From f530ed0e2d01aafc4d0e3cf8ab6b64bbdb7696a7 Mon Sep 17 00:00:00 2001 From: "Matthew Wilcox (Oracle)" Date: Fri, 2 Sep 2022 20:46:02 +0100 Subject: shmem: convert shmem_writepage() to use a folio throughout Even though we will split any large folio that comes in, write the code to handle large folios so as to not leave a trap for whoever tries to handle large folios in the swap cache. Link: https://lkml.kernel.org/r/20220902194653.1739778-7-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) Signed-off-by: Andrew Morton --- mm/shmem.c | 47 ++++++++++++++++++++++++----------------------- 1 file changed, 24 insertions(+), 23 deletions(-) (limited to 'mm/shmem.c') diff --git a/mm/shmem.c b/mm/shmem.c index 674bde8b3085..3d2d35728793 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -1328,17 +1328,18 @@ static int shmem_writepage(struct page *page, struct writeback_control *wbc) * "force", drivers/gpu/drm/i915/gem/i915_gem_shmem.c gets huge pages, * and its shmem_writeback() needs them to be split when swapping. */ - if (PageTransCompound(page)) { + if (folio_test_large(folio)) { /* Ensure the subpages are still dirty */ - SetPageDirty(page); + folio_test_set_dirty(folio); if (split_huge_page(page) < 0) goto redirty; - ClearPageDirty(page); + folio = page_folio(page); + folio_clear_dirty(folio); } - BUG_ON(!PageLocked(page)); - mapping = page->mapping; - index = page->index; + BUG_ON(!folio_test_locked(folio)); + mapping = folio->mapping; + index = folio->index; inode = mapping->host; info = SHMEM_I(inode); if (info->flags & VM_LOCKED) @@ -1361,15 +1362,15 @@ static int shmem_writepage(struct page *page, struct writeback_control *wbc) /* * This is somewhat ridiculous, but without plumbing a SWAP_MAP_FALLOC * value into swapfile.c, the only way we can correctly account for a - * fallocated page arriving here is now to initialize it and write it. + * fallocated folio arriving here is now to initialize it and write it. * - * That's okay for a page already fallocated earlier, but if we have + * That's okay for a folio already fallocated earlier, but if we have * not yet completed the fallocation, then (a) we want to keep track - * of this page in case we have to undo it, and (b) it may not be a + * of this folio in case we have to undo it, and (b) it may not be a * good idea to continue anyway, once we're pushing into swap. So - * reactivate the page, and let shmem_fallocate() quit when too many. + * reactivate the folio, and let shmem_fallocate() quit when too many. */ - if (!PageUptodate(page)) { + if (!folio_test_uptodate(folio)) { if (inode->i_private) { struct shmem_falloc *shmem_falloc; spin_lock(&inode->i_lock); @@ -1385,9 +1386,9 @@ static int shmem_writepage(struct page *page, struct writeback_control *wbc) if (shmem_falloc) goto redirty; } - clear_highpage(page); - flush_dcache_page(page); - SetPageUptodate(page); + folio_zero_range(folio, 0, folio_size(folio)); + flush_dcache_folio(folio); + folio_mark_uptodate(folio); } swap = folio_alloc_swap(folio); @@ -1396,7 +1397,7 @@ static int shmem_writepage(struct page *page, struct writeback_control *wbc) /* * Add inode to shmem_unuse()'s list of swapped-out inodes, - * if it's not already there. Do it now before the page is + * if it's not already there. Do it now before the folio is * moved to swap cache, when its pagelock no longer protects * the inode from eviction. But don't unlock the mutex until * we've incremented swapped, because shmem_unuse_inode() will @@ -1406,7 +1407,7 @@ static int shmem_writepage(struct page *page, struct writeback_control *wbc) if (list_empty(&info->swaplist)) list_add(&info->swaplist, &shmem_swaplist); - if (add_to_swap_cache(page, swap, + if (add_to_swap_cache(&folio->page, swap, __GFP_HIGH | __GFP_NOMEMALLOC | __GFP_NOWARN, NULL) == 0) { spin_lock_irq(&info->lock); @@ -1415,21 +1416,21 @@ static int shmem_writepage(struct page *page, struct writeback_control *wbc) spin_unlock_irq(&info->lock); swap_shmem_alloc(swap); - shmem_delete_from_page_cache(page, swp_to_radix_entry(swap)); + shmem_delete_from_page_cache(&folio->page, swp_to_radix_entry(swap)); mutex_unlock(&shmem_swaplist_mutex); - BUG_ON(page_mapped(page)); - swap_writepage(page, wbc); + BUG_ON(folio_mapped(folio)); + swap_writepage(&folio->page, wbc); return 0; } mutex_unlock(&shmem_swaplist_mutex); - put_swap_page(page, swap); + put_swap_page(&folio->page, swap); redirty: - set_page_dirty(page); + folio_mark_dirty(folio); if (wbc->for_reclaim) - return AOP_WRITEPAGE_ACTIVATE; /* Return with page locked */ - unlock_page(page); + return AOP_WRITEPAGE_ACTIVATE; /* Return with folio locked */ + folio_unlock(folio); return 0; } -- cgit v1.2.3