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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id AE406E68975 for ; Thu, 31 Oct 2024 11:18:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=m5sGiN35PQFL8rUGgMxPhoKpvl3YRPqT1auSO/v+iIc=; b=bNL0f0TIuGK23KpeBZp42CApEZ A84GPrNr9YL92N9IHnhcwAX0KqmamUfHGQMDq+oPldpjxilYeQs9BXxRksxZQjf3C00ZGH0yO2FSa 0sidDqLijMufWTKd02VtrOXcnYHzWZHTeUnNk0lalxb6ucVdA7A/6NAPFrEL4XqvVy1LcIFu7AEhA Kj5q6OvmynHrIDFc2Ob/nzmkjPPd5CkBfBcRI7EOLX211dqqtELZKCg0WdnSwwJjvZ9/goWBOmv8L LSdJiHVyitwp7oatgsT5StsT8AODZxYyFM/xly4c8qDekn8+325t/hdS8gECoRxspwblz6fDT8wx+ r1lMcY+g==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1t6TBq-00000003N96-3QRS; Thu, 31 Oct 2024 11:18:10 +0000 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by bombadil.infradead.org with esmtps (Exim 4.98 #2 (Red Hat Linux)) id 1t6TBn-00000003N7K-1MGf for linux-nvme@lists.infradead.org; Thu, 31 Oct 2024 11:18:09 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1730373485; h=from:from:reply-to:subject:subject: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=m5sGiN35PQFL8rUGgMxPhoKpvl3YRPqT1auSO/v+iIc=; b=Kk+n3/gUyHCm3lxAghMbsO4UyFBmK7vwJl6kFjruXup2CKxcQDIcisCu7eoyka7EVtAkxv TRwnzcGykKg3WQSRfPFg0mrGNpCjhkizhibsLKGodofpM+8ThweMcY2GlsMCtYZRjdLp65 SGN3JXVRP+ZCvWKTv/NJGnyVHR8OWd8= Received: from mx-prod-mc-01.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-195-ovA66PpLPayLORYMYV5Kag-1; Thu, 31 Oct 2024 07:18:00 -0400 X-MC-Unique: ovA66PpLPayLORYMYV5Kag-1 Received: from mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.4]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 8F6221956096; Thu, 31 Oct 2024 11:17:57 +0000 (UTC) Received: from fedora (unknown [10.72.116.94]) by mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 3DB06300018D; Thu, 31 Oct 2024 11:17:49 +0000 (UTC) Date: Thu, 31 Oct 2024 19:17:44 +0800 From: Ming Lei To: Klara Modin Cc: Christoph Hellwig , axboe@kernel.dk, akpm@linux-foundation.org, viro@zeniv.linux.org.uk, dhowells@redhat.com, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, linux-nvme@lists.infradead.org, klara@kasm.eu Subject: Re: [PATCH] iov_iter: don't require contiguous pages in iov_iter_extract_bvec_pages Message-ID: References: <20241024050021.627350-1-hch@lst.de> <2fd45655-9847-44a3-adf3-14ced29abd33@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <2fd45655-9847-44a3-adf3-14ced29abd33@gmail.com> X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.4 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20241031_041807_460276_3F3AB0AA X-CRM114-Status: GOOD ( 35.78 ) X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org On Thu, Oct 31, 2024 at 09:42:32AM +0100, Klara Modin wrote: > On 2024-10-31 01:22, Ming Lei wrote: > > On Thu, Oct 31, 2024 at 08:14:49AM +0800, Ming Lei wrote: > > > On Wed, Oct 30, 2024 at 06:56:48PM +0100, Klara Modin wrote: > > > > Hi, > > > > > > > > On 2024-10-24 07:00, Christoph Hellwig wrote: > > > > > From: Ming Lei > > > > > > > > > > The iov_iter_extract_pages interface allows to return physically > > > > > discontiguous pages, as long as all but the first and last page > > > > > in the array are page aligned and page size. Rewrite > > > > > iov_iter_extract_bvec_pages to take advantage of that instead of only > > > > > returning ranges of physically contiguous pages. > > > > > > > > > > Signed-off-by: Ming Lei > > > > > [hch: minor cleanups, new commit log] > > > > > Signed-off-by: Christoph Hellwig > > > > > > > > With this patch (e4e535bff2bc82bb49a633775f9834beeaa527db in next-20241030), > > > > I'm unable to connect via nvme-tcp with this in the log: > > > > > > > > nvme nvme1: failed to send request -5 > > > > nvme nvme1: Connect command failed: host path error > > > > nvme nvme1: failed to connect queue: 0 ret=880 > > > > > > > > With the patch reverted it works as expected: > > > > > > > > nvme nvme1: creating 24 I/O queues. > > > > nvme nvme1: mapped 24/0/0 default/read/poll queues. > > > > nvme nvme1: new ctrl: NQN > > > > "nqn.2018-06.eu.kasm.int:freenas:backup:parmesan.int.kasm.eu", addr > > > > [2001:0678:0a5c:1204:6245:cbff:fe9c:4f59]:4420, hostnqn: > > > > nqn.2018-06.eu.kasm.int:parmesan > > > > > > I can't reproduce it by running blktest 'nvme_trtype=tcp ./check nvme/' > > > on both next tree & for-6.13/block. > > > > > > Can you collect the following bpftrace log by running the script before > > > connecting to nvme-tcp? > > I didn't seem to get any output from the bpftrace script (I confirmed that I > had the config as you requested, but I'm not very familiar with bpftrace so > I could have done something wrong). I could, however, reproduce the issue in It works for me on Fedora(37, 40). > qemu and added breakpoints on nvmf_connect_io_queue and > iov_iter_extract_pages. The breakpoint on iov_iter_extract_pages got hit > once when running nvme connect: > > (gdb) break nvmf_connect_io_queue > Breakpoint 1 at 0xffffffff81a5d960: file > /home/klara/git/linux/drivers/nvme/host/fabrics.c, line 525. > (gdb) break iov_iter_extract_pages > Breakpoint 2 at 0xffffffff817633b0: file > /home/klara/git/linux/lib/iov_iter.c, line 1900. > (gdb) c > Continuing. > [Switching to Thread 1.1] Wow, debug kernel with gdb, cool! > > Thread 1 hit Breakpoint 2, iov_iter_extract_pages > (i=i@entry=0xffffc900001ebd68, > pages=pages@entry=0xffffc900001ebb08, maxsize=maxsize@entry=72, > maxpages=8, > extraction_flags=extraction_flags@entry=0, > offset0=offset0@entry=0xffffc900001ebb10) > at /home/klara/git/linux/lib/iov_iter.c:1900 > 1900 { > (gdb) print i->count > $5 = 72 > (gdb) print i->iov_offset > $6 = 0 > (gdb) print i->bvec->bv_offset > $7 = 3952 > (gdb) print i->bvec->bv_len > $8 = 72 > (gdb) c > Continuing. > > I didn't hit the breakpoint in nvmf_connect_io_queue, but I instead hit it > if I add it to nvmf_connect_admin_queue. I added this function to the > bpftrace script but that didn't produce any output either. Your kernel config shows all BTF related options are enabled, maybe bpftrace userspace issue? > > > > > And please try the following patch: > > > > diff --git a/lib/iov_iter.c b/lib/iov_iter.c > > index 9fc06f5fb748..c761f6db3cb4 100644 > > --- a/lib/iov_iter.c > > +++ b/lib/iov_iter.c > > @@ -1699,6 +1699,7 @@ static ssize_t iov_iter_extract_bvec_pages(struct iov_iter *i, > > i->bvec++; > > skip = 0; > > } > > + bi.bi_idx = 0; > > bi.bi_size = maxsize + skip; > > bi.bi_bvec_done = skip; > > > > > > Applying this seems to fix the problem. Thanks for the test, and the patch is sent out. thanks, Ming