Commit 606cdcca authored by Niu Yawei's avatar Niu Yawei Committed by Jan Kara
Browse files

quota: protect Q_GETFMT by dqonoff_mutex 



dqptr_sem will go away. Protect Q_GETFMT quotactl by
dqonoff_mutex instead. This is also enough to make sure
quota info will not go away while we are looking at it.

Signed-off-by: default avatarLai Siyao <lai.siyao@intel.com>
Signed-off-by: default avatarNiu Yawei <yawei.niu@intel.com>
Signed-off-by: default avatarJan Kara <jack@suse.cz>
parent d68aab6b

fs/quota/quota.c

+3 −3
Original line number Diff line number Diff line
@@ -79,13 +79,13 @@ static int quota_getfmt(struct super_block *sb, int type, void __user *addr) 
{

	__u32 fmt;



	down_read(&sb_dqopt(sb)->dqptr_sem);

	mutex_lock(&sb_dqopt(sb)->dqonoff_mutex);

	if (!sb_has_quota_active(sb, type)) {

		up_read(&sb_dqopt(sb)->dqptr_sem);

		mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);

		return -ESRCH;

	}

	fmt = sb_dqopt(sb)->info[type].dqi_format->qf_fmt_id;

	up_read(&sb_dqopt(sb)->dqptr_sem);

	mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);

	if (copy_to_user(addr, &fmt, sizeof(fmt)))

		return -EFAULT;

	return 0;