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=-7.0 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS autolearn=ham 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 D701FC43381 for ; Mon, 4 Mar 2019 07:22:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9D69620863 for ; Mon, 4 Mar 2019 07:22:55 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=javigon-com.20150623.gappssmtp.com header.i=@javigon-com.20150623.gappssmtp.com header.b="vl/O09A8" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725550AbfCDHWz (ORCPT ); Mon, 4 Mar 2019 02:22:55 -0500 Received: from mail-ed1-f67.google.com ([209.85.208.67]:38926 "EHLO mail-ed1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725938AbfCDHWz (ORCPT ); Mon, 4 Mar 2019 02:22:55 -0500 Received: by mail-ed1-f67.google.com with SMTP id p27so3352782edc.6 for ; Sun, 03 Mar 2019 23:22:53 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=javigon-com.20150623.gappssmtp.com; s=20150623; h=from:message-id:mime-version:subject:date:in-reply-to:cc:to :references; bh=e8qR4ZuQcKIWGKRrDBfFTVdpX4pv3vVLyIjiZIVM3EM=; b=vl/O09A8a01r7RdRJq2HOeYQpH6EpLA6daum9Yhh4abfE6LvJn5LnO2GFFIX69ewfc XI15hTb7IcO8066PEkzpX010HVzqIAQpVZOZ9SX5+DkUiG+oNGo620y09KEoVhAaHdGd OiE4jFIqb+9D5MZzpI6BeTk+X/DtJhWksaoMowAp+KQKHbZnodZpCQy7riGfOI0XVZ38 HJVQBtC0Vh7uUxAR7Q9eqSBbLOiTyyMdtHmSxHZ2AsU+Sk0iTBGF2Ut8rx5sZA/ajNVW hErSffOfIKy+GxmLgnYN3MncERGlnZ9c12++lCwKDCTeUJgREx751dRGcrwnsyfb78SO 5IIA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:message-id:mime-version:subject:date :in-reply-to:cc:to:references; bh=e8qR4ZuQcKIWGKRrDBfFTVdpX4pv3vVLyIjiZIVM3EM=; b=SWTKuZpe8wgm2NlvoFKRJtCIezxXwttBihAEldAnVSEXOSIcXLDul5/FJN2BoPfZY2 dVNeyHKcwTidO4h1mk2ei+B/O1zzkLjbHnVG9jUhDfTiQKqaNKYGSUI67gkSuxGMDGzb 4VLR6c5ZMRkydyGM9TTfqeJ+QSZ0Lj3y48cgmZgYSZLlgrD4yq5pEyPU5s26LAugbwaX NreK4qUwYYrTBINHHPnZJxRT0fwctbEDLOUtUrpin+cnNW8e8ZWh/EQ9tGVq8LKaYwbZ NC5xKy6LWdfXD0RG+HkeNoH+lVTPm53dN9I5y1i9wM2XfGOIHZ4VpxcqDM23l6ho+2yQ YD3g== X-Gm-Message-State: APjAAAUg58pupmpKBeHvpUYyQ3vIM17qQvCbe9q2+Rsgi1mgDiE/7y1D VFMBQ30womKwS81sQDbWOdPTmg== X-Google-Smtp-Source: APXvYqzeaZ+DbaKzxO9e6vFCL4H6UF5EHHKe6nX3/HMiZZ0kTMXhUxEzh3veUM10mAtb4FxDyUjRig== X-Received: by 2002:a17:906:b350:: with SMTP id cd16mr11802303ejb.203.1551684172513; Sun, 03 Mar 2019 23:22:52 -0800 (PST) Received: from [192.168.1.119] (ip-5-186-122-168.cgn.fibianet.dk. [5.186.122.168]) by smtp.gmail.com with ESMTPSA id b5sm1028034eju.74.2019.03.03.23.22.51 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sun, 03 Mar 2019 23:22:51 -0800 (PST) From: =?utf-8?Q?Javier_Gonz=C3=A1lez?= Message-Id: <4D377F9A-B347-43B1-B5BA-1F89B2631BDA@javigon.com> Content-Type: multipart/signed; boundary="Apple-Mail=_01288DA7-6091-4059-8D7E-CBCE0E287C65"; protocol="application/pgp-signature"; micalg=pgp-sha256 Mime-Version: 1.0 (Mac OS X Mail 12.2 \(3445.102.3\)) Subject: Re: [PATCH 03/13] lightnvm: pblk: Fix put line back behaviour Date: Mon, 4 Mar 2019 08:22:50 +0100 In-Reply-To: <20190227171442.11853-4-igor.j.konopko@intel.com> Cc: =?utf-8?Q?Matias_Bj=C3=B8rling?= , Hans Holmberg , linux-block@vger.kernel.org To: "Konopko, Igor J" References: <20190227171442.11853-1-igor.j.konopko@intel.com> <20190227171442.11853-4-igor.j.konopko@intel.com> X-Mailer: Apple Mail (2.3445.102.3) Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org --Apple-Mail=_01288DA7-6091-4059-8D7E-CBCE0E287C65 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=utf-8 > On 27 Feb 2019, at 18.14, Igor Konopko = wrote: >=20 > In current implementation of pblk_put_line_back behaviour > there are two cases which are not handled. >=20 > First one is the race condition with __pblk_map_invalidate in > which function we check for line state, which might be closed, > but still not added to any list and thus explode in list_move_tail. > This is due to lack of locking both gc_lock and line lock > in pblk_put_line_back current implementation. >=20 > The second issue is that when we are in that function, line > is not on any list and pblk_line_gc_list might hit the same > gc group and thus not return any move_list. Then our line > will stuck forever unassigned to any list. Simply resetting > gc_list to none will fix that. >=20 > Signed-off-by: Igor Konopko > --- > drivers/lightnvm/pblk-gc.c | 16 ++++++++++------ > 1 file changed, 10 insertions(+), 6 deletions(-) >=20 > diff --git a/drivers/lightnvm/pblk-gc.c b/drivers/lightnvm/pblk-gc.c > index 31fc1339faa8..511ed0d5333c 100644 > --- a/drivers/lightnvm/pblk-gc.c > +++ b/drivers/lightnvm/pblk-gc.c > @@ -64,19 +64,23 @@ static void pblk_put_line_back(struct pblk *pblk, = struct pblk_line *line) > struct pblk_line_mgmt *l_mg =3D &pblk->l_mg; > struct list_head *move_list; >=20 > + spin_lock(&l_mg->gc_lock); > spin_lock(&line->lock); > WARN_ON(line->state !=3D PBLK_LINESTATE_GC); > line->state =3D PBLK_LINESTATE_CLOSED; > trace_pblk_line_state(pblk_disk_name(pblk), line->id, > line->state); > + > + /* We need to reset gc_group in order to ensure that > + * pblk_line_gc_list will return proper move_list > + * since right now current line is not on any of the > + * gc lists. > + */ > + line->gc_group =3D PBLK_LINEGC_NONE; > move_list =3D pblk_line_gc_list(pblk, line); > spin_unlock(&line->lock); > - > - if (move_list) { > - spin_lock(&l_mg->gc_lock); > - list_add_tail(&line->list, move_list); > - spin_unlock(&l_mg->gc_lock); > - } > + list_add_tail(&line->list, move_list); > + spin_unlock(&l_mg->gc_lock); > } >=20 > static void pblk_gc_line_ws(struct work_struct *work) > -- > 2.17.1 This comes back from the time where GC was single threaded - I left out this when reimplementing the locking. Good catch. Please, add a fixes tag for this to be back ported. Reviewed-by: Javier Gonz=C3=A1lez --Apple-Mail=_01288DA7-6091-4059-8D7E-CBCE0E287C65 Content-Transfer-Encoding: 7bit Content-Disposition: attachment; filename=signature.asc Content-Type: application/pgp-signature; name=signature.asc Content-Description: Message signed with OpenPGP -----BEGIN PGP SIGNATURE----- iQIzBAEBCAAdFiEEU1dMZpvMIkj0jATvPEYBfS0leOAFAlx80koACgkQPEYBfS0l eOC/SBAAlFd0cwm/ufVmGWhc6ZQS2EFEAkxsJ1CtpN+hSaZF/RALpaY6fm6apyDV c5gpcRH7hxsrp6Ymhq9u/ta/GlEFnuBFrqhy3z72jN+jF4yQFhfGUkSsozuxeqjS 2fNyackLiLs6nsCMuYycxbvKFs2fW3U0dFsFnAtlykvDwf10yLHlhoCD6yxG7mS8 407V3PsU8mxiEP9iUN+60C8FWQS3yJ/tvtjt8xk+P9kC95YnIZipWh7knmeep2GD C0fAp2IONwrJ9C0QdjE8kRDFebQy4Uf1LhCP6UwaQgNtMQ9apXyRLsDzE+uUe6rA 3XNSGOdJtN+nHuWl01V62tjXepppMmxZVE/sROiLpvtwAD7396IqLRgqYwBiT4S3 iN+rGzOnTo++HBxLs+0LEsonUB3v8Z/tNJrb4HW+pO8If7YVJ+kRRN2KO+pp/2VW HEU/J3BqXjGayxMRAOXyTD9ewEpPInE8kZm+Qhjwe6B9ndpNY3M9GAXJ19vPOWeh 1QIJnU+bLZHrvrssUT18VTLTvvVnY3XtjmMHPcOabbEeTW8/WDUz7B19qUaz3KGF O3xKlTgWMNaDQ6OwZcCo11emTRLXcDxOKV6ihvmYzMZl9fPx5ZbXU+rIjoHFT3Vd kJH+fUCmMCiX65HusE7FekALrqjLMhPOeBYGtA/O7ovKqotfyvA= =xujx -----END PGP SIGNATURE----- --Apple-Mail=_01288DA7-6091-4059-8D7E-CBCE0E287C65--