Re: [PATCH] libata: add support for READ/WRITE LONG

[Tejun Heo <htejun@gmail.com>]

Mark Lord wrote:
> The READ/WRITE LONG commands are theoretically obsolete,
> but the majority of drives in existance still implement them.
> 
> The WRITE_LONG and WRITE_LONG_ONCE commands are of particular
> interest for fault injection testing -- eg. creating "media errors"
> at specific locations on a disk.
> 
> The fussy bit is that these commands require a non-standard
> sector size, usually 520 bytes instead of 512.
> 
> This patch adds support to libata for READ/WRITE LONG commands
> issued via SG_IO/ATA_16.
> 
> This patch was generated against a 2.6.21-rc3-git7 base:

I think it would be better if this comes in two patches.  One to add
qc->sect_size and convert all users of ATA_SECT_SIZE to qc->sect_size
and the other one to implement READ/WRITE LONG.  Another question is
whether this needs to be included into mainline.  This is definitely
useful but it is mostly for debugging/testing.

Hmmm... But we're gonna need qc->sect_size anyway for devices with
larger sector sizes and overhead for supporting READ/WRITE LONG is
nearly nill, so I'm voting for inclusion.

Thanks.

-- 
tejun