diff options
Diffstat (limited to 'lib/blkid/cache.c')
| -rw-r--r-- | lib/blkid/cache.c | 209 |
1 files changed, 209 insertions, 0 deletions
diff --git a/lib/blkid/cache.c b/lib/blkid/cache.c new file mode 100644 index 0000000..80c8089 --- /dev/null +++ b/lib/blkid/cache.c @@ -0,0 +1,209 @@ +/* + * cache.c - allocation/initialization/free routines for cache + * + * Copyright (C) 2001 Andreas Dilger + * Copyright (C) 2003 Theodore Ts'o + * + * %Begin-Header% + * This file may be redistributed under the terms of the + * GNU Lesser General Public License. + * %End-Header% + */ + +#include "config.h" +#if HAVE_UNISTD_H +#include <unistd.h> +#endif +#ifdef HAVE_ERRNO_H +#include <errno.h> +#endif +#include <stdlib.h> +#include <string.h> +#ifdef HAVE_SYS_PRCTL_H +#include <sys/prctl.h> +#else +#define PR_GET_DUMPABLE 3 +#endif +#if (!defined(HAVE_PRCTL) && defined(linux)) +#include <sys/syscall.h> +#endif +#ifdef HAVE_SYS_STAT_H +#include <sys/stat.h> +#endif +#include "blkidP.h" + +int blkid_debug_mask = 0; + + +static char *safe_getenv(const char *arg) +{ + if ((getuid() != geteuid()) || (getgid() != getegid())) + return NULL; +#if HAVE_PRCTL + if (prctl(PR_GET_DUMPABLE, 0, 0, 0, 0) == 0) + return NULL; +#else +#if (defined(linux) && defined(SYS_prctl)) + if (syscall(SYS_prctl, PR_GET_DUMPABLE, 0, 0, 0, 0) == 0) + return NULL; +#endif +#endif + +#if defined(HAVE_SECURE_GETENV) + return secure_getenv(arg); +#elif defined(HAVE___SECURE_GETENV) + return __secure_getenv(arg); +#else + return getenv(arg); +#endif +} + +#if 0 /* ifdef CONFIG_BLKID_DEBUG */ +static blkid_debug_dump_cache(int mask, blkid_cache cache) +{ + struct list_head *p; + + if (!cache) { + printf("cache: NULL\n"); + return; + } + + printf("cache: time = %lu\n", cache->bic_time); + printf("cache: flags = 0x%08X\n", cache->bic_flags); + + list_for_each(p, &cache->bic_devs) { + blkid_dev dev = list_entry(p, struct blkid_struct_dev, bid_devs); + blkid_debug_dump_dev(dev); + } +} +#endif + +int blkid_get_cache(blkid_cache *ret_cache, const char *filename) +{ + blkid_cache cache; + +#ifdef CONFIG_BLKID_DEBUG + if (!(blkid_debug_mask & DEBUG_INIT)) { + char *dstr = getenv("BLKID_DEBUG"); + + if (dstr) + blkid_debug_mask = strtoul(dstr, 0, 0); + blkid_debug_mask |= DEBUG_INIT; + } +#endif + + DBG(DEBUG_CACHE, printf("creating blkid cache (using %s)\n", + filename ? filename : "default cache")); + + if (!(cache = (blkid_cache) calloc(1, sizeof(struct blkid_struct_cache)))) + return -BLKID_ERR_MEM; + + INIT_LIST_HEAD(&cache->bic_devs); + INIT_LIST_HEAD(&cache->bic_tags); + + if (filename && !strlen(filename)) + filename = 0; + if (!filename) + filename = safe_getenv("BLKID_FILE"); + if (!filename) + filename = BLKID_CACHE_FILE; + cache->bic_filename = blkid_strdup(filename); + + blkid_read_cache(cache); + + *ret_cache = cache; + return 0; +} + +void blkid_put_cache(blkid_cache cache) +{ + if (!cache) + return; + + (void) blkid_flush_cache(cache); + + DBG(DEBUG_CACHE, printf("freeing cache struct\n")); + + /* DBG(DEBUG_CACHE, blkid_debug_dump_cache(cache)); */ + + while (!list_empty(&cache->bic_devs)) { + blkid_dev dev = list_entry(cache->bic_devs.next, + struct blkid_struct_dev, + bid_devs); + blkid_free_dev(dev); + } + + while (!list_empty(&cache->bic_tags)) { + blkid_tag tag = list_entry(cache->bic_tags.next, + struct blkid_struct_tag, + bit_tags); + + while (!list_empty(&tag->bit_names)) { + blkid_tag bad = list_entry(tag->bit_names.next, + struct blkid_struct_tag, + bit_names); + + DBG(DEBUG_CACHE, printf("warning: unfreed tag %s=%s\n", + bad->bit_name, bad->bit_val)); + blkid_free_tag(bad); + } + blkid_free_tag(tag); + } + free(cache->bic_filename); + + free(cache); +} + +void blkid_gc_cache(blkid_cache cache) +{ + struct list_head *p, *pnext; + struct stat st; + + if (!cache) + return; + + list_for_each_safe(p, pnext, &cache->bic_devs) { + blkid_dev dev = list_entry(p, struct blkid_struct_dev, bid_devs); + if (stat(dev->bid_name, &st) < 0) { + DBG(DEBUG_CACHE, + printf("freeing %s\n", dev->bid_name)); + blkid_free_dev(dev); + cache->bic_flags |= BLKID_BIC_FL_CHANGED; + } else { + DBG(DEBUG_CACHE, + printf("Device %s exists\n", dev->bid_name)); + } + } +} + + +#ifdef TEST_PROGRAM +int main(int argc, char** argv) +{ + blkid_cache cache = NULL; + int ret; + + blkid_debug_mask = DEBUG_ALL; + if ((argc > 2)) { + fprintf(stderr, "Usage: %s [filename] \n", argv[0]); + exit(1); + } + + if ((ret = blkid_get_cache(&cache, argv[1])) < 0) { + fprintf(stderr, "error %d parsing cache file %s\n", ret, + argv[1] ? argv[1] : BLKID_CACHE_FILE); + exit(1); + } + if ((ret = blkid_get_cache(&cache, "/dev/null")) != 0) { + fprintf(stderr, "%s: error creating cache (%d)\n", + argv[0], ret); + exit(1); + } + if ((ret = blkid_probe_all(cache) < 0)) + fprintf(stderr, "error probing devices\n"); + + blkid_put_cache(cache); + + return ret; +} +#endif |