diff options
| author | Breno Leitao <leitao@debian.org> | 2026-01-05 07:10:27 -0800 |
|---|---|---|
| committer | Christian Brauner <brauner@kernel.org> | 2026-01-06 22:48:15 +0100 |
| commit | a6b9f5b2f04bd7809cd72c5d33af944758c00ab1 (patch) | |
| tree | e9ecdf95473e6fb9e9e0ec02832551315192301b | |
| parent | 729d015ab230d1d6debd69744c6e0fb70c16a779 (diff) | |
fs/namei: Remove redundant DCACHE_MANAGED_DENTRY check in __follow_mount_rcu
The check for DCACHE_MANAGED_DENTRY at the start of __follow_mount_rcu()
is redundant because the only caller (handle_mounts) already verifies
d_managed(dentry) before calling this function, so, dentry in
__follow_mount_rcu() has always DCACHE_MANAGED_DENTRY set.
This early-out optimization never fires in practice - but it is marking
as likely().
This was detected with branch profiling, which shows 100% misprediction
in this likely.
Remove the whole if clause instead of removing the likely, given we
know for sure that dentry is not DCACHE_MANAGED_DENTRY.
Signed-off-by: Breno Leitao <leitao@debian.org>
Link: https://patch.msgid.link/20260105-dcache-v1-1-f0d904b4a7c2@debian.org
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Christian Brauner <brauner@kernel.org>
| -rw-r--r-- | fs/namei.c | 3 |
1 files changed, 0 insertions, 3 deletions
diff --git a/fs/namei.c b/fs/namei.c index 280c69e8fb99..e0d5ebdf43a3 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -1624,9 +1624,6 @@ static bool __follow_mount_rcu(struct nameidata *nd, struct path *path) struct dentry *dentry = path->dentry; unsigned int flags = dentry->d_flags; - if (likely(!(flags & DCACHE_MANAGED_DENTRY))) - return true; - if (unlikely(nd->flags & LOOKUP_NO_XDEV)) return false; |