From patchwork Fri Sep 28 15:42:32 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Miklos Szeredi X-Patchwork-Id: 10620125 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 9A38C15A6 for ; Fri, 28 Sep 2018 15:43:06 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 9215628708 for ; Fri, 28 Sep 2018 15:43:06 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 908E3289C6; Fri, 28 Sep 2018 15:43:06 +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=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI 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 241C728708 for ; Fri, 28 Sep 2018 15:43:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729672AbeI1WHL (ORCPT ); Fri, 28 Sep 2018 18:07:11 -0400 Received: from mail-wm1-f68.google.com ([209.85.128.68]:54558 "EHLO mail-wm1-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729623AbeI1WHK (ORCPT ); Fri, 28 Sep 2018 18:07:10 -0400 Received: by mail-wm1-f68.google.com with SMTP id c14-v6so2682879wmb.4 for ; Fri, 28 Sep 2018 08:42:50 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=EDWMFV49gBlH8cSAnLfUF8WzQZs8zpiaL/HwKhmVZBg=; b=hh3DiC0a1DkoDkru9LxpkTWBOxMh2pYtpHq6KIjrX7AWDDag3HDURSdzWDDSMjWtEN xYgdS4bd/BQZG/gGDnYkQNWdE1qweobbojdla3dS8PL1W5CVTLyN4VXluQmLRPH+Yb5i YFF8QfT/bcEbLYCkl44j0igPKXl26UsMAxZjKaG6RR4EhKBVWxkp4OcRyhg3yWCMhWMp 5U39PyvDigVzikUqa2+5Ql8ZQSgFxCVvCfroCDGXrjIY/aiFHqraYhCpmL30bF7bJs4h K+dP351AHyRhAKMt/PInIpZ2+A754NY5GPoa+4eS7o3TGqOtnTA3x79p8nGBh0e7yfYP GWwA== X-Gm-Message-State: ABuFfohS47YTG9soJMMyGtGVmOJHWoih++jFlyhqUZ1NT8U0JEQg86hf zf5YjN9+Qh5p2NOp3t5sy3vVq70J2Nk= X-Google-Smtp-Source: ACcGV61CXP/ZTXQp5KOeK4OpRmrHGGgRFQOm/HuhcNNoli10XSz2du4oMZ/cy5KyF5G7S6reLuQ/pA== X-Received: by 2002:a1c:1745:: with SMTP id 66-v6mr2251532wmx.38.1538149369223; Fri, 28 Sep 2018 08:42:49 -0700 (PDT) Received: from veci.piliscsaba.redhat.com (catv-212-96-48-140.catv.broadband.hu. [212.96.48.140]) by smtp.gmail.com with ESMTPSA id v2-v6sm2009877wme.36.2018.09.28.08.42.47 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Fri, 28 Sep 2018 08:42:48 -0700 (PDT) From: Miklos Szeredi To: linux-fsdevel@vger.kernel.org Cc: linux-kernel@vger.kernel.org Subject: [PATCH 7/9] fuse: use mtime for readdir cache verification Date: Fri, 28 Sep 2018 17:42:32 +0200 Message-Id: <20180928154234.19270-8-mszeredi@redhat.com> X-Mailer: git-send-email 2.14.3 In-Reply-To: <20180928154234.19270-1-mszeredi@redhat.com> References: <20180928154234.19270-1-mszeredi@redhat.com> Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Store the modification time of the directory in the cache, obtained before starting to fill the cache. When reading the cache, verify that the directory hasn't changed, by checking if current modification time is the same as the one stored in the cache. This only needs to be done when the current file position is at the beginning of the directory, as mandated by POSIX. Signed-off-by: Miklos Szeredi --- fs/fuse/fuse_i.h | 3 +++ fs/fuse/readdir.c | 38 ++++++++++++++++++++++++++++++++++---- 2 files changed, 37 insertions(+), 4 deletions(-) diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h index ef018ea5bcd9..e498f9edf01f 100644 --- a/fs/fuse/fuse_i.h +++ b/fs/fuse/fuse_i.h @@ -117,6 +117,9 @@ struct fuse_inode { /** version of the cache */ u64 version; + /** modification time of directory when cache was started */ + struct timespec64 mtime; + /** protects above fields */ spinlock_t lock; } rdc; diff --git a/fs/fuse/readdir.c b/fs/fuse/readdir.c index edb445c4cfbd..f96525cef518 100644 --- a/fs/fuse/readdir.c +++ b/fs/fuse/readdir.c @@ -397,8 +397,10 @@ static enum fuse_parse_result fuse_parse_cache(struct fuse_file *ff, return res; } -static void fuse_rdc_reset(struct fuse_inode *fi) +static void fuse_rdc_reset(struct inode *inode) { + struct fuse_inode *fi = get_fuse_inode(inode); + fi->rdc.cached = false; fi->rdc.version++; fi->rdc.size = 0; @@ -411,6 +413,7 @@ static int fuse_readdir_cached(struct file *file, struct dir_context *ctx) { struct fuse_file *ff = file->private_data; struct inode *inode = file_inode(file); + struct fuse_conn *fc = get_fuse_conn(inode); struct fuse_inode *fi = get_fuse_inode(inode); enum fuse_parse_result res; pgoff_t index; @@ -424,12 +427,40 @@ static int fuse_readdir_cached(struct file *file, struct dir_context *ctx) ff->readdir.cache_off = 0; } + /* + * We're just about to start reading into the cache or reading the + * cache; both cases require an up-to-date mtime value. + */ + if (!ctx->pos && fc->auto_inval_data) { + int err = fuse_update_attributes(inode, file); + + if (err) + return err; + } + retry: spin_lock(&fi->rdc.lock); +retry_locked: if (!fi->rdc.cached) { + /* Starting cache? Set cache mtime. */ + if (!ctx->pos && !fi->rdc.size) { + fi->rdc.mtime = inode->i_mtime; + } spin_unlock(&fi->rdc.lock); return UNCACHED; } + /* + * When at the beginning of the directory (i.e. just after opendir(3) or + * rewinddir(3)), then need to check whether directory contents have + * changed, and reset the cache if so. + */ + if (!ctx->pos) { + if (!timespec64_equal(&fi->rdc.mtime, &inode->i_mtime)) { + fuse_rdc_reset(inode); + goto retry_locked; + } + } + /* * If cache version changed since the last getdents() call, then reset * the cache stream. @@ -467,9 +498,8 @@ static int fuse_readdir_cached(struct file *file, struct dir_context *ctx) * Uh-oh: page gone missing, cache is useless */ if (fi->rdc.version == ff->readdir.version) - fuse_rdc_reset(fi); - spin_unlock(&fi->rdc.lock); - return UNCACHED; + fuse_rdc_reset(inode); + goto retry_locked; } /* Make sure it's still the same version after getting the page. */