//insert and uodate an inode to inode cache LRU
void set_inodeLRU(int inode_num, inode_cache *i)
{
inode_cache* n = get_inode(inode_num);
if (n!=NULL) {
put_inode(inode_num, i);
if (n!=last_inode) {
if (n==first_inode) first_inode = first_inode->next;
else n->prev->next = n->next;
n->next->prev = n->prev;
last_inode->next = n;
n->prev = last_inode;
n->next = NULL;
last_inode = n;
}
}
else {
if (inode_cache_cnt>=INODE_CACHESIZE) {
//rm_inode(first_inode->inode_num);
sync();
//write back dirty inode to block cache
if (first_inode->dirty) {
int block_num = inode_to_block(inode_num);
block_cache *b = read_block(block_num);
int idx = inode_num-(block_num-1)*(BLOCKSIZE/INODESIZE);
memcpy((void*)(b->data+idx*INODESIZE),(void*)(&(first_inode->data)),INODESIZE);
b->dirty = 1;
}
rm_inode(first_inode->inode_num);
inode_cache *tmp = first_inode;
first_inode = first_inode->next;
if (first_inode!=NULL) first_inode->prev = NULL;
else last_inode = NULL;
inode_cache_cnt--;
free(tmp);
}
if (first_inode==NULL || last_inode==NULL) first_inode = i;
else last_inode->next = i;
i->prev = last_inode;
last_inode = i;
put_inode(inode_num, i);
inode_cache_cnt++;
}
}
/* remove file/dir from fs */
int fs_unlink(const char *pathname)
{
struct inode_s *ino, *dir;
ino = dir = NULL;
dir = current_dir();
if ( (ino = find_inode(dir, pathname, FS_SEARCH_REMOVE)) == NULL)
goto err;
rm_inode(ino->i_num);
release_inode(dir);
release_inode(ino);
return OK;
err:
release_inode(dir);
release_inode(ino);
return ERROR;
}
/* remove directory (only if it is empty) */
int fs_rmdir(const char *pathname)
{
struct inode_s *ino, *dir, *tmpdir;
char path[MAX_PATH], name[MAX_NAME];
ino = dir = tmpdir = NULL;
process_path(pathname, path, name);
tmpdir = current_dir();
/* get inode numbers from parent and new dir */
if ( (dir = find_inode(tmpdir, path, FS_SEARCH_GET)) == NULL)
goto err;
release_inode(tmpdir);
if ( (ino = find_inode(dir, name, FS_SEARCH_ADD)) == NULL)
goto err;
/* check if its a dir and it is empty */
if (!IS_DIR(ino->i_mode) || ino->i_size != DIRENTRY_SIZE * 2)
goto err;
/* this cant give an error */
release_inode(find_inode(dir, name, FS_SEARCH_REMOVE));
/* free blocks and inode */
rm_inode(ino->i_num);
release_inode(dir);
release_inode(ino);
return OK;
err:
release_inode(tmpdir);
release_inode(dir);
release_inode(ino);
return ERROR;
}
