inode_operations_bsfs.c File Reference

Implementation of inode manipulation operations for BSFS. More...

Functions
int	read_inode (FILE *disk, btree_handle_t *handle, uint32_t inode_number, inode_t *out_inode)
	Reads an inode from the inode B-tree.
int	insert_inode (FILE *disk, superblock_t *sb, btree_handle_t *handle, const inode_t *inode)
	Inserts a new inode into the inode B-tree.
int	update_inode (FILE *disk, btree_handle_t *handle, const inode_t *inode)
	Updates an existing inode in the B-tree.
int	remove_inode (FILE *disk, superblock_t *sb, btree_handle_t *handle, uint32_t inode_number)
	Removes an inode from the inode B-tree.
uint32_t	get_next_inode_number (FILE *disk, btree_handle_t *inode_tree)
	Finds the next available inode number by scanning the inode B-tree.
int	inode_exists (FILE *disk, btree_handle_t *inode_tree, uint32_t inode_number)
	Checks if an inode with the given number exists in the inode B-tree.
int	inode_tree_init (FILE *disk, superblock_t *sb, btree_handle_t *out)
	Initialize (or load) the inode B-tree handle.

Detailed Description

Implementation of inode manipulation operations for BSFS.

This source file provides functions to manage inode entries within the inode B-tree in the BSFS file system.

It implements:

• Insertion of new inodes into the tree
• Lookup and reading of inodes by their inode number
• Inode updates that overwrite existing metadata
• Deletion of inodes from the tree

These functions encapsulate the B-tree logic and provide a clean interface for interacting with inodes without requiring direct manipulation of tree internals.

Function Documentation

get_next_inode_number()

uint32_t get_next_inode_number	(	FILE *	disk,
		btree_handle_t *	inode_tree )

Finds the next available inode number by scanning the inode B-tree.

This function scans the inode tree to find the highest inode number in use and returns the next available one. This ensures uniqueness of inode numbers without reusing deleted ones.

Parameters

disk	Pointer to the disk file.
inode_tree	Pointer to the B-tree handle for inodes.

Returns

The next available (unused) inode number.

inode_exists()

int inode_exists	(	FILE *	disk,
		btree_handle_t *	inode_tree,
		uint32_t	inode_number )

Checks if an inode with the given number exists in the inode B-tree.

This function performs a lookup in the inode B-tree to determine whether an inode with the specified number is currently present in the file system.

Parameters

disk	Pointer to the file representing the disk.
inode_tree	Pointer to the B-tree handle managing inodes.
inode_number	The inode number to check for existence.

Returns

1 if the inode exists, 0 if it does not.

inode_tree_init()

int inode_tree_init	(	FILE *	disk,
		superblock_t *	sb,
		btree_handle_t *	out )

Initialize (or load) the inode B-tree handle.

If the inode root does not exist yet in the superblock, this function allocates a fresh root node on disk (empty leaf), persists it, and stores the block number in both the handle and the superblock (via write_superblock). If the root already exists, the handle is configured to point to it.

Parameters

disk	Open filesystem image.
sb	Loaded superblock (may be updated/persisted if creating root).
out	Output: initialized inode B-tree handle (by value).

Returns

1 on success, 0 on failure.

insert_inode()

int insert_inode	(	FILE *	disk,
		superblock_t *	sb,
		btree_handle_t *	handle,
		const inode_t *	inode )

Inserts a new inode into the inode B-tree.

Parameters

disk	Pointer to the open filesystem image.
sb	Pointer to the superblock (for block allocation).
handle	Pointer to the B-tree handle for inode management.
inode	Pointer to the inode to be inserted.

read_inode()

int read_inode	(	FILE *	disk,
		btree_handle_t *	handle,
		uint32_t	inode_number,
		inode_t *	out_inode )

Reads an inode from the inode B-tree.

Parameters

disk	Pointer to the open filesystem image.
handle	Pointer to the B-tree handle for inode management.
inode_number	The unique identifier of the inode to read.
out_inode	Pointer to the inode_t structure to store the result.

Returns

1 if the inode was found, 0 otherwise.

remove_inode()

int remove_inode	(	FILE *	disk,
		superblock_t *	sb,
		btree_handle_t *	handle,
		uint32_t	inode_number )

Removes an inode from the inode B-tree.

This function removes the inode entry with the specified inode number from the B-tree structure.

Parameters

disk	Pointer to the open filesystem image.
sb	Pointer to the superblock (needed for possible deallocations).
handle	Pointer to the B-tree handle for inode management.
inode_number	The inode number to be removed.

Returns

1 if the inode was found and removed, 0 otherwise.

update_inode()

int update_inode	(	FILE *	disk,
		btree_handle_t *	handle,
		const inode_t *	inode )

Updates an existing inode in the B-tree.

Parameters

disk	Pointer to the open filesystem image.
handle	Pointer to the B-tree handle for inode management.
inode	Pointer to the modified inode to be written back.

Returns

1 if the inode was updated, 0 if not found.