From patchwork Mon Jan 29 15:15:06 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tony Solomonik X-Patchwork-Id: 13535856 Received: from mail-wm1-f41.google.com (mail-wm1-f41.google.com [209.85.128.41]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C55D71534FC for ; Mon, 29 Jan 2024 15:15:16 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.41 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706541318; cv=none; b=A9couu0hudPFiapWa8Elr3VmW/Anjr9WlcNOR/3O/jmr9NhS8oixIOONIqOGff1bAz5msP3xD6leDSkZ48htC3dwrntIY3/v3+l5PKTU9d6IZ6x8C53y83S/FRLhqF5UemEsc4jD9kPzh5mEsMUSKgHtRCg0SvDCsRxX7TXSagE= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706541318; c=relaxed/simple; bh=U7p7DBiwt36LOyfZjNcbX/+PeKY1AyT03L1jkN/LZPI=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=Z3QNM7M70yCNUoS0Rx/UjHz5wBduhq6rFy2o2a/ZJy7R8shHmbUYucemKzMmVYqce4MHStPJRnDPJN4dvIMP6VBFL+jThRhVSylpHnizGe2t3LwGmngO85Ma5nTOVLv9V7yRSDszSwyxkD1Kz7/GPA4+/BR7ORfSDW8iSmivdS0= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=TpYvwfbO; arc=none smtp.client-ip=209.85.128.41 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="TpYvwfbO" Received: by mail-wm1-f41.google.com with SMTP id 5b1f17b1804b1-40e775695c6so25297265e9.3 for ; Mon, 29 Jan 2024 07:15:16 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1706541315; x=1707146115; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=v71HBMYaLKl569swmb2xVX3+a05lKxuFejdDN7gWubU=; b=TpYvwfbOHas0dMlSIajpszsamQ/PvtzM4JfloUhOEvcLV2+QLx7zn02OpM/6i5gxOy kiBBItF78qBg4ZiKX/xxMRrU5AlrjDXRyF+otmzmSFC8E/iZs0rW9fRqQiJaldDJT0Et R5EkM5dp/wP/sHCYNgeoYKD3hAQRuTyX6vr2EYi33jJxQIFeVrJpCb5QcqVZTGYHZF89 knUMC1GlbP8nhkY0RN/gLlTt2IB0hXwxisUOpY8Pqx3kaAdlhv7IEiDL8tK3uqK0zATV rzI5GsvPKfU0YJ9MaaWnvwYGkMW+pfP/qtwFgLEG1Meyp8OGA8y9ql97XA8XzXBb19dL Y33Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1706541315; x=1707146115; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=v71HBMYaLKl569swmb2xVX3+a05lKxuFejdDN7gWubU=; b=WnHF5DhQx11oXFzr95jXelCg5DnUEyEcC3WLiZYPxI7IXsgni3EyXerTbQ+D1lSRkN 94FMidNH2XMhsd64WFMxfjKzZfrDrDxy465pE35i7ZlCO20lrlxWNkYFqTD8odGfyOCA DGlDM27727OAmfzVTZdftlIspwa8rWqNX0l8VpywZoUgIjXyx4OfxqWtZBK7NibGsmAq tVQG8rgQmyMh3NnNFUT/whqaKII6CSMJD3QnMJ9i9WmJJxSKfIAOTHiygjU1j9bBOLFS 3MkGW9mvsPDdhPmS4WdOFi0kX4DJmstbIpHDpnTWftuY+ClESyibPA7X/iilpbcWB0Lv ecuA== X-Gm-Message-State: AOJu0YxebGc0xTj2Zmn4RVzEdjGAvL4BjIfH4Oqi5CE5rqOdok5v+hlw +t21zDETeU4pzNQzr8wq4tbxu1wZuCG01BpnFOQiw9unIbFO7mrc X-Google-Smtp-Source: AGHT+IFHBi0is3gZyF09Tsk9tKmWCYjEVQ/EtrVffTvXjS7+432bJ8oZP/Bri9eYQKfItyFEmYh5Og== X-Received: by 2002:adf:f18d:0:b0:33a:eae4:aaf7 with SMTP id h13-20020adff18d000000b0033aeae4aaf7mr3344009wro.48.1706541314990; Mon, 29 Jan 2024 07:15:14 -0800 (PST) Received: from localhost.localdomain ([147.235.201.119]) by smtp.gmail.com with ESMTPSA id r6-20020adfca86000000b0033aed7423e8sm3060353wrh.11.2024.01.29.07.15.13 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 29 Jan 2024 07:15:14 -0800 (PST) From: Tony Solomonik To: Cc: willy@infradead.org, axboe@kernel.dk, linux-fsdevel@vger.kernel.org, brauner@kernel.org, Tony Solomonik Subject: [PATCH v8 1/2] Add do_ftruncate that truncates a struct file Date: Mon, 29 Jan 2024 17:15:06 +0200 Message-Id: <20240129151507.14885-2-tony.solomonik@gmail.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20240129151507.14885-1-tony.solomonik@gmail.com> References: <20240124083301.8661-1-tony.solomonik@gmail.com> <20240129151507.14885-1-tony.solomonik@gmail.com> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 do_sys_ftruncate receives a file descriptor, fgets the struct file, and finally actually truncates the file. do_ftruncate allows for passing in a file directly, with the caller already holding a reference to it. Signed-off-by: Tony Solomonik Reviewed-by: Matthew Wilcox (Oracle) --- fs/internal.h | 1 + fs/open.c | 52 ++++++++++++++++++++++++++++----------------------- 2 files changed, 30 insertions(+), 23 deletions(-) diff --git a/fs/internal.h b/fs/internal.h index 58e43341aebf..d35b1c05cf6d 100644 --- a/fs/internal.h +++ b/fs/internal.h @@ -182,6 +182,7 @@ extern struct open_how build_open_how(int flags, umode_t mode); extern int build_open_flags(const struct open_how *how, struct open_flags *op); extern struct file *__close_fd_get_file(unsigned int fd); +long do_ftruncate(struct file *file, loff_t length); long do_sys_ftruncate(unsigned int fd, loff_t length, int small); int chmod_common(const struct path *path, umode_t mode); int do_fchownat(int dfd, const char __user *filename, uid_t user, gid_t group, diff --git a/fs/open.c b/fs/open.c index 02dc608d40d8..6d608ff4a3f7 100644 --- a/fs/open.c +++ b/fs/open.c @@ -154,49 +154,55 @@ COMPAT_SYSCALL_DEFINE2(truncate, const char __user *, path, compat_off_t, length } #endif -long do_sys_ftruncate(unsigned int fd, loff_t length, int small) +long do_ftruncate(struct file *file, loff_t length) { struct inode *inode; struct dentry *dentry; + int error; + + dentry = file->f_path.dentry; + inode = dentry->d_inode; + if (!S_ISREG(inode->i_mode) || !(file->f_mode & FMODE_WRITE)) + return -EINVAL; + + /* Check IS_APPEND on real upper inode */ + if (IS_APPEND(file_inode(file))) + return -EPERM; + sb_start_write(inode->i_sb); + error = security_file_truncate(file); + if (!error) + error = do_truncate(file_mnt_idmap(file), dentry, length, + ATTR_MTIME | ATTR_CTIME, file); + sb_end_write(inode->i_sb); + + return error; +} + +long do_sys_ftruncate(unsigned int fd, loff_t length, int small) +{ struct fd f; int error; - error = -EINVAL; if (length < 0) - goto out; - error = -EBADF; + return -EINVAL; f = fdget(fd); if (!f.file) - goto out; + return -EBADF; /* explicitly opened as large or we are on 64-bit box */ if (f.file->f_flags & O_LARGEFILE) small = 0; - dentry = f.file->f_path.dentry; - inode = dentry->d_inode; error = -EINVAL; - if (!S_ISREG(inode->i_mode) || !(f.file->f_mode & FMODE_WRITE)) - goto out_putf; - error = -EINVAL; /* Cannot ftruncate over 2^31 bytes without large file support */ if (small && length > MAX_NON_LFS) - goto out_putf; + goto out; + + error = do_ftruncate(f.file, length); - error = -EPERM; - /* Check IS_APPEND on real upper inode */ - if (IS_APPEND(file_inode(f.file))) - goto out_putf; - sb_start_write(inode->i_sb); - error = security_file_truncate(f.file); - if (!error) - error = do_truncate(file_mnt_idmap(f.file), dentry, length, - ATTR_MTIME | ATTR_CTIME, f.file); - sb_end_write(inode->i_sb); -out_putf: - fdput(f); out: + fdput(f); return error; }