On 1/7/25 00:25, Bernd Schubert wrote:
On teardown struct file_operations::uring_cmd requests need to be completed by calling io_uring_cmd_done(). Not completing all ring entries would result in busy io-uring tasks giving warning messages in intervals and unreleased struct file. Additionally the fuse connection and with that the ring can only get released when all io-uring commands are completed. Completion is done with ring entries that are a) in waiting state for new fuse requests - io_uring_cmd_done is needed b) already in userspace - io_uring_cmd_done through teardown is not needed, the request can just get released. If fuse server is still active and commits such a ring entry, fuse_uring_cmd() already checks if the connection is active and then complete the io-uring itself with -ENOTCONN. I.e. special handling is not needed. This scheme is basically represented by the ring entry state FRRS_WAIT and FRRS_USERSPACE.
Looks reasonable Reviewed-by: Pavel Begunkov <asml.silence@xxxxxxxxx>
Entries in state: - FRRS_INIT: No action needed, do not contribute to ring->queue_refs yet - All other states: Are currently processed by other tasks, async teardown is needed and it has to wait for the two states above. It could be also solved without an async teardown task, but would require additional if conditions in hot code paths. Also in my personal opinion the code looks cleaner with async teardown. Signed-off-by: Bernd Schubert <bschubert@xxxxxxx> --- fs/fuse/dev.c | 9 +++ fs/fuse/dev_uring.c | 198 ++++++++++++++++++++++++++++++++++++++++++++++++++ fs/fuse/dev_uring_i.h | 51 +++++++++++++ 3 files changed, 258 insertions(+)
-- Pavel Begunkov
