tree-checker.c | Explore in Territory

// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (C) Qu Wenruo 2017.  All rights reserved.
 */

/*
 * The module is used to catch unexpected/corrupted tree block data.
 * Such behavior can be caused either by a fuzzed image or bugs.
 *
 * The objective is to do leaf/node validation checks when tree block is read
 * from disk, and check *every* possible member, so other code won't
 * need to checking them again.
 *
 * Due to the potential and unwanted damage, every checker needs to be
 * carefully reviewed otherwise so it does not prevent mount of valid images.
 */

#include <linux/types.h>
#include <linux/stddef.h>
#include <linux/error-injection.h>
#include "messages.h"
#include "ctree.h"
#include "tree-checker.h"
#include "compression.h"
#include "volumes.h"
#include "misc.h"
#include "fs.h"
#include "accessors.h"
#include "file-item.h"
#include "inode-item.h"
#include "dir-item.h"
#include "extent-tree.h"

/*
 * Error message should follow the following format:
 * corrupt <type>: <identifier>, <reason>[, <bad_value>]
 *
 * @type:	leaf or node
 * @identifier:	the necessary info to locate the leaf/node.
 * 		It's recommended to decode key.objecitd/offset if it's
 * 		meaningful.
 * @reason:	describe the error
 * @bad_value:	optional, it's recommended to output bad value and its
 *		expected value (range).
 *
 * Since comma is used to separate the components, only space is allowed
 * inside each component.
 */

/*
 * Append generic "corrupt leaf/node root=%llu block=%llu slot=%d: " to @fmt.
 * Allows callers to customize the output.
 */
__printf(3, 4)
__cold
static void generic_err(const struct extent_buffer *eb, int slot,
			const char *fmt, ...)
{ … }

/*
 * Customized reporter for extent data item, since its key objectid and
 * offset has its own meaning.
 */
__printf(3, 4)
__cold
static void file_extent_err(const struct extent_buffer *eb, int slot,
			    const char *fmt, ...)
{ … }

/*
 * Return 0 if the btrfs_file_extent_##name is aligned to @alignment
 * Else return 1
 */
#define CHECK_FE_ALIGNED(leaf, slot, fi, name, alignment) …

static u64 file_extent_end(struct extent_buffer *leaf,
			   struct btrfs_key *key,
			   struct btrfs_file_extent_item *extent)
{ … }

/*
 * Customized report for dir_item, the only new important information is
 * key->objectid, which represents inode number
 */
__printf(3, 4)
__cold
static void dir_item_err(const struct extent_buffer *eb, int slot,
			 const char *fmt, ...)
{ … }

/*
 * This functions checks prev_key->objectid, to ensure current key and prev_key
 * share the same objectid as inode number.
 *
 * This is to detect missing INODE_ITEM in subvolume trees.
 *
 * Return true if everything is OK or we don't need to check.
 * Return false if anything is wrong.
 */
static bool check_prev_ino(struct extent_buffer *leaf,
			   struct btrfs_key *key, int slot,
			   struct btrfs_key *prev_key)
{ … }
static int check_extent_data_item(struct extent_buffer *leaf,
				  struct btrfs_key *key, int slot,
				  struct btrfs_key *prev_key)
{ … }

static int check_csum_item(struct extent_buffer *leaf, struct btrfs_key *key,
			   int slot, struct btrfs_key *prev_key)
{ … }

/* Inode item error output has the same format as dir_item_err() */
#define inode_item_err(eb, slot, fmt, ...) …

static int check_inode_key(struct extent_buffer *leaf, struct btrfs_key *key,
			   int slot)
{ … }

static int check_root_key(struct extent_buffer *leaf, struct btrfs_key *key,
			  int slot)
{ … }

static int check_dir_item(struct extent_buffer *leaf,
			  struct btrfs_key *key, struct btrfs_key *prev_key,
			  int slot)
{ … }

__printf(3, 4)
__cold
static void block_group_err(const struct extent_buffer *eb, int slot,
			    const char *fmt, ...)
{ … }

static int check_block_group_item(struct extent_buffer *leaf,
				  struct btrfs_key *key, int slot)
{ … }

__printf(4, 5)
__cold
static void chunk_err(const struct extent_buffer *leaf,
		      const struct btrfs_chunk *chunk, u64 logical,
		      const char *fmt, ...)
{ … }

/*
 * The common chunk check which could also work on super block sys chunk array.
 *
 * Return -EUCLEAN if anything is corrupted.
 * Return 0 if everything is OK.
 */
int btrfs_check_chunk_valid(struct extent_buffer *leaf,
			    struct btrfs_chunk *chunk, u64 logical)
{ … }

/*
 * Enhanced version of chunk item checker.
 *
 * The common btrfs_check_chunk_valid() doesn't check item size since it needs
 * to work on super block sys_chunk_array which doesn't have full item ptr.
 */
static int check_leaf_chunk_item(struct extent_buffer *leaf,
				 struct btrfs_chunk *chunk,
				 struct btrfs_key *key, int slot)
{ … }

__printf(3, 4)
__cold
static void dev_item_err(const struct extent_buffer *eb, int slot,
			 const char *fmt, ...)
{ … }

static int check_dev_item(struct extent_buffer *leaf,
			  struct btrfs_key *key, int slot)
{ … }

static int check_inode_item(struct extent_buffer *leaf,
			    struct btrfs_key *key, int slot)
{ … }

static int check_root_item(struct extent_buffer *leaf, struct btrfs_key *key,
			   int slot)
{ … }

__printf(3,4)
__cold
static void extent_err(const struct extent_buffer *eb, int slot,
		       const char *fmt, ...)
{ … }

static bool is_valid_dref_root(u64 rootid)
{ … }

static int check_extent_item(struct extent_buffer *leaf,
			     struct btrfs_key *key, int slot,
			     struct btrfs_key *prev_key)
{ … }

static int check_simple_keyed_refs(struct extent_buffer *leaf,
				   struct btrfs_key *key, int slot)
{ … }

static int check_extent_data_ref(struct extent_buffer *leaf,
				 struct btrfs_key *key, int slot)
{ … }

#define inode_ref_err(eb, slot, fmt, args...) …
static int check_inode_ref(struct extent_buffer *leaf,
			   struct btrfs_key *key, struct btrfs_key *prev_key,
			   int slot)
{ … }

static int check_raid_stripe_extent(const struct extent_buffer *leaf,
				    const struct btrfs_key *key, int slot)
{ … }

/*
 * Common point to switch the item-specific validation.
 */
static enum btrfs_tree_block_status check_leaf_item(struct extent_buffer *leaf,
						    struct btrfs_key *key,
						    int slot,
						    struct btrfs_key *prev_key)
{ … }

enum btrfs_tree_block_status __btrfs_check_leaf(struct extent_buffer *leaf)
{ … }

int btrfs_check_leaf(struct extent_buffer *leaf)
{ … }
ALLOW_ERROR_INJECTION(…);

enum btrfs_tree_block_status __btrfs_check_node(struct extent_buffer *node)
{ … }

int btrfs_check_node(struct extent_buffer *node)
{ … }
ALLOW_ERROR_INJECTION(…);

int btrfs_check_eb_owner(const struct extent_buffer *eb, u64 root_owner)
{ … }

int btrfs_verify_level_key(struct extent_buffer *eb, int level,
			   struct btrfs_key *first_key, u64 parent_transid)
{ … }
linux/fs/btrfs/tree-checker.c
