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btrfs: Move leaf and node validation checker to tree-checker.c
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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>
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Qu Wenruo authored and David Sterba committed Oct 30, 2017
1 parent 1170862 commit 557ea5d
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Showing 4 changed files with 340 additions and 282 deletions.
2 changes: 1 addition & 1 deletion fs/btrfs/Makefile
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Original file line number Diff line number Diff line change
Expand Up @@ -9,7 +9,7 @@ btrfs-y += super.o ctree.o extent-tree.o print-tree.o root-tree.o dir-item.o \
export.o tree-log.o free-space-cache.o zlib.o lzo.o zstd.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
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285 changes: 4 additions & 281 deletions fs/btrfs/disk-io.c
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Original file line number Diff line number Diff line change
Expand Up @@ -50,6 +50,7 @@
#include "sysfs.h"
#include "qgroup.h"
#include "compression.h"
#include "tree-checker.h"

#ifdef CONFIG_X86
#include <asm/cpufeature.h>
Expand Down Expand Up @@ -543,284 +544,6 @@ static int check_tree_block_fsid(struct btrfs_fs_info *fs_info,
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->fs_info->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->fs_info->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)
{
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 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(fs_info);
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(fs_info)) {
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->fs_info)) {
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)
Expand Down Expand Up @@ -886,12 +609,12 @@ static int btree_readpage_end_io_hook(struct btrfs_io_bio *io_bio,
* 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)
Expand Down Expand Up @@ -4146,7 +3869,7 @@ void btrfs_mark_buffer_dirty(struct extent_buffer *buf)
buf->len,
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(buf);
ASSERT(0);
}
Expand Down
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