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=-17.2 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=unavailable 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 5BCC2C4320E for ; Thu, 5 Aug 2021 12:06:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3B1FE60E96 for ; Thu, 5 Aug 2021 12:06:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239551AbhHEMGd (ORCPT ); Thu, 5 Aug 2021 08:06:33 -0400 Received: from smtp-out2.suse.de ([195.135.220.29]:52432 "EHLO smtp-out2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239490AbhHEMGc (ORCPT ); Thu, 5 Aug 2021 08:06:32 -0400 Received: from relay2.suse.de (relay2.suse.de [149.44.160.134]) by smtp-out2.suse.de (Postfix) with ESMTP id 8D8332022E; Thu, 5 Aug 2021 12:06:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_rsa; t=1628165177; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=Abu3sivvRCriLg2uUugS/DDlzql2+fIOMsgRHkY6XEc=; b=2gwv6BporHXGnKCHtL+oBTiK3eb0byoDSwI1pBbcZFKha0S8O55ejfWiqB/Yimn/RfKXRz Xk2TX2iasrctzYo+QMS1xGKqJJwu4uveqz2jZYmRnW9x4OzESXbYzeZGTlJyAAWsbdMgEB RuS5e+ExYRbVuM2U0jQzDgpQxZ0UTfc= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_ed25519; t=1628165177; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=Abu3sivvRCriLg2uUugS/DDlzql2+fIOMsgRHkY6XEc=; b=5mVwHDIpb+k0V23CZ1LEZSG9peCA6iGnq7hBhh6flTTCQAPqbiesVJe59p0QecuewOwkaE fmFVznvaN1Oli/Dw== Received: from quack2.suse.cz (unknown [10.163.43.118]) by relay2.suse.de (Postfix) with ESMTP id 6FD96A3B85; Thu, 5 Aug 2021 12:06:17 +0000 (UTC) Received: by quack2.suse.cz (Postfix, from userid 1000) id B23011E1511; Thu, 5 Aug 2021 14:06:11 +0200 (CEST) Date: Thu, 5 Aug 2021 14:06:11 +0200 From: Jan Kara To: Gabriel Krisman Bertazi Cc: jack@suse.com, amir73il@gmail.com, 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, kernel@collabora.com Subject: Re: [PATCH v5 19/23] fanotify: Report fid info for file related file system errors Message-ID: <20210805120611.GK14483@quack2.suse.cz> References: <20210804160612.3575505-1-krisman@collabora.com> <20210804160612.3575505-20-krisman@collabora.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210804160612.3575505-20-krisman@collabora.com> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Wed 04-08-21 12:06:08, Gabriel Krisman Bertazi wrote: > Plumb the pieces to add a FID report to error records. Since all error > event memory must be pre-allocated, we estimate a file handler size and > if it is insuficient, we report an invalid FID and increase the > prediction for the next error slot allocation. > > For errors that don't expose a file handler report it with an invalid > FID. > > Signed-off-by: Gabriel Krisman Bertazi ... > @@ -715,6 +717,31 @@ static void fanotify_insert_error_event(struct fsnotify_group *group, > fee->fae.type = FANOTIFY_EVENT_TYPE_FS_ERROR; > fee->error = report->error; > fee->err_count = 1; > + fee->fsid = fee->sb_mark->fsn_mark.connector->fsid; > + > + /* > + * Error reporting needs to happen in atomic context. If this > + * inode's file handler length is more than we initially > + * predicted, there is nothing better we can do than report the > + * error with a bad file handler. > + */ > + fh_len = fanotify_encode_fh_len(inode); > + if (fh_len > fee->sb_mark->pred_fh_len) { > + pr_warn_ratelimited( > + "FH overflows error event. Drop inode information.\n"); > + /* > + * Update the handler size prediction for the next error > + * event allocation. This reduces the chance of another > + * overflow. > + */ > + fee->sb_mark->pred_fh_len = fh_len; > + > + /* For the current error, ignore the inode information. */ > + inode = NULL; > + fh_len = fanotify_encode_fh_len(NULL); > + } > + > + fanotify_encode_fh(&fee->object_fh, inode, fh_len, NULL, 0); > } I don't think calling fanotify_encode_fh() from under notification_lock is a good practice. It calls into a filesystem and god knows which locks it may need to take to get necessary info... See my reply to patch 18 how we could handle that better. Honza -- Jan Kara SUSE Labs, CR