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[2620:137:e000::1:20]) by mx.google.com with ESMTP id k20-20020a508ad4000000b00461c43d1113si1791922edk.569.2022.11.24.23.14.58; Thu, 24 Nov 2022 23:15:23 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@bytedance-com.20210112.gappssmtp.com header.s=20210112 header.b=Dp9qdYV3; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=bytedance.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229469AbiKYHKh (ORCPT + 99 others); Fri, 25 Nov 2022 02:10:37 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36518 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229455AbiKYHKg (ORCPT ); Fri, 25 Nov 2022 02:10:36 -0500 Received: from mail-pl1-x62a.google.com (mail-pl1-x62a.google.com [IPv6:2607:f8b0:4864:20::62a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 78BC6218A9 for ; Thu, 24 Nov 2022 23:10:35 -0800 (PST) Received: by mail-pl1-x62a.google.com with SMTP id jn7so3214777plb.13 for ; Thu, 24 Nov 2022 23:10:35 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bytedance-com.20210112.gappssmtp.com; s=20210112; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=lpI09D4mWcHJ7/K+doiGSv8YTaJguLCmdZoe5Iuc0aI=; b=Dp9qdYV3Qk2KwfyXvm+XfGzKSUxj0sUur9Ht8R5nXrw3GNf57sNHPQO1lNfJ/yj5ks ixg6x1HISo5F3qibG9UOBzghU/3isXfTPfG4g+x8+xMdBVSY1OHeJ9t7P0Wv9USubbbP UrYZzT5galnrH7u280HXSGOXCA7/cGSIdN+zsa9PPRI1YTjBzgolztLkYZaHENa14AZI dl388W8iHhl+E3sJz1VZq+9TXkYe6QZQKYQlo+rd/gZUP9rbL+X50IlBbFf/3adj1nWA Uan/AzmsYhiABaYo8ywM4yGvKm5k1/C1Br5pVoAxnFPJgKHLqMeUxJU9v0pgG2LvIvW8 cDTA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=lpI09D4mWcHJ7/K+doiGSv8YTaJguLCmdZoe5Iuc0aI=; b=QZnYlzlLpaJkqK6KrRH1qqRYT7M3VKAwtCast3tD8XE4YKE8A2XzgUK/rammUgIjx3 N1FemkMknLvwzRfNNXIBuNM1DTNXLOtXH4u/Z0h84ysPa2pwcOM228EXsbSRWwgj4ZfX rq5fmdZPdhD1JPTKpk0KmYMd2cktwLX5bZkZOfxUvOqdqNJatXd4gqR0cFnGjD74KLND PL8U4QZePsj0XsnN87H9qKjKQxnlkJb/uIl100qGR6lpGkdm8P4mpYIVkKDnTGrjkJkU ltXcPSrA9Lne8QMi1g17SFJoyJMB0AQRkeWqqcjFYVmdFAwo4bXt2na+7mcEQV0jBzoS iHeQ== X-Gm-Message-State: ANoB5pnWQWHmDxM21jyXM+cqxgP758mZqgj2s/uO6m/K4V3xA2rgC+xX P3NXAckm/zXLm5u1gH0IsLw5nA== X-Received: by 2002:a17:902:c611:b0:189:58a6:851d with SMTP id r17-20020a170902c61100b0018958a6851dmr6900338plr.146.1669360234978; Thu, 24 Nov 2022 23:10:34 -0800 (PST) Received: from localhost.localdomain ([139.177.225.238]) by smtp.gmail.com with ESMTPSA id a5-20020a170902710500b0017d97d13b18sm2555352pll.65.2022.11.24.23.10.31 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 24 Nov 2022 23:10:34 -0800 (PST) From: Jiachen Zhang To: "Matthew Wilcox (Oracle)" , Andrew Morton Cc: linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, xieyongji@bytedance.com, Jiachen Zhang Subject: [PATCH] filemap: Fix some misleading comments Date: Fri, 25 Nov 2022 15:09:59 +0800 Message-Id: <20221125070959.49027-1-zhangjiachen.jaycee@bytedance.com> X-Mailer: git-send-email 2.35.1 MIME-Version: 1.0 X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,RCVD_IN_DNSWL_NONE,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1750451380087318798?= X-GMAIL-MSGID: =?utf-8?q?1750451380087318798?= The users of filemap_write_and_wait_range() and file_write_and_wait_range() interfaces should set the lend parameter to LLONG_MAX, rather than -1, to indicate they want to writeback to the very end-of-file, as several kernel code paths are checking the 'wbc->range_end == LLONG_MAX' conditions. Signed-off-by: Jiachen Zhang --- mm/filemap.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/mm/filemap.c b/mm/filemap.c index 65eee6ec1066..c6d066a39425 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -661,7 +661,8 @@ EXPORT_SYMBOL_GPL(filemap_range_has_writeback); * Write out and wait upon file offsets lstart->lend, inclusive. * * Note that @lend is inclusive (describes the last byte to be written) so - * that this function can be used to write to the very end-of-file (end = -1). + * that this function can be used to write to the very end-of-file (@lend = + * LLONG_MAX). * * Return: error status of the address space. */ @@ -758,7 +759,8 @@ EXPORT_SYMBOL(file_check_and_advance_wb_err); * Write out and wait upon file offsets lstart->lend, inclusive. * * Note that @lend is inclusive (describes the last byte to be written) so - * that this function can be used to write to the very end-of-file (end = -1). + * that this function can be used to write to the very end-of-file (@lend = + * LLONG_MAX). * * After writing out and waiting on the data, we check and advance the * f_wb_err cursor to the latest value, and return any errors detected there.