int is_exist(struct inode *dir, const char *name){
/*判断目录是否有效*/
if(dir->ext2_inode.i_block[0] != UINT_MAX){
perror("inode_operations.c: check error! dir is a file!\n");
return -1;
}
char buf[BLOCK_SIZE];
struct ext2_dir_entry_2 *pentry;
int dir_datablocks = dir->ext2_inode.i_blocks;/*数据块个数*/
int i = 1;
int j = 0;
int num = BLOCK_SIZE/sizeof(struct ext2_dir_entry_2);
while(i <= dir_datablocks){
/*取出目录节点中第i块逻辑块所在的物理块的数据，放入buf*/
get_block_data(dir->ext2_inode.i_block[i],buf);
pentry = (struct ext2_dir_entry_2 *)buf;
//printf("inode_operations.c: check : dir_datablocks: %d\n",i);
/*比较每一项*/
while(j<num){
//printf("inode_operations.c: check : entry: %d\n",j);
/*比较pentry->inode不为0的每一项*/
if(pentry->inode && !strcmp(pentry->name,name)){
return 1;
}
j++;
pentry++;
}
i++;
}
return -1;
}
/*寻找当前节点号中是否含有名字为name的项目，如果有则返回name项目的i节点号，没有则返回-1*/
int namei(char *name, unsigned int cur_inode_num){
struct ext2_inode *current_inode;
if((current_inode=malloc(sizeof(struct ext2_inode))) == NULL){
perror("namei.c: fail to malloc inode\n");
exit(EXIT_FAILURE);
}
get_inode_data(cur_inode_num,current_inode);
char buf[BLOCK_SIZE];
struct ext2_dir_entry_2 *pentry;
int dir_datablocks = current_inode->i_blocks;/*数据块个数*/
int i = 1;
while(i <= dir_datablocks){
/*取出目录节点中第i块逻辑块所在的物理块的数据，放入buf*/
get_block_data(current_inode->i_block[i],buf);
pentry = (struct ext2_dir_entry_2 *)buf;
int j = 0;
int num = BLOCK_SIZE/sizeof(struct ext2_dir_entry_2);
/*比较每一项*/
while(j<num){
/*比较pentry->inode不为0的每一项*/
if(pentry->inode && !strcmp(&(pentry->name[0]),name)){
return pentry->inode;
}
j++;
pentry++;
}
i++;
}
free(current_inode);
return -1;
}
int remove_file(struct inode *dir, const char *name){
/*判断目录是否有效*/
if(dir->ext2_inode.i_block[0] != UINT_MAX){
perror("inode_operations.c: remove_file error! current dir is a file!\n");
return -1;
}
/*判断名字是否有效*/
if(checkname(name) == -1){
perror("inode_operations.c: remove_file error! filename is illegal!\n");
return -1;
}
char buf[BLOCK_SIZE];
struct ext2_dir_entry_2 *pentry;
int dir_datablocks = dir->ext2_inode.i_blocks;/*数据块个数*/
int i = 1;
int j = 0;
int num = BLOCK_SIZE/sizeof(struct ext2_dir_entry_2);
while(i <= dir_datablocks){
/*取出目录节点中第i块逻辑块所在的物理块的数据，放入buf*/
get_block_data(dir->ext2_inode.i_block[i],buf);
pentry = (struct ext2_dir_entry_2 *)buf;
//printf("inode_operations.c: check : dir_datablocks: %d\n",i);
/*比较每一项*/
while(j<num){
//printf("inode_operations.c: check : entry: %d\n",j);
/*比较pentry->inode不为0的每一项*/
if(pentry->inode && !strcmp(pentry->name,name)){
if(free_inode(pentry->inode) == -1){
perror("节点释放失败!\n");
return -1;
};
/*清空该目录项*/
memset(pentry,'\0',sizeof(struct ext2_dir_entry_2));
/*写回磁盘，更新数据*/
write_block_data(dir->ext2_inode.i_block[i],buf);
return 1;
}
j++;
pentry++;
}
i++;
}
printf("no such file,please check your filename!\n");
return -1;
}
int list(struct inode *dir){
if(dir->ext2_inode.i_block[0] != UINT_MAX){
perror("dir is a file!\n");
return -1;
}
struct ext2_dir_entry_2 *pentry;
char buf[1024];
int num = BLOCK_SIZE/sizeof(struct ext2_dir_entry_2);
int i = 1;
while(i <= dir->ext2_inode.i_blocks){
get_block_data(dir->ext2_inode.i_block[i],buf);
pentry = (struct ext2_dir_entry_2*)buf;
int j = 0;
for(;j<num;j++,pentry++){
if(pentry->inode == 0) continue;
printf("%-24s\n",pentry->name);
}
i++;
}
return 1;
}
int main(int argc, char *argv[])
{
FILE *f;
struct superblock sb;
int i, len;
char *block;
if (argc < 3) {
printf("Usage: %s <image file> <search string>\n", argv[0]);
return 1;
}
f = fopen(argv[1], "r");
if (f == NULL) {
perror("fopen");
return 1;
}
if (get_superblock(f, &sb))
return 1;
block = malloc(blocksize(&sb));
if (block == NULL)
return 1;
// Search free blocks
len = strlen(argv[2]);
for (i = 0; i < sb.s_blocks_count; i++) {
if (!is_block_free(&sb, i))
continue;
if (get_block_data(&sb, i, block))
return 1;
if (!strncmp(argv[2], block, len))
printf("%d\n", i);
}
free(block);
fclose(f);
return 0;
}
int create(struct inode *dir, const char *name, int len, int mode, struct inode ** res_inode){
/*判断目录是否有效*/
if(dir->ext2_inode.i_block[0] != UINT_MAX){
perror("inode_operations.c: create error! dir is a file!\n");
return -1;
}
/*判断名字是否有效*/
if(checkname(name) == -1){
perror("inode_operations.c: create error! filename is illegal!\n");
return -1;
}
/*判断是否已存在*/
if(is_exist(dir,name) == 1){
perror("inode_operations.c: create error! file is alreay exists!\n");
return -1;
}
char buf[BLOCK_SIZE];
struct ext2_dir_entry_2 *pentry;
int dir_datablocks = dir->ext2_inode.i_blocks;/*数据块个数*/
int i = 1;
int num = BLOCK_SIZE/sizeof(struct ext2_dir_entry_2);
while(i <= dir_datablocks){
/*取出目录节点中第i块逻辑块所在的物理块的数据，放入buf*/
get_block_data(dir->ext2_inode.i_block[i],buf);
pentry = (struct ext2_dir_entry_2 *)buf;
/*寻找pentry->inode为0的每一项，表示未使用,填写目录项*/
//printf("inode_operations.c: create : dir_datablocks: %d\n",i);
int j = 0;
while(j<num){
//printf("inode_operations.c: create : entry: %d\n",j);
if(!pentry->inode){
pentry->name_len = len;
strcpy(pentry->name,name);
pentry->file_type = mode;
pentry->rec_len = 8 + len;
pentry->inode = new_inode();
write_block_data(dir->ext2_inode.i_block[i],buf);//更新该数据块
*res_inode=(struct inode *)malloc(sizeof(struct inode));
if(*res_inode != NULL){
get_inode_data(pentry->inode,*res_inode);
return 1;
}
}
j++;
pentry++;
}
i++;
}
/*数据块表项已满，则需申请新的数据块来存放新的目录项*/
if(dir_datablocks>=14){
perror("inode_operations.c create error! dir_entry is full,no more sub_dir!\n");
return -1;
}
dir_datablocks = ++(dir->ext2_inode.i_blocks);
dir->ext2_inode.i_block[dir_datablocks] = new_block();
write_inode_data(dir->i_number,dir);//因为申请了新块，inode节点及时更新
get_block_data(dir->ext2_inode.i_block[dir_datablocks],buf);
pentry = (struct ext2_dir_entry_2 *)buf;
pentry->name_len = len;
strcpy(pentry->name,name);
pentry->file_type = mode;
pentry->rec_len = 8 + len;
pentry->inode = new_inode();
write_block_data(dir->ext2_inode.i_block[dir_datablocks],buf);//更新该数据块
if((*res_inode=(struct inode *)malloc(sizeof(struct inode))) != NULL){
get_inode_data(pentry->inode,*res_inode);
return 1;
}
return -1;
}
int mkdir(struct inode *dir, const char *name, int len, int mode){
/*判断目录是否有效*/
if(dir->ext2_inode.i_block[0] != UINT_MAX){
perror("inode_operations.c: mkdir error! dir is a file!\n");
return -1;
}
/*判断名字是否有效*/
if(checkname(name) == -1){
perror("inode_operations.c: mkdir error! dirname is illegal!\n");
return -1;
}
/*判断是否已存在*/
if(is_exist(dir,name) == 1){
perror("inode_operations.c: mkdir error! dirname is alreay exists!\n");
return -1;
}
char buf[BLOCK_SIZE];
struct inode *m_inode;
struct ext2_dir_entry_2 *pentry;
int dir_datablocks = dir->ext2_inode.i_blocks;/*数据块个数*/
int i = 1;
int num = BLOCK_SIZE/sizeof(struct ext2_dir_entry_2);
while(i <= dir_datablocks){
/*取出目录节点中第i块逻辑块所在的物理块的数据，放入buf*/
get_block_data(dir->ext2_inode.i_block[i],buf);
pentry = (struct ext2_dir_entry_2 *)buf;
/*寻找pentry->inode为0的每一项，表示未使用*/
int j = 0;
while(j<num){
if(!pentry->inode){
pentry->name_len = len;
strcpy(pentry->name,name);
pentry->file_type = mode;
pentry->rec_len = 8 + len;
pentry->inode = new_inode();
write_block_data(dir->ext2_inode.i_block[i],buf);//更新该数据块
/*下面更新为目录项（文件夹）申请的inode节点信息，并为其预分配一块数据块，用于存放子目录或文件*/
if((m_inode=(struct inode*)malloc(sizeof(struct inode))) != NULL){
get_inode_data(pentry->inode,m_inode);
m_inode->ext2_inode.i_block[0] = UINT_MAX;//表示该节点是目录节点
m_inode->ext2_inode.i_block[1] = new_block();//为每个目录节点预分配一块数据块，存放目录项
m_inode->ext2_inode.i_blocks = 1;
write_inode_data(pentry->inode,m_inode);
free(m_inode);
return 1;
}
}
j++;
pentry++;
}
i++;
}
/*数据块表项已满，则需申请新的数据块来存放新的目录项*/
if(dir_datablocks>=14){
perror("inode_operations.c mkdir error! dir_entry is full,no more sub_dir!\n");
return -1;
}
dir_datablocks = ++dir->ext2_inode.i_blocks;
dir->ext2_inode.i_block[dir_datablocks] = new_block();
write_inode_data(dir->i_number,dir);//因为申请了新块，inode节点及时更新
get_block_data(dir->ext2_inode.i_block[dir_datablocks],buf);
pentry = (struct ext2_dir_entry_2 *)buf;
pentry->name_len = len;
strcpy(pentry->name,name);
pentry->file_type = mode;
pentry->rec_len = 8 + len;
pentry->inode = new_inode();
write_block_data(dir->ext2_inode.i_block[dir_datablocks],buf);//更新该数据块
if((m_inode=(struct inode*)malloc(sizeof(struct inode))) != NULL){
get_inode_data(pentry->inode,m_inode);
m_inode->ext2_inode.i_block[0] = UINT_MAX;//表示该节点是目录节点
m_inode->ext2_inode.i_block[1] = new_block();//为每个目录节点预分配一块数据块，存放目录项
m_inode->ext2_inode.i_blocks = 1;
write_inode_data(pentry->inode,m_inode);
free(m_inode);
return 1;
}
return -1;
}
