Btrfs-progs: use atoll() for mkfs.btrfs size option

On 32 bit systems, a numerical parameter of 2147483648 or above to
the mkfs.btrfs -b option does not work. The parameter is stored in
an u64 but is read using atol() and thus not read correctly.
This patch changes it to use atoll().
Specifying a multiplier (k, m or g) like "100g" in the mkfs.btrfs
parameter list would also be a working workaround.

Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
Btrfs-progs: add btrfs-show-super tool

Just a small program to print the fields of a super block.

Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
Btrfs-progs: Make ioctl.h similar to the btrfs kernel ioctl.h

One of the ioctls numbers existed only in btrfs-progs ioctl.h, not
in the kernel btrfs ioctl.h. Remove it in btrfs-progs as well.

Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
Btrfs-progs: fix an off-by-one in write_dev_supers()

Fix an off-by-one in write_dev_supers().

Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
Btrfs-progs: add support for device replace procedure

This is the user mode part of the device replace patch series.

The command group "btrfs replace" is added with three commands:
- btrfs replace start srcdev|srcdevid targetdev [-Bfr] mount_point
- btrfs replace status mount_point [-1]
- btrfs replace cancel mount_point

Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>