dir.c

来自「elinux jffs初始版本 具体了解JFFS的文件系统！」· C语言 代码 · 共 1,279 行 · 第 1/2 页

                i->next->prev = i->prev;
                i->prev->next = i->next;

		DDPRINTK("ncp_free_inode_info: freeing %s\n",
			 i->finfo.i.entryName);

                ncp_kfree_s(i, sizeof(struct ncp_inode_info));

                if (dir == i) return;

                (dir->nused)--;
                i = dir;
        }
}
        
void
ncp_init_root(struct ncp_server *server)
{
        struct ncp_inode_info *root = &(server->root);
	struct nw_info_struct *i = &(root->finfo.i);
	unsigned short dummy;

	DPRINTK("ncp_init_root: server %s\n", server->m.server_name);
	DPRINTK("ncp_init_root: i = %x\n", (int)i);

        root->finfo.opened = 0;
	i->attributes  = aDIR;
	i->dataStreamSize = 1024;
	i->dirEntNum = i->DosDirNum = 0;
	i->volNumber = NCP_NUMBER_OF_VOLUMES+1;	/* illegal volnum */
	ncp_date_unix2dos(0, &(i->creationTime), &(i->creationDate));
	ncp_date_unix2dos(0, &(i->modifyTime), &(i->modifyDate));
	ncp_date_unix2dos(0, &dummy, &(i->lastAccessDate));
	i->nameLen = 0;
	i->entryName[0] = '\0';

        root->state = NCP_INODE_LOOKED_UP;
        root->nused = 1;
        root->dir   = root;
        root->next = root->prev = root;
        return;
}

int
ncp_conn_logged_in(struct ncp_server *server)
{
	if (server->m.mounted_vol[0] == '\0')
	{
		return 0;
	}

	str_upper(server->m.mounted_vol);
	if (ncp_lookup_volume(server, server->m.mounted_vol,
			      &(server->root.finfo.i)) != 0)
	{
		return -ENOENT;
	}
	str_lower(server->root.finfo.i.entryName);

	return 0;
}

void
ncp_free_all_inodes(struct ncp_server *server)
{
        /* Here nothing should be to do. I do not know whether it's
           better to leave some memory allocated or be stuck in an
           endless loop */
#if 1
        struct ncp_inode_info *root = &(server->root);

        if (root->next != root)
	{
                printk("ncp_free_all_inodes: INODES LEFT!!!\n");
        }

        while (root->next != root)
	{
                printk("ncp_free_all_inodes: freeing inode\n");
                ncp_free_inode_info(root->next);
                /* In case we have an endless loop.. */
                schedule();
        }
#endif        
        
        return;
}

/* We will search the inode that belongs to this name, currently by a
   complete linear search through the inodes belonging to this
   filesystem. This has to be fixed. */
static struct ncp_inode_info *
ncp_find_dir_inode(struct inode *dir, const char *name)
{
	struct ncp_server *server = NCP_SERVER(dir);
	struct nw_info_struct *dir_info = NCP_ISTRUCT(dir);
        struct ncp_inode_info *result = &(server->root);

        if (name == NULL)
	{
                return NULL;
	}

        do
	{
		if (   (result->dir->finfo.i.dirEntNum == dir_info->dirEntNum)
		    && (result->dir->finfo.i.volNumber == dir_info->volNumber)
		    && (strcmp(result->finfo.i.entryName, name) == 0)
		    /* The root dir is never looked up using this
		     * routine.  Without the following test a root
		     * directory 'sys' in a volume named 'sys' could
		     * never be looked up, because
		     * server->root->dir==server->root. */
		    && (result != &(server->root)))
		{
                        return result;
		}
                result = result->next;

        }
	while (result != &(server->root));

        return NULL;
}

static int 
ncp_lookup(struct inode *dir, const char *__name, int len,
           struct inode **result)
{
	struct nw_file_info finfo;
	struct ncp_server *server;
	struct ncp_inode_info *result_info;
	int found_in_cache;
	int down_case = 0;
	char name[len+1];

	*result = NULL;

	if (!dir || !S_ISDIR(dir->i_mode))
	{
		printk("ncp_lookup: inode is NULL or not a directory.\n");
		iput(dir);
		return -ENOENT;
	}

	server = NCP_SERVER(dir);

	if (!ncp_conn_valid(server))
	{
		iput(dir);
		return -EIO;
	}

	DPRINTK("ncp_lookup: %s, len %d\n", __name, len);

	/* Fast cheat for . */
	if (len == 0 || (len == 1 && __name[0] == '.'))
	{
		*result = dir;
		return 0;
	}

	/* ..and for .. */
	if (len == 2 && __name[0] == '.' && __name[1] == '.')
	{
		struct ncp_inode_info *parent = NCP_INOP(dir)->dir;

		if (parent->state == NCP_INODE_CACHED)
		{
			parent->state = NCP_INODE_LOOKED_UP;
		}

		*result = iget(dir->i_sb, ncp_info_ino(server, parent));
		iput(dir);
		if (*result == 0)
		{
			return -EACCES;
		}
		else
		{
			return 0;
		}
	}

	memcpy(name, __name, len);
	name[len] = 0;
	lock_super(dir->i_sb);
	result_info = ncp_find_dir_inode(dir, name);

        if (result_info != 0)
	{
                if (result_info->state == NCP_INODE_CACHED)
		{
                        result_info->state = NCP_INODE_LOOKED_UP;
		}

                /* Here we convert the inode_info address into an
                   inode number */

                *result = iget(dir->i_sb, ncp_info_ino(server, result_info));
		unlock_super(dir->i_sb);
                iput(dir);

                if (*result == NULL)
		{
                        return -EACCES;
                }

		return 0;
        }

        /* If the file is in the dir cache, we do not have to ask the
           server. */

        found_in_cache = 0;
	ncp_lock_dircache();

        if ((dir->i_dev == c_dev) && (dir->i_ino == c_ino))
	{
                int first = c_last_returned_index;
                int i;

                i = first;
                do
		{
                        DDPRINTK("ncp_lookup: trying index: %d, name: %s\n",
				 i, c_entry[i].i.entryName);

                        if (strcmp(c_entry[i].i.entryName, name) == 0)
			{
                                DPRINTK("ncp_lookup: found in cache!\n");
				finfo.i = c_entry[i].i;
				found_in_cache = 1;
				break;
                        }
                        i = (i + 1) % c_size;
                }
		while (i != first);
        }
	ncp_unlock_dircache();

        if (found_in_cache == 0)
	{
		int res;

		DDPRINTK("ncp_lookup: do_lookup on %s/%s\n",
			 NCP_ISTRUCT(dir)->entryName, name);

		if (ncp_is_server_root(dir))
		{
			str_upper(name);
			down_case = 1;
			res = ncp_lookup_volume(server, name, &(finfo.i));
		}
		else
		{
			if (!ncp_preserve_case(dir))
			{
				str_upper(name);
				down_case = 1;
			}
			res = ncp_obtain_info(server,
					      NCP_ISTRUCT(dir)->volNumber,
					      NCP_ISTRUCT(dir)->dirEntNum,
					      name, &(finfo.i));
		}
		if (res != 0)
		{
			unlock_super(dir->i_sb);
                        iput(dir);
                        return -ENOENT;
                }
        }

	finfo.opened = 0;

	if (down_case != 0)
	{
		str_lower(finfo.i.entryName);
	}

	if (!(*result = ncp_iget(dir, &finfo)))
	{
		unlock_super(dir->i_sb);
		iput(dir);
		return -EACCES;
	}

	unlock_super(dir->i_sb);
	iput(dir);
	return 0;
}

static int 
ncp_create(struct inode *dir, const char *name, int len, int mode,
           struct inode **result)
{
	struct nw_file_info finfo;
	__u8 _name[len+1];

	*result = NULL;

	if (!dir || !S_ISDIR(dir->i_mode))
	{
		printk("ncp_create: inode is NULL or not a directory\n");
		iput(dir);
		return -ENOENT;
	}
	if (!ncp_conn_valid(NCP_SERVER(dir)))
	{
		iput(dir);
		return -EIO;
	}

	strncpy(_name, name, len);
	_name[len] = '\0';

	if (!ncp_preserve_case(dir))
	{
		str_upper(_name);
	}

	lock_super(dir->i_sb);
	if (ncp_open_create_file_or_subdir(NCP_SERVER(dir),
					   NCP_ISTRUCT(dir), _name,
					   OC_MODE_CREATE|OC_MODE_OPEN|
					   OC_MODE_REPLACE,
					   0, AR_READ|AR_WRITE,
					   &finfo) != 0)
	{
		unlock_super(dir->i_sb);
		iput(dir);
		return -EACCES;
	}

	ncp_invalid_dir_cache(dir);

	if (!ncp_preserve_case(dir))
	{
		str_lower(finfo.i.entryName);
	}

	finfo.access = O_RDWR;

	if (!(*result = ncp_iget(dir, &finfo)) < 0)
	{
		ncp_close_file(NCP_SERVER(dir), finfo.file_handle);
		unlock_super(dir->i_sb);
		iput(dir);
		return -EINVAL;
	}

	unlock_super(dir->i_sb);
	iput(dir);
	return 0;	
}

static int
ncp_mkdir(struct inode *dir, const char *name, int len, int mode)
{
	int error;
	struct nw_file_info new_dir;
	__u8 _name[len+1];

	if (   (name[0] == '.')
	    && (   (len == 1)
		|| (   (len == 2)
		    && (name[1] == '.'))))
	{
		iput(dir);
		return -EEXIST;
	}

	strncpy(_name, name, len);
	_name[len] = '\0';

	if (!ncp_preserve_case(dir))
	{
		str_upper(_name);
	}

	if (!dir || !S_ISDIR(dir->i_mode))
	{
		printk("ncp_mkdir: inode is NULL or not a directory\n");
		iput(dir);
		return -ENOENT;
	}
	if (!ncp_conn_valid(NCP_SERVER(dir)))
	{
		iput(dir);
		return -EIO;
	}

	if (ncp_open_create_file_or_subdir(NCP_SERVER(dir),
					   NCP_ISTRUCT(dir), _name,
					   OC_MODE_CREATE, aDIR, 0xffff,
					   &new_dir) != 0)
	{
		error = -EACCES;
	}
	else
	{
		error = 0;
                ncp_invalid_dir_cache(dir);
        }

	iput(dir);
	return error;
}

static int
ncp_rmdir(struct inode *dir, const char *name, int len)
{
	int error;
	__u8 _name[len+1];

	if (!dir || !S_ISDIR(dir->i_mode))
	{
		printk("ncp_rmdir: inode is NULL or not a directory\n");
		iput(dir);
		return -ENOENT;
	}
	if (!ncp_conn_valid(NCP_SERVER(dir)))
	{
		iput(dir);
		return -EIO;
	}
        if (ncp_find_dir_inode(dir, name) != NULL)
	{
                error = -EBUSY;
        }
	else
	{

		strncpy(_name, name, len);
		_name[len] = '\0';

		if (!ncp_preserve_case(dir))
		{
			str_upper(_name);
		}

                if ((error = ncp_del_file_or_subdir(NCP_SERVER(dir),
						    NCP_ISTRUCT(dir),
						    _name)) == 0)
		{
                        ncp_invalid_dir_cache(dir);
		}
		else
		{
			error = -EACCES;
		}
        }
	iput(dir);
	return error;
}

static int
ncp_unlink(struct inode *dir, const char *name, int len)
{
	int error;
	__u8 _name[len+1];

	if (!dir || !S_ISDIR(dir->i_mode))
	{
		printk("ncp_unlink: inode is NULL or not a directory\n");
		iput(dir);
		return -ENOENT;
	}
	if (!ncp_conn_valid(NCP_SERVER(dir)))
	{
		iput(dir);
		return -EIO;
	}
        if (ncp_find_dir_inode(dir, name) != NULL)
	{
                error = -EBUSY;
        }
	else
	{
		strncpy(_name, name, len);
		_name[len] = '\0';

		if (!ncp_preserve_case(dir))
		{
			str_upper(_name);
		}

                if ((error = ncp_del_file_or_subdir(NCP_SERVER(dir),
						    NCP_ISTRUCT(dir),
						    _name)) == 0)
		{
                        ncp_invalid_dir_cache(dir);
		}
		else
		{
			error = -EACCES;
		}
        }
	iput(dir);
	return error;
}

static int
ncp_rename(struct inode *old_dir, const char *old_name, int old_len,
           struct inode *new_dir, const char *new_name, int new_len,
           int must_be_dir)
{
	int res;
	char _old_name[old_len+1];
	char _new_name[new_len+1];

	if (!old_dir || !S_ISDIR(old_dir->i_mode))
	{
		printk("ncp_rename: old inode is NULL or not a directory\n");
                res = -ENOENT;
                goto finished;
	}

	if (!ncp_conn_valid(NCP_SERVER(old_dir)))
	{
		res = -EIO;
		goto finished;
	}

	if (!new_dir || !S_ISDIR(new_dir->i_mode))
	{
		printk("ncp_rename: new inode is NULL or not a directory\n");
                res = -ENOENT;
                goto finished;
	}

        if (   (ncp_find_dir_inode(old_dir, old_name) != NULL)
            || (ncp_find_dir_inode(new_dir, new_name) != NULL))
	{
                res = -EBUSY;
                goto finished;
        }

	strncpy(_old_name, old_name, old_len);
	_old_name[old_len] = '\0';

	if (!ncp_preserve_case(old_dir))
	{
		str_upper(_old_name);
	}

	strncpy(_new_name, new_name, new_len);
	_new_name[new_len] = '\0';

	if (!ncp_preserve_case(new_dir))
	{
		str_upper(_new_name);
	}

	res = ncp_ren_or_mov_file_or_subdir(NCP_SERVER(old_dir),
					    NCP_ISTRUCT(old_dir), _old_name,
					    NCP_ISTRUCT(new_dir), _new_name);

        if (res == 0)
	{
                ncp_invalid_dir_cache(old_dir);
                ncp_invalid_dir_cache(new_dir);
        }
	else
	{
		res = -EACCES;
	}
	
 finished:
	iput(old_dir); 
	iput(new_dir);
	return res;
}

/* The following routines are taken directly from msdos-fs */

/* Linear day numbers of the respective 1sts in non-leap years. */

static int day_n[] = { 0,31,59,90,120,151,181,212,243,273,304,334,0,0,0,0 };
		  /* JanFebMarApr May Jun Jul Aug Sep Oct Nov Dec */


extern struct timezone sys_tz;

static int
utc2local(int time)
{
        return time - sys_tz.tz_minuteswest*60 + sys_tz.tz_dsttime*3600;
}

static int
local2utc(int time)
{
        return time + sys_tz.tz_minuteswest*60 - sys_tz.tz_dsttime*3600;
}

/* Convert a MS-DOS time/date pair to a UNIX date (seconds since 1 1 70). */

int
ncp_date_dos2unix(unsigned short time,unsigned short date)
{
	int month,year,secs;

	month = ((date >> 5) & 15)-1;
	year = date >> 9;
	secs = (time & 31)*2+60*((time >> 5) & 63)+(time >> 11)*3600+86400*
	    ((date & 31)-1+day_n[month]+(year/4)+year*365-((year & 3) == 0 &&
	    month < 2 ? 1 : 0)+3653);
			/* days since 1.1.70 plus 80's leap day */
	return local2utc(secs);
}


/* Convert linear UNIX date to a MS-DOS time/date pair. */
void
ncp_date_unix2dos(int unix_date,unsigned short *time, unsigned short *date)
{
	int day,year,nl_day,month;

	unix_date = utc2local(unix_date);
	*time = (unix_date % 60)/2+(((unix_date/60) % 60) << 5)+
	    (((unix_date/3600) % 24) << 11);
	day = unix_date/86400-3652;
	year = day/365;
	if ((year+3)/4+365*year > day) year--;
	day -= (year+3)/4+365*year;
	if (day == 59 && !(year & 3)) {
		nl_day = day;
		month = 2;
	}
	else {
		nl_day = (year & 3) || day <= 59 ? day : day-1;
		for (month = 0; month < 12; month++)
			if (day_n[month] > nl_day) break;
	}
	*date = nl_day-day_n[month-1]+1+(month << 5)+(year << 9);
}