From patchwork Mon Oct 18 23:59:47 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: 12568355 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id ADA13C4332F for ; Tue, 19 Oct 2021 00:00:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9312661212 for ; Tue, 19 Oct 2021 00:00:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233591AbhJSADD (ORCPT ); Mon, 18 Oct 2021 20:03:03 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37728 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229529AbhJSADC (ORCPT ); Mon, 18 Oct 2021 20:03:02 -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 0EDBDC06161C; Mon, 18 Oct 2021 17:00:51 -0700 (PDT) Received: from localhost (unknown [IPv6:2804:14c:124:8a08::1007]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) (Authenticated sender: krisman) by bhuna.collabora.co.uk (Postfix) with ESMTPSA id 8704A1F41A9C; Tue, 19 Oct 2021 01:00:49 +0100 (BST) From: Gabriel Krisman Bertazi To: jack@suse.com, amir73il@gmail.com Cc: djwong@kernel.org, tytso@mit.edu, david@fromorbit.com, dhowells@redhat.com, khazhy@google.com, linux-fsdevel@vger.kernel.org, linux-ext4@vger.kernel.org, linux-api@vger.kernel.org, Gabriel Krisman Bertazi , kernel@collabora.com, Jan Kara Subject: [PATCH v8 04/32] fsnotify: Don't insert unmergeable events in hashtable Date: Mon, 18 Oct 2021 20:59:47 -0300 Message-Id: <20211019000015.1666608-5-krisman@collabora.com> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20211019000015.1666608-1-krisman@collabora.com> References: <20211019000015.1666608-1-krisman@collabora.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Some events, like the overflow event, are not mergeable, so they are not hashed. But, when failing inside fsnotify_add_event for lack of space, fsnotify_add_event() still calls the insert hook, which adds the overflow event to the merge list. Add a check to prevent any kind of unmergeable event to be inserted in the hashtable. Fixes: 94e00d28a680 ("fsnotify: use hash table for faster events merge") Reviewed-by: Amir Goldstein Reviewed-by: Jan Kara Signed-off-by: Gabriel Krisman Bertazi --- Changes since v2: - Do check for hashed events inside the insert hook (Amir) --- fs/notify/fanotify/fanotify.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/fs/notify/fanotify/fanotify.c b/fs/notify/fanotify/fanotify.c index 057abd2cf887..310246f8d3f1 100644 --- a/fs/notify/fanotify/fanotify.c +++ b/fs/notify/fanotify/fanotify.c @@ -702,6 +702,9 @@ static void fanotify_insert_event(struct fsnotify_group *group, assert_spin_locked(&group->notification_lock); + if (!fanotify_is_hashed_event(event->mask)) + return; + pr_debug("%s: group=%p event=%p bucket=%u\n", __func__, group, event, bucket); @@ -779,8 +782,7 @@ static int fanotify_handle_event(struct fsnotify_group *group, u32 mask, fsn_event = &event->fse; ret = fsnotify_add_event(group, fsn_event, fanotify_merge, - fanotify_is_hashed_event(mask) ? - fanotify_insert_event : NULL); + fanotify_insert_event); if (ret) { /* Permission events shouldn't be merged */ BUG_ON(ret == 1 && mask & FANOTIFY_PERM_EVENTS);