[patch 17/18] scsi: select CRC_T10DIF only when necessary

[patch 17/18] scsi: select CRC_T10DIF only when necessary

[akpm]

From: Stefan Richter <stefanr@s5r6.in-berlin.de>

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 drivers/scsi/Kconfig |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff -puN drivers/scsi/Kconfig~scsi-select-crc_t10dif-only-when-necessary drivers/scsi/Kconfig
--- a/drivers/scsi/Kconfig~scsi-select-crc_t10dif-only-when-necessary
+++ a/drivers/scsi/Kconfig
@@ -63,7 +63,7 @@ comment "SCSI support type (disk, tape, 
 config BLK_DEV_SD
 	tristate "SCSI disk support"
 	depends on SCSI
-	select CRC_T10DIF
+	select CRC_T10DIF if BLK_DEV_INTEGRITY
 	---help---
 	  If you want to use SCSI hard disks, Fibre Channel disks,
 	  Serial ATA (SATA) or Parallel ATA (PATA) hard disks,
_

Re: [patch 17/18] scsi: select CRC_T10DIF only when necessary

[Martin K. Petersen]

-	select CRC_T10DIF
+	select CRC_T10DIF if BLK_DEV_INTEGRITY

Acked-by: Martin K. Petersen <martin.petersen@oracle.com>

-- 
Martin K. Petersen	Oracle Linux Engineering

Re: [patch 17/18] scsi: select CRC_T10DIF only when necessary

[James Bottomley]

On Thu, 2008-08-21 at 10:01 -0400, Martin K. Petersen wrote:
> -	select CRC_T10DIF
> +	select CRC_T10DIF if BLK_DEV_INTEGRITY
> 
> Acked-by: Martin K. Petersen <martin.petersen@oracle.com>

Actually, I don't think this is right at all.

This is a purely cosmetic fix and the tip of the iceberg.  If not
compiling in the integrity code matters on grounds of kernel bloat, and
I think it does, then the correct fix is to make sure none of it
compiles into SD if BLK_DEV_INTEGRITY isn't set.

James

Re: [patch 17/18] scsi: select CRC_T10DIF only when necessary

[Martin K. Petersen]

>>>>> "James" == James Bottomley <James.Bottomley@HansenPartnership.com> writes:

James> Actually, I don't think this is right at all.

James> This is a purely cosmetic fix and the tip of the iceberg.  If
James> not compiling in the integrity code matters on grounds of
James> kernel bloat, and I think it does, then the correct fix is to
James> make sure none of it compiles into SD if BLK_DEV_INTEGRITY
James> isn't set.

The only code that currently uses the T10 CRC is in sd_dif.c.  And
that file isn't compiled in if BLK_DEV_INTEGRITY isn't set.

-- 
Martin K. Petersen	Oracle Linux Engineering

Re: [patch 17/18] scsi: select CRC_T10DIF only when necessary

[James Bottomley]

On Thu, 2008-08-21 at 10:49 -0400, Martin K. Petersen wrote:
> >>>>> "James" == James Bottomley <James.Bottomley@HansenPartnership.com> writes:
> 
> James> Actually, I don't think this is right at all.
> 
> James> This is a purely cosmetic fix and the tip of the iceberg.  If
> James> not compiling in the integrity code matters on grounds of
> James> kernel bloat, and I think it does, then the correct fix is to
> James> make sure none of it compiles into SD if BLK_DEV_INTEGRITY
> James> isn't set.
> 
> The only code that currently uses the T10 CRC is in sd_dif.c.  And
> that file isn't compiled in if BLK_DEV_INTEGRITY isn't set.

Oh, OK ... I missed that bit, Thanks!

James