EXT2 driver. More...

Classes
struct	ext2_superblock_t
	The superblock contains all the information about the configuration of the filesystem. More...

struct	ext2_group_descriptor_t
	Entry of the Block Group Descriptor Table (BGDT). More...

struct	ext2_inode_t
	The ext2 inode. More...

struct	ext2_dirent_t
	The header of an ext2 directory entry. More...

struct	ext2_filesystem_t
	The details regarding the filesystem. More...

struct	ext2_direntry_search_t
	Structure used when searching for a directory entry. More...

struct	ext2_direntry_iterator_t
	Iterator for visiting the directory entries. More...

Macros
#define	__DEBUG_HEADER__ "[EXT2 ]"
	Change header.

#define	__DEBUG_LEVEL__ LOGLEVEL_NOTICE
	Set log level.

#define	EXT2_SUPERBLOCK_MAGIC 0xEF53
	Magic value used to identify an ext2 filesystem.

#define	EXT2_DIRECT_BLOCKS 12
	Amount of indirect blocks in an inode.

#define	EXT2_PATH_MAX 4096
	Maximum length of a pathname.

#define	EXT2_MAX_SYMLINK_COUNT 8
	Maximum nesting of symlinks, used to prevent a loop.

#define	EXT2_NAME_LEN 255
	The lenght of names inside directory entries.

#define	EXT2_S_ISUID 0x0800
	SUID.

#define	EXT2_S_ISGID 0x0400
	SGID.

#define	EXT2_S_ISVTX 0x0200
	Sticky Bit.

#define	EXT2_S_IRWXU 0x01C0
	rwx----— : User can read/write/execute

#define	EXT2_S_IRUSR 0x0100
	-r-----— : User can read

#define	EXT2_S_IWUSR 0x0080
	–w----— : User can write

#define	EXT2_S_IXUSR 0x0040
	—x---— : User can execute

#define	EXT2_S_IRWXG 0x0038
	-—rwx— : Group can read/write/execute

#define	EXT2_S_IRGRP 0x0020
	-—r--— : Group can read

#define	EXT2_S_IWGRP 0x0010
	--—w-— : Group can write

#define	EXT2_S_IXGRP 0x0008
	---—x— : Group can execute

#define	EXT2_S_IRWXO 0x0007
	----—rwx : Others can read/write/execute

#define	EXT2_S_IROTH 0x0004
	----—r– : Others can read

#define	EXT2_S_IWOTH 0x0002
	-----—w- : Others can write

#define	EXT2_S_IXOTH 0x0001
	------—x : Others can execute

Typedefs
typedef enum ext2_file_type_t	ext2_file_type_t
	Types of file in an EXT2 filesystem.

typedef struct ext2_superblock_t	ext2_superblock_t
	The superblock contains all the information about the configuration of the filesystem. More...

typedef struct ext2_group_descriptor_t	ext2_group_descriptor_t
	Entry of the Block Group Descriptor Table (BGDT).

typedef struct ext2_inode_t	ext2_inode_t
	The ext2 inode.

typedef struct ext2_dirent_t	ext2_dirent_t
	The header of an ext2 directory entry.

typedef struct ext2_filesystem_t	ext2_filesystem_t
	The details regarding the filesystem.

typedef struct ext2_direntry_search_t	ext2_direntry_search_t
	Structure used when searching for a directory entry.

typedef struct ext2_direntry_iterator_t	ext2_direntry_iterator_t
	Iterator for visiting the directory entries.

Enumerations
enum	ext2_file_type_t { ext2_file_type_unknown , ext2_file_type_regular_file , ext2_file_type_directory , ext2_file_type_character_device , ext2_file_type_block_device , ext2_file_type_named_pipe , ext2_file_type_socket , ext2_file_type_symbolic_link }
	Types of file in an EXT2 filesystem. More...

Functions
static int	ext2_bitmap_check (uint8_t *buffer, uint32_t offset)
	Cheks if the bit at the given linear index is free. More...

static void	ext2_bitmap_set (uint8_t *buffer, uint32_t offset)
	Sets the bit at the given index. More...

static void	ext2_bitmap_clear (uint8_t *buffer, uint32_t offset)
	Clears the bit at the given index. More...

static int	ext2_read_superblock (ext2_filesystem_t *fs)
	Reads the superblock from the block device associated with this filesystem. More...

static int	ext2_write_superblock (ext2_filesystem_t *fs)
	Writes the superblock on the block device associated with this filesystem. More...

static int	ext2_read_block (ext2_filesystem_t fs, uint32_t block_index, uint8_t buffer)
	Read a block from the block device associated with this filesystem. More...

static int	ext2_write_block (ext2_filesystem_t fs, uint32_t block_index, uint8_t buffer)
	Writes a block on the block device associated with this filesystem. More...

static int	ext2_read_bgdt (ext2_filesystem_t *fs)
	Reads the Block Group Descriptor Table (BGDT) from the block device associated with this filesystem. More...

static int	ext2_write_bgdt (ext2_filesystem_t *fs)
	Writes the Block Group Descriptor Table (BGDT) to the block device associated with this filesystem. More...

static int	ext2_read_inode (ext2_filesystem_t fs, ext2_inode_t inode, uint32_t inode_index)
	Reads an inode. More...

static int	ext2_write_inode (ext2_filesystem_t fs, ext2_inode_t inode, uint32_t inode_index)
	Writes the inode. More...

static vfs_file_t *	ext2_open (const char *path, int flags, mode_t mode)
	Open the file at the given path and returns its file descriptor. More...

static int	ext2_unlink (const char *path)
	Delete a name and possibly the file it refers to. More...

static int	ext2_close (vfs_file_t *file)
	Closes the given file. More...

static ssize_t	ext2_read (vfs_file_t file, char buffer, off_t offset, size_t nbyte)
	Reads from the file identified by the file descriptor. More...

static ssize_t	ext2_write (vfs_file_t file, const void buffer, off_t offset, size_t nbyte)
	Writes the given content inside the file. More...

static off_t	ext2_lseek (vfs_file_t *file, off_t offset, int whence)
	Repositions the file offset inside a file. More...

static int	ext2_fstat (vfs_file_t file, stat_t stat)
	Retrieves information concerning the file at the given position. More...

static int	ext2_ioctl (vfs_file_t file, int request, void data)
	Perform the I/O control operation specified by REQUEST on FD. One argument may follow; its presence and type depend on REQUEST. More...

static ssize_t	ext2_getdents (vfs_file_t file, dirent_t dirp, off_t doff, size_t count)
	Reads contents of the directories to a dirent buffer, updating the offset and returning the number of written bytes in the buffer, it assumes that all paths are well-formed. More...

static ssize_t	ext2_readlink (const char path, char buffer, size_t bufsize)
	Read the symbolic link, if present. More...

static int	ext2_fsetattr (vfs_file_t file, struct iattr attr)
	Set attributes of the file at the given position. More...

static int	ext2_mkdir (const char *path, mode_t permission)
	Creates a new directory at the given path. More...

static int	ext2_rmdir (const char *path)
	Removes the given directory. More...

static int	ext2_stat (const char path, stat_t stat)
	Retrieves information concerning the file at the given position. More...

static int	ext2_setattr (const char path, struct iattr attr)
	Set attributes of a file. More...

static vfs_file_t *	ext2_creat (const char *path, mode_t mode)
	Creates a new file or rewrite an existing one. More...

static vfs_file_t *	ext2_mount (vfs_file_t block_device, const char path)
	Mounts the block device as an EXT2 filesystem. More...

static uint32_t	ext2_get_real_block_index (ext2_filesystem_t fs, ext2_inode_t inode, uint32_t block_index)
	Returns the real block index starting from a block index inside an inode. More...

static const char *	uuid_to_string (uint8_t uuid[16])
	Turns an UUID to string. More...

static const char *	ext2_file_type_to_string (ext2_file_type_t ext2_type)
	Turns an ext2_file_type to string. More...

static int	ext2_file_type_to_vfs_file_type (int ext2_type)
	Turns the EXT2 file type to OS standard file types. More...

static const char *	time_to_string (uint32_t time)
	Turns the time to string. More...

static void	ext2_dump_superblock (ext2_superblock_t *sb)
	Dumps on debugging output the superblock. More...

static void	ext2_dump_group_descriptor (ext2_group_descriptor_t *gd)
	Dumps on debugging output the group descriptor. More...

static void	ext2_dump_inode (ext2_filesystem_t fs, ext2_inode_t inode)
	Dumps on debugging output the inode. More...

static void	ext2_dump_dirent (ext2_dirent_t *dirent)
	Dumps on debugging output the dirent. More...

static void	ext2_dump_bgdt (ext2_filesystem_t *fs)
	Dumps on debugging output the BGDT. More...

static void	ext2_dump_filesystem (ext2_filesystem_t *fs)
	Dumps on debugging output the filesystem. More...

static uint8_t *	ext2_alloc_cache (ext2_filesystem_t *fs)
	Allocate cache for EXT2 operations. More...

static void	ext2_dealloc_cache (uint8_t *cache)
	Free the cache. More...

static uint32_t	ext2_get_rec_len_from_name (const char *name)
	Returns the rec_len from the given name. More...

static uint32_t	ext2_get_rec_len_from_direntry (const ext2_dirent_t *direntry)
	Returns the rec_len from the given direntry. More...

static uint32_t	ext2_is_last_directory_entry (const ext2_dirent_t *direntry)
	If the real rec_len is different from the on in attribute rec_len, this is the last directory entry. More...

static uint32_t	ext2_inode_index_to_group_index (ext2_filesystem_t *fs, uint32_t inode_index)
	Determining which block group contains an inode. More...

static uint32_t	ext2_inode_index_to_group_offset (ext2_filesystem_t *fs, uint32_t inode_index)
	Determining the offest of the inode inside the inode group. More...

static uint32_t	ext2_inode_index_to_block_index (ext2_filesystem_t *fs, uint32_t inode_index)
	Determining the block index from the inode index. More...

static uint32_t	ext2_block_index_to_group_index (ext2_filesystem_t *fs, uint32_t block_index)
	Determining which block group contains a given block. More...

static uint32_t	ext2_block_index_to_group_offset (ext2_filesystem_t *fs, uint32_t block_index)
	Determining the offest of the block inside the block group. More...

static int	__valid_x_permission (task_struct task, ext2_inode_t inode)
	Checks if the task has x-permission for a given inode. More...

static int	ext2_find_free_inode_in_group (ext2_filesystem_t fs, uint8_t cache, uint32_t *group_offset, int skip_reserved)
	Searches for a free inode inside the group data loaded inside the cache. More...

static int	ext2_find_free_inode (ext2_filesystem_t fs, uint8_t cache, uint32_t group_index, uint32_t group_offset, uint32_t preferred_group)
	Searches for a free inode inside the Block Group Descriptor Table (BGDT). More...

static int	ext2_find_free_block_in_group (ext2_filesystem_t fs, uint8_t cache, uint32_t *block_offset)
	Searches for a free block inside the group data loaded inside the cache. More...

static int	ext2_find_free_block (ext2_filesystem_t fs, uint8_t cache, uint32_t group_index, uint32_t block_offset)
	Searches for a free block. More...

static int	ext2_allocate_inode (ext2_filesystem_t *fs, unsigned preferred_group)
	Allocate a new inode. More...

static uint32_t	ext2_allocate_block (ext2_filesystem_t *fs)
	Allocates a new block. More...

static void	ext2_free_block (ext2_filesystem_t *fs, uint32_t block_index)
	Frees a block. More...

static int	ext2_free_inode (ext2_filesystem_t fs, ext2_inode_t inode, uint32_t inode_index)
	Frees the given inode. More...

static int	__ext2_allocate_indexing_block_for_inode (ext2_filesystem_t fs, uint32_t current_index)
	Allocates a new block for storing block indices, for an inode. More...

static int	__ext2_read_and_allocate_indexing_block (ext2_filesystem_t fs, uint32_t indexing_block, uint8_t cache, uint32_t index)
	Allocates a new block for storing block indices, for a block containing block indices. More...

static int	ext2_set_real_block_index (ext2_filesystem_t fs, ext2_inode_t inode, uint32_t inode_index, uint32_t block_index, uint32_t real_index)
	Sets the real block index based on the block index inside an inode. More...

static int	ext2_allocate_inode_block (ext2_filesystem_t fs, ext2_inode_t inode, uint32_t inode_index, uint32_t block_index)
	Allocate a new block for an inode. More...

static ssize_t	ext2_read_inode_block (ext2_filesystem_t fs, ext2_inode_t inode, uint32_t block_index, uint8_t *buffer)
	Reads the real block starting from an inode and the block index inside the inode. More...

static ssize_t	ext2_write_inode_block (ext2_filesystem_t fs, ext2_inode_t inode, uint32_t inode_index, uint32_t block_index, uint8_t *buffer)
	Writes the real block starting from an inode and the block index inside the inode. More...

static ssize_t	ext2_read_inode_data (ext2_filesystem_t fs, ext2_inode_t inode, uint32_t inode_index, off_t offset, size_t nbyte, char *buffer)
	Reads the data from the given inode. More...

static ssize_t	ext2_write_inode_data (ext2_filesystem_t fs, ext2_inode_t inode, uint32_t inode_index, off_t offset, size_t nbyte, char *buffer)
	Writes the data on the given inode. More...

ext2_dirent_t *	ext2_direntry_iterator_get (ext2_direntry_iterator_t *it)
	Returns the ext2_dirent_t pointed by the iterator. More...

int	ext2_direntry_iterator_valid (ext2_direntry_iterator_t *it)
	Check if the iterator is valid. More...

ext2_direntry_iterator_t	ext2_direntry_iterator_begin (ext2_filesystem_t fs, uint8_t cache, ext2_inode_t *inode)
	Initializes the iterator and reads the first block. More...

void	ext2_direntry_iterator_next (ext2_direntry_iterator_t *it)
	Moves to the next direntry, and moves to the next block if necessary. More...

static int	ext2_directory_is_empty (ext2_filesystem_t fs, uint8_t cache, ext2_inode_t *inode)
	Checks if the directory is empty. More...

static int	ext2_clean_inode_content (ext2_filesystem_t fs, ext2_inode_t inode, uint32_t inode_index)
	Cleans the inode content. More...

static void	ext2_initialize_direntry (ext2_dirent_t direntry, const char name, ino_t inode_index, uint32_t rec_len, uint8_t file_type)
	Initializes a directory entry. More...

static int	ext2_initialize_new_direntry_block (ext2_filesystem_t *fs, uint32_t inode_index, uint32_t block_index)
	Initializes a new directory entry block for the specified inode. More...

static void	ext2_dump_direntries (ext2_filesystem_t fs, uint8_t cache, ext2_inode_t *parent_inode)
	Dumps the directory entries inside the parent directory. More...

static int	ext2_get_free_direntry (ext2_filesystem_t fs, uint8_t cache, ino_t parent_inode_index, const char *name, ino_t inode_index, uint8_t file_type)
	Searches for a free unused directory entry (inode == 0). More...

static int	ext2_append_new_direntry (ext2_filesystem_t fs, uint8_t cache, ino_t parent_inode_index, const char *name, ino_t inode_index, uint8_t file_type)
	Appends the new directory entry at the end of the last used block, if there is enough space. More...

static int	ext2_create_new_direntry (ext2_filesystem_t fs, uint8_t cache, ino_t parent_inode_index, const char *name, ino_t inode_index, uint8_t file_type)
	Allocates a new block, and creates a new directory entry inside that new block. More...

static int	ext2_allocate_direntry (ext2_filesystem_t fs, uint32_t parent_inode_index, uint32_t direntry_inode_index, const char name, uint8_t file_type)
	Allocates a directory entry. More...

static int	ext2_destroy_direntry (ext2_filesystem_t *fs, ext2_inode_t parent, ext2_inode_t inode, uint32_t parent_index, uint32_t inode_index, uint32_t block_index, uint32_t block_offset)
	Destroys a directory entry in the parent directory. More...

static int	ext2_find_direntry (ext2_filesystem_t fs, ino_t ino, const char name, ext2_direntry_search_t *search)
	Finds the entry with the given `name` inside the `directory`. More...

static int	ext2_resolve_path (vfs_file_t directory, const char path, ext2_direntry_search_t *search)
	Searches the entry specified in `path` starting from `directory`. More...

static ext2_filesystem_t *	get_ext2_filesystem (const char *absolute_path)
	Get the ext2 filesystem object starting from a path. More...

static int	ext2_init_vfs_file (ext2_filesystem_t fs, vfs_file_t file, ext2_inode_t inode, uint32_t inode_index, const char name, size_t name_len)
	Initializes the VFS file. More...

static vfs_file_t *	ext2_find_vfs_file_with_inode (ext2_filesystem_t *fs, ino_t inode)
	Finds the VFS file that is associated with the given inode index. More...

static int	ext2_create_inode (ext2_filesystem_t fs, ext2_inode_t inode, mode_t mode, uint32_t preferred_group)
	Creates and initializes a new inode. More...

static int	__ext2_stat (ext2_inode_t inode, stat_t stat)
	Saves the information concerning the file. More...

static int	__ext2_setattr (ext2_inode_t inode, struct iattr attr)
	Sets the attributes of an inode and saves it. More...

static int	__ext2_check_setattr_permission (uid_t file_owner)
	Checks the attributes permission. More...

static vfs_file_t *	ext2_mount_callback (const char path, const char device)
	The mount call-back, which prepares everything and calls the actual EXT2 mount function. More...

int	ext2_initialize (void)
	Initializes the EXT2 drivers. More...

int	ext2_finalize (void)
	De-initializes the EXT2 drivers. More...

Variables
static vfs_sys_operations_t	ext2_sys_operations
	Filesystem general operations. More...

static vfs_file_operations_t	ext2_fs_operations
	Filesystem file operations. More...

static file_system_type	ext2_file_system_type
	Filesystem information. More...

Detailed Description

EXT2 driver.

Copyright: (c) 2014-2024 This file is distributed under the MIT License. See LICENSE.md for details.

Typedef Documentation

◆ ext2_superblock_t

typedef struct ext2_superblock_t ext2_superblock_t

The superblock contains all the information about the configuration of the filesystem.

The primary copy of the superblock is stored at an offset of 1024 bytes from the start of the device, and it is essential to mounting the filesystem. Since it is so important, backup copies of the superblock are stored in block groups throughout the filesystem.

Enumeration Type Documentation

◆ ext2_file_type_t

enum ext2_file_type_t

Types of file in an EXT2 filesystem.

Enumerator
ext2_file_type_unknown	Unknown type.
ext2_file_type_regular_file	Regular file.
ext2_file_type_directory	Directory.
ext2_file_type_character_device	Character device.
ext2_file_type_block_device	Block device.
ext2_file_type_named_pipe	Named pipe.
ext2_file_type_socket	Socket.
ext2_file_type_symbolic_link	Symbolic link.

Function Documentation

◆ __ext2_allocate_indexing_block_for_inode()

static int __ext2_allocate_indexing_block_for_inode	(	ext2_filesystem_t *	fs,
		uint32_t *	current_index
	)

static

Allocates a new block for storing block indices, for an inode.

Parameters

fs	the filesystem.
current_index	the current index, or if 0, where we store the new one.

Returns: 0 on success, -1 on failure.

◆ __ext2_check_setattr_permission()

static int __ext2_check_setattr_permission ( uid_t file_owner )

static

Checks the attributes permission.

Parameters

file_owner the file owner we are checking against.

Returns: 1 if it has permission, 0 otherwise.

◆ __ext2_read_and_allocate_indexing_block()

static int __ext2_read_and_allocate_indexing_block	(	ext2_filesystem_t *	fs,
		uint32_t	indexing_block,
		uint8_t *	cache,
		uint32_t	index
	)

static

Allocates a new block for storing block indices, for a block containing block indices.

Parameters

fs	the filesystem.
indexing_block	the index of block that contains the indices.
cache	the cache were we load the block content.
index	the index inside the list of indices.

Returns: 0 on success, -1 on failure.

◆ __ext2_setattr()

static int __ext2_setattr	(	ext2_inode_t *	inode,
		struct iattr *	attr
	)

static

Sets the attributes of an inode and saves it.

Parameters

inode	The inode to set the attributes
attr	The structure where the attributes are stored.

Returns: 0 if success.

◆ __ext2_stat()

static int __ext2_stat	(	ext2_inode_t *	inode,
		stat_t *	stat
	)

static

Saves the information concerning the file.

Parameters

inode	The inode containing the data.
stat	The structure where the information are stored.

Returns: 0 if success.

◆ __valid_x_permission()

static int __valid_x_permission	(	task_struct *	task,
		ext2_inode_t *	inode
	)

static

Checks if the task has x-permission for a given inode.

Parameters

task	the task to check permission for.
inode	the inode to check permission.

Returns: 1 on success, 0 otherwise.

◆ ext2_alloc_cache()

static uint8_t* ext2_alloc_cache ( ext2_filesystem_t * fs )

inlinestatic

Allocate cache for EXT2 operations.

Parameters

fs	file system we are working with.

Returns: a pointer to the cache.

◆ ext2_allocate_block()

static uint32_t ext2_allocate_block ( ext2_filesystem_t * fs )

static

Allocates a new block.

Parameters

fs	the filesystem.

Returns: 0 on failure, or the index of the new block on success.

◆ ext2_allocate_direntry()

static int ext2_allocate_direntry	(	ext2_filesystem_t *	fs,
		uint32_t	parent_inode_index,
		uint32_t	direntry_inode_index,
		const char *	name,
		uint8_t	file_type
	)

static

Allocates a directory entry.

Parameters

fs	a pointer to the filesystem.
parent_inode_index	the inode index of the parent.
direntry_inode_index	the inode index of the new entry.
name	the name of the new entry.
file_type	the type of file.

Returns: 0 on success, a negative value on failure.

◆ ext2_allocate_inode()

static int ext2_allocate_inode	(	ext2_filesystem_t *	fs,
		unsigned	preferred_group
	)

static

Allocate a new inode.

Parameters

fs	the filesystem.
preferred_group	the preferred group.

Returns: index of the inode.

Here are the rules used to allocate new inodes:

the inode for a new file is allocated in the same group of the inode of its parent directory.
inodes are allocated equally between groups.

◆ ext2_allocate_inode_block()

static int ext2_allocate_inode_block	(	ext2_filesystem_t *	fs,
		ext2_inode_t *	inode,
		uint32_t	inode_index,
		uint32_t	block_index
	)

static

Allocate a new block for an inode.

Parameters

fs	the filesystem.
inode	the inode which we are working with.
inode_index	The index of the inode.
block_index	The index of the block within the inode.

Returns: 0 on success, -1 on failure.

◆ ext2_append_new_direntry()

static int ext2_append_new_direntry	(	ext2_filesystem_t *	fs,
		uint8_t *	cache,
		ino_t	parent_inode_index,
		const char *	name,
		ino_t	inode_index,
		uint8_t	file_type
	)

inlinestatic

Appends the new directory entry at the end of the last used block, if there is enough space.

Parameters

fs	a pointer to the filesystem.
cache	cache for memory EXT2 operations.
parent_inode_index	the parent inode index.
name	the name of the new entry.
inode_index	its inode index.
file_type	its file type.

Returns: 1 on success, 0 on failure.

◆ ext2_bitmap_check()

static int ext2_bitmap_check	(	uint8_t *	buffer,
		uint32_t	offset
	)

inlinestatic

Cheks if the bit at the given linear index is free.

Parameters

buffer	the buffer containing the bitmap
offset	the linear index we want to check.

Returns: if the bit is 0 or 1.

How we access the specific bits inside the bitmap takes inspiration from the mailman's algorithm.

◆ ext2_bitmap_clear()

static void ext2_bitmap_clear	(	uint8_t *	buffer,
		uint32_t	offset
	)

inlinestatic

Clears the bit at the given index.

Parameters

buffer	the buffer containing the bitmap
offset	the bit index we want to clear.

◆ ext2_bitmap_set()

static void ext2_bitmap_set	(	uint8_t *	buffer,
		uint32_t	offset
	)

inlinestatic

Sets the bit at the given index.

Parameters

buffer	the buffer containing the bitmap
offset	the bit index we want to set.

◆ ext2_block_index_to_group_index()

static uint32_t ext2_block_index_to_group_index	(	ext2_filesystem_t *	fs,
		uint32_t	block_index
	)

static

Determining which block group contains a given block.

Parameters

fs	the ext2 filesystem structure.
block_index	the block index.

Returns: the block group index.

◆ ext2_block_index_to_group_offset()

static uint32_t ext2_block_index_to_group_offset	(	ext2_filesystem_t *	fs,
		uint32_t	block_index
	)

static

Determining the offest of the block inside the block group.

Parameters

fs	the ext2 filesystem structure.
block_index	the block index.

Returns: the offset of the block inside the group.

◆ ext2_clean_inode_content()

static int ext2_clean_inode_content	(	ext2_filesystem_t *	fs,
		ext2_inode_t *	inode,
		uint32_t	inode_index
	)

static

Cleans the inode content.

Parameters

fs	a pointer to the filesystem.
inode	the inode.
inode_index	the inode index.

Returns: 0 on success, 1 on failure.

◆ ext2_close()

static int ext2_close ( vfs_file_t * file )

static

Closes the given file.

Parameters

file	The file structure.

Returns: 0 on success, -errno on failure.

◆ ext2_creat()

static vfs_file_t * ext2_creat	(	const char *	path,
		mode_t	mode
	)

static

Creates a new file or rewrite an existing one.

Parameters

path	path to the file.
mode	mode for file creation.

Returns: file descriptor number, -1 otherwise and errno is set to indicate the error.

It is equivalent to: open(path, O_WRONLY|O_CREAT|O_TRUNC, mode)

◆ ext2_create_inode()

static int ext2_create_inode	(	ext2_filesystem_t *	fs,
		ext2_inode_t *	inode,
		mode_t	mode,
		uint32_t	preferred_group
	)

static

Creates and initializes a new inode.

Parameters

fs	the filesystem.
inode	the inode we use to initialize the root of the filesystem.
mode	the creat mode.
preferred_group	the preferred group where the inode should be allocated.

Returns: the inode index on success, -1 on failure.

◆ ext2_create_new_direntry()

static int ext2_create_new_direntry	(	ext2_filesystem_t *	fs,
		uint8_t *	cache,
		ino_t	parent_inode_index,
		const char *	name,
		ino_t	inode_index,
		uint8_t	file_type
	)

inlinestatic

Allocates a new block, and creates a new directory entry inside that new block.

Parameters

fs	a pointer to the filesystem.
cache	cache for memory EXT2 operations.
parent_inode_index	the parent inode index.
name	the name of the new entry.
inode_index	its inode index.
file_type	its file type.

Returns: 1 on success, 0 on failure.

◆ ext2_dealloc_cache()

static void ext2_dealloc_cache ( uint8_t * cache )

inlinestatic

Free the cache.

Parameters

cache pointer to the cache.

◆ ext2_destroy_direntry()

static int ext2_destroy_direntry	(	ext2_filesystem_t *	fs,
		ext2_inode_t	parent,
		ext2_inode_t	inode,
		uint32_t	parent_index,
		uint32_t	inode_index,
		uint32_t	block_index,
		uint32_t	block_offset
	)

static

Destroys a directory entry in the parent directory.

Parameters

fs	A pointer to the filesystem structure.
parent	The inode of the parent directory.
inode	The inode of the directory entry to be destroyed.
parent_index	The index of the parent inode.
inode_index	The index of the directory entry's inode.
block_index	The block index where the directory entry resides.
block_offset	The offset within the block where the directory entry is located.

Returns: 0 on success, a negative value on failure.

◆ ext2_directory_is_empty()

static int ext2_directory_is_empty	(	ext2_filesystem_t *	fs,
		uint8_t *	cache,
		ext2_inode_t *	inode
	)

inlinestatic

Checks if the directory is empty.

Parameters

fs	a pointer to the filesystem.
cache	used for reading.
inode	the inode of the directory.

Returns: 1 if empty, 0 if not empty.

◆ ext2_direntry_iterator_begin()

ext2_direntry_iterator_t ext2_direntry_iterator_begin	(	ext2_filesystem_t *	fs,
		uint8_t *	cache,
		ext2_inode_t *	inode
	)

Initializes the iterator and reads the first block.

Parameters

fs	pointer to the filesystem.
cache	used for reading.
inode	pointer to the directory inode.

Returns: The initialized directory iterator.

◆ ext2_direntry_iterator_get()

ext2_dirent_t* ext2_direntry_iterator_get ( ext2_direntry_iterator_t * it )

Returns the ext2_dirent_t pointed by the iterator.

Parameters

it	the iterator.

Returns: pointer to the ext2_dirent_t

◆ ext2_direntry_iterator_next()

void ext2_direntry_iterator_next ( ext2_direntry_iterator_t * it )

Moves to the next direntry, and moves to the next block if necessary.

Parameters

it	the iterator.

◆ ext2_direntry_iterator_valid()

int ext2_direntry_iterator_valid ( ext2_direntry_iterator_t * it )

Check if the iterator is valid.

Parameters

it	the iterator to check.

Returns: 1 if valid, 0 otherwise.

◆ ext2_dump_bgdt()

static void ext2_dump_bgdt ( ext2_filesystem_t * fs )

static

Dumps on debugging output the BGDT.

Parameters

fs	the filesystem of which we print the BGDT.

◆ ext2_dump_dirent()

static void ext2_dump_dirent ( ext2_dirent_t * dirent )

static

Dumps on debugging output the dirent.

Parameters

dirent the object to dump.

◆ ext2_dump_direntries()

static void ext2_dump_direntries	(	ext2_filesystem_t *	fs,
		uint8_t *	cache,
		ext2_inode_t *	parent_inode
	)

inlinestatic

Dumps the directory entries inside the parent directory.

Parameters

fs	A pointer to the filesystem structure.
cache	A pointer to a memory cache used for EXT2 operations.
parent_inode	A pointer to the parent inode whose directory entries are to be dumped.

Initialize the directory entry iterator for the parent directory

Iterate through all directory entries in the parent directory

Dump debug information for the directory entry's block index and offset

Dump detailed information about the current directory entry

◆ ext2_dump_filesystem()

static void ext2_dump_filesystem ( ext2_filesystem_t * fs )

static

Dumps on debugging output the filesystem.

Parameters

fs	the object to dump.

◆ ext2_dump_group_descriptor()

static void ext2_dump_group_descriptor ( ext2_group_descriptor_t * gd )

static

Dumps on debugging output the group descriptor.

Parameters

gd	the object to dump.

◆ ext2_dump_inode()

static void ext2_dump_inode	(	ext2_filesystem_t *	fs,
		ext2_inode_t *	inode
	)

static

Dumps on debugging output the inode.

Parameters

fs	a pointer to the filesystem.
inode	the object to dump.

◆ ext2_dump_superblock()

static void ext2_dump_superblock ( ext2_superblock_t * sb )

static

Dumps on debugging output the superblock.

Parameters

sb	the object to dump.

◆ ext2_file_type_to_string()

static const char* ext2_file_type_to_string ( ext2_file_type_t ext2_type )

static

Turns an ext2_file_type to string.

Parameters

ext2_type the ext2_file_type to turn to string.

Returns: the string representing the ext2_file_type.

◆ ext2_file_type_to_vfs_file_type()

static int ext2_file_type_to_vfs_file_type ( int ext2_type )

static

Turns the EXT2 file type to OS standard file types.

Parameters

ext2_type the EXT2 file type.

Returns: the OS standard file types.

◆ ext2_finalize()

int ext2_finalize ( void )

De-initializes the EXT2 drivers.

Returns: 0 on success, 1 on error.

◆ ext2_find_direntry()

static int ext2_find_direntry	(	ext2_filesystem_t *	fs,
		ino_t	ino,
		const char *	name,
		ext2_direntry_search_t *	search
	)

static

Finds the entry with the given name inside the directory.

Parameters

fs	a pointer to the filesystem.
ino	the inodex of the directory entry.
name	the name of the entry we are looking for.
search	the output variable where we save the info about the entry.

Returns: 0 on success, -errno on failure.

◆ ext2_find_free_block()

static int ext2_find_free_block	(	ext2_filesystem_t *	fs,
		uint8_t *	cache,
		uint32_t *	group_index,
		uint32_t *	block_offset
	)

inlinestatic

Searches for a free block.

Parameters

fs	the ext2 filesystem structure.
cache	the cache from which we read the bgdt data.
group_index	the output variable where we store the group index.
block_offset	the output variable where we store the linear indes to the free block.

Returns: 1 if we found a free block, 0 otherwise.

◆ ext2_find_free_block_in_group()

static int ext2_find_free_block_in_group	(	ext2_filesystem_t *	fs,
		uint8_t *	cache,
		uint32_t *	block_offset
	)

inlinestatic

Searches for a free block inside the group data loaded inside the cache.

Parameters

fs	the ext2 filesystem structure.
cache	the cache from which we read the bgdt data.
block_offset	the output variable where we store the linear indes to the free block.

Returns: 1 if we found a free block, 0 otherwise.

◆ ext2_find_free_inode()

static int ext2_find_free_inode	(	ext2_filesystem_t *	fs,
		uint8_t *	cache,
		uint32_t *	group_index,
		uint32_t *	group_offset,
		uint32_t	preferred_group
	)

inlinestatic

Searches for a free inode inside the Block Group Descriptor Table (BGDT).

Parameters

fs	the ext2 filesystem structure.
cache	the cache from which we read the bgdt data.
group_index	the output variable where we store the group index.
group_offset	the output variable where we store the linear indes to the free inode.
preferred_group	we accept a preferred group, but only if available.

Returns: 1 if we found a free inode, 0 otherwise.

◆ ext2_find_free_inode_in_group()

static int ext2_find_free_inode_in_group	(	ext2_filesystem_t *	fs,
		uint8_t *	cache,
		uint32_t *	group_offset,
		int	skip_reserved
	)

inlinestatic

Searches for a free inode inside the group data loaded inside the cache.

Parameters

fs	the ext2 filesystem structure.
cache	the cache from which we read the bgdt data.
group_offset	the output variable where we store the linear indes to the free inode.
skip_reserved	should we skip reserved inodes.

Returns: 1 if we found a free inode, 0 otherwise.

◆ ext2_find_vfs_file_with_inode()

static vfs_file_t* ext2_find_vfs_file_with_inode	(	ext2_filesystem_t *	fs,
		ino_t	inode
	)

static

Finds the VFS file that is associated with the given inode index.

Parameters

fs	a pointer to the fileystem.
inode	the inode index.

Returns: a pointer to the VFS file.

◆ ext2_free_block()

static void ext2_free_block	(	ext2_filesystem_t *	fs,
		uint32_t	block_index
	)

static

Frees a block.

Parameters

fs	the filesystem.
block_index	the index of the block we are freeing.

◆ ext2_free_inode()

static int ext2_free_inode	(	ext2_filesystem_t *	fs,
		ext2_inode_t *	inode,
		uint32_t	inode_index
	)

static

Frees the given inode.

Parameters

fs	a pointer to the filesystem.
inode	the inode we free.
inode_index	its index.

Returns: 0 on success, otherwise it is a failure.

◆ ext2_fsetattr()

static int ext2_fsetattr	(	vfs_file_t *	file,
		struct iattr *	attr
	)

static

Set attributes of the file at the given position.

Parameters

file	The file struct.
attr	The structure where the attributes are stored.

Returns: 0 if success.

◆ ext2_fstat()

static int ext2_fstat	(	vfs_file_t *	file,
		stat_t *	stat
	)

static

Retrieves information concerning the file at the given position.

Parameters

file	The file struct.
stat	The structure where the information are stored.

Returns: 0 if success.

ID of device containing file.

◆ ext2_get_free_direntry()

static int ext2_get_free_direntry	(	ext2_filesystem_t *	fs,
		uint8_t *	cache,
		ino_t	parent_inode_index,
		const char *	name,
		ino_t	inode_index,
		uint8_t	file_type
	)

inlinestatic

Searches for a free unused directory entry (inode == 0).

Parameters

fs	a pointer to the filesystem.
cache	cache for memory EXT2 operations.
parent_inode_index	the parent inode index.
name	the name of the new entry.
inode_index	its inode index.
file_type	its file type.

Returns: 1 on success, 0 on failure.

◆ ext2_get_real_block_index()

static uint32_t ext2_get_real_block_index	(	ext2_filesystem_t *	fs,
		ext2_inode_t *	inode,
		uint32_t	block_index
	)

static

Returns the real block index starting from a block index inside an inode.

Parameters

fs	the filesystem.
inode	the inode which we are working with.
block_index	the block index inside the inode.

Returns: the real block number.

◆ ext2_get_rec_len_from_direntry()

static uint32_t ext2_get_rec_len_from_direntry ( const ext2_dirent_t * direntry )

inlinestatic

Returns the rec_len from the given direntry.

Parameters

direntry the direntry we use to compute the rec_len.

Returns: the rec_len value.

◆ ext2_get_rec_len_from_name()

static uint32_t ext2_get_rec_len_from_name ( const char * name )

inlinestatic

Returns the rec_len from the given name.

Parameters

name	the name we use to compute the rec_len.

Returns: the rec_len value.

◆ ext2_getdents()

static ssize_t ext2_getdents	(	vfs_file_t *	file,
		dirent_t *	dirp,
		off_t	doff,
		size_t	count
	)

static

Reads contents of the directories to a dirent buffer, updating the offset and returning the number of written bytes in the buffer, it assumes that all paths are well-formed.

Parameters

file	The directory handler.
dirp	The buffer where the data should be written.
doff	The offset inside the buffer where the data should be written.
count	The maximum length of the buffer.

Returns: The number of written bytes in the buffer.

◆ ext2_init_vfs_file()

static int ext2_init_vfs_file	(	ext2_filesystem_t *	fs,
		vfs_file_t *	file,
		ext2_inode_t *	inode,
		uint32_t	inode_index,
		const char *	name,
		size_t	name_len
	)

static

Initializes the VFS file.

Parameters

fs	a pointer to the filesystem.
file	the file we want to initialize.
inode	the inode we use to initialize the VFS file.
inode_index	the inode index.
name	the name of the file.
name_len	the length of the name.

Returns: 0 on success, -errno on failure.

◆ ext2_initialize()

int ext2_initialize ( void )

Initializes the EXT2 drivers.

Returns: 0 on success, 1 on error.

◆ ext2_initialize_direntry()

static void ext2_initialize_direntry	(	ext2_dirent_t *	direntry,
		const char *	name,
		ino_t	inode_index,
		uint32_t	rec_len,
		uint8_t	file_type
	)

inlinestatic

Initializes a directory entry.

Parameters

direntry	a pointer to the directory entry we want to initialize.
name	the name of the new entry.
inode_index	its inode index.
rec_len	the length of the new entry.
file_type	its file type.

◆ ext2_initialize_new_direntry_block()

static int ext2_initialize_new_direntry_block	(	ext2_filesystem_t *	fs,
		uint32_t	inode_index,
		uint32_t	block_index
	)

inlinestatic

Initializes a new directory entry block for the specified inode.

Parameters

fs	Pointer to the ext2 filesystem structure.
inode_index	The index of the inode for which the directory entry block is to be initialized.
block_index	The index of the block to be allocated.

Returns: 1 on success, 0 on failure.

◆ ext2_inode_index_to_block_index()

static uint32_t ext2_inode_index_to_block_index	(	ext2_filesystem_t *	fs,
		uint32_t	inode_index
	)

static

Determining the block index from the inode index.

Parameters

fs	the ext2 filesystem structure.
inode_index	the inode index.

Returns: the block index.

◆ ext2_inode_index_to_group_index()

static uint32_t ext2_inode_index_to_group_index	(	ext2_filesystem_t *	fs,
		uint32_t	inode_index
	)

static

Determining which block group contains an inode.

Parameters

fs	the ext2 filesystem structure.
inode_index	the inode index.

Returns: the group index.

Remember that inode addressing starts from 1.

◆ ext2_inode_index_to_group_offset()

static uint32_t ext2_inode_index_to_group_offset	(	ext2_filesystem_t *	fs,
		uint32_t	inode_index
	)

static

Determining the offest of the inode inside the inode group.

Parameters

fs	the ext2 filesystem structure.
inode_index	the inode index.

Returns: the offset of the inode inside the group.

Remember that inode addressing starts from 1.

◆ ext2_ioctl()

static int ext2_ioctl	(	vfs_file_t *	file,
		int	request,
		void *	data
	)

static

Perform the I/O control operation specified by REQUEST on FD. One argument may follow; its presence and type depend on REQUEST.

Parameters

file	the file on which we perform the operations.
request	the device-dependent request code
data	an untyped pointer to memory.

Returns: Return value depends on REQUEST. Usually -1 indicates error.

◆ ext2_is_last_directory_entry()

static uint32_t ext2_is_last_directory_entry ( const ext2_dirent_t * direntry )

inlinestatic

If the real rec_len is different from the on in attribute rec_len, this is the last directory entry.

Parameters

direntry the directory entry to check.

Returns: 1 if it is the last, 0 otherwise.

◆ ext2_lseek()

static off_t ext2_lseek	(	vfs_file_t *	file,
		off_t	offset,
		int	whence
	)

static

Repositions the file offset inside a file.

Parameters

file	the file we are working with.
offset	the offest to use for the operation.
whence	the type of operation.

Returns: Upon successful completion, returns the resulting offset location as measured in bytes from the beginning of the file. On error, the value (off_t) -1 is returned and errno is set to indicate the error.

◆ ext2_mkdir()

static int ext2_mkdir	(	const char *	path,
		mode_t	permission
	)

static

Creates a new directory at the given path.

Parameters

path	The path of the new directory.
permission	The permission of the new directory.

Returns: Returns a negative value on failure.

◆ ext2_mount()

static vfs_file_t * ext2_mount	(	vfs_file_t *	block_device,
		const char *	path
	)

static

Mounts the block device as an EXT2 filesystem.

Parameters

block_device	the block device formatted as EXT2.
path	location where we mount the filesystem.

Returns: the VFS root node of the EXT2 filesystem.

◆ ext2_mount_callback()

static vfs_file_t* ext2_mount_callback	(	const char *	path,
		const char *	device
	)

static

The mount call-back, which prepares everything and calls the actual EXT2 mount function.

Parameters

path	the path where the filesystem should be mounted.
device	the device we mount.

Returns: the VFS file of the filesystem.

◆ ext2_open()

static vfs_file_t * ext2_open	(	const char *	path,
		int	flags,
		mode_t	mode
	)

static

Open the file at the given path and returns its file descriptor.

Parameters

path	The path to the file.
flags	The flags used to determine the behavior of the function.
mode	The mode with which we open the file.

Returns: The file descriptor of the opened file, otherwise returns -1.

◆ ext2_read()

static ssize_t ext2_read	(	vfs_file_t *	file,
		char *	buffer,
		off_t	offset,
		size_t	nbyte
	)

static

Reads from the file identified by the file descriptor.

Parameters

file	The file.
buffer	Buffer where the read content must be placed.
offset	Offset from which we start reading from the file.
nbyte	The number of bytes to read.

Returns: The number of red bytes.

◆ ext2_read_bgdt()

static int ext2_read_bgdt ( ext2_filesystem_t * fs )

static

Reads the Block Group Descriptor Table (BGDT) from the block device associated with this filesystem.

Parameters

fs	the ext2 filesystem structure.

Returns: 0 on success, -1 on failure.

◆ ext2_read_block()

static int ext2_read_block	(	ext2_filesystem_t *	fs,
		uint32_t	block_index,
		uint8_t *	buffer
	)

static

Read a block from the block device associated with this filesystem.

Parameters

fs	the ext2 filesystem structure.
block_index	the index of the block we want to read.
buffer	the buffer where the content will be placed.

Returns: the amount of data we read, or negative value for an error.

◆ ext2_read_inode()

static int ext2_read_inode	(	ext2_filesystem_t *	fs,
		ext2_inode_t *	inode,
		uint32_t	inode_index
	)

static

Reads an inode.

Parameters

fs	the filesystem.
inode	the inode which we are working with.
inode_index	The index of the inode.

Returns: 0 on success, -1 on failure.

◆ ext2_read_inode_block()

static ssize_t ext2_read_inode_block	(	ext2_filesystem_t *	fs,
		ext2_inode_t *	inode,
		uint32_t	block_index,
		uint8_t *	buffer
	)

static

Reads the real block starting from an inode and the block index inside the inode.

Parameters

fs	the filesystem.
inode	the inode which we are working with.
block_index	the index of the block within the inode.
buffer	the buffer where to put the data.

Returns: the amount of data we read, or negative value for an error.

◆ ext2_read_inode_data()

static ssize_t ext2_read_inode_data	(	ext2_filesystem_t *	fs,
		ext2_inode_t *	inode,
		uint32_t	inode_index,
		off_t	offset,
		size_t	nbyte,
		char *	buffer
	)

static

Reads the data from the given inode.

Parameters

fs	the filesystem.
inode	the inode which we are working with.
inode_index	the index of the inode.
offset	the offset from which we start reading the data.
nbyte	the number of bytes to read.
buffer	the buffer containing the data.

Returns: the amount we read.

◆ ext2_read_superblock()

static int ext2_read_superblock ( ext2_filesystem_t * fs )

static

Reads the superblock from the block device associated with this filesystem.

Parameters

fs	the ext2 filesystem structure.

Returns: the amount of data we read, or negative value for an error.

◆ ext2_readlink()

static ssize_t ext2_readlink	(	const char *	path,
		char *	buffer,
		size_t	bufsize
	)

static

Read the symbolic link, if present.

Parameters

path	The path to the file for which we want to read the symbolic link information.
buffer	The buffer where we will store the symbolic link path.
bufsize	The size of the buffer.

Returns: The number of read characters on success, -1 on failure, with errno set to indicate the error.

◆ ext2_resolve_path()

static int ext2_resolve_path	(	vfs_file_t *	directory,
		const char *	path,
		ext2_direntry_search_t *	search
	)

static

Searches the entry specified in path starting from directory.

Parameters

directory	the directory from which we start performing the search.
path	the path of the entry we are looking for, it can be a relative path.
search	the output variable where we save the entry information.

Returns: 0 on success, -errno on failure.

◆ ext2_rmdir()

static int ext2_rmdir ( const char * path )

static

Removes the given directory.

Parameters

path	The path to the directory to remove.

Returns: Returns a negative value on failure.

◆ ext2_set_real_block_index()

static int ext2_set_real_block_index	(	ext2_filesystem_t *	fs,
		ext2_inode_t *	inode,
		uint32_t	inode_index,
		uint32_t	block_index,
		uint32_t	real_index
	)

static

Sets the real block index based on the block index inside an inode.

Parameters

fs	the filesystem.
inode	the inode which we are working with.
inode_index	thwe inode index.
block_index	the block index inside the inode.
real_index	the real block number.

Returns: 0 on success, a negative value on failure.

◆ ext2_setattr()

static int ext2_setattr	(	const char *	path,
		struct iattr *	attr
	)

static

Set attributes of a file.

Parameters

path	The path where the file resides.
attr	The structure where the information are stored.

Returns: 0 if success.

◆ ext2_stat()

static int ext2_stat	(	const char *	path,
		stat_t *	stat
	)

static

Retrieves information concerning the file at the given position.

Parameters

path	The path where the file resides.
stat	The structure where the information are stored.

Returns: 0 if success.

ID of device containing file.

◆ ext2_unlink()

static int ext2_unlink ( const char * path )

static

Delete a name and possibly the file it refers to.

Parameters

path	The path to the file.

Returns: 0 on success, -errno on failure.

◆ ext2_write()

static ssize_t ext2_write	(	vfs_file_t *	file,
		const void *	buffer,
		off_t	offset,
		size_t	nbyte
	)

static

Writes the given content inside the file.

Parameters

file	The file descriptor of the file.
buffer	The content to write.
offset	Offset from which we start writing in the file.
nbyte	The number of bytes to write.

Returns: The number of written bytes.

◆ ext2_write_bgdt()

static int ext2_write_bgdt ( ext2_filesystem_t * fs )

static

Writes the Block Group Descriptor Table (BGDT) to the block device associated with this filesystem.

Parameters

fs	the ext2 filesystem structure.

Returns: 0 on success, -1 on failure.

◆ ext2_write_block()

static int ext2_write_block	(	ext2_filesystem_t *	fs,
		uint32_t	block_index,
		uint8_t *	buffer
	)

static

Writes a block on the block device associated with this filesystem.

Parameters

fs	the ext2 filesystem structure.
block_index	the index of the block we want to read.
buffer	the buffer where the content will be placed.

Returns: the amount of data we wrote, or negative value for an error.

◆ ext2_write_inode()

static int ext2_write_inode	(	ext2_filesystem_t *	fs,
		ext2_inode_t *	inode,
		uint32_t	inode_index
	)

static

Writes the inode.

Parameters

fs	the filesystem.
inode	the inode which we are working with.
inode_index	The index of the inode.

Returns: 0 on success, -1 on failure.

◆ ext2_write_inode_block()

static ssize_t ext2_write_inode_block	(	ext2_filesystem_t *	fs,
		ext2_inode_t *	inode,
		uint32_t	inode_index,
		uint32_t	block_index,
		uint8_t *	buffer
	)

static

Writes the real block starting from an inode and the block index inside the inode.

Parameters

fs	the filesystem.
inode	the inode which we are working with.
inode_index	The index of the inode.
block_index	the index of the block within the inode.
buffer	the buffer where to put the data.

Returns: the amount of data we wrote, or negative value for an error.

◆ ext2_write_inode_data()

static ssize_t ext2_write_inode_data	(	ext2_filesystem_t *	fs,
		ext2_inode_t *	inode,
		uint32_t	inode_index,
		off_t	offset,
		size_t	nbyte,
		char *	buffer
	)

static

Writes the data on the given inode.

Parameters

fs	the filesystem.
inode	the inode which we are working with.
inode_index	the index of the inode.
offset	the offset from which we start writing the data.
nbyte	the number of bytes to write.
buffer	the buffer containing the data.

Returns: the amount written.

◆ ext2_write_superblock()

static int ext2_write_superblock ( ext2_filesystem_t * fs )

static

Writes the superblock on the block device associated with this filesystem.

Parameters

fs	the ext2 filesystem structure.

Returns: the amount of data we wrote, or negative value for an error.

◆ get_ext2_filesystem()

static ext2_filesystem_t* get_ext2_filesystem ( const char * absolute_path )

static

Get the ext2 filesystem object starting from a path.

Parameters

absolute_path the absolute path for which we want to find the associated EXT2 filesystem.

Returns: a pointer to the EXT2 filesystem, NULL otherwise.

◆ time_to_string()

static const char* time_to_string ( uint32_t time )

static

Turns the time to string.

Parameters

time	the UNIX time to turn to string.

Returns: time turned to string.

◆ uuid_to_string()

static const char* uuid_to_string ( uint8_t uuid[16] )

static

Turns an UUID to string.

Parameters

uuid	the UUID to turn to string.

Returns: the string representing the UUID.

Variable Documentation

◆ ext2_file_system_type

file_system_type ext2_file_system_type

static

Initial value:

= {
    .name     = "ext2",
    .fs_flags = 0,
    .mount    = ext2_mount_callback
}

Filesystem information.

◆ ext2_fs_operations

vfs_file_operations_t ext2_fs_operations

static

Initial value:

= {
    .open_f     = ext2_open,
    .unlink_f   = ext2_unlink,
    .close_f    = ext2_close,
    .read_f     = ext2_read,
    .write_f    = ext2_write,
    .lseek_f    = ext2_lseek,
    .stat_f     = ext2_fstat,
    .ioctl_f    = ext2_ioctl,
    .getdents_f = ext2_getdents,
    .readlink_f = ext2_readlink,
    .setattr_f  = ext2_fsetattr,
}

Filesystem file operations.

◆ ext2_sys_operations

vfs_sys_operations_t ext2_sys_operations

static

Initial value:

= {
    .mkdir_f   = ext2_mkdir,
    .rmdir_f   = ext2_rmdir,
    .stat_f    = ext2_stat,
    .creat_f   = ext2_creat,
    .symlink_f = NULL,
    .setattr_f = ext2_setattr,
}

Filesystem general operations.

Classes

Macros

Typedefs

Enumerations

Functions

Variables

Detailed Description

Typedef Documentation

◆ ext2_superblock_t

Enumeration Type Documentation

◆ ext2_file_type_t

Function Documentation

◆ __ext2_allocate_indexing_block_for_inode()

◆ __ext2_check_setattr_permission()

◆ __ext2_read_and_allocate_indexing_block()

◆ __ext2_setattr()

◆ __ext2_stat()

◆ __valid_x_permission()

◆ ext2_alloc_cache()

◆ ext2_allocate_block()

◆ ext2_allocate_direntry()

◆ ext2_allocate_inode()

◆ ext2_allocate_inode_block()

◆ ext2_append_new_direntry()

◆ ext2_bitmap_check()

◆ ext2_bitmap_clear()

◆ ext2_bitmap_set()

◆ ext2_block_index_to_group_index()

◆ ext2_block_index_to_group_offset()

◆ ext2_clean_inode_content()

◆ ext2_close()

◆ ext2_creat()

◆ ext2_create_inode()

◆ ext2_create_new_direntry()

◆ ext2_dealloc_cache()

◆ ext2_destroy_direntry()

◆ ext2_directory_is_empty()

◆ ext2_direntry_iterator_begin()

◆ ext2_direntry_iterator_get()

◆ ext2_direntry_iterator_next()

◆ ext2_direntry_iterator_valid()

◆ ext2_dump_bgdt()

◆ ext2_dump_dirent()

◆ ext2_dump_direntries()

◆ ext2_dump_filesystem()

◆ ext2_dump_group_descriptor()

◆ ext2_dump_inode()

◆ ext2_dump_superblock()

◆ ext2_file_type_to_string()

◆ ext2_file_type_to_vfs_file_type()

◆ ext2_finalize()

◆ ext2_find_direntry()

◆ ext2_find_free_block()

◆ ext2_find_free_block_in_group()

◆ ext2_find_free_inode()

◆ ext2_find_free_inode_in_group()

◆ ext2_find_vfs_file_with_inode()

◆ ext2_free_block()

◆ ext2_free_inode()

◆ ext2_fsetattr()

◆ ext2_fstat()

◆ ext2_get_free_direntry()

◆ ext2_get_real_block_index()

◆ ext2_get_rec_len_from_direntry()

◆ ext2_get_rec_len_from_name()

◆ ext2_getdents()

◆ ext2_init_vfs_file()

◆ ext2_initialize()

◆ ext2_initialize_direntry()

◆ ext2_initialize_new_direntry_block()

◆ ext2_inode_index_to_block_index()

◆ ext2_inode_index_to_group_index()

◆ ext2_inode_index_to_group_offset()

◆ ext2_ioctl()

◆ ext2_is_last_directory_entry()

◆ ext2_lseek()

◆ ext2_mkdir()

◆ ext2_mount()

◆ ext2_mount_callback()

◆ ext2_open()