linux-kernel - [PATCH] fs: Kill DCACHE_DONTCACHE dentry even if DCACHE

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-next>] [day] [month] [year] [list]

Message-ID: <20200821015953.22956-1-lihao2018.fnst@cn.fujitsu.com>
Date:   Fri, 21 Aug 2020 09:59:53 +0800
From:   Hao Li <lihao2018.fnst@...fujitsu.com>
To:     <viro@...iv.linux.org.uk>
CC:     <linux-fsdevel@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
        <lihao2018.fnst@...fujitsu.com>, <y-goto@...itsu.com>
Subject: [PATCH] fs: Kill DCACHE_DONTCACHE dentry even if DCACHE_REFERENCED is set

Currently, DCACHE_REFERENCED prevents the dentry with DCACHE_DONTCACHE
set from being killed, so the corresponding inode can't be evicted. If
the DAX policy of an inode is changed, we can't make policy changing
take effects unless dropping caches manually.

This patch fixes this problem and flushes the inode to disk to prepare
for evicting it.

Signed-off-by: Hao Li <lihao2018.fnst@...fujitsu.com>
---
 fs/dcache.c | 3 ++-
 fs/inode.c  | 2 +-
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/fs/dcache.c b/fs/dcache.c
index ea0485861d93..486c7409dc82 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -796,7 +796,8 @@ static inline bool fast_dput(struct dentry *dentry)
 	 */
 	smp_rmb();
 	d_flags = READ_ONCE(dentry->d_flags);
-	d_flags &= DCACHE_REFERENCED | DCACHE_LRU_LIST | DCACHE_DISCONNECTED;
+	d_flags &= DCACHE_REFERENCED | DCACHE_LRU_LIST | DCACHE_DISCONNECTED
+			| DCACHE_DONTCACHE;
 
 	/* Nothing to do? Dropping the reference was all we needed? */
 	if (d_flags == (DCACHE_REFERENCED | DCACHE_LRU_LIST) && !d_unhashed(dentry))
diff --git a/fs/inode.c b/fs/inode.c
index 72c4c347afb7..5218a8aebd7f 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -1632,7 +1632,7 @@ static void iput_final(struct inode *inode)
 	}
 
 	state = inode->i_state;
-	if (!drop) {
+	if (!drop || (drop && (inode->i_state & I_DONTCACHE))) {
 		WRITE_ONCE(inode->i_state, state | I_WILL_FREE);
 		spin_unlock(&inode->i_lock);
 
-- 
2.28.0