4.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: Qu Wenruo quwenruo.btrfs@gmx.com
commit 557ea5dd003d371536f6b4e8f7c8209a2b6fd4e3 upstream.
It's no doubt the comprehensive tree block checker will become larger, so moving them into their own files is quite reasonable.
Signed-off-by: Qu Wenruo quwenruo.btrfs@gmx.com [ wording adjustments ] Signed-off-by: David Sterba dsterba@suse.com [bwh: Backported to 4.9: The moved code is slightly different] Signed-off-by: Ben Hutchings ben.hutchings@codethink.co.uk Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/btrfs/Makefile | 2 fs/btrfs/disk-io.c | 284 -------------------------------------------- fs/btrfs/tree-checker.c | 309 ++++++++++++++++++++++++++++++++++++++++++++++++ fs/btrfs/tree-checker.h | 26 ++++ 4 files changed, 340 insertions(+), 281 deletions(-) create mode 100644 fs/btrfs/tree-checker.c create mode 100644 fs/btrfs/tree-checker.h
--- a/fs/btrfs/Makefile +++ b/fs/btrfs/Makefile @@ -9,7 +9,7 @@ btrfs-y += super.o ctree.o extent-tree.o export.o tree-log.o free-space-cache.o zlib.o lzo.o \ compression.o delayed-ref.o relocation.o delayed-inode.o scrub.o \ reada.o backref.o ulist.o qgroup.o send.o dev-replace.o raid56.o \ - uuid-tree.o props.o hash.o free-space-tree.o + uuid-tree.o props.o hash.o free-space-tree.o tree-checker.o
btrfs-$(CONFIG_BTRFS_FS_POSIX_ACL) += acl.o btrfs-$(CONFIG_BTRFS_FS_CHECK_INTEGRITY) += check-integrity.o --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -50,6 +50,7 @@ #include "sysfs.h" #include "qgroup.h" #include "compression.h" +#include "tree-checker.h"
#ifdef CONFIG_X86 #include <asm/cpufeature.h> @@ -538,283 +539,6 @@ static int check_tree_block_fsid(struct return ret; }
-#define CORRUPT(reason, eb, root, slot) \ - btrfs_crit(root->fs_info, "corrupt %s, %s: block=%llu," \ - " root=%llu, slot=%d", \ - btrfs_header_level(eb) == 0 ? "leaf" : "node",\ - reason, btrfs_header_bytenr(eb), root->objectid, slot) - -static int check_extent_data_item(struct btrfs_root *root, - struct extent_buffer *leaf, - struct btrfs_key *key, int slot) -{ - struct btrfs_file_extent_item *fi; - u32 sectorsize = root->sectorsize; - u32 item_size = btrfs_item_size_nr(leaf, slot); - - if (!IS_ALIGNED(key->offset, sectorsize)) { - CORRUPT("unaligned key offset for file extent", - leaf, root, slot); - return -EUCLEAN; - } - - fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item); - - if (btrfs_file_extent_type(leaf, fi) > BTRFS_FILE_EXTENT_TYPES) { - CORRUPT("invalid file extent type", leaf, root, slot); - return -EUCLEAN; - } - - /* - * Support for new compression/encrption must introduce incompat flag, - * and must be caught in open_ctree(). - */ - if (btrfs_file_extent_compression(leaf, fi) > BTRFS_COMPRESS_TYPES) { - CORRUPT("invalid file extent compression", leaf, root, slot); - return -EUCLEAN; - } - if (btrfs_file_extent_encryption(leaf, fi)) { - CORRUPT("invalid file extent encryption", leaf, root, slot); - return -EUCLEAN; - } - if (btrfs_file_extent_type(leaf, fi) == BTRFS_FILE_EXTENT_INLINE) { - /* Inline extent must have 0 as key offset */ - if (key->offset) { - CORRUPT("inline extent has non-zero key offset", - leaf, root, slot); - return -EUCLEAN; - } - - /* Compressed inline extent has no on-disk size, skip it */ - if (btrfs_file_extent_compression(leaf, fi) != - BTRFS_COMPRESS_NONE) - return 0; - - /* Uncompressed inline extent size must match item size */ - if (item_size != BTRFS_FILE_EXTENT_INLINE_DATA_START + - btrfs_file_extent_ram_bytes(leaf, fi)) { - CORRUPT("plaintext inline extent has invalid size", - leaf, root, slot); - return -EUCLEAN; - } - return 0; - } - - /* Regular or preallocated extent has fixed item size */ - if (item_size != sizeof(*fi)) { - CORRUPT( - "regluar or preallocated extent data item size is invalid", - leaf, root, slot); - return -EUCLEAN; - } - if (!IS_ALIGNED(btrfs_file_extent_ram_bytes(leaf, fi), sectorsize) || - !IS_ALIGNED(btrfs_file_extent_disk_bytenr(leaf, fi), sectorsize) || - !IS_ALIGNED(btrfs_file_extent_disk_num_bytes(leaf, fi), sectorsize) || - !IS_ALIGNED(btrfs_file_extent_offset(leaf, fi), sectorsize) || - !IS_ALIGNED(btrfs_file_extent_num_bytes(leaf, fi), sectorsize)) { - CORRUPT( - "regular or preallocated extent data item has unaligned value", - leaf, root, slot); - return -EUCLEAN; - } - - return 0; -} - -static int check_csum_item(struct btrfs_root *root, struct extent_buffer *leaf, - struct btrfs_key *key, int slot) -{ - u32 sectorsize = root->sectorsize; - u32 csumsize = btrfs_super_csum_size(root->fs_info->super_copy); - - if (key->objectid != BTRFS_EXTENT_CSUM_OBJECTID) { - CORRUPT("invalid objectid for csum item", leaf, root, slot); - return -EUCLEAN; - } - if (!IS_ALIGNED(key->offset, sectorsize)) { - CORRUPT("unaligned key offset for csum item", leaf, root, slot); - return -EUCLEAN; - } - if (!IS_ALIGNED(btrfs_item_size_nr(leaf, slot), csumsize)) { - CORRUPT("unaligned csum item size", leaf, root, slot); - return -EUCLEAN; - } - return 0; -} - -/* - * Common point to switch the item-specific validation. - */ -static int check_leaf_item(struct btrfs_root *root, - struct extent_buffer *leaf, - struct btrfs_key *key, int slot) -{ - int ret = 0; - - switch (key->type) { - case BTRFS_EXTENT_DATA_KEY: - ret = check_extent_data_item(root, leaf, key, slot); - break; - case BTRFS_EXTENT_CSUM_KEY: - ret = check_csum_item(root, leaf, key, slot); - break; - } - return ret; -} - -static noinline int check_leaf(struct btrfs_root *root, - struct extent_buffer *leaf) -{ - /* No valid key type is 0, so all key should be larger than this key */ - struct btrfs_key prev_key = {0, 0, 0}; - struct btrfs_key key; - u32 nritems = btrfs_header_nritems(leaf); - int slot; - - /* - * Extent buffers from a relocation tree have a owner field that - * corresponds to the subvolume tree they are based on. So just from an - * extent buffer alone we can not find out what is the id of the - * corresponding subvolume tree, so we can not figure out if the extent - * buffer corresponds to the root of the relocation tree or not. So skip - * this check for relocation trees. - */ - if (nritems == 0 && !btrfs_header_flag(leaf, BTRFS_HEADER_FLAG_RELOC)) { - struct btrfs_root *check_root; - - key.objectid = btrfs_header_owner(leaf); - key.type = BTRFS_ROOT_ITEM_KEY; - key.offset = (u64)-1; - - check_root = btrfs_get_fs_root(root->fs_info, &key, false); - /* - * The only reason we also check NULL here is that during - * open_ctree() some roots has not yet been set up. - */ - if (!IS_ERR_OR_NULL(check_root)) { - struct extent_buffer *eb; - - eb = btrfs_root_node(check_root); - /* if leaf is the root, then it's fine */ - if (leaf != eb) { - CORRUPT("non-root leaf's nritems is 0", - leaf, check_root, 0); - free_extent_buffer(eb); - return -EUCLEAN; - } - free_extent_buffer(eb); - } - return 0; - } - - if (nritems == 0) - return 0; - - /* - * Check the following things to make sure this is a good leaf, and - * leaf users won't need to bother with similar sanity checks: - * - * 1) key order - * 2) item offset and size - * No overlap, no hole, all inside the leaf. - * 3) item content - * If possible, do comprehensive sanity check. - * NOTE: All checks must only rely on the item data itself. - */ - for (slot = 0; slot < nritems; slot++) { - u32 item_end_expected; - int ret; - - btrfs_item_key_to_cpu(leaf, &key, slot); - - /* Make sure the keys are in the right order */ - if (btrfs_comp_cpu_keys(&prev_key, &key) >= 0) { - CORRUPT("bad key order", leaf, root, slot); - return -EUCLEAN; - } - - /* - * Make sure the offset and ends are right, remember that the - * item data starts at the end of the leaf and grows towards the - * front. - */ - if (slot == 0) - item_end_expected = BTRFS_LEAF_DATA_SIZE(root); - else - item_end_expected = btrfs_item_offset_nr(leaf, - slot - 1); - if (btrfs_item_end_nr(leaf, slot) != item_end_expected) { - CORRUPT("slot offset bad", leaf, root, slot); - return -EUCLEAN; - } - - /* - * Check to make sure that we don't point outside of the leaf, - * just in case all the items are consistent to each other, but - * all point outside of the leaf. - */ - if (btrfs_item_end_nr(leaf, slot) > - BTRFS_LEAF_DATA_SIZE(root)) { - CORRUPT("slot end outside of leaf", leaf, root, slot); - return -EUCLEAN; - } - - /* Also check if the item pointer overlaps with btrfs item. */ - if (btrfs_item_nr_offset(slot) + sizeof(struct btrfs_item) > - btrfs_item_ptr_offset(leaf, slot)) { - CORRUPT("slot overlap with its data", leaf, root, slot); - return -EUCLEAN; - } - - /* Check if the item size and content meet other criteria */ - ret = check_leaf_item(root, leaf, &key, slot); - if (ret < 0) - return ret; - - prev_key.objectid = key.objectid; - prev_key.type = key.type; - prev_key.offset = key.offset; - } - - return 0; -} - -static int check_node(struct btrfs_root *root, struct extent_buffer *node) -{ - unsigned long nr = btrfs_header_nritems(node); - struct btrfs_key key, next_key; - int slot; - u64 bytenr; - int ret = 0; - - if (nr == 0 || nr > BTRFS_NODEPTRS_PER_BLOCK(root)) { - btrfs_crit(root->fs_info, - "corrupt node: block %llu root %llu nritems %lu", - node->start, root->objectid, nr); - return -EIO; - } - - for (slot = 0; slot < nr - 1; slot++) { - bytenr = btrfs_node_blockptr(node, slot); - btrfs_node_key_to_cpu(node, &key, slot); - btrfs_node_key_to_cpu(node, &next_key, slot + 1); - - if (!bytenr) { - CORRUPT("invalid item slot", node, root, slot); - ret = -EIO; - goto out; - } - - if (btrfs_comp_cpu_keys(&key, &next_key) >= 0) { - CORRUPT("bad key order", node, root, slot); - ret = -EIO; - goto out; - } - } -out: - return ret; -} - static int btree_readpage_end_io_hook(struct btrfs_io_bio *io_bio, u64 phy_offset, struct page *page, u64 start, u64 end, int mirror) @@ -880,12 +604,12 @@ static int btree_readpage_end_io_hook(st * that we don't try and read the other copies of this block, just * return -EIO. */ - if (found_level == 0 && check_leaf(root, eb)) { + if (found_level == 0 && btrfs_check_leaf(root, eb)) { set_bit(EXTENT_BUFFER_CORRUPT, &eb->bflags); ret = -EIO; }
- if (found_level > 0 && check_node(root, eb)) + if (found_level > 0 && btrfs_check_node(root, eb)) ret = -EIO;
if (!ret) @@ -4216,7 +3940,7 @@ void btrfs_mark_buffer_dirty(struct exte buf->len, root->fs_info->dirty_metadata_batch); #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY - if (btrfs_header_level(buf) == 0 && check_leaf(root, buf)) { + if (btrfs_header_level(buf) == 0 && btrfs_check_leaf(root, buf)) { btrfs_print_leaf(root, buf); ASSERT(0); } --- /dev/null +++ b/fs/btrfs/tree-checker.c @@ -0,0 +1,309 @@ +/* + * Copyright (C) Qu Wenruo 2017. All rights reserved. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public + * License v2 as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public + * License along with this program. + */ + +/* + * 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 "ctree.h" +#include "tree-checker.h" +#include "disk-io.h" +#include "compression.h" + +#define CORRUPT(reason, eb, root, slot) \ + btrfs_crit(root->fs_info, \ + "corrupt %s, %s: block=%llu, root=%llu, slot=%d", \ + btrfs_header_level(eb) == 0 ? "leaf" : "node", \ + reason, btrfs_header_bytenr(eb), root->objectid, slot) + +static int check_extent_data_item(struct btrfs_root *root, + struct extent_buffer *leaf, + struct btrfs_key *key, int slot) +{ + struct btrfs_file_extent_item *fi; + u32 sectorsize = root->sectorsize; + u32 item_size = btrfs_item_size_nr(leaf, slot); + + if (!IS_ALIGNED(key->offset, sectorsize)) { + CORRUPT("unaligned key offset for file extent", + leaf, root, slot); + return -EUCLEAN; + } + + fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item); + + if (btrfs_file_extent_type(leaf, fi) > BTRFS_FILE_EXTENT_TYPES) { + CORRUPT("invalid file extent type", leaf, root, slot); + return -EUCLEAN; + } + + /* + * Support for new compression/encrption must introduce incompat flag, + * and must be caught in open_ctree(). + */ + if (btrfs_file_extent_compression(leaf, fi) > BTRFS_COMPRESS_TYPES) { + CORRUPT("invalid file extent compression", leaf, root, slot); + return -EUCLEAN; + } + if (btrfs_file_extent_encryption(leaf, fi)) { + CORRUPT("invalid file extent encryption", leaf, root, slot); + return -EUCLEAN; + } + if (btrfs_file_extent_type(leaf, fi) == BTRFS_FILE_EXTENT_INLINE) { + /* Inline extent must have 0 as key offset */ + if (key->offset) { + CORRUPT("inline extent has non-zero key offset", + leaf, root, slot); + return -EUCLEAN; + } + + /* Compressed inline extent has no on-disk size, skip it */ + if (btrfs_file_extent_compression(leaf, fi) != + BTRFS_COMPRESS_NONE) + return 0; + + /* Uncompressed inline extent size must match item size */ + if (item_size != BTRFS_FILE_EXTENT_INLINE_DATA_START + + btrfs_file_extent_ram_bytes(leaf, fi)) { + CORRUPT("plaintext inline extent has invalid size", + leaf, root, slot); + return -EUCLEAN; + } + return 0; + } + + /* Regular or preallocated extent has fixed item size */ + if (item_size != sizeof(*fi)) { + CORRUPT( + "regluar or preallocated extent data item size is invalid", + leaf, root, slot); + return -EUCLEAN; + } + if (!IS_ALIGNED(btrfs_file_extent_ram_bytes(leaf, fi), sectorsize) || + !IS_ALIGNED(btrfs_file_extent_disk_bytenr(leaf, fi), sectorsize) || + !IS_ALIGNED(btrfs_file_extent_disk_num_bytes(leaf, fi), sectorsize) || + !IS_ALIGNED(btrfs_file_extent_offset(leaf, fi), sectorsize) || + !IS_ALIGNED(btrfs_file_extent_num_bytes(leaf, fi), sectorsize)) { + CORRUPT( + "regular or preallocated extent data item has unaligned value", + leaf, root, slot); + return -EUCLEAN; + } + + return 0; +} + +static int check_csum_item(struct btrfs_root *root, struct extent_buffer *leaf, + struct btrfs_key *key, int slot) +{ + u32 sectorsize = root->sectorsize; + u32 csumsize = btrfs_super_csum_size(root->fs_info->super_copy); + + if (key->objectid != BTRFS_EXTENT_CSUM_OBJECTID) { + CORRUPT("invalid objectid for csum item", leaf, root, slot); + return -EUCLEAN; + } + if (!IS_ALIGNED(key->offset, sectorsize)) { + CORRUPT("unaligned key offset for csum item", leaf, root, slot); + return -EUCLEAN; + } + if (!IS_ALIGNED(btrfs_item_size_nr(leaf, slot), csumsize)) { + CORRUPT("unaligned csum item size", leaf, root, slot); + return -EUCLEAN; + } + return 0; +} + +/* + * Common point to switch the item-specific validation. + */ +static int check_leaf_item(struct btrfs_root *root, + struct extent_buffer *leaf, + struct btrfs_key *key, int slot) +{ + int ret = 0; + + switch (key->type) { + case BTRFS_EXTENT_DATA_KEY: + ret = check_extent_data_item(root, leaf, key, slot); + break; + case BTRFS_EXTENT_CSUM_KEY: + ret = check_csum_item(root, leaf, key, slot); + break; + } + return ret; +} + +int btrfs_check_leaf(struct btrfs_root *root, struct extent_buffer *leaf) +{ + struct btrfs_fs_info *fs_info = root->fs_info; + /* No valid key type is 0, so all key should be larger than this key */ + struct btrfs_key prev_key = {0, 0, 0}; + struct btrfs_key key; + u32 nritems = btrfs_header_nritems(leaf); + int slot; + + /* + * Extent buffers from a relocation tree have a owner field that + * corresponds to the subvolume tree they are based on. So just from an + * extent buffer alone we can not find out what is the id of the + * corresponding subvolume tree, so we can not figure out if the extent + * buffer corresponds to the root of the relocation tree or not. So + * skip this check for relocation trees. + */ + if (nritems == 0 && !btrfs_header_flag(leaf, BTRFS_HEADER_FLAG_RELOC)) { + struct btrfs_root *check_root; + + key.objectid = btrfs_header_owner(leaf); + key.type = BTRFS_ROOT_ITEM_KEY; + key.offset = (u64)-1; + + check_root = btrfs_get_fs_root(fs_info, &key, false); + /* + * The only reason we also check NULL here is that during + * open_ctree() some roots has not yet been set up. + */ + if (!IS_ERR_OR_NULL(check_root)) { + struct extent_buffer *eb; + + eb = btrfs_root_node(check_root); + /* if leaf is the root, then it's fine */ + if (leaf != eb) { + CORRUPT("non-root leaf's nritems is 0", + leaf, check_root, 0); + free_extent_buffer(eb); + return -EUCLEAN; + } + free_extent_buffer(eb); + } + return 0; + } + + if (nritems == 0) + return 0; + + /* + * Check the following things to make sure this is a good leaf, and + * leaf users won't need to bother with similar sanity checks: + * + * 1) key ordering + * 2) item offset and size + * No overlap, no hole, all inside the leaf. + * 3) item content + * If possible, do comprehensive sanity check. + * NOTE: All checks must only rely on the item data itself. + */ + for (slot = 0; slot < nritems; slot++) { + u32 item_end_expected; + int ret; + + btrfs_item_key_to_cpu(leaf, &key, slot); + + /* Make sure the keys are in the right order */ + if (btrfs_comp_cpu_keys(&prev_key, &key) >= 0) { + CORRUPT("bad key order", leaf, root, slot); + return -EUCLEAN; + } + + /* + * Make sure the offset and ends are right, remember that the + * item data starts at the end of the leaf and grows towards the + * front. + */ + if (slot == 0) + item_end_expected = BTRFS_LEAF_DATA_SIZE(root); + else + item_end_expected = btrfs_item_offset_nr(leaf, + slot - 1); + if (btrfs_item_end_nr(leaf, slot) != item_end_expected) { + CORRUPT("slot offset bad", leaf, root, slot); + return -EUCLEAN; + } + + /* + * Check to make sure that we don't point outside of the leaf, + * just in case all the items are consistent to each other, but + * all point outside of the leaf. + */ + if (btrfs_item_end_nr(leaf, slot) > + BTRFS_LEAF_DATA_SIZE(root)) { + CORRUPT("slot end outside of leaf", leaf, root, slot); + return -EUCLEAN; + } + + /* Also check if the item pointer overlaps with btrfs item. */ + if (btrfs_item_nr_offset(slot) + sizeof(struct btrfs_item) > + btrfs_item_ptr_offset(leaf, slot)) { + CORRUPT("slot overlap with its data", leaf, root, slot); + return -EUCLEAN; + } + + /* Check if the item size and content meet other criteria */ + ret = check_leaf_item(root, leaf, &key, slot); + if (ret < 0) + return ret; + + prev_key.objectid = key.objectid; + prev_key.type = key.type; + prev_key.offset = key.offset; + } + + return 0; +} + +int btrfs_check_node(struct btrfs_root *root, struct extent_buffer *node) +{ + unsigned long nr = btrfs_header_nritems(node); + struct btrfs_key key, next_key; + int slot; + u64 bytenr; + int ret = 0; + + if (nr == 0 || nr > BTRFS_NODEPTRS_PER_BLOCK(root)) { + btrfs_crit(root->fs_info, + "corrupt node: block %llu root %llu nritems %lu", + node->start, root->objectid, nr); + return -EIO; + } + + for (slot = 0; slot < nr - 1; slot++) { + bytenr = btrfs_node_blockptr(node, slot); + btrfs_node_key_to_cpu(node, &key, slot); + btrfs_node_key_to_cpu(node, &next_key, slot + 1); + + if (!bytenr) { + CORRUPT("invalid item slot", node, root, slot); + ret = -EIO; + goto out; + } + + if (btrfs_comp_cpu_keys(&key, &next_key) >= 0) { + CORRUPT("bad key order", node, root, slot); + ret = -EIO; + goto out; + } + } +out: + return ret; +} --- /dev/null +++ b/fs/btrfs/tree-checker.h @@ -0,0 +1,26 @@ +/* + * Copyright (C) Qu Wenruo 2017. All rights reserved. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public + * License v2 as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public + * License along with this program. + */ + +#ifndef __BTRFS_TREE_CHECKER__ +#define __BTRFS_TREE_CHECKER__ + +#include "ctree.h" +#include "extent_io.h" + +int btrfs_check_leaf(struct btrfs_root *root, struct extent_buffer *leaf); +int btrfs_check_node(struct btrfs_root *root, struct extent_buffer *node); + +#endif