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1 | /* |
2 | * fincore - count pages of file contents in core | |
3 | * | |
4 | * Copyright (C) 2017 Red Hat, Inc. All rights reserved. | |
5 | * Written by Masatake YAMATO <yamato@redhat.com> | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or modify | |
8 | * it under the terms of the GNU General Public License as published by | |
9 | * the Free Software Foundation; either version 2 of the License, or | |
10 | * (at your option) any later version. | |
11 | * | |
12 | * This program is distributed in the hope that it would be useful, | |
13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | * GNU General Public License for more details. | |
16 | * | |
17 | * You should have received a copy of the GNU General Public License along | |
18 | * with this program; if not, write to the Free Software Foundation, Inc., | |
19 | * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. | |
20 | */ | |
21 | ||
22 | #include <sys/mman.h> | |
23 | #include <sys/stat.h> | |
24 | #include <unistd.h> | |
25 | #include <getopt.h> | |
26 | #include <stdio.h> | |
27 | #include <string.h> | |
28 | ||
29 | #include "c.h" | |
30 | #include "nls.h" | |
31 | #include "closestream.h" | |
32 | ||
33 | /* For large files, mmap is called in iterative way. | |
34 | Window is the unit of vma prepared in each mmap | |
35 | calling. | |
36 | ||
37 | Window size depends on page size. | |
38 | e.g. 128MB on x86_64. ( = N_PAGES_IN_WINDOW * 4096 ). */ | |
39 | #define N_PAGES_IN_WINDOW (32 * 1024) | |
40 | ||
41 | static void __attribute__((__noreturn__)) usage(FILE *out) | |
42 | { | |
43 | const char *p = program_invocation_short_name; | |
44 | ||
45 | if (!*p) | |
46 | p = "fincore"; | |
47 | ||
48 | fputs(USAGE_HEADER, out); | |
49 | fprintf(out, _(" %s [options] file...\n"), program_invocation_short_name); | |
50 | fputs(USAGE_OPTIONS, out); | |
51 | fputs(USAGE_SEPARATOR, out); | |
52 | fputs(USAGE_HELP, out); | |
53 | fputs(USAGE_VERSION, out); | |
54 | fprintf(out, USAGE_MAN_TAIL("fincore(1)")); | |
55 | exit(out == stderr ? EXIT_FAILURE : EXIT_SUCCESS); | |
56 | } | |
57 | ||
58 | static void report_count (const char *name, off_t file_size, off_t count_incore) | |
59 | { | |
60 | printf ("%-10lu %-10lu %s\n", count_incore, file_size, name); | |
61 | } | |
62 | ||
63 | static void report_failure (const char *name) | |
64 | { | |
65 | printf ("%-10s %-10ld %s\n", "failed", -1L, name); | |
66 | } | |
67 | ||
68 | static int do_mincore (void *window, const size_t len, | |
69 | const char *name, const int pagesize, | |
70 | off_t *count_incore) | |
71 | { | |
72 | static unsigned char vec[N_PAGES_IN_WINDOW]; | |
73 | int n = (len / pagesize) + ((len % pagesize)? 1: 0); | |
74 | ||
75 | if (mincore (window, len, vec) < 0) { | |
76 | warn(_("failed to do mincore: %s"), name); | |
77 | return EXIT_FAILURE; | |
78 | } | |
79 | ||
80 | while (n > 0) | |
81 | { | |
82 | if (vec[--n] & 0x1) | |
83 | { | |
84 | vec[n] = 0; | |
85 | (*count_incore)++; | |
86 | } | |
87 | } | |
88 | ||
89 | return EXIT_SUCCESS; | |
90 | } | |
91 | ||
92 | static int fincore_fd (int fd, | |
93 | const char *name, const int pagesize, | |
94 | off_t file_size, | |
95 | off_t *count_incore) | |
96 | { | |
97 | size_t window_size = N_PAGES_IN_WINDOW * pagesize; | |
98 | off_t file_offset; | |
99 | void *window = NULL; | |
100 | int r = EXIT_SUCCESS; | |
101 | int warned_once = 0; | |
102 | ||
103 | for (file_offset = 0; file_offset < file_size; file_offset += window_size) { | |
104 | size_t len; | |
105 | ||
106 | len = file_size - file_offset; | |
107 | if (len >= window_size) | |
108 | len = window_size; | |
109 | ||
110 | window = mmap(window, len, PROT_NONE, MAP_PRIVATE, fd, file_offset); | |
111 | if (window == MAP_FAILED) { | |
112 | if (!warned_once) { | |
113 | r = EXIT_FAILURE; | |
114 | warn(_("failed to do mmap: %s"), name); | |
115 | warned_once = 1; | |
116 | } | |
117 | break; | |
118 | } | |
119 | ||
120 | if (do_mincore (window, len, name, pagesize, count_incore) != EXIT_SUCCESS) | |
121 | r = EXIT_FAILURE; | |
122 | ||
123 | munmap (window, len); | |
124 | } | |
125 | ||
126 | return r; | |
127 | } | |
128 | ||
129 | static int fincore_name (const char *name, | |
130 | const int pagesize, struct stat *sb, | |
131 | off_t *count_incore) | |
132 | { | |
133 | int fd; | |
134 | int r; | |
135 | ||
136 | if ((fd = open (name, O_RDONLY)) < 0) { | |
137 | warn(_("failed to open: %s"), name); | |
138 | return EXIT_FAILURE; | |
139 | } | |
140 | ||
141 | if (fstat (fd, sb) < 0) { | |
142 | warn(_("failed to do fstat: %s"), name); | |
143 | return EXIT_FAILURE; | |
144 | } | |
145 | ||
146 | if (sb->st_size) | |
147 | r = fincore_fd (fd, name, pagesize, sb->st_size, count_incore); | |
148 | else | |
149 | /* If the file is empty, | |
150 | we just report this file as "successful". */ | |
151 | r = EXIT_SUCCESS; | |
152 | ||
153 | close (fd); | |
154 | ||
155 | return r; | |
156 | } | |
157 | ||
158 | int main(int argc, char ** argv) | |
159 | { | |
160 | int c; | |
161 | int pagesize; | |
162 | int r; | |
163 | ||
164 | static const struct option longopts[] = { | |
165 | { "version", no_argument, NULL, 'V' }, | |
166 | { "help", no_argument, NULL, 'h' }, | |
167 | { NULL, 0, NULL, 0 }, | |
168 | }; | |
169 | ||
170 | setlocale(LC_ALL, ""); | |
171 | bindtextdomain(PACKAGE, LOCALEDIR); | |
172 | textdomain(PACKAGE); | |
173 | atexit(close_stdout); | |
174 | ||
175 | while ((c = getopt_long (argc, argv, "Vh", longopts, NULL)) != -1) { | |
176 | switch (c) { | |
177 | case 'V': | |
178 | printf(UTIL_LINUX_VERSION); | |
179 | return EXIT_SUCCESS; | |
180 | case 'h': | |
181 | usage(stdout); | |
182 | default: | |
183 | errtryhelp(EXIT_FAILURE); | |
184 | } | |
185 | } | |
186 | ||
187 | if (optind == argc) { | |
188 | warnx(_("file argument is missing")); | |
189 | usage(stderr); | |
190 | } | |
191 | ||
192 | ||
193 | pagesize = getpagesize(); | |
194 | r = EXIT_SUCCESS; | |
195 | for(; optind < argc; optind++) { | |
196 | char *name = argv[optind]; | |
197 | struct stat sb; | |
198 | off_t count_incore = 0; | |
199 | ||
200 | if (fincore_name (name, pagesize, &sb, &count_incore) == EXIT_SUCCESS) | |
201 | report_count (name, sb.st_size, count_incore); | |
202 | else { | |
203 | report_failure (name); | |
204 | r = EXIT_FAILURE; | |
205 | } | |
206 | } | |
207 | ||
208 | return r; | |
209 | } |