From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794047422; b=dk3ig8HcbXUK2vJ8KTp6mqoz3jZA3e+teYeBiVIf2HLhl5IEGjXxYuSveJsTi3mlGdgb MRrymOfqVR4RLYnvcQgBxL2Z3AutTrbRdORnPQQKtou+HobhvJTJU4BlzW/wtbPPlEuKf S2E7ckI9g0wqpTW9Pj+riae5Wz275DrA1LTel6PXd7KL1a7rKh1xt33oM1EkRQ5zVbNyx udq2YwjYAcXXwFKPJcO4bEILQdrgkrwJB8uFXsPj9aZqZZTMGAhSLudU3fIKE//m4yZsD FQ5N76egUaI654OOAoYMvugQhPOewUnR4Fv0AXbQmaTQjfqRq/Ywwr3+PFUTdN8SeyQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794047422; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: MIME-Version:Content-Type:Content-Transfer-Encoding; bh=mY5+AyVy0KLDQGUnrkzG2BDMD3LH8vLzV45Zssvek7Y=; b=3vXuHzEa0uRzksVu9kiqsjK+I2P82w0Wx9f6ucfsdvv+374VV4l4VzAsgRVEYiQ4tU45 n7VinRwvfpu3pCGU29P7HAVaqi0QCxwwU7TBBjzzKNt0Ptc19RKq/oEI8N3IuWjuznm6i fqazQWVUShQLTCmGXP0KSmRERVqkDBLLJ7G0dvO4MQ6sgZE7nvDpnwZMYl1uC28gljHF6 M6sKF29nZguBvU0Ox8qsieyOEEurofwzjqL/wxe/ubtlkw0GWXtzAD8mdHwllzIa7PA1Z uylIMyacZnF/HrQDo12ZwMRSZAPBbTk3UISex10n0AwDM6SEtCKUfI8feNuWQ5CCWIg== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=RZ5jMGFZ; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4C3A4606A32D for ; Sat, 7 Nov 2026 10:30:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=RZ5jMGFZ Received: by smtp.kernel.org (Postfix) with ESMTPSA id A58411F0089F; Sat, 7 Nov 2026 10:30:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794047422; bh=mY5+AyVy0KLDQGUnrkzG2BDMD3LH8vLzV45Zssvek7Y=; h=From:To:Cc:Subject:Date; b=RZ5jMGFZkUEnZhPQABM5SbFVUwb0bapFDw94pBTP7o32biFIdHLzSSDUvhj3OmGlb w+FX9Owb9og54TYZ9Ghr5fMExUVHYtgpYwx73JYwzMVt4i4Zxr2AWgv2/UEqHKujSh UEyQomQOSS5IXCTQRI199ZW9Iq9vxBtXtMu/0lDP1VFAzuhrQ+yhrs1rE+4sipudFH o967CUIYLdERb+YhruygL5sTpTGw9OFxz7Tlx87GCJiO8Xs+du/y8avh5Lrjv/0rqe vbu/6qOyohfsCZBJ8gJI0Wd+GuUwJe80SS/Rc1mZOehQiFZ36jM+t092wUypM8DcF4 t1/U5o39umRUA== From: Sasha Levin To: leitao@debian.org, paulmck@kernel.org, brauner@kernel.org Cc: stable@vger.kernel.org Subject: FAILED: patch "[PATCH] dcache: report a Tasks-RCU quiescent state in dentry_kill()" failed to apply to 6.6-stable tree Date: Sat, 7 Nov 2026 05:30:20 -0500 Message-ID: <20261107053020-failed-6.6-a647a53bc89a@kernel.org> X-Mailer: git-send-email 2.53.0 X-Mailing-List: stable@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The patch below does not apply to the 6.6-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y git checkout FETCH_HEAD git cherry-pick -x a647a53bc89a046bee4a12a0a5627f2dfaaef807 # git commit -s git send-email --to '' --in-reply-to '20261107053020-failed-6.6-a647a53bc89a@kernel.org' --subject-prefix 'PATCH 6.6.y' 'HEAD^..' Thanks, Sasha ------------------ original commit in Linus's tree ------------------ >From a647a53bc89a046bee4a12a0a5627f2dfaaef807 Mon Sep 17 00:00:00 2001 From: Breno Leitao Date: Fri, 18 Sep 2026 04:01:57 -0700 Subject: [PATCH] dcache: report a Tasks-RCU quiescent state in dentry_kill() I am constantly seeing the following warning on Meta's fleet: INFO: rcu_tasks detected stalls on tasks: native_queued_spin_lock_slowpath locked_inode_to_wb_and_lock_list inode_io_list_del evict __dentry_kill shrink_dentry_list shrink_dcache_tree d_invalidate btrfs_delete_subvolume btrfs_ioctl_snap_destroy btrfs_ioctl do_syscall_64 dentry_kill() is the common funnel for dentry teardown: dput(), shrink_dentry_list() and shrink_dcache_tree() all reach it, once per dentry, and its cond_resched() is the only reschedule point on that path. cond_resched() is not an RCU-tasks quiescent state. Use cond_resched_tasks_rcu_qs() so the teardown reports an RCU-tasks quiescent state as it proceeds. Fixes: 9c5f1d30199d ("dcache: move cond_resched() into the end of __dentry_kill()") Cc: stable@vger.kernel.org Signed-off-by: Breno Leitao Link: https://patch.msgid.link/20260918-dcache-task-rcu-qa-v1-1-963ec83e6d0b@debian.org Reviewed-by: Paul E. McKenney Signed-off-by: Christian Brauner (Amutable) --- fs/dcache.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/dcache.c b/fs/dcache.c index 8f17db2724b38..e974d42b03e72 100644 --- a/fs/dcache.c +++ b/fs/dcache.c @@ -843,7 +843,7 @@ static struct dentry *dentry_kill(struct dentry *dentry) if (dentry->d_op && dentry->d_op->d_release) dentry->d_op->d_release(dentry); - cond_resched(); + cond_resched_tasks_rcu_qs(); /* now that it's negative, ->d_parent is stable */ if (!IS_ROOT(dentry)) { parent = dentry->d_parent; -- 2.53.0