mm: increase usage of folio_next_index() helper

Simplify code pattern of 'folio->index + folio_nr_pages(folio)' by using
the existing helper folio_next_index().

Link: https://lkml.kernel.org/r/20230627174349.491803-1-sidhartha.kumar@oracle.comSigned-off-by: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Suggested-by: Christoph Hellwig <hch@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

fs/ext4/inode.c

@@ -1569,7 +1569,7 @@ static void mpage_release_unused_pages(struct mpage_da_data *mpd,
 
 			if (folio->index < mpd->first_page)
 				continue;
-			if (folio->index + folio_nr_pages(folio) - 1 > end)
+			if (folio_next_index(folio) - 1 > end)
 				continue;
 			BUG_ON(!folio_test_locked(folio));
 			BUG_ON(folio_test_writeback(folio));
@@ -2455,7 +2455,7 @@ static int mpage_prepare_extent_to_map(struct mpage_da_data *mpd)
 
 			if (mpd->map.m_len == 0)
 				mpd->first_page = folio->index;
-			mpd->next_page = folio->index + folio_nr_pages(folio);
+			mpd->next_page = folio_next_index(folio);
 			/*
 			 * Writeout when we cannot modify metadata is simple.
 			 * Just submit the page. For data=journal mode we

mm/filemap.c

@@ -2075,7 +2075,7 @@ unsigned find_lock_entries(struct address_space *mapping, pgoff_t *start,
 		if (!xa_is_value(folio)) {
 			if (folio->index < *start)
 				goto put;
-			if (folio->index + folio_nr_pages(folio) - 1 > end)
+			if (folio_next_index(folio) - 1 > end)
 				goto put;
 			if (!folio_trylock(folio))
 				goto put;
@@ -2174,7 +2174,7 @@ bool folio_more_pages(struct folio *folio, pgoff_t index, pgoff_t max)
 		return false;
 	if (index >= max)
 		return false;
-	return index < folio->index + folio_nr_pages(folio) - 1;
+	return index < folio_next_index(folio) - 1;
 }
 
 /**
@@ -2242,7 +2242,7 @@ unsigned filemap_get_folios_contig(struct address_space *mapping,
 		if (folio_test_hugetlb(folio))
 			*start = folio->index + 1;
 		else
-			*start = folio->index + folio_nr_pages(folio);
+			*start = folio_next_index(folio);
 	}
 out:
 	rcu_read_unlock();
@@ -2359,7 +2359,7 @@ static void filemap_get_read_batch(struct address_space *mapping,
 			break;
 		if (folio_test_readahead(folio))
 			break;
-		xas_advance(&xas, folio->index + folio_nr_pages(folio) - 1);
+		xas_advance(&xas, folio_next_index(folio) - 1);
 		continue;
 put_folio:
 		folio_put(folio);

mm/memory.c

@@ -3495,7 +3495,7 @@ void unmap_mapping_folio(struct folio *folio)
 	VM_BUG_ON(!folio_test_locked(folio));
 
 	first_index = folio->index;
-	last_index = folio->index + folio_nr_pages(folio) - 1;
+	last_index = folio_next_index(folio) - 1;
 
 	details.even_cows = false;
 	details.single_folio = folio;

mm/shmem.c

@@ -970,7 +970,7 @@ static void shmem_undo_range(struct inode *inode, loff_t lstart, loff_t lend,
 		same_folio = lend < folio_pos(folio) + folio_size(folio);
 		folio_mark_dirty(folio);
 		if (!truncate_inode_partial_folio(folio, lstart, lend)) {
-			start = folio->index + folio_nr_pages(folio);
+			start = folio_next_index(folio);
 			if (same_folio)
 				end = folio->index;
 		}

mm/truncate.c

@@ -378,7 +378,7 @@ void truncate_inode_pages_range(struct address_space *mapping,
 	if (!IS_ERR(folio)) {
 		same_folio = lend < folio_pos(folio) + folio_size(folio);
 		if (!truncate_inode_partial_folio(folio, lstart, lend)) {
-			start = folio->index + folio_nr_pages(folio);
+			start = folio_next_index(folio);
 			if (same_folio)
 				end = folio->index;
 		}