From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wg0-f44.google.com ([74.125.82.44]:54543 "EHLO mail-wg0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751067Ab3GEWXm (ORCPT ); Fri, 5 Jul 2013 18:23:42 -0400 Received: by mail-wg0-f44.google.com with SMTP id m15so2298192wgh.11 for ; Fri, 05 Jul 2013 15:23:41 -0700 (PDT) From: Filipe David Borba Manana To: linux-btrfs@vger.kernel.org Cc: Filipe David Borba Manana Subject: [PATCH] Btrfs-progs: optimize function btrfs_read_chunk_tree Date: Fri, 5 Jul 2013 23:23:04 +0100 Message-Id: <1373062984-12641-1-git-send-email-fdmanana@gmail.com> Sender: linux-btrfs-owner@vger.kernel.org List-ID: After reading all device items from the chunk tree, don't exit the loop and then navigate down the tree again to find the chunk items. Instead, if while reading the device items we find a chunk item in the leaf keep iterating over the leaf and process the chunk items - at the moment chunk items always follow immediately the device items in the chunk tree, and if this fact changes in the future, revert back to previous behaviour of exiting the loop and navigate down the tree again to search for chunk items, but use BTRFS_FIRST_CHUNK_TREE_OBJECTID as the object id for the search key, as any chunk item has a key that has this object id. This is a port of the corresponding kernel patch to keep both kernel and btrfs-progs identical: https://patchwork.kernel.org/patch/2816401/ Signed-off-by: Filipe David Borba Manana --- volumes.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/volumes.c b/volumes.c index 0ff2283..22d0f31 100644 --- a/volumes.c +++ b/volumes.c @@ -1740,8 +1740,13 @@ again: } btrfs_item_key_to_cpu(leaf, &found_key, slot); if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID) { - if (found_key.objectid != BTRFS_DEV_ITEMS_OBJECTID) + if (found_key.objectid != BTRFS_DEV_ITEMS_OBJECTID) { + if (found_key.type == BTRFS_CHUNK_ITEM_KEY) { + key.objectid = found_key.objectid; + continue; + } break; + } if (found_key.type == BTRFS_DEV_ITEM_KEY) { struct btrfs_dev_item *dev_item; dev_item = btrfs_item_ptr(leaf, slot, @@ -1758,7 +1763,7 @@ again: path->slots[0]++; } if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID) { - key.objectid = 0; + key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID; btrfs_release_path(root, path); goto again; } -- 1.7.9.5