freebsd-skq/sys/fs/ext2fs/ext2_extents.h
Fedor Uporov 5679656e09 Improve extents verification logic.
It is possible to walk thru inode extents if EXT2FS_PRINT_EXTENTS
macro is defined. The extents headers magics and physical blocks
ranges are checked during extents walk.

Reviewed by:    pfg
MFC after:      2 weeks
Differential Revision:  https://reviews.freebsd.org/D29932
2021-05-07 10:27:28 +03:00

137 lines
4.6 KiB
C

/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2012, 2010 Zheng Liu <lz@freebsd.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
#ifndef _FS_EXT2FS_EXT2_EXTENTS_H_
#define _FS_EXT2FS_EXT2_EXTENTS_H_
#include <sys/types.h>
#define EXT4_EXT_MAGIC 0xf30a
#define EXT4_MAX_BLOCKS 0xffffffff
#define EXT_INIT_MAX_LEN (1UL << 15)
#define EXT4_MAX_LEN (EXT_INIT_MAX_LEN - 1)
#define EXT4_EXT_DEPTH_MAX 5
#define EXT4_EXT_CACHE_NO 0
#define EXT4_EXT_CACHE_GAP 1
#define EXT4_EXT_CACHE_IN 2
/*
* Ext4 extent tail with csum
*/
struct ext4_extent_tail {
uint32_t et_checksum; /* crc32c(uuid+inum+extent_block) */
};
/*
* Ext4 file system extent on disk.
*/
struct ext4_extent {
uint32_t e_blk; /* first logical block */
uint16_t e_len; /* number of blocks */
uint16_t e_start_hi; /* high 16 bits of physical block */
uint32_t e_start_lo; /* low 32 bits of physical block */
};
/*
* Extent index on disk.
*/
struct ext4_extent_index {
uint32_t ei_blk; /* indexes logical blocks */
uint32_t ei_leaf_lo; /* points to physical block of the
* next level */
uint16_t ei_leaf_hi; /* high 16 bits of physical block */
uint16_t ei_unused;
};
/*
* Extent tree header.
*/
struct ext4_extent_header {
uint16_t eh_magic; /* magic number: 0xf30a */
uint16_t eh_ecount; /* number of valid entries */
uint16_t eh_max; /* capacity of store in entries */
uint16_t eh_depth; /* the depth of extent tree */
uint32_t eh_gen; /* generation of extent tree */
};
/*
* Save cached extent.
*/
struct ext4_extent_cache {
daddr_t ec_start; /* extent start */
uint32_t ec_blk; /* logical block */
uint32_t ec_len;
uint32_t ec_type;
};
/*
* Save path to some extent.
*/
struct ext4_extent_path {
int index_count;
uint16_t ep_depth;
uint64_t ep_blk;
char *ep_data;
struct ext4_extent *ep_ext;
struct ext4_extent_index *ep_index;
struct ext4_extent_header *ep_header;
};
#define EXT_FIRST_EXTENT(hdr) ((struct ext4_extent *)(((char *)(hdr)) + \
sizeof(struct ext4_extent_header)))
#define EXT_FIRST_INDEX(hdr) ((struct ext4_extent_index *)(((char *)(hdr)) + \
sizeof(struct ext4_extent_header)))
#define EXT_LAST_EXTENT(hdr) (EXT_FIRST_EXTENT((hdr)) + le16toh((hdr)->eh_ecount) - 1)
#define EXT_LAST_INDEX(hdr) (EXT_FIRST_INDEX((hdr)) + le16toh((hdr)->eh_ecount) - 1)
#define EXT4_EXTENT_TAIL_OFFSET(hdr) (sizeof(struct ext4_extent_header) + \
(sizeof(struct ext4_extent) * le16toh((hdr)->eh_max)))
#define EXT_HAS_FREE_INDEX(path) \
(le16toh((path)->ep_header->eh_ecount) < le16toh((path)->ep_header->eh_max))
#define EXT_MAX_EXTENT(hdr) (EXT_FIRST_EXTENT(hdr) + le16toh((hdr)->eh_max) - 1)
#define EXT_MAX_INDEX(hdr) (EXT_FIRST_INDEX((hdr)) + le16toh((hdr)->eh_max) - 1)
struct inode;
struct m_ext2fs;
void ext4_ext_tree_init(struct inode *ip);
int ext4_ext_in_cache(struct inode *, daddr_t, struct ext4_extent *);
void ext4_ext_put_cache(struct inode *, struct ext4_extent *, int);
int ext4_ext_find_extent(struct inode *, daddr_t, struct ext4_extent_path **);
void ext4_ext_path_free(struct ext4_extent_path *path);
int ext4_ext_remove_space(struct inode *ip, off_t length, int flags,
struct ucred *cred, struct thread *td);
int ext4_ext_get_blocks(struct inode *ip, int64_t iblock,
unsigned long max_blocks, struct ucred *cred, struct buf **bpp,
int *allocate, daddr_t *);
#ifdef EXT2FS_PRINT_EXTENTS
int ext4_ext_walk(struct inode *ip);
#endif
#endif /* !_FS_EXT2FS_EXT2_EXTENTS_H_ */