From patchwork Thu Oct 11 18:50:58 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Goffredo Baroncelli X-Patchwork-Id: 10637187 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 DFC62679F for ; Thu, 11 Oct 2018 18:51:25 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id CEAE92BFBE for ; Thu, 11 Oct 2018 18:51:25 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id CCAE92BFD0; Thu, 11 Oct 2018 18:51:25 +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=-8.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FROM,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 6DAB12BFD4 for ; Thu, 11 Oct 2018 18:51:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729857AbeJLCTw (ORCPT ); Thu, 11 Oct 2018 22:19:52 -0400 Received: from smtp-33-i6.italiaonline.it ([213.209.14.33]:37133 "EHLO libero.it" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1729786AbeJLCTp (ORCPT ); Thu, 11 Oct 2018 22:19:45 -0400 Received: from venice.bhome ([94.38.186.31]) by smtp-33.iol.local with ESMTPA id Ag3FgMwlrQGOzAg3HgbY02; Thu, 11 Oct 2018 20:51:15 +0200 x-libjamoibt: 1601 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=libero.it; s=s2014; t=1539283875; bh=GJkLQdHACkYyoGwEvpgE86CX50jb7ab2XaJVwqcHACg=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=U9jNxnstSVn3/91iWPG9sSlOl86FV8y76b/A1uE+AgKRZca0gR4ZcgQQ8qK3Zo+aS HRxB1ULiAp6zDGEzWTG6nX/DilO2eDg5r1nE0xR/DWsj0TGSn7X8gif6tRsKc7dP8n 2P9LZ44dNQ+eSaZAHi+bid6JQ1Bz3D7RmPrxgwrXAJSrOzjXfR/p1ExQcbR/tgrrDJ FSnjLHR3+yPJ/VJ+BRfhT5ym60JyLaRCowtGZBBMhbQpf9pEhG2HRIK51lXKg6ClnC B0Rf7aybrYFm1GeYAjSji5FW3M0+2C3lvSm1EeCDaahxKPRFNKpbbDUpP/hAHAXgRB vIp21WEdrcsCw== X-CNFS-Analysis: v=2.3 cv=OvCeNB3t c=1 sm=1 tr=0 a=I+JNyrl7/zjgsFWlY3jFdA==:117 a=I+JNyrl7/zjgsFWlY3jFdA==:17 a=wqVqdCQbwCNbCc34xW0A:9 From: Goffredo Baroncelli To: grub-devel@gnu.org Cc: Daniel Kiper , linux-btrfs@vger.kernel.org, Goffredo Baroncelli Subject: [PATCH 4/9] btrfs: Avoid a rescan for a device which was already not found. Date: Thu, 11 Oct 2018 20:50:58 +0200 Message-Id: <20181011185103.23146-5-kreijack@libero.it> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20181011185103.23146-1-kreijack@libero.it> References: <20181011185103.23146-1-kreijack@libero.it> MIME-Version: 1.0 X-CMAE-Envelope: MS4wfAOQ0iifhU0WYY0oY57gOQ1sRzzoHQ1p3kZH9AXynZPcZOAdcW/h8cGf3khroZoLd6ZLhS0ryzGJ90YmzoMDB8r8uRECD8mrjdMlcK/RwmZKWd2fdqla CnPlCYBOyq1CMnAImYTdlktNawuIoo+rgTAt9BM6W0SIpB0H9s58S0/N4qukv8GxiZJ3lqFdj5MI6C67eh+qnLawPSluQpwLiSZPz2wskncgBeFk9uyAvdzt KekuTSL7J2P3aZe7wD2Edh7Z8QtgtCPGraXHBKb1lfc= Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Goffredo Baroncelli Currently read from missing device triggers rescan. However, it is never recorded that the device is missing. So, each read of a missing device triggers rescan again and again. This behavior causes a lot of unneeded rescans leading to huge slowdowns. This patch fixes above mentioned issue. Information about missing devices is stored in the data->devices_attached[] array as NULL value in dev member. Rescan is triggered only if no information is found for a given device. This means that only first time read triggers rescan. The patch drops premature return. This way data->devices_attached[] is filled even when a given device is missing. Signed-off-by: Goffredo Baroncelli --- grub-core/fs/btrfs.c | 17 +++++++++-------- 1 file changed, 9 insertions(+), 8 deletions(-) diff --git a/grub-core/fs/btrfs.c b/grub-core/fs/btrfs.c index 2a87eb103..b2be80c33 100644 --- a/grub-core/fs/btrfs.c +++ b/grub-core/fs/btrfs.c @@ -588,7 +588,7 @@ find_device_iter (const char *name, void *data) } static grub_device_t -find_device (struct grub_btrfs_data *data, grub_uint64_t id, int do_rescan) +find_device (struct grub_btrfs_data *data, grub_uint64_t id) { struct find_device_ctx ctx = { .data = data, @@ -600,10 +600,9 @@ find_device (struct grub_btrfs_data *data, grub_uint64_t id, int do_rescan) for (i = 0; i < data->n_devices_attached; i++) if (id == data->devices_attached[i].id) return data->devices_attached[i].dev; - if (do_rescan) - grub_device_iterate (find_device_iter, &ctx); - if (!ctx.dev_found) - return NULL; + + grub_device_iterate (find_device_iter, &ctx); + data->n_devices_attached++; if (data->n_devices_attached > data->n_devices_allocated) { @@ -615,7 +614,8 @@ find_device (struct grub_btrfs_data *data, grub_uint64_t id, int do_rescan) * sizeof (data->devices_attached[0])); if (!data->devices_attached) { - grub_device_close (ctx.dev_found); + if (ctx.dev_found) + grub_device_close (ctx.dev_found); data->devices_attached = tmp; return NULL; } @@ -897,7 +897,7 @@ grub_btrfs_read_logical (struct grub_btrfs_data *data, grub_disk_addr_t addr, " for laddr 0x%" PRIxGRUB_UINT64_T "\n", paddr, addr); - dev = find_device (data, stripe->device_id, j); + dev = find_device (data, stripe->device_id); if (!dev) { grub_dprintf ("btrfs", @@ -974,7 +974,8 @@ grub_btrfs_unmount (struct grub_btrfs_data *data) unsigned i; /* The device 0 is closed one layer upper. */ for (i = 1; i < data->n_devices_attached; i++) - grub_device_close (data->devices_attached[i].dev); + if (data->devices_attached[i].dev) + grub_device_close (data->devices_attached[i].dev); grub_free (data->devices_attached); grub_free (data->extent); grub_free (data);