Re: 2.6.23-rc9 boot failure (megaraid?)

[Jens Axboe]

On Thu, Oct 04 2007, FUJITA Tomonori wrote:
> On Thu, 4 Oct 2007 09:28:34 +0200
> Jens Axboe <jens.axboe@xxxxxxxxxx> wrote:
> 
> > On Thu, Oct 04 2007, FUJITA Tomonori wrote:
> > > On Wed, 3 Oct 2007 17:32:55 -0600
> > > "Patro, Sumant" <Sumant.Patro@xxxxxxx> wrote:
> > > 
> > > >  
> > > > 
> > > > > -----Original Message-----
> > > > > From: FUJITA Tomonori [mailto:fujita.tomonori@xxxxxxxxxxxxx] 
> > > > > Sent: Tuesday, October 02, 2007 5:01 PM
> > > > > To: James.Bottomley@xxxxxxxxxxxx
> > > > > Cc: bunk@xxxxxxxxxx; bwindle@xxxxxxxx; 
> > > > > linux-kernel@xxxxxxxxxxxxxxx; jens.axboe@xxxxxxxxxx; 
> > > > > fujita.tomonori@xxxxxxxxxxxxx; Patro, Sumant; DL-MegaRAID 
> > > > > Linux; linux-scsi@xxxxxxxxxxxxxxx
> > > > > Subject: Re: 2.6.23-rc9 boot failure (megaraid?)
> > > > > 
> > > > > On Tue, 02 Oct 2007 15:38:13 -0500
> > > > > James Bottomley <James.Bottomley@xxxxxxxxxxxx> wrote:
> > > > > 
> > > > > > On Tue, 2007-10-02 at 20:15 +0200, Adrian Bunk wrote:
> > > > > > > Cc's added, the complete bug report is at
> > > > > > >   http://lkml.org/lkml/2007/10/2/243
> > > > > > > 
> > > > > > > On Tue, Oct 02, 2007 at 12:48:26PM -0400, Burton Windle wrote:
> > > > > > > > 2.6.23-rc9 fails to boot for me; 2.6.22.9 works fine.
> > > > > > > >
> > > > > > > > System is a Dell Poweredge with PERC 2/DC with RAID1 volume.
> > > > > > > >...
> > > > > > > 
> > > > > > > Thanks for your report.
> > > > > > > 
> > > > > > > Diff'ing the dmesg's shows:
> > > > > > > 
> > > > > > > <--  snip  -->
> > > > > > > 
> > > > > > >  scsi0: scanning scsi channel 4 [P0] for physical devices.
> > > > > > >  scsi0: scanning scsi channel 5 [P1] for physical devices.
> > > > > > >  st: Version 20070203, fixed bufsize 32768, s/g segs 256 -sd 
> > > > > > > 0:0:0:0: [sda] 17547264 512-byte hardware sectors (8984 MB)
> > > > > > > +sd 0:0:0:0: [sda] Sector size 0 reported, assuming 512.
> > > > > > > +sd 0:0:0:0: [sda] 1 512-byte hardware sectors (0 MB)
> > > > > > >  sd 0:0:0:0: [sda] Write Protect is off  sd 0:0:0:0: [sda] Asking 
> > > > > > > for cache data failed  sd 0:0:0:0: [sda] Assuming drive 
> > > > > cache: write 
> > > > > > > through -sd 0:0:0:0: [sda] 17547264 512-byte hardware 
> > > > > sectors (8984 
> > > > > > > MB)
> > > > > > > +sd 0:0:0:0: [sda] Sector size 0 reported, assuming 512.
> > > > > > > +sd 0:0:0:0: [sda] 1 512-byte hardware sectors (0 MB)
> > > > > > >  sd 0:0:0:0: [sda] Write Protect is off  sd 0:0:0:0: [sda] Asking 
> > > > > > > for cache data failed  sd 0:0:0:0: [sda] Assuming drive 
> > > > > cache: write 
> > > > > > > through
> > > > > > >   sda: sda1
> > > > > > > + sda: p1 exceeds device capacity
> > > > > > > 
> > > > > > > <--  snip  -->
> > > > > > > 
> > > > > > > -	case MEGA_BULK_DATA:
> > > > > > > -		if (scb->cmd->use_sg == 0)
> > > > > > > -			length = scb->cmd->request_bufflen;
> > > > > > > -		else {
> > > > > > > -			struct scatterlist *sgl =
> > > > > > > -				(struct scatterlist 
> > > > > *)scb->cmd->request_buffer;
> > > > > > > -			length = sgl->length;
> > > > > > > -		}
> > > > > > > -		pci_unmap_page(adapter->dev, scb->dma_h_bulkdata,
> > > > > > > -			       length, scb->dma_direction);
> > > > > > > -		break;
> > > > > > > -
> > > > > > 
> > > > > > This is the problem piece I think.  We've reintroduced a 
> > > > > very old bug:
> > > > > > 
> > > > > > commit 51c928c34fa7cff38df584ad01de988805877dba
> > > > > > Author: James Bottomley <James.Bottomley@xxxxxxxxxxxx>
> > > > > > Date:   Sat Oct 1 09:38:05 2005 -0500
> > > > > > 
> > > > > >     [SCSI] Legacy MegaRAID: Fix READ CAPACITY
> > > > > >     
> > > > > >     Some Legacy megaraid cards can't actually cope with the 
> > > > > scatter/gather
> > > > > >     version of the READ CAPACITY command (which is what we 
> > > > > now send them
> > > > > >     since altering all SCSI internal I/O to go via the 
> > > > > block layer).  Fix
> > > > > >     this (and a few other broken megaraid driver 
> > > > > assumptions) by sending
> > > > > >     the non-sg version of the command if the sg list only 
> > > > > has a single
> > > > > >     element.
> > > > > >     
> > > > > >     Signed-off-by: James Bottomley <James.Bottomley@xxxxxxxxxxxx>
> > > > > > 
> > > > > > So what we have to do is put back the check for use_sg == 1 
> > > > > and send 
> > > > > > that as a bulk transfer command.
> > > > > 
> > > > > Sorry about this. Can this fix the problem?
> > > > > 
> > > > > Thanks,
> > > > > 
> > > > > 
> > > > > diff --git a/drivers/scsi/megaraid.c 
> > > > > b/drivers/scsi/megaraid.c index 3907f67..da56163 100644
> > > > > --- a/drivers/scsi/megaraid.c
> > > > > +++ b/drivers/scsi/megaraid.c
> > > > > @@ -1753,6 +1753,14 @@ mega_build_sglist(adapter_t *adapter, 
> > > > > scb_t *scb, u32 *buf, u32 *len)
> > > > >  
> > > > >  	*len = 0;
> > > > >  
> > > > > +	if (scsi_sg_count(cmd) == 1 && !adapter->has_64bit_addr) {
> > > > > +		sg = scsi_sglist(cmd);
> > > > > +		scb->dma_h_bulkdata = sg_dma_address(sg);
> > > > > +		*buf = (u32)scb->dma_h_bulkdata;
> > > > > +		*len = sg_dma_len(sg);
> > > > > +		return 0;
> > > > > +	}
> > > > > +
> > > > >  	scsi_for_each_sg(cmd, sg, sgcnt, idx) {
> > > > >  		if (adapter->has_64bit_addr) {
> > > > >  			scb->sgl64[idx].address = sg_dma_address(sg);
> > > > > 
> > > > 
> > > > 
> > > > With this patch I see the correct logical disk size reported.
> > > > Thanks.
> > > 
> > > Great, thanks for testing!
> > > 
> > > Can you try the following patch instead of the above patch?
> > > 
> > > http://marc.info/?l=linux-scsi&m=119137033016550&w=2
> > > 
> > > 
> > > I know the changes are pretty trivial and it should work...
> > 
> > Tomo, this is the patch I added.
> 
> Thanks. I thought that it will be sent via scsi-misc because the scsi
> accessor patch introduced this bug. But either is ok with me.

If it only affects the driver _after_ the scsi accessor patch and as
such doesn't screw over git-block, then I'll drop it for sure.

-- 
Jens Axboe

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