libbpf-tools/biosnoop.c - platform/external/bcc - Git at Google

 // SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
 // Copyright (c) 2020 Wenbo Zhang
 //
 // Based on biosnoop(8) from BCC by Brendan Gregg.
 // 29-Jun-2020   Wenbo Zhang   Created this.
 #include <argp.h>
 #include <signal.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <unistd.h>
 #include <time.h>
 #include <bpf/libbpf.h>
 #include <sys/resource.h>
 #include <bpf/bpf.h>
 #include <fcntl.h>
 #include "blk_types.h"
 #include "biosnoop.h"
 #include "biosnoop.skel.h"
 #include "trace_helpers.h"

 #define PERF_BUFFER_PAGES	16
 #define PERF_POLL_TIMEOUT_MS	100

 static volatile sig_atomic_t exiting = 0;

 static struct env {
 	__u64 min_lat_ms;
 	char *disk;
 	int duration;
 	bool timestamp;
 	bool queued;
 	bool verbose;
 	char *cgroupspath;
 	bool cg;
 } env = {};

 static volatile __u64 start_ts;

 const char *argp_program_version = "biosnoop 0.1";
 const char *argp_program_bug_address =
 	"https://github.com/iovisor/bcc/tree/master/libbpf-tools";
 const char argp_program_doc[] =
 "Trace block I/O.\n"
 "\n"
 "USAGE: biosnoop [--help] [-d DISK] [-c CG] [-Q]\n"
 "\n"
 "EXAMPLES:\n"
 "    biosnoop              # trace all block I/O\n"
 "    biosnoop -Q           # include OS queued time in I/O time\n"
 "    biosnoop -t           # use timestamps instead\n"
 "    biosnoop 10           # trace for 10 seconds only\n"
 "    biosnoop -d sdc       # trace sdc only\n"
 "    biosnoop -c CG        # Trace process under cgroupsPath CG\n"
 "    biosnoop -m 1         # trace for slower than 1ms\n";

 static const struct argp_option opts[] = {
 	{ "queued", 'Q', NULL, 0, "Include OS queued time in I/O time" },
 	{ "disk",  'd', "DISK",  0, "Trace this disk only" },
 	{ "verbose", 'v', NULL, 0, "Verbose debug output" },
 	{ "cgroup", 'c', "/sys/fs/cgroup/unified/CG", 0, "Trace process in cgroup path"},
 	{ "min", 'm', "MIN", 0, "Min latency to trace, in ms" },
 	{ "timestamp", 't', NULL, 0, "Include timestamp on output" },
 	{ NULL, 'h', NULL, OPTION_HIDDEN, "Show the full help" },
 	{},
 };

 static error_t parse_arg(int key, char *arg, struct argp_state *state)
 {
 	static int pos_args;

 	switch (key) {
 	case 'h':
 		argp_state_help(state, stderr, ARGP_HELP_STD_HELP);
 		break;
 	case 'v':
 		env.verbose = true;
 		break;
 	case 'Q':
 		env.queued = true;
 		break;
 	case 'c':
 		env.cg = true;
 		env.cgroupspath = arg;
 		break;
 	case 'd':
 		env.disk = arg;
 		if (strlen(arg) + 1 > DISK_NAME_LEN) {
 			fprintf(stderr, "invaild disk name: too long\n");
 			argp_usage(state);
 		}
 		break;
 	case 'm':
 		errno = 0;
 		env.min_lat_ms = strtoll(arg, NULL, 10);
 		if (errno) {
 			fprintf(stderr, "invalid latency (in us): %s\n", arg);
 			argp_usage(state);
 		}
 		break;
 	case 't':
 		env.timestamp = true;
 		break;
 	case ARGP_KEY_ARG:
 		if (pos_args++) {
 			fprintf(stderr,
 				"unrecognized positional argument: %s\n", arg);
 			argp_usage(state);
 		}
 		errno = 0;
 		env.duration = strtoll(arg, NULL, 10);
 		if (errno || env.duration <= 0) {
 			fprintf(stderr, "invalid delay (in us): %s\n", arg);
 			argp_usage(state);
 		}
 		break;
 	default:
 		return ARGP_ERR_UNKNOWN;
 	}
 	return 0;
 }

 static int libbpf_print_fn(enum libbpf_print_level level, const char *format, va_list args)
 {
 	if (level == LIBBPF_DEBUG && !env.verbose)
 		return 0;
 	return vfprintf(stderr, format, args);
 }

 static void sig_int(int signo)
 {
 	exiting = 1;
 }

 static void blk_fill_rwbs(char *rwbs, unsigned int op)
 {
 	int i = 0;

 	if (op & REQ_PREFLUSH)
 		rwbs[i++] = 'F';

 	switch (op & REQ_OP_MASK) {
 	case REQ_OP_WRITE:
 	case REQ_OP_WRITE_SAME:
 		rwbs[i++] = 'W';
 		break;
 	case REQ_OP_DISCARD:
 		rwbs[i++] = 'D';
 		break;
 	case REQ_OP_SECURE_ERASE:
 		rwbs[i++] = 'D';
 		rwbs[i++] = 'E';
 		break;
 	case REQ_OP_FLUSH:
 		rwbs[i++] = 'F';
 		break;
 	case REQ_OP_READ:
 		rwbs[i++] = 'R';
 		break;
 	default:
 		rwbs[i++] = 'N';
 	}

 	if (op & REQ_FUA)
 		rwbs[i++] = 'F';
 	if (op & REQ_RAHEAD)
 		rwbs[i++] = 'A';
 	if (op & REQ_SYNC)
 		rwbs[i++] = 'S';
 	if (op & REQ_META)
 		rwbs[i++] = 'M';

 	rwbs[i] = '\0';
 }

 static struct partitions *partitions;

 void handle_event(void *ctx, int cpu, void *data, __u32 data_sz)
 {
 	const struct partition *partition;
 	const struct event *e = data;
 	char rwbs[RWBS_LEN];
 	struct timespec ct;
 	struct tm *tm;
 	char ts[32];

 	if (env.timestamp) {
 		/* Since `bpf_ktime_get_boot_ns` requires at least 5.8 kernel,
 		 * so get time from usespace instead */
 		clock_gettime(CLOCK_REALTIME, &ct);
 		tm = localtime(&ct.tv_sec);
 		strftime(ts, sizeof(ts), "%H:%M:%S", tm);
 		printf("%-8s.%03ld ", ts, ct.tv_nsec / 1000000);
 	} else {
 		if (!start_ts) {
 			start_ts = e->ts;
 		}
 		printf("%-11.6f ",(e->ts - start_ts) / 1000000000.0);
 	}
 	blk_fill_rwbs(rwbs, e->cmd_flags);
 	partition = partitions__get_by_dev(partitions, e->dev);
 	printf("%-14.14s %-7d %-7s %-4s %-10lld %-7d ",
 		e->comm, e->pid, partition ? partition->name : "Unknown", rwbs,
 		e->sector, e->len);
 	if (env.queued)
 		printf("%7.3f ", e->qdelta != -1 ?
 			e->qdelta / 1000000.0 : -1);
 	printf("%7.3f\n", e->delta / 1000000.0);
 }

 void handle_lost_events(void *ctx, int cpu, __u64 lost_cnt)
 {
 	fprintf(stderr, "lost %llu events on CPU #%d\n", lost_cnt, cpu);
 }

 static void blk_account_io_set_attach_target(struct biosnoop_bpf *obj)
 {
 	if (fentry_can_attach("blk_account_io_start", NULL))
 		bpf_program__set_attach_target(obj->progs.blk_account_io_start,
 					       0, "blk_account_io_start");
 	else
 		bpf_program__set_attach_target(obj->progs.blk_account_io_start,
 					       0, "__blk_account_io_start");
 }

 int main(int argc, char **argv)
 {
 	const struct partition *partition;
 	static const struct argp argp = {
 		.options = opts,
 		.parser = parse_arg,
 		.doc = argp_program_doc,
 	};
 	struct perf_buffer *pb = NULL;
 	struct ksyms *ksyms = NULL;
 	struct biosnoop_bpf *obj;
 	__u64 time_end = 0;
 	int err;
 	int idx, cg_map_fd;
 	int cgfd = -1;

 	err = argp_parse(&argp, argc, argv, 0, NULL, NULL);
 	if (err)
 		return err;

 	libbpf_set_print(libbpf_print_fn);

 	obj = biosnoop_bpf__open();
 	if (!obj) {
 		fprintf(stderr, "failed to open BPF object\n");
 		return 1;
 	}

 	partitions = partitions__load();
 	if (!partitions) {
 		fprintf(stderr, "failed to load partitions info\n");
 		goto cleanup;
 	}

 	/* initialize global data (filtering options) */
 	if (env.disk) {
 		partition = partitions__get_by_name(partitions, env.disk);
 		if (!partition) {
 			fprintf(stderr, "invaild partition name: not exist\n");
 			goto cleanup;
 		}
 		obj->rodata->filter_dev = true;
 		obj->rodata->targ_dev = partition->dev;
 	}
 	obj->rodata->targ_queued = env.queued;
 	obj->rodata->filter_cg = env.cg;
 	obj->rodata->min_ns = env.min_lat_ms * 1000000;

 	if (tracepoint_exists("block", "block_io_start"))
 		bpf_program__set_autoload(obj->progs.blk_account_io_start, false);
 	else {
 		bpf_program__set_autoload(obj->progs.block_io_start, false);
 		blk_account_io_set_attach_target(obj);
 	}

 	ksyms = ksyms__load();
 	if (!ksyms) {
 		fprintf(stderr, "failed to load kallsyms\n");
 		goto cleanup;
 	}
 	if (!ksyms__get_symbol(ksyms, "blk_account_io_merge_bio"))
 		bpf_program__set_autoload(obj->progs.blk_account_io_merge_bio, false);

 	if (!env.queued)
 		bpf_program__set_autoload(obj->progs.block_rq_insert, false);

 	err = biosnoop_bpf__load(obj);
 	if (err) {
 		fprintf(stderr, "failed to load BPF object: %d\n", err);
 		goto cleanup;
 	}

 	/* update cgroup path fd to map */
 	if (env.cg) {
 		idx = 0;
 		cg_map_fd = bpf_map__fd(obj->maps.cgroup_map);
 		cgfd = open(env.cgroupspath, O_RDONLY);
 		if (cgfd < 0) {
 			fprintf(stderr, "Failed opening Cgroup path: %s\n", env.cgroupspath);
 			goto cleanup;
 		}
 		if (bpf_map_update_elem(cg_map_fd, &idx, &cgfd, BPF_ANY)) {
 			fprintf(stderr, "Failed adding target cgroup to map\n");
 			goto cleanup;
 		}
 	}

 	err = biosnoop_bpf__attach(obj);
 	if (err) {
 		fprintf(stderr, "failed to attach BPF programs: %d\n", err);
 		goto cleanup;
 	}

 	pb = perf_buffer__new(bpf_map__fd(obj->maps.events), PERF_BUFFER_PAGES,
 			      handle_event, handle_lost_events, NULL, NULL);
 	if (!pb) {
 		err = -errno;
 		fprintf(stderr, "failed to open perf buffer: %d\n", err);
 		goto cleanup;
 	}

 	if (env.timestamp) {
 		printf("%-12s ", "TIMESTAMP");
 	} else {
 		printf("%-11s ", "TIME(s)");
 	}
 	printf("%-14s %-7s %-7s %-4s %-10s %-7s ",
 		"COMM", "PID", "DISK", "T", "SECTOR", "BYTES");
 	if (env.queued)
 		printf("%7s ", "QUE(ms)");
 	printf("%7s\n", "LAT(ms)");

 	/* setup duration */
 	if (env.duration)
 		time_end = get_ktime_ns() + env.duration * NSEC_PER_SEC;

 	if (signal(SIGINT, sig_int) == SIG_ERR) {
 		fprintf(stderr, "can't set signal handler: %s\n", strerror(errno));
 		err = 1;
 		goto cleanup;
 	}

 	/* main: poll */
 	while (!exiting) {
 		err = perf_buffer__poll(pb, PERF_POLL_TIMEOUT_MS);
 		if (err < 0 && err != -EINTR) {
 			fprintf(stderr, "error polling perf buffer: %s\n", strerror(-err));
 			goto cleanup;
 		}
 		/* reset err to return 0 if exiting */
 		err = 0;
 		if (env.duration && get_ktime_ns() > time_end)
 			break;
 	}

 cleanup:
 	perf_buffer__free(pb);
 	biosnoop_bpf__destroy(obj);
 	ksyms__free(ksyms);
 	partitions__free(partitions);
 	if (cgfd > 0)
 		close(cgfd);

 	return err != 0;
 }
	// SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
	// Copyright (c) 2020 Wenbo Zhang
	//
	// Based on biosnoop(8) from BCC by Brendan Gregg.
	// 29-Jun-2020 Wenbo Zhang Created this.
	#include <argp.h>
	#include <signal.h>
	#include <stdio.h>
	#include <stdlib.h>
	#include <unistd.h>
	#include <time.h>
	#include <bpf/libbpf.h>
	#include <sys/resource.h>
	#include <bpf/bpf.h>
	#include <fcntl.h>
	#include "blk_types.h"
	#include "biosnoop.h"
	#include "biosnoop.skel.h"
	#include "trace_helpers.h"

	#define PERF_BUFFER_PAGES 16
	#define PERF_POLL_TIMEOUT_MS 100

	static volatile sig_atomic_t exiting = 0;

	static struct env {
	__u64 min_lat_ms;
	char *disk;
	int duration;
	bool timestamp;
	bool queued;
	bool verbose;
	char *cgroupspath;
	bool cg;
	} env = {};

	static volatile __u64 start_ts;

	const char *argp_program_version = "biosnoop 0.1";
	const char *argp_program_bug_address =
	"https://github.com/iovisor/bcc/tree/master/libbpf-tools";
	const char argp_program_doc[] =
	"Trace block I/O.\n"
	"\n"
	"USAGE: biosnoop [--help] [-d DISK] [-c CG] [-Q]\n"
	"\n"
	"EXAMPLES:\n"
	" biosnoop # trace all block I/O\n"
	" biosnoop -Q # include OS queued time in I/O time\n"
	" biosnoop -t # use timestamps instead\n"
	" biosnoop 10 # trace for 10 seconds only\n"
	" biosnoop -d sdc # trace sdc only\n"
	" biosnoop -c CG # Trace process under cgroupsPath CG\n"
	" biosnoop -m 1 # trace for slower than 1ms\n";

	static const struct argp_option opts[] = {
	{ "queued", 'Q', NULL, 0, "Include OS queued time in I/O time" },
	{ "disk", 'd', "DISK", 0, "Trace this disk only" },
	{ "verbose", 'v', NULL, 0, "Verbose debug output" },
	{ "cgroup", 'c', "/sys/fs/cgroup/unified/CG", 0, "Trace process in cgroup path"},
	{ "min", 'm', "MIN", 0, "Min latency to trace, in ms" },
	{ "timestamp", 't', NULL, 0, "Include timestamp on output" },
	{ NULL, 'h', NULL, OPTION_HIDDEN, "Show the full help" },
	{},
	};

	static error_t parse_arg(int key, char arg, struct argp_state state)
	{
	static int pos_args;

	switch (key) {
	case 'h':
	argp_state_help(state, stderr, ARGP_HELP_STD_HELP);
	break;
	case 'v':
	env.verbose = true;
	break;
	case 'Q':
	env.queued = true;
	break;
	case 'c':
	env.cg = true;
	env.cgroupspath = arg;
	break;
	case 'd':
	env.disk = arg;
	if (strlen(arg) + 1 > DISK_NAME_LEN) {
	fprintf(stderr, "invaild disk name: too long\n");
	argp_usage(state);
	}
	break;
	case 'm':
	errno = 0;
	env.min_lat_ms = strtoll(arg, NULL, 10);
	if (errno) {
	fprintf(stderr, "invalid latency (in us): %s\n", arg);
	argp_usage(state);
	}
	break;
	case 't':
	env.timestamp = true;
	break;
	case ARGP_KEY_ARG:
	if (pos_args++) {
	fprintf(stderr,
	"unrecognized positional argument: %s\n", arg);
	argp_usage(state);
	}
	errno = 0;
	env.duration = strtoll(arg, NULL, 10);
	if (errno \|\| env.duration <= 0) {
	fprintf(stderr, "invalid delay (in us): %s\n", arg);
	argp_usage(state);
	}
	break;
	default:
	return ARGP_ERR_UNKNOWN;
	}
	return 0;
	}

	static int libbpf_print_fn(enum libbpf_print_level level, const char *format, va_list args)
	{
	if (level == LIBBPF_DEBUG && !env.verbose)
	return 0;
	return vfprintf(stderr, format, args);
	}

	static void sig_int(int signo)
	{
	exiting = 1;
	}

	static void blk_fill_rwbs(char *rwbs, unsigned int op)
	{
	int i = 0;

	if (op & REQ_PREFLUSH)
	rwbs[i++] = 'F';

	switch (op & REQ_OP_MASK) {
	case REQ_OP_WRITE:
	case REQ_OP_WRITE_SAME:
	rwbs[i++] = 'W';
	break;
	case REQ_OP_DISCARD:
	rwbs[i++] = 'D';
	break;
	case REQ_OP_SECURE_ERASE:
	rwbs[i++] = 'D';
	rwbs[i++] = 'E';
	break;
	case REQ_OP_FLUSH:
	rwbs[i++] = 'F';
	break;
	case REQ_OP_READ:
	rwbs[i++] = 'R';
	break;
	default:
	rwbs[i++] = 'N';
	}

	if (op & REQ_FUA)
	rwbs[i++] = 'F';
	if (op & REQ_RAHEAD)
	rwbs[i++] = 'A';
	if (op & REQ_SYNC)
	rwbs[i++] = 'S';
	if (op & REQ_META)
	rwbs[i++] = 'M';

	rwbs[i] = '\0';
	}

	static struct partitions *partitions;

	void handle_event(void ctx, int cpu, void data, __u32 data_sz)
	{
	const struct partition *partition;
	const struct event *e = data;
	char rwbs[RWBS_LEN];
	struct timespec ct;
	struct tm *tm;
	char ts[32];

	if (env.timestamp) {
	/* Since `bpf_ktime_get_boot_ns` requires at least 5.8 kernel,
	* so get time from usespace instead */
	clock_gettime(CLOCK_REALTIME, &ct);
	tm = localtime(&ct.tv_sec);
	strftime(ts, sizeof(ts), "%H:%M:%S", tm);
	printf("%-8s.%03ld ", ts, ct.tv_nsec / 1000000);
	} else {
	if (!start_ts) {
	start_ts = e->ts;
	}
	printf("%-11.6f ",(e->ts - start_ts) / 1000000000.0);
	}
	blk_fill_rwbs(rwbs, e->cmd_flags);
	partition = partitions__get_by_dev(partitions, e->dev);
	printf("%-14.14s %-7d %-7s %-4s %-10lld %-7d ",
	e->comm, e->pid, partition ? partition->name : "Unknown", rwbs,
	e->sector, e->len);
	if (env.queued)
	printf("%7.3f ", e->qdelta != -1 ?
	e->qdelta / 1000000.0 : -1);
	printf("%7.3f\n", e->delta / 1000000.0);
	}

	void handle_lost_events(void *ctx, int cpu, __u64 lost_cnt)
	{
	fprintf(stderr, "lost %llu events on CPU #%d\n", lost_cnt, cpu);
	}

	static void blk_account_io_set_attach_target(struct biosnoop_bpf *obj)
	{
	if (fentry_can_attach("blk_account_io_start", NULL))
	bpf_program__set_attach_target(obj->progs.blk_account_io_start,
	0, "blk_account_io_start");
	else
	bpf_program__set_attach_target(obj->progs.blk_account_io_start,
	0, "__blk_account_io_start");
	}

	int main(int argc, char **argv)
	{
	const struct partition *partition;
	static const struct argp argp = {
	.options = opts,
	.parser = parse_arg,
	.doc = argp_program_doc,
	};
	struct perf_buffer *pb = NULL;
	struct ksyms *ksyms = NULL;
	struct biosnoop_bpf *obj;
	__u64 time_end = 0;
	int err;
	int idx, cg_map_fd;
	int cgfd = -1;

	err = argp_parse(&argp, argc, argv, 0, NULL, NULL);
	if (err)
	return err;

	libbpf_set_print(libbpf_print_fn);

	obj = biosnoop_bpf__open();
	if (!obj) {
	fprintf(stderr, "failed to open BPF object\n");
	return 1;
	}

	partitions = partitions__load();
	if (!partitions) {
	fprintf(stderr, "failed to load partitions info\n");
	goto cleanup;
	}

	/* initialize global data (filtering options) */
	if (env.disk) {
	partition = partitions__get_by_name(partitions, env.disk);
	if (!partition) {
	fprintf(stderr, "invaild partition name: not exist\n");
	goto cleanup;
	}
	obj->rodata->filter_dev = true;
	obj->rodata->targ_dev = partition->dev;
	}
	obj->rodata->targ_queued = env.queued;
	obj->rodata->filter_cg = env.cg;
	obj->rodata->min_ns = env.min_lat_ms * 1000000;

	if (tracepoint_exists("block", "block_io_start"))
	bpf_program__set_autoload(obj->progs.blk_account_io_start, false);
	else {
	bpf_program__set_autoload(obj->progs.block_io_start, false);
	blk_account_io_set_attach_target(obj);
	}

	ksyms = ksyms__load();
	if (!ksyms) {
	fprintf(stderr, "failed to load kallsyms\n");
	goto cleanup;
	}
	if (!ksyms__get_symbol(ksyms, "blk_account_io_merge_bio"))
	bpf_program__set_autoload(obj->progs.blk_account_io_merge_bio, false);

	if (!env.queued)
	bpf_program__set_autoload(obj->progs.block_rq_insert, false);

	err = biosnoop_bpf__load(obj);
	if (err) {
	fprintf(stderr, "failed to load BPF object: %d\n", err);
	goto cleanup;
	}

	/* update cgroup path fd to map */
	if (env.cg) {
	idx = 0;
	cg_map_fd = bpf_map__fd(obj->maps.cgroup_map);
	cgfd = open(env.cgroupspath, O_RDONLY);
	if (cgfd < 0) {
	fprintf(stderr, "Failed opening Cgroup path: %s\n", env.cgroupspath);
	goto cleanup;
	}
	if (bpf_map_update_elem(cg_map_fd, &idx, &cgfd, BPF_ANY)) {
	fprintf(stderr, "Failed adding target cgroup to map\n");
	goto cleanup;
	}
	}

	err = biosnoop_bpf__attach(obj);
	if (err) {
	fprintf(stderr, "failed to attach BPF programs: %d\n", err);
	goto cleanup;
	}

	pb = perf_buffer__new(bpf_map__fd(obj->maps.events), PERF_BUFFER_PAGES,
	handle_event, handle_lost_events, NULL, NULL);
	if (!pb) {
	err = -errno;
	fprintf(stderr, "failed to open perf buffer: %d\n", err);
	goto cleanup;
	}

	if (env.timestamp) {
	printf("%-12s ", "TIMESTAMP");
	} else {
	printf("%-11s ", "TIME(s)");
	}
	printf("%-14s %-7s %-7s %-4s %-10s %-7s ",
	"COMM", "PID", "DISK", "T", "SECTOR", "BYTES");
	if (env.queued)
	printf("%7s ", "QUE(ms)");
	printf("%7s\n", "LAT(ms)");

	/* setup duration */
	if (env.duration)
	time_end = get_ktime_ns() + env.duration * NSEC_PER_SEC;

	if (signal(SIGINT, sig_int) == SIG_ERR) {
	fprintf(stderr, "can't set signal handler: %s\n", strerror(errno));
	err = 1;
	goto cleanup;
	}

	/* main: poll */
	while (!exiting) {
	err = perf_buffer__poll(pb, PERF_POLL_TIMEOUT_MS);
	if (err < 0 && err != -EINTR) {
	fprintf(stderr, "error polling perf buffer: %s\n", strerror(-err));
	goto cleanup;
	}
	/* reset err to return 0 if exiting */
	err = 0;
	if (env.duration && get_ktime_ns() > time_end)
	break;
	}

	cleanup:
	perf_buffer__free(pb);
	biosnoop_bpf__destroy(obj);
	ksyms__free(ksyms);
	partitions__free(partitions);
	if (cgfd > 0)
	close(cgfd);

	return err != 0;
	}