void create_file_from_file(int dir_inum, const char *name)
{
FILE *infile = fopen(name, "rb");
inode *in = new_inode(file_size(name), FILE_INODE);
write_inode_to_disk(in);
create_dir_entry(name, dir_inum, in->num);
append_file(in->num, infile, file_size(name));
free(in);
fclose(infile);
}
struct ref_cache *create_ref_cache(struct ref_store *refs,
fill_ref_dir_fn *fill_ref_dir)
{
struct ref_cache *ret = xcalloc(1, sizeof(*ret));
ret->ref_store = refs;
ret->fill_ref_dir = fill_ref_dir;
ret->root = create_dir_entry(ret, "", 0, 1);
return ret;
}
CassError CassandraFS::create_file(const char* path, mode_t mode) {
CassUuid uuid;
cass_uuid_gen_time(ctxt->uuid_gen, &uuid);
CassError error_value = CASS_OK;
CassFuture* result_future = NULL;
if (S_ISDIR(mode)) {
result_future = create_dir_entry(path, mode);
} else {
result_future = create_file_entry(path, &uuid, mode);
}
CassFuture* result_future2 = create_sub_entry(path);
CassFuture* result_future3 = NULL;
if (!S_ISDIR(mode)) {
result_future3 = create_physical_file(&uuid);
}
CassError err1 = cass_future_error_code(result_future);
CassError err2 = cass_future_error_code(result_future2);
CassError err3 = CASS_OK;
if (result_future3 != NULL) {
err3 = cass_future_error_code(result_future3);
}
if (err1 != CASS_OK) {
cassandra_log_error(result_future);
error_value = err1;
}
if (err2 != CASS_OK) {
cassandra_log_error(result_future2);
error_value = err2;
}
if (err3 != CASS_OK && result_future3 != NULL) {
cassandra_log_error(result_future3);
error_value = err3;
}
cass_future_free(result_future);
cass_future_free(result_future2);
if (result_future3 != NULL) {
cass_future_free(result_future3);
}
return error_value;
}
int check_page_dir(pid_t pid, char mode, addr_t address, frame_t *frame) {
addr_t dir_offset = GET_PAGE_IND(address);
bool present = false;
nanosleep(&ACCESS_TIME_RAM, NULL);
if (page_dir.dir_e[dir_offset].exists) {
sys_proc_table = page_dir.dir_e[dir_offset].table_ref;
check_page_table(pid, mode, address, frame);
}
else {
dir_entry directEntry = create_dir_entry(pid);
page_dir.dir_e[dir_offset] = directEntry;
}
sys_proc_table = NULL;
}
// creates a new file that can be used in an OS
byte create_file(dir_entry_t* de, char* filename, byte fn_length, byte* buf)
{
if(!create_dir_entry(de, filename, fn_length, buf))
{
#if DEBUG
pmsg("Couldn't create direntry!\r\n");
#endif
return 0;
}
if(!write_dir_entry(de, buf))
{
#if DEBUG
pmsg("problem writing direntry!\r\n");
#endif
return 0;
}
return 1;
}
/*
* Search for a directory entry directly within dir (without
* recursing). Sort dir if necessary. subdirname must be a directory
* name (i.e., end in '/'). If mkdir is set, then create the
* directory if it is missing; otherwise, return NULL if the desired
* directory cannot be found. dir must already be complete.
*/
static struct ref_dir *search_for_subdir(struct ref_dir *dir,
const char *subdirname, size_t len,
int mkdir)
{
int entry_index = search_ref_dir(dir, subdirname, len);
struct ref_entry *entry;
if (entry_index == -1) {
if (!mkdir)
return NULL;
/*
* Since dir is complete, the absence of a subdir
* means that the subdir really doesn't exist;
* therefore, create an empty record for it but mark
* the record complete.
*/
entry = create_dir_entry(dir->cache, subdirname, len, 0);
add_entry_to_dir(dir, entry);
} else {
entry = dir->entries[entry_index];
}
return get_ref_dir(entry);
}
/* 创建文件,若成功则返回文件描述符,否则返回-1 */
int32_t file_create(struct dir* parent_dir, char* filename, uint8_t flag) {
/* 后续操作的公共缓冲区 */
void* io_buf = sys_malloc(1024);
if (io_buf == NULL) {
printk("in file_creat: sys_malloc for io_buf failed\n");
return -1;
}
uint8_t rollback_step = 0; // 用于操作失败时回滚各资源状态
/* 为新文件分配inode */
int32_t inode_no = inode_bitmap_alloc(cur_part);
if (inode_no == -1) {
printk("in file_creat: allocate inode failed\n");
return -1;
}
/* 此inode要从堆中申请内存,不可生成局部变量(函数退出时会释放)
* 因为file_table数组中的文件描述符的inode指针要指向它.*/
struct inode* new_file_inode = (struct inode*)sys_malloc(sizeof(struct inode));
if (new_file_inode == NULL) {
printk("file_create: sys_malloc for inode failded\n");
rollback_step = 1;
goto rollback;
}
inode_init(inode_no, new_file_inode); // 初始化i结点
/* 返回的是file_table数组的下标 */
int fd_idx = get_free_slot_in_global();
if (fd_idx == -1) {
printk("exceed max open files\n");
rollback_step = 2;
goto rollback;
}
file_table[fd_idx].fd_inode = new_file_inode;
file_table[fd_idx].fd_pos = 0;
file_table[fd_idx].fd_flag = flag;
file_table[fd_idx].fd_inode->write_deny = false;
struct dir_entry new_dir_entry;
memset(&new_dir_entry, 0, sizeof(struct dir_entry));
create_dir_entry(filename, inode_no, FT_REGULAR, &new_dir_entry); // create_dir_entry只是内存操作不出意外,不会返回失败
/* 同步内存数据到硬盘 */
/* a 在目录parent_dir下安装目录项new_dir_entry, 写入硬盘后返回true,否则false */
if (!sync_dir_entry(parent_dir, &new_dir_entry, io_buf)) {
printk("sync dir_entry to disk failed\n");
rollback_step = 3;
goto rollback;
}
memset(io_buf, 0, 1024);
/* b 将父目录i结点的内容同步到硬盘 */
inode_sync(cur_part, parent_dir->inode, io_buf);
memset(io_buf, 0, 1024);
/* c 将新创建文件的i结点内容同步到硬盘 */
inode_sync(cur_part, new_file_inode, io_buf);
/* d 将inode_bitmap位图同步到硬盘 */
bitmap_sync(cur_part, inode_no, INODE_BITMAP);
/* e 将创建的文件i结点添加到open_inodes链表 */
list_push(&cur_part->open_inodes, &new_file_inode->inode_tag);
new_file_inode->i_open_cnts = 1;
sys_free(io_buf);
return pcb_fd_install(fd_idx);
/*创建文件需要创建相关的多个资源,若某步失败则会执行到下面的回滚步骤 */
rollback:
switch (rollback_step) {
case 3:
/* 失败时,将file_table中的相应位清空 */
memset(&file_table[fd_idx], 0, sizeof(struct file));
case 2:
sys_free(new_file_inode);
case 1:
/* 如果新文件的i结点创建失败,之前位图中分配的inode_no也要恢复 */
bitmap_set(&cur_part->inode_bitmap, inode_no, 0);
break;
}
sys_free(io_buf);
return -1;
}
