On Mon, Aug 3, 2015 at 9:45 AM, Peter Lieven <p...@kamp.de> wrote:
> Am 02.08.2015 um 13:42 schrieb Andrey Korolyov:
>>
>> Hello,
>>
>> As we will never pass LUN#0 as a storage lun, it would be better to
>> prohibit this at least in iscsi.c, otherwise it will result in an FPU
>> exception and emulator crash:
>>
>> traps: qemu-system-x86[32430] trap divide error ip:7f1dab7b5073
>> sp:7f1d713e4ae0 error:0 in block-iscsi.so[7f1dab7b0000+8000]
>>
>> 353 static bool is_request_lun_aligned(int64_t sector_num, int
>> nb_sectors,
>> 354 IscsiLun *iscsilun)
>> 355 {
>> 356 if ((sector_num * BDRV_SECTOR_SIZE) % iscsilun->block_size ||
>> 357 (nb_sectors * BDRV_SECTOR_SIZE) % iscsilun->block_size) {
>>
>> As far as I can see the LUN#0 can be thrown out on a top level, as one
>> will never use it directly as an iSCSI backend. Please correct me if
>> I`m wrong in this assumption.
>
>
> Hi Andrey,
>
> LUN 0 is quite common on iSCSI targets. I think what causes the problem
> is not the LUN ID, but the target which returns 0 for the blocksize. Which
> target are you using?
>
> Peter
Hi Peter,
I`ve mistyped lun for tgtd upon volume hotplug, which resulted in an
accidental crash, there is nothing but human factor. Until only LUN0
may possess such unusual properties, I`d vote to explicitly work it
around instead of adding generic protection from volumes with
advertized zero block size.
