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/* |
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* dircache.c |
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* Copyright (C) 2002 Florin Malita <mali@go.ro> |
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* |
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* This file is part of LUFS, a free userspace filesystem implementation. |
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* See http://lufs.sourceforge.net/ for updates. |
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* |
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* LUFS is free software; you can redistribute it and/or modify |
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* it under the terms of the GNU General Public License as published by |
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* the Free Software Foundation; either version 2 of the License, or |
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* (at your option) any later version. |
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* |
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* LUFS is distributed in the hope that it will be useful, |
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* but WITHOUT ANY WARRANTY; without even the implied warranty of |
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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* GNU General Public License for more details. |
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* |
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* You should have received a copy of the GNU General Public License |
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* along with this program; if not, write to the Free Software |
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
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*/ |
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|
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#include <unistd.h> |
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#include <stdlib.h> |
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#include <string.h> |
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#include <pthread.h> |
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|
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#include <sys/stat.h> |
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|
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#include <lufs/proto.h> |
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#include <lufs/fs.h> |
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|
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#include "list.h" |
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#include "dircache.h" |
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|
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static char root_dir[]="/"; |
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static char current_dir[]="."; |
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|
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static unsigned long |
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hash(char *name){ |
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unsigned long res = 0; |
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unsigned int i; |
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|
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for(i = 0; i < strlen(name); i++) |
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if(name[i] != '/') |
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res = 0x21413 * (res + name[i]); |
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|
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return res % NBUCKETS; |
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} |
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|
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static void |
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delete_dir(struct directory *d){ |
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struct list_head *p, *tmp; |
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struct direntry *de; |
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|
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TRACE("in"); |
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list_for_each_safe(p, tmp, &d->d_entries){ |
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de = list_entry(p, struct direntry, e_list); |
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list_del(&de->e_list); |
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free(de->e_name); |
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if(de->e_link) |
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free(de->e_link); |
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free(de); |
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} |
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|
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list_del(&d->d_list); |
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free(d->d_name); |
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free(d); |
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|
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TRACE("out"); |
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} |
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|
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struct dir_cache* |
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lu_cache_create(struct list_head *cfg){ |
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struct dir_cache *cache; |
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int i; |
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const char *c; |
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|
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TRACE("creating dir cache..."); |
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|
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if(!(cache = malloc(sizeof(struct dir_cache)))) |
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return NULL; |
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|
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memset(cache, 0, sizeof(struct dir_cache)); |
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|
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for(i = 0; i < NBUCKETS; i++) |
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INIT_LIST_HEAD(&cache->buckets[i]); |
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|
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pthread_mutex_init(&cache->lock, NULL); |
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|
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cache->ttl = DEF_TTL; |
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if((c = lu_opt_getchar(cfg, "LUFSD", "DirCacheTTL")) && atoi(c)) |
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cache->ttl = atoi(c); |
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if((c = lu_opt_getchar(cfg, "MOUNT", "dir_cache_ttl")) && atoi(c)) |
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cache->ttl = atoi(c); |
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|
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cache->entries = DEF_NENTRIES; |
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if((c = lu_opt_getchar(cfg, "LUFSD", "DirCacheEntries")) && atoi(c)) |
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cache->entries = atoi(c); |
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if((c = lu_opt_getchar(cfg, "MOUNT", "dir_cache_entries")) && atoi(c)) |
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cache->entries = atoi(c); |
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|
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TRACE("entries: %d, ttl: %d", cache->entries, cache->ttl); |
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|
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return cache; |
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} |
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|
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void |
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lu_cache_destroy(struct dir_cache *cache){ |
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struct list_head *p, *tmp; |
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int i; |
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|
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for(i = 0; i < NBUCKETS; i++){ |
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list_for_each_safe(p, tmp, &cache->buckets[i]){ |
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delete_dir(list_entry(p, struct directory, d_list)); |
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} |
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} |
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|
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free(cache); |
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} |
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|
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static struct directory* |
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search(struct dir_cache *cache, char *dir){ |
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struct list_head *p, *tmp; |
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struct directory *d; |
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int hsh; |
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|
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hsh = hash(dir); |
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|
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TRACE("search %s in bucket %u, size=%u", dir, hsh, cache->lengths[hsh]); |
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|
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list_for_each_safe(p, tmp, &cache->buckets[hsh]){ |
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d = list_entry(p, struct directory, d_list); |
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|
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if(time(NULL) - d->d_stamp >= (unsigned long) cache->ttl){ |
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TRACE("%s expired...", d->d_name); |
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delete_dir(d); |
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cache->lengths[hsh]--; |
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TRACE("directory deleted"); |
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}else if(!strcmp(dir, d->d_name)){ |
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TRACE("%s found", dir); |
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d->d_stamp = time(NULL); |
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return d; |
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} |
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} |
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|
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TRACE("dir not found"); |
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return NULL; |
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} |
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|
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int |
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lu_cache_lookup(struct dir_cache *cache, char *dir, char *file, struct lufs_fattr *fattr, char *link, int buflen){ |
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struct directory *d; |
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struct direntry *de; |
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struct list_head *p; |
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int res = -1; |
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|
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TRACE("looking up %s in dir %s", file, dir); |
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|
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pthread_mutex_lock(&cache->lock); |
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|
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if(!(d = search(cache, dir))) |
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goto out; |
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|
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list_for_each(p, &d->d_entries){ |
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de = list_entry(p, struct direntry, e_list); |
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if(!strcmp(file, de->e_name)){ |
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TRACE("file found"); |
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|
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memcpy(fattr, &de->e_attr, sizeof(struct lufs_fattr)); |
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if(link){ |
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if(de->e_link){ |
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if(snprintf(link, buflen, "%s", de->e_link) >= buflen){ |
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WARN("link too long!"); |
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link[buflen - 1] =0; |
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} |
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}else{ |
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link[0] = 0; |
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} |
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} |
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|
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res = 0; |
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goto out; |
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} |
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} |
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|
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TRACE("file not found!"); |
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|
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out: |
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pthread_mutex_unlock(&cache->lock); |
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return res; |
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} |
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|
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static void |
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shrink(struct dir_cache *cache, int hsh){ |
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struct directory *dir; |
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|
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TRACE("shrinking bucket %u, len=%u", hsh, cache->lengths[hsh]); |
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|
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if(list_empty(&cache->buckets[hsh])) |
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return; |
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|
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dir = list_entry(cache->buckets[hsh].prev, struct directory, d_list); |
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|
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TRACE("deleting dir %s", dir->d_name); |
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|
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delete_dir(dir); |
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cache->lengths[hsh]--; |
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} |
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|
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static void |
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check_dir(struct directory *d){ |
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struct list_head *p, *tmp; |
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struct direntry *e; |
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struct lufs_fattr dummy; |
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int dot = 0, dotdot = 0; |
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|
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memset(&dummy, 0, sizeof(struct lufs_fattr)); |
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dummy.f_nlink = 1; |
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dummy.f_uid = dummy.f_gid = 1; |
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dummy.f_mode = S_IFDIR | S_IRWXU | S_IRGRP | S_IXGRP; |
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dummy.f_mtime = dummy.f_atime = dummy.f_ctime = time(NULL); |
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dummy.f_size = 512; |
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|
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do{ |
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list_for_each_safe(p, tmp, &d->d_entries){ |
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e = list_entry(p, struct direntry, e_list); |
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|
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if(!strcmp(e->e_name, ".")){ |
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TRACE("'.' entry found"); |
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list_del(&e->e_list); |
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list_add(&e->e_list, &d->d_entries); |
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dot = 1; |
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continue; |
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} |
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|
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if(!strcmp(e->e_name, "..")){ |
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TRACE("'..' entry found"); |
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list_del(&e->e_list); |
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if(!dot) |
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list_add(&e->e_list, &d->d_entries); |
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else |
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list_add(&e->e_list, d->d_entries.next); |
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|
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dotdot = 1; |
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} |
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} |
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|
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if(!dot) |
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lu_cache_add2dir(d, ".", NULL, &dummy); |
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|
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if(!dotdot) |
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lu_cache_add2dir(d, "..", NULL, &dummy); |
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|
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}while((!dot) || (!dotdot)); |
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|
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} |
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|
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void |
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lu_cache_add_dir(struct dir_cache *cache, struct directory *d){ |
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struct directory *dir; |
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int hsh; |
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|
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hsh = hash(d->d_name); |
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|
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TRACE("adding dir %s to bucket %i", d->d_name, hsh); |
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|
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check_dir(d); |
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|
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pthread_mutex_lock(&cache->lock); |
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|
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if((dir = search(cache, d->d_name))){ |
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TRACE("directory already in cache, deleting..."); |
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delete_dir(dir); |
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cache->lengths[hsh]--; |
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} |
277 |
|
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d->d_stamp = time(NULL); |
279 |
|
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list_add(&d->d_list, &cache->buckets[hsh]); |
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cache->lengths[hsh]++; |
282 |
|
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while(cache->lengths[hsh] > cache->entries) |
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shrink(cache, hsh); |
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|
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pthread_mutex_unlock(&cache->lock); |
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|
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TRACE("out"); |
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} |
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|
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int lu_cache_readdir(struct dir_cache *cache, char *dir, |
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fuse_dirh_t h, fuse_dirfil_t filler) |
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{ |
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struct directory *d; |
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struct direntry *de; |
296 |
struct list_head *p; |
297 |
int res = -1; |
298 |
|
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TRACE("reading directory %s", dir); |
300 |
|
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pthread_mutex_lock(&cache->lock); |
302 |
|
303 |
if(!(d = search(cache, dir))) |
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goto out; |
305 |
|
306 |
list_for_each(p, &d->d_entries){ |
307 |
de = list_entry(p, struct direntry, e_list); |
308 |
filler(h, de->e_name, 0); |
309 |
} |
310 |
|
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d->d_stamp = time(NULL); |
312 |
|
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res = 0; |
314 |
|
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out: |
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pthread_mutex_unlock(&cache->lock); |
317 |
TRACE("out"); |
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return res; |
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} |
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|
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int |
322 |
lu_cache_lookup_file(struct dir_cache *cache, char *file, struct lufs_fattr *fattr, char *link, int buflen){ |
323 |
int res; |
324 |
|
325 |
char *sep, *dir; |
326 |
|
327 |
if(!(sep = strrchr(file, '/'))){ |
328 |
WARN("separator not present!"); |
329 |
return -1; |
330 |
} |
331 |
|
332 |
*sep = 0; |
333 |
|
334 |
if(sep == file) |
335 |
dir = root_dir; |
336 |
else |
337 |
dir = file; |
338 |
|
339 |
if(*(sep+1)) |
340 |
file = sep + 1; |
341 |
else |
342 |
file = current_dir; |
343 |
|
344 |
TRACE("dir: %s, file: %s", dir, file); |
345 |
|
346 |
res = lu_cache_lookup(cache, dir, file, fattr, link, buflen); |
347 |
*sep = '/'; |
348 |
|
349 |
return res; |
350 |
} |
351 |
|
352 |
int |
353 |
lu_cache_invalidate(struct dir_cache *cache, char *file){ |
354 |
struct directory *d; |
355 |
char *sep, *dir; |
356 |
|
357 |
if(!(sep = strrchr(file, '/'))){ |
358 |
WARN("separator not present!"); |
359 |
return -1; |
360 |
} |
361 |
|
362 |
*sep = 0; |
363 |
|
364 |
if(sep == file) |
365 |
dir = root_dir; |
366 |
else |
367 |
dir = file; |
368 |
|
369 |
TRACE("invalidating dir %s", dir); |
370 |
|
371 |
pthread_mutex_lock(&cache->lock); |
372 |
|
373 |
if(!(d = search(cache, dir))){ |
374 |
*sep = '/'; |
375 |
pthread_mutex_unlock(&cache->lock); |
376 |
return -1; |
377 |
} |
378 |
|
379 |
d->d_stamp = 0; |
380 |
|
381 |
pthread_mutex_unlock(&cache->lock); |
382 |
*sep = '/'; |
383 |
|
384 |
return 0; |
385 |
} |
386 |
|
387 |
struct directory* |
388 |
lu_cache_mkdir(char *dir){ |
389 |
struct directory *res; |
390 |
|
391 |
TRACE("create dir %s", dir); |
392 |
|
393 |
if(!(res = malloc(sizeof(struct directory)))){ |
394 |
WARN("out of mem!"); |
395 |
return NULL; |
396 |
} |
397 |
|
398 |
memset(res, 0, sizeof(struct directory)); |
399 |
|
400 |
if(!(res->d_name = malloc(strlen(dir) + 1))){ |
401 |
WARN("out of mem!"); |
402 |
free(res); |
403 |
return NULL; |
404 |
} |
405 |
|
406 |
INIT_LIST_HEAD(&res->d_entries); |
407 |
res->d_stamp = time(NULL); |
408 |
strcpy(res->d_name, dir); |
409 |
|
410 |
return res; |
411 |
} |
412 |
|
413 |
int |
414 |
lu_cache_add2dir(struct directory *d, char *fname, char *link, struct lufs_fattr *fattr){ |
415 |
struct direntry *de; |
416 |
|
417 |
TRACE("adding %s->%s to %s", fname, link, d->d_name); |
418 |
|
419 |
if(!(de = malloc(sizeof(struct direntry)))) |
420 |
goto fail; |
421 |
|
422 |
|
423 |
if(!(de->e_name = malloc(strlen(fname) + 1))) |
424 |
goto fail_de; |
425 |
|
426 |
|
427 |
if(link) |
428 |
de->e_link = malloc(strlen(link) + 1); |
429 |
else |
430 |
de->e_link = malloc(2); |
431 |
|
432 |
if(!de->e_link) |
433 |
goto fail_ename; |
434 |
|
435 |
memcpy(&de->e_attr, fattr, sizeof(struct lufs_fattr)); |
436 |
strcpy(de->e_name, fname); |
437 |
if(link) |
438 |
strcpy(de->e_link, link); |
439 |
else |
440 |
strcpy(de->e_link, ""); |
441 |
|
442 |
list_add_tail(&de->e_list, &d->d_entries); |
443 |
|
444 |
return 0; |
445 |
|
446 |
fail_ename: |
447 |
free(de->e_name); |
448 |
fail_de: |
449 |
free(de); |
450 |
fail: |
451 |
WARN("out of mem!"); |
452 |
return -1; |
453 |
} |
454 |
|
455 |
void |
456 |
lu_cache_killdir(struct directory *d){ |
457 |
struct list_head *p, *tmp; |
458 |
struct direntry *de; |
459 |
|
460 |
TRACE("in"); |
461 |
|
462 |
list_for_each_safe(p, tmp, &d->d_entries){ |
463 |
de = list_entry(p, struct direntry, e_list); |
464 |
list_del(&de->e_list); |
465 |
free(de->e_name); |
466 |
if(de->e_link) |
467 |
free(de->e_link); |
468 |
free(de); |
469 |
} |
470 |
|
471 |
free(d->d_name); |
472 |
free(d); |
473 |
|
474 |
} |