On Thu, Jun 26, 2014 at 10:02:47AM -0400, James Bottomley wrote: > Yes, but think what you're proposing. Every block command with a > special setup goes via scsi_setup_blk_pc_cmnd() because they usually > have to translate to something special. That logic is backwards. The "special" commands use scsi_setup_blk_pc_cmnd because that seemed the easiest we to do it when they were introduce. Looking back they should have just called scsi_init_io directly instead of doing enough setup to pretend to be BLOCK_PC enough to use scsi_setup_blk_pc_cmnd(). > If we did what you propose, > every time we add one, we'd have to modify these five places in the code > plus the setup ... it's a bit insane plus a maintenance nightmare. It's not. They need to be treated special because they _are_ special. If you look at the command types there's a pretty clear difference between BLOCK_PC and everything else: BLOCK_PC read/write discard/flush/write_same need to generate CDB no yes yes calls into the ULD no yes yes needs error handling no yes yes passes sense data up yes no no so they surely aren;t like BLOCK_PC, and treating them like BLOCK_PC would require major changes to our architecture. Not that I'm overly happy with them being _FS requests either - they probably should have a cmd_type assigned for each of them and come down from the block layer set up that way. I'll look into that once I get a little bit of time. > Since block gave us the command to set up as we please, we're entitled > to change the fields including cmd_type. The block layer doesn't care, but that doesn't make it right inside the SCSI code. -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
