diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2022-01-12 12:37:02 -0800 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2022-01-12 12:37:02 -0800 |
commit | 6020c204be997e3f5129839ff9c801800fb4336e (patch) | |
tree | 2125670ece9bed7951946b8badd6f40cf5963570 /mm/filemap.c | |
parent | 81ff0be4b9e3bcfee022d71cf89d72f7e2ed41ba (diff) | |
parent | 6b24ca4a1a8d4ee3221d6d44ddbb99f542e4bda3 (diff) |
Merge tag 'folio-5.17' of git://git.infradead.org/users/willy/pagecache
Pull folio conversion updates from Matthew Wilcox:
"Convert much of the page cache to use folios
This stops just short of actually enabling large folios. It converts
everything that I noticed needs to be converted, but there may still
be places I've overlooked which still have page size assumptions.
The big change here is using large entries in the page cache XArray
instead of many small entries. That only affects shmem for now, but
it's a pretty big change for shmem since it changes where memory needs
to be allocated (at split time instead of insertion)"
* tag 'folio-5.17' of git://git.infradead.org/users/willy/pagecache: (49 commits)
mm: Use multi-index entries in the page cache
XArray: Add xas_advance()
truncate,shmem: Handle truncates that split large folios
truncate: Convert invalidate_inode_pages2_range to folios
fs: Convert vfs_dedupe_file_range_compare to folios
mm: Remove pagevec_remove_exceptionals()
mm: Convert find_lock_entries() to use a folio_batch
filemap: Return only folios from find_get_entries()
filemap: Convert filemap_get_read_batch() to use a folio_batch
filemap: Convert filemap_read() to use a folio
truncate: Add invalidate_complete_folio2()
truncate: Convert invalidate_inode_pages2_range() to use a folio
truncate: Skip known-truncated indices
truncate,shmem: Add truncate_inode_folio()
shmem: Convert part of shmem_undo_range() to use a folio
mm: Add unmap_mapping_folio()
truncate: Add truncate_cleanup_folio()
filemap: Add filemap_release_folio()
filemap: Use a folio in filemap_page_mkwrite
filemap: Use a folio in filemap_map_pages
...
Diffstat (limited to 'mm/filemap.c')
-rw-r--r-- | mm/filemap.c | 1004 |
1 files changed, 481 insertions, 523 deletions
diff --git a/mm/filemap.c b/mm/filemap.c index 3baf03c0f608..2fd9b2f24025 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -121,99 +121,97 @@ */ static void page_cache_delete(struct address_space *mapping, - struct page *page, void *shadow) + struct folio *folio, void *shadow) { - XA_STATE(xas, &mapping->i_pages, page->index); - unsigned int nr = 1; + XA_STATE(xas, &mapping->i_pages, folio->index); + long nr = 1; mapping_set_update(&xas, mapping); /* hugetlb pages are represented by a single entry in the xarray */ - if (!PageHuge(page)) { - xas_set_order(&xas, page->index, compound_order(page)); - nr = compound_nr(page); + if (!folio_test_hugetlb(folio)) { + xas_set_order(&xas, folio->index, folio_order(folio)); + nr = folio_nr_pages(folio); } - VM_BUG_ON_PAGE(!PageLocked(page), page); - VM_BUG_ON_PAGE(PageTail(page), page); - VM_BUG_ON_PAGE(nr != 1 && shadow, page); + VM_BUG_ON_FOLIO(!folio_test_locked(folio), folio); xas_store(&xas, shadow); xas_init_marks(&xas); - page->mapping = NULL; + folio->mapping = NULL; /* Leave page->index set: truncation lookup relies upon it */ mapping->nrpages -= nr; } -static void unaccount_page_cache_page(struct address_space *mapping, - struct page *page) +static void filemap_unaccount_folio(struct address_space *mapping, + struct folio *folio) { - int nr; + long nr; /* * if we're uptodate, flush out into the cleancache, otherwise * invalidate any existing cleancache entries. We can't leave * stale data around in the cleancache once our page is gone */ - if (PageUptodate(page) && PageMappedToDisk(page)) - cleancache_put_page(page); + if (folio_test_uptodate(folio) && folio_test_mappedtodisk(folio)) + cleancache_put_page(&folio->page); else - cleancache_invalidate_page(mapping, page); + cleancache_invalidate_page(mapping, &folio->page); - VM_BUG_ON_PAGE(PageTail(page), page); - VM_BUG_ON_PAGE(page_mapped(page), page); - if (!IS_ENABLED(CONFIG_DEBUG_VM) && unlikely(page_mapped(page))) { + VM_BUG_ON_FOLIO(folio_mapped(folio), folio); + if (!IS_ENABLED(CONFIG_DEBUG_VM) && unlikely(folio_mapped(folio))) { int mapcount; pr_alert("BUG: Bad page cache in process %s pfn:%05lx\n", - current->comm, page_to_pfn(page)); - dump_page(page, "still mapped when deleted"); + current->comm, folio_pfn(folio)); + dump_page(&folio->page, "still mapped when deleted"); dump_stack(); add_taint(TAINT_BAD_PAGE, LOCKDEP_NOW_UNRELIABLE); - mapcount = page_mapcount(page); + mapcount = page_mapcount(&folio->page); if (mapping_exiting(mapping) && - page_count(page) >= mapcount + 2) { + folio_ref_count(folio) >= mapcount + 2) { /* * All vmas have already been torn down, so it's - * a good bet that actually the page is unmapped, + * a good bet that actually the folio is unmapped, * and we'd prefer not to leak it: if we're wrong, * some other bad page check should catch it later. */ - page_mapcount_reset(page); - page_ref_sub(page, mapcount); + page_mapcount_reset(&folio->page); + folio_ref_sub(folio, mapcount); } } - /* hugetlb pages do not participate in page cache accounting. */ - if (PageHuge(page)) + /* hugetlb folios do not participate in page cache accounting. */ + if (folio_test_hugetlb(folio)) return; - nr = thp_nr_pages(page); + nr = folio_nr_pages(folio); - __mod_lruvec_page_state(page, NR_FILE_PAGES, -nr); - if (PageSwapBacked(page)) { - __mod_lruvec_page_state(page, NR_SHMEM, -nr); - if (PageTransHuge(page)) - __mod_lruvec_page_state(page, NR_SHMEM_THPS, -nr); - } else if (PageTransHuge(page)) { - __mod_lruvec_page_state(page, NR_FILE_THPS, -nr); + __lruvec_stat_mod_folio(folio, NR_FILE_PAGES, -nr); + if (folio_test_swapbacked(folio)) { + __lruvec_stat_mod_folio(folio, NR_SHMEM, -nr); + if (folio_test_pmd_mappable(folio)) + __lruvec_stat_mod_folio(folio, NR_SHMEM_THPS, -nr); + } else if (folio_test_pmd_mappable(folio)) { + __lruvec_stat_mod_folio(folio, NR_FILE_THPS, -nr); filemap_nr_thps_dec(mapping); } /* - * At this point page must be either written or cleaned by - * truncate. Dirty page here signals a bug and loss of + * At this point folio must be either written or cleaned by + * truncate. Dirty folio here signals a bug and loss of * unwritten data. * - * This fixes dirty accounting after removing the page entirely - * but leaves PageDirty set: it has no effect for truncated - * page and anyway will be cleared before returning page into + * This fixes dirty accounting after removing the folio entirely + * but leaves the dirty flag set: it has no effect for truncated + * folio and anyway will be cleared before returning folio to * buddy allocator. */ - if (WARN_ON_ONCE(PageDirty(page))) - account_page_cleaned(page, mapping, inode_to_wb(mapping->host)); + if (WARN_ON_ONCE(folio_test_dirty(folio))) + folio_account_cleaned(folio, mapping, + inode_to_wb(mapping->host)); } /* @@ -221,87 +219,83 @@ static void unaccount_page_cache_page(struct address_space *mapping, * sure the page is locked and that nobody else uses it - or that usage * is safe. The caller must hold the i_pages lock. */ -void __delete_from_page_cache(struct page *page, void *shadow) +void __filemap_remove_folio(struct folio *folio, void *shadow) { - struct address_space *mapping = page->mapping; + struct address_space *mapping = folio->mapping; - trace_mm_filemap_delete_from_page_cache(page); - - unaccount_page_cache_page(mapping, page); - page_cache_delete(mapping, page, shadow); + trace_mm_filemap_delete_from_page_cache(folio); + filemap_unaccount_folio(mapping, folio); + page_cache_delete(mapping, folio, shadow); } -static void page_cache_free_page(struct address_space *mapping, - struct page *page) +void filemap_free_folio(struct address_space *mapping, struct folio *folio) { void (*freepage)(struct page *); freepage = mapping->a_ops->freepage; if (freepage) - freepage(page); + freepage(&folio->page); - if (PageTransHuge(page) && !PageHuge(page)) { - page_ref_sub(page, thp_nr_pages(page)); - VM_BUG_ON_PAGE(page_count(page) <= 0, page); + if (folio_test_large(folio) && !folio_test_hugetlb(folio)) { + folio_ref_sub(folio, folio_nr_pages(folio)); + VM_BUG_ON_FOLIO(folio_ref_count(folio) <= 0, folio); } else { - put_page(page); + folio_put(folio); } } /** - * delete_from_page_cache - delete page from page cache - * @page: the page which the kernel is trying to remove from page cache + * filemap_remove_folio - Remove folio from page cache. + * @folio: The folio. * - * This must be called only on pages that have been verified to be in the page - * cache and locked. It will never put the page into the free list, the caller - * has a reference on the page. + * This must be called only on folios that are locked and have been + * verified to be in the page cache. It will never put the folio into + * the free list because the caller has a reference on the page. */ -void delete_from_page_cache(struct page *page) +void filemap_remove_folio(struct folio *folio) { - struct address_space *mapping = page_mapping(page); + struct address_space *mapping = folio->mapping; - BUG_ON(!PageLocked(page)); + BUG_ON(!folio_test_locked(folio)); spin_lock(&mapping->host->i_lock); xa_lock_irq(&mapping->i_pages); - __delete_from_page_cache(page, NULL); + __filemap_remove_folio(folio, NULL); xa_unlock_irq(&mapping->i_pages); if (mapping_shrinkable(mapping)) inode_add_lru(mapping->host); spin_unlock(&mapping->host->i_lock); - page_cache_free_page(mapping, page); + filemap_free_folio(mapping, folio); } -EXPORT_SYMBOL(delete_from_page_cache); /* - * page_cache_delete_batch - delete several pages from page cache - * @mapping: the mapping to which pages belong - * @pvec: pagevec with pages to delete + * page_cache_delete_batch - delete several folios from page cache + * @mapping: the mapping to which folios belong + * @fbatch: batch of folios to delete * - * The function walks over mapping->i_pages and removes pages passed in @pvec - * from the mapping. The function expects @pvec to be sorted by page index - * and is optimised for it to be dense. - * It tolerates holes in @pvec (mapping entries at those indices are not - * modified). The function expects only THP head pages to be present in the - * @pvec. + * The function walks over mapping->i_pages and removes folios passed in + * @fbatch from the mapping. The function expects @fbatch to be sorted + * by page index and is optimised for it to be dense. + * It tolerates holes in @fbatch (mapping entries at those indices are not + * modified). * * The function expects the i_pages lock to be held. */ static void page_cache_delete_batch(struct address_space *mapping, - struct pagevec *pvec) + struct folio_batch *fbatch) { - XA_STATE(xas, &mapping->i_pages, pvec->pages[0]->index); - int total_pages = 0; + XA_STATE(xas, &mapping->i_pages, fbatch->folios[0]->index); + long total_pages = 0; int i = 0; - struct page *page; + struct folio *folio; mapping_set_update(&xas, mapping); - xas_for_each(&xas, page, ULONG_MAX) { - if (i >= pagevec_count(pvec)) + xas_for_each(&xas, folio, ULONG_MAX) { + if (i >= folio_batch_count(fbatch)) break; /* A swap/dax/shadow entry got inserted? Skip it. */ - if (xa_is_value(page)) + if (xa_is_value(folio)) continue; /* * A page got inserted in our range? Skip it. We have our @@ -310,54 +304,48 @@ static void page_cache_delete_batch(struct address_space *mapping, * means our page has been removed, which shouldn't be * possible because we're holding the PageLock. */ - if (page != pvec->pages[i]) { - VM_BUG_ON_PAGE(page->index > pvec->pages[i]->index, - page); + if (folio != fbatch->folios[i]) { + VM_BUG_ON_FOLIO(folio->index > + fbatch->folios[i]->index, folio); continue; } - WARN_ON_ONCE(!PageLocked(page)); + WARN_ON_ONCE(!folio_test_locked(folio)); - if (page->index == xas.xa_index) - page->mapping = NULL; - /* Leave page->index set: truncation lookup relies on it */ + folio->mapping = NULL; + /* Leave folio->index set: truncation lookup relies on it */ - /* - * Move to the next page in the vector if this is a regular - * page or the index is of the last sub-page of this compound - * page. - */ - if (page->index + compound_nr(page) - 1 == xas.xa_index) - i++; + i++; xas_store(&xas, NULL); - total_pages++; + total_pages += folio_nr_pages(folio); } mapping->nrpages -= total_pages; } void delete_from_page_cache_batch(struct address_space *mapping, - struct pagevec *pvec) + struct folio_batch *fbatch) { int i; - if (!pagevec_count(pvec)) + if (!folio_batch_count(fbatch)) return; spin_lock(&mapping->host->i_lock); xa_lock_irq(&mapping->i_pages); - for (i = 0; i < pagevec_count(pvec); i++) { - trace_mm_filemap_delete_from_page_cache(pvec->pages[i]); + for (i = 0; i < folio_batch_count(fbatch); i++) { + struct folio *folio = fbatch->folios[i]; - unaccount_page_cache_page(mapping, pvec->pages[i]); + trace_mm_filemap_delete_from_page_cache(folio); + filemap_unaccount_folio(mapping, folio); } - page_cache_delete_batch(mapping, pvec); + page_cache_delete_batch(mapping, fbatch); xa_unlock_irq(&mapping->i_pages); if (mapping_shrinkable(mapping)) inode_add_lru(mapping->host); spin_unlock(&mapping->host->i_lock); - for (i = 0; i < pagevec_count(pvec); i++) - page_cache_free_page(mapping, pvec->pages[i]); + for (i = 0; i < folio_batch_count(fbatch); i++) + filemap_free_folio(mapping, fbatch->folios[i]); } int filemap_check_errors(struct address_space *mapping) @@ -933,7 +921,7 @@ unlock: goto error; } - trace_mm_filemap_add_to_page_cache(&folio->page); + trace_mm_filemap_add_to_page_cache(folio); return 0; error: folio->mapping = NULL; @@ -1233,10 +1221,10 @@ enum behavior { * __folio_lock() waiting on then setting PG_locked. */ SHARED, /* Hold ref to page and check the bit when woken, like - * wait_on_page_writeback() waiting on PG_writeback. + * folio_wait_writeback() waiting on PG_writeback. */ DROP, /* Drop ref to page before wait, no check when woken, - * like put_and_wait_on_page_locked() on PG_locked. + * like folio_put_wait_locked() on PG_locked. */ }; @@ -1413,22 +1401,21 @@ int folio_wait_bit_killable(struct folio *folio, int bit_nr) EXPORT_SYMBOL(folio_wait_bit_killable); /** - * put_and_wait_on_page_locked - Drop a reference and wait for it to be unlocked - * @page: The page to wait for. + * folio_put_wait_locked - Drop a reference and wait for it to be unlocked + * @folio: The folio to wait for. * @state: The sleep state (TASK_KILLABLE, TASK_UNINTERRUPTIBLE, etc). * - * The caller should hold a reference on @page. They expect the page to + * The caller should hold a reference on @folio. They expect the page to * become unlocked relatively soon, but do not wish to hold up migration - * (for example) by holding the reference while waiting for the page to + * (for example) by holding the reference while waiting for the folio to * come unlocked. After this function returns, the caller should not - * dereference @page. + * dereference @folio. * - * Return: 0 if the page was unlocked or -EINTR if interrupted by a signal. + * Return: 0 if the folio was unlocked or -EINTR if interrupted by a signal. */ -int put_and_wait_on_page_locked(struct page *page, int state) +int folio_put_wait_locked(struct folio *folio, int state) { - return folio_wait_bit_common(page_folio(page), PG_locked, state, - DROP); + return folio_wait_bit_common(folio, PG_locked, state, DROP); } /** @@ -1953,37 +1940,36 @@ no_page: } EXPORT_SYMBOL(__filemap_get_folio); -static inline struct page *find_get_entry(struct xa_state *xas, pgoff_t max, +static inline struct folio *find_get_entry(struct xa_state *xas, pgoff_t max, xa_mark_t mark) { - struct page *page; + struct folio *folio; retry: if (mark == XA_PRESENT) - page = xas_find(xas, max); + folio = xas_find(xas, max); else - page = xas_find_marked(xas, max, mark); + folio = xas_find_marked(xas, max, mark); - if (xas_retry(xas, page)) + if (xas_retry(xas, folio)) goto retry; /* * A shadow entry of a recently evicted page, a swap * entry from shmem/tmpfs or a DAX entry. Return it * without attempting to raise page count. */ - if (!page || xa_is_value(page)) - return page; + if (!folio || xa_is_value(folio)) + return folio; - if (!page_cache_get_speculative(page)) + if (!folio_try_get_rcu(folio)) goto reset; - /* Has the page moved or been split? */ - if (unlikely(page != xas_reload(xas))) { - put_page(page); + if (unlikely(folio != xas_reload(xas))) { + folio_put(folio); goto reset; } - return page; + return folio; reset: xas_reset(xas); goto retry; @@ -1994,56 +1980,36 @@ reset: * @mapping: The address_space to search * @start: The starting page cache index * @end: The final page index (inclusive). - * @pvec: Where the resulting entries are placed. + * @fbatch: Where the resulting entries are placed. * @indices: The cache indices corresponding to the entries in @entries * * find_get_entries() will search for and return a batch of entries in - * the mapping. The entries are placed in @pvec. find_get_entries() - * takes a reference on any actual pages it returns. + * the mapping. The entries are placed in @fbatch. find_get_entries() + * takes a reference on any actual folios it returns. * - * The search returns a group of mapping-contiguous page cache entries - * with ascending indexes. There may be holes in the indices due to - * not-present pages. + * The entries have ascending indexes. The indices may not be consecutive + * due to not-present entries or large folios. * - * Any shadow entries of evicted pages, or swap entries from + * Any shadow entries of evicted folios, or swap entries from * shmem/tmpfs, are included in the returned array. * - * If it finds a Transparent Huge Page, head or tail, find_get_entries() - * stops at that page: the caller is likely to have a better way to handle - * the compound page as a whole, and then skip its extent, than repeatedly - * calling find_get_entries() to return all its tails. - * - * Return: the number of pages and shadow entries which were found. + * Return: The number of entries which were found. */ unsigned find_get_entries(struct address_space *mapping, pgoff_t start, - pgoff_t end, struct pagevec *pvec, pgoff_t *indices) + pgoff_t end, struct folio_batch *fbatch, pgoff_t *indices) { XA_STATE(xas, &mapping->i_pages, start); - struct page *page; - unsigned int ret = 0; - unsigned nr_entries = PAGEVEC_SIZE; + struct folio *folio; rcu_read_lock(); - while ((page = find_get_entry(&xas, end, XA_PRESENT))) { - /* - * Terminate early on finding a THP, to allow the caller to - * handle it all at once; but continue if this is hugetlbfs. - */ - if (!xa_is_value(page) && PageTransHuge(page) && - !PageHuge(page)) { - page = find_subpage(page, xas.xa_index); - nr_entries = ret + 1; - } - - indices[ret] = xas.xa_index; - pvec->pages[ret] = page; - if (++ret == nr_entries) + while ((folio = find_get_entry(&xas, end, XA_PRESENT)) != NULL) { + indices[fbatch->nr] = xas.xa_index; + if (!folio_batch_add(fbatch, folio)) break; } rcu_read_unlock(); - pvec->nr = ret; - return ret; + return folio_batch_count(fbatch); } /** @@ -2051,63 +2017,64 @@ unsigned find_get_entries(struct address_space *mapping, pgoff_t start, * @mapping: The address_space to search. * @start: The starting page cache index. * @end: The final page index (inclusive). - * @pvec: Where the resulting entries are placed. - * @indices: The cache indices of the entries in @pvec. + * @fbatch: Where the resulting entries are placed. + * @indices: The cache indices of the entries in @fbatch. * * find_lock_entries() will return a batch of entries from @mapping. - * Swap, shadow and DAX entries are included. Pages are returned - * locked and with an incremented refcount. Pages which are locked by - * somebody else or under writeback are skipped. Only the head page of - * a THP is returned. Pages which are partially outside the range are - * not returned. + * Swap, shadow and DAX entries are included. Folios are returned + * locked and with an incremented refcount. Folios which are locked + * by somebody else or under writeback are skipped. Folios which are + * partially outside the range are not returned. * * The entries have ascending indexes. The indices may not be consecutive - * due to not-present entries, THP pages, pages which could not be locked - * or pages under writeback. + * due to not-present entries, large folios, folios which could not be + * locked or folios under writeback. * * Return: The number of entries which were found. */ unsigned find_lock_entries(struct address_space *mapping, pgoff_t start, - pgoff_t end, struct pagevec *pvec, pgoff_t *indices) + pgoff_t end, struct folio_batch *fbatch, pgoff_t *indices) { XA_STATE(xas, &mapping->i_pages, start); - struct page *page; + struct folio *folio; rcu_read_lock(); - while ((page = find_get_entry(&xas, end, XA_PRESENT))) { - if (!xa_is_value(page)) { - if (page->index < start) + while ((folio = find_get_entry(&xas, end, XA_PRESENT))) { + if (!xa_is_value(folio)) { + if (folio->index < start) goto put; - if (page->index + thp_nr_pages(page) - 1 > end) + if (folio->index + folio_nr_pages(folio) - 1 > end) goto put; - if (!trylock_page(page)) + if (!folio_trylock(folio)) goto put; - if (page->mapping != mapping || PageWriteback(page)) + if (folio->mapping != mapping || + folio_test_writeback(folio)) goto unlock; - VM_BUG_ON_PAGE(!thp_contains(page, xas.xa_index), - page); + VM_BUG_ON_FOLIO(!folio_contains(folio, xas.xa_index), + folio); } - indices[pvec->nr] = xas.xa_index; - if (!pagevec_add(pvec, page)) + indices[fbatch->nr] = xas.xa_index; + if (!folio_batch_add(fbatch, folio)) break; - goto next; + continue; unlock: - unlock_page(page); + folio_unlock(folio); put: - put_page(page); -next: - if (!xa_is_value(page) && PageTransHuge(page)) { - unsigned int nr_pages = thp_nr_pages(page); - - /* Final THP may cross MAX_LFS_FILESIZE on 32-bit */ - xas_set(&xas, page->index + nr_pages); - if (xas.xa_index < nr_pages) - break; - } + folio_put(folio); } rcu_read_unlock(); - return pagevec_count(pvec); + return folio_batch_count(fbatch); +} + +static inline +bool folio_more_pages(struct folio *folio, pgoff_t index, pgoff_t max) +{ + if (!folio_test_large(folio) || folio_test_hugetlb(folio)) + return false; + if (index >= max) + return false; + return index < folio->index + folio_nr_pages(folio) - 1; } /** @@ -2136,23 +2103,29 @@ unsigned find_get_pages_range(struct address_space *mapping, pgoff_t *start, struct page **pages) { XA_STATE(xas, &mapping->i_pages, *start); - struct page *page; + struct folio *folio; unsigned ret = 0; if (unlikely(!nr_pages)) return 0; rcu_read_lock(); - while ((page = find_get_entry(&xas, end, XA_PRESENT))) { + while ((folio = find_get_entry(&xas, end, XA_PRESENT))) { /* Skip over shadow, swap and DAX entries */ - if (xa_is_value(page)) + if (xa_is_value(folio)) continue; - pages[ret] = find_subpage(page, xas.xa_index); +again: + pages[ret] = folio_file_page(folio, xas.xa_index); if (++ret == nr_pages) { *start = xas.xa_index + 1; goto out; } + if (folio_more_pages(folio, xas.xa_index, end)) { + xas.xa_index++; + folio_ref_inc(folio); + goto again; + } } /* @@ -2187,36 +2160,41 @@ unsigned find_get_pages_contig(struct address_space *mapping, pgoff_t index, unsigned int nr_pages, struct page **pages) { XA_STATE(xas, &mapping->i_pages, index); - struct page *page; + struct folio *folio; unsigned int ret = 0; if (unlikely(!nr_pages)) return 0; rcu_read_lock(); - for (page = xas_load(&xas); page; page = xas_next(&xas)) { - if (xas_retry(&xas, page)) + for (folio = xas_load(&xas); folio; folio = xas_next(&xas)) { + if (xas_retry(&xas, folio)) continue; /* * If the entry has been swapped out, we can stop looking. * No current caller is looking for DAX entries. */ - if (xa_is_value(page)) + if (xa_is_value(folio)) break; - if (!page_cache_get_speculative(page)) + if (!folio_try_get_rcu(folio)) goto retry; - /* Has the page moved or been split? */ - if (unlikely(page != xas_reload(&xas))) + if (unlikely(folio != xas_reload(&xas))) goto put_page; - pages[ret] = find_subpage(page, xas.xa_index); +again: + pages[ret] = folio_file_page(folio, xas.xa_index); if (++ret == nr_pages) break; + if (folio_more_pages(folio, xas.xa_index, ULONG_MAX)) { + xas.xa_index++; + folio_ref_inc(folio); + goto again; + } continue; put_page: - put_page(page); + folio_put(folio); retry: xas_reset(&xas); } @@ -2245,25 +2223,25 @@ unsigned find_get_pages_range_tag(struct address_space *mapping, pgoff_t *index, struct page **pages) { XA_STATE(xas, &mapping->i_pages, *index); - struct page *page; + struct folio *folio; unsigned ret = 0; if (unlikely(!nr_pages)) return 0; rcu_read_lock(); - while ((page = find_get_entry(&xas, end, tag))) { + while ((folio = find_get_entry(&xas, end, tag))) { /* * Shadow entries should never be tagged, but this iteration * is lockless so there is a window for page reclaim to evict * a page we saw tagged. Skip over it. */ - if (xa_is_value(page)) + if (xa_is_value(folio)) continue; - pages[ret] = page; + pages[ret] = &folio->page; if (++ret == nr_pages) { - *index = page->index + thp_nr_pages(page); + *index = folio->index + folio_nr_pages(folio); goto out; } } @@ -2306,52 +2284,50 @@ static void shrink_readahead_size_eio(struct file_ra_state *ra) } /* - * filemap_get_read_batch - Get a batch of pages for read + * filemap_get_read_batch - Get a batch of folios for read * - * Get a batch of pages which represent a contiguous range of bytes - * in the file. No tail pages will be returned. If @index is in the - * middle of a THP, the entire THP will be returned. The last page in - * the batch may have Readahead set or be not Uptodate so that the - * caller can take the appropriate action. + * Get a batch of folios which represent a contiguous range of bytes in + * the file. No exceptional entries will be returned. If @index is in + * the middle of a folio, the entire folio will be returned. The last + * folio in the batch may have the readahead flag set or the uptodate flag + * clear so that the caller can take the appropriate action. */ static void filemap_get_read_batch(struct address_space *mapping, - pgoff_t index, pgoff_t max, struct pagevec *pvec) + pgoff_t index, pgoff_t max, struct folio_batch *fbatch) { XA_STATE(xas, &mapping->i_pages, index); - struct page *head; + struct folio *folio; rcu_read_lock(); - for (head = xas_load(&xas); head; head = xas_next(&xas)) { - if (xas_retry(&xas, head)) + for (folio = xas_load(&xas); folio; folio = xas_next(&xas)) { + if (xas_retry(&xas, folio)) continue; - if (xas.xa_index > max || xa_is_value(head)) + if (xas.xa_index > max || xa_is_value(folio)) break; - if (!page_cache_get_speculative(head)) + if (!folio_try_get_rcu(folio)) goto retry; - /* Has the page moved or been split? */ - if (unlikely(head != xas_reload(&xas))) - goto put_page; + if (unlikely(folio != xas_reload(&xas))) + goto put_folio; - if (!pagevec_add(pvec, head)) + if (!folio_batch_add(fbatch, folio)) break; - if (!PageUptodate(head)) + if (!folio_test_uptodate(folio)) break; - if (PageReadahead(head)) + if (folio_test_readahead(folio)) break; - xas.xa_index = head->index + thp_nr_pages(head) - 1; - xas.xa_offset = (xas.xa_index >> xas.xa_shift) & XA_CHUNK_MASK; + xas_advance(&xas, folio->index + folio_nr_pages(folio) - 1); continue; -put_page: - put_page(head); +put_folio: + folio_put(folio); retry: xas_reset(&xas); } rcu_read_unlock(); } -static int filemap_read_page(struct file *file, struct address_space *mapping, - struct page *page) +static int filemap_read_folio(struct file *file, struct address_space *mapping, + struct folio *folio) { int error; @@ -2360,52 +2336,51 @@ static int filemap_read_page(struct file *file, struct address_space *mapping, * eg. multipath errors. PG_error will be set again if readpage * fails. */ - ClearPageError(page); + folio_clear_error(folio); /* Start the actual read. The read will unlock the page. */ - error = mapping->a_ops->readpage(file, page); + error = mapping->a_ops->readpage(file, &folio->page); if (error) return error; - error = wait_on_page_locked_killable(page); + error = folio_wait_locked_killable(folio); if (error) return error; - if (PageUptodate(page)) + if (folio_test_uptodate(folio)) return 0; shrink_readahead_size_eio(&file->f_ra); return -EIO; } static bool filemap_range_uptodate(struct address_space *mapping, - loff_t pos, struct iov_iter *iter, struct page *page) + loff_t pos, struct iov_iter *iter, struct folio *folio) { int count; - if (PageUptodate(page)) + if (folio_test_uptodate(folio)) return true; /* pipes can't handle partially uptodate pages */ if (iov_iter_is_pipe(iter)) return false; if (!mapping->a_ops->is_partially_uptodate) return false; - if (mapping->host->i_blkbits >= (PAGE_SHIFT + thp_order(page))) + if (mapping->host->i_blkbits >= folio_shift(folio)) return false; count = iter->count; - if (page_offset(page) > pos) { - count -= page_offset(page) - pos; + if (folio_pos(folio) > pos) { + count -= folio_pos(folio) - pos; pos = 0; } else { - pos -= page_offset(page); + pos -= folio_pos(folio); } - return mapping->a_ops->is_partially_uptodate(page, pos, count); + return mapping->a_ops->is_partially_uptodate(&folio->page, pos, count); } static int filemap_update_page(struct kiocb *iocb, struct address_space *mapping, struct iov_iter *iter, - struct page *page) + struct folio *folio) { - struct folio *folio = page_folio(page); int error; if (iocb->ki_flags & IOCB_NOWAIT) { @@ -2421,7 +2396,11 @@ static int filemap_update_page(struct kiocb *iocb, goto unlock_mapping; if (!(iocb->ki_flags & IOCB_WAITQ)) { filemap_invalidate_unlock_shared(mapping); - put_and_wait_on_page_locked(&folio->page, TASK_KILLABLE); + /* + * This is where we usually end up waiting for a + * previously submitted readahead to finish. + */ + folio_put_wait_locked(folio, TASK_KILLABLE); return AOP_TRUNCATED_PAGE; } error = __folio_lock_async(folio, iocb->ki_waitq); @@ -2434,14 +2413,14 @@ static int filemap_update_page(struct kiocb *iocb, goto unlock; error = 0; - if (filemap_range_uptodate(mapping, iocb->ki_pos, iter, &folio->page)) + if (filemap_range_uptodate(mapping, iocb->ki_pos, iter, folio)) goto unlock; error = -EAGAIN; if (iocb->ki_flags & (IOCB_NOIO | IOCB_NOWAIT | IOCB_WAITQ)) goto unlock; - error = filemap_read_page(iocb->ki_filp, mapping, &folio->page); + error = filemap_read_folio(iocb->ki_filp, mapping, folio); goto unlock_mapping; unlock: folio_unlock(folio); @@ -2452,70 +2431,72 @@ unlock_mapping: return error; } -static int filemap_create_page(struct file *file, +static int filemap_create_folio(struct file *file, struct address_space *mapping, pgoff_t index, - struct pagevec *pvec) + struct folio_batch *fbatch) { - struct page *page; + struct folio *folio; int error; - page = page_cache_alloc(mapping); - if (!page) + folio = filemap_alloc_folio(mapping_gfp_mask(mapping), 0); + if (!folio) return -ENOMEM; /* - * Protect against truncate / hole punch. Grabbing invalidate_lock here - * assures we cannot instantiate and bring uptodate new pagecache pages - * after evicting page cache during truncate and before actually - * freeing blocks. Note that we could release invalidate_lock after - * inserting the page into page cache as the locked page would then be - * enough to synchronize with hole punching. But there are code paths - * such as filemap_update_page() filling in partially uptodate pages or - * ->readpages() that need to hold invalidate_lock while mapping blocks - * for IO so let's hold the lock here as well to keep locking rules - * simple. + * Protect against truncate / hole punch. Grabbing invalidate_lock + * here assures we cannot instantiate and bring uptodate new + * pagecache folios after evicting page cache during truncate + * and before actually freeing blocks. Note that we could + * release invalidate_lock after inserting the folio into + * the page cache as the locked folio would then be enough to + * synchronize with hole punching. But there are code paths + * such as filemap_update_page() filling in partially uptodate + * pages or ->readpages() that need to hold invalidate_lock + * while mapping blocks for IO so let's hold the lock here as + * well to keep locking rules simple. */ filemap_invalidate_lock_shared(mapping); - error = add_to_page_cache_lru(page, mapping, index, + error = filemap_add_folio(mapping, folio, index, mapping_gfp_constraint(mapping, GFP_KERNEL)); if (error == -EEXIST) error = AOP_TRUNCATED_PAGE; if (error) goto error; - error = filemap_read_page(file, mapping, page); + error = filemap_read_folio(file, mapping, folio); if (error) goto error; filemap_invalidate_unlock_shared(mapping); - pagevec_add(pvec, page); + folio_batch_add(fbatch, folio); return 0; error: filemap_invalidate_unlock_shared(mapping); - put_page(page); + folio_put(folio); return error; } static int filemap_readahead(struct kiocb *iocb, struct file *file, - struct address_space *mapping, struct page *page, + struct address_space *mapping, struct folio *folio, pgoff_t last_index) { + DEFINE_READAHEAD(ractl, file, &file->f_ra, mapping, folio->index); + if (iocb->ki_flags & IOCB_NOIO) return -EAGAIN; - page_cache_async_readahead(mapping, &file->f_ra, file, page, - page->index, last_index - page->index); + page_cache_async_ra(&ractl, folio, last_index - folio->index); return 0; } static int filemap_get_pages(struct kiocb *iocb, struct iov_iter *iter, - struct pagevec *pvec) + struct folio_batch *fbatch) { struct file *filp = iocb->ki_filp; struct address_space *mapping = filp->f_mapping; struct file_ra_state *ra = &filp->f_ra; pgoff_t index = iocb->ki_pos >> PAGE_SHIFT; pgoff_t last_index; - struct page *page; + struct folio *folio; int err = 0; last_index = DIV_ROUND_UP(iocb->ki_pos + iter->count, PAGE_SIZE); @@ -2523,34 +2504,35 @@ retry: if (fatal_signal_pending(current)) return -EINTR; - filemap_get_read_batch(mapping, index, last_index, pvec); - if (!pagevec_count(pvec)) { + filemap_get_read_batch(mapping, index, last_index, fbatch); + if (!folio_batch_count(fbatch)) { if (iocb->ki_flags & IOCB_NOIO) return -EAGAIN; page_cache_sync_readahead(mapping, ra, filp, index, last_index - index); - filemap_get_read_batch(mapping, index, last_index, pvec); + filemap_get_read_batch(mapping, index, last_index, fbatch); } - if (!pagevec_count(pvec)) { + if (!folio_batch_count(fbatch)) { if (iocb->ki_flags & (IOCB_NOWAIT | IOCB_WAITQ)) return -EAGAIN; - err = filemap_create_page(filp, mapping, - iocb->ki_pos >> PAGE_SHIFT, pvec); + err = filemap_create_folio(filp, mapping, + iocb->ki_pos >> PAGE_SHIFT, fbatch); if (err == AOP_TRUNCATED_PAGE) goto retry; return err; } - page = pvec->pages[pagevec_count(pvec) - 1]; - if (PageReadahead(page)) { - err = filemap_readahead(iocb, filp, mapping, page, last_index); + folio = fbatch->folios[folio_batch_count(fbatch) - 1]; + if (folio_test_readahead(folio)) { + err = filemap_readahead(iocb, filp, mapping, folio, last_index); if (err) goto err; } - if (!PageUptodate(page)) { - if ((iocb->ki_flags & IOCB_WAITQ) && pagevec_count(pvec) > 1) + if (!folio_test_uptodate(folio)) { + if ((iocb->ki_flags & IOCB_WAITQ) && + folio_batch_count(fbatch) > 1) iocb->ki_flags |= IOCB_NOWAIT; - err = filemap_update_page(iocb, mapping, iter, page); + err = filemap_update_page(iocb, mapping, iter, folio); if (err) goto err; } @@ -2558,8 +2540,8 @@ retry: return 0; err: if (err < 0) - put_page(page); - if (likely(--pvec->nr)) + folio_put(folio); + if (likely(--fbatch->nr)) return 0; if (err == AOP_TRUNCATED_PAGE) goto retry; @@ -2586,7 +2568,7 @@ ssize_t filemap_read(struct kiocb *iocb, struct iov_iter *iter, struct file_ra_state *ra = &filp->f_ra; struct address_space *mapping = filp->f_mapping; struct inode *inode = mapping->host; - struct pagevec pvec; + struct folio_batch fbatch; int i, error = 0; bool writably_mapped; loff_t isize, end_offset; @@ -2597,7 +2579,7 @@ ssize_t filemap_read(struct kiocb *iocb, struct iov_iter *iter, return 0; iov_iter_truncate(iter, inode->i_sb->s_maxbytes); - pagevec_init(&pvec); + folio_batch_init(&fbatch); do { cond_resched(); @@ -2613,7 +2595,7 @@ ssize_t filemap_read(struct kiocb *iocb, struct iov_iter *iter, if (unlikely(iocb->ki_pos >= i_size_read(inode))) break; - error = filemap_get_pages(iocb, iter, &pvec); + error = filemap_get_pages(iocb, iter, &fbatch); if (error < 0) break; @@ -2627,7 +2609,7 @@ ssize_t filemap_read(struct kiocb *iocb, struct iov_iter *iter, */ isize = i_size_read(inode); if (unlikely(iocb->ki_pos >= isize)) - goto put_pages; + goto put_folios; end_offset = min_t(loff_t, isize, iocb->ki_pos + iter->count); /* @@ -2642,33 +2624,29 @@ ssize_t filemap_read(struct kiocb *iocb, struct iov_iter *iter, */ if (iocb->ki_pos >> PAGE_SHIFT != ra->prev_pos >> PAGE_SHIFT) - mark_page_accessed(pvec.pages[0]); + folio_mark_accessed(fbatch.folios[0]); - for (i = 0; i < pagevec_count(&pvec); i++) { - struct page *page = pvec.pages[i]; - size_t page_size = thp_size(page); - size_t offset = iocb->ki_pos & (page_size - 1); + for (i = 0; i < folio_batch_count(&fbatch); i++) { + struct folio *folio = fbatch.folios[i]; + size_t fsize = folio_size(folio); + size_t offset = iocb->ki_pos & (fsize - 1); size_t bytes = min_t(loff_t, end_offset - iocb->ki_pos, - page_size - offset); + fsize - offset); size_t copied; - if (end_offset < page_offset(page)) + if (end_offset < folio_pos(folio)) break; if (i > 0) - mark_page_accessed(page); + folio_mark_accessed(folio); /* - * If users can be writing to this page using arbitrary - * virtual addresses, take care about potential aliasing - * before reading the page on the kernel side. + * If users can be writing to this folio using arbitrary + * virtual addresses, take care of potential aliasing + * before reading the folio on the kernel side. */ - if (writably_mapped) { - int j; - - for (j = 0; j < thp_nr_pages(page); j++) - flush_dcache_page(page + j); - } + if (writably_mapped) + flush_dcache_folio(folio); - copied = copy_page_to_iter(page, offset, bytes, iter); + copied = copy_folio_to_iter(folio, offset, bytes, iter); already_read += copied; iocb->ki_pos += copied; @@ -2679,10 +2657,10 @@ ssize_t filemap_read(struct kiocb *iocb, struct iov_iter *iter, break; } } -put_pages: - for (i = 0; i < pagevec_count(&pvec); i++) - put_page(pvec.pages[i]); - pagevec_reinit(&pvec); +put_folios: + for (i = 0; i < folio_batch_count(&fbatch); i++) + folio_put(fbatch.folios[i]); + folio_batch_init(&fbatch); } while (iov_iter_count(iter) && iocb->ki_pos < isize && !error); file_accessed(filp); @@ -2767,44 +2745,44 @@ generic_file_read_iter(struct kiocb *iocb, struct iov_iter *iter) } EXPORT_SYMBOL(generic_file_read_iter); -static inline loff_t page_seek_hole_data(struct xa_state *xas, - struct address_space *mapping, struct page *page, +static inline loff_t folio_seek_hole_data(struct xa_state *xas, + struct address_space *mapping, struct folio *folio, loff_t start, loff_t end, bool seek_data) { const struct address_space_operations *ops = mapping->a_ops; size_t offset, bsz = i_blocksize(mapping->host); - if (xa_is_value(page) || PageUptodate(page)) + if (xa_is_value(folio) || folio_test_uptodate(folio)) return seek_data ? start : end; if (!ops->is_partially_uptodate) return seek_data ? end : start; xas_pause(xas); rcu_read_unlock(); - lock_page(page); - if (unlikely(page->mapping != mapping)) + folio_lock(folio); + if (unlikely(folio->mapping != mapping)) goto unlock; - offset = offset_in_thp(page, start) & ~(bsz - 1); + offset = offset_in_folio(folio, start) & ~(bsz - 1); do { - if (ops->is_partially_uptodate(page, offset, bsz) == seek_data) + if (ops->is_partially_uptodate(&folio->page, offset, bsz) == + seek_data) break; start = (start + bsz) & ~(bsz - 1); offset += bsz; - } while (offset < thp_size(page)); + } while (offset < folio_size(folio)); unlock: - unlock_page(page); + folio_unlock(folio); rcu_read_lock(); return start; } -static inline -unsigned int seek_page_size(struct xa_state *xas, struct page *page) +static inline size_t seek_folio_size(struct xa_state *xas, struct folio *folio) { - if (xa_is_value(page)) + if (xa_is_value(folio)) return PAGE_SIZE << xa_get_order(xas->xa, xas->xa_index); - return thp_size(page); + return folio_size(folio); } /** @@ -2831,15 +2809,15 @@ loff_t mapping_seek_hole_data(struct address_space *mapping, loff_t start, XA_STATE(xas, &mapping->i_pages, start >> PAGE_SHIFT); pgoff_t max = (end - 1) >> PAGE_SHIFT; bool seek_data = (whence == SEEK_DATA); - struct page *page; + struct folio *folio; if (end <= start) return -ENXIO; rcu_read_lock(); - while ((page = find_get_entry(&xas, max, XA_PRESENT))) { + while ((folio = find_get_entry(&xas, max, XA_PRESENT))) { loff_t pos = (u64)xas.xa_index << PAGE_SHIFT; - unsigned int seek_size; + size_t seek_size; if (start < pos) { if (!seek_data) @@ -2847,9 +2825,9 @@ loff_t mapping_seek_hole_data(struct address_space *mapping, loff_t start, start = pos; } - seek_size = seek_page_size(&xas, page); - pos = round_up(pos + 1, seek_size); - start = page_seek_hole_data(&xas, mapping, page, start, pos, + seek_size = seek_folio_size(&xas, folio); + pos = round_up((u64)pos + 1, seek_size); + start = folio_seek_hole_data(&xas, mapping, folio, start, pos, seek_data); if (start < pos) goto unlock; @@ -2857,15 +2835,15 @@ loff_t mapping_seek_hole_data(struct address_space *mapping, loff_t start, break; if (seek_size > PAGE_SIZE) xas_set(&xas, pos >> PAGE_SHIFT); - if (!xa_is_value(page)) - put_page(page); + if (!xa_is_value(folio)) + folio_put(folio); } if (seek_data) start = -ENXIO; unlock: rcu_read_unlock(); - if (page && !xa_is_value(page)) - put_page(page); + if (folio && !xa_is_value(folio)) + folio_put(folio); if (start > end) return end; return start; @@ -2874,21 +2852,20 @@ unlock: #ifdef CONFIG_MMU #define MMAP_LOTSAMISS (100) /* - * lock_page_maybe_drop_mmap - lock the page, possibly dropping the mmap_lock + * lock_folio_maybe_drop_mmap - lock the page, possibly dropping the mmap_lock * @vmf - the vm_fault for this fault. - * @page - the page to lock. + * @folio - the folio to lock. * @fpin - the pointer to the file we may pin (or is already pinned). * - * This works similar to lock_page_or_retry in that it can drop the mmap_lock. - * It differs in that it actually returns the page locked if it returns 1 and 0 - * if it couldn't lock the page. If we did have to drop the mmap_lock then fpin - * will point to the pinned file and needs to be fput()'ed at a later point. + * This works similar to lock_folio_or_retry in that it can drop the + * mmap_lock. It differs in that it actually returns the folio locked + * if it returns 1 and 0 if it couldn't lock the folio. If we did have + * to drop the mmap_lock then fpin will point to the pinned file and + * needs to be fput()'ed at a later point. */ -static int lock_page_maybe_drop_mmap(struct vm_fault *vmf, struct page *page, +static int lock_folio_maybe_drop_mmap(struct vm_fault *vmf, struct folio *folio, struct file **fpin) { - struct folio *folio = page_folio(page); - if (folio_trylock(folio)) return 1; @@ -2977,25 +2954,25 @@ static struct file *do_sync_mmap_readahead(struct vm_fault *vmf) * was pinned if we have to drop the mmap_lock in order to do IO. */ static struct file *do_async_mmap_readahead(struct vm_fault *vmf, - struct page *page) + struct folio *folio) { struct file *file = vmf->vma->vm_file; struct file_ra_state *ra = &file->f_ra; - struct address_space *mapping = file->f_mapping; + DEFINE_READAHEAD(ractl, file, ra, file->f_mapping, vmf->pgoff); struct file *fpin = NULL; unsigned int mmap_miss; - pgoff_t offset = vmf->pgoff; /* If we don't want any read-ahead, don't bother */ if (vmf->vma->vm_flags & VM_RAND_READ || !ra->ra_pages) return fpin; + mmap_miss = READ_ONCE(ra->mmap_miss); if (mmap_miss) WRITE_ONCE(ra->mmap_miss, --mmap_miss); - if (PageReadahead(page)) { + + if (folio_test_readahead(folio)) { fpin = maybe_unlock_mmap_for_io(vmf, fpin); - page_cache_async_readahead(mapping, ra, file, - page, offset, ra->ra_pages); + page_cache_async_ra(&ractl, folio, ra->ra_pages); } return fpin; } @@ -3014,7 +2991,7 @@ static struct file *do_async_mmap_readahead(struct vm_fault *vmf, * vma->vm_mm->mmap_lock must be held on entry. * * If our return value has VM_FAULT_RETRY set, it's because the mmap_lock - * may be dropped before doing I/O or by lock_page_maybe_drop_mmap(). + * may be dropped before doing I/O or by lock_folio_maybe_drop_mmap(). * * If our return value does not have VM_FAULT_RETRY set, the mmap_lock * has not been released. @@ -3030,28 +3007,27 @@ vm_fault_t filemap_fault(struct vm_fault *vmf) struct file *fpin = NULL; struct address_space *mapping = file->f_mapping; struct inode *inode = mapping->host; - pgoff_t offset = vmf->pgoff; - pgoff_t max_off; - struct page *page; + pgoff_t max_idx, index = vmf->pgoff; + struct folio *folio; vm_fault_t ret = 0; bool mapping_locked = false; - max_off = DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE); - if (unlikely(offset >= max_off)) + max_idx = DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE); + if (unlikely(index >= max_idx)) return VM_FAULT_SIGBUS; /* * Do we have something in the page cache already? */ - page = find_get_page(mapping, offset); - if (likely(page)) { + folio = filemap_get_folio(mapping, index); + if (likely(folio)) { /* * We found the page, so try async readahead before waiting for * the lock. */ if (!(vmf->flags & FAULT_FLAG_TRIED)) - fpin = do_async_mmap_readahead(vmf, page); - if (unlikely(!PageUptodate(page))) { + fpin = do_async_mmap_readahead(vmf, folio); + if (unlikely(!folio_test_uptodate(folio))) { filemap_invalidate_lock_shared(mapping); mapping_locked = true; } @@ -3063,17 +3039,17 @@ vm_fault_t filemap_fault(struct vm_fault *vmf) fpin = do_sync_mmap_readahead(vmf); retry_find: /* - * See comment in filemap_create_page() why we need + * See comment in filemap_create_folio() why we need * invalidate_lock */ if (!mapping_locked) { filemap_invalidate_lock_shared(mapping); mapping_locked = true; } - page = pagecache_get_page(mapping, offset, + folio = __filemap_get_folio(mapping, index, FGP_CREAT|FGP_FOR_MMAP, vmf->gfp_mask); - if (!page) { + if (!folio) { if (fpin) goto out_retry; filemap_invalidate_unlock_shared(mapping); @@ -3081,22 +3057,22 @@ retry_find: } } - if (!lock_page_maybe_drop_mmap(vmf, page, &fpin)) + if (!lock_folio_maybe_drop_mmap(vmf, folio, &fpin)) goto out_retry; /* Did it get truncated? */ - if (unlikely(compound_head(page)->mapping != mapping)) { - unlock_page(page); - put_page(page); + if (unlikely(folio->mapping != mapping)) { + folio_unlock(folio); + folio_put(folio); goto retry_find; } - VM_BUG_ON_PAGE(page_to_pgoff(page) != offset, page); + VM_BUG_ON_FOLIO(!folio_contains(folio, index), folio); /* * We have a locked page in the page cache, now we need to check * that it's up-to-date. If not, it is going to be due to an error. */ - if (unlikely(!PageUptodate(page))) { + if (unlikely(!folio_test_uptodate(folio))) { /* * The page was in cache and uptodate and now it is not. * Strange but possible since we didn't hold the page lock all @@ -3104,8 +3080,8 @@ retry_find: * try again. */ if (!mapping_locked) { - unlock_page(page); - put_page(page); + folio_unlock(folio); + folio_put(folio); goto retry_find; } goto page_not_uptodate; @@ -3117,7 +3093,7 @@ retry_find: * redo the fault. */ if (fpin) { - unlock_page(page); + folio_unlock(folio); goto out_retry; } if (mapping_locked) @@ -3127,14 +3103,14 @@ retry_find: * Found the page and have a reference on it. * We must recheck i_size under page lock. */ - max_off = DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE); - if (unlikely(offset >= max_off)) { - unlock_page(page); - put_page(page); + max_idx = DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE); + if (unlikely(index >= max_idx)) { + folio_unlock(folio); + folio_put(folio); return VM_FAULT_SIGBUS; } - vmf->page = page; + vmf->page = folio_file_page(folio, index); return ret | VM_FAULT_LOCKED; page_not_uptodate: @@ -3145,10 +3121,10 @@ page_not_uptodate: * and we need to check for errors. */ fpin = maybe_unlock_mmap_for_io(vmf, fpin); - error = filemap_read_page(file, mapping, page); + error = filemap_read_folio(file, mapping, folio); if (fpin) goto out_retry; - put_page(page); + folio_put(folio); if (!error || error == AOP_TRUNCATED_PAGE) goto retry_find; @@ -3162,8 +3138,8 @@ out_retry: * re-find the vma and come back and find our hopefully still populated * page. */ - if (page) - put_page(page); + if (folio) + folio_put(folio); if (mapping_locked) filemap_invalidate_unlock_shared(mapping); if (fpin) @@ -3205,48 +3181,48 @@ static bool filemap_map_pmd(struct vm_fault *vmf, struct page *page) return false; } -static struct page *next_uptodate_page(struct page *page, +static struct folio *next_uptodate_page(struct folio *folio, struct address_space *mapping, struct xa_state *xas, pgoff_t end_pgoff) { unsigned long max_idx; do { - if (!page) + if (!folio) return NULL; - if (xas_retry(xas, page)) + if (xas_retry(xas, folio)) continue; - if (xa_is_value(page)) + if (xa_is_value(folio)) continue; - if (PageLocked(page)) + if (folio_test_locked(folio)) continue; - if (!page_cache_get_speculative(page)) + if (!folio_try_get_rcu(folio)) continue; /* Has the page moved or been split? */ - if (unlikely(page != xas_reload(xas))) + if (unlikely(folio != xas_reload(xas))) goto skip; - if (!PageUptodate(page) || PageReadahead(page)) + if (!folio_test_uptodate(folio) || folio_test_readahead(folio)) goto skip; - if (!trylock_page(page)) + if (!folio_trylock(folio)) goto skip; - if (page->mapping != mapping) + if (folio->mapping != mapping) goto unlock; - if (!PageUptodate(page)) + if (!folio_test_uptodate(folio)) goto unlock; max_idx = DIV_ROUND_UP(i_size_read(mapping->host), PAGE_SIZE); if (xas->xa_index >= max_idx) goto unlock; - return page; + return folio; unlock: - unlock_page(page); + folio_unlock(folio); skip: - put_page(page); - } while ((page = xas_next_entry(xas, end_pgoff)) != NULL); + folio_put(folio); + } while ((folio = xas_next_entry(xas, end_pgoff)) != NULL); return NULL; } -static inline struct page *first_map_page(struct address_space *mapping, +static inline struct folio *first_map_page(struct address_space *mapping, struct xa_state *xas, pgoff_t end_pgoff) { @@ -3254,7 +3230,7 @@ static inline struct page *first_map_page(struct address_space *mapping, mapping, xas, end_pgoff); } -static inline struct page *next_map_page(struct address_space *mapping, +static inline struct folio *next_map_page(struct address_space *mapping, struct xa_state *xas, pgoff_t end_pgoff) { @@ -3271,16 +3247,17 @@ vm_fault_t filemap_map_pages(struct vm_fault *vmf, pgoff_t last_pgoff = start_pgoff; unsigned long addr; XA_STATE(xas, &mapping->i_pages, start_pgoff); - struct page *head, *page; + struct folio *folio; + struct page *page; unsigned int mmap_miss = READ_ONCE(file->f_ra.mmap_miss); vm_fault_t ret = 0; rcu_read_lock(); - head = first_map_page(mapping, &xas, end_pgoff); - if (!head) + folio = first_map_page(mapping, &xas, end_pgoff); + if (!folio) goto out; - if (filemap_map_pmd(vmf, head)) { + if (filemap_map_pmd(vmf, &folio->page)) { ret = VM_FAULT_NOPAGE; goto out; } @@ -3288,7 +3265,8 @@ vm_fault_t filemap_map_pages(struct vm_fault *vmf, addr = vma->vm_start + ((start_pgoff - vma->vm_pgoff) << PAGE_SHIFT); vmf->pte = pte_offset_map_lock(vma->vm_mm, vmf->pmd, addr, &vmf->ptl); do { - page = find_subpage(head, xas.xa_index); +again: + page = folio_file_page(folio, xas.xa_index); if (PageHWPoison(page)) goto unlock; @@ -3309,12 +3287,21 @@ vm_fault_t filemap_map_pages(struct vm_fault *vmf, do_set_pte(vmf, page, addr); /* no need to invalidate: a not-present page won't be cached */ update_mmu_cache(vma, addr, vmf->pte); - unlock_page(head); + if (folio_more_pages(folio, xas.xa_index, end_pgoff)) { + xas.xa_index++; + folio_ref_inc(folio); + goto again; + } + folio_unlock(folio); continue; unlock: - unlock_page(head); - put_page(head); - } while ((head = next_map_page(mapping, &xas, end_pgoff)) != NULL); + if (folio_more_pages(folio, xas.xa_index, end_pgoff)) { + xas.xa_index++; + goto again; + } + folio_unlock(folio); + folio_put(folio); + } while ((folio = next_map_page(mapping, &xas, end_pgoff)) != NULL); pte_unmap_unlock(vmf->pte, vmf->ptl); out: rcu_read_unlock(); @@ -3326,24 +3313,24 @@ EXPORT_SYMBOL(filemap_map_pages); vm_fault_t filemap_page_mkwrite(struct vm_fault *vmf) { struct address_space *mapping = vmf->vma->vm_file->f_mapping; - struct page *page = vmf->page; + struct folio *folio = page_folio(vmf->page); vm_fault_t ret = VM_FAULT_LOCKED; sb_start_pagefault(mapping->host->i_sb); file_update_time(vmf->vma->vm_file); - lock_page(page); - if (page->mapping != mapping) { - unlock_page(page); + folio_lock(folio); + if (folio->mapping != mapping) { + folio_unlock(folio); ret = VM_FAULT_NOPAGE; goto out; } /* - * We mark the page dirty already here so that when freeze is in + * We mark the folio dirty already here so that when freeze is in * progress, we are guaranteed that writeback during freezing will - * see the dirty page and writeprotect it again. + * see the dirty folio and writeprotect it again. */ - set_page_dirty(page); - wait_for_stable_page(page); + folio_mark_dirty(folio); + folio_wait_stable(folio); out: sb_end_pagefault(mapping->host->i_sb); return ret; @@ -3396,35 +3383,20 @@ EXPORT_SYMBOL(filemap_page_mkwrite); EXPORT_SYMBOL(generic_file_mmap); EXPORT_SYMBOL(generic_file_readonly_mmap); -static struct page *wait_on_page_read(struct page *page) +static struct folio *do_read_cache_folio(struct address_space *mapping, + pgoff_t index, filler_t filler, void *data, gfp_t gfp) { - if (!IS_ERR(page)) { - wait_on_page_locked(page); - if (!PageUptodate(page)) { - put_page(page); - page = ERR_PTR(-EIO); - } - } - return page; -} - -static struct page *do_read_cache_page(struct address_space *mapping, - pgoff_t index, - int (*filler)(void *, struct page *), - void *data, - gfp_t gfp) -{ - struct page *page; + struct folio *folio; int err; repeat: - page = find_get_page(mapping, index); - if (!page) { - page = __page_cache_alloc(gfp); - if (!page) + folio = filemap_get_folio(mapping, index); + if (!folio) { + folio = filemap_alloc_folio(gfp, 0); + if (!folio) return ERR_PTR(-ENOMEM); - err = add_to_page_cache_lru(page, mapping, index, gfp); + err = filemap_add_folio(mapping, folio, index, gfp); if (unlikely(err)) { - put_page(page); + folio_put(folio); if (err == -EEXIST) goto repeat; /* Presumably ENOMEM for xarray node */ @@ -3433,71 +3405,41 @@ repeat: filler: if (filler) - err = filler(data, page); + err = filler(data, &folio->page); else - err = mapping->a_ops->readpage(data, page); + err = mapping->a_ops->readpage(data, &folio->page); if (err < 0) { - put_page(page); + folio_put(folio); return ERR_PTR(err); } - page = wait_on_page_read(page); - if (IS_ERR(page)) - return page; + folio_wait_locked(folio); + if (!folio_test_uptodate(folio)) { + folio_put(folio); + return ERR_PTR(-EIO); + } + goto out; } - if (PageUptodate(page)) + if (folio_test_uptodate(folio)) goto out; - /* - * Page is not up to date and may be locked due to one of the following - * case a: Page is being filled and the page lock is held - * case b: Read/write error clearing the page uptodate status - * case c: Truncation in progress (page locked) - * case d: Reclaim in progress - * - * Case a, the page will be up to date when the page is unlocked. - * There is no need to serialise on the page lock here as the page - * is pinned so the lock gives no additional protection. Even if the - * page is truncated, the data is still valid if PageUptodate as - * it's a race vs truncate race. - * Case b, the page will not be up to date - * Case c, the page may be truncated but in itself, the data may still - * be valid after IO completes as it's a read vs truncate race. The - * operation must restart if the page is not uptodate on unlock but - * otherwise serialising on page lock to stabilise the mapping gives - * no additional guarantees to the caller as the page lock is - * released before return. - * Case d, similar to truncation. If reclaim holds the page lock, it - * will be a race with remove_mapping that determines if the mapping - * is valid on unlock but otherwise the data is valid and there is - * no need to serialise with page lock. - * - * As the page lock gives no additional guarantee, we optimistically - * wait on the page to be unlocked and check if it's up to date and - * use the page if it is. Otherwise, the page lock is required to - * distinguish between the different cases. The motivation is that we - * avoid spurious serialisations and wakeups when multiple processes - * wait on the same page for IO to complete. - */ - wait_on_page_locked(page); - if (PageUptodate(page)) - goto out; - - /* Distinguish between all the cases under the safety of the lock */ - lock_page(page); + if (!folio_trylock(folio)) { + folio_put_wait_locked(folio, TASK_UNINTERRUPTIBLE); + goto repeat; + } - /* Case c or d, restart the operation */ - if (!page->mapping) { - unlock_page(page); - put_page(page); + /* Folio was truncated from mapping */ + if (!folio->mapping) { + folio_unlock(folio); + folio_put(folio); goto repeat; } /* Someone else locked and filled the page in a very small window */ - if (PageUptodate(page)) { - unlock_page(page); + if (folio_test_uptodate(folio)) { + folio_unlock(folio); goto out; } @@ -3507,16 +3449,16 @@ filler: * Clear page error before actual read, PG_error will be * set again if read page fails. */ - ClearPageError(page); + folio_clear_error(folio); goto filler; out: - mark_page_accessed(page); - return page; + folio_mark_accessed(folio); + return folio; } /** - * read_cache_page - read into page cache, fill it if needed + * read_cache_folio - read into page cache, fill it if needed * @mapping: the page's address_space * @index: the page index * @filler: function to perform the read @@ -3531,10 +3473,27 @@ out: * * Return: up to date page on success, ERR_PTR() on failure. */ +struct folio *read_cache_folio(struct address_space *mapping, pgoff_t index, + filler_t filler, void *data) +{ + return do_read_cache_folio(mapping, index, filler, data, + mapping_gfp_mask(mapping)); +} +EXPORT_SYMBOL(read_cache_folio); + +static struct page *do_read_cache_page(struct address_space *mapping, + pgoff_t index, filler_t *filler, void *data, gfp_t gfp) +{ + struct folio *folio; + + folio = do_read_cache_folio(mapping, index, filler, data, gfp); + if (IS_ERR(folio)) + return &folio->page; + return folio_file_page(folio, index); +} + struct page *read_cache_page(struct address_space *mapping, - pgoff_t index, - int (*filler)(void *, struct page *), - void *data) + pgoff_t index, filler_t *filler, void *data) { return do_read_cache_page(mapping, index, filler, data, mapping_gfp_mask(mapping)); @@ -3894,33 +3853,32 @@ ssize_t generic_file_write_iter(struct kiocb *iocb, struct iov_iter *from) EXPORT_SYMBOL(generic_file_write_iter); /** - * try_to_release_page() - release old fs-specific metadata on a page - * - * @page: the page which the kernel is trying to free - * @gfp_mask: memory allocation flags (and I/O mode) + * filemap_release_folio() - Release fs-specific metadata on a folio. + * @folio: The folio which the kernel is trying to free. + * @gfp: Memory allocation flags (and I/O mode). * - * The address_space is to try to release any data against the page - * (presumably at page->private). + * The address_space is trying to release any data attached to a folio + * (presumably at folio->private). * - * This may also be called if PG_fscache is set on a page, indicating that the - * page is known to the local caching routines. + * This will also be called if the private_2 flag is set on a page, + * indicating that the folio has other metadata associated with it. * - * The @gfp_mask argument specifies whether I/O may be performed to release - * this page (__GFP_IO), and whether the call may block (__GFP_RECLAIM & __GFP_FS). + * The @gfp argument specifies whether I/O may be performed to release + * this page (__GFP_IO), and whether the call may block + * (__GFP_RECLAIM & __GFP_FS). * - * Return: %1 if the release was successful, otherwise return zero. + * Return: %true if the release was successful, otherwise %false. */ -int try_to_release_page(struct page *page, gfp_t gfp_mask) +bool filemap_release_folio(struct folio *folio, gfp_t gfp) { - struct address_space * const mapping = page->mapping; + struct address_space * const mapping = folio->mapping; - BUG_ON(!PageLocked(page)); - if (PageWriteback(page)) - return 0; + BUG_ON(!folio_test_locked(folio)); + if (folio_test_writeback(folio)) + return false; if (mapping && mapping->a_ops->releasepage) - return mapping->a_ops->releasepage(page, gfp_mask); - return try_to_free_buffers(page); + return mapping->a_ops->releasepage(&folio->page, gfp); + return try_to_free_buffers(&folio->page); } - -EXPORT_SYMBOL(try_to_release_page); +EXPORT_SYMBOL(filemap_release_folio); |