2019-10-08 15:10:06

by Chengguang Xu

Subject: [PATCH] quota: check quota type in early stage

Check quota type in early stage so we can avoid many
unncessary operations when the type is wrong.

Signed-off-by: Chengguang Xu <[email protected]>
---
fs/quota/quota.c | 7 +++----
1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/fs/quota/quota.c b/fs/quota/quota.c
index cb13fb76dbee..5444d3c4d93f 100644
--- a/fs/quota/quota.c
+++ b/fs/quota/quota.c
@@ -60,8 +60,6 @@ static int quota_sync_all(int type)
{
int ret;

- if (type >= MAXQUOTAS)
- return -EINVAL;
ret = security_quotactl(Q_SYNC, type, 0, NULL);
if (!ret)
iterate_supers(quota_sync_one, &type);
@@ -686,8 +684,6 @@ static int do_quotactl(struct super_block *sb, int type, int cmd, qid_t id,
{
int ret;

- if (type >= MAXQUOTAS)
- return -EINVAL;
type = array_index_nospec(type, MAXQUOTAS);
/*
* Quota not supported on this fs? Check this before s_quota_types
@@ -831,6 +827,9 @@ int kernel_quotactl(unsigned int cmd, const char __user *special,
cmds = cmd >> SUBCMDSHIFT;
type = cmd & SUBCMDMASK;

+ if (type >= MAXQUOTAS)
+ return -EINVAL;
+
/*
* As a special case Q_SYNC can be called without a specific device.
* It will iterate all superblocks that have quota enabled and call
--
2.21.0

2019-10-08 15:27:49

by Jan Kara

Subject: Re: [PATCH] quota: check quota type in early stage

On Tue 08-10-19 22:50:59, Chengguang Xu wrote:
> Check quota type in early stage so we can avoid many
> unncessary operations when the type is wrong.
>
> Signed-off-by: Chengguang Xu <[email protected]>

Yeah, checking earlier makes sense, especially since it consolidates two
checks into one. I've added your patch to my tree. Thanks!

Honza

> ---
> fs/quota/quota.c | 7 +++----
> 1 file changed, 3 insertions(+), 4 deletions(-)
>
> diff --git a/fs/quota/quota.c b/fs/quota/quota.c
> index cb13fb76dbee..5444d3c4d93f 100644
> --- a/fs/quota/quota.c
> +++ b/fs/quota/quota.c
> @@ -60,8 +60,6 @@ static int quota_sync_all(int type)
> {
> int ret;
>
> - if (type >= MAXQUOTAS)
> - return -EINVAL;
> ret = security_quotactl(Q_SYNC, type, 0, NULL);
> if (!ret)
> iterate_supers(quota_sync_one, &type);
> @@ -686,8 +684,6 @@ static int do_quotactl(struct super_block *sb, int type, int cmd, qid_t id,
> {
> int ret;
>
> - if (type >= MAXQUOTAS)
> - return -EINVAL;
> type = array_index_nospec(type, MAXQUOTAS);
> /*
> * Quota not supported on this fs? Check this before s_quota_types
> @@ -831,6 +827,9 @@ int kernel_quotactl(unsigned int cmd, const char __user *special,
> cmds = cmd >> SUBCMDSHIFT;
> type = cmd & SUBCMDMASK;
>
> + if (type >= MAXQUOTAS)
> + return -EINVAL;
> +
> /*
> * As a special case Q_SYNC can be called without a specific device.
> * It will iterate all superblocks that have quota enabled and call
> --
> 2.21.0
>
>
>
>
--
Jan Kara <[email protected]>
SUSE Labs, CR