linux_dsm_epyc7002/fs/btrfs
Filipe Manana ac765f83f1 Btrfs: fix data corruption due to cloning of eof block
We currently allow cloning a range from a file which includes the last
block of the file even if the file's size is not aligned to the block
size. This is fine and useful when the destination file has the same size,
but when it does not and the range ends somewhere in the middle of the
destination file, it leads to corruption because the bytes between the EOF
and the end of the block have undefined data (when there is support for
discard/trimming they have a value of 0x00).

Example:

 $ mkfs.btrfs -f /dev/sdb
 $ mount /dev/sdb /mnt

 $ export foo_size=$((256 * 1024 + 100))
 $ xfs_io -f -c "pwrite -S 0x3c 0 $foo_size" /mnt/foo
 $ xfs_io -f -c "pwrite -S 0xb5 0 1M" /mnt/bar

 $ xfs_io -c "reflink /mnt/foo 0 512K $foo_size" /mnt/bar

 $ od -A d -t x1 /mnt/bar
 0000000 b5 b5 b5 b5 b5 b5 b5 b5 b5 b5 b5 b5 b5 b5 b5 b5
 *
 0524288 3c 3c 3c 3c 3c 3c 3c 3c 3c 3c 3c 3c 3c 3c 3c 3c
 *
 0786528 3c 3c 3c 3c 00 00 00 00 00 00 00 00 00 00 00 00
 0786544 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 *
 0790528 b5 b5 b5 b5 b5 b5 b5 b5 b5 b5 b5 b5 b5 b5 b5 b5
 *
 1048576

The bytes in the range from 786532 (512Kb + 256Kb + 100 bytes) to 790527
(512Kb + 256Kb + 4Kb - 1) got corrupted, having now a value of 0x00 instead
of 0xb5.

This is similar to the problem we had for deduplication that got recently
fixed by commit de02b9f6bb ("Btrfs: fix data corruption when
deduplicating between different files").

Fix this by not allowing such operations to be performed and return the
errno -EINVAL to user space. This is what XFS is doing as well at the VFS
level. This change however now makes us return -EINVAL instead of
-EOPNOTSUPP for cases where the source range maps to an inline extent and
the destination range's end is smaller then the destination file's size,
since the detection of inline extents is done during the actual process of
dropping file extent items (at __btrfs_drop_extents()). Returning the
-EINVAL error is done early on and solely based on the input parameters
(offsets and length) and destination file's size. This makes us consistent
with XFS and anyone else supporting cloning since this case is now checked
at a higher level in the VFS and is where the -EINVAL will be returned
from starting with kernel 4.20 (the VFS changed was introduced in 4.20-rc1
by commit 07d19dc9fb ("vfs: avoid problematic remapping requests into
partial EOF block"). So this change is more geared towards stable kernels,
as it's unlikely the new VFS checks get removed intentionally.

A test case for fstests follows soon, as well as an update to filter
existing tests that expect -EOPNOTSUPP to accept -EINVAL as well.

CC: <stable@vger.kernel.org> # 4.4+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-11-06 16:42:41 +01:00
..
tests btrfs: tests: add separate stub for find_lock_delalloc_range 2018-10-15 17:23:34 +02:00
acl.c btrfs: remove unnecessary curly braces in btrfs_get_acl 2018-08-06 13:12:41 +02:00
async-thread.c btrfs: replace GPL boilerplate by SPDX -- sources 2018-04-12 16:29:51 +02:00
async-thread.h btrfs: replace GPL boilerplate by SPDX -- headers 2018-04-12 16:29:46 +02:00
backref.c Btrfs: preftree: use rb_first_cached 2018-10-15 17:23:33 +02:00
backref.h btrfs: replace GPL boilerplate by SPDX -- headers 2018-04-12 16:29:46 +02:00
btrfs_inode.h btrfs: Remove 'objectid' member from struct btrfs_root 2018-10-15 17:23:25 +02:00
check-integrity.c Btrfs: use args in the correct order for kcalloc in btrfsic_read_block 2018-10-15 17:23:30 +02:00
check-integrity.h btrfs: replace GPL boilerplate by SPDX -- headers 2018-04-12 16:29:46 +02:00
compression.c btrfs: remove unused pointer 'tree' in btrfs_submit_compressed_read 2018-10-15 17:23:28 +02:00
compression.h btrfs: compression: Add linux/sizes.h for compression.h 2018-05-29 18:13:00 +02:00
ctree.c Btrfs: fix deadlock when writing out free space caches 2018-10-17 17:46:24 +02:00
ctree.h Btrfs: fix deadlock on tree root leaf when finding free extent 2018-11-06 16:42:32 +01:00
dedupe.h btrfs: replace GPL boilerplate by SPDX -- headers 2018-04-12 16:29:46 +02:00
delayed-inode.c Btrfs: kill btrfs_clear_path_blocking 2018-10-15 17:23:38 +02:00
delayed-inode.h Btrfs: delayed-inode: use rb_first_cached for ins_root and del_root 2018-10-15 17:23:33 +02:00
delayed-ref.c btrfs: delayed-ref: extract find_first_ref_head from find_ref_head 2018-10-17 19:21:00 +02:00
delayed-ref.h btrfs: delayed-ref: pass delayed_refs directly to btrfs_delayed_ref_lock 2018-10-15 17:23:41 +02:00
dev-replace.c btrfs: dev-replace: remove pointless assert in write unlock 2018-10-15 17:23:38 +02:00
dev-replace.h btrfs: open code btrfs_after_dev_replace_commit 2018-10-15 17:23:37 +02:00
dir-item.c btrfs: Remove root parameter from btrfs_insert_dir_item 2018-10-15 17:23:25 +02:00
disk-io.c btrfs: fix pinned underflow after transaction aborted 2018-11-06 16:41:34 +01:00
disk-io.h btrfs: unify end_io callbacks of async_submit_bio 2018-08-06 13:12:55 +02:00
export.c btrfs: Remove 'objectid' member from struct btrfs_root 2018-10-15 17:23:25 +02:00
export.h btrfs: replace GPL boilerplate by SPDX -- headers 2018-04-12 16:29:46 +02:00
extent_io.c btrfs: tests: add separate stub for find_lock_delalloc_range 2018-10-15 17:23:34 +02:00
extent_io.h btrfs: tests: add separate stub for find_lock_delalloc_range 2018-10-15 17:23:34 +02:00
extent_map.c Btrfs: extent_map: use rb_first_cached 2018-10-15 17:23:33 +02:00
extent_map.h Btrfs: extent_map: use rb_first_cached 2018-10-15 17:23:33 +02:00
extent-tree.c btrfs: fix insert_reserved error handling 2018-10-19 12:20:03 +02:00
file-item.c btrfs: simplify pointer chasing of local fs_info variables 2018-08-06 13:12:43 +02:00
file.c btrfs: move the dio_sem higher up the callchain 2018-10-19 12:20:04 +02:00
free-space-cache.c Btrfs: fix deadlock on tree root leaf when finding free extent 2018-11-06 16:42:32 +01:00
free-space-cache.h btrfs: replace GPL boilerplate by SPDX -- headers 2018-04-12 16:29:46 +02:00
free-space-tree.c btrfs: Remove fs_info from btrfs_del_root 2018-08-06 13:13:00 +02:00
free-space-tree.h btrfs: Remove fs_info argument from add_to_free_space_tree 2018-05-28 18:07:36 +02:00
inode-item.c btrfs: replace GPL boilerplate by SPDX -- sources 2018-04-12 16:29:51 +02:00
inode-map.c btrfs: prune unused includes 2018-08-06 13:12:43 +02:00
inode-map.h btrfs: replace GPL boilerplate by SPDX -- headers 2018-04-12 16:29:46 +02:00
inode.c Btrfs: fix deadlock on tree root leaf when finding free extent 2018-11-06 16:42:32 +01:00
ioctl.c Btrfs: fix data corruption due to cloning of eof block 2018-11-06 16:42:41 +01:00
Kconfig btrfs: add SPDX header to Kconfig 2018-04-12 16:29:55 +02:00
locking.c btrfs: replace waitqueue_actvie with cond_wake_up 2018-05-28 18:23:09 +02:00
locking.h btrfs: replace GPL boilerplate by SPDX -- headers 2018-04-12 16:29:46 +02:00
lzo.c btrfs: lzo: Harden inline lzo compressed extent decompression 2018-05-30 16:46:43 +02:00
Makefile btrfs: Remove custom crc32c init code 2018-03-26 15:09:39 +02:00
math.h btrfs: replace GPL boilerplate by SPDX -- headers 2018-04-12 16:29:46 +02:00
ordered-data.c btrfs: prune unused includes 2018-08-06 13:12:43 +02:00
ordered-data.h btrfs: remove remaing full_sync logic from btrfs_sync_file 2018-08-06 13:12:31 +02:00
orphan.c btrfs: replace GPL boilerplate by SPDX -- sources 2018-04-12 16:29:51 +02:00
print-tree.c btrfs: annotate unlikely branches after V0 extent type removal 2018-08-06 13:12:41 +02:00
print-tree.h btrfs: print-tree: debugging output enhancement 2018-04-20 19:18:16 +02:00
props.c btrfs: property: Set incompat flag if lzo/zstd compression is set 2018-05-17 14:18:25 +02:00
props.h btrfs: replace GPL boilerplate by SPDX -- headers 2018-04-12 16:29:46 +02:00
qgroup.c btrfs: qgroup: move the qgroup->members check out from (!qgroup)'s else branch 2018-10-15 17:23:40 +02:00
qgroup.h btrfs: qgroup: Avoid calling qgroup functions if qgroup is not enabled 2018-10-15 17:23:40 +02:00
raid56.c btrfs: raid56: catch errors from full_stripe_write 2018-08-06 13:12:45 +02:00
raid56.h btrfs: replace GPL boilerplate by SPDX -- headers 2018-04-12 16:29:46 +02:00
rcu-string.h btrfs: replace GPL boilerplate by SPDX -- headers 2018-04-12 16:29:46 +02:00
reada.c btrfs: prune unused includes 2018-08-06 13:12:43 +02:00
ref-verify.c btrfs: Remove 'objectid' member from struct btrfs_root 2018-10-15 17:23:25 +02:00
ref-verify.h btrfs: replace GPL boilerplate by SPDX -- headers 2018-04-12 16:29:46 +02:00
relocation.c btrfs: relocation: Remove redundant tree level check 2018-10-15 17:23:40 +02:00
root-tree.c btrfs: Remove fs_info from btrfs_add_root_ref 2018-08-06 13:13:00 +02:00
scrub.c btrfs: open code btrfs_dev_replace_stats_inc 2018-10-15 17:23:37 +02:00
send.c Btrfs: unify error handling of btrfs_lookup_dir_item 2018-10-15 17:23:30 +02:00
send.h btrfs: replace GPL boilerplate by SPDX -- headers 2018-04-12 16:29:46 +02:00
struct-funcs.c btrfs: prune unused includes 2018-08-06 13:12:43 +02:00
super.c btrfs: avoid link error with CONFIG_NO_AUTO_INLINE 2018-11-06 16:42:08 +01:00
sysfs.c btrfs: prune unused includes 2018-08-06 13:12:43 +02:00
sysfs.h btrfs: sysfs: Use enum/define value for feature array definitions 2018-05-28 18:23:39 +02:00
transaction.c btrfs: don't run delayed_iputs in commit 2018-10-19 12:20:03 +02:00
transaction.h btrfs: replace get_seconds with new 64bit time API 2018-08-06 13:12:29 +02:00
tree-checker.c btrfs: tree-checker: Fix misleading group system information 2018-11-06 16:41:53 +01:00
tree-checker.h btrfs: replace GPL boilerplate by SPDX -- headers 2018-04-12 16:29:46 +02:00
tree-defrag.c btrfs: replace GPL boilerplate by SPDX -- sources 2018-04-12 16:29:51 +02:00
tree-log.c Btrfs: fix missing data checksums after a ranged fsync (msync) 2018-11-06 16:41:40 +01:00
tree-log.h btrfs: change btrfs_pin_log_trans to return void 2018-10-15 17:23:27 +02:00
ulist.c btrfs: replace GPL boilerplate by SPDX -- sources 2018-04-12 16:29:51 +02:00
ulist.h btrfs: replace GPL boilerplate by SPDX -- headers 2018-04-12 16:29:46 +02:00
uuid-tree.c btrfs: Remove fs_info argument from btrfs_uuid_tree_rem 2018-05-30 16:46:53 +02:00
volumes.c btrfs: open code btrfs_dev_replace_clear_lock_blocking 2018-10-15 17:23:37 +02:00
volumes.h btrfs: Make btrfs_find_device_by_devspec return btrfs_device directly 2018-10-15 17:23:30 +02:00
xattr.c btrfs: replace GPL boilerplate by SPDX -- sources 2018-04-12 16:29:51 +02:00
xattr.h btrfs: replace GPL boilerplate by SPDX -- headers 2018-04-12 16:29:46 +02:00
zlib.c btrfs: replace GPL boilerplate by SPDX -- sources 2018-04-12 16:29:51 +02:00
zstd.c btrfs: replace GPL boilerplate by SPDX -- sources 2018-04-12 16:29:51 +02:00