Re: [PATCH v2] generic/795: add unaligned boundary test cases for WRITE_ZEROES

On 7/10/26 10:23, Zhang Yi wrote:
> +CC ext4 list
> 
> On 7/9/2026 4:30 PM, Pankaj Raghav wrote:
>> During the review of WRITE_ZEROES support to XFS, Zhang Yi pointed out
>> some important semantics for the boundary blocks when WRITE_ZEROES
>> command is used.[1]
>>
>> The test cases check the boundary blocks when they are in different
>> states and WRITE_ZEROES are issued that straddle the boundary. Along with that,
>> test cases have been added when a EoF straddles an allocation unit.
>>
>> [1] https://lore.kernel.org/linux-xfs/[email protected]/
>>
>> Signed-off-by: Pankaj Raghav <[email protected]>
> 
> Thank you for the test! The changes look good to me, and it works well
> with my ext4 fixes as well.
> 
> Reviewed-by: Zhang Yi <[email protected]>
> 

Thanks.

> Unfortunately, I've found a bug in filefrag that causes delalloc extents
> to be reported with a length of 0. This means this test case can miss
> delalloc extents. The issue is in misc/filefrag.c's print_extent_info(),
> where ext_len is incorrectly set to 0 for the FIEMAP_EXTENT_UNKNOWN or
> EXT4_FIEMAP_EXTENT_HOLE cases. Could you please send a patch to fix this
> as well?
>


I think I see it here:
	if ((fm_extent->fe_flags & FIEMAP_EXTENT_UNKNOWN) ||
	    (fm_extent->fe_flags & EXT4_FIEMAP_EXTENT_HOLE)) {
		ext_len = 0;
		ext_blks_phys = 0;
	} else
		ext_blks_phys = ext_blks;

I will send a fix soon as a separate patch.

--
Pankaj