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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 1C296C433E0 for ; Mon, 8 Jun 2020 23:41:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EB4162078D for ; Mon, 8 Jun 2020 23:41:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1591659694; bh=fPVshrlSNTS6fyDkB0RG43f2uaJhun3DjBAjXW6z2rU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=2lduZYEE4XtOZPjjCyCsEqYDfAbV0XNMWZP30m+SCon1LGqEDFLGb+5x/24ttosnC lkezL1d38KyO0HIB52zUw0CHFt3SM6pjuG7tJx2wEtaqU0YqqzBhy3f3EY++2rgijh ZdWcVW7Uc8DrTGrhcTvvB9E1gclZWVfODQmqlkXQ= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731788AbgFHXlb (ORCPT ); Mon, 8 Jun 2020 19:41:31 -0400 Received: from mail.kernel.org ([198.145.29.99]:56090 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731840AbgFHX1l (ORCPT ); Mon, 8 Jun 2020 19:27:41 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 06B2820775; Mon, 8 Jun 2020 23:27:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1591658860; bh=fPVshrlSNTS6fyDkB0RG43f2uaJhun3DjBAjXW6z2rU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=CgDQ5j0GzTcdktmVqvZfHsQb2pMRgKA+UTjuC1oHi6hqwD9XNkH0Q5PUDY7ro74q/ itNXXr9W0Z7US0JXNfkkVJ9FIHIp5ClHp/rsebYtz/vo6YKPuZlowfoXfSxD0xzCIz DmT1uUXHOKZWzLpwpX438ajs7bQhh0MAt79ZFJbI= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Dave Chinner , Dave Chinner , Christoph Hellwig , "Darrick J . Wong" , Sasha Levin , linux-xfs@vger.kernel.org Subject: [PATCH AUTOSEL 4.9 44/50] xfs: gut error handling in xfs_trans_unreserve_and_mod_sb() Date: Mon, 8 Jun 2020 19:26:34 -0400 Message-Id: <20200608232640.3370262-44-sashal@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200608232640.3370262-1-sashal@kernel.org> References: <20200608232640.3370262-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Dave Chinner [ Upstream commit dc3ffbb14060c943469d5e12900db3a60bc3fa64 ] xfs: gut error handling in xfs_trans_unreserve_and_mod_sb() From: Dave Chinner The error handling in xfs_trans_unreserve_and_mod_sb() is largely incorrect - rolling back the changes in the transaction if only one counter underruns makes all the other counters incorrect. We still allow the change to proceed and committing the transaction, except now we have multiple incorrect counters instead of a single underflow. Further, we don't actually report the error to the caller, so this is completely silent except on debug kernels that will assert on failure before we even get to the rollback code. Hence this error handling is broken, untested, and largely unnecessary complexity. Just remove it. Signed-off-by: Dave Chinner Reviewed-by: Christoph Hellwig Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong Signed-off-by: Sasha Levin --- fs/xfs/xfs_trans.c | 163 ++++++--------------------------------------- 1 file changed, 20 insertions(+), 143 deletions(-) diff --git a/fs/xfs/xfs_trans.c b/fs/xfs/xfs_trans.c index a280e126491f..fb208944d77b 100644 --- a/fs/xfs/xfs_trans.c +++ b/fs/xfs/xfs_trans.c @@ -493,57 +493,9 @@ xfs_trans_apply_sb_deltas( sizeof(sbp->sb_frextents) - 1); } -STATIC int -xfs_sb_mod8( - uint8_t *field, - int8_t delta) -{ - int8_t counter = *field; - - counter += delta; - if (counter < 0) { - ASSERT(0); - return -EINVAL; - } - *field = counter; - return 0; -} - -STATIC int -xfs_sb_mod32( - uint32_t *field, - int32_t delta) -{ - int32_t counter = *field; - - counter += delta; - if (counter < 0) { - ASSERT(0); - return -EINVAL; - } - *field = counter; - return 0; -} - -STATIC int -xfs_sb_mod64( - uint64_t *field, - int64_t delta) -{ - int64_t counter = *field; - - counter += delta; - if (counter < 0) { - ASSERT(0); - return -EINVAL; - } - *field = counter; - return 0; -} - /* - * xfs_trans_unreserve_and_mod_sb() is called to release unused reservations - * and apply superblock counter changes to the in-core superblock. The + * xfs_trans_unreserve_and_mod_sb() is called to release unused reservations and + * apply superblock counter changes to the in-core superblock. The * t_res_fdblocks_delta and t_res_frextents_delta fields are explicitly NOT * applied to the in-core superblock. The idea is that that has already been * done. @@ -588,20 +540,17 @@ xfs_trans_unreserve_and_mod_sb( /* apply the per-cpu counters */ if (blkdelta) { error = xfs_mod_fdblocks(mp, blkdelta, rsvd); - if (error) - goto out; + ASSERT(!error); } if (idelta) { error = xfs_mod_icount(mp, idelta); - if (error) - goto out_undo_fdblocks; + ASSERT(!error); } if (ifreedelta) { error = xfs_mod_ifree(mp, ifreedelta); - if (error) - goto out_undo_icount; + ASSERT(!error); } if (rtxdelta == 0 && !(tp->t_flags & XFS_TRANS_SB_DIRTY)) @@ -609,95 +558,23 @@ xfs_trans_unreserve_and_mod_sb( /* apply remaining deltas */ spin_lock(&mp->m_sb_lock); - if (rtxdelta) { - error = xfs_sb_mod64(&mp->m_sb.sb_frextents, rtxdelta); - if (error) - goto out_undo_ifree; - } - - if (tp->t_dblocks_delta != 0) { - error = xfs_sb_mod64(&mp->m_sb.sb_dblocks, tp->t_dblocks_delta); - if (error) - goto out_undo_frextents; - } - if (tp->t_agcount_delta != 0) { - error = xfs_sb_mod32(&mp->m_sb.sb_agcount, tp->t_agcount_delta); - if (error) - goto out_undo_dblocks; - } - if (tp->t_imaxpct_delta != 0) { - error = xfs_sb_mod8(&mp->m_sb.sb_imax_pct, tp->t_imaxpct_delta); - if (error) - goto out_undo_agcount; - } - if (tp->t_rextsize_delta != 0) { - error = xfs_sb_mod32(&mp->m_sb.sb_rextsize, - tp->t_rextsize_delta); - if (error) - goto out_undo_imaxpct; - } - if (tp->t_rbmblocks_delta != 0) { - error = xfs_sb_mod32(&mp->m_sb.sb_rbmblocks, - tp->t_rbmblocks_delta); - if (error) - goto out_undo_rextsize; - } - if (tp->t_rblocks_delta != 0) { - error = xfs_sb_mod64(&mp->m_sb.sb_rblocks, tp->t_rblocks_delta); - if (error) - goto out_undo_rbmblocks; - } - if (tp->t_rextents_delta != 0) { - error = xfs_sb_mod64(&mp->m_sb.sb_rextents, - tp->t_rextents_delta); - if (error) - goto out_undo_rblocks; - } - if (tp->t_rextslog_delta != 0) { - error = xfs_sb_mod8(&mp->m_sb.sb_rextslog, - tp->t_rextslog_delta); - if (error) - goto out_undo_rextents; - } + mp->m_sb.sb_frextents += rtxdelta; + mp->m_sb.sb_dblocks += tp->t_dblocks_delta; + mp->m_sb.sb_agcount += tp->t_agcount_delta; + mp->m_sb.sb_imax_pct += tp->t_imaxpct_delta; + mp->m_sb.sb_rextsize += tp->t_rextsize_delta; + mp->m_sb.sb_rbmblocks += tp->t_rbmblocks_delta; + mp->m_sb.sb_rblocks += tp->t_rblocks_delta; + mp->m_sb.sb_rextents += tp->t_rextents_delta; + mp->m_sb.sb_rextslog += tp->t_rextslog_delta; spin_unlock(&mp->m_sb_lock); - return; -out_undo_rextents: - if (tp->t_rextents_delta) - xfs_sb_mod64(&mp->m_sb.sb_rextents, -tp->t_rextents_delta); -out_undo_rblocks: - if (tp->t_rblocks_delta) - xfs_sb_mod64(&mp->m_sb.sb_rblocks, -tp->t_rblocks_delta); -out_undo_rbmblocks: - if (tp->t_rbmblocks_delta) - xfs_sb_mod32(&mp->m_sb.sb_rbmblocks, -tp->t_rbmblocks_delta); -out_undo_rextsize: - if (tp->t_rextsize_delta) - xfs_sb_mod32(&mp->m_sb.sb_rextsize, -tp->t_rextsize_delta); -out_undo_imaxpct: - if (tp->t_rextsize_delta) - xfs_sb_mod8(&mp->m_sb.sb_imax_pct, -tp->t_imaxpct_delta); -out_undo_agcount: - if (tp->t_agcount_delta) - xfs_sb_mod32(&mp->m_sb.sb_agcount, -tp->t_agcount_delta); -out_undo_dblocks: - if (tp->t_dblocks_delta) - xfs_sb_mod64(&mp->m_sb.sb_dblocks, -tp->t_dblocks_delta); -out_undo_frextents: - if (rtxdelta) - xfs_sb_mod64(&mp->m_sb.sb_frextents, -rtxdelta); -out_undo_ifree: - spin_unlock(&mp->m_sb_lock); - if (ifreedelta) - xfs_mod_ifree(mp, -ifreedelta); -out_undo_icount: - if (idelta) - xfs_mod_icount(mp, -idelta); -out_undo_fdblocks: - if (blkdelta) - xfs_mod_fdblocks(mp, -blkdelta, rsvd); -out: - ASSERT(error == 0); + /* + * Debug checks outside of the spinlock so they don't lock up the + * machine if they fail. + */ + ASSERT(mp->m_sb.sb_imax_pct >= 0); + ASSERT(mp->m_sb.sb_rextslog >= 0); return; } -- 2.25.1