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 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 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 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 69 static char get_random_char() { 70 return 'A' + random() % ('Z' - 'A'); 71 } 72 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 } 120 121 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 } 138 139 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 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 create_unique_file(stay_dir, 167 hole_max - starting_max, 168 file_id++, 169 base_file_data, 170 MAX_IO_WRITE_CHUNK_SIZE); 171 create_unique_file(delete_dir, 172 hole_size, 173 file_id++, 174 base_file_data, 175 MAX_IO_WRITE_CHUNK_SIZE); 176 177 starting_max = hole_max + hole_size; 178 ending_max += increments; 179 } 180 create_unique_file(stay_dir, 181 (ending_max - increments - starting_max), 182 file_id++, 183 base_file_data, 184 MAX_IO_WRITE_CHUNK_SIZE); 185 fprintf(stderr, "\rSTAGE 1/2: 100%% Complete\n"); 186 fprintf(stderr, "\rSTAGE 2/2: 0%% Complete"); 187 free(base_file_data); 188 rm_bin_argv[2] = delete_dir; 189 if (android_fork_execvp_ext(ARRAY_SIZE(rm_bin_argv), rm_bin_argv, 190 NULL, 1, LOG_KLOG, 0, NULL, NULL, 0) < 0) { 191 fprintf(stderr, "\nFailed to delete %s\n", rm_bin_argv[2]); 192 return false; 193 } 194 fprintf(stderr, "\rSTAGE 2/2: 100%% Complete\n"); 195 return true; 196 } 197 198 int main (const int argc, char ** const argv) { 199 int opt; 200 int mandatory_opt; 201 char *path = NULL; 202 int seed = time(NULL); 203 204 u64 total_size = 0; 205 u64 hole_size = 0; 206 u64 total_hole_size = 0; 207 208 mandatory_opt = 2; 209 while ((opt = getopt(argc, argv, "s:h:t:")) != -1) { 210 switch(opt) { 211 case 's': 212 seed = atoi(optarg); 213 break; 214 case 'h': 215 hole_size = atoll(optarg); 216 mandatory_opt--; 217 break; 218 case 't': 219 total_hole_size = atoll(optarg); 220 mandatory_opt--; 221 break; 222 default: 223 usage(argv[0]); 224 exit(EXIT_FAILURE); 225 } 226 } 227 if (mandatory_opt) { 228 usage(argv[0]); 229 exit(EXIT_FAILURE); 230 } 231 if (optind >= argc) { 232 fprintf(stderr, "\nExpected path name after options.\n"); 233 usage(argv[0]); 234 exit(EXIT_FAILURE); 235 } 236 path = argv[optind++]; 237 238 if (optind < argc) { 239 fprintf(stderr, "\nUnexpected argument: %s\n", argv[optind]); 240 usage(argv[0]); 241 exit(EXIT_FAILURE); 242 } 243 244 srandom(seed); 245 fprintf(stderr, "\nRandom seed is: %d\n", seed); 246 247 total_size = get_free_space(path); 248 if (!total_size) { 249 exit(EXIT_FAILURE); 250 } 251 if (total_size < total_hole_size || total_hole_size < hole_size) { 252 fprintf(stderr, "\nInvalid sizes: total available size should be " 253 "larger than total hole size which is larger than " 254 "hole size\n"); 255 exit(EXIT_FAILURE); 256 } 257 258 if (!puncture_fs(path, total_size, hole_size, total_hole_size)) { 259 exit(EXIT_FAILURE); 260 } 261 return 0; 262 } 263
