[PATCH] [SCSI] sd: set BIO_MAPPED_INTEGRITY bit correctly in sd_dif_prepare().

[PATCH] [SCSI] sd: set BIO_MAPPED_INTEGRITY bit correctly in sd_dif_prepare().

[santosh nayak]

From: Santosh Nayak <santoshprasadnayak@gmail.com>

Value of BIO_MAPPED_INTEGRITY is 11. Intention was to set the 11th bit.

Signed-off-by: Santosh Nayak <santoshprasadnayak@gmail.com>
---
 drivers/scsi/sd_dif.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/drivers/scsi/sd_dif.c b/drivers/scsi/sd_dif.c
index e981d97..8ccaf53 100644
--- a/drivers/scsi/sd_dif.c
+++ b/drivers/scsi/sd_dif.c
@@ -408,7 +408,7 @@ int sd_dif_prepare(struct request *rq, sector_t hw_sector, unsigned int sector_s
 			kunmap_atomic(sdt);
 		}
 
-		bio->bi_flags |= BIO_MAPPED_INTEGRITY;
+		set_bit(BIO_MAPPED_INTEGRITY, &bio->bi_flags);
 	}
 
 	return 0;
-- 
1.7.4.4

Re: [PATCH] [SCSI] sd: set BIO_MAPPED_INTEGRITY bit correctly in sd_dif_prepare().

[Matthew Wilcox]

On Wed, Mar 07, 2012 at 08:11:35PM +0530, santosh nayak wrote:
> -		bio->bi_flags |= BIO_MAPPED_INTEGRITY;
> +		set_bit(BIO_MAPPED_INTEGRITY, &bio->bi_flags);

This uses an atomic operation; you should rather use __set_bit instead.

-- 
Matthew Wilcox				Intel Open Source Technology Centre
"Bill, look, we understand that you're interested in selling us this
operating system, but compare it to ours.  We can't possibly take such
a retrograde step."

Re: [PATCH] [SCSI] sd: set BIO_MAPPED_INTEGRITY bit correctly in sd_dif_prepare().

[Matthew Wilcox]

On Wed, Mar 07, 2012 at 08:11:35PM +0530, santosh nayak wrote:
> From: Santosh Nayak <santoshprasadnayak@gmail.com>
> 
> Value of BIO_MAPPED_INTEGRITY is 11. Intention was to set the 11th bit.

Also, can we introduce:

#define bio_set_flag(bio, flag)	((bio)->bi_flags |= (1 << (flag)))

Then hunt down and kill all the places that manipulate bi_flags by hand?
We might also need:

#define bio_set_flag_atomic(bio, flag) set_bit(&(bio)->bi_flags, (flag))

-- 
Matthew Wilcox				Intel Open Source Technology Centre
"Bill, look, we understand that you're interested in selling us this
operating system, but compare it to ours.  We can't possibly take such
a retrograde step."

Re: [PATCH] [SCSI] sd: set BIO_MAPPED_INTEGRITY bit correctly in sd_dif_prepare().

[santosh prasad nayak]

Thanks Matthew for your response.
I will resend the patch with required changes.


regards
Santosh

On Wed, Mar 7, 2012 at 9:26 PM, Matthew Wilcox <matthew@wil.cx> wrote:
> On Wed, Mar 07, 2012 at 08:11:35PM +0530, santosh nayak wrote:
>> From: Santosh Nayak <santoshprasadnayak@gmail.com>
>>
>> Value of BIO_MAPPED_INTEGRITY is 11. Intention was to set the 11th bit.
>
> Also, can we introduce:
>
> #define bio_set_flag(bio, flag) ((bio)->bi_flags |= (1 << (flag)))
>
> Then hunt down and kill all the places that manipulate bi_flags by hand?
> We might also need:
>
> #define bio_set_flag_atomic(bio, flag) set_bit(&(bio)->bi_flags, (flag))
>
> --
> Matthew Wilcox                          Intel Open Source Technology Centre
> "Bill, look, we understand that you're interested in selling us this
> operating system, but compare it to ours.  We can't possibly take such
> a retrograde step."

Re: [PATCH] [SCSI] sd: set BIO_MAPPED_INTEGRITY bit correctly in sd_dif_prepare().

[santosh prasad nayak]

On Wed, Mar 7, 2012 at 9:26 PM, Matthew Wilcox <matthew@wil.cx> wrote:
> On Wed, Mar 07, 2012 at 08:11:35PM +0530, santosh nayak wrote:
>> From: Santosh Nayak <santoshprasadnayak@gmail.com>
>>
>> Value of BIO_MAPPED_INTEGRITY is 11. Intention was to set the 11th bit.
>
> Also, can we introduce:
>
> #define bio_set_flag(bio, flag) ((bio)->bi_flags |= (1 << (flag)))
>

  set_bit() can do the same task.
  Can you please explain why do we need a new macro ?


> Then hunt down and kill all the places that manipulate bi_flags by hand?
> We might also need:
>
> #define bio_set_flag_atomic(bio, flag) set_bit(&(bio)->bi_flags, (flag))

for atomic operation we have __set_bit() . Is there any need to define
to new macro ?


Regards
Santosh

>
> --
> Matthew Wilcox                          Intel Open Source Technology Centre
> "Bill, look, we understand that you're interested in selling us this
> operating system, but compare it to ours.  We can't possibly take such
> a retrograde step."
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