From: Heinz Mauelshagen <heinzm@xxxxxxxxxx>
I'm enhancing the device mapper raid target (dm-raid) to take
advantage of so far unused md raid kernel funtionality:
takeover, reshape, resize, addition and removal of devices to/from raid sets.
This series of patches remove constraints doing so.
Patch #1:
add 2 API functions to allow dm-raid to access the raid takeover
and resize functionality (namely md_takeover() and md_resize());
reshape APIs are not needed in lieu of the existing personalilty ones
Patch #2:
because device mapper core manages a request queue per mapped device
utilizing the md make_request API to pass on bios via the dm-raid target,
no md instance underneath it needs to manage a request queue of its own.
Thus dm-raid can't use the md raid0 personality as is, because the latter
accesses the request queue unconditionally in 3 places via mddev->queue
which this patch addresses.
Patch #3:
when dm-raid processes a down takeover to raid0, it needs to destroy
any existing bitmap, because raid0 does not require one. The patch
exports the bitmap_destroy() API to allow dm-raid to remove bitmaps.
Heinz Mauelshagen (3):
md core: add 2 API functions for takeover and resize to support dm-raid
md raid0: access mddev->queue (request queue member) conditionally
because it is not set when accessed from dm-raid
md bitmap: export bitmap_destroy() to support dm-raid down takover to raid0
drivers/md/bitmap.c | 1 +
drivers/md/md.c | 39 ++++++++++++++++++++++++++++++---------
drivers/md/md.h | 3 +++
drivers/md/raid0.c | 48 +++++++++++++++++++++++++++---------------------
4 files changed, 61 insertions(+), 30 deletions(-)
--
2.1.0
--
dm-devel mailing list
dm-devel@xxxxxxxxxx
https://www.redhat.com/mailman/listinfo/dm-devel
