linux-ext4 - [PATCHv4 12/43] truncate: make sure invalidate_mapping

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: <20161025001342.76126-13-kirill.shutemov@linux.intel.com>
Date:   Tue, 25 Oct 2016 03:13:11 +0300
From:   "Kirill A. Shutemov" <kirill.shutemov@...ux.intel.com>
To:     "Theodore Ts'o" <tytso@....edu>,
        Andreas Dilger <adilger.kernel@...ger.ca>,
        Jan Kara <jack@...e.com>,
        Andrew Morton <akpm@...ux-foundation.org>
Cc:     Alexander Viro <viro@...iv.linux.org.uk>,
        Hugh Dickins <hughd@...gle.com>,
        Andrea Arcangeli <aarcange@...hat.com>,
        Dave Hansen <dave.hansen@...el.com>,
        Vlastimil Babka <vbabka@...e.cz>,
        Matthew Wilcox <willy@...radead.org>,
        Ross Zwisler <ross.zwisler@...ux.intel.com>,
        linux-ext4@...r.kernel.org, linux-fsdevel@...r.kernel.org,
        linux-kernel@...r.kernel.org, linux-mm@...ck.org,
        linux-block@...r.kernel.org,
        "Kirill A. Shutemov" <kirill.shutemov@...ux.intel.com>
Subject: [PATCHv4 12/43] truncate: make sure invalidate_mapping_pages() can discard huge pages

invalidate_inode_page() has expectation about page_count() of the page
-- if it's not 2 (one to caller, one to radix-tree), it will not be
dropped. That condition almost never met for THPs -- tail pages are
pinned to the pagevec.

Let's drop them, before calling invalidate_inode_page().

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@...ux.intel.com>
---
 mm/truncate.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/mm/truncate.c b/mm/truncate.c
index a01cce450a26..393bf9447231 100644
--- a/mm/truncate.c
+++ b/mm/truncate.c
@@ -504,10 +504,22 @@ unsigned long invalidate_mapping_pages(struct address_space *mapping,
 				/* 'end' is in the middle of THP */
 				if (index ==  round_down(end, HPAGE_PMD_NR))
 					continue;
+				/*
+				 * invalidate_inode_page() expects
+				 * page_count(page) == 2 to drop page from page
+				 * cache -- drop tail pages references.
+				 */
+				get_page(page);
+				pagevec_remove_exceptionals(&pvec);
+				pagevec_release(&pvec);
 			}
 
 			ret = invalidate_inode_page(page);
 			unlock_page(page);
+
+			if (PageTransHuge(page))
+				put_page(page);
+
 			/*
 			 * Invalidation is a hint that the page is no longer
 			 * of interest and try to speed up its reclaim.
-- 
2.9.3

--
To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html