#ifndef MY_ABC_HERE
#define MY_ABC_HERE
#endif
// SPDX-License-Identifier: GPL-2.0
/*
 * procfs-based user access to knfsd statistics
 *
 * /proc/net/rpc/nfsd
 *
 * Format:
 *	rc <hits> <misses> <nocache>
 *			Statistsics for the reply cache
 *	fh <stale> <total-lookups> <anonlookups> <dir-not-in-dcache> <nondir-not-in-dcache>
 *			statistics for filehandle lookup
 *	io <bytes-read> <bytes-written>
 *			statistics for IO throughput
 *	th <threads> <fullcnt> <10%-20%> <20%-30%> ... <90%-100%> <100%> 
 *			time (seconds) when nfsd thread usage above thresholds
 *			and number of times that all threads were in use
 *	ra cache-size  <10%  <20%  <30% ... <100% not-found
 *			number of times that read-ahead entry was found that deep in
 *			the cache.
 *	plus generic RPC stats (see net/sunrpc/stats.c)
 *
 * Copyright (C) 1995, 1996, 1997 Olaf Kirch <okir@monad.swb.de>
 */

#include <linux/seq_file.h>
#include <linux/module.h>
#include <linux/sunrpc/stats.h>
#include <net/net_namespace.h>

#include "nfsd.h"

struct nfsd_stats	nfsdstats;
struct svc_stat		nfsd_svcstats = {
	.program	= &nfsd_program,
};

static int nfsd_proc_show(struct seq_file *seq, void *v)
{
	int i;

	seq_printf(seq, "rc %u %u %u\nfh %u %u %u %u %u\nio %u %u\n",
		      nfsdstats.rchits,
		      nfsdstats.rcmisses,
		      nfsdstats.rcnocache,
		      nfsdstats.fh_stale,
		      nfsdstats.fh_lookup,
		      nfsdstats.fh_anon,
		      nfsdstats.fh_nocache_dir,
		      nfsdstats.fh_nocache_nondir,
		      nfsdstats.io_read,
		      nfsdstats.io_write);
	/* thread usage: */
	seq_printf(seq, "th %u %u", nfsdstats.th_cnt, nfsdstats.th_fullcnt);
	for (i=0; i<10; i++) {
		unsigned int jifs = nfsdstats.th_usage[i];
		unsigned int sec = jifs / HZ, msec = (jifs % HZ)*1000/HZ;
		seq_printf(seq, " %u.%03u", sec, msec);
	}

	/* newline and ra-cache */
	seq_printf(seq, "\nra %u", nfsdstats.ra_size);
	for (i=0; i<11; i++)
		seq_printf(seq, " %u", nfsdstats.ra_depth[i]);
	seq_putc(seq, '\n');
	
	/* show my rpc info */
	svc_seq_show(seq, &nfsd_svcstats);

#ifdef CONFIG_NFSD_V4
	/* Show count for individual nfsv4 operations */
	/* Writing operation numbers 0 1 2 also for maintaining uniformity */
	seq_printf(seq,"proc4ops %u", LAST_NFS4_OP + 1);
	for (i = 0; i <= LAST_NFS4_OP; i++)
		seq_printf(seq, " %u", nfsdstats.nfs4_opcount[i]);

	seq_putc(seq, '\n');
#endif

	return 0;
}

static int nfsd_proc_open(struct inode *inode, struct file *file)
{
	return single_open(file, nfsd_proc_show, NULL);
}

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

#ifdef MY_ABC_HERE
static int nfsd_lat_proc_show(struct seq_file *seq, void *v)
{
	struct svc_program *prog = nfsd_svcstats.program;
	const struct svc_version *vers;
	unsigned int i, j;

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

		seq_printf(seq, "proc%d_lat %u", i, vers->vs_nproc);
		for (j = 0; j < vers->vs_nproc; j++)
			seq_printf(seq, " %llu", (u64)atomic64_read(&vers->vs_latency[j].accu));
		seq_putc(seq, '\n');

		seq_printf(seq, "proc%d_maxlat %u", i, vers->vs_nproc);
		for (j = 0; j < vers->vs_nproc; j++)
			seq_printf(seq, " %u", (u32)atomic_read(&vers->vs_latency[j].max));
		seq_putc(seq, '\n');
	}

#ifdef CONFIG_NFSD_V4
	seq_printf(seq,"proc4ops %u", LAST_NFS4_OP + 1);
	for (i = 0; i <= LAST_NFS4_OP; i++)
		seq_printf(seq, " %u", nfsdstats.nfs4_opcount[i]);
	seq_putc(seq, '\n');

	seq_printf(seq,"proc4ops_lat %u", LAST_NFS4_OP + 1);
	for (i = 0; i <= LAST_NFS4_OP; i++)
		seq_printf(seq, " %llu", (u64)atomic64_read(&nfsdstats.nfs4_oplatency[i].accu));
	seq_putc(seq, '\n');

	seq_printf(seq,"proc4ops_maxlat %u", LAST_NFS4_OP + 1);
	for (i = 0; i <= LAST_NFS4_OP; i++)
		seq_printf(seq, " %u", (u32)atomic_read(&nfsdstats.nfs4_oplatency[i].max));
	seq_putc(seq, '\n');
#endif

	return 0;
}

static ssize_t nfsd_lat_write(struct file *file,
			  const char __user *buf, size_t size, loff_t * ppos)
{
	struct svc_program *prog = nfsd_svcstats.program;
	const struct svc_version *vers;
	ssize_t len = size;
	char kbuf[11];
	int val = 0;
	unsigned int i, j;

	if (len >= 10) {
		len = -EINVAL;
		goto End;
	}

	if (copy_from_user(kbuf, buf, len)) {
		len = -EFAULT;
		goto End;
	}

	if (1 != sscanf(kbuf, "%d", &val) || val < 0) {
		len = -EINVAL;
		goto End;
	}

	for (i = 0; i < prog->pg_nvers; i++) {
		if (!(vers = prog->pg_vers[i]))
			continue;
		for (j = 0; j < vers->vs_nproc; j++)
			atomic_set(&vers->vs_latency[j].max, val);
	}

#ifdef CONFIG_NFSD_V4
	for (i = 0; i <= LAST_NFS4_OP; i++)
		atomic_set(&nfsdstats.nfs4_oplatency[i].max, val);
#endif

End:
	return len;
}

static int nfsd_lat_proc_open(struct inode *inode, struct file *file)
{
	return single_open(file, nfsd_lat_proc_show, NULL);
}

static const struct proc_ops nfsd_lat_proc_ops = {
	.proc_open = nfsd_lat_proc_open,
	.proc_read  = seq_read,
	.proc_write = nfsd_lat_write,
	.proc_lseek = seq_lseek,
	.proc_release = single_release,
};
#endif /* MY_ABC_HERE */

void
nfsd_stat_init(void)
{
	svc_proc_register(&init_net, &nfsd_svcstats, &nfsd_proc_ops);
#ifdef MY_ABC_HERE
	svc_proc_register_name(&init_net, "nfsd_lat", &nfsd_svcstats, &nfsd_lat_proc_ops);
#endif /* MY_ABC_HERE */
}

void
nfsd_stat_shutdown(void)
{
	svc_proc_unregister(&init_net, "nfsd");
#ifdef MY_ABC_HERE
	svc_proc_unregister(&init_net, "nfsd_lat");
#endif /* MY_ABC_HERE */
}