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 #include "config.h" 14 #if HAVE_UNISTD_H 15 #include <unistd.h> 16 #endif 17 #ifdef HAVE_ERRNO_H 18 #include <errno.h> 19 #endif 20 #include <stdlib.h> 21 #include <string.h> 22 #ifdef HAVE_SYS_PRCTL_H 23 #include <sys/prctl.h> 24 #else 25 #define PR_GET_DUMPABLE 3 26 #endif 27 #if (!defined(HAVE_PRCTL) && defined(linux)) 28 #include <sys/syscall.h> 29 #endif 30 #ifdef HAVE_SYS_STAT_H 31 #include <sys/stat.h> 32 #endif 33 #include "blkidP.h" 34 35 int blkid_debug_mask = 0; 36 37 38 static char *safe_getenv(const char *arg) 39 { 40 if ((getuid() != geteuid()) || (getgid() != getegid())) 41 return NULL; 42 #if HAVE_PRCTL 43 if (prctl(PR_GET_DUMPABLE, 0, 0, 0, 0) == 0) 44 return NULL; 45 #else 46 #if (defined(linux) && defined(SYS_prctl)) 47 if (syscall(SYS_prctl, PR_GET_DUMPABLE, 0, 0, 0, 0) == 0) 48 return NULL; 49 #endif 50 #endif 51 52 #if defined(HAVE_SECURE_GETENV) 53 return secure_getenv(arg); 54 #elif defined(HAVE___SECURE_GETENV) 55 return __secure_getenv(arg); 56 #else 57 return getenv(arg); 58 #endif 59 } 60 61 #if 0 /* ifdef CONFIG_BLKID_DEBUG */ 62 static blkid_debug_dump_cache(int mask, blkid_cache cache) 63 { 64 struct list_head *p; 65 66 if (!cache) { 67 printf("cache: NULL\n"); 68 return; 69 } 70 71 printf("cache: time = %lu\n", cache->bic_time); 72 printf("cache: flags = 0x%08X\n", cache->bic_flags); 73 74 list_for_each(p, &cache->bic_devs) { 75 blkid_dev dev = list_entry(p, struct blkid_struct_dev, bid_devs); 76 blkid_debug_dump_dev(dev); 77 } 78 } 79 #endif 80 81 int blkid_get_cache(blkid_cache *ret_cache, const char *filename) 82 { 83 blkid_cache cache; 84 85 #ifdef CONFIG_BLKID_DEBUG 86 if (!(blkid_debug_mask & DEBUG_INIT)) { 87 char *dstr = getenv("BLKID_DEBUG"); 88 89 if (dstr) 90 blkid_debug_mask = strtoul(dstr, 0, 0); 91 blkid_debug_mask |= DEBUG_INIT; 92 } 93 #endif 94 95 DBG(DEBUG_CACHE, printf("creating blkid cache (using %s)\n", 96 filename ? filename : "default cache")); 97 98 if (!(cache = (blkid_cache) calloc(1, sizeof(struct blkid_struct_cache)))) 99 return -BLKID_ERR_MEM; 100 101 INIT_LIST_HEAD(&cache->bic_devs); 102 INIT_LIST_HEAD(&cache->bic_tags); 103 104 if (filename && !strlen(filename)) 105 filename = 0; 106 if (!filename) 107 filename = safe_getenv("BLKID_FILE"); 108 if (!filename) 109 filename = BLKID_CACHE_FILE; 110 cache->bic_filename = blkid_strdup(filename); 111 112 blkid_read_cache(cache); 113 114 *ret_cache = cache; 115 return 0; 116 } 117 118 void blkid_put_cache(blkid_cache cache) 119 { 120 if (!cache) 121 return; 122 123 (void) blkid_flush_cache(cache); 124 125 DBG(DEBUG_CACHE, printf("freeing cache struct\n")); 126 127 /* DBG(DEBUG_CACHE, blkid_debug_dump_cache(cache)); */ 128 129 while (!list_empty(&cache->bic_devs)) { 130 blkid_dev dev = list_entry(cache->bic_devs.next, 131 struct blkid_struct_dev, 132 bid_devs); 133 blkid_free_dev(dev); 134 } 135 136 while (!list_empty(&cache->bic_tags)) { 137 blkid_tag tag = list_entry(cache->bic_tags.next, 138 struct blkid_struct_tag, 139 bit_tags); 140 141 while (!list_empty(&tag->bit_names)) { 142 blkid_tag bad = list_entry(tag->bit_names.next, 143 struct blkid_struct_tag, 144 bit_names); 145 146 DBG(DEBUG_CACHE, printf("warning: unfreed tag %s=%s\n", 147 bad->bit_name, bad->bit_val)); 148 blkid_free_tag(bad); 149 } 150 blkid_free_tag(tag); 151 } 152 free(cache->bic_filename); 153 154 free(cache); 155 } 156 157 void blkid_gc_cache(blkid_cache cache) 158 { 159 struct list_head *p, *pnext; 160 struct stat st; 161 162 if (!cache) 163 return; 164 165 list_for_each_safe(p, pnext, &cache->bic_devs) { 166 blkid_dev dev = list_entry(p, struct blkid_struct_dev, bid_devs); 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
