[PATCHv3 0/9] introduce on-demand device creation

[Sergey Senozhatsky <sergey.senozhatsky@gmail.com>]

We currently don't support zram on-demand device creation.  The only way
to have N zram devices is to specify num_devices module parameter (default
value 1).  That means that if, for some reason, at some point, user wants
to have N + 1 devies he/she must umount all the existing devices, unload
the module, load the module passing num_devices equals to N + 1.

This patchset introduces zram-control sysfs class, which has two sysfs
attrs:

 - zram_add     -- add a new zram device
 - zram_remove  -- remove a specific (device_id) zram device

    Usage example:
        # add a new specific zram device
        cat /sys/class/zram-control/zram_add
        1

        # remove a specific zram device
        echo 4 > /sys/class/zram-control/zram_remove


V3:
-- rebase against 4.1
-- review comments from Minchan were addressed
-- no sysfs RO tricks anymore

V2:
-- quick rebase and cleanup in attempt to catch 4.1 merge window

Sergey Senozhatsky (9):
  zram: add `compact` sysfs entry to documentation
  zram: cosmetic ZRAM_ATTR_RO code formatting tweak
  zram: use idr instead of `zram_devices' array
  zram: reorganize code layout
  zram: remove max_num_devices limitation
  zram: report every added and removed device
  zram: trivial: correct flag operations comment
  zram: return zram device_id from zram_add()
  zram: add dynamic device add/remove functionality

 Documentation/blockdev/zram.txt |  29 +-
 drivers/block/zram/zram_drv.c   | 975 ++++++++++++++++++++++------------------
 drivers/block/zram/zram_drv.h   |   6 -
 3 files changed, 558 insertions(+), 452 deletions(-)

-- 
2.4.0.rc3.3.g6eb1401