Merge remote-tracking branch 'writeback/writeback-for-next'

diff --cc fs/buffer.c
Simple merge

diff --cc fs/ext4/inode.c
Simple merge

diff --cc fs/quota/quota.c
Simple merge

diff --cc include/linux/sched.h
Simple merge

diff --cc kernel/fork.c
Simple merge

diff --cc mm/vmscan.c
Simple merge