On Tue, Feb 2, 2021 at 5:41 AM Huang Jianan via fuse-devel
[off-list ref] wrote:

We found the following deadlock situations in low memory scenarios:
Thread A                         Thread B
- __writeback_single_inode
 - fuse_write_inode
  - fuse_simple_request
   - __fuse_request_send
    - request_wait_answer
                                 - fuse_dev_splice_read
                                  - fuse_copy_fill
                                   - __alloc_pages_direct_reclaim
                                    - do_shrink_slab
                                     - super_cache_scan
                                      - shrink_dentry_list
                                       - dentry_unlink_inode
                                        - iput_final
                                         - inode_wait_for_writeback

On what kernel are you seeing this?

I don't see how it can happen on upstream kernels, since there's a
"write_inode_now(inode, 1)" call in fuse_release() and nothing can
dirty the inode after the file has been released.

Thanks,
Miklos