Jan Kara <jack@xxxxxxx> wrote: > We have filesystems F1 & F2, where F1 is the network fs and F2 is the cache > fs. > > Thread 1 Thread 2 Thread 3 Thread 4 > write (F2) > sb_start_write() (F2) > prepares write > copy_from_user() > ... > Thread 2 continues > fault() cachefilesd is only doing I/O to/from kernel resident pages. It shouldn't fault there. I'm not sure it's even going to call copy_from_user() since it'll be using ITER_XARRAY. David
