On 11/01/2010 06:13 PM, Christoph Hellwig wrote: > On Tue, Oct 19, 2010 at 02:22:42PM +0200, Boaz Harrosh wrote: >> From: John A. Chandy <john.chandy@xxxxxxxxx> >> >> This is a trivial addition to the SG API that can receive kernel >> pointers. It is only used by the out-of-tree test module. So >> it's immediate need is questionable. For maintenance ease it might >> just get in, as it's very small. >> >> John. >> do you need this in the Kernel, or is it only for osd_ktest.ko? > > It really shouldn't be in the tree at all. s/g lists are not something > that should be passed to a logical I/O layer. > Please read the patch ;-) It has been asked before, these are not Linux Kernel sg(s). These are OSD scatter-gather. Osd scatter-gather are an array of extents [offset, length] to which to write/read to/from in the object. The memory buffer information is the same as a simple write/read. Only that the target will random-seek+fetch bytes in a single on-the-wire IO. There exist the same command for SCSI-disk targets as well. I know that the conceptual name means something else, and I should have perhaps chosen a new name. But the STD calls it Scatter-Gather and I have not yet invented any new names, and always used the STD names for things. It is not until people got mixed up that I realized it might have been a mistake to call it that. Should I submit a patch that renames anything "sg" to "extents", or some other name? (Please note, there is no name collision it is all osd_sg_xxx) Thanks Boaz -- 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
