tree 075fb31c1d415171267a652574eea3b139c96253
parent 04d25b7d5d1b43fbaffe4ad4bb21288f0f305338
author Chuck Lever <chuck.lever@oracle.com> 1496937116 -0400
committer Anna Schumaker <Anna.Schumaker@Netapp.com> 1499976010 -0400

xprtrdma: Pre-mark remotely invalidated MRs

There are rare cases where an rpcrdma_req and its matched
rpcrdma_rep can be re-used, via rpcrdma_buffer_put, while the RPC
reply handler is still using that req. This is typically due to a
signal firing at just the wrong instant.

As part of closing this race window, avoid using the wrong
rpcrdma_rep to detect remotely invalidated MRs. Mark MRs as
invalidated while we are sure the rep is still OK to use.

BugLink: https://bugzilla.linux-nfs.org/show_bug.cgi?id=305
Fixes: 68791649a725 ('xprtrdma: Invalidate in the RPC reply ... ')
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>