[PATCH 1/2] Btrfs: create the qgroup that limits root subvolume automatically

[PATCH 1/2] Btrfs: create the qgroup that limits root subvolume automatically

[Wang Shilong]

From: Wang Shilong <wangsl-fnst@cn.fujitsu.com>

Creating the root subvolume qgroup when enabling quota,with
this patch,it will be ok to limit the whole filesystem size.

Signed-off-by: Wang Shilong <wangsl-fnst@cn.fujitsu.com>
Reviewed-by: Miao Xie <miaox@cn.fujitsu.com>
Cc: Arne Jansen <sensille@gmx.net>
---
 fs/btrfs/qgroup.c |   12 ++++++++++++
 1 files changed, 12 insertions(+), 0 deletions(-)

diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c
index a5c8562..c409096 100644
--- a/fs/btrfs/qgroup.c
+++ b/fs/btrfs/qgroup.c
@@ -777,6 +777,7 @@ int btrfs_quota_enable(struct btrfs_trans_handle *trans,
 	struct extent_buffer *leaf;
 	struct btrfs_key key;
 	int ret = 0;
+	struct btrfs_qgroup *qgroup = NULL;
 
 	spin_lock(&fs_info->qgroup_lock);
 	if (fs_info->quota_root) {
@@ -823,7 +824,18 @@ int btrfs_quota_enable(struct btrfs_trans_handle *trans,
 
 	btrfs_mark_buffer_dirty(leaf);
 
+	btrfs_release_path(path);
+	ret = add_qgroup_item(trans, quota_root, BTRFS_FS_TREE_OBJECTID);
+	if (ret)
+		goto out;
+
 	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;
+	}
 	fs_info->quota_root = quota_root;
 	fs_info->pending_quota_state = 1;
 	spin_unlock(&fs_info->qgroup_lock);
-- 
1.7.7.6

Re: [PATCH 1/2] Btrfs: create the qgroup that limits root subvolume automatically

[Arne Jansen]

On 02/22/13 13:02, Wang Shilong wrote:
> From: Wang Shilong <wangsl-fnst@cn.fujitsu.com>
> 
> Creating the root subvolume qgroup when enabling quota,with

Why only create a qgroup for the root subvolume and not for
every existing subvolume?

> this patch,it will be ok to limit the whole filesystem size.

This will not limit the whole filesystem, but only the root
subvolume. To limit the whole filesystem you'd have to create
a level 1 qgroup and add all subvolumes to it.

-Arne

> 
> Signed-off-by: Wang Shilong <wangsl-fnst@cn.fujitsu.com>
> Reviewed-by: Miao Xie <miaox@cn.fujitsu.com>
> Cc: Arne Jansen <sensille@gmx.net>
> ---
>  fs/btrfs/qgroup.c |   12 ++++++++++++
>  1 files changed, 12 insertions(+), 0 deletions(-)
> 
> diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c
> index a5c8562..c409096 100644
> --- a/fs/btrfs/qgroup.c
> +++ b/fs/btrfs/qgroup.c
> @@ -777,6 +777,7 @@ int btrfs_quota_enable(struct btrfs_trans_handle *trans,
>  	struct extent_buffer *leaf;
>  	struct btrfs_key key;
>  	int ret = 0;
> +	struct btrfs_qgroup *qgroup = NULL;
>  
>  	spin_lock(&fs_info->qgroup_lock);
>  	if (fs_info->quota_root) {
> @@ -823,7 +824,18 @@ int btrfs_quota_enable(struct btrfs_trans_handle *trans,
>  
>  	btrfs_mark_buffer_dirty(leaf);
>  
> +	btrfs_release_path(path);
> +	ret = add_qgroup_item(trans, quota_root, BTRFS_FS_TREE_OBJECTID);
> +	if (ret)
> +		goto out;
> +
>  	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;
> +	}
>  	fs_info->quota_root = quota_root;
>  	fs_info->pending_quota_state = 1;
>  	spin_unlock(&fs_info->qgroup_lock);
> 

Re: [PATCH 1/2] Btrfs: create the qgroup that limits root subvolume automatically

[Shilong Wang]

2013/2/22 Arne Jansen <sensille@gmx.net>:
> On 02/22/13 13:02, Wang Shilong wrote:
>> From: Wang Shilong <wangsl-fnst@cn.fujitsu.com>
>>
>> Creating the root subvolume qgroup when enabling quota,with
>
> Why only create a qgroup for the root subvolume and not for
> every existing subvolume?
>

Yes，You are right.
Creating all the existed subvolume  qgroup is necessary when enabling
quota since we try to prevent
creating  group level 0...the subvolume/snapshot group should be
operated automatically...

Atfer this work.
I think it is necessary to delete the subvolume/snapshot qgroup  as
the deletion of sub volume/snapshot.

BTW, there is a thing  to think about...
During enabling quota...No new subvolume should be created before the
enabling quota is done.

I will try to implement such functions.....

>> this patch,it will be ok to limit the whole filesystem size.
>
> This will not limit the whole filesystem, but only the root
> subvolume. To limit the whole filesystem you'd have to create
> a level 1 qgroup and add all subvolumes to it.
>

Right, thanks for correcting it...

Thanks,
Wang


> -Arne
>
>>
>> Signed-off-by: Wang Shilong <wangsl-fnst@cn.fujitsu.com>
>> Reviewed-by: Miao Xie <miaox@cn.fujitsu.com>
>> Cc: Arne Jansen <sensille@gmx.net>
>> ---
>>  fs/btrfs/qgroup.c |   12 ++++++++++++
>>  1 files changed, 12 insertions(+), 0 deletions(-)
>>
>> diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c
>> index a5c8562..c409096 100644
>> --- a/fs/btrfs/qgroup.c
>> +++ b/fs/btrfs/qgroup.c
>> @@ -777,6 +777,7 @@ int btrfs_quota_enable(struct btrfs_trans_handle *trans,
>>       struct extent_buffer *leaf;
>>       struct btrfs_key key;
>>       int ret = 0;
>> +     struct btrfs_qgroup *qgroup = NULL;
>>
>>       spin_lock(&fs_info->qgroup_lock);
>>       if (fs_info->quota_root) {
>> @@ -823,7 +824,18 @@ int btrfs_quota_enable(struct btrfs_trans_handle *trans,
>>
>>       btrfs_mark_buffer_dirty(leaf);
>>
>> +     btrfs_release_path(path);
>> +     ret = add_qgroup_item(trans, quota_root, BTRFS_FS_TREE_OBJECTID);
>> +     if (ret)
>> +             goto out;
>> +
>>       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;
>> +     }
>>       fs_info->quota_root = quota_root;
>>       fs_info->pending_quota_state = 1;
>>       spin_unlock(&fs_info->qgroup_lock);
>>
>