From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.synology.com ([59.124.41.242]:14007 "EHLO mail.synology.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754443AbbBDMLA (ORCPT ); Wed, 4 Feb 2015 07:11:00 -0500 From: Forrest Liu To: linux-btrfs@vger.kernel.org Cc: Forrest Liu Subject: [PATCH v2] Btrfs: fix find_free_dev_extent() malfunction in case device tree has hole Date: Wed, 4 Feb 2015 20:10:53 +0800 Message-Id: <1423051853-25336-1-git-send-email-forrestl@synology.com> Sender: linux-btrfs-owner@vger.kernel.org List-ID: If device tree has hole, find_free_dev_extent() cannot find available address properly. The example below, has one BIG hole in device tree, and can only allocate just one chunk in a transaction. item 9 key (1 DEV_EXTENT 273841913856) itemoff 15811 itemsize 48 dev extent chunk_tree 3 chunk objectid 256 chunk offset 272759783424 length 1073741824 item 10 key (1 DEV_EXTENT 1071632089088) itemoff 15763 itemsize 48 dev extent chunk_tree 3 chunk objectid 256 chunk offset 1070549958656 length 1073741824 item 11 key (1 DEV_EXTENT 1072705830912) itemoff 15715 itemsize 48 dev extent chunk_tree 3 chunk objectid 256 chunk offset 1071623700480 length Signed-off-by: Forrest Liu Reviewed-by: Liu Bo --- changelog: v2: fix typo key_offset replace WARN_ON with WARN_ON_ONCE fs/btrfs/volumes.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index 50c5a87..da07eca 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -1060,6 +1060,7 @@ static int contains_pending_extent(struct btrfs_trans_handle *trans, struct extent_map *em; struct list_head *search_list = &trans->transaction->pending_chunks; int ret = 0; + u64 physical_start = *start; again: list_for_each_entry(em, search_list, list) { @@ -1070,9 +1071,9 @@ again: for (i = 0; i < map->num_stripes; i++) { if (map->stripes[i].dev != device) continue; - if (map->stripes[i].physical >= *start + len || + if (map->stripes[i].physical >= physical_start + len || map->stripes[i].physical + em->orig_block_len <= - *start) + physical_start) continue; *start = map->stripes[i].physical + em->orig_block_len; @@ -1195,8 +1196,14 @@ again: */ if (contains_pending_extent(trans, device, &search_start, - hole_size)) - hole_size = 0; + hole_size)) { + if (key.offset >= search_start) + hole_size = key.offset - search_start; + else { + WARN_ON_ONCE(1); + hole_size = 0; + } + } if (hole_size > max_hole_size) { max_hole_start = search_start; -- 1.9.1