On 5/27/06, Kai Makisara <Kai.Makisara@xxxxxxxxxxx> wrote:
On Thu, 25 May 2006, Kai Makisara wrote:
> I am adding linux-scsi to recipients (and quoting the whole message for
> readers of that list).
>
> On Tue, 23 May 2006, James Lamanna wrote:
>
> > So I was able to recreate this problem on a vanilla 2.6.16.18 with the
> > following oops..
> > I'd say this is a serious regression since I cannot restore backups
> > anymore (I could with 2.6.14.x, but that kernel series had other
> > issues...)
> >
> > amrestore does manage to read 1 32k block from tape before dying.
> >
> > Any help would be greatly appreciated.
> >
> I have tried 'amrestore' on my machine with 2.6.16.18 but was not able to
> reproduce the problem.
OK. Now I think I have found something, thanks to Mike Christie's reminder
yesterday in another thread that the patch at the end of this message has
not been merged into 2.6.16 (and 2.6.17-rcx) ;-)
[SNIP]
Next thing was to patch 2.6.16.18 with the patch at the end: No more
oopses with any alignment.
James, does this fix your problem ?
Kai-
Yes, the patch below does fix my problem and lets amrestore run.
Of course I still have the sense data problem, but I think I'm going
to replace some cables and terminators :)
So I would say that this should be included in 2.6.17, and perhaps a
2.6.16.19? :)
Thanks again!
Kai
-- James
--------------------------------8<------------------------------------------
Excerpt from a message from Brian Holty to linux-scsi and linux-kernel on
Wed, 22 Mar 2006 06:35:39:
...
Based on above, I think the most intuitive fix would be the offset addition of
the first entry to the initialization of nr_pages.
Without this change, for instance, with 4K io's every sg io that is
dma_aligned for direct io, but not page aligned will cause slab corruption
and an oops
I am able to run a number of tests with sg that cause the boundary to be
crossed, and with this fix there is no slab corruption or data corruption.
Thanks Dan, I had been hunting for this for a couple of days!!
Thoughts??
Signed-off-by: Bryan Holty <lgeek@xxxxxxxxxxxxxxx>
--- a/drivers/scsi/scsi_lib.c 2006-03-03 13:17:22.000000000 -0600
+++ b/drivers/scsi/scsi_lib.c 2006-03-22 06:09:09.669599539 -0600
@@ -368,7 +368,7 @@
int nsegs, unsigned bufflen, gfp_t gfp)
{
struct request_queue *q = rq->q;
- int nr_pages = (bufflen + PAGE_SIZE - 1) >> PAGE_SHIFT;
+ int nr_pages = (bufflen + sgl[0].offset + PAGE_SIZE - 1) >> PAGE_SHIFT;
unsigned int data_len = 0, len, bytes, off;
struct page *page;
struct bio *bio = NULL;
-
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