* Sebastian Hasler (sebastian.has...@stuvus.uni-stuttgart.de) wrote:
> With the current implementation, blocking flock can lead to
> deadlock. Thus, it's better to return EOPNOTSUPP if a user attempts
> to perform a blocking flock request.
>
> Signed-off-by: Sebastian Hasler <sebastian.has...@stuvus.uni-stuttgart.de>
Queued, apologies for the delay.
> ---
> tools/virtiofsd/passthrough_ll.c | 9 +++++++++
> 1 file changed, 9 insertions(+)
>
> diff --git a/tools/virtiofsd/passthrough_ll.c
> b/tools/virtiofsd/passthrough_ll.c
> index 64b5b4fbb1..faa62278c5 100644
> --- a/tools/virtiofsd/passthrough_ll.c
> +++ b/tools/virtiofsd/passthrough_ll.c
> @@ -2442,6 +2442,15 @@ static void lo_flock(fuse_req_t req, fuse_ino_t ino,
> struct fuse_file_info *fi,
> int res;
> (void)ino;
>
> + if (!(op & LOCK_NB)) {
> + /*
> + * Blocking flock can deadlock as there is only one thread
> + * serving the queue.
> + */
> + fuse_reply_err(req, EOPNOTSUPP);
> + return;
> + }
> +
> res = flock(lo_fi_fd(req, fi), op);
>
> fuse_reply_err(req, res == -1 ? errno : 0);
> --
> 2.33.1
--
Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK
