GNU bug report logs - #79267
cp --sparse=auto heuristic fails on a squashfs mounted drive.

Previous Next

Package: coreutils;

Reported by: Jeremy Allison <jallison <at> ciq.com>

Date: Tue, 19 Aug 2025 02:39:02 UTC

Severity: normal

Full log

Message #30 received at submit <at> debbugs.gnu.org (full text, mbox):

From: Phillip Lougher <phillip <at> squashfs.org.uk>
To: P <at> draigBrady.com
Cc: bug-coreutils <at> gnu.org
Subject: bug#79267: cp --sparse=auto heuristic fails on a squashfs mounted
 drive.
Date: Sat, 23 Aug 2025 05:26:26 +0100

Padraig Brady wrote:

> with --sparse=always. squashfs is giving the wrong info here after 
all, right?

No Squashfs is not giving the wrong information here.

Support for SEEK_HOLE/SEEK_DATA is not mandated, and no Linux filesystem 
is required to support it.

What you are seeing here is the default Linux VFS behaviour.

See 
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/fs/read_write.c#n102

Phillip

---
Squashfs author and maintainer
This bug report was last modified 17 days ago.

Previous Next

GNU bug tracking system
Copyright (C) 1999 Darren O. Benham, 1997,2003 nCipher Corporation Ltd, 1994-97 Ian Jackson.