Currently the st driver does not to break up write requests into smaller chunks to satisfy the ->max_hw_sectors limit of the underlying host driver. # modprobe -v scsi_debug ptype=1 opts=1 dev_size_mb=123 # dd if=/dev/zero of=/dev/st0 bs=$((1024*54321)) This leads to -EBUSY from this call chain: st_write -> st_do_scsi -> st_scsi_execute -> blk_rq_map_user What is the reason for this behaviour? Should st_write write in smaller chunks, or would that break real hardware because they expect certain block sizes? The specific issue at hand I have is that the (out-of-tree) Xen pvscsi has a ->max_hw_sectors limit of 200, which limits the block size in a guest to 100K. Olaf -- 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
