * @mapping: The address_space to search. * @index: The page index. - * @fgp_flags: %FGP flags modify how the page is returned. - * @gfp_mask: Memory allocation flags to use if %FGP_CREAT is specified. + * @fgp_flags: %FGP flags modify how the folio is returned. + * @gfp: Memory allocation flags to use if %FGP_CREAT is specified. * * Looks up the page cache entry at @mapping & @index. * * @fgp_flags can be zero or more of these flags: * - * * %FGP_ACCESSED - The page will be marked accessed. - * * %FGP_LOCK - The page is returned locked. - * * %FGP_HEAD - If the page is present and a THP, return the head page - * rather than the exact page specified by the index. + * * %FGP_ACCESSED - The folio will be marked accessed. + * * %FGP_LOCK - The folio is returned locked. * * %FGP_ENTRY - If there is a shadow / swap / DAX entry, return it - * instead of allocating a new page to replace it. + * instead of allocating a new folio to replace it. * * %FGP_CREAT - If no page is present then a new page is allocated using - * @gfp_mask and added to the page cache and the VM's LRU list. + * @gfp and added to the page cache and the VM's LRU list. * The page is returned locked and with an increased refcount. * * %FGP_FOR_MMAP - The caller wants to do its own locking dance if the * page is already in cache. If the page was allocated, unlock it before * returning so the caller can do the same dance. - * * %FGP_WRITE - The page will be written - * * %FGP_NOFS - __GFP_FS will get cleared in gfp mask - * * %FGP_NOWAIT - Don't get blocked by page lock + * * %FGP_WRITE - The page will be written to by the caller. + * * %FGP_NOFS - __GFP_FS will get cleared in gfp. + * * %FGP_NOWAIT - Don't get blocked by page lock. * * If %FGP_LOCK or %FGP_CREAT are specified then the function may sleep even * if the %GFP flags specified for %FGP_CREAT are atomic. * * If there is a page cache page, it is returned with an increased refcount. * - * Return: The found page or %NULL otherwise. + * Return: The found folio or %NULL otherwise. */ -struct page *pagecache_get_page(struct address_space *mapping, pgoff_t index, - int fgp_flags, gfp_t gfp_mask) +struct folio *__filemap_get_folio(struct address_space *mapping, pgoff_t index, + int fgp_flags, gfp_t gfp) { - struct page *page; + struct folio *folio; repeat: - page = mapping_get_entry(mapping, index); - if (xa_is_value(page)) { + folio = mapping_get_entry(mapping, index); + if (xa_is_value(folio)) { if (fgp_flags & FGP_ENTRY) - return page; - page = NULL; + return folio; + folio = NULL; } - if (!page) + if (!folio) goto no_page; if (fgp_flags & FGP_LOCK) { if (fgp_flags & FGP_NOWAIT) { - if (!trylock_page(page)) { - put_page(page); + if (!folio_trylock(folio)) { + folio_put(folio); return NULL; } } else { - lock_page(page); + folio_lock(folio); } /* Has the page been truncated? */ - if (unlikely(page->mapping != mapping)) { - unlock_page(page); - put_page(page); + if (unlikely(folio->mapping != mapping)) { + folio_unlock(folio); + folio_put(folio); goto repeat; } - VM_BUG_ON_PAGE(!thp_contains(page, index), page); + VM_BUG_ON_FOLIO(!folio_contains(folio, index), folio); } if (fgp_flags & FGP_ACCESSED) - mark_page_accessed(page); + folio_mark_accessed(folio); else if (fgp_flags & FGP_WRITE) { /* Clear idle flag for buffer write */ - if (page_is_idle(page)) - clear_page_idle(page); + if (folio_test_idle(folio)) + folio_clear_idle(folio); } - if (!(fgp_flags & FGP_HEAD)) - page = find_subpage(page, index); no_page: - if (!page && (fgp_flags & FGP_CREAT)) { + if (!folio && (fgp_flags & FGP_CREAT)) { int err; if ((fgp_flags & FGP_WRITE) && mapping_can_writeback(mapping)) - gfp_mask |= __GFP_WRITE; + gfp |= __GFP_WRITE; if (fgp_flags & FGP_NOFS) - gfp_mask &= ~__GFP_FS; + gfp &= ~__GFP_FS; - page = __page_cache_alloc(gfp_mask); - if (!page) + folio = filemap_alloc_folio(gfp, 0); + if (!folio) return NULL; if (WARN_ON_ONCE(!(fgp_flags & (FGP_LOCK | FGP_FOR_MMAP)))) @@ -1888,27 +1884,27 @@ struct page *pagecache_get_page(struct address_space *mapping, pgoff_t index, /* Init accessed so avoid atomic mark_page_accessed later */ if (fgp_flags & FGP_ACCESSED) - __SetPageReferenced(page); + __folio_set_referenced(folio); - err = add_to_page_cache_lru(page, mapping, index, gfp_mask); + err = filemap_add_folio(mapping, folio, index, gfp); if (unlikely(err)) { - put_page(page); - page = NULL; + folio_put(folio); + folio = NULL; if (err == -EEXIST) goto repeat; } /* - * add_to_page_cache_lru locks the page, and for mmap we expect - * an unlocked page. + * filemap_add_folio locks the page, and for mmap + * we expect an unlocked page. */ - if (page && (fgp_flags & FGP_FOR_MMAP)) - unlock_page(page); + if (folio && (fgp_flags & FGP_FOR_MMAP)) + folio_unlock(folio); } - return page; + return folio; } -EXPORT_SYMBOL(pagecache_get_page); +EXPORT_SYMBOL(__filemap_get_folio); static inline struct page *find_get_entry(struct xa_state *xas, pgoff_t max, xa_mark_t mark) diff --git a/mm/folio-compat.c b/mm/folio-compat.c index 6b19bc4ed6b0..e833e680e944 100644 --- a/mm/folio-compat.c +++ b/mm/folio-compat.c @@ -115,3 +115,15 @@ int add_to_page_cache_lru(struct page *page, struct address_space *mapping, return filemap_add_folio(mapping, page_folio(page), index, gfp); } EXPORT_SYMBOL(add_to_page_cache_lru); + +struct page *pagecache_get_page(struct address_space *mapping, pgoff_t index, + int fgp_flags, gfp_t gfp) +{ + struct folio *folio; + + folio = __filemap_get_folio(mapping, index, fgp_flags, gfp); + if ((fgp_flags & FGP_HEAD) || !folio || xa_is_value(folio)) + return &folio->page; + return folio_file_page(folio, index); +} +EXPORT_SYMBOL(pagecache_get_page);

[v14,38/39] mm/filemap: Add filemap_get_folio

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Patch