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Diffstat (limited to '')
-rw-r--r-- | libblkid/cache.c | 275 |
1 files changed, 0 insertions, 275 deletions
diff --git a/libblkid/cache.c b/libblkid/cache.c deleted file mode 100644 index cc2cf8e94..000000000 --- a/libblkid/cache.c +++ /dev/null @@ -1,275 +0,0 @@ -/* - * 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% - */ - -#ifdef HAVE_UNISTD_H -#include <unistd.h> -#endif -#ifdef HAVE_ERRNO_H -#include <errno.h> -#endif -#include <stdlib.h> -#include <string.h> -#ifdef HAVE_SYS_STAT_H -#include <sys/stat.h> -#endif -#include "blkidP.h" -#include "env.h" - -int blkid_debug_mask = 0; - -/** - * SECTION:cache - * @title: Cache - * @short_description: basic routines to work with libblkid cache - * - * Block device information is normally kept in a cache file blkid.tab and is - * verified to still be valid before being returned to the user (if the user has - * read permission on the raw block device, otherwise not). The cache file also - * allows unprivileged users (normally anyone other than root, or those not in the - * "disk" group) to locate devices by label/id. The standard location of the - * cache file can be overridden by the environment variable BLKID_FILE. - * - * In situations where one is getting information about a single known device, it - * does not impact performance whether the cache is used or not (unless you are - * not able to read the block device directly). If you are dealing with multiple - * devices, use of the cache is highly recommended (even if empty) as devices will - * be scanned at most one time and the on-disk cache will be updated if possible. - * There is rarely a reason not to use the cache. - * - * In some cases (modular kernels), block devices are not even visible until after - * they are accessed the first time, so it is critical that there is some way to - * locate these devices without enumerating only visible devices, so the use of - * the cache file is required in this situation. - */ - -#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 - -#ifdef CONFIG_BLKID_DEBUG -void blkid_init_debug(int mask) -{ - if (blkid_debug_mask & DEBUG_INIT) - return; - - if (!mask) - { - char *dstr = getenv("LIBBLKID_DEBUG"); - - if (!dstr) - dstr = getenv("BLKID_DEBUG"); /* for backward compatibility */ - if (dstr) - blkid_debug_mask = strtoul(dstr, 0, 0); - } else - blkid_debug_mask = mask; - - if (blkid_debug_mask) - printf("libblkid: debug mask set to 0x%04x.\n", blkid_debug_mask); - - blkid_debug_mask |= DEBUG_INIT; -} -#endif - -static const char *get_default_cache_filename(void) -{ - struct stat st; - - if (stat(BLKID_RUNTIME_TOPDIR, &st) == 0 && S_ISDIR(st.st_mode)) - return BLKID_CACHE_FILE; /* cache in /run */ - - return BLKID_CACHE_FILE_OLD; /* cache in /etc */ -} - -/* returns allocated path to cache */ -char *blkid_get_cache_filename(struct blkid_config *conf) -{ - char *filename; - - filename = safe_getenv("BLKID_FILE"); - if (filename) - filename = strdup(filename); - else if (conf) - filename = conf->cachefile ? strdup(conf->cachefile) : NULL; - else { - struct blkid_config *c = blkid_read_config(NULL); - if (!c) - filename = strdup(get_default_cache_filename()); - else { - filename = c->cachefile; /* already allocated */ - c->cachefile = NULL; - blkid_free_config(c); - } - } - return filename; -} - -/** - * blkid_get_cache: - * @cache: pointer to return cache handler - * @filename: path to the cache file or NULL for the default path - * - * Allocates and initialize librray cache handler. - * - * Returns: 0 on success or number less than zero in case of error. - */ -int blkid_get_cache(blkid_cache *ret_cache, const char *filename) -{ - blkid_cache cache; - - if (!ret_cache) - return -BLKID_ERR_PARAM; - - blkid_init_debug(0); - - 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 && !*filename) - filename = NULL; - if (filename) - cache->bic_filename = strdup(filename); - else - cache->bic_filename = blkid_get_cache_filename(NULL); - - blkid_read_cache(cache); - *ret_cache = cache; - return 0; -} - -/** - * blkid_put_cache: - * @cache: cache handler - * - * Saves changes to cache file. - */ -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); - } - - blkid_free_probe(cache->probe); - - free(cache->bic_filename); - free(cache); -} - -/** - * blkid_gc_cache: - * @cache: cache handler - * - * Removes garbage (non-existing devices) from the 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_init_debug(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_get_cache_filename(NULL)); - 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 |