linux-kernel - [PATCH v7 32/61] page cache: Convert filemap_range_has

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20180219194556.6575-33-willy@infradead.org>
Date:   Mon, 19 Feb 2018 11:45:27 -0800
From:   Matthew Wilcox <willy@...radead.org>
To:     Andrew Morton <akpm@...ux-foundation.org>
Cc:     Matthew Wilcox <mawilcox@...rosoft.com>,
        linux-kernel@...r.kernel.org, linux-mm@...ck.org,
        linux-fsdevel@...r.kernel.org
Subject: [PATCH v7 32/61] page cache: Convert filemap_range_has_page to XArray

From: Matthew Wilcox <mawilcox@...rosoft.com>

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@...rosoft.com>
---
 mm/filemap.c | 9 +--------
 1 file changed, 1 insertion(+), 8 deletions(-)

diff --git a/mm/filemap.c b/mm/filemap.c
index 3735ea6e3d19..a02d69a957e4 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -460,18 +460,11 @@ 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);
 
-- 
2.16.1