From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B7A62C28D13 for ; Sat, 20 Aug 2022 00:06:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244316AbiHTAGD (ORCPT ); Fri, 19 Aug 2022 20:06:03 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59074 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244099AbiHTAGC (ORCPT ); Fri, 19 Aug 2022 20:06:02 -0400 Received: from mail-pj1-x102b.google.com (mail-pj1-x102b.google.com [IPv6:2607:f8b0:4864:20::102b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C1CCAC57B6; Fri, 19 Aug 2022 17:06:01 -0700 (PDT) Received: by mail-pj1-x102b.google.com with SMTP id r14-20020a17090a4dce00b001faa76931beso8927594pjl.1; Fri, 19 Aug 2022 17:06:01 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:sender:from:to:cc; bh=yC00KE65j+Axy9FPULOY4KYbcVa1VjZuo+YDP6XI95c=; b=RMMBtA5Fx7V8blcknadGehzfeRW+h+ppNKjgIpKLfxTU/cZ1zlbKFM9VPw9VNZkEpG H1iehANPbjI3U5YxKzRq1K0nldERCwzoZywEThoJv5j9Js0MljA/umBi9uimEG0ThlOk 3Qh2gaeXVmDpuASGHyNtPDd+udonwXvnxxSjgnpRxwNk4KDl3WXI9LznxzPUh9ZKRAqp eYQbmSTai3LlBTfUxzW2/ZXOOBMuSFyJ/32q4fqPK8JJeTdSGu4KKqi/JCmtm7cI9EAE 2HH/1jZEmbFhf3mWtRIOOQHcSiLyFs8HH03vzOfumDGrngSjl250GpH84puPCU6XJXmQ WjCg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:sender:x-gm-message-state:from:to:cc; bh=yC00KE65j+Axy9FPULOY4KYbcVa1VjZuo+YDP6XI95c=; b=rxRPPGXg/sw0nYkKyyeNVgiXODHUoCpEaD0imTui4knMQOtjy/DhmBbK12l+XJ81R0 81wrbKFXDefS2Y8tdudPWuXU8jNyRrzfGNWNhHvAB5OM9Bz8DmrtmCLAPWbXiB71NQ55 o/Wm6tHMj6Wk+UETFta4LwcI5m9iHccsaVpnCrO0qi91UF909nMjlANOaxBe0jCAcPpp bMZAA8RF2HBp7oiMyyo5TRTHUhU1PD7Wvhaa91Lg9HoBcT5SXZIFV5siOQ+MyQoIfPf2 PE7zx9jJf2N4f8JITwc7A5aTmI7xIm+BYNJuhOiKOLBefesBP6FCzvMmxpsnZdjbETA6 8NMA== X-Gm-Message-State: ACgBeo2jNUGfjTHectf5Q2+X2/g+uh/oPohXEbL5ZDKKUd890GWtMtsc cmUSuXiWb+hEhZKVeV8vbGA= X-Google-Smtp-Source: AA6agR6uDi3t5sGu/sHmEspJdx7iqNOlWZ5ekNYrNy+qurpUU1ONjj6Q3BdIaqMCdIqsHj4RrHlpBQ== X-Received: by 2002:a17:902:d492:b0:16f:8583:9473 with SMTP id c18-20020a170902d49200b0016f85839473mr10037458plg.103.1660953961038; Fri, 19 Aug 2022 17:06:01 -0700 (PDT) Received: from localhost ([2620:10d:c090:400::5:a2f5]) by smtp.gmail.com with ESMTPSA id y23-20020a17090264d700b0016b81679c1fsm3676888pli.216.2022.08.19.17.05.59 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 19 Aug 2022 17:06:00 -0700 (PDT) Sender: Tejun Heo From: Tejun Heo To: Greg Kroah-Hartman Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, Chengming Zhou , Johannes Weiner , Imran Khan , kernel-team@fb.com Subject: [PATCHSET for-6.1] kernfs, cgroup: implement kernfs_deactivate() and cgroup_file_show() Date: Fri, 19 Aug 2022 14:05:44 -1000 Message-Id: <20220820000550.367085-1-tj@kernel.org> X-Mailer: git-send-email 2.37.2 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Hello, Currently, deactivated kernfs nodes are used for two purposes - during removal to kill and drain nodes and during creation to make multiple kernfs_nodes creations to succeed or fail as a group. This patchset make kernfs [de]activation generic so that it can be used anytime to deactivate (hide and drain) and activate (show) kernfs nodes, and, on top, implement cgroup_file_show() which allows toggling cgroup file visiblity. This is for the following pending patchset to allow disabling PSI on per-cgroup basis: https://lore.kernel.org/all/20220808110341.15799-1-zhouchengming@bytedance.com/t/#u which requires hiding the corresponding cgroup interface files while disabled. This patchset contains the following seven patches. 0001-kernfs-Simply-by-replacing-kernfs_deref_open_node-wi.patch 0002-kernfs-Drop-unnecessary-mutex-local-variable-initial.patch 0003-kernfs-Refactor-kernfs_get_open_node.patch 0004-kernfs-Skip-kernfs_drain_open_files-more-aggressivel.patch 0005-kernfs-Make-kernfs_drain-skip-draining-more-aggressi.patch 0006-kernfs-Allow-kernfs-nodes-to-be-deactivated-and-re-a.patch 0007-cgroup-Implement-cgroup_file_show.patch 0001-0003 are misc prep patches. 0004-0006 implement kernsf_deactivate(). 0008 implements cgroup_file_show() on top. The patches are also available in the following git branch: git://git.kernel.org/pub/scm/linux/kernel/git/tj/misc.git kernfs-deactivate diffstat follows. Thanks. fs/kernfs/dir.c | 120 +++++++++++++++++++++++++++++++++++++++++------------------- fs/kernfs/file.c | 139 +++++++++++++++++++++++++++++++--------------------------------------- fs/kernfs/kernfs-internal.h | 1 include/linux/cgroup.h | 1 include/linux/kernfs.h | 2 + kernel/cgroup/cgroup.c | 23 +++++++++++ 6 files changed, 172 insertions(+), 114 deletions(-) -- tejun