On Fri, 6 Jun 2008 09:54:33 +0200 Jens Axboe <jens.axboe@xxxxxxxxxx> wrote: > On Thu, Jun 05 2008, Anil kumar wrote: > > Hi, > > > > Can I call blk_queue_hardsect_size in a driver and set it to 520-byte > > as hardware sector size. How does the kernel and block layers take > > the request, will it be in multiples of 520-bytes aligned or 512 bytes > > aligned? > > No, Linux only supports power-of-2 hardware block sizes I'm afraid. And only some of those - which is why we can't support CP/M disks and also early smartmedia stuff (128/256 byte/sector) If you are trying to deal with 520 byte blocks that are 512 bytes file system data + 8 bytes of meta data then use 512 byte block sizes and put the meta-data somewhere else or provide a different way to access it - eg ATA uses 512 byte sectors for normal ATA but the sg_io() ioctl path allows the issuing of commands like READ_LONG for specific cases where the additional meta data is needed. Alan -- 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
