On Thu, Jan 03, 2019 at 10:50:01AM +0200, Nikolay Borisov wrote: > ihold is supposed to be used when the caller already has a reference to > the inode. In the case of cow_file_range_async this invariants holds, > since the 3 call chains leading to this function all take a reference: > > btrfs_writepage <--- does igrab > extent_write_full_page > __extent_writepage > writepage_delalloc > btrfs_run_delalloc_range > cow_file_range_async > > extent_write_cache_pages <--- does igrab > __extent_writepage (same callchain as above) > > and > > submit_compressed_extents <-- already called from async CoW submit path, > which would have done ihold. > extent_write_locked_range > __extent_writepage So by the logic the inode reference needs to be taken early, eg. in btrfs_writepage and all low-level callbacks or helpers are fine with ihold. Reviewed-by: David Sterba <dsterba@xxxxxxxx>
