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From:   Matthew Wilcox <willy@infradead.org>
To:     linux-fsdevel@vger.kernel.org
Cc:     "Matthew Wilcox (Oracle)" <willy@infradead.org>,
        linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: [PATCH v6 41/51] mm: Fix truncation for pages of arbitrary size
Date:   Wed, 10 Jun 2020 13:13:35 -0700
Message-Id: <20200610201345.13273-42-willy@infradead.org>
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From: "Matthew Wilcox (Oracle)" <willy@infradead.org>

Remove the assumption that a compound page is HPAGE_PMD_SIZE,
and the assumption that any page is PAGE_SIZE.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
---
 mm/truncate.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/mm/truncate.c b/mm/truncate.c
index 152974888124..a9fde773179b 100644
--- a/mm/truncate.c
+++ b/mm/truncate.c
@@ -168,7 +168,7 @@ void do_invalidatepage(struct page *page, unsigned int offset,
  * becomes orphaned.  It will be left on the LRU and may even be mapped into
  * user pagetables if we're racing with filemap_fault().
  *
- * We need to bale out if page->mapping is no longer equal to the original
+ * We need to bail out if page->mapping is no longer equal to the original
  * mapping.  This happens a) when the VM reclaimed the page while we waited on
  * its lock, b) when a concurrent invalidate_mapping_pages got there first and
  * c) when tmpfs swizzles a page between a tmpfs inode and swapper_space.
@@ -177,12 +177,12 @@ static void
 truncate_cleanup_page(struct address_space *mapping, struct page *page)
 {
 	if (page_mapped(page)) {
-		pgoff_t nr = PageTransHuge(page) ? HPAGE_PMD_NR : 1;
+		unsigned int nr = thp_nr_pages(page);
 		unmap_mapping_pages(mapping, page->index, nr, false);
 	}
 
 	if (page_has_private(page))
-		do_invalidatepage(page, 0, PAGE_SIZE);
+		do_invalidatepage(page, 0, thp_size(page));
 
 	/*
 	 * Some filesystems seem to re-dirty the page even after
-- 
2.26.2