NFSv4.1/pnfs: treat an oversized LAYOUTGET reply as -EMSGSIZE

decode_layoutget() already detects a server that sends a layout body
larger than the reply buffer we provided ("server cheating in
layoutget reply") but maps it to -EINVAL, which pnfs_update_layout()
treats as a transient error: the client falls back to the MDS for
this I/O only and re-sends a doomed LAYOUTGET on every subsequent
pageio attempt.

A server that overruns the reply buffer has ignored loga_maxcount, but
the client can recover the same way it recovers from a conformant
server's NFS4ERR_TOOSMALL: return -EMSGSIZE from exactly this check so
that the layoutget path retries once with a session-sized reply buffer
and otherwise marks the layout mode failed and falls back to the MDS.

Assisted-by: Claude:claude-opus-4-8
Signed-off-by: Benjamin Coddington <bcodding@hammerspace.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Anna Schumaker <anna.schumaker@hammerspace.com>

0 files changed, 0 insertions, 0 deletions