1 /* 2 * cache.c - allocation/initialization/free routines for cache 3 * 4 * Copyright (C) 2001 Andreas Dilger 5 * Copyright (C) 2003 Theodore Ts'o 6 * 7 * %Begin-Header% 8 * This file may be redistributed under the terms of the 9 * GNU Lesser General Public License. 10 * %End-Header% 11 */ 12 13 #if HAVE_UNISTD_H 14 #include <unistd.h> 15 #endif 16 #ifdef HAVE_ERRNO_H 17 #include <errno.h> 18 #endif 19 #include <stdlib.h> 20 #include <string.h> 21 #ifdef HAVE_SYS_PRCTL_H 22 #include <sys/prctl.h> 23 #else 24 #define PR_GET_DUMPABLE 3 25 #endif 26 #if (!defined(HAVE_PRCTL) && defined(linux)) 27 #include <sys/syscall.h> 28 #endif 29 #ifdef HAVE_SYS_STAT_H 30 #include <sys/stat.h> 31 #endif 32 #include "blkidP.h" 33 34 int blkid_debug_mask = 0; 35 36 37 static char *safe_getenv(const char *arg) 38 { 39 if ((getuid() != geteuid()) || (getgid() != getegid())) 40 return NULL; 41 #if HAVE_PRCTL 42 if (prctl(PR_GET_DUMPABLE, 0, 0, 0, 0) == 0) 43 return NULL; 44 #else 45 #if (defined(linux) && defined(SYS_prctl)) 46 if (syscall(SYS_prctl, PR_GET_DUMPABLE, 0, 0, 0, 0) == 0) 47 return NULL; 48 #endif 49 #endif 50 51 #ifdef HAVE___SECURE_GETENV 52 return __secure_getenv(arg); 53 #else 54 return getenv(arg); 55 #endif 56 } 57 58 #if 0 /* ifdef CONFIG_BLKID_DEBUG */ 59 static blkid_debug_dump_cache(int mask, blkid_cache cache) 60 { 61 struct list_head *p; 62 63 if (!cache) { 64 printf("cache: NULL\n"); 65 return; 66 } 67 68 printf("cache: time = %lu\n", cache->bic_time); 69 printf("cache: flags = 0x%08X\n", cache->bic_flags); 70 71 list_for_each(p, &cache->bic_devs) { 72 blkid_dev dev = list_entry(p, struct blkid_struct_dev, bid_devs); 73 blkid_debug_dump_dev(dev); 74 } 75 } 76 #endif 77 78 int blkid_get_cache(blkid_cache *ret_cache, const char *filename) 79 { 80 blkid_cache cache; 81 82 #ifdef CONFIG_BLKID_DEBUG 83 if (!(blkid_debug_mask & DEBUG_INIT)) { 84 char *dstr = getenv("BLKID_DEBUG"); 85 86 if (dstr) 87 blkid_debug_mask = strtoul(dstr, 0, 0); 88 blkid_debug_mask |= DEBUG_INIT; 89 } 90 #endif 91 92 DBG(DEBUG_CACHE, printf("creating blkid cache (using %s)\n", 93 filename ? filename : "default cache")); 94 95 if (!(cache = (blkid_cache) calloc(1, sizeof(struct blkid_struct_cache)))) 96 return -BLKID_ERR_MEM; 97 98 INIT_LIST_HEAD(&cache->bic_devs); 99 INIT_LIST_HEAD(&cache->bic_tags); 100 101 if (filename && !strlen(filename)) 102 filename = 0; 103 if (!filename) 104 filename = safe_getenv("BLKID_FILE"); 105 if (!filename) 106 filename = BLKID_CACHE_FILE; 107 cache->bic_filename = blkid_strdup(filename); 108 109 blkid_read_cache(cache); 110 111 *ret_cache = cache; 112 return 0; 113 } 114 115 void blkid_put_cache(blkid_cache cache) 116 { 117 if (!cache) 118 return; 119 120 (void) blkid_flush_cache(cache); 121 122 DBG(DEBUG_CACHE, printf("freeing cache struct\n")); 123 124 /* DBG(DEBUG_CACHE, blkid_debug_dump_cache(cache)); */ 125 126 while (!list_empty(&cache->bic_devs)) { 127 blkid_dev dev = list_entry(cache->bic_devs.next, 128 struct blkid_struct_dev, 129 bid_devs); 130 blkid_free_dev(dev); 131 } 132 133 while (!list_empty(&cache->bic_tags)) { 134 blkid_tag tag = list_entry(cache->bic_tags.next, 135 struct blkid_struct_tag, 136 bit_tags); 137 138 while (!list_empty(&tag->bit_names)) { 139 blkid_tag bad = list_entry(tag->bit_names.next, 140 struct blkid_struct_tag, 141 bit_names); 142 143 DBG(DEBUG_CACHE, printf("warning: unfreed tag %s=%s\n", 144 bad->bit_name, bad->bit_val)); 145 blkid_free_tag(bad); 146 } 147 blkid_free_tag(tag); 148 } 149 if (cache->bic_filename) 150 free(cache->bic_filename); 151 152 free(cache); 153 } 154 155 void blkid_gc_cache(blkid_cache cache) 156 { 157 struct list_head *p; 158 struct stat st; 159 160 if (!cache) 161 return; 162 163 list_for_each(p, &cache->bic_devs) { 164 blkid_dev dev = list_entry(p, struct blkid_struct_dev, bid_devs); 165 if (!p) 166 break; 167 if (stat(dev->bid_name, &st) < 0) { 168 DBG(DEBUG_CACHE, 169 printf("freeing %s\n", dev->bid_name)); 170 blkid_free_dev(dev); 171 cache->bic_flags |= BLKID_BIC_FL_CHANGED; 172 } else { 173 DBG(DEBUG_CACHE, 174 printf("Device %s exists\n", dev->bid_name)); 175 } 176 } 177 } 178 179 180 #ifdef TEST_PROGRAM 181 int main(int argc, char** argv) 182 { 183 blkid_cache cache = NULL; 184 int ret; 185 186 blkid_debug_mask = DEBUG_ALL; 187 if ((argc > 2)) { 188 fprintf(stderr, "Usage: %s [filename] \n", argv[0]); 189 exit(1); 190 } 191 192 if ((ret = blkid_get_cache(&cache, argv[1])) < 0) { 193 fprintf(stderr, "error %d parsing cache file %s\n", ret, 194 argv[1] ? argv[1] : BLKID_CACHE_FILE); 195 exit(1); 196 } 197 if ((ret = blkid_get_cache(&cache, "/dev/null")) != 0) { 198 fprintf(stderr, "%s: error creating cache (%d)\n", 199 argv[0], ret); 200 exit(1); 201 } 202 if ((ret = blkid_probe_all(cache) < 0)) 203 fprintf(stderr, "error probing devices\n"); 204 205 blkid_put_cache(cache); 206 207 return ret; 208 } 209 #endif 210
