9p semantics are such that clunk should trigger a flush of any outstanding write cache (otherwise there might not be a fid to flush with). Change the writeback semantics to always flush on close of the file.
We need two testing regimines to better understand this:
read/write -- need to make sure we are actually using writeback cache until close, simple testing from shell is hard to do this
don't interfere with read cache -- we might not want to flush read on close in higher cache modes, so make sure we aren't invalidating the cache just because we are closing the fid.
9p semantics are such that clunk should trigger a flush of any outstanding write cache (otherwise there might not be a fid to flush with). Change the writeback semantics to always flush on close of the file.
We need two testing regimines to better understand this: