#include <core/system.h>
#include <fs/vfs.h>

Data Structures
struct	ext2_superblock
	The superblock, as it is on the disk, 1024 bytes into it. More...
struct	ext2_group
	A block group descriptor, as it is on the disk. More...
struct	ext2_inode
	An inode, as it is on the disk. More...
struct	ext2_dentry
	A directory entry, as it is on the disk. More...
struct	ext2
	A mounted ext2 filesystem. More...

Macros
#define	EXT2_SIGNATURE 0xEF53
#define	EXT2_INCOMPAT_FILETYPE 0x0002
#define	EXT2_RO_COMPAT_SPARSE_SUPER 0x0001
#define	EXT2_RO_COMPAT_LARGE_FILE 0x0002
#define	EXT2_INCOMPAT_SUPPORTED EXT2_INCOMPAT_FILETYPE
#define	EXT2_RO_COMPAT_SUPPORTED (EXT2_RO_COMPAT_SPARSE_SUPER \| EXT2_RO_COMPAT_LARGE_FILE)
#define	EXT2_GOOD_OLD_INODE_SIZE 128
#define	EXT2_DENTRY_TYPE_BAD 0
#define	EXT2_DENTRY_TYPE_RGL 1
#define	EXT2_DENTRY_TYPE_DIR 2
#define	EXT2_DENTRY_TYPE_CHR 3
#define	EXT2_DENTRY_TYPE_BLK 4
#define	EXT2_DENTRY_TYPE_FIFO 5
#define	EXT2_DENTRY_TYPE_SCKT 6
#define	EXT2_DENTRY_TYPE_SLINK 7
#define	EXT2_DIRECT_POINTERS 12

Functions
int	ext2_superblock_rewrite (struct ext2 *desc)
	Writes the in-memory copy of the superblock back to the disk, after a change to its counts of free blocks and inodes.
int	ext2_io (struct ext2 desc, int write, off_t off, size_t size, void buf)
	Reads or writes bytes of the filesystem's disk, all of them.
int	ext2_bgd_table_rewrite (struct ext2 *desc)
	Writes the block group descriptor table back to the disk, after a change to a group's counts.
int	ext2_block_read (struct ext2 desc, uint32_t number, void buf)
	Reads a block from the disk.
int	ext2_block_write (struct ext2 desc, uint32_t number, void buf)
	Writes a block to the disk.
int	ext2_block_alloc (struct ext2 desc, uint32_t block)
	Allocates a free block: its bit is set in its group's block bitmap, the free counts go down, and the block is zeroed.
int	ext2_block_free (struct ext2 *desc, uint32_t block)
	Frees a block: its bit is cleared in its group's block bitmap, and the free counts go up.
int	ext2_inode_read (struct ext2 desc, ino_t inode, struct ext2_inode ref)
	Reads an inode from the disk.
int	ext2_inode_write (struct ext2 desc, ino_t inode, struct ext2_inode i)
	Writes an inode to the disk.
int	ext2_inode_block_read (struct ext2 desc, struct ext2_inode inode, size_t idx, void *buf)
	Reads a block of a file.
int	ext2_inode_block_write (struct ext2 desc, struct ext2_inode inode, uint32_t inode_nr, size_t idx, void *buf)
	Writes a block of a file, allocating it and the indirect blocks above it if they don't exist yet.
int	ext2_inode_alloc (struct ext2 desc, ino_t ino)
	Allocates a free inode: its bit is set in its group's inode bitmap, and the free counts go down.
int	ext2_dentry_find (struct ext2 desc, struct ext2_inode inode, const char name, ino_t ino)
	Finds the inode number of a name in a directory.
int	ext2_dentry_create (struct vnode dir, const char name, ino_t ino, mode_t mode)
	Adds an entry to a directory.
ssize_t	ext2_read (struct vnode node, off_t offset, struct iobuf io)
	Reads from a file.
ssize_t	ext2_write (struct vnode node, off_t offset, struct iobuf io)
	Writes to a file, which grows if the write goes past its end.
ssize_t	ext2_readdir (struct vnode dir, off_t offset, struct dirent dirent)
	Reads a directory's entry at an offset; unused entries don't count.
int	ext2_finddir (struct vnode dir, const char fn, struct dirent *dirent)
	Finds the entry of a directory that has a name.
int	ext2_trunc (struct vnode *inode, off_t len)
	Changes a file's length.
int	ext2_vmknod (struct vnode dir, const char fn, mode_t mode, dev_t dev, struct uio uio, struct vnode *ref)
	Makes a node in a directory: a new inode, and an entry for it.
int	ext2_vget (struct vnode super, ino_t ino, struct vnode *ref)
	Gets the vnode of an inode, by its number.
int	ext2_setattr (struct vnode *vnode)
	Stores a vnode's attributes (mode, owner, times) in its inode.
int	ext2_close (struct vnode *vnode)
	Releases a vnode when its last reference goes.
int	ext2_vunlink (struct vnode dir, const char fn, struct uio *uio)
	Removes an entry from a directory, and drops a link to its file.
int	ext2_vlink (struct vnode dir, const char fn, struct vnode vnode, struct uio uio)
	Adds an entry for an existing file (a hard link) to a directory.
int	ext2_vrename (struct vnode odir, const char ofn, struct vnode ndir, const char nfn, struct uio *uio)
	Renames an entry, possibly to another directory, replacing an entry at the new name (the VFS checked its type already).
void	ext2_blocks_free (struct ext2 desc, struct ext2_inode inode, size_t from)
	Frees a file's blocks, from a block on, when the file is truncated or removed.
void	ext2_inode_discard (struct ext2 *desc, ino_t ino)
	Frees an inode that has no links left, and the blocks it uses.
int	ext2_inode_build (struct ext2 desc, ino_t ino, struct vnode *ref_inode)
	Gets the vnode of an inode: the cached one if it's in use, or a new one made from the inode on the disk.
int	ext2_inode_sync (struct vnode *inode)
	Writes a vnode's attributes back to its inode on the disk.

Variables
struct fs	ext2fs

Macro Definition Documentation

◆ EXT2_DENTRY_TYPE_BAD

#define EXT2_DENTRY_TYPE_BAD 0

Definition at line 156 of file ext2.h.

Referenced by ext2_dentry_type().

◆ EXT2_DENTRY_TYPE_BLK

#define EXT2_DENTRY_TYPE_BLK 4

Definition at line 160 of file ext2.h.

Referenced by ext2_dentry_type().

◆ EXT2_DENTRY_TYPE_CHR

#define EXT2_DENTRY_TYPE_CHR 3

Definition at line 159 of file ext2.h.

Referenced by ext2_dentry_type().

◆ EXT2_DENTRY_TYPE_DIR

#define EXT2_DENTRY_TYPE_DIR 2

Definition at line 158 of file ext2.h.

Referenced by ext2_dentry_type(), and ext2_vmknod().

◆ EXT2_DENTRY_TYPE_FIFO

#define EXT2_DENTRY_TYPE_FIFO 5

Definition at line 161 of file ext2.h.

Referenced by ext2_dentry_type().

◆ EXT2_DENTRY_TYPE_RGL

#define EXT2_DENTRY_TYPE_RGL 1

Definition at line 157 of file ext2.h.

Referenced by ext2_dentry_type().

◆ EXT2_DENTRY_TYPE_SCKT

#define EXT2_DENTRY_TYPE_SCKT 6

Definition at line 162 of file ext2.h.

Referenced by ext2_dentry_type().

◆ EXT2_DENTRY_TYPE_SLINK

#define EXT2_DENTRY_TYPE_SLINK 7

Definition at line 163 of file ext2.h.

Referenced by ext2_dentry_type().

◆ EXT2_DIRECT_POINTERS

#define EXT2_DIRECT_POINTERS 12

Definition at line 165 of file ext2.h.

Referenced by block_tree(), and ext2_blocks_free().

◆ EXT2_GOOD_OLD_INODE_SIZE

#define EXT2_GOOD_OLD_INODE_SIZE 128

Definition at line 31 of file ext2.h.

Referenced by ext2_load().

◆ EXT2_INCOMPAT_FILETYPE

#define EXT2_INCOMPAT_FILETYPE 0x0002

Definition at line 21 of file ext2.h.

Referenced by ext2_load().

◆ EXT2_INCOMPAT_SUPPORTED

#define EXT2_INCOMPAT_SUPPORTED EXT2_INCOMPAT_FILETYPE

Definition at line 26 of file ext2.h.

Referenced by ext2_load().

◆ EXT2_RO_COMPAT_LARGE_FILE

#define EXT2_RO_COMPAT_LARGE_FILE 0x0002

Definition at line 23 of file ext2.h.

◆ EXT2_RO_COMPAT_SPARSE_SUPER

#define EXT2_RO_COMPAT_SPARSE_SUPER 0x0001

Definition at line 22 of file ext2.h.

◆ EXT2_RO_COMPAT_SUPPORTED

#define EXT2_RO_COMPAT_SUPPORTED (EXT2_RO_COMPAT_SPARSE_SUPER | EXT2_RO_COMPAT_LARGE_FILE)

Definition at line 27 of file ext2.h.

Referenced by ext2_load().

◆ EXT2_SIGNATURE

#define EXT2_SIGNATURE 0xEF53

Definition at line 16 of file ext2.h.

Referenced by ext2_load().

Function Documentation

◆ ext2_bgd_table_rewrite()

int ext2_bgd_table_rewrite ( struct ext2 * desc )

Writes the block group descriptor table back to the disk, after a change to a group's counts.

Parameters

desc	the mounted filesystem

Returns: 0, or a negative errno

Definition at line 34 of file block.c.

References ext2::bs, ext2_bgd_table_rewrite(), ext2_io(), ext2::groups, and ext2::ngroups.

Referenced by ext2_bgd_table_rewrite(), ext2_block_alloc(), ext2_block_free(), ext2_inode_alloc(), ext2_inode_free(), and ext2_vmknod().

◆ ext2_block_alloc()

int ext2_block_alloc	(	struct ext2 *	desc,
		uint32_t *	block )

Allocates a free block: its bit is set in its group's block bitmap, the free counts go down, and the block is zeroed.

A bitmap that couldn't be read isn't written back.

Parameters

desc	the mounted filesystem
block	set to the block's number

Returns: 0, -ENOSPC if the filesystem is full, -ENOMEM, or an I/O error

Definition at line 77 of file block.c.

References ext2_group::bmap, ext2::bs, ext2_superblock::dblock, ext2_bgd_table_rewrite(), ext2_block_alloc(), ext2_block_read(), ext2_block_write(), ext2_superblock_rewrite(), ext2_group::free_blocks, ext2_superblock::free_blocks, ext2_superblock::gblocks, ext2::groups, kfree(), kmalloc(), bitmap::map, bitmap::max_idx, memset(), ext2::ngroups, and ext2::superblock.

Referenced by ext2_block_alloc(), and ext2_inode_block_alloc().

◆ ext2_block_free()

int ext2_block_free	(	struct ext2 *	desc,
		uint32_t	block )

Frees a block: its bit is cleared in its group's block bitmap, and the free counts go up.

If the bitmap can't be read, the block stays used.

Parameters

desc	the mounted filesystem
block	the block's number

Returns: 0, -EINVAL for a block outside the filesystem, -ENOMEM, or an I/O error

Definition at line 145 of file block.c.

References ext2_group::bmap, ext2::bs, ext2_superblock::dblock, ext2_bgd_table_rewrite(), ext2_block_free(), ext2_block_read(), ext2_block_write(), ext2_superblock_rewrite(), ext2_group::free_blocks, ext2_superblock::free_blocks, ext2_superblock::gblocks, ext2::groups, kfree(), kmalloc(), bitmap::map, ext2_superblock::nblocks, and ext2::superblock.

Referenced by ext2_block_free(), and free_tree().

◆ ext2_block_read()

int ext2_block_read	(	struct ext2 *	desc,
		uint32_t	number,
		void *	buf )

Reads a block from the disk.

Parameters

desc	the mounted filesystem
number	the block number
buf	where it goes, a block's size

Returns: 0, or a negative errno

Definition at line 49 of file block.c.

References ext2::bs, ext2_block_read(), and ext2_io().

Referenced by ext2_block_alloc(), ext2_block_free(), ext2_block_read(), ext2_indirect_block_get(), ext2_inode_alloc(), ext2_inode_block_read(), ext2_inode_free(), and free_tree().

◆ ext2_block_write()

int ext2_block_write	(	struct ext2 *	desc,
		uint32_t	number,
		void *	buf )

Writes a block to the disk.

Parameters

desc	the mounted filesystem
number	the block number
buf	the block's new contents

Returns: 0, or a negative errno

Definition at line 62 of file block.c.

References ext2::bs, ext2_block_write(), and ext2_io().

Referenced by ext2_block_alloc(), ext2_block_free(), ext2_block_write(), ext2_indirect_block_get(), ext2_inode_alloc(), ext2_inode_block_write(), ext2_inode_free(), and free_tree().

◆ ext2_blocks_free()

void ext2_blocks_free	(	struct ext2 *	desc,
		struct ext2_inode *	inode,
		size_t	from )

Frees a file's blocks, from a block on, when the file is truncated or removed.

Parameters

desc	the mounted filesystem
inode	the file's inode, its block pointers cleared here
from	the index of the first block to free

Definition at line 69 of file remove.c.

References ext2_inode::blocks, ext2::bs, ext2_inode::direct_pointer, ext2_inode::doubly_indirect_pointer, ext2_blocks_free(), EXT2_DIRECT_POINTERS, free_tree(), ext2_inode::mode, ext2_inode::singly_indirect_pointer, and ext2_inode::triply_indirect_pointer.

Referenced by ext2_blocks_free(), ext2_inode_discard(), and ext2_trunc().

◆ ext2_close()

int ext2_close ( struct vnode * vnode )

Releases a vnode when its last reference goes.

A file that was unlinked while it was open is freed now, with its inode and blocks.

Parameters

vnode the vnode

Returns: 0

Definition at line 158 of file remove.c.

References ext2_close(), ext2_inode_discard(), vnode::ino, kfree(), vnode::nlink, vnode::p, ext2::vcache, vcache_remove(), and vnode_pages_free().

Referenced by ext2_close().

◆ ext2_dentry_create()

int ext2_dentry_create	(	struct vnode *	dir,
		const char *	name,
		ino_t	ino,
		mode_t	mode )

Adds an entry to a directory.

It takes an unused entry big enough, or splits an entry that has room after its name, or else gets a new block at the end of the directory.

Parameters

dir	the directory
name	the new entry's name
ino	its inode number
mode	its file's mode (for the entry's type)

Returns: 0, -ENOTDIR, -ENOMEM, or an I/O error

Definition at line 87 of file dentry.c.

References ext2::bs, ext2_dentry_create(), ext2_dentry_type(), ext2_inode_block_read(), ext2_inode_block_write(), ext2_inode_read(), ext2_inode_write(), ext2::filetype, ext2_dentry::ino, vnode::ino, kfree(), kmalloc(), ext2_dentry::length, memcpy(), memset(), vnode::mode, ext2_dentry::name, NULL, vnode::p, ext2_dentry::size, ext2_inode::size, vnode::size, and ext2_dentry::type.

Referenced by ext2_dentry_create(), ext2_vlink(), ext2_vmknod(), and ext2_vrename().

◆ ext2_dentry_find()

int ext2_dentry_find	(	struct ext2 *	desc,
		struct ext2_inode *	inode,
		const char *	name,
		ino_t *	ino )

Finds the inode number of a name in a directory.

Parameters

desc	the mounted filesystem
inode	the directory's inode
name	the name
ino	set to the inode number

Returns: 0, -ENOENT if there's no such name, -ENOTDIR, -ENOMEM, or an I/O error

Definition at line 20 of file dentry.c.

References ext2::bs, ext2_dentry_find(), ext2_inode_block_read(), ext2_dentry::ino, kfree(), kmalloc(), ext2_dentry::length, memcmp(), ext2_inode::mode, ext2_dentry::name, ext2_dentry::size, and ext2_inode::size.

Referenced by ext2_dentry_find(), ext2_finddir(), ext2_vlink(), ext2_vmknod(), and ext2_vrename().

◆ ext2_finddir()

int ext2_finddir	(	struct vnode *	dir,
		const char *	fn,
		struct dirent *	dirent )

Finds the entry of a directory that has a name.

Only the entry's inode number is filled in.

Parameters

dir	the directory
fn	the name
dirent	if not NULL, the entry

Returns: 0, -ENOENT, or a negative errno

Definition at line 414 of file vops.c.

References ext2_dentry_find(), ext2_finddir(), ext2_inode_read(), vnode::ino, and vnode::p.

Referenced by ext2_finddir().

◆ ext2_inode_alloc()

int ext2_inode_alloc	(	struct ext2 *	desc,
		ino_t *	ino )

Allocates a free inode: its bit is set in its group's inode bitmap, and the free counts go down.

A bitmap that couldn't be read isn't written back.

Parameters

desc	the mounted filesystem
ino	set to the inode number

Returns: 0, -ENOSPC if there's no free inode, -ENOMEM, or an I/O error

Definition at line 281 of file inode.c.

References ext2::bs, ext2_bgd_table_rewrite(), ext2_block_read(), ext2_block_write(), ext2_inode_alloc(), ext2_superblock_rewrite(), ext2_group::free_inodes, ext2_superblock::free_inodes, ext2_superblock::ginodes, ext2::groups, ext2_group::imap, kfree(), kmalloc(), LOG_DEBUG, bitmap::map, bitmap::max_idx, ext2::ngroups, and ext2::superblock.

Referenced by ext2_inode_alloc(), and ext2_vmknod().

◆ ext2_inode_block_read()

int ext2_inode_block_read	(	struct ext2 *	desc,
		struct ext2_inode *	inode,
		size_t	idx,
		void *	buf )

Reads a block of a file.

A block that was never written (the file is sparse there) reads as zeros.

Parameters

desc	the mounted filesystem
inode	the file's inode
idx	the block's index in the file
buf	where it goes, a block's size

Returns: 0, -EFBIG past the largest file, -ENOMEM, or an I/O error

Definition at line 144 of file inode.c.

References block_tree(), ext2::bs, ext2_block_read(), ext2_inode_block_read(), kfree(), kmalloc(), memset(), slot_get(), table(), and tree_span().

Referenced by dentry_update(), ext2_dentry_create(), ext2_dentry_find(), ext2_inode_block_read(), ext2_read(), ext2_readdir(), ext2_trunc(), and ext2_write().

◆ ext2_inode_block_write()

int ext2_inode_block_write	(	struct ext2 *	desc,
		struct ext2_inode *	inode,
		uint32_t	inode_nr,
		size_t	idx,
		void *	buf )

Writes a block of a file, allocating it and the indirect blocks above it if they don't exist yet.

The inode is written back if blocks were allocated.

Parameters

desc	the mounted filesystem
inode	the file's inode
inode_nr	its inode number
idx	the block's index in the file
buf	the block's new contents

Returns: 0, -EFBIG, -ENOSPC, -ENOMEM, or an I/O error

Definition at line 235 of file inode.c.

References block_tree(), ext2_inode::blocks, ext2_block_write(), ext2_indirect_block_get(), ext2_inode_block_alloc(), ext2_inode_block_write(), ext2_inode_write(), slot_get(), slot_set(), and tree_span().

Referenced by dentry_update(), ext2_dentry_create(), ext2_inode_block_write(), ext2_trunc(), ext2_vmknod(), and ext2_write().

◆ ext2_inode_build()

int ext2_inode_build	(	struct ext2 *	desc,
		ino_t	ino,
		struct vnode **	ref_inode )

Gets the vnode of an inode: the cached one if it's in use, or a new one made from the inode on the disk.

Parameters

desc	the mounted filesystem
ino	the inode number
ref_inode	if not NULL, set to the vnode

Returns: 0, -ENOMEM, or an I/O error

Definition at line 29 of file ext2.c.

References ext2_inode::atime, vnode::atime, ext2_inode::ctime, vnode::ctime, DEV, ext2_inode::direct_pointer, ext2_inode_build(), ext2_inode_read(), ext2fs, vnode::fs, ext2_inode::gid, vnode::gid, vnode::ino, kmalloc(), LOG_DEBUG, M_ZERO, ext2_inode::mode, vnode::mode, ext2_inode::mtime, vnode::mtime, ext2_inode::nlink, vnode::nlink, NULL, vnode::p, vnode::rdev, ext2_inode::size, vnode::size, timespec::tv_nsec, timespec::tv_sec, ext2_inode::uid, vnode::uid, ext2::vcache, vcache_find(), and vcache_insert().

Referenced by ext2_inode_build(), ext2_load(), ext2_vget(), ext2_vmknod(), ext2_vrename(), and ext2_vunlink().

◆ ext2_inode_discard()

void ext2_inode_discard	(	struct ext2 *	desc,
		ino_t	ino )

Frees an inode that has no links left, and the blocks it uses.

Parameters

desc	the mounted filesystem
ino	the inode number

Definition at line 131 of file remove.c.

References ext2_inode::dtime, ext2_blocks_free(), ext2_inode_discard(), ext2_inode_free(), ext2_inode_read(), ext2_inode_write(), gettime(), ext2_inode::mode, ext2_inode::nlink, ext2_inode::size, and timespec::tv_sec.

Referenced by ext2_close(), ext2_inode_discard(), and ext2_vmknod().

◆ ext2_inode_read()

int ext2_inode_read	(	struct ext2 *	desc,
		ino_t	ino,
		struct ext2_inode *	ref )

Reads an inode from the disk.

Parameters

desc	the mounted filesystem
ino	the inode number
ref	where it goes; NULL only checks the number

Returns: 0, -EINVAL for a bad inode number, or an I/O error

Definition at line 33 of file inode.c.

References ext2_inode_off(), ext2_inode_read(), and ext2_io().

Referenced by dentry_update(), ext2_dentry_create(), ext2_finddir(), ext2_inode_build(), ext2_inode_discard(), ext2_inode_read(), ext2_inode_sync(), ext2_read(), ext2_readdir(), ext2_setattr(), ext2_trunc(), ext2_vlink(), ext2_vmknod(), ext2_vrename(), and ext2_write().

◆ ext2_inode_sync()

int ext2_inode_sync ( struct vnode * inode )

Writes a vnode's attributes back to its inode on the disk.

Parameters

inode the vnode

Returns: 0, or an I/O error

Definition at line 93 of file ext2.c.

References ext2_inode::atime, vnode::atime, ext2_inode::ctime, vnode::ctime, ext2_inode_read(), ext2_inode_sync(), ext2_inode_write(), ext2_inode::gid, vnode::gid, vnode::ino, LOG_DEBUG, ext2_inode::mode, vnode::mode, ext2_inode::mtime, vnode::mtime, ext2_inode::nlink, vnode::nlink, vnode::p, ext2_inode::size, vnode::size, timespec::tv_sec, ext2_inode::uid, and vnode::uid.

Referenced by ext2_inode_sync(), ext2_trunc(), ext2_vlink(), ext2_vmknod(), ext2_vrename(), and ext2_vunlink().

◆ ext2_inode_write()

int ext2_inode_write	(	struct ext2 *	desc,
		ino_t	ino,
		struct ext2_inode *	ext2_inode )

Writes an inode to the disk.

Parameters

desc	the mounted filesystem
ino	the inode number
ext2_inode	the inode

Returns: 0, -EINVAL for a bad inode number, or an I/O error

Definition at line 51 of file inode.c.

References ext2_inode_off(), ext2_inode_write(), and ext2_io().

Referenced by ext2_dentry_create(), ext2_inode_block_write(), ext2_inode_discard(), ext2_inode_sync(), ext2_inode_write(), ext2_setattr(), ext2_trunc(), ext2_vmknod(), and ext2_write().

◆ ext2_io()

int ext2_io	(	struct ext2 *	desc,
		int	write,
		off_t	off,
		size_t	size,
		void *	buf )

Reads or writes bytes of the filesystem's disk, all of them.

Parameters

desc	the mounted filesystem
write	whether to write (1) or read (0)
off	where on the disk, in bytes
size	how many bytes
buf	the data

Returns: 0, the device's error, or -EIO if fewer bytes went

Definition at line 19 of file block.c.

References ext2_io(), ext2::supernode, vfs_read(), and vfs_write().

Referenced by ext2_bgd_table_rewrite(), ext2_block_read(), ext2_block_write(), ext2_inode_read(), ext2_inode_write(), ext2_io(), and ext2_superblock_rewrite().

◆ ext2_read()

ssize_t ext2_read	(	struct vnode *	node,
		off_t	offset,
		struct iobuf *	io )

Reads from a file.

Parameters

node	the file
offset	where to read from
io	where the data goes, and how much is wanted

Returns: the number of bytes read (0 at or past the end), or a negative errno if nothing was read

Definition at line 23 of file vops.c.

References ext2_inode::blocks, ext2::bs, ext2_inode::direct_pointer, ext2_inode_block_read(), ext2_inode_read(), ext2_read(), vnode::ino, iobuf_out(), kfree(), kmalloc(), MIN, ext2_inode::mode, vnode::p, iobuf::resid, and ext2_inode::size.

Referenced by ext2_read().

◆ ext2_readdir()

ssize_t ext2_readdir	(	struct vnode *	dir,
		off_t	offset,
		struct dirent *	dirent )

Reads a directory's entry at an offset; unused entries don't count.

Parameters

dir	the directory
offset	which entry
dirent	the entry, filled in

Returns: 1 if an entry was read, 0 past the last one, -ENOTDIR, -ENOMEM, or an I/O error

Definition at line 174 of file vops.c.

References ext2::bs, ext2_inode_block_read(), ext2_inode_read(), ext2_readdir(), ext2_dentry::ino, vnode::ino, kfree(), kmalloc(), ext2_dentry::length, memcpy(), ext2_inode::mode, vnode::mode, ext2_dentry::name, vnode::p, ext2_dentry::size, and ext2_inode::size.

Referenced by ext2_readdir().

◆ ext2_setattr()

int ext2_setattr ( struct vnode * vnode )

Stores a vnode's attributes (mode, owner, times) in its inode.

Parameters

vnode the vnode

Returns: 0, or an I/O error

Definition at line 456 of file vops.c.

References ext2_inode::atime, vnode::atime, ext2_inode::ctime, vnode::ctime, ext2_inode_read(), ext2_inode_write(), ext2_setattr(), ext2_inode::gid, vnode::gid, vnode::ino, ext2_inode::mode, vnode::mode, ext2_inode::mtime, vnode::mtime, vnode::p, timespec::tv_sec, ext2_inode::uid, and vnode::uid.

Referenced by ext2_setattr().

◆ ext2_superblock_rewrite()

int ext2_superblock_rewrite ( struct ext2 * desc )

Writes the in-memory copy of the superblock back to the disk, after a change to its counts of free blocks and inodes.

Parameters

desc	the mounted filesystem

Returns: 0, or a negative errno if the write failed

Definition at line 14 of file super.c.

References ext2_io(), ext2_superblock_rewrite(), and ext2::superblock.

Referenced by ext2_block_alloc(), ext2_block_free(), ext2_inode_alloc(), ext2_inode_free(), and ext2_superblock_rewrite().

◆ ext2_trunc()

int ext2_trunc	(	struct vnode *	inode,
		off_t	len )

Changes a file's length.

A file that grows reads zeros past its old end; a file that shrinks frees its blocks past the new end.

Parameters

inode	the file
len	the new length, in bytes

Returns: 0, -ENOMEM, or an I/O error

Definition at line 252 of file vops.c.

References ext2::bs, ext2_blocks_free(), ext2_inode_block_read(), ext2_inode_block_write(), ext2_inode_read(), ext2_inode_sync(), ext2_inode_write(), ext2_trunc(), vnode::ino, kfree(), kmalloc(), memset(), vnode::p, ext2_inode::size, and vnode::size.

Referenced by ext2_trunc(), and ext2_write().

◆ ext2_vget()

int ext2_vget	(	struct vnode *	super,
		ino_t	ino,
		struct vnode **	ref )

Gets the vnode of an inode, by its number.

Parameters

super	any vnode of the filesystem
ino	the inode number
ref	if not NULL, set to the vnode

Returns: 0, or a negative errno

Definition at line 443 of file vops.c.

References ext2_inode_build(), ext2_vget(), and vnode::p.

Referenced by ext2_vget().

◆ ext2_vlink()

int ext2_vlink	(	struct vnode *	dir,
		const char *	fn,
		struct vnode *	vnode,
		struct uio *	uio )

Adds an entry for an existing file (a hard link) to a directory.

Parameters

dir	the directory
fn	the new name
vnode	the file
uio	who is asking

Returns: 0, -EEXIST, or a negative errno

Definition at line 298 of file remove.c.

References vnode::ctime, ext2_dentry_create(), ext2_dentry_find(), ext2_inode_read(), ext2_inode_sync(), ext2_vlink(), gettime(), vnode::ino, vnode::mode, vnode::nlink, and vnode::p.

Referenced by ext2_vlink().

◆ ext2_vmknod()

int ext2_vmknod	(	struct vnode *	dir,
		const char *	fn,
		mode_t	mode,
		dev_t	dev,
		struct uio *	uio,
		struct vnode **	ref )

Makes a node in a directory: a new inode, and an entry for it.

A new directory gets a block with its . and .. entries.

Parameters

dir	the directory
fn	the new node's name
mode	its type (S_IF*) and permissions
dev	its device number, for a device node
uio	who is asking (the owner)
ref	if not NULL, set to the new vnode

Returns: 0, -EINVAL for an empty name, -EEXIST, -ENOSPC, -ENOMEM, or an I/O error

Definition at line 312 of file vops.c.

References ext2_inode::atime, ext2::bs, ext2_inode::ctime, DEV, DEV_MAJOR, DEV_MINOR, ext2_inode::direct_pointer, ext2_group::directories_count, ext2_bgd_table_rewrite(), ext2_dentry_create(), ext2_dentry_find(), EXT2_DENTRY_TYPE_DIR, ext2_inode_alloc(), ext2_inode_block_write(), ext2_inode_build(), ext2_inode_discard(), ext2_inode_read(), ext2_inode_sync(), ext2_inode_write(), ext2_vmknod(), ext2::filetype, gettime(), ext2_inode::gid, uio::gid, ext2_superblock::ginodes, ext2::groups, ext2_dentry::ino, vnode::ino, kfree(), kmalloc(), ext2_dentry::length, M_ZERO, memcpy(), memset(), ext2_inode::mode, ext2_inode::mtime, ext2_dentry::name, ext2_inode::nlink, vnode::nlink, vnode::p, ext2_dentry::size, ext2_inode::size, ext2::superblock, timespec::tv_sec, ext2_dentry::type, ext2_inode::uid, and uio::uid.

Referenced by ext2_vmknod().

◆ ext2_vrename()

int ext2_vrename	(	struct vnode *	odir,
		const char *	ofn,
		struct vnode *	ndir,
		const char *	nfn,
		struct uio *	uio )

Renames an entry, possibly to another directory, replacing an entry at the new name (the VFS checked its type already).

A directory that moves gets its .. pointed to its new parent.

Parameters

odir	the directory the entry is in
ofn	its name
ndir	the directory it goes to
nfn	its new name
uio	who is asking

Returns: 0, -ENOENT, or a negative errno

Definition at line 337 of file remove.c.

References vnode::ctime, dentry_remove(), dentry_set_ino(), dentry_update(), ext2_dentry_create(), ext2_dentry_find(), ext2_inode_build(), ext2_inode_read(), ext2_inode_sync(), ext2_vrename(), ext2_vunlink(), gettime(), vnode::ino, vnode::mode, vnode::mtime, vnode::nlink, NULL, and vnode::p.

Referenced by ext2_vrename().

◆ ext2_vunlink()

int ext2_vunlink	(	struct vnode *	dir,
		const char *	fn,
		struct uio *	uio )

Removes an entry from a directory, and drops a link to its file.

The file is freed when it has no links and nothing has it open.

Parameters

dir	the directory
fn	the entry's name
uio	who is asking

Returns: 0, -ENOENT, or a negative errno

Definition at line 249 of file remove.c.

References vnode::ctime, dentry_remove(), dentry_update(), ext2_inode_build(), ext2_inode_sync(), ext2_vunlink(), gettime(), vnode::mode, vnode::mtime, vnode::nlink, NULL, vnode::p, vnode::ref, and vfs_close().

Referenced by ext2_vrename(), and ext2_vunlink().

◆ ext2_write()

ssize_t ext2_write	(	struct vnode *	node,
		off_t	offset,
		struct iobuf *	io )

Writes to a file, which grows if the write goes past its end.

A short symbolic link keeps its target in the inode itself.

Parameters

node	the file
offset	where to write
io	the data, and how much of it

Returns: the number of bytes written, or a negative errno if nothing was written

Definition at line 83 of file vops.c.

References ext2_inode::blocks, ext2::bs, ext2_inode::direct_pointer, ext2_inode_block_read(), ext2_inode_block_write(), ext2_inode_read(), ext2_inode_write(), ext2_trunc(), ext2_write(), vnode::ino, iobuf_in(), kfree(), kmalloc(), LOG_DEBUG, MAX, MIN, vnode::mode, vnode::p, iobuf::resid, ext2_inode::size, and vnode::size.

Referenced by ext2_write().

Variable Documentation

◆ ext2fs

struct fs ext2fs

extern

Definition at line 282 of file ext2.c.

Referenced by ext2_init(), ext2_inode_build(), and ext2_mount().

Data Structures

Macros

Functions

Variables

Macro Definition Documentation

◆ EXT2_DENTRY_TYPE_BAD

◆ EXT2_DENTRY_TYPE_BLK

◆ EXT2_DENTRY_TYPE_CHR

◆ EXT2_DENTRY_TYPE_DIR

◆ EXT2_DENTRY_TYPE_FIFO

◆ EXT2_DENTRY_TYPE_RGL

◆ EXT2_DENTRY_TYPE_SCKT

◆ EXT2_DENTRY_TYPE_SLINK

◆ EXT2_DIRECT_POINTERS

◆ EXT2_GOOD_OLD_INODE_SIZE

◆ EXT2_INCOMPAT_FILETYPE

◆ EXT2_INCOMPAT_SUPPORTED

◆ EXT2_RO_COMPAT_LARGE_FILE

◆ EXT2_RO_COMPAT_SPARSE_SUPER

◆ EXT2_RO_COMPAT_SUPPORTED

◆ EXT2_SIGNATURE

Function Documentation

◆ ext2_bgd_table_rewrite()

◆ ext2_block_alloc()

◆ ext2_block_free()

◆ ext2_block_read()

◆ ext2_block_write()

◆ ext2_blocks_free()

◆ ext2_close()

◆ ext2_dentry_create()

◆ ext2_dentry_find()

◆ ext2_finddir()

◆ ext2_inode_alloc()

◆ ext2_inode_block_read()

◆ ext2_inode_block_write()

◆ ext2_inode_build()

◆ ext2_inode_discard()

◆ ext2_inode_read()

◆ ext2_inode_sync()

◆ ext2_inode_write()

◆ ext2_io()

◆ ext2_read()

◆ ext2_readdir()

◆ ext2_setattr()

◆ ext2_superblock_rewrite()

◆ ext2_trunc()

◆ ext2_vget()

◆ ext2_vlink()

◆ ext2_vmknod()

◆ ext2_vrename()

◆ ext2_vunlink()

◆ ext2_write()

Variable Documentation

◆ ext2fs