Re: bin/56300: gpt useless on gpt labels extending beyond disk size (also affects sysinst)

[David Brownlee <abs%absd.org@localhost>]

The following reply was made to PR bin/56300; it has been noted by GNATS.

From: David Brownlee <abs%absd.org@localhost>
To: gnats-bugs%netbsd.org@localhost
Cc: gnats-admin%netbsd.org@localhost, netbsd-bugs%netbsd.org@localhost
Subject: Re: bin/56300: gpt useless on gpt labels extending beyond disk size
 (also affects sysinst)
Date: Sun, 6 Aug 2023 15:15:05 +0100

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 Just hit this when trying to adjust some gpt-in-ccd settings
 
 Also - easy case to reproduce (without the 'gpt add' step it does not
 trigger)
 
 dd if=/dev/zero bs=1m count=10 > test.img
 gpt create test.img
 gpt add -t ffs test.img
 dd if=test.img of=smaller.img bs=1m count=9
 gpt destroy smaller.img
 
 One thought, there could be some kind of force option to bypass the size
 check - possibly by truncating or ignoring oversized entries, which could
 be useful for recovering damaged disk images
 
 Thanks
 
 David
 
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 <div dir=3D"ltr"><div>Just hit this when trying to adjust some gpt-in-ccd s=
 ettings</div><div><br></div><div>Also - easy case to reproduce (without the=
  &#39;gpt add&#39; step it does not trigger)<br></div><div><br></div><div>d=
 d if=3D/dev/zero bs=3D1m count=3D10 &gt; test.img</div><div>gpt create test=
 .img</div><div>gpt add -t ffs test.img <br></div><div>dd if=3Dtest.img of=
 =3Dsmaller.img bs=3D1m count=3D9</div><div>gpt destroy smaller.img</div><di=
 v><br></div><div>One thought, there could be some kind of force option to b=
 ypass the size check - possibly by truncating or ignoring oversized entries=
 , which could be useful for recovering damaged disk images</div><div><br></=
 div><div>Thanks</div><div><br></div><div>David<br></div></div>
 
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