Re: [PATCH] ext4: reject delalloc to nodelalloc before applying remount options

[guzebing]

On 8/14/26 3:41 PM, Ojaswin Mujoo wrote:
> Can you please add an xfstests for this. The test can stress this path and
> then use the _check_dmesg_for helper to detect if there were any
> i_reserved_data_blocks related warnings.
> 
> Regards,
> ojaswin

Hi Ojaswin,

Thanks for the review.

I have posted the corresponding fstests regression test here:

https://lore.kernel.org/linux-ext4/20260818064023.2309786-1-guzebing1612@xxxxxxxxx/

The test stresses buffered write/truncate operations in parallel with
the expected-failing remount,nodelalloc operation, and checks dmesg for
leaked delayed allocation reservations during unmount.

Locally, the test fails on an affected kernel with
i_reserved_data_blocks not cleared warnings, and passes with this patch
applied.

Thanks,
Guzebing