diff mbox

[RFC] Btrfs: fix confusing edquot happening case

Message ID 516BD85B.3050508@cn.fujitsu.com (mailing list archive)
State New, archived
Headers show

Commit Message

Wang Shilong April 15, 2013, 10:37 a.m. UTC
Step to reproduce:
	mkfs.btrfs <disk>
	mount <disk> <mnt>
	dd if=/dev/zero of=/<mnt>/data bs=1M count=10
	sync
	btrfs quota enable <mnt>
	btrfs qgroup create 0/5 <mnt>
	btrfs qgroup limit 5M 0/5 <mnt>
	rm -f /<mnt>/data
	sync
	btrfs qgroup show <mnt>
	dd if=/dev/zero of=data bs=1M count=1

From the perspective of users, qgroup's referenced or referenced

is negative,But user can not continue to write data! a workaround
way is to cast u64 to int64 when doing qgroup reservation.

Signed-off-by: Wang Shilong <wangsl-fnst@cn.fujitsu.com>
---
This confusing edquot may also happen after Jan's qgroup
rescan has been implemented.
---
 fs/btrfs/qgroup.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

Comments

Arne Jansen April 15, 2013, 10:45 a.m. UTC | #1
On 15.04.2013 12:37, Wang Shilong wrote:
> Step to reproduce:
> 	mkfs.btrfs <disk>
> 	mount <disk> <mnt>
> 	dd if=/dev/zero of=/<mnt>/data bs=1M count=10
> 	sync
> 	btrfs quota enable <mnt>
> 	btrfs qgroup create 0/5 <mnt>
> 	btrfs qgroup limit 5M 0/5 <mnt>
> 	rm -f /<mnt>/data
> 	sync
> 	btrfs qgroup show <mnt>
> 	dd if=/dev/zero of=data bs=1M count=1
> 
> From the perspective of users, qgroup's referenced or referenced
> 
> is negative,But user can not continue to write data! a workaround
> way is to cast u64 to int64 when doing qgroup reservation.
> 
> Signed-off-by: Wang Shilong <wangsl-fnst@cn.fujitsu.com>
> ---
> This confusing edquot may also happen after Jan's qgroup
> rescan has been implemented.
> ---
>  fs/btrfs/qgroup.c |    4 ++--
>  1 files changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c
> index b44124d..0178223 100644
> --- a/fs/btrfs/qgroup.c
> +++ b/fs/btrfs/qgroup.c
> @@ -1523,14 +1523,14 @@ int btrfs_qgroup_reserve(struct btrfs_root *root, u64 num_bytes)
>  		qg = (struct btrfs_qgroup *)(uintptr_t)unode->aux;
>  
>  		if ((qg->lim_flags & BTRFS_QGROUP_LIMIT_MAX_RFER) &&
> -		    qg->reserved + qg->rfer + num_bytes >
> +		    qg->reserved + (signed long long)qg->rfer + num_bytes >

why not use s64 instead of signed long long? Otherwise this is the right way to
solve this.

Thanks,
Arne

>  		    qg->max_rfer) {
>  			ret = -EDQUOT;
>  			goto out;
>  		}
>  
>  		if ((qg->lim_flags & BTRFS_QGROUP_LIMIT_MAX_EXCL) &&
> -		    qg->reserved + qg->excl + num_bytes >
> +		    qg->reserved + (signed long long)qg->excl + num_bytes >
>  		    qg->max_excl) {
>  			ret = -EDQUOT;
>  			goto out;

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Wang Shilong April 15, 2013, 11:43 a.m. UTC | #2
Hello Arne,

> On 15.04.2013 12:37, Wang Shilong wrote:
>> Step to reproduce:
>> 	mkfs.btrfs <disk>
>> 	mount <disk> <mnt>
>> 	dd if=/dev/zero of=/<mnt>/data bs=1M count=10
>> 	sync
>> 	btrfs quota enable <mnt>
>> 	btrfs qgroup create 0/5 <mnt>
>> 	btrfs qgroup limit 5M 0/5 <mnt>
>> 	rm -f /<mnt>/data
>> 	sync
>> 	btrfs qgroup show <mnt>
>> 	dd if=/dev/zero of=data bs=1M count=1
>> 
>> From the perspective of users, qgroup's referenced or referenced
>> 
>> is negative,But user can not continue to write data! a workaround
>> way is to cast u64 to int64 when doing qgroup reservation.
>> 
>> Signed-off-by: Wang Shilong <wangsl-fnst@cn.fujitsu.com>
>> ---
>> This confusing edquot may also happen after Jan's qgroup
>> rescan has been implemented.
>> ---
>> fs/btrfs/qgroup.c |    4 ++--
>> 1 files changed, 2 insertions(+), 2 deletions(-)
>> 
>> diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c
>> index b44124d..0178223 100644
>> --- a/fs/btrfs/qgroup.c
>> +++ b/fs/btrfs/qgroup.c
>> @@ -1523,14 +1523,14 @@ int btrfs_qgroup_reserve(struct btrfs_root *root, u64 num_bytes)
>> 		qg = (struct btrfs_qgroup *)(uintptr_t)unode->aux;
>> 
>> 		if ((qg->lim_flags & BTRFS_QGROUP_LIMIT_MAX_RFER) &&
>> -		    qg->reserved + qg->rfer + num_bytes >
>> +		    qg->reserved + (signed long long)qg->rfer + num_bytes >
> 
> why not use s64 instead of signed long long? Otherwise this is the right way to
> solve this.

Yeah,V2 is coming. By the way, do you mind that i add Acked-by: Arne Jasen <sensille@gmx.net>?

Thanks,
Wang
> 
> Thanks,
> Arne
> 
>> 		    qg->max_rfer) {
>> 			ret = -EDQUOT;
>> 			goto out;
>> 		}
>> 
>> 		if ((qg->lim_flags & BTRFS_QGROUP_LIMIT_MAX_EXCL) &&
>> -		    qg->reserved + qg->excl + num_bytes >
>> +		    qg->reserved + (signed long long)qg->excl + num_bytes >
>> 		    qg->max_excl) {
>> 			ret = -EDQUOT;
>> 			goto out;
> 
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> To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in
> the body of a message to majordomo@vger.kernel.org
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Arne Jansen April 15, 2013, 12:03 p.m. UTC | #3
On 15.04.2013 13:43, Wang Shilong wrote:
> Hello Arne,
> 
>> On 15.04.2013 12:37, Wang Shilong wrote:
>>> Step to reproduce:
>>> 	mkfs.btrfs <disk>
>>> 	mount <disk> <mnt>
>>> 	dd if=/dev/zero of=/<mnt>/data bs=1M count=10
>>> 	sync
>>> 	btrfs quota enable <mnt>
>>> 	btrfs qgroup create 0/5 <mnt>
>>> 	btrfs qgroup limit 5M 0/5 <mnt>
>>> 	rm -f /<mnt>/data
>>> 	sync
>>> 	btrfs qgroup show <mnt>
>>> 	dd if=/dev/zero of=data bs=1M count=1
>>>
>>> From the perspective of users, qgroup's referenced or referenced
>>>
>>> is negative,But user can not continue to write data! a workaround
>>> way is to cast u64 to int64 when doing qgroup reservation.
>>>
>>> Signed-off-by: Wang Shilong <wangsl-fnst@cn.fujitsu.com>
>>> ---
>>> This confusing edquot may also happen after Jan's qgroup
>>> rescan has been implemented.
>>> ---
>>> fs/btrfs/qgroup.c |    4 ++--
>>> 1 files changed, 2 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c
>>> index b44124d..0178223 100644
>>> --- a/fs/btrfs/qgroup.c
>>> +++ b/fs/btrfs/qgroup.c
>>> @@ -1523,14 +1523,14 @@ int btrfs_qgroup_reserve(struct btrfs_root *root, u64 num_bytes)
>>> 		qg = (struct btrfs_qgroup *)(uintptr_t)unode->aux;
>>>
>>> 		if ((qg->lim_flags & BTRFS_QGROUP_LIMIT_MAX_RFER) &&
>>> -		    qg->reserved + qg->rfer + num_bytes >
>>> +		    qg->reserved + (signed long long)qg->rfer + num_bytes >
>>
>> why not use s64 instead of signed long long? Otherwise this is the right way to
>> solve this.
> 
> Yeah,V2 is coming. By the way, do you mind that i add Acked-by: Arne Jasen <sensille@gmx.net>?

You can add a Reviewed-by: Arne Jansen <sensille@gmx.net>

Thanks,
Arne

> 
> Thanks,
> Wang
>>
>> Thanks,
>> Arne
>>
>>> 		    qg->max_rfer) {
>>> 			ret = -EDQUOT;
>>> 			goto out;
>>> 		}
>>>
>>> 		if ((qg->lim_flags & BTRFS_QGROUP_LIMIT_MAX_EXCL) &&
>>> -		    qg->reserved + qg->excl + num_bytes >
>>> +		    qg->reserved + (signed long long)qg->excl + num_bytes >
>>> 		    qg->max_excl) {
>>> 			ret = -EDQUOT;
>>> 			goto out;
>>
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in
>> the body of a message to majordomo@vger.kernel.org
>> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> 
> --
> To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in
> the body of a message to majordomo@vger.kernel.org
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diff mbox

Patch

diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c
index b44124d..0178223 100644
--- a/fs/btrfs/qgroup.c
+++ b/fs/btrfs/qgroup.c
@@ -1523,14 +1523,14 @@  int btrfs_qgroup_reserve(struct btrfs_root *root, u64 num_bytes)
 		qg = (struct btrfs_qgroup *)(uintptr_t)unode->aux;
 
 		if ((qg->lim_flags & BTRFS_QGROUP_LIMIT_MAX_RFER) &&
-		    qg->reserved + qg->rfer + num_bytes >
+		    qg->reserved + (signed long long)qg->rfer + num_bytes >
 		    qg->max_rfer) {
 			ret = -EDQUOT;
 			goto out;
 		}
 
 		if ((qg->lim_flags & BTRFS_QGROUP_LIMIT_MAX_EXCL) &&
-		    qg->reserved + qg->excl + num_bytes >
+		    qg->reserved + (signed long long)qg->excl + num_bytes >
 		    qg->max_excl) {
 			ret = -EDQUOT;
 			goto out;