Re: [PATCH 2/5] block: add function to issue compare and write

Martin K. Petersen
2014-10-17T23:38:37Z

>>>>> "Christoph" == Christoph Hellwig <hch@infradead.org> writes:

Christoph> We already have req->cmd_type which actually is a fairly good
Christoph> description of what we get except for REQ_TYPE_FS, which is a
Christoph> horrible overload using req->cmd_flags.

Christoph> Given that you're just one of many currently ongoing patches
Christoph> to add more flags here I think you need to byte the bullet
Christoph> and fix this up by replacing REQ_TYPE_FS with:

Christoph> REQ_TYPE_WRITE REQ_TYPE_READ REQ_TYPE_FLUSH REQ_TYPE_DISCARD
Christoph> REQ_TYPE_WRITE_SAME REQ_TYPE_CMP_AND_WRITE

The problem with this is that, as it stands, a bio has no type. And it
would suck if we couldn't keep bio rw and request flags in sync.

I wonder if it would make more sense to move the remaining rq types to
cmd_flags after I'm done with the 64-bit conversion?

--
Martin K. Petersen Oracle Linux Engineering