Created attachment 303733 [details]
mdb_copy reproducer

1. Please describe the problem:

The mdb_copy operation on btrfs produces a corrupted database. It works just fine on ext4!

Requirements:
sudo dnf install lmdb


## BTRFS

$ tar xf mdb_copy_reproducer.tar.xz            
$ ./reproducer.sh              
Current directory: /home/asn/mdb

Filesystem information for current directory:
Filesystem                                            Type  1024-blocks      Used Available Capacity Mounted on
/dev/mapper/luks-feea5c33-1033-4e33-a507-4ea83cbaf610 btrfs   248378368 209424480  37336592      85% /home

Checksum of samba-dc.ldb: 2307b6aef35ee923c9f9c2f02541ca72760116a39cad62d8455e972cddcabd0a

Backup samba-dc.ldb with mdb_copy to samba-dc.ldb.backup
LMDB 0.9.29: (March 16, 2021)


Checksum of samba-dc.ldb.backup: e9f8ede21831aec0da3897b5880b3008761fb8942d0f4fe086c637319fde4c61

FATAL: The checksums don't match!


## EXT4


$ ./reproducer.sh 
Current directory: /home/asn/mdb

Filesystem information for current directory:
Filesystem         Type 1024-blocks       Used Available Capacity Mounted on
/dev/mapper/cr_md1 ext4  1921722432 1752912108  71118376      97% /home

Checksum of samba-dc.ldb: 2307b6aef35ee923c9f9c2f02541ca72760116a39cad62d8455e972cddcabd0a

Backup samba-dc.ldb with mdb_copy to samba-dc.ldb.backup
LMDB 0.9.29: (March 16, 2021)


Checksum of samba-dc.ldb.backup: 2307b6aef35ee923c9f9c2f02541ca72760116a39cad62d8455e972cddcabd0a

The checksums match



2. What is the Version-Release number of the kernel:

Linux krikkit 6.1.9-200.fc37.x86_64 #1 SMP PREEMPT_DYNAMIC Thu Feb  2 00:21:48 UTC 2023 x86_64 x86_64 x86_64 GNU/Linux

3. Did it work previously?

It also fails on Fedora 36:

Linux samba-cli01 6.0.5-200.fc36.x86_64 #1 SMP PREEMPT_DYNAMIC Wed Oct 26 15:55:21 UTC 2022 x86_64 x86_64 x86_64 GNU/Linux