1 /*
2 * Copyright (C) 2014 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #include <assert.h>
18 #include <errno.h>
19 #include <fcntl.h>
20 #include <getopt.h>
21 #include <stdio.h>
22 #include <stdlib.h>
23 #include <string.h>
24 #include <unistd.h>
25
26 #include <logwrap/logwrap.h>
27 #include <sys/stat.h>
28 #include <sys/statvfs.h>
29 #include <utils/Log.h>
30
31 #define ARRAY_SIZE(a) (sizeof(a) / sizeof((a)[0]))
32
33 #define MAX_IO_WRITE_CHUNK_SIZE 0x100000
34
35 #ifndef min
36 #define min(a,b) ((a) < (b) ? (a) : (b))
37 #endif
38
39 typedef unsigned long u64;
40
usage(const char * const progname)41 static void usage(const char * const progname) {
42 fprintf(stderr,
43 "Usage: %s [-s <seed>] -h <hole size in bytes> -t <total hole size in bytes> "
44 "path\n",
45 progname);
46 }
47
get_free_space(const char * const path)48 static u64 get_free_space(const char * const path) {
49 struct statvfs s;
50
51 if (statvfs(path, &s) < 0) {
52 fprintf(stderr, "\nerrno: %d. Failed to get free disk space on %s\n",
53 errno, path);
54 return 0;
55 } else {
56 return (u64)s.f_bsize * (u64)s.f_bfree;
57 }
58 }
59
get_random_num(const u64 start,const u64 end)60 static u64 get_random_num(const u64 start, const u64 end) {
61 if (end - start <= 0)
62 return start;
63 assert(RAND_MAX >= 0x7FFFFFFF);
64 if ((end - start) > 0x7FFFFFFF)
65 return start + (((u64)random() << 31) | (u64)random()) % (end - start);
66 return start + (random() % (end - start));
67 }
68
get_random_char()69 static char get_random_char() {
70 return 'A' + random() % ('Z' - 'A');
71 }
72
create_unique_file(const char * const dir_path,const u64 size,const u64 id,char * const base,const u64 base_length)73 static bool create_unique_file(const char * const dir_path, const u64 size,
74 const u64 id, char * const base,
75 const u64 base_length) {
76 u64 length = 0;
77 int fd;
78 char file_path[FILENAME_MAX];
79 bool ret = true;
80
81 base[random() % min(base_length, size)] = get_random_char();
82
83 sprintf(file_path, "%s/file_%lu", dir_path, id);
84 fd = open(file_path, O_WRONLY | O_CREAT | O_SYNC, 0777);
85 if (fd < 0) {
86 // We suppress ENOSPC erros as that is common as we approach the
87 // last few MBs of the fs as we don't account for the size of the newly
88 // added meta data after the initial free space computation.
89 if (errno != 28) {
90 fprintf(stderr, "\nerrno: %d. Failed to create %s\n", errno, file_path);
91 }
92 return false;
93 }
94 while (length + base_length < size) {
95 if (write(fd, base, base_length) < 0) {
96 if (errno != 28) {
97 fprintf(stderr, "\nerrno: %d. Failed to write %lu bytes to %s\n",
98 errno, base_length, file_path);
99 }
100 ret = false;
101 goto done;
102 }
103 length += base_length;
104 }
105 if (write(fd, base, size - length) < 0) {
106 if (errno != 28) {
107 fprintf(stderr, "\nerrno: %d. Failed to write last %lu bytes to %s\n",
108 errno, size - length, file_path);
109 }
110 ret = false;
111 goto done;
112 }
113 done:
114 if (close(fd) < 0) {
115 fprintf(stderr, "\nFailed to close %s\n", file_path);
116 ret = false;
117 }
118 return ret;
119 }
120
create_unique_dir(char * dir,const char * const root_path)121 static bool create_unique_dir(char *dir, const char * const root_path) {
122 char random_string[15];
123 int i;
124
125 for (i = 0; i < 14; ++i) {
126 random_string[i] = get_random_char();
127 }
128 random_string[14] = '\0';
129
130 sprintf(dir, "%s/%s", root_path, random_string);
131
132 if (mkdir(dir, 0777) < 0) {
133 fprintf(stderr, "\nerrno: %d. Failed to create %s\n", errno, dir);
134 return false;
135 }
136 return true;
137 }
138
puncture_fs(const char * const path,const u64 total_size,const u64 hole_size,const u64 total_hole_size)139 static bool puncture_fs (const char * const path, const u64 total_size,
140 const u64 hole_size, const u64 total_hole_size) {
141 u64 increments = (hole_size * total_size) / total_hole_size;
142 u64 hole_max;
143 u64 starting_max = 0;
144 u64 ending_max = increments;
145 char stay_dir[FILENAME_MAX], delete_dir[FILENAME_MAX];
146 const char* rm_bin_argv[] = { "/system/bin/rm", "-rf", ""};
147 u64 file_id = 1;
148 char *base_file_data;
149 u64 i = 0;
150
151 if (!create_unique_dir(stay_dir, path) ||
152 !create_unique_dir(delete_dir, path)) {
153 return false;
154 }
155
156 base_file_data = (char*) malloc(MAX_IO_WRITE_CHUNK_SIZE);
157 for (i = 0; i < MAX_IO_WRITE_CHUNK_SIZE; ++i) {
158 base_file_data[i] = get_random_char();
159 }
160 fprintf(stderr, "\n");
161 while (ending_max <= total_size) {
162 fprintf(stderr, "\rSTAGE 1/2: %d%% Complete",
163 (int) (100.0 * starting_max / total_size));
164 hole_max = get_random_num(starting_max, ending_max);
165
166 do {
167 hole_max = get_random_num(starting_max, ending_max);
168 } while (hole_max == starting_max);
169
170 create_unique_file(stay_dir,
171 hole_max - starting_max,
172 file_id++,
173 base_file_data,
174 MAX_IO_WRITE_CHUNK_SIZE);
175 create_unique_file(delete_dir,
176 hole_size,
177 file_id++,
178 base_file_data,
179 MAX_IO_WRITE_CHUNK_SIZE);
180
181 starting_max = hole_max + hole_size;
182 ending_max += increments;
183 }
184 create_unique_file(stay_dir,
185 (ending_max - increments - starting_max),
186 file_id++,
187 base_file_data,
188 MAX_IO_WRITE_CHUNK_SIZE);
189 fprintf(stderr, "\rSTAGE 1/2: 100%% Complete\n");
190 fprintf(stderr, "\rSTAGE 2/2: 0%% Complete");
191 free(base_file_data);
192 rm_bin_argv[2] = delete_dir;
193 if (logwrap_fork_execvp(ARRAY_SIZE(rm_bin_argv), rm_bin_argv, nullptr,
194 false, LOG_KLOG, false, nullptr) < 0) {
195 fprintf(stderr, "\nFailed to delete %s\n", rm_bin_argv[2]);
196 return false;
197 }
198 fprintf(stderr, "\rSTAGE 2/2: 100%% Complete\n");
199 return true;
200 }
201
main(const int argc,char ** const argv)202 int main (const int argc, char ** const argv) {
203 int opt;
204 int mandatory_opt;
205 char *path = NULL;
206 int seed = time(NULL);
207
208 u64 total_size = 0;
209 u64 hole_size = 0;
210 u64 total_hole_size = 0;
211
212 mandatory_opt = 2;
213 while ((opt = getopt(argc, argv, "s:h:t:")) != -1) {
214 switch(opt) {
215 case 's':
216 seed = atoi(optarg);
217 break;
218 case 'h':
219 hole_size = atoll(optarg);
220 mandatory_opt--;
221 break;
222 case 't':
223 total_hole_size = atoll(optarg);
224 mandatory_opt--;
225 break;
226 default:
227 usage(argv[0]);
228 exit(EXIT_FAILURE);
229 }
230 }
231 if (mandatory_opt) {
232 usage(argv[0]);
233 exit(EXIT_FAILURE);
234 }
235 if (optind >= argc) {
236 fprintf(stderr, "\nExpected path name after options.\n");
237 usage(argv[0]);
238 exit(EXIT_FAILURE);
239 }
240 path = argv[optind++];
241
242 if (optind < argc) {
243 fprintf(stderr, "\nUnexpected argument: %s\n", argv[optind]);
244 usage(argv[0]);
245 exit(EXIT_FAILURE);
246 }
247
248 srandom(seed);
249 fprintf(stderr, "\nRandom seed is: %d\n", seed);
250
251 total_size = get_free_space(path);
252 if (!total_size) {
253 exit(EXIT_FAILURE);
254 }
255 if (total_size < total_hole_size || total_hole_size < hole_size) {
256 fprintf(stderr, "\nInvalid sizes: total available size should be "
257 "larger than total hole size which is larger than "
258 "hole size\n");
259 exit(EXIT_FAILURE);
260 }
261
262 if (!puncture_fs(path, total_size, hole_size, total_hole_size)) {
263 exit(EXIT_FAILURE);
264 }
265 return 0;
266 }
267