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 X-Spam-Level: X-Spam-Status: No, score=-11.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,UNPARSEABLE_RELAY,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4B154C433B4 for ; Fri, 21 May 2021 02:42:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2E34A611AB for ; Fri, 21 May 2021 02:42:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232417AbhEUCnW (ORCPT ); Thu, 20 May 2021 22:43:22 -0400 Received: from bhuna.collabora.co.uk ([46.235.227.227]:54832 "EHLO bhuna.collabora.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231681AbhEUCnV (ORCPT ); Thu, 20 May 2021 22:43:21 -0400 Received: from [127.0.0.1] (localhost [127.0.0.1]) (Authenticated sender: krisman) with ESMTPSA id 608271F43D2B From: Gabriel Krisman Bertazi To: amir73il@gmail.com Cc: Gabriel Krisman Bertazi , kernel@collabora.com, "Darrick J . Wong" , Theodore Ts'o , Dave Chinner , jack@suse.com, dhowells@redhat.com, khazhy@google.com, linux-fsdevel@vger.kernel.org, linux-ext4@vger.kernel.org Subject: [PATCH 00/11] File system wide monitoring Date: Thu, 20 May 2021 22:41:23 -0400 Message-Id: <20210521024134.1032503-1-krisman@collabora.com> X-Mailer: git-send-email 2.31.0 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Hi, This series follow up on my previous proposal [1] to support file system wide monitoring. As suggested by Amir, this proposal drops the ring buffer in favor of a single slot associated with each mark. This simplifies a bit the implementation, as you can see in the code. As a reminder, This proposal is limited to an interface for administrators to monitor the health of a file system, instead of a generic inteface for file errors. Therefore, this doesn't solve the problem of writeback errors or the need to watch a specific subtree. In comparison to the previous RFC, this implementation also drops the per-fs data and location, and leave those as future extensions. * Implementation The feature is implemented on top of fanotify, as a new type of fanotify mark, FAN_ERROR, which a file system monitoring tool can register to receive error notifications. When an error occurs a new notification is generated, in addition followed by this info field: - FS generic data: A file system agnostic structure that has a generic error code and identifies the filesystem. Basically, it let's userspace know something happened on a monitored filesystem. Since only the first error is recorded since the last read, this also includes a counter of errors that happened since the last read. * Testing This was tested by watching notifications flowing from an intentionally corrupted filesystem in different places. In addition, other events were watched in an attempt to detect regressions. Is there a specific testsuite for fanotify I should be running? * Patches This patchset is divided as follows: Patch 1 through 5 are refactoring to fsnotify/fanotify in preparation for FS_ERROR/FAN_ERROR; patch 6 and 7 implement the FS_ERROR API for filesystems to report error; patch 8 add support for FAN_ERROR in fanotify; Patch 9 is an example implementation for ext4; patch 10 and 11 provide a sample userspace code and documentation. I also pushed the full series to: https://gitlab.collabora.com/krisman/linux -b fanotify-notifications-single-slot [1] https://lwn.net/Articles/854545/ Cc: Darrick J. Wong Cc: Theodore Ts'o Cc: Dave Chinner Cc: jack@suse.com To: amir73il@gmail.com Cc: dhowells@redhat.com Cc: khazhy@google.com Cc: linux-fsdevel@vger.kernel.org Cc: linux-ext4@vger.kernel.org Gabriel Krisman Bertazi (11): fanotify: Fold event size calculation to its own function fanotify: Split fsid check from other fid mode checks fanotify: Simplify directory sanity check in DFID_NAME mode fanotify: Expose fanotify_mark inotify: Don't force FS_IN_IGNORED fsnotify: Support FS_ERROR event type fsnotify: Introduce helpers to send error_events fanotify: Introduce FAN_ERROR event ext4: Send notifications on error samples: Add fs error monitoring example Documentation: Document the FAN_ERROR event .../admin-guide/filesystem-monitoring.rst | 52 +++++ Documentation/admin-guide/index.rst | 1 + fs/ext4/super.c | 8 + fs/notify/fanotify/fanotify.c | 80 ++++++- fs/notify/fanotify/fanotify.h | 38 +++- fs/notify/fanotify/fanotify_user.c | 213 ++++++++++++++---- fs/notify/inotify/inotify_user.c | 6 +- include/linux/fanotify.h | 6 +- include/linux/fsnotify.h | 13 ++ include/linux/fsnotify_backend.h | 15 +- include/uapi/linux/fanotify.h | 10 + samples/Kconfig | 8 + samples/Makefile | 1 + samples/fanotify/Makefile | 3 + samples/fanotify/fs-monitor.c | 91 ++++++++ 15 files changed, 485 insertions(+), 60 deletions(-) create mode 100644 Documentation/admin-guide/filesystem-monitoring.rst create mode 100644 samples/fanotify/Makefile create mode 100644 samples/fanotify/fs-monitor.c -- 2.31.0