e6190dd003
In ublk_queue_rq(), Assume current request is a re-issued request aborted previously in monitor_work because the ubq_daemon(ioucmd's task) is PF_EXITING. For this request, we cannot call io_uring_cmd_complete_in_task() anymore because at that moment io_uring context may be freed in case that no inflight ioucmd exists. Otherwise, we may cause null-deref in ctx->fallback_work. Add a check on UBLK_IO_FLAG_ABORTED to prevent the above situation. This check is safe and makes sense. Note: monitor_work sets UBLK_IO_FLAG_ABORTED and ends this request (releasing the tag). Then the request is restarted(allocating the tag) and we are here. Since releasing/allocating a tag implies smp_mb(), finding UBLK_IO_FLAG_ABORTED guarantees that here is a re-issued request aborted previously. Suggested-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: ZiyangZhang <ZiyangZhang@linux.alibaba.com> Reviewed-by: Ming Lei <ming.lei@redhat.com> Link: https://lore.kernel.org/r/20220815023633.259825-4-ZiyangZhang@linux.alibaba.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.