[PATCH] quota: check quota type in early stage

From: Chengguang Xu
Date: Tue Oct 08 2019 - 11:06:32 EST


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

Signed-off-by: Chengguang Xu <cgxu519@xxxxxxxxxxxx>
---
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