tree 6047f570e0ec5de10303d29326d6f62f5d0e2065
parent 3c87ef6efb40f0e339d705c194b2224f854ec38e
author Jeff Layton <jlayton@poochiereds.net> 1433362466 -0400
committer Trond Myklebust <trond.myklebust@primarydata.com> 1433975178 -0400

sunrpc: make xprt->swapper an atomic_t

Split xs_swapper into enable/disable functions and eliminate the
"enable" flag.

Currently, it's racy if you have multiple swapon/swapoff operations
running in parallel over the same xprt. Also fix it so that we only
set it to a memalloc socket on a 0->1 transition and only clear it
on a 1->0 transition.

Cc: Mel Gorman <mgorman@suse.de>
Signed-off-by: Jeff Layton <jeff.layton@primarydata.com>
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>