The patch from LU-7325 fixes this issue: "Hitting "LDISKFS-fs error (device md66): ldiskfs_xattr_inode_iget: error while reading EA inode -2147483347" on large MDT volumes with large_xattr feature enabled."
This test should be added:
1. MDS should have more than 2G inodes
2. mdt fs should be created with large_xattr flag.
3. set inode_goal to get higher inode number allocated.
echo 2147483947 > /sys/fs/ldiskfs/md66/inode_goal
3. create a file
4. start adding hard links to that file