[PATCH v6 29/99] page cache: Convert filemap_range_has_page to XArray

From: Matthew Wilcox
Date: Wed Jan 17 2018 - 16:03:43 EST


From: Matthew Wilcox <mawilcox@xxxxxxxxxxxxx>

Instead of calling find_get_pages_range() and putting any reference,
just use xa_find() to look for a page in the right range.

Signed-off-by: Matthew Wilcox <mawilcox@xxxxxxxxxxxxx>
---
mm/filemap.c | 9 +--------
1 file changed, 1 insertion(+), 8 deletions(-)

diff --git a/mm/filemap.c b/mm/filemap.c
index 2536fcacb5bc..cd01f353cf6a 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -461,18 +461,11 @@ bool filemap_range_has_page(struct address_space *mapping,
{
pgoff_t index = start_byte >> PAGE_SHIFT;
pgoff_t end = end_byte >> PAGE_SHIFT;
- struct page *page;

if (end_byte < start_byte)
return false;

- if (mapping->nrpages == 0)
- return false;
-
- if (!find_get_pages_range(mapping, &index, end, 1, &page))
- return false;
- put_page(page);
- return true;
+ return xa_find(&mapping->pages, &index, end, XA_PRESENT);
}
EXPORT_SYMBOL(filemap_range_has_page);

--
2.15.1