Nfs client writing several dirty pages to the nfs server
nfs.aop.writepages
for_kupdate
a flag of writeback_control, indicates if it's a kupdate writeback
wpages
write size (in pages)
dev
device identifier
size
number of pages attempted to be written in this execution
ino
inode number
for_reclaim
a flag of writeback_control, indicates if it's invoked from the page allocator
nr_to_write
number of pages attempted to be written in this execution
wsize
write size
The priority of wb is decided by the flags for_reclaim and for_kupdate.