linux/include
Mike Snitzer a5664dad7e dm ioctl: make bio or request based device type immutable
Determine whether a mapped device is bio-based or request-based when
loading its first (inactive) table and don't allow that to be changed
later.

This patch performs different device initialisation in each of the two
cases.  (We don't think it's necessary to add code to support changing
between the two types.)

Allowed md->type transitions:
  DM_TYPE_NONE to DM_TYPE_BIO_BASED
  DM_TYPE_NONE to DM_TYPE_REQUEST_BASED

We now prevent table_load from replacing the inactive table with a
conflicting type of table even after an explicit table_clear.

Introduce 'type_lock' into the struct mapped_device to protect md->type
and to prepare for the next patch that will change the queue
initialization and allocate memory while md->type_lock is held.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

 drivers/md/dm-ioctl.c    |   15 +++++++++++++++
 drivers/md/dm.c          |   37 ++++++++++++++++++++++++++++++-------
 drivers/md/dm.h          |    5 +++++
 include/linux/dm-ioctl.h |    4 ++--
 4 files changed, 52 insertions(+), 9 deletions(-)
2010-08-12 04:14:01 +01:00
..
acpi
asm-generic dma-mapping: remove dma_is_consistent API 2010-08-11 08:59:21 -07:00
crypto
drm
keys
linux dm ioctl: make bio or request based device type immutable 2010-08-12 04:14:01 +01:00
math-emu
media
mtd
net
pcmcia
rdma
rxrpc
scsi scsi: use __uX types for headers exported to user space 2010-08-11 08:59:01 -07:00
sound
trace Merge branch 'for-2.6.36' of git://git.kernel.dk/linux-2.6-block 2010-08-10 15:22:42 -07:00
video
xen
Kbuild