remove_file_bsfs.c File Reference

Implementation of logical file removal in BSFS. More...

Functions
int	remove_file (FILE *disk, superblock_t *sb, btree_handle_t *inode_tree, btree_handle_t *rec_tree, const char *path, dir_t *cwd, uint16_t uid)
	Logically remove a file and snapshot it into the Recovery tree.

Detailed Description

Implementation of logical file removal in BSFS.

Removal here is logical: the file is unlinked from its directory and its inode is removed from the inode tree, but blocks are not freed. A snapshot is inserted into the Recovery tree to allow later restoration or purging.

Function Documentation

remove_file()

int remove_file	(	FILE *	disk,
		superblock_t *	sb,
		btree_handle_t *	inode_tree,
		btree_handle_t *	rec_tree,
		const char *	path,
		dir_t *	cwd,
		uint16_t	uid )

Logically remove a file and snapshot it into the Recovery tree.

Unlinks the directory entry for path, removes the file's inode from the inode tree (without freeing its data blocks), and inserts a snapshot of the file metadata into the Recovery B-tree to enable later restoration or purge.

Steps: 1) Resolve the parent directory and basename from path. 2) Lookup the file inode (must not be a directory). 3) Build and insert a rec_entry_t snapshot into the Recovery tree. 4) Remove the directory entry from its parent. 5) Remove the inode from the inode tree. 6) Update parent directory timestamps.

Rollback: If step 4 or 5 fails, the inserted recovery entry is removed to keep metadata consistent.

Parameters

disk	Open filesystem image.
sb	Loaded superblock.
inode_tree	Inode B-tree handle.
rec_tree	Recovery B-tree handle.
path	Absolute or relative path of the file to remove.
cwd	Current working directory (for resolving relative paths).
uid	Caller user id (currently unused; permission checks may use it).

Returns

0 on success; -1 on error.