From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8C9B5451071; Tue, 18 Aug 2026 10:58:16 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787050696; cv=none; b=ayTrn4nD4QtMNFfs0IeqUaL51nzZA6YTjTLPHiBJkjFM2i2jhzp05SDVCfCGCwqfF4nNt2W8yuQIwD4d2fatfqBKi/ZxftgXAHShjw9CB6G426m20JyHub4pNWkpMFeUVbCUavx9e+08JHmCRYt+wPDKwiizFvMgyPm7/Buvxlk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787050696; c=relaxed/simple; bh=r5NSFB0GQRcWvJS2ZewGRoiQwc0nvL37T45wc6VBUn8=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=HBRck6A9IPKnTQsrvk4WH5CWTQT0nex4IwoKthebvGyz8cph3Jbf/YmMvSGuokgzzvGpN/PCbzZmhvJ5OkOgUS9BRQ+R8z8cRKrmdVRKJxUcwXK5IRHa+ycBwhW6r8OC4ZNT3cGvHNP/kVGqppBIOcccob6ThvarSGIUVhdFCn0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=KJ1OeoLF; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="KJ1OeoLF" Received: by smtp.kernel.org (Postfix) with ESMTPS id 51733C19425; Tue, 18 Aug 2026 10:58:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1787050696; bh=r5NSFB0GQRcWvJS2ZewGRoiQwc0nvL37T45wc6VBUn8=; h=From:Date:Subject:References:In-Reply-To:To:Cc:Reply-To:From; b=KJ1OeoLFx2wSgQU1fwSuiIIoTRtdUPfEoRLP8fryB+EBay7inbBM4JdnTip5uChWq ZCelsd8mZ/5NNrHXuNu/AdHm0GFdLaA2Pq8r3A3o9W6jRwpXJ8ER1v1hjShXWaizWk Qcj7GqRB2O6KQIo/ZbD7JUlunhJXDwtcrO/z6QP9kma4NFVLW6JnqZKClsoDrKEYsY 0UF1e0L3Es5pvbOpAyMtAUAsnlzy+1i2mtJlLtL21GiFlVmeJWptNXgi1a7r7AleDl Uz1MjRvv39PVWdSXagZ+H1nTMaQAQqR9VaIshdWcnJyWX8IeBkHwIZsVvJVN3W2/cS x52M33A8sjApg== Received: from aws-us-west-2-korg-lkml-1.web.codeaurora.org (localhost.localdomain [127.0.0.1]) by smtp.lore.kernel.org (Postfix) with ESMTP id 39D90C5DF81; Tue, 18 Aug 2026 10:58:16 +0000 (UTC) From: Xiubo Li via B4 Relay Date: Tue, 18 Aug 2026 03:58:10 -0700 Subject: [PATCH v5 3/5] ceph: add wait_list_lock for wait-list serialization Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20260818-ceph-mdsc-mutex-optimization-v5-3-7d335a3a1d0b@clyso.com> References: <20260818-ceph-mdsc-mutex-optimization-v5-0-7d335a3a1d0b@clyso.com> In-Reply-To: <20260818-ceph-mdsc-mutex-optimization-v5-0-7d335a3a1d0b@clyso.com> To: Ilya Dryomov , Alex Markuze , Viacheslav Dubeyko Cc: ceph-devel@vger.kernel.org, linux-kernel@vger.kernel.org, Xiubo Li X-Mailer: b4 0.15.2 X-Developer-Signature: v=1; a=ed25519-sha256; t=1787050693; l=4398; i=xiubo.li@clyso.com; s=20260625; h=from:subject:message-id; bh=2KmjEKVQQSocgdYVXOQzPvN7CxFSrsQMZ0Mr/Vn+7cU=; b=cnuhx7/DDxgJUAnEOpAQBR/rfVP4XGtlmU/Ae+wu16+LYeuGLskG888HI7kdjVtc4ybz9ZlJE L90EOZn46qRA1yAz5/x6iyQlaETOWmWvpO8mYunV7hIZrbA++qmPzcu X-Developer-Key: i=xiubo.li@clyso.com; a=ed25519; pk=V3NGr0AgAopiUhaLY51ipBkLN5LlcLhjOEfLEq1RoZ8= X-Endpoint-Received: by B4 Relay for xiubo.li@clyso.com/20260625 with auth_id=840 X-Original-From: Xiubo Li Reply-To: xiubo.li@clyso.com From: Xiubo Li The per-MDS session wait list and the global waiting-for-map list are currently serialized by mdsc->mutex, even though the list operations themselves don't need the mutex's broader protection. Introduce a dedicated spinlock to guard these lists so that waking and kicking waiters can run outside the mutex. Reviewed-by: Viacheslav Dubeyko Signed-off-by: Xiubo Li --- fs/ceph/mds_client.c | 18 +++++++++++++++++- fs/ceph/mds_client.h | 3 +++ 2 files changed, 20 insertions(+), 1 deletion(-) diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c index c1df7e0ac051..f35aa194795e 100644 --- a/fs/ceph/mds_client.c +++ b/fs/ceph/mds_client.c @@ -3619,7 +3619,9 @@ static void __do_request(struct ceph_mds_client *mdsc, doutc(cl, "no mdsmap, waiting for map\n"); trace_ceph_mdsc_suspend_request(mdsc, session, req, ceph_mdsc_suspend_reason_no_mdsmap); + spin_lock(&mdsc->wait_list_lock); list_add(&req->r_wait, &mdsc->waiting_for_map); + spin_unlock(&mdsc->wait_list_lock); return; } if (!(mdsc->fsc->mount_options->flags & @@ -3642,7 +3644,9 @@ static void __do_request(struct ceph_mds_client *mdsc, doutc(cl, "no mds or not active, waiting for map\n"); trace_ceph_mdsc_suspend_request(mdsc, session, req, ceph_mdsc_suspend_reason_no_active_mds); + spin_lock(&mdsc->wait_list_lock); list_add(&req->r_wait, &mdsc->waiting_for_map); + spin_unlock(&mdsc->wait_list_lock); return; } @@ -3690,9 +3694,12 @@ static void __do_request(struct ceph_mds_client *mdsc, if (ceph_test_mount_opt(mdsc->fsc, CLEANRECOVER)) { trace_ceph_mdsc_suspend_request(mdsc, session, req, ceph_mdsc_suspend_reason_rejected); + spin_lock(&mdsc->wait_list_lock); list_add(&req->r_wait, &mdsc->waiting_for_map); - } else + spin_unlock(&mdsc->wait_list_lock); + } else { err = -EACCES; + } goto out_session; } @@ -3707,7 +3714,9 @@ static void __do_request(struct ceph_mds_client *mdsc, } trace_ceph_mdsc_suspend_request(mdsc, session, req, ceph_mdsc_suspend_reason_session); + spin_lock(&mdsc->wait_list_lock); list_add(&req->r_wait, &session->s_waiting); + spin_unlock(&mdsc->wait_list_lock); goto out_session; } @@ -3800,7 +3809,9 @@ static void __wake_requests(struct ceph_mds_client *mdsc, struct ceph_mds_request *req; LIST_HEAD(tmp_list); + spin_lock(&mdsc->wait_list_lock); list_splice_init(head, &tmp_list); + spin_unlock(&mdsc->wait_list_lock); while (!list_empty(&tmp_list)) { req = list_entry(tmp_list.next, @@ -3833,7 +3844,9 @@ static void kick_requests(struct ceph_mds_client *mdsc, int mds) if (req->r_session && req->r_session->s_mds == mds) { doutc(cl, " kicking tid %llu\n", req->r_tid); + spin_lock(&mdsc->wait_list_lock); list_del_init(&req->r_wait); + spin_unlock(&mdsc->wait_list_lock); trace_ceph_mdsc_resume_request(mdsc, req); __do_request(mdsc, req); } @@ -6278,6 +6291,7 @@ int ceph_mdsc_init(struct ceph_fs_client *fsc) mdsc->snap_realms = RB_ROOT; INIT_LIST_HEAD(&mdsc->snap_empty); spin_lock_init(&mdsc->snap_empty_lock); + spin_lock_init(&mdsc->wait_list_lock); xa_init(&mdsc->request_tree); INIT_DELAYED_WORK(&mdsc->delayed_work, delayed_work); mdsc->last_renew_caps = jiffies; @@ -6360,7 +6374,9 @@ static void wait_requests(struct ceph_mds_client *mdsc) mutex_lock(&mdsc->mutex); while ((req = __get_oldest_req(mdsc))) { doutc(cl, "timed out on tid %llu\n", req->r_tid); + spin_lock(&mdsc->wait_list_lock); list_del_init(&req->r_wait); + spin_unlock(&mdsc->wait_list_lock); __unregister_request(mdsc, req); } } diff --git a/fs/ceph/mds_client.h b/fs/ceph/mds_client.h index 976dc9ffac17..19d2eae9da5b 100644 --- a/fs/ceph/mds_client.h +++ b/fs/ceph/mds_client.h @@ -530,6 +530,9 @@ struct ceph_mds_client { struct list_head snap_empty; int num_snap_realms; spinlock_t snap_empty_lock; /* protect snap_empty */ + spinlock_t wait_list_lock; /* protect waiting_for_map + * and s_waiting lists + */ u64 last_tid; /* most recent mds request */ u64 oldest_tid; /* oldest incomplete mds request, -- 2.53.0