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To: Anil kumar <anils_r@yahoo.com>
Cc: Christof Schmitt <christof.schmitt@de.ibm.com>,
        linux-kernel@vger.kernel.org, linux-scsi@vger.kernel.org
Subject: Re: scsi_cmnd data_buffer checksum
From: "Martin K. Petersen" <martin.petersen@oracle.com>
Organization: Oracle
References: <215508.92384.qm@web32402.mail.mud.yahoo.com>
Date: Thu, 09 Sep 2010 09:23:24 -0400
In-Reply-To: <215508.92384.qm@web32402.mail.mud.yahoo.com> (Anil kumar's
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>>>>> "Anil" == Anil kumar <anils_r@yahoo.com> writes:

Anil> cmd-> write_buf = (u8 *)(kmap_atomic(sg->page, KM_IRQ0) + sg->offset);
Anil> memcpy(cmd->local_write_buf, cmd->write_buf, cmd->scsibufflen(scsi_cmnd));

You need to walk the scatterlist.  You can't assume that the pages are
contiguous in memory.

But why are you doing this checksumming stuff manually when the existing
DIX/DIF code can do it for you?

-- 
Martin K. Petersen	Oracle Linux Engineering