On 3/24/20 7:52 PM, Hannes Reinecke wrote: > On 3/24/20 12:02 PM, Bob Liu wrote: >> Motivation: >> dm-zoned exposes a zoned block device(ZBC) as a regular block device by storing >> metadata and buffering random writes in its conventional zones. >> This way is not flexible, there must be enough conventional zones and the >> performance may be constrained. >> >> This patchset split the metadata from zoned device to an extra regular device, >> with aim to increase the flexibility and potential performance. >> For example, now we can store metadata in a faster device like persistent memory. >> Also random writes can go to the regular devices in this version. >> >> Usage(will send user space patches later): >>> dmzadm --format $zoned_dev --regular=$regu_dev --force >>> echo "0 $size zoned $regu_dev $zoned_dev" | dmsetup create $dm-zoned-name >> >> v2: >> * emulate regular device zone info >> * support write both metadata and random writes to regular dev >> >> Bob Liu (3): >> dm zoned: rename dev name to zoned_dev >> dm zoned: introduce regular device to dm-zoned-target >> dm zoned: add regular device info to metadata >> >> drivers/md/dm-zoned-metadata.c | 205 +++++++++++++++++++++++++++-------------- >> drivers/md/dm-zoned-target.c | 205 +++++++++++++++++++++++------------------ >> drivers/md/dm-zoned.h | 53 ++++++++++- >> 3 files changed, 299 insertions(+), 164 deletions(-) >> > Well, surprise, surprise, both our patchsets are largely identical ... > You may missed my first rfc. https://www.redhat.com/archives/dm-devel/2020-January/msg00024.html > So how to proceed? I guess if you were using 'cdev' instead of 'regu_dm_dev' we should be having an overlap of about 90 percent. > > The main difference between our implementation is that I didn't move the metadata to the cache/regulard device, seeing that dmzadm will only write metadata onto the zoned device. I also patched dmzadm(will sent out soon) a lot, now my implementation can compatible with original usage. It supports two different usage: - Original zoned device only: #: dmzadm --format $zoned_dev #: echo "0 $size zoned $zoned_dev" | dmsetup create $dm-zoned-name (All data in zoned device) - With regular device： dmzadm --format $zoned_dev --regular=$regu_dev echo "0 $size zoned $regu_dev $zoned_dev" | dmsetup create $dm-zoned-name (Metadata in regular device, other data spread in both regular device and zoned device.) I haven't thought about store metadata in zoned dev while other data in both cache/regular device and zoned dev. Actually in my first rfc I just plan to split metadata to a fast device, so as to get performance improvement. > I would rather keep it that way (ie storing metadata on the zoned device, too, if possible) as we would be keeping backwards compability with that. > And we could always move metadata to the cache/regular device in a later patch; for doing it properly we'll need to update the metadata anyway as we need to introduce UUIDs to stitch those devices together. Sure. > Remember, one my have more than one zoned device and regular device... > > Should I try to merge both patchsets and send them out as an RFC? > Fine to me, just please keep my signed-off-by. Thanks, Bob -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
