From patchwork Mon Apr 26 18:41:57 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Gabriel Krisman Bertazi X-Patchwork-Id: 1470449 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=linux-ext4-owner@vger.kernel.org; receiver=) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 4FTYjZ3yWxz9sRf for ; Tue, 27 Apr 2021 04:45:06 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238556AbhDZSpp (ORCPT ); Mon, 26 Apr 2021 14:45:45 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47706 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239459AbhDZSnt (ORCPT ); Mon, 26 Apr 2021 14:43:49 -0400 Received: from bhuna.collabora.co.uk (bhuna.collabora.co.uk [IPv6:2a00:1098:0:82:1000:25:2eeb:e3e3]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2ADADC061760; Mon, 26 Apr 2021 11:43:06 -0700 (PDT) Received: from [127.0.0.1] (localhost [127.0.0.1]) (Authenticated sender: krisman) with ESMTPSA id BC1A81F422DA From: Gabriel Krisman Bertazi To: amir73il@gmail.com, tytso@mit.edu, djwong@kernel.org Cc: david@fromorbit.com, jack@suse.com, dhowells@redhat.com, khazhy@google.com, linux-fsdevel@vger.kernel.org, linux-ext4@vger.kernel.org, Gabriel Krisman Bertazi , kernel@collabora.com Subject: [PATCH RFC 11/15] fanotify: Introduce filesystem specific data record Date: Mon, 26 Apr 2021 14:41:57 -0400 Message-Id: <20210426184201.4177978-12-krisman@collabora.com> X-Mailer: git-send-email 2.31.0 In-Reply-To: <20210426184201.4177978-1-krisman@collabora.com> References: <20210426184201.4177978-1-krisman@collabora.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org Allow a FS_ERROR_TYPE notification to send a filesystem provided blob back to userspace. This is useful for filesystems who want to provide debug information for recovery tools. Signed-off-by: Gabriel Krisman Bertazi --- fs/notify/fanotify/fanotify_user.c | 27 +++++++++++++++++++++++++++ include/uapi/linux/fanotify.h | 10 ++++++++-- 2 files changed, 35 insertions(+), 2 deletions(-) diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c index cb79a4a8e6fb..e2f4599dfc25 100644 --- a/fs/notify/fanotify/fanotify_user.c +++ b/fs/notify/fanotify/fanotify_user.c @@ -69,6 +69,14 @@ static size_t fanotify_error_info_len(struct fanotify_error_event *fee) return sizeof(struct fanotify_event_info_error); } +static size_t fanotify_error_fsdata_len(struct fanotify_error_event *fee) +{ + if (!fee->fs_data_size) + return 0; + + return sizeof(struct fanotify_event_info_fsdata) + fee->fs_data_size; +} + static size_t fanotify_location_info_len(const struct fanotify_event_location *loc) { if (!loc->function) @@ -295,6 +303,25 @@ static size_t copy_location_info_to_user(struct fanotify_event_location *locatio return info.hdr.len; } +static ssize_t copy_error_fsdata_info_to_user(struct fanotify_error_event *fee, + char __user *buf, int count) +{ + struct fanotify_event_info_fsdata info; + + info.hdr.info_type = FAN_EVENT_INFO_TYPE_FSDATA; + info.hdr.len = fanotify_error_fsdata_len(fee); + + if (copy_to_user(buf, &info, sizeof(info))) + return -EFAULT; + + buf += sizeof(info); + + if (copy_to_user(buf, fee->fs_data, fee->fs_data_size)) + return -EFAULT; + + return info.hdr.len; +} + static int copy_info_to_user(__kernel_fsid_t *fsid, struct fanotify_fh *fh, int info_type, const char *name, size_t name_len, char __user *buf, size_t count) diff --git a/include/uapi/linux/fanotify.h b/include/uapi/linux/fanotify.h index 67217756dac9..49808c857ee1 100644 --- a/include/uapi/linux/fanotify.h +++ b/include/uapi/linux/fanotify.h @@ -124,8 +124,9 @@ struct fanotify_event_metadata { #define FAN_EVENT_INFO_TYPE_FID 1 #define FAN_EVENT_INFO_TYPE_DFID_NAME 2 #define FAN_EVENT_INFO_TYPE_DFID 3 -#define FAN_EVENT_INFO_TYPE_ERROR 4 -#define FAN_EVENT_INFO_TYPE_LOCATION 5 +#define FAN_EVENT_INFO_TYPE_LOCATION 4 +#define FAN_EVENT_INFO_TYPE_ERROR 5 +#define FAN_EVENT_INFO_TYPE_FSDATA 6 /* Variable length info record following event metadata */ struct fanotify_event_info_header { @@ -166,6 +167,11 @@ struct fanotify_event_info_location { char function[0]; }; +struct fanotify_event_info_fsdata { + struct fanotify_event_info_header hdr; + char data[0]; +}; + struct fanotify_response { __s32 fd; __u32 response;