From: Chuck Lever Date: Sun, 9 Nov 2014 01:15:09 +0000 (-0500) Subject: SUNRPC: serialize iostats updates X-Git-Tag: omap-for-v3.19/fixes-rc1~150^2~3^2~2 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=edef1297f33a4546559d905457b435a5ea160bab;p=pandora-kernel.git SUNRPC: serialize iostats updates Occasionally mountstats reports a negative retransmission rate. Ensure that two RPCs completing concurrently don't confuse the sums in the transport's op_metrics array. Since pNFS filelayout can invoke rpc_count_iostats() on another transport from xprt_release(), we can't rely on simply holding the transport_lock in xprt_release(). There's nothing for it but hard serialization. One spin lock per RPC operation should make this as painless as it can be. Signed-off-by: Chuck Lever Signed-off-by: Anna Schumaker --- Reading git-diff-tree failed