Re: [PATCH for-next v4 0/5] null_blk: improve write failure simulation

On 1/21/25 00:15, Shin'ichiro Kawasaki wrote:

Currently, null_blk has 'badblocks' parameter to simulate IO failures
for broken blocks. This helps checking if userland tools can handle IO
failures. However, this badblocks feature has two differences from the
IO failures on real storage devices. Firstly, when write operations fail
for the badblocks, null_blk does not write any data, while real storage
devices sometimes do partial data write. Secondly, null_blk always make
write operations fail for the specified badblocks, while real storage
devices can recover the bad blocks so that next write operations can
succeed after failure. Hence, real storage devices are required to check
if userland tools support such partial writes or bad blocks recovery.

This series improves write failure simulation by null_blk to allow
checking userland tools without real storage devices. The first patch
is a preparation to make new feature addition simpler. The second patch
introduces the 'badblocks_once' parameter to simulate bad blocks
recovery. The third patch fixes a bug, and the fourth patch adds a
function argument to prepare for the fifth patch. The fifth patch adds
the partial IO support and introduces the 'badblocks_partial_io'
parameter.

Looks good.

Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>

-ck