keeping track of free blocks

Signed-off-by: Andreas Rohner <andy641@gmx.at>
add mark_extent_dirty IOCTL

Signed-off-by: Andreas Rohner <andy641@gmx.at>
fix deadlock
improve deadlock fix
add lockdep classes
add ioctl to update sufile entries from userspace
add ioctl to nilfs_compat_ioctl
fix warning
fix counting of blocks for datfile, cpfile and sufile
fix block count
fix sui block counting
add debug printks
printk to track dec_segment_usage
fix block counting for segment usage
limit printk to specific segments
more debug messages
fix block counting
fix block counting
additional logging
put counting in segbuf (experiment)