Commit Graph

6 Commits

Author SHA1 Message Date
Heinz Mauelshagen afac6bd6d1 dm unstripe: remove unnecessary header includes
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2018-04-03 15:04:15 -04:00
Heinz Mauelshagen 91e065d8f2 dm unstripe: remove superfluous module init error path message
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Reviewed-by: Scott Bauer <Scott.Bauer@intel.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2018-04-03 15:04:14 -04:00
Heinz Mauelshagen ba5dfbb712 dm unstripe: add "dm-unstriped" module alias
This target's kernel module being named dm-unstripe.ko doesn't allow
lvm2's DM module autoload capability to load the dm-unstripe.ko
because lvm2 looks for dm-unstriped.ko due to the target name being
"unstriped".

Add the "dm-unstriped" module alias to resolve this oversight.

NOTE: this isn't needed for the "striped" target, despite its source
file being named dm-stripe.c, because it is part of dm-mod.ko.

Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2018-04-03 15:04:13 -04:00
Heinz Mauelshagen 2ae600cd15 dm unstripe: support non-power-of-2 chunk size
Address "FIXME: must support non power of 2 chunk_size, dm-stripe.c does".

Bump target version to indicate change.

Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Tested-by: Scott Bauer <Scott.Bauer@intel.com>
Reviewed-by: Scott Bauer <Scott.Bauer@intel.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2018-04-03 15:04:12 -04:00
Scott Bauer cc65661981 dm unstripe: fix target length versus number of stripes size check
Since the unstripe target takes a target length which is the
size of *one* striped member we're trying to expose, not the
total size of *all* the striped members, the check does not
make sense and fails for some striped setups.

For example, say we have a 4TB striped device:
or 3907018496 sectors per underlying device:

if (sector_div(width, uc->stripes)) :
   3907018496 / 2(num stripes)  == 1953509248

tmp_len = width;
if (sector_div(tmp_len, uc->chunk_size)) :
   1953509248 / 256(chunk size) == 7630895.5
   (fails)

Fix this by removing the first check which isn't valid for unstriping.

Signed-off-by: Scott Bauer <scott.bauer@intel.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2018-01-29 13:44:58 -05:00
Scott Bauer 18a5bf2705 dm: add unstriped target
This device mapper "unstriped" target remaps and unstripes I/O so it
is issued solely on a single drive in a HW RAID0 or dm-striped target.

In a 4 drive HW RAID0 the striped target exposes 1/4th of the LBA range
as a virtual drive.  Each I/O to that virtual drive will only be issued
to the 1 drive that was selected of the 4 drives in the HW RAID0.

This unstriped target is most useful for Intel NVMe drives that have
multiple cores but that do not have firmware control to pin separate LBA
ranges to each discrete cpu core.

Signed-off-by: Scott Bauer <scott.bauer@intel.com>
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Acked-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2018-01-17 09:16:00 -05:00