linux-kernel - [PATCH AUTOSEL 6.11 065/244] vfs: use RCU in ilookup

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: <20240925113641.1297102-65-sashal@kernel.org>
Date: Wed, 25 Sep 2024 07:24:46 -0400
From: Sasha Levin <sashal@...nel.org>
To: linux-kernel@...r.kernel.org,
	stable@...r.kernel.org
Cc: Mateusz Guzik <mjguzik@...il.com>,
	Jan Kara <jack@...e.cz>,
	Christian Brauner <brauner@...nel.org>,
	Sasha Levin <sashal@...nel.org>,
	viro@...iv.linux.org.uk,
	linux-fsdevel@...r.kernel.org
Subject: [PATCH AUTOSEL 6.11 065/244] vfs: use RCU in ilookup

From: Mateusz Guzik <mjguzik@...il.com>

[ Upstream commit 122381a46954ad592ee93d7da2bef5074b396247 ]

A soft lockup in ilookup was reported when stress-testing a 512-way
system [1] (see [2] for full context) and it was verified that not
taking the lock shifts issues back to mm.

[1] https://lore.kernel.org/linux-mm/56865e57-c250-44da-9713-cf1404595bcc@amd.com/
[2] https://lore.kernel.org/linux-mm/d2841226-e27b-4d3d-a578-63587a3aa4f3@amd.com/

Signed-off-by: Mateusz Guzik <mjguzik@...il.com>
Link: https://lore.kernel.org/r/20240715071324.265879-1-mjguzik@gmail.com
Reviewed-by: Jan Kara <jack@...e.cz>
Signed-off-by: Christian Brauner <brauner@...nel.org>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 fs/inode.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/fs/inode.c b/fs/inode.c
index d1a098e7d4087..a2af540102d7a 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -1574,9 +1574,7 @@ struct inode *ilookup(struct super_block *sb, unsigned long ino)
 	struct hlist_head *head = inode_hashtable + hash(sb, ino);
 	struct inode *inode;
 again:
-	spin_lock(&inode_hash_lock);
-	inode = find_inode_fast(sb, head, ino, true);
-	spin_unlock(&inode_hash_lock);
+	inode = find_inode_fast(sb, head, ino, false);
 
 	if (inode) {
 		if (IS_ERR(inode))
-- 
2.43.0