Messages in this thread | | | Date | Wed, 23 Feb 2000 15:06:32 -0500 (EST) | From | Ingo Molnar <> | Subject | Re: [patch] block device stacking support, raid-2.3.47-B6 |
| |
On Wed, 23 Feb 2000, Andrea Arcangeli wrote:
> >- renaming ->make_request_fn() to ->logical_volume_fn is both misleading > > and unnecessery. > > Note that with my proposal it was make_request_fn to be misleading because > all the code run within the callback had anything to do with the > make_request code.
ok, your variant was more like a ->map_buffer_fn() thing - like the old md_map() stuff. ->make_request_fn() is closer to 'make request' in the context of RAID1 and RAID5. (even if this is not visible now).
> > - device resolves recursion internally and returns 0 (future RAID0), > > returns 1 if recursion cannot be resolved internally. > > I don't think it worth to handle such case if it costs something for the > other cases. I'll check and test the code on the LVM side soon.
the cost is only in the device (not in the generic block IO code), it's a 'if (MAJOR(bh->b_rdev) == MD_MAJOR) goto repeat;' type of thing (analogous in the LVM code), nothing more. We will see how common it gets - it's just a nice side-effect that th possibility is there.
Ingo
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.rutgers.edu Please read the FAQ at http://www.tux.org/lkml/
| |