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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id AA634CCA47E for ; Thu, 9 Jun 2022 10:31:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231238AbiFIKbv (ORCPT ); Thu, 9 Jun 2022 06:31:51 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40168 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233862AbiFIKbt (ORCPT ); Thu, 9 Jun 2022 06:31:49 -0400 Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.220.28]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4411220EE96; Thu, 9 Jun 2022 03:31:48 -0700 (PDT) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id 03B3421E10; Thu, 9 Jun 2022 10:31:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1654770707; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=5I3kwWcGF0sqQZ0z5uVggswDypPeJhM7ZrZj3hd+LuM=; b=J+lNWprMqaVvOo4qdBkM+rsyO8pZRIzH5/O8gextgyxs2+zgc56O9kOvSckmp45i2ks/7B gV/oUe9wBMqqbBsd9f2xVSAyB9/GI3bOonQHhFY4qAanLQ6qIPGIu7E9POfX3xl36qReYe 1yPLc/pyRAtbu8QmrkAT5tiwexJevu0= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1654770707; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=5I3kwWcGF0sqQZ0z5uVggswDypPeJhM7ZrZj3hd+LuM=; b=728j16rk7HcpisXxo5EfqPdVq0i9pNfcbmXXLgkfYoWgFp25immNhPeFwV4aaYLvLe7kJu bxtdtsShUarTZ0DQ== Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id 9437113A8C; Thu, 9 Jun 2022 10:31:46 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id 5TExIRLMoWJgBwAAMHmgww (envelope-from ); Thu, 09 Jun 2022 10:31:46 +0000 Received: from localhost (brahms.olymp [local]) by brahms.olymp (OpenSMTPD) with ESMTPA id f9d9d251; Thu, 9 Jun 2022 10:32:28 +0000 (UTC) Date: Thu, 9 Jun 2022 11:32:28 +0100 From: =?iso-8859-1?Q?Lu=EDs?= Henriques To: Dave Chinner Cc: fstests@vger.kernel.org, Jeff Layton , Xiubo Li , ceph-devel@vger.kernel.org Subject: Re: [PATCH 2/2] src/attr_replace_test: dynamically adjust the max xattr size Message-ID: References: <20220607151513.26347-1-lhenriques@suse.de> <20220607151513.26347-3-lhenriques@suse.de> <20220608002315.GT1098723@dread.disaster.area> <20220608215950.GV1098723@dread.disaster.area> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20220608215950.GV1098723@dread.disaster.area> Precedence: bulk List-ID: X-Mailing-List: fstests@vger.kernel.org On Thu, Jun 09, 2022 at 07:59:50AM +1000, Dave Chinner wrote: > On Wed, Jun 08, 2022 at 10:57:22AM +0100, Luís Henriques wrote: > > On Wed, Jun 08, 2022 at 10:23:15AM +1000, Dave Chinner wrote: > > > On Tue, Jun 07, 2022 at 04:15:13PM +0100, Luís Henriques wrote: > > > > CephFS doesn't had a maximum xattr size. Instead, it imposes a maximum > > > > size for the full set of an inode's xattrs names+values, which by default > > > > is 64K but it can be changed by a cluster admin. > > > > > > > > Test generic/486 started to fail after fixing a ceph bug where this limit > > > > wasn't being imposed. Adjust dynamically the size of the xattr being set > > > > if the error returned is -ENOSPC. > > > > > > Ah, this shouldn't be getting anywhere near the 64kB limit unless > > > ceph is telling userspace it's block size is > 64kB: > > > > > > size = sbuf.st_blksize * 3 / 4; > > > ..... > > > size = MIN(size, XATTR_SIZE_MAX); > > > > Yep, that's exactly what is happening. The cephfs kernel client reports > > here the value that is being used for ceph "object size", which defaults > > to 4M. Hence, we'll set size to XATTR_SIZE_MAX. > > Yikes. This is known to break random applications that size buffers > based on a multiple of sbuf.st_blksize and assume that it is going > to be roughly 4kB. e.g. size a buffer at 1024 * sbuf.st_blksize, > expecting to get a ~4MB buffer, and instead it tries to allocate > a 4GB buffer.... > > > > Regardless, the correct thing to do here is pass the max supported > > > xattr size from the command line (because fstests knows what that it > > > for each filesystem type) rather than hard coding > > > XATTR_SIZE_MAX in the test. > > > > OK, makes sense. But then, for the ceph case, it becomes messy because we > > also need to know the attribute name to compute the maximum size. I guess > > we'll need an extra argument for that too. > > Just pass in a size for ceph that has enough spare space for the > attribute names in it, like for g/020. Don't make it more > complex than it needs to be. Well, in that case it's just easier for attr_replace_test.c to simply set the ceiling to (XATTR_SIZE_MAX - strlen(name+value)). This is because the fstests don't really know anymore the max xattr size for each filesystem type; that knowledge is local to generic/020. The other option is to move that code (back) to common/attr. Cheers, -- Luís