From patchwork Thu Jan 10 17:04:42 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Amir Goldstein X-Patchwork-Id: 10756291 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 6286913B4 for ; Thu, 10 Jan 2019 17:05:16 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 4EA6D29AC2 for ; Thu, 10 Jan 2019 17:05:16 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 42B5E29D01; Thu, 10 Jan 2019 17:05:16 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FROM,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 9A1A629AC2 for ; Thu, 10 Jan 2019 17:05:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729287AbfAJRFP (ORCPT ); Thu, 10 Jan 2019 12:05:15 -0500 Received: from mail-wr1-f67.google.com ([209.85.221.67]:36332 "EHLO mail-wr1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729240AbfAJRFO (ORCPT ); Thu, 10 Jan 2019 12:05:14 -0500 Received: by mail-wr1-f67.google.com with SMTP id u4so12244943wrp.3 for ; Thu, 10 Jan 2019 09:05:13 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=x1LEwPM1Vy7GgRKNCsAauAj9enilOSYNTrekyRKTA90=; b=AH46afFxHo+s5u1pYwdce7yE64mdrBViYx3+K4+gASwFeeoAMTvBVad1eUU/jH9tof E5nydl6DdgtK8kLgmb+SKEIPOQbiG2MMKEAyEFS06js6OB85wp6dd4MgHdT3GnFoVyVv P+NNXbMglwNo5J9LynAZvSSSsxd9dkOCIl89qT/P5DltpMI7wssxMAHQ+al9Oxo+JFig AeTow2Ojr8PQhh9tFZ7G33ZhBOeg9nS8bnlBRgIHT+VtghwJxSPZHmcm2DcEBal1cF3Q 9a35S7mj3QnNmr53J7fDjfTE+fO+mZOuHvgfHPsHQHt3xZ4kAS+ucYKWpBAzgL3z8/RX W4bw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=x1LEwPM1Vy7GgRKNCsAauAj9enilOSYNTrekyRKTA90=; b=PixJhWEs59UerXpv+4SI5qHMq/bQ5enCgvk/1K0TEEZetTlfqBmEmuXZhJjBHsP5Jy OQF5vFkvXey/45x6ZCjzlN9c2UJSL4u75+2vYyaToCslcK9279LwtCLvMkJw2ynn9oRX Vm3PKHLWL/X4+Ha3+b4GhJhbRV6UULcsocla6EJKq+iRU5juLTQz3mo4fTPMAKhWrMFl XEzYMQ3NloUX85Syg2NWr5tnBLgo0sNFY430gJ0RiNRT2Ir9CqULx2W7Lqige+TG/9F/ 3xufXBv8FOz91JqU3F5jxZeML6CrjRByh0xfBL2dgZndnIpKPZCi2TNgUvoHC23aqPH8 xhGg== X-Gm-Message-State: AJcUukdv/uxmt0+Xi/+UsWavrk03ZdsoGoit/vyNfmgu4EFm3OMT6mH8 IZA5hDrj4CldW6B9Iu1RQI8= X-Google-Smtp-Source: ALg8bN7WNbJCL/f9d1/8T5l2pe4HTbnyUIsw6h1nP5JGzxudcP9JxytMWq1oh98QezDN3BTderC7EA== X-Received: by 2002:adf:f785:: with SMTP id q5mr10616959wrp.9.1547139912511; Thu, 10 Jan 2019 09:05:12 -0800 (PST) Received: from amir-VirtualBox.ctera.local ([188.120.129.201]) by smtp.gmail.com with ESMTPSA id m4sm5725868wmi.3.2019.01.10.09.05.11 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 10 Jan 2019 09:05:11 -0800 (PST) From: Amir Goldstein To: Jan Kara Cc: Matthew Bobrowski , linux-fsdevel@vger.kernel.org Subject: [PATCH v5 15/17] fanotify: support events with data type FSNOTIFY_EVENT_INODE Date: Thu, 10 Jan 2019 19:04:42 +0200 Message-Id: <20190110170444.30616-16-amir73il@gmail.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190110170444.30616-1-amir73il@gmail.com> References: <20190110170444.30616-1-amir73il@gmail.com> Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP When event data type is FSNOTIFY_EVENT_INODE, we don't have a refernece to the mount, so we will not be able to open a file descriptor when user reads the event. However, if the listener has enabled reporting file identifier with the FAN_REPORT_FID init flag, we allow reporting those events and we use an identifier inode to encode fid. The inode to use as identifier when reporting fid depends on the event. For dirent modification events, we report the modified directory inode and we report the "victim" inode otherwise. For example: FS_ATTRIB reports the child inode even if reported on a watched parent. FS_CREATE reports the modified dir inode and not the created inode. Signed-off-by: Amir Goldstein --- fs/notify/fanotify/fanotify.c | 67 ++++++++++++++++++++---------- fs/notify/fanotify/fanotify.h | 2 +- fs/notify/fanotify/fanotify_user.c | 3 +- 3 files changed, 48 insertions(+), 24 deletions(-) diff --git a/fs/notify/fanotify/fanotify.c b/fs/notify/fanotify/fanotify.c index fcb98ea99508..e3ca1632feb8 100644 --- a/fs/notify/fanotify/fanotify.c +++ b/fs/notify/fanotify/fanotify.c @@ -96,7 +96,7 @@ static int fanotify_get_response(struct fsnotify_group *group, pr_debug("%s: group=%p event=%p about to return ret=%d\n", __func__, group, event, ret); - + return ret; } @@ -106,9 +106,10 @@ static int fanotify_get_response(struct fsnotify_group *group, * been included within the event mask, but have not been explicitly * requested by the user, will not be present in the returned mask. */ -static u32 fanotify_group_event_mask(struct fsnotify_iter_info *iter_info, - u32 event_mask, const void *data, - int data_type) +static u32 fanotify_group_event_mask(struct fsnotify_group *group, + struct fsnotify_iter_info *iter_info, + u32 event_mask, const void *data, + int data_type) { __u32 marks_mask = 0, marks_ignored_mask = 0; const struct path *path = data; @@ -118,14 +119,14 @@ static u32 fanotify_group_event_mask(struct fsnotify_iter_info *iter_info, pr_debug("%s: report_mask=%x mask=%x data=%p data_type=%d\n", __func__, iter_info->report_mask, event_mask, data, data_type); - /* If we don't have enough info to send an event to userspace say no */ - if (data_type != FSNOTIFY_EVENT_PATH) - return 0; - - /* Sorry, fanotify only gives a damn about files and dirs */ - if (!d_is_reg(path->dentry) && - !d_can_lookup(path->dentry)) + if (data_type == FSNOTIFY_EVENT_PATH) { + /* Path type events are only relevant for files and dirs */ + if (!d_is_reg(path->dentry) && !d_can_lookup(path->dentry)) + return 0; + } else if (!FAN_GROUP_FLAG(group, FAN_REPORT_FID)) { + /* Events without path data require FAN_REPORT_FID */ return 0; + } fsnotify_foreach_obj_type(type) { if (!fsnotify_iter_should_report_type(iter_info, type)) @@ -153,7 +154,7 @@ static u32 fanotify_group_event_mask(struct fsnotify_iter_info *iter_info, } static int fanotify_encode_fid(struct fanotify_event *event, - const struct path *path, gfp_t gfp, + struct inode *inode, gfp_t gfp, __kernel_fsid_t *fsid) { struct fanotify_fid *fid = &event->fid; @@ -166,7 +167,7 @@ static int fanotify_encode_fid(struct fanotify_event *event, fid->ext_fh = NULL; dwords = 0; err = -ENOENT; - type = exportfs_encode_fh(path->dentry, NULL, &dwords, 0); + type = exportfs_encode_inode_fh(inode, NULL, &dwords, NULL); if (!dwords) goto out_err; @@ -179,8 +180,8 @@ static int fanotify_encode_fid(struct fanotify_event *event, goto out_err; } - type = exportfs_encode_fh(path->dentry, fanotify_fid_fh(fid, bytes), - &dwords, 0); + type = exportfs_encode_inode_fh(inode, fanotify_fid_fh(fid, bytes), + &dwords, NULL); err = -EINVAL; if (!type || type == FILEID_INVALID || bytes != dwords << 2) goto out_err; @@ -201,13 +202,34 @@ static int fanotify_encode_fid(struct fanotify_event *event, return FILEID_INVALID; } +/* + * The inode to use as indentifier when reporting fid depends on the event. + * Report the modified directory inode on dirent modification events. + * Report the "victim" inode otherwise. + * For example: + * FS_ATTRIB reports the child inode even if reported on a watched parent. + * FS_CREATE reports the modified dir inode and not the created inode. + */ +static struct inode *fanotify_fid_inode(struct inode *to_tell, u32 event_mask, + const void *data, int data_type) +{ + if (event_mask & ALL_FSNOTIFY_DIRENT_EVENTS) + return to_tell; + else if (data_type == FSNOTIFY_EVENT_INODE) + return (struct inode *)data; + else if (data_type == FSNOTIFY_EVENT_PATH) + return d_inode(((struct path *)data)->dentry); + return NULL; +} + struct fanotify_event *fanotify_alloc_event(struct fsnotify_group *group, struct inode *inode, u32 mask, - const struct path *path, + const void *data, int data_type, __kernel_fsid_t *fsid) { struct fanotify_event *event = NULL; gfp_t gfp = GFP_KERNEL_ACCOUNT; + struct inode *id = fanotify_fid_inode(inode, mask, data, data_type); /* * For queues with unlimited length lost events are not expected and @@ -241,12 +263,12 @@ init: __maybe_unused else event->pid = get_pid(task_tgid(current)); event->fh_len = 0; - if (path && FAN_GROUP_FLAG(group, FAN_REPORT_FID)) { + if (id && FAN_GROUP_FLAG(group, FAN_REPORT_FID)) { /* Report the event without a file identifier on encode error */ - event->fh_type = fanotify_encode_fid(event, path, gfp, fsid); - } else if (path) { + event->fh_type = fanotify_encode_fid(event, id, gfp, fsid); + } else if (data_type == FSNOTIFY_EVENT_PATH) { event->fh_type = FILEID_ROOT; - event->path = *path; + event->path = *((struct path *)data); path_get(&event->path); } else { event->fh_type = FILEID_INVALID; @@ -306,7 +328,8 @@ static int fanotify_handle_event(struct fsnotify_group *group, BUILD_BUG_ON(HWEIGHT32(ALL_FANOTIFY_EVENT_BITS) != 12); - mask = fanotify_group_event_mask(iter_info, mask, data, data_type); + mask = fanotify_group_event_mask(group, iter_info, mask, data, + data_type); if (!mask) return 0; @@ -325,7 +348,7 @@ static int fanotify_handle_event(struct fsnotify_group *group, if (FAN_GROUP_FLAG(group, FAN_REPORT_FID)) fsid = fanotify_get_fsid(iter_info, &__fsid); - event = fanotify_alloc_event(group, inode, mask, data, fsid); + event = fanotify_alloc_event(group, inode, mask, data, data_type, fsid); ret = -ENOMEM; if (unlikely(!event)) { /* diff --git a/fs/notify/fanotify/fanotify.h b/fs/notify/fanotify/fanotify.h index 5b072afa4e19..e84d68c6840a 100644 --- a/fs/notify/fanotify/fanotify.h +++ b/fs/notify/fanotify/fanotify.h @@ -132,5 +132,5 @@ static inline struct fanotify_event *FANOTIFY_E(struct fsnotify_event *fse) struct fanotify_event *fanotify_alloc_event(struct fsnotify_group *group, struct inode *inode, u32 mask, - const struct path *path, + const void *data, int data_type, __kernel_fsid_t *fsid); diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c index 4254bfedb40b..8ac3ebc7b5ed 100644 --- a/fs/notify/fanotify/fanotify_user.c +++ b/fs/notify/fanotify/fanotify_user.c @@ -800,7 +800,8 @@ SYSCALL_DEFINE2(fanotify_init, unsigned int, flags, unsigned int, event_f_flags) atomic_inc(&user->fanotify_listeners); group->memcg = get_mem_cgroup_from_mm(current->mm); - oevent = fanotify_alloc_event(group, NULL, FS_Q_OVERFLOW, NULL, NULL); + oevent = fanotify_alloc_event(group, NULL, FS_Q_OVERFLOW, NULL, + FSNOTIFY_EVENT_NONE, NULL); if (unlikely(!oevent)) { fd = -ENOMEM; goto out_destroy_group;