file management system group members ramoly nathan hemmi florent azangue romo chouikh jaouher jridi...

FILE MANAGEMENT SYSTEM

Group MembersRAMOLY NathanHEMMI FlorentAZANGUE RoméoCHOUIKH Jaouher JRIDI BayremNINTIDEM Estelle Olivia

Supervisor M. TIMSIT Claude

Academic year 2011-2012 1

INTRODUCTIONPLAN

CONCLUSION

I. MATERIAL AND DIFFERENTS STAGES

II. METHODS AND SYSTEM DESIGN

III. PROBLEMS AND SOLUTIONS

IV. DEMONSTRATION

Nathan RAMOLY, Florent HEMMI, Roméo AZANGUE, Jaouher CHOUIKH, Bayrem JRIDI, Estelle NINTIDEM

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INTRODUCTION

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4RAMOLY Nathan, HEMMI Florent, AZANGUE Roméo, CHOUIKH Jaouher, JRIDI Bayrem, NINTIDEM Estelle

INTRODUCTION

The file management system

Software that manages data files

Create, enter, change and query files

EXT2, HFS PLUS , FAT

RAMOLY Nathan, HEMMI Florent, AZANGUE Roméo, CHOUIKH Jaouher, JRIDI Bayrem, NINTIDEM Estelle

INTRODUCTION

Requirements

Functional Requirements• Management module• Execution module• Documentation module

Non-Functional Requirements• Convenient GUI• Clear errors messages

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INTRODUCTION

Use Case Diagram

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I. MATERIAL AND DIFFERENT STAGES

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Material• Software

o Code blocks o QT

• Turtoise SVN (Subversion)

• Libraries

o Standard libraries

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Differents Stages

• The Theory • Realisation

• Debug

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• THE THEORY • HANDLING OF THE DISK• BITMAPS• INODES• DIRECTORIES• FILES

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The Theory

Simulation of the disk

o The disk is declared as statico It is composed of a number of blocks

that’s declared in the defines

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Handling of the disk

int8_t disk_access(Block** block, int pos)

Block* disk_ptr() int8_t disk_set_block(Block* block,

int pos) int8_t disk_get_block(Block* block,

int pos) int8_t save_disk_hard_drive() int8_t load_disk_hard_drive()…

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Bitmaps

Root

/

Boot block

Inode

bitmap

Block

bitmap

Inodes Blocks

Bitmap

We can consider the bitmap as a map that facilitates moving in the blocks of our disk

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Bitmaps

0 1 1 0 0 1 0 001 occupie

d10 corrupt00 free

Bitmap Inode

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0 1 0 0 0 1 1 001 occupied10 corrupt00 free



Bitmaps Bitmap

Block

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Bitmaps Implementation of some functions

int8_t bitmap_inode_init() int8_t bitmap_inode_get_status(int numInode) int8_t bitmap_inode_set_status(int numInode, int

status) int32_t bitmap_first_free_inode() int32_t bitmap_nb_free_inode()

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Bitmaps Bitmap Bloc

int8_t bitmap_block_init(). int8_t bitmap_block_get_status(int nBlock) int8_t bitmap_block_set_status(int nBlock, int

status) int32_t bitmap_first_free_block() int32_t bitmap_nb_free_block() int32_t bitmap_nb_occupied_block()

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Inodes• The structure

o Size (in bytes)o The last access timeo Type (file or folder)o 10 addresses blockso An address for the single

indirection blocko An address for the double

indirection block

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Inodes• Indirections

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Inodes• Indirections 1 block = N bytes 10 blocks: 10*N bytes Single indirection: N²/4 Double indirection: N3/16 Total: [10 + N/4 + (N/4)²]*N

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Inodes• Navigation functions Inode_get_next_block:

next adress block Inode_get_pos_block_from_byt

e:block adress which contains the byte number



Inodes• Inode low level function

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Function in charge allocating and freeing blocks

Two choices: Allocate and stop (no more free space) Don’t allocate if there is not enough

space Take two parameters:

A pointer to an inode A new size for the inode

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Inodes• Allocating a block Allocated an indirection block if

necessary Asked to the bitmap the address of

the first free block Added it to the inode by selecting the

corresponding block (10 blocks or indirections)

Indicated that the block in now occupied

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Inodes• Freeing a block Flagged the address block to -1 Removed indirection block from the

inode if necessary(memory leak possible if it is not done)

Indicated that the block in now free so it can be used by another



Inodes• Basic functions

Initialization:◦Size: 0◦Type: 1 for a file (by default)◦Last access time: system time◦Addresses: -1

Last access time Inode storage:

◦Get an inode from the RAM-disk◦Save an inode to the RAM-disk

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Needed in any file systemLists all the filesAllows the user to create

hierarchy◦Travel in the tree◦Main directory called root


Directories

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Directories Directory implementation

◦ A special file (inode, blocks, etc…)◦ Contains the list with the following

forms 4 bytes for the address 8+1 bytes for the name Not sorted

◦ First entry: “..” referring the parent directory

◦ Root corresponds to the first inode◦ Current directory saved as a global

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Addition of an element◦Two steps Increase the size Add the entry at the end

Directories


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Directories


Deleting an element◦Four main steps Save the last element Find the element to delete Replace it by the last one Reduce the size of the

directory◦No memory is released


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Directories


Deleting of an element◦Schemas of a deletion in the

system


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Directories


Searching a file◦Main interest of directory◦Simply do a loop Going through entry by entry

until the directory’s size is reached

Moving inside a block until there is no more space, then go on to the next block

Exiting as soon as the file is foundNathan RAMOLY, Florent HEMMI, Roméo AZANGUE, Jaouher CHOUIKH, Bayrem JRIDI, Estelle

NINTIDEM31

Directories


Creating a directory◦Four steps Check if it doesn’t already

exists Allocate an inode Create a basic inode and put

it in the allocated space Add the entry “..”


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Directories


Deleting a directory◦Delete all the content Loop to read all the content File: call the specified

function Directory: recall this function

◦Set the size to 0◦Free the inode◦Remove the entry from the

parent directory Nathan RAMOLY, Florent HEMMI, Roméo AZANGUE, Jaouher CHOUIKH, Bayrem JRIDI, Estelle

NINTIDEM33

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Directories


Printing◦ Extraction of the directory’s content as a

linked list◦ Sorting the list

Using comparison functions (Size, date and name)

Using a bubble sort algorithm ◦ Printing the list◦ Function ls

Simply allow the user to select : The kind of sort Ascendant or not Complete or not


Directories


Moving in the tree◦Move the current directory◦Path syntax used:

“dir1/dir2/dir3”◦Path interpretation by cut_dir◦Movement done by mini_cd Moves the current directory


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Files



HEADER FUNCTIONS

Mini _format : int8_t mini_format () This function allows to free all the inodes and blocks and set status of Bitmaps to available.

Mini_ls : void mini_ls (char* input, int8_t dataSort, int8_t asc, int8_t complete) This function allows to view the content of our directories

Mini_rm : int8_t mini_rm (char* dir, char* name) It removes file in the directory dir

toto/titi .. titi

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Files



Mini_open : Fs_file* mini_open (char* file_name, int8_t mode) It works like fopen we pass in parameter the file name and the flag

FS_CREATE/ FS_RDWR write at the beginning FS_RDONLYFS_WRONLYFS_WRONLY/FS_APPEND write at the end

Mini_read : int32_t mini_read (void* data, size_t size, Fs_file* file)

Mini_write : int32_t mini_write (void* data, size_t size, Fs_file* file)

Flag

Files



Mini_cd : int32_t mini_cd (char* directory) Mini_df : int8_t mini_df (Fs_stat* st)

Mini_close : : int8_t mini_close (Fs_file* file)

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None technical problems

Technical problemsConception

“disk.img”

File Structure

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TestsThe Inodes

The directoriesThe files

Inode_get_next_block(Inode *inode);

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Error management#define RET_SUCCESS 0#define RET_TRUE1#define RET_FALSE0#define ERROR -1#define ERR_NULL -2#define ERR_READ -3#define ERR_CORRUPT -4#define ERR_OUT_OF_RANGE -5#define ERR_PARAMETER -6#define ERR_INIT -7#define ERR_ALLOC -8#define ERR_FILE -9


IV. DEMONSTRATION

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44Nathan RAMOLY, Florent HEMMI, Roméo AZANGUE, Jaouher CHOUIKH, Bayrem JRIDI, Estelle NINTIDEM

CONCLUSION

CONCLUSION


FMS with a GUIUNIX BasedFurther improvementsIndirection algorithmAlias & shortcutsImprove the block structureUpper layer applications -> OS

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46Nathan RAMOLY, Florent HEMMI, Roméo AZANGUE, Jaouher CHOUIKH, Bayrem JRIDI, Estelle NINTIDEM

THANK FOR YOUR ATTENTION

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