Bug#550010: CONFIG_LBD has gone missing sometime after 2.6.18

2009-10-07 Thread Dan Dennison 

$ ls /boot/config*
/boot/config-2.6.18-6-amd64 /boot/config-2.6.29-2-amd64
/boot/config-2.6.26-1-amd64 /boot/config-2.6.30-1-amd64

$ grep LBD /boot/config*
/boot/config-2.6.18-6-amd64:CONFIG_LBD=y

Is it at all concerning that the sd driver tries a read capacity 16 and
fails?

I propose the following sequence of events:

1) 'sd' block device tries to read capacity 16 and fails because CONFIG_LBD
is not asserted, defaulting to a size of 2TB
2) 'hfsplus' then tries to mount this larger-than-2TB filesystem and is
successful
3) Writes to this inappropriately mounted filesystem fail once they run off
of the edge

I submit that the proposed patch is in error, and that hfsplus does very
well support 2TB filesystems on Linux. Further, hfsplus and all filesystem
drivers should check for the degenerate case of block device 

Dan Dennison

Bug#550010: CONFIG_LBD has gone missing sometime after 2.6.18

2009-10-07 Thread Ben Hutchings 
On Wed, 2009-10-07 at 16:26 -0400, Dan Dennison wrote:
 $ ls /boot/config*
 /boot/config-2.6.18-6-amd64  /boot/config-2.6.29-2-amd64
 /boot/config-2.6.26-1-amd64  /boot/config-2.6.30-1-amd64
 
 $ grep LBD /boot/config*
 /boot/config-2.6.18-6-amd64:CONFIG_LBD=y

CONFIG_LBD is irrelevant on 64-bit architectures.

 Is it at all concerning that the sd driver tries a read capacity 16
 and fails?
 
 I propose the following sequence of events:
 
 1) 'sd' block device tries to read capacity 16 and fails because
 CONFIG_LBD is not asserted, defaulting to a size of 2TB
 2) 'hfsplus' then tries to mount this larger-than-2TB filesystem and
 is successful
 3) Writes to this inappropriately mounted filesystem fail once they
 run off of the edge
 
 I submit that the proposed patch is in error, and that hfsplus does
 very well support 2TB filesystems on Linux.
[...]

For starters, hfsplus_get_block() calculates a sector number using
32-bit values.  Even on 64-bit architectures.

Ben.

-- 
Ben Hutchings
To err is human; to really foul things up requires a computer.


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Bug#550010: CONFIG_LBD has gone missing sometime after 2.6.18

2009-10-07 Thread Dan Dennison 
-original message-
From: Ben Hutchings b...@decadent.org.uk
To: Dan Dennison d...@thedennisons.org, 550...@bugs.debian.org
Date: Wed, 07 Oct 2009 23:02:40 +0100
-
 CONFIG_LBD is irrelevant on 64-bit architectures.

Good to know.

 I propose the following sequence of events:
 
 1) 'sd' block device tries to read capacity 16 and fails because
 CONFIG_LBD is not asserted, defaulting to a size of 2TB

So _something_else_ is causing read capacity 16 to fail in this case.
Thoughts?

dan :)





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