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 <fcntl.h> 19 #include <getopt.h> 20 #include <stdio.h> 21 #include <stdlib.h> 22 #include <string.h> 23 #include <unistd.h> 24 25 #include <logwrap/logwrap.h> 26 #include <sys/stat.h> 27 #include <sys/statvfs.h> 28 #include <utils/Log.h> 29 30 #define ARRAY_SIZE(a) (sizeof(a) / sizeof((a)[0])) 31 32 #define MAX_IO_WRITE_CHUNK_SIZE 0x100000 33 34 #ifndef min 35 #define min(a,b) ((a) < (b) ? (a) : (b)) 36 #endif 37 38 typedef unsigned long u64; 39 40 static void usage(const char * const progname) { 41 fprintf(stderr, 42 "Usage: %s [-s <seed>] -h <hole size in bytes> -t <total hole size in bytes> " 43 "path\n", 44 progname); 45 } 46 47 static u64 get_free_space(const char * const path) { 48 struct statvfs s; 49 50 if (statvfs(path, &s) < 0) { 51 fprintf(stderr, "\nerrno: %d. Failed to get free disk space on %s\n", 52 errno, path); 53 return 0; 54 } else { 55 return (u64)s.f_bsize * (u64)s.f_bfree; 56 } 57 } 58 59 static u64 get_random_num(const u64 start, const u64 end) { 60 if (end - start <= 0) 61 return start; 62 assert(RAND_MAX >= 0x7FFFFFFF); 63 if ((end - start) > 0x7FFFFFFF) 64 return start + (((u64)random() << 31) | (u64)random()) % (end - start); 65 return start + (random() % (end - start)); 66 } 67 68 static char get_random_char() { 69 return 'A' + random() % ('Z' - 'A'); 70 } 71 72 static bool create_unique_file(const char * const dir_path, const u64 size, 73 const u64 id, char * const base, 74 const u64 base_length) { 75 u64 length = 0; 76 int fd; 77 char file_path[FILENAME_MAX]; 78 bool ret = true; 79 80 base[random() % min(base_length, size)] = get_random_char(); 81 82 sprintf(file_path, "%s/file_%lu", dir_path, id); 83 fd = open(file_path, O_WRONLY | O_CREAT | O_SYNC, 0777); 84 if (fd < 0) { 85 // We suppress ENOSPC erros as that is common as we approach the 86 // last few MBs of the fs as we don't account for the size of the newly 87 // added meta data after the initial free space computation. 88 if (errno != 28) { 89 fprintf(stderr, "\nerrno: %d. Failed to create %s\n", errno, file_path); 90 } 91 return false; 92 } 93 while (length + base_length < size) { 94 if (write(fd, base, base_length) < 0) { 95 if (errno != 28) { 96 fprintf(stderr, "\nerrno: %d. Failed to write %lu bytes to %s\n", 97 errno, base_length, file_path); 98 } 99 ret = false; 100 goto done; 101 } 102 length += base_length; 103 } 104 if (write(fd, base, size - length) < 0) { 105 if (errno != 28) { 106 fprintf(stderr, "\nerrno: %d. Failed to write last %lu bytes to %s\n", 107 errno, size - length, file_path); 108 } 109 ret = false; 110 goto done; 111 } 112 done: 113 if (close(fd) < 0) { 114 fprintf(stderr, "\nFailed to close %s\n", file_path); 115 ret = false; 116 } 117 return ret; 118 } 119 120 static bool create_unique_dir(char *dir, const char * const root_path) { 121 char random_string[15]; 122 int i; 123 124 for (i = 0; i < 14; ++i) { 125 random_string[i] = get_random_char(); 126 } 127 random_string[14] = '\0'; 128 129 sprintf(dir, "%s/%s", root_path, random_string); 130 131 if (mkdir(dir, 0777) < 0) { 132 fprintf(stderr, "\nerrno: %d. Failed to create %s\n", errno, dir); 133 return false; 134 } 135 return true; 136 } 137 138 static bool puncture_fs (const char * const path, const u64 total_size, 139 const u64 hole_size, const u64 total_hole_size) { 140 u64 increments = (hole_size * total_size) / total_hole_size; 141 u64 hole_max; 142 u64 starting_max = 0; 143 u64 ending_max = increments; 144 char stay_dir[FILENAME_MAX], delete_dir[FILENAME_MAX]; 145 char *rm_bin_argv[] = { "/system/bin/rm", "-rf", ""}; 146 u64 file_id = 1; 147 char *base_file_data; 148 u64 i = 0; 149 150 if (!create_unique_dir(stay_dir, path) || 151 !create_unique_dir(delete_dir, path)) { 152 return false; 153 } 154 155 base_file_data = (char*) malloc(MAX_IO_WRITE_CHUNK_SIZE); 156 for (i = 0; i < MAX_IO_WRITE_CHUNK_SIZE; ++i) { 157 base_file_data[i] = get_random_char(); 158 } 159 fprintf(stderr, "\n"); 160 while (ending_max <= total_size) { 161 fprintf(stderr, "\rSTAGE 1/2: %d%% Complete", 162 (int) (100.0 * starting_max / total_size)); 163 hole_max = get_random_num(starting_max, ending_max); 164 165 create_unique_file(stay_dir, 166 hole_max - starting_max, 167 file_id++, 168 base_file_data, 169 MAX_IO_WRITE_CHUNK_SIZE); 170 create_unique_file(delete_dir, 171 hole_size, 172 file_id++, 173 base_file_data, 174 MAX_IO_WRITE_CHUNK_SIZE); 175 176 starting_max = hole_max + hole_size; 177 ending_max += increments; 178 } 179 create_unique_file(stay_dir, 180 (ending_max - increments - starting_max), 181 file_id++, 182 base_file_data, 183 MAX_IO_WRITE_CHUNK_SIZE); 184 fprintf(stderr, "\rSTAGE 1/2: 100%% Complete\n"); 185 fprintf(stderr, "\rSTAGE 2/2: 0%% Complete"); 186 free(base_file_data); 187 rm_bin_argv[2] = delete_dir; 188 if (android_fork_execvp_ext(ARRAY_SIZE(rm_bin_argv), rm_bin_argv, 189 NULL, 1, LOG_KLOG, 0, NULL) < 0) { 190 fprintf(stderr, "\nFailed to delete %s\n", rm_bin_argv[2]); 191 return false; 192 } 193 fprintf(stderr, "\rSTAGE 2/2: 100%% Complete\n"); 194 return true; 195 } 196 197 int main (const int argc, char ** const argv) { 198 int opt; 199 int mandatory_opt; 200 char *path = NULL; 201 int seed = time(NULL); 202 203 u64 total_size = 0; 204 u64 hole_size = 0; 205 u64 total_hole_size = 0; 206 207 mandatory_opt = 2; 208 while ((opt = getopt(argc, argv, "s:h:t:")) != -1) { 209 switch(opt) { 210 case 's': 211 seed = atoi(optarg); 212 break; 213 case 'h': 214 hole_size = atoll(optarg); 215 mandatory_opt--; 216 break; 217 case 't': 218 total_hole_size = atoll(optarg); 219 mandatory_opt--; 220 break; 221 default: 222 usage(argv[0]); 223 exit(EXIT_FAILURE); 224 } 225 } 226 if (mandatory_opt) { 227 usage(argv[0]); 228 exit(EXIT_FAILURE); 229 } 230 if (optind >= argc) { 231 fprintf(stderr, "\nExpected path name after options.\n"); 232 usage(argv[0]); 233 exit(EXIT_FAILURE); 234 } 235 path = argv[optind++]; 236 237 if (optind < argc) { 238 fprintf(stderr, "\nUnexpected argument: %s\n", argv[optind]); 239 usage(argv[0]); 240 exit(EXIT_FAILURE); 241 } 242 243 srandom(seed); 244 fprintf(stderr, "\nRandom seed is: %d\n", seed); 245 246 total_size = get_free_space(path); 247 if (!total_size) { 248 exit(EXIT_FAILURE); 249 } 250 if (total_size < total_hole_size || total_hole_size < hole_size) { 251 fprintf(stderr, "\nInvalid sizes: total available size should be " 252 "larger than total hole size which is larger than " 253 "hole size\n"); 254 exit(EXIT_FAILURE); 255 } 256 257 if (!puncture_fs(path, total_size, hole_size, total_hole_size)) { 258 exit(EXIT_FAILURE); 259 } 260 return 0; 261 } 262
