blob: 2b8188682d386d0c749b34328748e5ccdf956392 [file] [log] [blame]
/*
* 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%
*/
#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
#ifdef 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 (!p)
break;
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