On Thu, Feb 22, 2007 at 03:41:24PM -0600, James Bottomley wrote:
> On Thu, 2007-02-22 at 13:24 -0800, Andrew Morton wrote:
> > > On Thu, 22 Feb 2007 10:51:23 -0600 "Mike Miller (OS Dev)" <mikem@xxxxxxxxxxxxxxxxxxxxxxx> wrote:
> > > On Wed, Feb 21, 2007 at 07:14:27PM -0800, Andrew Morton wrote:
> > > > On Wed, 21 Feb 2007 15:10:39 -0600 "Mike Miller (OS Dev)" <mikem@xxxxxxxxxxxxxxxxxxxxxxx> wrote:
> > > >
> > > > > Patch 1/2
> > > > > + if (total_size == 0xFFFFFFFF) {
> > > >
> > > > I seem to remember having already questioned this. total_size is sector_t, which
> > > > can be either 32-bit or 64-bit. Are you sure that comparison works as
> > > > intended in both cases?
> > > >
> > > >
> > > > > + if(total_size == 0xFFFFFFFF) {
> > > > > cciss_read_capacity_16(cntl_num, i, 0,
> > > > > &total_size, &block_size);
> > > > > hba[cntl_num]->cciss_read = CCISS_READ_16;
> > > >
> > > > Here too.
> > > It has worked in all of the configs I've tested. Should I change it from sector_t to a
> > > __64? I have not tested all possible configs.
> > >
> >
> > I'd suggest using -1: that just works.
>
> Actually, no, that won't work.
>
> This is a SCSI heuristic for determining when to use the 16 byte version
> of the read capacity command. The 10 byte command can only return 32
> bits of information (this is in sectors, so it returns up to 2TB of
> bytes).
>
> The heuristic requirement is that if the size is exactly 0xffffffff then
> you should try the 16 byte command (which can return 64 bits of
> information). If that fails then you assume the 0xfffffff is a real
> size otherwize, you assume it was truncated and take the real result
> from the 16 byte command.
>
> You can see a far more elaborate version of this in operation in
> sd.c:sd_read_capacity().
>
> The only thing I'd suggest is to use 0xFFFFFFFFULL as the constant to
> prevent sign extension issues.
>
> James
>
>
Will this patch for my patch work for now?
diff --git a/drivers/block/cciss.c b/drivers/block/cciss.c
index 1abf1f5..a1f1d9f 100644
--- a/drivers/block/cciss.c
+++ b/drivers/block/cciss.c
@@ -1303,7 +1303,7 @@ static void cciss_update_drive_info(int
/* if read_capacity returns all F's this volume is >2TB in size */
/* so we switch to 16-byte CDB's for all read/write ops */
- if (total_size == 0xFFFFFFFF) {
+ if (total_size == 0xFFFFFFFFULL) {
cciss_read_capacity_16(ctlr, drv_index, 1,
&total_size, &block_size);
h->cciss_read = CCISS_READ_16;
@@ -3129,7 +3129,7 @@ #endif /* CCISS_DEBUG */
/* If read_capacity returns all F's the logical is >2TB */
/* so we switch to 16-byte CDBs for all read/write ops */
- if(total_size == 0xFFFFFFFF) {
+ if(total_size == 0xFFFFFFFFULL) {
cciss_read_capacity_16(cntl_num, i, 0,
&total_size, &block_size);
hba[cntl_num]->cciss_read = CCISS_READ_16;
-
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
