From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from aserp1040.oracle.com ([141.146.126.69]:27038 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755020Ab2LMByh (ORCPT ); Wed, 12 Dec 2012 20:54:37 -0500 From: Liu Bo To: linux-btrfs@vger.kernel.org Cc: Jim Schutt Subject: [PATCH] Btrfs: fix a deadlock on chunk mutex Date: Thu, 13 Dec 2012 09:52:37 +0800 Message-Id: <1355363557-2962-1-git-send-email-bo.li.liu@oracle.com> Sender: linux-btrfs-owner@vger.kernel.org List-ID: An user reported that he has hit an annoying deadlock while playing with ceph based on btrfs. Current updating device tree requires space from METADATA chunk, so we -may- need to do a recursive chunk allocation when adding/updating dev extent, that is where the deadlock comes from. If we use SYSTEM metadata to update device tree, we can avoid the recursive stuff. Reported-by: Jim Schutt Signed-off-by: Liu Bo --- fs/btrfs/extent-tree.c | 8 +++++--- 1 files changed, 5 insertions(+), 3 deletions(-) diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index 3d3e2c1..561dad5 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -3346,7 +3346,8 @@ u64 btrfs_get_alloc_profile(struct btrfs_root *root, int data) if (data) flags = BTRFS_BLOCK_GROUP_DATA; - else if (root == root->fs_info->chunk_root) + else if (root == root->fs_info->chunk_root || + root == root->fs_info->dev_root) flags = BTRFS_BLOCK_GROUP_SYSTEM; else flags = BTRFS_BLOCK_GROUP_METADATA; @@ -3534,7 +3535,8 @@ static u64 get_system_chunk_thresh(struct btrfs_root *root, u64 type) else num_dev = 1; /* DUP or single */ - /* metadata for updaing devices and chunk tree */ + /* metadata for adding/updating devices and chunk tree */ + num_dev = num_dev << 1 return btrfs_calc_trans_metadata_size(root, num_dev + 1); } @@ -4351,7 +4353,7 @@ static void init_global_block_rsv(struct btrfs_fs_info *fs_info) fs_info->extent_root->block_rsv = &fs_info->global_block_rsv; fs_info->csum_root->block_rsv = &fs_info->global_block_rsv; - fs_info->dev_root->block_rsv = &fs_info->global_block_rsv; + fs_info->dev_root->block_rsv = &fs_info->chunk_block_rsv; fs_info->tree_root->block_rsv = &fs_info->global_block_rsv; fs_info->chunk_root->block_rsv = &fs_info->chunk_block_rsv; -- 1.7.7.6