Hanna Czenczek <[email protected]> writes:
> The documentation for this type is a bit sparse right now, and
> specifically does not explain why it is limited to read/write only;
> "I/O operation type" could well imply this should distinguish a much
> broader range of operations like flushes, discards, etc., but it does
> not.
>
> Make a note why that is, which is that these types reflect the block
> device on-error policy settings that we have, which are rerror for read
> and werror for write.
>
> Signed-off-by: Hanna Czenczek <[email protected]>
> ---
> qapi/common.json | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/qapi/common.json b/qapi/common.json
> index 1352e664b23..880eb87a9cb 100644
> --- a/qapi/common.json
> +++ b/qapi/common.json
> @@ -9,7 +9,10 @@
>
> ##
> # @IoOperationType:
> -# An enumeration of the I/O operation types
> +# An enumeration of the I/O operation types, limited to the block
> +# device on-error policy settings we have (rerror and werror).
> +# For reference, the corresponding error policy values are set in
> +# `BlockdevOnError`.
> #
> # @read: read operation
> #
I believe I get what you mean only because I read the cover letter
first.
My first attempt
I/O operation types that may have a block device on-error policy.
is still confusing, because we use "block device" both for frontends and
backends. I believe "block device on-error policy" refers to the qdev
properties "rerror" and "werror" certain block frontends / device models
have (virtio-blk-device, scsi-hd, scsi-cd, usb-storage). Possible
clarification:
These are the properties "rerror" and "werror" certain block device
models have.
And then maybe
@read: read operation, corresponding to property "rerror"
@write: write operation, corresponding to property "werror"
