linux-kernel - [PATCH 24/28] staging/lustre/llite: ll_revalidate

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: <1466388463-1817551-25-git-send-email-green@linuxhacker.ru>
Date:	Sun, 19 Jun 2016 22:07:39 -0400
From:	Oleg Drokin <green@...uxhacker.ru>
To:	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	devel@...verdev.osuosl.org,
	Andreas Dilger <andreas.dilger@...el.com>
Cc:	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
	Lustre Development List <lustre-devel@...ts.lustre.org>,
	Oleg Drokin <oleg.drokin@...el.com>,
	Oleg Drokin <green@...uxhacker.ru>
Subject: [PATCH 24/28] staging/lustre/llite: ll_revalidate_dentry update

From: Oleg Drokin <oleg.drokin@...el.com>

There are a couple of cases in ll_revalidate_dentry() where
we are pretty sure the dentry is valid, so check for them early
and save more expensive checks for later.

Signed-off-by: Oleg Drokin <green@...uxhacker.ru>
---
 drivers/staging/lustre/lustre/llite/dcache.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/drivers/staging/lustre/lustre/llite/dcache.c b/drivers/staging/lustre/lustre/llite/dcache.c
index d964f4f..581a63a 100644
--- a/drivers/staging/lustre/lustre/llite/dcache.c
+++ b/drivers/staging/lustre/lustre/llite/dcache.c
@@ -302,6 +302,17 @@ static int ll_revalidate_dentry(struct dentry *dentry,
 {
 	struct inode *dir = d_inode(dentry->d_parent);
 
+	/* If this is intermediate component path lookup and we were able to get
+	 * to this dentry, then its lock has not been revoked and the
+	 * path component is valid.
+	 */
+	if (lookup_flags & LOOKUP_PARENT)
+		return 1;
+
+	/* Symlink - always valid as long as the dentry was found */
+	if (dentry->d_inode && S_ISLNK(dentry->d_inode->i_mode))
+		return 1;
+
 	/*
 	 * if open&create is set, talk to MDS to make sure file is created if
 	 * necessary, because we can't do this in ->open() later since that's
-- 
2.7.4