Re: [PATCH v1] io_uring_cqe_get_data() only requires a const struct io_uring_cqe *cqe

[Jens Axboe <axboe@kernel.dk>]

On 2/6/20 10:05 AM, Stefan Metzmacher wrote:
>>> While researching that I noticed that IOSQE_FIXED_FILE
>>> seems to be ignored for some new commands, I think that
>>> all commands with on input fd, should be able to use that flag.
>>> Can this be fixed before 5.6 final?
>>
>> Do you have specifics? Generally the file grabbing happens as part of
>> request prep, and the individual opcodes should not need to bother with
>> it.
> 
> io_statx_prep():
> io_openat_prep():
> io_openat2_prep():
> 
>   req->open.dfd = READ_ONCE(sqe->fd);
> 
> 
> io_statx():
>   ret = filename_lookup(ctx->dfd, ctx->filename, lookup_flags...
> 
> io_openat2():
> 
>   file = do_filp_open(req->open.dfd, req->open.filename, &op);
> 
> io_close_prep(): has this to make it clear that IOSQE_FIXED_FILE is not
> supported, I guess because FILE_UPDATE with -1 needs to be used instead?
> 
>         if (sqe->flags & IOSQE_FIXED_FILE)
>                 return -EINVAL;
> 
>         req->close.fd = READ_ONCE(sqe->fd);
> 
> 
> I guess at least we need if (sqe->flags & IOSQE_FIXED_FILE) in all
> cases, if we can't just fix it.

Ah yes good point, on both honoring it and failing it for close() when
we do honor it. I'll fix that up.

-- 
Jens Axboe