Am 22.11.2012 10:07, schrieb Stefan Priebe:
> When acb->cmd is WRITE or DISCARD block/rbd stores rcb->size into acb->ret
>
> Look here:
> if (acb->cmd == RBD_AIO_WRITE ||
> acb->cmd == RBD_AIO_DISCARD) {
> if (r < 0) {
> acb->ret = r;
> acb->error = 1;
> } else if (!acb->error) {
> acb->ret = rcb->size;
> }
>
> right now acb->ret is just an int and we might get an overflow if size is too
> big.
> For discards rcb->size holds the size of the discard - this might be some TB
> if you
> discard a whole device.
>
> The steps to reproduce are:
> mkfs.xfs -f a whole device bigger than int in bytes. mkfs.xfs sends a
> discard. Important is that you use scsi-hd and set discard_granularity=512.
> Otherwise rbd disabled discard support.
Whatever type you decide to use, please add an identifying topic such as
"block/rbd:" in the subject (int ret is very generic!), and this patch
is missing a Signed-off-by.
Regards,
Andreas
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