Development and Implementation of a File System for Gannet Virtual ...

3.2.2.5 Stat Data Structure
GannetFS file system uses stat data structure to maintain characteristic of file. It
means, stat stores all information about a file. Stat data structure uses stripped
down version of POSIX’s stat structure to save more space.
The first field is flag which is set on how the file was opened. There are two types of
flag that is supported, namely read only and write only. File cannot open for both
read and write purpose. Next field is file’s mode which represent file’s type and
permission.
Inode field represents a pointer to an inode that associated to a file. Then, offset field
records the offset within the file being reading or reading. The default is zero and
will be increased by each subsequent read or write operation.
3.2.3 File System Programming Interface Design
Having discussion regarding the file system data structure, the following section
describes how the file system interacts with users or modules. This mechanism also
called as an interface. It provides communication mechanisms between modules or
systems. Through this interface, the collaboration between modules and objects
takes place. The requirement stated that the file system must be platform
independent. Thus, a good design interface of file system is crucial for this project.
However, there is a POSIX which describes the contract between the application and
its library on the operating system. It is an international standard with set of
definitions and assertions which can be used to verify compliance. A conforming
POSIX application gains the confidence level that a system is a platform independent
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