Pagecache tags are used for dirty page writeback.  Since dirtiness is
tracked on a per-THP basis, we only want to return the head page rather
than each subpage of a tagged page.  All the filesystems which use huge
pages today are in-memory, so there are no tagged huge pages today.

Signed-off-by: Matthew Wilcox (Oracle) <wi...@infradead.org>
Reviewed-by: Jan Kara <j...@suse.cz>
Reviewed-by: William Kucharski <william.kuchar...@oracle.com>
---
 mm/filemap.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/mm/filemap.c b/mm/filemap.c
index d5e7c2029d16..edde5dc0d28f 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -2066,7 +2066,7 @@ unsigned find_get_pages_contig(struct address_space 
*mapping, pgoff_t index,
 EXPORT_SYMBOL(find_get_pages_contig);
 
 /**
- * find_get_pages_range_tag - find and return pages in given range matching 
@tag
+ * find_get_pages_range_tag - Find and return head pages matching @tag.
  * @mapping:   the address_space to search
  * @index:     the starting page index
  * @end:       The final page index (inclusive)
@@ -2074,8 +2074,8 @@ EXPORT_SYMBOL(find_get_pages_contig);
  * @nr_pages:  the maximum number of pages
  * @pages:     where the resulting pages are placed
  *
- * Like find_get_pages, except we only return pages which are tagged with
- * @tag.   We update @index to index the next page for the traversal.
+ * Like find_get_pages(), except we only return head pages which are tagged
+ * with @tag.   We update @index to index the next page for the traversal.
  *
  * Return: the number of pages which were found.
  */
@@ -2109,9 +2109,9 @@ unsigned find_get_pages_range_tag(struct address_space 
*mapping, pgoff_t *index,
                if (unlikely(page != xas_reload(&xas)))
                        goto put_page;
 
-               pages[ret] = find_subpage(page, xas.xa_index);
+               pages[ret] = page;
                if (++ret == nr_pages) {
-                       *index = xas.xa_index + 1;
+                       *index = page->index + thp_nr_pages(page);
                        goto out;
                }
                continue;
-- 
2.28.0

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