linux-kernel - [PATCH] fs: unconditionally use atime_needs_update() in pick

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Message-ID: <20250408073641.1799151-1-mjguzik@gmail.com>
Date: Tue,  8 Apr 2025 09:36:41 +0200
From: Mateusz Guzik <mjguzik@...il.com>
To: brauner@...nel.org
Cc: viro@...iv.linux.org.uk,
	jack@...e.cz,
	linux-kernel@...r.kernel.org,
	linux-fsdevel@...r.kernel.org,
	Mateusz Guzik <mjguzik@...il.com>
Subject: [PATCH] fs: unconditionally use atime_needs_update() in pick_link()

Vast majority of the time the func returns false.

This avoids a branch to determine whether we are in RCU mode.

Signed-off-by: Mateusz Guzik <mjguzik@...il.com>
---
 fs/namei.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/fs/namei.c b/fs/namei.c
index 360a86ca1f02..ae2643ff14dc 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -1905,13 +1905,13 @@ static const char *pick_link(struct nameidata *nd, struct path *link,
 			unlikely(link->mnt->mnt_flags & MNT_NOSYMFOLLOW))
 		return ERR_PTR(-ELOOP);
 
-	if (!(nd->flags & LOOKUP_RCU)) {
+	if (unlikely(atime_needs_update(&last->link, inode))) {
+		if (nd->flags & LOOKUP_RCU) {
+			if (!try_to_unlazy(nd))
+				return ERR_PTR(-ECHILD);
+		}
 		touch_atime(&last->link);
 		cond_resched();
-	} else if (atime_needs_update(&last->link, inode)) {
-		if (!try_to_unlazy(nd))
-			return ERR_PTR(-ECHILD);
-		touch_atime(&last->link);
 	}
 
 	error = security_inode_follow_link(link->dentry, inode,
-- 
2.43.0