2019-04-28 05:44:54

by Chengguang Xu

Subject: [PATCH] quota: set init_needed flag only when successfully getting dquot

Set init_needed flag only when successfully getting dquot,
so that we can skip unnecessary subsequent operation.

Signed-off-by: Chengguang Xu <[email protected]>
---
fs/quota/dquot.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/fs/quota/dquot.c b/fs/quota/dquot.c
index fc20e06c56ba..8d4ce2a2b5c8 100644
--- a/fs/quota/dquot.c
+++ b/fs/quota/dquot.c
@@ -1449,8 +1449,6 @@ static int __dquot_initialize(struct inode *inode, int type)
if (!sb_has_quota_active(sb, cnt))
continue;

- init_needed = 1;
-
switch (cnt) {
case USRQUOTA:
qid = make_kqid_uid(inode->i_uid);
@@ -1475,6 +1473,9 @@ static int __dquot_initialize(struct inode *inode, int type)
dquot = NULL;
}
got[cnt] = dquot;
+
+ if (got[cnt])
+ init_needed = 1;
}

/* All required i_dquot has been initialized */
--
2.20.1

2019-04-29 21:52:44

by Jan Kara

Subject: Re: [PATCH] quota: set init_needed flag only when successfully getting dquot

On Sun 28-04-19 13:39:21, Chengguang Xu wrote:
> Set init_needed flag only when successfully getting dquot,
> so that we can skip unnecessary subsequent operation.
>
> Signed-off-by: Chengguang Xu <[email protected]>

Thanks for the patch but I don't think it's really useful. It will be very
rare that we race with quotaoff of dqget() fails due to error. So the
additional overhead of iterating over dquots doesn't really matter in that
case.

Honza

> ---
> fs/quota/dquot.c | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/fs/quota/dquot.c b/fs/quota/dquot.c
> index fc20e06c56ba..8d4ce2a2b5c8 100644
> --- a/fs/quota/dquot.c
> +++ b/fs/quota/dquot.c
> @@ -1449,8 +1449,6 @@ static int __dquot_initialize(struct inode *inode, int type)
> if (!sb_has_quota_active(sb, cnt))
> continue;
>
> - init_needed = 1;
> -
> switch (cnt) {
> case USRQUOTA:
> qid = make_kqid_uid(inode->i_uid);
> @@ -1475,6 +1473,9 @@ static int __dquot_initialize(struct inode *inode, int type)
> dquot = NULL;
> }
> got[cnt] = dquot;
> +
> + if (got[cnt])
> + init_needed = 1;
> }
>
> /* All required i_dquot has been initialized */
> --
> 2.20.1
>
>
--
Jan Kara <[email protected]>
SUSE Labs, CR

2019-04-30 02:28:34

by Chengguang Xu

Subject: Re: [PATCH] quota: set init_needed flag only when successfully getting dquot

On 4/30/19 5:49 AM, Jan Kara wrote:
> On Sun 28-04-19 13:39:21, Chengguang Xu wrote:
>> Set init_needed flag only when successfully getting dquot,
>> so that we can skip unnecessary subsequent operation.
>>
>> Signed-off-by: Chengguang Xu <[email protected]>
> Thanks for the patch but I don't think it's really useful. It will be very
> rare that we race with quotaoff of dqget() fails due to error. So the
> additional overhead of iterating over dquots doesn't really matter in that
> case.

Hi Jan,

Thanks for the comment, I got it.

Chengguang.