From: Wang Shilong <[email protected]>
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 <[email protected]>
---
Since this patch relies on my previous patchset, so it
is based on the latest btrfs-next branch.
---
fs/btrfs/qgroup.c | 46 +++++++++++++++++++++++++++++++++++++++++-----
1 file changed, 41 insertions(+), 5 deletions(-)
diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c
index f9fb52e..f175471 100644
--- a/fs/btrfs/qgroup.c
+++ b/fs/btrfs/qgroup.c
@@ -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);
--
1.7.11.7
--
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