[PATCH] fs/dcache: Re-use value stored to dentry->d_flags instead of re-reading

From: linke li <lilinke99@qq.com>
Cc: xujianhao01@gmail.com, linke li <lilinke99@qq.com>,
	Alexander Viro <viro@zeniv.linux.org.uk>,
	Christian Brauner <brauner@kernel.org>, Jan Kara <jack@suse.cz>,
	linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH] fs/dcache: Re-use value stored to dentry->d_flags instead of re-reading
Date: Wed,  3 Apr 2024 10:10:08 +0800	[thread overview]
Message-ID: <tencent_5E187BD0A61BA28605E85405F15228254D0A@qq.com> (raw)

Currently, the __d_clear_type_and_inode() writes the value flags to
dentry->d_flags, then immediately re-reads it in order to use it in a if
statement. This re-read is useless because no other update to 
dentry->d_flags can occur at this point.

This commit therefore re-use flags in the if statement instead of
re-reading dentry->d_flags.


Signed-off-by: linke li <lilinke99@qq.com>
---
 fs/dcache.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/dcache.c b/fs/dcache.c
index b813528fb147..79da415d7995 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -355,7 +355,7 @@ static inline void __d_clear_type_and_inode(struct dentry *dentry)
 	flags &= ~DCACHE_ENTRY_TYPE;
 	WRITE_ONCE(dentry->d_flags, flags);
 	dentry->d_inode = NULL;
-	if (dentry->d_flags & DCACHE_LRU_LIST)
+	if (flags & DCACHE_LRU_LIST)
 		this_cpu_inc(nr_dentry_negative);
 }
 
-- 
2.39.3 (Apple Git-146)

