On 20.10.26 07:58, Markus Armbruster wrote:
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"
Sure, thanks!
Unless you stop me ( :) ), I’ll keep the reference in, in addition.
Hanna
