ntfs3: convert ntfs_zero_range() to use a folio

Use the folio API throughout, saving six hidden calls to compound_head().

Link: https://lkml.kernel.org/r/20231016201114.1928083-21-willy@infradead.orgSigned-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Andreas Gruenbacher <agruenba@redhat.com>
Cc: Pankaj Raghav <p.raghav@samsung.com>
Cc: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

fs/ntfs3/file.c

@@ -187,7 +187,7 @@ static int ntfs_zero_range(struct inode *inode, u64 vbo, u64 vbo_to)
 	struct buffer_head *head, *bh;
 	u32 bh_next, bh_off, to;
 	sector_t iblock;
-	struct page *page;
+	struct folio *folio;
 
 	for (; idx < idx_end; idx += 1, from = 0) {
 		page_off = (loff_t)idx << PAGE_SHIFT;
@@ -195,16 +195,17 @@ static int ntfs_zero_range(struct inode *inode, u64 vbo, u64 vbo_to)
 						       PAGE_SIZE;
 		iblock = page_off >> inode->i_blkbits;
 
-		page = find_or_create_page(mapping, idx,
-					   mapping_gfp_constraint(mapping,
-								  ~__GFP_FS));
-		if (!page)
-			return -ENOMEM;
+		folio = __filemap_get_folio(mapping, idx,
+				FGP_LOCK | FGP_ACCESSED | FGP_CREAT,
+				mapping_gfp_constraint(mapping, ~__GFP_FS));
+		if (IS_ERR(folio))
+			return PTR_ERR(folio);
 
-		if (!page_has_buffers(page))
-			create_empty_buffers(page, blocksize, 0);
+		head = folio_buffers(folio);
+		if (!head)
+			head = folio_create_empty_buffers(folio, blocksize, 0);
 
-		bh = head = page_buffers(page);
+		bh = head;
 		bh_off = 0;
 		do {
 			bh_next = bh_off + blocksize;
@@ -220,14 +221,14 @@ static int ntfs_zero_range(struct inode *inode, u64 vbo, u64 vbo_to)
 			}
 
 			/* Ok, it's mapped. Make sure it's up-to-date. */
-			if (PageUptodate(page))
+			if (folio_test_uptodate(folio))
 				set_buffer_uptodate(bh);
 
 			if (!buffer_uptodate(bh)) {
 				err = bh_read(bh, 0);
 				if (err < 0) {
-					unlock_page(page);
-					put_page(page);
+					folio_unlock(folio);
+					folio_put(folio);
 					goto out;
 				}
 			}
@@ -237,10 +238,10 @@ static int ntfs_zero_range(struct inode *inode, u64 vbo, u64 vbo_to)
 		} while (bh_off = bh_next, iblock += 1,
 			 head != (bh = bh->b_this_page));
 
-		zero_user_segment(page, from, to);
+		folio_zero_segment(folio, from, to);
 
-		unlock_page(page);
-		put_page(page);
+		folio_unlock(folio);
+		folio_put(folio);
 		cond_resched();
 	}
 out: