Revert "btrfs: add ASSERTs on prealloc in qgroup functions"

This reverts commit 252877a8701530fde861a4f27710c1e718e97caa.

Commit 252877a87015 ("btrfs: add ASSERTs on prealloc in qgroup
functions") tries to remove the kfree() on preallocated qgroup during
several call sites, but this cannot work as intended:

- btrfs_quota_enable()
- btrfs_create_qgroup()
  If add_qgroup_item() failed, we go out_free_path() and at that time
  prealloc is not yet utilized and will trigger the new ASSERT().

- btrfs_qgroup_inherit()
  If qgroup_auto_inherit() failed, prealloc is not yet utilized and
  will trigger the new ASSERT()

Reported-by: syzbot+b44d4a4885bc82af2a06@syzkaller.appspotmail.com
Link: https://lore.kernel.org/linux-btrfs/69369331.a70a0220.38f243.009e.GAE@google.com/
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c
index 9e2b53e90dcbe3bde380065e4333c1b8e84b98da..d9d8d9968a58268082c0ccd23140d217247fd6ee 100644 (file)
--- a/fs/btrfs/qgroup.c
+++ b/fs/btrfs/qgroup.c
@@ -1243,14 +1243,7 @@ out:
                btrfs_end_transaction(trans);
        else if (trans)
                ret = btrfs_end_transaction(trans);
-
-       /*
-        * At this point we either failed at allocating prealloc, or we
-        * succeeded and passed the ownership to it to add_qgroup_rb(). In any
-        * case, this needs to be NULL or there is something wrong.
-        */
-       ASSERT(prealloc == NULL);
-
+       kfree(prealloc);
        return ret;
 }
 
@@ -1682,12 +1675,7 @@ int btrfs_create_qgroup(struct btrfs_trans_handle *trans, u64 qgroupid)
        ret = btrfs_sysfs_add_one_qgroup(fs_info, qgroup);
 out:
        mutex_unlock(&fs_info->qgroup_ioctl_lock);
-       /*
-        * At this point we either failed at allocating prealloc, or we
-        * succeeded and passed the ownership to it to add_qgroup_rb(). In any
-        * case, this needs to be NULL or there is something wrong.
-        */
-       ASSERT(prealloc == NULL);
+       kfree(prealloc);
        return ret;
 }
 
@@ -3279,7 +3267,7 @@ int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans, u64 srcid,
        struct btrfs_root *quota_root;
        struct btrfs_qgroup *srcgroup;
        struct btrfs_qgroup *dstgroup;
-       struct btrfs_qgroup *prealloc = NULL;
+       struct btrfs_qgroup *prealloc;
        struct btrfs_qgroup_list **qlist_prealloc = NULL;
        bool free_inherit = false;
        bool need_rescan = false;
@@ -3520,14 +3508,7 @@ out:
        }
        if (free_inherit)
                kfree(inherit);
-
-       /*
-        * At this point we either failed at allocating prealloc, or we
-        * succeeded and passed the ownership to it to add_qgroup_rb(). In any
-        * case, this needs to be NULL or there is something wrong.
-        */
-       ASSERT(prealloc == NULL);
-
+       kfree(prealloc);
        return ret;
 }