Hello Josef Bacik,
The patch bc44d7c4b2b1: "btrfs: push btrfs_grab_fs_root into
btrfs_get_fs_root" from Jan 24, 2020, leads to the following static
checker warning:
fs/btrfs/backref.c:565 resolve_indirect_ref()
warn: 'root' can also be NULL
fs/btrfs/backref.c
1537 struct btrfs_root *btrfs_get_fs_root(struct btrfs_fs_info *fs_info,
1538 u64 objectid, bool check_ref)
1539 {
1540 struct btrfs_root *root;
1541 struct btrfs_path *path;
1542 struct btrfs_key key;
1543 int ret;
1544
1545 if (objectid == BTRFS_ROOT_TREE_OBJECTID)
1546 return btrfs_grab_root(fs_info->tree_root);
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
1547 if (objectid == BTRFS_EXTENT_TREE_OBJECTID)
1548 return btrfs_grab_root(fs_info->extent_root);
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
These return NULL on error and it leads to an OOps in the caller.
1549 if (objectid == BTRFS_CHUNK_TREE_OBJECTID)
1550 return btrfs_grab_root(fs_info->chunk_root);
1551 if (objectid == BTRFS_DEV_TREE_OBJECTID)
1552 return btrfs_grab_root(fs_info->dev_root);
1553 if (objectid == BTRFS_CSUM_TREE_OBJECTID)
1554 return btrfs_grab_root(fs_info->csum_root);
1555 if (objectid == BTRFS_QUOTA_TREE_OBJECTID)
1556 return btrfs_grab_root(fs_info->quota_root) ?
1557 fs_info->quota_root : ERR_PTR(-ENOENT);
It should probably return ERR_PTR(-ENOENT).
1558 if (objectid == BTRFS_UUID_TREE_OBJECTID)
1559 return btrfs_grab_root(fs_info->uuid_root) ?
1560 fs_info->uuid_root : ERR_PTR(-ENOENT);
1561 if (objectid == BTRFS_FREE_SPACE_TREE_OBJECTID)
1562 return btrfs_grab_root(fs_info->free_space_root) ?
1563 fs_info->free_space_root : ERR_PTR(-ENOENT);
1564 again:
regards,
dan carpenter
