linux-kernel - [PATCH v3 05/21] shrink_dentry_list(): no need to check that dentry refcount is marked dead

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Message-Id: <20231124060422.576198-5-viro@zeniv.linux.org.uk>
Date:   Fri, 24 Nov 2023 06:04:06 +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 05/21] shrink_dentry_list(): no need to check that dentry refcount is marked dead

... we won't see DCACHE_MAY_FREE on anything that is *not* dead
and checking d_flags is just as cheap as checking refcount.

Reviewed-by: Christian Brauner <brauner@...nel.org>
Signed-off-by: Al Viro <viro@...iv.linux.org.uk>
---
 fs/dcache.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/fs/dcache.c b/fs/dcache.c
index bb862a304e1b..c1025921f8d3 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -1191,11 +1191,10 @@ void shrink_dentry_list(struct list_head *list)
 		spin_lock(&dentry->d_lock);
 		rcu_read_lock();
 		if (!shrink_lock_dentry(dentry)) {
-			bool can_free = false;
+			bool can_free;
 			rcu_read_unlock();
 			d_shrink_del(dentry);
-			if (dentry->d_lockref.count < 0)
-				can_free = dentry->d_flags & DCACHE_MAY_FREE;
+			can_free = dentry->d_flags & DCACHE_MAY_FREE;
 			spin_unlock(&dentry->d_lock);
 			if (can_free)
 				dentry_free(dentry);
-- 
2.39.2