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 2D1FDC433EF for ; Tue, 29 Mar 2022 11:07:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235551AbiC2LJQ (ORCPT ); Tue, 29 Mar 2022 07:09:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38670 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235556AbiC2LJJ (ORCPT ); Tue, 29 Mar 2022 07:09:09 -0400 Received: from mail-yb1-xb29.google.com (mail-yb1-xb29.google.com [IPv6:2607:f8b0:4864:20::b29]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C617026107; Tue, 29 Mar 2022 04:07:24 -0700 (PDT) Received: by mail-yb1-xb29.google.com with SMTP id e203so22089219ybc.12; Tue, 29 Mar 2022 04:07:24 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=DKGDPd33h/ATv4J4XO1IkueCMjSvnZm6IMyLd4ES814=; b=EQgZe02QCAY+nUAJ0SZq3XSr76Pwa0LWYCsFzPtNPEsdyZWX/YZDQXl0sSHB56c4mu UE4kMswtjyAVryNti07QpKbb3R3H2/8+iJpY+zesF1diqwsB1PjtZAlv0X2ogJ/TYtmV ncbzf+VY0n2Ik7V5iA+gGXMdr+0bDOenxA6qm5rOoD4iVPtRHkhDFu3m9/Dokcpl7nay YqMLpaV6SrB5vRy+/K4RGymo7BN084l34Fvx18N3s4UaVkgdEfnReJKHmtSndr+E8+jl /yJqU9LmScIWoOW4/H9bZUKxayurvgnunlQWP2Qwnc1st8SRTHRKwIs2QlejtvFxdopG QqnQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=DKGDPd33h/ATv4J4XO1IkueCMjSvnZm6IMyLd4ES814=; b=dyNbvAzCZxwi+eBScWLQj68ZNRI5PbwlcEFR/3TobWN51q8halAgrVXg4R6oz/xpmh xWGuZA73/5/LTXlS4xXfpirZneqin8jXuu+la/cNwhRDVTQQpo4/JCsyxRu8RpLpm7xL 22RLsuq7kiYPowG6//ywHwwUe92ku1RlvGqvOzGtVerUg6Oy8XIVRpPTdS18I+0GuzbT fB92snnBViPdUM6GpJKAUKZwrb6uCnp52NJerZqeFFFzdah2+0HgQ/92eNcTDuG2rlog wkaFrgz0bPcJQzbVZo0IUM/6ifU/Vs7LhonAckxDsz9Xr4io9nlyleQUa4VicKxmDmWy Aydg== X-Gm-Message-State: AOAM533at5PLXlgy18qwzpyVWEioR48UPhiNkPJWLxd+N8OFtjKOjqpu KvQfgKXoXWdILZEvkQM70Y6WZ6TjKzKsMGQ6qbY= X-Google-Smtp-Source: ABdhPJxugplLaRknO6i+6leR0kQkRWR95XOSCEZHfh0swZ29OBN2fFErEAmzySovfJhahdvuW1vYDGkOOxk6pQa42R4= X-Received: by 2002:a5b:906:0:b0:633:93a1:32c4 with SMTP id a6-20020a5b0906000000b0063393a132c4mr26481002ybq.376.1648552043867; Tue, 29 Mar 2022 04:07:23 -0700 (PDT) MIME-Version: 1.0 References: <20220322115148.3870-1-dharamhans87@gmail.com> In-Reply-To: <20220322115148.3870-1-dharamhans87@gmail.com> From: Dharmendra Hans Date: Tue, 29 Mar 2022 16:37:12 +0530 Message-ID: Subject: Re: [PATCH v2 0/2] FUSE: Implement atomic lookup + open To: Miklos Szeredi Cc: linux-fsdevel@vger.kernel.org, fuse-devel , linux-kernel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Mar 22, 2022 at 5:22 PM Dharmendra Singh wrote: > > In FUSE, as of now, uncached lookups are expensive over the wire. > E.g additional latencies and stressing (meta data) servers from > thousands of clients. These lookup calls possibly can be avoided > in some cases. Incoming two patches addresses this issue. > > First patch handles the case where we open first time a file/dir or create > a file (O_CREAT) but do a lookup first on it. After lookup is performed > we make another call into libfuse to open the file. Now these two separate > calls into libfuse can be combined and performed as a single call into > libfuse. > > Second patch handles the case when we are opening an already existing file > (positive dentry). Before this open call, we re-validate the inode and > this re-validation does a lookup on the file and verify the inode. > This separate lookup also can be avoided (for non-dir) and combined > with open call into libfuse. > > Here is the link to the libfuse pull request which implements atomic open > https://github.com/libfuse/libfuse/pull/644 > > I am going to post performance results shortly. > > > Dharmendra Singh (2): > FUSE: Implement atomic lookup + open > FUSE: Avoid lookup in d_revalidate() A gentle reminder to look into the above patch set.