From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on archive.lwn.net X-Spam-Level: X-Spam-Status: No, score=-13.6 required=5.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI,SPF_HELO_NONE,SPF_NONE,T_DKIMWL_WL_MED, USER_IN_DEF_DKIM_WL autolearn=unavailable autolearn_force=no version=3.4.2 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by archive.lwn.net (Postfix) with ESMTP id 97FF17D2EF for ; Thu, 30 May 2019 00:53:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727253AbfE3Ax2 (ORCPT ); Wed, 29 May 2019 20:53:28 -0400 Received: from mail-qt1-f201.google.com ([209.85.160.201]:40923 "EHLO mail-qt1-f201.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727248AbfE3Ax1 (ORCPT ); Wed, 29 May 2019 20:53:27 -0400 Received: by mail-qt1-f201.google.com with SMTP id 37so3531866qtc.7 for ; Wed, 29 May 2019 17:53:26 -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=pFDT61UYE6+362eUPJJuMi+49iBrHpoUZVksNkDJA2o=; b=tq0C+xLpxnScJrE7KGvLRNW1EvyW7w8fxZLYhMG38iqb6B65iu+pJNUwkSmSw9Wsl3 /9PNywbClVW9JA9DR/Dh1tSwsF6mMdgLrRvRMdWic+A+8I5sxRkeLEB1Ob2MAWWJm9jL 6ev53ORFgvokwK4cHk17Y7Ckh2RQmG74ba2tYgemlhSg7VkheKlADWDbsqwFIwOUSizD ZYBWe2VO+7gH+pPgHLcdOlhkOX4cS9lzTtfup83L3evOB0ATtVcM/T1mPq4hDcSUF5Uc u/Y86bsvfsu8KvdNmkA/2KSKxTBI0UsTGqIlC4MAGZr2YM/9PfAUtAnGcsXxF7iTVQkS YuCg== 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=pFDT61UYE6+362eUPJJuMi+49iBrHpoUZVksNkDJA2o=; b=GwAfAv7ibIQzV26NPWsOvlD9U2q/7U+SR3tcQQf74ZuHYnsYPkByvXQZVm9DRnr+Ue Pb09Zy0Z4juZ99CPcZgEu/1GmyjitPE9WMIyFWlK3VOYWXUCa5FIIeiYJRKwdW8fphhh f5stnjEoeclzgGMV7HB5kb2UUBFucpIWzIEPFTY089TPjPmKkt++jnIwPZ9mO8Kne1Kf sbZwmS9HikE9S8SMYQpIBi2o7kWEttrr1jPXqLqMu1hm3NI+AGU+BMhx9wcIpZMosMYR uWALub51Nb4yaYySgjIDZLGZd7K27Aur0wvPb+7ccyRJOCkW0M3xA37D4tQ4l60bgtRQ 2phQ== X-Gm-Message-State: APjAAAX1BaqjvBO0helgTb8UqRCdfwj149spG7S39MEsXAvr0pln97Ad 432eejDApPfqr5Wk37l17KAJmb7gg6Q= X-Google-Smtp-Source: APXvYqzdUz6c4pIj7GBI7bppXtBGbR717H7HlhysYDM55NbncVD1VFEeIv2JijSIJKEof8AzW57Fcs/wZys= X-Received: by 2002:a37:660b:: with SMTP id a11mr723548qkc.342.1559177606029; Wed, 29 May 2019 17:53:26 -0700 (PDT) Date: Wed, 29 May 2019 17:49:05 -0700 In-Reply-To: <20190530004906.261170-1-drosen@google.com> Message-Id: <20190530004906.261170-4-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 3/4] f2fs: Fix accounting for unusable blocks 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-doc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org Fixes possible underflows when dealing with unusable blocks. Signed-off-by: Daniel Rosenberg --- fs/f2fs/f2fs.h | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h index 9b3d9977cd1ef..a39cc4ffeb4b1 100644 --- a/fs/f2fs/f2fs.h +++ b/fs/f2fs/f2fs.h @@ -1769,8 +1769,12 @@ static inline int inc_valid_block_count(struct f2fs_sb_info *sbi, if (!__allow_reserved_blocks(sbi, inode, true)) avail_user_block_count -= F2FS_OPTION(sbi).root_reserved_blocks; - if (unlikely(is_sbi_flag_set(sbi, SBI_CP_DISABLED))) - avail_user_block_count -= sbi->unusable_block_count; + if (unlikely(is_sbi_flag_set(sbi, SBI_CP_DISABLED))) { + if (avail_user_block_count > sbi->unusable_block_count) + avail_user_block_count = 0; + else + avail_user_block_count -= sbi->unusable_block_count; + } if (unlikely(sbi->total_valid_block_count > avail_user_block_count)) { diff = sbi->total_valid_block_count - avail_user_block_count; if (diff > *count) @@ -1970,7 +1974,7 @@ static inline int inc_valid_node_count(struct f2fs_sb_info *sbi, struct inode *inode, bool is_inode) { block_t valid_block_count; - unsigned int valid_node_count; + unsigned int valid_node_count, user_block_count; int err; if (is_inode) { @@ -1997,10 +2001,11 @@ static inline int inc_valid_node_count(struct f2fs_sb_info *sbi, if (!__allow_reserved_blocks(sbi, inode, false)) valid_block_count += F2FS_OPTION(sbi).root_reserved_blocks; + user_block_count = sbi->user_block_count; if (unlikely(is_sbi_flag_set(sbi, SBI_CP_DISABLED))) - valid_block_count += sbi->unusable_block_count; + user_block_count -= sbi->unusable_block_count; - if (unlikely(valid_block_count > sbi->user_block_count)) { + if (unlikely(valid_block_count > user_block_count)) { spin_unlock(&sbi->stat_lock); goto enospc; } -- 2.22.0.rc1.257.g3120a18244-goog