From f5a6b1c53bdd44f79e3904c0f5e59f956b49b2c8 Mon Sep 17 00:00:00 2001 From: Dongsheng Yang Date: Mon, 24 Nov 2014 10:27:09 -0500 Subject: [PATCH] btrfs: qgroup: allow to remove qgroup which has parent but no child. When a qgroup has parents but no child, it should be removable in Theory I think. But currently, we can not remove it when it has either parent or child. Example: # btrfs quota enable /mnt # btrfs qgroup create 1/0 /mnt # btrfs qgroup create 2/0 /mnt # btrfs qgroup assign 1/0 2/0 /mnt # btrfs qgroup show -pcre /mnt qgroupid rfer excl max_rfer max_excl parent child -------- ---- ---- -------- -------- ------ ----- 0/5 16384 16384 0 0 --- --- 1/0 0 0 0 0 2/0 --- 2/0 0 0 0 0 --- 1/0 At this time, there is no subvol or qgroup depending on it. Just a qgroup 2/0 is its parent, but 2/0 can work well without 1/0. So I think 1/0 should be removalbe. But: # btrfs qgroup destroy 1/0 /mnt ERROR: unable to destroy quota group: Device or resource busy This patch remove the check of qgroup->parent in removing it, then we can remove a qgroup when it has a parent. Signed-off-by: Dongsheng Yang Signed-off-by: Chris Mason --- fs/btrfs/qgroup.c | 30 +++++++++++++++++++++++++----- 1 file changed, 25 insertions(+), 5 deletions(-) diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c index 4ec86b3eee21..464d1e237512 100644 --- a/fs/btrfs/qgroup.c +++ b/fs/btrfs/qgroup.c @@ -1048,7 +1048,7 @@ out: return ret; } -int btrfs_del_qgroup_relation(struct btrfs_trans_handle *trans, +int __del_qgroup_relation(struct btrfs_trans_handle *trans, struct btrfs_fs_info *fs_info, u64 src, u64 dst) { struct btrfs_root *quota_root; @@ -1058,7 +1058,6 @@ int btrfs_del_qgroup_relation(struct btrfs_trans_handle *trans, int ret = 0; int err; - mutex_lock(&fs_info->qgroup_ioctl_lock); quota_root = fs_info->quota_root; if (!quota_root) { ret = -EINVAL; @@ -1089,7 +1088,18 @@ exist: del_relation_rb(fs_info, src, dst); spin_unlock(&fs_info->qgroup_lock); out: + return ret; +} + +int btrfs_del_qgroup_relation(struct btrfs_trans_handle *trans, + struct btrfs_fs_info *fs_info, u64 src, u64 dst) +{ + int ret = 0; + + mutex_lock(&fs_info->qgroup_ioctl_lock); + ret = __del_qgroup_relation(trans, fs_info, src, dst); mutex_unlock(&fs_info->qgroup_ioctl_lock); + return ret; } @@ -1132,6 +1142,7 @@ int btrfs_remove_qgroup(struct btrfs_trans_handle *trans, { struct btrfs_root *quota_root; struct btrfs_qgroup *qgroup; + struct btrfs_qgroup_list *list; int ret = 0; mutex_lock(&fs_info->qgroup_ioctl_lock); @@ -1146,15 +1157,24 @@ int btrfs_remove_qgroup(struct btrfs_trans_handle *trans, ret = -ENOENT; goto out; } else { - /* check if there are no relations to this qgroup */ - if (!list_empty(&qgroup->groups) || - !list_empty(&qgroup->members)) { + /* check if there are no children of this qgroup */ + if (!list_empty(&qgroup->members)) { ret = -EBUSY; goto out; } } ret = del_qgroup_item(trans, quota_root, qgroupid); + while (!list_empty(&qgroup->groups)) { + list = list_first_entry(&qgroup->groups, + struct btrfs_qgroup_list, next_group); + ret = __del_qgroup_relation(trans, fs_info, + qgroupid, + list->group->qgroupid); + if (ret) + goto out; + } + spin_lock(&fs_info->qgroup_lock); del_qgroup_rb(quota_root->fs_info, qgroupid); spin_unlock(&fs_info->qgroup_lock); -- 2.30.2