generic: regression test of ext4_lblk_t overflow

Append writes to a file with logical block numbers close to 0xffffffff and
observe if a kernel crash is caused by ext4_lblk_t overflow triggering
BUG_ON at ext4_mb_new_inode_pa(). This is a regression test for commit
bc056e7163ac ("ext4: fix BUG in ext4_mb_new_inode_pa() due to overflow")

Signed-off-by: Baokun Li <>
Reviewed-by: Zorro Lang <>
Reviewed-by: "Darrick J. Wong" <>
Signed-off-by: Zorro Lang <>
2 files changed