RE: Problems with loopback device

Ray Van Tassle-CRV004 (Ray_Van_Tassle-CRV004@email.mot.com)
Fri, 3 Jan 1997 10:16:44 -0600


Send me a script that duplicates this problem, and I'll look at it.

Regards,
Ray
________________________________________________________
To: linux-kernel@vger.rutgers.edu@INTERNET
From: hjw@zvw.de@INTERNET on Fri, Jan 3, 1997 3:43 AM
Subject: z-Problems with loopback device

In order to test my newly written mkaffs, I decided to
create a 'filesystem' using the loopback device. This
way nothing much could happen and it would be easy and
fast to look at the result by just hex-dumping it.
So I created an empty image with 'dd if=/dev/zero
of=fs.img count=1760'. Attaching this to /dev/loop0
worked, but it wasn't usable:

Dec 27 13:40:42 savong kernel: loop: block 513 not present
Dec 27 13:40:42 savong kernel: end_request: I/O error, dev 07:00, sector
1027
Dec 27 13:40:42 savong kernel: loop: block 4 not present
Dec 27 13:40:42 savong kernel: end_request: I/O error, dev 07:00, sector
8
Dec 27 13:40:42 savong kernel: loop: block 4 not present
Dec 27 13:40:42 savong kernel: end_request: I/O error, dev 07:00, sector
9
[...]

It seems as if the loopback device didn't like sparse
files. When I took 1760 blocks from a non-empty file
everything worked. Is this intended behaviour?

jbhr