linux-kernel - [PATCH v3 17/21] to_shrink_list(): call only if refcount is 0

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Message-Id: <20231124060422.576198-17-viro@zeniv.linux.org.uk>
Date:   Fri, 24 Nov 2023 06:04:18 +0000
From:   Al Viro <viro@...iv.linux.org.uk>
To:     linux-fsdevel@...r.kernel.org
Cc:     Linus Torvalds <torvalds@...ux-foundation.org>,
        Christian Brauner <brauner@...nel.org>,
        linux-kernel@...r.kernel.org
Subject: [PATCH v3 17/21] to_shrink_list(): call only if refcount is 0

The only thing it does if refcount is not zero is d_lru_del(); no
point, IMO, seeing that plain dput() does nothing of that sort...

Note that 2 of 3 current callers are guaranteed that refcount is 0.

Acked-by: Christian Brauner <brauner@...nel.org>
Signed-off-by: Al Viro <viro@...iv.linux.org.uk>
---
 fs/dcache.c | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/fs/dcache.c b/fs/dcache.c
index 5284b02747cd..704676bf06fd 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -915,8 +915,7 @@ __must_hold(&dentry->d_lock)
 	if (!(dentry->d_flags & DCACHE_SHRINK_LIST)) {
 		if (dentry->d_flags & DCACHE_LRU_LIST)
 			d_lru_del(dentry);
-		if (!dentry->d_lockref.count)
-			d_shrink_add(dentry, list);
+		d_shrink_add(dentry, list);
 	}
 }
 
@@ -1115,10 +1114,8 @@ EXPORT_SYMBOL(d_prune_aliases);
 static inline void shrink_kill(struct dentry *victim, struct list_head *list)
 {
 	struct dentry *parent = victim->d_parent;
-	if (parent != victim) {
-		--parent->d_lockref.count;
+	if (parent != victim && !--parent->d_lockref.count)
 		to_shrink_list(parent, list);
-	}
 	__dentry_kill(victim);
 }
 
-- 
2.39.2