From patchwork Fri Oct 31 04:11:20 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Anand Jain X-Patchwork-Id: 5201591 Return-Path: X-Original-To: patchwork-linux-btrfs@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id DD857C11AC for ; Fri, 31 Oct 2014 02:27:48 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id D17D020149 for ; Fri, 31 Oct 2014 02:27:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B653D20158 for ; Fri, 31 Oct 2014 02:27:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1422701AbaJaC1o (ORCPT ); Thu, 30 Oct 2014 22:27:44 -0400 Received: from userp1040.oracle.com ([156.151.31.81]:17099 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1422652AbaJaC1n (ORCPT ); Thu, 30 Oct 2014 22:27:43 -0400 Received: from ucsinet22.oracle.com (ucsinet22.oracle.com [156.151.31.94]) by userp1040.oracle.com (Sentrion-MTA-4.3.2/Sentrion-MTA-4.3.2) with ESMTP id s9V2Rd8p024282 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Fri, 31 Oct 2014 02:27:40 GMT Received: from aserz7021.oracle.com (aserz7021.oracle.com [141.146.126.230]) by ucsinet22.oracle.com (8.14.5+Sun/8.14.5) with ESMTP id s9V1dSp0005686 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=FAIL); Fri, 31 Oct 2014 01:39:28 GMT Received: from abhmp0012.oracle.com (abhmp0012.oracle.com [141.146.116.18]) by aserz7021.oracle.com (8.14.4+Sun/8.14.4) with ESMTP id s9V2Rc2d015425; Fri, 31 Oct 2014 02:27:38 GMT Received: from OL.sg.oracle.com (/10.186.101.34) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Thu, 30 Oct 2014 19:27:38 -0700 From: Anand Jain To: linux-btrfs@vger.kernel.org Cc: dsterba@suse.cz Subject: [PATCH 2/2 v4] btrfs-progs: optimize btrfs_scan_lblkid() for multiple calls Date: Fri, 31 Oct 2014 12:11:20 +0800 Message-Id: <1414728680-25468-2-git-send-email-anand.jain@oracle.com> X-Mailer: git-send-email 2.0.0.153.g79dcccc In-Reply-To: <1414728680-25468-1-git-send-email-anand.jain@oracle.com> References: <1413334270-25766-1-git-send-email-anand.jain@oracle.com> <1414728680-25468-1-git-send-email-anand.jain@oracle.com> X-Source-IP: ucsinet22.oracle.com [156.151.31.94] Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org X-Spam-Status: No, score=-7.5 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP btrfs_scan_lblikd() is called by most the device related command functions. And btrfs_scan_lblkid() is most expensive function and it becomes more expensive as number of devices in the system increase. Further some threads call this function more than once for absolutely no extra benefit and the real waste of resources. Below list of threads and number of times btrfs_scan_lblkid() is called in that thread. btrfs-find-root 1 btrfs rescue super-recover 2 btrfs-debug-tree 1 btrfs-image -r 2 btrfs check 2 btrfs restore 2 calc-size NC btrfs-corrupt-block NC btrfs-image NC btrfs-map-logical 1 btrfs-select-super NC btrfstune 2 btrfs-zero-log NC tester NC quick-test.c NC btrfs-convert 0 mkfs #number of devices to be mkfs btrfs label set unmounted 2 btrfs get label unmounted 2 This patch will: move out calling register_one_device with in btrfs_scan_lblkid() and so function setting the BTRFS_UPDATE_KERNEL to yes will call btrfs_register_all_devices() separately. introduce a global variable scan_done, which is set when scan is done succssfully per thread. So that following calls to this function will just return success. Further if any function needs to force scan after scan_done is set, then it can be done when there is such a requirement, but as of now there isn't any such requirement. Signed-off-by: Anand Jain --- v2: rebase on 3.17. And add more info to commit v3: accepts David review comments. thanks. v4: now no need to include volumes.h, update commit a bit. cmds-device.c | 6 ++++-- cmds-filesystem.c | 2 +- disk-io.c | 2 +- utils.c | 14 ++++++++++---- utils.h | 2 +- 5 files changed, 17 insertions(+), 9 deletions(-) diff --git a/cmds-device.c b/cmds-device.c index 8a33634..23784c5 100644 --- a/cmds-device.c +++ b/cmds-device.c @@ -28,7 +28,6 @@ #include "ctree.h" #include "ioctl.h" #include "utils.h" - #include "commands.h" static const char * const device_cmd_group_usage[] = { @@ -235,9 +234,12 @@ static int cmd_scan_dev(int argc, char **argv) if (all || argc == 1) { printf("Scanning for Btrfs filesystems\n"); - ret = btrfs_scan_lblkid(BTRFS_UPDATE_KERNEL); + ret = btrfs_scan_lblkid(); if (ret) fprintf(stderr, "ERROR: error %d while scanning\n", ret); + ret = btrfs_register_all_devices(); + if (ret) + fprintf(stderr, "ERROR: error %d while registering\n", ret); goto out; } diff --git a/cmds-filesystem.c b/cmds-filesystem.c index 695a3d5..011907d 100644 --- a/cmds-filesystem.c +++ b/cmds-filesystem.c @@ -698,7 +698,7 @@ static int cmd_show(int argc, char **argv) goto out; devs_only: - ret = btrfs_scan_lblkid(!BTRFS_UPDATE_KERNEL); + ret = btrfs_scan_lblkid(); if (ret) { fprintf(stderr, "ERROR: %d while scanning\n", ret); diff --git a/disk-io.c b/disk-io.c index 77fc610..2fb50f9 100644 --- a/disk-io.c +++ b/disk-io.c @@ -1012,7 +1012,7 @@ int btrfs_scan_fs_devices(int fd, const char *path, } if (total_devs != 1) { - ret = btrfs_scan_lblkid(!BTRFS_UPDATE_KERNEL); + ret = btrfs_scan_lblkid(); if (ret) return ret; } diff --git a/utils.c b/utils.c index aef0e5e..b83d980 100644 --- a/utils.c +++ b/utils.c @@ -52,6 +52,8 @@ #define BLKDISCARD _IO(0x12,119) #endif +static int btrfs_scan_done = 0; + static char argv0_buf[ARGV0_BUF_SIZE] = "btrfs"; void fixup_argv0(char **argv, const char *token) @@ -1186,7 +1188,7 @@ int check_mounted_where(int fd, const char *file, char *where, int size, /* scan other devices */ if (is_btrfs && total_devs > 1) { - ret = btrfs_scan_lblkid(!BTRFS_UPDATE_KERNEL); + ret = btrfs_scan_lblkid(); if (ret) return ret; } @@ -2196,7 +2198,7 @@ int test_dev_for_mkfs(char *file, int force_overwrite, char *estr) return 0; } -int btrfs_scan_lblkid(int update_kernel) +int btrfs_scan_lblkid() { int fd = -1; int ret; @@ -2207,6 +2209,9 @@ int btrfs_scan_lblkid(int update_kernel) blkid_cache cache = NULL; char path[PATH_MAX]; + if (btrfs_scan_done) + return 0; + if (blkid_get_cache(&cache, 0) < 0) { printf("ERROR: lblkid cache get failed\n"); return 1; @@ -2235,11 +2240,12 @@ int btrfs_scan_lblkid(int update_kernel) } close(fd); - if (update_kernel) - btrfs_register_one_device(path); } blkid_dev_iterate_end(iter); blkid_put_cache(cache); + + btrfs_scan_done = 1; + return 0; } diff --git a/utils.h b/utils.h index 65df2e4..926ef7d 100644 --- a/utils.h +++ b/utils.h @@ -128,7 +128,7 @@ int csum_tree_block(struct btrfs_root *root, struct extent_buffer *buf, int verify); int ask_user(char *question); int lookup_ino_rootid(int fd, u64 *rootid); -int btrfs_scan_lblkid(int update_kernel); +int btrfs_scan_lblkid(void); int get_btrfs_mount(const char *dev, char *mp, size_t mp_size); int find_mount_root(const char *path, char **mount_root); int get_device_info(int fd, u64 devid,