// SPDX-License-Identifier: GPL-2.0
#include <linux/ceph/ceph_debug.h>

#include <linux/device.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/ctype.h>
#include <linux/debugfs.h>
#include <linux/seq_file.h>
#include <linux/math64.h>
#include <linux/ktime.h>
#include <linux/atomic.h>

#include <linux/ceph/libceph.h>
#include <linux/ceph/mon_client.h>
#include <linux/ceph/auth.h>
#include <linux/ceph/debugfs.h>
#include <linux/ceph/decode.h>

#include "super.h"

#ifdef CONFIG_DEBUG_FS

#include "mds_client.h"
#include "metric.h"
#include "subvolume_metrics.h"

/**
 * struct ceph_session_feature_desc - Maps feature bits to names for debugfs
 * @bit: Feature bit number from enum ceph_feature_type (see mds_client.h)
 * @name: Human-readable feature name for debugfs output
 *
 * Used by metric_features_show() to display negotiated session features.
 */
struct ceph_session_feature_desc {
	unsigned int bit;
	const char *name;
};

static const struct ceph_session_feature_desc ceph_session_feature_table[] = {
	{ CEPHFS_FEATURE_METRIC_COLLECT, "METRIC_COLLECT" },
	{ CEPHFS_FEATURE_REPLY_ENCODING, "REPLY_ENCODING" },
	{ CEPHFS_FEATURE_RECLAIM_CLIENT, "RECLAIM_CLIENT" },
	{ CEPHFS_FEATURE_LAZY_CAP_WANTED, "LAZY_CAP_WANTED" },
	{ CEPHFS_FEATURE_MULTI_RECONNECT, "MULTI_RECONNECT" },
	{ CEPHFS_FEATURE_DELEG_INO, "DELEG_INO" },
	{ CEPHFS_FEATURE_ALTERNATE_NAME, "ALTERNATE_NAME" },
	{ CEPHFS_FEATURE_NOTIFY_SESSION_STATE, "NOTIFY_SESSION_STATE" },
	{ CEPHFS_FEATURE_OP_GETVXATTR, "OP_GETVXATTR" },
	{ CEPHFS_FEATURE_32BITS_RETRY_FWD, "32BITS_RETRY_FWD" },
	{ CEPHFS_FEATURE_NEW_SNAPREALM_INFO, "NEW_SNAPREALM_INFO" },
	{ CEPHFS_FEATURE_HAS_OWNER_UIDGID, "HAS_OWNER_UIDGID" },
	{ CEPHFS_FEATURE_MDS_AUTH_CAPS_CHECK, "MDS_AUTH_CAPS_CHECK" },
	{ CEPHFS_FEATURE_SUBVOLUME_METRICS, "SUBVOLUME_METRICS" },
};

static int mdsmap_show(struct seq_file *s, void *p)
{
	int i;
	struct ceph_fs_client *fsc = s->private;
	struct ceph_mdsmap *mdsmap;

	if (!fsc->mdsc || !fsc->mdsc->mdsmap)
		return 0;
	mdsmap = fsc->mdsc->mdsmap;
	seq_printf(s, "epoch %d\n", mdsmap->m_epoch);
	seq_printf(s, "root %d\n", mdsmap->m_root);
	seq_printf(s, "max_mds %d\n", mdsmap->m_max_mds);
	seq_printf(s, "session_timeout %d\n", mdsmap->m_session_timeout);
	seq_printf(s, "session_autoclose %d\n", mdsmap->m_session_autoclose);
	for (i = 0; i < mdsmap->possible_max_rank; i++) {
		struct ceph_entity_addr *addr = &mdsmap->m_info[i].addr;
		int state = mdsmap->m_info[i].state;
		seq_printf(s, "\tmds%d\t%s\t(%s)\n", i,
			       ceph_pr_addr(addr),
			       ceph_mds_state_name(state));
	}
	return 0;
}

/*
 * mdsc debugfs
 */
static int mdsc_show(struct seq_file *s, void *p)
{
	struct ceph_fs_client *fsc = s->private;
	struct ceph_mds_client *mdsc = fsc->mdsc;
	struct ceph_mds_request *req;
	struct rb_node *rp;
	char *path;

	mutex_lock(&mdsc->mutex);
	for (rp = rb_first(&mdsc->request_tree); rp; rp = rb_next(rp)) {
		req = rb_entry(rp, struct ceph_mds_request, r_node);

		if (req->r_request && req->r_session)
			seq_printf(s, "%lld\tmds%d\t", req->r_tid,
				   req->r_session->s_mds);
		else if (!req->r_request)
			seq_printf(s, "%lld\t(no request)\t", req->r_tid);
		else
			seq_printf(s, "%lld\t(no session)\t", req->r_tid);

		seq_printf(s, "%s", ceph_mds_op_name(req->r_op));

		if (test_bit(CEPH_MDS_R_GOT_UNSAFE, &req->r_req_flags))
			seq_puts(s, "\t(unsafe)");
		else
			seq_puts(s, "\t");

		if (req->r_inode) {
			seq_printf(s, " #%llx", ceph_ino(req->r_inode));
		} else if (req->r_dentry) {
			struct ceph_path_info path_info = {0};
			path = ceph_mdsc_build_path(mdsc, req->r_dentry, &path_info, 0);
			if (IS_ERR(path))
				path = NULL;
			spin_lock(&req->r_dentry->d_lock);
			seq_printf(s, " #%llx/%pd (%s)",
				   ceph_ino(d_inode(req->r_dentry->d_parent)),
				   req->r_dentry,
				   path ? path : "");
			spin_unlock(&req->r_dentry->d_lock);
			ceph_mdsc_free_path_info(&path_info);
		} else if (req->r_path1) {
			seq_printf(s, " #%llx/%s", req->r_ino1.ino,
				   req->r_path1);
		} else {
			seq_printf(s, " #%llx", req->r_ino1.ino);
		}

		if (req->r_old_dentry) {
			struct ceph_path_info path_info = {0};
			path = ceph_mdsc_build_path(mdsc, req->r_old_dentry, &path_info, 0);
			if (IS_ERR(path))
				path = NULL;
			spin_lock(&req->r_old_dentry->d_lock);
			seq_printf(s, " #%llx/%pd (%s)",
				   req->r_old_dentry_dir ?
				   ceph_ino(req->r_old_dentry_dir) : 0,
				   req->r_old_dentry,
				   path ? path : "");
			spin_unlock(&req->r_old_dentry->d_lock);
			ceph_mdsc_free_path_info(&path_info);
		} else if (req->r_path2 && req->r_op != CEPH_MDS_OP_SYMLINK) {
			if (req->r_ino2.ino)
				seq_printf(s, " #%llx/%s", req->r_ino2.ino,
					   req->r_path2);
			else
				seq_printf(s, " %s", req->r_path2);
		}

		seq_puts(s, "\n");
	}
	mutex_unlock(&mdsc->mutex);

	return 0;
}

#define CEPH_LAT_METRIC_SHOW(name, total, avg, min, max, sq) {		\
	s64 _total, _avg, _min, _max, _sq, _st;				\
	_avg = ktime_to_us(avg);					\
	_min = ktime_to_us(min == KTIME_MAX ? 0 : min);			\
	_max = ktime_to_us(max);					\
	_total = total - 1;						\
	_sq = _total > 0 ? DIV64_U64_ROUND_CLOSEST(sq, _total) : 0;	\
	_st = int_sqrt64(_sq);						\
	_st = ktime_to_us(_st);						\
	seq_printf(s, "%-14s%-12lld%-16lld%-16lld%-16lld%lld\n",	\
		   name, total, _avg, _min, _max, _st);			\
}

#define CEPH_SZ_METRIC_SHOW(name, total, avg, min, max, sum) {		\
	u64 _min = min == U64_MAX ? 0 : min;				\
	seq_printf(s, "%-14s%-12lld%-16llu%-16llu%-16llu%llu\n",	\
		   name, total, avg, _min, max, sum);			\
}

static int metrics_file_show(struct seq_file *s, void *p)
{
	struct ceph_fs_client *fsc = s->private;
	struct ceph_client_metric *m = &fsc->mdsc->metric;

	seq_printf(s, "item                               total\n");
	seq_printf(s, "------------------------------------------\n");
	seq_printf(s, "%-35s%lld\n", "total inodes",
		   percpu_counter_sum(&m->total_inodes));
	seq_printf(s, "%-35s%lld\n", "opened files",
		   atomic64_read(&m->opened_files));
	seq_printf(s, "%-35s%lld\n", "pinned i_caps",
		   atomic64_read(&m->total_caps));
	seq_printf(s, "%-35s%lld\n", "opened inodes",
		   percpu_counter_sum(&m->opened_inodes));
	return 0;
}

static const char * const metric_str[] = {
	"read",
	"write",
	"metadata",
	"copyfrom"
};
static int metrics_latency_show(struct seq_file *s, void *p)
{
	struct ceph_fs_client *fsc = s->private;
	struct ceph_client_metric *cm = &fsc->mdsc->metric;
	struct ceph_metric *m;
	s64 total, avg, min, max, sq;
	int i;

	seq_printf(s, "item          total       avg_lat(us)     min_lat(us)     max_lat(us)     stdev(us)\n");
	seq_printf(s, "-----------------------------------------------------------------------------------\n");

	for (i = 0; i < METRIC_MAX; i++) {
		m = &cm->metric[i];
		spin_lock(&m->lock);
		total = m->total;
		avg = m->latency_avg;
		min = m->latency_min;
		max = m->latency_max;
		sq = m->latency_sq_sum;
		spin_unlock(&m->lock);
		CEPH_LAT_METRIC_SHOW(metric_str[i], total, avg, min, max, sq);
	}

	return 0;
}

static int metrics_size_show(struct seq_file *s, void *p)
{
	struct ceph_fs_client *fsc = s->private;
	struct ceph_client_metric *cm = &fsc->mdsc->metric;
	struct ceph_metric *m;
	s64 total;
	u64 sum, avg, min, max;
	int i;

	seq_printf(s, "item          total       avg_sz(bytes)   min_sz(bytes)   max_sz(bytes)  total_sz(bytes)\n");
	seq_printf(s, "----------------------------------------------------------------------------------------\n");

	for (i = 0; i < METRIC_MAX; i++) {
		/* skip 'metadata' as it doesn't use the size metric */
		if (i == METRIC_METADATA)
			continue;
		m = &cm->metric[i];
		spin_lock(&m->lock);
		total = m->total;
		sum = m->size_sum;
		avg = total > 0 ? DIV64_U64_ROUND_CLOSEST(sum, total) : 0;
		min = m->size_min;
		max = m->size_max;
		spin_unlock(&m->lock);
		CEPH_SZ_METRIC_SHOW(metric_str[i], total, avg, min, max, sum);
	}

	return 0;
}

static int metrics_caps_show(struct seq_file *s, void *p)
{
	struct ceph_fs_client *fsc = s->private;
	struct ceph_client_metric *m = &fsc->mdsc->metric;
	int nr_caps = 0;

	seq_printf(s, "item          total           miss            hit\n");
	seq_printf(s, "-------------------------------------------------\n");

	seq_printf(s, "%-14s%-16lld%-16lld%lld\n", "d_lease",
		   atomic64_read(&m->total_dentries),
		   percpu_counter_sum(&m->d_lease_mis),
		   percpu_counter_sum(&m->d_lease_hit));

	nr_caps = atomic64_read(&m->total_caps);
	seq_printf(s, "%-14s%-16d%-16lld%lld\n", "caps", nr_caps,
		   percpu_counter_sum(&m->i_caps_mis),
		   percpu_counter_sum(&m->i_caps_hit));

	return 0;
}

static int caps_show_cb(struct inode *inode, int mds, void *p)
{
	struct ceph_inode_info *ci = ceph_inode(inode);
	struct seq_file *s = p;
	struct ceph_cap *cap;

	spin_lock(&ci->i_ceph_lock);
	cap = __get_cap_for_mds(ci, mds);
	if (cap)
		seq_printf(s, "0x%-17llx%-3d%-17s%-17s\n", ceph_ino(inode),
			   cap->session->s_mds,
			   ceph_cap_string(cap->issued),
			   ceph_cap_string(cap->implemented));
	spin_unlock(&ci->i_ceph_lock);
	return 0;
}

static int caps_show(struct seq_file *s, void *p)
{
	struct ceph_fs_client *fsc = s->private;
	struct ceph_mds_client *mdsc = fsc->mdsc;
	int total, avail, used, reserved, min, i;
	struct cap_wait	*cw;

	ceph_reservation_status(fsc, &total, &avail, &used, &reserved, &min);
	seq_printf(s, "total\t\t%d\n"
		   "avail\t\t%d\n"
		   "used\t\t%d\n"
		   "reserved\t%d\n"
		   "min\t\t%d\n\n",
		   total, avail, used, reserved, min);
	seq_printf(s, "ino              mds  issued           implemented\n");
	seq_printf(s, "--------------------------------------------------\n");

	mutex_lock(&mdsc->mutex);
	for (i = 0; i < mdsc->max_sessions; i++) {
		struct ceph_mds_session *session;

		session = __ceph_lookup_mds_session(mdsc, i);
		if (!session)
			continue;
		mutex_unlock(&mdsc->mutex);
		mutex_lock(&session->s_mutex);
		ceph_iterate_session_caps(session, caps_show_cb, s);
		mutex_unlock(&session->s_mutex);
		ceph_put_mds_session(session);
		mutex_lock(&mdsc->mutex);
	}
	mutex_unlock(&mdsc->mutex);

	seq_printf(s, "\n\nWaiters:\n--------\n");
	seq_printf(s, "tgid         ino                need             want\n");
	seq_printf(s, "-----------------------------------------------------\n");

	spin_lock(&mdsc->caps_list_lock);
	list_for_each_entry(cw, &mdsc->cap_wait_list, list) {
		seq_printf(s, "%-13d0x%-17llx%-17s%-17s\n", cw->tgid, cw->ino,
				ceph_cap_string(cw->need),
				ceph_cap_string(cw->want));
	}
	spin_unlock(&mdsc->caps_list_lock);

	return 0;
}

static int mds_sessions_show(struct seq_file *s, void *ptr)
{
	struct ceph_fs_client *fsc = s->private;
	struct ceph_mds_client *mdsc = fsc->mdsc;
	struct ceph_auth_client *ac = fsc->client->monc.auth;
	struct ceph_options *opt = fsc->client->options;
	int mds;

	mutex_lock(&mdsc->mutex);

	/* The 'num' portion of an 'entity name' */
	seq_printf(s, "global_id %llu\n", ac->global_id);

	/* The -o name mount argument */
	seq_printf(s, "name \"%s\"\n", opt->name ? opt->name : "");

	/* The list of MDS session rank+state */
	for (mds = 0; mds < mdsc->max_sessions; mds++) {
		struct ceph_mds_session *session =
			__ceph_lookup_mds_session(mdsc, mds);
		if (!session) {
			continue;
		}
		mutex_unlock(&mdsc->mutex);
		seq_printf(s, "mds.%d %s\n",
				session->s_mds,
				ceph_session_state_name(session->s_state));

		ceph_put_mds_session(session);
		mutex_lock(&mdsc->mutex);
	}
	mutex_unlock(&mdsc->mutex);

	return 0;
}

static int status_show(struct seq_file *s, void *p)
{
	struct ceph_fs_client *fsc = s->private;
	struct ceph_entity_inst *inst = &fsc->client->msgr.inst;
	struct ceph_entity_addr *client_addr = ceph_client_addr(fsc->client);

	seq_printf(s, "instance: %s.%lld %s/%u\n", ENTITY_NAME(inst->name),
		   ceph_pr_addr(client_addr), le32_to_cpu(client_addr->nonce));
	seq_printf(s, "blocklisted: %s\n", str_true_false(fsc->blocklisted));

	return 0;
}

static int subvolume_metrics_show(struct seq_file *s, void *p)
{
	struct ceph_fs_client *fsc = s->private;
	struct ceph_mds_client *mdsc = fsc->mdsc;
	struct ceph_subvol_metric_snapshot *snapshot = NULL;
	u32 nr = 0;
	u64 total_sent = 0;
	u64 nonzero_sends = 0;
	u32 i;

	if (!mdsc) {
		seq_puts(s, "mds client unavailable\n");
		return 0;
	}

	mutex_lock(&mdsc->subvol_metrics_last_mutex);
	if (mdsc->subvol_metrics_last && mdsc->subvol_metrics_last_nr) {
		nr = mdsc->subvol_metrics_last_nr;
		snapshot = kmemdup_array(mdsc->subvol_metrics_last, nr,
					 sizeof(*snapshot), GFP_KERNEL);
		if (!snapshot)
			nr = 0;
	}
	total_sent = mdsc->subvol_metrics_sent;
	nonzero_sends = mdsc->subvol_metrics_nonzero_sends;
	mutex_unlock(&mdsc->subvol_metrics_last_mutex);

	seq_puts(s, "Last sent subvolume metrics:\n");
	if (!nr) {
		seq_puts(s, "  (none)\n");
	} else {
		seq_puts(s, "  subvol_id          rd_ops    wr_ops    rd_bytes       wr_bytes       rd_lat_us      wr_lat_us\n");
		for (i = 0; i < nr; i++) {
			const struct ceph_subvol_metric_snapshot *e = &snapshot[i];

			seq_printf(s, "  %-18llu %-9llu %-9llu %-14llu %-14llu %-14llu %-14llu\n",
				   e->subvolume_id,
				   e->read_ops, e->write_ops,
				   e->read_bytes, e->write_bytes,
				   e->read_latency_us, e->write_latency_us);
		}
	}
	kfree(snapshot);

	seq_puts(s, "\nStatistics:\n");
	seq_printf(s, "  entries_sent:      %llu\n", total_sent);
	seq_printf(s, "  non_zero_sends:    %llu\n", nonzero_sends);

	seq_puts(s, "\nPending (unsent) subvolume metrics:\n");
	ceph_subvolume_metrics_dump(&mdsc->subvol_metrics, s);
	return 0;
}

DEFINE_SHOW_ATTRIBUTE(mdsmap);
DEFINE_SHOW_ATTRIBUTE(mdsc);
DEFINE_SHOW_ATTRIBUTE(caps);
DEFINE_SHOW_ATTRIBUTE(mds_sessions);
DEFINE_SHOW_ATTRIBUTE(status);
DEFINE_SHOW_ATTRIBUTE(metrics_file);
DEFINE_SHOW_ATTRIBUTE(metrics_latency);
DEFINE_SHOW_ATTRIBUTE(metrics_size);
DEFINE_SHOW_ATTRIBUTE(metrics_caps);
DEFINE_SHOW_ATTRIBUTE(subvolume_metrics);

static int metric_features_show(struct seq_file *s, void *p)
{
	struct ceph_fs_client *fsc = s->private;
	struct ceph_mds_client *mdsc = fsc->mdsc;
	unsigned long session_features = 0;
	bool have_session = false;
	bool metric_collect = false;
	bool subvol_support = false;
	bool metrics_enabled = false;
	bool subvol_enabled = false;
	int i;

	if (!mdsc) {
		seq_puts(s, "mds client unavailable\n");
		return 0;
	}

	mutex_lock(&mdsc->mutex);
	if (mdsc->metric.session) {
		have_session = true;
		session_features = mdsc->metric.session->s_features;
	}
	mutex_unlock(&mdsc->mutex);

	if (have_session) {
		metric_collect =
			test_bit(CEPHFS_FEATURE_METRIC_COLLECT,
				 &session_features);
		subvol_support =
			test_bit(CEPHFS_FEATURE_SUBVOLUME_METRICS,
				 &session_features);
	}

	metrics_enabled = !disable_send_metrics && have_session && metric_collect;
	subvol_enabled = metrics_enabled && subvol_support;

	seq_printf(s,
		   "metrics_enabled: %s (disable_send_metrics=%d, session=%s, metric_collect=%s)\n",
		   metrics_enabled ? "yes" : "no",
		   disable_send_metrics ? 1 : 0,
		   have_session ? "yes" : "no",
		   metric_collect ? "yes" : "no");
	seq_printf(s, "subvolume_metrics_enabled: %s\n",
		   subvol_enabled ? "yes" : "no");
	seq_printf(s, "session_feature_bits: 0x%lx\n", session_features);

	if (!have_session) {
		seq_puts(s, "(no active MDS session for metrics)\n");
		return 0;
	}

	for (i = 0; i < ARRAY_SIZE(ceph_session_feature_table); i++) {
		const struct ceph_session_feature_desc *desc =
			&ceph_session_feature_table[i];
		bool set = test_bit(desc->bit, &session_features);

		seq_printf(s, "  %-24s : %s\n", desc->name,
			   set ? "yes" : "no");
	}

	return 0;
}

DEFINE_SHOW_ATTRIBUTE(metric_features);

/*
 * debugfs
 */
static int congestion_kb_set(void *data, u64 val)
{
	struct ceph_fs_client *fsc = (struct ceph_fs_client *)data;

	fsc->mount_options->congestion_kb = (int)val;
	return 0;
}

static int congestion_kb_get(void *data, u64 *val)
{
	struct ceph_fs_client *fsc = (struct ceph_fs_client *)data;

	*val = (u64)fsc->mount_options->congestion_kb;
	return 0;
}

DEFINE_SIMPLE_ATTRIBUTE(congestion_kb_fops, congestion_kb_get,
			congestion_kb_set, "%llu\n");


void ceph_fs_debugfs_cleanup(struct ceph_fs_client *fsc)
{
	doutc(fsc->client, "begin\n");
	debugfs_remove(fsc->debugfs_bdi);
	debugfs_remove(fsc->debugfs_congestion_kb);
	debugfs_remove(fsc->debugfs_mdsmap);
	debugfs_remove(fsc->debugfs_mds_sessions);
	debugfs_remove(fsc->debugfs_caps);
	debugfs_remove(fsc->debugfs_status);
	debugfs_remove(fsc->debugfs_mdsc);
	debugfs_remove(fsc->debugfs_subvolume_metrics);
	debugfs_remove_recursive(fsc->debugfs_metrics_dir);
	doutc(fsc->client, "done\n");
}

void ceph_fs_debugfs_init(struct ceph_fs_client *fsc)
{
	char name[NAME_MAX];

	doutc(fsc->client, "begin\n");
	fsc->debugfs_congestion_kb =
		debugfs_create_file("writeback_congestion_kb",
				    0600,
				    fsc->client->debugfs_dir,
				    fsc,
				    &congestion_kb_fops);

	snprintf(name, sizeof(name), "../../bdi/%s",
		 bdi_dev_name(fsc->sb->s_bdi));
	fsc->debugfs_bdi =
		debugfs_create_symlink("bdi",
				       fsc->client->debugfs_dir,
				       name);

	fsc->debugfs_mdsmap = debugfs_create_file("mdsmap",
					0400,
					fsc->client->debugfs_dir,
					fsc,
					&mdsmap_fops);

	fsc->debugfs_mds_sessions = debugfs_create_file("mds_sessions",
					0400,
					fsc->client->debugfs_dir,
					fsc,
					&mds_sessions_fops);

	fsc->debugfs_mdsc = debugfs_create_file("mdsc",
						0400,
						fsc->client->debugfs_dir,
						fsc,
						&mdsc_fops);

	fsc->debugfs_caps = debugfs_create_file("caps",
						0400,
						fsc->client->debugfs_dir,
						fsc,
						&caps_fops);

	fsc->debugfs_status = debugfs_create_file("status",
						  0400,
						  fsc->client->debugfs_dir,
						  fsc,
						  &status_fops);

	fsc->debugfs_metrics_dir = debugfs_create_dir("metrics",
						      fsc->client->debugfs_dir);

	debugfs_create_file("file", 0400, fsc->debugfs_metrics_dir, fsc,
			    &metrics_file_fops);
	debugfs_create_file("latency", 0400, fsc->debugfs_metrics_dir, fsc,
			    &metrics_latency_fops);
	debugfs_create_file("size", 0400, fsc->debugfs_metrics_dir, fsc,
			    &metrics_size_fops);
	debugfs_create_file("caps", 0400, fsc->debugfs_metrics_dir, fsc,
			    &metrics_caps_fops);
	debugfs_create_file("metric_features", 0400, fsc->debugfs_metrics_dir,
			    fsc, &metric_features_fops);
	fsc->debugfs_subvolume_metrics =
		debugfs_create_file("subvolumes", 0400,
				    fsc->debugfs_metrics_dir, fsc,
				    &subvolume_metrics_fops);
	doutc(fsc->client, "done\n");
}


#else  /* CONFIG_DEBUG_FS */

void ceph_fs_debugfs_init(struct ceph_fs_client *fsc)
{
}

void ceph_fs_debugfs_cleanup(struct ceph_fs_client *fsc)
{
}

#endif  /* CONFIG_DEBUG_FS */