From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id F28B241A82 for ; Tue, 14 Nov 2023 15:33:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="CSWHdgjK" Received: from mail-wr1-x436.google.com (mail-wr1-x436.google.com [IPv6:2a00:1450:4864:20::436]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 44EF6D40 for ; Tue, 14 Nov 2023 07:33:37 -0800 (PST) Received: by mail-wr1-x436.google.com with SMTP id ffacd0b85a97d-32da9ef390fso3684517f8f.2 for ; Tue, 14 Nov 2023 07:33:37 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1699976015; x=1700580815; 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=+iUDFGsO/+8YjOBlEcGZTYITE7ntldQEt+ZaUoKpjOc=; b=CSWHdgjKnbuSwcS9rQOYakZ/pvYqBL7wYm/S2DTyS5yZZxmnZplNDNUGZlPFKCSSDA 4nDgXA0FAcn2V8uKgD/WpXSq8QagxfngPZZjTIfIHaqHyk8TxV0Cbw5j6Cm6fDr+bBes gBYYkBzsxeTlExMEnOMC1LAbDanZCAunUUKSdt0aTKqK1/Ryz8mrN8ZpQbCwlYimbs68 U/UozNaFnVzvhRycqySi9vuP3TwK2wg8nMZUSgDOuys6g6y+0AoRIoaFAkT+VWx9IaLu Cx9jFEK6eI301z0InA8XBMcHl5cs66x064MpYGI/gtugRPGPD/TAp3/+tvD6jpfHY8LD Ak+A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1699976015; x=1700580815; 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=+iUDFGsO/+8YjOBlEcGZTYITE7ntldQEt+ZaUoKpjOc=; b=UDhIeCSGy1N7uQ7evP6Ycm3s/Joyaf5qrl6m6qe0c1Ctxz5Sg88BR/YUtgKtUnRUCw SU8RrcEKX7WnILb+UfE3zzi/u7gdtfmLSvHbrbrIL5rqWQCKS7S/K6+AWJPLy5XtFxuW tf9/tOK3xTnRMUa98YMj/Yl695/V7X5N9VB88ViJadGMGfNjfkAe80Oj9M4BX++5Rpxa xaGSfAXLRwZjrb2Co+pr1jTzv83xG6tkCodC2MsLOHhHWqbFxF+jab19zGTc9WNABRKP An6NOGPtB523JuClmVzf/Q7f94/aJAgbjUAg2A7RPbXla37lJhI8wNt6yyw5ZofZU1M3 7wTw== X-Gm-Message-State: AOJu0YzuJaxB2ZlhFrhVwyp5ktyFnW/nmTRfcVa0MSBY/EOfwiqxKp62 Hh0eElR/ay2Kl3w2UVzKKJEnGJ0Q9w0= X-Google-Smtp-Source: AGHT+IHxpld7SgoEEJ9lycz0UhiH9UAOUCT6NXWUm0BX06pwWtPKQzf2QmIQTKAgMkir3Q4AI9aqLw== X-Received: by 2002:adf:f0ce:0:b0:32f:7c6c:aa18 with SMTP id x14-20020adff0ce000000b0032f7c6caa18mr7233461wro.38.1699976015675; Tue, 14 Nov 2023 07:33:35 -0800 (PST) Received: from amir-ThinkPad-T480.lan ([5.29.249.86]) by smtp.gmail.com with ESMTPSA id o9-20020a5d58c9000000b0032d9caeab0fsm8146527wrf.77.2023.11.14.07.33.34 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 14 Nov 2023 07:33:35 -0800 (PST) From: Amir Goldstein To: Christian Brauner Cc: Al Viro , Jan Kara , Jens Axboe , Miklos Szeredi , David Howells , linux-fsdevel@vger.kernel.org Subject: [PATCH 07/15] remap_range: move file_start_write() to after permission hook Date: Tue, 14 Nov 2023 17:33:13 +0200 Message-Id: <20231114153321.1716028-8-amir73il@gmail.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20231114153321.1716028-1-amir73il@gmail.com> References: <20231114153321.1716028-1-amir73il@gmail.com> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit In vfs code, file_start_write() is usually called after the permission hook in rw_verify_area(). vfs_dedupe_file_range_one() is an exception to this rule. In vfs_dedupe_file_range_one(), move file_start_write() to after the the rw_verify_area() checks to make them "start-write-safe". This is needed for fanotify "pre content" events. Signed-off-by: Amir Goldstein --- fs/remap_range.c | 32 +++++++++++++------------------- 1 file changed, 13 insertions(+), 19 deletions(-) diff --git a/fs/remap_range.c b/fs/remap_range.c index 42f79cb2b1b1..de4b09d0ba1d 100644 --- a/fs/remap_range.c +++ b/fs/remap_range.c @@ -445,46 +445,40 @@ loff_t vfs_dedupe_file_range_one(struct file *src_file, loff_t src_pos, WARN_ON_ONCE(remap_flags & ~(REMAP_FILE_DEDUP | REMAP_FILE_CAN_SHORTEN)); - ret = mnt_want_write_file(dst_file); - if (ret) - return ret; - /* * This is redundant if called from vfs_dedupe_file_range(), but other * callers need it and it's not performance sesitive... */ ret = remap_verify_area(src_file, src_pos, len, false); if (ret) - goto out_drop_write; + return ret; ret = remap_verify_area(dst_file, dst_pos, len, true); if (ret) - goto out_drop_write; + return ret; - ret = -EPERM; if (!allow_file_dedupe(dst_file)) - goto out_drop_write; + return -EPERM; - ret = -EXDEV; if (file_inode(src_file)->i_sb != file_inode(dst_file)->i_sb) - goto out_drop_write; + return -EXDEV; - ret = -EISDIR; if (S_ISDIR(file_inode(dst_file)->i_mode)) - goto out_drop_write; + return -EISDIR; - ret = -EINVAL; if (!dst_file->f_op->remap_file_range) - goto out_drop_write; + return -EINVAL; - if (len == 0) { - ret = 0; - goto out_drop_write; - } + if (len == 0) + return 0; + + ret = mnt_want_write_file(dst_file); + if (ret) + return ret; ret = dst_file->f_op->remap_file_range(src_file, src_pos, dst_file, dst_pos, len, remap_flags | REMAP_FILE_DEDUP); -out_drop_write: + mnt_drop_write_file(dst_file); return ret; -- 2.34.1