#include <stdint.h>
#include <time.h>
#include "tar.h"

Data Structures
struct	tarfs_inode_t
	TARFS inode structure, 12..20 bytes per inode; 1000 files require ~16KiB of RAM to store the filesystem index. More...

Functions
tart_t	inode_getinfo (struct tarfs_inode const const index, int idx, size_t size, time_t mtime)
	Get information about an inode.
tart_t	inode_type (struct tarfs_inode const *ino)
tart_t	inode_rawtype (struct tarfs_inode const *ino)
	Return raw inode type: TART_HARDLINK, TART_SYMLINK, TART_DIR, TART_FILE or TART_BAD.
bool	inode_islink (struct tarfs_inode const *ino)
int	inode_lookup (struct tarfs_inode const const index, size_t num_inodes, const char *path)
	Find an inode by pathname.
struct tarfs_inode **	inode_alloc (size_t count)
	Allocate an inode index.
void	inode_free (struct tarfs_inode **index, size_t count, uintptr_t tar_start, size_t tar_length)
	Destroy an inode index.
void	inode_unmount (struct tarfs_fs fs, const void tar_start, size_t tar_size)
	Unmount a TAR image.
int	inode_mount (struct tarfs_fs fs, const unsigned char buf, size_t size, const char rebase_link, const char path_rebase)
	Build an inode index for a TAR image.
void	inode_dumphash_sorted (struct tarfs_inode const const index, size_t count)
	Dump the inode hash table in sorted order.
void	inode_dumppath_sorted (struct tarfs_inode const *root)
	Dump the directory tree sorted by pathname.

Function Documentation

◆ inode_alloc()

struct tarfs_inode ** inode_alloc ( size_t count )

Allocate an inode index.

Returns an array of pointers to tarfs_inode structures.

Allocates an array of inode pointers capable of holding count entries.

Parameters

count Number of inode pointers to allocate.

Returns: Newly allocated inode index, or NULL on failure.

Allocate an inode index.

Inodes are allocated and initialized to all zeros, array of pointers is allocated in populated with pointers to individual inodes Memory layout, single chunk: 0x3fc00000 .. [[index][inodes]] ..3fcxxxxx ---> memory grows this way

Definition at line 303 of file inode.c.

References log, and tarfs_calloc().

Referenced by inode_mount().

◆ inode_dumphash_sorted()

void inode_dumphash_sorted	(	struct tarfs_inode const const	index,
		size_t	count )

Dump the inode hash table in sorted order.

Displays inodes sorted by hash.

Debug helper used to inspect the inode index.

Parameters

index	Inode index.
count	Number of entries.

Dump the inode hash table in sorted order.

Definition at line 1032 of file inode.c.

References inode_getinfo().

◆ inode_dumppath_sorted()

void inode_dumppath_sorted ( struct tarfs_inode const * root )

Dump the directory tree sorted by pathname.

Displays inodes sorted by path.

Debug helper that recursively prints the filesystem hierarchy.

Parameters

root	Root inode.

Dump the directory tree sorted by pathname.

Definition at line 1057 of file inode.c.

◆ inode_free()

void inode_free	(	struct tarfs_inode **	index,
		size_t	count,
		uintptr_t	tar_start,
		size_t	tar_length )

Destroy an inode index.

Free inodes.

Frees an inode index previously created by inode_alloc() together with all associated inode objects.

Parameters

index	Inode index.
count	Number of entries in the index.
tar_start	Start address of the mounted TAR image.
tar_length	TAR image size in bytes.

Destroy an inode index.

All memory associated with inodes is freed: inodes and index array. Some inodes may have allocated names. There is no way to distiguish allocated name from a TAR name, except for checking pointer address to NOT BE in the mmaped TAR file

Definition at line 342 of file inode.c.

References tarfs_os_free().

Referenced by inode_unmount().

◆ inode_getinfo()

tart_t inode_getinfo	(	struct tarfs_inode const const	index,
		int	idx,
		size_t *	size,
		time_t *	mtime )

Get information about an inode.

inode_getinfo() : get inode's Type, Size and Mtime These are not precached and must be calculated every time.

Retrieves metadata for the inode referenced by an inode index entry. Either size or mtime may be NULL if the corresponding value is not required.

Parameters

index	Inode index.
idx	Inode number within the index.
size	Optional output for file size.
mtime	Optional output for modification time.

Returns: TAR entry type.

Get information about an inode.

Having this information in the tarfs_inode will increase the size of inode list dramatically

Parameters

fs	a pointer to mounted FS
idx	inode of intereset (inode index)
size	if not NULL, provides the location to store the entry size
mtime	if not NULL, provides the location to store the entry mtime

Returns: Entry type (e.g. TART_FILE or TART_DIR etc). If return value is TART_BAD, then this is an indication of an invalid/unusable inode

Definition at line 466 of file inode.c.

References mtime, tarhdr_t::mtime, size, tarhdr_t::size, tar_octal(), tart_t, and tarhdr_t::type.

Referenced by inode_dumphash_sorted(), inode_resolve(), tarf_fstat(), and tarf_open().

◆ inode_islink()

bool inode_islink ( struct tarfs_inode const * ino )

Definition at line 521 of file inode.c.

References tarhdr_t::type.

◆ inode_lookup()

int inode_lookup	(	struct tarfs_inode const const	index,
		size_t	num_inodes,
		const char *	path )

Find an inode by pathname.

Find an inode that corresponds to given path name.

Performs a pathname lookup in the inode index.

Parameters

index	Inode index.
num_inodes	Number of entries in the index.
path	Absolute path to search for.

Returns: Inode index on success, or -1 if not found.

Find an inode by pathname.

Performs a binary search in the array of pointers to struct tarfs_inode (index array). The array is sorted by ->in_hash

Inode pointer can be retrieved as node_ptr = index[i] where i is node index as returned by inode_lookup()

Returns inode index (>=0) or -errno

< Init vector for 32bit hash

Definition at line 399 of file inode.c.

References hash32(), HASH32_IV, inode_pathcmp(), and log.

Referenced by inode_resolve(), and tarf_open().

◆ inode_mount()

int inode_mount	(	struct tarfs_fs *	fs,
		const unsigned char *	buf,
		size_t	size,
		const char *	rebase_link,
		const char *	path_rebase )

Build an inode index for a TAR image.

Scans the TAR archive, creates the inode index and initializes the filesystem state.

Parameters

fs	Filesystem instance.
buf	Start address of the TAR image.
size	TAR image size in bytes.
rebase_link	Optional path prefix substracted from symbolic links.
path_rebase	Optional path prefix substracted from every TAR entry. Normally this one is autodetected (the very first directory in the archive becomes the 'path_rebase' parameter) and then substracted from every path in the archive, so archive gets "/" entry