From patchwork Sat Oct 3 05:56:22 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chandan Babu R X-Patchwork-Id: 11815061 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id D87B56CB for ; Sat, 3 Oct 2020 05:56:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BD738206DB for ; Sat, 3 Oct 2020 05:56:49 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="Zes5p3Lc" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725681AbgJCF4t (ORCPT ); Sat, 3 Oct 2020 01:56:49 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56386 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725446AbgJCF4t (ORCPT ); Sat, 3 Oct 2020 01:56:49 -0400 Received: from mail-pg1-x544.google.com (mail-pg1-x544.google.com [IPv6:2607:f8b0:4864:20::544]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 14074C0613D0 for ; Fri, 2 Oct 2020 22:56:49 -0700 (PDT) Received: by mail-pg1-x544.google.com with SMTP id o25so2333689pgm.0 for ; Fri, 02 Oct 2020 22:56:49 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=Xf86IZJ2O3sKEIprAhp2qWm7Jz8QBRKVGV3tBB+AcuY=; b=Zes5p3Lc+TfVvsaBO+U3bSPhZwN1NyTBvNP86tzo1QwtP27p7YdoNzxiiKQuK96w1Z TJPX2klXbE8C0LNF4cwUkUMtkTG+b7l2fgqEIPRMT/r/JTJkN4UCLZRXhL+ShQABK1IK cPMW+oqmZte99qdiYbcp2tzSqreOR4h5Jzq3wMTOMTwIdeGJtiYNKu4+2u28KFqDncqF WYZAiWUJvhyXJLBxVXKL2ucMnnDfEuV+ytxj3c7E1r7mQMmg/paP1sSbSGBbiNhYjBC1 ltEyuqKERfjCtfxlxybLRt3PvxBqMqrZwSJ1aXwULtZlN43V919JHhBT2LWMPV3j3ECH 77bA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=Xf86IZJ2O3sKEIprAhp2qWm7Jz8QBRKVGV3tBB+AcuY=; b=dBumDLIE1JdvXLFQ1KlQbz43UIalb6javuJNgKS/NYqim9gai+v4xeJ/SZ0IvVTiqq 5IGx3WHhwQ6/0AwrJ86QGAnwddK8eZI6c4YqWJNxoJlgf6sGviRfwxoks3Kauwfr03Qk Bl/DuJdCvxjt5nRElsX27I8ZPVQB12yHEoU3xMOcW0vvG0ah/sWdljOy5/GqJlB0waLX zfcr/zTgnjG6r0gFRcHU/OD/slezuEYeKsXQ9TAeBr77wg3hlrMVKZC/RUgjoZGLkcby VzmhJydKR+DU8rqw+MK24hSJ3N9+y1YRItyM5DcJNK4n76bbQ/J1n4x5JxhlGIP2FsjN +ylQ== X-Gm-Message-State: AOAM530cYfacHfmPFOB0+755hgHzzK3J3ZJ8IbbQNuZFpOC8im5t9F/3 YB3TtGhwMylc3BanRm/xpV+P8/84YCs= X-Google-Smtp-Source: ABdhPJzen9JOGAAkE1oEpgv4CReHJ1V06RHPV4GTq6qDbf5eu242M6mvZ1gTQ1vv5c22OTodfwtrdw== X-Received: by 2002:a63:ff4e:: with SMTP id s14mr5244711pgk.137.1601704608123; Fri, 02 Oct 2020 22:56:48 -0700 (PDT) Received: from localhost.localdomain ([122.171.168.96]) by smtp.gmail.com with ESMTPSA id 125sm4106664pff.59.2020.10.02.22.56.46 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 02 Oct 2020 22:56:47 -0700 (PDT) From: Chandan Babu R To: linux-xfs@vger.kernel.org Cc: Chandan Babu R , darrick.wong@oracle.com, david@fromorbit.com Subject: [PATCH V5 01/12] xfs: Add helper for checking per-inode extent count overflow Date: Sat, 3 Oct 2020 11:26:22 +0530 Message-Id: <20201003055633.9379-2-chandanrlinux@gmail.com> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20201003055633.9379-1-chandanrlinux@gmail.com> References: <20201003055633.9379-1-chandanrlinux@gmail.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org XFS does not check for possible overflow of per-inode extent counter fields when adding extents to either data or attr fork. For e.g. 1. Insert 5 million xattrs (each having a value size of 255 bytes) and then delete 50% of them in an alternating manner. 2. On a 4k block sized XFS filesystem instance, the above causes 98511 extents to be created in the attr fork of the inode. xfsaild/loop0 2008 [003] 1475.127209: probe:xfs_inode_to_disk: (ffffffffa43fb6b0) if_nextents=98511 i_ino=131 3. The incore inode fork extent counter is a signed 32-bit quantity. However the on-disk extent counter is an unsigned 16-bit quantity and hence cannot hold 98511 extents. 4. The following incorrect value is stored in the attr extent counter, # xfs_db -f -c 'inode 131' -c 'print core.naextents' /dev/loop0 core.naextents = -32561 This commit adds a new helper function (i.e. xfs_iext_count_may_overflow()) to check for overflow of the per-inode data and xattr extent counters. Future patches will use this function to make sure that an FS operation won't cause the extent counter to overflow. Suggested-by: Darrick J. Wong Reviewed-by: Darrick J. Wong Signed-off-by: Chandan Babu R --- fs/xfs/libxfs/xfs_inode_fork.c | 23 +++++++++++++++++++++++ fs/xfs/libxfs/xfs_inode_fork.h | 2 ++ 2 files changed, 25 insertions(+) diff --git a/fs/xfs/libxfs/xfs_inode_fork.c b/fs/xfs/libxfs/xfs_inode_fork.c index 7575de5cecb1..8d48716547e5 100644 --- a/fs/xfs/libxfs/xfs_inode_fork.c +++ b/fs/xfs/libxfs/xfs_inode_fork.c @@ -23,6 +23,7 @@ #include "xfs_da_btree.h" #include "xfs_dir2_priv.h" #include "xfs_attr_leaf.h" +#include "xfs_types.h" kmem_zone_t *xfs_ifork_zone; @@ -728,3 +729,25 @@ xfs_ifork_verify_local_attr( return 0; } + +int +xfs_iext_count_may_overflow( + struct xfs_inode *ip, + int whichfork, + int nr_to_add) +{ + struct xfs_ifork *ifp = XFS_IFORK_PTR(ip, whichfork); + uint64_t max_exts; + uint64_t nr_exts; + + if (whichfork == XFS_COW_FORK) + return 0; + + max_exts = (whichfork == XFS_ATTR_FORK) ? MAXAEXTNUM : MAXEXTNUM; + + nr_exts = ifp->if_nextents + nr_to_add; + if (nr_exts < ifp->if_nextents || nr_exts > max_exts) + return -EFBIG; + + return 0; +} diff --git a/fs/xfs/libxfs/xfs_inode_fork.h b/fs/xfs/libxfs/xfs_inode_fork.h index a4953e95c4f3..0beb8e2a00be 100644 --- a/fs/xfs/libxfs/xfs_inode_fork.h +++ b/fs/xfs/libxfs/xfs_inode_fork.h @@ -172,5 +172,7 @@ extern void xfs_ifork_init_cow(struct xfs_inode *ip); int xfs_ifork_verify_local_data(struct xfs_inode *ip); int xfs_ifork_verify_local_attr(struct xfs_inode *ip); +int xfs_iext_count_may_overflow(struct xfs_inode *ip, int whichfork, + int nr_to_add); #endif /* __XFS_INODE_FORK_H__ */