From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4FB6AC7EE2E for ; Tue, 13 Jun 2023 05:32:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240095AbjFMFcX (ORCPT ); Tue, 13 Jun 2023 01:32:23 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40060 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234080AbjFMFb7 (ORCPT ); Tue, 13 Jun 2023 01:31:59 -0400 Received: from mail-qt1-x82d.google.com (mail-qt1-x82d.google.com [IPv6:2607:f8b0:4864:20::82d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D56A51711 for ; Mon, 12 Jun 2023 22:30:23 -0700 (PDT) Received: by mail-qt1-x82d.google.com with SMTP id d75a77b69052e-3f9e5c011cfso5956321cf.1 for ; Mon, 12 Jun 2023 22:30:23 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1686634222; x=1689226222; h=in-reply-to:subject:cc:to:from:message-id:date:from:to:cc:subject :date:message-id:reply-to; bh=yNjW5QXHksOvUW8JnWDub7KJ4E5HMj8BbaQmIyxgfrw=; b=r/YZLBVLwurP/fJAkMZqoflOpSObZIL8jKFmZWtqXbShyZ8JzC6U78OMf9km8YLwft sz10OVQnxgc5xhWBbOsTFAJysmN9u3oaITdir6KlSagXPA1cJciOhXQeq2b+nFcR06E8 nCZiXxD5/Mdshgjo2PUAsFnDfCKZ2rTArk/3SgtKWQ53gI+3De5i/55tbZLlvXx5sRR7 6xbFZT47w9BjD5muXjyW+6P4LGFBcNX0zAHqeZJGPK/qYqSHzXRrlAlPgMs2ViaN7GeM S0hwgpIFrt0orxrL1XxlrSzwRxNLWJnrmb5yfKqnhB6pqZBSSFi5E/fjZH+grBpzxVl7 aOpg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1686634222; x=1689226222; h=in-reply-to:subject:cc:to:from:message-id:date:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=yNjW5QXHksOvUW8JnWDub7KJ4E5HMj8BbaQmIyxgfrw=; b=V6GNvRhtQ+xh36CY174igIrrKFiovLj2hXmE6L6VW019BXn1ulwSnYq6z9VR7IXPCt 2eJ30+xazoWYJQEIgaM1RqvWLzv+LtvJAEiI337cDg78jNPQimLHLeM8p9/2cl3CdBlq 6kBU25ggBbZh6t+FvA5GCdQA8BwvlGPP8pe71jAe169jR/JYfMNdJeQJELFuOV018bRm A2vGAfJdFmr6P7KELoL7f8Wm+ETVgEVX0xQ3G3I05XeTfUc+Namc00e7LjeKwzHJ5Wyo lv/w8tlrrFkzP4mZTDwvDOZ/3WmKlhzf3gAPKqyMSVrH3n2UbHHAKI9cwW2hohGcN9vE 0yvQ== X-Gm-Message-State: AC+VfDzJknOO2SAiv7uVPiV0pF9lL8JBAZcnuL4RZFum248BnZNFCNX4 k1CWIzl91M/CVjrWt1nTT+7FLt3CcMM= X-Google-Smtp-Source: ACHHUZ4Xies0FPgeC7HwdC4SRr5KoEYohVBvlaJuhYPaIMEv69J0o5w1nzVvJJNThDuqDoDq2aeW2w== X-Received: by 2002:a05:622a:1a25:b0:3f5:c9f:1b27 with SMTP id f37-20020a05622a1a2500b003f50c9f1b27mr15306377qtb.1.1686634222574; Mon, 12 Jun 2023 22:30:22 -0700 (PDT) Received: from dw-tp ([49.207.220.159]) by smtp.gmail.com with ESMTPSA id h13-20020a65518d000000b0053f5ff753e2sm7752483pgq.23.2023.06.12.22.30.20 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 12 Jun 2023 22:30:21 -0700 (PDT) Date: Tue, 13 Jun 2023 11:00:19 +0530 Message-Id: <87wn0853pw.fsf@doe.com> From: Ritesh Harjani (IBM) To: Christoph Hellwig , tytso@mit.edu Cc: linux-ext4@vger.kernel.org Subject: Re: [PATCH] ext4: set FMODE_CAN_ODIRECT instead of a dummy direct_IO method In-Reply-To: <20230612053731.585947-1-hch@lst.de> Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org Christoph Hellwig writes: > Since commit a2ad63daa88b ("VFS: add FMODE_CAN_ODIRECT file flag") file > systems can just set the FMODE_CAN_ODIRECT flag at open time instead of > wiring up a dummy direct_IO method to indicate support for direct I/O. > > Do that for ext4 so that noop_direct_IO can eventually be removed. Looks straight forward change to me. However I got some query... > diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c > index 02de439bf1f04e..b9c1cfa1864779 100644 > --- a/fs/ext4/inode.c > +++ b/fs/ext4/inode.c > @@ -3573,7 +3571,6 @@ static const struct address_space_operations ext4_da_aops = { > .bmap = ext4_bmap, > .invalidate_folio = ext4_invalidate_folio, > .release_folio = ext4_release_folio, > - .direct_IO = noop_direct_IO, > .migrate_folio = buffer_migrate_folio, > .is_partially_uptodate = block_is_partially_uptodate, > .error_remove_page = generic_error_remove_page, > @@ -3582,7 +3579,6 @@ static const struct address_space_operations ext4_da_aops = { > > static const struct address_space_operations ext4_dax_aops = { > .writepages = ext4_dax_writepages, > - .direct_IO = noop_direct_IO, > .dirty_folio = noop_dirty_folio, > .bmap = ext4_bmap, > .swap_activate = ext4_iomap_swap_activate, why do we require .direct_IO function op for any of the dax_aops? IIUC, any inode if it supports DAX i.e. IS_DAX(inode), then it takes the separate path in file read/write iter path. so it should never do ->direct_IO on an inode which supports DAX right? Maybe I am missing something and I will have to check when does ->direct_IO gets called for DAX... ... Or is it due to CONFIG_FS_DAX? e.g. ext4_file_write_iter(struct kiocb *iocb, struct iov_iter *from) { struct inode *inode = file_inode(iocb->ki_filp); if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb)))) return -EIO; #ifdef CONFIG_FS_DAX if (IS_DAX(inode)) return ext4_dax_write_iter(iocb, from); #endif if (iocb->ki_flags & IOCB_DIRECT) return ext4_dio_write_iter(iocb, from); else return ext4_buffered_write_iter(iocb, from); } -ritesh