Hi Tytso,
Tune2fs does not recognize writes to the manipulated filesystem in another
namespace, there will be two simultaneous write operations on a
block, resulting in filesystem inconsistencies.
The operation is as follows:
first terminal second terminal
mkfs.ext4 /dev/sdb;
mount /dev/sdb /test-sdb;
dd if=/dev/zero of=/test-sdb/test1 bs=1M count=100;
unshare -m;
umount;
gdb tune2fs;
b io_channel_write_byte
r -e remount-ro /dev/sdb
c(Write a byte of old data into the cache)
exit;
(gdb finish)
tune2fs -l /dev/sdb;
tune2fs 1.46.4 (18-Aug-2021)
tune2fs: Superblock checksum does not match superblock while trying to
open /dev/sdb
Couldn't find valid filesystem superblock.
- bin.
