I enlarged an encrypted lvm ext4 partition from ~100 to 160gb. Afterwards, I ran fstrim and got a "Bad message" error. I ran it again and got a "bad block bitmap checksum". In detail: I ran e2fsck -n /dev/mapper/xmnt-db while mounted, which showed some bitmap differences but no other errors. I then ran resize2fs /dev/mapper/xmnt-db: resize2fs 1.44.5 (15-Dec-2018) Filesystem at /dev/mapper/xmnt-db is mounted on /db; on-line resizing required old_desc_blocks = 13, new_desc_blocks = 19 The filesystem on /dev/mapper/xmnt-db is now 39321600 (4k) blocks long. kernel messages: [524855.273199] EXT4-fs (dm-24): resizing filesystem from 26214400 to 39321600 blocks [524855.273202] EXT4-fs (dm-24): Converting file system to meta_bg [524855.516896] EXT4-fs (dm-24): resized filesystem to 39321600 I then immediately ran fstrim on the filesystem and got: fstrim: /db: FITRIM ioctl failed: Bad message Which struck me as quite odd :) After looking around a bit I re-ran fstrim and got message: fstrim: /db: FITRIM ioctl failed: Structure needs cleaning And this kernel message: [524880.940693] EXT4-fs error (device dm-24): ext4_validate_block_bitmap:376: comm fstrim: bg 63: bad block bitmap checksum And lo and behold, e2fsck -n now also complains in addition to bitmap differences: Block bitmap differences: Group 63 block bitmap does not match checksum. IGNORED. The filesystem was (probably) formatted like this: mke2fs -t ext4 -b 4096 -E lazy_itable_init=0,lazy_journal_init=0,packed_meta_blocks=1 -N 65536 -L DB -O extents,filetype,dir_index,^flex_bg,^has_journal,^resize_inode,sparse_super,^uninit_bg -v And it is force-checked on every mount (the last of which was 6 days before). My assumption is that ext4 will not immediately destrroy my data and, on the next possible point in time, will unmount and e2fsck the filesystem. I do not require assistance (or any feedback :), but I also might not be able to debug this much further, so feel free to just close if not helpful. tune2fs -l output: tune2fs 1.44.5 (15-Dec-2018) Filesystem volume name: DB Last mounted on: /db Filesystem UUID: 2f3e32c4-8150-46bc-8139-cb9a1e67d55e Filesystem magic number: 0xEF53 Filesystem revision #: 1 (dynamic) Filesystem features: ext_attr dir_index filetype meta_bg extent 64bit sparse_super large_file huge_file dir_nlink extra_isize metadata_csum Filesystem flags: signed_directory_hash Default mount options: user_xattr acl Filesystem state: not clean with errors Errors behavior: Continue Filesystem OS type: Linux Inode count: 115200 Block count: 39321600 Reserved block count: 1835048 Free blocks: 20843524 Free inodes: 114673 First block: 0 Block size: 4096 Fragment size: 4096 Group descriptor size: 64 Blocks per group: 32768 Fragments per group: 32768 Inodes per group: 96 Inode blocks per group: 6 First meta block group: 13 Filesystem created: Fri Nov 30 20:35:51 2018 Last mount time: Wed Jan 29 22:08:01 2020 Last write time: Tue Feb 4 23:53:37 2020 Mount count: 1 Maximum mount count: -1 Last checked: Wed Jan 29 22:08:00 2020 Check interval: 0 (<none>) Lifetime writes: 1121 GB Reserved blocks uid: 0 (user root) Reserved blocks gid: 0 (group root) First inode: 11 Inode size: 256 Required extra isize: 32 Desired extra isize: 32 Default directory hash: half_md4 Directory Hash Seed: 06460dbe-b67f-4c81-9293-53599ec2349e FS Error count: 1 First error time: Tue Feb 4 23:53:37 2020 First error function: ext4_validate_block_bitmap First error line #: 376 First error inode #: 0 First error block #: 0 Last error time: Tue Feb 4 23:53:37 2020 Last error function: ext4_validate_block_bitmap Last error line #: 376 Last error inode #: 0 Last error block #: 0 Checksum type: crc32c Checksum: 0x17079f52
I was able to umount the filesystem and ran e2fsck, which offered: Inode 34852 extent tree (at level 2) could be narrower. Optimize<y>? yes And then went on to correct bitmpa differences - no sign of the bitmap block checksum error. Afterwards, I mounted again and now fstrim works without complaints.