On Wed, 2005-04-20 at 08:01 -0700, Dheeraj Pandey wrote: > I was wondering if I did a simple writev to a SCSI disk, does it take > the sg path to the device? I am guessing sg (REQ_SPECIAL) is only > true for character devices (and ioctl's) and not block devices. ? I think you misunderstand how writev works. It's design is to take a list of scattered buffers in a user program and consolidate them into a single write. This (in the current implementation) is a separate entity from the block level Scatter Gather. If by sg write path, if you mean scatter-gather write path, then yes, that single write would be split up again into a sg list based on the device parameters if you mean does the writev sg list control where on the disk the data ends up, then no, if you use a disk device as a simple file, writev consolidates all writes to the current file position. James - : 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
