Commit 5582863f authored by Chuck Lever's avatar Chuck Lever Committed by Anna Schumaker
Browse files

SUNRPC: Add XDR overflow trace event 



This can help field troubleshooting without needing the overhead of
a full network capture (ie, tcpdump).

Signed-off-by: default avatarChuck Lever <chuck.lever@oracle.com>
Signed-off-by: default avatarAnna Schumaker <Anna.Schumaker@Netapp.com>
parent 0ccc61b1

include/trace/events/sunrpc.h

+67 −0
Original line number Diff line number Diff line
@@ -254,6 +254,73 @@ TRACE_EVENT(rpc_stats_latency, 
		__entry->backlog, __entry->rtt, __entry->execute)

);



TRACE_EVENT(rpc_xdr_overflow,

	TP_PROTO(

		const struct xdr_stream *xdr,

		size_t requested

	),



	TP_ARGS(xdr, requested),



	TP_STRUCT__entry(

		__field(unsigned int, task_id)

		__field(unsigned int, client_id)

		__field(int, version)

		__field(size_t, requested)

		__field(const void *, end)

		__field(const void *, p)

		__field(const void *, head_base)

		__field(size_t, head_len)

		__field(const void *, tail_base)

		__field(size_t, tail_len)

		__field(unsigned int, page_len)

		__field(unsigned int, len)

		__string(progname,

			 xdr->rqst->rq_task->tk_client->cl_program->name)

		__string(procedure,

			 xdr->rqst->rq_task->tk_msg.rpc_proc->p_name)

	),



	TP_fast_assign(

		if (xdr->rqst) {

			const struct rpc_task *task = xdr->rqst->rq_task;



			__entry->task_id = task->tk_pid;

			__entry->client_id = task->tk_client->cl_clid;

			__assign_str(progname,

				     task->tk_client->cl_program->name)

			__entry->version = task->tk_client->cl_vers;

			__assign_str(procedure, task->tk_msg.rpc_proc->p_name)

		} else {

			__entry->task_id = 0;

			__entry->client_id = 0;

			__assign_str(progname, "unknown")

			__entry->version = 0;

			__assign_str(procedure, "unknown")

		}

		__entry->requested = requested;

		__entry->end = xdr->end;

		__entry->p = xdr->p;

		__entry->head_base = xdr->buf->head[0].iov_base,

		__entry->head_len = xdr->buf->head[0].iov_len,

		__entry->page_len = xdr->buf->page_len,

		__entry->tail_base = xdr->buf->tail[0].iov_base,

		__entry->tail_len = xdr->buf->tail[0].iov_len,

		__entry->len = xdr->buf->len;

	),



	TP_printk(

		"task:%u@%u %sv%d %s requested=%zu p=%p end=%p xdr=[%p,%zu]/%u/[%p,%zu]/%u\n",

		__entry->task_id, __entry->client_id,

		__get_str(progname), __entry->version, __get_str(procedure),

		__entry->requested, __entry->p, __entry->end,

		__entry->head_base, __entry->head_len,

		__entry->page_len,

		__entry->tail_base, __entry->tail_len,

		__entry->len

	)

);



/*

 * First define the enums in the below macros to be exported to userspace

 * via TRACE_DEFINE_ENUM().

net/sunrpc/xdr.c

+17 −7
Original line number Diff line number Diff line
@@ -16,6 +16,7 @@ 
#include <linux/sunrpc/xdr.h>

#include <linux/sunrpc/msg_prot.h>

#include <linux/bvec.h>

#include <trace/events/sunrpc.h>



/*

 * XDR functions for basic NFS types
@@ -554,9 +555,9 @@ static __be32 *xdr_get_next_encode_buffer(struct xdr_stream *xdr, 
	int frag1bytes, frag2bytes;



	if (nbytes > PAGE_SIZE)

		return NULL; /* Bigger buffers require special handling */

		goto out_overflow; /* Bigger buffers require special handling */

	if (xdr->buf->len + nbytes > xdr->buf->buflen)

		return NULL; /* Sorry, we're totally out of space */

		goto out_overflow; /* Sorry, we're totally out of space */

	frag1bytes = (xdr->end - xdr->p) << 2;

	frag2bytes = nbytes - frag1bytes;

	if (xdr->iov)
@@ -585,6 +586,9 @@ static __be32 *xdr_get_next_encode_buffer(struct xdr_stream *xdr, 
	xdr->buf->page_len += frag2bytes;

	xdr->buf->len += nbytes;

	return p;

out_overflow:

	trace_rpc_xdr_overflow(xdr, nbytes);

	return NULL;

}



/**
@@ -902,20 +906,23 @@ static __be32 *xdr_copy_to_scratch(struct xdr_stream *xdr, size_t nbytes) 
	size_t cplen = (char *)xdr->end - (char *)xdr->p;



	if (nbytes > xdr->scratch.iov_len)

		return NULL;

		goto out_overflow;

	p = __xdr_inline_decode(xdr, cplen);

	if (p == NULL)

		return NULL;

	memcpy(cpdest, p, cplen);

	if (!xdr_set_next_buffer(xdr))

		goto out_overflow;

	cpdest += cplen;

	nbytes -= cplen;

	if (!xdr_set_next_buffer(xdr))

		return NULL;

	p = __xdr_inline_decode(xdr, nbytes);

	if (p == NULL)

		return NULL;

	memcpy(cpdest, p, nbytes);

	return xdr->scratch.iov_base;

out_overflow:

	trace_rpc_xdr_overflow(xdr, nbytes);

	return NULL;

}



/**
@@ -932,14 +939,17 @@ __be32 * xdr_inline_decode(struct xdr_stream *xdr, size_t nbytes) 
{

	__be32 *p;



	if (nbytes == 0)

	if (unlikely(nbytes == 0))

		return xdr->p;

	if (xdr->p == xdr->end && !xdr_set_next_buffer(xdr))

		return NULL;

		goto out_overflow;

	p = __xdr_inline_decode(xdr, nbytes);

	if (p != NULL)

		return p;

	return xdr_copy_to_scratch(xdr, nbytes);

out_overflow:

	trace_rpc_xdr_overflow(xdr, nbytes);

	return NULL;

}

EXPORT_SYMBOL_GPL(xdr_inline_decode);