1/*
2 * blktrace output analysis: generate a timeline & gather statistics
3 *
4 * Copyright (C) 2006 Alan D. Brunelle <Alan.Brunelle@hp.com>
5 *
6 *  This program is free software; you can redistribute it and/or modify
7 *  it under the terms of the GNU General Public License as published by
8 *  the Free Software Foundation; either version 2 of the License, or
9 *  (at your option) any later version.
10 *
11 *  This program is distributed in the hope that it will be useful,
12 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
13 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14 *  GNU General Public License for more details.
15 *
16 *  You should have received a copy of the GNU General Public License
17 *  along with this program; if not, write to the Free Software
18 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
19 *
20 */
21
22#include <stdio.h>
23#include <unistd.h>
24#include <sys/types.h>
25#include <sys/stat.h>
26#include <fcntl.h>
27#include <sys/mman.h>
28#include <string.h>
29
30#include "blktrace.h"
31#include "globals.h"
32
33#define DEF_LEN	(16 * 1024 * 1024)
34
35static int fd;
36static void *cur_map = MAP_FAILED;
37static off_t cur_min, cur, cur_max, total_size;
38static size_t len;
39static struct blk_io_trace *next_t;
40static long pgsz;
41
42int data_is_native = -1;
43
44static inline size_t min_len(size_t a, size_t b)
45{
46	return a < b ? a : b;
47}
48
49static inline size_t convert_to_cpu(struct blk_io_trace *t,
50                                    struct blk_io_trace *tp,
51				    void **pdu)
52{
53	if (data_is_native == -1)
54		check_data_endianness(t->magic);
55
56	if (data_is_native)
57		memcpy(tp, t, sizeof(*tp));
58	else {
59		tp->magic	= be32_to_cpu(t->magic);
60		tp->sequence	= be32_to_cpu(t->sequence);
61		tp->time	= be64_to_cpu(t->time);
62		tp->sector	= be64_to_cpu(t->sector);
63		tp->bytes	= be32_to_cpu(t->bytes);
64		tp->action	= be32_to_cpu(t->action);
65		tp->pid		= be32_to_cpu(t->pid);
66		tp->device	= be32_to_cpu(t->device);
67		tp->cpu		= be16_to_cpu(t->cpu);
68		tp->error	= be16_to_cpu(t->error);
69		tp->pdu_len	= be16_to_cpu(t->pdu_len);
70	}
71
72	if (tp->pdu_len) {
73		*pdu = malloc(tp->pdu_len);
74		memcpy(*pdu, t+1, tp->pdu_len);
75	} else
76		*pdu = NULL;
77
78	return sizeof(*tp) + tp->pdu_len;
79}
80
81static int move_map(void)
82{
83	if (cur_map != MAP_FAILED)
84		munmap(cur_map, len);
85
86	cur_min = (cur & ~(pgsz-1));
87	len = min_len(DEF_LEN, total_size - cur_min);
88	if (len < sizeof(*next_t))
89		return 0;
90
91	cur_map = mmap(NULL, len, PROT_READ, MAP_SHARED, fd,
92		       cur_min);
93	if (cur_map == MAP_FAILED) {
94		perror("mmap");
95		exit(1);
96	}
97
98	cur_max = cur_min + len;
99	return (cur < cur_max);
100}
101
102void setup_ifile(char *fname)
103{
104	struct stat buf;
105
106	pgsz = sysconf(_SC_PAGESIZE);
107
108	fd = my_open(fname, O_RDONLY);
109	if (fd < 0) {
110		perror(fname);
111		exit(1);
112	}
113	if (fstat(fd, &buf) < 0) {
114		perror(fname);
115		exit(1);
116	}
117	total_size = buf.st_size;
118
119	if (!move_map())
120		exit(0);
121}
122
123void cleanup_ifile(void)
124{
125	if (cur_map != MAP_FAILED)
126		munmap(cur_map, len);
127	close(fd);
128}
129
130int next_trace(struct blk_io_trace *t, void **pdu)
131{
132	size_t this_len;
133
134	if ((cur + 512) > cur_max)
135		if (!move_map()) {
136			cleanup_ifile();
137			return 0;
138		}
139
140	next_t = cur_map + (cur - cur_min);
141	this_len = convert_to_cpu(next_t, t, pdu);
142	cur += this_len;
143
144	return 1;
145}
146
147double pct_done(void)
148{
149	return 100.0 * ((double)cur / (double)total_size);
150}
151