kernel.git/net/sunrpc/stats.c, branch linux-4.18.y

sunrpc: Add static trace point to report RPC latency stats

2018-04-10T20:06:22Z

Introduce a low-overhead mechanism to report information about latencies of individual RPCs. The goal is to enable user space to filter the trace record for latency outliers, or build histograms, etc. Signed-off-by: Chuck Lever Signed-off-by: Anna Schumaker

sunrpc: move pc_count out of struct svc_procinfo

2017-05-15T15:42:30Z

pc_count is the only writeable memeber of struct svc_procinfo, which is a good candidate to be const-ified as it contains function pointers. This patch moves it into out out struct svc_procinfo, and into a separate writable array that is pointed to by struct svc_version. Signed-off-by: Christoph Hellwig

sunrpc: mark all struct rpc_procinfo instances as const

2017-05-15T15:42:20Z

struct rpc_procinfo contains function pointers, and marking it as constant avoids it being able to be used as an attach vector for code injections. Signed-off-by: Christoph Hellwig Acked-by: Trond Myklebust

sunrpc: move p_count out of struct rpc_procinfo

2017-05-15T15:42:18Z

p_count is the only writeable memeber of struct rpc_procinfo, which is a good candidate to be const-ified as it contains function pointers. This patch moves it into out out struct rpc_procinfo, and into a separate writable array that is pointed to by struct rpc_version and indexed by p_statidx. Signed-off-by: Christoph Hellwig

SUNRPC: Proper metric accounting when RPC is not transmitted

2016-11-29T21:45:44Z

I noticed recently that during an xfstests on a krb5i mount, the retransmit count for certain operations had gone negative, and the backlog value became unreasonably large. I recall that Andy has pointed this out to me in the past. When call_refresh fails to find a valid credential for an RPC, the RPC exits immediately without sending anything on the wire. This leaves rq_ntrans, rq_xtime, and rq_rtt set to zero. The solution for om_queue is to not add the to RPC's running backlog queue total whenever rq_xtime is zero. For om_ntrans, it's a bit more difficult. A zero rq_ntrans causes om_ops to become larger than om_ntrans. The design of the RPC metrics API assumes that ntrans will always be equal to or larger than the ops count. The result is that when an RPC fails to find credentials, the RPC operation's reported retransmit count, which is computed in user space as the difference between ops and ntrans, goes negative. Ideally the kernel API should report a separate retransmit and "exited before initial transmission" metric, so that user space can sort out the difference properly. To avoid kernel API changes and changes to the way rq_ntrans is used when performing transport locking, account for untransmitted RPCs so that om_ntrans keeps up with om_ops: always add one or more to om_ntrans. Signed-off-by: Chuck Lever Signed-off-by: Anna Schumaker

sunrpc: add rpc_count_iostats_idx

2015-02-03T19:06:38Z

Add a call to tally stats for a task under a different statsidx than what's contained in the task structure. This is needed to properly account for pnfs reads/writes when the DS nfs version != the MDS version. Signed-off-by: Weston Andros Adamson Signed-off-by: Tom Haynes

SUNRPC: serialize iostats updates

2014-11-25T21:22:15Z

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

SUNRPC: Deprecate rpc_client->cl_protname

2013-08-30T13:19:34Z

It just duplicates the cl_program->name, and is not used in any fast paths where the extra dereference will cause a hit. Signed-off-by: Trond Myklebust

procfs: new helper - PDE_DATA(inode)

2013-04-09T18:13:32Z

The only part of proc_dir_entry the code outside of fs/proc really cares about is PDE(inode)->data. Provide a helper for that; static inline for now, eventually will be moved to fs/proc, along with the knowledge of struct proc_dir_entry layout. Signed-off-by: Al Viro

SUNRPC: Use RCU to dereference the rpc_clnt.cl_xprt field

2012-03-02T20:36:38Z

A migration event will replace the rpc_xprt used by an rpc_clnt. To ensure this can be done safely, all references to cl_xprt must now use a form of rcu_dereference(). Special care is taken with rpc_peeraddr2str(), which returns a pointer to memory whose lifetime is the same as the rpc_xprt. Signed-off-by: Trond Myklebust [ cel: fix lockdep splats and layering violations ] [ cel: forward ported to 3.4 ] [ cel: remove rpc_max_reqs(), add rpc_net_ns() ] Signed-off-by: Chuck Lever Signed-off-by: Trond Myklebust