On Wed, 2011-11-16 at 08:57 -0500, Christoph Hellwig wrote: > On Wed, Nov 16, 2011 at 08:32:20AM +0000, Nicholas A. Bellinger wrote: > > From: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx> > > > > This patch changes transport_generic_map_mem_to_cmd() to reject SCSI data > > overflow and to send exception status with CHECK_CONDITION + TCM_INVALID_CDB_FIELD > > for fabrics that are passing a pre-populated struct scatterlist (eg: tcm_loop > > and iscsi-target) being mapped into se_cmd->t_data_sg and se_cmd->t_data_nents. > > > > This addresses an OOPs where transport_allocate_data_tasks() would walk > > the incorrect post OVERFLOW cmd->data_length value beyond the end of > > the passed scatterlist. > > Maybe this is a sign that at least the iscsi target should stop > allocating its own pages and switch back to the core allocation, which > should be easily possible after the s/g list conversion. > I started thinking about this a bit too, but got distracted with other non iscsi-target related items.. Handling SCSI overflow properly for iscsi-target would be nice, but it's probably not a huge item atm. The main thing that makes this type of conversion somewhat difficult is the immediate data handling w/o having to take the extra context switch. AFAICT this would be a reasonable conversion, but would have to consider the details more. > I also wonder if keeping this special case for tcm_loop is a good idea - > it surely is a nice optimization, but then again tcm_loop is more a > debugging and testing tool than something we should optimize for. > Well, this is the main path for a virtio host driver as well.. --nab -- To unsubscribe from this list: send the line "unsubscribe target-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
