The tree checker checks the extent ref hash at read and write time to
make sure we do not corrupt the file system. Generally extent
references go inline, but if we have enough of them we need to make an
item, which looks like
key.objectid = <bytenr>
key.type = <BTRFS_EXTENT_DATA_REF_KEY|BTRFS_TREE_BLOCK_REF_KEY>
key.offset = hash(tree, owner, offset)
However if key.offset collide with an unrelated extent reference we'll
simply key.offset++ until we get something that doesn't collide.
Obviously this doesn't match at tree checker time, and thus we error
while writing out the transaction. This is relatively easy to
reproduce, simply do something like the following
xfs_io -f -c "pwrite 0 1M" file
offset=2
for i in {0..10000}
do
xfs_io -c "reflink file 0 ${offset}M 1M" file
offset=$(( offset + 2 ))
done
xfs_io -c "reflink file 0 17999258914816 1M" file
xfs_io -c "reflink file 0 35998517829632 1M" file
xfs_io -c "reflink file 0 53752752058368 1M" file
btrfs filesystem sync
And the sync will error out because we'll abort the transaction. The
magic values above are used because they generate hash collisions with
the first file in the main subvol.
The fix for this is to remove the hash value check from tree checker, as
we have no idea which offset ours should belong to.
Reported-by: Tuomas Lähdekorpi <tuomas.lahdekorpi@gmail.com>
Fixes: 0785a9aacf ("btrfs: tree-checker: Add EXTENT_DATA_REF check")
CC: stable@vger.kernel.org # 5.4+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ add comment]
Signed-off-by: David Sterba <dsterba@suse.com>
The tree checker is called many times as it verifies metadata at
read/write time. The checks follow a simple pattern:
if (error_condition) {
report_error();
return -EUCLEAN;
}
All the error reporting functions are annotated as __cold that is
supposed to hint the compiler to move the statement block out of the hot
path. This does not seem to happen that often.
As the error condition is expected to be false almost always, we can
annotate it with 'unlikely' as this satisfies one of the few use cases
for the annotation. The expected outcome is a stronger hint to compiler
to reorder the checks
test
jump to exit
test
jump to exit
...
which can be observed in asm of eg. check_dir_item,
btrfs_check_chunk_valid, check_root_item or check_leaf.
There's a measurable run time improvement reported by Josef, the testing
workload went from 655 MiB/s to 677 MiB/s, which is about +3%.
There should be no functional changes but some of the conditions have
been rewritten to produce more readable result, some lines are longer
than 80, for the sake of readability.
Signed-off-by: David Sterba <dsterba@suse.com>
The fs_info value is 32bit, switch also the local u16 variables. This
leads to a better assembly code generated due to movzwl.
This simple change will shave some bytes on x86_64 and release config:
text data bss dec hex filename
1090000 17980 14912 1122892 11224c pre/btrfs.ko
1089794 17980 14912 1122686 11217e post/btrfs.ko
DELTA: -206
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
btrfs_get_16 shows up in the system performance profiles (helper to read
16bit values from on-disk structures). This is partially because of the
checksum size that's frequently read along with data reads/writes, other
u16 uses are from item size or directory entries.
Replace all calls to btrfs_super_csum_size by the cached value from
fs_info.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The drop_level member is used directly unlike all the other int types in
root_item. Add the definition and use it everywhere. The type is u8 so
there's no conversion necessary and the helpers are properly inlined,
this is for consistency.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
There are sectorsize alignment checks that are reported but then
check_extent_data_ref continues. This was not intended, wrong alignment
is not a minor problem and we should return with error.
CC: stable@vger.kernel.org # 5.4+
Fixes: 0785a9aacf ("btrfs: tree-checker: Add EXTENT_DATA_REF check")
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
There's a missing return statement after an error is found in the
root_item, this can cause further problems when a crafted image triggers
the error.
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=210181
Fixes: 259ee7754b ("btrfs: tree-checker: Add ROOT_ITEM check")
CC: stable@vger.kernel.org # 5.4+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Daniel Xu <dxu@dxuuu.xyz>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
If there's no parity and num_stripes < ncopies, a crafted image can
trigger a division by zero in calc_stripe_length().
The image was generated through fuzzing.
CC: stable@vger.kernel.org # 5.4+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=209587
Signed-off-by: Daniel Xu <dxu@dxuuu.xyz>
Signed-off-by: David Sterba <dsterba@suse.com>
Commit 259ee7754b ("btrfs: tree-checker: Add ROOT_ITEM check")
introduced btrfs root item size check, however btrfs root item has two
versions, the legacy one which just ends before generation_v2 member, is
smaller than current btrfs root item size.
This caused btrfs kernel to reject valid but old tree root leaves.
Fix this problem by also allowing legacy root item, since kernel can
already handle them pretty well and upgrade to newer root item format
when needed.
Reported-by: Martin Steigerwald <martin@lichtvoll.de>
Fixes: 259ee7754b ("btrfs: tree-checker: Add ROOT_ITEM check")
CC: stable@vger.kernel.org # 5.4+
Tested-By: Martin Steigerwald <martin@lichtvoll.de>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The error message for inode transid is the same as for inode generation,
which makes us unable to detect the real problem.
Reported-by: Tyler Richmond <t.d.richmond@gmail.com>
Fixes: 496245cac5 ("btrfs: tree-checker: Verify inode item")
CC: stable@vger.kernel.org # 5.4+
Reviewed-by: Marcos Paulo de Souza <mpdesouza@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Remove the duplicate definition of 'inode_item_err' in the file
tree-checker.c that got there by accident in c23c77b097 ("btrfs:
tree-checker: Refactor inode key check into seperate function").
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Zheng Wei <wei.zheng@vivo.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
[PROBLEM]
There is a user report in the mail list, showing the following corrupted
tree blocks:
item 62 key (486836 DIR_ITEM 2543451757) itemoff 6273 itemsize 74
location key (4065004 INODE_ITEM 1073741824) type FILE
transid 21397 data_len 0 name_len 44
name: FILENAME
Note that location key, its offset should be 0 for all INODE_ITEMS.
This caused failed lookup of the inode.
[CAUSE]
That offending value, 1073741824, is 0x40000000. So this looks like a
memory bit flip.
[FIX]
This patch will enhance tree-checker to check location key of
DIR_INDEX/DIR_ITEM/XATTR_ITEM.
There are several different combinations needs to check:
- item_key.type == DIR_INDEX/DIR_ITEM
* location_key.type == BTRFS_INODE_ITEM_KEY
This location_key should follow the check in inode_item check.
* location_key.type == BTRFS_ROOT_ITEM_KEY
Despite the existing check, DIR_INDEX/DIR_ITEM can only points to
subvolume trees.
* All other keys are not allowed.
- item_key.type == XATTR_ITEM
location_key should be all 0.
Reported-by: Mike Gilbert <floppymaster@gmail.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
ROOT_ITEM key check itself is not as simple as single line check, and
will be reused for both ROOT_ITEM and DIR_ITEM/DIR_INDEX location key
check, so refactor such check into check_root_key().
Also since we are here, fix a comment error about ROOT_ITEM offset,
which is transid of snapshot creation, not some "older kernel behavior".
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Inode key check is not as easy as several lines, and it will be called
in more than one location (INODE_ITEM check and
DIR_ITEM/DIR_INDEX/XATTR_ITEM location key check).
So here refactor such check into check_inode_key(). And add extra
checks for XATTR_ITEM.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The @fs_info parameter can be extracted from extent_buffer structure,
and there are already some wrappers getting rid of the @fs_info
parameter.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Inspired by btrfs-progs github issue #208, where chunk item in chunk
tree has invalid num_stripes (0).
Although that can already be caught by current btrfs_check_chunk_valid(),
that function doesn't really check item size as it needs to handle chunk
item in super block sys_chunk_array().
This patch will add two extra checks for chunk items in chunk tree:
- Basic chunk item size
If the item is smaller than btrfs_chunk (which already contains one
stripe), exit right now as reading num_stripes may even go beyond
eb boundary.
- Item size check against num_stripes
If item size doesn't match with calculated chunk size, then either the
item size or the num_stripes is corrupted. Error out anyway.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Having checksum items, either on the checksums tree or in a log tree, that
represent ranges that overlap each other is a sign of a corruption. Such
case confuses the checksum lookup code and can result in not being able to
find checksums or find stale checksums.
So add a check for such case.
This is motivated by a recent fix for a case where a log tree had checksum
items covering ranges that overlap each other due to extent cloning, and
resulted in missing checksums after replaying the log tree. It also helps
detect past issues such as stale and outdated checksums due to overlapping,
commit 27b9a8122f ("Btrfs: fix csum tree corruption, duplicate and
outdated checksums").
CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Argument BTRFS_FILE_EXTENT_INLINE_DATA_START is defined as offsetof(),
which returns type size_t, so we need %zu instead of %lu.
This fixes a build warning on 32-bit ARM:
../fs/btrfs/tree-checker.c: In function 'check_extent_data_item':
../fs/btrfs/tree-checker.c:230:43: warning: format '%lu' expects argument of type 'long unsigned int', but argument 5 has type 'unsigned int' [-Wformat=]
230 | "invalid item size, have %u expect [%lu, %u)",
| ~~^
| long unsigned int
| %u
Fixes: 153a6d2999 ("btrfs: tree-checker: Check item size before reading file extent type")
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andreas Färber <afaerber@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
In check_extent_data_item(), we read file extent type without verifying
if the item size is valid.
Add such check to ensure the file extent type we read is correct.
The check is not as accurate as we need to cover both inline and regular
extents, so it only checks if the item size is larger or equal to inline
header.
So the existing size checks on inline/regular extents are still needed.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
All accessors defined by BTRFS_SETGET_STACK_FUNCS contain _stack_ in the
name, the block group ones were not following that scheme, so let's
switch them.
Signed-off-by: David Sterba <dsterba@suse.com>
The compression type upper limit constant is the same as the last value
and this is confusing. In order to keep coding style consistent, use
BTRFS_NR_COMPRESS_TYPES as the total number that follows the idom of
'NR' being one more than the last value.
Signed-off-by: Chengguang Xu <cgxu519@mykernel.net>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Use enum to replace macro definitions of extent types.
Signed-off-by: Chengguang Xu <cgxu519@mykernel.net>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Refactor the check for prev_key->objectid of the following key types
into one function, check_prev_ino():
- EXTENT_DATA
- INODE_REF
- DIR_INDEX
- DIR_ITEM
- XATTR_ITEM
Also add the check of prev_key for INODE_REF.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Replace is_power_of_2 with the helper that is self-documenting and
remove the open coded call in alloc_profile_is_valid.
Signed-off-by: David Sterba <dsterba@suse.com>
For INODE_REF we will check:
- Objectid (ino) against previous key
To detect missing INODE_ITEM.
- No overflow/padding in the data payload
Much like DIR_ITEM, but with less members to check.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
For the following items, key->objectid is inode number:
- DIR_ITEM
- DIR_INDEX
- XATTR_ITEM
- EXTENT_DATA
- INODE_REF
So in the subvolume tree, such items must have its previous item share the
same objectid, e.g.:
(257 INODE_ITEM 0)
(257 DIR_INDEX xxx)
(257 DIR_ITEM xxx)
(258 INODE_ITEM 0)
(258 INODE_REF 0)
(258 XATTR_ITEM 0)
(258 EXTENT_DATA 0)
But if we have the following sequence, then there is definitely
something wrong, normally some INODE_ITEM is missing, like:
(257 INODE_ITEM 0)
(257 DIR_INDEX xxx)
(257 DIR_ITEM xxx)
(258 XATTR_ITEM 0) <<< objecitd suddenly changed to 258
(258 EXTENT_DATA 0)
So just by checking the previous key for above inode based key types, we
can detect a missing inode item.
For INODE_REF key type, the check will be added along with INODE_REF
checker.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
[BUG]
The following script will cause false alert on devid check.
#!/bin/bash
dev1=/dev/test/test
dev2=/dev/test/scratch1
mnt=/mnt/btrfs
umount $dev1 &> /dev/null
umount $dev2 &> /dev/null
umount $mnt &> /dev/null
mkfs.btrfs -f $dev1
mount $dev1 $mnt
_fail()
{
echo "!!! FAILED !!!"
exit 1
}
for ((i = 0; i < 4096; i++)); do
btrfs dev add -f $dev2 $mnt || _fail
btrfs dev del $dev1 $mnt || _fail
dev_tmp=$dev1
dev1=$dev2
dev2=$dev_tmp
done
[CAUSE]
Tree-checker uses BTRFS_MAX_DEVS() and BTRFS_MAX_DEVS_SYS_CHUNK() as
upper limit for devid. But we can have devid holes just like above
script.
So the check for devid is incorrect and could cause false alert.
[FIX]
Just remove the whole devid check. We don't have any hard requirement
for devid assignment.
Furthermore, even devid could get corrupted by a bitflip, we still have
dev extents verification at mount time, so corrupted data won't sneak
in.
This fixes fstests btrfs/194.
Reported-by: Anand Jain <anand.jain@oracle.com>
Fixes: ab4ba2e133 ("btrfs: tree-checker: Verify dev item")
CC: stable@vger.kernel.org # 5.2+
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
EXTENT_DATA_REF is a little like DIR_ITEM which contains hash in its
key->offset.
This patch will check the following contents:
- Key->objectid
Basic alignment check.
- Hash
Hash of each extent_data_ref item must match key->offset.
- Offset
Basic alignment check.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
For TREE_BLOCK_REF, SHARED_DATA_REF and SHARED_BLOCK_REF we need to
check:
| TREE_BLOCK_REF | SHARED_BLOCK_REF | SHARED_BLOCK_REF
--------------+----------------+-----------------+------------------
key->objectid | Alignment | Alignment | Alignment
key->offset | Any value | Alignment | Alignment
item_size | 0 | 0 | sizeof(le32) (*)
*: sizeof(struct btrfs_shared_data_ref)
So introduce a check to check all these 3 key types together.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This patch introduces the ability to check extent items.
This check involves:
- key->objectid check
Basic alignment check.
- key->type check
Against btrfs_extent_item::type and SKINNY_METADATA feature.
- key->offset alignment check for EXTENT_ITEM
- key->offset check for METADATA_ITEM
- item size check
Both against minimal size and stepping check.
- btrfs_extent_item check
Checks its flags and generation.
- btrfs_extent_inline_ref checks
Against 4 types inline ref.
Checks bytenr alignment and tree level.
- btrfs_extent_item::refs check
Check against total refs found in inline refs.
This check would be the most complex single item check due to its nature
of inlined items.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This patch will introduce ROOT_ITEM check, which includes:
- Key->objectid and key->offset check
Currently only some easy check, e.g. 0 as rootid is invalid.
- Item size check
Root item size is fixed.
- Generation checks
Generation, generation_v2 and last_snapshot should not be greater than
super generation + 1
- Level and alignment check
Level should be in [0, 7], and bytenr must be aligned to sector size.
- Flags check
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=203261
Reported-by: Jungyeon Yoon <jungyeon.yoon@gmail.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Under certain conditions, we could have strange file extent item in log
tree like:
item 18 key (69599 108 397312) itemoff 15208 itemsize 53
extent data disk bytenr 0 nr 0
extent data offset 0 nr 18446744073709547520 ram 18446744073709547520
The num_bytes + ram_bytes overflow 64 bit type.
For num_bytes part, we can detect such overflow along with file offset
(key->offset), as file_offset + num_bytes should never go beyond u64.
For ram_bytes part, it's about the decompressed size of the extent, not
directly related to the size.
In theory it is OK to have a large value, and put extra limitation
on RAM bytes may cause unexpected false alerts.
So in tree-checker, we only check if the file offset and num bytes
overflow.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Having file extent items with ranges that overlap each other is a
serious issue that leads to all sorts of corruptions and crashes (like a
BUG_ON() during the course of __btrfs_drop_extents() when it traims file
extent items). Therefore teach the tree checker to detect such cases.
This is motivated by a recently fixed bug (race between ranged full
fsync and writeback or adjacent ranges).
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Allowing error injection for btrfs_check_leaf_full() and
btrfs_check_node() is useful to test the failure path of btrfs write
time tree check.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Commit 1ba98d086f ("Btrfs: detect corruption when non-root leaf has
zero item") introduced comprehensive root owner checker.
However it's pretty expensive tree search to locate the owner root,
especially when it get reused by mandatory read and write time
tree-checker.
This patch will remove that check, and completely rely on owner based
empty leaf check, which is much faster and still works fine for most
case.
And since we skip the old root owner check, now write time tree check
can be merged with btrfs_check_leaf_full().
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
