From patchwork Thu Oct 18 17:55:36 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Goffredo Baroncelli X-Patchwork-Id: 10647713 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 907E517DE for ; Thu, 18 Oct 2018 17:55:57 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 8199728E65 for ; Thu, 18 Oct 2018 17:55:57 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 75B5928E87; Thu, 18 Oct 2018 17:55:57 +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 D18A728E65 for ; Thu, 18 Oct 2018 17:55:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728354AbeJSB57 (ORCPT ); Thu, 18 Oct 2018 21:57:59 -0400 Received: from smtp-34-i6.italiaonline.it ([213.209.14.34]:52820 "EHLO libero.it" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728331AbeJSB57 (ORCPT ); Thu, 18 Oct 2018 21:57:59 -0400 Received: from venice.bhome ([94.38.16.140]) by smtp-34.iol.local with ESMTPA id DCWVgs2H18KmnDCWXgOdV4; Thu, 18 Oct 2018 19:55:53 +0200 x-libjamoibt: 1601 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=libero.it; s=s2014; t=1539885353; bh=d6AQBEgz0RNa61javY0WhaXZw6LSZcXpCmyDysS3KyU=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=WE5TgxFI7iF+lNU3BkD5Zrk9ECxcTnMRg1HZsUvQA+hNdUF89mYdWwqQQV7j2CsWd Zr7kfn3tKpbZm8FGkq+dJiQzdBSit0/HVjJuHns405pc0qhZoNnyAvkBcWk5qvbd92 fbtr5YN99+ATJTjxNVBhpfVrwM749rxHmKMV8AzOnrF8tWawSJas3aqkpVRTtls9vW qck4LAgasgHYGI+g9ZsZLIp33YvJaZ+6tEZ0aDPket7HPXAVdv8lOFDrKeg4uyOWCR keMQyeWz9sLijDNC9y8+Uu/RDxL0OtYZ3DlmhK6t9wlKDV98/S3U1hutzWk1UXiSj/ VYRS0vVLbdc8w== X-CNFS-Analysis: v=2.3 cv=ZbLMyfdA c=1 sm=1 tr=0 a=nqgIlLay6LNLiZJCVl9G2Q==:117 a=nqgIlLay6LNLiZJCVl9G2Q==:17 a=yPCof4ZbAAAA:8 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, 18 Oct 2018 19:55:36 +0200 Message-Id: <20181018175541.9532-5-kreijack@libero.it> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20181018175541.9532-1-kreijack@libero.it> References: <20181018175541.9532-1-kreijack@libero.it> MIME-Version: 1.0 X-CMAE-Envelope: MS4wfKA6V6PKlekOD9Xx3BgJQdYoZIsHhxncncqu7jLtqWvEsiVogfu1H92MLiQbTtt9HjZJhtYm4tUgQYEchll6c5BLL+9qYzxNirSzF0KT1ErLgBOh9x38 5Ir5fpb0ZxA5F8q7FDDzf4Pq4/dPxFTuclskxMOZRmj0fVmHs+cFjjoyObV9uIBEIiFzAjW9WxPtrauquePY6FgUsrZdyxDAu6a4d20GtH4kuLTDZHo/uwnC sMBtTZuGEWCZ3UsF24TlbU+01MLtO3hAjSkBaHOoXqQ= 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 Signed-off-by: Daniel Kiper Reviewed-by: Daniel Kiper --- 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 6b6e91cd1..81f3bc120 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);