Re: fs/bio.c - Hardcoded sector size ?

[Jens Axboe]

On Fri, Sep 29 2006, Roger Gammans wrote:
> On Fri, Sep 29, 2006 at 01:32:05PM -0700, Randy Dunlap wrote:
> > > How about adding kerneldoc for sector_t itself?
> > 
> > Good idea, but afaik it would have to be added for the entire
> > struct, not just one field.
> 
> sector_t 's a simple typedef from unsigned long or u64 depending on
> config rather than a struct - will kerneldoc still pick up the comments
> on theese?
> 
> Assuming it will I suggest the following. I've kept my shorter text in
> the bi_sector field as it is now more fully explained with sector_t.
> 
> 
> Signed-Off-By: Roger Gammans <rgammans@xxxxxxxxxxxxxxxxxxxxxx>
> 
> diff --git a/include/linux/bio.h b/include/linux/bio.h
> index 76bdaea..77a8e6b 100644
> --- a/include/linux/bio.h
> +++ b/include/linux/bio.h
> @@ -70,7 +70,8 @@ typedef void (bio_destructor_t) (struct
>   * stacking drivers)
>   */
>  struct bio {
> -       sector_t                bi_sector;
> +       sector_t                bi_sector;      /* device address in 512 byte
> +                                                  sectors */
>         struct bio              *bi_next;       /* request queue link */
>         struct block_device     *bi_bdev;
>         unsigned long           bi_flags;       /* status, command, etc
> */
> diff --git a/include/linux/types.h b/include/linux/types.h
> index 3f23566..0ddfa1a 100644
> --- a/include/linux/types.h
> +++ b/include/linux/types.h
> @@ -127,8 +127,12 @@ #endif
>  /* this is a special 64bit data type that is 8-byte aligned */
>  #define aligned_u64 unsigned long long __attribute__((aligned(8)))
> 
> -/*
> +/**
>   * The type used for indexing onto a disc or disc partition.
> + *
> + * Linux always considers sectors to be 512 bytes long independently
> + * of the devices real block size.
> + *
>   * If required, asm/types.h can override it and define
>   * HAVE_SECTOR_T
>   */

Looks fine to me, I'll add it (although I tend to prefer disk :-)

-- 
Jens Axboe

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