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=-16.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,T_DKIMWL_WL_MED,USER_AGENT_GIT, USER_IN_DEF_DKIM_WL 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 538E6C28CC0 for ; Thu, 30 May 2019 00:53:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2A081243B7 for ; Thu, 30 May 2019 00:53:29 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="Ax2EXMsd" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727243AbfE3AxZ (ORCPT ); Wed, 29 May 2019 20:53:25 -0400 Received: from mail-yw1-f73.google.com ([209.85.161.73]:47712 "EHLO mail-yw1-f73.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727194AbfE3AxY (ORCPT ); Wed, 29 May 2019 20:53:24 -0400 Received: by mail-yw1-f73.google.com with SMTP id y18so3911915ywy.14 for ; Wed, 29 May 2019 17:53:23 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=d6X4/k5B5WeQgyIvpn8Af86NqovFLF22qTA1Y2V4Fe8=; b=Ax2EXMsdAnoEHIrqzhP0Cv23VlEaDoSoO1OWqhvxtcuBXmnYYLbiiBAZQlVXUUtGgA i6w+G4d54N8mfV0D6KY3vURUd55d8xA1pwqYEpTzjK68EmxEOCRJVDhq648b4GXT1jGV 3YrMacqCMm6wtkWM9ach4dG7xfETTseNfVw9UM/pxIHth0Ji7tonp1P9tLbqoqqtynbi DiENSJNzIdEipIykCMGLgC1Nz8YKxon3Gno9T6HkP2TBj6bY9GFxNm0etPi64anLqTnl aFpqLIUEQL5Pswsuq9dgOrW+1PKzioUiwtMYbgzR/a96OB4IOOCPkunrKKKeoQnMXWxu 4Y7A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=d6X4/k5B5WeQgyIvpn8Af86NqovFLF22qTA1Y2V4Fe8=; b=iCZLoMm3fldiREIbpjBtJgpUI1Jqfcg/DZ7zcI/0cgdpUy/sPL1N8aewvaxzGnxAcX W9oXnDluKoZC0K8hIBELKAI/6JxQT9prPXL5M8klXcNfO9aF48c5UfK9DFsOZ1WStPWf 1hh8nsysnffjNFqq4FddUYH505Etx1g4xFN0HN+ht+OT9tz3ABfpABEBPM8Z2it9+ca6 c7+lc1xHkOFqNy7nFi4C/1vxOgGiaNoxSd9KviMZ7ujweOAR313q84dw2r7fJ1CyI5QE dywo5IR0w6i4XDjBjTzGq3MYrxJmIbbthzIbtB9xqH3buT1xaxlEJMpS5qvpUFJY/ZOb AnQg== X-Gm-Message-State: APjAAAVSBz/8b0YkaN2OLiPCnj1J3+akNFTeNdvKTLW+/bxZHDv/Kt3t XfuzN5g422rMrIeTKtO4wsStJdwD4Tw= X-Google-Smtp-Source: APXvYqzY+oI/v3047+rLfAdqlDZ9Z79kMZvQRPmWfGPVRdyfWVyQ3mLlfGRyfTAwrOQom+6CDZKVd7elYDo= X-Received: by 2002:a81:300c:: with SMTP id w12mr555304yww.57.1559177603199; Wed, 29 May 2019 17:53:23 -0700 (PDT) Date: Wed, 29 May 2019 17:49:04 -0700 In-Reply-To: <20190530004906.261170-1-drosen@google.com> Message-Id: <20190530004906.261170-3-drosen@google.com> Mime-Version: 1.0 References: <20190530004906.261170-1-drosen@google.com> X-Mailer: git-send-email 2.22.0.rc1.257.g3120a18244-goog Subject: [PATCH v3 2/4] f2fs: Fix root reserved on remount From: Daniel Rosenberg To: Jaegeuk Kim , Chao Yu , Jonathan Corbet , linux-f2fs-devel@lists.sourceforge.net Cc: linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-fsdevel@vger.kernel.org, kernel-team@android.com, Daniel Rosenberg Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On a remount, you can currently set root reserved if it was not previously set. This can cause an underflow if reserved has been set to a very high value, since then root reserved + current reserved could be greater than user_block_count. inc_valid_block_count later subtracts out these values from user_block_count, causing an underflow. Signed-off-by: Daniel Rosenberg --- fs/f2fs/super.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c index 912e2619d581b..359fd68509d16 100644 --- a/fs/f2fs/super.c +++ b/fs/f2fs/super.c @@ -213,7 +213,8 @@ void f2fs_msg(struct super_block *sb, const char *level, const char *fmt, ...) static inline void limit_reserve_root(struct f2fs_sb_info *sbi) { - block_t limit = (sbi->user_block_count << 1) / 1000; + block_t limit = min((sbi->user_block_count << 1) / 1000, + sbi->user_block_count - sbi->reserved_blocks); /* limit is 0.2% */ if (test_opt(sbi, RESERVE_ROOT) && -- 2.22.0.rc1.257.g3120a18244-goog