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Btrfs: add all ioctl checks before user change for quota operations

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Since all the quota configurations are loaded in memory, and we can
have ioctl checks before operating in the disk. It is safe to do such
things because qgroup_ioctl_lock is held outside.

Without these extra checks firstly, it should be ok to do user change
for quota operations. For example:

if we want to add an existed qgroup, we will do:
	->add_qgroup_item()
		->add_qgroup_rb()

add_qgroup_item() will return -EEXIST to us, however, qgroups are all
in memory, why not check them in memory firstly.

Signed-off-by: Wang Shilong <wangsl-fnst@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
This commit is contained in:
Wang Shilong 2013-04-17 14:49:51 +00:00 committed by Josef Bacik
parent 3c97185c65
commit 534e6623b7
1 changed files with 41 additions and 5 deletions
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46
fs/btrfs/qgroup.c
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@ -956,6 +956,7 @@ int btrfs_add_qgroup_relation(struct btrfs_trans_handle *trans,
struct btrfs_root *quota_root;
struct btrfs_qgroup *parent;
struct btrfs_qgroup *member;
struct btrfs_qgroup_list *list;
int ret = 0;
mutex_lock(&fs_info->qgroup_ioctl_lock);
@ -971,6 +972,14 @@ int btrfs_add_qgroup_relation(struct btrfs_trans_handle *trans,
goto out;
}
/* check if such qgroup relation exist firstly */
list_for_each_entry(list, &member->groups, next_group) {
if (list->group == parent) {
ret = -EEXIST;
goto out;
}
}
ret = add_qgroup_relation_item(trans, quota_root, src, dst);
if (ret)
goto out;
@ -993,6 +1002,9 @@ int btrfs_del_qgroup_relation(struct btrfs_trans_handle *trans,
struct btrfs_fs_info *fs_info, u64 src, u64 dst)
{
struct btrfs_root *quota_root;
struct btrfs_qgroup *parent;
struct btrfs_qgroup *member;
struct btrfs_qgroup_list *list;
int ret = 0;
int err;
@ -1003,6 +1015,21 @@ int btrfs_del_qgroup_relation(struct btrfs_trans_handle *trans,
goto out;
}
member = find_qgroup_rb(fs_info, src);
parent = find_qgroup_rb(fs_info, dst);
if (!member || !parent) {
ret = -EINVAL;
goto out;
}
/* check if such qgroup relation exist firstly */
list_for_each_entry(list, &member->groups, next_group) {
if (list->group == parent)
goto exist;
}
ret = -ENOENT;
goto out;
exist:
ret = del_qgroup_relation_item(trans, quota_root, src, dst);
err = del_qgroup_relation_item(trans, quota_root, dst, src);
if (err && !ret)
@ -1010,7 +1037,6 @@ int btrfs_del_qgroup_relation(struct btrfs_trans_handle *trans,
spin_lock(&fs_info->qgroup_lock);
del_relation_rb(fs_info, src, dst);
spin_unlock(&fs_info->qgroup_lock);
out:
mutex_unlock(&fs_info->qgroup_ioctl_lock);
@ -1030,8 +1056,15 @@ int btrfs_create_qgroup(struct btrfs_trans_handle *trans,
ret = -EINVAL;
goto out;
}
qgroup = find_qgroup_rb(fs_info, qgroupid);
if (qgroup) {
ret = -EEXIST;
goto out;
}
ret = add_qgroup_item(trans, quota_root, qgroupid);
if (ret)
goto out;
spin_lock(&fs_info->qgroup_lock);
qgroup = add_qgroup_rb(fs_info, qgroupid);
@ -1058,15 +1091,18 @@ int btrfs_remove_qgroup(struct btrfs_trans_handle *trans,
goto out;
}
/* check if there are no relations to this qgroup */
qgroup = find_qgroup_rb(fs_info, qgroupid);
if (qgroup) {
if (!list_empty(&qgroup->groups) || !list_empty(&qgroup->members)) {
if (!qgroup) {
ret = -ENOENT;
goto out;
} else {
/* check if there are no relations to this qgroup */
if (!list_empty(&qgroup->groups) ||
!list_empty(&qgroup->members)) {
ret = -EBUSY;
goto out;
}
}
ret = del_qgroup_item(trans, quota_root, qgroupid);
spin_lock(&fs_info->qgroup_lock);