Return-Path: Received: from zeniv.linux.org.uk ([195.92.253.2]:49458 "EHLO ZenIV.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752916AbbGBHuP (ORCPT ); Thu, 2 Jul 2015 03:50:15 -0400 Date: Thu, 2 Jul 2015 08:50:08 +0100 From: Al Viro To: Andrey Ryabinin Cc: Linus Torvalds , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, "Aneesh Kumar K.V" , Eric Van Hensbergen , linux-nfs@vger.kernel.org Subject: Re: running out of tags in 9P (was Re: [git pull] vfs part 2) Message-ID: <20150702075007.GH17109@ZenIV.linux.org.uk> References: <20150701062752.GC17109@ZenIV.linux.org.uk> <55939BE3.6040902@samsung.com> <20150701082753.GD17109@ZenIV.linux.org.uk> <5593A7A0.6050400@samsung.com> <20150701085507.GE17109@ZenIV.linux.org.uk> <5593CE37.4070307@samsung.com> <20150701184408.GF17109@ZenIV.linux.org.uk> <20150702032042.GA32613@ZenIV.linux.org.uk> <20150702041046.GG17109@ZenIV.linux.org.uk> <5594E5EB.4030808@samsung.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <5594E5EB.4030808@samsung.com> Sender: linux-nfs-owner@vger.kernel.org List-ID: On Thu, Jul 02, 2015 at 10:19:07AM +0300, Andrey Ryabinin wrote: > On 07/02/2015 07:10 AM, Al Viro wrote: > >> > >> It should be easy to confirm - in p9_client_prepare_req() add > >> if (WARN_ON_ONCE(tag != (u16)tag)) { > >> p9_idpool_put(tag, c->tagpool); > >> return ERR_PTR(-ENOMEM); > >> } > >> right after > >> tag = p9_idpool_get(c->tagpool); > >> if (tag < 0) > >> return ERR_PTR(-ENOMEM); > >> > >> and see if it triggers. I'm not sure if failing with ENOMEM is the > >> right response (another variant is to sleep there until the pile > >> gets cleaned or until we get killed), and WARN_ON_ONCE() is definitely > >> not for the real work, but it will do for confirming that this is what > >> we are hitting. > > > > Apparently, I'm seeing something else. That WARN_ON_ONCE didn't trigger. While the one in p9_client_write() (on rsize < count) did?