Re: Subject: [PATCH 1/3] Let scsi_cmnd->cmnd use request->cmd buffer

[Christoph Hellwig <hch@infradead.org>]

On Sun, Feb 10, 2008 at 09:05:17PM +0200, Boaz Harrosh wrote:
> - Lots of drivers still use MAX_COMMAND_SIZE. So I have left
>   that #define but equate it to BLK_MAX_CDB. The way I see it
>   and is reflected in the patch below is.
>   MAX_COMMAND_SIZE - means: The longest fixed-length (*) SCSI CDB
>                      as per the SCSI standard and is not related
>                      to the implementation.
>   BLK_MAX_CDB.     - The allocated space at the request level
> 
> (*)fixed-length here means commands that their size can be determined
>    by their opcode and the CDB does not carry a length specifier, like
>    the VARIABLE_LENGTH_CMD(0x7f) command. This is actually not exactly
>    true and the SCSI standard also defines extended commands and
>    vendor specific commands that can be bigger than 16 bytes. The kernel
>    will support these using the same infrastructure used for VARLEN CDB's.
>    So in effect MAX_COMMAND_SIZE means the maximum size command
>    scsi-ml supports without specifying a cmd_len by ULD's

A comment like this should be near the declaration of MAX_COMMAND_SIZE

> +#define MAX_COMMAND_SIZE 16
> +#if (MAX_COMMAND_SIZE > BLK_MAX_CDB)
> +#	error MAX_COMMAND_SIZE can not be smaller than BLK_MAX_CDB
> +#endif

No tabs between the # and the rest of the cpp command, please.  Either
nothing or a single space as indentation instead.

Except for those two small nitpicks this looks very good to me.  Nice
memory saving aswel.