dir.c

elinux jffs初始版本 具体了解JFFS的文件系统！

		{
			return;
		}
		dir->nused -= 1;
		i = dir;
	}
}

void
smb_init_root(struct smb_server *server)
{
	struct smb_inode_info *root = &(server->root);

	root->state = SMB_INODE_LOOKED_UP;
	root->nused = 1;
	root->dir = NULL;
	root->next = root->prev = root;

	return;
}

void
smb_free_all_inodes(struct smb_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 smb_inode_info *root = &(server->root);

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

	return;
}

/* This has to be called when a connection has gone down, so that all
   file-handles we got from the server are invalid */
void
smb_invalidate_all_inodes(struct smb_server *server)
{
	struct smb_inode_info *ino = &(server->root);

	do
	{
		ino->finfo.opened = 0;
		ino = ino->next;
	}
	while (ino != &(server->root));

	return;
}

static int
compare_filename(const struct smb_server *server,
		 const char *s1, int len, struct smb_dirent *entry)
{
	if (len != entry->len)
	{
#if 0
		/* Check whether the entry is about to be removed */
		if (!entry->len)
			printk("SMBFS: dead entry %s\n", entry->name);
#endif
		return 1;
	}
	if (server->case_handling == CASE_DEFAULT)
	{
		return strncasecmp(s1, entry->name, len);
	}
	return strncmp(s1, entry->name, len);
}

/*
 * Search for the smb_inode_info that belongs to this name,
 * currently by a complete linear search through the inodes
 * belonging to this filesystem.
 *
 * Note that this returns files as well as directories.
 */
static struct smb_inode_info *
smb_find_dir_inode(struct inode *parent, const char *name, int len)
{
	struct smb_server *server = SMB_SERVER(parent);
	struct smb_inode_info *dir = SMB_INOP(parent);
	struct smb_inode_info *result = &(server->root);

	if (name == NULL)
	{
		return NULL;
	}
	if ((len == 1) && (name[0] == '.'))
	{
		return dir;
	}
	if ((len == 2) && (name[0] == '.') && (name[1] == '.'))
	{
		return dir->dir;
	}
	do
	{
		if (result->dir == dir)
		{
			if (compare_filename(server, name, len,
					     &(result->finfo)) == 0)
			{
				return result;
			}
		}
		result = result->next;
	}
	while (result != &(server->root));

	return NULL;
}

static int
smb_lookup(struct inode *dir, const char *name, int len,
	   struct inode **result)
{
	struct smb_dirent finfo;
	struct smb_inode_info *result_info;
	int error;
	int found_in_cache;

	struct smb_inode_info *new_inode_info = NULL;

	*result = NULL;

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

	/* Fast cheat for . */
	if (len == 0 || (len == 1 && name[0] == '.'))
	{
		*result = dir;
		return 0;
	}
	/* ..and for .. */
	if (len == 2 && name[0] == '.' && name[1] == '.')
	{
		struct smb_inode_info *parent = SMB_INOP(dir)->dir;

		if (parent->state == SMB_INODE_CACHED)
		{
			parent->state = SMB_INODE_LOOKED_UP;
		}
		*result = iget(dir->i_sb, smb_info_ino(parent));
		iput(dir);
		if (*result == 0)
		{
			return -EACCES;
		}
		return 0;
	}
	result_info = smb_find_dir_inode(dir, name, len);

      in_tree:
	if (result_info != NULL)
	{
		if (result_info->state == SMB_INODE_CACHED)
		{
			result_info->state = SMB_INODE_LOOKED_UP;
		}
		*result = iget(dir->i_sb, smb_info_ino(result_info));
		iput(dir);

		if (new_inode_info != NULL)
		{
			smb_kfree_s(new_inode_info,
				    sizeof(struct smb_inode_info));
		}
		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;

	if ((dir->i_dev == c_dev) && (dir->i_ino == c_ino) && (c_size != 0))
	{
		int first = c_last_returned_index;
		int i;

		i = first;
		do
		{
			if (compare_filename(SMB_SERVER(dir), name, len,
					     &(c_entry[i])) == 0)
			{
				finfo = c_entry[i];
				found_in_cache = 1;
				break;
			}
			i = (i + 1) % c_size;
		}
		while (i != first);
	}
	if (found_in_cache == 0)
	{
		DPRINTK("smb_lookup: not found in cache: %s\n", name);
		if (len > SMB_MAXNAMELEN)
		{
			iput(dir);
			return -ENAMETOOLONG;
		}
		error = smb_proc_getattr(dir, name, len, &finfo);
		if (error < 0)
		{
			iput(dir);
			return error;
		}
		finfo.f_ino = smb_fresh_inodes(SMB_SERVER(dir), 1);
	}
	new_inode_info = smb_kmalloc(sizeof(struct smb_inode_info),
				     GFP_KERNEL);

	/* Here somebody else might have inserted the inode */

	result_info = smb_find_dir_inode(dir, name, len);
	if (result_info != NULL)
	{
		goto in_tree;
	}

	if (new_inode_info == NULL)
	{
		iput(dir);
		return -ENOMEM;
	}
	new_inode_info->finfo = finfo;

	DPRINTK("attr: %x\n", finfo.attr);

	if ((*result = smb_iget(dir, new_inode_info)) == NULL)
	{
		iput(dir);
		return -EACCES;
	}
	DDPRINTK("smb_lookup: %s => %lu\n", name, (unsigned long) result_info);
	iput(dir);
	return 0;
}

static int
smb_create(struct inode *dir, const char *name, int len, int mode,
	   struct inode **result)
{
	int error;
	struct smb_dirent entry;
	struct smb_inode_info *new_inode_info;

	*result = NULL;

	if (!dir || !S_ISDIR(dir->i_mode))
	{
		printk("smb_create: inode is NULL or not a directory\n");
		iput(dir);
		return -ENOENT;
	}
	new_inode_info = smb_kmalloc(sizeof(struct smb_inode_info),
				     GFP_KERNEL);
	if (new_inode_info == NULL)
	{
		iput(dir);
		return -ENOMEM;
	}
	error = smb_proc_create(dir, name, len, 0, CURRENT_TIME);
	if (error < 0)
	{
		smb_kfree_s(new_inode_info, sizeof(struct smb_inode_info));
		iput(dir);
		return error;
	}
	smb_invalid_dir_cache(dir->i_ino);

	if ((error = smb_proc_getattr(dir, name, len, &entry)) < 0)
	{
		smb_kfree_s(new_inode_info, sizeof(struct smb_inode_info));
		iput(dir);
		return error;
	}
	entry.f_ino = smb_fresh_inodes(SMB_SERVER(dir), 1);

	new_inode_info->finfo = entry;

	if ((*result = smb_iget(dir, new_inode_info)) == NULL)
	{
		iput(dir);
		return error;
	}
	iput(dir);
	return 0;
}

static int
smb_mkdir(struct inode *dir, const char *name, int len, int mode)
{
	int error;

	if (!dir || !S_ISDIR(dir->i_mode))
	{
		iput(dir);
		return -EINVAL;
	}
	if ((error = smb_proc_mkdir(dir, name, len)) == 0)
	{
		smb_invalid_dir_cache(dir->i_ino);
	}
	iput(dir);
	return error;
}

static int
smb_rmdir(struct inode *dir, const char *name, int len)
{
	int error;

	if (!dir || !S_ISDIR(dir->i_mode))
	{
		printk("smb_rmdir: inode is NULL or not a directory\n");
		iput(dir);
		return -ENOENT;
	}
	if (smb_find_dir_inode(dir, name, len) != NULL)
	{
		error = -EBUSY;
	} else
	{
		if ((error = smb_proc_rmdir(dir, name, len)) == 0)
		{
			smb_invalid_dir_cache(dir->i_ino);
		}
	}
	iput(dir);
	return error;
}

static int
smb_unlink(struct inode *dir, const char *name, int len)
{
	int error;

	if (!dir || !S_ISDIR(dir->i_mode))
	{
		printk("smb_unlink: inode is NULL or not a directory\n");
		iput(dir);
		return -ENOENT;
	}
	if (smb_find_dir_inode(dir, name, len) != NULL)
	{
		error = -EBUSY;
	} else
	{
		if ((error = smb_proc_unlink(dir, name, len)) == 0)
		{
			smb_invalid_dir_cache(dir->i_ino);
		}
	}
	iput(dir);
	return error;
}

static int
smb_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;

	if (!old_dir || !S_ISDIR(old_dir->i_mode))
	{
		printk("smb_rename: old inode is NULL or not a directory\n");
		res = -ENOENT;
		goto finished;
	}
	if (!new_dir || !S_ISDIR(new_dir->i_mode))
	{
		printk("smb_rename: new inode is NULL or not a directory\n");
		res = -ENOENT;
		goto finished;
	}
	if ((smb_find_dir_inode(old_dir, old_name, old_len) != NULL)
	    || (smb_find_dir_inode(new_dir, new_name, new_len) != NULL))
	{
		res = -EBUSY;
		goto finished;
	}
	res = smb_proc_mv(old_dir, old_name, old_len,
			  new_dir, new_name, new_len);

	if (res == -EEXIST)
	{
		int res1 = smb_proc_unlink(old_dir, new_name, new_len);

		if (res1 == 0)
		{
			res = smb_proc_mv(old_dir, old_name, old_len,
					  new_dir, new_name, new_len);
		}
	}
	if (res == 0)
	{
		smb_invalid_dir_cache(old_dir->i_ino);
		smb_invalid_dir_cache(new_dir->i_ino);
	}
      finished:
	iput(old_dir);
	iput(new_dir);
	return res;
}