Re: [PATCH v2] btrfs: qgroup: Dirty all qgroups before rescan

2018-08-09 Thread Qu Wenruo


On 8/9/18 5:17 PM, Filipe Manana wrote:
> On Thu, Aug 9, 2018 at 8:08 AM, Qu Wenruo  wrote:
>> [BUG]
>> In the following case, rescan won't zero out the number of qgroup 1/0:
>> --
>> $ mkfs.btrfs -fq $DEV
>> $ mount $DEV /mnt
>>
>> $ btrfs quota enable /mnt
>> $ btrfs qgroup create 1/0 /mnt
>> $ btrfs sub create /mnt/sub
>> $ btrfs qgroup assign 0/257 1/0 /mnt
>>
>> $ dd if=/dev/urandom of=/mnt/sub/file bs=1k count=1000
>> $ btrfs sub snap /mnt/sub /mnt/snap
>> $ btrfs quota rescan -w /mnt
>> $ btrfs qgroup show -pcre /mnt
>> qgroupid rfer excl max_rfer max_excl parent  child
>>      --  -
>> 0/5  16.00KiB 16.00KiB none none --- ---
>> 0/257  1016.00KiB 16.00KiB none none 1/0 ---
>> 0/258  1016.00KiB 16.00KiB none none --- ---
>> 1/01016.00KiB 16.00KiB none none --- 0/257
>>
>> so far so good, but:
>>
>> $ btrfs qgroup remove 0/257 1/0 /mnt
>> WARNING: quotas may be inconsistent, rescan needed
>> $ btrfs quota rescan -w /mnt
>> $ btrfs qgroup show -pcre  /mnt
>> qgoupid rfer excl max_rfer max_excl parent  child
>>      --  -
>> 0/5  16.00KiB 16.00KiB none none --- ---
>> 0/257  1016.00KiB 16.00KiB none none --- ---
>> 0/258  1016.00KiB 16.00KiB none none --- ---
>> 1/01016.00KiB 16.00KiB none none --- ---
>>^^  not cleared
>> --
>>
>> [CAUSE]
>> Before rescan we call qgroup_rescan_zero_tracking() to zero out all
>> qgroups' accounting numbers.
>>
>> However we don't mark all qgroups dirty, but rely on rescan to mark
>> qgroups dirty.
>>
>> If we have any high level qgroup but without any child (orphan group),
> 
> That sentence is confusing. An orphan, by definition [1], is someone
> (or something in this case) without parents.
> But you mention a group without children, so that should be named
> "childless" or simply say "without children".

Makes sense, I'll correct the commit message in next version.

Thanks,
Qu

> So one part of the sentence is wrong, either what is in parenthesis or
> what comes before them.
> 
> [1] https://www.thefreedictionary.com/orphan
> 
>> it
>> won't be marked dirty during rescan, since we can not reach that qgroup.
>>
>> This will cause QGROUP_INFO items of orphan qgroups never get updated in
>> quota tree, thus their numbers will stay the same in "btrfs qgroup show"
>> output.
>>
>> [FIX]
>> Just mark all qgroups dirty in qgroup_rescan_zero_tracking(), so even we
>> have orphan qgroups their QGROUP_INFO items will still get updated during
>> rescan.
>>
>> Reported-by: Misono Tomohiro 
>> Signed-off-by: Qu Wenruo 
>> ---
>> changelog:
>> v2:
>>   Fix some grammar errors in commit message.
>> ---
>>  fs/btrfs/qgroup.c | 1 +
>>  1 file changed, 1 insertion(+)
>>
>> diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c
>> index 48c1c3e7baf3..5a5372b33d96 100644
>> --- a/fs/btrfs/qgroup.c
>> +++ b/fs/btrfs/qgroup.c
>> @@ -2864,6 +2864,7 @@ qgroup_rescan_zero_tracking(struct btrfs_fs_info 
>> *fs_info)
>> qgroup->rfer_cmpr = 0;
>> qgroup->excl = 0;
>> qgroup->excl_cmpr = 0;
>> +   qgroup_dirty(fs_info, qgroup);
>> }
>> spin_unlock(_info->qgroup_lock);
>>  }
>> --
>> 2.18.0
>>
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in
>> the body of a message to majord...@vger.kernel.org
>> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> 
> 
> 



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Re: [PATCH v2] btrfs: qgroup: Dirty all qgroups before rescan

2018-08-09 Thread Filipe Manana
On Thu, Aug 9, 2018 at 8:08 AM, Qu Wenruo  wrote:
> [BUG]
> In the following case, rescan won't zero out the number of qgroup 1/0:
> --
> $ mkfs.btrfs -fq $DEV
> $ mount $DEV /mnt
>
> $ btrfs quota enable /mnt
> $ btrfs qgroup create 1/0 /mnt
> $ btrfs sub create /mnt/sub
> $ btrfs qgroup assign 0/257 1/0 /mnt
>
> $ dd if=/dev/urandom of=/mnt/sub/file bs=1k count=1000
> $ btrfs sub snap /mnt/sub /mnt/snap
> $ btrfs quota rescan -w /mnt
> $ btrfs qgroup show -pcre /mnt
> qgroupid rfer excl max_rfer max_excl parent  child
>      --  -
> 0/5  16.00KiB 16.00KiB none none --- ---
> 0/257  1016.00KiB 16.00KiB none none 1/0 ---
> 0/258  1016.00KiB 16.00KiB none none --- ---
> 1/01016.00KiB 16.00KiB none none --- 0/257
>
> so far so good, but:
>
> $ btrfs qgroup remove 0/257 1/0 /mnt
> WARNING: quotas may be inconsistent, rescan needed
> $ btrfs quota rescan -w /mnt
> $ btrfs qgroup show -pcre  /mnt
> qgoupid rfer excl max_rfer max_excl parent  child
>      --  -
> 0/5  16.00KiB 16.00KiB none none --- ---
> 0/257  1016.00KiB 16.00KiB none none --- ---
> 0/258  1016.00KiB 16.00KiB none none --- ---
> 1/01016.00KiB 16.00KiB none none --- ---
>^^  not cleared
> --
>
> [CAUSE]
> Before rescan we call qgroup_rescan_zero_tracking() to zero out all
> qgroups' accounting numbers.
>
> However we don't mark all qgroups dirty, but rely on rescan to mark
> qgroups dirty.
>
> If we have any high level qgroup but without any child (orphan group),

That sentence is confusing. An orphan, by definition [1], is someone
(or something in this case) without parents.
But you mention a group without children, so that should be named
"childless" or simply say "without children".
So one part of the sentence is wrong, either what is in parenthesis or
what comes before them.

[1] https://www.thefreedictionary.com/orphan

> it
> won't be marked dirty during rescan, since we can not reach that qgroup.
>
> This will cause QGROUP_INFO items of orphan qgroups never get updated in
> quota tree, thus their numbers will stay the same in "btrfs qgroup show"
> output.
>
> [FIX]
> Just mark all qgroups dirty in qgroup_rescan_zero_tracking(), so even we
> have orphan qgroups their QGROUP_INFO items will still get updated during
> rescan.
>
> Reported-by: Misono Tomohiro 
> Signed-off-by: Qu Wenruo 
> ---
> changelog:
> v2:
>   Fix some grammar errors in commit message.
> ---
>  fs/btrfs/qgroup.c | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c
> index 48c1c3e7baf3..5a5372b33d96 100644
> --- a/fs/btrfs/qgroup.c
> +++ b/fs/btrfs/qgroup.c
> @@ -2864,6 +2864,7 @@ qgroup_rescan_zero_tracking(struct btrfs_fs_info 
> *fs_info)
> qgroup->rfer_cmpr = 0;
> qgroup->excl = 0;
> qgroup->excl_cmpr = 0;
> +   qgroup_dirty(fs_info, qgroup);
> }
> spin_unlock(_info->qgroup_lock);
>  }
> --
> 2.18.0
>
> --
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-- 
Filipe David Manana,

“Whether you think you can, or you think you can't — you're right.”
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Re: [PATCH v2] btrfs: qgroup: Dirty all qgroups before rescan

2018-08-09 Thread Misono Tomohiro
On 2018/08/09 16:08, Qu Wenruo wrote:
> [BUG]
> In the following case, rescan won't zero out the number of qgroup 1/0:
> --
> $ mkfs.btrfs -fq $DEV
> $ mount $DEV /mnt
> 
> $ btrfs quota enable /mnt
> $ btrfs qgroup create 1/0 /mnt
> $ btrfs sub create /mnt/sub
> $ btrfs qgroup assign 0/257 1/0 /mnt
> 
> $ dd if=/dev/urandom of=/mnt/sub/file bs=1k count=1000
> $ btrfs sub snap /mnt/sub /mnt/snap
> $ btrfs quota rescan -w /mnt
> $ btrfs qgroup show -pcre /mnt
> qgroupid rfer excl max_rfer max_excl parent  child
>      --  -
> 0/5  16.00KiB 16.00KiB none none --- ---
> 0/257  1016.00KiB 16.00KiB none none 1/0 ---
> 0/258  1016.00KiB 16.00KiB none none --- ---
> 1/01016.00KiB 16.00KiB none none --- 0/257
> 
> so far so good, but:
> 
> $ btrfs qgroup remove 0/257 1/0 /mnt
> WARNING: quotas may be inconsistent, rescan needed
> $ btrfs quota rescan -w /mnt
> $ btrfs qgroup show -pcre  /mnt
> qgoupid rfer excl max_rfer max_excl parent  child
>      --  -
> 0/5  16.00KiB 16.00KiB none none --- ---
> 0/257  1016.00KiB 16.00KiB none none --- ---
> 0/258  1016.00KiB 16.00KiB none none --- ---
> 1/01016.00KiB 16.00KiB none none --- ---
>^^  not cleared
> --
> 
> [CAUSE]
> Before rescan we call qgroup_rescan_zero_tracking() to zero out all
> qgroups' accounting numbers.
> 
> However we don't mark all qgroups dirty, but rely on rescan to mark
> qgroups dirty.
> 
> If we have any high level qgroup but without any child (orphan group), it
> won't be marked dirty during rescan, since we can not reach that qgroup.
> 
> This will cause QGROUP_INFO items of orphan qgroups never get updated in
> quota tree, thus their numbers will stay the same in "btrfs qgroup show"
> output.
> 
> [FIX]
> Just mark all qgroups dirty in qgroup_rescan_zero_tracking(), so even we
> have orphan qgroups their QGROUP_INFO items will still get updated during
> rescan.
> 
> Reported-by: Misono Tomohiro 
> Signed-off-by: Qu Wenruo 
> ---
> changelog:
> v2:
>   Fix some grammar errors in commit message.
> ---
>  fs/btrfs/qgroup.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c
> index 48c1c3e7baf3..5a5372b33d96 100644
> --- a/fs/btrfs/qgroup.c
> +++ b/fs/btrfs/qgroup.c
> @@ -2864,6 +2864,7 @@ qgroup_rescan_zero_tracking(struct btrfs_fs_info 
> *fs_info)
>   qgroup->rfer_cmpr = 0;
>   qgroup->excl = 0;
>   qgroup->excl_cmpr = 0;
> + qgroup_dirty(fs_info, qgroup);
>   }
>   spin_unlock(_info->qgroup_lock);
>  }
> 
Yes, this and previous patch
  [PATCH] btrfs: qgroup: Don't populating excl numbers for snapshot src if it 
belongs to other qgroups
resolves the problem I see.

So, this will reset all the qgroup items not rescanned in first transaction 
commit
by btrfs_run_qgroups(), but I don't think it is a problem.

Tested-by/Reviewed-by: Misono Tomohiro 

Thanks,
Misono

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[PATCH v2] btrfs: qgroup: Dirty all qgroups before rescan

2018-08-09 Thread Qu Wenruo
[BUG]
In the following case, rescan won't zero out the number of qgroup 1/0:
--
$ mkfs.btrfs -fq $DEV
$ mount $DEV /mnt

$ btrfs quota enable /mnt
$ btrfs qgroup create 1/0 /mnt
$ btrfs sub create /mnt/sub
$ btrfs qgroup assign 0/257 1/0 /mnt

$ dd if=/dev/urandom of=/mnt/sub/file bs=1k count=1000
$ btrfs sub snap /mnt/sub /mnt/snap
$ btrfs quota rescan -w /mnt
$ btrfs qgroup show -pcre /mnt
qgroupid rfer excl max_rfer max_excl parent  child
     --  -
0/5  16.00KiB 16.00KiB none none --- ---
0/257  1016.00KiB 16.00KiB none none 1/0 ---
0/258  1016.00KiB 16.00KiB none none --- ---
1/01016.00KiB 16.00KiB none none --- 0/257

so far so good, but:

$ btrfs qgroup remove 0/257 1/0 /mnt
WARNING: quotas may be inconsistent, rescan needed
$ btrfs quota rescan -w /mnt
$ btrfs qgroup show -pcre  /mnt
qgoupid rfer excl max_rfer max_excl parent  child
     --  -
0/5  16.00KiB 16.00KiB none none --- ---
0/257  1016.00KiB 16.00KiB none none --- ---
0/258  1016.00KiB 16.00KiB none none --- ---
1/01016.00KiB 16.00KiB none none --- ---
   ^^  not cleared
--

[CAUSE]
Before rescan we call qgroup_rescan_zero_tracking() to zero out all
qgroups' accounting numbers.

However we don't mark all qgroups dirty, but rely on rescan to mark
qgroups dirty.

If we have any high level qgroup but without any child (orphan group), it
won't be marked dirty during rescan, since we can not reach that qgroup.

This will cause QGROUP_INFO items of orphan qgroups never get updated in
quota tree, thus their numbers will stay the same in "btrfs qgroup show"
output.

[FIX]
Just mark all qgroups dirty in qgroup_rescan_zero_tracking(), so even we
have orphan qgroups their QGROUP_INFO items will still get updated during
rescan.

Reported-by: Misono Tomohiro 
Signed-off-by: Qu Wenruo 
---
changelog:
v2:
  Fix some grammar errors in commit message.
---
 fs/btrfs/qgroup.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c
index 48c1c3e7baf3..5a5372b33d96 100644
--- a/fs/btrfs/qgroup.c
+++ b/fs/btrfs/qgroup.c
@@ -2864,6 +2864,7 @@ qgroup_rescan_zero_tracking(struct btrfs_fs_info *fs_info)
qgroup->rfer_cmpr = 0;
qgroup->excl = 0;
qgroup->excl_cmpr = 0;
+   qgroup_dirty(fs_info, qgroup);
}
spin_unlock(_info->qgroup_lock);
 }
-- 
2.18.0

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