From: Wang Shilong <[email protected]> We use mutex lock to protect all the user change operations. So when we are calling find_qgroup_rb() to check whether qgroup exists, we don't have to hold spin_lock.
Besides, when enabling/disabling quota, it must be single thread when operations come here. spin lock must be firstly used to clear quota_root when disabling quota, while enabling quota, spin lock must be used to complete the last assign work. Signed-off-by: Wang Shilong <[email protected]> Reviewed-by: Miao Xie <[email protected]> --- fs/btrfs/qgroup.c | 27 ++++++--------------------- 1 file changed, 6 insertions(+), 21 deletions(-) diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c index 5837cb5..466bcd6 100644 --- a/fs/btrfs/qgroup.c +++ b/fs/btrfs/qgroup.c @@ -98,7 +98,7 @@ struct btrfs_qgroup_list { struct btrfs_qgroup *member; }; -/* must be called with qgroup_lock held */ +/* must be called with qgroup_ioctl_lock held */ static struct btrfs_qgroup *find_qgroup_rb(struct btrfs_fs_info *fs_info, u64 qgroupid) { @@ -794,13 +794,10 @@ int btrfs_quota_enable(struct btrfs_trans_handle *trans, int slot; mutex_lock(&fs_info->qgroup_ioctl_lock); - spin_lock(&fs_info->qgroup_lock); if (fs_info->quota_root) { fs_info->pending_quota_state = 1; - spin_unlock(&fs_info->qgroup_lock); goto out; } - spin_unlock(&fs_info->qgroup_lock); /* * initially create the quota tree @@ -862,14 +859,11 @@ int btrfs_quota_enable(struct btrfs_trans_handle *trans, if (ret) goto out_free_path; - spin_lock(&fs_info->qgroup_lock); qgroup = add_qgroup_rb(fs_info, found_key.offset); if (IS_ERR(qgroup)) { - spin_unlock(&fs_info->qgroup_lock); ret = PTR_ERR(qgroup); goto out_free_path; } - spin_unlock(&fs_info->qgroup_lock); } ret = btrfs_next_item(tree_root, path); if (ret < 0) @@ -884,13 +878,12 @@ out_add_root: if (ret) goto out_free_path; - spin_lock(&fs_info->qgroup_lock); qgroup = add_qgroup_rb(fs_info, BTRFS_FS_TREE_OBJECTID); if (IS_ERR(qgroup)) { - spin_unlock(&fs_info->qgroup_lock); ret = PTR_ERR(qgroup); goto out_free_path; } + spin_lock(&fs_info->qgroup_lock); fs_info->quota_root = quota_root; fs_info->pending_quota_state = 1; spin_unlock(&fs_info->qgroup_lock); @@ -915,11 +908,9 @@ int btrfs_quota_disable(struct btrfs_trans_handle *trans, int ret = 0; mutex_lock(&fs_info->qgroup_ioctl_lock); - spin_lock(&fs_info->qgroup_lock); - if (!fs_info->quota_root) { - spin_unlock(&fs_info->qgroup_lock); + if (!fs_info->quota_root) goto out; - } + spin_lock(&fs_info->qgroup_lock); fs_info->quota_enabled = 0; fs_info->pending_quota_state = 0; quota_root = fs_info->quota_root; @@ -1062,16 +1053,13 @@ int btrfs_remove_qgroup(struct btrfs_trans_handle *trans, } /* check if there are no relations to this qgroup */ - spin_lock(&fs_info->qgroup_lock); qgroup = find_qgroup_rb(fs_info, qgroupid); if (qgroup) { if (!list_empty(&qgroup->groups) || !list_empty(&qgroup->members)) { - spin_unlock(&fs_info->qgroup_lock); ret = -EBUSY; goto out; } } - spin_unlock(&fs_info->qgroup_lock); ret = del_qgroup_item(trans, quota_root, qgroupid); @@ -1108,20 +1096,17 @@ int btrfs_limit_qgroup(struct btrfs_trans_handle *trans, (unsigned long long)qgroupid); } - spin_lock(&fs_info->qgroup_lock); - qgroup = find_qgroup_rb(fs_info, qgroupid); if (!qgroup) { ret = -ENOENT; - goto unlock; + goto out; } + spin_lock(&fs_info->qgroup_lock); qgroup->lim_flags = limit->flags; qgroup->max_rfer = limit->max_rfer; qgroup->max_excl = limit->max_excl; qgroup->rsv_rfer = limit->rsv_rfer; qgroup->rsv_excl = limit->rsv_excl; - -unlock: spin_unlock(&fs_info->qgroup_lock); out: mutex_unlock(&fs_info->qgroup_ioctl_lock); -- 1.7.11.7 -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
