From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wolfram Sang Subject: Re: WARNINGs because of ide-proc handling Date: Thu, 2 Sep 2010 23:28:39 +0200 Message-ID: <20100902212839.GA20070@pengutronix.de> References: <20100831205605.GA23636@pengutronix.de> <20100901.193332.77341159.davem@davemloft.net> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="2fHTh5uZTiUOsy+g" Return-path: Received: from metis.ext.pengutronix.de ([92.198.50.35]:36611 "EHLO metis.ext.pengutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753478Ab0IBV2k (ORCPT ); Thu, 2 Sep 2010 17:28:40 -0400 Content-Disposition: inline In-Reply-To: <20100901.193332.77341159.davem@davemloft.net> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: David Miller Cc: linux-ide@vger.kernel.org, Bartlomiej Zolnierkiewicz --2fHTh5uZTiUOsy+g Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, Sep 01, 2010 at 07:33:32PM -0700, David Miller wrote: Adding Bartlomiej to CC, maybe he has something to add :) > From: Wolfram Sang > Date: Tue, 31 Aug 2010 22:56:05 +0200 >=20 > > Hello, > >=20 > > I get the following warning (and some similar ones) on my laptop running > > 2.6.36-rc3 when removing a CF card via pcmcia: > >=20 > > [ 1087.602129] WARNING: at fs/proc/generic.c:816 remove_proc_entry+0x18= 5/0x1d0() > > [ 1087.602137] Hardware name: Amilo M14255 > > [ 1087.602142] name 'cache' > > ... > >=20 > > It turned out that none of the entries in ide_disk_proc[] gets created = when > > inserting the card, so trying to remove them triggers this warning. Add= ing > > some debug printouts >=20 > Hmmm, at some point ide_host_add() or ide_host_register() should be invok= ed, > which should create the drive->proc and hwif->proc PROCFS directories. >=20 > What driver is your pcmcia IDE card using? ide-cs. I did some more debugging and have a function_graph-trace which proves the following callchain: ide_host_add -> ... -> ide_host_register This calls _first_ hwif_register_devices() and only _later_ ide_proc_register_port() and ide_proc_port_register_devices() which are responsible for creating the needed directories. In hwif_register_devices()= , a device gets created and immediately attached to the driver, ide-gd in this case. The probe-function calls disk_ops->setup() which wants to create the proc-entries, but the directories are not there yet. This patch helps, combining two loops and moving hwif_register_devices() to the end: diff --git a/drivers/ide/ide-probe.c b/drivers/ide/ide-probe.c index 4c3d1bf..068cef0 100644 --- a/drivers/ide/ide-probe.c +++ b/drivers/ide/ide-probe.c @@ -1448,19 +1448,13 @@ int ide_host_register(struct ide_host *host, const = struct ide_port_info *d, if (hwif =3D=3D NULL) continue; =20 - if (hwif->present) - hwif_register_devices(hwif); - } - - ide_host_for_each_port(i, hwif, host) { - if (hwif =3D=3D NULL) - continue; - ide_sysfs_register_port(hwif); ide_proc_register_port(hwif); =20 - if (hwif->present) + if (hwif->present) { ide_proc_port_register_devices(hwif); + hwif_register_devices(hwif); + } } =20 return j ? 0 : -1; Dunno, if it is correct, though. The strange thing is that the code is like this for two years and, surprisingly, I don't see the problem with 2.6.33. Also, the proc-entry for my hard-disk is fine. I can't see any suspicious commits in the ide-directory except maybe the BKL pushdown had a side-effect regarding the serialization of the sequence? Ah, too late today to seriously think about such issues... Thanks for the input, Wolfram --=20 Pengutronix e.K. | Wolfram Sang | Industrial Linux Solutions | http://www.pengutronix.de/ | --2fHTh5uZTiUOsy+g Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (GNU/Linux) iEYEARECAAYFAkyAFwcACgkQD27XaX1/VRtl+gCdEU1u9dc7lksP3TZW1ur1srlT ndYAoLrexjqviviGgrTFHw11+EkIc1Lo =7egH -----END PGP SIGNATURE----- --2fHTh5uZTiUOsy+g--