From patchwork Wed Jun 27 20:53:01 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Trond Myklebust X-Patchwork-Id: 10492649 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 4A17D60375 for ; Wed, 27 Jun 2018 20:53:26 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 4E64829F93 for ; Wed, 27 Jun 2018 20:53:26 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 40C9A29FE8; Wed, 27 Jun 2018 20:53:26 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.8 required=2.0 tests=BAYES_00, DKIM_ADSP_CUSTOM_MED, DKIM_SIGNED, FREEMAIL_FROM, MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI, T_DKIM_INVALID autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id B7BA029F93 for ; Wed, 27 Jun 2018 20:53:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965010AbeF0UxZ (ORCPT ); Wed, 27 Jun 2018 16:53:25 -0400 Received: from mail-it0-f67.google.com ([209.85.214.67]:39262 "EHLO mail-it0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965026AbeF0UxY (ORCPT ); Wed, 27 Jun 2018 16:53:24 -0400 Received: by mail-it0-f67.google.com with SMTP id p185-v6so9376096itp.4 for ; Wed, 27 Jun 2018 13:53:24 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:subject:date:message-id:mime-version :content-transfer-encoding; bh=bcEri8gqwtEXNketibfugsprw5qImlv/m8T6jR+pP8o=; b=gfnCuOGrVP8htqXCUQ5dUn08zCqqIevRVRUnAdCtYrs0lg+ojYEuCoBhoH4M2Mo1UY TqiPGoFmY6HEpolMKEZsCNOZ2sElMUcZ/Ob7maMx6/3DaIYclv4FACEfXBvQiVD7h/9Q wCfcKqHZQ1PA+P/pg3jQ1DNuemnHP0fU+kAHqNcITZN8vlHKXd2s2ovFhfw8nZHe43cH af3PUQ1Y+llyE44TPZo3MiGfIVtqYWZEzYsYR1TDPyc+2WknJw4/FrqPbQmOn2Zcak2o GziHpXbpY45I94BWHxLiSy+l0yeAXAVcHyWqnA/ycFdRSfPCqm08oFrykajdL07aI9FQ Sz7g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:subject:date:message-id:mime-version :content-transfer-encoding; bh=bcEri8gqwtEXNketibfugsprw5qImlv/m8T6jR+pP8o=; b=mk+f7XKDu6PhdA2O0zu6QOCQFZ2tCMEv6KEDk8EwbPmaILu6NpTRdx5Z7K0JXiuiEx C7do9cuW7MyYK82VibSTnuWxntm5P69kpZm1TiYlACFRPtbBL5GGORFy4kx5oZeFOcfz rH3OMTgDtPjI45cqgLGFVNDfY0r5UWOP66MzoPP3FTpFtb0tHbicBsMy8Qcx85GAKODZ YcFCZNaKgy79vJg944F6r1+ky2VV4J+g8rKsXCgo5I7fzR2bekxLTvwDXD+vh+pRBVgd N4ZKiies1xHYcOsE/2d4xmeJ0gDzM6ek3qxw/kwLVm6eIzIak2SsjfZHi6Lmp+IktZzX 6eEQ== X-Gm-Message-State: APt69E3QzdfKKnoPBOcCxVPZCmuF138TMHAlI6YS8aGHMKKwhePRbw9h jtpXVoJWa0uUzdkvyaOYY9DDnHY= X-Google-Smtp-Source: AAOMgpceaKJMA3fxxhe5aRuAj5XY/QBwL9FlRT23ZlEOvwtceDGwEYqTAzcbTh1WwYBhXbeloAxRLw== X-Received: by 2002:a24:310d:: with SMTP id y13-v6mr5901032ity.122.1530132803472; Wed, 27 Jun 2018 13:53:23 -0700 (PDT) Received: from leira.trondhjem.org.localdomain ([50.105.87.45]) by smtp.gmail.com with ESMTPSA id 16-v6sm2201887itv.19.2018.06.27.13.53.22 for (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Wed, 27 Jun 2018 13:53:22 -0700 (PDT) From: Trond Myklebust X-Google-Original-From: Trond Myklebust To: linux-nfs@vger.kernel.org Subject: [PATCH] NFS: Allow optimisation of lseek(fd, SEEK_CUR, 0) on directories Date: Wed, 27 Jun 2018 16:53:01 -0400 Message-Id: <20180627205301.31401-1-trond.myklebust@hammerspace.com> X-Mailer: git-send-email 2.17.1 MIME-Version: 1.0 Sender: linux-nfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP There should be no need to grab the inode lock if we're only reading the file offset. Signed-off-by: Trond Myklebust --- fs/nfs/dir.c | 26 ++++++++++++++++---------- 1 file changed, 16 insertions(+), 10 deletions(-) diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c index 7a9c14426855..8f8e9e9f2a79 100644 --- a/fs/nfs/dir.c +++ b/fs/nfs/dir.c @@ -904,23 +904,29 @@ static loff_t nfs_llseek_dir(struct file *filp, loff_t offset, int whence) dfprintk(FILE, "NFS: llseek dir(%pD2, %lld, %d)\n", filp, offset, whence); - inode_lock(inode); switch (whence) { - case 1: - offset += filp->f_pos; - case 0: - if (offset >= 0) - break; - default: - offset = -EINVAL; - goto out; + default: + return -EINVAL; + case SEEK_SET: + if (offset < 0) + return -EINVAL; + inode_lock(inode); + break; + case SEEK_CUR: + if (offset == 0) + return filp->f_pos; + inode_lock(inode); + offset += filp->f_pos; + if (offset < 0) { + inode_unlock(inode); + return -EINVAL; + } } if (offset != filp->f_pos) { filp->f_pos = offset; dir_ctx->dir_cookie = 0; dir_ctx->duped = 0; } -out: inode_unlock(inode); return offset; }