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filelife.py update with debug
#!/usr/bin/python
# @lint-avoid-python-3-compatibility-imports
#
# filelife Trace the lifespan of short-lived files.
# For Linux, uses BCC, eBPF. Embedded C.
#
# This traces the creation and deletion of files, providing information
# on who deleted the file, the file age, and the file name. The intent is to
# provide information on short-lived files, for debugging or performance
# analysis.
#
# USAGE: filelife [-h] [-p PID]
#
# Copyright 2016 Netflix, Inc.
# Licensed under the Apache License, Version 2.0 (the "License")
#
# 08-Feb-2015 Brendan Gregg Created this.
# 17-Feb-2016 Allan McAleavy updated for BPF_PERF_OUTPUT
from __future__ import print_function
from bcc import BPF
import argparse
from time import strftime
import ctypes as ct
# arguments
examples = """examples:
./filelife # trace all stat() syscalls
./filelife -p 181 # only trace PID 181
"""
parser = argparse.ArgumentParser(
description="Trace stat() syscalls",
formatter_class=argparse.RawDescriptionHelpFormatter,
epilog=examples)
parser.add_argument("-p", "--pid",
help="trace this PID only")
args = parser.parse_args()
debug = 1
# define BPF program
bpf_text = """
#include <uapi/linux/ptrace.h>
#include <linux/fs.h>
#include <linux/sched.h>
struct data_t {
u32 pid;
u64 delta;
char comm[TASK_COMM_LEN];
char fname[DNAME_INLINE_LEN];
};
BPF_HASH(birth, struct dentry *);
BPF_PERF_OUTPUT(events);
// trace file creation time
int trace_create(struct pt_regs *ctx, struct inode *dir, struct dentry *dentry)
{
u32 pid = bpf_get_current_pid_tgid();
FILTER
u64 ts = bpf_ktime_get_ns();
bpf_trace_printk("at %llu, create of %x\\n", ts, dentry);
birth.update(&dentry, &ts);
return 0;
};
// trace file deletion and output details
int trace_unlink(struct pt_regs *ctx, struct inode *dir, struct dentry *dentry)
{
struct data_t data = {};
u32 pid = bpf_get_current_pid_tgid();
bpf_trace_printk("unlink of %x\\n", dentry);
FILTER
u64 *tsp, delta;
tsp = birth.lookup(&dentry);
if (tsp == 0) {
return 0; // missed create
}
u64 ts = bpf_ktime_get_ns();
delta = (ts - *tsp) / 1000000;
bpf_trace_printk("at %llu, delta %d\\n", ts, delta);
birth.delete(&dentry);
if (dentry->d_name.len == 0)
return 0;
if (bpf_get_current_comm(&data.comm, sizeof(data.comm)) == 0) {
data.pid = pid;
data.delta = delta;
bpf_probe_read(&data.fname, sizeof(data.fname),
(void *)dentry->d_name.name);
}
events.perf_submit(ctx, &data, sizeof(data));
return 0;
}
"""
TASK_COMM_LEN = 16 # linux/sched.h
DNAME_INLINE_LEN = 255 # linux/dcache.h
class Data(ct.Structure):
_fields_ = [
("pid", ct.c_ulonglong),
("delta", ct.c_ulonglong),
("comm", ct.c_char * TASK_COMM_LEN),
("fname", ct.c_char * DNAME_INLINE_LEN)
]
if args.pid:
bpf_text = bpf_text.replace('FILTER',
'if (pid != %s) { return 0; }' % args.pid)
else:
bpf_text = bpf_text.replace('FILTER', '')
if debug:
print(bpf_text)
# initialize BPF
b = BPF(text=bpf_text)
b.attach_kprobe(event="vfs_create", fn_name="trace_create")
b.attach_kprobe(event="security_inode_create", fn_name="trace_create")
b.attach_kprobe(event="vfs_unlink", fn_name="trace_unlink")
# header
print("%-8s %-6s %-16s %-7s %s" % ("TIME", "PID", "COMM", "AGE(s)", "FILE"))
# process event
def print_event(cpu, data, size):
event = ct.cast(data, ct.POINTER(Data)).contents
print("%-8s %-6d %-16s %-7.2f %s" % (strftime("%H:%M:%S"), event.pid,
event.comm, float(event.delta) / 1000, event.fname))
b["events"].open_perf_buffer(print_event)
while 1:
b.kprobe_poll()
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