linux-ext4 - [PATCH 03/10] ext4: Convert mpage_release_unused_pages() to use filemap_get

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Date:   Sun,  5 Jun 2022 20:38:47 +0100
From:   "Matthew Wilcox (Oracle)" <willy@...radead.org>
To:     linux-fsdevel@...r.kernel.org
Cc:     "Matthew Wilcox (Oracle)" <willy@...radead.org>,
        linux-kernel@...r.kernel.org, linux-ext4@...r.kernel.org,
        linux-f2fs-devel@...ts.sourceforge.net, linux-mm@...ck.org,
        linux-nilfs@...r.kernel.org
Subject: [PATCH 03/10] ext4: Convert mpage_release_unused_pages() to use filemap_get_folios()

If the folio is large, it may overlap the beginning or end of the
unused range.  If it does, we need to avoid invalidating it.

Signed-off-by: Matthew Wilcox (Oracle) <willy@...radead.org>
---
 fs/ext4/inode.c | 21 ++++++++++++---------
 1 file changed, 12 insertions(+), 9 deletions(-)

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 3dce7d058985..32a7f5e024d6 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -1554,9 +1554,9 @@ struct mpage_da_data {
 static void mpage_release_unused_pages(struct mpage_da_data *mpd,
 				       bool invalidate)
 {
-	int nr_pages, i;
+	unsigned nr, i;
 	pgoff_t index, end;
-	struct pagevec pvec;
+	struct folio_batch fbatch;
 	struct inode *inode = mpd->inode;
 	struct address_space *mapping = inode->i_mapping;
 
@@ -1574,15 +1574,18 @@ static void mpage_release_unused_pages(struct mpage_da_data *mpd,
 		ext4_es_remove_extent(inode, start, last - start + 1);
 	}
 
-	pagevec_init(&pvec);
+	folio_batch_init(&fbatch);
 	while (index <= end) {
-		nr_pages = pagevec_lookup_range(&pvec, mapping, &index, end);
-		if (nr_pages == 0)
+		nr = filemap_get_folios(mapping, &index, end, &fbatch);
+		if (nr == 0)
 			break;
-		for (i = 0; i < nr_pages; i++) {
-			struct page *page = pvec.pages[i];
-			struct folio *folio = page_folio(page);
+		for (i = 0; i < nr; i++) {
+			struct folio *folio = fbatch.folios[i];
 
+			if (folio->index < mpd->first_page)
+				continue;
+			if (folio->index + folio_nr_pages(folio) - 1 > end)
+				continue;
 			BUG_ON(!folio_test_locked(folio));
 			BUG_ON(folio_test_writeback(folio));
 			if (invalidate) {
@@ -1594,7 +1597,7 @@ static void mpage_release_unused_pages(struct mpage_da_data *mpd,
 			}
 			folio_unlock(folio);
 		}
-		pagevec_release(&pvec);
+		folio_batch_release(&fbatch);
 	}
 }
 
-- 
2.35.1