Re: [PATCH] block: fix residual byte count handling

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



FUJITA Tomonori wrote:
sum(sg) == rq->data_len is already broken; sg sends such requests
(though it would be nice if it doesn't).


Actually, I think I was half wrong on that when you asked about scsi_debug. The scatterlist that sg.c uses is never seen by the block layer or scsi layer. It is just used as a container to hold segments. sg.c and st.c use their scatterlist to manage their preallocated pages/segments. When they pass it to scsi_execute_async, that function will create a request struct and add bios for the pages.

In 2.6.24 and below, sg.c will send a scatterlist length that does not match the IO length, and scsi_execute_async will goof up and send a rq->data_len that does not match the sum of the bios. That is what I was trying to fix in 2.6.24, but the patch got messed up. In 2.6.25-rc2 and above that is fixed and scsi_execute_async will catch sg.c doing this and set rq->data_len and the bio lengths correctly.

So hopefully that helps any fixes you might have planned.
--
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

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Index of Archives]     [SCSI Target Devel]     [Linux SCSI Target Infrastructure]     [Kernel Newbies]     [IDE]     [Security]     [Git]     [Netfilter]     [Bugtraq]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Linux ATA RAID]     [Linux IIO]     [Samba]     [Device Mapper]
  Powered by Linux