Subject: Re: bug#79267: cp --sparse=auto heuristic fails on a squashfs mounted drive.

From: Paul Eggert <[email-masked]>
Date: Sat, 23 Aug 2025 09:46:38 -0700

On 2025-08-22 19:11, Phillip Lougher wrote:
> any Squashfs SEEK_HOLE/SEEK_DATA implementation will not
> behave like other Linux filesystems, because it won't report sparseness
> at the 4K granularity that most people or programs will expect it to.

Coreutils doesn't expect 4 KiB granularity for LSEEK_DATA+LSEEK_HOLE, 
and I don't know of any programs that do expect it. I fail to see why 
squashfs should penalize the performance of core programs like 'cp' 
merely because some (which?) programs are poorly written.