"df" shows used space is not accurate

[frostwind]

What happened:
We use Ceph 16.2.x RADOS as backend storage and use PostgreSQL 17 as metadata storage. After many operation of rsync/juicefs sync, "df" is showing much larger space usage(263GB) than its real use in both RADOS pool(29GB) and "du -sh " on juicefs. Seems "df" used space is reported from jfs_counter.usedSpace. I've tried all the command available in juicefs, eg gc/fsck/compact but none of them help to fix it. Seems there is not providing a function to recalculate jfs_counter.usedSpace from underlying metadata , if there is any available function to do so , please let me know. Thanks

[root@vbakjob05 jfs]# df -h
Filesystem Size Used Avail Use% Mounted on
JuiceFS:myjfs 2.0P 263G 2.0P 1% /jfs

[root@ceph1 ~]# ceph df|grep jfs
--- POOLS ---
POOL ID PGS STORED OBJECTS USED %USED MAX AVAIL
jfs 59 32 29 GiB 57.34k 85 GiB 0.02 119 TiB

[root@vbakjob05 jfs]# du -sh
29G .

postgresql metadata

jfs=# select * from jfs_counter;
name | value
---------------------+--------------
nextTrash | 7
nextSession | 32
nextInode | 507906
lastCleanupFiles | 1727581443
nextCleanupSlices | 1727581457
lastCleanupSessions | 1727581492
nextChunk | 475137
lastCleanupTrash | 1727578016
usedSpace | 281507139584
totalInodes | 251264
(10 rows)

Environment:

• JuiceFS version (use juicefs --version) or Hadoop Java SDK version: juicefs version 1.2.1+2024-08-30.cd871d19ba57 (compiled with juicefs.ceph)
• Cloud provider or hardware configuration running JuiceFS: --self hosted
• OS (e.g cat /etc/os-release):Rocky Linux release 8.8 (Green Obsidian)
• Kernel (e.g. uname -a): 4.18.0-477.27.1.el8_8.x86_64 #1 SMP Wed Sep 20 15:55:39 UTC 2023 x86_64 x86_64 x86_64 GNU/Linux
• Object storage (cloud provider and region, or self maintained): self hosted ceph 16.2.7 RADOS
• Metadata engine info (version, cloud provider managed or self maintained): postgresql 17
• Network connectivity (JuiceFS to metadata engine, JuiceFS to object storage): on-prem DC internal traffic
• Others:

[davies]

We should provide a way to fix it.