// SPDX-License-Identifier: GPL-2.0-only
/*
 * linux/net/sunrpc/stats.c
 *
 * procfs-based user access to generic RPC statistics. The stats files
 * reside in /proc/net/rpc.
 *
 * The read routines assume that the buffer passed in is just big enough.
 * If you implement an RPC service that has its own stats routine which
 * appends the generic RPC stats, make sure you don't exceed the PAGE_SIZE
 * limit.
 *
 * Copyright (C) 1995, 1996, 1997 Olaf Kirch <okir@monad.swb.de>
 */

#include <linux/module.h>
#include <linux/slab.h>

#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/sunrpc/clnt.h>
#include <linux/sunrpc/svcsock.h>
#include <linux/sunrpc/metrics.h>
#include <linux/rcupdate.h>

#include <trace/events/sunrpc.h>

#include "netns.h"

#define RPCDBG_FACILITY RPCDBG_MISC

/*
 * Get RPC client stats
 */
static int rpc_proc_show(struct seq_file *seq, void *v) {
        const struct rpc_stat   *statp = seq->private;
        const struct rpc_program *prog = statp->program;
        unsigned int i, j;

        seq_printf(seq,
                "net %u %u %u %u\n",
                        statp->netcnt,
                        statp->netudpcnt,
                        statp->nettcpcnt,
                        statp->nettcpconn);
        seq_printf(seq,
                "rpc %u %u %u\n",
                        statp->rpccnt,
                        statp->rpcretrans,
                        statp->rpcauthrefresh);

        for (i = 0; i < prog->nrvers; i++) {
                const struct rpc_version *vers = prog->version[i];
                if (!vers)
                        continue;
                seq_printf(seq, "proc%u %u",
                                        vers->number, vers->nrprocs);
                for (j = 0; j < vers->nrprocs; j++)
                        seq_printf(seq, " %u", vers->counts[j]);
                seq_putc(seq, '\n');
        }
        return 0;
}

static int rpc_proc_open(struct inode *inode, struct file *file)
{
        return single_open(file, rpc_proc_show, pde_data(inode));
}

static const struct proc_ops rpc_proc_ops = {
        .proc_open      = rpc_proc_open,
        .proc_read      = seq_read,
        .proc_lseek     = seq_lseek,
        .proc_release   = single_release,
};

/*
 * Get RPC server stats
 */
void svc_seq_show(struct seq_file *seq, const struct svc_stat *statp)
{
        const struct svc_program *prog = statp->program;
        const struct svc_version *vers;
        unsigned int i, j, k;
        unsigned long count;

        seq_printf(seq,
                "net %u %u %u %u\n",
                        statp->netcnt,
                        statp->netudpcnt,
                        statp->nettcpcnt,
                        statp->nettcpconn);
        seq_printf(seq,
                "rpc %u %u %u %u %u\n",
                        statp->rpccnt,
                        statp->rpcbadfmt+statp->rpcbadauth+statp->rpcbadclnt,
                        statp->rpcbadfmt,
                        statp->rpcbadauth,
                        statp->rpcbadclnt);

        for (i = 0; i < prog->pg_nvers; i++) {
                vers = prog->pg_vers[i];
                if (!vers)
                        continue;
                seq_printf(seq, "proc%d %u", i, vers->vs_nproc);
                for (j = 0; j < vers->vs_nproc; j++) {
                        count = 0;
                        for_each_possible_cpu(k)
                                count += per_cpu(vers->vs_count[j], k);
                        seq_printf(seq, " %lu", count);
                }
                seq_putc(seq, '\n');
        }
}
EXPORT_SYMBOL_GPL(svc_seq_show);

/**
 * rpc_alloc_iostats - allocate an rpc_iostats structure
 * @clnt: RPC program, version, and xprt
 *
 */
struct rpc_iostats *rpc_alloc_iostats(struct rpc_clnt *clnt)
{
        struct rpc_iostats *stats;
        int i;

        stats = kzalloc_objs(*stats, clnt->cl_maxproc);
        if (stats) {
                for (i = 0; i < clnt->cl_maxproc; i++)
                        spin_lock_init(&stats[i].om_lock);
        }
        return stats;
}
EXPORT_SYMBOL_GPL(rpc_alloc_iostats);

/**
 * rpc_free_iostats - release an rpc_iostats structure
 * @stats: doomed rpc_iostats structure
 *
 */
void rpc_free_iostats(struct rpc_iostats *stats)
{
        kfree(stats);
}
EXPORT_SYMBOL_GPL(rpc_free_iostats);

/**
 * rpc_count_iostats_metrics - tally up per-task stats
 * @task: completed rpc_task
 * @op_metrics: stat structure for OP that will accumulate stats from @task
 */
void rpc_count_iostats_metrics(const struct rpc_task *task,
                               struct rpc_iostats *op_metrics)
{
        struct rpc_rqst *req = task->tk_rqstp;
        ktime_t backlog, execute, now;

        if (!op_metrics || !req)
                return;

        now = ktime_get();
        spin_lock(&op_metrics->om_lock);

        op_metrics->om_ops++;
        /* kernel API: om_ops must never become larger than om_ntrans */
        op_metrics->om_ntrans += max(req->rq_ntrans, 1);
        op_metrics->om_timeouts += task->tk_timeouts;

        op_metrics->om_bytes_sent += req->rq_xmit_bytes_sent;
        op_metrics->om_bytes_recv += req->rq_reply_bytes_recvd;

        backlog = 0;
        if (ktime_to_ns(req->rq_xtime)) {
                backlog = ktime_sub(req->rq_xtime, task->tk_start);
                op_metrics->om_queue = ktime_add(op_metrics->om_queue, backlog);
        }

        op_metrics->om_rtt = ktime_add(op_metrics->om_rtt, req->rq_rtt);

        execute = ktime_sub(now, task->tk_start);
        op_metrics->om_execute = ktime_add(op_metrics->om_execute, execute);
        if (task->tk_status < 0)
                op_metrics->om_error_status++;

        spin_unlock(&op_metrics->om_lock);

        trace_rpc_stats_latency(req->rq_task, backlog, req->rq_rtt, execute);
}
EXPORT_SYMBOL_GPL(rpc_count_iostats_metrics);

/**
 * rpc_count_iostats - tally up per-task stats
 * @task: completed rpc_task
 * @stats: array of stat structures
 *
 * Uses the statidx from @task
 */
void rpc_count_iostats(const struct rpc_task *task, struct rpc_iostats *stats)
{
        rpc_count_iostats_metrics(task,
                                  &stats[task->tk_msg.rpc_proc->p_statidx]);
}
EXPORT_SYMBOL_GPL(rpc_count_iostats);

static void _print_name(struct seq_file *seq, unsigned int op,
                        const struct rpc_procinfo *procs)
{
        if (procs[op].p_name)
                seq_printf(seq, "\t%12s: ", procs[op].p_name);
        else if (op == 0)
                seq_printf(seq, "\t        NULL: ");
        else
                seq_printf(seq, "\t%12u: ", op);
}

static void _add_rpc_iostats(struct rpc_iostats *a, struct rpc_iostats *b)
{
        a->om_ops += b->om_ops;
        a->om_ntrans += b->om_ntrans;
        a->om_timeouts += b->om_timeouts;
        a->om_bytes_sent += b->om_bytes_sent;
        a->om_bytes_recv += b->om_bytes_recv;
        a->om_queue = ktime_add(a->om_queue, b->om_queue);
        a->om_rtt = ktime_add(a->om_rtt, b->om_rtt);
        a->om_execute = ktime_add(a->om_execute, b->om_execute);
        a->om_error_status += b->om_error_status;
}

static void _print_rpc_iostats(struct seq_file *seq, struct rpc_iostats *stats,
                               int op, const struct rpc_procinfo *procs)
{
        _print_name(seq, op, procs);
        seq_printf(seq, "%lu %lu %lu %llu %llu %llu %llu %llu %lu\n",
                   stats->om_ops,
                   stats->om_ntrans,
                   stats->om_timeouts,
                   stats->om_bytes_sent,
                   stats->om_bytes_recv,
                   ktime_to_ms(stats->om_queue),
                   ktime_to_ms(stats->om_rtt),
                   ktime_to_ms(stats->om_execute),
                   stats->om_error_status);
}

static int do_print_stats(struct rpc_clnt *clnt, struct rpc_xprt *xprt, void *seqv)
{
        struct seq_file *seq = seqv;

        xprt->ops->print_stats(xprt, seq);
        return 0;
}

void rpc_clnt_show_stats(struct seq_file *seq, struct rpc_clnt *clnt)
{
        unsigned int op, maxproc = clnt->cl_maxproc;

        if (!clnt->cl_metrics)
                return;

        seq_printf(seq, "\tRPC iostats version: %s  ", RPC_IOSTATS_VERS);
        seq_printf(seq, "p/v: %u/%u (%s)\n",
                        clnt->cl_prog, clnt->cl_vers, clnt->cl_program->name);

        rpc_clnt_iterate_for_each_xprt(clnt, do_print_stats, seq);

        seq_printf(seq, "\tper-op statistics\n");
        for (op = 0; op < maxproc; op++) {
                struct rpc_iostats stats = {};
                struct rpc_clnt *next = clnt;
                do {
                        _add_rpc_iostats(&stats, &next->cl_metrics[op]);
                        if (next == next->cl_parent)
                                break;
                        next = next->cl_parent;
                } while (next);
                _print_rpc_iostats(seq, &stats, op, clnt->cl_procinfo);
        }
}
EXPORT_SYMBOL_GPL(rpc_clnt_show_stats);

/*
 * Register/unregister RPC proc files
 */
static inline struct proc_dir_entry *
do_register(struct net *net, const char *name, void *data,
            const struct proc_ops *proc_ops)
{
        struct sunrpc_net *sn;

        dprintk("RPC:       registering /proc/net/rpc/%s\n", name);
        sn = net_generic(net, sunrpc_net_id);
        return proc_create_data(name, 0, sn->proc_net_rpc, proc_ops, data);
}

struct proc_dir_entry *
rpc_proc_register(struct net *net, struct rpc_stat *statp)
{
        return do_register(net, statp->program->name, statp, &rpc_proc_ops);
}
EXPORT_SYMBOL_GPL(rpc_proc_register);

void
rpc_proc_unregister(struct net *net, const char *name)
{
        struct sunrpc_net *sn;

        sn = net_generic(net, sunrpc_net_id);
        remove_proc_entry(name, sn->proc_net_rpc);
}
EXPORT_SYMBOL_GPL(rpc_proc_unregister);

struct proc_dir_entry *
svc_proc_register(struct net *net, struct svc_stat *statp, const struct proc_ops *proc_ops)
{
        return do_register(net, statp->program->pg_name, net, proc_ops);
}
EXPORT_SYMBOL_GPL(svc_proc_register);

void
svc_proc_unregister(struct net *net, const char *name)
{
        struct sunrpc_net *sn;

        sn = net_generic(net, sunrpc_net_id);
        remove_proc_entry(name, sn->proc_net_rpc);
}
EXPORT_SYMBOL_GPL(svc_proc_unregister);

int rpc_proc_init(struct net *net)
{
        struct sunrpc_net *sn;

        dprintk("RPC:       registering /proc/net/rpc\n");
        sn = net_generic(net, sunrpc_net_id);
        sn->proc_net_rpc = proc_mkdir("rpc", net->proc_net);
        if (sn->proc_net_rpc == NULL)
                return -ENOMEM;

        return 0;
}

void rpc_proc_exit(struct net *net)
{
        dprintk("RPC:       unregistering /proc/net/rpc\n");
        remove_proc_entry("rpc", net->proc_net);
}