From patchwork Fri Jan 17 21:25:51 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Josef Bacik X-Patchwork-Id: 11339817 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 A4632186E for ; Fri, 17 Jan 2020 21:27:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8257A2082F for ; Fri, 17 Jan 2020 21:27:05 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=toxicpanda-com.20150623.gappssmtp.com header.i=@toxicpanda-com.20150623.gappssmtp.com header.b="n4ZPV/RY" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729144AbgAQV1D (ORCPT ); Fri, 17 Jan 2020 16:27:03 -0500 Received: from mail-qv1-f68.google.com ([209.85.219.68]:38059 "EHLO mail-qv1-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729117AbgAQV1C (ORCPT ); Fri, 17 Jan 2020 16:27:02 -0500 Received: by mail-qv1-f68.google.com with SMTP id t6so11369906qvs.5 for ; Fri, 17 Jan 2020 13:27:02 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=toxicpanda-com.20150623.gappssmtp.com; s=20150623; h=from:to:subject:date:message-id:in-reply-to:references:mime-version :content-transfer-encoding; bh=v3jy/bucDHb1mxW6er9m37yXCMVg9C8Ly2cHcVVVXag=; b=n4ZPV/RYJdTKBaiTucNLsxCLXe74G1QzIl/TIrx4N2YshpsxqMSnGJ4URh194dZEGa ANB00Qq4eY9Cm0wpafpjv1BVAQmq3PywMB3NEfVe4VOwc6We6c8v7EPZ2SZOak7xyLO3 IR3LJyUYGvYFI342B2DcGyX3VsbfYLE9NB/9/7yR9ur5cK6F/pw9a7XrMf6E7G1dwmHE yH/mSVKeh4Ug1Vy74dXf3kS7ZqITrrsYx5ooJLOLzyKvUPGBr4zf4cncaq48uzgc3w3O qyPJanoNfKZpPJbHBnEoGo9i7ng/CFl7ulRwxifkASmfW9f+q2QyZ0A4di3WxSradvdM m7tg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=v3jy/bucDHb1mxW6er9m37yXCMVg9C8Ly2cHcVVVXag=; b=CpsNTy0Xli4G6d24RfVf1YIBRPn0XpZybweNZUiVuPdug9ZeFqOx9LxMv8NiZvWAIJ xKNhLHy1YJH3YM/03gb45vQ2YqxaQdObww9WsJxxQ/ON0NFxw1qJ9UoDSI0YfqkEEY68 rXIzygNGMiw4KW3Lxt8Z4b1Xd+i+d4H7twy7F8aN90EzHycZKDzgbEp7sVaT7Sjy1VIX ACAccVz5ZyyxvyvYBXyNLBWmfyBIbNn/UsMJIMg31R/xMVnLSPDwGY2HTWpYJ3KorK5g Cye4o11ChCgLwzOJobSqNk6oPX2jbnSEv48zJu46VxzgDxh+Ta4vTHs04TeT3ofngnrr SXIQ== X-Gm-Message-State: APjAAAU9cW2yzkSTvgliN3gZjjhuA+lVOV57f2VhnpIXVCiMsMsWZeN2 ZUHcElvIJOdD3eNt7Y9UU3LBlfrjacxIdg== X-Google-Smtp-Source: APXvYqxIbdLsEXeFfK7zKw34m5iwdL62tQPUxiNt7aLtCA2P1u0l+DAfzoDN26LA9lt213NTdKoabQ== X-Received: by 2002:a0c:c389:: with SMTP id o9mr9980629qvi.232.1579296421486; Fri, 17 Jan 2020 13:27:01 -0800 (PST) Received: from localhost ([107.15.81.208]) by smtp.gmail.com with ESMTPSA id d143sm12425030qke.123.2020.01.17.13.27.00 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 17 Jan 2020 13:27:00 -0800 (PST) From: Josef Bacik To: linux-btrfs@vger.kernel.org, kernel-team@fb.com Subject: [PATCH 32/43] btrfs: hold a ref on the root in get_subvol_name_from_objectid Date: Fri, 17 Jan 2020 16:25:51 -0500 Message-Id: <20200117212602.6737-33-josef@toxicpanda.com> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20200117212602.6737-1-josef@toxicpanda.com> References: <20200117212602.6737-1-josef@toxicpanda.com> MIME-Version: 1.0 Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org We lookup the name of a subvol which means we'll cross into different roots. Hold a ref while we're doing the look ups in the fs_root we're searching. Signed-off-by: Josef Bacik --- fs/btrfs/super.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c index 3118bc01321e..5c3a1b7de6ee 100644 --- a/fs/btrfs/super.c +++ b/fs/btrfs/super.c @@ -1101,6 +1101,10 @@ static char *get_subvol_name_from_objectid(struct btrfs_fs_info *fs_info, ret = PTR_ERR(fs_root); goto err; } + if (!btrfs_grab_fs_root(fs_root)) { + ret = -ENOENT; + goto err; + } /* * Walk up the filesystem tree by inode refs until we hit the @@ -1113,13 +1117,16 @@ static char *get_subvol_name_from_objectid(struct btrfs_fs_info *fs_info, ret = btrfs_search_slot(NULL, fs_root, &key, path, 0, 0); if (ret < 0) { + btrfs_put_fs_root(fs_root); goto err; } else if (ret > 0) { ret = btrfs_previous_item(fs_root, path, dirid, BTRFS_INODE_REF_KEY); if (ret < 0) { + btrfs_put_fs_root(fs_root); goto err; } else if (ret > 0) { + btrfs_put_fs_root(fs_root); ret = -ENOENT; goto err; } @@ -1136,6 +1143,7 @@ static char *get_subvol_name_from_objectid(struct btrfs_fs_info *fs_info, ptr -= len + 1; if (ptr < name) { ret = -ENAMETOOLONG; + btrfs_put_fs_root(fs_root); goto err; } read_extent_buffer(path->nodes[0], ptr + 1, @@ -1143,6 +1151,7 @@ static char *get_subvol_name_from_objectid(struct btrfs_fs_info *fs_info, ptr[0] = '/'; btrfs_release_path(path); } + btrfs_put_fs_root(fs_root); } btrfs_free_path(path);